doc: update NEWS

sys_linux: allow getrandom in seccomp filter
This fixes commit c5735ebfe9.
2025-12-03 18:45:07 -05:00 · 2017-07-25 17:54:01 +02:00 · 2017-07-25 17:40:35 +02:00 · 2017-07-25 17:40:35 +02:00 · 2017-07-25 17:40:35 +02:00 · 2017-07-25 17:40:35 +02:00
181 changed files with 20287 additions and 16562 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -2,20 +2,24 @@
 .vimrc
 *.o
 *.swp
-RELEASES
-Makefile
-chrony.conf.5
-chrony.info
-chrony.html
-chrony.texi
-chrony.txt
-chronyc
-chronyc.1
-chronyd
-chronyd.8
-config.h
-config.log
+*.dSYM
+*.DS_Store
 tags
-version.h
+/RELEASES
+/Makefile
+/chronyc
+/chronyd
+/config.h
+/config.log
+/doc/Makefile
+/doc/*.html
+/doc/*.man
+/doc/*.man.in
+/doc/*.txt
+/getdate.c
+/version.h
 /test/simulation/clknetsim
 /test/simulation/tmp
+/test/unit/Makefile
+/test/unit/*.test
+/test/unit/*.o
--- a/Makefile.in
+++ b/Makefile.in
@@ -24,9 +24,6 @@
 SYSCONFDIR=@SYSCONFDIR@
 BINDIR=@BINDIR@
 SBINDIR=@SBINDIR@
-MANDIR=@MANDIR@
-INFODIR=@INFODIR@
-DOCDIR=@DOCDIR@
 LOCALSTATEDIR=@LOCALSTATEDIR@
 CHRONYVARDIR=@CHRONYVARDIR@

@@ -38,13 +35,13 @@ DESTDIR=

 HASH_OBJ = @HASH_OBJ@

-OBJS = array.o cmdparse.o conf.o local.o logging.o main.o memory.o mkdirpp.o \
+OBJS = array.o cmdparse.o conf.o local.o logging.o main.o memory.o \
       reference.o regress.o rtc.o sched.o sources.o sourcestats.o stubs.o \
-       sys.o tempcomp.o util.o $(HASH_OBJ)
+       smooth.o sys.o sys_null.o tempcomp.o util.o $(HASH_OBJ)

 EXTRA_OBJS=@EXTRA_OBJECTS@

-CLI_OBJS = client.o nameserv.o getdate.o cmdparse.o \
+CLI_OBJS = array.o client.o cmdparse.o getdate.o memory.o nameserv.o \
           pktlength.o util.o $(HASH_OBJ)

 ALL_OBJS = $(OBJS) $(EXTRA_OBJS) $(CLI_OBJS)
@@ -66,21 +63,18 @@ chronyd : $(OBJS) $(EXTRA_OBJS)
 chronyc : $(CLI_OBJS)
 	$(CC) $(CFLAGS) -o chronyc $(CLI_OBJS) $(LDFLAGS) $(LIBS) $(EXTRA_CLI_LIBS)

-client.o : client.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) @READLINE_COMPILE@ -c $<
-
-$(HASH_OBJ) : $(patsubst %.o,%.c,$(HASH_OBJ))
-	$(CC) $(CFLAGS) $(CPPFLAGS) @HASH_COMPILE@ -c $<
-
 distclean : clean
-	-rm -f Makefile
-	-rm -f chrony.conf.5 chrony.texi chronyc.1 chronyd.8
+	$(MAKE) -C doc distclean
+	$(MAKE) -C test/unit distclean
+	-rm -f .DS_Store
+	-rm -f Makefile config.h config.log

 clean :
-	-rm -f *.o *.s chronyc chronyd core *~ chrony.info chrony.html chrony.txt
+	-rm -f *.o *.s chronyc chronyd core *~
 	-rm -rf .deps
+	-rm -rf *.dSYM

-getdate.c :
+getdate.c : getdate.y
 	bison -o getdate.c getdate.y

 # This can be used to force regeneration of getdate.c
@@ -90,15 +84,10 @@ getdate :
 # For install, don't use the install command, because its switches
 # seem to vary between systems.

-install: chronyd chronyc chrony.txt
+install: chronyd chronyc
 	[ -d $(DESTDIR)$(SYSCONFDIR) ] || mkdir -p $(DESTDIR)$(SYSCONFDIR)
 	[ -d $(DESTDIR)$(SBINDIR) ] || mkdir -p $(DESTDIR)$(SBINDIR)
 	[ -d $(DESTDIR)$(BINDIR) ] || mkdir -p $(DESTDIR)$(BINDIR)
-	[ -d $(DESTDIR)$(DOCDIR) ] || mkdir -p $(DESTDIR)$(DOCDIR)
-	[ -d $(DESTDIR)$(MANDIR)/man1 ] || mkdir -p $(DESTDIR)$(MANDIR)/man1
-	[ -d $(DESTDIR)$(MANDIR)/man5 ] || mkdir -p $(DESTDIR)$(MANDIR)/man5
-	[ -d $(DESTDIR)$(MANDIR)/man8 ] || mkdir -p $(DESTDIR)$(MANDIR)/man8
-	[ -d $(DESTDIR)$(DOCDIR) ] || mkdir -p $(DESTDIR)$(DOCDIR)
 	[ -d $(DESTDIR)$(CHRONYVARDIR) ] || mkdir -p $(DESTDIR)$(CHRONYVARDIR)
 	if [ -f $(DESTDIR)$(SBINDIR)/chronyd ]; then rm -f $(DESTDIR)$(SBINDIR)/chronyd ; fi
 	if [ -f $(DESTDIR)$(BINDIR)/chronyc ]; then rm -f $(DESTDIR)$(BINDIR)/chronyc ; fi
@@ -106,20 +95,13 @@ install: chronyd chronyc chrony.txt
 	chmod 755 $(DESTDIR)$(SBINDIR)/chronyd
 	cp chronyc $(DESTDIR)$(BINDIR)/chronyc
 	chmod 755 $(DESTDIR)$(BINDIR)/chronyc
-	cp chrony.txt $(DESTDIR)$(DOCDIR)/chrony.txt
-	chmod 644 $(DESTDIR)$(DOCDIR)/chrony.txt
-	cp COPYING $(DESTDIR)$(DOCDIR)/COPYING
-	chmod 644 $(DESTDIR)$(DOCDIR)/COPYING
-	cp README $(DESTDIR)$(DOCDIR)/README
-	chmod 644 $(DESTDIR)$(DOCDIR)/README
-	cp chrony.1 $(DESTDIR)$(MANDIR)/man1
-	chmod 644 $(DESTDIR)$(MANDIR)/man1/chrony.1
-	cp chronyc.1 $(DESTDIR)$(MANDIR)/man1
-	chmod 644 $(DESTDIR)$(MANDIR)/man1/chronyc.1
-	cp chronyd.8 $(DESTDIR)$(MANDIR)/man8
-	chmod 644 $(DESTDIR)$(MANDIR)/man8/chronyd.8
-	cp chrony.conf.5 $(DESTDIR)$(MANDIR)/man5
-	chmod 644 $(DESTDIR)$(MANDIR)/man5/chrony.conf.5
+	$(MAKE) -C doc install
+
+docs :
+	$(MAKE) -C doc docs
+
+install-docs :
+	$(MAKE) -C doc install-docs

 %.o : %.c
 	$(CC) $(CFLAGS) $(CPPFLAGS) -c $<
@@ -127,30 +109,19 @@ install: chronyd chronyc chrony.txt
 %.s : %.c
 	$(CC) $(CFLAGS) $(CPPFLAGS) -S $<

-check : chronyd chronyc
+quickcheck : chronyd chronyc
+	$(MAKE) -C test/unit check
 	cd test/simulation && ./run

-install-docs : docs
-	[ -d $(DESTDIR)$(DOCDIR) ] || mkdir -p $(DESTDIR)$(DOCDIR)
-	cp chrony.txt $(DESTDIR)$(DOCDIR)/chrony.txt
-	chmod 644 $(DESTDIR)$(DOCDIR)/chrony.txt
-	cp chrony.html $(DESTDIR)$(DOCDIR)/chrony.html
-	chmod 644 $(DESTDIR)$(DOCDIR)/chrony.html
-	[ -d $(DESTDIR)$(INFODIR) ] || mkdir -p $(DESTDIR)$(INFODIR)
-	cp chrony.info* $(DESTDIR)$(INFODIR)
-	chmod 644 $(DESTDIR)$(INFODIR)/chrony.info*
+check : chronyd chronyc
+	$(MAKE) -C test/unit check
+	cd test/simulation && ./run -i 20 -m 2

-docs : chrony.txt chrony.html chrony.info
-
-chrony.txt : chrony.texi
-	makeinfo --no-headers --number-sections -o chrony.txt chrony.texi
-
-chrony.html : chrony.texi
-	command -v texi2html > /dev/null 2>&1 && texi2html chrony.texi || \
-	  makeinfo --no-split --html --number-sections -o chrony.html chrony.texi
-
-chrony.info : chrony.texi
-	makeinfo chrony.texi
+Makefile : Makefile.in configure
+	@echo
+	@echo Makefile needs to be regenerated, run ./configure
+	@echo
+	@exit 1

 .deps:
 	@mkdir .deps
--- a/235
+++ b/235
@@ -1,3 +1,215 @@
+New in version 3.2
+==================
+
+Enhancements
+------------
+* Improve stability with NTP sources and reference clocks
+* Improve support for NTP interleaved modes
+* Control frequency of system clock on macOS 10.13 and later
+* Set TAI-UTC offset of system clock with leapsectz directive
+* Add support for new HW timestamping options added in Linux 4.13
+* Add rxfilter option to hwtimestamp directive
+* Add extpps option to PHC refclock to timestamp external PPS signal
+* Add pps option to refclock directive to treat any refclock as PPS
+* Add width option to refclock directive to filter wrong pulse edges
+* Add -x option to disable control of system clock
+* Add -l option to log to specified file instead of syslog
+* Allow multiple command-line options to be specified together
+* Allow starting without root privileges with -Q option
+* Update seccomp filter for new glibc versions
+* Dump history on exit by default with dumpdir directive
+* Use hardening compiler options by default
+
+Bug fixes
+---------
+* Don't drop PHC samples with low-resolution system clock
+* Ignore outliers in PHC tracking, RTC tracking, manual input
+* Increase polling interval when peer is not responding
+* Exit with error message when include directive fails
+* Don't allow slash after hostname in allow/deny directive/command
+* Try to connect to all addresses in chronyc before giving up
+
+New in version 3.1
+==================
+
+Enhancements
+------------
+* Add support for precise cross timestamping of PHC on Linux
+* Add minpoll, precision, nocrossts options to hwtimestamp directive
+* Add rawmeasurements option to log directive and modify measurements
+  option to log only valid measurements from synchronised sources
+* Allow sub-second polling interval with NTP sources
+
+Bug fixes
+---------
+* Fix time smoothing in interleaved mode
+
+New in version 3.0
+==================
+
+Enhancements
+------------
+* Add support for software and hardware timestamping on Linux
+* Add support for client/server and symmetric interleaved modes
+* Add support for MS-SNTP authentication in Samba
+* Add support for truncated MACs in NTPv4 packets
+* Estimate and correct for asymmetric network jitter
+* Increase default minsamples and polltarget to improve stability
+  with very low jitter
+* Add maxjitter directive to limit source selection by jitter
+* Add offset option to server/pool/peer directive
+* Add maxlockage option to refclock directive
+* Add -t option to chronyd to exit after specified time
+* Add partial protection against replay attacks on symmetric mode
+* Don't reset polling interval when switching sources to online state
+* Allow rate limiting with very short intervals
+* Improve maximum server throughput on Linux and NetBSD
+* Remove dump files after start
+* Add tab-completion to chronyc with libedit/readline
+* Add ntpdata command to print details about NTP measurements
+* Allow all source options to be set in add server/peer command
+* Indicate truncated addresses/hostnames in chronyc output
+* Print reference IDs as hexadecimal numbers to avoid confusion with
+  IPv4 addresses
+
+Bug fixes
+---------
+* Fix crash with disabled asynchronous name resolving
+
+New in version 2.4.1
+====================
+
+Bug fixes
+---------
+* Fix processing of kernel timestamps on non-Linux systems
+* Fix crash with smoothtime directive
+* Fix validation of refclock sample times
+* Fix parsing of refclock directive
+
+New in version 2.4
+==================
+
+Enhancements
+------------
+* Add orphan option to local directive for orphan mode compatible with ntpd
+* Add distance option to local directive to set activation threshold
+  (1 second by default)
+* Add maxdrift directive to set maximum allowed drift of system clock
+* Try to replace NTP sources exceeding maximum distance
+* Randomise source replacement to avoid getting stuck with bad sources
+* Randomise selection of sources from pools on start
+* Ignore reference timestamp as ntpd doesn't always set it correctly
+* Modify tracking report to use same values as seen by NTP clients
+* Add -c option to chronyc to write reports in CSV format
+* Provide detailed manual pages
+
+Bug fixes
+---------
+* Fix SOCK refclock to work correctly when not specified as last refclock
+* Fix initstepslew and -q/-Q options to accept time from own NTP clients
+* Fix authentication with keys using 512-bit hash functions
+* Fix crash on exit when multiple signals are received
+* Fix conversion of very small floating-point numbers in command packets
+
+Removed features
+----------------
+* Drop documentation in Texinfo format
+
+New in version 2.3
+==================
+
+Enhancements
+------------
+* Add support for NTP and command response rate limiting
+* Add support for dropping root privileges on Mac OS X, FreeBSD, Solaris
+* Add require and trust options for source selection
+* Enable logchange by default (1 second threshold)
+* Set RTC on Mac OS X with rtcsync directive
+* Allow binding to NTP port after dropping root privileges on NetBSD
+* Drop CAP_NET_BIND_SERVICE capability on Linux when NTP port is disabled
+* Resolve names in separate process when seccomp filter is enabled
+* Replace old records in client log when memory limit is reached
+* Don't reveal local time and synchronisation state in client packets
+* Don't keep client sockets open for longer than necessary
+* Ignore poll in KoD RATE packets as ntpd doesn't always set it correctly
+* Warn when using keys shorter than 80 bits
+* Add keygen command to generate random keys easily
+* Add serverstats command to report NTP and command packet statistics
+
+Bug fixes
+---------
+* Fix clock correction after making step on Mac OS X
+* Fix building on Solaris
+
+New in version 2.2.1
+====================
+
+Security fixes
+--------------
+* Restrict authentication of NTP server/peer to specified key (CVE-2016-1567)
+
+New in version 2.2
+==================
+
+Enhancements
+------------
+* Add support for configuration and monitoring over Unix domain socket
+  (accessible by root or chrony user when root privileges are dropped)
+* Add support for system call filtering with seccomp on Linux (experimental)
+* Add support for dropping root privileges on NetBSD
+* Control frequency of system clock on FreeBSD, NetBSD, Solaris
+* Add system leap second handling mode on FreeBSD, NetBSD, Solaris
+* Add dynamic drift removal on Mac OS X
+* Add support for setting real-time priority on Mac OS X
+* Add maxdistance directive to limit source selection by root distance
+  (3 seconds by default)
+* Add refresh command to get new addresses of NTP sources
+* Allow wildcard patterns in include directive
+* Restore time from driftfile with -s option if later than RTC time
+* Add configure option to set default hwclockfile
+* Add -d option to chronyc to enable debug messages
+* Allow multiple addresses to be specified for chronyc with -h option
+  and reconnect when no valid reply is received
+* Make check interval in waitsync command configurable
+
+Bug fixes
+---------
+* Fix building on NetBSD, Solaris
+* Restore time from driftfile with -s option if reading RTC failed
+
+Removed features
+----------------
+* Drop support for authentication with command key (run-time configuration
+  is now allowed only for local users that can access the Unix domain socket)
+
+New in version 2.1.1
+====================
+
+Bug fixes
+---------
+* Fix clock stepping by integer number of seconds on Linux
+
+New in version 2.1
+==================
+
+Enhancements
+------------
+* Add support for Mac OS X
+* Try to replace unreachable and falseticker servers/peers specified
+  by name like pool sources
+* Add leaponly option to smoothtime directive to allow synchronised
+  leap smear between multiple servers
+* Use specific reference ID when smoothing served time
+* Add smoothing command to report time smoothing status
+* Add smoothtime command to activate or reset time smoothing
+
+Bug fixes
+---------
+* Fix crash in source selection with preferred sources
+* Fix resetting of time smoothing
+* Include packet precision in peer dispersion
+* Fix crash in chronyc on invalid command syntax
+
 New in version 2.0
 ==================

@@ -5,6 +217,8 @@ Enhancements
 ------------
 * Update to NTP version 4 (RFC 5905)
 * Add pool directive to specify pool of NTP servers
+* Add leapsecmode directive to select how to correct clock for leap second
+* Add smoothtime directive to smooth served time and enable leap smear
 * Add minsources directive to set required number of selectable sources
 * Add minsamples and maxsamples options for all sources
 * Add tempcomp configuration with list of points
@@ -13,8 +227,9 @@ Enhancements
 * Improve source selection
 * Handle offline sources as unreachable
 * Open NTP server port only when necessary (client access is allowed by
-  allow directive/command, peer or broadcast is configured)
+  allow directive/command or peer/broadcast is configured)
 * Change default bindcmdaddress to loopback address
+* Change default maxdelay to 3 seconds
 * Change default stratumweight to 0.001
 * Update adjtimex synchronisation status
 * Use system headers for adjtimex
@@ -25,9 +240,21 @@ Enhancements

 Bug fixes
 ---------
-* Fix accepting requests from configured sources when acquisitionport
-  is equal to server port
-* Fix allocation of slots saving replies to authenticated commands
+* Add sanity checks for time and frequency offset
+* Don't report synchronised status during leap second
+* Don't combine reference clocks with close NTP sources
+* Fix accepting requests from configured sources
+* Fix initial fallback drift setting
+
+New in version 1.31.1
+=====================
+
+Security fixes
+--------------
+* Protect authenticated symmetric NTP associations against DoS attacks
+  (CVE-2015-1853)
+* Fix access configuration with subnet size indivisible by 4 (CVE-2015-1821)
+* Fix initialization of reply slots for authenticated commands (CVE-2015-1822)

 New in version 1.31
 ===================
--- a/141
+++ b/141
@@ -3,67 +3,35 @@ This is the README for chrony.
 What is chrony?
 ===============

-Chrony is a pair of programs for maintaining the accuracy of computer
-clocks.
+chrony is a versatile implementation of the Network Time Protocol (NTP).
+It can synchronize the system clock with NTP servers, reference clocks
+(e.g. GPS receiver), and manual input using wristwatch and keyboard.
+It can also operate as an NTPv4 (RFC 5905) server and peer to provide
+a time service to other computers in the network.

-chronyd is a (background) daemon program that can be started at boot
-time.  This does most of the work.
+It is designed to perform well in a wide range of conditions, including
+intermittent network connections, heavily congested networks, changing
+temperatures (ordinary computer clocks are sensitive to temperature),
+and systems that do not run continuosly, or run on a virtual machine.

-chronyc is a command-line interface program which can be used to
-monitor chronyd's performance and to change various operating
-parameters whilst it is running.
-
-chronyd's main function is to obtain measurements of the true (UTC)
-time from one of several sources, and correct the system clock
-accordingly.  It also works out the rate at which the system clock
-gains or loses time and uses this information to keep it accurate
-between measurements from the reference.
-
-The reference time can be derived from Network Time Protocol (NTP)
-servers, reference clocks, or wristwatch-and-keyboard (via chronyc).
-The main source of information about the Network Time Protocol is
-http://www.ntp.org.
-
-It is designed so that it can work on computers which only have
-intermittent access to reference sources, for example computers which
-use a dial-up account to access the Internet or laptops.  Of course, it
-will work well on computers with permanent connections too.
-
-In addition, on Linux it can monitor the system's real time clock
-performance, so the system can maintain accurate time even across
-reboots.
-
-Typical accuracies available between 2 machines are
-
-On an ethernet LAN : 100-200 microseconds, often much better
-On a V32bis dial-up modem connection : 10's of milliseconds (from one
-session to the next)
-
-With a good reference clock the accuracy can reach one microsecond.
-
-chronyd can also operate as an NTPv4 (RFC 5905) server, peer and broadcast
-server.
+Typical accuracy between two machines synchronised over the Internet is
+within a few milliseconds; on a LAN, accuracy is typically in tens of
+microseconds.  With hardware timestamping, or a hardware reference clock,
+sub-microsecond accuracy may be possible.

+Two programs are included in chrony, chronyd is a daemon that can be
+started at boot time and chronyc is a command-line interface program
+which can be used to monitor chronyd's performance and to change various
+operating parameters whilst it is running.

 What will chrony run on?
 ========================

-Chrony can be successfully built and run on
-
-1. Linux 2.2.x, 2.3.x, 2.4.x, 2.6.x, 3.x
-
-2. Solaris 2.5/2.5.1/2.6/2.7/2.8 (various platforms) 
-
-3. SunOS 4.1.4 (Sparc 2 and Sparc 20)
-
-4. BSD/386 v1.1 has been reported to work using the SunOS 4.1 driver.
-
-5. NetBSD.
-
-Any other system will require a porting exercise.  You would need to
-start from one of the existing system-specific drivers and look into
-the quirks of certain system calls and the kernel on your target
-system.
+The software is known to work on Linux, FreeBSD, NetBSD, macOS and
+Solaris.  Closely related systems may work too.  Any other system will
+likely require a porting exercise.  You would need to start from one
+of the existing system-specific drivers and look into the quirks of
+certain system calls and the kernel on your target system.

 How do I set it up?
 ===================
@@ -85,7 +53,7 @@ ready-formatted plain text (chrony.txt) in the distribution.
 There is also information available on the chrony web pages, accessible
 through the URL 

-    http://chrony.tuxfamily.org/
+    https://chrony.tuxfamily.org/

 Where are new versions announced?
 =================================
@@ -116,25 +84,36 @@ chrony-dev-request@chrony.tuxfamily.org

 as applicable.

+When you are reporting a bug, please send us all the information you can.
+Unfortunately, chrony has proven to be one of those programs where it is very
+difficult to reproduce bugs in a different environment. So we may have to
+interact with you quite a lot to obtain enough extra logging and tracing to
+pin-point the problem in some cases. Please be patient and plan for this!

-Author
-======
+License
+=======
+
+chrony is distributed under the GNU General Public License version 2.
+
+Authors
+=======

 Richard P. Curnow <rc@rc0.org.uk>
-
-
-Maintainers
-===========
-
 Miroslav Lichvar <mlichvar@redhat.com>

-
 Acknowledgements
 ================

+In writing the chronyd program, extensive use has been made of RFC 1305
+and RFC 5905, written by David Mills. The source code of the NTP reference
+implementation has been used to check the details of the protocol.
+
 The following people have provided patches and other major contributions
 to the program :

+Lonnie Abelbeck <lonnie@abelbeck.com>
+    Patch to add tab-completion to chronyc
+
 Benny Lyne Amorsen <benny@amorsen.dk>
    Patch to add minstratum option

@@ -155,6 +134,11 @@ Stephan I. Boettcher <stephan@nevis1.columbia.edu>
 Erik Bryer <ebryer@spots.ab.ca>
    Entries in contrib directory

+Bryan Christianson <bryan@whatroute.net>
+    Support for macOS
+    Support for privilege separation
+    Entries in contrib directory
+
 Juliusz Chroboczek <jch@pps.jussieu.fr>
    Fix install rule in Makefile if chronyd file is in use.

@@ -169,6 +153,9 @@ Alexander Gretencord <arutha@gmx.de>
    Changes to installation directory system to make it easier for
    package builders.

+Andrew Griffiths <agriffit@redhat.com>
+    Patch to add support for seccomp filter
+
 Walter Haidinger <walter.haidinger@gmx.at>
    Providing me with login access to a Linux installation where v1.12
    wouldn't compile, so I could develop the fixes for v1.13.  Also, for
@@ -207,18 +194,6 @@ Jim Knoble <jmknoble@pobox.com>
 Antti Jrvinen <costello@iki.fi>
    Advice on configuring for BSD/386

-Miroslav Lichvar <mlichvar@redhat.com>
-    Reference clock support
-    IPv6 support
-    Linux capabilities support
-    Leap second support
-    Improved source selection
-    Improved sample history trimming
-    Improved polling interval adjustment
-    Improved stability with temporary asymmetric delays
-    Temperature compensation
-    Many other bug fixes and improvements
-
 Victor Moroz <vim@prv.adlum.ru>
    Patch to support Linux with HZ!=100

@@ -228,12 +203,24 @@ Kalle Olavi Niemitalo  <tosi@stekt.oulu.fi>
 Frank Otto <sandwichmacher@web.de>
    Handling arbitrary HZ values

+Denny Page <dennypage@me.com>
+    Advice on support for hardware timestamping
+
+Gautier PHILIPPON <gautier.philippon@ensimag.grenoble-inp.fr>
+    Patch to add refresh command to chronyc
+
 Andreas Piesk <apiesk@virbus.de>
    Patch to make chronyc use the readline library if available

 Timo Teras <timo.teras@iki.fi>
    Patch to reply correctly on multihomed hosts

+Bill Unruh <unruh@physics.ubc.ca>
+    Advice on statistics
+
+Stephen Wadeley <swadeley@redhat.com>
+    Improvements to man pages
+
 Wolfgang Weisselberg <weissel@netcologne.de>
    Entries in contrib directory

@@ -247,5 +234,5 @@ Ulrich Windl <ulrich.windl@rz.uni-regensburg.de> for the
 Doug Woodward <dougw@whistler.com>
    Advice on configuring for Solaris 2.8 on x86

-Many other people have contributed bug reports and suggestions.  I'm
-sorry I can't identify all of you individually.
+Many other people have contributed bug reports and suggestions.  We are sorry
+we cannot identify all of you individually.
--- a/addressing.h
+++ b/addressing.h
@@ -42,6 +42,7 @@ typedef struct {
    uint8_t in6[16];
  } addr;
  uint16_t family;
+  uint16_t _pad;
 } IPAddr;

 typedef struct {
@@ -49,8 +50,11 @@ typedef struct {
  unsigned short port;
 } NTP_Remote_Address;

+#define INVALID_IF_INDEX -1
+
 typedef struct {
  IPAddr ip_addr;
+  int if_index;
  int sock_fd;
 } NTP_Local_Address;

--- a/addrfilt.c
+++ b/addrfilt.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997,1998,1999,2000,2001,2002,2005
- * Copyright (C) Miroslav Lichvar  2009
+ * Copyright (C) Miroslav Lichvar  2009, 2015
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -62,7 +62,7 @@ split_ip6(IPAddr *ip, uint32_t *dst)
  int i;

  for (i = 0; i < 4; i++)
-    dst[i] = ip->addr.in6[i * 4 + 0] << 24 |
+    dst[i] = (uint32_t)ip->addr.in6[i * 4 + 0] << 24 |
             ip->addr.in6[i * 4 + 1] << 16 |
             ip->addr.in6[i * 4 + 2] << 8 |
             ip->addr.in6[i * 4 + 3];
@@ -199,7 +199,10 @@ set_subnet(TableNode *start_node,

      /* How many subnet entries to set : 1->8, 2->4, 3->2 */
      N = 1 << (NBITS-bits_to_go);
-      subnet = get_subnet(ip, bits_consumed);
+
+      subnet = get_subnet(ip, bits_consumed) & ~(N - 1);
+      assert(subnet + N <= TABLE_SIZE);
+
      if (!(node->extended)) {
        open_node(node);
      }
@@ -398,117 +401,3 @@ ADF_IsAnyAllowed(ADF_AuthTable table, int family)
      return 0;
  }
 }
-
-/* ================================================== */
-
-#if defined TEST
-
-static void print_node(TableNode *node, uint32_t *addr, int ip_len, int shift, int subnet_bits)
-{
-  uint32_t new_addr[4];
-  int i;
-  TableNode *sub_node;
-
-  for (i=0; i<subnet_bits; i++) putchar(' ');
-
-  if (ip_len == 1)
-      printf("%d.%d.%d.%d",
-          ((addr[0] >> 24) & 255),
-          ((addr[0] >> 16) & 255),
-          ((addr[0] >>  8) & 255),
-          ((addr[0]      ) & 255));
-  else {
-    for (i=0; i<4; i++) {
-      if (addr[i])
-        printf("%d.%d.%d.%d",
-            ((addr[i] >> 24) & 255),
-            ((addr[i] >> 16) & 255),
-            ((addr[i] >>  8) & 255),
-            ((addr[i]      ) & 255));
-      putchar(i < 3 ? ':' : '\0');
-    }
-  }
-  printf("/%d : %s\n",
-         subnet_bits,
-         (node->state == ALLOW) ? "allow" :
-         (node->state == DENY)  ? "deny" : "as parent");
-  if (node->extended) {
-    for (i=0; i<16; i++) {
-      sub_node = &(node->extended[i]);
-      new_addr[0] = addr[0];
-      new_addr[1] = addr[1];
-      new_addr[2] = addr[2];
-      new_addr[3] = addr[3];
-      new_addr[ip_len - 1 - shift / 32] |= ((uint32_t)i << (shift % 32));
-      print_node(sub_node, new_addr, ip_len, shift - 4, subnet_bits + 4);
-    }
-  }
-}
-
-
-static void print_table(ADF_AuthTable table)
-{
-  uint32_t addr[4];
-
-  memset(addr, 0, sizeof (addr));
-  printf("IPv4 table:\n");
-  print_node(&table->base4, addr, 1, 28, 0);
-
-  memset(addr, 0, sizeof (addr));
-  printf("IPv6 table:\n");
-  print_node(&table->base6, addr, 4, 124, 0);
-}
-
-/* ================================================== */
-
-int main (int argc, char **argv)
-{
-  IPAddr ip;
-  ADF_AuthTable table;
-  table = ADF_CreateTable();
-
-  ip.family = IPADDR_INET4;
-
-  ip.addr.in4 = 0x7e800000;
-  ADF_Allow(table, &ip, 9);
-  ip.addr.in4 = 0x7ecc0000;
-  ADF_Deny(table, &ip, 14);
-#if 0
-  ip.addr.in4 = 0x7f000001;
-  ADF_Deny(table, &ip, 32);
-  ip.addr.in4 = 0x7f000000;
-  ADF_Allow(table, &ip, 8);
-#endif
-
-  printf("allowed: %d\n", ADF_IsAllowed(table, &ip));
-  ip.addr.in4 ^= 1;
-  printf("allowed: %d\n", ADF_IsAllowed(table, &ip));
-
-  ip.family = IPADDR_INET6;
-
-  memcpy(ip.addr.in6, "abcdefghijklmnop", 16);
-  ADF_Deny(table, &ip, 66);
-  ADF_Allow(table, &ip, 59);
-
-  memcpy(ip.addr.in6, "xbcdefghijklmnop", 16);
-  ADF_Deny(table, &ip, 128);
-  ip.addr.in6[15] ^= 3;
-  ADF_Allow(table, &ip, 127);
-
-  printf("allowed: %d\n", ADF_IsAllowed(table, &ip));
-  ip.addr.in4 ^= 1;
-  printf("allowed: %d\n", ADF_IsAllowed(table, &ip));
-
-  print_table(table);
-
-  ADF_DestroyTable(table);
-  return 0;
-}
-
-
-
-#endif /* defined TEST */
-
-
-
-
--- a/array.c
+++ b/array.c
@@ -44,6 +44,8 @@ ARR_CreateInstance(unsigned int elem_size)
 {
  ARR_Instance array;

+  assert(elem_size > 0);
+
  array = MallocNew(struct ARR_Instance_Record);

  array->data = NULL;
@@ -64,6 +66,9 @@ ARR_DestroyInstance(ARR_Instance array)
 static void
 realloc_array(ARR_Instance array, unsigned int min_size)
 {
+  size_t data_size;
+
+  assert(min_size <= 2 * min_size);
  if (array->allocated >= min_size && array->allocated <= 2 * min_size)
    return;

@@ -74,7 +79,10 @@ realloc_array(ARR_Instance array, unsigned int min_size)
    array->allocated = min_size;
  }

-  array->data = Realloc(array->data, array->elem_size * array->allocated);
+  data_size = (size_t)array->elem_size * array->allocated;
+  assert(data_size / array->elem_size == array->allocated);
+
+  array->data = Realloc(array->data, data_size);
 }

 void *
@@ -89,12 +97,18 @@ void *
 ARR_GetElement(ARR_Instance array, unsigned int index)
 {
  assert(index < array->used);
-  return (void *)((char *)array->data + index * array->elem_size);
+  return (void *)((char *)array->data + (size_t)index * array->elem_size);
 }

 void *
 ARR_GetElements(ARR_Instance array)
 {
+  /* Return a non-NULL pointer when the array has zero size */
+  if (!array->data) {
+    assert(!array->used);
+    return array;
+  }
+
  return array->data;
 }

--- a/candm.h
+++ b/candm.h
@@ -31,7 +31,6 @@

 #include "sysincl.h"
 #include "addressing.h"
-#include "hash.h"

 /* This is the default port to use for CANDM, if no alternative is
   defined */
@@ -89,18 +88,23 @@
 #define REQ_RESELECT 48
 #define REQ_RESELECTDISTANCE 49
 #define REQ_MODIFY_MAKESTEP 50
-#define N_REQUEST_TYPES 51
+#define REQ_SMOOTHING 51
+#define REQ_SMOOTHTIME 52
+#define REQ_REFRESH 53
+#define REQ_SERVER_STATS 54
+#define REQ_CLIENT_ACCESSES_BY_INDEX2 55
+#define REQ_LOCAL2 56
+#define REQ_NTP_DATA 57
+#define REQ_ADD_SERVER2 58
+#define REQ_ADD_PEER2 59
+#define N_REQUEST_TYPES 60

-/* Special utoken value used to log on with first exchange being the
-   password.  (This time value has long since gone by) */
-#define SPECIAL_UTOKEN 0x10101010
-
-/* Structure used to exchange timevals independent on size of time_t */
+/* Structure used to exchange timespecs independent of time_t size */
 typedef struct {
  uint32_t tv_sec_high;
  uint32_t tv_sec_low;
  uint32_t tv_nsec;
-} Timeval;
+} Timespec;

 /* This is used in tv_sec_high for 32-bit timestamps */
 #define TV_NOHIGHSEC 0x7fffffff
@@ -116,6 +120,10 @@ typedef struct {
   pktlength.c, to get the number of bytes that ought to be
   transmitted for each packet type. */

+typedef struct {
+  int32_t EOR;
+} REQ_Null;
+
 typedef struct {
  IPAddr mask;
  IPAddr address;
@@ -195,18 +203,20 @@ typedef struct {
 } REQ_Modify_Makestep;

 typedef struct {
-  Timeval ts;
+  Timespec ts;
  int32_t EOR;
 } REQ_Logon;

 typedef struct {
-  Timeval ts;
+  Timespec ts;
  int32_t EOR;
 } REQ_Settime;

 typedef struct {
  int32_t on_off;
  int32_t stratum;
+  Float distance;
+  int32_t orphan;
  int32_t EOR;
 } REQ_Local;

@@ -215,19 +225,11 @@ typedef struct {
  int32_t EOR;
 } REQ_Manual;

-typedef struct {
-  int32_t EOR;
-} REQ_N_Sources;
-
 typedef struct {
  int32_t index;
  int32_t EOR;
 } REQ_Source_Data;

-typedef struct {
-  int32_t EOR;
-} REQ_Rekey;
-
 typedef struct {
  IPAddr ip;
  int32_t subnet_bits;
@@ -245,6 +247,9 @@ typedef struct {
 #define REQ_ADDSRC_IBURST 0x4
 #define REQ_ADDSRC_PREFER 0x8
 #define REQ_ADDSRC_NOSELECT 0x10
+#define REQ_ADDSRC_TRUST 0x20
+#define REQ_ADDSRC_REQUIRE 0x40
+#define REQ_ADDSRC_INTERLEAVED 0x80

 typedef struct {
  IPAddr ip_addr;
@@ -252,9 +257,17 @@ typedef struct {
  int32_t minpoll;
  int32_t maxpoll;
  int32_t presend_minpoll;
+  uint32_t min_stratum;
+  uint32_t poll_target;
+  uint32_t version;
+  uint32_t max_sources;
+  int32_t min_samples;
+  int32_t max_samples;
  uint32_t authkey;
  Float max_delay;
  Float max_delay_ratio;
+  Float max_delay_dev_ratio;
+  Float offset;
  uint32_t flags;
  int32_t EOR;
 } REQ_NTP_Source;
@@ -264,10 +277,6 @@ typedef struct {
  int32_t EOR;
 } REQ_Del_Source;

-typedef struct {
-  int32_t EOR;
-} REQ_WriteRtc;
-
 typedef struct {
  Float dfreq;
  int32_t EOR;
@@ -279,68 +288,44 @@ typedef struct {
  int32_t EOR;
 } REQ_Doffset;

-typedef struct {
-  int32_t EOR;
-} REQ_Tracking;
-
 typedef struct {
  uint32_t index;
  int32_t EOR;
 } REQ_Sourcestats;

-typedef struct {
-  int32_t EOR;
-} REQ_RTCReport;
-
-typedef struct {
-  int32_t EOR;
-} REQ_TrimRTC;
-
-typedef struct {
-  int32_t EOR;
-} REQ_CycleLogs;
-
-typedef struct {
-  IPAddr ip;
-  uint32_t bits_specd;
-} REQ_SubnetsAccessed_Subnet;
-
 /* This is based on the response size rather than the
   request size */
 #define MAX_CLIENT_ACCESSES 8

 typedef struct {
  uint32_t first_index;
-  uint32_t n_indices;
+  uint32_t n_clients;
  int32_t EOR;
 } REQ_ClientAccessesByIndex;

-typedef struct {
-  int32_t EOR;
-} REQ_ManualList;
-
 typedef struct {
  int32_t index;
  int32_t EOR;
 } REQ_ManualDelete;

-typedef struct {
-  int32_t EOR;
-} REQ_MakeStep;
-
-typedef struct {
-  int32_t EOR;
-} REQ_Activity;
-
-typedef struct {
-  int32_t EOR;
-} REQ_Reselect;
-
 typedef struct {
  Float distance;
  int32_t EOR;
 } REQ_ReselectDistance;

+#define REQ_SMOOTHTIME_RESET 0
+#define REQ_SMOOTHTIME_ACTIVATE 1
+
+typedef struct {
+  int32_t option;
+  int32_t EOR;
+} REQ_SmoothTime;
+
+typedef struct {
+  IPAddr ip_addr;
+  int32_t EOR;
+} REQ_NTPData;
+
 /* ================================================== */

 #define PKT_TYPE_CMD_REQUEST 1
@@ -370,7 +355,16 @@ typedef struct {

   Version 6 : added padding to requests to prevent amplification attack,
   changed maximum number of samples in manual list to 16, new commands: modify
-   makestep
+   makestep, smoothing, smoothtime
+
+   Support for authentication was removed later in version 6 of the protocol
+   and commands that required authentication are allowed only locally over Unix
+   domain socket.
+
+   Version 6 (no authentication) : changed format of client accesses by index
+   (using new request/reply types) and manual timestamp, new fields and flags
+   in NTP source request and report, new commands: ntpdata, refresh,
+   serverstats
 */

 #define PROTO_VERSION_NUMBER 6
@@ -384,7 +378,7 @@ typedef struct {
 #define PROTO_VERSION_PADDING 6

 /* The maximum length of padding in request packet, currently
-   defined by CLIENT_ACCESSES_BY_INDEX and MANUAL_LIST */
+   defined by MANUAL_LIST */
 #define MAX_PADDING_LENGTH 396

 /* ================================================== */
@@ -399,10 +393,11 @@ typedef struct {
                             (count up from zero for same sequence
                             number) */
  uint32_t sequence; /* Client's sequence number */
-  uint32_t utoken; /* Unique token per incarnation of daemon */
-  uint32_t token; /* Command token (to prevent replay attack) */
+  uint32_t pad1;
+  uint32_t pad2;

  union {
+    REQ_Null null;
    REQ_Online online;
    REQ_Offline offline;
    REQ_Burst burst;
@@ -420,39 +415,25 @@ typedef struct {
    REQ_Settime settime;
    REQ_Local local;
    REQ_Manual manual;
-    REQ_N_Sources n_sources;
    REQ_Source_Data source_data;
-    REQ_Rekey rekey;
    REQ_Allow_Deny allow_deny;
    REQ_Ac_Check ac_check;
    REQ_NTP_Source ntp_source;
    REQ_Del_Source del_source;
-    REQ_WriteRtc writertc;
    REQ_Dfreq dfreq;
    REQ_Doffset doffset;
-    REQ_Tracking tracking;
    REQ_Sourcestats sourcestats;
-    REQ_RTCReport rtcreport;
-    REQ_TrimRTC trimrtc;
-    REQ_CycleLogs cyclelogs;
    REQ_ClientAccessesByIndex client_accesses_by_index;
-    REQ_ManualList manual_list;
    REQ_ManualDelete manual_delete;
-    REQ_MakeStep make_step;
-    REQ_Activity activity;
-    REQ_Reselect reselect;
    REQ_ReselectDistance reselect_distance;
+    REQ_SmoothTime smoothtime;
+    REQ_NTPData ntp_data;
  } data; /* Command specific parameters */

-  /* The following fields only set the maximum size of the packet.
-     There are no holes between them and the actual data. */
-
-  /* Padding used to prevent traffic amplification */
+  /* Padding used to prevent traffic amplification.  It only defines the
+     maximum size of the packet, there is no hole after the data field. */
  uint8_t padding[MAX_PADDING_LENGTH];

-  /* Authentication data */
-  uint8_t auth[MAX_HASH_LENGTH];
-
 } CMD_Request;

 /* ================================================== */
@@ -477,7 +458,12 @@ typedef struct {
 #define RPY_CLIENT_ACCESSES_BY_INDEX 10
 #define RPY_MANUAL_LIST 11
 #define RPY_ACTIVITY 12
-#define N_REPLY_TYPES 13
+#define RPY_SMOOTHING 13
+#define RPY_SERVER_STATS 14
+#define RPY_CLIENT_ACCESSES_BY_INDEX2 15
+#define RPY_NTP_DATA 16
+#define RPY_MANUAL_TIMESTAMP2 17
+#define N_REPLY_TYPES 18

 /* Status codes */
 #define STT_SUCCESS 0
@@ -524,6 +510,8 @@ typedef struct {

 #define RPY_SD_FLAG_NOSELECT 0x1
 #define RPY_SD_FLAG_PREFER 0x2
+#define RPY_SD_FLAG_TRUST 0x4
+#define RPY_SD_FLAG_REQUIRE 0x8

 typedef struct {
  IPAddr ip_addr;
@@ -545,7 +533,7 @@ typedef struct {
  IPAddr ip_addr;
  uint16_t stratum;
  uint16_t leap_status;
-  Timeval ref_time;
+  Timespec ref_time;
  Float current_correction;
  Float last_offset;
  Float rms_offset;
@@ -573,7 +561,7 @@ typedef struct {
 } RPY_Sourcestats;

 typedef struct {
-  Timeval ref_time;
+  Timespec ref_time;
  uint16_t n_samples;
  uint16_t n_runs;
  uint32_t span_seconds;
@@ -583,7 +571,7 @@ typedef struct {
 } RPY_Rtc;

 typedef struct {
-  uint32_t centiseconds;
+  Float offset;
  Float dfreq_ppm;
  Float new_afreq_ppm;
  int32_t EOR;
@@ -591,17 +579,14 @@ typedef struct {

 typedef struct {
  IPAddr ip;
-  uint32_t bits_specd;
-  uint32_t bitmap[8];
-} RPY_SubnetsAccessed_Subnet;
-
-typedef struct {
-  IPAddr ip;
-  uint32_t client_hits;
-  uint32_t peer_hits;
-  uint32_t cmd_hits_auth;
-  uint32_t cmd_hits_normal;
-  uint32_t cmd_hits_bad;
+  uint32_t ntp_hits;
+  uint32_t cmd_hits;
+  uint32_t ntp_drops;
+  uint32_t cmd_drops;
+  int8_t ntp_interval;
+  int8_t cmd_interval;
+  int8_t ntp_timeout_interval;
+  int8_t pad;
  uint32_t last_ntp_hit_ago;
  uint32_t last_cmd_hit_ago;
 } RPY_ClientAccesses_Client;
@@ -614,10 +599,19 @@ typedef struct {
  int32_t EOR;
 } RPY_ClientAccessesByIndex;

+typedef struct {
+  uint32_t ntp_hits;
+  uint32_t cmd_hits;
+  uint32_t ntp_drops;
+  uint32_t cmd_drops;
+  uint32_t log_drops;
+  int32_t EOR;
+} RPY_ServerStats;
+
 #define MAX_MANUAL_LIST_SAMPLES 16

 typedef struct {
-  Timeval when;
+  Timespec when;
  Float slewed_offset;
  Float orig_offset;
  Float residual;
@@ -638,6 +632,52 @@ typedef struct {
  int32_t EOR;
 } RPY_Activity;

+#define RPY_SMT_FLAG_ACTIVE 0x1
+#define RPY_SMT_FLAG_LEAPONLY 0x2
+
+typedef struct {
+  uint32_t flags;
+  Float offset;
+  Float freq_ppm;
+  Float wander_ppm;
+  Float last_update_ago;
+  Float remaining_time;
+  int32_t EOR;
+} RPY_Smoothing;
+
+#define RPY_NTP_FLAGS_TESTS 0x3ff
+#define RPY_NTP_FLAG_INTERLEAVED 0x4000
+#define RPY_NTP_FLAG_AUTHENTICATED 0x8000
+
+typedef struct {
+  IPAddr remote_addr;
+  IPAddr local_addr;
+  uint16_t remote_port;
+  uint8_t leap;
+  uint8_t version;
+  uint8_t mode;
+  uint8_t stratum;
+  int8_t poll;
+  int8_t precision;
+  Float root_delay;
+  Float root_dispersion;
+  uint32_t ref_id;
+  Timespec ref_time;
+  Float offset;
+  Float peer_delay;
+  Float peer_dispersion;
+  Float response_time;
+  Float jitter_asymmetry;
+  uint16_t flags;
+  uint8_t tx_tss_char;
+  uint8_t rx_tss_char;
+  uint32_t total_tx_count;
+  uint32_t total_rx_count;
+  uint32_t total_valid_count;
+  uint32_t reserved[4];
+  int32_t EOR;
+} RPY_NTPData;
+
 typedef struct {
  uint8_t version;
  uint8_t pkt_type;
@@ -650,9 +690,9 @@ typedef struct {
  uint16_t pad2;
  uint16_t pad3;
  uint32_t sequence; /* Echo of client's sequence number */
-  uint32_t utoken; /* Unique token per incarnation of daemon */
-  uint32_t token; /* New command token (only if command was successfully
-                          authenticated) */
+  uint32_t pad4;
+  uint32_t pad5;
+
  union {
    RPY_Null null;
    RPY_N_Sources n_sources;
@@ -662,14 +702,13 @@ typedef struct {
    RPY_Sourcestats sourcestats;
    RPY_Rtc rtc;
    RPY_ClientAccessesByIndex client_accesses_by_index;
+    RPY_ServerStats server_stats;
    RPY_ManualList manual_list;
    RPY_Activity activity;
+    RPY_Smoothing smoothing;
+    RPY_NTPData ntp_data;
  } data; /* Reply specific parameters */

-  /* authentication of the packet, there is no hole after the actual data
-     from the data union, this field only sets the maximum auth size */
-  uint8_t auth[MAX_HASH_LENGTH];
-
 } CMD_Reply;

 /* ================================================== */
--- a/chrony.1
+++ b/chrony.1
@@ -1,72 +0,0 @@
-.TH CHRONY 1 "@MAN_DATE@" "chrony @VERSION@" "User's Manual"
-.SH NAME
-chrony \- programs for keeping computer clocks accurate
-
-.SH SYNOPSIS
-\fBchronyc\fR [\fIOPTIONS\fR]
-
-\fBchronyd\fR [\fIOPTIONS\fR]
-
-.SH DESCRIPTION
-\fBchrony\fR is a pair of programs for keeping computer clocks accurate.
-\fIchronyd\fR is a background (daemon) program and \fIchronyc\fR is a
-command-line interface to it. Time reference sources for chronyd can be
-NTP servers, human (via keyboard and \fIchronyc\fR), or the computer's
-real-time clock at boot time (Linux only). chronyd can determine the rate at
-which the computer gains or loses time and compensate for it while no external
-reference is present. Its use of NTP servers can be switched on and off
-(through \fIchronyc\fR) to support computers with dial-up/intermittent access
-to the Internet, and it can also act as an NTP server.
-
-.SH USAGE
-\fIchronyc\fR is a command-line interface program which can be used to
-monitor \fIchronyd\fR's performance and to change various operating
-parameters whilst it is running.
-
-\fIchronyd\fR's main function is to obtain measurements of the true (UTC)
-time from one of several sources, and correct the system clock
-accordingly.  It also works out the rate at which the system clock
-gains or loses time and uses this information to keep it accurate
-between measurements from the reference.
-
-The reference time can be derived from either Network Time Protocol
-(NTP) servers, reference clocks, or wristwatch-and-keyboard (via \fIchronyc\fR).
-The main source of information about the Network Time Protocol is
-\fIhttp://www.ntp.org\fR.
-
-It is designed so that it can work on computers which only have
-intermittent access to reference sources, for example computers which
-use a dial-up account to access the Internet or laptops.  Of course, it
-will work well on computers with permanent connections too.
-
-In addition, on Linux it can monitor the system's real time clock
-performance, so the system can maintain accurate time even across
-reboots.
-
-Typical accuracies available between 2 machines are
-
-On an ethernet LAN : 100-200 microseconds, often much better
-On a V32bis dial-up modem connection : 10's of milliseconds (from one
-session to the next)
-
-With a good reference clock the accuracy can reach one microsecond.
-
-\fIchronyd\fR can also operate as an NTPv4 (RFC 5905) server, peer and
-broadcast server.
-
-.SH "SEE ALSO"
-.BR chronyc(1),
-.BR chrony.conf(5),
-.BR chronyd(8)
-
-.I http://chrony.tuxfamily.org/
-
-.SH AUTHOR
-Richard Curnow <rc@rc0.org.uk>
-
-This man-page was written by Jan Schaumann <jschauma@netmeister.org> as part
-of "The Missing Man Pages Project".  Please see
-\fIhttp://www.netmeister.org/misc/m2p2/index.html\fR for details.
-
-The complete chrony documentation is supplied in texinfo format.
-
--- a/chrony.conf.5.in
+++ b/chrony.conf.5.in
@@ -1,69 +0,0 @@
-.TH chrony.conf 5 "@MAN_DATE@" "chrony @VERSION@" "Configuration Files"
-.SH NAME
-chrony.conf \- chronyd configuration file
-
-.SH SYNOPSIS
-.B @SYSCONFDIR@/chrony.conf
-
-.SH DESCRIPTION
-\fIchrony\fR is a pair of programs for maintaining the accuracy of computer
-clocks. \fIchronyd\fR is a background daemon program that can be started at
-boot time.
-
-Assuming that you have found some servers, you need to set up a
-configuration file to run \fIchrony\fR.  The (compiled-in) default location
-for this file is \fB@SYSCONFDIR@/chrony.conf\fR.  Assuming that your NTP
-servers are called `foo.example.net', `bar.example.net' and `baz.example.net',
-your \fBchrony.conf\fR file could contain as a minimum
-
-.EX
-     server foo.example.net
-     server bar.example.net
-     server baz.example.net
-.EE
-
-However, you will probably want to include some of the other directives
-described in detail in the documentation supplied with the distribution
-(\fIchrony.txt\fR and \fIchrony.texi\fR). The following directives may be
-particularly useful : `driftfile',  `makestep', `rtcsync'.  Also, the `iburst'
-server option is useful to speed up the initial synchronization.  The smallest
-useful configuration file would look something like
-
-.EX
-     server foo.example.net iburst
-     server bar.example.net iburst
-     server baz.example.net iburst
-     driftfile @CHRONYVARDIR@/drift
-     makestep 10 3
-     rtcsync
-.EE
-
-When using a pool of NTP servers (one name is used for multiple servers which
-may change over time), it's better to specify them with the `pool' directive
-instead of multiple `server' directives in order to allow \fIchronyd\fR to
-replace unreachable or bad servers automatically.  The configuration file could
-in this case look like
-
-.EX
-     pool pool.ntp.org iburst
-     driftfile @CHRONYVARDIR@/drift
-     makestep 10 3
-     rtcsync
-.EE
-
-.SH "SEE ALSO"
-.BR chrony(1),
-.BR chronyc(1),
-.BR chronyd(8)
-
-.I http://chrony.tuxfamily.org/
-
-.SH AUTHOR
-Richard Curnow <rc@rc0.org.uk>
-
-This man-page was written by Jan Schaumann <jschauma@netmeister.org> as part of "The Missing
-Man Pages Project".  Please see \fIhttp://www.netmeister.org/misc/m2p2/index.html\fR
-for details.
-
-The complete chrony documentation is supplied in texinfo format.
-
--- a/chrony.texi.in
+++ b/chrony.texi.in
--- a/chronyc.1.in
+++ b/chronyc.1.in
@@ -1,75 +0,0 @@
-.TH CHRONYC 1 "@MAN_DATE@" "chrony @VERSION@" "User's Manual"
-.SH NAME
-chronyc \- command-line interface for chronyd
-
-.SH SYNOPSIS
-.B chronyc
-[\fIOPTIONS\fR]
-
-.SH DESCRIPTION
-\fIchrony\fR is a pair of programs for maintaining the accuracy of computer
-clocks.
-
-\fBchronyc\fR is a command-line interface program which can be used to
-monitor \fIchronyd\fR's performance and to change various operating
-parameters whilst it is running.
-
-.SH USAGE
-A detailed description of all commands supported by \fBchronyc\fR is available
-via the documentation supplied with the distribution (\fIchrony.txt\fR and
-\fIchrony.texi\fR).
-
-.SH OPTIONS
-A summary of the options supported by \fBchronyc\fR is included below.
-
-.TP
-\fB\-h\fR \fIhostname\fR
-specify hostname (default 127.0.0.1)
-.TP
-\fB\-p\fR \fIport-number\fR
-specify port-number
-.TP
-\fB\-n\fR
-display raw IP addresses (don't attempt to look up hostnames)
-.TP
-\fB\-4\fR
-resolve hostnames only to IPv4 addresses
-.TP
-\fB\-6\fR
-resolve hostnames only to IPv6 addresses
-.TP
-\fB\-m\fR
-allow multiple commands to be specified on the command line.  Each argument
-will be interpreted as a whole command.
-.TP
-\fB\-f\fR \fIconf-file\fR
-This option can be used to specify an alternate location for the
-configuration file (default \fI@SYSCONFDIR@/chrony.conf\fR). The configuration file is
-needed for the \fB-a\fR option.
-.TP
-\fB\-a\fR
-With this option chronyc will try to authenticate automatically on
-start. It will read the configuration file, read the command key from the
-keyfile and run the authhash and password commands.
-.TP
-\fIcommand\fR
-specify command.  If no command is given, chronyc will read commands
-interactively.
-
-.SH BUGS
-To report bugs, please visit \fIhttp://chrony.tuxfamily.org\fR
-
-.SH "SEE ALSO"
-.BR chronyd(8),
-.BR chrony(1)
-
-.I http://chrony.tuxfamily.org/
-
-.SH AUTHOR
-Richard Curnow <rc@rc0.org.uk>
-
-This man-page was written by Jan Schaumann <jschauma@netmeister.org> as part of "The Missing
-Man Pages Project".  Please see \fIhttp://www.netmeister.org/misc/m2p2/index.html\fR
-for details.
-
-The complete chrony documentation is supplied in texinfo format.
--- a/chronyd.8.in
+++ b/chronyd.8.in
@@ -1,154 +0,0 @@
-.TH CHRONYD 8 "@MAN_DATE@" "chrony @VERSION@" "System Administration"
-.SH NAME
-chronyd \- chrony background daemon
-
-.SH SYNOPSIS
-.B chronyd
-[\fIOPTIONS\fR] [\fIconfiguration commands\fR]
-
-.SH DESCRIPTION
-\fIchrony\fR is a pair of programs for maintaining the accuracy of computer
-clocks. \fBchronyd\fR is a background daemon program that can be started at boot
-time.
-
-\fBchronyd\fR is a daemon which runs in background on the
-system.  It obtains measurements (e.g. via the network) of the
-system's offset relative to other systems, and adjusts the system
-time accordingly.  For isolated systems, the user can periodically
-enter the correct time by hand (using \fIchronyc\fR).  In either case,
-\fBchronyd\fR determines the rate at which the computer
-gains or loses time, and compensates for this.
-
-.SH USAGE
-\fBchronyd\fR is usually started at boot-time and requires superuser
-privileges.
-
-If \fBchronyd\fR has been installed to its default location
-\fI@SBINDIR@/chronyd\fR, starting it is simply a matter of entering the
-command:
-
-\fI@SBINDIR@/chronyd\fR
-
-Information messages and warnings will be logged to syslog.
-
-If no configuration commands are specified on the command line,
-\fBchronyd\fR will read the commands from the configuration file
-(default \fI@SYSCONFDIR@/chrony.conf\fR).
-
-.SH OPTIONS
-A summary of the options supported by \fBchronyd\fR is included below.
-
-.TP
-\fB\-P\fR \fIpriority\fR
-This option will select the SCHED_FIFO real-time scheduler at the specified
-priority (which must be between 0 and 100).  This mode is supported only on
-Linux.
-.TP
-.B \-m
-This option will lock chronyd into RAM so that it will never be paged out.
-This mode is only supported on Linux.
-.TP
-.B \-n
-When run in this mode, the program will not detach itself from the
-terminal.
-.TP
-.B \-d
-When run in this mode, the program will not detach itself from the
-terminal, and all messages will be sent to the terminal instead of
-to syslog.  When \fBchronyd\fR was compiled with debugging support,
-this option can be used twice to print also debugging messages.
-.TP
-\fB\-f\fR \fIconf-file\fR
-This option can be used to specify an alternate location for the
-configuration file (default \fI@SYSCONFDIR@/chrony.conf\fR).
-.TP
-.B \-r
-This option will reload sample histories for each of the servers being used.
-These histories are created by using the \fIdump\fR command in \fIchronyc\fR,
-or by setting the \fIdumponexit\fR directive in the configuration file.  This
-option is useful if you want to stop and restart \fBchronyd\fR briefly for any
-reason, e.g. to install a new version.  However, it only makes sense on
-systems where the kernel can maintain clock compensation whilst not under
-\fBchronyd\fR's control.  The only version where this happens so far is Linux.
-On systems where this is not the case, e.g. Solaris and SunOS the option
-should not be used.
-.TP
-.B \-R
-When this option is used, the \fIinitstepslew\fR directive and the
-\fImakestep\fR directive used with a positive limit will be ignored. This
-option is useful when restarting \fBchronyd\fR and can be used in conjunction
-with the \fB-r\fR option.
-.TP
-.B \-s
-This option will set the system clock from the computer's real-time
-clock.  This is analogous to supplying the \fI-s\fR flag to the
-\fI/sbin/hwclock\fR program during the Linux boot sequence.
-
-Support for real-time clocks is limited at present - the criteria
-are described in the section on the \fIrtcfile\fR directive in the
-documentation supplied with the distribution.
-
-If used in conjunction with the \fB-r\fR flag, \fBchronyd\fR will attempt
-to preserve the old samples after setting the system clock from
-the real time clock (RTC).  This can be used to allow \fBchronyd\fR to
-perform long term averaging of the gain or loss rate across system
-reboots, and is useful for dial-up systems that are shut down when
-not in use.  For this to work well, it relies on \fBchronyd\fR having
-been able to determine accurate statistics for the difference
-between the RTC and system clock last time the computer was on.
-
-If \fBchronyd\fR doesn't support the RTC on your computer or there is no RTC
-installed, the system clock will be set with this option forward to the time of
-the last modification of the drift file (specified by the \fIdriftfile\fR
-directive) to restore the system time at which \fBchronyd\fR was previously
-stopped.
-.TP
-\fB\-u\fR \fIuser\fR
-This option sets the name of the user to which will \fBchronyd\fR switch to
-drop root privileges if compiled with Linux capabilities support (default
-\fB@DEFAULT_USER@\fR).
-.TP
-.B \-q
-When run in this mode, chronyd will set the system clock once
-and exit.  It will not detach from the terminal.
-.TP
-.B \-Q
-This option is similar to \fB\-q\fR, but it will only print the offset and
-not correct the clock.
-.TP
-.B \-v
-This option displays \fBchronyd\fR's version number to the terminal and exits
-.TP
-.B \-4
-Resolve hostnames only to IPv4 addresses and create only IPv4 sockets.
-.TP
-.B \-6
-Resolve hostnames only to IPv6 addresses and create only IPv6 sockets.
-
-.SH FILES
-\fI@SYSCONFDIR@/chrony.conf\fR
-
-.SH BUGS
-To report bugs, please visit \fIhttp://chrony.tuxfamily.org/\fR
-
-.SH "SEE ALSO"
-\fBchronyd\fR is documented in detail in the documentation supplied with the
-distribution (\fIchrony.txt\fR and \fIchrony.texi\fR).
-
-.BR chrony(1),
-.BR chronyc(1),
-.BR chrony.conf(5),
-.BR hwclock(8),
-.BR ntpd(8)
-
-.I http://chrony.tuxfamily.org/
-
-.SH AUTHOR
-Richard Curnow <rc@rc0.org.uk>
-
-This man-page was written by Jan Schaumann <jschauma@netmeister.org> as part
-of "The Missing Man Pages Project".  Please see
-\fIhttp://www.netmeister.org/misc/m2p2/index.html\fR for details.
-
-The complete chrony documentation is supplied in texinfo format.
-
--- a/client.c
+++ b/client.c
--- a/clientlog.c
+++ b/clientlog.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009
+ * Copyright (C) Miroslav Lichvar  2009, 2015-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -34,117 +34,271 @@
 #include "config.h"

 #include "sysincl.h"
+
+#include "array.h"
 #include "clientlog.h"
 #include "conf.h"
 #include "memory.h"
+#include "ntp.h"
 #include "reports.h"
 #include "util.h"
 #include "logging.h"

-/* Number of bits of address per layer of the table.  This value has
-   been chosen on the basis that a server will predominantly be serving
-   a lot of hosts in a few subnets, rather than a few hosts scattered
-   across many subnets. */
-
-#define NBITS 8
-
-/* Number of entries in each subtable */
-#define TABLE_SIZE (1UL<<NBITS)
-
-typedef struct _Node {
+typedef struct {
  IPAddr ip_addr;
-  unsigned long client_hits;
-  unsigned long peer_hits;
-  unsigned long cmd_hits_bad;
-  unsigned long cmd_hits_normal;
-  unsigned long cmd_hits_auth;
-  time_t last_ntp_hit;
-  time_t last_cmd_hit;
-} Node;
+  uint32_t last_ntp_hit;
+  uint32_t last_cmd_hit;
+  uint32_t ntp_hits;
+  uint32_t cmd_hits;
+  uint16_t ntp_drops;
+  uint16_t cmd_drops;
+  uint16_t ntp_tokens;
+  uint16_t cmd_tokens;
+  int8_t ntp_rate;
+  int8_t cmd_rate;
+  int8_t ntp_timeout_rate;
+  uint8_t flags;
+  NTP_int64 ntp_rx_ts;
+  NTP_int64 ntp_tx_ts;
+} Record;

-typedef struct _Subnet {
-  void *entry[TABLE_SIZE];
-} Subnet;
+/* Hash table of records, there is a fixed number of records per slot */
+static ARR_Instance records;

-/* ================================================== */
+#define SLOT_BITS 4

-/* Table for the IPv4 class A subnet */
-static Subnet top_subnet4;
-/* Table for IPv6 */
-static Subnet top_subnet6;
+/* Number of records in one slot of the hash table */
+#define SLOT_SIZE (1U << SLOT_BITS)

-/* Table containing pointers directly to all nodes that have been
-   allocated. */
-static Node **nodes = NULL;
+/* Minimum number of slots */
+#define MIN_SLOTS 1

-/* Number of nodes actually in the table. */
-static int n_nodes = 0;
+/* Maximum number of slots, this is a hard limit */
+#define MAX_SLOTS (1U << (24 - SLOT_BITS))

-/* Number of entries for which the table has been sized. */
-static int max_nodes = 0;
+/* Number of slots in the hash table */
+static unsigned int slots;
+
+/* Maximum number of slots given memory allocation limit */
+static unsigned int max_slots;
+
+/* Times of last hits are saved as 32-bit fixed point values */
+#define TS_FRAC 4
+#define INVALID_TS 0
+
+/* Static offset included in conversion to the fixed-point timestamps to
+   randomise their alignment */
+static uint32_t ts_offset;
+
+/* Request rates are saved in the record as 8-bit scaled log2 values */
+#define RATE_SCALE 4
+#define MIN_RATE (-14 * RATE_SCALE)
+#define INVALID_RATE -128
+
+/* Response rates are controlled by token buckets.  The capacity and
+   number of tokens spent on response are determined from configured
+   minimum inverval between responses (in log2) and burst length. */
+
+#define MIN_LIMIT_INTERVAL (-15 - TS_FRAC)
+#define MAX_LIMIT_INTERVAL 12
+#define MIN_LIMIT_BURST 1
+#define MAX_LIMIT_BURST 255
+
+static uint16_t max_ntp_tokens;
+static uint16_t max_cmd_tokens;
+static uint16_t ntp_tokens_per_packet;
+static uint16_t cmd_tokens_per_packet;
+
+/* Reduction of token rates to avoid overflow of 16-bit counters.  Negative
+   shift is used for coarse limiting with intervals shorter than -TS_FRAC. */
+static int ntp_token_shift;
+static int cmd_token_shift;
+
+/* Rates at which responses are randomly allowed (in log2) when the
+   buckets don't have enough tokens.  This is necessary in order to
+   prevent an attacker sending requests with spoofed source address
+   from blocking responses to the address completely. */
+
+#define MIN_LEAK_RATE 1
+#define MAX_LEAK_RATE 4
+
+static int ntp_leak_rate;
+static int cmd_leak_rate;
+
+/* Flag indicating whether the last response was dropped */
+#define FLAG_NTP_DROPPED 0x1
+
+/* NTP limit interval in log2 */
+static int ntp_limit_interval;

 /* Flag indicating whether facility is turned on or not */
-static int active = 0;
+static int active;

-/* Flag indicating whether memory allocation limit has been reached
-   and no new nodes or subnets should be allocated */
-static int alloc_limit_reached;
+/* Global statistics */
+static uint32_t total_ntp_hits;
+static uint32_t total_cmd_hits;
+static uint32_t total_ntp_drops;
+static uint32_t total_cmd_drops;
+static uint32_t total_record_drops;

-static unsigned long alloc_limit;
-static unsigned long alloced;
+#define NSEC_PER_SEC 1000000000U

 /* ================================================== */

-static void
-split_ip6(IPAddr *ip, uint32_t *dst)
-{
-  int i;
+static int expand_hashtable(void);

-  for (i = 0; i < 4; i++)
-    dst[i] = ip->addr.in6[i * 4 + 0] << 24 |
-             ip->addr.in6[i * 4 + 1] << 16 |
-             ip->addr.in6[i * 4 + 2] << 8 |
-             ip->addr.in6[i * 4 + 3];
+/* ================================================== */
+
+static int
+compare_ts(uint32_t x, uint32_t y)
+{
+  if (x == y)
+    return 0;
+  if (y == INVALID_TS)
+    return 1;
+  return (int32_t)(x - y) > 0 ? 1 : -1;
 }

 /* ================================================== */

-inline static uint32_t
-get_subnet(uint32_t *addr, unsigned int where)
+static Record *
+get_record(IPAddr *ip)
 {
-  int off;
+  unsigned int first, i;
+  time_t last_hit, oldest_hit = 0;
+  Record *record, *oldest_record;

-  off = where / 32;
-  where %= 32;
+  if (!active || (ip->family != IPADDR_INET4 && ip->family != IPADDR_INET6))
+    return NULL;

-  return (addr[off] >> (32 - NBITS - where)) & ((1UL << NBITS) - 1);
+  while (1) {
+    /* Get index of the first record in the slot */
+    first = UTI_IPToHash(ip) % slots * SLOT_SIZE;
+
+    for (i = 0, oldest_record = NULL; i < SLOT_SIZE; i++) {
+      record = ARR_GetElement(records, first + i);
+
+      if (!UTI_CompareIPs(ip, &record->ip_addr, NULL))
+        return record;
+
+      if (record->ip_addr.family == IPADDR_UNSPEC)
+        break;
+
+      last_hit = compare_ts(record->last_ntp_hit, record->last_cmd_hit) > 0 ?
+                 record->last_ntp_hit : record->last_cmd_hit;
+
+      if (!oldest_record || compare_ts(oldest_hit, last_hit) > 0 ||
+          (oldest_hit == last_hit && record->ntp_hits + record->cmd_hits <
+           oldest_record->ntp_hits + oldest_record->cmd_hits)) {
+        oldest_record = record;
+        oldest_hit = last_hit;
+      }
+    }
+
+    /* If the slot still has an empty record, use it */
+    if (record->ip_addr.family == IPADDR_UNSPEC)
+      break;
+
+    /* Resize the table if possible and try again as the new slot may
+       have some empty records */
+    if (expand_hashtable())
+      continue;
+
+    /* There is no other option, replace the oldest record */
+    record = oldest_record;
+    total_record_drops++;
+    break;
+  }
+
+  record->ip_addr = *ip;
+  record->last_ntp_hit = record->last_cmd_hit = INVALID_TS;
+  record->ntp_hits = record->cmd_hits = 0;
+  record->ntp_drops = record->cmd_drops = 0;
+  record->ntp_tokens = max_ntp_tokens;
+  record->cmd_tokens = max_cmd_tokens;
+  record->ntp_rate = record->cmd_rate = INVALID_RATE;
+  record->ntp_timeout_rate = INVALID_RATE;
+  record->flags = 0;
+  UTI_ZeroNtp64(&record->ntp_rx_ts);
+  UTI_ZeroNtp64(&record->ntp_tx_ts);
+
+  return record;
 }

 /* ================================================== */

-
-static void
-clear_subnet(Subnet *subnet)
+static int
+expand_hashtable(void)
 {
-  int i;
+  ARR_Instance old_records;
+  Record *old_record, *new_record;
+  unsigned int i;

-  for (i=0; i<TABLE_SIZE; i++) {
-    subnet->entry[i] = NULL;
+  old_records = records;
+
+  if (2 * slots > max_slots)
+    return 0;
+
+  records = ARR_CreateInstance(sizeof (Record));
+
+  slots = MAX(MIN_SLOTS, 2 * slots);
+  assert(slots <= max_slots);
+
+  ARR_SetSize(records, slots * SLOT_SIZE);
+
+  /* Mark all new records as empty */
+  for (i = 0; i < slots * SLOT_SIZE; i++) {
+    new_record = ARR_GetElement(records, i);
+    new_record->ip_addr.family = IPADDR_UNSPEC;
  }
+
+  if (!old_records)
+    return 1;
+
+  /* Copy old records to the new hash table */
+  for (i = 0; i < ARR_GetSize(old_records); i++) {
+    old_record = ARR_GetElement(old_records, i);
+    if (old_record->ip_addr.family == IPADDR_UNSPEC)
+      continue;
+
+    new_record = get_record(&old_record->ip_addr);
+
+    assert(new_record);
+    *new_record = *old_record;
+  }
+
+  ARR_DestroyInstance(old_records);
+
+  return 1;
 }

 /* ================================================== */

 static void
-clear_node(Node *node)
+set_bucket_params(int interval, int burst, uint16_t *max_tokens,
+                  uint16_t *tokens_per_packet, int *token_shift)
 {
-  node->client_hits = 0;
-  node->peer_hits = 0;
-  node->cmd_hits_auth = 0;
-  node->cmd_hits_normal = 0;
-  node->cmd_hits_bad = 0;
-  node->last_ntp_hit = (time_t) 0;
-  node->last_cmd_hit = (time_t) 0;
+  interval = CLAMP(MIN_LIMIT_INTERVAL, interval, MAX_LIMIT_INTERVAL);
+  burst = CLAMP(MIN_LIMIT_BURST, burst, MAX_LIMIT_BURST);
+
+  if (interval >= -TS_FRAC) {
+    /* Find the smallest shift with which the maximum number fits in 16 bits */
+    for (*token_shift = 0; *token_shift < interval + TS_FRAC; (*token_shift)++) {
+      if (burst << (TS_FRAC + interval - *token_shift) < 1U << 16)
+        break;
+    }
+  } else {
+    /* Coarse rate limiting */
+    *token_shift = interval + TS_FRAC;
+    *tokens_per_packet = 1;
+    burst = MAX(1U << -*token_shift, burst);
+  }
+
+  *tokens_per_packet = 1U << (TS_FRAC + interval - *token_shift);
+  *max_tokens = *tokens_per_packet * burst;
+
+  DEBUG_LOG("Tokens max %d packet %d shift %d",
+            *max_tokens, *tokens_per_packet, *token_shift);
 }

 /* ================================================== */
@@ -152,21 +306,47 @@ clear_node(Node *node)
 void
 CLG_Initialise(void)
 {
-  clear_subnet(&top_subnet4);
-  clear_subnet(&top_subnet6);
-  if (CNF_GetNoClientLog()) {
-    active = 0;
-  } else {
-    active = 1;
+  int interval, burst, leak_rate;
+
+  max_ntp_tokens = max_cmd_tokens = 0;
+  ntp_tokens_per_packet = cmd_tokens_per_packet = 0;
+  ntp_token_shift = cmd_token_shift = 0;
+  ntp_leak_rate = cmd_leak_rate = 0;
+  ntp_limit_interval = MIN_LIMIT_INTERVAL;
+
+  if (CNF_GetNTPRateLimit(&interval, &burst, &leak_rate)) {
+    set_bucket_params(interval, burst, &max_ntp_tokens, &ntp_tokens_per_packet,
+                      &ntp_token_shift);
+    ntp_leak_rate = CLAMP(MIN_LEAK_RATE, leak_rate, MAX_LEAK_RATE);
+    ntp_limit_interval = CLAMP(MIN_LIMIT_INTERVAL, interval, MAX_LIMIT_INTERVAL);
  }

-  nodes = NULL;
-  max_nodes = 0;
-  n_nodes = 0;
+  if (CNF_GetCommandRateLimit(&interval, &burst, &leak_rate)) {
+    set_bucket_params(interval, burst, &max_cmd_tokens, &cmd_tokens_per_packet,
+                      &cmd_token_shift);
+    cmd_leak_rate = CLAMP(MIN_LEAK_RATE, leak_rate, MAX_LEAK_RATE);
+  }

-  alloced = 0;
-  alloc_limit = CNF_GetClientLogLimit();
-  alloc_limit_reached = 0;
+  active = !CNF_GetNoClientLog();
+  if (!active) {
+    if (ntp_leak_rate || cmd_leak_rate)
+      LOG_FATAL("ratelimit cannot be used with noclientlog");
+    return;
+  }
+
+  /* Calculate the maximum number of slots that can be allocated in the
+     configured memory limit.  Take into account expanding of the hash
+     table where two copies exist at the same time. */
+  max_slots = CNF_GetClientLogLimit() / (sizeof (Record) * SLOT_SIZE * 3 / 2);
+  max_slots = CLAMP(MIN_SLOTS, max_slots, MAX_SLOTS);
+
+  slots = 0;
+  records = NULL;
+
+  expand_hashtable();
+
+  UTI_GetRandomBytes(&ts_offset, sizeof (ts_offset));
+  ts_offset %= NSEC_PER_SEC / (1U << TS_FRAC);
 }

 /* ================================================== */
@@ -174,226 +354,342 @@ CLG_Initialise(void)
 void
 CLG_Finalise(void)
 {
-  int i;
+  if (!active)
+    return;

-  for (i = 0; i < n_nodes; i++)
-    Free(nodes[i]);
-  Free(nodes);
+  ARR_DestroyInstance(records);
 }

 /* ================================================== */

-static void check_alloc_limit() {
-  if (alloc_limit_reached)
-    return;
+static uint32_t
+get_ts_from_timespec(struct timespec *ts)
+{
+  uint32_t sec = ts->tv_sec, nsec = ts->tv_nsec;

-  if (alloced >= alloc_limit) {
-    LOG(LOGS_WARN, LOGF_ClientLog, "Client log memory limit reached");
-    alloc_limit_reached = 1;
+  nsec += ts_offset;
+  if (nsec >= NSEC_PER_SEC) {
+    nsec -= NSEC_PER_SEC;
+    sec++;
  }
+
+  /* This is fast and accurate enough */
+  return sec << TS_FRAC | (140740U * (nsec >> 15)) >> (32 - TS_FRAC);
 }

 /* ================================================== */

 static void
-create_subnet(Subnet *parent_subnet, int the_entry)
+update_record(struct timespec *now, uint32_t *last_hit, uint32_t *hits,
+              uint16_t *tokens, uint32_t max_tokens, int token_shift, int8_t *rate)
 {
-  parent_subnet->entry[the_entry] = (void *) MallocNew(Subnet);
-  clear_subnet((Subnet *) parent_subnet->entry[the_entry]);
-  alloced += sizeof (Subnet);
-  check_alloc_limit();
+  uint32_t interval, now_ts, prev_hit, new_tokens;
+  int interval2;
+
+  now_ts = get_ts_from_timespec(now);
+
+  prev_hit = *last_hit;
+  *last_hit = now_ts;
+  (*hits)++;
+
+  interval = now_ts - prev_hit;
+
+  if (prev_hit == INVALID_TS || (int32_t)interval < 0)
+    return;
+
+  if (token_shift >= 0)
+    new_tokens = (now_ts >> token_shift) - (prev_hit >> token_shift);
+  else if (now_ts - prev_hit > max_tokens)
+    new_tokens = max_tokens;
+  else
+    new_tokens = (now_ts - prev_hit) << -token_shift;
+  *tokens = MIN(*tokens + new_tokens, max_tokens);
+
+  /* Convert the interval to scaled and rounded log2 */
+  if (interval) {
+    interval += interval >> 1;
+    for (interval2 = -RATE_SCALE * TS_FRAC; interval2 < -MIN_RATE;
+         interval2 += RATE_SCALE) {
+      if (interval <= 1)
+        break;
+      interval >>= 1;
+    }
+  } else {
+    interval2 = -RATE_SCALE * (TS_FRAC + 1);
+  }
+
+  /* Update the rate in a rough approximation of exponential moving average */
+  if (*rate == INVALID_RATE) {
+    *rate = -interval2;
+  } else {
+    if (*rate < -interval2) {
+      (*rate)++;
+    } else if (*rate > -interval2) {
+      if (*rate > RATE_SCALE * 5 / 2 - interval2)
+        *rate = RATE_SCALE * 5 / 2 - interval2;
+      else
+        *rate = (*rate - interval2 - 1) / 2;
+    }
+  }
 }

 /* ================================================== */

-static void
-create_node(Subnet *parent_subnet, int the_entry)
+static int
+get_index(Record *record)
 {
-  Node *new_node;
-  new_node = MallocNew(Node);
-  parent_subnet->entry[the_entry] = (void *) new_node;
-  clear_node(new_node);
-
-  alloced += sizeof (Node);
-
-  if (n_nodes == max_nodes) {
-    if (nodes) {
-      assert(max_nodes > 0);
-      max_nodes *= 2;
-      nodes = ReallocArray(Node *, max_nodes, nodes);
-    } else {
-      assert(max_nodes == 0);
-      max_nodes = 16;
-      nodes = MallocArray(Node *, max_nodes);
-    }
-    alloced += sizeof (Node *) * (max_nodes - n_nodes);
-  }
-  nodes[n_nodes++] = (Node *) new_node;
-  check_alloc_limit();
+  return record - (Record *)ARR_GetElements(records);
 }

 /* ================================================== */
-/* Recursively seek out the Node entry for a particular address,
-   expanding subnet tables and node entries as we go if necessary. */

-static void *
-find_subnet(Subnet *subnet, uint32_t *addr, int addr_len, int bits_consumed)
+int
+CLG_GetClientIndex(IPAddr *client)
 {
-  uint32_t this_subnet;
+  Record *record;

-  this_subnet = get_subnet(addr, bits_consumed);
-  bits_consumed += NBITS;
+  record = get_record(client);
+  if (record == NULL)
+    return -1;

-  if (bits_consumed < 32 * addr_len) {
-    if (!subnet->entry[this_subnet]) {
-      if (alloc_limit_reached)
-        return NULL;
-      create_subnet(subnet, this_subnet);
+  return get_index(record);
 }
-    return find_subnet((Subnet *) subnet->entry[this_subnet], addr, addr_len, bits_consumed);
-  } else {
-    if (!subnet->entry[this_subnet]) {
-      if (alloc_limit_reached)
-        return NULL;
-      create_node(subnet, this_subnet);
+
+/* ================================================== */
+
+int
+CLG_LogNTPAccess(IPAddr *client, struct timespec *now)
+{
+  Record *record;
+
+  total_ntp_hits++;
+
+  record = get_record(client);
+  if (record == NULL)
+    return -1;
+
+  /* Update one of the two rates depending on whether the previous request
+     of the client had a reply or it timed out */
+  update_record(now, &record->last_ntp_hit, &record->ntp_hits,
+                &record->ntp_tokens, max_ntp_tokens, ntp_token_shift,
+                record->flags & FLAG_NTP_DROPPED ?
+                &record->ntp_timeout_rate : &record->ntp_rate);
+
+  DEBUG_LOG("NTP hits %"PRIu32" rate %d trate %d tokens %d",
+            record->ntp_hits, record->ntp_rate, record->ntp_timeout_rate,
+            record->ntp_tokens);
+
+  return get_index(record);
 }
-    return subnet->entry[this_subnet];
+
+/* ================================================== */
+
+int
+CLG_LogCommandAccess(IPAddr *client, struct timespec *now)
+{
+  Record *record;
+
+  total_cmd_hits++;
+
+  record = get_record(client);
+  if (record == NULL)
+    return -1;
+
+  update_record(now, &record->last_cmd_hit, &record->cmd_hits,
+                &record->cmd_tokens, max_cmd_tokens, cmd_token_shift,
+                &record->cmd_rate);
+
+  DEBUG_LOG("Cmd hits %"PRIu32" rate %d tokens %d",
+            record->cmd_hits, record->cmd_rate, record->cmd_tokens);
+
+  return get_index(record);
 }
+
+/* ================================================== */
+
+static int
+limit_response_random(int leak_rate)
+{
+  static uint32_t rnd;
+  static int bits_left = 0;
+  int r;
+
+  if (bits_left < leak_rate) {
+    UTI_GetRandomBytes(&rnd, sizeof (rnd));
+    bits_left = 8 * sizeof (rnd);
+  }
+
+  /* Return zero on average once per 2^leak_rate */
+  r = rnd % (1U << leak_rate) ? 1 : 0;
+  rnd >>= leak_rate;
+  bits_left -= leak_rate;
+
+  return r;
+}
+
+/* ================================================== */
+
+int
+CLG_LimitNTPResponseRate(int index)
+{
+  Record *record;
+  int drop;
+
+  if (!ntp_tokens_per_packet)
+    return 0;
+
+  record = ARR_GetElement(records, index);
+  record->flags &= ~FLAG_NTP_DROPPED;
+
+  if (record->ntp_tokens >= ntp_tokens_per_packet) {
+    record->ntp_tokens -= ntp_tokens_per_packet;
+    return 0;
+  }
+
+  drop = limit_response_random(ntp_leak_rate);
+
+  /* Poorly implemented clients may send new requests at even a higher rate
+     when they are not getting replies.  If the request rate seems to be more
+     than twice as much as when replies are sent, give up on rate limiting to
+     reduce the amount of traffic.  Invert the sense of the leak to respond to
+     most of the requests, but still keep the estimated rate updated. */
+  if (record->ntp_timeout_rate != INVALID_RATE &&
+      record->ntp_timeout_rate > record->ntp_rate + RATE_SCALE)
+    drop = !drop;
+
+  if (!drop) {
+    record->ntp_tokens = 0;
+    return 0;
+  }
+
+  record->flags |= FLAG_NTP_DROPPED;
+  record->ntp_drops++;
+  total_ntp_drops++;
+
+  return 1;
+}
+
+/* ================================================== */
+
+int
+CLG_LimitCommandResponseRate(int index)
+{
+  Record *record;
+
+  if (!cmd_tokens_per_packet)
+    return 0;
+
+  record = ARR_GetElement(records, index);
+
+  if (record->cmd_tokens >= cmd_tokens_per_packet) {
+    record->cmd_tokens -= cmd_tokens_per_packet;
+    return 0;
+  }
+
+  if (!limit_response_random(cmd_leak_rate)) {
+    record->cmd_tokens = 0;
+    return 0;
+  }
+
+  record->cmd_drops++;
+  total_cmd_drops++;
+
+  return 1;
+}
+
+/* ================================================== */
+
+void CLG_GetNtpTimestamps(int index, NTP_int64 **rx_ts, NTP_int64 **tx_ts)
+{
+  Record *record;
+
+  record = ARR_GetElement(records, index);
+
+  *rx_ts = &record->ntp_rx_ts;
+  *tx_ts = &record->ntp_tx_ts;
+}
+
+/* ================================================== */
+
+int
+CLG_GetNtpMinPoll(void)
+{
+  return ntp_limit_interval;
+}
+
+/* ================================================== */
+
+int
+CLG_GetNumberOfIndices(void)
+{
+  if (!active)
+    return -1;
+
+  return ARR_GetSize(records);
+}
+
+/* ================================================== */
+
+static int get_interval(int rate)
+{
+  if (rate == INVALID_RATE)
+    return 127;
+
+  rate += rate > 0 ? RATE_SCALE / 2 : -RATE_SCALE / 2;
+
+  return rate / -RATE_SCALE;
+}
+
+/* ================================================== */
+
+static uint32_t get_last_ago(uint32_t x, uint32_t y)
+{
+  if (y == INVALID_TS || (int32_t)(x - y) < 0)
+    return -1;
+
+  return (x - y) >> TS_FRAC;
+}
+
+/* ================================================== */
+
+int
+CLG_GetClientAccessReportByIndex(int index, RPT_ClientAccessByIndex_Report *report, struct timespec *now)
+{
+  Record *record;
+  uint32_t now_ts;
+
+  if (!active || index < 0 || index >= ARR_GetSize(records))
+    return 0;
+
+  record = ARR_GetElement(records, index);
+
+  if (record->ip_addr.family == IPADDR_UNSPEC)
+    return 0;
+
+  now_ts = get_ts_from_timespec(now);
+
+  report->ip_addr = record->ip_addr;
+  report->ntp_hits = record->ntp_hits;
+  report->cmd_hits = record->cmd_hits;
+  report->ntp_drops = record->ntp_drops;
+  report->cmd_drops = record->cmd_drops;
+  report->ntp_interval = get_interval(record->ntp_rate);
+  report->cmd_interval = get_interval(record->cmd_rate);
+  report->ntp_timeout_interval = get_interval(record->ntp_timeout_rate);
+  report->last_ntp_hit_ago = get_last_ago(now_ts, record->last_ntp_hit);
+  report->last_cmd_hit_ago = get_last_ago(now_ts, record->last_cmd_hit);
+
+  return 1;
 }

 /* ================================================== */

 void
-CLG_LogNTPClientAccess (IPAddr *client, time_t now)
+CLG_GetServerStatsReport(RPT_ServerStatsReport *report)
 {
-  uint32_t ip6[4];
-  Node *node;
-
-  if (active) {
-    switch (client->family) {
-      case IPADDR_INET4:
-        node = (Node *) find_subnet(&top_subnet4, &client->addr.in4, 1, 0);
-        break;
-      case IPADDR_INET6:
-        split_ip6(client, ip6);
-        node = (Node *) find_subnet(&top_subnet6, ip6, 4, 0);
-        break;
-      default:
-        assert(0);
-    }
-
-    if (node == NULL)
-      return;
-
-    node->ip_addr = *client;
-    ++node->client_hits;
-    node->last_ntp_hit = now;
-  }
-}
-
-/* ================================================== */
-
-void
-CLG_LogNTPPeerAccess(IPAddr *client, time_t now)
-{
-  uint32_t ip6[4];
-  Node *node;
-
-  if (active) {
-    switch (client->family) {
-      case IPADDR_INET4:
-        node = (Node *) find_subnet(&top_subnet4, &client->addr.in4, 1, 0);
-        break;
-      case IPADDR_INET6:
-        split_ip6(client, ip6);
-        node = (Node *) find_subnet(&top_subnet6, ip6, 4, 0);
-        break;
-      default:
-        assert(0);
-    }
-
-    if (node == NULL)
-      return;
-
-    node->ip_addr = *client;
-    ++node->peer_hits;
-    node->last_ntp_hit = now;
-  }
-}
-
-/* ================================================== */
-
-void
-CLG_LogCommandAccess(IPAddr *client, CLG_Command_Type type, time_t now)
-{
-  uint32_t ip6[4];
-  Node *node;
-
-  if (active) {
-    switch (client->family) {
-      case IPADDR_INET4:
-        node = (Node *) find_subnet(&top_subnet4, &client->addr.in4, 1, 0);
-        break;
-      case IPADDR_INET6:
-        split_ip6(client, ip6);
-        node = (Node *) find_subnet(&top_subnet6, ip6, 4, 0);
-        break;
-      default:
-        assert(0);
-    }
-
-    if (node == NULL)
-      return;
-
-    node->ip_addr = *client;
-    node->last_cmd_hit = now;
-    switch (type) {
-      case CLG_CMD_AUTH:
-        ++node->cmd_hits_auth;
-        break;
-      case CLG_CMD_NORMAL:
-        ++node->cmd_hits_normal;
-        break;
-      case CLG_CMD_BAD_PKT:
-        ++node->cmd_hits_bad;
-        break;
-      default:
-        assert(0);
-        break;
-    }
-  }
-}
-
-/* ================================================== */
-
-CLG_Status
-CLG_GetClientAccessReportByIndex(int index, RPT_ClientAccessByIndex_Report *report,
-                                 time_t now, unsigned long *n_indices)
-{
-  Node *node;
-
-  *n_indices = n_nodes;
-
-  if (!active) {
-    return CLG_INACTIVE;
-  } else {
-
-    if ((index < 0) || (index >= n_nodes)) {
-      return CLG_INDEXTOOLARGE;
-    }
-    
-    node = nodes[index];
-    
-    report->ip_addr = node->ip_addr;
-    report->client_hits = node->client_hits;
-    report->peer_hits = node->peer_hits;
-    report->cmd_hits_auth = node->cmd_hits_auth;
-    report->cmd_hits_normal = node->cmd_hits_normal;
-    report->cmd_hits_bad = node->cmd_hits_bad;
-    report->last_ntp_hit_ago = now - node->last_ntp_hit;
-    report->last_cmd_hit_ago = now - node->last_cmd_hit;
-    
-    return CLG_SUCCESS;
-  }
-
+  report->ntp_hits = total_ntp_hits;
+  report->cmd_hits = total_cmd_hits;
+  report->ntp_drops = total_ntp_drops;
+  report->cmd_drops = total_cmd_drops;
+  report->log_drops = total_record_drops;
 }
--- a/clientlog.h
+++ b/clientlog.h
@@ -33,32 +33,18 @@

 extern void CLG_Initialise(void);
 extern void CLG_Finalise(void);
-extern void CLG_LogNTPClientAccess(IPAddr *client, time_t now);
-extern void CLG_LogNTPPeerAccess(IPAddr *client, time_t now);
-
-/* When logging command packets, there are several subtypes */
-
-typedef enum {
-  CLG_CMD_AUTH,                 /* authenticated */
-  CLG_CMD_NORMAL,               /* normal */
-  CLG_CMD_BAD_PKT               /* bad version or packet length */
-} CLG_Command_Type;
-
-extern void CLG_LogCommandAccess(IPAddr *client, CLG_Command_Type type, time_t now);
+extern int CLG_GetClientIndex(IPAddr *client);
+extern int CLG_LogNTPAccess(IPAddr *client, struct timespec *now);
+extern int CLG_LogCommandAccess(IPAddr *client, struct timespec *now);
+extern int CLG_LimitNTPResponseRate(int index);
+extern int CLG_LimitCommandResponseRate(int index);
+extern void CLG_GetNtpTimestamps(int index, NTP_int64 **rx_ts, NTP_int64 **tx_ts);
+extern int CLG_GetNtpMinPoll(void);

 /* And some reporting functions, for use by chronyc. */
-/* TBD */

-typedef enum {
-  CLG_SUCCESS,                  /* All is well */
-  CLG_EMPTYSUBNET,              /* No hosts logged in requested subnet */
-  CLG_BADSUBNET,                /* Subnet requested is not 0, 8, 16 or 24 bits */
-  CLG_INACTIVE,                 /* Facility not active */
-  CLG_INDEXTOOLARGE             /* Node index is higher than number of nodes present */
-} CLG_Status;
-
-CLG_Status
-CLG_GetClientAccessReportByIndex(int index, RPT_ClientAccessByIndex_Report *report,
-                                 time_t now, unsigned long *n_indices);
+extern int CLG_GetNumberOfIndices(void);
+extern int CLG_GetClientAccessReportByIndex(int index, RPT_ClientAccessByIndex_Report *report, struct timespec *now);
+extern void CLG_GetServerStatsReport(RPT_ServerStatsReport *report);

 #endif /* GOT_CLIENTLOG_H */
--- a/cmdmon.c
+++ b/cmdmon.c
--- a/cmdmon.h
+++ b/cmdmon.h
@@ -33,6 +33,7 @@ extern void CAM_Initialise(int family);

 extern void CAM_Finalise(void);

+extern void CAM_OpenUnixSocket(void);
 extern int CAM_AddAccessRestriction(IPAddr *ip_addr, int subnet_bits, int allow, int all);
 extern int CAM_CheckAccessRestriction(IPAddr *ip_addr);

--- a/cmdparse.c
+++ b/cmdparse.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2013
+ * Copyright (C) Miroslav Lichvar  2013-2014, 2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -39,246 +39,151 @@

 /* ================================================== */

-CPS_Status
+int
 CPS_ParseNTPSourceAdd(char *line, CPS_NTP_Source *src)
 {
  char *hostname, *cmd;
-  int n, done;
-  CPS_Status result;
+  int n;
  
  src->port = SRC_DEFAULT_PORT;
  src->params.minpoll = SRC_DEFAULT_MINPOLL;
  src->params.maxpoll = SRC_DEFAULT_MAXPOLL;
+  src->params.online = 1;
+  src->params.auto_offline = 0;
  src->params.presend_minpoll = SRC_DEFAULT_PRESEND_MINPOLL;
+  src->params.iburst = 0;
+  src->params.min_stratum = SRC_DEFAULT_MINSTRATUM;
+  src->params.poll_target = SRC_DEFAULT_POLLTARGET;
+  src->params.version = 0;
+  src->params.max_sources = SRC_DEFAULT_MAXSOURCES;
+  src->params.min_samples = SRC_DEFAULT_MINSAMPLES;
+  src->params.max_samples = SRC_DEFAULT_MAXSAMPLES;
+  src->params.interleaved = 0;
+  src->params.sel_options = 0;
  src->params.authkey = INACTIVE_AUTHKEY;
  src->params.max_delay = SRC_DEFAULT_MAXDELAY;
  src->params.max_delay_ratio = SRC_DEFAULT_MAXDELAYRATIO;
  src->params.max_delay_dev_ratio = SRC_DEFAULT_MAXDELAYDEVRATIO;
-  src->params.online = 1;
-  src->params.auto_offline = 0;
-  src->params.iburst = 0;
-  src->params.min_stratum = SRC_DEFAULT_MINSTRATUM;
-  src->params.poll_target = SRC_DEFAULT_POLLTARGET;
-  src->params.version = NTP_VERSION;
-  src->params.max_sources = SRC_DEFAULT_MAXSOURCES;
-  src->params.min_samples = SRC_DEFAULT_MINSAMPLES;
-  src->params.max_samples = SRC_DEFAULT_MAXSAMPLES;
-  src->params.sel_option = SRC_SelectNormal;
-
-  result = CPS_Success;
+  src->params.offset = 0.0;

  hostname = line;
  line = CPS_SplitWord(line);

-  if (!*hostname) {
-    result = CPS_BadHost;
-  } else {
+  if (!*hostname)
+    return 0;
+
  src->name = hostname;

-    /* Parse subfields */
-    done = 0;
-    do {
+  /* Parse options */
+  for (; *line; line += n) {
    cmd = line;
    line = CPS_SplitWord(line);
+    n = 0;

-      if (*cmd) {
-        if (!strcasecmp(cmd, "port")) {
-          if (sscanf(line, "%hu%n", &src->port, &n) != 1) {
-            result = CPS_BadPort;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "minpoll")) {
-          if (sscanf(line, "%d%n", &src->params.minpoll, &n) != 1) {
-            result = CPS_BadMinpoll;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "maxpoll")) {
-          if (sscanf(line, "%d%n", &src->params.maxpoll, &n) != 1) {
-            result = CPS_BadMaxpoll;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "presend")) {
-          if (sscanf(line, "%d%n", &src->params.presend_minpoll, &n) != 1) {
-            result = CPS_BadPresend;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "maxdelaydevratio")) {
-          if (sscanf(line, "%lf%n", &src->params.max_delay_dev_ratio, &n) != 1) {
-            result = CPS_BadMaxdelaydevratio;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "maxdelayratio")) {
-          if (sscanf(line, "%lf%n", &src->params.max_delay_ratio, &n) != 1) {
-            result = CPS_BadMaxdelayratio;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "maxdelay")) {
-          if (sscanf(line, "%lf%n", &src->params.max_delay, &n) != 1) {
-            result = CPS_BadMaxdelay;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "key")) {
-          if (sscanf(line, "%"SCNu32"%n", &src->params.authkey, &n) != 1 ||
-              src->params.authkey == INACTIVE_AUTHKEY) {
-            result = CPS_BadKey;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "offline")) {
-          src->params.online = 0;
-
-        } else if (!strcasecmp(cmd, "auto_offline")) {
+    if (!strcasecmp(cmd, "auto_offline")) {
      src->params.auto_offline = 1;
-        
    } else if (!strcasecmp(cmd, "iburst")) {
      src->params.iburst = 1;
-
-        } else if (!strcasecmp(cmd, "minstratum")) {
-          if (sscanf(line, "%d%n", &src->params.min_stratum, &n) != 1) {
-            result = CPS_BadMinstratum;
-            done = 1;
-          } else {
-            line += n;
-          }
-
-        } else if (!strcasecmp(cmd, "polltarget")) {
-          if (sscanf(line, "%d%n", &src->params.poll_target, &n) != 1) {
-            result = CPS_BadPolltarget;
-            done = 1;
-          } else {
-            line += n;
-          }
-
+    } else if (!strcasecmp(cmd, "offline")) {
+      src->params.online = 0;
    } else if (!strcasecmp(cmd, "noselect")) {
-          src->params.sel_option = SRC_SelectNoselect;
-        
+      src->params.sel_options |= SRC_SELECT_NOSELECT;
    } else if (!strcasecmp(cmd, "prefer")) {
-          src->params.sel_option = SRC_SelectPrefer;
-        
-        } else if (!strcasecmp(cmd, "version")) {
-          if (sscanf(line, "%d%n", &src->params.version, &n) != 1) {
-            result = CPS_BadVersion;
-            done = 1;
-          } else {
-            line += n;
-          }
-
-        } else if (!strcasecmp(cmd, "maxsources")) {
-          if (sscanf(line, "%d%n", &src->params.max_sources, &n) != 1) {
-            result = CPS_BadMaxsources;
-            done = 1;
-          } else {
-            line += n;
-          }
-
-        } else if (!strcasecmp(cmd, "minsamples")) {
-          if (sscanf(line, "%d%n", &src->params.min_samples, &n) != 1) {
-            result = CPS_BadMinsamples;
-            done = 1;
-          } else {
-            line += n;
-          }
-
+      src->params.sel_options |= SRC_SELECT_PREFER;
+    } else if (!strcasecmp(cmd, "require")) {
+      src->params.sel_options |= SRC_SELECT_REQUIRE;
+    } else if (!strcasecmp(cmd, "trust")) {
+      src->params.sel_options |= SRC_SELECT_TRUST;
+    } else if (!strcasecmp(cmd, "key")) {
+      if (sscanf(line, "%"SCNu32"%n", &src->params.authkey, &n) != 1 ||
+          src->params.authkey == INACTIVE_AUTHKEY)
+        return 0;
+    } else if (!strcasecmp(cmd, "maxdelay")) {
+      if (sscanf(line, "%lf%n", &src->params.max_delay, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "maxdelayratio")) {
+      if (sscanf(line, "%lf%n", &src->params.max_delay_ratio, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "maxdelaydevratio")) {
+      if (sscanf(line, "%lf%n", &src->params.max_delay_dev_ratio, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "maxpoll")) {
+      if (sscanf(line, "%d%n", &src->params.maxpoll, &n) != 1)
+        return 0;
    } else if (!strcasecmp(cmd, "maxsamples")) {
-          if (sscanf(line, "%d%n", &src->params.max_samples, &n) != 1) {
-            result = CPS_BadMaxsamples;
-            done = 1;
+      if (sscanf(line, "%d%n", &src->params.max_samples, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "maxsources")) {
+      if (sscanf(line, "%d%n", &src->params.max_sources, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "minpoll")) {
+      if (sscanf(line, "%d%n", &src->params.minpoll, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "minsamples")) {
+      if (sscanf(line, "%d%n", &src->params.min_samples, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "minstratum")) {
+      if (sscanf(line, "%d%n", &src->params.min_stratum, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "offset")) {
+      if (sscanf(line, "%lf%n", &src->params.offset, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "port")) {
+      if (sscanf(line, "%hu%n", &src->port, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "polltarget")) {
+      if (sscanf(line, "%d%n", &src->params.poll_target, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "presend")) {
+      if (sscanf(line, "%d%n", &src->params.presend_minpoll, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "version")) {
+      if (sscanf(line, "%d%n", &src->params.version, &n) != 1)
+        return 0;
+    } else if (!strcasecmp(cmd, "xleave")) {
+      src->params.interleaved = 1;
    } else {
-            line += n;
+      return 0;
+    }
  }

-        } else {
-          result = CPS_BadOption;
-          done = 1;
-        }
-      } else {
-        done = 1;
-      }
-    } while (!done);
-  }
-
-  return result;
+  return 1;
 }

 /* ================================================== */

-void
-CPS_StatusToString(CPS_Status status, char *dest, int len)
+int
+CPS_ParseLocal(char *line, int *stratum, int *orphan, double *distance)
 {
-  const char *s = NULL;
+  int n;
+  char *cmd;

-  if (len > 0)
-    dest[0] = '\0';
+  *stratum = 10;
+  *distance = 1.0;
+  *orphan = 0;

-  switch (status) {
-    case CPS_Success:
-      return;
-    case CPS_BadOption:
-      s = "server/peer/pool option";
-      break;
-    case CPS_BadHost:
-      s = "address";
-      break;
-    case CPS_BadPort:
-      s = "port";
-      break;
-    case CPS_BadMinpoll:
-      s = "minpoll";
-      break;
-    case CPS_BadMaxpoll:
-      s = "maxpoll";
-      break;
-    case CPS_BadPresend:
-      s = "presend";
-      break;
-    case CPS_BadMaxdelaydevratio:
-      s = "maxdelaydevratio";
-      break;
-    case CPS_BadMaxdelayratio:
-      s = "maxdelayratio";
-      break;
-    case CPS_BadMaxdelay:
-      s = "maxdelay";
-      break;
-    case CPS_BadKey:
-      s = "key";
-      break;
-    case CPS_BadMinstratum:
-      s = "minstratum";
-      break;
-    case CPS_BadPolltarget:
-      s = "polltarget";
-      break;
-    case CPS_BadVersion:
-      s = "version";
-      break;
-    case CPS_BadMaxsources:
-      s = "maxsources";
-      break;
-    case CPS_BadMinsamples:
-      s = "minsamples";
-      break;
-    case CPS_BadMaxsamples:
-      s = "maxsamples";
-      break;
+  while (*line) {
+    cmd = line;
+    line = CPS_SplitWord(line);
+
+    if (!strcasecmp(cmd, "stratum")) {
+      if (sscanf(line, "%d%n", stratum, &n) != 1 ||
+          *stratum >= NTP_MAX_STRATUM || *stratum <= 0)
+        return 0;
+    } else if (!strcasecmp(cmd, "orphan")) {
+      *orphan = 1;
+      n = 0;
+    } else if (!strcasecmp(cmd, "distance")) {
+      if (sscanf(line, "%lf%n", distance, &n) != 1)
+        return 0;
+    } else {
+      return 0;
    }

-  snprintf(dest, len, "Invalid %s", s);
+    line += n;
+  }
+
+  return 1;
 }

 /* ================================================== */
--- a/cmdparse.h
+++ b/cmdparse.h
@@ -30,26 +30,6 @@
 #include "srcparams.h"
 #include "addressing.h"

-typedef enum {
-  CPS_Success,
-  CPS_BadOption,
-  CPS_BadHost,
-  CPS_BadPort,
-  CPS_BadMinpoll,
-  CPS_BadMaxpoll,
-  CPS_BadPresend,
-  CPS_BadMaxdelaydevratio,
-  CPS_BadMaxdelayratio,
-  CPS_BadMaxdelay,
-  CPS_BadKey,
-  CPS_BadMinstratum,
-  CPS_BadPolltarget,
-  CPS_BadVersion,
-  CPS_BadMaxsources,
-  CPS_BadMinsamples,
-  CPS_BadMaxsamples,
-} CPS_Status;
-
 typedef struct {
  char *name;
  unsigned short port;
@@ -57,10 +37,10 @@ typedef struct {
 } CPS_NTP_Source;

 /* Parse a command to add an NTP server or peer */
-extern CPS_Status CPS_ParseNTPSourceAdd(char *line, CPS_NTP_Source *src);
+extern int CPS_ParseNTPSourceAdd(char *line, CPS_NTP_Source *src);
  
-/* Get a string describing error status */
-extern void CPS_StatusToString(CPS_Status status, char *dest, int len);
+/* Parse a command to enable local reference */
+extern int CPS_ParseLocal(char *line, int *stratum, int *orphan, double *distance);

 /* Remove extra white-space and comments */
 extern void CPS_NormalizeLine(char *line);
--- a/conf.c
+++ b/conf.c
--- a/conf.h
+++ b/conf.h
@@ -29,8 +29,9 @@
 #define GOT_CONF_H

 #include "addressing.h"
+#include "reference.h"

-extern void CNF_Initialise(int restarted);
+extern void CNF_Initialise(int restarted, int client_only);
 extern void CNF_Finalise(void);

 extern char *CNF_GetRtcDevice(void);
@@ -38,6 +39,8 @@ extern char *CNF_GetRtcDevice(void);
 extern void CNF_ReadFile(const char *filename);
 extern void CNF_ParseLine(const char *filename, int number, char *line);

+extern void CNF_CreateDirs(uid_t uid, gid_t gid);
+
 extern void CNF_AddInitSources(void);
 extern void CNF_AddSources(void);
 extern void CNF_AddBroadcasts(void);
@@ -49,7 +52,7 @@ extern char *CNF_GetDriftFile(void);
 extern char *CNF_GetLogDir(void);
 extern char *CNF_GetDumpDir(void);
 extern int CNF_GetLogBanner(void);
-extern int CNF_GetLogMeasurements(void);
+extern int CNF_GetLogMeasurements(int *raw);
 extern int CNF_GetLogStatistics(void);
 extern int CNF_GetLogTracking(void);
 extern int CNF_GetLogRtc(void);
@@ -57,16 +60,13 @@ extern int CNF_GetLogRefclocks(void);
 extern int CNF_GetLogTempComp(void);
 extern char *CNF_GetKeysFile(void);
 extern char *CNF_GetRtcFile(void);
-extern uint32_t CNF_GetCommandKey(void);
-extern int CNF_GetGenerateCommandKey(void);
-extern int CNF_GetDumpOnExit(void);
 extern int CNF_GetManualEnabled(void);
 extern int CNF_GetCommandPort(void);
 extern int CNF_GetRtcOnUtc(void);
 extern int CNF_GetRtcSync(void);
 extern void CNF_GetMakeStep(int *limit, double *threshold);
 extern void CNF_GetMaxChange(int *delay, int *ignore, double *offset);
-extern void CNF_GetLogChange(int *enabled, double *threshold);
+extern double CNF_GetLogChange(void);
 extern void CNF_GetMailOnChange(int *enabled, double *threshold, char **user);
 extern int CNF_GetNoClientLog(void);
 extern unsigned long CNF_GetClientLogLimit(void);
@@ -74,26 +74,35 @@ extern void CNF_GetFallbackDrifts(int *min, int *max);
 extern void CNF_GetBindAddress(int family, IPAddr *addr);
 extern void CNF_GetBindAcquisitionAddress(int family, IPAddr *addr);
 extern void CNF_GetBindCommandAddress(int family, IPAddr *addr);
+extern char *CNF_GetBindCommandPath(void);
+extern char *CNF_GetNtpSigndSocket(void);
 extern char *CNF_GetPidFile(void);
+extern REF_LeapMode CNF_GetLeapSecMode(void);
 extern char *CNF_GetLeapSecTimezone(void);

 /* Value returned in ppm, as read from file */
 extern double CNF_GetMaxUpdateSkew(void);
 extern double CNF_GetMaxClockError(void);
+extern double CNF_GetMaxDrift(void);
 extern double CNF_GetCorrectionTimeRatio(void);
 extern double CNF_GetMaxSlewRate(void);

+extern double CNF_GetMaxDistance(void);
+extern double CNF_GetMaxJitter(void);
 extern double CNF_GetReselectDistance(void);
 extern double CNF_GetStratumWeight(void);
 extern double CNF_GetCombineLimit(void);

-extern int CNF_AllowLocalReference(int *stratum);
+extern int CNF_AllowLocalReference(int *stratum, int *orphan, double *distance);

 extern void CNF_SetupAccessRestrictions(void);

 extern int CNF_GetSchedPriority(void);
 extern int CNF_GetLockMemory(void);

+extern int CNF_GetNTPRateLimit(int *interval, int *burst, int *leak);
+extern int CNF_GetCommandRateLimit(int *interval, int *burst, int *leak);
+extern void CNF_GetSmooth(double *max_freq, double *max_wander, int *leap_only);
 extern void CNF_GetTempComp(char **file, double *interval, char **point_file, double *T0, double *k0, double *k1, double *k2);

 extern char *CNF_GetUser(void);
@@ -109,4 +118,20 @@ extern char *CNF_GetHwclockFile(void);
 extern int CNF_GetInitSources(void);
 extern double CNF_GetInitStepThreshold(void);

+#define CNF_HWTS_RXFILTER_NONE 0
+#define CNF_HWTS_RXFILTER_NTP 1
+#define CNF_HWTS_RXFILTER_ALL 2
+
+typedef struct {
+  char *name;
+  int minpoll;
+  int nocrossts;
+  int rxfilter;
+  double precision;
+  double tx_comp;
+  double rx_comp;
+} CNF_HwTsInterface;
+
+extern int CNF_GetHwTsInterface(unsigned int index, CNF_HwTsInterface **iface);
+
 #endif /* GOT_CONF_H */
--- a/439
+++ b/439
@@ -4,32 +4,13 @@
 # chronyd/chronyc - Programs for keeping computer clocks accurate.
 #
 # Copyright (C) Richard P. Curnow  1997-2003
-# Copyright (C) Miroslav Lichvar  2009, 2012-2014
+# Copyright (C) Bryan Christianson  2016
+# Copyright (C) Miroslav Lichvar  2009, 2012-2016
 #
 # =======================================================================

 # This configure script determines the operating system type and version

-if [ "x${CC}" = "x" ]; then
-  MYCC="gcc"
-else
-  MYCC="${CC}"
-fi
-
-if [ "x${CFLAGS}" = "x" ]; then
-  MYCFLAGS="-O2 -g"
-else
-  MYCFLAGS="${CFLAGS}"
-fi
-
-MYCPPFLAGS="${CPPFLAGS}"
-
-if [ "x${MYCC}" = "xgcc" ]; then
-  MYCFLAGS="${MYCFLAGS} -Wmissing-prototypes -Wall"
-fi
-
-MYLDFLAGS="${LDFLAGS}"
-
 # ======================================================================
 # FUNCTIONS

@@ -41,9 +22,10 @@ test_code () {
  ldflags=$4
  code=$5

-  echo -n "Checking for $name : "
+  printf "%s" "Checking for $name : "

  (
+    echo "#include \"config.h\""
    for h in $headers; do
      echo "#include <$h>"
    done
@@ -99,9 +81,8 @@ For better control, use the options below.
  --disable-readline     Disable line editing support
  --without-readline     Don't use GNU readline even if it is available
  --without-editline     Don't use editline even if it is available
-  --readline-dir=DIR     Specify parent of readline include and lib directories
-  --readline-inc-dir=DIR Specify where readline include directory is
-  --readline-lib-dir=DIR Specify where readline lib directory is
+  --with-readline-includes=DIR Specify where readline include directory is
+  --with-readline-library=DIR Specify where readline lib directory is
  --with-ncurses-library=DIR Specify where ncurses lib directory is
  --disable-sechash      Disable support for hashes other than MD5
  --without-nss          Don't use NSS even if it is available
@@ -113,12 +94,21 @@ For better control, use the options below.
  --disable-pps          Disable PPS refclock driver
  --disable-ipv6         Disable IPv6 support
  --disable-rtc          Don't include RTC even on Linux
-  --disable-linuxcaps    Disable libcap (Linux capabilities) support
+  --disable-privdrop     Disable support for dropping root privileges
+  --without-libcap       Don't use libcap even if it is available
+  --enable-scfilter      Enable support for system call filtering
+  --without-seccomp      Don't use seccomp even if it is available
  --disable-asyncdns     Disable asynchronous name resolving
  --disable-forcednsretry Don't retry on permanent DNS error
+  --without-clock-gettime Don't use clock_gettime() even if it is available
+  --disable-timestamping Disable support for SW/HW timestamping
+  --enable-ntp-signd     Enable support for MS-SNTP authentication in Samba
  --with-ntp-era=SECONDS Specify earliest assumed NTP time in seconds
                         since 1970-01-01 [50*365 days ago]
  --with-user=USER       Specify default chronyd user [root]
+  --with-hwclockfile=PATH Specify default path to hwclock(8) adjtime file
+  --with-pidfile=PATH    Specify default pidfile [/var/run/chronyd.pid]
+  --with-rtcdevice=PATH  Specify default path to RTC device [/dev/rtc]
  --with-sendmail=PATH   Path to sendmail binary [/usr/lib/sendmail]
  --enable-debug         Enable debugging support

@@ -127,10 +117,10 @@ Fine tuning of the installation directories:
  --bindir=DIR           user executables [EPREFIX/bin]
  --sbindir=DIR          system admin executables [EPREFIX/sbin]
  --datarootdir=DIR      data root [PREFIX/share]
-  --infodir=DIR          info documentation [DATAROOTDIR/info]
  --mandir=DIR           man documentation [DATAROOTDIR/man]
  --docdir=DIR           documentation root [DATAROOTDIR/doc/chrony]
  --localstatedir=DIR    modifiable single-machine data [/var]
+  --chronyrundir=DIR     location for chrony sockets [LOCALSTATEDIR/run/chrony]
  --chronyvardir=DIR     location for chrony data [LOCALSTATEDIR/lib/chrony]

 Overriding system detection when cross-compiling:
@@ -174,12 +164,12 @@ get_features () {
  ff=1
  for f; do
    if [ "$ff" = "0" ]; then
-      echo -n " "
+      printf " "
    fi
    if grep "define FEAT_$f" config.h > /dev/null; then
-      echo -n "+$f"
+      printf "%s" "+$f"
    else
-      echo -n "-$f"
+      printf "%s" "-$f"
    fi
    ff=0
  done
@@ -213,7 +203,11 @@ try_tomcrypt=1
 feat_rtc=1
 try_rtc=0
 feat_droproot=1
-try_libcap=0
+try_libcap=-1
+try_clockctl=0
+feat_scfilter=0
+try_seccomp=-1
+priv_ops=""
 readline_lib=""
 readline_inc=""
 ncurses_lib=""
@@ -225,8 +219,16 @@ try_setsched=0
 try_lockmem=0
 feat_asyncdns=1
 feat_forcednsretry=1
+try_clock_gettime=1
+try_recvmmsg=1
+feat_timestamping=1
+try_timestamping=0
+feat_ntp_signd=0
 ntp_era_split=""
 default_user="root"
+default_hwclockfile=""
+default_pidfile="/var/run/chronyd.pid"
+default_rtcdevice="/dev/rtc"
 mail_program="/usr/lib/sendmail"

 for option
@@ -271,9 +273,6 @@ do
    --datarootdir=* )
      SETDATAROOTDIR=`echo $option | sed -e 's/^.*=//;'`
    ;;
-    --infodir=* )
-      SETINFODIR=`echo $option | sed -e 's/^.*=//;'`
-    ;;
    --mandir=* )
      SETMANDIR=`echo $option | sed -e 's/^.*=//;'`
    ;;
@@ -283,6 +282,9 @@ do
    --localstatedir=* )
      SETLOCALSTATEDIR=`echo $option | sed -e 's/^.*=//;'`
    ;;
+    --chronyrundir=* | --chronysockdir=* )
+      SETCHRONYRUNDIR=`echo $option | sed -e 's/^.*=//;'`
+    ;;
    --chronyvardir=* )
      SETCHRONYVARDIR=`echo $option | sed -e 's/^.*=//;'`
    ;;
@@ -307,21 +309,51 @@ do
    --disable-pps)
      feat_pps=0
    ;;
-    --disable-linuxcaps)
+    --disable-privdrop)
      feat_droproot=0
    ;;
+    --without-libcap|--disable-linuxcaps)
+      try_libcap=0
+    ;;
+    --enable-scfilter)
+      feat_scfilter=1
+    ;;
+    --disable-scfilter)
+      feat_scfilter=0
+    ;;
+    --without-seccomp)
+      try_seccomp=0
+    ;;
    --disable-asyncdns)
      feat_asyncdns=0
    ;;
    --disable-forcednsretry)
      feat_forcednsretry=0
    ;;
+    --without-clock-gettime)
+      try_clock_gettime=0
+    ;;
+    --disable-timestamping)
+      feat_timestamping=0
+    ;;
+    --enable-ntp-signd)
+      feat_ntp_signd=1
+    ;;
    --with-ntp-era=* )
      ntp_era_split=`echo $option | sed -e 's/^.*=//;'`
    ;;
    --with-user=* )
      default_user=`echo $option | sed -e 's/^.*=//;'`
    ;;
+    --with-hwclockfile=* )
+      default_hwclockfile=`echo $option | sed -e 's/^.*=//;'`
+    ;;
+    --with-pidfile=* )
+      default_pidfile=`echo $option | sed -e 's/^.*=//;'`
+    ;;
+    --with-rtcdevice=* )
+      default_rtcdevice=`echo $option | sed -e 's/^.*=//;'`
+    ;;
    --with-sendmail=* )
      mail_program=`echo $option | sed -e 's/^.*=//;'`
    ;;
@@ -356,71 +388,74 @@ rm -f config.h config.log

 SYSTEM=${OPERATINGSYSTEM}-${MACHINE}

-case $SYSTEM in
-    SunOS-sun4* )
-    case $VERSION in
-        4.* )
-            EXTRA_OBJECTS="sys_sunos.o strerror.o"
-            EXTRA_LIBS="-lkvm"
-            add_def SUNOS
-            echo "Configuring for SunOS (" $SYSTEM "version" $VERSION ")"
-        ;;
-        5.* )
-            EXTRA_OBJECTS="sys_solaris.o"
-            EXTRA_LIBS="-lsocket -lnsl -lkvm -lelf"
-            EXTRA_CLI_LIBS="-lsocket -lnsl"
-            add_def SOLARIS
-            echo "Configuring for Solaris (" $SYSTEM "SunOS version" $VERSION ")"
-        ;;
-    esac
-    ;;
-    Linux* )
-        EXTRA_OBJECTS="sys_generic.o sys_linux.o wrap_adjtimex.o"
-        try_libcap=1
+case $OPERATINGSYSTEM in
+    Linux)
+        EXTRA_OBJECTS="sys_generic.o sys_linux.o sys_timex.o"
+        [ $try_libcap != "0" ] && try_libcap=1
        try_rtc=1
+        [ $try_seccomp != "0" ] && try_seccomp=1
+        try_timestamping=1
        try_setsched=1
        try_lockmem=1
        try_phc=1
        add_def LINUX
        echo "Configuring for " $SYSTEM
-        if [ "${MACHINE}" = "alpha" ]; then
-           echo "Enabling -mieee"
-           # FIXME: Should really test for GCC
-           MYCFLAGS="$MYCFLAGS -mieee"
+    ;;
+    FreeBSD)
+        # recvmmsg() seems to be broken on FreeBSD 11.0 and it's just
+        # a wrapper around recvmsg()
+        try_recvmmsg=0
+        EXTRA_OBJECTS="sys_generic.o sys_netbsd.o sys_timex.o"
+        add_def FREEBSD
+        if [ $feat_droproot = "1" ]; then
+          add_def FEAT_PRIVDROP
+          priv_ops="ADJUSTTIME ADJUSTTIMEX SETTIME BINDSOCKET"
        fi
-    ;;
-
-    BSD/386-i[3456]86|FreeBSD-i386|FreeBSD-amd64 )
-        # Antti Jrvinen <costello@iki.fi> reported that this system can
-        # be supported with the SunOS 4.x driver files.
-        EXTRA_OBJECTS="sys_sunos.o strerror.o"
-        EXTRA_LIBS="-lkvm"
-        add_def SUNOS
-        echo "Configuring for $SYSTEM (using SunOS driver)"
-    ;;
-    NetBSD-* )
-        EXTRA_OBJECTS="sys_netbsd.o"
-        EXTRA_LIBS="-lkvm"
-        SYSDEFS=""
        echo "Configuring for $SYSTEM"
    ;;
-    SunOS-i86pc* )                                          
-        # Doug Woodward <dougw@whistler.com> reported that this configuration
-        # works for Solaris 2.8 / SunOS 5.8 on x86 platforms
-        EXTRA_OBJECTS="sys_solaris.o"                
-        EXTRA_LIBS="-lsocket -lnsl -lkvm -lelf"      
-        EXTRA_CLI_LIBS="-lsocket -lnsl"                              
+    NetBSD)
+        EXTRA_OBJECTS="sys_generic.o sys_netbsd.o sys_timex.o"
+        try_clockctl=1
+        add_def NETBSD
+        echo "Configuring for $SYSTEM"
+    ;;
+    Darwin)
+        EXTRA_OBJECTS="sys_macosx.o"
+        EXTRA_LIBS="-lresolv"
+        EXTRA_CLI_LIBS="-lresolv"
+        add_def MACOSX
+        if [ $feat_droproot = "1" ]; then
+          add_def FEAT_PRIVDROP
+          priv_ops="ADJUSTTIME SETTIME BINDSOCKET"
+        fi
+        major=`echo $VERSION | cut -d. -f1`
+        # ntp_adjtime is not available in macOS 10.12 (Darwin 16.x.x) and earlier
+        if [ $major -gt "16" ]; then
+          add_def HAVE_MACOS_SYS_TIMEX
+          EXTRA_OBJECTS="$EXTRA_OBJECTS sys_generic.o sys_netbsd.o sys_timex.o"
+          if [ $feat_droproot = "1" ]; then
+            priv_ops="$priv_ops ADJUSTTIMEX"
+          fi
+        fi
+        echo "Configuring for macOS (" $SYSTEM "macOS version" $VERSION ")"
+    ;;
+    SunOS)
+        EXTRA_OBJECTS="sys_generic.o sys_solaris.o sys_timex.o"
+        EXTRA_LIBS="-lsocket -lnsl -lresolv"
+        EXTRA_CLI_LIBS="-lsocket -lnsl -lresolv"
        add_def SOLARIS
+        # These are needed to have msg_control in struct msghdr
+        add_def __EXTENSIONS__
+        add_def _XOPEN_SOURCE 1
+        add_def _XOPEN_SOURCE_EXTENDED 1
+        if [ $feat_droproot = "1" ]; then
+          add_def FEAT_PRIVDROP
+          priv_ops="ADJUSTTIMEX SETTIME BINDSOCKET"
+        fi
        echo "Configuring for Solaris (" $SYSTEM "SunOS version" $VERSION ")" 
    ;;                                                                        
-    CYGWIN32_NT-i[3456]86 )
-        EXTRA_OBJECTS="sys_winnt.o"
-        EXTRA_LIBS=""
-        add_def WINNT
-        echo "Configuring for Windows NT (Cygwin32)"
-    ;;
    * )
-        echo "Sorry, I don't know how to build this software on your system."
+        echo "error: $SYSTEM is not supported (yet?)"
        exit 1
    ;;
 esac
@@ -438,8 +473,13 @@ fi
 if [ $feat_ntp = "1" ]; then
  add_def FEAT_NTP
  EXTRA_OBJECTS="$EXTRA_OBJECTS ntp_core.o ntp_io.o ntp_sources.o"
+  if [ $feat_ntp_signd = "1" ]; then
+    add_def FEAT_SIGND
+    EXTRA_OBJECTS="$EXTRA_OBJECTS ntp_signd.o"
+  fi
 else
  feat_asyncdns=0
+  feat_timestamping=0
 fi

 if [ "$feat_cmdmon" = "1" ] || [ $feat_ntp = "1" ]; then
@@ -453,6 +493,53 @@ if [ $feat_refclock = "1" ]; then
  EXTRA_OBJECTS="$EXTRA_OBJECTS refclock.o refclock_phc.o refclock_pps.o refclock_shm.o refclock_sock.o"
 fi

+MYCC="$CC"
+MYCFLAGS="$CFLAGS"
+MYCPPFLAGS="$CPPFLAGS"
+MYLDFLAGS="$LDFLAGS"
+
+if [ "x$MYCC" = "x" ]; then
+  for cc in gcc clang cc ""; do
+    if [ "x$cc" = "x" ]; then
+      echo "error: no C compiler found"
+      exit 1
+    fi
+    MYCC=$cc
+    if test_code "$MYCC" '' '' '' ''; then
+      break
+    fi
+  done
+else
+  if ! test_code "$MYCC" '' '' '' ''; then
+    echo "error: C compiler $MYCC cannot create executables"
+    exit 1
+  fi
+fi
+
+if [ "x$MYCFLAGS" = "x" ]; then
+  MYCFLAGS="-O2 -g"
+
+  TESTCFLAGS="-D_FORTIFY_SOURCE=2 -fPIE"
+  TESTLDFLAGS="-pie -Wl,-z,relro,-z,now"
+  if test_code 'hardening compiler options' '' "$TESTCFLAGS" "$TESTLDFLAGS" ''; then
+    MYCFLAGS="$MYCFLAGS $TESTCFLAGS"
+    MYLDFLAGS="$MYLDFLAGS $TESTLDFLAGS"
+  fi
+  TESTCFLAGS="-fstack-protector-strong --param=ssp-buffer-size=4"
+  if test_code '-fstack-protector-strong' '' "$TESTCFLAGS" '' ''; then
+    MYCFLAGS="$MYCFLAGS $TESTCFLAGS"
+  else
+    TESTCFLAGS="-fstack-protector --param=ssp-buffer-size=4"
+    if test_code '-fstack-protector' '' "$TESTCFLAGS" '' ''; then
+      MYCFLAGS="$MYCFLAGS $TESTCFLAGS"
+    fi
+  fi
+fi
+
+if [ "x$MYCC" = "xgcc" ] || [ "x$MYCC" = "xclang" ]; then
+  MYCFLAGS="$MYCFLAGS -Wmissing-prototypes -Wall"
+fi
+
 if test_code '64-bit time_t' 'time.h' '' '' '
  char x[sizeof(time_t) > 4 ? 1 : -1] = {0};
  return x[0];'
@@ -464,8 +551,8 @@ then
    split_days=0
  else
    split_seconds=`date '+%s'`
-    if [ "x$split_seconds" = "" ]; then
-      echo "Could not get current time, --with-ntp-era option is needed"
+    if [ "x$split_seconds" = "x" ]; then
+      echo "error: could not get current time, --with-ntp-era option is needed"
      exit 1
    fi
    split_days=$((50 * 365))
@@ -494,7 +581,7 @@ else
  if test_code 'math in -lm' 'math.h' '' '-lm' "$MATHCODE"; then
    LIBS="-lm"
  else
-    echo "Can't compile/link a program which uses sqrt(), log(), pow(), bailing out"
+    echo "error: could not compile/link a program which uses sqrt(), log(), pow()"
    exit 1
  fi
 fi
@@ -507,21 +594,28 @@ if test_code '<inttypes.h>' 'inttypes.h' '' '' ''; then
  add_def HAVE_INTTYPES_H
 fi

+if test_code 'struct in_pktinfo' 'sys/socket.h netinet/in.h' '' '' '
+  struct in_pktinfo ipi;
+  return sizeof (ipi.ipi_spec_dst.s_addr) + IP_PKTINFO;'
+then
+  add_def HAVE_IN_PKTINFO
+fi
+
 if [ $feat_ipv6 = "1" ] && \
-  test_code 'IPv6 support' 'arpa/inet.h sys/socket.h netinet/in.h' '' '' '
+  test_code 'IPv6 support' 'arpa/inet.h sys/socket.h netinet/in.h' '' "$EXTRA_LIBS" '
    struct sockaddr_in6 n;
    char p[100];
    n.sin6_addr = in6addr_any;
    return !inet_ntop(AF_INET6, &n.sin6_addr.s6_addr, p, sizeof(p));'
 then
  add_def FEAT_IPV6
-  if test_code 'in6_pktinfo' 'sys/socket.h netinet/in.h' '' '' '
-    return sizeof(struct in6_pktinfo);'
+  if test_code 'struct in6_pktinfo' 'sys/socket.h netinet/in.h' '' '' '
+    return sizeof (struct in6_pktinfo) + IPV6_PKTINFO;'
  then
    add_def HAVE_IN6_PKTINFO
  else
-    if test_code 'in6_pktinfo with _GNU_SOURCE' 'sys/socket.h netinet/in.h' \
-      '-D_GNU_SOURCE' '' 'return sizeof(struct in6_pktinfo);'
+    if test_code 'struct in6_pktinfo with _GNU_SOURCE' 'sys/socket.h netinet/in.h' \
+      '-D_GNU_SOURCE' '' 'return sizeof (struct in6_pktinfo) + IPV6_PKTINFO;'
    then
      add_def _GNU_SOURCE
      add_def HAVE_IN6_PKTINFO
@@ -529,7 +623,22 @@ then
  fi
 fi

-if test_code 'getaddrinfo()' 'sys/types.h sys/socket.h netdb.h' '' '' \
+if [ $try_clock_gettime = "1" ]; then
+  if test_code 'clock_gettime()' 'time.h' '' '' \
+    'clock_gettime(CLOCK_REALTIME, NULL);'
+  then
+    add_def HAVE_CLOCK_GETTIME
+  else
+    if test_code 'clock_gettime() in -lrt' 'time.h' '' '-lrt' \
+      'clock_gettime(CLOCK_REALTIME, NULL);'
+    then
+      add_def HAVE_CLOCK_GETTIME
+      EXTRA_LIBS="$EXTRA_LIBS -lrt"
+    fi
+  fi
+fi
+
+if test_code 'getaddrinfo()' 'sys/types.h sys/socket.h netdb.h' '' "$EXTRA_LIBS" \
  'return getaddrinfo(0, 0, 0, 0);'
 then
  add_def HAVE_GETADDRINFO
@@ -545,6 +654,55 @@ then
  MYCFLAGS="$MYCFLAGS -pthread"
 fi

+if test_code 'arc4random_buf()' 'stdlib.h' '' '' 'arc4random_buf(NULL, 0);'; then
+  add_def HAVE_ARC4RANDOM
+fi
+
+if test_code 'getrandom()' 'stdlib.h sys/random.h' '' '' \
+    'return getrandom(NULL, 256, 0);'; then
+  add_def HAVE_GETRANDOM
+fi
+
+RECVMMSG_CODE='
+  struct mmsghdr hdr;
+  return !recvmmsg(0, &hdr, 1, MSG_DONTWAIT, 0);'
+if [ $try_recvmmsg = "1" ]; then
+  if test_code 'recvmmsg()' 'sys/socket.h' '' "$EXTRA_LIBS" "$RECVMMSG_CODE"; then
+    add_def HAVE_RECVMMSG
+  else
+    if test_code 'recvmmsg() with _GNU_SOURCE' 'sys/socket.h' '-D_GNU_SOURCE' \
+      "$EXTRA_LIBS" "$RECVMMSG_CODE"
+    then
+      add_def _GNU_SOURCE
+      add_def HAVE_RECVMMSG
+    fi
+  fi
+fi
+
+if [ $feat_timestamping = "1" ] && [ $try_timestamping = "1" ] &&
+  test_code 'SW/HW timestamping' 'sys/types.h sys/socket.h linux/net_tstamp.h
+                                  linux/errqueue.h linux/ptp_clock.h' '' '' '
+    int val = SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_RX_SOFTWARE |
+              SOF_TIMESTAMPING_RAW_HARDWARE | SOF_TIMESTAMPING_OPT_CMSG;
+    return sizeof (struct scm_timestamping) + SCM_TSTAMP_SND + PTP_SYS_OFFSET +
+           setsockopt(0, SOL_SOCKET, SO_SELECT_ERR_QUEUE + SO_TIMESTAMPING,
+                      &val, sizeof (val));'
+then
+  add_def HAVE_LINUX_TIMESTAMPING
+  EXTRA_OBJECTS="$EXTRA_OBJECTS hwclock.o ntp_io_linux.o"
+
+  if test_code 'other timestamping options' \
+    'sys/types.h sys/socket.h linux/net_tstamp.h' '' '' '
+    struct scm_ts_pktinfo pktinfo;
+    pktinfo.if_index = pktinfo.pkt_length = 0;
+    return pktinfo.if_index + pktinfo.pkt_length + HWTSTAMP_FILTER_NTP_ALL +
+           SOF_TIMESTAMPING_OPT_PKTINFO + SOF_TIMESTAMPING_OPT_TX_SWHW;'; then
+    add_def HAVE_LINUX_TIMESTAMPING_RXFILTER_NTP 1
+    add_def HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO 1
+    add_def HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW 1
+  fi
+fi
+
 timepps_h=""
 if [ $feat_refclock = "1" ] && [ $feat_pps = "1" ]; then
  if test_code '<sys/timepps.h>' 'sys/timepps.h' '' '' ''; then
@@ -579,6 +737,33 @@ then
    EXTRA_LIBS="$EXTRA_LIBS -lcap"
 fi

+if [ $feat_droproot = "1" ] && [ $try_clockctl = "1" ] && \
+  test_code '<sys/clockctl.h>' 'sys/clockctl.h' '' '' ''
+then
+  add_def FEAT_PRIVDROP
+  priv_ops="BINDSOCKET"
+fi
+
+if [ $feat_scfilter = "1" ] && [ $try_seccomp = "1" ] && \
+  test_code seccomp 'seccomp.h' '' '-lseccomp' \
+    'seccomp_init(SCMP_ACT_KILL);'
+then
+  add_def FEAT_SCFILTER
+  # NAME2IPADDRESS shouldn't be enabled with other operations as the helper
+  # process works on one request at the time and the async resolver could
+  # block the main thread
+  priv_ops="NAME2IPADDRESS RELOADDNS"
+  EXTRA_LIBS="$EXTRA_LIBS -lseccomp"
+fi
+
+if [ "x$priv_ops" != "x" ]; then
+  EXTRA_OBJECTS="$EXTRA_OBJECTS privops.o"
+  add_def PRIVOPS_HELPER
+  for o in $priv_ops; do
+    add_def PRIVOPS_$o
+  done
+fi
+
 if [ $feat_rtc = "1" ] && [ $try_rtc = "1" ] && \
  test_code '<linux/rtc.h>' 'sys/ioctl.h linux/rtc.h' '' '' \
    'ioctl(1, RTC_UIE_ON&RTC_UIE_OFF&RTC_RD_TIME&RTC_SET_TIME, 0&RTC_UF);'
@@ -588,19 +773,13 @@ then
 fi

 if [ $feat_refclock = "1" ] && [ $feat_phc = "1" ] && [ $try_phc = "1" ] && \
+  grep '#define HAVE_CLOCK_GETTIME' config.h > /dev/null && \
  test_code '<linux/ptp_clock.h>' 'sys/ioctl.h linux/ptp_clock.h' '' '' \
-    'ioctl(1, PTP_CLOCK_GETCAPS, 0);'
+    'ioctl(1, PTP_CLOCK_GETCAPS + PTP_SYS_OFFSET, 0);'
 then
-  if test_code 'clock_gettime()' 'time.h' '' '' 'clock_gettime(0, NULL);'; then
+  grep 'HAVE_LINUX_TIMESTAMPING' config.h > /dev/null ||
+    EXTRA_OBJECTS="$EXTRA_OBJECTS hwclock.o"
  add_def FEAT_PHC
-  else
-    if test_code 'clock_gettime() in -lrt' 'time.h' '' '-lrt' \
-      'clock_gettime(0, NULL);'
-    then
-      EXTRA_LIBS="$EXTRA_LIBS -lrt"
-      add_def FEAT_PHC
-    fi
-  fi
 fi

 if [ $try_setsched = "1" ] && \
@@ -630,7 +809,6 @@ then
  add_def FORCE_DNSRETRY
 fi

-READLINE_COMPILE=""
 READLINE_LINK=""
 if [ $feat_readline = "1" ]; then
  if [ $try_editline = "1" ]; then
@@ -640,7 +818,7 @@ if [ $feat_readline = "1" ]; then
    then
      add_def FEAT_READLINE
      add_def USE_EDITLINE
-      READLINE_COMPILE="$readline_inc"
+      MYCPPFLAGS="$MYCPPFLAGS $readline_inc"
      READLINE_LINK="$readline_lib -ledit"
    fi
  fi
@@ -651,7 +829,7 @@ if [ $feat_readline = "1" ]; then
      'add_history(readline("prompt"));'
    then
      add_def FEAT_READLINE
-      READLINE_COMPILE="$readline_inc"
+      MYCPPFLAGS="$MYCPPFLAGS $readline_inc"
      READLINE_LINK="$readline_lib -lreadline"
    fi
  fi
@@ -663,7 +841,7 @@ if [ $feat_readline = "1" ]; then
      'add_history(readline("prompt"));'
    then
      add_def FEAT_READLINE
-      READLINE_COMPILE="$readline_inc"
+      MYCPPFLAGS="$MYCPPFLAGS $readline_inc"
      READLINE_LINK="$readline_lib $ncurses_lib -lreadline -lncurses"
    fi
  fi
@@ -672,7 +850,6 @@ if [ $feat_readline = "1" ]; then
 fi

 HASH_OBJ="hash_intmd5.o"
-HASH_COMPILE=""
 HASH_LINK=""

 if [ $feat_sechash = "1" ] && [ $try_nss = "1" ]; then
@@ -683,9 +860,9 @@ if [ $feat_sechash = "1" ] && [ $try_nss = "1" ]; then
    'NSSLOWHASH_Begin(NSSLOWHASH_NewContext(NSSLOW_Init(), HASH_AlgSHA512));'
  then
    HASH_OBJ="hash_nss.o"
-    HASH_COMPILE="$test_cflags"
    HASH_LINK="$test_link"
    LIBS="$LIBS $HASH_LINK"
+    MYCPPFLAGS="$MYCPPFLAGS $test_cflags"
    add_def FEAT_SECHASH
  fi
 fi
@@ -695,9 +872,9 @@ if [ $feat_sechash = "1" ] && [ "x$HASH_LINK" = "x" ] && [ $try_tomcrypt = "1" ]
    'hash_memory_multi(find_hash("md5"), NULL, NULL, NULL, 0, NULL, 0);'
  then
    HASH_OBJ="hash_tomcrypt.o"
-    HASH_COMPILE="-I/usr/include/tomcrypt"
    HASH_LINK="-ltomcrypt"
    LIBS="$LIBS $HASH_LINK"
+    MYCPPFLAGS="$MYCPPFLAGS -I/usr/include/tomcrypt"
    add_def FEAT_SECHASH
  fi
 fi
@@ -732,11 +909,6 @@ if [ "x$SETDATAROOTDIR" != "x" ]; then
  DATAROOTDIR=$SETDATAROOTDIR
 fi

-INFODIR=${DATAROOTDIR}/info
-if [ "x$SETINFODIR" != "x" ]; then
-  INFODIR=$SETINFODIR
-fi
-
 MANDIR=${DATAROOTDIR}/man
 if [ "x$SETMANDIR" != "x" ]; then
  MANDIR=$SETMANDIR
@@ -752,29 +924,40 @@ if [ "x$SETLOCALSTATEDIR" != "x" ]; then
  LOCALSTATEDIR=$SETLOCALSTATEDIR
 fi

+CHRONYRUNDIR=${LOCALSTATEDIR}/run/chrony
+if [ "x$SETCHRONYRUNDIR" != "x" ]; then
+  CHRONYRUNDIR=$SETCHRONYRUNDIR
+fi
+
 CHRONYVARDIR=${LOCALSTATEDIR}/lib/chrony
 if [ "x$SETCHRONYVARDIR" != "x" ]; then
  CHRONYVARDIR=$SETCHRONYVARDIR
 fi

 add_def DEFAULT_CONF_FILE "\"$SYSCONFDIR/chrony.conf\""
+add_def DEFAULT_HWCLOCK_FILE "\"$default_hwclockfile\""
+add_def DEFAULT_PID_FILE "\"$default_pidfile\""
+add_def DEFAULT_RTC_DEVICE "\"$default_rtcdevice\""
 add_def DEFAULT_USER "\"$default_user\""
+add_def DEFAULT_COMMAND_SOCKET "\"$CHRONYRUNDIR/chronyd.sock\""
 add_def MAIL_PROGRAM "\"$mail_program\""

-common_features="`get_features ASYNCDNS IPV6 SECHASH`"
+common_features="`get_features IPV6 DEBUG`"
 chronyc_features="`get_features READLINE`"
-chronyd_features="`get_features CMDMON NTP REFCLOCK RTC PRIVDROP DEBUG`"
+chronyd_features="`get_features CMDMON NTP REFCLOCK RTC PRIVDROP SCFILTER SECHASH SIGND ASYNCDNS`"
 add_def CHRONYC_FEATURES "\"$chronyc_features $common_features\""
 add_def CHRONYD_FEATURES "\"$chronyd_features $common_features\""
 echo "Features : $chronyd_features $chronyc_features $common_features"

 if [ -f version.txt ]; then
-  add_def CHRONY_VERSION "\"`cat version.txt`\""
+  CHRONY_VERSION="`cat version.txt`"
 else
-  add_def CHRONY_VERSION "\"DEVELOPMENT\""
+  CHRONY_VERSION="DEVELOPMENT"
 fi

-for f in Makefile chrony.conf.5 chrony.texi chronyc.1 chronyd.8
+add_def CHRONY_VERSION "\"${CHRONY_VERSION}\""
+
+for f in Makefile doc/Makefile test/unit/Makefile
 do
  echo Creating $f
  sed -e "s%@EXTRA_OBJECTS@%${EXTRA_OBJECTS}%;\
@@ -785,18 +968,20 @@ do
          s%@LDFLAGS@%${MYLDFLAGS}%;\
          s%@EXTRA_LIBS@%${EXTRA_LIBS}%;\
          s%@EXTRA_CLI_LIBS@%${EXTRA_CLI_LIBS}%;\
-          s%@READLINE_COMPILE@%${READLINE_COMPILE}%;\
          s%@HASH_OBJ@%${HASH_OBJ}%;\
-          s%@HASH_COMPILE@%${HASH_COMPILE}%;\
          s%@SYSCONFDIR@%${SYSCONFDIR}%;\
          s%@BINDIR@%${BINDIR}%;\
          s%@SBINDIR@%${SBINDIR}%;\
          s%@DOCDIR@%${DOCDIR}%;\
          s%@MANDIR@%${MANDIR}%;\
-          s%@INFODIR@%${INFODIR}%;\
          s%@LOCALSTATEDIR@%${LOCALSTATEDIR}%;\
+          s%@CHRONYRUNDIR@%${CHRONYRUNDIR}%;\
          s%@CHRONYVARDIR@%${CHRONYVARDIR}%;\
-          s%@DEFAULT_USER@%${default_user}%;"\
+          s%@DEFAULT_HWCLOCK_FILE@%${default_hwclockfile}%;\
+          s%@DEFAULT_PID_FILE@%${default_pidfile}%;\
+          s%@DEFAULT_RTC_DEVICE@%${default_rtcdevice}%;\
+          s%@DEFAULT_USER@%${default_user}%;\
+          s%@CHRONY_VERSION@%${CHRONY_VERSION}%;" \
          < ${f}.in > $f
 done

--- a/contrib/bryan_christianson_1/README.txt
+++ b/contrib/bryan_christianson_1/README.txt
@@ -0,0 +1,103 @@
+Notes for installing chrony on macOS
+Author: Bryan Christianson (bryan@whatroute.net)
+------------------------------------------------
+
+These files are for those admins/users who would prefer to install chrony
+from the source distribution and are intended as guidelines rather than
+being definitive. They can be edited with a plain text editor, such as
+vi, emacs or your favourite IDE (Xcode)
+
+It is assumed you are comfortable with installing software from the
+terminal command line and know how to use sudo to acquire root access.
+
+If you are not familiar with the macOS command line then
+please consider using ChronyControl from http://whatroute.net/chronycontrol.html
+
+ChronyControl provides a gui wrapper for installing these files and sets the
+necessary permissions on each file.
+
+
+Install the chrony software
+---------------------------
+
+You will need xcode and the commandline additions to build and install chrony.
+These can be obtained from Apple's website via the App Store.
+
+cd to the chrony directory
+./configure
+make
+sudo make install
+
+chrony is now installed in default locations (/usr/local/sbin/chronyd,
+/usr/local/bin/chronyc)
+
+Create a chrony.conf file - see the chrony website for details
+
+The support files here assume the following directives are specified in the
+chrony.conf file
+
+keyfile /etc/chrony.d/chrony.keys
+driftfile /var/db/chrony/chrony.drift
+bindcmdaddress /var/db/chrony/chronyd.sock
+logdir /var/log/chrony
+dumpdir /var/db/chrony
+
+Install this file as /etc/chrony.d/chrony.conf and create
+the directories specified in the above directives if they don't exist.
+You will need root permissions to create the directories.
+
+
+Running chronyd
+---------------
+At this point chronyd *could* be run as a daemon. Apple discourage running
+daemons and their preferred method uses the launchd facility. The
+support files here provide a launchd configuration file for chronyd and also
+a shell script and launchd configuration file to rotate the chronyd logs on a daily basis.
+
+
+Support files
+-------------
+Dates and sizes may differ
+-rw-r--r--  1 yourname  staff  2084  4 Aug 22:54 README.txt
+-rwxr-xr-x  1 yourname  staff   676  4 Aug 21:18 chronylogrotate.sh
+-rw-r--r--  1 yourname  staff   543 18 Jul 20:10 org.tuxfamily.chronyc.plist
+-rw-r--r--  1 yourname  staff   511 19 Jun 18:30 org.tuxfamily.chronyd.plist
+
+If you have used chrony support directories other than those suggested, you
+will need to edit each file and make the appropriate changes.
+
+
+Installing the support files
+----------------------------
+
+1. chronylogrotate.sh
+This is a simple shell script that deletes old log files. Unfortunately because
+of the need to run chronyc, the standard macOS logrotation does not work with
+chrony logs.
+
+This script runs on a daily basis under control of launchd and should be
+installed in the /usr/local/bin directory
+
+sudo cp chronylogrotate.sh /usr/local/bin
+sudo chmod +x /usr/local/bin/chronylogrotate.sh
+sudo chown root:wheel /usr/local/bin/chronylogrotate.sh
+
+
+2. org.tuxfamily.chronyc.plist
+This file is the launchd plist that runs logrotation each day. You may
+wish to edit this file to change the time of day at which the rotation
+will run, currently 04:05 am
+
+sudo cp org.tuxfamily.chronyc.plist /Library/LaunchDaemons
+sudo chown root:wheel /Library/LaunchDaemons/org.tuxfamily.chronyc.plist
+sudo chmod 0644 /Library/LaunchDaemons/org.tuxfamily.chronyc.plist
+sudo launchctl load -w /Library/LaunchDaemons/org.tuxfamily.chronyc.plist
+
+
+3. org.tuxfamily.chronyd.plist
+This file is the launchd plist that runs chronyd when the Macintosh starts.
+
+sudo cp org.tuxfamily.chronyd.plist /Library/LaunchDaemons
+sudo chown root:wheel /Library/LaunchDaemons/org.tuxfamily.chronyd.plist
+sudo chmod 0644 /Library/LaunchDaemons/org.tuxfamily.chronyd.plist
+sudo launchctl load -w /Library/LaunchDaemons/org.tuxfamily.chronyd.plist
--- a/contrib/bryan_christianson_1/chronylogrotate.sh
+++ b/contrib/bryan_christianson_1/chronylogrotate.sh
@@ -0,0 +1,58 @@
+#!/bin/sh
+
+#  chronyd/chronyc - Programs for keeping computer clocks accurate.
+#
+#  **********************************************************************
+#  * Copyright (C) Bryan Christianson  2015
+#  *
+#  * This program is free software; you can redistribute it and/or modify
+#  * it under the terms of version 2 of the GNU General Public License as
+#  * published by the Free Software Foundation.
+#  *
+#  * This program is distributed in the hope that it will be useful, but
+#  * WITHOUT ANY WARRANTY; without even the implied warranty of
+#  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#  * General Public License for more details.
+#  *
+#  * You should have received a copy of the GNU General Public License along
+#  * with this program; if not, write to the Free Software Foundation, Inc.,
+#  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#  *
+#  **********************************************************************
+
+LOGDIR=/var/log/chrony
+
+rotate () {
+  prefix=$1
+
+  rm -f $prefix.log.10
+
+  for (( count=9; count>= 0; count-- ))
+  do
+    next=$(( $count+1 ))
+    if [ -f $prefix.log.$count ]; then
+      mv $prefix.log.$count $prefix.log.$next
+    fi
+  done
+
+  if [ -f $prefix.log ]; then
+    mv $prefix.log $prefix.log.0
+  fi
+}
+
+if [ ! -e "$LOGDIR" ]; then
+  logger -s "missing directory: $LOGDIR"
+  exit 1
+fi
+
+cd $LOGDIR
+
+rotate measurements
+rotate statistics
+rotate tracking
+
+#
+# signal chronyd via chronyc
+/usr/local/bin/chronyc cyclelogs > /dev/null
+
+exit $?
--- a/contrib/bryan_christianson_1/org.tuxfamily.chronyc.plist
+++ b/contrib/bryan_christianson_1/org.tuxfamily.chronyc.plist
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>Label</key>
+	<string>org.tuxfamily.logrotate</string>
+	<key>KeepAlive</key>
+	<false/>
+	<key>ProgramArguments</key>
+	<array>
+		<string>/bin/sh</string>
+		<string>/usr/local/bin/chronylogrotate.sh</string>
+	</array>
+	<key>StartCalendarInterval</key>
+	<dict>
+		<key>Minute</key>
+		<integer>5</integer>
+		<key>Hour</key>
+		<integer>4</integer>
+	</dict>
+</dict>
+</plist>
--- a/contrib/bryan_christianson_1/org.tuxfamily.chronyd.plist
+++ b/contrib/bryan_christianson_1/org.tuxfamily.chronyd.plist
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>Label</key>
+	<string>org.tuxfamily.chronyd</string>
+	<key>Program</key>
+	<string>/usr/local/sbin/chronyd</string>
+	<key>ProgramArguments</key>
+	<array>
+		<string>chronyd</string>
+		<string>-n</string>
+		<string>-f</string>
+		<string>/private/etc/chrony.d/chrony.conf</string>
+	</array>
+	<key>KeepAlive</key>
+	<true/>
+</dict>
+</plist>
--- a/doc/Makefile.in
+++ b/doc/Makefile.in
@@ -0,0 +1,76 @@
+ADOC = asciidoctor
+ADOC_FLAGS =
+SED = sed
+HTML_TO_TXT = w3m -dump -T text/html
+
+MAN_FILES = chrony.conf.man chronyc.man chronyd.man
+TXT_FILES = faq.txt installation.txt
+HTML_FILES = $(MAN_FILES:%.man=%.html) $(TXT_FILES:%.txt=%.html)
+MAN_IN_FILES = $(MAN_FILES:%.man=%.man.in)
+
+SYSCONFDIR = @SYSCONFDIR@
+BINDIR = @BINDIR@
+SBINDIR = @SBINDIR@
+MANDIR = @MANDIR@
+DOCDIR = @DOCDIR@
+CHRONYRUNDIR = @CHRONYRUNDIR@
+CHRONYVARDIR = @CHRONYVARDIR@
+CHRONY_VERSION = @CHRONY_VERSION@
+DEFAULT_USER = @DEFAULT_USER@
+DEFAULT_HWCLOCK_FILE = @DEFAULT_HWCLOCK_FILE@
+DEFAULT_PID_FILE = @DEFAULT_PID_FILE@
+DEFAULT_RTC_DEVICE = @DEFAULT_RTC_DEVICE@
+
+SED_COMMANDS = "s%\@SYSCONFDIR\@%$(SYSCONFDIR)%g;\
+	       s%\@BINDIR\@%$(BINDIR)%g;\
+	       s%\@SBINDIR\@%$(SBINDIR)%g;\
+	       s%\@CHRONY_VERSION\@%$(CHRONY_VERSION)%g;\
+	       s%\@DEFAULT_HWCLOCK_FILE\@%$(DEFAULT_HWCLOCK_FILE)%g;\
+	       s%\@DEFAULT_PID_FILE\@%$(DEFAULT_PID_FILE)%g;\
+	       s%\@DEFAULT_RTC_DEVICE\@%$(DEFAULT_RTC_DEVICE)%g;\
+	       s%\@DEFAULT_USER\@%$(DEFAULT_USER)%g;\
+	       s%\@CHRONYRUNDIR\@%$(CHRONYRUNDIR)%g;\
+	       s%\@CHRONYVARDIR\@%$(CHRONYVARDIR)%g;"
+
+man: $(MAN_FILES) $(MAN_IN_FILES)
+html: $(HTML_FILES)
+txt: $(TXT_FILES)
+docs: man html
+
+%.html: %.adoc
+	$(ADOC) $(ADOC_FLAGS) -b html -o - $< | $(SED) -e $(SED_COMMANDS) > $@
+
+%.man.in: %.adoc
+	$(ADOC) $(ADOC_FLAGS) -b manpage -o $@ $<
+
+%.man: %.man.in
+	$(SED) -e $(SED_COMMANDS) < $< > $@
+
+%.txt: %.html
+	$(HTML_TO_TXT) < $< > $@
+
+install: $(MAN_FILES)
+	[ -d $(DESTDIR)$(MANDIR)/man1 ] || mkdir -p $(DESTDIR)$(MANDIR)/man1
+	[ -d $(DESTDIR)$(MANDIR)/man5 ] || mkdir -p $(DESTDIR)$(MANDIR)/man5
+	[ -d $(DESTDIR)$(MANDIR)/man8 ] || mkdir -p $(DESTDIR)$(MANDIR)/man8
+	cp chronyc.man $(DESTDIR)$(MANDIR)/man1/chronyc.1
+	chmod 644 $(DESTDIR)$(MANDIR)/man1/chronyc.1
+	cp chronyd.man $(DESTDIR)$(MANDIR)/man8/chronyd.8
+	chmod 644 $(DESTDIR)$(MANDIR)/man8/chronyd.8
+	cp chrony.conf.man $(DESTDIR)$(MANDIR)/man5/chrony.conf.5
+	chmod 644 $(DESTDIR)$(MANDIR)/man5/chrony.conf.5
+
+install-docs: $(HTML_FILES)
+	[ -d $(DESTDIR)$(DOCDIR) ] || mkdir -p $(DESTDIR)$(DOCDIR)
+	for f in $(HTML_FILES); do \
+	  cp $$f $(DESTDIR)$(DOCDIR); \
+	  chmod 644 $(DESTDIR)$(DOCDIR)/$$f; \
+	done
+
+clean:
+	rm -f $(MAN_FILES) $(TXT_FILES) $(HTML_FILES)
+	rm -f $(MAN_IN_FILES)
+
+distclean:
+	rm -f $(MAN_FILES) $(TXT_FILES) $(HTML_FILES)
+	rm -f Makefile
--- a/doc/chrony.conf.adoc
+++ b/doc/chrony.conf.adoc
--- a/doc/chronyc.adoc
+++ b/doc/chronyc.adoc
--- a/doc/chronyd.adoc
+++ b/doc/chronyd.adoc
@@ -0,0 +1,184 @@
+// This file is part of chrony
+//
+// Copyright (C) Richard P. Curnow  1997-2003
+// Copyright (C) Miroslav Lichvar  2009-2016
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of version 2 of the GNU General Public License as
+// published by the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, write to the Free Software Foundation, Inc.,
+// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+= chronyd(8)
+:doctype: manpage
+:man manual: System Administration
+:man source: chrony @CHRONY_VERSION@
+
+== NAME
+
+chronyd - chrony daemon
+
+== SYNOPSIS
+
+*chronyd* [_OPTION_]... [_DIRECTIVE_]...
+
+== DESCRIPTION
+
+*chronyd* is a daemon for synchronisation of the system clock. It can
+synchronise the clock with NTP servers, reference clocks (e.g. a GPS receiver),
+and manual input using wristwatch and keyboard via *chronyc*. It can also
+operate as an NTPv4 (RFC 5905) server and peer to provide a time service to
+other computers in the network.
+
+If no configuration directives are specified on the command line, *chronyd*
+will read them from a configuration file. The compiled-in default location of
+the file is _@SYSCONFDIR@/chrony.conf_.
+
+Information messages and warnings will be logged to syslog.
+
+== OPTIONS
+
+*-4*::
+With this option hostnames will be resolved only to IPv4 addresses and only
+IPv4 sockets will be created.
+
+*-6*::
+With this option hostnames will be resolved only to IPv6 addresses and only
+IPv6 sockets will be created.
+
+*-f* _file_::
+This option can be used to specify an alternate location for the configuration
+file (default _@SYSCONFDIR@/chrony.conf_).
+
+*-n*::
+When run in this mode, the program will not detach itself from the terminal.
+
+*-d*::
+When run in this mode, the program will not detach itself from the terminal,
+and all messages will be written to the terminal instead of syslog. When
+*chronyd* was compiled with debugging support, this option can be used twice to
+print also debugging messages.
+
+*-l* _file_::
+This option specifies a file which should be used for logging instead of syslog
+or terminal.
+
+*-q*::
+When run in this mode, *chronyd* will set the system clock once and exit. It
+will not detach from the terminal.
+
+*-Q*::
+This option is similar to the *-q* option, except it only prints the offset
+without making any corrections of the clock and it allows *chronyd* to be
+started without root privileges.
+
+*-r*::
+This option will try to reload and then delete files containing sample
+histories for each of the servers and reference clocks being used. These
+histories are created by using the <<chronyc.adoc#dump,*dump*>> command in
+*chronyc*, or by setting the <<chrony.conf.adoc#dumponexit,*dumponexit*>>
+directive in the configuration file. This option is useful if you want to stop
+and restart *chronyd* briefly for any reason, e.g. to install a new version.
+However, it should be used only on systems where the kernel can maintain clock
+compensation whilst not under *chronyd*'s control (i.e. Linux, FreeBSD, NetBSD,
+Solaris, and macOS 10.13 or later).
+
+*-R*::
+When this option is used, the <<chrony.conf.adoc#initstepslew,*initstepslew*>>
+directive and the <<chrony.conf.adoc#makestep,*makestep*>> directive used with
+a positive limit will be ignored. This option is useful when restarting
+*chronyd* and can be used in conjunction with the *-r* option.
+
+*-s*::
+This option will set the system clock from the computer's real-time clock (RTC)
+or to the last modification time of the file specified by the
+<<chrony.conf.adoc#driftfile,*driftfile*>> directive. Real-time clocks are
+supported only on Linux.
+
+If used in conjunction with the *-r* flag, *chronyd* will attempt to preserve
+the old samples after setting the system clock from the RTC. This can be used
+to allow *chronyd* to perform long term averaging of the gain or loss rate
+across system reboots, and is useful for systems with intermittent access to
+network that are shut down when not in use. For this to work well, it relies
+on *chronyd* having been able to determine accurate statistics for the
+difference between the RTC and system clock last time the computer was on.
+
+If the last modification time of the drift file is later than both the current
+time and the RTC time, the system time will be set to it to restore the time
+when *chronyd* was previously stopped. This is useful on computers that have no
+RTC or the RTC is broken (e.g. it has no battery).
+
+*-t* _timeout_::
+This option sets a timeout (in seconds) after which *chronyd* will exit. If the
+clock is not synchronised, it will exit with a non-zero status. This is useful
+with the *-q* or *-Q* option to shorten the maximum time waiting for
+measurements, or with the *-r* option to limit the time when *chronyd* is
+running, but still allow it to adjust the frequency of the system clock.
+
+*-u* _user_::
+This option sets the name of the system user to which *chronyd* will switch
+after start in order to drop root privileges. It overrides the
+<<chrony.conf.adoc#user,*user*>> directive (default _@DEFAULT_USER@_).
+
+On Linux, *chronyd* needs to be compiled with support for the *libcap* library.
+On macOS, FreeBSD, NetBSD and Solaris *chronyd* forks into two processes.
+The child process retains root privileges, but can only perform a very limited
+range of privileged system calls on behalf of the parent.
+
+*-F* _level_::
+This option configures a system call filter when *chronyd* is compiled with
+support for the Linux secure computing (seccomp) facility. In level 1 the
+process is killed when a forbidden system call is made, in level -1 the SYSSIG
+signal is thrown instead and in level 0 the filter is disabled (default 0).
+
+It's recommended to enable the filter only when it's known to work on the
+version of the system where *chrony* is installed as the filter needs to allow
+also system calls made from libraries that *chronyd* is using (e.g. libc) and
+different versions or implementations of the libraries may make different
+system calls. If the filter is missing some system call, *chronyd* could be
+killed even in normal operation.
+
+*-P* _priority_::
+On Linux, this option will select the SCHED_FIFO real-time scheduler at the
+specified priority (which must be between 0 and 100). On macOS, this option
+must have either a value of 0 (the default) to disable the thread time
+constraint policy or 1 for the policy to be enabled. Other systems do not
+support this option.
+
+*-m*::
+This option will lock *chronyd* into RAM so that it will never be paged out.
+This mode is only supported on Linux.
+
+*-x*::
+This option disables the control of the system clock. *chronyd* will not make
+any adjustments of the clock, but it will still track its offset and frequency
+relative to the estimated true time, and be able to operate as an NTP server.
+This allows *chronyd* to run without the capability to adjust or set the system
+clock (e.g. in some containers).
+
+*-v*::
+With this option *chronyd* will print version number to the terminal and exit.
+
+== FILES
+
+_@SYSCONFDIR@/chrony.conf_
+
+== SEE ALSO
+
+<<chronyc.adoc#,*chronyc(1)*>>, <<chrony.conf.adoc#,*chrony.conf(5)*>>
+
+== BUGS
+
+For instructions on how to report bugs, please visit
+https://chrony.tuxfamily.org/.
+
+== AUTHORS
+
+chrony was written by Richard Curnow, Miroslav Lichvar, and others.
--- a/doc/faq.adoc
+++ b/doc/faq.adoc
@@ -0,0 +1,444 @@
+// This file is part of chrony
+//
+// Copyright (C) Richard P. Curnow  1997-2003
+// Copyright (C) Miroslav Lichvar  2014-2016
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of version 2 of the GNU General Public License as
+// published by the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, write to the Free Software Foundation, Inc.,
+// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+= Frequently Asked Questions
+:toc:
+:numbered:
+
+== `chrony` compared to other programs
+
+=== How does `chrony` compare to `ntpd`?
+
+`chronyd` was designed to work well in a wide range of conditions and it can
+usually synchronise the system clock faster and with better time accuracy. It
+doesn't implement some of the less useful NTP modes like broadcast client or
+multicast server/client.
+
+If your computer is connected to the Internet only for few minutes at a time,
+the network connection is often congested, you turn your computer off or
+suspend it frequently, the clock is not very stable (e.g. there are rapid
+changes in the temperature or it's a virtual machine), or you want to use NTP
+on an isolated network with no hardware reference clocks in sight, `chrony`
+will probably work much better for you.
+
+For a more detailed comparison of features and performance, see the
+https://chrony.tuxfamily.org/comparison.html[comparison page] on the `chrony`
+website.
+
+== Configuration issues
+
+=== What is the minimum recommended configuration for an NTP client?
+
+First, the client needs to know which NTP servers it should ask for the current
+time. They are specified by the `server` or `pool` directive. The `pool`
+directive can be used for names that resolve to multiple addresses. For good
+reliability the client should have at least three servers. The `iburst` option
+speeds up the initial synchronisation.
+
+To stabilize the initial synchronisation on the next start, the estimated drift
+of the system clock is saved to a file specified by the `driftfile` directive.
+
+If the system clock can be far from the true time after boot for any reason,
+`chronyd` should be allowed to correct it quickly by stepping instead of
+slewing, which would take a very long time. The `makestep` directive does
+that.
+
+In order to keep the real-time clock (RTC) close to the true time, so the
+system time is reasonably close to the true time when it's initialized on the
+next boot from the RTC, the `rtcsync` directive enables a mode in which the
+system time is periodically copied to the RTC. It is supported on Linux and
+macOS.
+
+If you want to use public NTP servers from the
+http://www.pool.ntp.org/[pool.ntp.org] project, the minimal _chrony.conf_ file
+could be:
+
+----
+pool pool.ntp.org iburst
+driftfile /var/lib/chrony/drift
+makestep 1 3
+rtcsync
+----
+
+=== How do I make an NTP server from an NTP client?
+
+You need to add an `allow` directive to the _chrony.conf_ file in order to open
+the NTP port and allow `chronyd` to reply to client requests. `allow` with no
+specified subnet allows access from all IPv4 and IPv6 addresses.
+
+=== I have several computers on a LAN. Should be all clients of an external server?
+
+The best configuration is usually to make one computer the server, with
+the others as clients of it. Add a `local` directive to the server's
+_chrony.conf_ file. This configuration will be better because
+
+* the load on the external connection is less
+* the load on the external NTP server(s) is less
+* if your external connection goes down, the computers on the LAN
+  will maintain a common time with each other.
+
+=== Must I specify servers by IP address if DNS is not available on chronyd start?
+
+No. Starting from version 1.25, `chronyd` will keep trying to resolve
+the names specified by the `server`, `pool`, and `peer` directives in an
+increasing interval until it succeeds. The `online` command can be issued from
+`chronyc` to force `chronyd` to try to resolve the names immediately.
+
+=== How can I make `chronyd` more secure?
+
+If you don't need to serve time to NTP clients or peers, you can add `port 0`
+to the _chrony.conf_ file to completely disable the NTP server functionality
+and prevent NTP requests from reaching `chronyd`. Starting from version 2.0,
+the NTP server port is open only when client access is allowed by the `allow`
+directive or command, an NTP peer is configured, or the `broadcast` directive
+is used.
+
+If you don't need to use `chronyc` remotely, you can add the following
+directives to the configuration file to bind the command sockets to the
+loopback interface. This is done by default since version 2.0.
+
+----
+bindcmdaddress 127.0.0.1
+bindcmdaddress ::1
+----
+
+If you don't need to use `chronyc` at all or you need to run `chronyc` only
+under the root or _chrony_ user (which can access `chronyd` through a Unix
+domain socket since version 2.2), you can disable the internet command sockets
+completely by adding `cmdport 0` to the configuration file.
+
+You can specify an unprivileged user with the `-u` option, or the `user`
+directive in the _chrony.conf_ file, to which `chronyd` will switch after start
+in order to drop root privileges. The configure script has a `--with-user`
+option, which sets the default user. On Linux, `chronyd` needs to be compiled
+with support for the `libcap` library. On other systems, `chronyd` forks into
+two processes. The child process retains root privileges, but can only perform
+a very limited range of privileged system calls on behalf of the parent.
+
+Also, if `chronyd` is compiled with support for the Linux secure computing
+(seccomp) facility, you can enable a system call filter with the `-F` option.
+It will significantly reduce the kernel attack surface and possibly prevent
+kernel exploits from the `chronyd` process if it's compromised. It's
+recommended to enable the filter only when it's known to work on the version of
+the system where `chrony` is installed as the filter needs to allow also system
+calls made from libraries that `chronyd` is using (e.g. libc) and different
+versions or implementations of the libraries may make different system calls.
+If the filter is missing some system call, `chronyd` could be killed even in
+normal operation.
+
+=== How can I improve the accuracy of the system clock with NTP sources?
+
+Select NTP servers that are well synchronised, stable and close to your
+network. It's better to use more than one server, three or four is usually
+recommended as the minimum, so `chronyd` can detect servers that serve false
+time and combine measurements from multiple sources.
+
+If you have a network card with hardware timestamping supported on Linux, it
+can be enabled by the *hwtimestamp* directive in the _chrony.conf_ file. It
+should make local receive and transmit timestamps of NTP packets much more
+accurate.
+
+There are also useful options which can be set in the `server` directive, they
+are `minpoll`, `maxpoll`, `polltarget`, `maxdelay`, `maxdelayratio`,
+`maxdelaydevratio`, and `xleave`.
+
+The first three options set the minimum and maximum allowed polling interval,
+and how should be the actual interval adjusted in the specified range. Their
+default values are 6 (64 seconds) for `minpoll`, 10 (1024 seconds) for
+`maxpoll` and 8 (samples) for `polltarget`. The default values should be used
+for general servers on the Internet. With your own NTP servers, or if you have
+permission to poll some servers more frequently, setting these options for
+shorter polling intervals may significantly improve the accuracy of the system
+clock.
+
+The optimal polling interval depends mainly on two factors, stability of the
+network latency and stability of the system clock (which mainly depends on the
+temperature sensitivity of the crystal oscillator and the maximum rate of the
+temperature change).
+
+An example of the directive for an NTP server on the Internet that you are
+allowed to poll frequently could be
+
+----
+server foo.example.net minpoll 4 maxpoll 6 polltarget 16
+----
+
+An example using very short polling intervals for a server located in the same
+LAN could be
+
+----
+server ntp.local minpoll 2 maxpoll 4 polltarget 30
+----
+
+The maxdelay options are useful to ignore measurements with larger delay (e.g.
+due to congestion in the network) and improve the stability of the
+synchronisation. The `maxdelaydevratio` option could be added to the example
+with local NTP server
+
+----
+server ntp.local minpoll 2 maxpoll 4 polltarget 30 maxdelaydevratio 2
+----
+
+If your server supports the interleaved mode, the `xleave` option should be
+added to the `server` directive in order to allow the server to send the
+client more accurate hardware or kernel transmit timestamps. When combined with
+local hardware timestamping, sub-microsecond accuracy may be possible. An
+example could be
+
+----
+server ntp.local minpoll 2 maxpoll 2 xleave
+hwtimestamp eth0
+----
+
+=== Does `chronyd` have an ntpdate mode?
+
+Yes. With the `-q` option `chronyd` will set the system clock once and exit.
+With the `-Q` option it will print the measured offset without setting the
+clock. If you don't want to use a configuration file, NTP servers can be
+specified on the command line. For example:
+
+----
+# chronyd -q 'pool pool.ntp.org iburst'
+----
+
+=== What happened to the `commandkey` and `generatecommandkey` directives?
+
+They were removed in version 2.2. Authentication is no longer supported in the
+command protocol. Commands that required authentication are now allowed only
+through a Unix domain socket, which is accessible only by the root and _chrony_
+users. If you need to configure `chronyd` remotely or locally without the root
+password, please consider using ssh and/or sudo to run `chronyc` under the root
+or _chrony_ user on the host where `chronyd` is running.
+
+== Computer is not synchronising
+
+This is the most common problem. There are a number of reasons, see the
+following questions.
+
+=== Behind a firewall?
+
+Check the `Reach` value printed by the ``chronyc``'s `sources` command. If it's
+zero, it means `chronyd` did not get any valid responses from the NTP server
+you are trying to use. If there is a firewall between you and the server, the
+packets may be blocked. Try using a tool like `wireshark` or `tcpdump` to see
+if you're getting any responses from the server.
+
+When `chronyd` is receiving responses from the servers, the output of the
+`sources` command issued few minutes after `chronyd` start might look like
+this:
+
+----
+210 Number of sources = 3
+MS Name/IP address         Stratum Poll Reach LastRx Last sample
+===============================================================================
+^* foo.example.net               2   6   377    34   +484us[ -157us] +/-   30ms
+^- bar.example.net               2   6   377    34    +33ms[  +32ms] +/-   47ms
+^+ baz.example.net               3   6   377    35  -1397us[-2033us] +/-   60ms
+----
+
+=== Are NTP servers specified with the `offline` option?
+
+Check that you're using ``chronyc``'s `online` and `offline` commands
+appropriately. The `activity` command prints the number of sources that are
+currently online and offline. For example:
+
+----
+200 OK
+3 sources online
+0 sources offline
+0 sources doing burst (return to online)
+0 sources doing burst (return to offline)
+0 sources with unknown address
+----
+
+=== Is `chronyd` allowed to step the system clock?
+
+By default, `chronyd` adjusts the clock gradually by slowing it down or
+speeding it up. If the clock is too far from the true time, it will take
+a long time to correct the error. The `System time` value printed by the
+``chronyc``'s `tracking` command is the remaining correction that needs to be
+applied to the system clock.
+
+The `makestep` directive can be used to allow `chronyd` to step the clock. For
+example, if _chrony.conf_ had
+
+----
+makestep 1 3
+----
+
+the clock would be stepped in the first three updates if its offset was larger
+than one second. Normally, it's recommended to allow the step only in the first
+few updates, but in some cases (e.g. a computer without an RTC or virtual
+machine which can be suspended and resumed with an incorrect time) it may be
+necessary to allow the step on any clock update. The example above would change
+to
+
+----
+makestep 1 -1
+----
+
+== Issues with `chronyc`
+
+=== I keep getting the error `506 Cannot talk to daemon`
+
+When accessing `chronyd` remotely, make sure that the _chrony.conf_ file (on
+the computer where `chronyd` is running) has a `cmdallow` entry for the
+computer you are running `chronyc` on and an appropriate `bindcmdaddress`
+directive. This isn't necessary for localhost.
+
+Perhaps `chronyd` is not running. Try using the `ps` command (e.g. on Linux,
+`ps -auxw`) to see if it's running. Or try `netstat -a` and see if the ports
+123/udp and 323/udp are listening. If `chronyd` is not running, you may have a
+problem with the way you are trying to start it (e.g. at boot time).
+
+Perhaps you have a firewall set up in a way that blocks packets on port
+323/udp. You need to amend the firewall configuration in this case.
+
+=== I keep getting the error `501 Not authorised`
+
+Since version 2.2, the `password` command doesn't do anything and `chronyc`
+needs to run locally under the root or _chrony_ user, which are allowed to
+access the ``chronyd``'s Unix domain command socket.
+
+With older versions, you need to authenticate with the `password` command first
+or use the `-a` option to authenticate automatically on start. The
+configuration file needs to specify a file which contains keys (`keyfile`
+directive) and which key in the key file should be used for `chronyc`
+authentication (`commandkey` directive).
+
+=== Why does `chronyc tracking` always print an IPv4 address as reference ID?
+
+The reference ID is a 32-bit value and in versions before 3.0 it was printed in
+quad-dotted notation, even if the reference source did not actually have an
+IPv4 address. For IPv4 addresses, the reference ID is equal to the address, but
+for IPv6 addresses it is the first 32 bits of the MD5 sum of the address. For
+reference clocks, the reference ID is the value specified with the `refid`
+option in the `refclock` directive.
+
+Since version 3.0, the reference ID is printed as a hexadecimal number to avoid
+confusion with IPv4 addresses.
+
+If you need to get the IP address of the current reference source, use the `-n`
+option to disable resolving of IP addresses and read the second field (printed
+in parentheses) on the `Reference ID` line.
+
+=== Is the `chronyc` / `chronyd` protocol documented anywhere?
+
+Only by the source code. See _cmdmon.c_ (`chronyd` side) and _client.c_
+(`chronyc` side).
+
+== Real-time clock issues
+
+=== What is the real-time clock (RTC)?
+
+This is the clock which keeps the time even when your computer is turned off.
+It is used to initialize the system clock on boot. It normally doesn't drift
+more than few seconds per day.
+
+There are two approaches how `chronyd` can work with it. One is to use the
+`rtcsync` directive, which tells `chronyd` to enable a kernel mode which sets
+the RTC from the system clock every 11 minutes. `chronyd` itself won't touch
+the RTC. If the computer is not turned off for a long time, the RTC should
+still be close to the true time when the system clock will be initialized from
+it on the next boot.
+
+The other option is to use the `rtcfile` directive, which tells `chronyd` to
+monitor the rate at which the RTC gains or loses time. When `chronyd` is
+started with the `-s` option on the next boot, it will set the system time from
+the RTC and also compensate for the drift it has measured previously. The
+`rtcautotrim` directive can be used to keep the RTC close to the true time, but
+it's not strictly necessary if its only purpose is to set the system clock when
+`chronyd` is started on boot. See the documentation for details.
+
+=== I want to use ``chronyd``'s RTC support. Must I disable `hwclock`?
+
+The `hwclock` program is often set-up by default in the boot and shutdown
+scripts with many Linux installations. With the kernel RTC synchronisation
+(`rtcsync` directive), the RTC will be set also every 11 minutes as long as the
+system clock is synchronised. If you want to use ``chronyd``'s RTC monitoring
+(`rtcfile` directive), it's important to disable `hwclock` in the shutdown
+procedure. If you don't, it will over-write the RTC with a new value, unknown
+to `chronyd`. At the next reboot, `chronyd` started with the `-s` option will
+compensate this (wrong) time with its estimate of how far the RTC has drifted
+whilst the power was off, giving a meaningless initial system time.
+
+There is no need to remove `hwclock` from the boot process, as long as `chronyd`
+is started after it has run.
+
+=== I just keep getting the `513 RTC driver not running` message
+
+For the real-time clock support to work, you need the following three
+things
+
+* an RTC in your computer
+* a Linux kernel with enabled RTC support
+* an `rtcfile` directive in your _chrony.conf_ file
+
+=== I get `Could not open /dev/rtc, Device or resource busy` in my syslog file
+
+Some other program running on the system may be using the device.
+
+== NTP-specific issues
+
+=== Can `chronyd` be driven from broadcast NTP servers?
+
+No, the broadcast client mode is not supported and there is currently no plan
+to implement it. The broadcast and multicast modes are inherently less
+accurate and less secure (even with authentication) than the ordinary
+server/client mode and they are not as useful as they used to be. Even with
+very modest hardware a single NTP server can serve time to hundreds of
+thousands of clients using the ordinary mode.
+
+=== Can `chronyd` transmit broadcast NTP packets?
+
+Yes, the `broadcast` directive can be used to enable the broadcast server mode
+to serve time to clients in the network which support the broadcast client mode
+(it's not supported in `chronyd`, see the previous question).
+
+=== Can `chronyd` keep the system clock a fixed offset away from real time?
+
+Yes. Starting from version 3.0, an offset can be specified by the `offset`
+option for all time sources in the _chrony.conf_ file.
+
+=== What happens if the network connection is dropped without using ``chronyc``'s `offline` command first?
+
+`chronyd` will keep trying to access the sources that it thinks are online, and
+it will take longer before new measurements are actually made and the clock is
+corrected when the network is connected again. If the sources were set to
+offline, `chronyd` would make new measurements immediately after issuing the
+`online` command.
+
+Unless the network connection lasts only few minutes (less than the maximum
+polling interval), the delay is usually not a problem, and it may be acceptable
+to keep all sources online all the time.
+
+== Operating systems
+
+=== Does `chrony` support Windows?
+
+No. The `chronyc` program (the command-line client used for configuring
+`chronyd` while it is running) has been successfully built and run under
+Cygwin in the past. `chronyd` is not portable, because part of it is
+very system-dependent. It needs adapting to work with Windows'
+equivalent of the adjtimex() call, and it needs to be made to work as a
+service.
+
+=== Are there any plans to support Windows?
+
+We have no plans to do this. Anyone is welcome to pick this work up and
+contribute it back to the project.
--- a/doc/installation.adoc
+++ b/doc/installation.adoc
@@ -0,0 +1,189 @@
+// This file is part of chrony
+//
+// Copyright (C) Richard P. Curnow  1997-2003
+// Copyright (C) Miroslav Lichvar  2009-2016
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of version 2 of the GNU General Public License as
+// published by the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, write to the Free Software Foundation, Inc.,
+// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+= Installation
+
+The software is distributed as source code which has to be compiled. The source
+code is supplied in the form of a gzipped tar file, which unpacks to a
+subdirectory identifying the name and version of the program.
+
+After unpacking the source code, change directory into it, and type
+
+----
+./configure
+----
+
+This is a shell script that automatically determines the system type. There is
+a single optional parameter, `--prefix` which indicates the directory tree
+where the software should be installed. For example,
+
+----
+./configure --prefix=/opt/free
+----
+
+will install the `chronyd` daemon into `/opt/free/sbin` and the `chronyc`
+control program into `/opt/free/bin`. The default value for the prefix is
+`/usr/local`.
+
+The configure script assumes you want to use gcc as your compiler. If you want
+to use a different compiler, you can configure this way:
+
+----
+CC=cc CFLAGS=-O ./configure --prefix=/opt/free
+----
+
+for Bourne-family shells, or
+
+----
+setenv CC cc
+setenv CFLAGS -O
+./configure --prefix=/opt/free
+----
+
+for C-family shells.
+
+If the software cannot (yet) be built on your system, an error message will be
+shown. Otherwise, `Makefile` will be generated.
+
+On Linux, if development files for the libcap library are available, `chronyd`
+will be built with support for dropping root privileges. On other systems no
+extra library is needed. The default user which `chronyd` should run as can be
+specified with the `--with-user` option of the configure script.
+
+If development files for the editline or readline library are available,
+`chronyc` will be built with line editing support. If you don't want this,
+specify the `--disable-readline` flag to configure.
+
+If a `timepps.h` header is available (e.g. from the
+http://linuxpps.org[LinuxPPS project]), `chronyd` will be built with PPS API
+reference clock driver. If the header is installed in a location that isn't
+normally searched by the compiler, you can add it to the searched locations by
+setting the `CPPFLAGS` variable to `-I/path/to/timepps`.
+
+Now type
+
+----
+make
+----
+
+to build the programs.
+
+If you want to build the manual in HTML, type
+
+----
+make docs
+----
+
+Once the programs have been successfully compiled, they need to be installed in
+their target locations. This step normally needs to be performed by the
+superuser, and requires the following command to be entered.
+
+----
+make install
+----
+
+This will install the binaries and man pages.
+
+To install the HTML version of the manual, enter the command
+
+----
+make install-docs
+----
+
+Now that the software is successfully installed, the next step is to set up a
+configuration file. The default location of the file is _/etc/chrony.conf_.
+Several examples of configuration with comments are included in the examples
+directory. Suppose you want to use public NTP servers from the pool.ntp.org
+project as your time reference. A minimal useful configuration file could be
+
+----
+pool pool.ntp.org iburst
+makestep 1.0 3
+rtcsync
+----
+
+Then, `chronyd` can be run. For security reasons, it's recommended to create an
+unprivileged user for `chronyd` and specify it with the `-u` command-line
+option or the `user` directive in the configuration file, or set the default
+user with the `--with-user` configure option before building.
+
+== Support for line editing libraries
+
+`chronyc` can be built with support for line editing, this allows you to use
+the cursor keys to replay and edit old commands. Two libraries are supported
+which provide such functionality, editline and GNU readline.
+
+Please note that readline since version 6.0 is licensed under GPLv3+ which is
+incompatible with chrony's license GPLv2. You should use editline instead if
+you don't want to use older readline versions.
+
+The configure script will automatically enable the line editing support if one
+of the supported libraries is available. If they are both available, the
+editline library will be used.
+
+If you don't want to use it (in which case chronyc will use a minimal command
+line interface), invoke configure like this:
+
+----
+./configure --disable-readline other-options...
+----
+
+If you have editline, readline or ncurses installed in locations that aren't
+normally searched by the compiler and linker, you need to use extra options:
+
+`--with-readline-includes=directory_name`::
+  This defines the name of the directory above the one where `readline.h` is.
+  `readline.h` is assumed to be in `editline` or `readline` subdirectory of the
+  named directory.
+
+`--with-readline-library=directory_name`::
+  This defines the directory containing the `libedit.a` or `libedit.so` file,
+  or `libreadline.a` or `libreadline.so` file.
+
+`--with-ncurses-library=directory_name`::
+  This defines the directory containing the `libncurses.a` or `libncurses.so`
+  file.
+
+== Extra options for package builders
+
+The configure and make procedures have some extra options that may be useful if
+you are building a distribution package for chrony.
+
+The `--mandir=DIR` option to configure specifies an install directory for the
+man pages. This overrides the `man` subdirectory of the argument to the
+--prefix option.
+
+----
+./configure --prefix=/usr --mandir=/usr/share/man
+----
+
+to set both options together.
+
+The final option is the `DESTDIR` option to the make command. For example, you
+could use the commands
+
+----
+./configure --prefix=/usr --mandir=/usr/share/man
+make all docs
+make install DESTDIR=./tmp
+cd tmp
+tar cvf - . | gzip -9 > chrony.tar.gz
+----
+
+to build a package. When untarred within the root directory, this will install
+the files to the intended final locations.
--- a/examples/chrony-wait.service
+++ b/examples/chrony-wait.service
@@ -1,5 +1,6 @@
 [Unit]
 Description=Wait for chrony to synchronize system clock
+Documentation=man:chronyc(1)
 After=chronyd.service
 Requires=chronyd.service
 Before=time-sync.target
@@ -9,7 +10,7 @@ Wants=time-sync.target
 Type=oneshot
 # Wait up to ~10 minutes for chronyd to synchronize and the remaining
 # clock correction to be less than 0.1 seconds
-ExecStart=/usr/bin/chronyc waitsync 60 0.1
+ExecStart=/usr/bin/chronyc -h 127.0.0.1,::1 waitsync 600 0.1 0.0 1
 RemainAfterExit=yes
 StandardOutput=null

--- a/examples/chrony.conf.example1
+++ b/examples/chrony.conf.example1
@@ -4,9 +4,9 @@ pool pool.ntp.org iburst
 # Record the rate at which the system clock gains/losses time.
 driftfile /var/lib/chrony/drift

-# In first three updates step the system clock instead of slew
-# if the adjustment is larger than 10 seconds.
-makestep 10 3
+# Allow the system clock to be stepped in the first three updates
+# if its offset is larger than 1 second.
+makestep 1.0 3

 # Enable kernel synchronization of the real-time clock (RTC).
 rtcsync
--- a/examples/chrony.conf.example2
+++ b/examples/chrony.conf.example2
@@ -5,33 +5,28 @@ pool pool.ntp.org iburst
 # Record the rate at which the system clock gains/losses time.
 driftfile /var/lib/chrony/drift

-# In first three updates step the system clock instead of slew
-# if the adjustment is larger than 10 seconds.
-makestep 10 3
+# Allow the system clock to be stepped in the first three updates
+# if its offset is larger than 1 second.
+makestep 1.0 3

 # Enable kernel synchronization of the real-time clock (RTC).
 rtcsync

-# Allow NTP client access from local network.
-#allow 192.168/16
+# Enable hardware timestamping on all interfaces that support it.
+#hwtimestamp *

-# Serve time even if not synchronized to any NTP server.
+# Increase the minimum number of selectable sources required to adjust
+# the system clock.
+#minsources 2
+
+# Allow NTP client access from local network.
+#allow 192.168.0.0/16
+
+# Serve time even if not synchronized to a time source.
 #local stratum 10

-# Specify file containing keys for NTP and command authentication.
-keyfile /etc/chrony.keys
-
-# Specify key number for command authentication.
-commandkey 1
-
-# Generate new command key on start if missing.
-generatecommandkey
-
-# Disable logging of client accesses.
-noclientlog
-
-# Send message to syslog when clock adjustment is larger than 0.5 seconds.
-logchange 0.5
+# Specify file containing keys for NTP authentication.
+#keyfile /etc/chrony.keys

 # Specify directory for log files.
 logdir /var/log/chrony
--- a/examples/chrony.conf.example3
+++ b/examples/chrony.conf.example3
@@ -5,22 +5,6 @@
 # want to enable.  The more obscure options are not included.  Refer
 # to the documentation for these.
 #
-# Copyright 2002 Richard P. Curnow
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of version 2 of the GNU General Public License as
-# published by the Free Software Foundation.
-# 
-# This program is distributed in the hope that it will be useful, but
-# WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-# General Public License for more details.
-# 
-# You should have received a copy of the GNU General Public License along
-# with this program; if not, write to the Free Software Foundation, Inc.,
-# 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
-# 
-#
 #######################################################################
 ### COMMENTS
 # Any of the following lines are comments (you have a choice of
@@ -49,42 +33,30 @@

 ! pool pool.ntp.org iburst
 
-# However, for dial-up use you probably want these instead.  The word
-# 'offline' means that the server is not visible at boot time.  Use
-# chronyc's 'online' command to tell chronyd that these servers have
-# become visible after you go on-line.
-
-! server foo.example.net offline
-! server bar.example.net offline
-! server baz.example.net offline
-
-! pool pool.ntp.org offline
-
-# You may want to specify NTP 'peers' instead.  If you run a network
-# with a lot of computers and want several computers running chrony to
-# have the 'front-line' interface to the public NTP servers, you can
-# 'peer' these machines together to increase robustness.
-
-! peer foo.example.net
-
-# There are other options to the 'server' and 'peer' directives that you
-# might want to use.  For example, you can ignore measurements whose
-# round-trip-time is too large (indicating that the measurement is
-# probably useless, because you don't know which way the measurement
-# message got held up.)  Consult the full documentation for details.
-
 #######################################################################
 ### AVOIDING POTENTIALLY BOGUS CHANGES TO YOUR CLOCK
 #
 # To avoid changes being made to your computer's gain/loss compensation
 # when the measurement history is too erratic, you might want to enable
-# one of the following lines.  The first seems good for dial-up (or
-# other high-latency connections like slow leased lines), the second
-# seems OK for a LAN environment.
+# one of the following lines.  The first seems good with servers on the
+# Internet, the second seems OK for a LAN environment.

 ! maxupdateskew 100
 ! maxupdateskew 5

+# If you want to increase the minimum number of selectable sources
+# required to update the system clock in order to make the
+# synchronisation more reliable, uncomment (and edit) the following
+# line.
+
+! minsources 2
+
+# If your computer has a good stable clock (e.g. it is not a virtual
+# machine), you might also want to reduce the maximum assumed drift
+# (frequency error) of the clock (the value is specified in ppm).
+
+! maxdrift 100
+
 #######################################################################
 ### FILENAMES ETC
 # Chrony likes to keep information about your computer's clock in files.
@@ -95,24 +67,10 @@

 driftfile /var/lib/chrony/drift

-# If you want to use the program called chronyc to configure aspects of
-# chronyd's operation once it is running (e.g. tell it the Internet link
-# has gone up or down), you need a password.  This is stored in the
-# following keys file.  (You also need keys to support authenticated NTP
-# exchanges between cooperating machines.)  Again, this option is
-# assumed by default.
+# If you want to enable NTP authentication with symmetric keys, you will need
+# to uncomment the following line and edit the file to set up the keys.

-keyfile /etc/chrony.keys
-
-# Tell chronyd which numbered key in the file is used as the password
-# for chronyc. (You can pick any integer up to 2**32-1.  '1' is just a
-# default.  Using another value will _NOT_ increase security.)
-
-commandkey 1
-
-# With this directive a random password will be generated automatically.
-
-generatecommandkey
+! keyfile /etc/chrony.keys

 # chronyd can save the measurement history for the servers to files when
 # it it exits.  This is useful in 2 situations:
@@ -142,15 +100,15 @@ generatecommandkey
 #######################################################################
 ### INITIAL CLOCK CORRECTION
 # This option is useful to quickly correct the clock on start if it's
-# off by a large amount.  The value '10' means that if the error is less
-# than 10 seconds, it will be gradually removed by speeding up or
-# slowing down your computer's clock until it is correct.  If the error
-# is above 10 seconds, an immediate time jump will be applied to correct
-# it.  The value '1' means the step is allowed only on the first update
-# of the clock.  Some software can get upset if the system clock jumps
+# off by a large amount.  The value '1.0' means that if the error is less
+# than 1 second, it will be gradually removed by speeding up or slowing
+# down your computer's clock until it is correct.  If the error is above
+# 1 second, an immediate time jump will be applied to correct it.  The
+# value '3' means the step is allowed only in the first three updates of
+# the clock.  Some software can get upset if the system clock jumps
 # (especially backwards), so be careful!

-! makestep 10 1
+! makestep 1.0 3

 #######################################################################
 ### LOGGING
@@ -211,16 +169,22 @@ generatecommandkey
 # machine accesses it.  The information can be accessed by the 'clients'
 # command of chronyc.  You can disable this facility by uncommenting the
 # following line.  This will save a bit of memory if you have many
-# clients.
+# clients and it will also disable support for the interleaved mode.

 ! noclientlog

 # The clientlog size is limited to 512KB by default.  If you have many
-# clients, especially in many different subnets, you might want to
-# increase the limit. 
+# clients, you might want to increase the limit.

 ! clientloglimit 4194304

+# By default, chronyd tries to respond to all valid NTP requests from
+# allowed addresses.  If you want to limit the response rate for NTP
+# clients that are sending requests too frequently, uncomment and edit
+# the following line.
+
+! ratelimit interval 3 burst 8
+
 #######################################################################
 ### REPORTING BIG CLOCK CHANGES
 # Perhaps you want to know if chronyd suddenly detects any large error
@@ -247,6 +211,7 @@ generatecommandkey

 # By default chronyd binds to the loopback interface.  Uncomment the
 # following lines to allow receiving command packets from remote hosts.
+
 ! bindcmdaddress 0.0.0.0
 ! bindcmdaddress ::

@@ -262,10 +227,20 @@ generatecommandkey
 # syntax and meaning is the same as for 'allow' and 'deny', except that
 # 'cmdallow' and 'cmddeny' control access to the chronyd's command port.

-# NOTE, even if the host where you run chronyc is granted access, you
-# still need a command key set up and you have to know the password to
-# put into chronyc to allow you to modify chronyd's parameters.  By
-# default all you can do is view information about chronyd's operation.
+# Rate limiting can be enabled also for command packets.  (Note,
+# commands from localhost are never limited.)
+
+! cmdratelimit interval -4 burst 16
+
+#######################################################################
+### HARDWARE TIMESTAMPING
+# On Linux, if the network interface controller and its driver support
+# hardware timestamping, it can significantly improve the accuracy of
+# synchronisation. It can be enabled on specified interfaces only, or it
+# can be enabled on all interfaces that support it.
+
+! hwtimestamp eth0
+! hwtimestamp *

 #######################################################################
 ### REAL TIME CLOCK
@@ -296,6 +271,12 @@ generatecommandkey

 ! rtcdevice /dev/misc/rtc

+# Alternatively, if not using the -s option, this directive can be used
+# to enable a mode in which the RTC is periodically set to the system
+# time, with no tracking of its drift.
+
+! rtcsync
+
 #######################################################################
 ### REAL TIME SCHEDULER
 # This directive tells chronyd to use the real-time FIFO scheduler with the
--- a/examples/chrony.keys.example
+++ b/examples/chrony.keys.example
@@ -1,29 +1,12 @@
-#######################################################################
+# This is an example chrony keys file.  It is used for NTP authentication with
+# symmetric keys.  It should be readable only by root or the user to which
+# chronyd is configured to switch to after start.
 #
-# This is an example chrony keys file.  You should copy it to /etc/chrony.keys
-# after editing it to set up the key(s) you want to use.  It should be readable
-# only by root or the user chronyd drops the root privileges to.  In most
-# situations, you will require a single key (the 'commandkey') so that you can
-# supply a password to chronyc to enable you to modify chronyd's operation
-# whilst it is running.
-#
-# Copyright 2002 Richard P. Curnow
-#
-######################################################################
+# Don't use the example keys!  It's recommended to generate random keys using
+# the chronyc keygen command.

 # Examples of valid keys:

-#1 ALongAndRandomPassword
-#2 MD5 HEX:B028F91EA5C38D06C2E140B26C7F41EC
-#3 SHA1 HEX:1DC764E0791B11FA67EFC7ECBC4B0D73F68A070C
-
-# The keys should be random for maximum security.  If you wanted to use a key
-# with ID 1 as your commandkey (i.e. chronyc password) you would put
-# "commandkey 1" into chrony.conf.  If no commandkey is present in the keys
-# file and the generatecommandkey directive is specified in chrony.conf,
-# a random commandkey will be generated and added to the keys file
-# automatically on chronyd start.
-
-# You might want to define more keys if you use the authentication facility
-# in the network time protocol to authenticate request/response packets between
-# trusted clients and servers.
+#1 MD5 AVeryLongAndRandomPassword
+#2 MD5 HEX:12114855C7931009B4049EF3EFC48A139C3F989F
+#3 SHA1 HEX:B2159C05D6A219673A3B7E896B6DE07F6A440995
--- a/examples/chrony.logrotate
+++ b/examples/chrony.logrotate
@@ -3,6 +3,6 @@
    nocreate
    sharedscripts
    postrotate
-        /usr/bin/chronyc -a cyclelogs > /dev/null 2>&1 || true
+        /usr/bin/chronyc cyclelogs > /dev/null 2>&1 || true
    endscript
 }
--- a/examples/chrony.nm-dispatcher
+++ b/examples/chrony.nm-dispatcher
@@ -6,12 +6,12 @@ export LC_ALL=C

 if [ "$2" = "up" ]; then
 	/sbin/ip route list dev "$1" | grep -q '^default' &&
-		/usr/bin/chronyc -a online > /dev/null 2>&1
+		/usr/bin/chronyc online > /dev/null 2>&1
 fi

 if [ "$2" = "down" ]; then
 	/sbin/ip route list | grep -q '^default' ||
-		/usr/bin/chronyc -a offline > /dev/null 2>&1
+		/usr/bin/chronyc offline > /dev/null 2>&1
 fi

 exit 0
--- a/examples/chrony.spec
+++ b/examples/chrony.spec
@@ -10,7 +10,6 @@ Source: chrony-%{version}%{?prerelease:-%{prerelease}}.tar.gz
 License: GPLv2
 Group: Applications/Utilities
 BuildRoot: %{_tmppath}/%{name}-%{version}-root-%(id -u -n)
-Requires: info

 %description
 chrony is a client and server for the Network Time Protocol (NTP).
@@ -28,30 +27,20 @@ manual input as time references.
 	--prefix=%{_prefix} \
 	--bindir=%{_bindir} \
 	--sbindir=%{_sbindir} \
-	--infodir=%{_infodir} \
 	--mandir=%{_mandir}
 make
-make chrony.txt
-make chrony.info

 %install
 rm -rf $RPM_BUILD_ROOT
 make install DESTDIR=$RPM_BUILD_ROOT
-rm -rf $RPM_BUILD_ROOT%{_docdir}
-mkdir -p $RPM_BUILD_ROOT%{_infodir}
-cp chrony.info* $RPM_BUILD_ROOT%{_infodir}

 %files
 %{_sbindir}/chronyd
 %{_bindir}/chronyc
-%{_infodir}/chrony.info*
-%{_mandir}/man1/chrony.1.gz
 %{_mandir}/man1/chronyc.1.gz
 %{_mandir}/man5/chrony.conf.5.gz
 %{_mandir}/man8/chronyd.8.gz
-%doc README
-%doc chrony.txt
-%doc COPYING
+%doc README FAQ NEWS COPYING
 %doc examples/chrony.conf.example*
 %doc examples/chrony.keys.example

--- a/examples/chronyd.service
+++ b/examples/chronyd.service
@@ -1,13 +1,18 @@
 [Unit]
 Description=NTP client/server
+Documentation=man:chronyd(8) man:chrony.conf(5)
 After=ntpdate.service sntp.service ntpd.service
 Conflicts=ntpd.service systemd-timesyncd.service
+ConditionCapability=CAP_SYS_TIME

 [Service]
 Type=forking
 PIDFile=/var/run/chronyd.pid
 EnvironmentFile=-/etc/sysconfig/chronyd
 ExecStart=/usr/sbin/chronyd $OPTIONS
+PrivateTmp=yes
+ProtectHome=yes
+ProtectSystem=full

 [Install]
 WantedBy=multi-user.target
--- a/getdate.c
+++ b/getdate.c
--- a/getdate.y
+++ b/getdate.y
@@ -8,12 +8,7 @@
 **  This code is in the public domain and has no copyright.
 */

-#ifdef HAVE_CONFIG_H
-# include <config.h>
-# ifdef HAVE_ALLOCA_H
-#  include <alloca.h>
-# endif
-#endif
+#include "config.h"

 /* Since the code of getdate.y is not included in the Emacs executable
   itself, there is no need to #define static in this file.  Even if
--- a/hash_nss.c
+++ b/hash_nss.c
@@ -25,11 +25,12 @@

  */

+#include "config.h"
+
 #include <nss.h>
 #include <hasht.h>
 #include <nsslowhash.h>

-/* #include "config.h" */
 #include "hash.h"

 static NSSLOWInitContext *ictx;
--- a/hwclock.c
+++ b/hwclock.c
@@ -0,0 +1,209 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Tracking of hardware clocks (e.g. RTC, PHC)
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "array.h"
+#include "hwclock.h"
+#include "local.h"
+#include "logging.h"
+#include "memory.h"
+#include "regress.h"
+#include "util.h"
+
+/* Maximum number of samples per clock */
+#define MAX_SAMPLES 16
+
+struct HCL_Instance_Record {
+  /* HW and local reference timestamp */
+  struct timespec hw_ref;
+  struct timespec local_ref;
+
+  /* Samples stored as intervals (uncorrected for frequency error)
+     relative to local_ref and hw_ref */
+  double x_data[MAX_SAMPLES];
+  double y_data[MAX_SAMPLES];
+
+  /* Number of samples */
+  int n_samples;
+
+  /* Maximum error of the last sample */
+  double last_err;
+
+  /* Minimum interval between samples */
+  double min_separation;
+
+  /* Flag indicating the offset and frequency values are valid */
+  int valid_coefs;
+
+  /* Estimated offset and frequency of HW clock relative to local clock */
+  double offset;
+  double frequency;
+};
+
+/* ================================================== */
+
+static void
+handle_slew(struct timespec *raw, struct timespec *cooked, double dfreq,
+            double doffset, LCL_ChangeType change_type, void *anything)
+{
+  HCL_Instance clock;
+  double delta;
+
+  clock = anything;
+
+  if (clock->n_samples)
+    UTI_AdjustTimespec(&clock->local_ref, cooked, &clock->local_ref, &delta, dfreq, doffset);
+  if (clock->valid_coefs)
+    clock->frequency /= 1.0 - dfreq;
+}
+
+/* ================================================== */
+
+HCL_Instance
+HCL_CreateInstance(double min_separation)
+{
+  HCL_Instance clock;
+
+  clock = MallocNew(struct HCL_Instance_Record);
+  clock->x_data[MAX_SAMPLES - 1] = 0.0;
+  clock->y_data[MAX_SAMPLES - 1] = 0.0;
+  clock->n_samples = 0;
+  clock->valid_coefs = 0;
+  clock->min_separation = min_separation;
+
+  LCL_AddParameterChangeHandler(handle_slew, clock);
+
+  return clock;
+}
+
+/* ================================================== */
+
+void HCL_DestroyInstance(HCL_Instance clock)
+{
+  LCL_RemoveParameterChangeHandler(handle_slew, clock);
+  Free(clock);
+}
+
+/* ================================================== */
+
+int
+HCL_NeedsNewSample(HCL_Instance clock, struct timespec *now)
+{
+  if (!clock->n_samples ||
+      fabs(UTI_DiffTimespecsToDouble(now, &clock->local_ref)) >= clock->min_separation)
+    return 1;
+
+  return 0;
+}
+
+/* ================================================== */
+
+void
+HCL_AccumulateSample(HCL_Instance clock, struct timespec *hw_ts,
+                     struct timespec *local_ts, double err)
+{
+  double hw_delta, local_delta, local_freq, raw_freq;
+  int i, n_runs, best_start;
+
+  local_freq = 1.0 - LCL_ReadAbsoluteFrequency() / 1.0e6;
+
+  /* Shift old samples */
+  if (clock->n_samples) {
+    if (clock->n_samples >= MAX_SAMPLES)
+      clock->n_samples--;
+
+    hw_delta = UTI_DiffTimespecsToDouble(hw_ts, &clock->hw_ref);
+    local_delta = UTI_DiffTimespecsToDouble(local_ts, &clock->local_ref) / local_freq;
+
+    if (hw_delta <= 0.0 || local_delta < clock->min_separation / 2.0) {
+      clock->n_samples = 0;
+      DEBUG_LOG("HW clock reset interval=%f", local_delta);
+    }
+
+    for (i = MAX_SAMPLES - clock->n_samples; i < MAX_SAMPLES; i++) {
+      clock->y_data[i - 1] = clock->y_data[i] - hw_delta;
+      clock->x_data[i - 1] = clock->x_data[i] - local_delta;
+    }
+  }
+
+  clock->n_samples++;
+  clock->hw_ref = *hw_ts;
+  clock->local_ref = *local_ts;
+  clock->last_err = err;
+
+  /* Get new coefficients */
+  clock->valid_coefs =
+    RGR_FindBestRobustRegression(clock->x_data + MAX_SAMPLES - clock->n_samples,
+                                 clock->y_data + MAX_SAMPLES - clock->n_samples,
+                                 clock->n_samples, 1.0e-10, &clock->offset, &raw_freq,
+                                 &n_runs, &best_start);
+
+  if (!clock->valid_coefs) {
+    DEBUG_LOG("HW clock needs more samples");
+    return;
+  }
+
+  clock->frequency = raw_freq / local_freq;
+
+  /* Drop unneeded samples */
+  clock->n_samples -= best_start;
+
+  /* If the fit doesn't cross the error interval of the last sample, throw away
+     all previous samples and keep only the frequency estimate */
+  if (fabs(clock->offset) > err) {
+    DEBUG_LOG("HW clock reset offset=%e", clock->offset);
+    clock->offset = 0.0;
+    clock->n_samples = 1;
+  }
+
+  DEBUG_LOG("HW clock samples=%d offset=%e freq=%.9e raw_freq=%.9e err=%e ref_diff=%e",
+            clock->n_samples, clock->offset, clock->frequency, raw_freq, err,
+            UTI_DiffTimespecsToDouble(&clock->hw_ref, &clock->local_ref));
+}
+
+/* ================================================== */
+
+int
+HCL_CookTime(HCL_Instance clock, struct timespec *raw, struct timespec *cooked, double *err)
+{
+  double offset, elapsed;
+
+  if (!clock->valid_coefs)
+    return 0;
+
+  elapsed = UTI_DiffTimespecsToDouble(raw, &clock->hw_ref);
+  offset = clock->offset + elapsed / clock->frequency;
+  UTI_AddDoubleToTimespec(&clock->local_ref, offset, cooked);
+
+  /* Fow now, just return the error of the last sample */
+  if (err)
+    *err = clock->last_err;
+
+  return 1;
+}
--- a/hwclock.h
+++ b/hwclock.h
@@ -0,0 +1,48 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Header for tracking of hardware clocks */
+
+#ifndef GOT_HWCLOCK_H
+#define GOT_HWCLOCK_H
+
+typedef struct HCL_Instance_Record *HCL_Instance;
+
+/* Create a new HW clock instance */
+extern HCL_Instance HCL_CreateInstance(double min_separation);
+
+/* Destroy a HW clock instance */
+extern void HCL_DestroyInstance(HCL_Instance clock);
+
+/* Check if a new sample should be accumulated at this time */
+extern int HCL_NeedsNewSample(HCL_Instance clock, struct timespec *now);
+
+/* Accumulate a new sample */
+extern void HCL_AccumulateSample(HCL_Instance clock, struct timespec *hw_ts,
+                                 struct timespec *local_ts, double err);
+
+/* Convert raw hardware time to cooked local time */
+extern int HCL_CookTime(HCL_Instance clock, struct timespec *raw, struct timespec *cooked,
+                        double *err);
+
+#endif
--- a/keys.c
+++ b/keys.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2012-2014
+ * Copyright (C) Miroslav Lichvar  2012-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -39,6 +39,8 @@
 #include "local.h"
 #include "logging.h"

+/* Consider 80 bits as the absolute minimum for a secure key */
+#define MIN_SECURE_KEY_LENGTH 10

 typedef struct {
  uint32_t id;
@@ -50,72 +52,12 @@ typedef struct {

 static ARR_Instance keys;

-static int command_key_valid;
-static uint32_t command_key_id;
 static int cache_valid;
 static uint32_t cache_key_id;
 static int cache_key_pos;

 /* ================================================== */

-static int
-generate_key(uint32_t key_id)
-{
-#ifdef FEAT_SECHASH
-  unsigned char key[20];
-  const char *hashname = "SHA1";
-#else
-  unsigned char key[16];
-  const char *hashname = "MD5";
-#endif
-  const char *key_file, *rand_dev = "/dev/urandom";
-  FILE *f;
-  struct stat st;
-  int i;
-
-  key_file = CNF_GetKeysFile();
-
-  if (!key_file)
-    return 0;
-
-  f = fopen(rand_dev, "r");
-  if (!f || fread(key, sizeof (key), 1, f) != 1) {
-    if (f)
-      fclose(f);
-    LOG_FATAL(LOGF_Keys, "Could not read %s", rand_dev);
-    return 0;
-  }
-  fclose(f);
-
-  f = fopen(key_file, "a");
-  if (!f) {
-    LOG_FATAL(LOGF_Keys, "Could not open keyfile %s for writing", key_file);
-    return 0;
-  }
-
-  /* Make sure the keyfile is not world-readable */
-  if (stat(key_file, &st) || chmod(key_file, st.st_mode & 0770)) {
-    fclose(f);
-    LOG_FATAL(LOGF_Keys, "Could not change permissions of keyfile %s", key_file);
-    return 0;
-  }
-
-  fprintf(f, "\n%"PRIu32" %s HEX:", key_id, hashname);
-  for (i = 0; i < sizeof (key); i++)
-    fprintf(f, "%02hhX", key[i]);
-  fprintf(f, "\n");
-  fclose(f);
-
-  /* Erase the key from stack */
-  memset(key, 0, sizeof (key));
-
-  LOG(LOGS_INFO, LOGF_Keys, "Generated key %"PRIu32, key_id);
-
-  return 1;
-}
-
-/* ================================================== */
-
 static void
 free_keys(void)
 {
@@ -125,7 +67,6 @@ free_keys(void)
    Free(((Key *)ARR_GetElement(keys, i))->val);

  ARR_SetSize(keys, 0);
-  command_key_valid = 0;
  cache_valid = 0;
 }

@@ -135,14 +76,8 @@ void
 KEY_Initialise(void)
 {
  keys = ARR_CreateInstance(sizeof (Key));
-  command_key_valid = 0;
  cache_valid = 0;
  KEY_Reload();
-
-  if (CNF_GetGenerateCommandKey() && !KEY_KeyKnown(KEY_GetCommandKey())) {
-    if (generate_key(KEY_GetCommandKey()))
-      KEY_Reload();
-  }
 }

 /* ================================================== */
@@ -168,9 +103,9 @@ static int
 determine_hash_delay(uint32_t key_id)
 {
  NTP_Packet pkt;
-  struct timeval before, after;
-  unsigned long usecs, min_usecs=0;
-  int i;
+  struct timespec before, after;
+  double diff, min_diff;
+  int i, nsecs;

  for (i = 0; i < 10; i++) {
    LCL_ReadRawTime(&before);
@@ -178,19 +113,49 @@ determine_hash_delay(uint32_t key_id)
        (unsigned char *)&pkt.auth_data, sizeof (pkt.auth_data));
    LCL_ReadRawTime(&after);

-    usecs = (after.tv_sec - before.tv_sec) * 1000000 + (after.tv_usec - before.tv_usec);
+    diff = UTI_DiffTimespecsToDouble(&after, &before);

-    if (i == 0 || usecs < min_usecs) {
-      min_usecs = usecs;
-    }
+    if (i == 0 || min_diff > diff)
+      min_diff = diff;
  }

  /* Add on a bit extra to allow for copying, conversions etc */
-  min_usecs += min_usecs >> 4;
+  nsecs = 1.0625e9 * min_diff;

-  DEBUG_LOG(LOGF_Keys, "authentication delay for key %"PRIu32": %ld useconds", key_id, min_usecs);
+  DEBUG_LOG("authentication delay for key %"PRIu32": %d nsecs", key_id, nsecs);

-  return min_usecs;
+  return nsecs;
+}
+
+/* ================================================== */
+/* Decode password encoded in ASCII or HEX */
+
+static int
+decode_password(char *key)
+{
+  int i, j, len = strlen(key);
+  char buf[3], *p;
+
+  if (!strncmp(key, "ASCII:", 6)) {
+    memmove(key, key + 6, len - 6);
+    return len - 6;
+  } else if (!strncmp(key, "HEX:", 4)) {
+    if ((len - 4) % 2)
+      return 0;
+
+    for (i = 0, j = 4; j + 1 < len; i++, j += 2) {
+      buf[0] = key[j], buf[1] = key[j + 1], buf[2] = '\0';
+      key[i] = strtol(buf, &p, 16);
+
+      if (p != buf + 2)
+        return 0;
+    }
+
+    return i;
+  } else {
+    /* assume ASCII */
+    return len;
+  }
 }

 /* ================================================== */
@@ -235,7 +200,7 @@ KEY_Reload(void)

  in = fopen(key_file, "r");
  if (!in) {
-    LOG(LOGS_WARN, LOGF_Keys, "Could not open keyfile %s", key_file);
+    LOG(LOGS_WARN, "Could not open keyfile %s", key_file);
    return;
  }

@@ -247,19 +212,19 @@ KEY_Reload(void)
      continue;

    if (!CPS_ParseKey(line, &key_id, &hashname, &keyval)) {
-      LOG(LOGS_WARN, LOGF_Keys, "Could not parse key at line %d in file %s", line_number, key_file);
+      LOG(LOGS_WARN, "Could not parse key at line %d in file %s", line_number, key_file);
      continue;
    }

    key.hash_id = HSH_GetHashId(hashname);
    if (key.hash_id < 0) {
-      LOG(LOGS_WARN, LOGF_Keys, "Unknown hash function in key %"PRIu32, key_id);
+      LOG(LOGS_WARN, "Unknown hash function in key %"PRIu32, key_id);
      continue;
    }

-    key.len = UTI_DecodePasswordFromText(keyval);
+    key.len = decode_password(keyval);
    if (!key.len) {
-      LOG(LOGS_WARN, LOGF_Keys, "Could not decode password in key %"PRIu32, key_id);
+      LOG(LOGS_WARN, "Could not decode password in key %"PRIu32, key_id);
      continue;
    }

@@ -279,7 +244,7 @@ KEY_Reload(void)
  /* Check for duplicates */
  for (i = 1; i < ARR_GetSize(keys); i++) {
    if (get_key(i - 1)->id == get_key(i)->id)
-      LOG(LOGS_WARN, LOGF_Keys, "Detected duplicate key %"PRIu32, get_key(i - 1)->id);
+      LOG(LOGS_WARN, "Detected duplicate key %"PRIu32, get_key(i - 1)->id);
  }

  /* Erase any passwords from stack */
@@ -334,18 +299,6 @@ get_key_by_id(uint32_t key_id)

 /* ================================================== */

-uint32_t
-KEY_GetCommandKey(void)
-{
-  if (!command_key_valid) {
-    command_key_id = CNF_GetCommandKey();
-  }
-
-  return command_key_id;
-}
-
-/* ================================================== */
-
 int
 KEY_KeyKnown(uint32_t key_id)
 {
@@ -369,6 +322,62 @@ KEY_GetAuthDelay(uint32_t key_id)

 /* ================================================== */

+int
+KEY_GetAuthLength(uint32_t key_id)
+{
+  unsigned char buf[MAX_HASH_LENGTH];
+  Key *key;
+
+  key = get_key_by_id(key_id);
+
+  if (!key)
+    return 0;
+
+  return HSH_Hash(key->hash_id, buf, 0, buf, 0, buf, sizeof (buf));
+}
+
+/* ================================================== */
+
+int
+KEY_CheckKeyLength(uint32_t key_id)
+{
+  Key *key;
+
+  key = get_key_by_id(key_id);
+
+  if (!key)
+    return 0;
+
+  return key->len >= MIN_SECURE_KEY_LENGTH;
+}
+
+/* ================================================== */
+
+static int
+generate_ntp_auth(int hash_id, const unsigned char *key, int key_len,
+                  const unsigned char *data, int data_len,
+                  unsigned char *auth, int auth_len)
+{
+  return HSH_Hash(hash_id, key, key_len, data, data_len, auth, auth_len);
+}
+
+/* ================================================== */
+
+static int
+check_ntp_auth(int hash_id, const unsigned char *key, int key_len,
+               const unsigned char *data, int data_len,
+               const unsigned char *auth, int auth_len, int trunc_len)
+{
+  unsigned char buf[MAX_HASH_LENGTH];
+  int hash_len;
+
+  hash_len = generate_ntp_auth(hash_id, key, key_len, data, data_len, buf, sizeof (buf));
+
+  return MIN(hash_len, trunc_len) == auth_len && !memcmp(buf, auth, auth_len);
+}
+
+/* ================================================== */
+
 int
 KEY_GenerateAuth(uint32_t key_id, const unsigned char *data, int data_len,
    unsigned char *auth, int auth_len)
@@ -380,15 +389,15 @@ KEY_GenerateAuth(uint32_t key_id, const unsigned char *data, int data_len,
  if (!key)
    return 0;

-  return UTI_GenerateNTPAuth(key->hash_id, (unsigned char *)key->val,
-                             key->len, data, data_len, auth, auth_len);
+  return generate_ntp_auth(key->hash_id, (unsigned char *)key->val, key->len,
+                           data, data_len, auth, auth_len);
 }

 /* ================================================== */

 int
 KEY_CheckAuth(uint32_t key_id, const unsigned char *data, int data_len,
-    const unsigned char *auth, int auth_len)
+              const unsigned char *auth, int auth_len, int trunc_len)
 {
  Key *key;

@@ -397,6 +406,6 @@ KEY_CheckAuth(uint32_t key_id, const unsigned char *data, int data_len,
  if (!key)
    return 0;

-  return UTI_CheckNTPAuth(key->hash_id, (unsigned char *)key->val,
-                          key->len, data, data_len, auth, auth_len);
+  return check_ntp_auth(key->hash_id, (unsigned char *)key->val, key->len,
+                        data, data_len, auth, auth_len, trunc_len);
 }
--- a/keys.h
+++ b/keys.h
@@ -34,15 +34,15 @@ extern void KEY_Finalise(void);

 extern void KEY_Reload(void);

-extern uint32_t KEY_GetCommandKey(void);
-
 extern int KEY_GetKey(uint32_t key_id, char **key, int *len);
 extern int KEY_KeyKnown(uint32_t key_id);
 extern int KEY_GetAuthDelay(uint32_t key_id);
+extern int KEY_GetAuthLength(uint32_t key_id);
+extern int KEY_CheckKeyLength(uint32_t key_id);

 extern int KEY_GenerateAuth(uint32_t key_id, const unsigned char *data,
    int data_len, unsigned char *auth, int auth_len);
-extern int KEY_CheckAuth(uint32_t key_id, const unsigned char *data,
-    int data_len, const unsigned char *auth, int auth_len);
+extern int KEY_CheckAuth(uint32_t key_id, const unsigned char *data, int data_len,
+                         const unsigned char *auth, int auth_len, int trunc_len);

 #endif /* GOT_KEYS_H */
--- a/local.c
+++ b/local.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011, 2014
+ * Copyright (C) Miroslav Lichvar  2011, 2014-2015
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -36,6 +36,7 @@
 #include "local.h"
 #include "localp.h"
 #include "memory.h"
+#include "smooth.h"
 #include "util.h"
 #include "logging.h"

@@ -44,6 +45,9 @@
 /* Variable to store the current frequency, in ppm */
 static double current_freq_ppm;

+/* Maximum allowed frequency, in ppm */
+static double max_freq_ppm;
+
 /* Temperature compensation, in ppm */
 static double temp_comp_ppm;

@@ -102,40 +106,47 @@ static double max_clock_error;
   under 1s of busy waiting. */
 #define NITERS 100

+#define NSEC_PER_SEC 1000000000
+
 static void
 calculate_sys_precision(void)
 {
-  struct timeval tv, old_tv;
-  int dusec, best_dusec;
-  int iters;
+  struct timespec ts, old_ts;
+  int iters, diff, best;

-  gettimeofday(&old_tv, NULL);
-  best_dusec = 1000000; /* Assume we must be better than a second */
+  LCL_ReadRawTime(&old_ts);
+
+  /* Assume we must be better than a second */
+  best = NSEC_PER_SEC;
  iters = 0;
+
  do {
-    gettimeofday(&tv, NULL);
-    dusec = 1000000*(tv.tv_sec - old_tv.tv_sec) + (tv.tv_usec - old_tv.tv_usec);
-    old_tv = tv;
-    if (dusec > 0)  {
-      if (dusec < best_dusec) {
-        best_dusec = dusec;
-      }
+    LCL_ReadRawTime(&ts);
+
+    diff = NSEC_PER_SEC * (ts.tv_sec - old_ts.tv_sec) + (ts.tv_nsec - old_ts.tv_nsec);
+
+    old_ts = ts;
+    if (diff > 0) {
+      if (diff < best)
+        best = diff;
      iters++;
    }
  } while (iters < NITERS);

-  assert(best_dusec > 0);
+  assert(best > 0);

-  precision_quantum = best_dusec * 1.0e-6;
+  precision_quantum = 1.0e-9 * best;

  /* Get rounded log2 value of the measured precision */
  precision_log = 0;
-  while (best_dusec < 707107) {
+  while (best < 707106781) {
    precision_log--;
-    best_dusec *= 2;
+    best *= 2;
  }

-  DEBUG_LOG(LOGF_Local, "Clock precision %.9f (%d)", precision_quantum, precision_log);
+  assert(precision_log >= -30);
+
+  DEBUG_LOG("Clock precision %.9f (%d)", precision_quantum, precision_log);
 }

 /* ================================================== */
@@ -161,6 +172,11 @@ LCL_Initialise(void)

  calculate_sys_precision();

+  /* This is the maximum allowed frequency offset in ppm, the time must
+     never stop or run backwards */
+  max_freq_ppm = CNF_GetMaxDrift();
+  max_freq_ppm = CLAMP(0.0, max_freq_ppm, 500000.0);
+
  max_clock_error = CNF_GetMaxClockError() * 1e-6;
 }

@@ -269,7 +285,7 @@ LCL_IsFirstParameterChangeHandler(LCL_ParameterChangeHandler handler)
 /* ================================================== */

 static void
-invoke_parameter_change_handlers(struct timeval *raw, struct timeval *cooked,
+invoke_parameter_change_handlers(struct timespec *raw, struct timespec *cooked,
                                 double dfreq, double doffset,
                                 LCL_ChangeType change_type)
 {
@@ -336,23 +352,29 @@ void LCL_RemoveDispersionNotifyHandler(LCL_DispersionNotifyHandler handler, void
 }

 /* ================================================== */
-/* At the moment, this is just gettimeofday(), because
-   I can't think of a Unix system where it would not be */

 void
-LCL_ReadRawTime(struct timeval *result)
+LCL_ReadRawTime(struct timespec *ts)
 {
-  if (gettimeofday(result, NULL) < 0) {
-    LOG_FATAL(LOGF_Local, "gettimeofday() failed");
-  }
+#if HAVE_CLOCK_GETTIME
+  if (clock_gettime(CLOCK_REALTIME, ts) < 0)
+    LOG_FATAL("clock_gettime() failed : %s", strerror(errno));
+#else
+  struct timeval tv;
+
+  if (gettimeofday(&tv, NULL) < 0)
+    LOG_FATAL("gettimeofday() failed : %s", strerror(errno));
+
+  UTI_TimevalToTimespec(&tv, ts);
+#endif
 }

 /* ================================================== */

 void
-LCL_ReadCookedTime(struct timeval *result, double *err)
+LCL_ReadCookedTime(struct timespec *result, double *err)
 {
-  struct timeval raw;
+  struct timespec raw;

  LCL_ReadRawTime(&raw);
  LCL_CookTime(&raw, result, err);
@@ -361,18 +383,18 @@ LCL_ReadCookedTime(struct timeval *result, double *err)
 /* ================================================== */

 void
-LCL_CookTime(struct timeval *raw, struct timeval *cooked, double *err)
+LCL_CookTime(struct timespec *raw, struct timespec *cooked, double *err)
 {
  double correction;

  LCL_GetOffsetCorrection(raw, &correction, err);
-  UTI_AddDoubleToTimeval(raw, correction, cooked);
+  UTI_AddDoubleToTimespec(raw, correction, cooked);
 }

 /* ================================================== */

 void
-LCL_GetOffsetCorrection(struct timeval *raw, double *correction, double *err)
+LCL_GetOffsetCorrection(struct timespec *raw, double *correction, double *err)
 {
  /* Call system specific driver to get correction */
  (*drv_offset_convert)(raw, correction, err);
@@ -397,15 +419,44 @@ LCL_ReadAbsoluteFrequency(void)
 }

 /* ================================================== */
+
+static double
+clamp_freq(double freq)
+{
+  if (freq <= max_freq_ppm && freq >= -max_freq_ppm)
+    return freq;
+
+  LOG(LOGS_WARN, "Frequency %.1f ppm exceeds allowed maximum", freq);
+
+  return CLAMP(-max_freq_ppm, freq, max_freq_ppm);
+}
+
+/* ================================================== */
+
+static int
+check_offset(struct timespec *now, double offset)
+{
+  /* Check if the time will be still sane with accumulated offset */
+  if (UTI_IsTimeOffsetSane(now, -offset))
+      return 1;
+
+  LOG(LOGS_WARN, "Adjustment of %.1f seconds is invalid", -offset);
+  return 0;
+}
+
+/* ================================================== */
+
 /* This involves both setting the absolute frequency with the
   system-specific driver, as well as calling all notify handlers */

 void
 LCL_SetAbsoluteFrequency(double afreq_ppm)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;
  double dfreq;
  
+  afreq_ppm = clamp_freq(afreq_ppm);
+
  /* Apply temperature compensation */
  if (temp_comp_ppm != 0.0) {
    afreq_ppm = afreq_ppm * (1.0 - 1.0e-6 * temp_comp_ppm) - temp_comp_ppm;
@@ -432,7 +483,7 @@ LCL_SetAbsoluteFrequency(double afreq_ppm)
 void
 LCL_AccumulateDeltaFrequency(double dfreq)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;
  double old_freq_ppm;

  old_freq_ppm = current_freq_ppm;
@@ -443,6 +494,8 @@ LCL_AccumulateDeltaFrequency(double dfreq)

  current_freq_ppm += dfreq * (1.0e6 - current_freq_ppm);

+  current_freq_ppm = clamp_freq(current_freq_ppm);
+
  /* Call the system-specific driver for setting the frequency */
  current_freq_ppm = (*drv_set_freq)(current_freq_ppm);
  dfreq = (current_freq_ppm - old_freq_ppm) / (1.0e6 - old_freq_ppm);
@@ -459,7 +512,7 @@ LCL_AccumulateDeltaFrequency(double dfreq)
 void
 LCL_AccumulateOffset(double offset, double corr_rate)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;

  /* In this case, the cooked time to be passed to the notify clients
     has to be the cooked time BEFORE the change was made */
@@ -467,6 +520,9 @@ LCL_AccumulateOffset(double offset, double corr_rate)
  LCL_ReadRawTime(&raw);
  LCL_CookTime(&raw, &cooked, NULL);

+  if (!check_offset(&cooked, offset))
+      return;
+
  (*drv_accrue_offset)(offset, corr_rate);

  /* Dispatch to all handlers */
@@ -475,10 +531,10 @@ LCL_AccumulateOffset(double offset, double corr_rate)

 /* ================================================== */

-void
+int
 LCL_ApplyStepOffset(double offset)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;

  /* In this case, the cooked time to be passed to the notify clients
     has to be the cooked time BEFORE the change was made */
@@ -486,16 +542,27 @@ LCL_ApplyStepOffset(double offset)
  LCL_ReadRawTime(&raw);
  LCL_CookTime(&raw, &cooked, NULL);

-  (*drv_apply_step_offset)(offset);
+  if (!check_offset(&raw, offset))
+      return 0;
+
+  if (!(*drv_apply_step_offset)(offset)) {
+    LOG(LOGS_ERR, "Could not step system clock");
+    return 0;
+  }
+
+  /* Reset smoothing on all clock steps */
+  SMT_Reset(&cooked);

  /* Dispatch to all handlers */
  invoke_parameter_change_handlers(&raw, &cooked, 0.0, offset, LCL_ChangeStep);
+
+  return 1;
 }

 /* ================================================== */

 void
-LCL_NotifyExternalTimeStep(struct timeval *raw, struct timeval *cooked,
+LCL_NotifyExternalTimeStep(struct timespec *raw, struct timespec *cooked,
    double offset, double dispersion)
 {
  /* Dispatch to all handlers */
@@ -506,10 +573,27 @@ LCL_NotifyExternalTimeStep(struct timeval *raw, struct timeval *cooked,

 /* ================================================== */

+void
+LCL_NotifyLeap(int leap)
+{
+  struct timespec raw, cooked;
+
+  LCL_ReadRawTime(&raw);
+  LCL_CookTime(&raw, &cooked, NULL);
+
+  /* Smooth the leap second out */
+  SMT_Leap(&cooked, leap);
+
+  /* Dispatch to all handlers as if the clock was stepped */
+  invoke_parameter_change_handlers(&raw, &cooked, 0.0, -leap, LCL_ChangeStep);
+}
+
+/* ================================================== */
+
 void
 LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;
  double old_freq_ppm;

  LCL_ReadRawTime(&raw);
@@ -517,6 +601,9 @@ LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate)
     to the change we are about to make */
  LCL_CookTime(&raw, &cooked, NULL);

+  if (!check_offset(&cooked, doffset))
+      return;
+
  old_freq_ppm = current_freq_ppm;

  /* Work out new absolute frequency.  Note that absolute frequencies
@@ -524,7 +611,9 @@ LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate)
   terms of the gradient of the (offset) v (local time) function. */
  current_freq_ppm += dfreq * (1.0e6 - current_freq_ppm);

-  DEBUG_LOG(LOGF_Local, "old_freq=%.3fppm new_freq=%.3fppm offset=%.6fsec",
+  current_freq_ppm = clamp_freq(current_freq_ppm);
+
+  DEBUG_LOG("old_freq=%.3fppm new_freq=%.3fppm offset=%.6fsec",
      old_freq_ppm, current_freq_ppm, doffset);

  /* Call the system-specific driver for setting the frequency */
@@ -571,7 +660,7 @@ lcl_RegisterSystemDrivers(lcl_ReadFrequencyDriver read_freq,

  current_freq_ppm = (*drv_read_freq)();

-  DEBUG_LOG(LOGF_Local, "Local freq=%.3fppm", current_freq_ppm);
+  DEBUG_LOG("Local freq=%.3fppm", current_freq_ppm);
 }

 /* ================================================== */
@@ -581,28 +670,40 @@ lcl_RegisterSystemDrivers(lcl_ReadFrequencyDriver read_freq,
 int
 LCL_MakeStep(void)
 {
-  struct timeval raw;
+  struct timespec raw;
  double correction;

  LCL_ReadRawTime(&raw);
  LCL_GetOffsetCorrection(&raw, &correction, NULL);

+  if (!check_offset(&raw, -correction))
+      return 0;
+
  /* Cancel remaining slew and make the step */
  LCL_AccumulateOffset(correction, 0.0);
-  LCL_ApplyStepOffset(-correction);
+  if (!LCL_ApplyStepOffset(-correction))
+    return 0;

-  LOG(LOGS_WARN, LOGF_Local, "System clock was stepped by %.6f seconds", correction);
+  LOG(LOGS_WARN, "System clock was stepped by %.6f seconds", correction);

  return 1;
 }

 /* ================================================== */

+int
+LCL_CanSystemLeap(void)
+{
+  return drv_set_leap ? 1 : 0;
+}
+
+/* ================================================== */
+
 void
-LCL_SetLeap(int leap)
+LCL_SetSystemLeap(int leap, int tai_offset)
 {
  if (drv_set_leap) {
-    (drv_set_leap)(leap);
+    (drv_set_leap)(leap, tai_offset);
  }
 }

--- a/local.h
+++ b/local.h
@@ -31,9 +31,8 @@

 #include "sysincl.h"

-/* Read the system clock.  This is analogous to gettimeofday(),
-   but with the timezone information ignored */
-extern void LCL_ReadRawTime(struct timeval *);
+/* Read the system clock */
+extern void LCL_ReadRawTime(struct timespec *ts);

 /* Read the system clock, corrected according to all accumulated
   drifts and uncompensated offsets.
@@ -44,15 +43,15 @@ extern void LCL_ReadRawTime(struct timeval *);
   adjtime()-like interface to correct offsets, and to adjust the
   frequency), we must correct the raw time to get this value */

-extern void LCL_ReadCookedTime(struct timeval *t, double *err);
+extern void LCL_ReadCookedTime(struct timespec *ts, double *err);

 /* Convert raw time to cooked. */
-extern void LCL_CookTime(struct timeval *raw, struct timeval *cooked, double *err);
+extern void LCL_CookTime(struct timespec *raw, struct timespec *cooked, double *err);

 /* Read the current offset between the system clock and true time
   (i.e. 'cooked' - 'raw') (in seconds). */

-extern void LCL_GetOffsetCorrection(struct timeval *raw, double *correction, double *err);
+extern void LCL_GetOffsetCorrection(struct timespec *raw, double *correction, double *err);

 /* Type of routines that may be invoked as callbacks when there is a
   change to the frequency or offset.
@@ -79,7 +78,7 @@ typedef enum {
 } LCL_ChangeType;

 typedef void (*LCL_ParameterChangeHandler)
-     (struct timeval *raw, struct timeval *cooked,
+     (struct timespec *raw, struct timespec *cooked,
      double dfreq,
      double doffset,
      LCL_ChangeType change_type,
@@ -159,13 +158,17 @@ extern void LCL_AccumulateOffset(double offset, double corr_rate);
   the system clock is fast on true time, i.e. it needs to be stepped
   backwards. (Same convention as for AccumulateOffset routine). */

-extern void LCL_ApplyStepOffset(double offset);
+extern int LCL_ApplyStepOffset(double offset);

 /* Routine to invoke notify handlers on an unexpected time jump
   in system clock */
-extern void LCL_NotifyExternalTimeStep(struct timeval *raw, struct timeval *cooked,
+extern void LCL_NotifyExternalTimeStep(struct timespec *raw, struct timespec *cooked,
    double offset, double dispersion);

+/* Routine to invoke notify handlers on leap second when the system clock
+   doesn't correct itself */
+extern void LCL_NotifyLeap(int leap);
+
 /* Perform the combination of modifying the frequency and applying
   a slew, in one easy step */
 extern void LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate);
@@ -194,10 +197,15 @@ extern void LCL_Finalise(void);
   to a timezone problem. */
 extern int LCL_MakeStep(void);

-/* Routine to schedule a leap second. Leap second will be inserted
-   at the end of the day if argument is positive, deleted if negative,
-   and zero cancels scheduled leap second. */
-extern void LCL_SetLeap(int leap);
+/* Check if the system driver supports leap seconds, i.e. LCL_SetSystemLeap
+   does something */
+extern int LCL_CanSystemLeap(void);
+
+/* Routine to set the system clock to correct itself for a leap second and also
+   set its TAI-UTC offset.  If supported, leap second will be inserted at the
+   end of the day if the argument is positive, deleted if negative, and zero
+   resets the setting. */
+extern void LCL_SetSystemLeap(int leap, int tai_offset);

 /* Routine to set a frequency correction (in ppm) that should be applied
   to local clock to compensate for temperature changes.  A positive
--- a/localp.h
+++ b/localp.h
@@ -47,15 +47,15 @@ typedef void (*lcl_AccrueOffsetDriver)(double offset, double corr_rate);

 /* System driver to apply a step offset. A positive argument means step
   the clock forwards. */
-typedef void (*lcl_ApplyStepOffsetDriver)(double offset);
+typedef int (*lcl_ApplyStepOffsetDriver)(double offset);

 /* System driver to convert a raw time to an adjusted (cooked) time.
   The number of seconds returned in 'corr' have to be added to the
   raw time to get the corrected time */
-typedef void (*lcl_OffsetCorrectionDriver)(struct timeval *raw, double *corr, double *err);
+typedef void (*lcl_OffsetCorrectionDriver)(struct timespec *raw, double *corr, double *err);

-/* System driver to schedule leap second */
-typedef void (*lcl_SetLeapDriver)(int leap);
+/* System driver to schedule leap seconds and set TAI-UTC offset */
+typedef void (*lcl_SetLeapDriver)(int leap, int tai_offset);

 /* System driver to set the synchronisation status */
 typedef void (*lcl_SetSyncStatusDriver)(int synchronised, double est_error, double max_error);
--- a/logging.c
+++ b/logging.c
@@ -31,7 +31,6 @@

 #include "conf.h"
 #include "logging.h"
-#include "mkdirpp.h"
 #include "util.h"

 /* This is used by DEBUG_LOG macro */
@@ -41,6 +40,7 @@ int log_debug_enabled = 0;
 /* Flag indicating we have initialised */
 static int initialised = 0;

+static FILE *file_log;
 static int system_log = 0;

 static int parent_fd = 0;
@@ -49,10 +49,6 @@ static int parent_fd = 0;
 #define DEBUG_LEVEL_PRINT_DEBUG 2
 static int debug_level = 0;

-#ifdef WINNT
-static FILE *logfile;
-#endif
-
 struct LogFile {
  const char *name;
  const char *banner;
@@ -74,10 +70,7 @@ void
 LOG_Initialise(void)
 {
  initialised = 1;
-
-#ifdef WINNT
-  logfile = fopen("./chronyd.err", "a");
-#endif
+  file_log = stderr;
 }

 /* ================================================== */
@@ -86,15 +79,11 @@ LOG_Initialise(void)
 void
 LOG_Finalise(void)
 {
-#ifdef WINNT
-  if (logfile) {
-    fclose(logfile);
-  }
-#else
  if (system_log) {
    closelog();
+  } else {
+    fclose(file_log);
  }
-#endif

  LOG_CycleLogFiles();

@@ -105,11 +94,6 @@ LOG_Finalise(void)

 static void log_message(int fatal, LOG_Severity severity, const char *message)
 {
-#ifdef WINNT
-  if (logfile) {
-    fprintf(logfile, fatal ? "Fatal error : %s\n" : "%s\n", message);
-  }
-#else
  if (system_log) {
    int priority;
    switch (severity) {
@@ -133,34 +117,34 @@ static void log_message(int fatal, LOG_Severity severity, const char *message)
    }
    syslog(priority, fatal ? "Fatal error : %s" : "%s", message);
  } else {
-    fprintf(stderr, fatal ? "Fatal error : %s\n" : "%s\n", message);
+    fprintf(file_log, fatal ? "Fatal error : %s\n" : "%s\n", message);
  }
-#endif
 }

 /* ================================================== */

-void LOG_Message(LOG_Severity severity, LOG_Facility facility,
-                 int line_number, const char *filename,
-                 const char *function_name, const char *format, ...)
+void LOG_Message(LOG_Severity severity,
+#if DEBUG > 0
+                 int line_number, const char *filename, const char *function_name,
+#endif
+                 const char *format, ...)
 {
  char buf[2048];
  va_list other_args;
  time_t t;
  struct tm stm;

-#ifdef WINNT
-#else
  if (!system_log) {
    /* Don't clutter up syslog with timestamps and internal debugging info */
    time(&t);
    stm = *gmtime(&t);
    strftime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%SZ", &stm);
-    fprintf(stderr, "%s ", buf);
+    fprintf(file_log, "%s ", buf);
+#if DEBUG > 0
    if (debug_level >= DEBUG_LEVEL_PRINT_FUNCTION)
-      fprintf(stderr, "%s:%d:(%s) ", filename, line_number, function_name);
-  }
+      fprintf(file_log, "%s:%d:(%s) ", filename, line_number, function_name);
 #endif
+  }

  va_start(other_args, format);
  vsnprintf(buf, sizeof(buf), format, other_args);
@@ -193,16 +177,28 @@ void LOG_Message(LOG_Severity severity, LOG_Facility facility,
  }
 }

+/* ================================================== */
+
+void
+LOG_OpenFileLog(const char *log_file)
+{
+  FILE *f;
+
+  f = fopen(log_file, "a");
+  if (!f)
+    LOG_FATAL("Could not open log file %s", log_file);
+
+  file_log = f;
+}
+
+
 /* ================================================== */

 void
 LOG_OpenSystemLog(void)
 {
-#ifdef WINNT
-#else
  system_log = 1;
  openlog("chronyd", LOG_PID, LOG_DAEMON);
-#endif
 }

 /* ================================================== */
@@ -260,12 +256,18 @@ LOG_FileWrite(LOG_FileID id, const char *format, ...)
    return;

  if (!logfiles[id].file) {
-    char filename[512];
+    char filename[512], *logdir = CNF_GetLogDir();
+
+    if (logdir[0] == '\0') {
+      LOG(LOGS_WARN, "logdir not specified");
+      logfiles[id].name = NULL;
+      return;
+    }

    if (snprintf(filename, sizeof(filename), "%s/%s.log",
-          CNF_GetLogDir(), logfiles[id].name) >= sizeof(filename) ||
+                 logdir, logfiles[id].name) >= sizeof (filename) ||
        !(logfiles[id].file = fopen(filename, "a"))) {
-      LOG(LOGS_WARN, LOGF_Refclock, "Couldn't open logfile %s for update", filename);
+      LOG(LOGS_WARN, "Could not open log file %s", filename);
      logfiles[id].name = NULL;
      return;
    }
@@ -300,20 +302,6 @@ LOG_FileWrite(LOG_FileID id, const char *format, ...)

 /* ================================================== */

-void
-LOG_CreateLogFileDir(void)
-{
-  const char *logdir;
-
-  logdir = CNF_GetLogDir();
-
-  if (!mkdir_and_parents(logdir)) {
-    LOG(LOGS_ERR, LOGF_Logging, "Could not create directory %s", logdir);
-  }
-}
-
-/* ================================================== */
-
 void
 LOG_CycleLogFiles(void)
 {
--- a/logging.h
+++ b/logging.h
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2002
- * Copyright (C) Miroslav Lichvar  2013-2014
+ * Copyright (C) Miroslav Lichvar  2013-2015
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -45,18 +45,28 @@ extern int log_debug_enabled;
 #define FORMAT_ATTRIBUTE_PRINTF(str, first)
 #endif

-#define DEBUG_LOG(facility, ...) \
+#if DEBUG > 0
+#define LOG_MESSAGE(severity, ...) \
+  LOG_Message(severity, __LINE__, __FILE__, FUNCTION_NAME, __VA_ARGS__)
+#else
+#define LOG_MESSAGE(severity, ...) \
+  LOG_Message(severity, __VA_ARGS__)
+#endif
+
+#define DEBUG_LOG(...) \
  do { \
    if (DEBUG && log_debug_enabled) \
-      LOG_Message(LOGS_DEBUG, facility, __LINE__, __FILE__, FUNCTION_NAME, __VA_ARGS__); \
+      LOG_MESSAGE(LOGS_DEBUG, __VA_ARGS__); \
  } while (0)
-#define LOG(severity, facility, ...) LOG_Message(severity, facility, __LINE__, __FILE__, FUNCTION_NAME, __VA_ARGS__)
-#define LOG_FATAL(facility, ...) \
+
+#define LOG_FATAL(...) \
  do { \
-    LOG_Message(LOGS_FATAL, facility, __LINE__, __FILE__, FUNCTION_NAME, __VA_ARGS__); \
+    LOG_MESSAGE(LOGS_FATAL, __VA_ARGS__); \
    exit(1); \
  } while (0)

+#define LOG(severity, ...) LOG_MESSAGE(severity, __VA_ARGS__)
+
 /* Definition of severity */
 typedef enum {
  LOGS_INFO,
@@ -66,43 +76,6 @@ typedef enum {
  LOGS_DEBUG
 } LOG_Severity;

-/* Definition of facility.  Each message is tagged with who generated
-   it, so that the user can customise what level of reporting he gets
-   for each area of the software */
-typedef enum {
-  LOGF_Reference,
-  LOGF_NtpIO,
-  LOGF_NtpCore,
-  LOGF_NtpSources,
-  LOGF_Scheduler,
-  LOGF_SourceStats,
-  LOGF_Sources,
-  LOGF_Local,
-  LOGF_Util,
-  LOGF_Main,
-  LOGF_Memory,
-  LOGF_ClientLog,
-  LOGF_Configure,
-  LOGF_CmdMon,
-  LOGF_Acquire,
-  LOGF_Manual,
-  LOGF_Keys,
-  LOGF_Logging,
-  LOGF_Nameserv,
-  LOGF_Rtc,
-  LOGF_Regress,
-  LOGF_Sys,
-  LOGF_SysGeneric,
-  LOGF_SysLinux,
-  LOGF_SysNetBSD,
-  LOGF_SysSolaris,
-  LOGF_SysSunOS,
-  LOGF_SysWinnt,
-  LOGF_TempComp,
-  LOGF_RtcLinux,
-  LOGF_Refclock
-} LOG_Facility;
-
 /* Init function */
 extern void LOG_Initialise(void);

@@ -110,10 +83,14 @@ extern void LOG_Initialise(void);
 extern void LOG_Finalise(void);

 /* Line logging function */
-FORMAT_ATTRIBUTE_PRINTF(6, 7)
-extern void LOG_Message(LOG_Severity severity, LOG_Facility facility,
-                        int line_number, const char *filename,
+#if DEBUG > 0
+FORMAT_ATTRIBUTE_PRINTF(5, 6)
+extern void LOG_Message(LOG_Severity severity, int line_number, const char *filename,
                        const char *function_name, const char *format, ...);
+#else
+FORMAT_ATTRIBUTE_PRINTF(2, 3)
+extern void LOG_Message(LOG_Severity severity, const char *format, ...);
+#endif

 /* Set debug level:
   0, 1 - only non-debug messages are logged
@@ -122,6 +99,9 @@ extern void LOG_Message(LOG_Severity severity, LOG_Facility facility,
   */
 extern void LOG_SetDebugLevel(int level);

+/* Log messages to a file instead of stderr */
+extern void LOG_OpenFileLog(const char *log_file);
+
 /* Log messages to syslog instead of stderr */
 extern void LOG_OpenSystemLog(void);

@@ -140,7 +120,6 @@ extern LOG_FileID LOG_FileOpen(const char *name, const char *banner);
 FORMAT_ATTRIBUTE_PRINTF(2, 3)
 extern void LOG_FileWrite(LOG_FileID id, const char *format, ...);

-extern void LOG_CreateLogFileDir(void);
 extern void LOG_CycleLogFiles(void);

 #endif /* GOT_LOGGING_H */
--- a/main.c
+++ b/main.c
@@ -4,7 +4,7 @@
 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
 * Copyright (C) John G. Hasler  2009
- * Copyright (C) Miroslav Lichvar  2012-2014
+ * Copyright (C) Miroslav Lichvar  2012-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -35,6 +35,7 @@
 #include "local.h"
 #include "sys.h"
 #include "ntp_io.h"
+#include "ntp_signd.h"
 #include "ntp_sources.h"
 #include "ntp_core.h"
 #include "sources.h"
@@ -49,7 +50,10 @@
 #include "refclock.h"
 #include "clientlog.h"
 #include "nameserv.h"
+#include "privops.h"
+#include "smooth.h"
 #include "tempcomp.h"
+#include "util.h"

 /* ================================================== */

@@ -66,10 +70,26 @@ static REF_Mode ref_mode = REF_ModeNormal;

 /* ================================================== */

+static void
+do_platform_checks(void)
+{
+  /* Require at least 32-bit integers, two's complement representation and
+     the usual implementation of conversion of unsigned integers */
+  assert(sizeof (int) >= 4);
+  assert(-1 == ~0);
+  assert((int32_t)4294967295U == (int32_t)-1);
+}
+
+/* ================================================== */
+
 static void
 delete_pidfile(void)
 {
  const char *pidfile = CNF_GetPidFile();
+
+  if (!pidfile[0])
+    return;
+
  /* Don't care if this fails, there's not a lot we can do */
  unlink(pidfile);
 }
@@ -81,21 +101,23 @@ MAI_CleanupAndExit(void)
 {
  if (!initialised) exit(exit_status);
  
-  if (CNF_GetDumpOnExit()) {
+  if (CNF_GetDumpDir()[0] != '\0') {
    SRC_DumpSources();
  }

  /* Don't update clock when removing sources */
  REF_SetMode(REF_ModeIgnore);

+  SMT_Finalise();
  TMC_Finalise();
  MNL_Finalise();
  CLG_Finalise();
+  NSD_Finalise();
  NSR_Finalise();
-  NCR_Finalise();
-  CAM_Finalise();
-  NIO_Finalise();
  SST_Finalise();
+  NCR_Finalise();
+  NIO_Finalise();
+  CAM_Finalise();
  KEY_Finalise();
  RCL_Finalise();
  SRC_Finalise();
@@ -104,13 +126,13 @@ MAI_CleanupAndExit(void)
  SYS_Finalise();
  SCH_Finalise();
  LCL_Finalise();
+  PRV_Finalise();

  delete_pidfile();
  
  CNF_Finalise();
-  LOG_Finalise();
-
  HSH_Finalise();
+  LOG_Finalise();

  exit(exit_status);
 }
@@ -126,6 +148,16 @@ signal_cleanup(int x)

 /* ================================================== */

+static void
+quit_timeout(void *arg)
+{
+  /* Return with non-zero status if the clock is not synchronised */
+  exit_status = REF_GetOurStratum() >= NTP_MAX_STRATUM;
+  SCH_QuitProgram();
+}
+
+/* ================================================== */
+
 static void
 ntp_source_resolving_end(void)
 {
@@ -139,6 +171,7 @@ ntp_source_resolving_end(void)
    SRC_ReloadSources();
  }

+  SRC_RemoveDumpFiles();
  RTC_StartMeasurements();
  RCL_StartRefclocks();
  NSR_StartSources();
@@ -212,57 +245,47 @@ post_init_rtc_hook(void *anything)
 }

 /* ================================================== */
-/* Return 1 if the process exists on the system. */

-static int
-does_process_exist(int pid)
-{
-  int status;
-  status = getsid(pid);
-  if (status >= 0) {
-    return 1;
-  } else {
-    return 0;
-  }
-}
-
-/* ================================================== */
-
-static int
-maybe_another_chronyd_running(int *other_pid)
+static void
+check_pidfile(void)
 {
  const char *pidfile = CNF_GetPidFile();
  FILE *in;
  int pid, count;
  
-  *other_pid = 0;
-
  in = fopen(pidfile, "r");
-  if (!in) return 0;
+  if (!in)
+    return;

  count = fscanf(in, "%d", &pid);
  fclose(in);
  
-  if (count != 1) return 0;
+  if (count != 1)
+    return;

-  *other_pid = pid;
-  return does_process_exist(pid);
+  if (getsid(pid) < 0)
+    return;

+  LOG_FATAL("Another chronyd may already be running (pid=%d), check %s",
+            pid, pidfile);
 }

 /* ================================================== */

 static void
-write_lockfile(void)
+write_pidfile(void)
 {
  const char *pidfile = CNF_GetPidFile();
  FILE *out;

+  if (!pidfile[0])
+    return;
+
  out = fopen(pidfile, "w");
  if (!out) {
-    LOG_FATAL(LOGF_Main, "could not open lockfile %s for writing", pidfile);
+    LOG_FATAL("Could not open %s : %s", pidfile, strerror(errno));
  } else {
-    fprintf(out, "%d\n", getpid());
+    fprintf(out, "%d\n", (int)getpid());
    fclose(out);
  }
 }
@@ -272,24 +295,19 @@ write_lockfile(void)
 static void
 go_daemon(void)
 {
-#ifdef WINNT
-
-
-#else
-
  int pid, fd, pipefd[2];

  /* Create pipe which will the daemon use to notify the grandparent
     when it's initialised or send an error message */
  if (pipe(pipefd)) {
-    LOG_FATAL(LOGF_Logging, "Could not detach, pipe failed : %s", strerror(errno));
+    LOG_FATAL("pipe() failed : %s", strerror(errno));
  }

  /* Does this preserve existing signal handlers? */
  pid = fork();

  if (pid < 0) {
-    LOG_FATAL(LOGF_Logging, "Could not detach, fork failed : %s", strerror(errno));
+    LOG_FATAL("fork() failed : %s", strerror(errno));
  } else if (pid > 0) {
    /* In the 'grandparent' */
    char message[1024];
@@ -300,7 +318,8 @@ go_daemon(void)
    if (r) {
      if (r > 0) {
        /* Print the error message from the child */
-        fprintf(stderr, "%.1024s\n", message);
+        message[sizeof (message) - 1] = '\0';
+        fprintf(stderr, "%s\n", message);
      }
      exit(1);
    } else
@@ -314,7 +333,7 @@ go_daemon(void)
    pid = fork();

    if (pid < 0) {
-      LOG_FATAL(LOGF_Logging, "Could not detach, fork failed : %s", strerror(errno));
+      LOG_FATAL("fork() failed : %s", strerror(errno));
    } else if (pid > 0) {
      exit(0); /* In the 'parent' */
    } else {
@@ -322,7 +341,7 @@ go_daemon(void)

      /* Change current directory to / */
      if (chdir("/") < 0) {
-        LOG_FATAL(LOGF_Logging, "Could not chdir to / : %s", strerror(errno));
+        LOG_FATAL("chdir() failed : %s", strerror(errno));
      }

      /* Don't keep stdin/out/err from before. But don't close
@@ -335,8 +354,35 @@ go_daemon(void)
      LOG_SetParentFd(pipefd[1]);
    }
  }
+}

-#endif
+/* ================================================== */
+
+static void
+print_help(const char *progname)
+{
+      printf("Usage: %s [-4|-6] [-n|-d] [-q|-Q] [-r] [-R] [-s] [-t TIMEOUT] [-f FILE|COMMAND...]\n",
+             progname);
+}
+
+/* ================================================== */
+
+static void
+print_version(void)
+{
+  printf("chronyd (chrony) version %s (%s)\n", CHRONY_VERSION, CHRONYD_FEATURES);
+}
+
+/* ================================================== */
+
+static int
+parse_int_arg(const char *arg)
+{
+  int i;
+
+  if (sscanf(arg, "%d", &i) != 1)
+    LOG_FATAL("Invalid argument %s", arg);
+  return i;
 }

 /* ================================================== */
@@ -345,126 +391,149 @@ int main
 (int argc, char **argv)
 {
  const char *conf_file = DEFAULT_CONF_FILE;
-  char *user = NULL;
-  int debug = 0, nofork = 0, address_family = IPADDR_UNSPEC;
-  int do_init_rtc = 0, restarted = 0;
-  int other_pid;
-  int lock_memory = 0, sched_priority = 0;
-  int system_log = 1;
+  const char *progname = argv[0];
+  char *user = NULL, *log_file = NULL;
+  struct passwd *pw;
+  int opt, debug = 0, nofork = 0, address_family = IPADDR_UNSPEC;
+  int do_init_rtc = 0, restarted = 0, client_only = 0, timeout = 0;
+  int scfilter_level = 0, lock_memory = 0, sched_priority = 0;
+  int clock_control = 1, system_log = 1;
  int config_args = 0;

+  do_platform_checks();
+
  LOG_Initialise();

-  /* Parse command line options */
-  while (++argv, (--argc)>0) {
+  /* Parse (undocumented) long command-line options */
+  for (optind = 1; optind < argc; optind++) {
+    if (!strcmp("--help", argv[optind])) {
+      print_help(progname);
+      return 0;
+    } else if (!strcmp("--version", argv[optind])) {
+      print_version();
+      return 0;
+    }
+  }

-    if (!strcmp("-f", *argv)) {
-      ++argv, --argc;
-      conf_file = *argv;
-    } else if (!strcmp("-P", *argv)) {
-      ++argv, --argc;
-      if (argc == 0 || sscanf(*argv, "%d", &sched_priority) != 1) {
-        LOG_FATAL(LOGF_Main, "Bad scheduler priority");
-      }
-    } else if (!strcmp("-m", *argv)) {
-      lock_memory = 1;
-    } else if (!strcmp("-r", *argv)) {
-      reload = 1;
-    } else if (!strcmp("-R", *argv)) {
-      restarted = 1;
-    } else if (!strcmp("-u", *argv)) {
-      ++argv, --argc;
-      if (argc == 0) {
-        LOG_FATAL(LOGF_Main, "Missing user name");
-      } else {
-        user = *argv;
-      }
-    } else if (!strcmp("-s", *argv)) {
-      do_init_rtc = 1;
-    } else if (!strcmp("-v", *argv) || !strcmp("--version",*argv)) {
-      /* This write to the terminal is OK, it comes before we turn into a daemon */
-      printf("chronyd (chrony) version %s (%s)\n", CHRONY_VERSION, CHRONYD_FEATURES);
-      exit(0);
-    } else if (!strcmp("-n", *argv)) {
-      nofork = 1;
-    } else if (!strcmp("-d", *argv)) {
+  optind = 1;
+
+  /* Parse short command-line options */
+  while ((opt = getopt(argc, argv, "46df:F:hl:mnP:qQrRst:u:vx")) != -1) {
+    switch (opt) {
+      case '4':
+      case '6':
+        address_family = opt == '4' ? IPADDR_INET4 : IPADDR_INET6;
+        break;
+      case 'd':
        debug++;
        nofork = 1;
        system_log = 0;
-    } else if (!strcmp("-q", *argv)) {
-      ref_mode = REF_ModeUpdateOnce;
-      nofork = 1;
-      system_log = 0;
-    } else if (!strcmp("-Q", *argv)) {
-      ref_mode = REF_ModePrintOnce;
-      nofork = 1;
-      system_log = 0;
-    } else if (!strcmp("-4", *argv)) {
-      address_family = IPADDR_INET4;
-    } else if (!strcmp("-6", *argv)) {
-      address_family = IPADDR_INET6;
-    } else if (*argv[0] == '-') {
-      LOG_FATAL(LOGF_Main, "Unrecognized command line option [%s]", *argv);
-    } else {
-      /* Process remaining arguments and configuration lines */
-      config_args = argc;
        break;
+      case 'f':
+        conf_file = optarg;
+        break;
+      case 'F':
+        scfilter_level = parse_int_arg(optarg);
+        break;
+      case 'l':
+        log_file = optarg;
+        break;
+      case 'm':
+        lock_memory = 1;
+        break;
+      case 'n':
+        nofork = 1;
+        break;
+      case 'P':
+        sched_priority = parse_int_arg(optarg);
+        break;
+      case 'q':
+      case 'Q':
+        ref_mode = opt == 'q' ? REF_ModeUpdateOnce : REF_ModePrintOnce;
+        nofork = 1;
+        client_only = 1;
+        clock_control = 0;
+        system_log = 0;
+        break;
+      case 'r':
+        reload = 1;
+        break;
+      case 'R':
+        restarted = 1;
+        break;
+      case 's':
+        do_init_rtc = 1;
+        break;
+      case 't':
+        timeout = parse_int_arg(optarg);
+        break;
+      case 'u':
+        user = optarg;
+        break;
+      case 'v':
+        print_version();
+        return 0;
+      case 'x':
+        clock_control = 0;
+        break;
+      default:
+        print_help(progname);
+        return opt != 'h';
    }
  }

-  if (getuid() != 0) {
-    /* This write to the terminal is OK, it comes before we turn into a daemon */
-    fprintf(stderr,"Not superuser\n");
-    exit(1);
-  }
+  if (getuid() && !client_only)
+    LOG_FATAL("Not superuser");

  /* Turn into a daemon */
  if (!nofork) {
    go_daemon();
  }

-  if (system_log) {
+  if (log_file) {
+    LOG_OpenFileLog(log_file);
+  } else if (system_log) {
    LOG_OpenSystemLog();
  }
  
  LOG_SetDebugLevel(debug);
  
-  LOG(LOGS_INFO, LOGF_Main, "chronyd version %s starting (%s)",
-      CHRONY_VERSION, CHRONYD_FEATURES);
+  LOG(LOGS_INFO, "chronyd version %s starting (%s)", CHRONY_VERSION, CHRONYD_FEATURES);

  DNS_SetAddressFamily(address_family);

-  CNF_Initialise(restarted);
+  CNF_Initialise(restarted, client_only);

  /* Parse the config file or the remaining command line arguments */
+  config_args = argc - optind;
  if (!config_args) {
    CNF_ReadFile(conf_file);
  } else {
-    do {
-      CNF_ParseLine(NULL, config_args - argc + 1, *argv);
-    } while (++argv, --argc);
+    for (; optind < argc; optind++)
+      CNF_ParseLine(NULL, config_args + optind - argc + 1, argv[optind]);
  }

-  /* Check whether another chronyd may already be running.  Do this after
-   * forking, so that message logging goes to the right place (i.e. syslog), in
-   * case this chronyd is being run from a boot script. */
-  if (maybe_another_chronyd_running(&other_pid)) {
-    LOG_FATAL(LOGF_Main, "Another chronyd may already be running (pid=%d), check lockfile (%s)",
-              other_pid, CNF_GetPidFile());
-  }
+  /* Check whether another chronyd may already be running */
+  check_pidfile();

-  /* Write our lockfile to prevent other chronyds running.  This has *GOT* to
-   * be done *AFTER* the daemon-creation fork() */
-  write_lockfile();
+  /* Write our pidfile to prevent other chronyds running */
+  write_pidfile();

+  PRV_Initialise();
  LCL_Initialise();
  SCH_Initialise();
-  SYS_Initialise();
+  SYS_Initialise(clock_control);
  RTC_Initialise(do_init_rtc);
  SRC_Initialise();
  RCL_Initialise();
  KEY_Initialise();

+  /* Open privileged ports before dropping root */
+  CAM_Initialise(address_family);
+  NIO_Initialise(address_family);
+  NCR_Initialise();
+  CNF_SetupAccessRestrictions();
+
  /* Command-line switch must have priority */
  if (!sched_priority) {
    sched_priority = CNF_GetSchedPriority();
@@ -480,26 +549,35 @@ int main
  if (!user) {
    user = CNF_GetUser();
  }
-  if (user && strcmp(user, "root")) {
-    SYS_DropRoot(user);
-  }

-  LOG_CreateLogFileDir();
+  if ((pw = getpwnam(user)) == NULL)
+    LOG_FATAL("Could not get %s uid/gid", user);
+
+  /* Create all directories before dropping root */
+  CNF_CreateDirs(pw->pw_uid, pw->pw_gid);
+
+  /* Drop root privileges if the specified user has a non-zero UID */
+  if (!geteuid() && (pw->pw_uid || pw->pw_gid))
+    SYS_DropRoot(pw->pw_uid, pw->pw_gid);

  REF_Initialise();
  SST_Initialise();
-  NIO_Initialise(address_family);
-  CAM_Initialise(address_family);
-  NCR_Initialise();
  NSR_Initialise();
+  NSD_Initialise();
  CLG_Initialise();
  MNL_Initialise();
  TMC_Initialise();
+  SMT_Initialise();

  /* From now on, it is safe to do finalisation on exit */
  initialised = 1;

-  CNF_SetupAccessRestrictions();
+  UTI_SetQuitSignalsHandler(signal_cleanup);
+
+  CAM_OpenUnixSocket();
+
+  if (scfilter_level)
+    SYS_EnableSystemCallFilter(scfilter_level);

  if (ref_mode == REF_ModeNormal && CNF_GetInitSources() > 0) {
    ref_mode = REF_ModeInitStepSlew;
@@ -508,24 +586,20 @@ int main
  REF_SetModeEndHandler(reference_mode_end);
  REF_SetMode(ref_mode);

+  if (timeout > 0)
+    SCH_AddTimeoutByDelay(timeout, quit_timeout, NULL);
+
  if (do_init_rtc) {
    RTC_TimeInit(post_init_rtc_hook, NULL);
  } else {
    post_init_rtc_hook(NULL);
  }

-  signal(SIGINT, signal_cleanup);
-  signal(SIGTERM, signal_cleanup);
-#if !defined(WINNT)
-  signal(SIGQUIT, signal_cleanup);
-  signal(SIGHUP, signal_cleanup);
-#endif /* WINNT */
-
  /* The program normally runs under control of the main loop in
     the scheduler. */
  SCH_MainLoop();

-  LOG(LOGS_INFO, LOGF_Main, "chronyd exiting");
+  LOG(LOGS_INFO, "chronyd exiting");

  MAI_CleanupAndExit();

--- a/37
+++ b/37
@@ -1,6 +1,6 @@
 #!/bin/sh

-LANG=C
+LANG=C.UTF-8
 export LANG

 if [ $# -ne 1 ]; then
@@ -11,7 +11,6 @@ fi
 version=$1
 tag=$version
 subdir=chrony-${version}
-mandate=$(date +'%B %Y')

 umask 022

@@ -39,37 +38,13 @@ echo $version > version.txt

 sed -i -e "s%@@VERSION@@%${version}%" examples/chrony.spec

-for m in chrony.1 chronyc.1.in chrony.conf.5.in chronyd.8.in; do
-  sed -e "s%@VERSION@%${version}%;s%@MAN_DATE@%${mandate}%" \
-    < $m > ${m}_
-  mv -f ${m}_ $m
-done
+./configure && make -C doc man txt || exit 1
+
+iconv -f utf-8 -t ascii//TRANSLIT < doc/installation.txt > INSTALL
+iconv -f utf-8 -t ascii//TRANSLIT < doc/faq.txt > FAQ

-./configure && make chrony.txt || exit 1
-mv chrony.txt chrony.txt_
 make distclean
-mv chrony.txt_ chrony.txt
-
-awk '/^[1-9] Installation$/{p=1}
-     /^[1-9]\.. Support for line editing/{exit}; p' chrony.txt | \
-  tail -n +4 > INSTALL
-
-if [ $(wc -l < INSTALL) -gt 100 -o $(wc -l < INSTALL) -lt 85 ]; then
-  echo "INSTALL generated incorrectly?"
-  exit 3
-fi
-
-awk '/^[1-9] Frequently asked questions$/{p=1}
-     /^Appendix A GNU General Public License$/{exit}; p' chrony.txt | \
- tail -n +4 | sed 's/^[1-9]\.\([1-9]\)/\1/' | sed 's/^----/--/' | \
- sed 's/^====/==/' > FAQ
-
-if [ $(wc -l < FAQ) -gt 400 -o $(wc -l < FAQ) -lt 200 ]; then
-  echo "FAQ generated incorrectly?"
-  exit 3
-fi
-
-rm -f config.h config.log make_release .gitignore
+rm -f make_release .gitignore

 cd ..
 tar cv --owner root --group root $subdir | gzip -9 > ${subdir}.tar.gz
--- a/manual.c
+++ b/manual.c
@@ -47,13 +47,15 @@ static int enabled = 0;

 /* More recent samples at highest indices */
 typedef struct {
-  struct timeval when; /* This is our 'cooked' time */
+  struct timespec when; /* This is our 'cooked' time */
  double orig_offset; /*+ Not modified by slew samples */
  double offset; /*+ if we are fast of the supplied reference */
  double residual; /*+ regression residual (sign convention given by
                     (measured-predicted)) */
 } Sample;

+#define MIN_SAMPLE_SEPARATION 1.0
+
 #define MAX_SAMPLES 16

 static Sample samples[16];
@@ -62,8 +64,8 @@ static int n_samples;
 /* ================================================== */

 static void
-slew_samples(struct timeval *raw,
-             struct timeval *cooked, 
+slew_samples(struct timespec *raw,
+             struct timespec *cooked,
             double dfreq,
             double doffset,
             LCL_ChangeType change_type,
@@ -95,7 +97,8 @@ MNL_Finalise(void)
 /* ================================================== */

 static void
-estimate_and_set_system(struct timeval *now, int offset_provided, double offset, long *offset_cs, double *dfreq_ppm, double *new_afreq_ppm)
+estimate_and_set_system(struct timespec *now, int offset_provided, double offset,
+                        double *reg_offset, double *dfreq_ppm, double *new_afreq_ppm)
 {
  double agos[MAX_SAMPLES], offsets[MAX_SAMPLES];
  double b0, b1;
@@ -106,32 +109,26 @@ estimate_and_set_system(struct timeval *now, int offset_provided, double offset,
  int found_freq;
  double slew_by;

+  b0 = offset_provided ? offset : 0.0;
+  b1 = freq = 0.0;
+  found_freq = 0;
+
  if (n_samples > 1) {
    for (i=0; i<n_samples; i++) {
-      UTI_DiffTimevalsToDouble(&agos[i], &samples[n_samples-1].when, &samples[i].when);
+      agos[i] = UTI_DiffTimespecsToDouble(&samples[n_samples - 1].when, &samples[i].when);
      offsets[i] = samples[i].offset;
    }
    
-    RGR_FindBestRobustRegression(agos, offsets, n_samples,
-                                 1.0e-8, /* 0.01ppm easily good enough for this! */
-                                 &b0, &b1, &n_runs, &best_start);
-    
-    
+    if (RGR_FindBestRobustRegression(agos, offsets, n_samples, 1.0e-8,
+                                     &b0, &b1, &n_runs, &best_start)) {
      /* Ignore b0 from regression; treat offset as being the most
         recently entered value.  (If the administrator knows he's put
         an outlier in, he will rerun the settime operation.)   However,
         the frequency estimate comes from the regression. */
-    
      freq = -b1;
      found_freq = 1;
-  } else {
-    if (offset_provided) {
-      b0 = offset;
-    } else {
-      b0 = 0.0;
    }
-    b1 = freq = 0.0;
-    found_freq = 0;
+  } else {
    agos[0] = 0.0;
    offsets[0] = b0;
  }
@@ -143,21 +140,20 @@ estimate_and_set_system(struct timeval *now, int offset_provided, double offset,
  }
  
  if (found_freq) {
-    LOG(LOGS_INFO, LOGF_Manual,
-        "Making a frequency change of %.3f ppm and a slew of %.6f",
+    LOG(LOGS_INFO, "Making a frequency change of %.3f ppm and a slew of %.6f",
        1.0e6 * freq, slew_by);
    
    REF_SetManualReference(now,
                           slew_by,
                           freq, skew);
  } else {
-    LOG(LOGS_INFO, LOGF_Manual, "Making a slew of %.6f", slew_by);
+    LOG(LOGS_INFO, "Making a slew of %.6f", slew_by);
    REF_SetManualReference(now,
                           slew_by,
                           0.0, skew);
  }
  
-  if (offset_cs) *offset_cs = (long)(0.5 + 100.0 * b0);
+  if (reg_offset) *reg_offset = b0;
  if (dfreq_ppm) *dfreq_ppm = 1.0e6 * freq;
  if (new_afreq_ppm) *new_afreq_ppm = LCL_ReadAbsoluteFrequency();
  
@@ -171,18 +167,28 @@ estimate_and_set_system(struct timeval *now, int offset_provided, double offset,
 /* ================================================== */

 int
-MNL_AcceptTimestamp(struct timeval *ts, long *offset_cs, double *dfreq_ppm, double *new_afreq_ppm)
+MNL_AcceptTimestamp(struct timespec *ts, double *reg_offset, double *dfreq_ppm, double *new_afreq_ppm)
 {
-  struct timeval now;
-  double offset;
+  struct timespec now;
+  double offset, diff;
  int i;

  if (enabled) {
-
-    /* Check whether timestamp is within margin of old one */
    LCL_ReadCookedTime(&now, NULL);

-    UTI_DiffTimevalsToDouble(&offset, &now, ts);
+    /* Make sure the provided timestamp is sane and the sample
+       is not too close to the last one */
+
+    if (!UTI_IsTimeOffsetSane(ts, 0.0))
+     return 0;
+
+    if (n_samples) {
+      diff = UTI_DiffTimespecsToDouble(&now, &samples[n_samples - 1].when);
+      if (diff < MIN_SAMPLE_SEPARATION)
+        return 0;
+    }
+
+    offset = UTI_DiffTimespecsToDouble(&now, ts);

    /* Check if buffer full up */
    if (n_samples == MAX_SAMPLES) {
@@ -198,7 +204,7 @@ MNL_AcceptTimestamp(struct timeval *ts, long *offset_cs, double *dfreq_ppm, doub
    samples[n_samples].orig_offset = offset;
    ++n_samples;

-    estimate_and_set_system(&now, 1, offset, offset_cs, dfreq_ppm, new_afreq_ppm);
+    estimate_and_set_system(&now, 1, offset, reg_offset, dfreq_ppm, new_afreq_ppm);

    return 1;

@@ -212,8 +218,8 @@ MNL_AcceptTimestamp(struct timeval *ts, long *offset_cs, double *dfreq_ppm, doub
 /* ================================================== */

 static void
-slew_samples(struct timeval *raw,
-             struct timeval *cooked, 
+slew_samples(struct timespec *raw,
+             struct timespec *cooked,
             double dfreq,
             double doffset,
             LCL_ChangeType change_type,
@@ -227,7 +233,7 @@ slew_samples(struct timeval *raw,
  }

  for (i=0; i<n_samples; i++) {
-    UTI_AdjustTimeval(&samples[i].when, cooked, &samples[i].when, &delta_time,
+    UTI_AdjustTimespec(&samples[i].when, cooked, &samples[i].when, &delta_time,
        dfreq, doffset);
    samples[i].offset += delta_time;
  }
@@ -258,6 +264,14 @@ MNL_Reset(void)
  n_samples = 0;
 }

+/* ================================================== */
+
+int
+MNL_IsEnabled(void)
+{
+  return enabled;
+}
+
 /* ================================================== */
 /* Generate report data for the REQ_MANUAL_LIST command/monitoring
   protocol */
@@ -289,7 +303,7 @@ int
 MNL_DeleteSample(int index)
 {
  int i;
-  struct timeval now;
+  struct timespec now;

  if ((index < 0) || (index >= n_samples)) {
    return 0;
--- a/manual.h
+++ b/manual.h
@@ -33,11 +33,12 @@

 extern void MNL_Initialise(void);
 extern void MNL_Finalise(void);
-extern int MNL_AcceptTimestamp(struct timeval *ts, long *offset_cs, double *dfreq_ppm, double *new_afreq_ppm);
+extern int MNL_AcceptTimestamp(struct timespec *ts, double *reg_offset, double *dfreq_ppm, double *new_afreq_ppm);

 extern void MNL_Enable(void);
 extern void MNL_Disable(void);
 extern void MNL_Reset(void);
+extern int MNL_IsEnabled(void);

 extern void MNL_ReportSamples(RPT_ManualSamplesReport *report, int max, int *n);
 extern int MNL_DeleteSample(int index);
--- a/memory.c
+++ b/memory.c
@@ -37,7 +37,7 @@ Malloc(size_t size)

  r = malloc(size);
  if (!r && size)
-    LOG_FATAL(LOGF_Memory, "Could not allocate memory");
+    LOG_FATAL("Could not allocate memory");

  return r;
 }
@@ -49,7 +49,7 @@ Realloc(void *ptr, size_t size)

  r = realloc(ptr, size);
  if (!r && size)
-    LOG_FATAL(LOGF_Memory, "Could not allocate memory");
+    LOG_FATAL("Could not allocate memory");

  return r;
 }
@@ -61,7 +61,7 @@ Strdup(const char *s)

  r = strdup(s);
  if (!r)
-    LOG_FATAL(LOGF_Memory, "Could not allocate memory");
+    LOG_FATAL("Could not allocate memory");

  return r;
 }
--- a/mkdirpp.c
+++ b/mkdirpp.c
@@ -1,135 +0,0 @@
-/*
-  chronyd/chronyc - Programs for keeping computer clocks accurate.
-
- **********************************************************************
- * Copyright (C) Richard P. Curnow  1997-2002
- * 
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of version 2 of the GNU General Public License as
- * published by the Free Software Foundation.
- * 
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
- * 
- **********************************************************************
-
-  =======================================================================
-
-  A function for creating a directory and any parent directories that
-  don't exist.
-
-  */
-
-#include "config.h"
-
-#include "sysincl.h"
-
-#include "memory.h"
-#include "mkdirpp.h"
-
-static int
-do_dir(char *p)
-{
-  int status;
-  struct stat buf;
-
-#if defined(TEST)
-  fprintf(stderr, "do_dir(%s)\n", p);
-#endif
-
-  /* See if directory exists */
-  status = stat(p, &buf);
-
-  if (status < 0) {
-    if (errno == ENOENT) {
-      /* Try to create directory */
-      status = mkdir(p, 0755);
-      return status;
-    } else {
-      return status;
-    }
-  }
-
-  if (!S_ISDIR(buf.st_mode)) {
-    return -1;
-  }
-
-  return 0;
-}
-
-/* ================================================== */
-/* Return 0 if the directory couldn't be created, 1 if it could (or
-   already existed) */
-
-int
-mkdir_and_parents(const char *path)
-{
-  char *p;
-  int len;
-  int i, j, k, last;
-  len = strlen(path);
-
-  p = (char *)Malloc(1 + len);
-
-  i = k = 0;
-  while (1) {
-    p[i++] = path[k++];
-    
-    if (path[k] == '/' || !path[k]) {
-      p[i] = 0;
-
-      if (do_dir(p) < 0) {
-        Free(p);
-        return 0;
-      }
-
-      if (!path[k]) {
-        /* End of the string */
-        break;
-      }
-
-      /* check whether its a trailing / or group of / */
-      last = 1;
-      j = k+1;
-      while (path[j]) {
-        if (path[j] != '/') {
-          k = j - 1; /* Pick up a / into p[] thru the assignment at the top of the loop */
-          last = 0;
-          break;
-        }
-        j++;
-      }
-
-      if (last) {
-        break;
-      }
-    }
-
-    if (!path[k]) break;
-
-  }  
-
-  Free(p);
-  return 1;
-
-}
-
-/* ================================================== */
-
-#if defined(TEST)
-int main(int argc, char **argv) {
-  if (argc > 1) {
-    /* Invert sense of result */
-    return mkdir_and_parents(argv[1]) ? 0 : 1;
-  } else {
-    return 1;
-  }
-}
-#endif
-                                  
--- a/nameserv.c
+++ b/nameserv.c
@@ -50,6 +50,8 @@ DNS_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs)
  struct addrinfo hints, *res, *ai;
  int i, result;

+  max_addrs = MIN(max_addrs, DNS_MAX_ADDRESSES);
+
  memset(&hints, 0, sizeof (hints));
  hints.ai_family = AF_UNSPEC;
  hints.ai_socktype = SOCK_STREAM;
@@ -99,6 +101,8 @@ DNS_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs)
  if (address_family != IPADDR_UNSPEC && address_family != IPADDR_INET4)
    return DNS_Failure;

+  max_addrs = MIN(max_addrs, DNS_MAX_ADDRESSES);
+
  host = gethostbyname(name);

  if (host == NULL) {
--- a/nameserv.h
+++ b/nameserv.h
@@ -39,6 +39,9 @@ typedef enum {
 /* Resolve names only to selected address family */
 extern void DNS_SetAddressFamily(int family);

+/* Maximum number of addresses returned by DNS_Name2IPAddress */
+#define DNS_MAX_ADDRESSES 16
+
 extern DNS_Status DNS_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs);

 extern int DNS_IPAddress2Name(IPAddr *ip_addr, char *name, int len);
--- a/nameserv_async.c
+++ b/nameserv_async.c
@@ -31,20 +31,19 @@
 #include "nameserv_async.h"
 #include "logging.h"
 #include "memory.h"
+#include "privops.h"
 #include "sched.h"
 #include "util.h"

 #ifdef USE_PTHREAD_ASYNCDNS
 #include <pthread.h>

-#define MAX_ADDRESSES 16
-
 /* ================================================== */

 struct DNS_Async_Instance {
  const char *name;
  DNS_Status status;
-  IPAddr addresses[MAX_ADDRESSES];
+  IPAddr addresses[DNS_MAX_ADDRESSES];
  DNS_NameResolveHandler handler;
  void *arg;

@@ -61,7 +60,7 @@ start_resolving(void *anything)
 {
  struct DNS_Async_Instance *inst = (struct DNS_Async_Instance *)anything;

-  inst->status = DNS_Name2IPAddress(inst->name, inst->addresses, MAX_ADDRESSES);
+  inst->status = PRV_Name2IPAddress(inst->name, inst->addresses, DNS_MAX_ADDRESSES);

  /* Notify the main thread that the result is ready */
  if (write(inst->pipe[1], "", 1) < 0)
@@ -73,22 +72,22 @@ start_resolving(void *anything)
 /* ================================================== */

 static void
-end_resolving(void *anything)
+end_resolving(int fd, int event, void *anything)
 {
  struct DNS_Async_Instance *inst = (struct DNS_Async_Instance *)anything;
  int i;

  if (pthread_join(inst->thread, NULL)) {
-    LOG_FATAL(LOGF_Nameserv, "pthread_join() failed");
+    LOG_FATAL("pthread_join() failed");
  }

  resolving_threads--;

-  SCH_RemoveInputFileHandler(inst->pipe[0]);
+  SCH_RemoveFileHandler(inst->pipe[0]);
  close(inst->pipe[0]);
  close(inst->pipe[1]);

-  for (i = 0; inst->status == DNS_Success && i < MAX_ADDRESSES &&
+  for (i = 0; inst->status == DNS_Success && i < DNS_MAX_ADDRESSES &&
              inst->addresses[i].family != IPADDR_UNSPEC; i++)
    ;

@@ -111,17 +110,20 @@ DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *
  inst->status = DNS_Failure;

  if (pipe(inst->pipe)) {
-    LOG_FATAL(LOGF_Nameserv, "pipe() failed");
+    LOG_FATAL("pipe() failed");
  }

+  UTI_FdSetCloexec(inst->pipe[0]);
+  UTI_FdSetCloexec(inst->pipe[1]);
+
  resolving_threads++;
  assert(resolving_threads <= 1);

  if (pthread_create(&inst->thread, NULL, start_resolving, inst)) {
-    LOG_FATAL(LOGF_Nameserv, "pthread_create() failed");
+    LOG_FATAL("pthread_create() failed");
  }

-  SCH_AddInputFileHandler(inst->pipe[0], end_resolving, inst);
+  SCH_AddFileHandler(inst->pipe[0], SCH_FILE_INPUT, end_resolving, inst);
 }

 /* ================================================== */
--- a/nameserv_async.h
+++ b/nameserv_async.h
@@ -34,8 +34,7 @@
 typedef void (*DNS_NameResolveHandler)(DNS_Status status, int n_addrs, IPAddr *ip_addrs, void *anything);

 /* Request resolving of a name to IP address. The handler will be
-   called when the result is available, but it may be also called
-   directly from this function call. */
+   called when the result is available. */
 extern void DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *anything);

 #endif
--- a/ntp.h
+++ b/ntp.h
@@ -38,6 +38,9 @@ typedef struct {

 typedef uint32_t NTP_int32;

+/* The UDP port number used by NTP */
+#define NTP_PORT 123
+
 /* The NTP protocol version that we support */
 #define NTP_VERSION 4

@@ -53,8 +56,12 @@ typedef uint32_t NTP_int32;
 #define NTP_MAX_EXTENSIONS_LENGTH 1024

 /* The minimum and maximum supported length of MAC */
-#define NTP_MIN_MAC_LENGTH 16
-#define NTP_MAX_MAC_LENGTH MAX_HASH_LENGTH
+#define NTP_MIN_MAC_LENGTH (4 + 16)
+#define NTP_MAX_MAC_LENGTH (4 + MAX_HASH_LENGTH)
+
+/* The maximum length of MAC in NTPv4 packets which allows deterministic
+   parsing of extension fields (RFC 7822) */
+#define NTP_MAX_V4_MAC_LENGTH (4 + 20)

 /* Type definition for leap bits */
 typedef enum {
@@ -91,7 +98,7 @@ typedef struct {

  /* Optional message authentication code (MAC) */
  NTP_int32 auth_keyid;
-  uint8_t auth_data[NTP_MAX_MAC_LENGTH];
+  uint8_t auth_data[NTP_MAX_MAC_LENGTH - 4];
 } NTP_Packet;

 #define NTP_NORMAL_PACKET_LENGTH (int)offsetof(NTP_Packet, auth_keyid)
@@ -109,4 +116,9 @@ typedef struct {
 #define NTP_LVM(leap, version, mode) \
  ((((leap) << 6) & 0xc0) | (((version) << 3) & 0x38) | ((mode) & 0x07))

+/* Special NTP reference IDs */
+#define NTP_REFID_UNSYNC 0x0UL
+#define NTP_REFID_LOCAL 0x7F7F0101UL /* 127.127.1.1 */
+#define NTP_REFID_SMOOTH 0x7F7F01FFUL /* 127.127.1.255 */
+
 #endif /* GOT_NTP_H */
--- a/ntp_core.c
+++ b/ntp_core.c
--- a/ntp_core.h
+++ b/ntp_core.h
@@ -38,6 +38,18 @@ typedef enum {
  NTP_SERVER, NTP_PEER
 } NTP_Source_Type;

+typedef enum {
+  NTP_TS_DAEMON = 0,
+  NTP_TS_KERNEL,
+  NTP_TS_HARDWARE
+} NTP_Timestamp_Source;
+
+typedef struct {
+  struct timespec ts;
+  double err;
+  NTP_Timestamp_Source source;
+} NTP_Local_Timestamp;
+
 /* This is a private data type used for storing the instance record for
   each source that we are chiming with */
 typedef struct NCR_Instance_Record *NCR_Instance;
@@ -58,19 +70,34 @@ extern void NCR_StartInstance(NCR_Instance instance);
 /* Reset an instance */
 extern void NCR_ResetInstance(NCR_Instance inst);

+/* Reset polling interval of an instance */
+extern void NCR_ResetPoll(NCR_Instance instance);
+
 /* Change the remote address of an instance */
 extern void NCR_ChangeRemoteAddress(NCR_Instance inst, NTP_Remote_Address *remote_addr);

 /* This routine is called when a new packet arrives off the network,
   and it relates to a source we have an ongoing protocol exchange with */
-extern int NCR_ProcessKnown(NTP_Packet *message, struct timeval *now, double now_err, NCR_Instance data, NTP_Local_Address *local_addr, int length);
+extern int NCR_ProcessRxKnown(NCR_Instance inst, NTP_Local_Address *local_addr,
+                              NTP_Local_Timestamp *rx_ts, NTP_Packet *message, int length);

 /* This routine is called when a new packet arrives off the network,
   and we do not recognize its source */
-extern void NCR_ProcessUnknown(NTP_Packet *message, struct timeval *now, double now_err, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
+extern void NCR_ProcessRxUnknown(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+                                 NTP_Local_Timestamp *rx_ts, NTP_Packet *message, int length);
+
+/* This routine is called when a packet is sent to a source we have
+   an ongoing protocol exchange with */
+extern void NCR_ProcessTxKnown(NCR_Instance inst, NTP_Local_Address *local_addr,
+                               NTP_Local_Timestamp *tx_ts, NTP_Packet *message, int length);
+
+/* This routine is called when a packet is sent to a destination we
+   do not recognize */
+extern void NCR_ProcessTxUnknown(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+                                 NTP_Local_Timestamp *tx_ts, NTP_Packet *message, int length);

 /* Slew receive and transmit times in instance records */
-extern void NCR_SlewTimes(NCR_Instance inst, struct timeval *when, double dfreq, double doffset);
+extern void NCR_SlewTimes(NCR_Instance inst, struct timespec *when, double dfreq, double doffset);

 /* Take a particular source online (i.e. start sampling it) */
 extern void NCR_TakeSourceOnline(NCR_Instance inst);
@@ -95,7 +122,8 @@ extern void NCR_ModifyPolltarget(NCR_Instance inst, int new_poll_target);

 extern void NCR_InitiateSampleBurst(NCR_Instance inst, int n_good_samples, int n_total_samples);

-extern void NCR_ReportSource(NCR_Instance inst, RPT_SourceReport *report, struct timeval *now);
+extern void NCR_ReportSource(NCR_Instance inst, RPT_SourceReport *report, struct timespec *now);
+extern void NCR_GetNTPReport(NCR_Instance inst, RPT_NTPReport *report);

 extern int NCR_AddAccessRestriction(IPAddr *ip_addr, int subnet_bits, int allow, int all);
 extern int NCR_CheckAccessRestriction(IPAddr *ip_addr);
@@ -105,6 +133,8 @@ extern void NCR_IncrementActivityCounters(NCR_Instance inst, int *online, int *o

 extern NTP_Remote_Address *NCR_GetRemoteAddress(NCR_Instance instance);

+extern uint32_t NCR_GetLocalRefid(NCR_Instance inst);
+
 extern int NCR_IsSyncPeer(NCR_Instance instance);

 extern void NCR_AddBroadcastDestination(IPAddr *addr, unsigned short port, int interval);
--- a/ntp_io.c
+++ b/ntp_io.c
@@ -4,7 +4,7 @@
 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
 * Copyright (C) Timo Teras  2009
- * Copyright (C) Miroslav Lichvar  2009, 2013-2014
+ * Copyright (C) Miroslav Lichvar  2009, 2013-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -30,6 +30,7 @@

 #include "sysincl.h"

+#include "array.h"
 #include "ntp_io.h"
 #include "ntp_core.h"
 #include "ntp_sources.h"
@@ -37,9 +38,15 @@
 #include "local.h"
 #include "logging.h"
 #include "conf.h"
+#include "privops.h"
 #include "util.h"

+#ifdef HAVE_LINUX_TIMESTAMPING
+#include "ntp_io_linux.h"
+#endif
+
 #define INVALID_SOCK_FD -1
+#define CMSGBUF_SIZE 256

 union sockaddr_in46 {
  struct sockaddr_in in4;
@@ -49,6 +56,31 @@ union sockaddr_in46 {
  struct sockaddr u;
 };

+struct Message {
+  union sockaddr_in46 name;
+  struct iovec iov;
+  NTP_Receive_Buffer buf;
+  /* Aligned buffer for control messages */
+  struct cmsghdr cmsgbuf[CMSGBUF_SIZE / sizeof (struct cmsghdr)];
+};
+
+#ifdef HAVE_RECVMMSG
+#define MAX_RECV_MESSAGES 4
+#define MessageHeader mmsghdr
+#else
+/* Compatible with mmsghdr */
+struct MessageHeader {
+  struct msghdr msg_hdr;
+  unsigned int msg_len;
+};
+
+#define MAX_RECV_MESSAGES 1
+#endif
+
+/* Arrays of Message and MessageHeader */
+static ARR_Instance recv_messages;
+static ARR_Instance recv_headers;
+
 /* The server/peer and client sockets for IPv4 and IPv6 */
 static int server_sock_fd4;
 static int client_sock_fd4;
@@ -79,7 +111,7 @@ static int initialised=0;
 /* ================================================== */

 /* Forward prototypes */
-static void read_from_socket(void *anything);
+static void read_from_socket(int sock_fd, int event, void *anything);

 /* ================================================== */

@@ -90,15 +122,20 @@ prepare_socket(int family, int port_number, int client_only)
  socklen_t my_addr_len;
  int sock_fd;
  IPAddr bind_address;
-  int on_off = 1;
+  int events = SCH_FILE_INPUT, on_off = 1;

  /* Open Internet domain UDP socket for NTP message transmissions */

  sock_fd = socket(family, SOCK_DGRAM, 0);

  if (sock_fd < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not open %s NTP socket : %s",
-        family == AF_INET ? "IPv4" : "IPv6", strerror(errno));
+    if (!client_only) {
+      LOG(LOGS_ERR, "Could not open %s NTP socket : %s",
+          UTI_SockaddrFamilyToString(family), strerror(errno));
+    } else {
+      DEBUG_LOG("Could not open %s NTP socket : %s",
+                UTI_SockaddrFamilyToString(family), strerror(errno));
+    }
    return INVALID_SOCK_FD;
  }

@@ -156,38 +193,43 @@ prepare_socket(int family, int port_number, int client_only)
  /* Make the socket capable of re-using an old address if binding to a specific port */
  if (port_number &&
      setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, (char *)&on_off, sizeof(on_off)) < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not set reuseaddr socket options");
+    LOG(LOGS_ERR, "Could not set %s socket option", "SO_REUSEADDR");
    /* Don't quit - we might survive anyway */
  }
  
  /* Make the socket capable of sending broadcast pkts - needed for NTP broadcast mode */
  if (!client_only &&
      setsockopt(sock_fd, SOL_SOCKET, SO_BROADCAST, (char *)&on_off, sizeof(on_off)) < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not set broadcast socket options");
+    LOG(LOGS_ERR, "Could not set %s socket option", "SO_BROADCAST");
    /* Don't quit - we might survive anyway */
  }

-#ifdef SO_TIMESTAMP
-  /* Enable receiving of timestamp control messages */
-  if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMP, (char *)&on_off, sizeof(on_off)) < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not set timestamp socket options");
-    /* Don't quit - we might survive anyway */
-  }
+  /* Enable kernel/HW timestamping of packets */
+#ifdef HAVE_LINUX_TIMESTAMPING
+  if (!NIO_Linux_SetTimestampSocketOptions(sock_fd, client_only, &events))
 #endif
+#ifdef SO_TIMESTAMPNS
+    if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMPNS, (char *)&on_off, sizeof(on_off)) < 0)
+#endif
+#ifdef SO_TIMESTAMP
+      if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMP, (char *)&on_off, sizeof(on_off)) < 0)
+        LOG(LOGS_ERR, "Could not set %s socket option", "SO_TIMESTAMP");
+#endif
+      ;

 #ifdef IP_FREEBIND
  /* Allow binding to address that doesn't exist yet */
  if (my_addr_len > 0 &&
      setsockopt(sock_fd, IPPROTO_IP, IP_FREEBIND, (char *)&on_off, sizeof(on_off)) < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not set free bind socket option");
+    LOG(LOGS_ERR, "Could not set %s socket option", "IP_FREEBIND");
  }
 #endif

  if (family == AF_INET) {
-#ifdef IP_PKTINFO
+#ifdef HAVE_IN_PKTINFO
    /* We want the local IP info on server sockets */
    if (setsockopt(sock_fd, IPPROTO_IP, IP_PKTINFO, (char *)&on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not set packet info socket option");
+      LOG(LOGS_ERR, "Could not set %s socket option", "IP_PKTINFO");
      /* Don't quit - we might survive anyway */
    }
 #endif
@@ -197,32 +239,34 @@ prepare_socket(int family, int port_number, int client_only)
 #ifdef IPV6_V6ONLY
    /* Receive IPv6 packets only */
    if (setsockopt(sock_fd, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not set IPV6_V6ONLY socket option");
+      LOG(LOGS_ERR, "Could not set %s socket option", "IPV6_V6ONLY");
    }
 #endif

+#ifdef HAVE_IN6_PKTINFO
 #ifdef IPV6_RECVPKTINFO
    if (setsockopt(sock_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, (char *)&on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not set IPv6 packet info socket option");
+      LOG(LOGS_ERR, "Could not set %s socket option", "IPV6_RECVPKTINFO");
    }
-#elif defined(IPV6_PKTINFO)
+#else
    if (setsockopt(sock_fd, IPPROTO_IPV6, IPV6_PKTINFO, (char *)&on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not set IPv6 packet info socket option");
+      LOG(LOGS_ERR, "Could not set %s socket option", "IPV6_PKTINFO");
    }
+#endif
 #endif
  }
 #endif

  /* Bind the socket if a port or address was specified */
-  if (my_addr_len > 0 && bind(sock_fd, &my_addr.u, my_addr_len) < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not bind %s NTP socket : %s",
-        family == AF_INET ? "IPv4" : "IPv6", strerror(errno));
+  if (my_addr_len > 0 && PRV_BindSocket(sock_fd, &my_addr.u, my_addr_len) < 0) {
+    LOG(LOGS_ERR, "Could not bind %s NTP socket : %s",
+        UTI_SockaddrFamilyToString(family), strerror(errno));
    close(sock_fd);
    return INVALID_SOCK_FD;
  }

-  /* Register handler for read events on the socket */
-  SCH_AddInputFileHandler(sock_fd, read_from_socket, (void *)(long)sock_fd);
+  /* Register handler for read and possibly exception events on the socket */
+  SCH_AddFileHandler(sock_fd, events, read_from_socket, NULL);

  return sock_fd;
 }
@@ -257,7 +301,7 @@ connect_socket(int sock_fd, NTP_Remote_Address *remote_addr)
  assert(addr_len);

  if (connect(sock_fd, &addr.u, addr_len) < 0) {
-    DEBUG_LOG(LOGF_NtpIO, "Could not connect NTP socket to %s:%d : %s",
+    DEBUG_LOG("Could not connect NTP socket to %s:%d : %s",
        UTI_IPToString(&remote_addr->ip_addr), remote_addr->port,
        strerror(errno));
    return 0;
@@ -274,11 +318,38 @@ close_socket(int sock_fd)
  if (sock_fd == INVALID_SOCK_FD)
    return;

-  SCH_RemoveInputFileHandler(sock_fd);
+  SCH_RemoveFileHandler(sock_fd);
  close(sock_fd);
 }

 /* ================================================== */
+
+static void
+prepare_buffers(unsigned int n)
+{
+  struct MessageHeader *hdr;
+  struct Message *msg;
+  unsigned int i;
+
+  for (i = 0; i < n; i++) {
+    msg = ARR_GetElement(recv_messages, i);
+    hdr = ARR_GetElement(recv_headers, i);
+
+    msg->iov.iov_base = &msg->buf;
+    msg->iov.iov_len = sizeof (msg->buf);
+    hdr->msg_hdr.msg_name = &msg->name;
+    hdr->msg_hdr.msg_namelen = sizeof (msg->name);
+    hdr->msg_hdr.msg_iov = &msg->iov;
+    hdr->msg_hdr.msg_iovlen = 1;
+    hdr->msg_hdr.msg_control = &msg->cmsgbuf;
+    hdr->msg_hdr.msg_controllen = sizeof (msg->cmsgbuf);
+    hdr->msg_hdr.msg_flags = 0;
+    hdr->msg_len = 0;
+  }
+}
+
+/* ================================================== */
+
 void
 NIO_Initialise(int family)
 {
@@ -287,6 +358,22 @@ NIO_Initialise(int family)
  assert(!initialised);
  initialised = 1;

+#ifdef HAVE_LINUX_TIMESTAMPING
+  NIO_Linux_Initialise();
+#else
+  if (1) {
+    CNF_HwTsInterface *conf_iface;
+    if (CNF_GetHwTsInterface(0, &conf_iface))
+      LOG_FATAL("HW timestamping not supported");
+  }
+#endif
+
+  recv_messages = ARR_CreateInstance(sizeof (struct Message));
+  ARR_SetSize(recv_messages, MAX_RECV_MESSAGES);
+  recv_headers = ARR_CreateInstance(sizeof (struct MessageHeader));
+  ARR_SetSize(recv_headers, MAX_RECV_MESSAGES);
+  prepare_buffers(MAX_RECV_MESSAGES);
+
  server_port = CNF_GetNTPPort();
  client_port = CNF_GetAcquisitionPort();

@@ -340,7 +427,7 @@ NIO_Initialise(int family)
       && client_sock_fd6 == INVALID_SOCK_FD
 #endif
      )) {
-    LOG_FATAL(LOGF_NtpIO, "Could not open NTP sockets");
+    LOG_FATAL("Could not open NTP sockets");
  }
 }

@@ -359,6 +446,13 @@ NIO_Finalise(void)
  close_socket(server_sock_fd6);
  server_sock_fd6 = client_sock_fd6 = INVALID_SOCK_FD;
 #endif
+  ARR_DestroyInstance(recv_headers);
+  ARR_DestroyInstance(recv_messages);
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+  NIO_Linux_Finalise();
+#endif
+
  initialised = 0;
 }

@@ -474,69 +568,59 @@ NIO_IsServerSocket(int sock_fd)
 /* ================================================== */

 static void
-read_from_socket(void *anything)
+process_message(struct msghdr *hdr, int length, int sock_fd)
 {
-  /* This should only be called when there is something
-     to read, otherwise it will block. */
-
-  int status, sock_fd;
-  NTP_Receive_Buffer message;
-  union sockaddr_in46 where_from;
-  unsigned int flags = 0;
-  struct timeval now;
-  double now_err;
  NTP_Remote_Address remote_addr;
  NTP_Local_Address local_addr;
-  char cmsgbuf[256];
-  struct msghdr msg;
-  struct iovec iov;
+  NTP_Local_Timestamp local_ts;
+  struct timespec sched_ts;
  struct cmsghdr *cmsg;

-  assert(initialised);
+  SCH_GetLastEventTime(&local_ts.ts, &local_ts.err, NULL);
+  local_ts.source = NTP_TS_DAEMON;
+  sched_ts = local_ts.ts;

-  SCH_GetLastEventTime(&now, &now_err, NULL);
+  if (hdr->msg_namelen > sizeof (union sockaddr_in46)) {
+    DEBUG_LOG("Truncated source address");
+    return;
+  }

-  iov.iov_base = &message.ntp_pkt;
-  iov.iov_len = sizeof(message);
-  msg.msg_name = &where_from;
-  msg.msg_namelen = sizeof(where_from);
-  msg.msg_iov = &iov;
-  msg.msg_iovlen = 1;
-  msg.msg_control = (void *) cmsgbuf;
-  msg.msg_controllen = sizeof(cmsgbuf);
-  msg.msg_flags = 0;
-
-  sock_fd = (long)anything;
-  status = recvmsg(sock_fd, &msg, flags);
-
-  /* Don't bother checking if read failed or why if it did.  More
-     likely than not, it will be connection refused, resulting from a
-     previous sendto() directing a datagram at a port that is not
-     listening (which appears to generate an ICMP response, and on
-     some architectures e.g. Linux this is translated into an error
-     reponse on a subsequent recvfrom). */
-
-  if (status > 0) {
-    if (msg.msg_namelen > sizeof (where_from))
-      LOG_FATAL(LOGF_NtpIO, "Truncated source address");
-
-    UTI_SockaddrToIPAndPort(&where_from.u, &remote_addr.ip_addr, &remote_addr.port);
+  if (hdr->msg_namelen >= sizeof (((struct sockaddr *)hdr->msg_name)->sa_family)) {
+    UTI_SockaddrToIPAndPort((struct sockaddr *)hdr->msg_name,
+                            &remote_addr.ip_addr, &remote_addr.port);
+  } else {
+    remote_addr.ip_addr.family = IPADDR_UNSPEC;
+    remote_addr.port = 0;
+  }

  local_addr.ip_addr.family = IPADDR_UNSPEC;
+  local_addr.if_index = INVALID_IF_INDEX;
  local_addr.sock_fd = sock_fd;

-    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-#ifdef IP_PKTINFO
+  if (hdr->msg_flags & MSG_TRUNC) {
+    DEBUG_LOG("Received truncated message from %s:%d",
+              UTI_IPToString(&remote_addr.ip_addr), remote_addr.port);
+    return;
+  }
+
+  if (hdr->msg_flags & MSG_CTRUNC) {
+    DEBUG_LOG("Truncated control message");
+    /* Continue */
+  }
+
+  for (cmsg = CMSG_FIRSTHDR(hdr); cmsg; cmsg = CMSG_NXTHDR(hdr, cmsg)) {
+#ifdef HAVE_IN_PKTINFO
    if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO) {
      struct in_pktinfo ipi;

      memcpy(&ipi, CMSG_DATA(cmsg), sizeof(ipi));
-        local_addr.ip_addr.addr.in4 = ntohl(ipi.ipi_spec_dst.s_addr);
+      local_addr.ip_addr.addr.in4 = ntohl(ipi.ipi_addr.s_addr);
      local_addr.ip_addr.family = IPADDR_INET4;
+      local_addr.if_index = ipi.ipi_ifindex;
    }
 #endif

-#if defined(IPV6_PKTINFO) && defined(HAVE_IN6_PKTINFO)
+#ifdef HAVE_IN6_PKTINFO
    if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
      struct in6_pktinfo ipi;

@@ -544,63 +628,125 @@ read_from_socket(void *anything)
      memcpy(&local_addr.ip_addr.addr.in6, &ipi.ipi6_addr.s6_addr,
             sizeof (local_addr.ip_addr.addr.in6));
      local_addr.ip_addr.family = IPADDR_INET6;
+      local_addr.if_index = ipi.ipi6_ifindex;
    }
 #endif

-#ifdef SO_TIMESTAMP
-      if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SO_TIMESTAMP) {
+#ifdef SCM_TIMESTAMP
+    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMP) {
      struct timeval tv;
+      struct timespec ts;

      memcpy(&tv, CMSG_DATA(cmsg), sizeof(tv));
-        LCL_CookTime(&tv, &now, &now_err);
+      UTI_TimevalToTimespec(&tv, &ts);
+      LCL_CookTime(&ts, &local_ts.ts, &local_ts.err);
+      local_ts.source = NTP_TS_KERNEL;
+    }
+#endif
+
+#ifdef SCM_TIMESTAMPNS
+    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPNS) {
+      struct timespec ts;
+
+      memcpy(&ts, CMSG_DATA(cmsg), sizeof (ts));
+      LCL_CookTime(&ts, &local_ts.ts, &local_ts.err);
+      local_ts.source = NTP_TS_KERNEL;
    }
 #endif
  }

-    DEBUG_LOG(LOGF_NtpIO, "Received %d bytes from %s:%d to %s fd %d",
-              status, UTI_IPToString(&remote_addr.ip_addr), remote_addr.port,
-              UTI_IPToString(&local_addr.ip_addr), local_addr.sock_fd);
+#ifdef HAVE_LINUX_TIMESTAMPING
+  if (NIO_Linux_ProcessMessage(&remote_addr, &local_addr, &local_ts, hdr, length))
+    return;
+#endif

-    if (status >= NTP_NORMAL_PACKET_LENGTH) {
-
-      NSR_ProcessReceive((NTP_Packet *) &message.ntp_pkt, &now, now_err,
-                         &remote_addr, &local_addr, status);
-
-    } else {
+  DEBUG_LOG("Received %d bytes from %s:%d to %s fd=%d if=%d tss=%d delay=%.9f",
+            length, UTI_IPToString(&remote_addr.ip_addr), remote_addr.port,
+            UTI_IPToString(&local_addr.ip_addr), local_addr.sock_fd, local_addr.if_index,
+            local_ts.source, UTI_DiffTimespecsToDouble(&sched_ts, &local_ts.ts));

  /* Just ignore the packet if it's not of a recognized length */
+  if (length < NTP_NORMAL_PACKET_LENGTH || length > sizeof (NTP_Receive_Buffer))
+    return;

+  NSR_ProcessRx(&remote_addr, &local_addr, &local_ts,
+                (NTP_Packet *)hdr->msg_iov[0].iov_base, length);
 }
+
+/* ================================================== */
+
+static void
+read_from_socket(int sock_fd, int event, void *anything)
+{
+  /* This should only be called when there is something
+     to read, otherwise it may block */
+
+  struct MessageHeader *hdr;
+  unsigned int i, n;
+  int status, flags = 0;
+
+  hdr = ARR_GetElements(recv_headers);
+  n = ARR_GetSize(recv_headers);
+  assert(n >= 1);
+
+  if (event == SCH_FILE_EXCEPTION) {
+#ifdef HAVE_LINUX_TIMESTAMPING
+    flags |= MSG_ERRQUEUE;
+#else
+    assert(0);
+#endif
  }
+
+#ifdef HAVE_RECVMMSG
+  status = recvmmsg(sock_fd, hdr, n, flags | MSG_DONTWAIT, NULL);
+  if (status >= 0)
+    n = status;
+#else
+  n = 1;
+  status = recvmsg(sock_fd, &hdr[0].msg_hdr, flags);
+  if (status >= 0)
+    hdr[0].msg_len = status;
+#endif
+
+  if (status < 0) {
+    DEBUG_LOG("Could not receive from fd %d : %s", sock_fd,
+              strerror(errno));
+    return;
+  }
+
+  for (i = 0; i < n; i++) {
+    hdr = ARR_GetElement(recv_headers, i);
+    process_message(&hdr->msg_hdr, hdr->msg_len, sock_fd);
+  }
+
+  /* Restore the buffers to their original state */
+  prepare_buffers(n);
 }

 /* ================================================== */
 /* Send a packet to remote address from local address */

-static int
-send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr)
+int
+NIO_SendPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr,
+               NTP_Local_Address *local_addr, int length, int process_tx)
 {
  union sockaddr_in46 remote;
  struct msghdr msg;
  struct iovec iov;
-  char cmsgbuf[256];
+  struct cmsghdr *cmsg, cmsgbuf[CMSGBUF_SIZE / sizeof (struct cmsghdr)];
  int cmsglen;
  socklen_t addrlen = 0;

  assert(initialised);

  if (local_addr->sock_fd == INVALID_SOCK_FD) {
-    DEBUG_LOG(LOGF_NtpIO, "No socket to send to %s:%d",
+    DEBUG_LOG("No socket to send to %s:%d",
              UTI_IPToString(&remote_addr->ip_addr), remote_addr->port);
    return 0;
  }

  /* Don't set address with connected socket */
-  if (local_addr->sock_fd == server_sock_fd4 ||
-#ifdef FEAT_IPV6
-      local_addr->sock_fd == server_sock_fd6 ||
-#endif
-      !separate_client_sockets) {
+  if (NIO_IsServerSocket(local_addr->sock_fd) || !separate_client_sockets) {
    addrlen = UTI_IPAndPortToSockaddr(&remote_addr->ip_addr, remote_addr->port,
                                      &remote.u);
    if (!addrlen)
@@ -616,7 +762,7 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Lo
  }

  iov.iov_base = packet;
-  iov.iov_len = packetlen;
+  iov.iov_len = length;
  msg.msg_iov = &iov;
  msg.msg_iovlen = 1;
  msg.msg_control = cmsgbuf;
@@ -624,9 +770,8 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Lo
  msg.msg_flags = 0;
  cmsglen = 0;

-#ifdef IP_PKTINFO
+#ifdef HAVE_IN_PKTINFO
  if (local_addr->ip_addr.family == IPADDR_INET4) {
-    struct cmsghdr *cmsg;
    struct in_pktinfo *ipi;

    cmsg = CMSG_FIRSTHDR(&msg);
@@ -642,9 +787,8 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Lo
  }
 #endif

-#if defined(IPV6_PKTINFO) && defined(HAVE_IN6_PKTINFO)
+#ifdef HAVE_IN6_PKTINFO
  if (local_addr->ip_addr.family == IPADDR_INET6) {
-    struct cmsghdr *cmsg;
    struct in6_pktinfo *ipi;

    cmsg = CMSG_FIRSTHDR(&msg);
@@ -661,31 +805,27 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Lo
  }
 #endif

+#ifdef HAVE_LINUX_TIMESTAMPING
+  if (process_tx)
+   cmsglen = NIO_Linux_RequestTxTimestamp(&msg, cmsglen, local_addr->sock_fd);
+#endif
+
  msg.msg_controllen = cmsglen;
  /* This is apparently required on some systems */
  if (!cmsglen)
    msg.msg_control = NULL;

  if (sendmsg(local_addr->sock_fd, &msg, 0) < 0) {
-    DEBUG_LOG(LOGF_NtpIO, "Could not send to %s:%d from %s fd %d : %s",
+    DEBUG_LOG("Could not send to %s:%d from %s fd %d : %s",
        UTI_IPToString(&remote_addr->ip_addr), remote_addr->port,
        UTI_IPToString(&local_addr->ip_addr), local_addr->sock_fd,
        strerror(errno));
    return 0;
  }

-  DEBUG_LOG(LOGF_NtpIO, "Sent %d bytes to %s:%d from %s fd %d", packetlen,
+  DEBUG_LOG("Sent %d bytes to %s:%d from %s fd %d", length,
      UTI_IPToString(&remote_addr->ip_addr), remote_addr->port,
      UTI_IPToString(&local_addr->ip_addr), local_addr->sock_fd);

  return 1;
 }
-
-/* ================================================== */
-/* Send a packet to a given address */
-
-int
-NIO_SendPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
-{
-  return send_packet((void *) packet, length, remote_addr, local_addr);
-}
--- a/ntp_io.h
+++ b/ntp_io.h
@@ -54,6 +54,7 @@ extern void NIO_CloseServerSocket(int sock_fd);
 extern int NIO_IsServerSocket(int sock_fd);

 /* Function to transmit a packet */
-extern int NIO_SendPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
+extern int NIO_SendPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr,
+                          NTP_Local_Address *local_addr, int length, int process_tx);

 #endif /* GOT_NTP_IO_H */
--- a/ntp_io_linux.c
+++ b/ntp_io_linux.c
@@ -0,0 +1,665 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016-2017
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Functions for NTP I/O specific to Linux
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include <ifaddrs.h>
+#include <linux/errqueue.h>
+#include <linux/ethtool.h>
+#include <linux/net_tstamp.h>
+#include <linux/sockios.h>
+#include <net/if.h>
+
+#include "array.h"
+#include "conf.h"
+#include "hwclock.h"
+#include "local.h"
+#include "logging.h"
+#include "ntp_core.h"
+#include "ntp_io.h"
+#include "ntp_io_linux.h"
+#include "ntp_sources.h"
+#include "sched.h"
+#include "sys_linux.h"
+#include "util.h"
+
+union sockaddr_in46 {
+  struct sockaddr_in in4;
+#ifdef FEAT_IPV6
+  struct sockaddr_in6 in6;
+#endif
+  struct sockaddr u;
+};
+
+struct Interface {
+  char name[IF_NAMESIZE];
+  int if_index;
+  int phc_fd;
+  int phc_mode;
+  int phc_nocrossts;
+  /* Link speed in mbit/s */
+  int link_speed;
+  /* Start of UDP data at layer 2 for IPv4 and IPv6 */
+  int l2_udp4_ntp_start;
+  int l2_udp6_ntp_start;
+  /* Precision of PHC readings */
+  double precision;
+  /* Compensation of errors in TX and RX timestamping */
+  double tx_comp;
+  double rx_comp;
+  HCL_Instance clock;
+};
+
+/* Number of PHC readings per HW clock sample */
+#define PHC_READINGS 10
+
+/* Minimum interval between PHC readings */
+#define MIN_PHC_POLL -6
+
+/* Maximum acceptable offset between HW and daemon/kernel timestamp */
+#define MAX_TS_DELAY 1.0
+
+/* Array of Interfaces */
+static ARR_Instance interfaces;
+
+/* RX/TX and TX-specific timestamping socket options */
+static int ts_flags;
+static int ts_tx_flags;
+
+/* Flag indicating the socket options can't be changed in control messages */
+static int permanent_ts_options;
+
+/* ================================================== */
+
+static int
+add_interface(CNF_HwTsInterface *conf_iface)
+{
+  struct ethtool_ts_info ts_info;
+  struct hwtstamp_config ts_config;
+  struct ifreq req;
+  int sock_fd, if_index, phc_fd, req_hwts_flags;
+  unsigned int i;
+  struct Interface *iface;
+
+  /* Check if the interface was not already added */
+  for (i = 0; i < ARR_GetSize(interfaces); i++) {
+    if (!strcmp(conf_iface->name, ((struct Interface *)ARR_GetElement(interfaces, i))->name))
+      return 1;
+  }
+
+  sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (sock_fd < 0)
+    return 0;
+
+  memset(&req, 0, sizeof (req));
+  memset(&ts_info, 0, sizeof (ts_info));
+
+  if (snprintf(req.ifr_name, sizeof (req.ifr_name), "%s", conf_iface->name) >=
+      sizeof (req.ifr_name)) {
+    close(sock_fd);
+    return 0;
+  }
+
+  if (ioctl(sock_fd, SIOCGIFINDEX, &req)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "SIOCGIFINDEX", strerror(errno));
+    close(sock_fd);
+    return 0;
+  }
+
+  if_index = req.ifr_ifindex;
+
+  ts_info.cmd = ETHTOOL_GET_TS_INFO;
+  req.ifr_data = (char *)&ts_info;
+
+  if (ioctl(sock_fd, SIOCETHTOOL, &req)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "SIOCETHTOOL", strerror(errno));
+    close(sock_fd);
+    return 0;
+  }
+
+  req_hwts_flags = SOF_TIMESTAMPING_RX_HARDWARE | SOF_TIMESTAMPING_TX_HARDWARE |
+                   SOF_TIMESTAMPING_RAW_HARDWARE;
+  if ((ts_info.so_timestamping & req_hwts_flags) != req_hwts_flags) {
+    DEBUG_LOG("HW timestamping not supported on %s", req.ifr_name);
+    close(sock_fd);
+    return 0;
+  }
+
+  ts_config.flags = 0;
+  ts_config.tx_type = HWTSTAMP_TX_ON;
+
+  switch (conf_iface->rxfilter) {
+    case CNF_HWTS_RXFILTER_NONE:
+      ts_config.rx_filter = HWTSTAMP_FILTER_NONE;
+      break;
+    case CNF_HWTS_RXFILTER_NTP:
+#ifdef HAVE_LINUX_TIMESTAMPING_RXFILTER_NTP
+      if (ts_info.rx_filters & (1 << HWTSTAMP_FILTER_NTP_ALL)) {
+        ts_config.rx_filter = HWTSTAMP_FILTER_NTP_ALL;
+        break;
+      }
+#endif
+      /* Fall through */
+    default:
+      ts_config.rx_filter = HWTSTAMP_FILTER_ALL;
+      break;
+  }
+
+  req.ifr_data = (char *)&ts_config;
+
+  if (ioctl(sock_fd, SIOCSHWTSTAMP, &req)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "SIOCSHWTSTAMP", strerror(errno));
+    close(sock_fd);
+    return 0;
+  }
+
+  close(sock_fd);
+
+  phc_fd = SYS_Linux_OpenPHC(NULL, ts_info.phc_index);
+  if (phc_fd < 0)
+    return 0;
+
+  iface = ARR_GetNewElement(interfaces);
+
+  snprintf(iface->name, sizeof (iface->name), "%s", conf_iface->name);
+  iface->if_index = if_index;
+  iface->phc_fd = phc_fd;
+  iface->phc_mode = 0;
+  iface->phc_nocrossts = conf_iface->nocrossts;
+
+  /* Start with 1 gbit and no VLANs or IPv4/IPv6 options */
+  iface->link_speed = 1000;
+  iface->l2_udp4_ntp_start = 42;
+  iface->l2_udp6_ntp_start = 62;
+
+  iface->precision = conf_iface->precision;
+  iface->tx_comp = conf_iface->tx_comp;
+  iface->rx_comp = conf_iface->rx_comp;
+
+  iface->clock = HCL_CreateInstance(UTI_Log2ToDouble(MAX(conf_iface->minpoll, MIN_PHC_POLL)));
+
+  LOG(LOGS_INFO, "Enabled HW timestamping on %s", iface->name);
+
+  return 1;
+}
+
+/* ================================================== */
+
+static int
+add_all_interfaces(CNF_HwTsInterface *conf_iface_all)
+{
+  CNF_HwTsInterface conf_iface;
+  struct ifaddrs *ifaddr, *ifa;
+  int r;
+
+  conf_iface = *conf_iface_all;
+
+  if (getifaddrs(&ifaddr)) {
+    DEBUG_LOG("getifaddrs() failed : %s", strerror(errno));
+    return 0;
+  }
+
+  for (r = 0, ifa = ifaddr; ifa; ifa = ifa->ifa_next) {
+    conf_iface.name = ifa->ifa_name;
+    if (add_interface(&conf_iface))
+      r = 1;
+  }
+  
+  freeifaddrs(ifaddr);
+
+  /* Return success if at least one interface was added */
+  return r;
+}
+
+/* ================================================== */
+
+static void
+update_interface_speed(struct Interface *iface)
+{
+  struct ethtool_cmd cmd;
+  struct ifreq req;
+  int sock_fd;
+
+  sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (sock_fd < 0)
+    return;
+
+  memset(&req, 0, sizeof (req));
+  memset(&cmd, 0, sizeof (cmd));
+
+  snprintf(req.ifr_name, sizeof (req.ifr_name), "%s", iface->name);
+  cmd.cmd = ETHTOOL_GSET;
+  req.ifr_data = (char *)&cmd;
+
+  if (ioctl(sock_fd, SIOCETHTOOL, &req)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "SIOCETHTOOL", strerror(errno));
+    close(sock_fd);
+    return;
+  }
+
+  close(sock_fd);
+
+  iface->link_speed = ethtool_cmd_speed(&cmd);
+}
+
+/* ================================================== */
+
+#if defined(HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO) || defined(HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW)
+static int
+check_timestamping_option(int option)
+{
+  int sock_fd;
+
+  sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (sock_fd < 0)
+    return 0;
+
+  if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMPING, &option, sizeof (option)) < 0) {
+    DEBUG_LOG("Could not enable timestamping option %x", option);
+    close(sock_fd);
+    return 0;
+  }
+
+  close(sock_fd);
+  return 1;
+}
+#endif
+
+/* ================================================== */
+
+void
+NIO_Linux_Initialise(void)
+{
+  CNF_HwTsInterface *conf_iface;
+  unsigned int i;
+  int hwts;
+
+  interfaces = ARR_CreateInstance(sizeof (struct Interface));
+
+  /* Enable HW timestamping on specified interfaces.  If "*" was specified, try
+     all interfaces.  If no interface was specified, enable SW timestamping. */
+
+  for (i = hwts = 0; CNF_GetHwTsInterface(i, &conf_iface); i++) {
+    if (!strcmp("*", conf_iface->name))
+      continue;
+    if (!add_interface(conf_iface))
+      LOG_FATAL("Could not enable HW timestamping on %s", conf_iface->name);
+    hwts = 1;
+  }
+
+  for (i = 0; CNF_GetHwTsInterface(i, &conf_iface); i++) {
+    if (strcmp("*", conf_iface->name))
+      continue;
+    if (add_all_interfaces(conf_iface))
+      hwts = 1;
+    break;
+  }
+
+  ts_flags = SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_RX_SOFTWARE;
+  ts_tx_flags = SOF_TIMESTAMPING_TX_SOFTWARE;
+
+  if (hwts) {
+    ts_flags |= SOF_TIMESTAMPING_RAW_HARDWARE | SOF_TIMESTAMPING_RX_HARDWARE;
+    ts_tx_flags |= SOF_TIMESTAMPING_TX_HARDWARE;
+#ifdef HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO
+    if (check_timestamping_option(SOF_TIMESTAMPING_OPT_PKTINFO))
+      ts_flags |= SOF_TIMESTAMPING_OPT_PKTINFO;
+#endif
+#ifdef HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW
+    if (check_timestamping_option(SOF_TIMESTAMPING_OPT_TX_SWHW))
+      ts_flags |= SOF_TIMESTAMPING_OPT_TX_SWHW;
+#endif
+  }
+
+  /* Enable IP_PKTINFO in messages looped back to the error queue */
+  ts_flags |= SOF_TIMESTAMPING_OPT_CMSG;
+
+  /* Kernels before 4.7 ignore timestamping flags set in control messages */
+  permanent_ts_options = !SYS_Linux_CheckKernelVersion(4, 7);
+}
+
+/* ================================================== */
+
+void
+NIO_Linux_Finalise(void)
+{
+  struct Interface *iface;
+  unsigned int i;
+
+  for (i = 0; i < ARR_GetSize(interfaces); i++) {
+    iface = ARR_GetElement(interfaces, i);
+    HCL_DestroyInstance(iface->clock);
+    close(iface->phc_fd);
+  }
+
+  ARR_DestroyInstance(interfaces);
+}
+
+/* ================================================== */
+
+int
+NIO_Linux_SetTimestampSocketOptions(int sock_fd, int client_only, int *events)
+{
+  int val, flags;
+
+  if (!ts_flags)
+    return 0;
+
+  /* Enable SCM_TIMESTAMPING control messages and the socket's error queue in
+     order to receive our transmitted packets with more accurate timestamps */
+
+  val = 1;
+  flags = ts_flags;
+
+  if (client_only || permanent_ts_options)
+    flags |= ts_tx_flags;
+
+  if (setsockopt(sock_fd, SOL_SOCKET, SO_SELECT_ERR_QUEUE, &val, sizeof (val)) < 0) {
+    LOG(LOGS_ERR, "Could not set %s socket option", "SO_SELECT_ERR_QUEUE");
+    ts_flags = 0;
+    return 0;
+  }
+
+  if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMPING, &flags, sizeof (flags)) < 0) {
+    LOG(LOGS_ERR, "Could not set %s socket option", "SO_TIMESTAMPING");
+    ts_flags = 0;
+    return 0;
+  }
+
+  *events |= SCH_FILE_EXCEPTION;
+  return 1;
+}
+
+/* ================================================== */
+
+static struct Interface *
+get_interface(int if_index)
+{
+  struct Interface *iface;
+  unsigned int i;
+
+  for (i = 0; i < ARR_GetSize(interfaces); i++) {
+    iface = ARR_GetElement(interfaces, i);
+    if (iface->if_index != if_index)
+      continue;
+
+    return iface;
+  }
+
+  return NULL;
+}
+
+/* ================================================== */
+
+static void
+process_hw_timestamp(struct Interface *iface, struct timespec *hw_ts,
+                     NTP_Local_Timestamp *local_ts, int rx_ntp_length, int family,
+                     int l2_length)
+{
+  struct timespec sample_phc_ts, sample_sys_ts, sample_local_ts, ts;
+  double rx_correction, ts_delay, phc_err, local_err;
+
+  if (HCL_NeedsNewSample(iface->clock, &local_ts->ts)) {
+    if (!SYS_Linux_GetPHCSample(iface->phc_fd, iface->phc_nocrossts, iface->precision,
+                                &iface->phc_mode, &sample_phc_ts, &sample_sys_ts,
+                                &phc_err))
+      return;
+
+    LCL_CookTime(&sample_sys_ts, &sample_local_ts, &local_err);
+    HCL_AccumulateSample(iface->clock, &sample_phc_ts, &sample_local_ts,
+                         phc_err + local_err);
+
+    update_interface_speed(iface);
+  }
+
+  /* We need to transpose RX timestamps as hardware timestamps are normally
+     preamble timestamps and RX timestamps in NTP are supposed to be trailer
+     timestamps.  If we don't know the length of the packet at layer 2, we
+     make an assumption that UDP data start at the same position as in the
+     last transmitted packet which had a HW TX timestamp. */
+  if (rx_ntp_length && iface->link_speed) {
+    if (!l2_length)
+      l2_length = (family == IPADDR_INET4 ? iface->l2_udp4_ntp_start :
+                   iface->l2_udp6_ntp_start) + rx_ntp_length + 4;
+    rx_correction = l2_length / (1.0e6 / 8 * iface->link_speed);
+
+    UTI_AddDoubleToTimespec(hw_ts, rx_correction, hw_ts);
+  }
+
+  if (!HCL_CookTime(iface->clock, hw_ts, &ts, &local_err))
+    return;
+
+  if (!rx_ntp_length && iface->tx_comp)
+    UTI_AddDoubleToTimespec(&ts, iface->tx_comp, &ts);
+  else if (rx_ntp_length && iface->rx_comp)
+    UTI_AddDoubleToTimespec(&ts, -iface->rx_comp, &ts);
+
+  ts_delay = UTI_DiffTimespecsToDouble(&local_ts->ts, &ts);
+
+  if (fabs(ts_delay) > MAX_TS_DELAY) {
+    DEBUG_LOG("Unacceptable timestamp delay %.9f", ts_delay);
+    return;
+  }
+
+  local_ts->ts = ts;
+  local_ts->err = local_err;
+  local_ts->source = NTP_TS_HARDWARE;
+}
+
+/* ================================================== */
+/* Extract UDP data from a layer 2 message.  Supported is Ethernet
+   with optional VLAN tags. */
+
+static int
+extract_udp_data(unsigned char *msg, NTP_Remote_Address *remote_addr, int len)
+{
+  unsigned char *msg_start = msg;
+  union sockaddr_in46 addr;
+
+  remote_addr->ip_addr.family = IPADDR_UNSPEC;
+  remote_addr->port = 0;
+
+  /* Skip MACs */
+  if (len < 12)
+    return 0;
+  len -= 12, msg += 12;
+
+  /* Skip VLAN tag(s) if present */
+  while (len >= 4 && msg[0] == 0x81 && msg[1] == 0x00)
+    len -= 4, msg += 4;
+
+  /* Skip IPv4 or IPv6 ethertype */
+  if (len < 2 || !((msg[0] == 0x08 && msg[1] == 0x00) ||
+                   (msg[0] == 0x86 && msg[1] == 0xdd)))
+    return 0;
+  len -= 2, msg += 2;
+
+  /* Parse destination address and port from IPv4/IPv6 and UDP headers */
+  if (len >= 20 && msg[0] >> 4 == 4) {
+    int ihl = (msg[0] & 0xf) * 4;
+
+    if (len < ihl + 8 || msg[9] != 17)
+      return 0;
+
+    memcpy(&addr.in4.sin_addr.s_addr, msg + 16, sizeof (uint32_t));
+    addr.in4.sin_port = *(uint16_t *)(msg + ihl + 2);
+    addr.in4.sin_family = AF_INET;
+    len -= ihl + 8, msg += ihl + 8;
+#ifdef FEAT_IPV6
+  } else if (len >= 48 && msg[0] >> 4 == 6) {
+    /* IPv6 extension headers are not supported */
+    if (msg[6] != 17)
+      return 0;
+
+    memcpy(&addr.in6.sin6_addr.s6_addr, msg + 24, 16);
+    addr.in6.sin6_port = *(uint16_t *)(msg + 40 + 2);
+    addr.in6.sin6_family = AF_INET6;
+    len -= 48, msg += 48;
+#endif
+  } else {
+    return 0;
+  }
+
+  UTI_SockaddrToIPAndPort(&addr.u, &remote_addr->ip_addr, &remote_addr->port);
+
+  /* Move the message to fix alignment of its fields */
+  if (len > 0)
+    memmove(msg_start, msg, len);
+
+  return len;
+}
+
+/* ================================================== */
+
+int
+NIO_Linux_ProcessMessage(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+                         NTP_Local_Timestamp *local_ts, struct msghdr *hdr, int length)
+{
+  struct Interface *iface;
+  struct cmsghdr *cmsg;
+  int is_tx, ts_if_index, l2_length;
+
+  is_tx = hdr->msg_flags & MSG_ERRQUEUE;
+  iface = NULL;
+  ts_if_index = local_addr->if_index;
+  l2_length = 0;
+
+  for (cmsg = CMSG_FIRSTHDR(hdr); cmsg; cmsg = CMSG_NXTHDR(hdr, cmsg)) {
+#ifdef HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO
+    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPING_PKTINFO) {
+      struct scm_ts_pktinfo ts_pktinfo;
+
+      memcpy(&ts_pktinfo, CMSG_DATA(cmsg), sizeof (ts_pktinfo));
+
+      ts_if_index = ts_pktinfo.if_index;
+      l2_length = ts_pktinfo.pkt_length;
+
+      DEBUG_LOG("Received HW timestamp info if=%d length=%d", ts_if_index, l2_length);
+    }
+#endif
+
+    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPING) {
+      struct scm_timestamping ts3;
+
+      memcpy(&ts3, CMSG_DATA(cmsg), sizeof (ts3));
+
+      if (!UTI_IsZeroTimespec(&ts3.ts[2])) {
+        iface = get_interface(ts_if_index);
+        if (iface) {
+          process_hw_timestamp(iface, &ts3.ts[2], local_ts, !is_tx ? length : 0,
+                               remote_addr->ip_addr.family, l2_length);
+        } else {
+          DEBUG_LOG("HW clock not found for interface %d", ts_if_index);
+        }
+      }
+
+      if (local_ts->source == NTP_TS_DAEMON && !UTI_IsZeroTimespec(&ts3.ts[0]) &&
+          (!is_tx || UTI_IsZeroTimespec(&ts3.ts[2]))) {
+        LCL_CookTime(&ts3.ts[0], &local_ts->ts, &local_ts->err);
+        local_ts->source = NTP_TS_KERNEL;
+      }
+    }
+
+    if ((cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR) ||
+        (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_RECVERR)) {
+      struct sock_extended_err err;
+
+      memcpy(&err, CMSG_DATA(cmsg), sizeof (err));
+
+      if (err.ee_errno != ENOMSG || err.ee_info != SCM_TSTAMP_SND ||
+          err.ee_origin != SO_EE_ORIGIN_TIMESTAMPING) {
+        DEBUG_LOG("Unknown extended error");
+        /* Drop the message */
+        return 1;
+      }
+    }
+  }
+
+  /* Return the message if it's not received from the error queue */
+  if (!is_tx)
+    return 0;
+
+  /* The data from the error queue includes all layers up to UDP.  We have to
+     extract the UDP data and also the destination address with port as there
+     currently doesn't seem to be a better way to get them both. */
+  l2_length = length;
+  length = extract_udp_data(hdr->msg_iov[0].iov_base, remote_addr, length);
+
+  DEBUG_LOG("Received %d (%d) bytes from error queue for %s:%d fd=%d if=%d tss=%d",
+            l2_length, length, UTI_IPToString(&remote_addr->ip_addr), remote_addr->port,
+            local_addr->sock_fd, local_addr->if_index, local_ts->source);
+
+  /* Update assumed position of UDP data at layer 2 for next received packet */
+  if (iface && length) {
+    if (remote_addr->ip_addr.family == IPADDR_INET4)
+      iface->l2_udp4_ntp_start = l2_length - length;
+    else if (remote_addr->ip_addr.family == IPADDR_INET6)
+      iface->l2_udp6_ntp_start = l2_length - length;
+  }
+
+  /* Drop the message if it has no timestamp or its processing failed */
+  if (local_ts->source == NTP_TS_DAEMON) {
+    DEBUG_LOG("Missing TX timestamp");
+    return 1;
+  }
+
+  if (length < NTP_NORMAL_PACKET_LENGTH)
+    return 1;
+
+  NSR_ProcessTx(remote_addr, local_addr, local_ts,
+                (NTP_Packet *)hdr->msg_iov[0].iov_base, length);
+
+  return 1;
+}
+
+/* ================================================== */
+
+int
+NIO_Linux_RequestTxTimestamp(struct msghdr *msg, int cmsglen, int sock_fd)
+{
+  struct cmsghdr *cmsg;
+
+  /* Check if TX timestamping is disabled on this socket */
+  if (permanent_ts_options || !NIO_IsServerSocket(sock_fd))
+    return cmsglen;
+
+  /* Add control message that will enable TX timestamping for this message.
+     Don't use CMSG_NXTHDR as the one in glibc is buggy for creating new
+     control messages. */
+  cmsg = (struct cmsghdr *)((char *)CMSG_FIRSTHDR(msg) + cmsglen);
+  memset(cmsg, 0, CMSG_SPACE(sizeof (ts_tx_flags)));
+  cmsglen += CMSG_SPACE(sizeof (ts_tx_flags));
+
+  cmsg->cmsg_level = SOL_SOCKET;
+  cmsg->cmsg_type = SO_TIMESTAMPING;
+  cmsg->cmsg_len = CMSG_LEN(sizeof (ts_tx_flags));
+
+  memcpy(CMSG_DATA(cmsg), &ts_tx_flags, sizeof (ts_tx_flags));
+
+  return cmsglen;
+}
--- a/ntp_io_linux.h
+++ b/ntp_io_linux.h
@@ -2,7 +2,7 @@
  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************
- * Copyright (C) Richard P. Curnow  1997-2002
+ * Copyright (C) Miroslav Lichvar  2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -21,11 +21,16 @@

  =======================================================================

+  This is the header file for the Linux-specific NTP socket I/O bits.
  */

-#ifndef GOT_MKDIRPP_H
-#define GOT_MKDIRPP_H
+extern void NIO_Linux_Initialise(void);

-extern int mkdir_and_parents(const char *path);
+extern void NIO_Linux_Finalise(void);

-#endif
+extern int NIO_Linux_SetTimestampSocketOptions(int sock_fd, int client_only, int *events);
+
+extern int NIO_Linux_ProcessMessage(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+                                    NTP_Local_Timestamp *local_ts, struct msghdr *hdr, int length);
+
+extern int NIO_Linux_RequestTxTimestamp(struct msghdr *msg, int cmsglen, int sock_fd);
--- a/ntp_signd.c
+++ b/ntp_signd.c
@@ -0,0 +1,379 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Support for MS-SNTP authentication in Samba (ntp_signd)
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "array.h"
+#include "conf.h"
+#include "logging.h"
+#include "ntp_io.h"
+#include "ntp_signd.h"
+#include "sched.h"
+#include "util.h"
+
+/* Declarations per samba/source4/librpc/idl/ntp_signd.idl */
+
+#define SIGND_VERSION 0
+
+typedef enum {
+  SIGN_TO_CLIENT = 0,
+  ASK_SERVER_TO_SIGN = 1,
+  CHECK_SERVER_SIGNATURE = 2,
+  SIGNING_SUCCESS = 3,
+  SIGNING_FAILURE = 4,
+} SigndOp;
+
+typedef struct {
+  uint32_t length;
+  uint32_t version;
+  uint32_t op;
+  uint16_t packet_id;
+  uint16_t _pad;
+  uint32_t key_id;
+  NTP_Packet packet_to_sign;
+} SigndRequest;
+
+typedef struct {
+  uint32_t length;
+  uint32_t version;
+  uint32_t op;
+  uint32_t packet_id;
+  NTP_Packet signed_packet;
+} SigndResponse;
+
+typedef struct {
+  NTP_Remote_Address remote_addr;
+  NTP_Local_Address local_addr;
+
+  int sent;
+  int received;
+  int request_length;
+  struct timespec request_ts;
+  SigndRequest request;
+  SigndResponse response;
+} SignInstance;
+
+/* As the communication with ntp_signd is asynchronous, incoming packets are
+   saved in a queue in order to avoid loss when they come in bursts */
+
+#define MAX_QUEUE_LENGTH 16U
+#define NEXT_QUEUE_INDEX(index) (((index) + 1) % MAX_QUEUE_LENGTH)
+#define IS_QUEUE_EMPTY() (queue_head == queue_tail)
+
+/* Fixed-size array of SignInstance */
+static ARR_Instance queue;
+static unsigned int queue_head;
+static unsigned int queue_tail;
+
+#define INVALID_SOCK_FD -1
+
+/* Unix domain socket connected to ntp_signd */
+static int sock_fd;
+
+#define MIN_AUTH_DELAY 1.0e-5
+#define MAX_AUTH_DELAY 1.0e-2
+
+/* Average time needed for signing one packet.  This is used to adjust the
+   transmit timestamp in NTP packets.  The timestamp won't be very accurate as
+   the delay is variable, but it should be good enough for MS-SNTP clients. */
+static double auth_delay;
+
+/* Flag indicating if the MS-SNTP authentication is enabled */
+static int enabled;
+
+/* ================================================== */
+
+static void read_write_socket(int sock_fd, int event, void *anything);
+
+/* ================================================== */
+
+static void
+close_socket(void)
+{
+  SCH_RemoveFileHandler(sock_fd);
+  close(sock_fd);
+  sock_fd = INVALID_SOCK_FD;
+
+  /* Empty the queue */
+  queue_head = queue_tail = 0;
+}
+
+/* ================================================== */
+
+static int
+open_socket(void)
+{
+  struct sockaddr_un s;
+
+  if (sock_fd >= 0)
+    return 1;
+
+  sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
+  if (sock_fd < 0) {
+    DEBUG_LOG("Could not open signd socket : %s", strerror(errno));
+    return 0;
+  }
+
+  UTI_FdSetCloexec(sock_fd);
+  SCH_AddFileHandler(sock_fd, SCH_FILE_INPUT, read_write_socket, NULL);
+
+  s.sun_family = AF_UNIX;
+  if (snprintf(s.sun_path, sizeof (s.sun_path), "%s/socket",
+               CNF_GetNtpSigndSocket()) >= sizeof (s.sun_path)) {
+    DEBUG_LOG("signd socket path too long");
+    close_socket();
+    return 0;
+  }
+
+  if (connect(sock_fd, (struct sockaddr *)&s, sizeof (s)) < 0) {
+    DEBUG_LOG("Could not connect to signd : %s", strerror(errno));
+    close_socket();
+    return 0;
+  }
+
+  DEBUG_LOG("Connected to signd");
+
+  return 1;
+}
+
+/* ================================================== */
+
+static void
+process_response(SignInstance *inst)
+{
+  struct timespec ts;
+  double delay;
+
+  if (ntohs(inst->request.packet_id) != ntohl(inst->response.packet_id)) {
+    DEBUG_LOG("Invalid response ID");
+    return;
+  }
+
+  if (ntohl(inst->response.op) != SIGNING_SUCCESS) {
+    DEBUG_LOG("Signing failed");
+    return;
+  }
+
+  /* Check if the file descriptor is still valid */
+  if (!NIO_IsServerSocket(inst->local_addr.sock_fd)) {
+    DEBUG_LOG("Invalid NTP socket");
+    return;
+  }
+
+  SCH_GetLastEventTime(NULL, NULL, &ts);
+  delay = UTI_DiffTimespecsToDouble(&ts, &inst->request_ts);
+
+  DEBUG_LOG("Signing succeeded (delay %f)", delay);
+
+  /* Send the signed NTP packet */
+  NIO_SendPacket(&inst->response.signed_packet, &inst->remote_addr, &inst->local_addr,
+                 ntohl(inst->response.length) + sizeof (inst->response.length) -
+                 offsetof(SigndResponse, signed_packet), 0);
+
+  /* Update exponential moving average of the authentication delay */
+  delay = CLAMP(MIN_AUTH_DELAY, delay, MAX_AUTH_DELAY);
+  auth_delay += 0.1 * (delay - auth_delay);
+}
+
+/* ================================================== */
+
+static void
+read_write_socket(int sock_fd, int event, void *anything)
+{
+  SignInstance *inst;
+  uint32_t response_length;
+  int s;
+
+  inst = ARR_GetElement(queue, queue_head);
+
+  if (event == SCH_FILE_OUTPUT) {
+    assert(!IS_QUEUE_EMPTY());
+    assert(inst->sent < inst->request_length);
+
+    if (!inst->sent)
+      SCH_GetLastEventTime(NULL, NULL, &inst->request_ts);
+
+    s = send(sock_fd, (char *)&inst->request + inst->sent,
+             inst->request_length - inst->sent, 0);
+
+    if (s < 0) {
+      DEBUG_LOG("signd socket error: %s", strerror(errno));
+      close_socket();
+      return;
+    }
+
+    DEBUG_LOG("Sent %d bytes to signd", s);
+    inst->sent += s;
+
+    /* Try again later if the request is not complete yet */
+    if (inst->sent < inst->request_length)
+      return;
+
+    /* Disable output and wait for a response */
+    SCH_SetFileHandlerEvents(sock_fd, SCH_FILE_INPUT);
+  }
+
+  if (event == SCH_FILE_INPUT) {
+    if (IS_QUEUE_EMPTY()) {
+        DEBUG_LOG("Unexpected signd response");
+        close_socket();
+        return;
+    }
+
+    assert(inst->received < sizeof (inst->response));
+    s = recv(sock_fd, (char *)&inst->response + inst->received,
+             sizeof (inst->response) - inst->received, 0);
+
+    if (s <= 0) {
+      if (s < 0)
+        DEBUG_LOG("signd socket error: %s", strerror(errno));
+      else
+        DEBUG_LOG("signd socket closed");
+
+      close_socket();
+      return;
+    }
+
+    DEBUG_LOG("Received %d bytes from signd", s);
+    inst->received += s;
+
+    if (inst->received < sizeof (inst->response.length))
+      return;
+
+    response_length = ntohl(inst->response.length) + sizeof (inst->response.length);
+
+    if (response_length < offsetof(SigndResponse, signed_packet) ||
+        response_length > sizeof (SigndResponse)) {
+      DEBUG_LOG("Invalid response length");
+      close_socket();
+      return;
+    }
+
+    /* Wait for more data if not complete yet */
+    if (inst->received < response_length)
+      return;
+
+    process_response(inst);
+
+    /* Move the head and enable output for the next packet */
+    queue_head = NEXT_QUEUE_INDEX(queue_head);
+    if (!IS_QUEUE_EMPTY())
+      SCH_SetFileHandlerEvents(sock_fd, SCH_FILE_INPUT | SCH_FILE_OUTPUT);
+  }
+}
+
+/* ================================================== */
+
+void
+NSD_Initialise()
+{
+  sock_fd = INVALID_SOCK_FD;
+  auth_delay = MIN_AUTH_DELAY;
+  enabled = CNF_GetNtpSigndSocket() && CNF_GetNtpSigndSocket()[0];
+
+  if (!enabled)
+    return;
+
+  queue = ARR_CreateInstance(sizeof (SignInstance));
+  ARR_SetSize(queue, MAX_QUEUE_LENGTH);
+  queue_head = queue_tail = 0;
+
+  LOG(LOGS_INFO, "MS-SNTP authentication enabled");
+}
+
+/* ================================================== */
+
+void
+NSD_Finalise()
+{
+  if (!enabled)
+    return;
+  if (sock_fd != INVALID_SOCK_FD)
+    close_socket();
+  ARR_DestroyInstance(queue);
+}
+
+/* ================================================== */
+
+extern int NSD_GetAuthDelay(uint32_t key_id)
+{
+  return 1.0e9 * auth_delay;
+}
+
+/* ================================================== */
+
+int
+NSD_SignAndSendPacket(uint32_t key_id, NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
+{
+  SignInstance *inst;
+
+  if (!enabled) {
+    DEBUG_LOG("signd disabled");
+    return 0;
+  }
+
+  if (queue_head == NEXT_QUEUE_INDEX(queue_tail)) {
+    DEBUG_LOG("signd queue full");
+    return 0;
+  }
+
+  if (length != NTP_NORMAL_PACKET_LENGTH) {
+    DEBUG_LOG("Invalid packet length");
+    return 0;
+  }
+
+  if (!open_socket())
+    return 0;
+
+  inst = ARR_GetElement(queue, queue_tail);
+  inst->remote_addr = *remote_addr;
+  inst->local_addr = *local_addr;
+  inst->sent = 0;
+  inst->received = 0;
+  inst->request_length = offsetof(SigndRequest, packet_to_sign) + length;
+
+  /* The length field doesn't include itself */
+  inst->request.length = htonl(inst->request_length - sizeof (inst->request.length));
+  inst->request.version = htonl(SIGND_VERSION);
+  inst->request.op = htonl(SIGN_TO_CLIENT);
+  inst->request.packet_id = htons(queue_tail);
+  inst->request._pad = 0;
+  inst->request.key_id = htonl(key_id);
+
+  memcpy(&inst->request.packet_to_sign, packet, length);
+
+  /* Enable output if there was no pending request */
+  if (IS_QUEUE_EMPTY())
+    SCH_SetFileHandlerEvents(sock_fd, SCH_FILE_INPUT | SCH_FILE_OUTPUT);
+
+  queue_tail = NEXT_QUEUE_INDEX(queue_tail);
+
+  DEBUG_LOG("Packet added to signd queue (%u:%u)", queue_head, queue_tail);
+
+  return 1;
+}
--- a/ntp_signd.h
+++ b/ntp_signd.h
@@ -0,0 +1,44 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Header for MS-SNTP authentication via Samba (ntp_signd) */
+
+#ifndef GOT_NTP_SIGND_H
+#define GOT_NTP_SIGND_H
+
+#include "addressing.h"
+#include "ntp.h"
+
+/* Initialisation function */
+extern void NSD_Initialise(void);
+
+/* Finalisation function */
+extern void NSD_Finalise(void);
+
+/* Function to get an estimate of delay due to signing */
+extern int NSD_GetAuthDelay(uint32_t key_id);
+
+/* Function to sign an NTP packet and send it */
+extern int NSD_SignAndSendPacket(uint32_t key_id, NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
+
+#endif
--- a/ntp_sources.c
+++ b/ntp_sources.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2012, 2014
+ * Copyright (C) Miroslav Lichvar  2011-2012, 2014, 2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -39,6 +39,7 @@
 #include "local.h"
 #include "memory.h"
 #include "nameserv_async.h"
+#include "privops.h"
 #include "sched.h"

 /* ================================================== */
@@ -49,14 +50,15 @@ typedef struct {
  NTP_Remote_Address *remote_addr; /* The address of this source, non-NULL
                                      means this slot in table is in use */
  NCR_Instance data;            /* Data for the protocol engine for this source */
+  char *name;                   /* Name of the source, may be NULL */
  int pool;                     /* Number of the pool from which was this source
                                   added or INVALID_POOL */
  int tentative;                /* Flag indicating there was no valid response
-                                   yet and the source may be removed if other
-                                   sources from the pool respond first */
+                                   received from the source yet */
 } SourceRecord;

-/* Hash table of SourceRecord, the size should be a power of two */
+/* Hash table of SourceRecord, its size is a power of two and it's never
+   more than half full */
 static ARR_Instance records;

 /* Number of sources in the hash table */
@@ -69,6 +71,7 @@ static int auto_start_sources = 0;
 struct UnresolvedSource {
  char *name;
  int port;
+  int random_order;
  int replacement;
  union {
    struct {
@@ -85,6 +88,7 @@ struct UnresolvedSource {
 #define RESOLVE_INTERVAL_UNIT 7
 #define MIN_RESOLVE_INTERVAL 2
 #define MAX_RESOLVE_INTERVAL 9
+#define MIN_REPLACEMENT_INTERVAL 8

 static struct UnresolvedSource *unresolved_sources = NULL;
 static int resolving_interval = 0;
@@ -92,15 +96,11 @@ static SCH_TimeoutID resolving_id;
 static struct UnresolvedSource *resolving_source = NULL;
 static NSR_SourceResolvingEndHandler resolving_end_handler = NULL;

-#define MIN_POOL_RESOLVE_INTERVAL 5
 #define MAX_POOL_SOURCES 16
 #define INVALID_POOL (-1)

-/* Pool of sources, the name is expected to resolve to multiple addresses
-   which change over time */
+/* Pool of sources with the same name */
 struct SourcePool {
-  char *name;
-  int port;
  /* Number of sources added from this pool (ignoring tentative sources) */
  int sources;
  /* Maximum number of sources */
@@ -115,10 +115,11 @@ static ARR_Instance pools;

 static void resolve_sources(void *arg);
 static void rehash_records(void);
+static void clean_source_record(SourceRecord *record);

 static void
-slew_sources(struct timeval *raw,
-             struct timeval *cooked,
+slew_sources(struct timespec *raw,
+             struct timespec *cooked,
             double dfreq,
             double doffset,
             LCL_ChangeType change_type,
@@ -162,16 +163,12 @@ NSR_Finalise(void)
  struct UnresolvedSource *us;
  unsigned int i;

-  for (i = 0; i < ARR_GetSize(pools); i++)
-    Free(((struct SourcePool *)ARR_GetElement(pools, i))->name);
  ARR_DestroyInstance(pools);

  for (i = 0; i < ARR_GetSize(records); i++) {
    record = get_record(i);
-    if (!record->remote_addr)
-      continue;
-    record->remote_addr = NULL;
-    NCR_DestroyInstance(record->data);
+    if (record->remote_addr)
+      clean_source_record(record);
  }

  ARR_DestroyInstance(records);
@@ -207,26 +204,16 @@ find_slot(NTP_Remote_Address *remote_addr, int *slot, int *found)
  uint32_t hash;
  unsigned int i, size;
  unsigned short port;
-  uint8_t *ip6;

  size = ARR_GetSize(records);
  
-  switch (remote_addr->ip_addr.family) {
-    case IPADDR_INET6:
-      ip6 = remote_addr->ip_addr.addr.in6;
-      hash = (ip6[0] ^ ip6[4] ^ ip6[8] ^ ip6[12]) |
-           (ip6[1] ^ ip6[5] ^ ip6[9] ^ ip6[13]) << 8 |
-           (ip6[2] ^ ip6[6] ^ ip6[10] ^ ip6[14]) << 16 |
-           (ip6[3] ^ ip6[7] ^ ip6[11] ^ ip6[15]) << 24;
-      break;
-    case IPADDR_INET4:
-      hash = remote_addr->ip_addr.addr.in4;
-      break;
-    default:
+  if (remote_addr->ip_addr.family != IPADDR_INET4 &&
+      remote_addr->ip_addr.family != IPADDR_INET6) {
    *found = *slot = 0;
    return;
  }

+  hash = UTI_IPToHash(&remote_addr->ip_addr);
  port = remote_addr->port;

  for (i = 0; i < size / 2; i++) {
@@ -248,12 +235,12 @@ find_slot(NTP_Remote_Address *remote_addr, int *slot, int *found)
 }

 /* ================================================== */
-
 /* Check if hash table of given size is sufficient to contain sources */
+
 static int
 check_hashtable_size(unsigned int sources, unsigned int size)
 {
-  return sources * 2 + 1 < size;
+  return sources * 2 <= size;
 }

 /* ================================================== */
@@ -271,7 +258,7 @@ rehash_records(void)
  memcpy(temp_records, ARR_GetElements(records), old_size * sizeof (SourceRecord));

  /* The size of the hash table is always a power of two */
-  for (new_size = 4; !check_hashtable_size(n_sources, new_size); new_size *= 2)
+  for (new_size = 1; !check_hashtable_size(n_sources, new_size); new_size *= 2)
    ;

  ARR_SetSize(records, new_size);
@@ -296,7 +283,7 @@ rehash_records(void)

 /* Procedure to add a new source */
 static NSR_Status
-add_source(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourceParameters *params, int pool)
+add_source(NTP_Remote_Address *remote_addr, char *name, NTP_Source_Type type, SourceParameters *params, int pool)
 {
  SourceRecord *record;
  int slot, found;
@@ -323,8 +310,9 @@ add_source(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourceParamete
      record = get_record(slot);
      record->data = NCR_GetInstance(remote_addr, type, params);
      record->remote_addr = NCR_GetRemoteAddress(record->data);
+      record->name = name ? Strdup(name) : NULL;
      record->pool = pool;
-      record->tentative = pool != INVALID_POOL ? 1 : 0;
+      record->tentative = 1;

      if (auto_start_sources)
        NCR_StartInstance(record->data);
@@ -341,6 +329,7 @@ replace_source(NTP_Remote_Address *old_addr, NTP_Remote_Address *new_addr)
 {
  int slot1, slot2, found;
  SourceRecord *record;
+  struct SourcePool *pool;

  find_slot(old_addr, &slot1, &found);
  if (!found)
@@ -354,10 +343,19 @@ replace_source(NTP_Remote_Address *old_addr, NTP_Remote_Address *new_addr)
  NCR_ChangeRemoteAddress(record->data, new_addr);
  record->remote_addr = NCR_GetRemoteAddress(record->data);

+  if (!record->tentative) {
+    record->tentative = 1;
+
+    if (record->pool != INVALID_POOL) {
+      pool = ARR_GetElement(pools, record->pool);
+      pool->sources--;
+    }
+  }
+
  /* The hash table must be rebuilt for the new address */
  rehash_records();

-  LOG(LOGS_INFO, LOGF_NtpSources, "Source %s replaced with %s",
+  LOG(LOGS_INFO, "Source %s replaced with %s",
      UTI_IPToString(&old_addr->ip_addr),
      UTI_IPToString(&new_addr->ip_addr));

@@ -371,18 +369,22 @@ process_resolved_name(struct UnresolvedSource *us, IPAddr *ip_addrs, int n_addrs
 {
  NTP_Remote_Address address;
  int i, added;
+  unsigned short first = 0;
+
+  if (us->random_order)
+    UTI_GetRandomBytes(&first, sizeof (first));

  for (i = added = 0; i < n_addrs; i++) {
-    DEBUG_LOG(LOGF_NtpSources, "%s resolved to %s", us->name, UTI_IPToString(&ip_addrs[i]));
-
-    address.ip_addr = ip_addrs[i];
+    address.ip_addr = ip_addrs[((unsigned int)i + first) % n_addrs];
    address.port = us->port;

+    DEBUG_LOG("(%d) %s", i + 1, UTI_IPToString(&address.ip_addr));
+
    if (us->replacement) {
      if (replace_source(&us->replace_source, &address) != NSR_AlreadyInUse)
        break;
    } else {
-      if (add_source(&address, us->new_source.type, &us->new_source.params,
+      if (add_source(&address, us->name, us->new_source.type, &us->new_source.params,
                     us->new_source.pool) == NSR_Success)
        added++;

@@ -403,6 +405,8 @@ name_resolve_handler(DNS_Status status, int n_addrs, IPAddr *ip_addrs, void *any

  assert(us == resolving_source);

+  DEBUG_LOG("%s resolved to %d addrs", us->name, n_addrs);
+
  switch (status) {
    case DNS_TryAgain:
      break;
@@ -410,7 +414,7 @@ name_resolve_handler(DNS_Status status, int n_addrs, IPAddr *ip_addrs, void *any
      process_resolved_name(us, ip_addrs, n_addrs);
      break;
    case DNS_Failure:
-      LOG(LOGS_WARN, LOGF_NtpSources, "Invalid host %s", us->name);
+      LOG(LOGS_WARN, "Invalid host %s", us->name);
      break;
    default:
      assert(0);
@@ -435,7 +439,7 @@ name_resolve_handler(DNS_Status status, int n_addrs, IPAddr *ip_addrs, void *any

  if (next) {
    /* Continue with the next source in the list */
-    DEBUG_LOG(LOGF_NtpSources, "resolving %s", next->name);
+    DEBUG_LOG("resolving %s", next->name);
    DNS_Name2IPAddressAsync(next->name, name_resolve_handler, next);
  } else {
    /* This was the last source in the list. If some sources couldn't
@@ -466,14 +470,14 @@ resolve_sources(void *arg)

  assert(!resolving_source);

-  DNS_Reload();
+  PRV_ReloadDNS();

  /* Start with the first source in the list, name_resolve_handler
     will iterate over the rest */
  us = unresolved_sources;

  resolving_source = us;
-  DEBUG_LOG(LOGF_NtpSources, "resolving %s", us->name);
+  DEBUG_LOG("resolving %s", us->name);
  DNS_Name2IPAddressAsync(us->name, name_resolve_handler, us);
 }

@@ -495,7 +499,7 @@ append_unresolved_source(struct UnresolvedSource *us)
 NSR_Status
 NSR_AddSource(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourceParameters *params)
 {
-  return add_source(remote_addr, type, params, INVALID_POOL);
+  return add_source(remote_addr, NULL, type, params, INVALID_POOL);
 }

 /* ================================================== */
@@ -505,10 +509,20 @@ NSR_AddSourceByName(char *name, int port, int pool, NTP_Source_Type type, Source
 {
  struct UnresolvedSource *us;
  struct SourcePool *sp;
+  NTP_Remote_Address remote_addr;
+
+  /* If the name is an IP address, don't bother with full resolving now
+     or later when trying to replace the source */
+  if (UTI_StringToIP(name, &remote_addr.ip_addr)) {
+    remote_addr.port = port;
+    NSR_AddSource(&remote_addr, type, params);
+    return;
+  }

  us = MallocNew(struct UnresolvedSource);
  us->name = Strdup(name);
  us->port = port;
+  us->random_order = 0;
  us->replacement = 0;
  us->new_source.type = type;
  us->new_source.params = *params;
@@ -518,8 +532,6 @@ NSR_AddSourceByName(char *name, int port, int pool, NTP_Source_Type type, Source
    us->new_source.max_new_sources = 1;
  } else {
    sp = (struct SourcePool *)ARR_GetNewElement(pools);
-    sp->name = Strdup(name);
-    sp->port = port;
    sp->sources = 0;
    sp->max_sources = params->max_sources;
    us->new_source.pool = ARR_GetSize(pools) - 1;
@@ -587,6 +599,8 @@ clean_source_record(SourceRecord *record)
  assert(record->remote_addr);
  record->remote_addr = NULL;
  NCR_DestroyInstance(record->data);
+  if (record->name)
+    Free(record->name);

  n_sources--;
 }
@@ -640,15 +654,22 @@ NSR_RemoveAllSources(void)
 /* ================================================== */

 static void
-resolve_pool_replacement(struct SourcePool *sp, NTP_Remote_Address *addr)
+resolve_source_replacement(SourceRecord *record)
 {
  struct UnresolvedSource *us;

+  DEBUG_LOG("trying to replace %s", UTI_IPToString(&record->remote_addr->ip_addr));
+
  us = MallocNew(struct UnresolvedSource);
-  us->name = Strdup(sp->name);
-  us->port = sp->port;
+  us->name = Strdup(record->name);
+  us->port = record->remote_addr->port;
+  /* If there never was a valid reply from this source (e.g. it was a bad
+     replacement), ignore the order of addresses from the resolver to not get
+     stuck to a pair of addresses if the order doesn't change, or a group of
+     IPv4/IPv6 addresses if the resolver prefers inaccessible IP family */
+  us->random_order = record->tentative;
  us->replacement = 1;
-  us->replace_source = *addr;
+  us->replace_source = *record->remote_addr;

  append_unresolved_source(us);
  NSR_ResolveSources();
@@ -659,35 +680,53 @@ resolve_pool_replacement(struct SourcePool *sp, NTP_Remote_Address *addr)
 void
 NSR_HandleBadSource(IPAddr *address)
 {
-  static struct timeval last_replacement;
-  struct timeval now;
+  static struct timespec last_replacement;
+  struct timespec now;
  NTP_Remote_Address remote_addr;
-  struct SourcePool *pool;
-  int pool_index, slot, found;
+  SourceRecord *record;
+  int slot, found;
  double diff;

  remote_addr.ip_addr = *address;
  remote_addr.port = 0;

-  /* Only sources from a pool can be replaced */
  find_slot(&remote_addr, &slot, &found);
-  if (!found || (pool_index = get_record(slot)->pool) == INVALID_POOL)
+  if (!found)
    return;

-  pool = (struct SourcePool *)ARR_GetElement(pools, pool_index);
+  record = get_record(slot);

-  /* Don't resolve the pool name too frequently */
+  /* Only sources with a name can be replaced */
+  if (!record->name)
+    return;
+
+  /* Don't resolve names too frequently */
  SCH_GetLastEventTime(NULL, NULL, &now);
-  UTI_DiffTimevalsToDouble(&diff, &now, &last_replacement);
-  if (fabs(diff) < RESOLVE_INTERVAL_UNIT * (1 << MIN_POOL_RESOLVE_INTERVAL)) {
-    DEBUG_LOG(LOGF_NtpSources, "replacement postponed");
+  diff = UTI_DiffTimespecsToDouble(&now, &last_replacement);
+  if (fabs(diff) < RESOLVE_INTERVAL_UNIT * (1 << MIN_REPLACEMENT_INTERVAL)) {
+    DEBUG_LOG("replacement postponed");
    return;
  }
  last_replacement = now;

-  DEBUG_LOG(LOGF_NtpSources, "pool replacement for %s", UTI_IPToString(address));
+  resolve_source_replacement(record);
+}

-  resolve_pool_replacement(pool, &remote_addr);
+/* ================================================== */
+
+void
+NSR_RefreshAddresses(void)
+{
+  SourceRecord *record;
+  unsigned int i;
+
+  for (i = 0; i < ARR_GetSize(records); i++) {
+    record = get_record(i);
+    if (!record->remote_addr || !record->name)
+      continue;
+
+    resolve_source_replacement(record);
+  }
 }

 /* ================================================== */
@@ -703,7 +742,7 @@ static void remove_tentative_pool_sources(int pool)
    if (!record->remote_addr || record->pool != pool || !record->tentative)
      continue;

-    DEBUG_LOG(LOGF_NtpSources, "removing tentative source %s",
+    DEBUG_LOG("removing tentative source %s",
              UTI_IPToString(&record->remote_addr->ip_addr));

    clean_source_record(record);
@@ -714,10 +753,31 @@ static void remove_tentative_pool_sources(int pool)
    rehash_records();
 }

+/* ================================================== */
+
+uint32_t
+NSR_GetLocalRefid(IPAddr *address)
+{
+  NTP_Remote_Address remote_addr;
+  int slot, found;
+
+  remote_addr.ip_addr = *address;
+  remote_addr.port = 0;
+
+  find_slot(&remote_addr, &slot, &found);
+  if (!found)
+    return 0;
+
+  return NCR_GetLocalRefid(get_record(slot)->data);
+}
+
+/* ================================================== */
+
 /* This routine is called by ntp_io when a new packet arrives off the network,
   possibly with an authentication tail */
 void
-NSR_ProcessReceive(NTP_Packet *message, struct timeval *now, double now_err, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
+NSR_ProcessRx(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+              NTP_Local_Timestamp *rx_ts, NTP_Packet *message, int length)
 {
  SourceRecord *record;
  struct SourcePool *pool;
@@ -729,35 +789,54 @@ NSR_ProcessReceive(NTP_Packet *message, struct timeval *now, double now_err, NTP
  if (found == 2) { /* Must match IP address AND port number */
    record = get_record(slot);

-    if (!NCR_ProcessKnown(message, now, now_err, record->data, local_addr, length))
+    if (!NCR_ProcessRxKnown(record->data, local_addr, rx_ts, message, length))
      return;

    if (record->tentative) {
-      /* First reply from a pool source */
+      /* This was the first good reply from the source */
      record->tentative = 0;

-      assert(record->pool != INVALID_POOL);
-      pool = (struct SourcePool *)ARR_GetElement(pools, record->pool);
+      if (record->pool != INVALID_POOL) {
+        pool = ARR_GetElement(pools, record->pool);
        pool->sources++;

-      DEBUG_LOG(LOGF_NtpSources, "pool %s has %d confirmed sources",
-                pool->name, pool->sources);
+        DEBUG_LOG("pool %s has %d confirmed sources", record->name, pool->sources);

-      /* If the number of sources reached the configured maximum, remove
-         the tentative sources added from this pool */
+        /* If the number of sources from the pool reached the configured
+           maximum, remove the remaining tentative sources */
        if (pool->sources >= pool->max_sources)
          remove_tentative_pool_sources(record->pool);
      }
+    }
  } else {
-    NCR_ProcessUnknown(message, now, now_err, remote_addr, local_addr, length);
+    NCR_ProcessRxUnknown(remote_addr, local_addr, rx_ts, message, length);
+  }
+}
+
+/* ================================================== */
+
+void
+NSR_ProcessTx(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+              NTP_Local_Timestamp *tx_ts, NTP_Packet *message, int length)
+{
+  SourceRecord *record;
+  int slot, found;
+
+  find_slot(remote_addr, &slot, &found);
+
+  if (found == 2) { /* Must match IP address AND port number */
+    record = get_record(slot);
+    NCR_ProcessTxKnown(record->data, local_addr, tx_ts, message, length);
+  } else {
+    NCR_ProcessTxUnknown(remote_addr, local_addr, tx_ts, message, length);
  }
 }

 /* ================================================== */

 static void
-slew_sources(struct timeval *raw,
-             struct timeval *cooked,
+slew_sources(struct timespec *raw,
+             struct timespec *cooked,
             double dfreq,
             double doffset,
             LCL_ChangeType change_type,
@@ -771,6 +850,7 @@ slew_sources(struct timeval *raw,
    if (record->remote_addr) {
      if (change_type == LCL_ChangeUnknownStep) {
        NCR_ResetInstance(record->data);
+        NCR_ResetPoll(record->data);
      } else {
        NCR_SlewTimes(record->data, cooked, dfreq, doffset);
      }
@@ -1023,7 +1103,7 @@ NSR_InitiateSampleBurst(int n_good_samples, int n_total_samples,
   identify the source record. */

 void
-NSR_ReportSource(RPT_SourceReport *report, struct timeval *now)
+NSR_ReportSource(RPT_SourceReport *report, struct timespec *now)
 {
  NTP_Remote_Address rem_addr;
  int slot, found;
@@ -1039,6 +1119,26 @@ NSR_ReportSource(RPT_SourceReport *report, struct timeval *now)
  }
 }

+/* ================================================== */
+/* The ip address is assumed to be completed on input, that is how we
+   identify the source record. */
+
+int
+NSR_GetNTPReport(RPT_NTPReport *report)
+{
+  NTP_Remote_Address rem_addr;
+  int slot, found;
+
+  rem_addr.ip_addr = report->remote_addr;
+  rem_addr.port = 0;
+  find_slot(&rem_addr, &slot, &found);
+  if (!found)
+    return 0;
+
+  NCR_GetNTPReport(get_record(slot)->data, report);
+  return 1;
+}
+
 /* ================================================== */

 void
--- a/ntp_sources.h
+++ b/ntp_sources.h
@@ -80,8 +80,20 @@ extern void NSR_RemoveAllSources(void);
 /* Procedure to try to find a replacement for a bad source */
 extern void NSR_HandleBadSource(IPAddr *address);

+/* Procedure to resolve all names again */
+extern void NSR_RefreshAddresses(void);
+
+/* Procedure to get local reference ID corresponding to a source */
+extern uint32_t NSR_GetLocalRefid(IPAddr *address);
+
 /* This routine is called by ntp_io when a new packet arrives off the network */
-extern void NSR_ProcessReceive(NTP_Packet *message, struct timeval *now, double now_err, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
+extern void NSR_ProcessRx(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+                          NTP_Local_Timestamp *rx_ts, NTP_Packet *message, int length);
+
+/* This routine is called by ntp_io when a packet was sent to the network and
+   an accurate transmit timestamp was captured */
+extern void NSR_ProcessTx(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+                          NTP_Local_Timestamp *tx_ts, NTP_Packet *message, int length);

 /* Initialisation function */
 extern void NSR_Initialise(void);
@@ -115,7 +127,9 @@ extern int NSR_ModifyPolltarget(IPAddr *address, int new_poll_target);

 extern int NSR_InitiateSampleBurst(int n_good_samples, int n_total_samples, IPAddr *mask, IPAddr *address);

-extern void NSR_ReportSource(RPT_SourceReport *report, struct timeval *now);
+extern void NSR_ReportSource(RPT_SourceReport *report, struct timespec *now);
+
+extern int NSR_GetNTPReport(RPT_NTPReport *report);

 extern void NSR_GetActivityReport(RPT_ActivityReport *report);

--- a/pktlength.c
+++ b/pktlength.c
@@ -3,6 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2002
+ * Copyright (C) Miroslav Lichvar  2014-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -33,140 +34,126 @@
 #include "util.h"
 #include "pktlength.h"

+#define PADDING_LENGTH_(request_length, reply_length) \
+  (uint16_t)((request_length) < (reply_length) ? (reply_length) - (request_length) : 0)
+
+#define PADDING_LENGTH(request_data, reply_data) \
+  PADDING_LENGTH_(offsetof(CMD_Request, request_data), offsetof(CMD_Reply, reply_data))
+
+#define REQ_LENGTH_ENTRY(request_data_field, reply_data_field) \
+  { offsetof(CMD_Request, data.request_data_field.EOR), \
+    PADDING_LENGTH(data.request_data_field.EOR, data.reply_data_field.EOR) }
+
+#define RPY_LENGTH_ENTRY(reply_data_field) \
+  offsetof(CMD_Reply, data.reply_data_field.EOR)
+
 /* ================================================== */

-static int
-command_unpadded_length(CMD_Request *r)
-{
-  int type;
-  type = ntohs(r->command);
-  if (type < 0 || type >= N_REQUEST_TYPES) {
-    return 0;
-  } else {
-    switch (type) {
+struct request_length {
+  uint16_t command;
+  uint16_t padding;
+};

-      case REQ_NULL:
-        return offsetof(CMD_Request, data);
-      case REQ_ONLINE:
-        return offsetof(CMD_Request, data.online.EOR);
-      case REQ_OFFLINE:
-        return offsetof(CMD_Request, data.offline.EOR);
-      case REQ_BURST:
-        return offsetof(CMD_Request, data.burst.EOR);
-      case REQ_MODIFY_MINPOLL:
-        return offsetof(CMD_Request, data.modify_minpoll.EOR);
-      case REQ_MODIFY_MAXPOLL:
-        return offsetof(CMD_Request, data.modify_maxpoll.EOR);
-      case REQ_DUMP:
-        return offsetof(CMD_Request, data.dump.EOR);
-      case REQ_MODIFY_MAXDELAY:
-        return offsetof(CMD_Request, data.modify_maxdelay.EOR);
-      case REQ_MODIFY_MAXDELAYRATIO:
-        return offsetof(CMD_Request, data.modify_maxdelayratio.EOR);
-      case REQ_MODIFY_MAXDELAYDEVRATIO:
-        return offsetof(CMD_Request, data.modify_maxdelaydevratio.EOR);
-      case REQ_MODIFY_MAXUPDATESKEW:
-        return offsetof(CMD_Request, data.modify_maxupdateskew.EOR);
-      case REQ_MODIFY_MAKESTEP:
-        return offsetof(CMD_Request, data.modify_makestep.EOR);
-      case REQ_LOGON :
-        return offsetof(CMD_Request, data.logon.EOR);
-      case REQ_SETTIME :
-        return offsetof(CMD_Request, data.settime.EOR);
-      case REQ_LOCAL :
-        return offsetof(CMD_Request, data.local.EOR);
-      case REQ_MANUAL :
-        return offsetof(CMD_Request, data.manual.EOR);
-      case REQ_N_SOURCES :
-        return offsetof(CMD_Request, data.n_sources.EOR);
-      case REQ_SOURCE_DATA :
-        return offsetof(CMD_Request, data.source_data.EOR);
-      case REQ_REKEY :
-        return offsetof(CMD_Request, data.rekey.EOR);
-      case REQ_ALLOW :
-        return offsetof(CMD_Request, data.allow_deny.EOR);
-      case REQ_ALLOWALL :
-        return offsetof(CMD_Request, data.allow_deny.EOR);
-      case REQ_DENY :
-        return offsetof(CMD_Request, data.allow_deny.EOR);
-      case REQ_DENYALL :
-        return offsetof(CMD_Request, data.allow_deny.EOR);
-      case REQ_CMDALLOW :
-        return offsetof(CMD_Request, data.allow_deny.EOR);
-      case REQ_CMDALLOWALL :
-        return offsetof(CMD_Request, data.allow_deny.EOR);
-      case REQ_CMDDENY :
-        return offsetof(CMD_Request, data.allow_deny.EOR);
-      case REQ_CMDDENYALL :
-        return offsetof(CMD_Request, data.allow_deny.EOR);
-      case REQ_ACCHECK :
-        return offsetof(CMD_Request, data.ac_check.EOR);
-      case REQ_CMDACCHECK :
-        return offsetof(CMD_Request, data.ac_check.EOR);
-      case REQ_ADD_SERVER :
-        return offsetof(CMD_Request, data.ntp_source.EOR);
-      case REQ_ADD_PEER :
-        return offsetof(CMD_Request, data.ntp_source.EOR);
-      case REQ_DEL_SOURCE :
-        return offsetof(CMD_Request, data.del_source.EOR);
-      case REQ_WRITERTC :
-        return offsetof(CMD_Request, data.writertc.EOR);
-      case REQ_DFREQ :
-        return offsetof(CMD_Request, data.dfreq.EOR);
-      case REQ_DOFFSET :
-        return offsetof(CMD_Request, data.doffset.EOR);
-      case REQ_TRACKING :
-        return offsetof(CMD_Request, data.tracking.EOR);
-      case REQ_SOURCESTATS :
-        return offsetof(CMD_Request, data.sourcestats.EOR);
-      case REQ_RTCREPORT :
-        return offsetof(CMD_Request, data.rtcreport.EOR);
-      case REQ_TRIMRTC :
-        return offsetof(CMD_Request, data.trimrtc.EOR);
-      case REQ_CYCLELOGS :
-        return offsetof(CMD_Request, data.cyclelogs.EOR);
-      case REQ_SUBNETS_ACCESSED :
-      case REQ_CLIENT_ACCESSES:
-        /* No longer supported */
-        return 0;
-      case REQ_CLIENT_ACCESSES_BY_INDEX:
-        return offsetof(CMD_Request, data.client_accesses_by_index.EOR);
-      case REQ_MANUAL_LIST:
-        return offsetof(CMD_Request, data.manual_list.EOR);
-      case REQ_MANUAL_DELETE:
-        return offsetof(CMD_Request, data.manual_delete.EOR);
-      case REQ_MAKESTEP:
-        return offsetof(CMD_Request, data.make_step.EOR);
-      case REQ_ACTIVITY:
-        return offsetof(CMD_Request, data.activity.EOR);
-      case REQ_RESELECT:
-        return offsetof(CMD_Request, data.reselect.EOR);
-      case REQ_RESELECTDISTANCE:
-        return offsetof(CMD_Request, data.reselect_distance.EOR);
-      case REQ_MODIFY_MINSTRATUM:
-        return offsetof(CMD_Request, data.modify_minstratum.EOR);
-      case REQ_MODIFY_POLLTARGET:
-        return offsetof(CMD_Request, data.modify_polltarget.EOR);
-      default:
-        /* If we fall through the switch, it most likely means we've forgotten to implement a new case */
-        assert(0);
-    }
-  }
-
-  /* Catch-all case */
-  return 0;
-
-}
+static const struct request_length request_lengths[] = {
+  REQ_LENGTH_ENTRY(null, null),                 /* NULL */
+  REQ_LENGTH_ENTRY(online, null),               /* ONLINE */
+  REQ_LENGTH_ENTRY(offline, null),              /* OFFLINE */
+  REQ_LENGTH_ENTRY(burst, null),                /* BURST */
+  REQ_LENGTH_ENTRY(modify_minpoll, null),       /* MODIFY_MINPOLL */
+  REQ_LENGTH_ENTRY(modify_maxpoll, null),       /* MODIFY_MAXPOLL */
+  REQ_LENGTH_ENTRY(dump, null),                 /* DUMP */
+  REQ_LENGTH_ENTRY(modify_maxdelay, null),      /* MODIFY_MAXDELAY */
+  REQ_LENGTH_ENTRY(modify_maxdelayratio, null), /* MODIFY_MAXDELAYRATIO */
+  REQ_LENGTH_ENTRY(modify_maxupdateskew, null), /* MODIFY_MAXUPDATESKEW */
+  REQ_LENGTH_ENTRY(logon, null),                /* LOGON */
+  REQ_LENGTH_ENTRY(settime, manual_timestamp),  /* SETTIME */
+  { 0, 0 },                                     /* LOCAL */
+  REQ_LENGTH_ENTRY(manual, null),               /* MANUAL */
+  REQ_LENGTH_ENTRY(null, n_sources),            /* N_SOURCES */
+  REQ_LENGTH_ENTRY(source_data, source_data),   /* SOURCE_DATA */
+  REQ_LENGTH_ENTRY(null, null),                 /* REKEY */
+  REQ_LENGTH_ENTRY(allow_deny, null),           /* ALLOW */
+  REQ_LENGTH_ENTRY(allow_deny, null),           /* ALLOWALL */
+  REQ_LENGTH_ENTRY(allow_deny, null),           /* DENY */
+  REQ_LENGTH_ENTRY(allow_deny, null),           /* DENYALL */
+  REQ_LENGTH_ENTRY(allow_deny, null),           /* CMDALLOW */
+  REQ_LENGTH_ENTRY(allow_deny, null),           /* CMDALLOWALL */
+  REQ_LENGTH_ENTRY(allow_deny, null),           /* CMDDENY */
+  REQ_LENGTH_ENTRY(allow_deny, null),           /* CMDDENYALL */
+  REQ_LENGTH_ENTRY(ac_check, null),             /* ACCHECK */
+  REQ_LENGTH_ENTRY(ac_check, null),             /* CMDACCHECK */
+  { 0, 0 },                                     /* ADD_SERVER */
+  { 0, 0 },                                     /* ADD_PEER */
+  REQ_LENGTH_ENTRY(del_source, null),           /* DEL_SOURCE */
+  REQ_LENGTH_ENTRY(null, null),                 /* WRITERTC */
+  REQ_LENGTH_ENTRY(dfreq, null),                /* DFREQ */
+  REQ_LENGTH_ENTRY(doffset, null),              /* DOFFSET */
+  REQ_LENGTH_ENTRY(null, tracking),             /* TRACKING */
+  REQ_LENGTH_ENTRY(sourcestats, sourcestats),   /* SOURCESTATS */
+  REQ_LENGTH_ENTRY(null, rtc),                  /* RTCREPORT */
+  REQ_LENGTH_ENTRY(null, null),                 /* TRIMRTC */
+  REQ_LENGTH_ENTRY(null, null),                 /* CYCLELOGS */
+  { 0, 0 },                                     /* SUBNETS_ACCESSED - not supported */
+  { 0, 0 },                                     /* CLIENT_ACCESSES - not supported */
+  { 0, 0 },                                     /* CLIENT_ACCESSES_BY_INDEX - not supported */
+  REQ_LENGTH_ENTRY(null, manual_list),          /* MANUAL_LIST */
+  REQ_LENGTH_ENTRY(manual_delete, null),        /* MANUAL_DELETE */
+  REQ_LENGTH_ENTRY(null, null),                 /* MAKESTEP */
+  REQ_LENGTH_ENTRY(null, activity),             /* ACTIVITY */
+  REQ_LENGTH_ENTRY(modify_minstratum, null),    /* MODIFY_MINSTRATUM */
+  REQ_LENGTH_ENTRY(modify_polltarget, null),    /* MODIFY_POLLTARGET */
+  REQ_LENGTH_ENTRY(modify_maxdelaydevratio, null), /* MODIFY_MAXDELAYDEVRATIO */
+  REQ_LENGTH_ENTRY(null, null),                 /* RESELECT */
+  REQ_LENGTH_ENTRY(reselect_distance, null),    /* RESELECTDISTANCE */
+  REQ_LENGTH_ENTRY(modify_makestep, null),      /* MODIFY_MAKESTEP */
+  REQ_LENGTH_ENTRY(null, smoothing),            /* SMOOTHING */
+  REQ_LENGTH_ENTRY(smoothtime, null),           /* SMOOTHTIME */
+  REQ_LENGTH_ENTRY(null, null),                 /* REFRESH */
+  REQ_LENGTH_ENTRY(null, server_stats),         /* SERVER_STATS */
+  REQ_LENGTH_ENTRY(client_accesses_by_index,
+                   client_accesses_by_index),   /* CLIENT_ACCESSES_BY_INDEX2 */
+  REQ_LENGTH_ENTRY(local, null),                /* LOCAL2 */
+  REQ_LENGTH_ENTRY(ntp_data, ntp_data),         /* NTP_DATA */
+  REQ_LENGTH_ENTRY(ntp_source, null),           /* ADD_SERVER2 */
+  REQ_LENGTH_ENTRY(ntp_source, null),           /* ADD_PEER2 */
+};

+static const uint16_t reply_lengths[] = {
+  0,                                            /* empty slot */
+  RPY_LENGTH_ENTRY(null),                       /* NULL */
+  RPY_LENGTH_ENTRY(n_sources),                  /* N_SOURCES */
+  RPY_LENGTH_ENTRY(source_data),                /* SOURCE_DATA */
+  0,                                            /* MANUAL_TIMESTAMP */
+  RPY_LENGTH_ENTRY(tracking),                   /* TRACKING */
+  RPY_LENGTH_ENTRY(sourcestats),                /* SOURCESTATS */
+  RPY_LENGTH_ENTRY(rtc),                        /* RTC */
+  0,                                            /* SUBNETS_ACCESSED - not supported */
+  0,                                            /* CLIENT_ACCESSES - not supported */
+  0,                                            /* CLIENT_ACCESSES_BY_INDEX - not supported */
+  0,                                            /* MANUAL_LIST - variable length */
+  RPY_LENGTH_ENTRY(activity),                   /* ACTIVITY */
+  RPY_LENGTH_ENTRY(smoothing),                  /* SMOOTHING */
+  RPY_LENGTH_ENTRY(server_stats),               /* SERVER_STATS */
+  RPY_LENGTH_ENTRY(client_accesses_by_index),   /* CLIENT_ACCESSES_BY_INDEX2 */
+  RPY_LENGTH_ENTRY(ntp_data),                   /* NTP_DATA */
+  RPY_LENGTH_ENTRY(manual_timestamp),           /* MANUAL_TIMESTAMP2 */
+};

 /* ================================================== */

 int
 PKL_CommandLength(CMD_Request *r)
 {
+  uint32_t type;
  int command_length;

-  command_length = command_unpadded_length(r);
+  assert(sizeof (request_lengths) / sizeof (request_lengths[0]) == N_REQUEST_TYPES);
+
+  type = ntohs(r->command);
+  if (type >= N_REQUEST_TYPES)
+    return 0;
+
+  command_length = request_lengths[type].command;
  if (!command_length)
    return 0;

@@ -175,133 +162,20 @@ PKL_CommandLength(CMD_Request *r)

 /* ================================================== */

-#define PADDING_LENGTH_(request_length, reply_length) \
-  ((request_length) < (reply_length) ? (reply_length) - (request_length) : 0)
-
-#define PADDING_LENGTH(request_data, reply_data) \
-  PADDING_LENGTH_(offsetof(CMD_Request, request_data), offsetof(CMD_Reply, reply_data))
-
 int
 PKL_CommandPaddingLength(CMD_Request *r)
 {
-  int type;
+  uint32_t type;

  if (r->version < PROTO_VERSION_PADDING)
    return 0;

  type = ntohs(r->command);

-  if (type < 0 || type >= N_REQUEST_TYPES)
+  if (type >= N_REQUEST_TYPES)
    return 0;

-  switch (type) {
-    case REQ_NULL:
-      return PADDING_LENGTH(data, data.null.EOR);
-    case REQ_ONLINE:
-      return PADDING_LENGTH(data.online.EOR, data.null.EOR);
-    case REQ_OFFLINE:
-      return PADDING_LENGTH(data.offline.EOR, data.null.EOR);
-    case REQ_BURST:
-      return PADDING_LENGTH(data.burst.EOR, data.null.EOR);
-    case REQ_MODIFY_MINPOLL:
-      return PADDING_LENGTH(data.modify_minpoll.EOR, data.null.EOR);
-    case REQ_MODIFY_MAXPOLL:
-      return PADDING_LENGTH(data.modify_maxpoll.EOR, data.null.EOR);
-    case REQ_DUMP:
-      return PADDING_LENGTH(data.dump.EOR, data.null.EOR);
-    case REQ_MODIFY_MAXDELAY:
-      return PADDING_LENGTH(data.modify_maxdelay.EOR, data.null.EOR);
-    case REQ_MODIFY_MAXDELAYRATIO:
-      return PADDING_LENGTH(data.modify_maxdelayratio.EOR, data.null.EOR);
-    case REQ_MODIFY_MAXDELAYDEVRATIO:
-      return PADDING_LENGTH(data.modify_maxdelaydevratio.EOR, data.null.EOR);
-    case REQ_MODIFY_MAXUPDATESKEW:
-      return PADDING_LENGTH(data.modify_maxupdateskew.EOR, data.null.EOR);
-    case REQ_MODIFY_MAKESTEP:
-      return PADDING_LENGTH(data.modify_makestep.EOR, data.null.EOR);
-    case REQ_LOGON:
-      return PADDING_LENGTH(data.logon.EOR, data.null.EOR);
-    case REQ_SETTIME:
-      return PADDING_LENGTH(data.settime.EOR, data.manual_timestamp.EOR);
-    case REQ_LOCAL:
-      return PADDING_LENGTH(data.local.EOR, data.null.EOR);
-    case REQ_MANUAL:
-      return PADDING_LENGTH(data.manual.EOR, data.null.EOR);
-    case REQ_N_SOURCES:
-      return PADDING_LENGTH(data.n_sources.EOR, data.n_sources.EOR);
-    case REQ_SOURCE_DATA:
-      return PADDING_LENGTH(data.source_data.EOR, data.source_data.EOR);
-    case REQ_REKEY:
-      return PADDING_LENGTH(data.rekey.EOR, data.null.EOR);
-    case REQ_ALLOW:
-      return PADDING_LENGTH(data.allow_deny.EOR, data.null.EOR);
-    case REQ_ALLOWALL:
-      return PADDING_LENGTH(data.allow_deny.EOR, data.null.EOR);
-    case REQ_DENY:
-      return PADDING_LENGTH(data.allow_deny.EOR, data.null.EOR);
-    case REQ_DENYALL:
-      return PADDING_LENGTH(data.allow_deny.EOR, data.null.EOR);
-    case REQ_CMDALLOW:
-      return PADDING_LENGTH(data.allow_deny.EOR, data.null.EOR);
-    case REQ_CMDALLOWALL:
-      return PADDING_LENGTH(data.allow_deny.EOR, data.null.EOR);
-    case REQ_CMDDENY:
-      return PADDING_LENGTH(data.allow_deny.EOR, data.null.EOR);
-    case REQ_CMDDENYALL:
-      return PADDING_LENGTH(data.allow_deny.EOR, data.null.EOR);
-    case REQ_ACCHECK:
-      return PADDING_LENGTH(data.ac_check.EOR, data.null.EOR);
-    case REQ_CMDACCHECK:
-      return PADDING_LENGTH(data.ac_check.EOR, data.null.EOR);
-    case REQ_ADD_SERVER:
-      return PADDING_LENGTH(data.ntp_source.EOR, data.null.EOR);
-    case REQ_ADD_PEER:
-      return PADDING_LENGTH(data.ntp_source.EOR, data.null.EOR);
-    case REQ_DEL_SOURCE:
-      return PADDING_LENGTH(data.del_source.EOR, data.null.EOR);
-    case REQ_WRITERTC:
-      return PADDING_LENGTH(data.writertc.EOR, data.null.EOR);
-    case REQ_DFREQ:
-      return PADDING_LENGTH(data.dfreq.EOR, data.null.EOR);
-    case REQ_DOFFSET:
-      return PADDING_LENGTH(data.doffset.EOR, data.null.EOR);
-    case REQ_TRACKING:
-      return PADDING_LENGTH(data.tracking.EOR, data.tracking.EOR);
-    case REQ_SOURCESTATS:
-      return PADDING_LENGTH(data.sourcestats.EOR, data.sourcestats.EOR);
-    case REQ_RTCREPORT:
-      return PADDING_LENGTH(data.rtcreport.EOR, data.rtc.EOR);
-    case REQ_TRIMRTC:
-      return PADDING_LENGTH(data.trimrtc.EOR, data.null.EOR);
-    case REQ_CYCLELOGS:
-      return PADDING_LENGTH(data.cyclelogs.EOR, data.null.EOR);
-    case REQ_SUBNETS_ACCESSED:
-    case REQ_CLIENT_ACCESSES:
-      /* No longer supported */
-      return 0;
-    case REQ_CLIENT_ACCESSES_BY_INDEX:
-      return PADDING_LENGTH(data.client_accesses_by_index.EOR, data.client_accesses_by_index.EOR);
-    case REQ_MANUAL_LIST:
-      return PADDING_LENGTH(data.manual_list.EOR, data.manual_list.EOR);
-    case REQ_MANUAL_DELETE:
-      return PADDING_LENGTH(data.manual_delete.EOR, data.null.EOR);
-    case REQ_MAKESTEP:
-      return PADDING_LENGTH(data.make_step.EOR, data.null.EOR);
-    case REQ_ACTIVITY:
-      return PADDING_LENGTH(data.activity.EOR, data.activity.EOR);
-    case REQ_RESELECT:
-      return PADDING_LENGTH(data.reselect.EOR, data.null.EOR);
-    case REQ_RESELECTDISTANCE:
-      return PADDING_LENGTH(data.reselect_distance.EOR, data.null.EOR);
-    case REQ_MODIFY_MINSTRATUM:
-      return PADDING_LENGTH(data.modify_minstratum.EOR, data.null.EOR);
-    case REQ_MODIFY_POLLTARGET:
-      return PADDING_LENGTH(data.modify_polltarget.EOR, data.null.EOR);
-    default:
-      /* If we fall through the switch, it most likely means we've forgotten to implement a new case */
-      assert(0);
-      return 0;
-  }
+  return request_lengths[ntohs(r->command)].padding;
 }

 /* ================================================== */
@@ -309,64 +183,32 @@ PKL_CommandPaddingLength(CMD_Request *r)
 int
 PKL_ReplyLength(CMD_Reply *r)
 {
-  int type;
+  uint32_t type;
+
+  assert(sizeof (reply_lengths) / sizeof (reply_lengths[0]) == N_REPLY_TYPES);
+
  type = ntohs(r->reply);
+
  /* Note that reply type codes start from 1, not 0 */
-  if (type < 1 || type >= N_REPLY_TYPES) {
+  if (type < 1 || type >= N_REPLY_TYPES)
    return 0;
-  } else {
-    switch (type) {
-      case RPY_NULL:
-        return offsetof(CMD_Reply, data.null.EOR);
-      case RPY_N_SOURCES:
-        return offsetof(CMD_Reply, data.n_sources.EOR);
-      case RPY_SOURCE_DATA:
-        return offsetof(CMD_Reply, data.source_data.EOR);
-      case RPY_MANUAL_TIMESTAMP:
-        return offsetof(CMD_Reply, data.manual_timestamp.EOR);
-      case RPY_TRACKING:
-        return offsetof(CMD_Reply, data.tracking.EOR);
-      case RPY_SOURCESTATS:
-        return offsetof(CMD_Reply, data.sourcestats.EOR);
-      case RPY_RTC:
-        return offsetof(CMD_Reply, data.rtc.EOR);
-      case RPY_SUBNETS_ACCESSED :
-      case RPY_CLIENT_ACCESSES:
-        /* No longer supported */
-        return 0;
-      case RPY_CLIENT_ACCESSES_BY_INDEX:
-        {
-          unsigned long nc = ntohl(r->data.client_accesses_by_index.n_clients);
-          if (r->status == htons(STT_SUCCESS)) {
-            if (nc > MAX_CLIENT_ACCESSES)
-              return 0;
-            return (offsetof(CMD_Reply, data.client_accesses_by_index.clients) +
-                    nc * sizeof(RPY_ClientAccesses_Client));
-          } else {
+
+  /* Length of MANUAL_LIST depends on number of samples stored in it */
+  if (type == RPY_MANUAL_LIST) {
+    uint32_t ns;
+
+    if (r->status != htons(STT_SUCCESS))
      return offsetof(CMD_Reply, data);
-          }
-        }
-      case RPY_MANUAL_LIST:
-        {
-          unsigned long ns = ntohl(r->data.manual_list.n_samples);
+
+    ns = ntohl(r->data.manual_list.n_samples);
    if (ns > MAX_MANUAL_LIST_SAMPLES)
      return 0;
-          if (r->status == htons(STT_SUCCESS)) {
-            return (offsetof(CMD_Reply, data.manual_list.samples) +
-                    ns * sizeof(RPY_ManualListSample));
-          } else {
-            return offsetof(CMD_Reply, data);
-          }
-        }
-      case RPY_ACTIVITY:
-        return offsetof(CMD_Reply, data.activity.EOR);

-      default:
-        assert(0);
-    }
+    return offsetof(CMD_Reply, data.manual_list.samples) +
+           ns * sizeof (RPY_ManualListSample);
  }

-  return 0;
+  return reply_lengths[type];
 }

 /* ================================================== */
--- a/privops.c
+++ b/privops.c
@@ -0,0 +1,730 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Bryan Christianson 2015
+ * Copyright (C) Miroslav Lichvar  2016
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ **********************************************************************
+
+  =======================================================================
+
+  Perform privileged operations over a unix socket to a privileged fork.
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "conf.h"
+#include "nameserv.h"
+#include "logging.h"
+#include "privops.h"
+#include "util.h"
+
+#define OP_ADJUSTTIME     1024
+#define OP_ADJUSTTIMEX    1025
+#define OP_SETTIME        1026
+#define OP_BINDSOCKET     1027
+#define OP_NAME2IPADDRESS 1028
+#define OP_RELOADDNS      1029
+#define OP_QUIT           1099
+
+union sockaddr_in46 {
+  struct sockaddr_in in4;
+#ifdef FEAT_IPV6
+  struct sockaddr_in6 in6;
+#endif
+  struct sockaddr u;
+};
+
+/* daemon request structs */
+
+typedef struct {
+  struct timeval tv;
+} ReqAdjustTime;
+
+#ifdef PRIVOPS_ADJUSTTIMEX
+typedef struct {
+  struct timex tmx;
+} ReqAdjustTimex;
+#endif
+
+typedef struct {
+  struct timeval tv;
+} ReqSetTime;
+
+typedef struct {
+  int sock;
+  socklen_t sa_len;
+  union sockaddr_in46 sa;
+} ReqBindSocket;
+
+typedef struct {
+  char name[256];
+} ReqName2IPAddress;
+
+typedef struct {
+  int op;
+  union {
+    ReqAdjustTime adjust_time;
+#ifdef PRIVOPS_ADJUSTTIMEX
+    ReqAdjustTimex adjust_timex;
+#endif
+    ReqSetTime set_time;
+    ReqBindSocket bind_socket;
+#ifdef PRIVOPS_NAME2IPADDRESS
+    ReqName2IPAddress name_to_ipaddress;
+#endif
+  } data;
+} PrvRequest;
+
+/* helper response structs */
+
+typedef struct {
+  struct timeval tv;
+} ResAdjustTime;
+
+#ifdef PRIVOPS_ADJUSTTIMEX
+typedef struct {
+  struct timex tmx;
+} ResAdjustTimex;
+#endif
+
+typedef struct {
+  IPAddr addresses[DNS_MAX_ADDRESSES];
+} ResName2IPAddress;
+
+typedef struct {
+  char msg[256];
+} ResFatalMsg;
+
+typedef struct {
+  int fatal_error;
+  int rc;
+  int res_errno;
+  union {
+    ResFatalMsg fatal_msg;
+    ResAdjustTime adjust_time;
+#ifdef PRIVOPS_ADJUSTTIMEX
+    ResAdjustTimex adjust_timex;
+#endif
+#ifdef PRIVOPS_NAME2IPADDRESS
+    ResName2IPAddress name_to_ipaddress;
+#endif
+  } data;
+} PrvResponse;
+
+static int helper_fd;
+static pid_t helper_pid;
+
+static int
+have_helper(void)
+{
+  return helper_fd >= 0;
+}
+
+/* ======================================================================= */
+
+/* HELPER - prepare fatal error for daemon */
+static void
+res_fatal(PrvResponse *res, const char *fmt, ...)
+{
+  va_list ap;
+
+  res->fatal_error = 1;
+  va_start(ap, fmt);
+  vsnprintf(res->data.fatal_msg.msg, sizeof (res->data.fatal_msg.msg), fmt, ap);
+  va_end(ap);
+}
+
+/* ======================================================================= */
+
+/* HELPER - send response to the fd */
+
+static int
+send_response(int fd, const PrvResponse *res)
+{
+  if (send(fd, res, sizeof (*res), 0) != sizeof (*res))
+    return 0;
+
+  return 1;
+}
+
+/* ======================================================================= */
+/* receive daemon request plus optional file descriptor over a unix socket */
+
+static int
+receive_from_daemon(int fd, PrvRequest *req)
+{
+  struct msghdr msg;
+  struct cmsghdr *cmsg;
+  struct iovec iov;
+  char cmsgbuf[256];
+
+  iov.iov_base = req;
+  iov.iov_len = sizeof (*req);
+
+  msg.msg_name = NULL;
+  msg.msg_namelen = 0;
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+  msg.msg_control = (void *)cmsgbuf;
+  msg.msg_controllen = sizeof (cmsgbuf);
+  msg.msg_flags = MSG_WAITALL;
+
+  /* read the data */
+  if (recvmsg(fd, &msg, 0) != sizeof (*req))
+    return 0;
+
+  if (req->op == OP_BINDSOCKET) {
+    /* extract transferred descriptor */
+    req->data.bind_socket.sock = -1;
+    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+      if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS)
+        memcpy(&req->data.bind_socket.sock, CMSG_DATA(cmsg), sizeof (int));
+    }
+
+    /* return error if valid descriptor not found */
+    if (req->data.bind_socket.sock < 0)
+      return 0;
+  }
+
+  return 1;
+}
+
+/* ======================================================================= */
+
+/* HELPER - perform adjtime() */
+
+#ifdef PRIVOPS_ADJUSTTIME
+static void
+do_adjust_time(const ReqAdjustTime *req, PrvResponse *res)
+{
+  res->rc = adjtime(&req->tv, &res->data.adjust_time.tv);
+  if (res->rc)
+    res->res_errno = errno;
+}
+#endif
+
+/* ======================================================================= */
+
+/* HELPER - perform ntp_adjtime() */
+
+#ifdef PRIVOPS_ADJUSTTIMEX
+static void
+do_adjust_timex(const ReqAdjustTimex *req, PrvResponse *res)
+{
+  res->data.adjust_timex.tmx = req->tmx;
+  res->rc = ntp_adjtime(&res->data.adjust_timex.tmx);
+  if (res->rc < 0)
+    res->res_errno = errno;
+}
+#endif
+
+/* ======================================================================= */
+
+/* HELPER - perform settimeofday() */
+
+#ifdef PRIVOPS_SETTIME
+static void
+do_set_time(const ReqSetTime *req, PrvResponse *res)
+{
+  res->rc = settimeofday(&req->tv, NULL);
+  if (res->rc)
+    res->res_errno = errno;
+}
+#endif
+
+/* ======================================================================= */
+
+/* HELPER - perform bind() */
+
+#ifdef PRIVOPS_BINDSOCKET
+static void
+do_bind_socket(ReqBindSocket *req, PrvResponse *res)
+{
+  unsigned short port;
+  IPAddr ip;
+  int sock_fd;
+  struct sockaddr *sa;
+  socklen_t sa_len;
+
+  sa = &req->sa.u;
+  sa_len = req->sa_len;
+  sock_fd = req->sock;
+
+  UTI_SockaddrToIPAndPort(sa, &ip, &port);
+  if (port && port != CNF_GetNTPPort()) {
+    close(sock_fd);
+    res_fatal(res, "Invalid port %d", port);
+    return;
+  }
+
+  res->rc = bind(sock_fd, sa, sa_len);
+  if (res->rc)
+    res->res_errno = errno;
+
+  /* sock is still open on daemon side, but we're done with it in the helper */
+  close(sock_fd);
+}
+#endif
+
+/* ======================================================================= */
+
+/* HELPER - perform DNS_Name2IPAddress() */
+
+#ifdef PRIVOPS_NAME2IPADDRESS
+static void
+do_name_to_ipaddress(ReqName2IPAddress *req, PrvResponse *res)
+{
+  /* make sure the string is terminated */
+  req->name[sizeof (req->name) - 1] = '\0';
+
+  res->rc = DNS_Name2IPAddress(req->name, res->data.name_to_ipaddress.addresses,
+                               DNS_MAX_ADDRESSES);
+}
+#endif
+
+/* ======================================================================= */
+
+/* HELPER - perform DNS_Reload() */
+
+#ifdef PRIVOPS_RELOADDNS
+static void
+do_reload_dns(PrvResponse *res)
+{
+  DNS_Reload();
+  res->rc = 0;
+}
+#endif
+
+/* ======================================================================= */
+
+/* HELPER - main loop - action requests from the daemon */
+
+static void
+helper_main(int fd)
+{
+  PrvRequest req;
+  PrvResponse res;
+  int quit = 0;
+
+  while (!quit) {
+    if (!receive_from_daemon(fd, &req))
+      /* read error or closed input - we cannot recover - give up */
+      break;
+
+    memset(&res, 0, sizeof (res));
+
+    switch (req.op) {
+#ifdef PRIVOPS_ADJUSTTIME
+      case OP_ADJUSTTIME:
+        do_adjust_time(&req.data.adjust_time, &res);
+        break;
+#endif
+#ifdef PRIVOPS_ADJUSTTIMEX
+      case OP_ADJUSTTIMEX:
+        do_adjust_timex(&req.data.adjust_timex, &res);
+        break;
+#endif
+#ifdef PRIVOPS_SETTIME
+      case OP_SETTIME:
+        do_set_time(&req.data.set_time, &res);
+        break;
+#endif
+#ifdef PRIVOPS_BINDSOCKET
+      case OP_BINDSOCKET:
+        do_bind_socket(&req.data.bind_socket, &res);
+        break;
+#endif
+#ifdef PRIVOPS_NAME2IPADDRESS
+      case OP_NAME2IPADDRESS:
+        do_name_to_ipaddress(&req.data.name_to_ipaddress, &res);
+        break;
+#endif
+#ifdef PRIVOPS_RELOADDNS
+      case OP_RELOADDNS:
+        do_reload_dns(&res);
+        break;
+#endif
+      case OP_QUIT:
+        quit = 1;
+        continue;
+
+      default:
+        res_fatal(&res, "Unexpected operator %d", req.op);
+        break;
+    }
+
+    send_response(fd, &res);
+  }
+
+  close(fd);
+  exit(0);
+}
+
+/* ======================================================================= */
+
+/* DAEMON - receive helper response */
+
+static void
+receive_response(PrvResponse *res)
+{
+  int resp_len;
+
+  resp_len = recv(helper_fd, res, sizeof (*res), 0);
+  if (resp_len < 0)
+    LOG_FATAL("Could not read from helper : %s", strerror(errno));
+  if (resp_len != sizeof (*res))
+    LOG_FATAL("Invalid helper response");
+
+  if (res->fatal_error)
+    LOG_FATAL("Error in helper : %s", res->data.fatal_msg.msg);
+
+  DEBUG_LOG("Received response rc=%d", res->rc);
+
+  /* if operation failed in the helper, set errno so daemon can print log message */
+  if (res->res_errno)
+    errno = res->res_errno;
+}
+
+/* ======================================================================= */
+
+/* DAEMON - send daemon request to the helper */
+
+static void
+send_request(PrvRequest *req)
+{
+  struct msghdr msg;
+  struct iovec iov;
+  char cmsgbuf[256];
+
+  iov.iov_base = req;
+  iov.iov_len = sizeof (*req);
+
+  msg.msg_name = NULL;
+  msg.msg_namelen = 0;
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+  msg.msg_control = NULL;
+  msg.msg_controllen = 0;
+  msg.msg_flags = 0;
+
+  if (req->op == OP_BINDSOCKET) {
+    /* send file descriptor as a control message */
+    struct cmsghdr *cmsg;
+    int *ptr_send_fd;
+
+    msg.msg_control = cmsgbuf;
+    msg.msg_controllen = CMSG_SPACE(sizeof (int));
+
+    cmsg = CMSG_FIRSTHDR(&msg);
+    memset(cmsg, 0, CMSG_SPACE(sizeof (int)));
+
+    cmsg->cmsg_level = SOL_SOCKET;
+    cmsg->cmsg_type = SCM_RIGHTS;
+    cmsg->cmsg_len = CMSG_LEN(sizeof (int));
+
+    ptr_send_fd = (int *)CMSG_DATA(cmsg);
+    *ptr_send_fd = req->data.bind_socket.sock;
+  }
+
+  if (sendmsg(helper_fd, &msg, 0) < 0) {
+    /* don't try to send another request from exit() */
+    helper_fd = -1;
+    LOG_FATAL("Could not send to helper : %s", strerror(errno));
+  }
+
+  DEBUG_LOG("Sent request op=%d", req->op);
+}
+
+/* ======================================================================= */
+
+/* DAEMON - send daemon request and wait for response */
+
+static void
+submit_request(PrvRequest *req, PrvResponse *res)
+{
+  send_request(req);
+  receive_response(res);
+}
+
+/* ======================================================================= */
+
+/* DAEMON - send the helper a request to exit and wait until it exits */
+
+static void
+stop_helper(void)
+{
+  PrvRequest req;
+  int status;
+
+  if (!have_helper())
+    return;
+
+  memset(&req, 0, sizeof (req));
+  req.op = OP_QUIT;
+  send_request(&req);
+
+  waitpid(helper_pid, &status, 0);
+}
+
+/* ======================================================================= */
+
+/* DAEMON - request adjtime() */
+
+#ifdef PRIVOPS_ADJUSTTIME
+int
+PRV_AdjustTime(const struct timeval *delta, struct timeval *olddelta)
+{
+  PrvRequest req;
+  PrvResponse res;
+
+  if (!have_helper() || delta == NULL)
+    /* helper is not running or read adjustment call */
+    return adjtime(delta, olddelta);
+
+  memset(&req, 0, sizeof (req));
+  req.op = OP_ADJUSTTIME;
+  req.data.adjust_time.tv = *delta;
+
+  submit_request(&req, &res);
+
+  if (olddelta)
+    *olddelta = res.data.adjust_time.tv;
+
+  return res.rc;
+}
+#endif
+
+/* ======================================================================= */
+
+/* DAEMON - request ntp_adjtime() */
+
+#ifdef PRIVOPS_ADJUSTTIMEX
+int
+PRV_AdjustTimex(struct timex *tmx)
+{
+  PrvRequest req;
+  PrvResponse res;
+
+  if (!have_helper())
+    return ntp_adjtime(tmx);
+
+  memset(&req, 0, sizeof (req));
+  req.op = OP_ADJUSTTIMEX;
+  req.data.adjust_timex.tmx = *tmx;
+
+  submit_request(&req, &res);
+
+  *tmx = res.data.adjust_timex.tmx;
+
+  return res.rc;
+}
+#endif
+
+/* ======================================================================= */
+
+/* DAEMON - request settimeofday() */
+
+#ifdef PRIVOPS_SETTIME
+int
+PRV_SetTime(const struct timeval *tp, const struct timezone *tzp)
+{
+  PrvRequest req;
+  PrvResponse res;
+
+  /* only support setting the time */
+  assert(tp != NULL);
+  assert(tzp == NULL);
+
+  if (!have_helper())
+    return settimeofday(tp, NULL);
+
+  memset(&req, 0, sizeof (req));
+  req.op = OP_SETTIME;
+  req.data.set_time.tv = *tp;
+
+  submit_request(&req, &res);
+
+  return res.rc;
+}
+#endif
+
+/* ======================================================================= */
+
+/* DAEMON - request bind() */
+
+#ifdef PRIVOPS_BINDSOCKET
+int
+PRV_BindSocket(int sock, struct sockaddr *address, socklen_t address_len)
+{
+  PrvRequest req;
+  PrvResponse res;
+  IPAddr ip;
+  unsigned short port;
+
+  UTI_SockaddrToIPAndPort(address, &ip, &port);
+  assert(!port || port == CNF_GetNTPPort());
+
+  if (!have_helper())
+    return bind(sock, address, address_len);
+
+  memset(&req, 0, sizeof (req));
+  req.op = OP_BINDSOCKET;
+  req.data.bind_socket.sock = sock;
+  req.data.bind_socket.sa_len = address_len;
+  memcpy(&req.data.bind_socket.sa.u, address, address_len);
+
+  submit_request(&req, &res);
+
+  return res.rc;
+}
+#endif
+
+/* ======================================================================= */
+
+/* DAEMON - request DNS_Name2IPAddress() */
+
+#ifdef PRIVOPS_NAME2IPADDRESS
+int
+PRV_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs)
+{
+  PrvRequest req;
+  PrvResponse res;
+  int i;
+
+  if (!have_helper())
+    return DNS_Name2IPAddress(name, ip_addrs, max_addrs);
+
+  memset(&req, 0, sizeof (req));
+  req.op = OP_NAME2IPADDRESS;
+  if (snprintf(req.data.name_to_ipaddress.name, sizeof (req.data.name_to_ipaddress.name),
+               "%s", name) >= sizeof (req.data.name_to_ipaddress.name)) {
+    DEBUG_LOG("Name too long");
+    return DNS_Failure;
+  }
+
+  submit_request(&req, &res);
+
+  for (i = 0; i < max_addrs && i < DNS_MAX_ADDRESSES; i++)
+    ip_addrs[i] = res.data.name_to_ipaddress.addresses[i];
+
+  return res.rc;
+}
+#endif
+
+/* ======================================================================= */
+
+/* DAEMON - request res_init() */
+
+#ifdef PRIVOPS_RELOADDNS
+void
+PRV_ReloadDNS(void)
+{
+  PrvRequest req;
+  PrvResponse res;
+
+  if (!have_helper()) {
+    DNS_Reload();
+    return;
+  }
+
+  memset(&req, 0, sizeof (req));
+  req.op = OP_RELOADDNS;
+
+  submit_request(&req, &res);
+  assert(!res.rc);
+}
+#endif
+
+/* ======================================================================= */
+
+void
+PRV_Initialise(void)
+{
+  helper_fd = -1;
+}
+
+/* ======================================================================= */
+
+/* DAEMON - setup socket(s) then fork to run the helper */
+/* must be called before privileges are dropped */
+
+void
+PRV_StartHelper(void)
+{
+  pid_t pid;
+  int fd, sock_pair[2];
+
+  if (have_helper())
+    LOG_FATAL("Helper already running");
+
+  if (
+#ifdef SOCK_SEQPACKET
+      socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sock_pair) &&
+#endif
+      socketpair(AF_UNIX, SOCK_DGRAM, 0, sock_pair))
+    LOG_FATAL("socketpair() failed : %s", strerror(errno));
+
+  UTI_FdSetCloexec(sock_pair[0]);
+  UTI_FdSetCloexec(sock_pair[1]);
+
+  pid = fork();
+  if (pid < 0)
+    LOG_FATAL("fork() failed : %s", strerror(errno));
+
+  if (pid == 0) {
+    /* child process */
+    close(sock_pair[0]);
+
+    /* close other descriptors inherited from the parent process */
+    for (fd = 0; fd < 1024; fd++) {
+      if (fd != sock_pair[1])
+        close(fd);
+    }
+
+    /* ignore signals, the process will exit on OP_QUIT request */
+    UTI_SetQuitSignalsHandler(SIG_IGN);
+
+    helper_main(sock_pair[1]);
+
+  } else {
+    /* parent process */
+    close(sock_pair[1]);
+    helper_fd = sock_pair[0];
+    helper_pid = pid;
+
+    /* stop the helper even when not exiting cleanly from the main function */
+    atexit(stop_helper);
+  }
+}
+
+/* ======================================================================= */
+
+/* DAEMON - graceful shutdown of the helper */
+
+void
+PRV_Finalise(void)
+{
+  if (!have_helper())
+    return;
+
+  stop_helper();
+  close(helper_fd);
+  helper_fd = -1;
+}
--- a/privops.h
+++ b/privops.h
@@ -0,0 +1,77 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Bryan Christianson 2015
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ **********************************************************************
+
+  =======================================================================
+
+  Perform privileged operations over a unix socket to a privileged fork.
+
+*/
+
+#ifndef GOT_PRIVOPS_H
+#define GOT_PRIVOPS_H
+
+#ifdef PRIVOPS_ADJUSTTIME
+int PRV_AdjustTime(const struct timeval *delta, struct timeval *olddelta);
+#else
+#define PRV_AdjustTime adjtime
+#endif
+
+#ifdef PRIVOPS_ADJUSTTIMEX
+int PRV_AdjustTimex(struct timex *txc);
+#else
+#define PRV_AdjustTimex ntp_adjtime
+#endif
+
+#ifdef PRIVOPS_SETTIME
+int PRV_SetTime(const struct timeval *tp, const struct timezone *tzp);
+#else
+#define PRV_SetTime settimeofday
+#endif
+
+#ifdef PRIVOPS_BINDSOCKET
+int PRV_BindSocket(int sock, struct sockaddr *address, socklen_t address_len);
+#else
+#define PRV_BindSocket bind
+#endif
+
+#ifdef PRIVOPS_NAME2IPADDRESS
+int PRV_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs);
+#else
+#define PRV_Name2IPAddress DNS_Name2IPAddress
+#endif
+
+#ifdef PRIVOPS_RELOADDNS
+void PRV_ReloadDNS(void);
+#else
+#define PRV_ReloadDNS DNS_Reload
+#endif
+
+#ifdef PRIVOPS_HELPER
+void PRV_Initialise(void);
+void PRV_StartHelper(void);
+void PRV_Finalise(void);
+#else
+#define PRV_Initialise()
+#define PRV_StartHelper()
+#define PRV_Finalise()
+#endif
+
+#endif
--- a/refclock.c
+++ b/refclock.c
@@ -2,7 +2,7 @@
  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************
- * Copyright (C) Miroslav Lichvar  2009-2011, 2013-2014
+ * Copyright (C) Miroslav Lichvar  2009-2011, 2013-2014, 2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -48,7 +48,7 @@ extern RefclockDriver RCL_PHC_driver;
 struct FilterSample {
  double offset;
  double dispersion;
-  struct timeval sample_time;
+  struct timespec sample_time;
 };

 struct MedianFilter {
@@ -75,52 +75,56 @@ struct RCL_Instance_Record {
  int driver_polled;
  int poll;
  int leap_status;
+  int pps_forced;
  int pps_rate;
  int pps_active;
+  int max_lock_age;
  struct MedianFilter filter;
  uint32_t ref_id;
  uint32_t lock_ref;
  double offset;
  double delay;
  double precision;
+  double pulse_width;
  SCH_TimeoutID timeout_id;
  SRC_Instance source;
 };

-/* Array of RCL_Instance_Record */
+/* Array of pointers to RCL_Instance_Record */
 static ARR_Instance refclocks;

 static LOG_FileID logfileid;

-static int valid_sample_time(RCL_Instance instance, struct timeval *tv);
-static int pps_stratum(RCL_Instance instance, struct timeval *tv);
+static int valid_sample_time(RCL_Instance instance, struct timespec *sample_time);
+static int pps_stratum(RCL_Instance instance, struct timespec *ts);
 static void poll_timeout(void *arg);
-static void slew_samples(struct timeval *raw, struct timeval *cooked, double dfreq,
+static void slew_samples(struct timespec *raw, struct timespec *cooked, double dfreq,
             double doffset, LCL_ChangeType change_type, void *anything);
 static void add_dispersion(double dispersion, void *anything);
-static void log_sample(RCL_Instance instance, struct timeval *sample_time, int filtered, int pulse, double raw_offset, double cooked_offset, double dispersion);
+static void log_sample(RCL_Instance instance, struct timespec *sample_time, int filtered, int pulse, double raw_offset, double cooked_offset, double dispersion);

 static void filter_init(struct MedianFilter *filter, int length, double max_dispersion);
 static void filter_fini(struct MedianFilter *filter);
 static void filter_reset(struct MedianFilter *filter);
 static double filter_get_avg_sample_dispersion(struct MedianFilter *filter);
-static void filter_add_sample(struct MedianFilter *filter, struct timeval *sample_time, double offset, double dispersion);
-static int filter_get_last_sample(struct MedianFilter *filter, struct timeval *sample_time, double *offset, double *dispersion);
+static void filter_add_sample(struct MedianFilter *filter, struct timespec *sample_time, double offset, double dispersion);
+static int filter_get_last_sample(struct MedianFilter *filter, struct timespec *sample_time, double *offset, double *dispersion);
+static int filter_get_samples(struct MedianFilter *filter);
 static int filter_select_samples(struct MedianFilter *filter);
-static int filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, double *offset, double *dispersion);
-static void filter_slew_samples(struct MedianFilter *filter, struct timeval *when, double dfreq, double doffset);
+static int filter_get_sample(struct MedianFilter *filter, struct timespec *sample_time, double *offset, double *dispersion);
+static void filter_slew_samples(struct MedianFilter *filter, struct timespec *when, double dfreq, double doffset);
 static void filter_add_dispersion(struct MedianFilter *filter, double dispersion);

 static RCL_Instance
 get_refclock(unsigned int index)
 {
-  return (RCL_Instance)ARR_GetElement(refclocks, index);
+  return *(RCL_Instance *)ARR_GetElement(refclocks, index);
 }

 void
 RCL_Initialise(void)
 {
-  refclocks = ARR_CreateInstance(sizeof (struct RCL_Instance_Record));
+  refclocks = ARR_CreateInstance(sizeof (RCL_Instance));

  CNF_AddRefclocks();

@@ -148,6 +152,7 @@ RCL_Finalise(void)
    filter_fini(&inst->filter);
    Free(inst->driver_parameter);
    SRC_DestroyInstance(inst->source);
+    Free(inst);
  }

  if (ARR_GetSize(refclocks) > 0) {
@@ -161,31 +166,26 @@ RCL_Finalise(void)
 int
 RCL_AddRefclock(RefclockParameters *params)
 {
-  int pps_source = 0;
+  RCL_Instance inst;

-  RCL_Instance inst = ARR_GetNewElement(refclocks);
+  inst = MallocNew(struct RCL_Instance_Record);
+  *(RCL_Instance *)ARR_GetNewElement(refclocks) = inst;

  if (strcmp(params->driver_name, "SHM") == 0) {
    inst->driver = &RCL_SHM_driver;
-    inst->precision = 1e-6;
  } else if (strcmp(params->driver_name, "SOCK") == 0) {
    inst->driver = &RCL_SOCK_driver;
-    inst->precision = 1e-9;
-    pps_source = 1;
  } else if (strcmp(params->driver_name, "PPS") == 0) {
    inst->driver = &RCL_PPS_driver;
-    inst->precision = 1e-9;
-    pps_source = 1;
  } else if (strcmp(params->driver_name, "PHC") == 0) {
    inst->driver = &RCL_PHC_driver;
-    inst->precision = 1e-9;
  } else {
-    LOG_FATAL(LOGF_Refclock, "unknown refclock driver %s", params->driver_name);
+    LOG_FATAL("unknown refclock driver %s", params->driver_name);
    return 0;
  }

  if (!inst->driver->init && !inst->driver->poll) {
-    LOG_FATAL(LOGF_Refclock, "refclock driver %s is not compiled in", params->driver_name);
+    LOG_FATAL("refclock driver %s is not compiled in", params->driver_name);
    return 0;
  }

@@ -196,13 +196,16 @@ RCL_AddRefclock(RefclockParameters *params)
  inst->poll = params->poll;
  inst->driver_polled = 0;
  inst->leap_status = LEAP_Normal;
+  inst->pps_forced = params->pps_forced;
  inst->pps_rate = params->pps_rate;
  inst->pps_active = 0;
+  inst->max_lock_age = params->max_lock_age;
  inst->lock_ref = params->lock_ref_id;
  inst->offset = params->offset;
  inst->delay = params->delay;
-  if (params->precision > 0.0)
-    inst->precision = params->precision;
+  inst->precision = LCL_GetSysPrecisionAsQuantum();
+  inst->precision = MAX(inst->precision, params->precision);
+  inst->pulse_width = params->pulse_width;
  inst->timeout_id = -1;
  inst->source = NULL;

@@ -215,25 +218,21 @@ RCL_AddRefclock(RefclockParameters *params)
        inst->driver_parameter[i] = '\0';
  }

-  if (pps_source) {
  if (inst->pps_rate < 1)
    inst->pps_rate = 1;
-  } else {
-    inst->pps_rate = 0;
-  }

  if (params->ref_id)
    inst->ref_id = params->ref_id;
  else {
    unsigned char ref[5] = { 0, 0, 0, 0, 0 };
-    unsigned int index = ARR_GetSize(refclocks);
+    unsigned int index = ARR_GetSize(refclocks) - 1;

    snprintf((char *)ref, sizeof (ref), "%3.3s", params->driver_name);
    ref[3] = index % 10 + '0';
    if (index >= 10)
      ref[2] = (index / 10) % 10 + '0';

-    inst->ref_id = ref[0] << 24 | ref[1] << 16 | ref[2] << 8 | ref[3];
+    inst->ref_id = (uint32_t)ref[0] << 24 | ref[1] << 16 | ref[2] << 8 | ref[3];
  }

  if (inst->driver->poll) {
@@ -245,7 +244,7 @@ RCL_AddRefclock(RefclockParameters *params)
    max_samples = 1 << (inst->poll - inst->driver_poll);
    if (max_samples < params->filter_length) {
      if (max_samples < 4) {
-        LOG(LOGS_WARN, LOGF_Refclock, "Setting filter length for %s to %d",
+        LOG(LOGS_WARN, "Setting filter length for %s to %d",
            UTI_RefidToString(inst->ref_id), max_samples);
      }
      params->filter_length = max_samples;
@@ -254,16 +253,16 @@ RCL_AddRefclock(RefclockParameters *params)

  if (inst->driver->init)
    if (!inst->driver->init(inst)) {
-      LOG_FATAL(LOGF_Refclock, "refclock %s initialisation failed", params->driver_name);
+      LOG_FATAL("refclock %s initialisation failed", params->driver_name);
      return 0;
    }

  filter_init(&inst->filter, params->filter_length, params->max_dispersion);

-  inst->source = SRC_CreateNewInstance(inst->ref_id, SRC_REFCLOCK, params->sel_option, NULL,
+  inst->source = SRC_CreateNewInstance(inst->ref_id, SRC_REFCLOCK, params->sel_options, NULL,
                                       params->min_samples, params->max_samples);

-  DEBUG_LOG(LOGF_Refclock, "refclock %s refid=%s poll=%d dpoll=%d filter=%d",
+  DEBUG_LOG("refclock %s refid=%s poll=%d dpoll=%d filter=%d",
      params->driver_name, UTI_RefidToString(inst->ref_id),
      inst->poll, inst->driver_poll, params->filter_length);

@@ -296,7 +295,7 @@ RCL_StartRefclocks(void)
 }

 void
-RCL_ReportSource(RPT_SourceReport *report, struct timeval *now)
+RCL_ReportSource(RPT_SourceReport *report, struct timespec *now)
 {
  unsigned int i;
  uint32_t ref_id;
@@ -358,20 +357,23 @@ RCL_GetDriverOption(RCL_Instance instance, char *name)
 }

 int
-RCL_AddSample(RCL_Instance instance, struct timeval *sample_time, double offset, int leap)
+RCL_AddSample(RCL_Instance instance, struct timespec *sample_time, double offset, int leap)
 {
  double correction, dispersion;
-  struct timeval cooked_time;
+  struct timespec cooked_time;
+
+  if (instance->pps_forced)
+    return RCL_AddPulse(instance, sample_time, -offset);

  LCL_GetOffsetCorrection(sample_time, &correction, &dispersion);
-  UTI_AddDoubleToTimeval(sample_time, correction, &cooked_time);
+  UTI_AddDoubleToTimespec(sample_time, correction, &cooked_time);
  dispersion += instance->precision;

-  if (!valid_sample_time(instance, sample_time))
+  /* Make sure the timestamp and offset provided by the driver are sane */
+  if (!UTI_IsTimeOffsetSane(sample_time, offset) ||
+      !valid_sample_time(instance, &cooked_time))
    return 0;

-  filter_add_sample(&instance->filter, &cooked_time, offset - correction + instance->offset, dispersion);
-
  switch (leap) {
    case LEAP_Normal:
    case LEAP_InsertSecond:
@@ -379,10 +381,11 @@ RCL_AddSample(RCL_Instance instance, struct timeval *sample_time, double offset,
      instance->leap_status = leap;
      break;
    default:
-      instance->leap_status = LEAP_Unsynchronised;
-      break;
+      DEBUG_LOG("refclock sample ignored bad leap %d", leap);
+      return 0;
  }

+  filter_add_sample(&instance->filter, &cooked_time, offset - correction + instance->offset, dispersion);
  instance->pps_active = 0;

  log_sample(instance, &cooked_time, 0, 0, offset, offset - correction + instance->offset, dispersion);
@@ -395,25 +398,59 @@ RCL_AddSample(RCL_Instance instance, struct timeval *sample_time, double offset,
 }

 int
-RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
+RCL_AddPulse(RCL_Instance instance, struct timespec *pulse_time, double second)
 {
-  double correction, dispersion, offset;
-  struct timeval cooked_time;
+  double correction, dispersion;
+  struct timespec cooked_time;
+
+  LCL_GetOffsetCorrection(pulse_time, &correction, &dispersion);
+  UTI_AddDoubleToTimespec(pulse_time, correction, &cooked_time);
+  second += correction;
+
+  if (!UTI_IsTimeOffsetSane(pulse_time, 0.0))
+    return 0;
+
+  return RCL_AddCookedPulse(instance, &cooked_time, second, dispersion, correction);
+}
+
+static int
+check_pulse_edge(RCL_Instance instance, double offset, double distance)
+{
+  double max_error;
+
+  if (instance->pulse_width <= 0.0)
+    return 1;
+
+  max_error = 1.0 / instance->pps_rate - instance->pulse_width;
+  max_error = MIN(instance->pulse_width, max_error);
+  max_error *= 0.5;
+
+  if (fabs(offset) > max_error || distance > max_error) {
+      DEBUG_LOG("refclock pulse ignored offset=%.9f distance=%.9f max_error=%.9f",
+                offset, distance, max_error);
+      return 0;
+  }
+
+  return 1;
+}
+
+int
+RCL_AddCookedPulse(RCL_Instance instance, struct timespec *cooked_time,
+                   double second, double dispersion, double raw_correction)
+{
+  double offset;
  int rate;
  NTP_Leap leap;

-  leap = LEAP_Normal;
-  LCL_GetOffsetCorrection(pulse_time, &correction, &dispersion);
-  UTI_AddDoubleToTimeval(pulse_time, correction, &cooked_time);
-  dispersion += instance->precision;
-
-  if (!valid_sample_time(instance, pulse_time))
+  if (!UTI_IsTimeOffsetSane(cooked_time, second) ||
+      !valid_sample_time(instance, cooked_time))
    return 0;

+  leap = LEAP_Normal;
+  dispersion += instance->precision;
  rate = instance->pps_rate;
-  assert(rate > 0);

-  offset = -second - correction + instance->offset;
+  offset = -second + instance->offset;

  /* Adjust the offset to [-0.5/rate, 0.5/rate) interval */
  offset -= (long)(offset * rate) / (double)rate;
@@ -424,22 +461,22 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)

  if (instance->lock_ref != -1) {
    RCL_Instance lock_refclock;
-    struct timeval ref_sample_time;
+    struct timespec ref_sample_time;
    double sample_diff, ref_offset, ref_dispersion, shift;

    lock_refclock = get_refclock(instance->lock_ref);

    if (!filter_get_last_sample(&lock_refclock->filter,
          &ref_sample_time, &ref_offset, &ref_dispersion)) {
-      DEBUG_LOG(LOGF_Refclock, "refclock pulse ignored no ref sample");
+      DEBUG_LOG("refclock pulse ignored no ref sample");
      return 0;
    }

    ref_dispersion += filter_get_avg_sample_dispersion(&lock_refclock->filter);

-    UTI_DiffTimevalsToDouble(&sample_diff, &cooked_time, &ref_sample_time);
-    if (fabs(sample_diff) >= 2.0 / rate) {
-      DEBUG_LOG(LOGF_Refclock, "refclock pulse ignored samplediff=%.9f",
+    sample_diff = UTI_DiffTimespecsToDouble(cooked_time, &ref_sample_time);
+    if (fabs(sample_diff) >= (double)instance->max_lock_age / rate) {
+      DEBUG_LOG("refclock pulse ignored samplediff=%.9f",
          sample_diff);
      return 0;
    }
@@ -453,41 +490,49 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
    offset += shift;

    if (fabs(ref_offset - offset) + ref_dispersion + dispersion >= 0.2 / rate) {
-      DEBUG_LOG(LOGF_Refclock, "refclock pulse ignored offdiff=%.9f refdisp=%.9f disp=%.9f",
+      DEBUG_LOG("refclock pulse ignored offdiff=%.9f refdisp=%.9f disp=%.9f",
          ref_offset - offset, ref_dispersion, dispersion);
      return 0;
    }

+    if (!check_pulse_edge(instance, ref_offset - offset, 0.0))
+      return 0;
+
    leap = lock_refclock->leap_status;

-    DEBUG_LOG(LOGF_Refclock, "refclock pulse second=%.9f offset=%.9f offdiff=%.9f samplediff=%.9f",
-        second, offset, ref_offset - offset, sample_diff);
+    DEBUG_LOG("refclock pulse offset=%.9f offdiff=%.9f samplediff=%.9f",
+              offset, ref_offset - offset, sample_diff);
  } else {
-    struct timeval ref_time;
+    struct timespec ref_time;
    int is_synchronised, stratum;
    double root_delay, root_dispersion, distance;
    uint32_t ref_id;

-    /* Ignore the pulse if we are not well synchronized */
+    /* Ignore the pulse if we are not well synchronized and the local
+       reference is not active */

-    REF_GetReferenceParams(&cooked_time, &is_synchronised, &leap, &stratum,
+    REF_GetReferenceParams(cooked_time, &is_synchronised, &leap, &stratum,
        &ref_id, &ref_time, &root_delay, &root_dispersion);
    distance = fabs(root_delay) / 2 + root_dispersion;

-    if (!is_synchronised || distance >= 0.5 / rate) {
-      DEBUG_LOG(LOGF_Refclock, "refclock pulse ignored second=%.9f sync=%d dist=%.9f",
-          second, is_synchronised, distance);
+    if (leap == LEAP_Unsynchronised || distance >= 0.5 / rate) {
+      DEBUG_LOG("refclock pulse ignored offset=%.9f sync=%d dist=%.9f",
+                offset, leap != LEAP_Unsynchronised, distance);
      /* Drop also all stored samples */
      filter_reset(&instance->filter);
      return 0;
    }
+
+    if (!check_pulse_edge(instance, offset, distance))
+      return 0;
  }

-  filter_add_sample(&instance->filter, &cooked_time, offset, dispersion);
+  filter_add_sample(&instance->filter, cooked_time, offset, dispersion);
  instance->leap_status = leap;
  instance->pps_active = 1;

-  log_sample(instance, &cooked_time, 0, 1, offset + correction - instance->offset, offset, dispersion);
+  log_sample(instance, cooked_time, 0, 1, offset + raw_correction - instance->offset,
+             offset, dispersion);

  /* for logging purposes */
  if (!instance->driver->poll)
@@ -496,35 +541,45 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
  return 1;
 }

-static double
-poll_interval(int poll)
+double
+RCL_GetPrecision(RCL_Instance instance)
 {
-  if (poll >= 0)
-    return 1 << poll;
-  else
-    return 1.0 / (1 << -poll);
+  return instance->precision;
+}
+
+int
+RCL_GetDriverPoll(RCL_Instance instance)
+{
+  return instance->driver_poll;
 }

 static int
-valid_sample_time(RCL_Instance instance, struct timeval *tv)
+valid_sample_time(RCL_Instance instance, struct timespec *sample_time)
 {
-  struct timeval raw_time;
-  double diff;
+  struct timespec now, last_sample_time;
+  double diff, last_offset, last_dispersion;

-  LCL_ReadRawTime(&raw_time);
-  UTI_DiffTimevalsToDouble(&diff, &raw_time, tv);
-  if (diff < 0.0 || diff > poll_interval(instance->poll + 1)) {
-    DEBUG_LOG(LOGF_Refclock, "%s refclock sample not valid age=%.6f tv=%s",
-        UTI_RefidToString(instance->ref_id), diff, UTI_TimevalToString(tv));
+  LCL_ReadCookedTime(&now, NULL);
+  diff = UTI_DiffTimespecsToDouble(&now, sample_time);
+
+  if (diff < 0.0 || diff > UTI_Log2ToDouble(instance->poll + 1) ||
+      (filter_get_samples(&instance->filter) > 0 &&
+       filter_get_last_sample(&instance->filter, &last_sample_time,
+                              &last_offset, &last_dispersion) &&
+       UTI_CompareTimespecs(&last_sample_time, sample_time) >= 0)) {
+    DEBUG_LOG("%s refclock sample time %s not valid age=%.6f",
+              UTI_RefidToString(instance->ref_id),
+              UTI_TimespecToString(sample_time), diff);
    return 0;
  }
+
  return 1;
 }

 static int
-pps_stratum(RCL_Instance instance, struct timeval *tv)
+pps_stratum(RCL_Instance instance, struct timespec *ts)
 {
-  struct timeval ref_time;
+  struct timespec ref_time;
  int is_synchronised, stratum;
  unsigned int i;
  double root_delay, root_dispersion;
@@ -532,12 +587,13 @@ pps_stratum(RCL_Instance instance, struct timeval *tv)
  uint32_t ref_id;
  RCL_Instance refclock;

-  REF_GetReferenceParams(tv, &is_synchronised, &leap, &stratum,
+  REF_GetReferenceParams(ts, &is_synchronised, &leap, &stratum,
      &ref_id, &ref_time, &root_delay, &root_dispersion);

-  /* Don't change our stratum if local stratum is active
+  /* Don't change our stratum if the local reference is active
     or this is the current source */
-  if (ref_id == instance->ref_id || REF_IsLocalActive())
+  if (ref_id == instance->ref_id ||
+      (!is_synchronised && leap != LEAP_Unsynchronised))
    return stratum - 1;

  /* Or the current source is another PPS refclock */ 
@@ -568,7 +624,7 @@ poll_timeout(void *arg)
  
  if (!(inst->driver->poll && inst->driver_polled < (1 << (inst->poll - inst->driver_poll)))) {
    double offset, dispersion;
-    struct timeval sample_time;
+    struct timespec sample_time;
    int sample_ok, stratum;

    sample_ok = filter_get_sample(&inst->filter, &sample_time, &offset, &dispersion);
@@ -592,11 +648,11 @@ poll_timeout(void *arg)
    }
  }

-  inst->timeout_id = SCH_AddTimeoutByDelay(poll_interval(poll), poll_timeout, arg);
+  inst->timeout_id = SCH_AddTimeoutByDelay(UTI_Log2ToDouble(poll), poll_timeout, arg);
 }

 static void
-slew_samples(struct timeval *raw, struct timeval *cooked, double dfreq,
+slew_samples(struct timespec *raw, struct timespec *cooked, double dfreq,
             double doffset, LCL_ChangeType change_type, void *anything)
 {
  unsigned int i;
@@ -619,7 +675,7 @@ add_dispersion(double dispersion, void *anything)
 }

 static void
-log_sample(RCL_Instance instance, struct timeval *sample_time, int filtered, int pulse, double raw_offset, double cooked_offset, double dispersion)
+log_sample(RCL_Instance instance, struct timespec *sample_time, int filtered, int pulse, double raw_offset, double cooked_offset, double dispersion)
 {
  char sync_stats[4] = {'N', '+', '-', '?'};

@@ -629,7 +685,7 @@ log_sample(RCL_Instance instance, struct timeval *sample_time, int filtered, int
  if (!filtered) {
    LOG_FileWrite(logfileid, "%s.%06d %-5s %3d %1c %1d %13.6e %13.6e %10.3e",
      UTI_TimeToLogForm(sample_time->tv_sec),
-      (int)sample_time->tv_usec,
+      (int)sample_time->tv_nsec / 1000,
      UTI_RefidToString(instance->ref_id),
      instance->driver_polled,
      sync_stats[instance->leap_status],
@@ -640,7 +696,7 @@ log_sample(RCL_Instance instance, struct timeval *sample_time, int filtered, int
  } else {
    LOG_FileWrite(logfileid, "%s.%06d %-5s   - %1c -       -       %13.6e %10.3e",
      UTI_TimeToLogForm(sample_time->tv_sec),
-      (int)sample_time->tv_usec,
+      (int)sample_time->tv_nsec / 1000,
      UTI_RefidToString(instance->ref_id),
      sync_stats[instance->leap_status],
      cooked_offset,
@@ -693,7 +749,7 @@ filter_get_avg_sample_dispersion(struct MedianFilter *filter)
 }

 static void
-filter_add_sample(struct MedianFilter *filter, struct timeval *sample_time, double offset, double dispersion)
+filter_add_sample(struct MedianFilter *filter, struct timespec *sample_time, double offset, double dispersion)
 {
  filter->index++;
  filter->index %= filter->length;
@@ -705,12 +761,12 @@ filter_add_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
  filter->samples[filter->index].offset = offset;
  filter->samples[filter->index].dispersion = dispersion;

-  DEBUG_LOG(LOGF_Refclock, "filter sample %d t=%s offset=%.9f dispersion=%.9f",
-      filter->index, UTI_TimevalToString(sample_time), offset, dispersion);
+  DEBUG_LOG("filter sample %d t=%s offset=%.9f dispersion=%.9f",
+      filter->index, UTI_TimespecToString(sample_time), offset, dispersion);
 }

 static int
-filter_get_last_sample(struct MedianFilter *filter, struct timeval *sample_time, double *offset, double *dispersion)
+filter_get_last_sample(struct MedianFilter *filter, struct timespec *sample_time, double *offset, double *dispersion)
 {
  if (filter->last < 0)
    return 0;
@@ -721,6 +777,12 @@ filter_get_last_sample(struct MedianFilter *filter, struct timeval *sample_time,
  return 1;
 }

+static int
+filter_get_samples(struct MedianFilter *filter)
+{
+  return filter->used;
+}
+
 static const struct FilterSample *tmp_sorted_array;

 static int
@@ -823,7 +885,7 @@ filter_select_samples(struct MedianFilter *filter)
 }

 static int
-filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, double *offset, double *dispersion)
+filter_get_sample(struct MedianFilter *filter, struct timespec *sample_time, double *offset, double *dispersion)
 {
  struct FilterSample *s, *ls;
  int i, n, dof;
@@ -840,7 +902,7 @@ filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
  for (i = 0; i < n; i++) {
    s = &filter->samples[filter->selected[i]];

-    UTI_DiffTimevalsToDouble(&filter->x_data[i], &s->sample_time, &ls->sample_time);
+    filter->x_data[i] = UTI_DiffTimespecsToDouble(&s->sample_time, &ls->sample_time);
    filter->y_data[i] = s->offset;
    filter->w_data[i] = s->dispersion;
  }
@@ -889,7 +951,7 @@ filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, doub

  /* drop the sample if variance is larger than allowed maximum */
  if (filter->max_var > 0.0 && var > filter->max_var) {
-    DEBUG_LOG(LOGF_Refclock, "filter dispersion too large disp=%.9f max=%.9f",
+    DEBUG_LOG("filter dispersion too large disp=%.9f max=%.9f",
        sqrt(var), sqrt(filter->max_var));
    return 0;
  }
@@ -915,7 +977,7 @@ filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
  if (d < e)
    d = e;

-  UTI_AddDoubleToTimeval(&ls->sample_time, x, sample_time);
+  UTI_AddDoubleToTimespec(&ls->sample_time, x, sample_time);
  *offset = y;
  *dispersion = d;

@@ -925,15 +987,26 @@ filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
 }

 static void
-filter_slew_samples(struct MedianFilter *filter, struct timeval *when, double dfreq, double doffset)
+filter_slew_samples(struct MedianFilter *filter, struct timespec *when, double dfreq, double doffset)
 {
-  int i;
+  int i, first, last;
  double delta_time;
-  struct timeval *sample;
+  struct timespec *sample;

-  for (i = 0; i < filter->used; i++) {
+  if (filter->last < 0)
+    return;
+
+  /* always slew the last sample as it may be needed by PPS refclocks */
+  if (filter->used > 0) {
+    first = 0;
+    last = filter->used - 1;
+  } else {
+    first = last = filter->last;
+  }
+
+  for (i = first; i <= last; i++) {
    sample = &filter->samples[i].sample_time;
-    UTI_AdjustTimeval(sample, when, sample, &delta_time, dfreq, doffset);
+    UTI_AdjustTimespec(sample, when, sample, &delta_time, dfreq, doffset);
    filter->samples[i].offset -= delta_time;
  }
 }
--- a/refclock.h
+++ b/refclock.h
@@ -37,16 +37,19 @@ typedef struct {
  int driver_poll;
  int poll;
  int filter_length;
+  int pps_forced;
  int pps_rate;
  int min_samples;
  int max_samples;
+  int sel_options;
+  int max_lock_age;
  uint32_t ref_id;
  uint32_t lock_ref_id;
  double offset;
  double delay;
  double precision;
  double max_dispersion;
-  SRC_SelectOption sel_option;
+  double pulse_width;
 } RefclockParameters;

 typedef struct RCL_Instance_Record *RCL_Instance;
@@ -61,14 +64,18 @@ extern void RCL_Initialise(void);
 extern void RCL_Finalise(void);
 extern int RCL_AddRefclock(RefclockParameters *params);
 extern void RCL_StartRefclocks(void);
-extern void RCL_ReportSource(RPT_SourceReport *report, struct timeval *now);
+extern void RCL_ReportSource(RPT_SourceReport *report, struct timespec *now);

 /* functions used by drivers */
 extern void RCL_SetDriverData(RCL_Instance instance, void *data);
 extern void *RCL_GetDriverData(RCL_Instance instance);
 extern char *RCL_GetDriverParameter(RCL_Instance instance);
 extern char *RCL_GetDriverOption(RCL_Instance instance, char *name);
-extern int RCL_AddSample(RCL_Instance instance, struct timeval *sample_time, double offset, int leap);
-extern int RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second);
+extern int RCL_AddSample(RCL_Instance instance, struct timespec *sample_time, double offset, int leap);
+extern int RCL_AddPulse(RCL_Instance instance, struct timespec *pulse_time, double second);
+extern int RCL_AddCookedPulse(RCL_Instance instance, struct timespec *cooked_time,
+                              double second, double dispersion, double raw_correction);
+extern double RCL_GetPrecision(RCL_Instance instance);
+extern int RCL_GetDriverPoll(RCL_Instance instance);

 #endif
--- a/refclock_phc.c
+++ b/refclock_phc.c
@@ -2,7 +2,7 @@
  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************
- * Copyright (C) Miroslav Lichvar  2013
+ * Copyright (C) Miroslav Lichvar  2013, 2017
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -33,151 +33,134 @@

 #include "sysincl.h"

-#include <linux/ptp_clock.h>
-
 #include "refclock.h"
+#include "hwclock.h"
+#include "local.h"
 #include "logging.h"
+#include "memory.h"
 #include "util.h"
+#include "sched.h"
+#include "sys_linux.h"

-/* From linux/include/linux/posix-timers.h */
-#define CPUCLOCK_MAX            3
-#define CLOCKFD                 CPUCLOCK_MAX
-#define CLOCKFD_MASK            (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)
-
-#define FD_TO_CLOCKID(fd)       ((~(clockid_t) (fd) << 3) | CLOCKFD)
-
-#define NUM_READINGS 10
-
-static int no_sys_offset_ioctl = 0;
-
-struct phc_reading {
-  struct timespec sys_ts1;
-  struct timespec phc_ts;;
-  struct timespec sys_ts2;
+struct phc_instance {
+  int fd;
+  int mode;
+  int nocrossts;
+  int extpps;
+  int pin;
+  int channel;
+  HCL_Instance clock;
 };

-static double diff_ts(struct timespec *ts1, struct timespec *ts2)
-{
-  return (ts1->tv_sec - ts2->tv_sec) + (ts1->tv_nsec - ts2->tv_nsec) / 1e9;
-}
-
-static int read_phc_ioctl(struct phc_reading *readings, int phc_fd, int n)
-{
-#if defined(PTP_SYS_OFFSET) && NUM_READINGS <= PTP_MAX_SAMPLES
-  struct ptp_sys_offset sys_off;
-  int i;
-
-  /* Silence valgrind */
-  memset(&sys_off, 0, sizeof (sys_off));
-
-  sys_off.n_samples = n;
-  if (ioctl(phc_fd, PTP_SYS_OFFSET, &sys_off)) {
-    LOG(LOGS_ERR, LOGF_Refclock, "ioctl(PTP_SYS_OFFSET) failed : %s", strerror(errno));
-    return 0;
-  }
-
-  for (i = 0; i < n; i++) {
-    readings[i].sys_ts1.tv_sec = sys_off.ts[i * 2].sec;
-    readings[i].sys_ts1.tv_nsec = sys_off.ts[i * 2].nsec;
-    readings[i].phc_ts.tv_sec = sys_off.ts[i * 2 + 1].sec;
-    readings[i].phc_ts.tv_nsec = sys_off.ts[i * 2 + 1].nsec;
-    readings[i].sys_ts2.tv_sec = sys_off.ts[i * 2 + 2].sec;
-    readings[i].sys_ts2.tv_nsec = sys_off.ts[i * 2 + 2].nsec;
-  }
-
-  return 1;
-#else
-  /* Not available */
-  return 0;
-#endif
-}
-
-static int read_phc_user(struct phc_reading *readings, int phc_fd, int n)
-{
-  clockid_t phc_id;
-  int i;
-
-  phc_id = FD_TO_CLOCKID(phc_fd);
-
-  for (i = 0; i < n; i++) {
-    if (clock_gettime(CLOCK_REALTIME, &readings[i].sys_ts1) ||
-        clock_gettime(phc_id, &readings[i].phc_ts) ||
-        clock_gettime(CLOCK_REALTIME, &readings[i].sys_ts2)) {
-      LOG(LOGS_ERR, LOGF_Refclock, "clock_gettime() failed : %s", strerror(errno));
-      return 0;
-    }
-  }
-
-  return 1;
-}
+static void read_ext_pulse(int sockfd, int event, void *anything);

 static int phc_initialise(RCL_Instance instance)
 {
-  struct ptp_clock_caps caps;
-  int phc_fd;
-  char *path;
+  struct phc_instance *phc;
+  int phc_fd, rising_edge;
+  char *path, *s;

  path = RCL_GetDriverParameter(instance);
 
-  phc_fd = open(path, O_RDONLY);
+  phc_fd = SYS_Linux_OpenPHC(path, 0);
  if (phc_fd < 0) {
-    LOG_FATAL(LOGF_Refclock, "open() failed on %s", path);
+    LOG_FATAL("Could not open PHC");
    return 0;
  }

-  /* Make sure it is a PHC */
-  if (ioctl(phc_fd, PTP_CLOCK_GETCAPS, &caps)) {
-    LOG_FATAL(LOGF_Refclock, "ioctl(PTP_CLOCK_GETCAPS) failed : %s", strerror(errno));
-    return 0;
+  phc = MallocNew(struct phc_instance);
+  phc->fd = phc_fd;
+  phc->mode = 0;
+  phc->nocrossts = RCL_GetDriverOption(instance, "nocrossts") ? 1 : 0;
+  phc->extpps = RCL_GetDriverOption(instance, "extpps") ? 1 : 0;
+
+  if (phc->extpps) {
+    s = RCL_GetDriverOption(instance, "pin");
+    phc->pin = s ? atoi(s) : 0;
+    s = RCL_GetDriverOption(instance, "channel");
+    phc->channel = s ? atoi(s) : 0;
+    rising_edge = RCL_GetDriverOption(instance, "clear") ? 0 : 1;
+    phc->clock = HCL_CreateInstance(UTI_Log2ToDouble(RCL_GetDriverPoll(instance)));
+
+    if (!SYS_Linux_SetPHCExtTimestamping(phc->fd, phc->pin, phc->channel,
+                                         rising_edge, !rising_edge, 1))
+      LOG_FATAL("Could not enable external PHC timestamping");
+
+    SCH_AddFileHandler(phc->fd, SCH_FILE_INPUT, read_ext_pulse, instance);
+  } else {
+    phc->pin = phc->channel = 0;
+    phc->clock = NULL;
  }

-  UTI_FdSetCloexec(phc_fd);
-
-  RCL_SetDriverData(instance, (void *)(long)phc_fd);
+  RCL_SetDriverData(instance, phc);
  return 1;
 }

 static void phc_finalise(RCL_Instance instance)
 {
-  close((long)RCL_GetDriverData(instance));
+  struct phc_instance *phc;
+
+  phc = (struct phc_instance *)RCL_GetDriverData(instance);
+
+  if (phc->extpps) {
+    SCH_RemoveFileHandler(phc->fd);
+    SYS_Linux_SetPHCExtTimestamping(phc->fd, phc->pin, phc->channel, 0, 0, 0);
+    HCL_DestroyInstance(phc->clock);
+  }
+
+  close(phc->fd);
+  Free(phc);
+}
+
+static void read_ext_pulse(int fd, int event, void *anything)
+{
+  RCL_Instance instance;
+  struct phc_instance *phc;
+  struct timespec phc_ts, local_ts;
+  double local_err;
+  int channel;
+
+  instance = anything;
+  phc = RCL_GetDriverData(instance);
+
+  if (!SYS_Linux_ReadPHCExtTimestamp(phc->fd, &phc_ts, &channel))
+    return;
+
+  if (channel != phc->channel) {
+    DEBUG_LOG("Unexpected extts channel %d\n", channel);
+    return;
+  }
+
+  if (!HCL_CookTime(phc->clock, &phc_ts, &local_ts, &local_err))
+    return;
+
+  RCL_AddCookedPulse(instance, &local_ts, 1.0e-9 * local_ts.tv_nsec, local_err,
+                     UTI_DiffTimespecsToDouble(&phc_ts, &local_ts));
 }

 static int phc_poll(RCL_Instance instance)
 {
-  struct phc_reading readings[NUM_READINGS];
-  struct timeval tv;
-  double offset = 0.0, delay, best_delay = 0.0;
-  int i, phc_fd, best;
+  struct phc_instance *phc;
+  struct timespec phc_ts, sys_ts, local_ts;
+  double offset, phc_err, local_err;

-  phc_fd = (long)RCL_GetDriverData(instance);
+  phc = (struct phc_instance *)RCL_GetDriverData(instance);

-  if (!no_sys_offset_ioctl) {
-    if (!read_phc_ioctl(readings, phc_fd, NUM_READINGS)) {
-      no_sys_offset_ioctl = 1;
+  if (!SYS_Linux_GetPHCSample(phc->fd, phc->nocrossts, RCL_GetPrecision(instance),
+                              &phc->mode, &phc_ts, &sys_ts, &phc_err))
    return 0;
-    }
-  } else {
-    if (!read_phc_user(readings, phc_fd, NUM_READINGS))
+
+  if (phc->extpps) {
+    LCL_CookTime(&sys_ts, &local_ts, &local_err);
+    HCL_AccumulateSample(phc->clock, &phc_ts, &local_ts, phc_err + local_err);
    return 0;
  }

-  /* Find the fastest reading */
-  for (i = 0; i < NUM_READINGS; i++) {
-    delay = diff_ts(&readings[i].sys_ts2, &readings[i].sys_ts1);
+  offset = UTI_DiffTimespecsToDouble(&phc_ts, &sys_ts);

-    if (!i || best_delay > delay) {
-      best = i;
-      best_delay = delay;
-    }
-  }
+  DEBUG_LOG("PHC offset: %+.9f err: %.9f", offset, phc_err);

-  offset = diff_ts(&readings[best].phc_ts, &readings[best].sys_ts2) + best_delay / 2.0;
-  tv.tv_sec = readings[best].sys_ts2.tv_sec;
-  tv.tv_usec = readings[best].sys_ts2.tv_nsec / 1000;
-
-  DEBUG_LOG(LOGF_Refclock, "PHC offset: %+.9f delay: %.9f", offset, best_delay);
-
-  return RCL_AddSample(instance, &tv, offset, LEAP_Normal);
+  return RCL_AddSample(instance, &sys_ts, offset, LEAP_Normal);
 }

 RefclockDriver RCL_PHC_driver = {
--- a/refclock_pps.c
+++ b/refclock_pps.c
@@ -59,37 +59,37 @@ static int pps_initialise(RCL_Instance instance) {

  fd = open(path, O_RDWR);
  if (fd < 0) {
-    LOG_FATAL(LOGF_Refclock, "open() failed on %s", path);
+    LOG_FATAL("open() failed on %s", path);
    return 0;
  }

  UTI_FdSetCloexec(fd);

  if (time_pps_create(fd, &handle) < 0) {
-    LOG_FATAL(LOGF_Refclock, "time_pps_create() failed on %s", path);
+    LOG_FATAL("time_pps_create() failed on %s", path);
    return 0;
  }

  if (time_pps_getcap(handle, &mode) < 0) {
-    LOG_FATAL(LOGF_Refclock, "time_pps_getcap() failed on %s", path);
+    LOG_FATAL("time_pps_getcap() failed on %s", path);
    return 0;
  }

  if (time_pps_getparams(handle, &params) < 0) {
-    LOG_FATAL(LOGF_Refclock, "time_pps_getparams() failed on %s", path);
+    LOG_FATAL("time_pps_getparams() failed on %s", path);
    return 0;
  }

  if (!edge_clear) {
    if (!(mode & PPS_CAPTUREASSERT)) {
-      LOG_FATAL(LOGF_Refclock, "CAPTUREASSERT not supported on %s", path);
+      LOG_FATAL("CAPTUREASSERT not supported on %s", path);
      return 0;
    }
    params.mode |= PPS_CAPTUREASSERT;
    params.mode &= ~PPS_CAPTURECLEAR;
  } else {
    if (!(mode & PPS_CAPTURECLEAR)) {
-      LOG_FATAL(LOGF_Refclock, "CAPTURECLEAR not supported on %s", path);
+      LOG_FATAL("CAPTURECLEAR not supported on %s", path);
      return 0;
    }
    params.mode |= PPS_CAPTURECLEAR;
@@ -97,7 +97,7 @@ static int pps_initialise(RCL_Instance instance) {
  }

  if (time_pps_setparams(handle, &params) < 0) {
-    LOG_FATAL(LOGF_Refclock, "time_pps_setparams() failed on %s", path);
+    LOG_FATAL("time_pps_setparams() failed on %s", path);
    return 0;
  }

@@ -124,7 +124,6 @@ static int pps_poll(RCL_Instance instance)
 {
  struct pps_instance *pps; 
  struct timespec ts;
-  struct timeval tv;
  pps_info_t pps_info;
  pps_seq_t seq;

@@ -134,7 +133,7 @@ static int pps_poll(RCL_Instance instance)
  ts.tv_nsec = 0;

  if (time_pps_fetch(pps->handle, PPS_TSFMT_TSPEC, &pps_info, &ts) < 0) {
-    LOG(LOGS_ERR, LOGF_Refclock, "time_pps_fetch() failed : %s", strerror(errno));
+    LOG(LOGS_ERR, "time_pps_fetch() failed : %s", strerror(errno));
    return 0;
  }

@@ -146,17 +145,15 @@ static int pps_poll(RCL_Instance instance)
    ts = pps_info.clear_timestamp;
  }

-  if (seq == pps->last_seq || (ts.tv_sec == 0 && ts.tv_nsec == 0)) { 
-    DEBUG_LOG(LOGF_Refclock, "PPS sample ignored seq=%lu ts=%lu.%09lu",
-        seq, ts.tv_sec, ts.tv_nsec);
+  if (seq == pps->last_seq || UTI_IsZeroTimespec(&ts)) {
+    DEBUG_LOG("PPS sample ignored seq=%lu ts=%s",
+              seq, UTI_TimespecToString(&ts));
    return 0;
  }

  pps->last_seq = seq;
-  tv.tv_sec = ts.tv_sec;
-  tv.tv_usec = ts.tv_nsec / 1000;

-  return RCL_AddPulse(instance, &tv, ts.tv_nsec / 1e9);
+  return RCL_AddPulse(instance, &ts, 1.0e-9 * ts.tv_nsec);
 }

 RefclockDriver RCL_PPS_driver = {
--- a/refclock_shm.c
+++ b/refclock_shm.c
@@ -69,13 +69,13 @@ static int shm_initialise(RCL_Instance instance) {

  id = shmget(SHMKEY + param, sizeof (struct shmTime), IPC_CREAT | perm);
  if (id == -1) {
-    LOG_FATAL(LOGF_Refclock, "shmget() failed");
+    LOG_FATAL("shmget() failed");
    return 0;
  }
   
  shm = (struct shmTime *)shmat(id, 0, 0);
  if ((long)shm == -1) {
-    LOG_FATAL(LOGF_Refclock, "shmat() failed");
+    LOG_FATAL("shmat() failed");
    return 0;
  }

@@ -90,7 +90,7 @@ static void shm_finalise(RCL_Instance instance)

 static int shm_poll(RCL_Instance instance)
 {
-  struct timeval tv;
+  struct timespec receive_ts, clock_ts;
  struct shmTime t, *shm;
  double offset;

@@ -100,24 +100,30 @@ static int shm_poll(RCL_Instance instance)
  
  if ((t.mode == 1 && t.count != shm->count) ||
    !(t.mode == 0 || t.mode == 1) || !t.valid) {
-    DEBUG_LOG(LOGF_Refclock, "SHM sample ignored mode=%d count=%d valid=%d",
+    DEBUG_LOG("SHM sample ignored mode=%d count=%d valid=%d",
        t.mode, t.count, t.valid);
    return 0;
  }

  shm->valid = 0;

-  tv.tv_sec = t.receiveTimeStampSec;
-  tv.tv_usec = t.receiveTimeStampUSec;
+  receive_ts.tv_sec = t.receiveTimeStampSec;
+  clock_ts.tv_sec = t.clockTimeStampSec;

-  offset = t.clockTimeStampSec - t.receiveTimeStampSec;
  if (t.clockTimeStampNSec / 1000 == t.clockTimeStampUSec &&
-      t.receiveTimeStampNSec / 1000 == t.receiveTimeStampUSec)
-    offset += (t.clockTimeStampNSec - t.receiveTimeStampNSec) * 1e-9;
-  else
-    offset += (t.clockTimeStampUSec - t.receiveTimeStampUSec) * 1e-6;
+      t.receiveTimeStampNSec / 1000 == t.receiveTimeStampUSec) {
+    receive_ts.tv_nsec = t.receiveTimeStampNSec;
+    clock_ts.tv_nsec = t.clockTimeStampNSec;
+  } else {
+    receive_ts.tv_nsec = 1000 * t.receiveTimeStampUSec;
+    clock_ts.tv_nsec = 1000 * t.clockTimeStampUSec;
+  }

-  return RCL_AddSample(instance, &tv, offset, t.leap);
+  UTI_NormaliseTimespec(&clock_ts);
+  UTI_NormaliseTimespec(&receive_ts);
+  offset = UTI_DiffTimespecsToDouble(&clock_ts, &receive_ts);
+
+  return RCL_AddSample(instance, &receive_ts, offset, t.leap);
 }

 RefclockDriver RCL_SHM_driver = {
--- a/refclock_sock.c
+++ b/refclock_sock.c
@@ -37,47 +37,62 @@
 #define SOCK_MAGIC 0x534f434b

 struct sock_sample {
+  /* Time of the measurement (system time) */
  struct timeval tv;
+
+  /* Offset between the true time and the system time (in seconds) */
  double offset;
+
+  /* Non-zero if the sample is from a PPS signal, i.e. another source
+     is needed to obtain seconds */
  int pulse;
+
+  /* 0 - normal, 1 - insert leap second, 2 - delete leap second */
  int leap;
+
+  /* Padding, ignored */
  int _pad;
+
+  /* Protocol identifier (0x534f434b) */
  int magic;
 };

-static void read_sample(void *anything)
+static void read_sample(int sockfd, int event, void *anything)
 {
  struct sock_sample sample;
+  struct timespec ts;
  RCL_Instance instance;
-  int sockfd, s;
+  int s;

  instance = (RCL_Instance)anything;
-  sockfd = (long)RCL_GetDriverData(instance);

  s = recv(sockfd, &sample, sizeof (sample), 0);

  if (s < 0) {
-    LOG(LOGS_ERR, LOGF_Refclock, "Could not read SOCK sample : %s",
+    LOG(LOGS_ERR, "Could not read SOCK sample : %s",
        strerror(errno));
    return;
  }

  if (s != sizeof (sample)) {
-    LOG(LOGS_WARN, LOGF_Refclock, "Unexpected length of SOCK sample : %d != %ld",
+    LOG(LOGS_WARN, "Unexpected length of SOCK sample : %d != %ld",
        s, (long)sizeof (sample));
    return;
  }

  if (sample.magic != SOCK_MAGIC) {
-    LOG(LOGS_WARN, LOGF_Refclock, "Unexpected magic number in SOCK sample : %x != %x",
+    LOG(LOGS_WARN, "Unexpected magic number in SOCK sample : %x != %x",
        sample.magic, SOCK_MAGIC);
    return;
  }

+  UTI_TimevalToTimespec(&sample.tv, &ts);
+  UTI_NormaliseTimespec(&ts);
+
  if (sample.pulse) {
-    RCL_AddPulse(instance, &sample.tv, sample.offset);
+    RCL_AddPulse(instance, &ts, sample.offset);
  } else {
-    RCL_AddSample(instance, &sample.tv, sample.offset, sample.leap);
+    RCL_AddSample(instance, &ts, sample.offset, sample.leap);
  }
 }

@@ -91,13 +106,13 @@ static int sock_initialise(RCL_Instance instance)
 
  s.sun_family = AF_UNIX;
  if (snprintf(s.sun_path, sizeof (s.sun_path), "%s", path) >= sizeof (s.sun_path)) {
-    LOG_FATAL(LOGF_Refclock, "path %s is too long", path);
+    LOG_FATAL("path %s is too long", path);
    return 0;
  }

  sockfd = socket(AF_UNIX, SOCK_DGRAM, 0);
  if (sockfd < 0) {
-    LOG_FATAL(LOGF_Refclock, "socket() failed");
+    LOG_FATAL("socket() failed");
    return 0;
  }

@@ -105,12 +120,12 @@ static int sock_initialise(RCL_Instance instance)

  unlink(path);
  if (bind(sockfd, (struct sockaddr *)&s, sizeof (s)) < 0) {
-    LOG_FATAL(LOGF_Refclock, "bind() failed");
+    LOG_FATAL("bind() failed");
    return 0;
  }

  RCL_SetDriverData(instance, (void *)(long)sockfd);
-  SCH_AddInputFileHandler(sockfd, read_sample, instance);
+  SCH_AddFileHandler(sockfd, SCH_FILE_INPUT, read_sample, instance);
  return 1;
 }

@@ -119,7 +134,7 @@ static void sock_finalise(RCL_Instance instance)
  int sockfd;

  sockfd = (long)RCL_GetDriverData(instance);
-  SCH_RemoveInputFileHandler(sockfd);
+  SCH_RemoveFileHandler(sockfd);
  close(sockfd);
 }

--- a/reference.c
+++ b/reference.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2014
+ * Copyright (C) Miroslav Lichvar  2009-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -45,12 +45,15 @@
 static int are_we_synchronised;
 static int enable_local_stratum;
 static int local_stratum;
+static int local_orphan;
+static double local_distance;
 static NTP_Leap our_leap_status;
 static int our_leap_sec;
+static int our_tai_offset;
 static int our_stratum;
 static uint32_t our_ref_id;
 static IPAddr our_ref_ip;
-struct timeval our_ref_time; /* Stored relative to reference, NOT local time */
+static struct timespec our_ref_time;
 static double our_skew;
 static double our_residual_freq;
 static double our_root_delay;
@@ -80,8 +83,7 @@ static int max_offset_delay;
 static int max_offset_ignore;
 static double max_offset;

-/* Flag and threshold for logging clock changes to syslog */
-static int do_log_change;
+/* Threshold for logging clock changes to syslog */
 static double log_change_threshold;

 /* Flag, threshold and user for sending mail notification on large clock changes */
@@ -98,10 +100,18 @@ static double drift_file_age;

 static void update_drift_file(double, double);

+/* Leap second handling mode */
+static REF_LeapMode leap_mode;
+
+/* Flag indicating the clock was recently corrected for leap second and it may
+   not have correct time yet (missing 23:59:60 in the UTC time scale) */
+static int leap_in_progress;
+
+/* Timer for the leap second handler */
+static SCH_TimeoutID leap_timeout_id;
+
 /* Name of a system timezone containing leap seconds occuring at midnight */
 static char *leap_tzname;
-static time_t last_tz_leap_check;
-static NTP_Leap tz_leap;

 /* ================================================== */

@@ -109,11 +119,6 @@ static LOG_FileID logfileid;

 /* ================================================== */

-/* Reference ID supplied when we are locally referenced */
-#define LOCAL_REFERENCE_ID 0x7f7f0101UL
-
-/* ================================================== */
-
 /* Exponential moving averages of absolute clock frequencies
   used as a fallback when synchronisation is lost. */

@@ -130,30 +135,40 @@ static int next_fb_drift;
 static SCH_TimeoutID fb_drift_timeout_id;

 /* Timestamp of last reference update */
-static struct timeval last_ref_update;
+static struct timespec last_ref_update;
 static double last_ref_update_interval;

 /* ================================================== */

-static NTP_Leap get_tz_leap(time_t when);
+static NTP_Leap get_tz_leap(time_t when, int *tai_offset);
+static void update_leap_status(NTP_Leap leap, time_t now, int reset);

 /* ================================================== */

 static void
-handle_slew(struct timeval *raw,
-            struct timeval *cooked,
+handle_slew(struct timespec *raw,
+            struct timespec *cooked,
            double dfreq,
            double doffset,
            LCL_ChangeType change_type,
            void *anything)
 {
  double delta;
+  struct timespec now;
+
+  UTI_AdjustTimespec(&our_ref_time, cooked, &our_ref_time, &delta, dfreq, doffset);

  if (change_type == LCL_ChangeUnknownStep) {
-    last_ref_update.tv_sec = 0;
-    last_ref_update.tv_usec = 0;
+    UTI_ZeroTimespec(&last_ref_update);
  } else if (last_ref_update.tv_sec) {
-    UTI_AdjustTimeval(&last_ref_update, cooked, &last_ref_update, &delta, dfreq, doffset);
+    UTI_AdjustTimespec(&last_ref_update, cooked, &last_ref_update, &delta, dfreq, doffset);
+  }
+
+  /* When the clock was stepped, check if that doesn't change our leap status
+     and also reset the leap timeout to undo the shift in the scheduler */
+  if (change_type != LCL_ChangeAdjust && our_leap_sec && !leap_in_progress) {
+    LCL_ReadRawTime(&now);
+    update_leap_status(our_leap_status, now.tv_sec, 1);
  }
 }

@@ -165,11 +180,13 @@ REF_Initialise(void)
  FILE *in;
  double file_freq_ppm, file_skew_ppm;
  double our_frequency_ppm;
+  int tai_offset;

  mode = REF_ModeNormal;
  are_we_synchronised = 0;
  our_leap_status = LEAP_Unsynchronised;
  our_leap_sec = 0;
+  our_tai_offset = 0;
  initialised = 1;
  our_root_dispersion = 1.0;
  our_root_delay = 1.0;
@@ -189,11 +206,11 @@ REF_Initialise(void)
        our_skew = 1.0e-6 * file_skew_ppm;
        if (our_skew < MIN_SKEW)
          our_skew = MIN_SKEW;
-        LOG(LOGS_INFO, LOGF_Reference, "Frequency %.3f +/- %.3f ppm read from %s",
+        LOG(LOGS_INFO, "Frequency %.3f +/- %.3f ppm read from %s",
            file_freq_ppm, file_skew_ppm, drift_file);
        LCL_SetAbsoluteFrequency(our_frequency_ppm);
      } else {
-        LOG(LOGS_WARN, LOGF_Reference, "Could not read valid frequency and skew from driftfile %s",
+        LOG(LOGS_WARN, "Could not read valid frequency and skew from driftfile %s",
            drift_file);
      }
      fclose(in);
@@ -203,7 +220,7 @@ REF_Initialise(void)
  if (our_frequency_ppm == 0.0) {
    our_frequency_ppm = LCL_ReadAbsoluteFrequency();
    if (our_frequency_ppm != 0.0) {
-      LOG(LOGS_INFO, LOGF_Reference, "Initial frequency %.3f ppm", our_frequency_ppm);
+      LOG(LOGS_INFO, "Initial frequency %.3f ppm", our_frequency_ppm);
    }
  }

@@ -215,24 +232,31 @@ REF_Initialise(void)

  correction_time_ratio = CNF_GetCorrectionTimeRatio();

-  enable_local_stratum = CNF_AllowLocalReference(&local_stratum);
+  enable_local_stratum = CNF_AllowLocalReference(&local_stratum, &local_orphan, &local_distance);
+
+  leap_timeout_id = 0;
+  leap_in_progress = 0;
+  leap_mode = CNF_GetLeapSecMode();
+  /* Switch to step mode if the system driver doesn't support leap */
+  if (leap_mode == REF_LeapModeSystem && !LCL_CanSystemLeap())
+    leap_mode = REF_LeapModeStep;

  leap_tzname = CNF_GetLeapSecTimezone();
  if (leap_tzname) {
-    /* Check that the timezone has good data for Jun 30 2008 and Dec 31 2008 */
-    if (get_tz_leap(1214784000) == LEAP_Normal &&
-        get_tz_leap(1230681600) == LEAP_InsertSecond) {
-      LOG(LOGS_INFO, LOGF_Reference, "Using %s timezone to obtain leap second data", leap_tzname);
+    /* Check that the timezone has good data for Jun 30 2012 and Dec 31 2012 */
+    if (get_tz_leap(1341014400, &tai_offset) == LEAP_InsertSecond && tai_offset == 34 &&
+        get_tz_leap(1356912000, &tai_offset) == LEAP_Normal && tai_offset == 35) {
+      LOG(LOGS_INFO, "Using %s timezone to obtain leap second data", leap_tzname);
    } else {
-      LOG(LOGS_WARN, LOGF_Reference, "Timezone %s failed leap second check, ignoring", leap_tzname);
+      LOG(LOGS_WARN, "Timezone %s failed leap second check, ignoring", leap_tzname);
      leap_tzname = NULL;
    }
  }

  CNF_GetMakeStep(&make_step_limit, &make_step_threshold);
  CNF_GetMaxChange(&max_offset_delay, &max_offset_ignore, &max_offset);
-  CNF_GetLogChange(&do_log_change, &log_change_threshold);
  CNF_GetMailOnChange(&do_mail_change, &mail_change_threshold, &mail_change_user);
+  log_change_threshold = CNF_GetLogChange();

  CNF_GetFallbackDrifts(&fb_drift_min, &fb_drift_max);

@@ -240,20 +264,14 @@ REF_Initialise(void)
    fb_drifts = MallocArray(struct fb_drift, fb_drift_max - fb_drift_min + 1);
    memset(fb_drifts, 0, sizeof (struct fb_drift) * (fb_drift_max - fb_drift_min + 1));
    next_fb_drift = 0;
-    fb_drift_timeout_id = -1;
+    fb_drift_timeout_id = 0;
  }

-  last_ref_update.tv_sec = 0;
-  last_ref_update.tv_usec = 0;
+  UTI_ZeroTimespec(&last_ref_update);
  last_ref_update_interval = 0.0;

  LCL_AddParameterChangeHandler(handle_slew, NULL);

-  /* And just to prevent anything wierd ... */
-  if (do_log_change) {
-    log_change_threshold = fabs(log_change_threshold);
-  }
-
  /* Make first entry in tracking log */
  REF_SetUnsynchronised();
 }
@@ -263,9 +281,7 @@ REF_Initialise(void)
 void
 REF_Finalise(void)
 {
-  if (our_leap_sec) {
-    LCL_SetLeap(0);
-  }
+  update_leap_status(LEAP_Unsynchronised, 0, 0);

  if (drift_file) {
    update_drift_file(LCL_ReadAbsoluteFrequency(), our_skew);
@@ -301,6 +317,14 @@ REF_SetModeEndHandler(REF_ModeEndHandler handler)

 /* ================================================== */

+REF_LeapMode
+REF_GetLeapMode(void)
+{
+  return leap_mode;
+}
+
+/* ================================================== */
+
 static double
 Sqr(double x)
 {
@@ -341,7 +365,7 @@ update_drift_file(double freq_ppm, double skew)
  out = fopen(temp_drift_file, "w");
  if (!out) {
    Free(temp_drift_file);
-    LOG(LOGS_WARN, LOGF_Reference, "Could not open temporary driftfile %s.tmp for writing",
+    LOG(LOGS_WARN, "Could not open temporary driftfile %s.tmp for writing",
        drift_file);
    return;
  }
@@ -351,7 +375,7 @@ update_drift_file(double freq_ppm, double skew)
  r2 = fclose(out);
  if (r1 < 0 || r2) {
    Free(temp_drift_file);
-    LOG(LOGS_WARN, LOGF_Reference, "Could not write to temporary driftfile %s.tmp",
+    LOG(LOGS_WARN, "Could not write to temporary driftfile %s.tmp",
        drift_file);
    return;
  }
@@ -361,8 +385,7 @@ update_drift_file(double freq_ppm, double skew)
  if (!stat(drift_file,&buf)) {
    if (chown(temp_drift_file,buf.st_uid,buf.st_gid) ||
        chmod(temp_drift_file,buf.st_mode & 0777)) {
-      LOG(LOGS_WARN, LOGF_Reference,
-          "Could not change ownership or permissions of temporary driftfile %s.tmp",
+      LOG(LOGS_WARN, "Could not change ownership or permissions of temporary driftfile %s.tmp",
          drift_file);
    }
  }
@@ -372,7 +395,7 @@ update_drift_file(double freq_ppm, double skew)
  if (rename(temp_drift_file,drift_file)) {
    unlink(temp_drift_file);
    Free(temp_drift_file);
-    LOG(LOGS_WARN, LOGF_Reference, "Could not replace old driftfile %s with new one %s.tmp",
+    LOG(LOGS_WARN, "Could not replace old driftfile %s with new one %s.tmp",
        drift_file,drift_file);
    return;
  }
@@ -398,19 +421,13 @@ update_fb_drifts(double freq_ppm, double update_interval)
    next_fb_drift = 0;
  }

-  if (fb_drift_timeout_id != -1) {
  SCH_RemoveTimeout(fb_drift_timeout_id);
-    fb_drift_timeout_id = -1;
-  }
+  fb_drift_timeout_id = 0;

-  if (update_interval < 0.0 || update_interval > last_ref_update_interval * 4.0)
+  if (update_interval < 1.0 || update_interval > last_ref_update_interval * 4.0)
    return;

  for (i = 0; i < fb_drift_max - fb_drift_min + 1; i++) {
-    /* Don't allow differences larger than 10 ppm */
-    if (fabs(freq_ppm - fb_drifts[i].freq) > 10.0)
-      fb_drifts[i].secs = 0.0;
-
    secs = 1 << (i + fb_drift_min);
    if (fb_drifts[i].secs < secs) {
      /* Calculate average over 2 * secs interval before switching to
@@ -426,7 +443,7 @@ update_fb_drifts(double freq_ppm, double update_interval)
        (freq_ppm - fb_drifts[i].freq);
    }

-    DEBUG_LOG(LOGF_Reference, "Fallback drift %d updated: %f ppm %f seconds",
+    DEBUG_LOG("Fallback drift %d updated: %f ppm %f seconds",
              i + fb_drift_min, fb_drifts[i].freq, fb_drifts[i].secs);
  }
 }
@@ -436,11 +453,12 @@ update_fb_drifts(double freq_ppm, double update_interval)
 static void
 fb_drift_timeout(void *arg)
 {
-  assert(are_we_synchronised == 0);
  assert(next_fb_drift >= fb_drift_min && next_fb_drift <= fb_drift_max);

-  fb_drift_timeout_id = -1;
+  fb_drift_timeout_id = 0;

+  DEBUG_LOG("Fallback drift %d active: %f ppm",
+            next_fb_drift, fb_drifts[next_fb_drift - fb_drift_min].freq);
  LCL_SetAbsoluteFrequency(fb_drifts[next_fb_drift - fb_drift_min].freq);
  REF_SetUnsynchronised();
 }
@@ -448,16 +466,16 @@ fb_drift_timeout(void *arg)
 /* ================================================== */

 static void
-schedule_fb_drift(struct timeval *now)
+schedule_fb_drift(struct timespec *now)
 {
  int i, c, secs;
  double unsynchronised;
-  struct timeval when;
+  struct timespec when;

-  if (fb_drift_timeout_id != -1)
+  if (fb_drift_timeout_id)
    return; /* already scheduled */

-  UTI_DiffTimevalsToDouble(&unsynchronised, now, &last_ref_update);
+  unsynchronised = UTI_DiffTimespecsToDouble(now, &last_ref_update);

  for (c = secs = 0, i = fb_drift_min; i <= fb_drift_max; i++) {
    secs = 1 << i;
@@ -474,14 +492,14 @@ schedule_fb_drift(struct timeval *now)
  if (c > next_fb_drift) {
    LCL_SetAbsoluteFrequency(fb_drifts[c - fb_drift_min].freq);
    next_fb_drift = c;
-    DEBUG_LOG(LOGF_Reference, "Fallback drift %d set", c);
+    DEBUG_LOG("Fallback drift %d set", c);
  }

  if (i <= fb_drift_max) {
    next_fb_drift = i;
-    UTI_AddDoubleToTimeval(now, secs - unsynchronised, &when);
+    UTI_AddDoubleToTimespec(now, secs - unsynchronised, &when);
    fb_drift_timeout_id = SCH_AddTimeout(&when, fb_drift_timeout, NULL);
-    DEBUG_LOG(LOGF_Reference, "Fallback drift %d scheduled", i);
+    DEBUG_LOG("Fallback drift %d scheduled", i);
  }
 }

@@ -512,10 +530,8 @@ maybe_log_offset(double offset, time_t now)

  abs_offset = fabs(offset);

-  if (do_log_change &&
-      (abs_offset > log_change_threshold)) {
-    LOG(LOGS_WARN, LOGF_Reference,
-        "System clock wrong by %.6f seconds, adjustment started",
+  if (abs_offset > log_change_threshold) {
+    LOG(LOGS_WARN, "System clock wrong by %.6f seconds, adjustment started",
        -offset);
  }

@@ -541,8 +557,7 @@ maybe_log_offset(double offset, time_t now)
              -offset, mail_change_threshold);
      pclose(p);
    } else {
-      LOG(LOGS_ERR, LOGF_Reference,
-          "Could not send mail notification to user %s\n",
+      LOG(LOGS_ERR, "Could not send mail notification to user %s\n",
          mail_change_user);
    }
  }
@@ -577,7 +592,7 @@ is_offset_ok(double offset)

  offset = fabs(offset);
  if (offset > max_offset) {
-    LOG(LOGS_WARN, LOGF_Reference,
+    LOG(LOGS_WARN, 
        "Adjustment of %.3f seconds exceeds the allowed maximum of %.3f seconds (%s) ",
        -offset, max_offset, !max_offset_ignore ? "exiting" : "ignored");
    if (!max_offset_ignore)
@@ -601,12 +616,18 @@ is_leap_second_day(struct tm *stm) {
 /* ================================================== */

 static NTP_Leap
-get_tz_leap(time_t when)
+get_tz_leap(time_t when, int *tai_offset)
 {
+  static time_t last_tz_leap_check;
+  static NTP_Leap tz_leap;
+  static int tz_tai_offset;
+
  struct tm stm;
  time_t t;
  char *tz_env, tz_orig[128];

+  *tai_offset = tz_tai_offset;
+
  /* Do this check at most twice a day */
  when = when / (12 * 3600) * (12 * 3600);
  if (last_tz_leap_check == when)
@@ -614,12 +635,10 @@ get_tz_leap(time_t when)

  last_tz_leap_check = when;
  tz_leap = LEAP_Normal;
+  tz_tai_offset = 0;

  stm = *gmtime(&when);

-  if (!is_leap_second_day(&stm))
-    return tz_leap;
-
  /* Temporarily switch to the timezone containing leap seconds */
  tz_env = getenv("TZ");
  if (tz_env) {
@@ -630,6 +649,11 @@ get_tz_leap(time_t when)
  setenv("TZ", leap_tzname, 1);
  tzset();

+  /* Get the TAI-UTC offset, which started at the epoch at 10 seconds */
+  t = mktime(&stm);
+  if (t != -1)
+    tz_tai_offset = t - when + 10;
+
  /* Set the time to 23:59:60 and see how it overflows in mktime() */
  stm.tm_sec = 60;
  stm.tm_min = 59;
@@ -651,20 +675,109 @@ get_tz_leap(time_t when)
  else if (stm.tm_sec == 1)
    tz_leap = LEAP_DeleteSecond;

+  *tai_offset = tz_tai_offset;
+
  return tz_leap;
 }

 /* ================================================== */

 static void
-update_leap_status(NTP_Leap leap, time_t now)
+leap_end_timeout(void *arg)
 {
-  int leap_sec;
+  leap_timeout_id = 0;
+  leap_in_progress = 0;
+
+  if (our_tai_offset)
+    our_tai_offset += our_leap_sec;
+  our_leap_sec = 0;
+
+  if (leap_mode == REF_LeapModeSystem)
+    LCL_SetSystemLeap(our_leap_sec, our_tai_offset);
+
+  if (our_leap_status == LEAP_InsertSecond ||
+      our_leap_status == LEAP_DeleteSecond)
+    our_leap_status = LEAP_Normal;
+}
+
+/* ================================================== */
+
+static void
+leap_start_timeout(void *arg)
+{
+  leap_in_progress = 1;
+
+  switch (leap_mode) {
+    case REF_LeapModeSystem:
+      DEBUG_LOG("Waiting for system clock leap second correction");
+      break;
+    case REF_LeapModeSlew:
+      LCL_NotifyLeap(our_leap_sec);
+      LCL_AccumulateOffset(our_leap_sec, 0.0);
+      LOG(LOGS_WARN, "Adjusting system clock for leap second");
+      break;
+    case REF_LeapModeStep:
+      LCL_NotifyLeap(our_leap_sec);
+      LCL_ApplyStepOffset(our_leap_sec);
+      LOG(LOGS_WARN, "System clock was stepped for leap second");
+      break;
+    case REF_LeapModeIgnore:
+      LOG(LOGS_WARN, "Ignoring leap second");
+      break;
+    default:
+      break;
+  }
+
+  /* Wait until the leap second is over with some extra room to be safe */
+  leap_timeout_id = SCH_AddTimeoutByDelay(2.0, leap_end_timeout, NULL);
+}
+
+/* ================================================== */
+
+static void
+set_leap_timeout(time_t now)
+{
+  struct timespec when;
+
+  /* Stop old timer if there is one */
+  SCH_RemoveTimeout(leap_timeout_id);
+  leap_timeout_id = 0;
+  leap_in_progress = 0;
+
+  if (!our_leap_sec)
+    return;
+
+  /* Insert leap second at 0:00:00 UTC, delete at 23:59:59 UTC.  If the clock
+     will be corrected by the system, timeout slightly sooner to be sure it
+     will happen before the system correction. */
+  when.tv_sec = (now / (24 * 3600) + 1) * (24 * 3600);
+  when.tv_nsec = 0;
+  if (our_leap_sec < 0)
+    when.tv_sec--;
+  if (leap_mode == REF_LeapModeSystem) {
+    when.tv_sec--;
+    when.tv_nsec = 500000000;
+  }
+
+  leap_timeout_id = SCH_AddTimeout(&when, leap_start_timeout, NULL);
+}
+
+/* ================================================== */
+
+static void
+update_leap_status(NTP_Leap leap, time_t now, int reset)
+{
+  NTP_Leap tz_leap;
+  int leap_sec, tai_offset;

  leap_sec = 0;
+  tai_offset = 0;

-  if (leap_tzname && now && leap == LEAP_Normal)
-    leap = get_tz_leap(now);
+  if (leap_tzname && now) {
+    tz_leap = get_tz_leap(now, &tai_offset);
+    if (leap == LEAP_Normal)
+      leap = tz_leap;
+  }

  if (leap == LEAP_InsertSecond || leap == LEAP_DeleteSecond) {
    /* Check that leap second is allowed today */
@@ -680,9 +793,26 @@ update_leap_status(NTP_Leap leap, time_t now)
    }
  }
  
-  if (leap_sec != our_leap_sec && !REF_IsLeapSecondClose()) {
-    LCL_SetLeap(leap_sec);
+  if ((leap_sec != our_leap_sec || tai_offset != our_tai_offset)
+      && !REF_IsLeapSecondClose()) {
    our_leap_sec = leap_sec;
+    our_tai_offset = tai_offset;
+
+    switch (leap_mode) {
+      case REF_LeapModeSystem:
+        LCL_SetSystemLeap(our_leap_sec, our_tai_offset);
+        /* Fall through */
+      case REF_LeapModeSlew:
+      case REF_LeapModeStep:
+      case REF_LeapModeIgnore:
+        set_leap_timeout(now);
+        break;
+      default:
+        assert(0);
+        break;
+    }
+  } else if (reset) {
+    set_leap_timeout(now);
  }

  our_leap_status = leap;
@@ -691,7 +821,7 @@ update_leap_status(NTP_Leap leap, time_t now)
 /* ================================================== */

 static void
-write_log(struct timeval *ref_time, char *ref, int stratum, NTP_Leap leap,
+write_log(struct timespec *ref_time, char *ref, int stratum, NTP_Leap leap,
    double freq, double skew, double offset, int combined_sources,
    double offset_sd, double uncorrected_offset)
 {
@@ -714,15 +844,14 @@ special_mode_sync(int valid, double offset)
  switch (mode) {
    case REF_ModeInitStepSlew:
      if (!valid) {
-        LOG(LOGS_WARN, LOGF_Reference, "No suitable source for initstepslew");
+        LOG(LOGS_WARN, "No suitable source for initstepslew");
        end_ref_mode(0);
        break;
      }

      step = fabs(offset) >= CNF_GetInitStepThreshold();

-      LOG(LOGS_INFO, LOGF_Reference,
-          "System's initial offset : %.6f seconds %s of true (%s)",
+      LOG(LOGS_INFO, "System's initial offset : %.6f seconds %s of true (%s)",
          fabs(offset), offset >= 0 ? "fast" : "slow", step ? "step" : "slew");

      if (step)
@@ -736,14 +865,14 @@ special_mode_sync(int valid, double offset)
    case REF_ModeUpdateOnce:
    case REF_ModePrintOnce:
      if (!valid) {
-        LOG(LOGS_WARN, LOGF_Reference, "No suitable source for synchronisation");
+        LOG(LOGS_WARN, "No suitable source for synchronisation");
        end_ref_mode(0);
        break;
      }

      step = mode == REF_ModeUpdateOnce;

-      LOG(LOGS_INFO, LOGF_Reference, "System clock wrong by %.6f seconds (%s)",
+      LOG(LOGS_INFO, "System clock wrong by %.6f seconds (%s)",
          -offset, step ? "step" : "ignored");

      if (step)
@@ -768,7 +897,7 @@ REF_SetReference(int stratum,
                 int combined_sources,
                 uint32_t ref_id,
                 IPAddr *ref_ip,
-                 struct timeval *ref_time,
+                 struct timespec *ref_time,
                 double offset,
                 double offset_sd,
                 double frequency,
@@ -789,7 +918,8 @@ REF_SetReference(int stratum,
  double elapsed;
  double correction_rate;
  double uncorrected_offset, accumulate_offset, step_offset;
-  struct timeval now, raw_now;
+  struct timespec now, raw_now;
+  NTP_int64 ref_fuzz;

  assert(initialised);

@@ -816,16 +946,16 @@ REF_SetReference(int stratum,
    double t;
    t = (skew + skew) / skew; /* Skew shouldn't be zero either */
    if ((t < 1.9) || (t > 2.1)) {
-      LOG(LOGS_WARN, LOGF_Reference, "Bogus skew value encountered");
+      LOG(LOGS_WARN, "Bogus skew value encountered");
      return;
    }
  }
    
  LCL_ReadRawTime(&raw_now);
  LCL_GetOffsetCorrection(&raw_now, &uncorrected_offset, NULL);
-  UTI_AddDoubleToTimeval(&raw_now, uncorrected_offset, &now);
+  UTI_AddDoubleToTimespec(&raw_now, uncorrected_offset, &now);

-  UTI_DiffTimevalsToDouble(&elapsed, &now, ref_time);
+  elapsed = UTI_DiffTimespecsToDouble(&now, ref_time);
  our_offset = offset + elapsed * frequency;

  if (!is_offset_ok(our_offset))
@@ -843,7 +973,7 @@ REF_SetReference(int stratum,
  our_root_dispersion = root_dispersion;

  if (last_ref_update.tv_sec) {
-    UTI_DiffTimevalsToDouble(&update_interval, &now, &last_ref_update);
+    update_interval = UTI_DiffTimespecsToDouble(&now, &last_ref_update);
    if (update_interval < 0.0)
      update_interval = 0.0;
  } else {
@@ -913,23 +1043,32 @@ REF_SetReference(int stratum,
    LCL_AccumulateFrequencyAndOffset(our_frequency, accumulate_offset, correction_rate);
    
  } else {
-    DEBUG_LOG(LOGF_Reference, "Skew %f too large to track, offset=%f", skew, accumulate_offset);
+    DEBUG_LOG("Skew %f too large to track, offset=%f", skew, accumulate_offset);

    LCL_AccumulateOffset(accumulate_offset, correction_rate);

    our_residual_freq = frequency;
  }

-  update_leap_status(leap, raw_now.tv_sec);
+  update_leap_status(leap, raw_now.tv_sec, 0);
  maybe_log_offset(our_offset, raw_now.tv_sec);

  if (step_offset != 0.0) {
-    LCL_ApplyStepOffset(step_offset);
-    LOG(LOGS_WARN, LOGF_Reference, "System clock was stepped by %.6f seconds", -step_offset);
+    if (LCL_ApplyStepOffset(step_offset))
+      LOG(LOGS_WARN, "System clock was stepped by %.6f seconds", -step_offset);
  }

  LCL_SetSyncStatus(are_we_synchronised, offset_sd, offset_sd + root_delay / 2.0 + root_dispersion);

+  /* Add a random error of up to one second to the reference time to make it
+     less useful when disclosed to NTP and cmdmon clients for estimating
+     receive timestamps in the interleaved symmetric NTP mode */
+  UTI_GetNtp64Fuzz(&ref_fuzz, 0);
+  UTI_TimespecToNtp64(&our_ref_time, &ref_fuzz, &ref_fuzz);
+  UTI_Ntp64ToTimespec(&ref_fuzz, &our_ref_time);
+  if (UTI_CompareTimespecs(&our_ref_time, ref_time) >= 0)
+    our_ref_time.tv_sec--;
+
  abs_freq_ppm = LCL_ReadAbsoluteFrequency();

  write_log(&now,
@@ -955,6 +1094,7 @@ REF_SetReference(int stratum,
  /* Update fallback drifts */
  if (fb_drifts) {
    update_fb_drifts(abs_freq_ppm, update_interval);
+    schedule_fb_drift(&now);
  }

  last_ref_update_interval = update_interval;
@@ -975,18 +1115,16 @@ REF_SetReference(int stratum,
 void
 REF_SetManualReference
 (
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double offset,
 double frequency,
 double skew
 )
 {
-  uint32_t manual_refid = 0x4D414E55; /* MANU */
-
  /* We are not synchronised to an external source, as such.  This is
-   only supposed to be used with the local source option, really
-   ... */
-  REF_SetReference(0, LEAP_Unsynchronised, 1, manual_refid, NULL,
+     only supposed to be used with the local source option, really.
+     Log as MANU in the tracking log, packets will have NTP_REFID_LOCAL. */
+  REF_SetReference(0, LEAP_Unsynchronised, 1, 0x4D414E55UL, NULL,
                   ref_time, offset, 0.0, frequency, skew, 0.0, 0.0);
 }

@@ -996,7 +1134,7 @@ void
 REF_SetUnsynchronised(void)
 {
  /* Variables required for logging to statistics log */
-  struct timeval now, now_raw;
+  struct timespec now, now_raw;
  double uncorrected_offset;

  assert(initialised);
@@ -1009,13 +1147,13 @@ REF_SetUnsynchronised(void)

  LCL_ReadRawTime(&now_raw);
  LCL_GetOffsetCorrection(&now_raw, &uncorrected_offset, NULL);
-  UTI_AddDoubleToTimeval(&now_raw, uncorrected_offset, &now);
+  UTI_AddDoubleToTimespec(&now_raw, uncorrected_offset, &now);

  if (fb_drifts) {
    schedule_fb_drift(&now);
  }

-  update_leap_status(LEAP_Unsynchronised, 0);
+  update_leap_status(LEAP_Unsynchronised, 0, 0);
  are_we_synchronised = 0;

  LCL_SetSyncStatus(0, 0.0, 0.0);
@@ -1037,42 +1175,50 @@ REF_SetUnsynchronised(void)
 void
 REF_GetReferenceParams
 (
- struct timeval *local_time,
+ struct timespec *local_time,
 int *is_synchronised,
 NTP_Leap *leap_status,
 int *stratum,
 uint32_t *ref_id,
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double *root_delay,
 double *root_dispersion
 )
 {
-  double elapsed;
-  double extra_dispersion;
+  double elapsed, dispersion;

  assert(initialised);

  if (are_we_synchronised) {
+    elapsed = UTI_DiffTimespecsToDouble(local_time, &our_ref_time);
+    dispersion = our_root_dispersion +
+      (our_skew + fabs(our_residual_freq) + LCL_GetMaxClockError()) * elapsed;
+  } else {
+    dispersion = 0.0;
+  }
+
+  /* Local reference is active when enabled and the clock is not synchronised
+     or the root distance exceeds the threshold */
+
+  if (are_we_synchronised &&
+      !(enable_local_stratum && our_root_delay / 2 + dispersion > local_distance)) {

    *is_synchronised = 1;

    *stratum = our_stratum;

-    UTI_DiffTimevalsToDouble(&elapsed, local_time, &our_ref_time);
-    extra_dispersion = (our_skew + fabs(our_residual_freq) + LCL_GetMaxClockError()) * elapsed;
-
-    *leap_status = our_leap_status;
+    *leap_status = !leap_in_progress ? our_leap_status : LEAP_Unsynchronised;
    *ref_id = our_ref_id;
    *ref_time = our_ref_time;
    *root_delay = our_root_delay;
-    *root_dispersion = our_root_dispersion + extra_dispersion;
+    *root_dispersion = dispersion;

  } else if (enable_local_stratum) {

-    *is_synchronised = 1;
+    *is_synchronised = 0;

    *stratum = local_stratum;
-    *ref_id = LOCAL_REFERENCE_ID;
+    *ref_id = NTP_REFID_LOCAL;
    /* Make the reference time be now less a second - this will
       scarcely affect the client, but will ensure that the transmit
       timestamp cannot come before this (which would cause test 7 to
@@ -1086,7 +1232,7 @@ REF_GetReferenceParams
    *leap_status = LEAP_Normal;
    
    *root_delay = 0.0;
-    *root_dispersion = LCL_GetSysPrecisionAsQuantum();
+    *root_dispersion = 0.0;
    
  } else {

@@ -1094,8 +1240,8 @@ REF_GetReferenceParams

    *leap_status = LEAP_Unsynchronised;
    *stratum = NTP_MAX_STRATUM;
-    *ref_id = 0;
-    ref_time->tv_sec = ref_time->tv_usec = 0;
+    *ref_id = NTP_REFID_UNSYNC;
+    UTI_ZeroTimespec(ref_time);
    /* These values seem to be standard for a client, and
       any peer or client of ours will ignore them anyway because
       we don't claim to be synchronised */
@@ -1110,13 +1256,35 @@ REF_GetReferenceParams
 int
 REF_GetOurStratum(void)
 {
-  if (are_we_synchronised) {
-    return our_stratum;
-  } else if (enable_local_stratum) {
-    return local_stratum;
-  } else {
-    return NTP_MAX_STRATUM;
+  struct timespec now_cooked, ref_time;
+  int synchronised, stratum;
+  NTP_Leap leap_status;
+  uint32_t ref_id;
+  double root_delay, root_dispersion;
+
+  SCH_GetLastEventTime(&now_cooked, NULL, NULL);
+  REF_GetReferenceParams(&now_cooked, &synchronised, &leap_status, &stratum,
+                         &ref_id, &ref_time, &root_delay, &root_dispersion);
+
+  return stratum;
 }
+
+/* ================================================== */
+
+int
+REF_GetOrphanStratum(void)
+{
+  if (!enable_local_stratum || !local_orphan || mode != REF_ModeNormal)
+    return NTP_MAX_STRATUM;
+  return local_stratum;
+}
+
+/* ================================================== */
+
+double
+REF_GetSkew(void)
+{
+  return our_skew;
 }

 /* ================================================== */
@@ -1139,10 +1307,12 @@ REF_ModifyMakestep(int limit, double threshold)
 /* ================================================== */

 void
-REF_EnableLocal(int stratum)
+REF_EnableLocal(int stratum, double distance, int orphan)
 {
  enable_local_stratum = 1;
-  local_stratum = stratum;
+  local_stratum = CLAMP(1, stratum, NTP_MAX_STRATUM - 1);
+  local_distance = distance;
+  local_orphan = !!orphan;
 }

 /* ================================================== */
@@ -1155,19 +1325,11 @@ REF_DisableLocal(void)

 /* ================================================== */

-int
-REF_IsLocalActive(void)
-{
-  return !are_we_synchronised && enable_local_stratum;
-}
-
-/* ================================================== */
-
 #define LEAP_SECOND_CLOSE 5

 int REF_IsLeapSecondClose(void)
 {
-  struct timeval now, now_raw;
+  struct timespec now, now_raw;
  time_t t;

  if (!our_leap_sec)
@@ -1191,52 +1353,34 @@ int REF_IsLeapSecondClose(void)
 void
 REF_GetTrackingReport(RPT_TrackingReport *rep)
 {
-  double elapsed;
-  double extra_dispersion;
-  struct timeval now_raw, now_cooked;
+  struct timespec now_raw, now_cooked;
  double correction;
+  int synchronised;

  LCL_ReadRawTime(&now_raw);
  LCL_GetOffsetCorrection(&now_raw, &correction, NULL);
-  UTI_AddDoubleToTimeval(&now_raw, correction, &now_cooked);
+  UTI_AddDoubleToTimespec(&now_raw, correction, &now_cooked);

-  rep->ref_id = 0;
-  rep->ip_addr.family = IPADDR_UNSPEC;
+  REF_GetReferenceParams(&now_cooked, &synchronised,
+                         &rep->leap_status, &rep->stratum,
+                         &rep->ref_id, &rep->ref_time,
+                         &rep->root_delay, &rep->root_dispersion);
+
+  if (rep->stratum == NTP_MAX_STRATUM && !synchronised)
    rep->stratum = 0;
-  rep->leap_status = our_leap_status;
-  rep->ref_time.tv_sec = 0;
-  rep->ref_time.tv_usec = 0;
+
+  rep->ip_addr.family = IPADDR_UNSPEC;
  rep->current_correction = correction;
  rep->freq_ppm = LCL_ReadAbsoluteFrequency();
  rep->resid_freq_ppm = 0.0;
  rep->skew_ppm = 0.0;
-  rep->root_delay = 0.0;
-  rep->root_dispersion = 0.0;
  rep->last_update_interval = last_ref_update_interval;
  rep->last_offset = last_offset;
  rep->rms_offset = sqrt(avg2_offset);

-  if (are_we_synchronised) {
-    
-    UTI_DiffTimevalsToDouble(&elapsed, &now_cooked, &our_ref_time);
-    extra_dispersion = (our_skew + fabs(our_residual_freq) + LCL_GetMaxClockError()) * elapsed;
-    
-    rep->ref_id = our_ref_id;
+  if (synchronised) {
    rep->ip_addr = our_ref_ip;
-    rep->stratum = our_stratum;
-    rep->ref_time = our_ref_time;
    rep->resid_freq_ppm = 1.0e6 * our_residual_freq;
    rep->skew_ppm = 1.0e6 * our_skew;
-    rep->root_delay = our_root_delay;
-    rep->root_dispersion = our_root_dispersion + extra_dispersion;
-
-  } else if (enable_local_stratum) {
-
-    rep->ref_id = LOCAL_REFERENCE_ID;
-    rep->ip_addr.family = IPADDR_UNSPEC;
-    rep->stratum = local_stratum;
-    rep->ref_time = now_cooked;
-    rep->root_dispersion = LCL_GetSysPrecisionAsQuantum();
  }
-
 }
--- a/reference.h
+++ b/reference.h
@@ -35,6 +35,14 @@
 #include "ntp.h"
 #include "reports.h"

+/* Leap second handling modes */
+typedef enum {
+  REF_LeapModeSystem,
+  REF_LeapModeSlew,
+  REF_LeapModeStep,
+  REF_LeapModeIgnore,
+} REF_LeapMode;
+
 /* Init function */
 extern void REF_Initialise(void);

@@ -61,6 +69,9 @@ typedef void (*REF_ModeEndHandler)(int result);
 /* Set the handler for being notified of mode ending */
 extern void REF_SetModeEndHandler(REF_ModeEndHandler handler);

+/* Get leap second handling mode */
+extern REF_LeapMode REF_GetLeapMode(void);
+
 /* Function which takes a local cooked time and returns the estimated
   time of the reference.  It also returns the other parameters
   required for forming the outgoing NTP packet.
@@ -88,12 +99,12 @@ extern void REF_SetModeEndHandler(REF_ModeEndHandler handler);

 extern void REF_GetReferenceParams
 (
- struct timeval *local_time,
+ struct timespec *local_time,
 int *is_synchronised,
 NTP_Leap *leap,
 int *stratum,
 uint32_t *ref_id,
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double *root_delay,
 double *root_dispersion
 );
@@ -129,7 +140,7 @@ extern void REF_SetReference
 int combined_sources,
 uint32_t ref_id,
 IPAddr *ref_ip,
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double offset,
 double offset_sd,
 double frequency,
@@ -140,7 +151,7 @@ extern void REF_SetReference

 extern void REF_SetManualReference
 (
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double offset,
 double frequency,
 double skew
@@ -154,15 +165,20 @@ REF_SetUnsynchronised(void);
   synchronised */
 extern int REF_GetOurStratum(void);

+/* Return stratum of the local reference if orphan mode is enabled */
+extern int REF_GetOrphanStratum(void);
+
+/* Return the current skew */
+extern double REF_GetSkew(void);
+
 /* Modify the setting for the maximum skew we are prepared to allow updates on (in ppm). */
 extern void REF_ModifyMaxupdateskew(double new_max_update_skew);

 /* Modify makestep settings */
 extern void REF_ModifyMakestep(int limit, double threshold);

-extern void REF_EnableLocal(int stratum);
+extern void REF_EnableLocal(int stratum, double distance, int orphan);
 extern void REF_DisableLocal(void);
-extern int REF_IsLocalActive(void);

 /* Check if current raw or cooked time is close to a leap second
   and is better to discard any measurements */
--- a/regress.c
+++ b/regress.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011
+ * Copyright (C) Miroslav Lichvar  2011, 2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -34,7 +34,7 @@
 #include "logging.h"
 #include "util.h"

-#define MAX_POINTS 128
+#define MAX_POINTS 64

 void
 RGR_WeightedRegression
@@ -109,7 +109,7 @@ double
 RGR_GetTCoef(int dof)
 {
  /* Assuming now the 99.95% quantile */
-  static double coefs[] =
+  static const float coefs[] =
  { 636.6, 31.6, 12.92, 8.61, 6.869,
    5.959, 5.408, 5.041, 4.781, 4.587,
    4.437, 4.318, 4.221, 4.140, 4.073,
@@ -132,7 +132,7 @@ RGR_GetTCoef(int dof)
 double
 RGR_GetChi2Coef(int dof)
 {
-  static double coefs[] = {
+  static const float coefs[] = {
    2.706, 4.605, 6.251, 7.779, 9.236, 10.645, 12.017, 13.362,
    14.684, 15.987, 17.275, 18.549, 19.812, 21.064, 22.307, 23.542,
    24.769, 25.989, 27.204, 28.412, 29.615, 30.813, 32.007, 33.196,
@@ -150,20 +150,6 @@ RGR_GetChi2Coef(int dof)
  }
 }

-/* ================================================== */
-/* Structure used for holding results of each regression */
-
-typedef struct {
-  double variance;
-  double slope_sd;
-  double slope;
-  double offset;
-  double offset_sd;
-  double K2; /* Variance / slope_var */
-  int n; /* Number of points */
-  int dof; /* Number of degrees of freedom */
-} RegressionResult;
-
 /* ================================================== */
 /* Critical value for number of runs of residuals with same sign.
   5% critical region for now. */
@@ -299,7 +285,7 @@ RGR_FindBestRegression
        n - start <= min_samples) {
      if (start != resid_start) {
        /* Ignore extra samples in returned nruns */
-        nruns = n_runs_from_residuals(resid - resid_start + start, n - start);
+        nruns = n_runs_from_residuals(resid + (start - resid_start), n - start);
      }
      break;
    } else {
@@ -354,7 +340,7 @@ RGR_FindBestRegression
   0-521-43108-5). */

 static double
-find_ordered_entry_with_flags(double *x, int n, int index, int *flags)
+find_ordered_entry_with_flags(double *x, int n, int index, char *flags)
 {
  int u, v, l, r;
  double temp;
@@ -417,9 +403,9 @@ find_ordered_entry_with_flags(double *x, int n, int index, int *flags)
 static double
 find_ordered_entry(double *x, int n, int index)
 {
-  int flags[MAX_POINTS];
+  char flags[MAX_POINTS];

-  memset(flags, 0, n * sizeof(int));
+  memset(flags, 0, n * sizeof (flags[0]));
  return find_ordered_entry_with_flags(x, n, index, flags);
 }
 #endif
@@ -431,9 +417,9 @@ static double
 find_median(double *x, int n)
 {
  int k;
-  int flags[MAX_POINTS];
+  char flags[MAX_POINTS];

-  memset(flags, 0, n*sizeof(int));
+  memset(flags, 0, n * sizeof (flags[0]));
  k = n>>1;
  if (n&1) {
    return find_ordered_entry_with_flags(x, n, k, flags);
@@ -443,6 +429,19 @@ find_median(double *x, int n)
  }
 }

+/* ================================================== */
+
+double
+RGR_FindMedian(double *x, int n)
+{
+  double tmp[MAX_POINTS];
+
+  assert(n > 0 && n <= MAX_POINTS);
+  memcpy(tmp, x, n * sizeof (tmp[0]));
+
+  return find_median(tmp, n);
+}
+
 /* ================================================== */
 /* This function evaluates the equation

@@ -523,7 +522,7 @@ RGR_FindBestRobustRegression
  double mx, dx, my, dy;
  int nruns = 0;

-  assert(n < MAX_POINTS);
+  assert(n <= MAX_POINTS);

  if (n < 2) {
    return 0;
@@ -580,23 +579,17 @@ RGR_FindBestRobustRegression
       Estimate standard deviation of b and expand range about b based
       on that. */
    sb = sqrt(s2 * W/V);
-    if (sb > tol) {
-      incr = 3.0 * sb;
-    } else {
-      incr = 3.0 * tol;
-    }
-  
-    blo = b;
-    bhi = b;
+    incr = MAX(sb, tol);
  
    do {
-      /* Make sure incr is significant to blo and bhi */
-      while (bhi + incr == bhi || blo - incr == blo) {
-        incr *= 2;
-      }
+      incr *= 2.0;

-      blo -= incr;
-      bhi += incr;
+      /* Give up if the interval is too large */
+      if (incr > 100.0)
+        return 0;
+
+      blo = b - incr;
+      bhi = b + incr;

      /* We don't want 'a' yet */
      eval_robust_residual(x + start, y + start, n_points, blo, &a, &rlo);
@@ -608,6 +601,8 @@ RGR_FindBestRobustRegression
    /* OK, so the root for b lies in (blo, bhi). Start bisecting */
    do {
      bmid = 0.5 * (blo + bhi);
+      if (!(blo < bmid && bmid < bhi))
+        break;
      eval_robust_residual(x + start, y + start, n_points, bmid, &a, &rmid);
      if (rmid == 0.0) {
        break;
@@ -620,7 +615,7 @@ RGR_FindBestRobustRegression
      } else {
        assert(0);
      }
-    } while ((bhi - blo) > tol && (bmid - blo) * (bhi - bmid) > 0.0);
+    } while (bhi - blo > tol);

    *b0 = a;
    *b1 = bmid;
@@ -653,3 +648,57 @@ RGR_FindBestRobustRegression
 }

 /* ================================================== */
+/* This routine performs linear regression with two independent variables.
+   It returns non-zero status if there were enough data points and there
+   was a solution. */
+
+int
+RGR_MultipleRegress
+(double *x1,                    /* first independent variable */
+ double *x2,                    /* second independent variable */
+ double *y,                     /* measured data */
+
+ int n,                         /* number of data points */
+
+ /* The results */
+ double *b2                     /* estimated second slope */
+                                /* other values are not needed yet */
+)
+{
+  double Sx1, Sx2, Sx1x1, Sx1x2, Sx2x2, Sx1y, Sx2y, Sy;
+  double U, V, V1, V2, V3;
+  int i;
+
+  if (n < 4)
+    return 0;
+
+  Sx1 = Sx2 = Sx1x1 = Sx1x2 = Sx2x2 = Sx1y = Sx2y = Sy = 0.0;
+
+  for (i = 0; i < n; i++) {
+    Sx1 += x1[i];
+    Sx2 += x2[i];
+    Sx1x1 += x1[i] * x1[i];
+    Sx1x2 += x1[i] * x2[i];
+    Sx2x2 += x2[i] * x2[i];
+    Sx1y += x1[i] * y[i];
+    Sx2y += x2[i] * y[i];
+    Sy += y[i];
+  }
+
+  U = n * (Sx1x2 * Sx1y - Sx1x1 * Sx2y) +
+      Sx1 * Sx1 * Sx2y - Sx1 * Sx2 * Sx1y +
+      Sy * (Sx2 * Sx1x1 - Sx1 * Sx1x2);
+
+  V1 = n * (Sx1x2 * Sx1x2 - Sx1x1 * Sx2x2);
+  V2 = Sx1 * Sx1 * Sx2x2 + Sx2 * Sx2 * Sx1x1;
+  V3 = -2.0 * Sx1 * Sx2 * Sx1x2;
+  V = V1 + V2 + V3;
+
+  /* Check if there is a (numerically stable) solution */
+  if (fabs(V) * 1.0e10 <= -V1 + V2 + fabs(V3))
+    return 0;
+
+  *b2 = U / V;
+
+  return 1;
+}
--- a/regress.h
+++ b/regress.h
@@ -119,4 +119,19 @@ RGR_FindBestRobustRegression
 int *n_runs,
 int *best_start);

+int
+RGR_MultipleRegress
+(double *x1,                    /* first independent variable */
+ double *x2,                    /* second independent variable */
+ double *y,                     /* measured data */
+
+ int n,                         /* number of data points */
+
+ /* The results */
+ double *b2                     /* estimated second slope */
+);
+
+/* Return the median value from an array */
+extern double RGR_FindMedian(double *x, int n);
+
 #endif /* GOT_REGRESS_H */
--- a/reports.h
+++ b/reports.h
@@ -29,8 +29,7 @@

 #include "sysincl.h"
 #include "addressing.h"
-
-#define REPORT_INVALID_OFFSET 0x80000000
+#include "ntp.h"

 typedef struct {
  IPAddr ip_addr;
@@ -38,7 +37,7 @@ typedef struct {
  int poll;
  enum {RPT_NTP_CLIENT, RPT_NTP_PEER, RPT_LOCAL_REFERENCE} mode;
  enum {RPT_SYNC, RPT_UNREACH, RPT_FALSETICKER, RPT_JITTERY, RPT_CANDIDATE, RPT_OUTLIER} state;
-  enum {RPT_NORMAL, RPT_PREFER, RPT_NOSELECT} sel_option;
+  int sel_options;

  int reachability;
  unsigned long latest_meas_ago; /* seconds */
@@ -50,9 +49,9 @@ typedef struct {
 typedef struct {
  uint32_t ref_id;
  IPAddr ip_addr;
-  unsigned long stratum;
-  unsigned long leap_status;
-  struct timeval ref_time;
+  int stratum;
+  NTP_Leap leap_status;
+  struct timespec ref_time;
  double current_correction;
  double last_offset;
  double rms_offset;
@@ -78,7 +77,7 @@ typedef struct {
 } RPT_SourcestatsReport;

 typedef struct {
-  struct timeval ref_time;
+  struct timespec ref_time;
  unsigned short n_samples;
  unsigned short n_runs;
  unsigned long span_seconds;
@@ -88,17 +87,27 @@ typedef struct {

 typedef struct {
  IPAddr ip_addr;
-  unsigned long client_hits;
-  unsigned long peer_hits;
-  unsigned long cmd_hits_auth;
-  unsigned long cmd_hits_normal;
-  unsigned long cmd_hits_bad;
-  unsigned long last_ntp_hit_ago;
-  unsigned long last_cmd_hit_ago;
+  uint32_t ntp_hits;
+  uint32_t cmd_hits;
+  uint16_t ntp_drops;
+  uint16_t cmd_drops;
+  int8_t ntp_interval;
+  int8_t cmd_interval;
+  int8_t ntp_timeout_interval;
+  uint32_t last_ntp_hit_ago;
+  uint32_t last_cmd_hit_ago;
 } RPT_ClientAccessByIndex_Report;

 typedef struct {
-  struct timeval when;
+  uint32_t ntp_hits;
+  uint32_t cmd_hits;
+  uint32_t ntp_drops;
+  uint32_t cmd_drops;
+  uint32_t log_drops;
+} RPT_ServerStatsReport;
+
+typedef struct {
+  struct timespec when;
  double slewed_offset;
  double orig_offset;
  double residual;
@@ -112,4 +121,43 @@ typedef struct {
  int unresolved;
 } RPT_ActivityReport;

+typedef struct {
+  int active;
+  int leap_only;
+  double offset;
+  double freq_ppm;
+  double wander_ppm;
+  double last_update_ago;
+  double remaining_time;
+} RPT_SmoothingReport;
+
+typedef struct {
+  IPAddr remote_addr;
+  IPAddr local_addr;
+  uint16_t remote_port;
+  uint8_t leap;
+  uint8_t version;
+  uint8_t mode;
+  uint8_t stratum;
+  int8_t poll;
+  int8_t precision;
+  double root_delay;
+  double root_dispersion;
+  uint32_t ref_id;
+  struct timespec ref_time;
+  double offset;
+  double peer_delay;
+  double peer_dispersion;
+  double response_time;
+  double jitter_asymmetry;
+  uint16_t tests;
+  int interleaved;
+  int authenticated;
+  char tx_tss_char;
+  char rx_tss_char;
+  uint32_t total_tx_count;
+  uint32_t total_rx_count;
+  uint32_t total_valid_count;
+} RPT_NTPReport;
+
 #endif /* GOT_REPORTS_H */
--- a/rtc.c
+++ b/rtc.c
@@ -39,11 +39,12 @@
 /* ================================================== */

 static int driver_initialised = 0;
+static int driver_preinit_ok = 0;

 static struct {
  int  (*init)(void);
  void (*fini)(void);
-  int  (*time_pre_init)(void);
+  int  (*time_pre_init)(time_t driftfile_time);
  void (*time_init)(void (*after_hook)(void*), void *anything);
  void (*start_measurements)(void);
  int  (*write_parameters)(void);
@@ -73,29 +74,37 @@ static struct {
 };
     
 /* ================================================== */
-/* Set the system clock to the time of last modification of driftfile
-   if it's in the future */
+/* Get the last modification time of the driftfile */

-static void
-fallback_time_init(void)
+static time_t
+get_driftfile_time(void)
 {
-  struct timeval now;
  struct stat buf;
  char *drift_file;

  drift_file = CNF_GetDriftFile();
  if (!drift_file)
-    return;
+    return 0;

  if (stat(drift_file, &buf))
-    return;
+    return 0;
+
+  return buf.st_mtime;
+}
+
+/* ================================================== */
+/* Set the system time to the driftfile time if it's in the future */
+
+static void
+apply_driftfile_time(time_t t)
+{
+  struct timespec now;

  LCL_ReadCookedTime(&now, NULL);

-  if (now.tv_sec < buf.st_mtime) {
-    LCL_ApplyStepOffset(now.tv_sec - buf.st_mtime);
-    LOG(LOGS_INFO, LOGF_Rtc,
-        "System clock set from driftfile %s", drift_file);
+  if (now.tv_sec < t) {
+    if (LCL_ApplyStepOffset(now.tv_sec - t))
+      LOG(LOGS_INFO, "System time restored from driftfile");
  }
 }

@@ -104,15 +113,24 @@ fallback_time_init(void)
 void
 RTC_Initialise(int initial_set)
 {
+  time_t driftfile_time;
  char *file_name;

-  /* Do an initial read of the RTC and set the system time to it.  This
-     is analogous to what /sbin/hwclock -s would do on Linux.  If that fails
-     or RTC is not supported, set the clock to the time of the last
-     modification of driftfile, so we at least get closer to the truth. */
+  /* If the -s option was specified, try to do an initial read of the RTC and
+     set the system time to it.  Also, read the last modification time of the
+     driftfile (i.e. system time when chronyd was previously stopped) and set
+     the system time to it if it's in the future to bring the clock closer to
+     the true time when the RTC is broken (e.g. it has no battery), is missing,
+     or there is no RTC driver. */
  if (initial_set) {
-    if (!driver.time_pre_init || !driver.time_pre_init()) {
-      fallback_time_init();
+    driftfile_time = get_driftfile_time();
+
+    if (driver.time_pre_init && driver.time_pre_init(driftfile_time)) {
+      driver_preinit_ok = 1;
+    } else {
+      driver_preinit_ok = 0;
+      if (driftfile_time)
+        apply_driftfile_time(driftfile_time);
    }
  }

@@ -124,7 +142,7 @@ RTC_Initialise(int initial_set)

  if (file_name) {
    if (CNF_GetRtcSync()) {
-      LOG_FATAL(LOGF_Rtc, "rtcfile directive cannot be used with rtcsync");
+      LOG_FATAL("rtcfile directive cannot be used with rtcsync");
    }

    if (driver.init) {
@@ -132,7 +150,7 @@ RTC_Initialise(int initial_set)
        driver_initialised = 1;
      }
    } else {
-      LOG(LOGS_ERR, LOGF_Rtc, "RTC not supported on this operating system");
+      LOG(LOGS_ERR, "RTC not supported on this operating system");
    }
  }
 }
@@ -150,9 +168,9 @@ RTC_Finalise(void)
 /* ================================================== */
 /* Start the processing to get a single measurement from the real time
   clock, and use it to trim the system time, based on knowing the
-   drift rate of the RTC and the error the last time we set it.  The
-   TimePreInit routine has already run, so we can be sure that the
-   trim required is not *too* large.
+   drift rate of the RTC and the error the last time we set it.  If the
+   TimePreInit routine has succeeded, we can be sure that the trim required
+   is not *too* large.

   We are called with a hook to a function to be called after the
   initialisation is complete.  We also call this if we cannot do the
@@ -161,7 +179,7 @@ RTC_Finalise(void)
 void
 RTC_TimeInit(void (*after_hook)(void *), void *anything)
 {
-  if (driver_initialised) {
+  if (driver_initialised && driver_preinit_ok) {
    (driver.time_init)(after_hook, anything);
  } else {
    (after_hook)(anything);
--- a/rtc_linux.c
+++ b/rtc_linux.c
@@ -50,7 +50,7 @@

 static void measurement_timeout(void *any);

-static void read_from_device(void *any);
+static void read_from_device(int fd_, int event, void *any);

 /* ================================================== */

@@ -72,8 +72,7 @@ static int fd = -1;

 static int measurement_period = LOWEST_MEASUREMENT_PERIOD;

-static int timeout_running = 0;
-static SCH_TimeoutID timeout_id;
+static SCH_TimeoutID timeout_id = 0;

 static int skip_interrupts;

@@ -93,9 +92,8 @@ static double *rtc_trim = NULL;
 static time_t rtc_ref;


-/* System clock (gettimeofday) samples associated with the above
-   samples. */
-static struct timeval *system_times = NULL;
+/* System clock samples associated with the above samples. */
+static struct timespec *system_times = NULL;

 /* Number of samples currently stored. */
 static int n_samples;   
@@ -171,7 +169,7 @@ discard_samples(int new_first)

  memmove(rtc_sec, rtc_sec + new_first, n_to_save * sizeof(time_t));
  memmove(rtc_trim, rtc_trim + new_first, n_to_save * sizeof(double));
-  memmove(system_times, system_times + new_first, n_to_save * sizeof(struct timeval));
+  memmove(system_times, system_times + new_first, n_to_save * sizeof(struct timespec));

  n_samples = n_to_save;
 }
@@ -181,7 +179,7 @@ discard_samples(int new_first)
 #define NEW_FIRST_WHEN_FULL 4

 static void
-accumulate_sample(time_t rtc, struct timeval *sys)
+accumulate_sample(time_t rtc, struct timespec *sys)
 {

  if (n_samples == MAX_SAMPLES) {
@@ -189,6 +187,11 @@ accumulate_sample(time_t rtc, struct timeval *sys)
    discard_samples(NEW_FIRST_WHEN_FULL);
  }

+  /* Discard all samples if the RTC was stepped back (not our trim) */
+  if (n_samples > 0 && rtc_sec[n_samples - 1] - rtc >= rtc_trim[n_samples - 1]) {
+    DEBUG_LOG("RTC samples discarded");
+    n_samples = 0;
+  }

  /* Always use most recent sample as reference */
  /* use sample only if n_sample is not negative*/
@@ -226,7 +229,7 @@ run_regression(int new_sample,
    for (i=0; i<n_samples; i++) {
      rtc_rel[i] = rtc_trim[i] + (double)(rtc_sec[i] - rtc_ref);
      offsets[i] = ((double) (rtc_ref - system_times[i].tv_sec) -
-                    (1.0e-6 * (double) system_times[i].tv_usec) +
+                    (1.0e-9 * system_times[i].tv_nsec) +
                    rtc_rel[i]);

    }
@@ -263,7 +266,7 @@ run_regression(int new_sample,

 static void
 slew_samples
-(struct timeval *raw, struct timeval *cooked,
+(struct timespec *raw, struct timespec *cooked,
 double dfreq,
 double doffset,
 LCL_ChangeType change_type,
@@ -279,7 +282,7 @@ slew_samples
  }

  for (i=0; i<n_samples; i++) {
-    UTI_AdjustTimeval(system_times + i, cooked, system_times + i, &delta_time,
+    UTI_AdjustTimespec(system_times + i, cooked, system_times + i, &delta_time,
        dfreq, doffset);
  }

@@ -291,7 +294,7 @@ slew_samples
    coef_gain_rate += dfreq * (1.0 - coef_gain_rate);
  }

-  DEBUG_LOG(LOGF_RtcLinux, "dfreq=%.8f doffset=%.6f old_fast=%.6f old_rate=%.3f new_fast=%.6f new_rate=%.3f",
+  DEBUG_LOG("dfreq=%.8f doffset=%.6f old_fast=%.6f old_rate=%.3f new_fast=%.6f new_rate=%.3f",
      dfreq, doffset,
      old_seconds_fast, 1.0e6 * old_gain_rate,
      coef_seconds_fast, 1.0e6 * coef_gain_rate);
@@ -367,6 +370,9 @@ t_from_rtc(struct tm *stm) {
  t2 = mktime(&temp2);
  diff = t2 - t1;

+  if (t1 - diff == -1)
+    DEBUG_LOG("Could not convert RTC time");
+
  return t1 - diff;
 }

@@ -379,13 +385,13 @@ read_hwclock_file(const char *hwclock_file)
  char line[256];
  int i;

-  if (!hwclock_file)
+  if (!hwclock_file || !hwclock_file[0])
    return;

  in = fopen(hwclock_file, "r");
  if (!in) {
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not open hwclockfile %s",
-        hwclock_file);
+    LOG(LOGS_WARN, "Could not open %s : %s",
+        hwclock_file, strerror(errno));
    return;
  }

@@ -402,8 +408,7 @@ read_hwclock_file(const char *hwclock_file)
  } else if (i == 3 && !strncmp(line, "UTC", 3)) {
    rtc_on_utc = 1;
  } else {
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not read LOCAL/UTC setting from hwclockfile %s",
-        hwclock_file);
+    LOG(LOGS_WARN, "Could not read RTC LOCAL/UTC setting from %s", hwclock_file);
  }
 }

@@ -445,8 +450,7 @@ read_coefs_from_file(void)
                 &file_ref_offset,
                 &file_rate_ppm) == 4) {
      } else {
-        LOG(LOGS_WARN, LOGF_RtcLinux, "Could not read coefficients from RTC file %s",
-            coefs_file_name);
+        LOG(LOGS_WARN, "Could not read coefficients from %s", coefs_file_name);
      }
      fclose(in);
    }
@@ -479,7 +483,7 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  out = fopen(temp_coefs_file_name, "w");
  if (!out) {
    Free(temp_coefs_file_name);
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not open temporary RTC file %s.tmp for writing",
+    LOG(LOGS_WARN, "Could not open temporary RTC file %s.tmp for writing",
        coefs_file_name);
    return RTC_ST_BADFILE;
  }
@@ -490,7 +494,7 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  r2 = fclose(out);
  if (r1 < 0 || r2) {
    Free(temp_coefs_file_name);
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not write to temporary RTC file %s.tmp",
+    LOG(LOGS_WARN, "Could not write to temporary RTC file %s.tmp",
        coefs_file_name);
    return RTC_ST_BADFILE;
  }
@@ -500,7 +504,7 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  if (!stat(coefs_file_name,&buf)) {
    if (chown(temp_coefs_file_name,buf.st_uid,buf.st_gid) ||
        chmod(temp_coefs_file_name,buf.st_mode & 0777)) {
-      LOG(LOGS_WARN, LOGF_RtcLinux,
+      LOG(LOGS_WARN,
          "Could not change ownership or permissions of temporary RTC file %s.tmp",
          coefs_file_name);
    }
@@ -511,7 +515,7 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  if (rename(temp_coefs_file_name,coefs_file_name)) {
    unlink(temp_coefs_file_name);
    Free(temp_coefs_file_name);
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not replace old RTC file %s.tmp with new one %s",
+    LOG(LOGS_WARN, "Could not replace old RTC file %s.tmp with new one %s",
        coefs_file_name, coefs_file_name);
    return RTC_ST_BADFILE;
  }
@@ -532,7 +536,7 @@ RTC_Linux_Initialise(void)
 {
  rtc_sec = MallocArray(time_t, MAX_SAMPLES);
  rtc_trim = MallocArray(double, MAX_SAMPLES);
-  system_times = MallocArray(struct timeval, MAX_SAMPLES);
+  system_times = MallocArray(struct timespec, MAX_SAMPLES);

  /* Setup details depending on configuration options */
  setup_config();
@@ -544,7 +548,7 @@ RTC_Linux_Initialise(void)

  fd = open (CNF_GetRtcDevice(), O_RDWR);
  if (fd < 0) {
-    LOG(LOGS_ERR, LOGF_RtcLinux, "Could not open RTC device %s : %s",
+    LOG(LOGS_ERR, "Could not open RTC device %s : %s",
        CNF_GetRtcDevice(), strerror(errno));
    return 0;
  }
@@ -562,7 +566,7 @@ RTC_Linux_Initialise(void)
  operating_mode = OM_NORMAL;

  /* Register file handler */
-  SCH_AddInputFileHandler(fd, read_from_device, NULL);
+  SCH_AddFileHandler(fd, SCH_FILE_INPUT, read_from_device, NULL);

  /* Register slew handler */
  LCL_AddParameterChangeHandler(slew_samples, NULL);
@@ -578,14 +582,12 @@ RTC_Linux_Initialise(void)
 void
 RTC_Linux_Finalise(void)
 {
-  if (timeout_running) {
  SCH_RemoveTimeout(timeout_id);
-    timeout_running = 0;
-  }
+  timeout_id = 0;

  /* Remove input file handler */
  if (fd >= 0) {
-    SCH_RemoveInputFileHandler(fd);
+    SCH_RemoveFileHandler(fd);
    close(fd);

    /* Save the RTC data */
@@ -607,14 +609,14 @@ switch_interrupts(int onoff)
  if (onoff) {
    status = ioctl(fd, RTC_UIE_ON, 0);
    if (status < 0) {
-      LOG(LOGS_ERR, LOGF_RtcLinux, "Could not start measurement : %s", strerror(errno));
+      LOG(LOGS_ERR, "Could not %s RTC interrupt : %s", "enable", strerror(errno));
      return;
    }
    skip_interrupts = 1;
  } else {
    status = ioctl(fd, RTC_UIE_OFF, 0);
    if (status < 0) {
-      LOG(LOGS_ERR, LOGF_RtcLinux, "Could not stop measurement : %s", strerror(errno));
+      LOG(LOGS_ERR, "Could not %s RTC interrupt : %s", "disable", strerror(errno));
      return;
    }
  }
@@ -625,7 +627,7 @@ switch_interrupts(int onoff)
 static void
 measurement_timeout(void *any)
 {
-  timeout_running = 0;
+  timeout_id = 0;
  switch_interrupts(1);
 }

@@ -652,7 +654,7 @@ set_rtc(time_t new_rtc_time)

  status = ioctl(fd, RTC_SET_TIME, &rtc_raw);
  if (status < 0) {
-    LOG(LOGS_ERR, LOGF_RtcLinux, "Could not set RTC time");
+    LOG(LOGS_ERR, "Could not set RTC time");
  }

 }
@@ -694,10 +696,11 @@ handle_initial_trim(void)
    /* sys_error_now is positive if the system clock is fast */
    sys_error_now = rtc_error_now - coef_seconds_fast;
          
-    LOG(LOGS_INFO, LOGF_RtcLinux, "System trim from RTC = %f", sys_error_now);
    LCL_AccumulateOffset(sys_error_now, 0.0);
+    LOG(LOGS_INFO, "System clock off from RTC by %f seconds (slew)",
+        sys_error_now);
  } else {
-    LOG(LOGS_WARN, LOGF_RtcLinux, "No valid file coefficients, cannot trim system time");
+    LOG(LOGS_WARN, "No valid rtcfile coefficients");
  }
  
  coefs_valid = 0;
@@ -722,7 +725,7 @@ handle_relock_after_trim(void)
  if (valid) {
    write_coefs_to_file(1,ref,fast,saved_coef_gain_rate);
  } else {
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not do regression after trim");
+    DEBUG_LOG("Could not do regression after trim");
  }

  coefs_valid = 0;
@@ -755,7 +758,7 @@ maybe_autotrim(void)
 /* ================================================== */

 static void
-process_reading(time_t rtc_time, struct timeval *system_time)
+process_reading(time_t rtc_time, struct timespec *system_time)
 {
  double rtc_fast;

@@ -788,7 +791,7 @@ process_reading(time_t rtc_time, struct timeval *system_time)


  if (logfileid != -1) {
-    rtc_fast = (double)(rtc_time - system_time->tv_sec) - 1.0e-6 * (double) system_time->tv_usec;
+    rtc_fast = (rtc_time - system_time->tv_sec) - 1.0e-9 * system_time->tv_nsec;

    LOG_FileWrite(logfileid, "%s %14.6f %1d  %14.6f  %12.3f  %2d  %2d %4d",
            UTI_TimeToLogForm(system_time->tv_sec),
@@ -802,11 +805,11 @@ process_reading(time_t rtc_time, struct timeval *system_time)
 /* ================================================== */

 static void
-read_from_device(void *any)
+read_from_device(int fd_, int event, void *any)
 {
  int status;
  unsigned long data;
-  struct timeval sys_time;
+  struct timespec sys_time;
  struct rtc_time rtc_raw;
  struct tm rtc_tm;
  time_t rtc_t;
@@ -817,8 +820,8 @@ read_from_device(void *any)
  if (status < 0) {
    /* This looks like a bad error : the file descriptor was indicating it was
     * ready to read but we couldn't read anything.  Give up. */
-    LOG(LOGS_ERR, LOGF_RtcLinux, "Could not read flags %s : %s", CNF_GetRtcDevice(), strerror(errno));
-    SCH_RemoveInputFileHandler(fd);
+    LOG(LOGS_ERR, "Could not read flags %s : %s", CNF_GetRtcDevice(), strerror(errno));
+    SCH_RemoveFileHandler(fd);
    switch_interrupts(0); /* Likely to raise error too, but just to be sure... */
    close(fd);
    fd = -1;
@@ -841,12 +844,12 @@ read_from_device(void *any)

    status = ioctl(fd, RTC_RD_TIME, &rtc_raw);
    if (status < 0) {
-      LOG(LOGS_ERR, LOGF_RtcLinux, "Could not read time from %s : %s", CNF_GetRtcDevice(), strerror(errno));
+      LOG(LOGS_ERR, "Could not read time from %s : %s", CNF_GetRtcDevice(), strerror(errno));
      error = 1;
      goto turn_off_interrupt;
    }

-    /* Convert RTC time into a struct timeval */
+    /* Convert RTC time into a struct timespec */
    rtc_tm.tm_sec = rtc_raw.tm_sec;
    rtc_tm.tm_min = rtc_raw.tm_min;
    rtc_tm.tm_hour = rtc_raw.tm_hour;
@@ -857,7 +860,6 @@ read_from_device(void *any)
    rtc_t = t_from_rtc(&rtc_tm);

    if (rtc_t == (time_t)(-1)) {
-      LOG(LOGS_ERR, LOGF_RtcLinux, "Could not convert RTC time to timeval");
      error = 1;
      goto turn_off_interrupt;
    }      
@@ -883,13 +885,12 @@ turn_off_interrupt:
  switch (operating_mode) {
    case OM_INITIAL:
      if (error) {
-        LOG(LOGS_WARN, LOGF_RtcLinux, "Could not complete initial step due to errors");
+        DEBUG_LOG("Could not complete initial step due to errors");
        operating_mode = OM_NORMAL;
        (after_init_hook)(after_init_hook_arg);

        switch_interrupts(0);
    
-        timeout_running = 1;
        timeout_id = SCH_AddTimeoutByDelay((double) measurement_period, measurement_timeout, NULL);
      }

@@ -897,12 +898,11 @@ turn_off_interrupt:

    case OM_AFTERTRIM:
      if (error) {
-        LOG(LOGS_WARN, LOGF_RtcLinux, "Could not complete after trim relock due to errors");
+        DEBUG_LOG("Could not complete after trim relock due to errors");
        operating_mode = OM_NORMAL;

        switch_interrupts(0);
    
-        timeout_running = 1;
        timeout_id = SCH_AddTimeoutByDelay((double) measurement_period, measurement_timeout, NULL);
      }
      
@@ -911,7 +911,6 @@ turn_off_interrupt:
    case OM_NORMAL:
      switch_interrupts(0);
    
-      timeout_running = 1;
      timeout_id = SCH_AddTimeoutByDelay((double) measurement_period, measurement_timeout, NULL);

      break;
@@ -931,9 +930,8 @@ RTC_Linux_TimeInit(void (*after_hook)(void *), void *anything)
  after_init_hook_arg = anything;

  operating_mode = OM_INITIAL;
-  timeout_running = 0;
+  timeout_id = 0;
  switch_interrupts(1);
-
 }

 /* ================================================== */
@@ -941,7 +939,6 @@ RTC_Linux_TimeInit(void (*after_hook)(void *), void *anything)
 void
 RTC_Linux_StartMeasurements(void)
 {
-  timeout_running = 0;
  measurement_timeout(NULL);
 }

@@ -974,14 +971,14 @@ RTC_Linux_WriteParameters(void)
   RTC behaviour than we do for the rest of the module. */

 int
-RTC_Linux_TimePreInit(void)
+RTC_Linux_TimePreInit(time_t driftfile_time)
 {
  int fd, status;
  struct rtc_time rtc_raw, rtc_raw_retry;
  struct tm rtc_tm;
  time_t rtc_t;
  double accumulated_error, sys_offset;
-  struct timeval new_sys_time, old_sys_time;
+  struct timespec new_sys_time, old_sys_time;

  coefs_file_name = CNF_GetRtcFile();

@@ -1035,22 +1032,27 @@ RTC_Linux_TimePreInit(void)

      new_sys_time.tv_sec = rtc_t;
      /* Average error in the RTC reading */
-      new_sys_time.tv_usec = 500000;
+      new_sys_time.tv_nsec = 500000000;

-      UTI_AddDoubleToTimeval(&new_sys_time, -accumulated_error, &new_sys_time);
+      UTI_AddDoubleToTimespec(&new_sys_time, -accumulated_error, &new_sys_time);

-      UTI_DiffTimevalsToDouble(&sys_offset, &old_sys_time, &new_sys_time);
+      if (new_sys_time.tv_sec < driftfile_time) {
+        LOG(LOGS_WARN, "RTC time before last driftfile modification (ignored)");
+        return 0;
+      }
+
+      sys_offset = UTI_DiffTimespecsToDouble(&old_sys_time, &new_sys_time);

      /* Set system time only if the step is larger than 1 second */
      if (fabs(sys_offset) >= 1.0) {
-        LOG(LOGS_INFO, LOGF_RtcLinux, "Set system time, error in RTC = %f",
-            accumulated_error);
-        LCL_ApplyStepOffset(sys_offset);
+        if (LCL_ApplyStepOffset(sys_offset))
+          LOG(LOGS_INFO, "System time set from RTC");
      }
    } else {
-      LOG(LOGS_WARN, LOGF_RtcLinux, "Could not convert RTC reading to seconds since 1/1/1970");
      return 0;
    }
+  } else {
+    return 0;
  }

  return 1;
@@ -1062,7 +1064,7 @@ int
 RTC_Linux_GetReport(RPT_RTC_Report *report)
 {
  report->ref_time.tv_sec = coef_ref_time;
-  report->ref_time.tv_usec = 0;
+  report->ref_time.tv_nsec = 0;
  report->n_samples = n_samples;
  report->n_runs = n_runs;
  if (n_samples > 1) {
@@ -1081,8 +1083,7 @@ RTC_Linux_GetReport(RPT_RTC_Report *report)
 int
 RTC_Linux_Trim(void)
 {
-  struct timeval now;
-
+  struct timespec now;

  /* Remember the slope coefficient - we won't be able to determine a
     good one in a few seconds when we determine the new offset! */
@@ -1090,7 +1091,8 @@ RTC_Linux_Trim(void)

  if (fabs(coef_seconds_fast) > 1.0) {

-    LOG(LOGS_INFO, LOGF_RtcLinux, "Trimming RTC, error = %.3f seconds", coef_seconds_fast);
+    LOG(LOGS_INFO, "RTC wrong by %.3f seconds (step)",
+        coef_seconds_fast);

    /* Do processing to set clock.  Let R be the value we set the
       RTC to, then in 500ms the RTC ticks (R+1) (see comments in
@@ -1111,14 +1113,12 @@ RTC_Linux_Trim(void)

    /* Estimate the offset in case writertc is called or chronyd
       is terminated during rapid sampling */
-    coef_seconds_fast = -now.tv_usec / 1e6 + 0.5;
+    coef_seconds_fast = -now.tv_nsec / 1.0e9 + 0.5;
    coef_ref_time = now.tv_sec;

    /* And start rapid sampling, interrupts on now */
-    if (timeout_running) {
    SCH_RemoveTimeout(timeout_id);
-      timeout_running = 0;
-    }
+    timeout_id = 0;
    switch_interrupts(1);
  }

--- a/rtc_linux.h
+++ b/rtc_linux.h
@@ -30,7 +30,7 @@

 extern int RTC_Linux_Initialise(void);
 extern void RTC_Linux_Finalise(void);
-extern int RTC_Linux_TimePreInit(void);
+extern int RTC_Linux_TimePreInit(time_t driftile_time);
 extern void RTC_Linux_TimeInit(void (*after_hook)(void *), void *anything);
 extern void RTC_Linux_StartMeasurements(void);

--- a/sched.c
+++ b/sched.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011, 2013-2014
+ * Copyright (C) Miroslav Lichvar  2011, 2013-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -44,17 +44,6 @@ static int initialised = 0;

 /* ================================================== */

-/* Variables to handle the capability to dispatch on particular file
-   handles becoming readable */
-
-/* Each bit set in this fd set corresponds to a read descriptor that
-   we are watching and with which we have a handler associated in the
-   file_handlers array */
-static fd_set read_fds;
-
-/* This is the number of bits that we have set in read_fds */
-static unsigned int n_read_fds;
-
 /* One more than the highest file descriptor that is registered */
 static unsigned int one_highest_fd;

@@ -67,12 +56,13 @@ static unsigned int one_highest_fd;
 typedef struct {
  SCH_FileHandler       handler;
  SCH_ArbitraryArgument arg;
+  int                   events;
 } FileHandlerEntry;

 static ARR_Instance file_handlers;

 /* Timestamp when last select() returned */
-static struct timeval last_select_ts, last_select_ts_raw;
+static struct timespec last_select_ts, last_select_ts_raw;
 static double last_select_ts_err;

 /* ================================================== */
@@ -83,7 +73,7 @@ typedef struct _TimerQueueEntry
 {
  struct _TimerQueueEntry *next; /* Forward and back links in the list */
  struct _TimerQueueEntry *prev;
-  struct timeval tv;            /* Local system time at which the
+  struct timespec ts;           /* Local system time at which the
                                   timeout is to expire.  Clearly this
                                   must be in terms of what the
                                   operating system thinks of as
@@ -111,7 +101,7 @@ static SCH_TimeoutID next_tqe_id;
 static TimerQueueEntry *tqe_free_list = NULL;

 /* Timestamp when was last timeout dispatched for each class */
-static struct timeval last_class_dispatch[SCH_NumberOfClasses];
+static struct timespec last_class_dispatch[SCH_NumberOfClasses];

 /* ================================================== */

@@ -120,8 +110,8 @@ static int need_to_exit;
 /* ================================================== */

 static void
-handle_slew(struct timeval *raw,
-            struct timeval *cooked,
+handle_slew(struct timespec *raw,
+            struct timespec *cooked,
            double dfreq,
            double doffset,
            LCL_ChangeType change_type,
@@ -132,9 +122,6 @@ handle_slew(struct timeval *raw,
 void
 SCH_Initialise(void)
 {
-  FD_ZERO(&read_fds);
-  n_read_fds = 0;
-
  file_handlers = ARR_CreateInstance(sizeof (FileHandlerEntry));

  n_timer_queue_entries = 0;
@@ -150,8 +137,6 @@ SCH_Initialise(void)
  LCL_ReadRawTime(&last_select_ts_raw);
  last_select_ts = last_select_ts_raw;

-  srandom(last_select_ts.tv_sec << 16 ^ last_select_ts.tv_usec);
-
  initialised = 1;
 }

@@ -168,71 +153,85 @@ SCH_Finalise(void) {
 /* ================================================== */

 void
-SCH_AddInputFileHandler
-(int fd, SCH_FileHandler handler, SCH_ArbitraryArgument arg)
+SCH_AddFileHandler
+(int fd, int events, SCH_FileHandler handler, SCH_ArbitraryArgument arg)
+{
+  FileHandlerEntry *ptr;
+
+  assert(initialised);
+  assert(events);
+  assert(fd >= 0);
+  
+  if (fd >= FD_SETSIZE)
+    LOG_FATAL("Too many file descriptors");
+
+  /* Resize the array if the descriptor is highest so far */
+  while (ARR_GetSize(file_handlers) <= fd) {
+    ptr = ARR_GetNewElement(file_handlers);
+    ptr->handler = NULL;
+    ptr->arg = NULL;
+    ptr->events = 0;
+  }
+
+  ptr = ARR_GetElement(file_handlers, fd);
+
+  /* Don't want to allow the same fd to register a handler more than
+     once without deleting a previous association - this suggests
+     a bug somewhere else in the program. */
+  assert(!ptr->handler);
+
+  ptr->handler = handler;
+  ptr->arg = arg;
+  ptr->events = events;
+
+  if (one_highest_fd < fd + 1)
+    one_highest_fd = fd + 1;
+}
+
+
+/* ================================================== */
+
+void
+SCH_RemoveFileHandler(int fd)
 {
  FileHandlerEntry *ptr;

  assert(initialised);

-  if (fd >= FD_SETSIZE)
-    LOG_FATAL(LOGF_Scheduler, "Too many file descriptors");
-
-  /* Don't want to allow the same fd to register a handler more than
-     once without deleting a previous association - this suggests
-     a bug somewhere else in the program. */
-  assert(!FD_ISSET(fd, &read_fds));
-
-  ++n_read_fds;
-  
-  if (ARR_GetSize(file_handlers) < fd + 1)
-    ARR_SetSize(file_handlers, fd + 1);
-
-  ptr = (FileHandlerEntry *)ARR_GetElement(file_handlers, fd);
-  ptr->handler = handler;
-  ptr->arg = arg;
-
-  FD_SET(fd, &read_fds);
-
-  if ((fd + 1) > one_highest_fd) {
-    one_highest_fd = fd + 1;
-  }
-}
-
-
-/* ================================================== */
-
-void
-SCH_RemoveInputFileHandler(int fd)
-{
-  int fds_left, fd_to_check;
-
-  assert(initialised);
+  ptr = ARR_GetElement(file_handlers, fd);

  /* Check that a handler was registered for the fd in question */
-  assert(FD_ISSET(fd, &read_fds));
+  assert(ptr->handler);

-  --n_read_fds;
-
-  FD_CLR(fd, &read_fds);
+  ptr->handler = NULL;
+  ptr->arg = NULL;
+  ptr->events = 0;

  /* Find new highest file descriptor */
-  fds_left = n_read_fds;
-  fd_to_check = 0;
-  while (fds_left > 0) {
-    if (FD_ISSET(fd_to_check, &read_fds)) {
-      --fds_left;
+  while (one_highest_fd > 0) {
+    ptr = ARR_GetElement(file_handlers, one_highest_fd - 1);
+    if (ptr->handler)
+      break;
+    one_highest_fd--;
  }
-    ++fd_to_check;
-  }
-
-  one_highest_fd = fd_to_check;
 }

 /* ================================================== */

 void
-SCH_GetLastEventTime(struct timeval *cooked, double *err, struct timeval *raw)
+SCH_SetFileHandlerEvents(int fd, int events)
+{
+  FileHandlerEntry *ptr;
+
+  assert(events);
+  ptr = ARR_GetElement(file_handlers, fd);
+  ptr->events = events;
+}
+
+/* ================================================== */
+
+void
+SCH_GetLastEventTime(struct timespec *cooked, double *err, struct timespec *raw)
 {
  if (cooked) {
    *cooked = last_select_ts;
@@ -278,8 +277,28 @@ release_tqe(TimerQueueEntry *node)

 /* ================================================== */

+static SCH_TimeoutID
+get_new_tqe_id(void)
+{
+  TimerQueueEntry *ptr;
+
+try_again:
+  next_tqe_id++;
+  if (!next_tqe_id)
+    goto try_again;
+
+  /* Make sure the ID isn't already used */
+  for (ptr = timer_queue.next; ptr != &timer_queue; ptr = ptr->next)
+    if (ptr->id == next_tqe_id)
+      goto try_again;
+
+  return next_tqe_id;
+}
+
+/* ================================================== */
+
 SCH_TimeoutID
-SCH_AddTimeout(struct timeval *tv, SCH_TimeoutHandler handler, SCH_ArbitraryArgument arg)
+SCH_AddTimeout(struct timespec *ts, SCH_TimeoutHandler handler, SCH_ArbitraryArgument arg)
 {
  TimerQueueEntry *new_tqe;
  TimerQueueEntry *ptr;
@@ -288,15 +307,15 @@ SCH_AddTimeout(struct timeval *tv, SCH_TimeoutHandler handler, SCH_ArbitraryArgu

  new_tqe = allocate_tqe();

-  new_tqe->id = next_tqe_id++;
+  new_tqe->id = get_new_tqe_id();
  new_tqe->handler = handler;
  new_tqe->arg = arg;
-  new_tqe->tv = *tv;
+  new_tqe->ts = *ts;
  new_tqe->class = SCH_ReservedTimeoutValue;

  /* Now work out where to insert the new entry in the list */
  for (ptr = timer_queue.next; ptr != &timer_queue; ptr = ptr->next) {
-    if (UTI_CompareTimevals(&new_tqe->tv, &ptr->tv) == -1) {
+    if (UTI_CompareTimespecs(&new_tqe->ts, &ptr->ts) == -1) {
      /* If the new entry comes before the current pointer location in
         the list, we want to insert the new entry just before ptr. */
      break;
@@ -323,13 +342,17 @@ SCH_AddTimeout(struct timeval *tv, SCH_TimeoutHandler handler, SCH_ArbitraryArgu
 SCH_TimeoutID
 SCH_AddTimeoutByDelay(double delay, SCH_TimeoutHandler handler, SCH_ArbitraryArgument arg)
 {
-  struct timeval now, then;
+  struct timespec now, then;

  assert(initialised);
  assert(delay >= 0.0);

  LCL_ReadRawTime(&now);
-  UTI_AddDoubleToTimeval(&now, delay, &then);
+  UTI_AddDoubleToTimespec(&now, delay, &then);
+  if (UTI_CompareTimespecs(&now, &then) > 0) {
+    LOG_FATAL("Timeout overflow");
+  }
+
  return SCH_AddTimeout(&then, handler, arg);

 }
@@ -343,7 +366,7 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
 {
  TimerQueueEntry *new_tqe;
  TimerQueueEntry *ptr;
-  struct timeval now;
+  struct timespec now;
  double diff, r;
  double new_min_delay;

@@ -352,7 +375,10 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
  assert(class < SCH_NumberOfClasses);

  if (randomness > 0.0) {
-    r = random() % 0xffff / (0xffff - 1.0) * randomness + 1.0;
+    uint32_t rnd;
+
+    UTI_GetRandomBytes(&rnd, sizeof (rnd));
+    r = rnd * (randomness / (uint32_t)-1) + 1.0;
    min_delay *= r;
    separation *= r;
  }
@@ -361,7 +387,7 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
  new_min_delay = min_delay;

  /* Check the separation from the last dispatched timeout */
-  UTI_DiffTimevalsToDouble(&diff, &now, &last_class_dispatch[class]);
+  diff = UTI_DiffTimespecsToDouble(&now, &last_class_dispatch[class]);
  if (diff < separation && diff >= 0.0 && diff + new_min_delay < separation) {
    new_min_delay = separation - diff;
  }
@@ -370,7 +396,7 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
     if necessary to keep at least the separation away */
  for (ptr = timer_queue.next; ptr != &timer_queue; ptr = ptr->next) {
    if (ptr->class == class) {
-      UTI_DiffTimevalsToDouble(&diff, &ptr->tv, &now);
+      diff = UTI_DiffTimespecsToDouble(&ptr->ts, &now);
      if (new_min_delay > diff) {
        if (new_min_delay - diff < separation) {
          new_min_delay = diff + separation;
@@ -384,7 +410,7 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
  }

  for (ptr = timer_queue.next; ptr != &timer_queue; ptr = ptr->next) {
-    UTI_DiffTimevalsToDouble(&diff, &ptr->tv, &now);
+    diff = UTI_DiffTimespecsToDouble(&ptr->ts, &now);
    if (diff > new_min_delay) {
      break;
    }
@@ -393,10 +419,10 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
  /* We have located the insertion point */
  new_tqe = allocate_tqe();

-  new_tqe->id = next_tqe_id++;
+  new_tqe->id = get_new_tqe_id();
  new_tqe->handler = handler;
  new_tqe->arg = arg;
-  UTI_AddDoubleToTimeval(&now, new_min_delay, &new_tqe->tv);
+  UTI_AddDoubleToTimespec(&now, new_min_delay, &new_tqe->ts);
  new_tqe->class = class;

  new_tqe->next = ptr;
@@ -417,6 +443,9 @@ SCH_RemoveTimeout(SCH_TimeoutID id)

  assert(initialised);

+  if (!id)
+    return;
+
  for (ptr = timer_queue.next; ptr != &timer_queue; ptr = ptr->next) {

    if (ptr->id == id) {
@@ -432,9 +461,12 @@ SCH_RemoveTimeout(SCH_TimeoutID id)
      /* Release memory back to the operating system */
      release_tqe(ptr);

-      break;
+      return;
    }
  }
+
+  /* Catch calls with invalid non-zero ID */
+  assert(0);
 }

 /* ================================================== */
@@ -444,7 +476,7 @@ SCH_RemoveTimeout(SCH_TimeoutID id)
   completed). */

 static void
-dispatch_timeouts(struct timeval *now) {
+dispatch_timeouts(struct timespec *now) {
  TimerQueueEntry *ptr;
  SCH_TimeoutHandler handler;
  SCH_ArbitraryArgument arg;
@@ -454,7 +486,7 @@ dispatch_timeouts(struct timeval *now) {
    LCL_ReadRawTime(now);

    if (!(n_timer_queue_entries > 0 &&
-          UTI_CompareTimevals(now, &(timer_queue.next->tv)) >= 0)) {
+          UTI_CompareTimespecs(now, &timer_queue.next->ts) >= 0)) {
      break;
    }

@@ -480,42 +512,56 @@ dispatch_timeouts(struct timeval *now) {
       more time than was delay of a scheduled timeout. */
    if (n_done > n_timer_queue_entries * 4 &&
        n_done > n_entries_on_start * 4) {
-      LOG_FATAL(LOGF_Scheduler, "Possible infinite loop in scheduling");
+      LOG_FATAL("Possible infinite loop in scheduling");
    }
  }
 }

 /* ================================================== */

-/* nfh is the number of bits set in fhs */
+/* nfd is the number of bits set in all fd_sets */

 static void
-dispatch_filehandlers(int nfh, fd_set *fhs)
+dispatch_filehandlers(int nfd, fd_set *read_fds, fd_set *write_fds, fd_set *except_fds)
 {
  FileHandlerEntry *ptr;
-  int fh = 0;
+  int fd;
  
-  while (nfh > 0) {
-    if (FD_ISSET(fh, fhs)) {
+  for (fd = 0; nfd && fd < one_highest_fd; fd++) {
+    if (except_fds && FD_ISSET(fd, except_fds)) {
+      /* This descriptor has an exception, dispatch its handler */
+      ptr = (FileHandlerEntry *)ARR_GetElement(file_handlers, fd);
+      (ptr->handler)(fd, SCH_FILE_EXCEPTION, ptr->arg);
+      nfd--;

+      /* Don't try to read from it now */
+      if (read_fds && FD_ISSET(fd, read_fds)) {
+        FD_CLR(fd, read_fds);
+        nfd--;
+      }
+    }
+
+    if (read_fds && FD_ISSET(fd, read_fds)) {
      /* This descriptor can be read from, dispatch its handler */
-      ptr = (FileHandlerEntry *)ARR_GetElement(file_handlers, fh);
-      (ptr->handler)(ptr->arg);
-
-      /* Decrement number of readable files still to find */
-      --nfh;
+      ptr = (FileHandlerEntry *)ARR_GetElement(file_handlers, fd);
+      (ptr->handler)(fd, SCH_FILE_INPUT, ptr->arg);
+      nfd--;
    }

-    ++fh;
+    if (write_fds && FD_ISSET(fd, write_fds)) {
+      /* This descriptor can be written to, dispatch its handler */
+      ptr = (FileHandlerEntry *)ARR_GetElement(file_handlers, fd);
+      (ptr->handler)(fd, SCH_FILE_OUTPUT, ptr->arg);
+      nfd--;
+    }
  }
-
 }

 /* ================================================== */

 static void
-handle_slew(struct timeval *raw,
-            struct timeval *cooked,
+handle_slew(struct timespec *raw,
+            struct timespec *cooked,
            double dfreq,
            double doffset,
            LCL_ChangeType change_type,
@@ -533,17 +579,69 @@ handle_slew(struct timeval *raw,
    /* If a step change occurs, just shift all raw time stamps by the offset */
    
    for (ptr = timer_queue.next; ptr != &timer_queue; ptr = ptr->next) {
-      UTI_AddDoubleToTimeval(&ptr->tv, -doffset, &ptr->tv);
+      UTI_AddDoubleToTimespec(&ptr->ts, -doffset, &ptr->ts);
    }

    for (i = 0; i < SCH_NumberOfClasses; i++) {
-      UTI_AddDoubleToTimeval(&last_class_dispatch[i], -doffset, &last_class_dispatch[i]);
+      UTI_AddDoubleToTimespec(&last_class_dispatch[i], -doffset, &last_class_dispatch[i]);
    }

-    UTI_AddDoubleToTimeval(&last_select_ts_raw, -doffset, &last_select_ts_raw);
+    UTI_AddDoubleToTimespec(&last_select_ts_raw, -doffset, &last_select_ts_raw);
  }

-  UTI_AdjustTimeval(&last_select_ts, cooked, &last_select_ts, &delta, dfreq, doffset);
+  UTI_AdjustTimespec(&last_select_ts, cooked, &last_select_ts, &delta, dfreq, doffset);
+}
+
+/* ================================================== */
+
+static void
+fill_fd_sets(fd_set **read_fds, fd_set **write_fds, fd_set **except_fds)
+{
+  FileHandlerEntry *handlers;
+  fd_set *rd, *wr, *ex;
+  int i, n, events;
+
+  n = ARR_GetSize(file_handlers);
+  handlers = ARR_GetElements(file_handlers);
+  rd = wr = ex = NULL;
+
+  for (i = 0; i < n; i++) {
+    events = handlers[i].events;
+
+    if (!events)
+      continue;
+
+    if (events & SCH_FILE_INPUT) {
+      if (!rd) {
+        rd = *read_fds;
+        FD_ZERO(rd);
+      }
+      FD_SET(i, rd);
+    }
+
+    if (events & SCH_FILE_OUTPUT) {
+      if (!wr) {
+        wr = *write_fds;
+        FD_ZERO(wr);
+      }
+      FD_SET(i, wr);
+    }
+
+    if (events & SCH_FILE_EXCEPTION) {
+      if (!ex) {
+        ex = *except_fds;
+        FD_ZERO(ex);
+      }
+      FD_SET(i, ex);
+    }
+  }
+
+  if (!rd)
+    *read_fds = NULL;
+  if (!wr)
+    *write_fds = NULL;
+  if (!ex)
+    *except_fds = NULL;
 }

 /* ================================================== */
@@ -551,45 +649,47 @@ handle_slew(struct timeval *raw,
 #define JUMP_DETECT_THRESHOLD 10

 static int
-check_current_time(struct timeval *prev_raw, struct timeval *raw, int timeout,
+check_current_time(struct timespec *prev_raw, struct timespec *raw, int timeout,
                   struct timeval *orig_select_tv,
                   struct timeval *rem_select_tv)
 {
-  struct timeval elapsed_min, elapsed_max;
+  struct timespec elapsed_min, elapsed_max, orig_select_ts, rem_select_ts;
  double step, elapsed;

+  UTI_TimevalToTimespec(orig_select_tv, &orig_select_ts);
+
  /* Get an estimate of the time spent waiting in the select() call. On some
     systems (e.g. Linux) the timeout timeval is modified to return the
     remaining time, use that information. */
  if (timeout) {
-    elapsed_max = elapsed_min = *orig_select_tv;
+    elapsed_max = elapsed_min = orig_select_ts;
  } else if (rem_select_tv && rem_select_tv->tv_sec >= 0 &&
             rem_select_tv->tv_sec <= orig_select_tv->tv_sec &&
             (rem_select_tv->tv_sec != orig_select_tv->tv_sec ||
              rem_select_tv->tv_usec != orig_select_tv->tv_usec)) {
-    UTI_DiffTimevals(&elapsed_min, orig_select_tv, rem_select_tv);
+    UTI_TimevalToTimespec(rem_select_tv, &rem_select_ts);
+    UTI_DiffTimespecs(&elapsed_min, &orig_select_ts, &rem_select_ts);
    elapsed_max = elapsed_min;
  } else {
    if (rem_select_tv)
-      elapsed_max = *orig_select_tv;
+      elapsed_max = orig_select_ts;
    else
-      UTI_DiffTimevals(&elapsed_max, raw, prev_raw);
-    elapsed_min.tv_sec = 0;
-    elapsed_min.tv_usec = 0;
+      UTI_DiffTimespecs(&elapsed_max, raw, prev_raw);
+    UTI_ZeroTimespec(&elapsed_min);
  }

  if (last_select_ts_raw.tv_sec + elapsed_min.tv_sec >
      raw->tv_sec + JUMP_DETECT_THRESHOLD) {
-    LOG(LOGS_WARN, LOGF_Scheduler, "Backward time jump detected!");
+    LOG(LOGS_WARN, "Backward time jump detected!");
  } else if (prev_raw->tv_sec + elapsed_max.tv_sec + JUMP_DETECT_THRESHOLD <
             raw->tv_sec) {
-    LOG(LOGS_WARN, LOGF_Scheduler, "Forward time jump detected!");
+    LOG(LOGS_WARN, "Forward time jump detected!");
  } else {
    return 1;
  }

-  UTI_DiffTimevalsToDouble(&step, &last_select_ts_raw, raw);
-  UTI_TimevalToDouble(&elapsed_min, &elapsed);
+  step = UTI_DiffTimespecsToDouble(&last_select_ts_raw, raw);
+  elapsed = UTI_TimespecToDouble(&elapsed_min);
  step += elapsed;

  /* Cooked time may no longer be valid after dispatching the handlers */
@@ -603,10 +703,11 @@ check_current_time(struct timeval *prev_raw, struct timeval *raw, int timeout,
 void
 SCH_MainLoop(void)
 {
-  fd_set rd;
+  fd_set read_fds, write_fds, except_fds;
+  fd_set *p_read_fds, *p_write_fds, *p_except_fds;
  int status, errsv;
  struct timeval tv, saved_tv, *ptv;
-  struct timeval now, saved_now, cooked;
+  struct timespec ts, now, saved_now, cooked;
  double err;

  assert(initialised);
@@ -622,28 +723,28 @@ SCH_MainLoop(void)

    /* Check whether there is a timeout and set it up */
    if (n_timer_queue_entries > 0) {
+      UTI_DiffTimespecs(&ts, &timer_queue.next->ts, &now);
+      assert(ts.tv_sec > 0 || ts.tv_nsec > 0);

-      UTI_DiffTimevals(&tv, &(timer_queue.next->tv), &now);
+      UTI_TimespecToTimeval(&ts, &tv);
      ptv = &tv;
-      assert(tv.tv_sec > 0 || tv.tv_usec > 0);
      saved_tv = tv;
-
    } else {
      ptv = NULL;
-      /* This is needed to fix a compiler warning */
-      saved_tv.tv_sec = 0;
+      saved_tv.tv_sec = saved_tv.tv_usec = 0;
    }

+    p_read_fds = &read_fds;
+    p_write_fds = &write_fds;
+    p_except_fds = &except_fds;
+    fill_fd_sets(&p_read_fds, &p_write_fds, &p_except_fds);
+
    /* if there are no file descriptors being waited on and no
       timeout set, this is clearly ridiculous, so stop the run */
-    if (!ptv && !n_read_fds) {
-      LOG_FATAL(LOGF_Scheduler, "Nothing to do");
-    }
+    if (!ptv && !p_read_fds && !p_write_fds)
+      LOG_FATAL("Nothing to do");

-    /* Copy current set of read file descriptors */
-    memcpy((void *) &rd, (void *) &read_fds, sizeof(fd_set));
-
-    status = select(one_highest_fd, &rd, NULL, NULL, ptv);
+    status = select(one_highest_fd, p_read_fds, p_write_fds, p_except_fds, ptv);
    errsv = errno;

    LCL_ReadRawTime(&now);
@@ -661,13 +762,11 @@ SCH_MainLoop(void)

    if (status < 0) {
      if (!need_to_exit && errsv != EINTR) {
-        LOG_FATAL(LOGF_Scheduler, "select() failed : %s", strerror(errsv));
+        LOG_FATAL("select() failed : %s", strerror(errsv));
      }
    } else if (status > 0) {
-      /* A file descriptor is ready to read */
-
-      dispatch_filehandlers(status, &rd);
-
+      /* A file descriptor is ready for input or output */
+      dispatch_filehandlers(status, p_read_fds, p_write_fds, p_except_fds);
    } else {
      /* No descriptors readable, timeout must have elapsed.
       Therefore, tv must be non-null */
@@ -686,7 +785,6 @@ SCH_MainLoop(void)
 void
 SCH_QuitProgram(void)
 {
-  assert(initialised);
  need_to_exit = 1;
 }

--- a/sched.h
+++ b/sched.h
@@ -29,7 +29,8 @@

 #include "sysincl.h"

-typedef unsigned long SCH_TimeoutID;
+/* Type for timeout IDs, valid IDs are always greater than zero */
+typedef unsigned int SCH_TimeoutID;

 typedef enum {
  SCH_ReservedTimeoutValue = 0,
@@ -39,7 +40,7 @@ typedef enum {
 } SCH_TimeoutClass;

 typedef void* SCH_ArbitraryArgument;
-typedef void (*SCH_FileHandler)(SCH_ArbitraryArgument);
+typedef void (*SCH_FileHandler)(int fd, int event, SCH_ArbitraryArgument);
 typedef void (*SCH_TimeoutHandler)(SCH_ArbitraryArgument);

 /* Exported functions */
@@ -50,19 +51,21 @@ extern void SCH_Initialise(void);
 /* Finalisation function for the module */
 extern void SCH_Finalise(void);

+/* File events */
+#define SCH_FILE_INPUT 1
+#define SCH_FILE_OUTPUT 2
+#define SCH_FILE_EXCEPTION 4
+
 /* Register a handler for when select goes true on a file descriptor */
-extern void SCH_AddInputFileHandler
-(int fd,                        /* The file descriptor */
- SCH_FileHandler,               /* The handler routine */
- SCH_ArbitraryArgument          /* An arbitrary passthrough argument to the handler */
-);
-extern void SCH_RemoveInputFileHandler(int fd);
+extern void SCH_AddFileHandler(int fd, int events, SCH_FileHandler handler, SCH_ArbitraryArgument arg);
+extern void SCH_RemoveFileHandler(int fd);
+extern void SCH_SetFileHandlerEvents(int fd, int events);

 /* Get the time stamp taken after a file descriptor became ready or a timeout expired */
-extern void SCH_GetLastEventTime(struct timeval *cooked, double *err, struct timeval *raw);
+extern void SCH_GetLastEventTime(struct timespec *cooked, double *err, struct timespec *raw);

 /* This queues a timeout to elapse at a given (raw) local time */
-extern SCH_TimeoutID SCH_AddTimeout(struct timeval *tv, SCH_TimeoutHandler, SCH_ArbitraryArgument);
+extern SCH_TimeoutID SCH_AddTimeout(struct timespec *ts, SCH_TimeoutHandler handler, SCH_ArbitraryArgument arg);

 /* This queues a timeout to elapse at a given delta time relative to the current (raw) time */
 extern SCH_TimeoutID SCH_AddTimeoutByDelay(double delay, SCH_TimeoutHandler, SCH_ArbitraryArgument);
--- a/smooth.c
+++ b/smooth.c
@@ -0,0 +1,361 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2015
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Routines implementing time smoothing.
+
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "conf.h"
+#include "local.h"
+#include "logging.h"
+#include "reference.h"
+#include "smooth.h"
+#include "util.h"
+
+/*
+  Time smoothing determines an offset that needs to be applied to the cooked
+  time to make it smooth for external observers.  Observed offset and frequency
+  change slowly and there are no discontinuities.  This can be used on an NTP
+  server to make it easier for the clients to track the time and keep their
+  clocks close together even when large offset or frequency corrections are
+  applied to the server's clock (e.g. after being offline for longer time).
+
+  Accumulated offset and frequency are smoothed out in three stages.  In the
+  first stage, the frequency is changed at a constant rate (wander) up to a
+  maximum, in the second stage the frequency stays at the maximum for as long
+  as needed and in the third stage the frequency is brought back to zero.
+
+              |
+    max_freq  +-------/--------\-------------
+              |      /|        |\
+        freq  |     / |        | \
+              |    /  |        |  \
+              |   /   |        |   \
+           0  +--/----+--------+----\--------
+              | /     |        |    |    time
+              |/      |        |    |
+
+        stage     1       2      3
+
+  Integral of this function is the smoothed out offset.  It's a continuous
+  piecewise polynomial with two quadratic parts and one linear.
+*/
+
+struct stage {
+  double wander;
+  double length;
+};
+
+#define NUM_STAGES 3
+
+static struct stage stages[NUM_STAGES];
+
+/* Enabled/disabled smoothing */
+static int enabled;
+
+/* Enabled/disabled mode where only leap seconds are smoothed out and normal
+   offset/frequency changes are ignored */
+static int leap_only_mode;
+
+/* Maximum skew/max_wander ratio to start updating offset and frequency */
+#define UNLOCK_SKEW_WANDER_RATIO 10000
+
+static int locked;
+
+/* Maximum wander and frequency offset */
+static double max_wander;
+static double max_freq;
+
+/* Frequency offset, time offset and the time of the last smoothing update */
+static double smooth_freq;
+static double smooth_offset;
+static struct timespec last_update;
+
+
+static void
+get_smoothing(struct timespec *now, double *poffset, double *pfreq,
+              double *pwander)
+{
+  double elapsed, length, offset, freq, wander;
+  int i;
+
+  elapsed = UTI_DiffTimespecsToDouble(now, &last_update);
+
+  offset = smooth_offset;
+  freq = smooth_freq;
+  wander = 0.0;
+
+  for (i = 0; i < NUM_STAGES; i++) {
+    if (elapsed <= 0.0)
+      break;
+
+    length = stages[i].length;
+    if (length >= elapsed)
+      length = elapsed;
+
+    wander = stages[i].wander;
+    offset -= length * (2.0 * freq + wander * length) / 2.0;
+    freq += wander * length;
+    elapsed -= length;
+  }
+
+  if (elapsed > 0.0) {
+    wander = 0.0;
+    offset -= elapsed * freq;
+  }
+
+  *poffset = offset;
+  *pfreq = freq;
+  if (pwander)
+    *pwander = wander;
+}
+
+static void
+update_stages(void)
+{
+  double s1, s2, s, l1, l2, l3, lc, f, f2, l1t[2], l3t[2], err[2];
+  int i, dir;
+
+  /* Prepare the three stages so that the integral of the frequency offset
+     is equal to the offset that should be smoothed out */
+
+  s1 = smooth_offset / max_wander;
+  s2 = smooth_freq * smooth_freq / (2.0 * max_wander * max_wander);
+  
+  /* Calculate the lengths of the 1st and 3rd stage assuming there is no
+     frequency limit.  The direction of the 1st stage is selected so that
+     the lengths will not be negative.  With extremely small offsets both
+     directions may give a negative length due to numerical errors, so select
+     the one which gives a smaller error. */
+
+  for (i = 0, dir = -1; i <= 1; i++, dir += 2) {
+    err[i] = 0.0;
+    s = dir * s1 + s2;
+
+    if (s < 0.0) {
+      err[i] += -s;
+      s = 0.0;
+    }
+
+    l3t[i] = sqrt(s);
+    l1t[i] = l3t[i] - dir * smooth_freq / max_wander;
+
+    if (l1t[i] < 0.0) {
+      err[i] += l1t[i] * l1t[i];
+      l1t[i] = 0.0;
+    }
+  }
+
+  if (err[0] < err[1]) {
+    l1 = l1t[0];
+    l3 = l3t[0];
+    dir = -1;
+  } else {
+    l1 = l1t[1];
+    l3 = l3t[1];
+    dir = 1;
+  }
+
+  l2 = 0.0;
+
+  /* If the limit was reached, shorten 1st+3rd stages and set a 2nd stage */
+  f = dir * smooth_freq + l1 * max_wander - max_freq;
+  if (f > 0.0) {
+    lc = f / max_wander;
+
+    /* No 1st stage if the frequency is already above the maximum */
+    if (lc > l1) {
+      lc = l1;
+      f2 = dir * smooth_freq;
+    } else {
+      f2 = max_freq;
+    }
+
+    l2 = lc * (2.0 + f / f2);
+    l1 -= lc;
+    l3 -= lc;
+  }
+
+  stages[0].wander = dir * max_wander;
+  stages[0].length = l1;
+  stages[1].wander = 0.0;
+  stages[1].length = l2;
+  stages[2].wander = -dir * max_wander;
+  stages[2].length = l3;
+
+  for (i = 0; i < NUM_STAGES; i++) {
+    DEBUG_LOG("Smooth stage %d wander %e length %f",
+              i + 1, stages[i].wander, stages[i].length);
+  }
+}
+
+static void
+update_smoothing(struct timespec *now, double offset, double freq)
+{
+  /* Don't accept offset/frequency until the clock has stabilized */
+  if (locked) {
+    if (REF_GetSkew() / max_wander < UNLOCK_SKEW_WANDER_RATIO || leap_only_mode)
+      SMT_Activate(now);
+    return;
+  }
+
+  get_smoothing(now, &smooth_offset, &smooth_freq, NULL);
+  smooth_offset += offset;
+  smooth_freq = (smooth_freq - freq) / (1.0 - freq);
+  last_update = *now;
+
+  update_stages();
+
+  DEBUG_LOG("Smooth offset %e freq %e", smooth_offset, smooth_freq);
+}
+
+static void
+handle_slew(struct timespec *raw, struct timespec *cooked, double dfreq,
+            double doffset, LCL_ChangeType change_type, void *anything)
+{
+  double delta;
+
+  if (change_type == LCL_ChangeAdjust) {
+    if (leap_only_mode)
+      update_smoothing(cooked, 0.0, 0.0);
+    else
+      update_smoothing(cooked, doffset, dfreq);
+  }
+
+  UTI_AdjustTimespec(&last_update, cooked, &last_update, &delta, dfreq, doffset);
+}
+
+void SMT_Initialise(void)
+{
+  CNF_GetSmooth(&max_freq, &max_wander, &leap_only_mode);
+  if (max_freq <= 0.0 || max_wander <= 0.0) {
+      enabled = 0;
+      return;
+  }
+
+  enabled = 1;
+  locked = 1;
+
+  /* Convert from ppm */
+  max_freq *= 1e-6;
+  max_wander *= 1e-6;
+
+  LCL_AddParameterChangeHandler(handle_slew, NULL);
+}
+
+void SMT_Finalise(void)
+{
+}
+
+int SMT_IsEnabled(void)
+{
+  return enabled;
+}
+
+double
+SMT_GetOffset(struct timespec *now)
+{
+  double offset, freq;
+
+  if (!enabled)
+    return 0.0;
+  
+  get_smoothing(now, &offset, &freq, NULL);
+
+  return offset;
+}
+
+void
+SMT_Activate(struct timespec *now)
+{
+  if (!enabled || !locked)
+    return;
+
+  LOG(LOGS_INFO, "Time smoothing activated%s", leap_only_mode ?
+      " (leap seconds only)" : "");
+  locked = 0;
+  last_update = *now;
+}
+
+void
+SMT_Reset(struct timespec *now)
+{
+  int i;
+
+  if (!enabled)
+    return;
+
+  smooth_offset = 0.0;
+  smooth_freq = 0.0;
+  last_update = *now;
+
+  for (i = 0; i < NUM_STAGES; i++)
+    stages[i].wander = stages[i].length = 0.0;
+}
+
+void
+SMT_Leap(struct timespec *now, int leap)
+{
+  /* When the leap-only mode is disabled, the leap second will be accumulated
+     in handle_slew() as a normal offset */
+  if (!enabled || !leap_only_mode)
+    return;
+
+  update_smoothing(now, leap, 0.0);
+}
+
+int
+SMT_GetSmoothingReport(RPT_SmoothingReport *report, struct timespec *now)
+{
+  double length, elapsed;
+  int i;
+
+  if (!enabled)
+    return 0;
+
+  report->active = !locked;
+  report->leap_only = leap_only_mode;
+
+  get_smoothing(now, &report->offset, &report->freq_ppm, &report->wander_ppm);
+
+  /* Convert to ppm and negate (positive values mean faster/speeding up) */
+  report->freq_ppm *= -1.0e6;
+  report->wander_ppm *= -1.0e6;
+
+  elapsed = UTI_DiffTimespecsToDouble(now, &last_update);
+  if (!locked && elapsed >= 0.0) {
+    for (i = 0, length = 0.0; i < NUM_STAGES; i++)
+      length += stages[i].length;
+    report->last_update_ago = elapsed;
+    report->remaining_time = elapsed < length ? length - elapsed : 0.0;
+  } else {
+    report->last_update_ago = 0.0;
+    report->remaining_time = 0.0;
+  }
+
+  return 1;
+}
--- a/wrap_adjtimex.h
+++ b/wrap_adjtimex.h
@@ -2,7 +2,7 @@
  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************
- * Copyright (C) Richard P. Curnow  1997-2002
+ * Copyright (C) Miroslav Lichvar  2015
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -21,19 +21,28 @@

  =======================================================================

-  The header file for the adjtimex wrapper
+  This module implements time smoothing.
  */

-#ifndef GOT_WRAP_ADJTIMEX_H
-#define GOT_WRAP_ADJTIMEX_H
+#ifndef GOT_SMOOTH_H
+#define GOT_SMOOTH_H

-int TMX_ResetOffset(void);
-int TMX_SetFrequency(double *freq, long tick);
-int TMX_GetFrequency(double *freq, long *tick);
-int TMX_SetLeap(int leap);
-int TMX_SetSync(int sync, double est_error, double max_error);
-int TMX_TestStepOffset(void);
-int TMX_ApplyStepOffset(double offset);
+#include "reports.h"

-#endif  /* GOT_WRAP_ADJTIMEX_H */
+extern void SMT_Initialise(void);

+extern void SMT_Finalise(void);
+
+extern int SMT_IsEnabled(void);
+
+extern double SMT_GetOffset(struct timespec *now);
+
+extern void SMT_Activate(struct timespec *now);
+
+extern void SMT_Reset(struct timespec *now);
+
+extern void SMT_Leap(struct timespec *now, int leap);
+
+extern int SMT_GetSmoothingReport(RPT_SmoothingReport *report, struct timespec *now);
+
+#endif
--- a/sources.c
+++ b/sources.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2014
+ * Copyright (C) Miroslav Lichvar  2011-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -44,7 +44,6 @@
 #include "logging.h"
 #include "reports.h"
 #include "nameserv.h"
-#include "mkdirpp.h"
 #include "sched.h"
 #include "regress.h"

@@ -57,7 +56,7 @@ static int initialised = 0;
 struct SelectInfo {
  int stratum;
  int select_ok;
-  double variance;
+  double std_dev;
  double root_distance;
  double lo_limit;
  double hi_limit;
@@ -71,10 +70,13 @@ typedef enum {
  SRC_OK,               /* OK so far, not a final status! */
  SRC_UNSELECTABLE,     /* Has noselect option set */
  SRC_BAD_STATS,        /* Doesn't have valid stats data */
+  SRC_BAD_DISTANCE,     /* Has root distance longer than allowed maximum */
+  SRC_JITTERY,          /* Had std dev larger than allowed maximum */
  SRC_WAITS_STATS,      /* Others have bad stats, selection postponed */
  SRC_STALE,            /* Has older samples than others */
+  SRC_ORPHAN,           /* Has stratum equal or larger than orphan stratum */
+  SRC_UNTRUSTED,        /* Overlaps trusted sources */
  SRC_FALSETICKER,      /* Doesn't agree with others */
-  SRC_JITTERY,          /* Scatter worse than other's dispersion (not used) */
  SRC_WAITS_SOURCES,    /* Not enough sources, selection postponed */
  SRC_NONPREFERRED,     /* Others have prefer option */
  SRC_WAITS_UPDATE,     /* No updates, selection postponed */
@@ -118,7 +120,7 @@ struct SRC_Instance_Record {
  SRC_Type type;

  /* Options used when selecting sources */ 
-  SRC_SelectOption sel_option;
+  int sel_options;

  /* Score against currently selected source */
  double sel_score;
@@ -156,6 +158,8 @@ static int selected_source_index; /* Which source index is currently
 /* Number of updates needed to reset the distant status */
 #define DISTANT_PENALTY 32

+static double max_distance;
+static double max_jitter;
 static double reselect_distance;
 static double stratum_weight;
 static double combine_limit;
@@ -164,7 +168,7 @@ static double combine_limit;
 /* Forward prototype */

 static void
-slew_sources(struct timeval *raw, struct timeval *cooked, double dfreq,
+slew_sources(struct timespec *raw, struct timespec *cooked, double dfreq,
             double doffset, LCL_ChangeType change_type, void *anything);
 static void
 add_dispersion(double dispersion, void *anything);
@@ -180,6 +184,8 @@ void SRC_Initialise(void) {
  n_sources = 0;
  max_n_sources = 0;
  selected_source_index = INVALID_SOURCE;
+  max_distance = CNF_GetMaxDistance();
+  max_jitter = CNF_GetMaxJitter();
  reselect_distance = CNF_GetReselectDistance();
  stratum_weight = CNF_GetStratumWeight();
  combine_limit = CNF_GetCombineLimit();
@@ -207,7 +213,7 @@ void SRC_Finalise(void)
 /* Function to create a new instance.  This would be called by one of
   the individual source-type instance creation routines. */

-SRC_Instance SRC_CreateNewInstance(uint32_t ref_id, SRC_Type type, SRC_SelectOption sel_option, IPAddr *addr, int min_samples, int max_samples)
+SRC_Instance SRC_CreateNewInstance(uint32_t ref_id, SRC_Type type, int sel_options, IPAddr *addr, int min_samples, int max_samples)
 {
  SRC_Instance result;

@@ -239,7 +245,7 @@ SRC_Instance SRC_CreateNewInstance(uint32_t ref_id, SRC_Type type, SRC_SelectOpt

  result->index = n_sources;
  result->type = type;
-  result->sel_option = sel_option;
+  result->sel_options = sel_options;

  SRC_SetRefid(result, ref_id, addr);
  SRC_ResetInstance(result);
@@ -305,22 +311,12 @@ SRC_SetRefid(SRC_Instance instance, uint32_t ref_id, IPAddr *addr)
 }

 /* ================================================== */
-/* Function to get the range of frequencies, relative to the given
-   source, that we believe the local clock lies within.  The return
-   values are in terms of the number of seconds fast (+ve) or slow
-   (-ve) relative to the source that the local clock becomes after a
-   given amount of local time has elapsed.

-   Suppose the initial offset relative to the source is U (fast +ve,
-   slow -ve) and a time interval T elapses measured in terms of the
-   local clock.  Then the error relative to the source at the end of
-   the interval should lie in the interval [U+T*lo, U+T*hi]. */
-
-void SRC_GetFrequencyRange(SRC_Instance instance, double *lo, double *hi)
+SST_Stats
+SRC_GetSourcestats(SRC_Instance instance)
 {
  assert(initialised);
-
-  SST_GetFrequencyRange(instance->stats, lo, hi);
+  return instance->stats;
 }

 /* ================================================== */
@@ -338,7 +334,7 @@ void SRC_GetFrequencyRange(SRC_Instance instance, double *lo, double *hi)

 void SRC_AccumulateSample
 (SRC_Instance inst, 
- struct timeval *sample_time, 
+ struct timespec *sample_time,
 double offset, 
 double peer_delay,
 double peer_dispersion,
@@ -352,11 +348,12 @@ void SRC_AccumulateSample

  inst->leap_status = leap_status;

-  DEBUG_LOG(LOGF_Sources, "ip=[%s] t=%s ofs=%f del=%f disp=%f str=%d",
-      source_to_string(inst), UTI_TimevalToString(sample_time), -offset, root_delay, root_dispersion, stratum);
+  DEBUG_LOG("ip=[%s] t=%s ofs=%f del=%f disp=%f str=%d",
+            source_to_string(inst), UTI_TimespecToString(sample_time), -offset,
+            root_delay, root_dispersion, stratum);

  if (REF_IsLeapSecondClose()) {
-    LOG(LOGS_INFO, LOGF_Sources, "Dropping sample around leap second");
+    LOG(LOGS_INFO, "Dropping sample around leap second");
    return;
  }

@@ -400,7 +397,7 @@ special_mode_end(void)

      /* Check if the source could still have enough samples to be selectable */
      if (SOURCE_REACH_BITS - 1 - sources[i]->reachability_size +
-            SRC_Samples(sources[i]) >= MIN_SAMPLES_FOR_REGRESS)
+            SST_Samples(sources[i]->stats) >= MIN_SAMPLES_FOR_REGRESS)
        return 0;
    }

@@ -412,7 +409,7 @@ SRC_UpdateReachability(SRC_Instance inst, int reachable)
 {
  inst->reachability <<= 1;
  inst->reachability |= !!reachable;
-  inst->reachability &= ~(-1 << SOURCE_REACH_BITS);
+  inst->reachability %= 1U << SOURCE_REACH_BITS;

  if (inst->reachability_size < SOURCE_REACH_BITS)
      inst->reachability_size++;
@@ -427,9 +424,12 @@ SRC_UpdateReachability(SRC_Instance inst, int reachable)
    REF_SetUnsynchronised();
  }

-  /* Try to replace NTP sources that are unreachable or falsetickers */
-  if (inst->type == SRC_NTP && (inst->status == SRC_FALSETICKER ||
-      (!inst->reachability && inst->reachability_size == SOURCE_REACH_BITS))) {
+  /* Try to replace NTP sources that are unreachable, falsetickers, or
+     have root distance or jitter larger than the allowed maximums */
+  if (inst->type == SRC_NTP &&
+      ((!inst->reachability && inst->reachability_size == SOURCE_REACH_BITS) ||
+       inst->status == SRC_BAD_DISTANCE || inst->status == SRC_JITTERY ||
+       inst->status == SRC_FALSETICKER)) {
    NSR_HandleBadSource(inst->ip_addr);
  }
 }
@@ -451,7 +451,7 @@ log_selection_message(char *format, char *arg)
 {
  if (REF_GetMode() != REF_ModeNormal)
    return;
-  LOG(LOGS_INFO, LOGF_Sources, format, arg);
+  LOG(LOGS_INFO, format, arg);
 }

 /* ================================================== */
@@ -508,12 +508,12 @@ mark_ok_sources(SRC_Status status)
 /* ================================================== */

 static int
-combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
+combine_sources(int n_sel_sources, struct timespec *ref_time, double *offset,
                double *offset_sd, double *frequency, double *skew)
 {
-  struct timeval src_ref_time;
+  struct timespec src_ref_time;
  double src_offset, src_offset_sd, src_frequency, src_skew;
-  double src_root_delay, src_root_dispersion, elapsed;
+  double src_root_delay, src_root_dispersion, sel_src_distance, elapsed;
  double offset_weight, sum_offset_weight, sum_offset, sum2_offset_sd;
  double frequency_weight, sum_frequency_weight, sum_frequency, inv_sum2_skew;
  int i, index, combined;
@@ -524,6 +524,10 @@ combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
  sum_offset_weight = sum_offset = sum2_offset_sd = 0.0;
  sum_frequency_weight = sum_frequency = inv_sum2_skew = 0.0;

+  sel_src_distance = sources[selected_source_index]->sel_info.root_distance;
+  if (sources[selected_source_index]->type == SRC_NTP)
+    sel_src_distance += reselect_distance;
+
  for (i = combined = 0; i < n_sel_sources; i++) {
    index = sel_sources[i];
    SST_GetTrackingData(sources[index]->stats, &src_ref_time,
@@ -536,8 +540,7 @@ combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
       are not close, or it was recently marked as distant */

    if (index != selected_source_index &&
-        (sources[index]->sel_info.root_distance > combine_limit *
-           (reselect_distance + sources[selected_source_index]->sel_info.root_distance) ||
+        (sources[index]->sel_info.root_distance > combine_limit * sel_src_distance ||
         fabs(*frequency - src_frequency) >
           combine_limit * (*skew + src_skew + LCL_GetMaxClockError()))) {
      /* Use a smaller penalty in first few updates */
@@ -555,12 +558,12 @@ combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
    if (sources[index]->status == SRC_OK)
      sources[index]->status = SRC_UNSELECTED;

-    UTI_DiffTimevalsToDouble(&elapsed, ref_time, &src_ref_time);
+    elapsed = UTI_DiffTimespecsToDouble(ref_time, &src_ref_time);
    src_offset += elapsed * src_frequency;
    offset_weight = 1.0 / sources[index]->sel_info.root_distance;
    frequency_weight = 1.0 / src_skew;

-    DEBUG_LOG(LOGF_Sources, "combining index=%d oweight=%e offset=%e sd=%e fweight=%e freq=%e skew=%e",
+    DEBUG_LOG("combining index=%d oweight=%e offset=%e sd=%e fweight=%e freq=%e skew=%e",
        index, offset_weight, src_offset, src_offset_sd, frequency_weight, src_frequency, src_skew);

    sum_offset_weight += offset_weight;
@@ -581,7 +584,7 @@ combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
  *frequency = sum_frequency / sum_frequency_weight;
  *skew = 1.0 / sqrt(inv_sum2_skew);

-  DEBUG_LOG(LOGF_Sources, "combined result offset=%e sd=%e freq=%e skew=%e",
+  DEBUG_LOG("combined result offset=%e sd=%e freq=%e skew=%e",
      *offset, *offset_sd, *frequency, *skew);

  return combined;
@@ -595,10 +598,12 @@ void
 SRC_SelectSource(SRC_Instance updated_inst)
 {
  struct SelectInfo *si;
-  struct timeval now, ref_time;
+  struct timespec now, ref_time;
  int i, j, j1, j2, index, sel_prefer, n_endpoints, n_sel_sources;
-  int n_badstats_sources, max_sel_reach, max_badstat_reach;
-  int depth, best_depth, combined, stratum, min_stratum, max_score_index;
+  int n_badstats_sources, max_sel_reach, max_badstat_reach, sel_req_source;
+  int depth, best_depth, trust_depth, best_trust_depth;
+  int combined, stratum, min_stratum, max_score_index;
+  int orphan_stratum, orphan_source, leap_votes, leap_ins, leap_del;
  double src_offset, src_offset_sd, src_frequency, src_skew;
  double src_root_delay, src_root_dispersion;
  double best_lo, best_hi, distance, sel_src_distance, max_score;
@@ -625,14 +630,20 @@ SRC_SelectSource(SRC_Instance updated_inst)
  n_endpoints = 0;
  n_sel_sources = 0;
  n_badstats_sources = 0;
+  sel_req_source = 0;
  max_sel_reach = max_badstat_reach = 0;
  max_reach_sample_ago = 0.0;

  for (i = 0; i < n_sources; i++) {
    assert(sources[i]->status != SRC_OK);

+    /* If some sources are specified with the require option, at least one
+       of them will have to be selectable in order to update the clock */
+    if (sources[i]->sel_options & SRC_SELECT_REQUIRE)
+      sel_req_source = 1;
+
    /* Ignore sources which were added with the noselect option */
-    if (sources[i]->sel_option == SRC_SelectNoselect) {
+    if (sources[i]->sel_options & SRC_SELECT_NOSELECT) {
      sources[i]->status = SRC_UNSELECTABLE;
      continue;
    }
@@ -640,7 +651,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
    si = &sources[i]->sel_info;
    SST_GetSelectionData(sources[i]->stats, &now, &si->stratum,
                         &si->lo_limit, &si->hi_limit, &si->root_distance,
-                         &si->variance, &first_sample_ago,
+                         &si->std_dev, &first_sample_ago,
                         &si->last_sample_ago, &si->select_ok);

    if (!si->select_ok) {
@@ -651,6 +662,18 @@ SRC_SelectSource(SRC_Instance updated_inst)
      continue;
    }

+    /* Require the root distance to be below the allowed maximum */
+    if (si->root_distance > max_distance) {
+      sources[i]->status = SRC_BAD_DISTANCE;
+      continue;
+    }
+
+    /* And the same applies for the estimated standard deviation */
+    if (si->std_dev > max_jitter) {
+      sources[i]->status = SRC_JITTERY;
+      continue;
+    }
+
    sources[i]->status = SRC_OK; /* For now */

    if (sources[i]->reachability && max_reach_sample_ago < first_sample_ago)
@@ -660,6 +683,9 @@ SRC_SelectSource(SRC_Instance updated_inst)
      max_sel_reach = sources[i]->reachability;
  }

+  orphan_stratum = REF_GetOrphanStratum();
+  orphan_source = INVALID_SOURCE;
+
  for (i = 0; i < n_sources; i++) {
    if (sources[i]->status != SRC_OK)
      continue;
@@ -674,7 +700,55 @@ SRC_SelectSource(SRC_Instance updated_inst)
      continue;
    }

+    /* When the local reference is configured with the orphan option, NTP
+       sources that have stratum equal to the configured local stratum are
+       considered to be orphans (i.e. serving local time while not being
+       synchronised with real time) and are excluded from the normal source
+       selection.  Sources with stratum larger than the local stratum are
+       considered to be directly on indirectly synchronised to an orphan and
+       are always ignored.
+
+       If no selectable source is available and all orphan sources have
+       reference IDs larger than the local ID, no source will be selected and
+       the local reference mode will be activated at some point, i.e. this host
+       will become an orphan.  Otherwise, the orphan source with the smallest
+       reference ID will be selected.  This ensures a group of servers polling
+       each other (with the same orphan configuration) which have no external
+       source can settle down to a state where only one server is serving its
+       local unsychronised time and others are synchronised to it. */
+
+    if (si->stratum >= orphan_stratum && sources[i]->type == SRC_NTP) {
+      sources[i]->status = SRC_ORPHAN;
+
+      if (si->stratum == orphan_stratum && sources[i]->reachability &&
+          (orphan_source == INVALID_SOURCE ||
+           sources[i]->ref_id < sources[orphan_source]->ref_id))
+        orphan_source = i;
+
+      continue;
+    }
+
    ++n_sel_sources;
+  }
+
+  /* If no selectable source is available, consider the orphan source */
+  if (!n_sel_sources && orphan_source != INVALID_SOURCE) {
+    uint32_t local_ref_id = NSR_GetLocalRefid(sources[orphan_source]->ip_addr);
+
+    if (!local_ref_id) {
+      LOG(LOGS_ERR, "Unknown local refid in orphan mode");
+    } else if (sources[orphan_source]->ref_id < local_ref_id) {
+      sources[orphan_source]->status = SRC_OK;
+      n_sel_sources = 1;
+      DEBUG_LOG("selecting orphan refid=%"PRIx32, sources[orphan_source]->ref_id);
+    }
+  }
+
+  for (i = 0; i < n_sources; i++) {
+    if (sources[i]->status != SRC_OK)
+      continue;
+
+    si = &sources[i]->sel_info;

    j1 = n_endpoints;
    j2 = j1 + 1;
@@ -690,7 +764,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
    n_endpoints += 2;
  }

-  DEBUG_LOG(LOGF_Sources, "badstat=%d sel=%d badstat_reach=%x sel_reach=%x max_reach_ago=%f",
+  DEBUG_LOG("badstat=%d sel=%d badstat_reach=%x sel_reach=%x max_reach_ago=%f",
            n_badstats_sources, n_sel_sources, max_badstat_reach,
            max_sel_reach, max_reach_sample_ago);

@@ -730,6 +804,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
         <===========>

     we will build the interval as shown with '=', whereas with an extra source we get
+
     <----------------------->
        <------->
         <-->
@@ -739,8 +814,12 @@ SRC_SelectSource(SRC_Instance updated_inst)
     The first case is just bad luck - we need extra sources to
     detect the falseticker, so just make an arbitrary choice based
     on stratum & stability etc.
+
+     Intervals from sources specified with the trust option have higher
+     priority in the search.
     */

+  trust_depth = best_trust_depth = 0;
  depth = best_depth = 0;
  best_lo = best_hi = 0.0;

@@ -748,14 +827,20 @@ SRC_SelectSource(SRC_Instance updated_inst)
    switch (sort_list[i].tag) {
      case LOW:
        depth++;
-        if (depth > best_depth) {
+        if (sources[sort_list[i].index]->sel_options & SRC_SELECT_TRUST)
+          trust_depth++;
+        if (trust_depth > best_trust_depth ||
+            (trust_depth == best_trust_depth && depth > best_depth)) {
+          best_trust_depth = trust_depth;
          best_depth = depth;
          best_lo = sort_list[i].offset;
        }
        break;
      case HIGH:
-        if (depth == best_depth)
+        if (trust_depth == best_trust_depth && depth == best_depth)
          best_hi = sort_list[i].offset;
+        if (sources[sort_list[i].index]->sel_options & SRC_SELECT_TRUST)
+          trust_depth--;
        depth--;
        break;
      default:
@@ -763,9 +848,9 @@ SRC_SelectSource(SRC_Instance updated_inst)
    }
  }

-  if (best_depth <= n_sel_sources / 2) {
-    /* Could not even get half the reachable sources to agree -
-       clearly we can't synchronise. */
+  if (best_depth <= n_sel_sources / 2 && !best_trust_depth) {
+    /* Could not even get half the reachable sources to agree and there
+       are no trusted sources - clearly we can't synchronise */

    if (selected_source_index != INVALID_SOURCE) {
      log_selection_message("Can't synchronise: no majority", NULL);
@@ -786,99 +871,78 @@ SRC_SelectSource(SRC_Instance updated_inst)
  n_sel_sources = 0;

  for (i = 0; i < n_sources; i++) {
+    /* This should be the same condition to get into the endpoint
+       list */
    if (sources[i]->status != SRC_OK)
      continue;

-    /* This should be the same condition to get into the endpoint
-       list */
-    /* Check if source's interval contains the best interval, or
-       is wholly contained within it */
-    if ((sources[i]->sel_info.lo_limit <= best_lo &&
+    /* Check if source's interval contains the best interval, or is wholly
+       contained within it.  If there are any trusted sources the first
+       condition is applied only to them to not allow non-trusted sources to
+       move the final offset outside the interval. */
+    if (((!best_trust_depth || sources[i]->sel_options & SRC_SELECT_TRUST) &&
+         sources[i]->sel_info.lo_limit <= best_lo &&
         sources[i]->sel_info.hi_limit >= best_hi) ||
        (sources[i]->sel_info.lo_limit >= best_lo &&
         sources[i]->sel_info.hi_limit <= best_hi)) {

      sel_sources[n_sel_sources++] = i;
+
+      if (sources[i]->sel_options & SRC_SELECT_REQUIRE)
+        sel_req_source = 0;
+    } else if (sources[i]->sel_info.lo_limit <= best_lo &&
+               sources[i]->sel_info.hi_limit >= best_hi) {
+      sources[i]->status = SRC_UNTRUSTED;
    } else {
      sources[i]->status = SRC_FALSETICKER;
    }
  }

-#if 0
-  /* We now have a list of indices for the sources which pass the
-     false-ticker test.  Now go on to reject those whose variance is
-     greater than the minimum distance of any other */
-
-  /* Find minimum distance */
-  index = sel_sources[0];
-  min_distance = sources[index]->sel_info.root_distance;
-  for (i = 1; i < n_sel_sources; i++) {
-    index = sel_sources[i];
-    distance = sources[index]->sel_info.root_distance;
-    if (distance < min_distance) {
-      min_distance = distance;
-    }
-  }
-
-  /* Now go through and prune any NTP sources that have excessive
-     variance */
-  for (i = 0; i < n_sel_sources; i++) {
-    index = sel_sources[i];
-    if (sources[index]->type == SRC_NTP &&
-        sqrt(sources[index]->sel_info.variance) > min_distance) {
-      sel_sources[i] = INVALID_SOURCE;
-      sources[index]->status = SRC_JITTERY;
-    }
-  }
-
-  /* Now crunch the list and mark all sources as selectable */
-  for (i = j = 0; i < n_sel_sources; i++) {
-    index = sel_sources[i];
-    if (index == INVALID_SOURCE)
-      continue;
-    sel_sources[j++] = index;
-  }
-  n_sel_sources = j;
-#endif
-
-  if (n_sel_sources == 0 || n_sel_sources < CNF_GetMinSources()) {
+  if (!n_sel_sources || sel_req_source || n_sel_sources < CNF_GetMinSources()) {
    if (selected_source_index != INVALID_SOURCE) {
      log_selection_message("Can't synchronise: %s selectable sources",
-                            n_sel_sources ? "not enough" : "no");
+                            !n_sel_sources ? "no" :
+                            sel_req_source ? "no required source in" : "not enough");
      selected_source_index = INVALID_SOURCE;
    }
    mark_ok_sources(SRC_WAITS_SOURCES);
    return;
  }

-  /* Accept leap second status if more than half of selectable sources agree */
-  for (i = j1 = j2 = 0; i < n_sel_sources; i++) {
+  /* Accept leap second status if more than half of selectable (and trusted
+     if there are any) sources agree */
+  for (i = leap_ins = leap_del = leap_votes = 0; i < n_sel_sources; i++) {
    index = sel_sources[i];
+    if (best_trust_depth && !(sources[index]->sel_options & SRC_SELECT_TRUST))
+      continue;
+    leap_votes++;
    if (sources[index]->leap_status == LEAP_InsertSecond)
-      j1++;
+      leap_ins++;
    else if (sources[index]->leap_status == LEAP_DeleteSecond)
-      j2++;
+      leap_del++;
  }

-  if (j1 > n_sel_sources / 2)
+  if (leap_ins > leap_votes / 2)
    leap_status = LEAP_InsertSecond;
-  else if (j2 > n_sel_sources / 2)
+  else if (leap_del > leap_votes / 2)
    leap_status = LEAP_DeleteSecond;
  else
    leap_status = LEAP_Normal;

  /* If there are any sources with prefer option, reduce the list again
     only to the preferred sources */
+  for (i = 0; i < n_sel_sources; i++) {
+    if (sources[sel_sources[i]]->sel_options & SRC_SELECT_PREFER)
+      break;
+  }
+  if (i < n_sel_sources) {
    for (i = j = 0; i < n_sel_sources; i++) {
-    if (sources[sel_sources[i]]->sel_option == SRC_SelectPrefer)
+      if (!(sources[sel_sources[i]]->sel_options & SRC_SELECT_PREFER))
+        sources[sel_sources[i]]->status = SRC_NONPREFERRED;
+      else
        sel_sources[j++] = sel_sources[i];
    }
-
-  if (j > 0) {
-    for (i = 0; i < n_sel_sources; i++) {
-      if (sources[sel_sources[i]]->sel_option != SRC_SelectPrefer)
-        sources[sel_sources[i]]->status = SRC_NONPREFERRED;
-    }
+    assert(j > 0);
    n_sel_sources = j;
    sel_prefer = 1;
  } else {
@@ -909,7 +973,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
  for (i = 0; i < n_sources; i++) {
    /* Reset score for non-selectable sources */
    if (sources[i]->status != SRC_OK ||
-        (sel_prefer && sources[i]->sel_option != SRC_SelectPrefer)) {
+        (sel_prefer && !(sources[i]->sel_options & SRC_SELECT_PREFER))) {
      sources[i]->sel_score = 1.0;
      sources[i]->distant = DISTANT_PENALTY;
      continue;
@@ -938,7 +1002,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
      sources[i]->sel_score = 1.0 / distance;
    }

-    DEBUG_LOG(LOGF_Sources, "select score=%f refid=%"PRIx32" match_refid=%"PRIx32" status=%d dist=%f",
+    DEBUG_LOG("select score=%f refid=%"PRIx32" match_refid=%"PRIx32" status=%d dist=%f",
              sources[i]->sel_score, sources[i]->ref_id,
              updated_inst ? updated_inst->ref_id : 0,
              sources[i]->status, distance);
@@ -962,7 +1026,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
    if (sources[max_score_index]->updates == 0) {
      selected_source_index = INVALID_SOURCE;
      mark_ok_sources(SRC_WAITS_UPDATE);
-      DEBUG_LOG(LOGF_Sources, "best source has no updates");
+      DEBUG_LOG("best source has no updates");
      return;
    }

@@ -1033,36 +1097,10 @@ SRC_SetReselectDistance(double distance)
 {
  if (reselect_distance != distance) {
    reselect_distance = distance;
-    LOG(LOGS_INFO, LOGF_Sources, "New reselect distance %f", distance);
+    LOG(LOGS_INFO, "New reselect distance %f", distance);
  }
 }

-/* ================================================== */
-
-double
-SRC_PredictOffset(SRC_Instance inst, struct timeval *when)
-{
-  return SST_PredictOffset(inst->stats, when);
-}
-
-/* ================================================== */
-
-double
-SRC_MinRoundTripDelay(SRC_Instance inst)
-{
-  return SST_MinRoundTripDelay(inst->stats);
-}
-
-/* ================================================== */
-
-int
-SRC_IsGoodSample(SRC_Instance inst, double offset, double delay,
-   double max_delay_dev_ratio, double clock_error, struct timeval *when)
-{
-  return SST_IsGoodSample(inst->stats, offset, delay, max_delay_dev_ratio,
-      clock_error, when);
-}
-
 /* ================================================== */
 /* This routine is registered as a callback with the local clock
   module, to be called whenever the local clock changes frequency or
@@ -1071,12 +1109,8 @@ SRC_IsGoodSample(SRC_Instance inst, double offset, double delay,
   the new regime. */

 static void
-slew_sources(struct timeval *raw,
-             struct timeval *cooked,
-             double dfreq,
-             double doffset,
-             LCL_ChangeType change_type,
-             void *anything)
+slew_sources(struct timespec *raw, struct timespec *cooked, double dfreq,
+             double doffset, LCL_ChangeType change_type, void *anything)
 {
  int i;

@@ -1108,6 +1142,39 @@ add_dispersion(double dispersion, void *anything)
  }
 }

+/* ================================================== */
+
+static
+FILE *open_dumpfile(SRC_Instance inst, const char *mode)
+{
+  FILE *f;
+  char filename[1024], *dumpdir;
+
+  dumpdir = CNF_GetDumpDir();
+  if (dumpdir[0] == '\0') {
+    LOG(LOGS_WARN, "dumpdir not specified");
+    return NULL;
+  }
+
+  /* Include IP address in the name for NTP sources, or reference ID in hex */
+  if ((inst->type == SRC_NTP &&
+       snprintf(filename, sizeof (filename), "%s/%s.dat", dumpdir,
+                source_to_string(inst)) >= sizeof (filename)) ||
+      (inst->type != SRC_NTP &&
+       snprintf(filename, sizeof (filename), "%s/refid:%08"PRIx32".dat",
+                dumpdir, inst->ref_id) >= sizeof (filename))) {
+    LOG(LOGS_WARN, "dumpdir too long");
+    return NULL;
+  }
+
+  f = fopen(filename, mode);
+  if (!f && mode[0] != 'r')
+    LOG(LOGS_WARN, "Could not open dump file for %s",
+        source_to_string(inst));
+
+  return f;
+}
+
 /* ================================================== */
 /* This is called to dump out the source measurement registers */

@@ -1115,37 +1182,16 @@ void
 SRC_DumpSources(void)
 {
  FILE *out;
-  int direc_len, file_len;
-  char *filename;
-  unsigned int a, b, c, d;
  int i;
-  char *direc;

-  direc = CNF_GetDumpDir();
-  direc_len = strlen(direc);
-  file_len = direc_len + 24;
-  filename = MallocArray(char, file_len); /* a bit of slack */
-  if (mkdir_and_parents(direc)) {
  for (i = 0; i < n_sources; i++) {
-      a = (sources[i]->ref_id) >> 24;
-      b = ((sources[i]->ref_id) >> 16) & 0xff;
-      c = ((sources[i]->ref_id) >> 8) & 0xff;
-      d = ((sources[i]->ref_id)) & 0xff;
-      
-      snprintf(filename, file_len-1, "%s/%d.%d.%d.%d.dat", direc, a, b, c, d);
-      out = fopen(filename, "w");
-      if (!out) {
-        LOG(LOGS_WARN, LOGF_Sources, "Could not open dump file %s", filename);
-      } else {
+    out = open_dumpfile(sources[i], "w");
+    if (!out)
+      continue;
    SST_SaveToFile(sources[i]->stats, out);
    fclose(out);
  }
 }
-  } else {
-    LOG(LOGS_ERR, LOGF_Sources, "Could not create directory %s", direc);
-  }
-  Free(filename);
-}

 /* ================================================== */

@@ -1153,36 +1199,59 @@ void
 SRC_ReloadSources(void)
 {
  FILE *in;
-  char *filename;
-  unsigned int a, b, c, d;
  int i;
-  char *dumpdir;
-  int dumpdirlen, filelen;

  for (i = 0; i < n_sources; i++) {
-    a = (sources[i]->ref_id) >> 24;
-    b = ((sources[i]->ref_id) >> 16) & 0xff;
-    c = ((sources[i]->ref_id) >> 8) & 0xff;
-    d = ((sources[i]->ref_id)) & 0xff;
-
-    dumpdir = CNF_GetDumpDir();
-    dumpdirlen = strlen(dumpdir);
-    filelen = dumpdirlen + 24;
-    filename = MallocArray(char, filelen);
-    snprintf(filename, filelen-1, "%s/%d.%d.%d.%d.dat", dumpdir, a, b, c, d);
-    in = fopen(filename, "r");
-    if (!in) {
-      LOG(LOGS_WARN, LOGF_Sources, "Could not open dump file %s", filename);
-    } else {
-      if (SST_LoadFromFile(sources[i]->stats, in)) {
-        SST_DoNewRegression(sources[i]->stats);
-      } else {
-        LOG(LOGS_WARN, LOGF_Sources, "Problem loading from file %s", filename);
-      }
+    in = open_dumpfile(sources[i], "r");
+    if (!in)
+      continue;
+    if (!SST_LoadFromFile(sources[i]->stats, in))
+      LOG(LOGS_WARN, "Could not load dump file for %s",
+          source_to_string(sources[i]));
+    else
+      LOG(LOGS_INFO, "Loaded dump file for %s",
+          source_to_string(sources[i]));
    fclose(in);
  }
-    Free(filename);
 }
+
+/* ================================================== */
+
+void
+SRC_RemoveDumpFiles(void)
+{
+  char pattern[1024], name[64], *dumpdir, *s;
+  IPAddr ip_addr;
+  glob_t gl;
+  size_t i;
+
+  dumpdir = CNF_GetDumpDir();
+  if (dumpdir[0] == '\0' ||
+      snprintf(pattern, sizeof (pattern), "%s/*.dat", dumpdir) >= sizeof (pattern))
+    return;
+
+  if (glob(pattern, 0, NULL, &gl))
+    return;
+
+  for (i = 0; i < gl.gl_pathc; i++) {
+    s = strrchr(gl.gl_pathv[i], '/');
+    if (!s || snprintf(name, sizeof (name), "%s", s + 1) >= sizeof (name))
+      continue;
+
+    /* Remove .dat extension */
+    if (strlen(name) < 4)
+      continue;
+    name[strlen(name) - 4] = '\0';
+
+    /* Check if it looks like name of an actual dump file */
+    if (strncmp(name, "refid:", 6) && !UTI_StringToIP(name, &ip_addr))
+      continue;
+
+    DEBUG_LOG("Removing %s", gl.gl_pathv[i]);
+    unlink(gl.gl_pathv[i]);
+  }
+
+  globfree(&gl);
 }

 /* ================================================== */
@@ -1231,7 +1300,7 @@ SRC_ActiveSources(void)
 /* ================================================== */

 int
-SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
+SRC_ReportSource(int index, RPT_SourceReport *report, struct timespec *now)
 {
  SRC_Instance src;
  if ((index >= n_sources) || (index < 0)) {
@@ -1239,7 +1308,6 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
  } else {
    src = sources[index];

-    memset(&report->ip_addr, 0, sizeof (report->ip_addr));
    if (src->ip_addr)
      report->ip_addr = *src->ip_addr;
    else {
@@ -1249,18 +1317,13 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
    }

    switch (src->status) {
-      case SRC_UNSELECTABLE:
-      case SRC_BAD_STATS:
-      case SRC_STALE:
-      case SRC_WAITS_STATS:
-        report->state = RPT_UNREACH;
-        break;
      case SRC_FALSETICKER:
        report->state = RPT_FALSETICKER;
        break;
      case SRC_JITTERY:
        report->state = RPT_JITTERY;
        break;
+      case SRC_UNTRUSTED:
      case SRC_WAITS_SOURCES:
      case SRC_NONPREFERRED:
      case SRC_WAITS_UPDATE:
@@ -1274,26 +1337,12 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
      case SRC_SELECTED:
        report->state = RPT_SYNC;
        break;
-      case SRC_OK:
      default:
-        assert(0);
+        report->state = RPT_UNREACH;
        break;
    }

-    switch (src->sel_option) {
-      case SRC_SelectNormal:
-        report->sel_option = RPT_NORMAL;
-        break;
-      case SRC_SelectPrefer:
-        report->sel_option = RPT_PREFER;
-        break;
-      case SRC_SelectNoselect:
-        report->sel_option = RPT_NOSELECT;
-        break;
-      default:
-        assert(0);
-    }
-
+    report->sel_options = src->sel_options;
    report->reachability = src->reachability;

    /* Call stats module to fill out estimates */
@@ -1307,7 +1356,7 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
 /* ================================================== */

 int
-SRC_ReportSourcestats(int index, RPT_SourcestatsReport *report, struct timeval *now)
+SRC_ReportSourcestats(int index, RPT_SourcestatsReport *report, struct timespec *now)
 { 
  SRC_Instance src;

@@ -1336,11 +1385,3 @@ SRC_GetType(int index)
 }

 /* ================================================== */
-
-int
-SRC_Samples(SRC_Instance inst)
-{
-  return SST_Samples(inst->stats);
-}
-
-/* ================================================== */
--- a/sources.h
+++ b/sources.h
@@ -34,6 +34,7 @@

 #include "ntp.h"
 #include "reports.h"
+#include "sourcestats.h"

 /* Size of the source reachability register */
 #define SOURCE_REACH_BITS 8
@@ -55,17 +56,10 @@ typedef enum {
  SRC_REFCLOCK                  /* Rerefence clock */
 } SRC_Type;

-/* Options used when selecting sources */ 
-typedef enum {
-  SRC_SelectNormal,
-  SRC_SelectNoselect,
-  SRC_SelectPrefer
-} SRC_SelectOption;
-
 /* Function to create a new instance.  This would be called by one of
   the individual source-type instance creation routines. */

-extern SRC_Instance SRC_CreateNewInstance(uint32_t ref_id, SRC_Type type, SRC_SelectOption sel_option, IPAddr *addr, int min_samples, int max_samples);
+extern SRC_Instance SRC_CreateNewInstance(uint32_t ref_id, SRC_Type type, int sel_options, IPAddr *addr, int min_samples, int max_samples);

 /* Function to get rid of a source when it is being unconfigured.
   This may cause the current reference source to be reselected, if this
@@ -80,18 +74,8 @@ extern void SRC_ResetInstance(SRC_Instance instance);
 /* Function to change the sources's reference ID and IP address */
 extern void SRC_SetRefid(SRC_Instance instance, uint32_t ref_id, IPAddr *addr);

-/* Function to get the range of frequencies, relative to the given
-   source, that we believe the local clock lies within.  The return
-   values are in terms of the number of seconds fast (+ve) or slow
-   (-ve) relative to the source that the local clock becomes after a
-   given amount of local time has elapsed.
-
-   Suppose the initial offset relative to the source is U (fast +ve,
-   slow -ve) and a time interval T elapses measured in terms of the
-   local clock.  Then the error relative to the source at the end of
-   the interval should lie in the interval [U+T*lo, U+T*hi]. */
-
-extern void SRC_GetFrequencyRange(SRC_Instance instance, double *lo, double *hi);
+/* Function to get access to the sourcestats instance */
+extern SST_Stats SRC_GetSourcestats(SRC_Instance instance);

 /* This function is called by one of the source drivers when it has
   a new sample that is to be accumulated.
@@ -121,7 +105,7 @@ extern void SRC_GetFrequencyRange(SRC_Instance instance, double *lo, double *hi)

   */

-extern void SRC_AccumulateSample(SRC_Instance instance, struct timeval *sample_time, double offset, double peer_delay, double peer_dispersion, double root_delay, double root_dispersion, int stratum, NTP_Leap leap_status);
+extern void SRC_AccumulateSample(SRC_Instance instance, struct timespec *sample_time, double offset, double peer_delay, double peer_dispersion, double root_delay, double root_dispersion, int stratum, NTP_Leap leap_status);

 /* This routine sets the source as receiving reachability updates */
 extern void SRC_SetActive(SRC_Instance inst);
@@ -150,34 +134,18 @@ extern void SRC_ReselectSource(void);
 /* Set reselect distance */
 extern void SRC_SetReselectDistance(double distance);

-/* Predict the offset of the local clock relative to a given source at
-   a given local cooked time. Positive indicates local clock is FAST
-   relative to reference. */
-extern double SRC_PredictOffset(SRC_Instance inst, struct timeval *when);
-
-/* Return the minimum peer delay amongst the previous samples
-   currently held in the register */
-extern double SRC_MinRoundTripDelay(SRC_Instance inst);
-
-/* This routine determines if a new sample is good enough that it should be
-   accumulated */
-extern int SRC_IsGoodSample(SRC_Instance inst, double offset, double delay, double max_delay_dev_ratio, double clock_error, struct timeval *when);
-
 extern void SRC_DumpSources(void);
-
 extern void SRC_ReloadSources(void);
+extern void SRC_RemoveDumpFiles(void);

 extern int SRC_IsSyncPeer(SRC_Instance inst);
 extern int SRC_IsReachable(SRC_Instance inst);
 extern int SRC_ReadNumberOfSources(void);
 extern int SRC_ActiveSources(void);
-extern int SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now);
+extern int SRC_ReportSource(int index, RPT_SourceReport *report, struct timespec *now);

-extern int SRC_ReportSourcestats(int index, RPT_SourcestatsReport *report, struct timeval *now);
+extern int SRC_ReportSourcestats(int index, RPT_SourcestatsReport *report, struct timespec *now);

 extern SRC_Type SRC_GetType(int index);

-extern int SRC_Samples(SRC_Instance inst);
-
 #endif /* GOT_SOURCES_H */
-
--- a/sourcestats.c
+++ b/sourcestats.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2014
+ * Copyright (C) Miroslav Lichvar  2011-2014, 2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -47,8 +47,22 @@
   2000ppm, which would be pretty bad */
 #define WORST_CASE_FREQ_BOUND (2000.0/1.0e6)

-/* The minimum allowed skew */
+/* The minimum and maximum assumed skew */
 #define MIN_SKEW 1.0e-12
+#define MAX_SKEW 1.0e+02
+
+/* The asymmetry of network jitter when all jitter is in one direction */
+#define MAX_ASYMMETRY 0.5
+
+/* The minimum estimated asymmetry that can activate the offset correction */
+#define MIN_ASYMMETRY 0.45
+
+/* The minimum number of consecutive asymmetries with the same sign needed
+   to activate the offset correction */
+#define MIN_ASYMMETRY_RUN 10
+
+/* The maximum value of the counter */
+#define MAX_ASYMMETRY_RUN 1000

 /* ================================================== */

@@ -72,8 +86,8 @@ struct SST_Stats_Record {
     buffer. */
  int n_samples;

-  /* Number of extra samples stored in sample_times and offsets arrays that are
-     used to extend runs test */
+  /* Number of extra samples stored in sample_times, offsets and peer_delays
+     arrays that are used to extend the runs test */
  int runs_samples;

  /* The index of the newest sample */
@@ -92,11 +106,18 @@ struct SST_Stats_Record {
  /* This is the estimated offset (+ve => local fast) at a particular time */
  double estimated_offset;
  double estimated_offset_sd;
-  struct timeval offset_time;
+  struct timespec offset_time;

  /* Number of runs of the same sign amongst the residuals */
  int nruns;

+  /* Number of consecutive estimated asymmetries with the same sign.
+     The sign of the number encodes the sign of the asymmetry. */
+  int asymmetry_run;
+
+  /* This is the latest estimated asymmetry of network jitter */
+  double asymmetry;
+
  /* This value contains the estimated frequency.  This is the number
     of seconds that the local clock gains relative to the reference
     source per unit local time.  (Positive => local clock fast,
@@ -108,12 +129,12 @@ struct SST_Stats_Record {
     about estimated_frequency */
  double skew;

-  /* This is the estimated residual variance of the data points */
-  double variance;
+  /* This is the estimated standard deviation of the data points */
+  double std_dev;

  /* This array contains the sample epochs, in terms of the local
     clock. */
-  struct timeval sample_times[MAX_SAMPLES * REGRESS_RUNS_RATIO];
+  struct timespec sample_times[MAX_SAMPLES * REGRESS_RUNS_RATIO];

  /* This is an array of offsets, in seconds, corresponding to the
     sample times.  In this module, we use the convention that
@@ -131,7 +152,7 @@ struct SST_Stats_Record {

  /* This is an array of peer delays, in seconds, being the roundtrip
     measurement delay to the peer */
-  double peer_delays[MAX_SAMPLES];
+  double peer_delays[MAX_SAMPLES * REGRESS_RUNS_RATIO];

  /* This is an array of peer dispersions, being the skew and local
     precision dispersion terms from sampling the peer */
@@ -161,7 +182,7 @@ void
 SST_Initialise(void)
 {
  logfileid = CNF_GetLogStatistics() ? LOG_FileOpen("statistics",
-      "   Date (UTC) Time     IP Address    Std dev'n Est offset  Offset sd  Diff freq   Est skew  Stress  Ns  Bs  Nr")
+      "   Date (UTC) Time     IP Address    Std dev'n Est offset  Offset sd  Diff freq   Est skew  Stress  Ns  Bs  Nr  Asym")
    : -1;
 }

@@ -214,10 +235,11 @@ SST_ResetInstance(SST_Stats inst)
  inst->skew = 2000.0e-6;
  inst->estimated_offset = 0.0;
  inst->estimated_offset_sd = 86400.0; /* Assume it's at least within a day! */
-  inst->offset_time.tv_sec = 0;
-  inst->offset_time.tv_usec = 0;
-  inst->variance = 16.0;
+  UTI_ZeroTimespec(&inst->offset_time);
+  inst->std_dev = 4.0;
  inst->nruns = 0;
+  inst->asymmetry_run = 0;
+  inst->asymmetry = 0.0;
 }

 /* ================================================== */
@@ -253,7 +275,7 @@ prune_register(SST_Stats inst, int new_oldest)
 /* ================================================== */

 void
-SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time,
+SST_AccumulateSample(SST_Stats inst, struct timespec *sample_time,
                     double offset,
                     double peer_delay, double peer_dispersion,
                     double root_delay, double root_dispersion,
@@ -269,8 +291,8 @@ SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time,

  /* Make sure it's newer than the last sample */
  if (inst->n_samples &&
-      UTI_CompareTimevals(&inst->sample_times[inst->last_sample], sample_time) >= 0) {
-    LOG(LOGS_WARN, LOGF_SourceStats, "Out of order sample detected, discarding history for %s",
+      UTI_CompareTimespecs(&inst->sample_times[inst->last_sample], sample_time) >= 0) {
+    LOG(LOGS_WARN, "Out of order sample detected, discarding history for %s",
        inst->ip_addr ? UTI_IPToString(inst->ip_addr) : UTI_RefidToString(inst->refid));
    SST_ResetInstance(inst);
  }
@@ -282,14 +304,14 @@ SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time,
  inst->sample_times[n] = *sample_time;
  inst->offsets[n] = offset;
  inst->orig_offsets[m] = offset;
-  inst->peer_delays[m] = peer_delay;
+  inst->peer_delays[n] = peer_delay;
  inst->peer_dispersions[m] = peer_dispersion;
  inst->root_delays[m] = root_delay;
  inst->root_dispersions[m] = root_dispersion;
  inst->strata[m] = stratum;
 
-  if (!inst->n_samples || inst->peer_delays[m] < inst->peer_delays[inst->min_delay_sample])
-    inst->min_delay_sample = m;
+  if (!inst->n_samples || inst->peer_delays[n] < inst->peer_delays[inst->min_delay_sample])
+    inst->min_delay_sample = n;

  ++inst->n_samples;
 }
@@ -323,14 +345,13 @@ get_buf_index(SST_Stats inst, int i)
 static void
 convert_to_intervals(SST_Stats inst, double *times_back)
 {
-  struct timeval *newest_tv;
+  struct timespec *ts;
  int i;

-  newest_tv = &(inst->sample_times[inst->last_sample]);
+  ts = &inst->sample_times[inst->last_sample];
  for (i = -inst->runs_samples; i < inst->n_samples; i++) {
    /* The entries in times_back[] should end up negative */
-    UTI_DiffTimevalsToDouble(&times_back[i],
-        &inst->sample_times[get_runsbuf_index(inst, i)], newest_tv);
+    times_back[i] = UTI_DiffTimespecsToDouble(&inst->sample_times[get_runsbuf_index(inst, i)], ts);
  }
 }

@@ -376,15 +397,65 @@ find_min_delay_sample(SST_Stats inst)
 {
  int i, index;

-  inst->min_delay_sample = get_buf_index(inst, 0);
+  inst->min_delay_sample = get_runsbuf_index(inst, -inst->runs_samples);

-  for (i = 1; i < inst->n_samples; i++) {
-    index = get_buf_index(inst, i);
+  for (i = -inst->runs_samples + 1; i < inst->n_samples; i++) {
+    index = get_runsbuf_index(inst, i);
    if (inst->peer_delays[index] < inst->peer_delays[inst->min_delay_sample])
      inst->min_delay_sample = index;
  }
 }

+/* ================================================== */
+/* This function estimates asymmetry of network jitter on the path to the
+   source as a slope of offset against network delay in multiple linear
+   regression.  If the asymmetry is significant and its sign doesn't change
+   frequently, the measured offsets (which are used later to estimate the
+   offset and frequency of the clock) are corrected to correspond to the
+   minimum network delay.  This can significantly improve the accuracy and
+   stability of the estimated offset and frequency. */
+
+static void
+correct_asymmetry(SST_Stats inst, double *times_back, double *offsets)
+{
+  double asymmetry, delays[MAX_SAMPLES * REGRESS_RUNS_RATIO];
+  int i, n;
+
+  /* Don't try to estimate the asymmetry with reference clocks */
+  if (!inst->ip_addr)
+    return;
+
+  n = inst->runs_samples + inst->n_samples;
+
+  for (i = 0; i < n; i++)
+    delays[i] = inst->peer_delays[get_runsbuf_index(inst, i - inst->runs_samples)] -
+                inst->peer_delays[inst->min_delay_sample];
+
+  /* Reset the counter when the regression fails or the sign changes */
+  if (!RGR_MultipleRegress(times_back, delays, offsets, n, &asymmetry) ||
+      asymmetry * inst->asymmetry_run < 0.0) {
+    inst->asymmetry_run = 0;
+    inst->asymmetry = 0.0;
+    return;
+  }
+
+  asymmetry = CLAMP(-MAX_ASYMMETRY, asymmetry, MAX_ASYMMETRY);
+
+  if (asymmetry <= -MIN_ASYMMETRY && inst->asymmetry_run > -MAX_ASYMMETRY_RUN)
+    inst->asymmetry_run--;
+  else if (asymmetry >= MIN_ASYMMETRY && inst->asymmetry_run < MAX_ASYMMETRY_RUN)
+    inst->asymmetry_run++;
+
+  if (abs(inst->asymmetry_run) < MIN_ASYMMETRY_RUN)
+    return;
+
+  /* Correct the offsets */
+  for (i = 0; i < n; i++)
+    offsets[i] -= asymmetry * delays[i];
+
+  inst->asymmetry = asymmetry;
+}
+
 /* ================================================== */

 /* This defines the assumed ratio between the standard deviation of
@@ -392,7 +463,7 @@ find_min_delay_sample(SST_Stats inst)
   time.  E.g. a value of 4 means that we think the standard deviation
   is four times the fluctuation  of the peer distance */

-#define SD_TO_DIST_RATIO 1.0
+#define SD_TO_DIST_RATIO 0.7

 /* ================================================== */
 /* This function runs the linear regression operation on the data.  It
@@ -412,9 +483,10 @@ SST_DoNewRegression(SST_Stats inst)
  int best_start, times_back_start;
  double est_intercept, est_slope, est_var, est_intercept_sd, est_slope_sd;
  int i, j, nruns;
-  double min_distance, mean_distance;
+  double min_distance, median_distance;
  double sd_weight, sd;
  double old_skew, old_freq, stress;
+  double precision;

  convert_to_intervals(inst, times_back + inst->runs_samples);

@@ -423,28 +495,34 @@ SST_DoNewRegression(SST_Stats inst)
      offsets[i + inst->runs_samples] = inst->offsets[get_runsbuf_index(inst, i)];
    }
  
-    for (i = 0, mean_distance = 0.0, min_distance = DBL_MAX; i < inst->n_samples; i++) {
+    for (i = 0, min_distance = DBL_MAX; i < inst->n_samples; i++) {
      j = get_buf_index(inst, i);
-      peer_distances[i] = 0.5 * inst->peer_delays[j] + inst->peer_dispersions[j];
-      mean_distance += peer_distances[i];
+      peer_distances[i] = 0.5 * inst->peer_delays[get_runsbuf_index(inst, i)] +
+                          inst->peer_dispersions[j];
      if (peer_distances[i] < min_distance) {
        min_distance = peer_distances[i];
      }
    }
-    mean_distance /= inst->n_samples;

    /* And now, work out the weight vector */

-    sd = mean_distance - min_distance;
-    if (sd > min_distance || sd <= 0.0)
-      sd = min_distance;
+    precision = LCL_GetSysPrecisionAsQuantum();
+    median_distance = RGR_FindMedian(peer_distances, inst->n_samples);
+
+    sd = (median_distance - min_distance) / SD_TO_DIST_RATIO;
+    sd = CLAMP(precision, sd, min_distance);
+    min_distance += precision;

    for (i=0; i<inst->n_samples; i++) {
-      sd_weight = 1.0 + SD_TO_DIST_RATIO * (peer_distances[i] - min_distance) / sd;
+      sd_weight = 1.0;
+      if (peer_distances[i] > min_distance)
+        sd_weight += (peer_distances[i] - min_distance) / sd;
      weights[i] = sd_weight * sd_weight;
    }
  }

+  correct_asymmetry(inst, times_back, offsets);
+
  inst->regression_ok = RGR_FindBestRegression(times_back + inst->runs_samples,
                                         offsets + inst->runs_samples, weights,
                                         inst->n_samples, inst->runs_samples,
@@ -463,26 +541,26 @@ SST_DoNewRegression(SST_Stats inst)
    inst->estimated_offset = est_intercept;
    inst->offset_time = inst->sample_times[inst->last_sample];
    inst->estimated_offset_sd = est_intercept_sd;
-    inst->variance = est_var;
+    inst->std_dev = sqrt(est_var);
    inst->nruns = nruns;

-    if (inst->skew < MIN_SKEW)
-      inst->skew = MIN_SKEW;
-
+    inst->skew = CLAMP(MIN_SKEW, inst->skew, MAX_SKEW);
    stress = fabs(old_freq - inst->estimated_frequency) / old_skew;

+    DEBUG_LOG("off=%e freq=%e skew=%e n=%d bs=%d runs=%d asym=%f arun=%d",
+              inst->estimated_offset, inst->estimated_frequency, inst->skew,
+              inst->n_samples, best_start, inst->nruns,
+              inst->asymmetry, inst->asymmetry_run);
+
    if (logfileid != -1) {
-      LOG_FileWrite(logfileid, "%s %-15s %10.3e %10.3e %10.3e %10.3e %10.3e %7.1e %3d %3d %3d",
+      LOG_FileWrite(logfileid, "%s %-15s %10.3e %10.3e %10.3e %10.3e %10.3e %7.1e %3d %3d %3d %5.2f",
              UTI_TimeToLogForm(inst->offset_time.tv_sec),
              inst->ip_addr ? UTI_IPToString(inst->ip_addr) : UTI_RefidToString(inst->refid),
-              sqrt(inst->variance),
-              inst->estimated_offset,
-              inst->estimated_offset_sd,
-              inst->estimated_frequency,
-              inst->skew,
-              stress,
-              inst->n_samples,
-              best_start, nruns);
+              inst->std_dev,
+              inst->estimated_offset, inst->estimated_offset_sd,
+              inst->estimated_frequency, inst->skew, stress,
+              inst->n_samples, best_start, inst->nruns,
+              inst->asymmetry);
    }

    times_back_start = inst->runs_samples + best_start;
@@ -524,12 +602,12 @@ SST_GetFrequencyRange(SST_Stats inst,
 /* ================================================== */

 void
-SST_GetSelectionData(SST_Stats inst, struct timeval *now,
+SST_GetSelectionData(SST_Stats inst, struct timespec *now,
                     int *stratum,
                     double *offset_lo_limit,
                     double *offset_hi_limit,
                     double *root_distance,
-                     double *variance,
+                     double *std_dev,
                     double *first_sample_ago,
                     double *last_sample_ago,
                     int *select_ok)
@@ -546,9 +624,9 @@ SST_GetSelectionData(SST_Stats inst, struct timeval *now,
  j = get_buf_index(inst, inst->best_single_sample);

  *stratum = inst->strata[get_buf_index(inst, inst->n_samples - 1)];
-  *variance = inst->variance;
+  *std_dev = inst->std_dev;

-  UTI_DiffTimevalsToDouble(&sample_elapsed, now, &inst->sample_times[i]);
+  sample_elapsed = fabs(UTI_DiffTimespecsToDouble(now, &inst->sample_times[i]));
  offset = inst->offsets[i] + sample_elapsed * inst->estimated_frequency;
  *root_distance = 0.5 * inst->root_delays[j] +
    inst->root_dispersions[j] + sample_elapsed * inst->skew;
@@ -560,10 +638,10 @@ SST_GetSelectionData(SST_Stats inst, struct timeval *now,
  double average_offset, elapsed;
  int average_ok;
  /* average_ok ignored for now */
-  UTI_DiffTimevalsToDouble(&elapsed, now, &(inst->offset_time));
+  elapsed = UTI_DiffTimespecsToDouble(now, &inst->offset_time);
  average_offset = inst->estimated_offset + inst->estimated_frequency * elapsed;
  if (fabs(average_offset - offset) <=
-      inst->peer_dispersions[j] + 0.5 * inst->peer_delays[j]) {
+      inst->peer_dispersions[j] + 0.5 * inst->peer_delays[i]) {
    average_ok = 1;
  } else {
    average_ok = 0;
@@ -571,21 +649,21 @@ SST_GetSelectionData(SST_Stats inst, struct timeval *now,
 #endif

  i = get_runsbuf_index(inst, 0);
-  UTI_DiffTimevalsToDouble(first_sample_ago, now, &inst->sample_times[i]);
+  *first_sample_ago = UTI_DiffTimespecsToDouble(now, &inst->sample_times[i]);
  i = get_runsbuf_index(inst, inst->n_samples - 1);
-  UTI_DiffTimevalsToDouble(last_sample_ago, now, &inst->sample_times[i]);
+  *last_sample_ago = UTI_DiffTimespecsToDouble(now, &inst->sample_times[i]);

  *select_ok = inst->regression_ok;

-  DEBUG_LOG(LOGF_SourceStats, "n=%d off=%f dist=%f var=%f first_ago=%f last_ago=%f selok=%d",
-            inst->n_samples, offset, *root_distance, *variance,
+  DEBUG_LOG("n=%d off=%f dist=%f sd=%f first_ago=%f last_ago=%f selok=%d",
+            inst->n_samples, offset, *root_distance, *std_dev,
            *first_sample_ago, *last_sample_ago, *select_ok);
 }

 /* ================================================== */

 void
-SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,
+SST_GetTrackingData(SST_Stats inst, struct timespec *ref_time,
                    double *average_offset, double *offset_sd,
                    double *frequency, double *skew,
                    double *root_delay, double *root_dispersion)
@@ -605,22 +683,23 @@ SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,
  *skew = inst->skew;
  *root_delay = inst->root_delays[j];

-  UTI_DiffTimevalsToDouble(&elapsed_sample, &inst->offset_time, &inst->sample_times[i]);
+  elapsed_sample = UTI_DiffTimespecsToDouble(&inst->offset_time, &inst->sample_times[i]);
  *root_dispersion = inst->root_dispersions[j] + inst->skew * elapsed_sample;

-  DEBUG_LOG(LOGF_SourceStats, "n=%d freq=%f (%.3fppm) skew=%f (%.3fppm) avoff=%f offsd=%f disp=%f",
-      inst->n_samples, *frequency, 1.0e6* *frequency, *skew, 1.0e6* *skew, *average_offset, *offset_sd, *root_dispersion);
+  DEBUG_LOG("n=%d freq=%f (%.3fppm) skew=%f (%.3fppm) avoff=%f offsd=%f disp=%f",
+            inst->n_samples, *frequency, 1.0e6* *frequency, *skew, 1.0e6* *skew,
+            *average_offset, *offset_sd, *root_dispersion);

 }

 /* ================================================== */

 void
-SST_SlewSamples(SST_Stats inst, struct timeval *when, double dfreq, double doffset)
+SST_SlewSamples(SST_Stats inst, struct timespec *when, double dfreq, double doffset)
 {
  int m, i;
  double delta_time;
-  struct timeval *sample, prev;
+  struct timespec *sample, prev;
  double prev_offset, prev_freq;

  if (!inst->n_samples)
@@ -628,24 +707,24 @@ SST_SlewSamples(SST_Stats inst, struct timeval *when, double dfreq, double doffs

  for (m = -inst->runs_samples; m < inst->n_samples; m++) {
    i = get_runsbuf_index(inst, m);
-    sample = &(inst->sample_times[i]);
+    sample = &inst->sample_times[i];
    prev = *sample;
-    UTI_AdjustTimeval(sample, when, sample, &delta_time, dfreq, doffset);
+    UTI_AdjustTimespec(sample, when, sample, &delta_time, dfreq, doffset);
    inst->offsets[i] += delta_time;
  }

-  /* Do a half-baked update to the regression estimates */
+  /* Update the regression estimates */
  prev = inst->offset_time;
  prev_offset = inst->estimated_offset;
  prev_freq = inst->estimated_frequency;
-  UTI_AdjustTimeval(&(inst->offset_time), when, &(inst->offset_time),
+  UTI_AdjustTimespec(&inst->offset_time, when, &inst->offset_time,
      &delta_time, dfreq, doffset);
  inst->estimated_offset += delta_time;
-  inst->estimated_frequency -= dfreq;
+  inst->estimated_frequency = (inst->estimated_frequency - dfreq) / (1.0 - dfreq);

-  DEBUG_LOG(LOGF_SourceStats, "n=%d m=%d old_off_time=%s new=%s old_off=%f new_off=%f old_freq=%.3f new_freq=%.3f",
+  DEBUG_LOG("n=%d m=%d old_off_time=%s new=%s old_off=%f new_off=%f old_freq=%.3f new_freq=%.3f",
            inst->n_samples, inst->runs_samples,
-            UTI_TimevalToString(&prev), UTI_TimevalToString(&(inst->offset_time)),
+            UTI_TimespecToString(&prev), UTI_TimespecToString(&inst->offset_time),
            prev_offset, inst->estimated_offset,
            1.0e6 * prev_freq, 1.0e6 * inst->estimated_frequency);
 }
@@ -667,7 +746,7 @@ SST_AddDispersion(SST_Stats inst, double dispersion)
 /* ================================================== */

 double
-SST_PredictOffset(SST_Stats inst, struct timeval *when)
+SST_PredictOffset(SST_Stats inst, struct timespec *when)
 {
  double elapsed;
  
@@ -681,7 +760,7 @@ SST_PredictOffset(SST_Stats inst, struct timeval *when)
      return 0.0;
    }
  } else {
-    UTI_DiffTimevalsToDouble(&elapsed, when, &inst->offset_time);
+    elapsed = UTI_DiffTimespecsToDouble(when, &inst->offset_time);
    return inst->estimated_offset + elapsed * inst->estimated_frequency;
  }

@@ -701,20 +780,20 @@ SST_MinRoundTripDelay(SST_Stats inst)

 int
 SST_IsGoodSample(SST_Stats inst, double offset, double delay,
-    double max_delay_dev_ratio, double clock_error, struct timeval *when)
+    double max_delay_dev_ratio, double clock_error, struct timespec *when)
 {
  double elapsed, allowed_increase, delay_increase;

-  if (inst->n_samples < 3)
+  if (inst->n_samples < 6)
    return 1;

-  UTI_DiffTimevalsToDouble(&elapsed, when, &inst->offset_time);
+  elapsed = UTI_DiffTimespecsToDouble(when, &inst->offset_time);

  /* Require that the ratio of the increase in delay from the minimum to the
     standard deviation is less than max_delay_dev_ratio. In the allowed
     increase in delay include also skew and clock_error. */
    
-  allowed_increase = sqrt(inst->variance) * max_delay_dev_ratio +
+  allowed_increase = inst->std_dev * max_delay_dev_ratio +
    elapsed * (inst->skew + clock_error);
  delay_increase = (delay - SST_MinRoundTripDelay(inst)) / 2.0;

@@ -729,8 +808,8 @@ SST_IsGoodSample(SST_Stats inst, double offset, double delay,
  if (fabs(offset) - delay_increase > allowed_increase)
    return 1;

-  DEBUG_LOG(LOGF_SourceStats, "Bad sample: offset=%f delay=%f incr_delay=%f allowed=%f",
-      offset, delay, allowed_increase, delay_increase);
+  DEBUG_LOG("Bad sample: offset=%f delay=%f incr_delay=%f allowed=%f",
+            offset, delay, delay_increase, allowed_increase);

  return 0;
 }
@@ -750,12 +829,18 @@ SST_SaveToFile(SST_Stats inst, FILE *out)
    i = get_runsbuf_index(inst, m);
    j = get_buf_index(inst, m);

-    fprintf(out, "%08lx %08lx %.6e %.6e %.6e %.6e %.6e %.6e %.6e %d\n",
+    fprintf(out,
+#ifdef HAVE_LONG_TIME_T
+            "%08"PRIx64" %08lx %.6e %.6e %.6e %.6e %.6e %.6e %.6e %d\n",
+            (uint64_t)inst->sample_times[i].tv_sec,
+#else
+            "%08lx %08lx %.6e %.6e %.6e %.6e %.6e %.6e %.6e %d\n",
            (unsigned long)inst->sample_times[i].tv_sec,
-            (unsigned long) inst->sample_times[i].tv_usec,
+#endif
+            (unsigned long)inst->sample_times[i].tv_nsec / 1000,
            inst->offsets[i],
            inst->orig_offsets[j],
-            inst->peer_delays[j],
+            inst->peer_delays[i],
            inst->peer_dispersions[j],
            inst->root_delays[j],
            inst->root_dispersions[j],
@@ -763,6 +848,8 @@ SST_SaveToFile(SST_Stats inst, FILE *out)
            inst->strata[j]);

  }
+
+  fprintf(out, "%d\n", inst->asymmetry_run);
 }

 /* ================================================== */
@@ -771,22 +858,30 @@ SST_SaveToFile(SST_Stats inst, FILE *out)
 int
 SST_LoadFromFile(SST_Stats inst, FILE *in)
 {
-  int i, line_number;
+#ifdef HAVE_LONG_TIME_T
+  uint64_t sec;
+#else
+  unsigned long sec;
+#endif
+  unsigned long usec;
+  int i;
  char line[1024];
-  unsigned long sec, usec;
  double weight;

  assert(!inst->n_samples);

  if (fgets(line, sizeof(line), in) &&
      sscanf(line, "%d", &inst->n_samples) == 1 &&
-      inst->n_samples > 0 && inst->n_samples <= MAX_SAMPLES) {
-
-    line_number = 2;
+      inst->n_samples >= 0 && inst->n_samples <= MAX_SAMPLES) {

    for (i=0; i<inst->n_samples; i++) {
      if (!fgets(line, sizeof(line), in) ||
-          (sscanf(line, "%lx%lx%lf%lf%lf%lf%lf%lf%lf%d\n",
+          (sscanf(line,
+#ifdef HAVE_LONG_TIME_T
+                  "%"SCNx64"%lx%lf%lf%lf%lf%lf%lf%lf%d\n",
+#else
+                  "%lx%lx%lf%lf%lf%lf%lf%lf%lf%d\n",
+#endif
                  &(sec), &(usec),
                  &(inst->offsets[i]),
                  &(inst->orig_offsets[i]),
@@ -799,40 +894,44 @@ SST_LoadFromFile(SST_Stats inst, FILE *in)

        /* This is the branch taken if the read FAILED */

-        LOG(LOGS_WARN, LOGF_SourceStats, "Failed to read data from line %d of dump file", line_number);
        inst->n_samples = 0; /* Load abandoned if any sign of corruption */
        return 0;
      } else {

        /* This is the branch taken if the read is SUCCESSFUL */
        inst->sample_times[i].tv_sec = sec;
-        inst->sample_times[i].tv_usec = usec;
+        inst->sample_times[i].tv_nsec = 1000 * usec;
+        UTI_NormaliseTimespec(&inst->sample_times[i]);
+      }
+    }

-        line_number++;
-      }
-    }
+    /* This field was not saved in older versions */
+    if (!fgets(line, sizeof(line), in) || sscanf(line, "%d\n", &inst->asymmetry_run) != 1)
+      inst->asymmetry_run = 0;
  } else {
-    LOG(LOGS_WARN, LOGF_SourceStats, "Could not read number of samples from dump file");
    inst->n_samples = 0; /* Load abandoned if any sign of corruption */
    return 0;
  }

+  if (!inst->n_samples)
+    return 1;
+
  inst->last_sample = inst->n_samples - 1;
  inst->runs_samples = 0;

  find_min_delay_sample(inst);
+  SST_DoNewRegression(inst);

  return 1;
-
 }

 /* ================================================== */

 void
-SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timeval *now)
+SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timespec *now)
 {
  int i, j;
-  struct timeval ago;
+  struct timespec last_sample_time;

  if (inst->n_samples > 0) {
    i = get_runsbuf_index(inst, inst->n_samples - 1);
@@ -842,10 +941,12 @@ SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timeval *now
    report->latest_meas_err = 0.5*inst->root_delays[j] + inst->root_dispersions[j];
    report->stratum = inst->strata[j];

-    UTI_DiffTimevals(&ago, now, &inst->sample_times[i]);
-    report->latest_meas_ago = ago.tv_sec;
+    /* Align the sample time to reduce the leak of the receive timestamp */
+    last_sample_time = inst->sample_times[i];
+    last_sample_time.tv_nsec = 0;
+    report->latest_meas_ago = UTI_DiffTimespecsToDouble(now, &last_sample_time);
  } else {
-    report->latest_meas_ago = 86400 * 365 * 10;
+    report->latest_meas_ago = (uint32_t)-1;
    report->orig_latest_meas = 0;
    report->latest_meas = 0;
    report->latest_meas_err = 0;
@@ -864,7 +965,7 @@ SST_Samples(SST_Stats inst)
 /* ================================================== */

 void
-SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct timeval *now)
+SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct timespec *now)
 {
  double dspan;
  double elapsed, sample_elapsed;
@@ -876,15 +977,15 @@ SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct ti
  if (inst->n_samples > 1) {
    li = get_runsbuf_index(inst, inst->n_samples - 1);
    lj = get_buf_index(inst, inst->n_samples - 1);
-    UTI_DiffTimevalsToDouble(&dspan, &inst->sample_times[li],
+    dspan = UTI_DiffTimespecsToDouble(&inst->sample_times[li],
        &inst->sample_times[get_runsbuf_index(inst, 0)]);
    report->span_seconds = (unsigned long) (dspan + 0.5);

    if (inst->n_samples > 3) {
-      UTI_DiffTimevalsToDouble(&elapsed, now, &inst->offset_time);
+      elapsed = UTI_DiffTimespecsToDouble(now, &inst->offset_time);
      bi = get_runsbuf_index(inst, inst->best_single_sample);
      bj = get_buf_index(inst, inst->best_single_sample);
-      UTI_DiffTimevalsToDouble(&sample_elapsed, now, &inst->sample_times[bi]);
+      sample_elapsed = UTI_DiffTimespecsToDouble(now, &inst->sample_times[bi]);
      report->est_offset = inst->estimated_offset + elapsed * inst->estimated_frequency;
      report->est_offset_err = (inst->estimated_offset_sd +
                 sample_elapsed * inst->skew +
@@ -901,7 +1002,15 @@ SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct ti

  report->resid_freq_ppm = 1.0e6 * inst->estimated_frequency;
  report->skew_ppm = 1.0e6 * inst->skew;
-  report->sd = sqrt(inst->variance);
+  report->sd = inst->std_dev;
+}
+
+/* ================================================== */
+
+double
+SST_GetJitterAsymmetry(SST_Stats inst)
+{
+  return inst->asymmetry;
 }

 /* ================================================== */
--- a/sourcestats.h
+++ b/sourcestats.h
@@ -61,7 +61,7 @@ extern void SST_SetRefid(SST_Stats inst, uint32_t refid, IPAddr *addr);
   stratum is the stratum of the source from which the sample came.
  */

-extern void SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time, double offset, double peer_delay, double peer_dispersion, double root_delay, double root_dispersion, int stratum);
+extern void SST_AccumulateSample(SST_Stats inst, struct timespec *sample_time, double offset, double peer_delay, double peer_dispersion, double root_delay, double root_dispersion, int stratum);

 /* This function runs the linear regression operation on the data.  It
   finds the set of most recent samples that give the tightest
@@ -77,7 +77,7 @@ extern void SST_GetFrequencyRange(SST_Stats inst, double *lo, double *hi);

 /* Get data needed for selection */
 extern void
-SST_GetSelectionData(SST_Stats inst, struct timeval *now,
+SST_GetSelectionData(SST_Stats inst, struct timespec *now,
                     int *stratum,
                     double *offset_lo_limit,
                     double *offset_hi_limit,
@@ -89,7 +89,7 @@ SST_GetSelectionData(SST_Stats inst, struct timeval *now,

 /* Get data needed when setting up tracking on this source */
 extern void
-SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,
+SST_GetTrackingData(SST_Stats inst, struct timespec *ref_time,
                    double *average_offset, double *offset_sd,
                    double *frequency, double *skew,
                    double *root_delay, double *root_dispersion);
@@ -110,7 +110,7 @@ SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,

 */

-extern void SST_SlewSamples(SST_Stats inst, struct timeval *when, double dfreq, double doffset);
+extern void SST_SlewSamples(SST_Stats inst, struct timespec *when, double dfreq, double doffset);

 /* This routine is called when an indeterminate offset is introduced
   into the local time. */
@@ -119,7 +119,7 @@ extern void SST_AddDispersion(SST_Stats inst, double dispersion);
 /* Predict the offset of the local clock relative to a given source at
   a given local cooked time. Positive indicates local clock is FAST
   relative to reference. */
-extern double SST_PredictOffset(SST_Stats inst, struct timeval *when);
+extern double SST_PredictOffset(SST_Stats inst, struct timespec *when);

 /* Find the minimum round trip delay in the register */
 extern double SST_MinRoundTripDelay(SST_Stats inst);
@@ -127,17 +127,19 @@ extern double SST_MinRoundTripDelay(SST_Stats inst);
 /* This routine determines if a new sample is good enough that it should be
   accumulated */
 extern int SST_IsGoodSample(SST_Stats inst, double offset, double delay,
-   double max_delay_dev_ratio, double clock_error, struct timeval *when);
+   double max_delay_dev_ratio, double clock_error, struct timespec *when);

 extern void SST_SaveToFile(SST_Stats inst, FILE *out);

 extern int SST_LoadFromFile(SST_Stats inst, FILE *in);

-extern void SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timeval *now);
+extern void SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timespec *now);

-extern void SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct timeval *now);
+extern void SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct timespec *now);

 extern int SST_Samples(SST_Stats inst);

+extern double SST_GetJitterAsymmetry(SST_Stats inst);
+
 #endif /* GOT_SOURCESTATS_H */

--- a/Show More
+++ b/Show More