doc: update NEWS

clientlog: enable NTP response rate limiting by default
Change the default interval of both NTP and command rate limiting to -10 (1024 packets per second) and the burst to 16. The default NTP leak is 2 (rate limiting is enabled by default) and the default command leak is 0 (rate limiting is disabled by default).
2025-12-03 18:35:06 -05:00 · 2016-12-15 13:47:41 +01:00 · 2016-12-15 13:47:41 +01:00 · 2016-12-15 13:47:41 +01:00 · 2016-12-15 13:47:41 +01:00 · 2016-12-15 13:47:41 +01:00
172 changed files with 15961 additions and 15533 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -4,20 +4,22 @@
 *.swp
 *.dSYM
 *.DS_Store
-RELEASES
-Makefile
-chrony.conf.5
-chrony.info
-chrony.html
-chrony.texi
-chrony.txt
-chronyc
-chronyc.1
-chronyd
-chronyd.8
-config.h
-config.log
 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 smooth.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)
@@ -66,23 +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 .DS_Store
-	-rm -f Makefile
-	-rm -f chrony.conf.5 chrony.texi chronyc.1 chronyd.8
+	-rm -f Makefile config.h config.log
+	$(MAKE) -C doc distclean
+	$(MAKE) -C test/unit distclean

 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
@@ -92,15 +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
@@ -108,18 +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 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 $<
@@ -128,30 +110,9 @@ install: chronyd chronyc chrony.txt
 	$(CC) $(CFLAGS) $(CPPFLAGS) -S $<

 check : 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*
-
-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
--- a/139
+++ b/139
@@ -1,3 +1,142 @@
+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
+* Enable NTP response rate limiting by default
+  (1024 packets per second per IP address and 25% leak)
+* 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
 ====================

--- a/68
+++ b/68
@@ -14,10 +14,10 @@ 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.

-Typical accuracy between two machines on a LAN is in tens, or a few
-hundreds, of microseconds; over the Internet, accuracy is typically
-within a few milliseconds.  With a good hardware reference clock
-sub-microsecond accuracy is possible.
+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
@@ -27,7 +27,7 @@ operating parameters whilst it is running.
 What will chrony run on?
 ========================

-The software is known to work on Linux, FreeBSD, NetBSD, Mac OS X and
+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
@@ -53,7 +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?
 =================================
@@ -84,30 +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!
+
 License
 =======

 chrony is distributed under the GNU General Public License version 2.

-
-Author
-======
+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

@@ -129,7 +135,9 @@ Erik Bryer <ebryer@spots.ab.ca>
    Entries in contrib directory

 Bryan Christianson <bryan@whatroute.net>
-    Support for Mac OS X
+    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.
@@ -145,6 +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
@@ -183,18 +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

@@ -204,12 +203,21 @@ Kalle Olavi Niemitalo  <tosi@stekt.oulu.fi>
 Frank Otto <sandwichmacher@web.de>
    Handling arbitrary HZ values

+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

@@ -223,5 +231,5 @@ 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 {
--- a/addrfilt.c
+++ b/addrfilt.c
@@ -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];
@@ -401,117 +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
@@ -103,6 +103,12 @@ ARR_GetElement(ARR_Instance array, unsigned int index)
 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 */
@@ -91,18 +90,21 @@
 #define REQ_MODIFY_MAKESTEP 50
 #define REQ_SMOOTHING 51
 #define REQ_SMOOTHTIME 52
-#define N_REQUEST_TYPES 53
+#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
@@ -201,18 +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;

@@ -243,6 +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;
@@ -250,9 +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;
@@ -284,7 +299,7 @@ typedef struct {

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

@@ -306,6 +321,11 @@ typedef struct {
  int32_t EOR;
 } REQ_SmoothTime;

+typedef struct {
+  IPAddr ip_addr;
+  int32_t EOR;
+} REQ_NTPData;
+
 /* ================================================== */

 #define PKT_TYPE_CMD_REQUEST 1
@@ -335,7 +355,15 @@ 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, smoothing report, smoothtime command
+   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), new fields and flags in NTP source request
+   and report, new commands: ntpdata, refresh, serverstats
 */

 #define PROTO_VERSION_NUMBER 6
@@ -349,7 +377,7 @@ 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

 /* ================================================== */
@@ -364,8 +392,8 @@ 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;
@@ -398,17 +426,13 @@ typedef struct {
    REQ_ManualDelete manual_delete;
    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;

 /* ================================================== */
@@ -434,7 +458,10 @@ typedef struct {
 #define RPY_MANUAL_LIST 11
 #define RPY_ACTIVITY 12
 #define RPY_SMOOTHING 13
-#define N_REPLY_TYPES 14
+#define RPY_SERVER_STATS 14
+#define RPY_CLIENT_ACCESSES_BY_INDEX2 15
+#define RPY_NTP_DATA 16
+#define N_REPLY_TYPES 17

 /* Status codes */
 #define STT_SUCCESS 0
@@ -481,6 +508,8 @@ 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;
@@ -502,7 +531,7 @@ 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;
@@ -530,7 +559,7 @@ typedef struct {
 } RPY_Sourcestats;

 typedef struct {
-  Timeval ref_time;
+  Timespec ref_time;
  uint16_t n_samples;
  uint16_t n_runs;
  uint32_t span_seconds;
@@ -548,11 +577,14 @@ typedef struct {

 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;
@@ -565,10 +597,19 @@ 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;
@@ -602,6 +643,39 @@ typedef struct {
  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;
@@ -614,9 +688,9 @@ 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;
@@ -626,15 +700,13 @@ 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.conf.5.in
+++ b/chrony.conf.5.in
@@ -1,67 +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.  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 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
@@ -1,74 +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)
-
-.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
@@ -1,152 +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 other systems this 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 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 +34,268 @@
 #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 0
+#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

 /* 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;

-static void
-clear_subnet(Subnet *subnet)
-{
-  int i;
+      if (record->ip_addr.family == IPADDR_UNSPEC)
+        break;

-  for (i=0; i<TABLE_SIZE; i++) {
-    subnet->entry[i] = NULL;
+      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 int
+expand_hashtable(void)
+{
+  ARR_Instance old_records;
+  Record *old_record, *new_record;
+  unsigned int i;
+
+  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(LOGF_ClientLog, "Tokens max %d packet %d shift %d",
+            *max_tokens, *tokens_per_packet, *token_shift);
 }

 /* ================================================== */
@@ -152,21 +303,35 @@ 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;

-  nodes = NULL;
-  max_nodes = 0;
-  n_nodes = 0;
+  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);

-  alloced = 0;
-  alloc_limit = CNF_GetClientLogLimit();
-  alloc_limit_reached = 0;
+  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);
+
+  active = !CNF_GetNoClientLog();
+  if (!active)
+    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 +339,334 @@ CLG_Initialise(void)
 void
 CLG_Finalise(void)
 {
-  int i;
-  
-  for (i = 0; i < n_nodes; i++)
-    Free(nodes[i]);
-  Free(nodes);
-}
-
-/* ================================================== */
-
-static void check_alloc_limit() {
-  if (alloc_limit_reached)
+  if (!active)
    return;

-  if (alloced >= alloc_limit) {
-    LOG(LOGS_WARN, LOGF_ClientLog, "Client log memory limit reached");
-    alloc_limit_reached = 1;
+  ARR_DestroyInstance(records);
+}
+
+/* ================================================== */
+
+static uint32_t
+get_ts_from_timespec(struct timespec *ts)
+{
+  uint32_t sec = ts->tv_sec, nsec = ts->tv_nsec;
+
+  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);

-static void
-create_node(Subnet *parent_subnet, int the_entry)
-{
-  Node *new_node;
-  new_node = MallocNew(Node);
-  parent_subnet->entry[the_entry] = (void *) new_node;
-  clear_node(new_node);
+  prev_hit = *last_hit;
+  *last_hit = now_ts;
+  (*hits)++;

-  alloced += sizeof (Node);
+  interval = now_ts - prev_hit;

-  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);
+  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;
    }
-    alloced += sizeof (Node *) * (max_nodes - n_nodes);
-  }
-  nodes[n_nodes++] = (Node *) new_node;
-  check_alloc_limit();
-}
-
-/* ================================================== */
-/* 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)
-{
-  uint32_t this_subnet;
-
-  this_subnet = get_subnet(addr, bits_consumed);
-  bits_consumed += NBITS;
-
-  if (bits_consumed < 32 * addr_len) {
-    if (!subnet->entry[this_subnet]) {
-      if (alloc_limit_reached)
-        return NULL;
-      create_subnet(subnet, this_subnet);
-    }
-    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);
-    }
-    return subnet->entry[this_subnet];
+    interval2 = -RATE_SCALE * (TS_FRAC + 1);
  }
-}

-/* ================================================== */
-
-void
-CLG_LogNTPClientAccess (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->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;
+  /* Update the rate in a rough approximation of exponential moving average */
+  if (*rate == INVALID_RATE) {
+    *rate = -interval2;
  } else {
-
-    if ((index < 0) || (index >= n_nodes)) {
-      return CLG_INDEXTOOLARGE;
+    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;
    }
-    
-    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;
+  }
+}
+
+/* ================================================== */
+
+static int
+get_index(Record *record)
+{
+  return record - (Record *)ARR_GetElements(records);
+}
+
+/* ================================================== */
+
+int
+CLG_GetClientIndex(IPAddr *client)
+{
+  Record *record;
+
+  record = get_record(client);
+  if (record == NULL)
+    return -1;
+
+  return get_index(record);
+}
+
+/* ================================================== */
+
+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(LOGF_ClientLog, "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);
+}
+
+/* ================================================== */
+
+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(LOGF_ClientLog, "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_leak_rate)
+    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_leak_rate)
+    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_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_GetServerStatsReport(RPT_ServerStatsReport *report)
+{
+  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 +33,17 @@

 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);

 /* 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  2013-2014
+ * 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;
+  src->params.offset = 0.0;

-  result = CPS_Success;
-  
  hostname = line;
  line = CPS_SplitWord(line);

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

-    /* Parse subfields */
-    done = 0;
-    do {
-      cmd = line;
-      line = CPS_SplitWord(line);
+  src->name = hostname;

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

-        } else 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, "noselect")) {
-          src->params.sel_option = SRC_SelectNoselect;
-        
-        } 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;
-          }
-
-        } else if (!strcasecmp(cmd, "maxsamples")) {
-          if (sscanf(line, "%d%n", &src->params.max_samples, &n) != 1) {
-            result = CPS_BadMaxsamples;
-            done = 1;
-          } else {
-            line += n;
-          }
-
-        } else {
-          result = CPS_BadOption;
-          done = 1;
-        }
-      } else {
-        done = 1;
-      }
-    } while (!done);
+    if (!strcasecmp(cmd, "auto_offline")) {
+      src->params.auto_offline = 1;
+    } else if (!strcasecmp(cmd, "iburst")) {
+      src->params.iburst = 1;
+    } else if (!strcasecmp(cmd, "offline")) {
+      src->params.online = 0;
+    } else if (!strcasecmp(cmd, "noselect")) {
+      src->params.sel_options |= SRC_SELECT_NOSELECT;
+    } else if (!strcasecmp(cmd, "prefer")) {
+      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)
+        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 {
+      return 0;
+    }
  }

-  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;
+    }
+
+    line += n;
  }

-  snprintf(dest, len, "Invalid %s", s);
+  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
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2015
+ * 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
@@ -47,20 +47,17 @@

 static int parse_string(char *line, char **result);
 static int parse_int(char *line, int *result);
-static int parse_uint32(char *, uint32_t *result);
 static int parse_double(char *line, double *result);
 static int parse_null(char *line);

-static void parse_allow(char *);
+static void parse_allow_deny(char *line, ARR_Instance restrictions, int allow);
 static void parse_bindacqaddress(char *);
 static void parse_bindaddress(char *);
 static void parse_bindcmdaddress(char *);
 static void parse_broadcast(char *);
 static void parse_clientloglimit(char *);
-static void parse_cmdallow(char *);
-static void parse_cmddeny(char *);
-static void parse_deny(char *);
 static void parse_fallbackdrift(char *);
+static void parse_hwtimestamp(char *);
 static void parse_include(char *);
 static void parse_initstepslew(char *);
 static void parse_leapsecmode(char *);
@@ -69,30 +66,30 @@ static void parse_log(char *);
 static void parse_mailonchange(char *);
 static void parse_makestep(char *);
 static void parse_maxchange(char *);
-static void parse_peer(char *);
-static void parse_pool(char *);
+static void parse_ratelimit(char *line, int *interval, int *burst, int *leak);
 static void parse_refclock(char *);
-static void parse_server(char *);
 static void parse_smoothtime(char *);
+static void parse_source(char *line, NTP_Source_Type type, int pool);
 static void parse_tempcomp(char *);

 /* ================================================== */
 /* Configuration variables */

 static int restarted = 0;
-static int generate_command_key = 0;
 static char *rtc_device;
 static int acquisition_port = -1;
 static int ntp_port = 123;
 static char *keys_file = NULL;
 static char *drift_file = NULL;
 static char *rtc_file = NULL;
-static uint32_t command_key_id;
 static double max_update_skew = 1000.0;
 static double correction_time_ratio = 3.0;
 static double max_clock_error = 1.0; /* in ppm */
+static double max_drift = 500000.0; /* in ppm */
 static double max_slew_rate = 1e6 / 12.0; /* in ppm */

+static double max_distance = 3.0;
+static double max_jitter = 1.0;
 static double reselect_distance = 1e-4;
 static double stratum_weight = 1e-3;
 static double combine_limit = 3.0;
@@ -112,6 +109,8 @@ static char *dumpdir;

 static int enable_local=0;
 static int local_stratum;
+static int local_orphan;
+static double local_distance;

 /* Threshold (in seconds) - if absolute value of initial error is less
   than this, slew instead of stepping */
@@ -126,7 +125,7 @@ static int enable_manual=0;
 static int rtc_on_utc = 0;

 /* Filename used to read the hwclock(8) LOCAL/UTC setting */
-static char *hwclock_file = NULL;
+static char *hwclock_file;

 /* Flag set if the RTC should be automatically synchronised by kernel */
 static int rtc_sync = 0;
@@ -149,12 +148,10 @@ static double max_offset;

 /* Maximum and minimum number of samples per source */
 static int max_samples = 0; /* no limit */
-static int min_samples = 0;
+static int min_samples = 6;

-/* Flag set if we should log to syslog when a time adjustment
-   exceeding the threshold is initiated */
-static int do_log_change = 0;
-static double log_change_threshold = 0.0;
+/* Threshold for a time adjustment to be logged to syslog */
+static double log_change_threshold = 1.0;

 static char *mail_user_on_change = NULL;
 static double mail_change_threshold = 0.0;
@@ -182,10 +179,24 @@ static IPAddr bind_acq_address4, bind_acq_address6;
   the loopback address will be used */
 static IPAddr bind_cmd_address4, bind_cmd_address6;

+/* Path to the Unix domain command socket. */
+static char *bind_cmd_path;
+
+/* Path to Samba (ntp_signd) socket. */
+static char *ntp_signd_socket = NULL;
+
 /* Filename to use for storing pid of running chronyd, to prevent multiple
 * chronyds being started. */
 static char *pidfile;

+/* Rate limiting parameters */
+static int ntp_ratelimit_interval = -10;
+static int ntp_ratelimit_burst = 16;
+static int ntp_ratelimit_leak = 2;
+static int cmd_ratelimit_interval = -10;
+static int cmd_ratelimit_burst = 16;
+static int cmd_ratelimit_leak = 0;
+
 /* Smoothing constants */
 static double smooth_max_freq = 0.0; /* in ppm */
 static double smooth_max_wander = 0.0; /* in ppm/s */
@@ -209,6 +220,9 @@ static char *leapsec_tz = NULL;
 /* Name of the user to which will be dropped root privileges. */
 static char *user;

+/* Array of strings for interfaces with HW timestamping */
+static ARR_Instance hwts_interfaces;
+
 typedef struct {
  NTP_Source_Type type;
  int pool;
@@ -310,6 +324,8 @@ CNF_Initialise(int r)
 {
  restarted = r;

+  hwts_interfaces = ARR_CreateInstance(sizeof (char *));
+
  init_sources = ARR_CreateInstance(sizeof (IPAddr));
  ntp_sources = ARR_CreateInstance(sizeof (NTP_Source));
  refclock_sources = ARR_CreateInstance(sizeof (RefclockParameters));
@@ -318,10 +334,12 @@ CNF_Initialise(int r)
  ntp_restrictions = ARR_CreateInstance(sizeof (AllowDeny));
  cmd_restrictions = ARR_CreateInstance(sizeof (AllowDeny));

-  dumpdir = Strdup(".");
-  logdir = Strdup(".");
-  pidfile = Strdup("/var/run/chronyd.pid");
-  rtc_device = Strdup("/dev/rtc");
+  dumpdir = Strdup("");
+  logdir = Strdup("");
+  bind_cmd_path = Strdup(DEFAULT_COMMAND_SOCKET);
+  pidfile = Strdup(DEFAULT_PID_FILE);
+  rtc_device = Strdup(DEFAULT_RTC_DEVICE);
+  hwclock_file = Strdup(DEFAULT_HWCLOCK_FILE);
  user = Strdup(DEFAULT_USER);
 }

@@ -332,6 +350,10 @@ CNF_Finalise(void)
 {
  unsigned int i;

+  for (i = 0; i < ARR_GetSize(hwts_interfaces); i++)
+    Free(*(char **)ARR_GetElement(hwts_interfaces, i));
+  ARR_DestroyInstance(hwts_interfaces);
+
  for (i = 0; i < ARR_GetSize(ntp_sources); i++)
    Free(((NTP_Source *)ARR_GetElement(ntp_sources, i))->params.name);

@@ -349,6 +371,8 @@ CNF_Finalise(void)
  Free(keys_file);
  Free(leapsec_tz);
  Free(logdir);
+  Free(bind_cmd_path);
+  Free(ntp_signd_socket);
  Free(pidfile);
  Free(rtc_device);
  Free(rtc_file);
@@ -370,10 +394,13 @@ CNF_ReadFile(const char *filename)

  in = fopen(filename, "r");
  if (!in) {
-    LOG_FATAL(LOGF_Configure, "Could not open configuration file %s", filename);
+    LOG_FATAL(LOGF_Configure, "Could not open configuration file %s : %s",
+              filename, strerror(errno));
    return;
  }

+  DEBUG_LOG(LOGF_Configure, "Reading %s", filename);
+
  for (i = 1; fgets(line, sizeof(line), in); i++) {
    CNF_ParseLine(filename, i, line);
  }
@@ -407,7 +434,7 @@ CNF_ParseLine(const char *filename, int number, char *line)
  if (!strcasecmp(command, "acquisitionport")) {
    parse_int(p, &acquisition_port);
  } else if (!strcasecmp(command, "allow")) {
-    parse_allow(p);
+    parse_allow_deny(p, ntp_restrictions, 1);
  } else if (!strcasecmp(command, "bindacqaddress")) {
    parse_bindacqaddress(p);
  } else if (!strcasecmp(command, "bindaddress")) {
@@ -419,19 +446,19 @@ CNF_ParseLine(const char *filename, int number, char *line)
  } else if (!strcasecmp(command, "clientloglimit")) {
    parse_clientloglimit(p);
  } else if (!strcasecmp(command, "cmdallow")) {
-    parse_cmdallow(p);
+    parse_allow_deny(p, cmd_restrictions, 1);
  } else if (!strcasecmp(command, "cmddeny")) {
-    parse_cmddeny(p);
+    parse_allow_deny(p, cmd_restrictions, 0);
  } else if (!strcasecmp(command, "cmdport")) {
    parse_int(p, &cmd_port);
+  } else if (!strcasecmp(command, "cmdratelimit")) {
+    parse_ratelimit(p, &cmd_ratelimit_interval, &cmd_ratelimit_burst, &cmd_ratelimit_leak);
  } else if (!strcasecmp(command, "combinelimit")) {
    parse_double(p, &combine_limit);
-  } else if (!strcasecmp(command, "commandkey")) {
-    parse_uint32(p, &command_key_id);
  } else if (!strcasecmp(command, "corrtimeratio")) {
    parse_double(p, &correction_time_ratio);
  } else if (!strcasecmp(command, "deny")) {
-    parse_deny(p);
+    parse_allow_deny(p, ntp_restrictions, 0);
  } else if (!strcasecmp(command, "driftfile")) {
    parse_string(p, &drift_file);
  } else if (!strcasecmp(command, "dumpdir")) {
@@ -440,10 +467,10 @@ CNF_ParseLine(const char *filename, int number, char *line)
    do_dump_on_exit = parse_null(p);
  } else if (!strcasecmp(command, "fallbackdrift")) {
    parse_fallbackdrift(p);
-  } else if (!strcasecmp(command, "generatecommandkey")) {
-    generate_command_key = parse_null(p);
  } else if (!strcasecmp(command, "hwclockfile")) {
    parse_string(p, &hwclock_file);
+  } else if (!strcasecmp(command, "hwtimestamp")) {
+    parse_hwtimestamp(p);
  } else if (!strcasecmp(command, "include")) {
    parse_include(p);
  } else if (!strcasecmp(command, "initstepslew")) {
@@ -454,10 +481,6 @@ CNF_ParseLine(const char *filename, int number, char *line)
    parse_leapsecmode(p);
  } else if (!strcasecmp(command, "leapsectz")) {
    parse_string(p, &leapsec_tz);
-  } else if (!strcasecmp(command, "linux_freq_scale")) {
-    LOG(LOGS_WARN, LOGF_Configure, "%s directive is no longer supported", command);
-  } else if (!strcasecmp(command, "linux_hz")) {
-    LOG(LOGS_WARN, LOGF_Configure, "%s directive is no longer supported", command);
  } else if (!strcasecmp(command, "local")) {
    parse_local(p);
  } else if (!strcasecmp(command, "lock_all")) {
@@ -467,7 +490,7 @@ CNF_ParseLine(const char *filename, int number, char *line)
  } else if (!strcasecmp(command, "logbanner")) {
    parse_int(p, &log_banner);
  } else if (!strcasecmp(command, "logchange")) {
-    do_log_change = parse_double(p, &log_change_threshold);
+    parse_double(p, &log_change_threshold);
  } else if (!strcasecmp(command, "logdir")) {
    parse_string(p, &logdir);
  } else if (!strcasecmp(command, "mailonchange")) {
@@ -480,6 +503,12 @@ CNF_ParseLine(const char *filename, int number, char *line)
    parse_maxchange(p);
  } else if (!strcasecmp(command, "maxclockerror")) {
    parse_double(p, &max_clock_error);
+  } else if (!strcasecmp(command, "maxdistance")) {
+    parse_double(p, &max_distance);
+  } else if (!strcasecmp(command, "maxdrift")) {
+    parse_double(p, &max_drift);
+  } else if (!strcasecmp(command, "maxjitter")) {
+    parse_double(p, &max_jitter);
  } else if (!strcasecmp(command, "maxsamples")) {
    parse_int(p, &max_samples);
  } else if (!strcasecmp(command, "maxslewrate")) {
@@ -492,14 +521,18 @@ CNF_ParseLine(const char *filename, int number, char *line)
    parse_int(p, &min_sources);
  } else if (!strcasecmp(command, "noclientlog")) {
    no_client_log = parse_null(p);
+  } else if (!strcasecmp(command, "ntpsigndsocket")) {
+    parse_string(p, &ntp_signd_socket);
  } else if (!strcasecmp(command, "peer")) {
-    parse_peer(p);
+    parse_source(p, NTP_PEER, 0);
  } else if (!strcasecmp(command, "pidfile")) {
    parse_string(p, &pidfile);
  } else if (!strcasecmp(command, "pool")) {
-    parse_pool(p);
+    parse_source(p, NTP_SERVER, 1);
  } else if (!strcasecmp(command, "port")) {
    parse_int(p, &ntp_port);
+  } else if (!strcasecmp(command, "ratelimit")) {
+    parse_ratelimit(p, &ntp_ratelimit_interval, &ntp_ratelimit_burst, &ntp_ratelimit_leak);
  } else if (!strcasecmp(command, "refclock")) {
    parse_refclock(p);
  } else if (!strcasecmp(command, "reselectdist")) {
@@ -517,7 +550,7 @@ CNF_ParseLine(const char *filename, int number, char *line)
  } else if (!strcasecmp(command, "sched_priority")) {
    parse_int(p, &sched_priority);
  } else if (!strcasecmp(command, "server")) {
-    parse_server(p);
+    parse_source(p, NTP_SERVER, 0);
  } else if (!strcasecmp(command, "smoothtime")) {
    parse_smoothtime(p);
  } else if (!strcasecmp(command, "stratumweight")) {
@@ -526,6 +559,11 @@ CNF_ParseLine(const char *filename, int number, char *line)
    parse_tempcomp(p);
  } else if (!strcasecmp(command, "user")) {
    parse_string(p, &user);
+  } else if (!strcasecmp(command, "commandkey") ||
+             !strcasecmp(command, "generatecommandkey") ||
+             !strcasecmp(command, "linux_freq_scale") ||
+             !strcasecmp(command, "linux_hz")) {
+    LOG(LOGS_WARN, LOGF_Configure, "%s directive is no longer supported", command);
  } else {
    other_parse_error("Invalid command");
  }
@@ -557,19 +595,6 @@ parse_int(char *line, int *result)

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

-static int
-parse_uint32(char *line, uint32_t *result)
-{
-  check_number_of_args(line, 1);
-  if (sscanf(line, "%"SCNu32, result) != 1) {
-    command_parse_error();
-    return 0;
-  }
-  return 1;
-}
-
-/* ================================================== */
-
 static int
 parse_double(char *line, double *result)
 {
@@ -595,17 +620,13 @@ parse_null(char *line)
 static void
 parse_source(char *line, NTP_Source_Type type, int pool)
 {
-  CPS_Status status;
  NTP_Source source;
-  char str[64];

  source.type = type;
  source.pool = pool;
-  status = CPS_ParseNTPSourceAdd(line, &source.params);

-  if (status != CPS_Success) {
-    CPS_StatusToString(status, str, sizeof (str));
-    other_parse_error(str);
+  if (!CPS_ParseNTPSourceAdd(line, &source.params)) {
+    command_parse_error();
    return;
  }

@@ -616,25 +637,28 @@ parse_source(char *line, NTP_Source_Type type, int pool)
 /* ================================================== */

 static void
-parse_server(char *line)
+parse_ratelimit(char *line, int *interval, int *burst, int *leak)
 {
-  parse_source(line, NTP_SERVER, 0);
-}
+  int n, val;
+  char *opt;

-/* ================================================== */
-
-static void
-parse_peer(char *line)
-{
-  parse_source(line, NTP_PEER, 0);
-}
-
-/* ================================================== */
-
-static void
-parse_pool(char *line)
-{
-  parse_source(line, NTP_SERVER, 1);
+  while (*line) {
+    opt = line;
+    line = CPS_SplitWord(line);
+    if (sscanf(line, "%d%n", &val, &n) != 1) {
+      command_parse_error();
+      return;
+    }
+    line += n;
+    if (!strcasecmp(opt, "interval"))
+      *interval = val;
+    else if (!strcasecmp(opt, "burst"))
+      *burst = val;
+    else if (!strcasecmp(opt, "leak"))
+      *leak = val;
+    else
+      command_parse_error();
+  }
 }

 /* ================================================== */
@@ -642,12 +666,12 @@ parse_pool(char *line)
 static void
 parse_refclock(char *line)
 {
-  int n, poll, dpoll, filter_length, pps_rate, min_samples, max_samples;
+  int n, poll, dpoll, filter_length, pps_rate, min_samples, max_samples, sel_options;
+  int max_lock_age;
  uint32_t ref_id, lock_ref_id;
  double offset, delay, precision, max_dispersion;
  char *p, *cmd, *name, *param;
  unsigned char ref[5];
-  SRC_SelectOption sel_option;
  RefclockParameters *refclock;

  poll = 4;
@@ -656,13 +680,14 @@ parse_refclock(char *line)
  pps_rate = 0;
  min_samples = SRC_DEFAULT_MINSAMPLES;
  max_samples = SRC_DEFAULT_MAXSAMPLES;
+  sel_options = 0;
  offset = 0.0;
  delay = 1e-9;
  precision = 0.0;
  max_dispersion = 0.0;
  ref_id = 0;
+  max_lock_age = 2;
  lock_ref_id = 0;
-  sel_option = SRC_SelectNormal;

  if (!*line) {
    command_parse_error();
@@ -683,17 +708,17 @@ parse_refclock(char *line)
  line = CPS_SplitWord(line);
  param = Strdup(p);

-  while (*line) {
-    cmd = line;
+  for (cmd = line; *cmd; line += n, cmd = line) {
    line = CPS_SplitWord(line);
+
    if (!strcasecmp(cmd, "refid")) {
      if (sscanf(line, "%4s%n", (char *)ref, &n) != 1)
        break;
-      ref_id = ref[0] << 24 | ref[1] << 16 | ref[2] << 8 | ref[3];
+      ref_id = (uint32_t)ref[0] << 24 | ref[1] << 16 | ref[2] << 8 | ref[3];
    } else if (!strcasecmp(cmd, "lock")) {
      if (sscanf(line, "%4s%n", (char *)ref, &n) != 1)
        break;
-      lock_ref_id = ref[0] << 24 | ref[1] << 16 | ref[2] << 8 | ref[3];
+      lock_ref_id = (uint32_t)ref[0] << 24 | ref[1] << 16 | ref[2] << 8 | ref[3];
    } else if (!strcasecmp(cmd, "poll")) {
      if (sscanf(line, "%d%n", &poll, &n) != 1) {
        break;
@@ -712,6 +737,9 @@ parse_refclock(char *line)
    } else if (!strcasecmp(cmd, "minsamples")) {
      if (sscanf(line, "%d%n", &min_samples, &n) != 1)
        break;
+    } else if (!strcasecmp(cmd, "maxlockage")) {
+      if (sscanf(line, "%d%n", &max_lock_age, &n) != 1)
+        break;
    } else if (!strcasecmp(cmd, "maxsamples")) {
      if (sscanf(line, "%d%n", &max_samples, &n) != 1)
        break;
@@ -729,18 +757,24 @@ parse_refclock(char *line)
        break;
    } else if (!strcasecmp(cmd, "noselect")) {
      n = 0;
-      sel_option = SRC_SelectNoselect;
+      sel_options |= SRC_SELECT_NOSELECT;
    } else if (!strcasecmp(cmd, "prefer")) {
      n = 0;
-      sel_option = SRC_SelectPrefer;
+      sel_options |= SRC_SELECT_PREFER;
+    } else if (!strcasecmp(cmd, "trust")) {
+      n = 0;
+      sel_options |= SRC_SELECT_TRUST;
+    } else if (!strcasecmp(cmd, "require")) {
+      n = 0;
+      sel_options |= SRC_SELECT_REQUIRE;
    } else {
-      break;
+      other_parse_error("Invalid refclock option");
+      return;
    }
-    line += n;
  }

-  if (*line) {
-    other_parse_error("Invalid/unreadable refclock parameter");
+  if (*cmd) {
+    command_parse_error();
    return;
  }

@@ -753,12 +787,13 @@ parse_refclock(char *line)
  refclock->pps_rate = pps_rate;
  refclock->min_samples = min_samples;
  refclock->max_samples = max_samples;
+  refclock->sel_options = sel_options;
  refclock->offset = offset;
  refclock->delay = delay;
  refclock->precision = precision;
  refclock->max_dispersion = max_dispersion;
-  refclock->sel_option = sel_option;
  refclock->ref_id = ref_id;
+  refclock->max_lock_age = max_lock_age;
  refclock->lock_ref_id = lock_ref_id;
 }

@@ -799,13 +834,9 @@ parse_log(char *line)
 static void
 parse_local(char *line)
 {
-  int stratum;
-  if (sscanf(line, "stratum%d", &stratum) == 1) {
-    local_stratum = stratum;
-    enable_local = 1;
-  } else {
+  if (!CPS_ParseLocal(line, &local_stratum, &local_orphan, &local_distance))
    command_parse_error();
-  }
+  enable_local = 1;
 }

 /* ================================================== */
@@ -868,11 +899,6 @@ parse_clientloglimit(char *line)
  if (sscanf(line, "%lu", &client_log_limit) != 1) {
    command_parse_error();
  }
-
-  if (client_log_limit == 0) {
-    /* unlimited */
-    client_log_limit = (unsigned long)-1;
-  }
 }

 /* ================================================== */
@@ -1034,41 +1060,6 @@ parse_allow_deny(char *line, ARR_Instance restrictions, int allow)
  }
 }
  
-
-/* ================================================== */
-
-static void
-parse_allow(char *line)
-{
-  parse_allow_deny(line, ntp_restrictions, 1);
-}
-
-
-/* ================================================== */
-
-static void
-parse_deny(char *line)
-{
-  parse_allow_deny(line, ntp_restrictions, 0);
-}
-
-/* ================================================== */
-
-static void
-parse_cmdallow(char *line)
-{
-  parse_allow_deny(line, cmd_restrictions, 1);
-}
-
-
-/* ================================================== */
-
-static void
-parse_cmddeny(char *line)
-{
-  parse_allow_deny(line, cmd_restrictions, 0);
-}
-
 /* ================================================== */

 static void
@@ -1113,7 +1104,14 @@ parse_bindcmdaddress(char *line)
  IPAddr ip;

  check_number_of_args(line, 1);
-  if (UTI_StringToIP(line, &ip)) {
+
+  /* Address starting with / is for the Unix domain socket */
+  if (line[0] == '/') {
+    parse_string(line, &bind_cmd_path);
+    /* / disables the socket */
+    if (!strcmp(bind_cmd_path, "/"))
+        bind_cmd_path[0] = '\0';
+  } else if (UTI_StringToIP(line, &ip)) {
    if (ip.family == IPADDR_INET4)
      bind_cmd_address4 = ip;
    else if (ip.family == IPADDR_INET6)
@@ -1238,10 +1236,60 @@ parse_tempcomp(char *line)
 /* ================================================== */

 static void
-parse_include(char *line)
+parse_hwtimestamp(char *line)
 {
  check_number_of_args(line, 1);
-  CNF_ReadFile(line);
+  *(char **)ARR_GetNewElement(hwts_interfaces) = Strdup(line);
+}
+
+/* ================================================== */
+
+static void
+parse_include(char *line)
+{
+  glob_t gl;
+  size_t i;
+
+  check_number_of_args(line, 1);
+
+  if (glob(line, 0, NULL, &gl)) {
+    DEBUG_LOG(LOGF_Configure, "glob of %s failed", line);
+    return;
+  }
+
+  for (i = 0; i < gl.gl_pathc; i++)
+    CNF_ReadFile(gl.gl_pathv[i]);
+
+  globfree(&gl);
+}
+
+/* ================================================== */
+
+void
+CNF_CreateDirs(uid_t uid, gid_t gid)
+{
+  char *dir;
+
+  /* Create a directory for the Unix domain command socket */
+  if (bind_cmd_path[0]) {
+    dir = UTI_PathToDir(bind_cmd_path);
+    UTI_CreateDirAndParents(dir, 0770, uid, gid);
+
+    /* Check the permissions and owner/group in case the directory already
+       existed.  It MUST NOT be accessible by others as permissions on Unix
+       domain sockets are ignored on some systems (e.g. Solaris). */
+    if (!UTI_CheckDirPermissions(dir, 0770, uid, gid)) {
+      LOG(LOGS_WARN, LOGF_Configure, "Disabled command socket %s", bind_cmd_path);
+      bind_cmd_path[0] = '\0';
+    }
+
+    Free(dir);
+  }
+
+  if (logdir[0])
+    UTI_CreateDirAndParents(logdir, 0755, uid, gid);
+  if (dumpdir[0])
+    UTI_CreateDirAndParents(dumpdir, 0755, uid, gid);
 }

 /* ================================================== */
@@ -1449,22 +1497,6 @@ CNF_GetRtcDevice(void)

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

-uint32_t
-CNF_GetCommandKey(void)
-{
-  return command_key_id;
-}
-
-/* ================================================== */
-
-int
-CNF_GetGenerateCommandKey(void)
-{
-  return generate_command_key;
-}
-
-/* ================================================== */
-
 int
 CNF_GetDumpOnExit(void)
 {
@@ -1481,6 +1513,14 @@ CNF_GetMaxUpdateSkew(void)

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

+double
+CNF_GetMaxDrift(void)
+{
+  return max_drift;
+}
+
+/* ================================================== */
+
 double
 CNF_GetMaxClockError(void)
 {
@@ -1505,6 +1545,22 @@ CNF_GetMaxSlewRate(void)

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

+double
+CNF_GetMaxDistance(void)
+{
+  return max_distance;
+}
+
+/* ================================================== */
+
+double
+CNF_GetMaxJitter(void)
+{
+  return max_jitter;
+}
+
+/* ================================================== */
+
 double
 CNF_GetReselectDistance(void)
 {
@@ -1545,10 +1601,12 @@ CNF_GetCommandPort(void) {
 /* ================================================== */

 int
-CNF_AllowLocalReference(int *stratum)
+CNF_AllowLocalReference(int *stratum, int *orphan, double *distance)
 {
  if (enable_local) {
    *stratum = local_stratum;
+    *orphan = local_orphan;
+    *distance = local_distance;
    return 1;
  } else {
    return 0;
@@ -1592,11 +1650,10 @@ CNF_GetMaxChange(int *delay, int *ignore, double *offset)

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

-void
-CNF_GetLogChange(int *enabled, double *threshold)
+double
+CNF_GetLogChange(void)
 {
-  *enabled = do_log_change;
-  *threshold = log_change_threshold;
+  return log_change_threshold;
 }

 /* ================================================== */
@@ -1697,6 +1754,14 @@ CNF_GetBindAcquisitionAddress(int family, IPAddr *addr)

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

+char *
+CNF_GetBindCommandPath(void)
+{
+  return bind_cmd_path;
+}
+
+/* ================================================== */
+
 void
 CNF_GetBindCommandAddress(int family, IPAddr *addr)
 {
@@ -1710,6 +1775,14 @@ CNF_GetBindCommandAddress(int family, IPAddr *addr)

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

+char *
+CNF_GetNtpSigndSocket(void)
+{
+  return ntp_signd_socket;
+}
+
+/* ================================================== */
+
 char *
 CNF_GetPidFile(void)
 {
@@ -1750,6 +1823,24 @@ CNF_GetLockMemory(void)

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

+void CNF_GetNTPRateLimit(int *interval, int *burst, int *leak)
+{
+  *interval = ntp_ratelimit_interval;
+  *burst = ntp_ratelimit_burst;
+  *leak = ntp_ratelimit_leak;
+}
+
+/* ================================================== */
+
+void CNF_GetCommandRateLimit(int *interval, int *burst, int *leak)
+{
+  *interval = cmd_ratelimit_interval;
+  *burst = cmd_ratelimit_burst;
+  *leak = cmd_ratelimit_leak;
+}
+
+/* ================================================== */
+
 void
 CNF_GetSmooth(double *max_freq, double *max_wander, int *leap_only)
 {
@@ -1827,3 +1918,11 @@ CNF_GetInitStepThreshold(void)
 {
  return init_slew_threshold;
 }
+
+/* ================================================== */
+
+ARR_Instance
+CNF_GetHwTsInterfaces(void)
+{
+  return hwts_interfaces;
+}
--- a/conf.h
+++ b/conf.h
@@ -29,6 +29,7 @@
 #define GOT_CONF_H

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

 extern void CNF_Initialise(int restarted);
@@ -39,6 +40,8 @@ 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);
@@ -58,8 +61,6 @@ 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);
@@ -67,7 +68,7 @@ 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);
@@ -75,6 +76,8 @@ 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);
@@ -82,20 +85,25 @@ 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 void CNF_GetNTPRateLimit(int *interval, int *burst, int *leak);
+extern void 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);

@@ -112,4 +120,6 @@ extern char *CNF_GetHwclockFile(void);
 extern int CNF_GetInitSources(void);
 extern double CNF_GetInitStepThreshold(void);

+extern ARR_Instance CNF_GetHwTsInterfaces(void);
+
 #endif /* GOT_CONF_H */
--- a/390
+++ b/390
@@ -4,32 +4,12 @@
 # chronyd/chronyc - Programs for keeping computer clocks accurate.
 #
 # Copyright (C) Richard P. Curnow  1997-2003
-# Copyright (C) Miroslav Lichvar  2009, 2012-2014
+# Copyright (C) Miroslav Lichvar  2009, 2012-2015
 #
 # =======================================================================

 # 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 +21,10 @@ 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 +80,8 @@ 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 +93,21 @@ 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 +116,10 @@ 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 +163,12 @@ 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 +202,11 @@ 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 +218,16 @@ 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 +272,6 @@ do
    --datarootdir=* )
      SETDATAROOTDIR=`echo $option | sed -e 's/^.*=//;'`
    ;;
-    --infodir=* )
-      SETINFODIR=`echo $option | sed -e 's/^.*=//;'`
-    ;;
    --mandir=* )
      SETMANDIR=`echo $option | sed -e 's/^.*=//;'`
    ;;
@@ -283,6 +281,9 @@ 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 +308,51 @@ 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/^.*=//;'`
    ;;
@@ -356,78 +387,65 @@ 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"
    ;;
-    Darwin-* )
+    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
-        echo "Configuring for MacOS X (" $SYSTEM "MacOS X version" $VERSION ")"
+        if [ $feat_droproot = "1" ]; then
+          add_def FEAT_PRIVDROP
+          priv_ops="ADJUSTTIME SETTIME BINDSOCKET"
+        fi
+        echo "Configuring for macOS (" $SYSTEM "macOS version" $VERSION ")"
    ;;
-    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"                              
+    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
@@ -445,8 +463,13 @@ 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
@@ -460,6 +483,35 @@ 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$MYCC" = "x" ]; then
+  MYCC=gcc
+  if ! test_code "$MYCC" '' '' '' ''; then
+    MYCC=cc
+    if ! test_code "$MYCC" '' '' '' ''; then
+      echo "error: no C compiler found"
+      exit 1
+    fi
+  fi
+else
+  if ! test_code "$MYCC" '' '' '' ''; then
+    echo "error: C compiler $MYCC cannot create executables"
+    exit 1
+  fi
+fi
+
+if [ "x$MYCFLAGS" = "x" ]; then
+  MYCFLAGS="-O2 -g"
+fi
+
+if [ "x$MYCC" = "xgcc" ]; then
+  MYCFLAGS="$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];'
@@ -471,8 +523,8 @@ 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=$((50 * 365))
@@ -501,7 +553,7 @@ else
  if test_code 'math in -lm' 'math.h' '' '-lm' "$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
@@ -514,21 +566,28 @@ 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
@@ -536,7 +595,22 @@ 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' '' "$EXTRA_LIBS" \
  'return getaddrinfo(0, 0, 0, 0);'
 then
  add_def HAVE_GETADDRINFO
@@ -552,6 +626,39 @@ then
  MYCFLAGS="$MYCFLAGS -pthread"
 fi

+if test_code 'arc4random_buf()' 'stdlib.h' '' '' 'arc4random_buf(NULL, 0);'; then
+  add_def HAVE_ARC4RANDOM
+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"
+fi
+
 timepps_h=""
 if [ $feat_refclock = "1" ] && [ $feat_pps = "1" ]; then
  if test_code '<sys/timepps.h>' 'sys/timepps.h' '' '' ''; then
@@ -586,6 +693,33 @@ then
    EXTRA_LIBS="$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" ] && [ $try_seccomp = "1" ] && \
+  test_code seccomp 'seccomp.h' '' '-lseccomp' \
+    'seccomp_init(SCMP_ACT_KILL);'
+then
+  add_def FEAT_SCFILTER
+  # NAME2IPADDRESS shouldn't be enabled with other operations as the helper
+  # process works on one request at the time and the async resolver could
+  # block the main thread
+  priv_ops="NAME2IPADDRESS"
+  EXTRA_LIBS="$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);'
@@ -595,19 +729,11 @@ then
 fi

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

 if [ $try_setsched = "1" ] && \
@@ -637,7 +763,6 @@ then
  add_def FORCE_DNSRETRY
 fi

-READLINE_COMPILE=""
 READLINE_LINK=""
 if [ $feat_readline = "1" ]; then
  if [ $try_editline = "1" ]; then
@@ -647,7 +772,7 @@ 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
@@ -658,7 +783,7 @@ 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
@@ -670,7 +795,7 @@ 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
@@ -679,7 +804,6 @@ if [ $feat_readline = "1" ]; then
 fi

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

 if [ $feat_sechash = "1" ] && [ $try_nss = "1" ]; then
@@ -690,9 +814,9 @@ 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
@@ -702,9 +826,9 @@ 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
@@ -739,11 +863,6 @@ 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
@@ -759,29 +878,40 @@ 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}%;\
@@ -792,18 +922,20 @@ 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 +1,172 @@
+// 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 sent to the terminal instead of to syslog. When
+*chronyd* was compiled with debugging support, this option can be used twice to
+print also debugging messages.
+
+*-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 *-q*, but it will only print the offset without any
+corrections of the clock.
+
+*-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
+and Solaris).
+
+*-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.
+
+*-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
@@ -1,55 +1,91 @@
+// 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:

-Frequently Asked Questions
-==========================
+== `chrony` compared to other programs

-== Chrony compared to other programs
+=== How does `chrony` compare to `ntpd`?

-=== 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.

-+chrony+ can usually synchronise the system clock faster and with better time
-accuracy, but it doesn't implement all NTP features, e.g. broadcast/multicast
-mode, or authentication based on public-key cryptography.  For a more detailed
-comparison, see the http://chrony.tuxfamily.org/comparison.html[comparison
-page] on the chrony website and section
-http://chrony.tuxfamily.org/manual.html#Comparison-with-ntpd[Comparison with
-ntpd] in the manual.
+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.

-If your computer connects to the 'net only for few minutes at a time, you turn
-your Linux computer off or suspend it frequently, the clock is not very stable
-(e.g. it is a virtual machine), or you want to use NTP on an isolated network
-with no hardware clocks in sight, +chrony+ will probably work much better for
-you.
-
-The original reason +chrony+ was written was that ntpd (called xntpd at the
-time) could not to do anything sensible on a PC which was connected to the 'net
-only for about 5 minutes once or twice a day, mainly to upload/download email
-and news.  The requirements were
-
-* slew the time to correct it when going online and NTP servers
-  become visible
-* determine the rate at which the computer gains or loses time and
-  use this information to keep it reasonably correct between connects
-  to the 'net.  This has to be done using a method that does not care
-  about the intermittent availability of the references or the fact
-  the computer is turned off between groups of measurements.
-* maintain the time across reboots, by working out the error and
-  drift rate of the computer's real-time clock and using this
-  information to set the system clock correctly at boot up.
-
-Also, when working with isolated networks with no true time references at all
-ntpd was found to give no help with managing the local clock's gain/loss rate
-on the NTP master node (which was set from watch).  Some automated support was
-added to +chrony+ to deal with this.
+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 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 master, with
-the others as clients of it.  Add a +local+ directive to the master's
-'chrony.conf' file.  This configuration will be better because
+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
@@ -58,64 +94,84 @@ the others as clients of it.  Add a +local+ directive to the master's

 === 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 hostnames specified in the +server+ and +peer+ directives in
-increasing intervals until it succeeds.  The +online+ command can be
-issued from +chronyc+ to try to resolve them immediately.
+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 try to resolve them immediately.

-=== How can I make chronyd more secure?
+=== 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
+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
+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.
+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, you can disable the command sockets
-by adding +cmdport 0+ to the configuration file.
+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.

-On Linux, if +chronyd+ is compiled with support for Linux capabilities
-(available in the libcap library), you can specify an unprivileged user with
-the +-u+ option or +user+ directive in the 'chrony.conf' file to drop root
-privileges after start.  The configure option +--with-user+ can be used to drop
-the privileges by default.
+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 falsetickers and combine
-measurements from multiple sources.
+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.

-There are also useful options which can be set in the +server+ directive, they
-are +minpoll+, +maxpoll+, +polltarget+, +maxdelay+, +maxdelayratio+ and
-+maxdelaydevratio+.
+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 6 (samples) for +polltarget+.  The default values should be used
-for general servers on the internet.  With your own NTP servers or if have
+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 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 on many factors, including the ratio
-between the wander of the clock and the network jitter (sometimes expressed in
-NTP documents as the Allan intercept), the temperature sensitivity of the
-crystal oscillator and the maximum rate of change of the temperature.
+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
+An example of the directive for an NTP server on the Internet that you are
 allowed to poll frequently could be

 ----
@@ -131,143 +187,237 @@ 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
+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 receive server's more accurate
+hardware or kernel transmit timestamps. When combined with local hardware
+timestamping, a sub-microsecond accuracy may be possible. An example could be
+
+----
+server ntp.local minpoll 2 maxpoll 2 xleave
+hwtimestamp eth0
+----
+
+=== 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
+This is the most common problem. There are a number of reasons, see the
 following questions.

 === Behind a firewall?

-If there is a firewall between you and the NTP server you're trying to use, the
-packets may be blocked.  Try using a tool like wireshark or tcpdump to see if
-you're getting responses from the server.  If you have an external modem, see
-if the receive light blinks straight after the transmit light (when the link is
-quiet apart from the NTP traffic.)  Try adding +log measurements+ to the
-'chrony.conf' file and look in the 'measurements.log' file after +chrony+ has
-been running for a short period. See if any measurements appear.
+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.

-=== Are NTP servers specified with the +offline+ option?
+When `chronyd` is receiving responses from the servers, the output of the
+`sources` command issued few minutes after `chronyd` start might look like
+this:

-Check that you're using +chronyc+\'s +online+ and +offline+ commands
-appropriately.  Again, check in 'measurements.log' to see if you're getting any
+----
+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. Again, check in _measurements.log_ to see if you're getting any
 data back from the server.

-== Issues with +chronyc+
+=== Is `chronyd` allowed to step the system clock?

-=== I keep getting the error +506 Cannot talk to daemon+
+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.

-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.
+The `makestep` directive can be used to allow `chronyd` to step the clock. For
+example, if _chrony.conf_ had

-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).
+----
+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.
+323/udp. You need to amend the firewall configuration in this case.

-=== Is the +chronyc+ / +chronyd+ protocol documented anywhere?
+=== I keep getting the error `501 Not authorised`

-Only by the source code :-) See 'cmdmon.c' (+chronyd+ side) and 'client.c'
-(+chronyc+ side).
+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 works with 1 second resolution.  +chronyd+ can monitor the rate at which the
-real-time clock gains or loses time, and compensate for it when you set the
-system time from it at the next reboot.  See the documentation for details.
+It is used to initialize the system clock on boot. It normally doesn't drift
+more than few seconds per day.

-=== I want to use +chronyd+'s real-time clock support. Must I disable hwclock?
+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 hwclock program is often set-up by default in the boot and shutdown scripts
-with many Linux installations.  If you want to use +chronyd+'s real-time clock
-support, the important thing is 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+ 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.
+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.

-There is no need to remove hwclock from the boot process, as long as +chronyd+
+=== 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
+=== I just keep getting the `513 RTC driver not running` message

-For the real time clock support to work, you need the following three
+For the real-time clock support to work, you need the following three
 things

-* a kernel that is supported (e.g. 2.2 onwards)
-* enhanced RTC support compiled into the kernel
-* an +rtcfile+ directive in your 'chrony.conf' file
+* an RTC in your computer
+* a Linux kernel with enabled RTC support
+* an `rtcfile` directive in your _chrony.conf_ file

-== Microsoft Windows
+=== I get `Could not open /dev/rtc, Device or resource busy` in my syslog file

-=== Does +chrony+ support Windows?
+Some other program running on the system may be using the device.

-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'
+== 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 server(s) that it thinks are online.
+When the network is connected again, it will take some time (on average half of
+the maximum polling interval) before new measurements are made and the clock is
+corrected. If the servers were set to offline and the `online` command was
+issued when the network was connected, `chronyd` would make new measurements
+immediately.
+
+The `auto_offline` option to the `server` entry in the _chrony.conf_ file may
+be useful to switch the servers to the offline state automatically.
+
+== 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
+We have no plans to do this. Anyone is welcome to pick this work up and
 contribute it back to the project.
-
-== NTP-specific issues
-
-=== Can +chrony+ be driven from broadcast NTP servers?
-
-No, this NTP mode is not implemented yet.
-
-=== Can chronyd transmit broadcast NTP packets (e.g. to synchronise other computers on a private LAN)?
-
-Yes.  Starting from version 1.17, +chrony+ has this capability.
-
-=== Can +chrony+ keep the system clock a fixed offset away from real time?
-
-This is not possible as the program currently stands.
-
-=== What happens if the network connection is dropped without using +chronyc+'s +offline+ command first?
-
-+chronyd+ will keep trying to access the server(s) that it thinks are online.
-When the network is connected again, it will take some time (on average half of
-the current polling interval) before new measurements are made and the clock is
-corrected. If the servers were set to offline and the +online+ command was
-issued when the network was connected, +chronyd+ would make new measurements
-immediately.
-
-The +auto_offline+ option to the +server+ entry in the 'chrony.conf' file may
-be useful to switch the servers to the offline state automatically.
-
-== Linux-specific issues
-
-=== 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.
-
-== Solaris-specific issues
-
-=== I get an error message about not being able to open kvm to change dosynctodr
-
-(The dosynctodr variable controls whether Solaris couples the equivalent
-of its BIOS clock into its system clock at regular intervals).  The
-Solaris port of +chrony+ was developed in the Solaris 2.5 era.  Some
-aspect of the Solaris kernel has changed which prevents the same
-technique working.  We no longer have root access to any Solaris
-machines to work on this, and we are reliant on somebody developing the
-patch and testing it.
--- 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
@@ -9,7 +9,7 @@ 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
@@ -5,8 +5,8 @@ pool pool.ntp.org iburst
 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
+# if the adjustment 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
@@ -6,8 +6,8 @@ pool pool.ntp.org iburst
 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
+# if the adjustment is larger than 1 second.
+makestep 1.0 3

 # Enable kernel synchronization of the real-time clock (RTC).
 rtcsync
@@ -18,20 +18,8 @@ rtcsync
 # Serve time even if not synchronized to any NTP server.
 #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
@@ -95,24 +79,10 @@

 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 +112,15 @@ 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
@@ -221,6 +191,13 @@ generatecommandkey

 ! 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.
+
+! limitrate interval 3 burst 8
+
 #######################################################################
 ### REPORTING BIG CLOCK CHANGES
 # Perhaps you want to know if chronyd suddenly detects any large error
@@ -247,6 +224,7 @@ 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 +240,10 @@ 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 1 burst 16

 #######################################################################
 ### REAL TIME CLOCK
--- 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).
@@ -28,29 +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/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/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 +1,204 @@
+/*
+  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
+
+/* Minimum interval between samples (in seconds) */
+#define MIN_SAMPLE_SEPARATION 1.0
+
+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;
+
+  /* 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(void)
+{
+  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;
+
+  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)) >= MIN_SAMPLE_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 < MIN_SAMPLE_SEPARATION / 2.0) {
+      clock->n_samples = 0;
+      DEBUG_LOG(LOGF_HwClocks, "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;
+
+  /* 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-9, &clock->offset, &raw_freq,
+                                 &n_runs, &best_start);
+
+  if (!clock->valid_coefs) {
+    DEBUG_LOG(LOGF_HwClocks, "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(LOGF_HwClocks, "HW clock reset offset=%e", clock->offset);
+    clock->offset = 0.0;
+    clock->n_samples = 1;
+  }
+
+  DEBUG_LOG(LOGF_HwClocks, "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);
+
+  /* Estimation of the error is not implemented yet */
+  if (err)
+    *err = 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  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
@@ -21,20 +21,28 @@

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

-  The header file for the adjtimex wrapper
-  */
+  Header for tracking of hardware clocks */

-#ifndef GOT_WRAP_ADJTIMEX_H
-#define GOT_WRAP_ADJTIMEX_H
+#ifndef GOT_HWCLOCK_H
+#define GOT_HWCLOCK_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_GetLeap(int *leap);
-int TMX_SetSync(int sync, double est_error, double max_error);
-int TMX_TestStepOffset(void);
-int TMX_ApplyStepOffset(double offset);
+typedef struct HCL_Instance_Record *HCL_Instance;

-#endif  /* GOT_WRAP_ADJTIMEX_H */
+/* Create a new HW clock instance */
+extern HCL_Instance HCL_CreateInstance(void);

+/* 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(LOGF_Keys, "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;
+  }
 }

 /* ================================================== */
@@ -257,7 +222,7 @@ KEY_Reload(void)
      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);
      continue;
@@ -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
@@ -42,13 +42,12 @@

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

-/* Maximum allowed frequency offset in ppm, the time must not stop
-   or run backwards */
-#define MAX_FREQ 500000.0
-
 /* 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;

@@ -107,37 +106,42 @@ 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);
@@ -166,6 +170,11 @@ 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;
 }

@@ -274,7 +283,7 @@ 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)
 {
@@ -341,23 +350,29 @@ 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(LOGF_Local, "clock_gettime() failed : %s", strerror(errno));
+#else
+  struct timeval tv;
+
+  if (gettimeofday(&tv, NULL) < 0)
+    LOG_FATAL(LOGF_Local, "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);
@@ -366,18 +381,18 @@ 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);
@@ -406,18 +421,18 @@ LCL_ReadAbsoluteFrequency(void)
 static double
 clamp_freq(double freq)
 {
-  if (freq <= MAX_FREQ && freq >= -MAX_FREQ)
+  if (freq <= max_freq_ppm && freq >= -max_freq_ppm)
    return freq;

  LOG(LOGS_WARN, LOGF_Local, "Frequency %.1f ppm exceeds allowed maximum", freq);

-  return freq >= MAX_FREQ ? MAX_FREQ : -MAX_FREQ;
+  return CLAMP(-max_freq_ppm, freq, max_freq_ppm);
 }

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

 static int
-check_offset(struct timeval *now, double offset)
+check_offset(struct timespec *now, double offset)
 {
  /* Check if the time will be still sane with accumulated offset */
  if (UTI_IsTimeOffsetSane(now, -offset))
@@ -435,7 +450,7 @@ check_offset(struct timeval *now, double offset)
 void
 LCL_SetAbsoluteFrequency(double afreq_ppm)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;
  double dfreq;
  
  afreq_ppm = clamp_freq(afreq_ppm);
@@ -466,7 +481,7 @@ 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;
@@ -495,7 +510,7 @@ 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 */
@@ -517,7 +532,7 @@ LCL_AccumulateOffset(double offset, double corr_rate)
 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 */
@@ -545,7 +560,7 @@ LCL_ApplyStepOffset(double offset)
 /* ================================================== */

 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 */
@@ -559,7 +574,7 @@ LCL_NotifyExternalTimeStep(struct timeval *raw, struct timeval *cooked,
 void
 LCL_NotifyLeap(int leap)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;

  LCL_ReadRawTime(&raw);
  LCL_CookTime(&raw, &cooked, NULL);
@@ -576,7 +591,7 @@ LCL_NotifyLeap(int leap)
 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);
@@ -653,7 +668,7 @@ lcl_RegisterSystemDrivers(lcl_ReadFrequencyDriver read_freq,
 int
 LCL_MakeStep(void)
 {
-  struct timeval raw;
+  struct timespec raw;
  double correction;

  LCL_ReadRawTime(&raw);
--- 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,
@@ -163,7 +162,7 @@ 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
--- a/localp.h
+++ b/localp.h
@@ -52,7 +52,7 @@ 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);
--- 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 */
@@ -49,10 +48,6 @@ 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 +69,6 @@ void
 LOG_Initialise(void)
 {
  initialised = 1;
-
-#ifdef WINNT
-  logfile = fopen("./chronyd.err", "a");
-#endif
 }

 /* ================================================== */
@@ -86,15 +77,9 @@ LOG_Initialise(void)
 void
 LOG_Finalise(void)
 {
-#ifdef WINNT
-  if (logfile) {
-    fclose(logfile);
-  }
-#else
  if (system_log) {
    closelog();
  }
-#endif

  LOG_CycleLogFiles();

@@ -105,11 +90,6 @@ 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) {
@@ -135,32 +115,33 @@ static void log_message(int fatal, LOG_Severity severity, const char *message)
  } else {
    fprintf(stderr, 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
+                 LOG_Facility facility, 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);
+#if DEBUG > 0
    if (debug_level >= DEBUG_LEVEL_PRINT_FUNCTION)
      fprintf(stderr, "%s:%d:(%s) ", filename, line_number, function_name);
-  }
 #endif
+  }

  va_start(other_args, format);
  vsnprintf(buf, sizeof(buf), format, other_args);
@@ -198,11 +179,8 @@ void LOG_Message(LOG_Severity severity, LOG_Facility facility,
 void
 LOG_OpenSystemLog(void)
 {
-#ifdef WINNT
-#else
  system_log = 1;
  openlog("chronyd", LOG_PID, LOG_DAEMON);
-#endif
 }

 /* ================================================== */
@@ -260,12 +238,18 @@ 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, LOGF_Logging, "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, LOGF_Logging, "Could not open log file %s", filename);
      logfiles[id].name = NULL;
      return;
    }
@@ -300,20 +284,6 @@ 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

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

+#define LOG(severity, facility, ...) LOG_MESSAGE(severity, facility, __VA_ARGS__)
+
 /* Definition of severity */
 typedef enum {
  LOGS_INFO,
@@ -72,7 +82,9 @@ typedef enum {
 typedef enum {
  LOGF_Reference,
  LOGF_NtpIO,
+  LOGF_NtpIOLinux,
  LOGF_NtpCore,
+  LOGF_NtpSignd,
  LOGF_NtpSources,
  LOGF_Scheduler,
  LOGF_SourceStats,
@@ -81,6 +93,7 @@ typedef enum {
  LOGF_Util,
  LOGF_Main,
  LOGF_Memory,
+  LOGF_Client,
  LOGF_ClientLog,
  LOGF_Configure,
  LOGF_CmdMon,
@@ -89,6 +102,7 @@ typedef enum {
  LOGF_Keys,
  LOGF_Logging,
  LOGF_Nameserv,
+  LOGF_PrivOps,
  LOGF_Rtc,
  LOGF_Regress,
  LOGF_Sys,
@@ -97,11 +111,12 @@ typedef enum {
  LOGF_SysMacOSX,
  LOGF_SysNetBSD,
  LOGF_SysSolaris,
-  LOGF_SysSunOS,
+  LOGF_SysTimex,
  LOGF_SysWinnt,
  LOGF_TempComp,
  LOGF_RtcLinux,
  LOGF_Refclock,
+  LOGF_HwClocks,
  LOGF_Smooth,
 } LOG_Facility;

@@ -112,10 +127,15 @@ extern void LOG_Initialise(void);
 extern void LOG_Finalise(void);

 /* Line logging function */
+#if DEBUG > 0
 FORMAT_ATTRIBUTE_PRINTF(6, 7)
 extern void LOG_Message(LOG_Severity severity, LOG_Facility facility,
                        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
@@ -142,7 +162,6 @@ 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  2012-2015
 * 
 * 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
@@ -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"
@@ -49,8 +50,10 @@
 #include "refclock.h"
 #include "clientlog.h"
 #include "nameserv.h"
+#include "privops.h"
 #include "smooth.h"
 #include "tempcomp.h"
+#include "util.h"

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

@@ -67,6 +70,18 @@ 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)
 {
@@ -93,11 +108,12 @@ MAI_CleanupAndExit(void)
  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();
@@ -106,6 +122,7 @@ MAI_CleanupAndExit(void)
  SYS_Finalise();
  SCH_Finalise();
  LCL_Finalise();
+  PRV_Finalise();

  delete_pidfile();
  
@@ -128,6 +145,16 @@ 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)
 {
@@ -141,6 +168,7 @@ ntp_source_resolving_end(void)
    SRC_ReloadSources();
  }

+  SRC_RemoveDumpFiles();
  RTC_StartMeasurements();
  RCL_StartRefclocks();
  NSR_StartSources();
@@ -264,7 +292,7 @@ write_lockfile(void)
  if (!out) {
    LOG_FATAL(LOGF_Main, "could not open lockfile %s for writing", pidfile);
  } else {
-    fprintf(out, "%d\n", getpid());
+    fprintf(out, "%d\n", (int)getpid());
    fclose(out);
  }
 }
@@ -274,24 +302,19 @@ 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(LOGF_Main, "Could not detach, 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(LOGF_Main, "Could not detach, fork failed : %s", strerror(errno));
  } else if (pid > 0) {
    /* In the 'grandparent' */
    char message[1024];
@@ -316,7 +339,7 @@ go_daemon(void)
    pid = fork();

    if (pid < 0) {
-      LOG_FATAL(LOGF_Logging, "Could not detach, fork failed : %s", strerror(errno));
+      LOG_FATAL(LOGF_Main, "Could not detach, fork failed : %s", strerror(errno));
    } else if (pid > 0) {
      exit(0); /* In the 'parent' */
    } else {
@@ -324,7 +347,7 @@ go_daemon(void)

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

      /* Don't keep stdin/out/err from before. But don't close
@@ -337,8 +360,6 @@ go_daemon(void)
      LOG_SetParentFd(pipefd[1]);
    }
  }
-
-#endif
 }

 /* ================================================== */
@@ -349,13 +370,16 @@ int main
  const char *conf_file = DEFAULT_CONF_FILE;
  const char *progname = argv[0];
  char *user = NULL;
+  struct passwd *pw;
  int debug = 0, nofork = 0, address_family = IPADDR_UNSPEC;
-  int do_init_rtc = 0, restarted = 0;
+  int do_init_rtc = 0, restarted = 0, timeout = 0;
  int other_pid;
-  int lock_memory = 0, sched_priority = 0;
+  int scfilter_level = 0, lock_memory = 0, sched_priority = 0;
  int system_log = 1;
  int config_args = 0;

+  do_platform_checks();
+
  LOG_Initialise();

  /* Parse command line options */
@@ -382,6 +406,10 @@ int main
      } else {
        user = *argv;
      }
+    } else if (!strcmp("-F", *argv)) {
+      ++argv, --argc;
+      if (argc == 0 || sscanf(*argv, "%d", &scfilter_level) != 1)
+        LOG_FATAL(LOGF_Main, "Bad syscall filter level");
    } else if (!strcmp("-s", *argv)) {
      do_init_rtc = 1;
    } else if (!strcmp("-v", *argv) || !strcmp("--version",*argv)) {
@@ -402,12 +430,16 @@ int main
      ref_mode = REF_ModePrintOnce;
      nofork = 1;
      system_log = 0;
+    } else if (!strcmp("-t", *argv)) {
+      ++argv, --argc;
+      if (argc == 0 || sscanf(*argv, "%d", &timeout) != 1 || timeout <= 0)
+        LOG_FATAL(LOGF_Main, "Bad timeout");
    } else if (!strcmp("-4", *argv)) {
      address_family = IPADDR_INET4;
    } else if (!strcmp("-6", *argv)) {
      address_family = IPADDR_INET6;
    } else if (!strcmp("-h", *argv) || !strcmp("--help", *argv)) {
-      printf("Usage: %s [-4|-6] [-n|-d] [-q|-Q] [-r] [-R] [-s] [-f FILE|COMMAND...]\n",
+      printf("Usage: %s [-4|-6] [-n|-d] [-q|-Q] [-r] [-R] [-s] [-t TIMEOUT] [-f FILE|COMMAND...]\n",
             progname);
      return 0;
    } else if (*argv[0] == '-') {
@@ -464,6 +496,7 @@ int main
   * be done *AFTER* the daemon-creation fork() */
  write_lockfile();

+  PRV_Initialise();
  LCL_Initialise();
  SCH_Initialise();
  SYS_Initialise();
@@ -472,6 +505,12 @@ int main
  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();
@@ -487,18 +526,21 @@ int main
  if (!user) {
    user = CNF_GetUser();
  }
-  if (user && strcmp(user, "root")) {
-    SYS_DropRoot(user);
-  }

-  LOG_CreateLogFileDir();
+  if ((pw = getpwnam(user)) == NULL)
+    LOG_FATAL(LOGF_Main, "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 user has non-zero uid or gid */
+  if (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();
@@ -507,7 +549,12 @@ int main
  /* 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;
@@ -516,19 +563,15 @@ int main
  REF_SetModeEndHandler(reference_mode_end);
  REF_SetMode(ref_mode);

+  if (timeout)
+    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();
--- a/31
+++ b/31
@@ -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

@@ -39,31 +38,13 @@ echo $version > version.txt

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

-for m in 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
-
-a2x --lynx -f text doc/faq.adoc || exit 1
-mv doc/faq.text FAQ
-rm -rf doc
-
-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
@@ -47,7 +47,7 @@ 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
@@ -64,8 +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,
@@ -97,7 +97,7 @@ 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, long *offset_cs, double *dfreq_ppm, double *new_afreq_ppm)
 {
  double agos[MAX_SAMPLES], offsets[MAX_SAMPLES];
  double b0, b1;
@@ -110,7 +110,7 @@ estimate_and_set_system(struct timeval *now, int offset_provided, double offset,

  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;
    }
    
@@ -173,9 +173,9 @@ 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, long *offset_cs, double *dfreq_ppm, double *new_afreq_ppm)
 {
-  struct timeval now;
+  struct timespec now;
  double offset, diff;
  int i;

@@ -189,12 +189,12 @@ MNL_AcceptTimestamp(struct timeval *ts, long *offset_cs, double *dfreq_ppm, doub
     return 0;

    if (n_samples) {
-      UTI_DiffTimevalsToDouble(&diff, &now, &samples[n_samples - 1].when);
+      diff = UTI_DiffTimespecsToDouble(&now, &samples[n_samples - 1].when);
      if (diff < MIN_SAMPLE_SEPARATION)
        return 0;
    }

-    UTI_DiffTimevalsToDouble(&offset, &now, ts);
+    offset = UTI_DiffTimespecsToDouble(&now, ts);

    /* Check if buffer full up */
    if (n_samples == MAX_SAMPLES) {
@@ -224,8 +224,8 @@ 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,
@@ -239,7 +239,7 @@ 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;
  }
@@ -309,7 +309,7 @@ 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
@@ -33,7 +33,7 @@

 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, long *offset_cs, double *dfreq_ppm, double *new_afreq_ppm);

 extern void MNL_Enable(void);
 extern void MNL_Disable(void);
--- 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
@@ -49,7 +49,9 @@ DNS_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs)
 #ifdef HAVE_GETADDRINFO
  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)
@@ -73,7 +72,7 @@ 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;
@@ -84,11 +83,11 @@ end_resolving(void *anything)

  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++)
    ;

@@ -114,6 +113,9 @@ DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *
    LOG_FATAL(LOGF_Nameserv, "pipe() failed");
  }

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

@@ -121,7 +123,7 @@ DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *
    LOG_FATAL(LOGF_Nameserv, "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
@@ -53,8 +53,12 @@ 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 +95,7 @@ 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)
--- 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
@@ -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);

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

@@ -90,8 +122,8 @@ 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);
@@ -99,10 +131,10 @@ prepare_socket(int family, int port_number, int client_only)
  if (sock_fd < 0) {
    if (!client_only) {
      LOG(LOGS_ERR, LOGF_NtpIO, "Could not open %s NTP socket : %s",
-          family == AF_INET ? "IPv4" : "IPv6", strerror(errno));
+          UTI_SockaddrFamilyToString(family), strerror(errno));
    } else {
      DEBUG_LOG(LOGF_NtpIO, "Could not open %s NTP socket : %s",
-                family == AF_INET ? "IPv4" : "IPv6", strerror(errno));
+                UTI_SockaddrFamilyToString(family), strerror(errno));
    }
    return INVALID_SOCK_FD;
  }
@@ -161,38 +193,46 @@ 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, LOGF_NtpIO, "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, LOGF_NtpIO, "Could not set %s socket option", "SO_BROADCAST");
    /* Don't quit - we might survive anyway */
  }

 #ifdef SO_TIMESTAMP
  /* Enable receiving of timestamp control messages */
+#ifdef SO_TIMESTAMPNS
+  /* Try nanosecond resolution first */
+  if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMPNS, (char *)&on_off, sizeof(on_off)) < 0)
+#endif
  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");
+    LOG(LOGS_ERR, LOGF_NtpIO, "Could not set %s socket option", "SO_TIMESTAMP");
    /* Don't quit - we might survive anyway */
  }
 #endif

+#ifdef HAVE_LINUX_TIMESTAMPING
+  NIO_Linux_SetTimestampSocketOptions(sock_fd, client_only, &events);
+#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, LOGF_NtpIO, "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, LOGF_NtpIO, "Could not set %s socket option", "IP_PKTINFO");
      /* Don't quit - we might survive anyway */
    }
 #endif
@@ -202,32 +242,34 @@ 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, LOGF_NtpIO, "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, LOGF_NtpIO, "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, LOGF_NtpIO, "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) {
+  if (my_addr_len > 0 && PRV_BindSocket(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));
+        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;
 }
@@ -279,11 +321,38 @@ 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)
 {
@@ -292,6 +361,19 @@ NIO_Initialise(int family)
  assert(!initialised);
  initialised = 1;

+#ifdef HAVE_LINUX_TIMESTAMPING
+  NIO_Linux_Initialise();
+#else
+  if (ARR_GetSize(CNF_GetHwTsInterfaces()))
+    LOG_FATAL(LOGF_NtpIO, "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();

@@ -364,6 +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;
 }

@@ -479,116 +568,174 @@ 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;
+  int if_index;

-  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);
-
-  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);
-
-    local_addr.ip_addr.family = IPADDR_UNSPEC;
-    local_addr.sock_fd = sock_fd;
-
-    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-#ifdef IP_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.family = IPADDR_INET4;
-      }
-#endif
-
-#if defined(IPV6_PKTINFO) && defined(HAVE_IN6_PKTINFO)
-      if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
-        struct in6_pktinfo ipi;
-
-        memcpy(&ipi, CMSG_DATA(cmsg), sizeof(ipi));
-        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;
-      }
-#endif
-
-#ifdef SO_TIMESTAMP
-      if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SO_TIMESTAMP) {
-        struct timeval tv;
-
-        memcpy(&tv, CMSG_DATA(cmsg), sizeof(tv));
-        LCL_CookTime(&tv, &now, &now_err);
-      }
-#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);
-
-    if (status >= NTP_NORMAL_PACKET_LENGTH) {
-
-      NSR_ProcessReceive((NTP_Packet *) &message.ntp_pkt, &now, now_err,
-                         &remote_addr, &local_addr, status);
-
-    } else {
-
-      /* Just ignore the packet if it's not of a recognized length */
-
-    }
+  if (hdr->msg_namelen > sizeof (union sockaddr_in46)) {
+    DEBUG_LOG(LOGF_NtpIO, "Truncated source address");
+    return;
  }
+
+  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.sock_fd = sock_fd;
+  if_index = -1;
+
+  if (hdr->msg_flags & MSG_TRUNC) {
+    DEBUG_LOG(LOGF_NtpIO, "Received truncated message from %s:%d",
+              UTI_IPToString(&remote_addr.ip_addr), remote_addr.port);
+    return;
+  }
+
+  if (hdr->msg_flags & MSG_CTRUNC) {
+    DEBUG_LOG(LOGF_NtpIO, "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_addr.s_addr);
+      local_addr.ip_addr.family = IPADDR_INET4;
+      if_index = ipi.ipi_ifindex;
+    }
+#endif
+
+#ifdef HAVE_IN6_PKTINFO
+    if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
+      struct in6_pktinfo ipi;
+
+      memcpy(&ipi, CMSG_DATA(cmsg), sizeof(ipi));
+      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;
+      if_index = ipi.ipi6_ifindex;
+    }
+#endif
+
+#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));
+      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
+  }
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+  if (NIO_Linux_ProcessMessage(&remote_addr, &local_addr, &local_ts,
+                               hdr, length, sock_fd, if_index))
+    return;
+#endif
+
+  DEBUG_LOG(LOGF_NtpIO, "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, 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(LOGF_NtpIO, "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;

@@ -601,11 +748,7 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Lo
  }

  /* 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)
@@ -621,7 +764,7 @@ 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;
@@ -629,9 +772,8 @@ 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);
@@ -647,9 +789,8 @@ 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);
@@ -666,6 +807,11 @@ 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)
@@ -679,18 +825,9 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Lo
    return 0;
  }

-  DEBUG_LOG(LOGF_NtpIO, "Sent %d bytes to %s:%d from %s fd %d", packetlen,
+  DEBUG_LOG(LOGF_NtpIO, "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 +1,627 @@
+/*
+  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.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  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/ptp_clock.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;
+  /* 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;
+  HCL_Instance clock;
+};
+
+/* Number of PHC readings per HW clock sample */
+#define PHC_READINGS 10
+
+/* 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(const char *name)
+{
+  struct ethtool_ts_info ts_info;
+  struct hwtstamp_config ts_config;
+  struct ifreq req;
+  int sock_fd, if_index, phc_index, phc_fd;
+  unsigned int i;
+  struct Interface *iface;
+  char phc_path[64];
+
+  /* Check if the interface was not already added */
+  for (i = 0; i < ARR_GetSize(interfaces); i++) {
+    if (!strcmp(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", name) >= sizeof (req.ifr_name)) {
+    close(sock_fd);
+    return 0;
+  }
+
+  if (ioctl(sock_fd, SIOCGIFINDEX, &req)) {
+    DEBUG_LOG(LOGF_NtpIOLinux, "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(LOGF_NtpIOLinux, "ioctl(%s) failed : %s", "SIOCETHTOOL", strerror(errno));
+    close(sock_fd);
+    return 0;
+  }
+
+  ts_config.flags = 0;
+  ts_config.tx_type = HWTSTAMP_TX_ON;
+  ts_config.rx_filter = HWTSTAMP_FILTER_ALL;
+  req.ifr_data = (char *)&ts_config;
+
+  if (ioctl(sock_fd, SIOCSHWTSTAMP, &req)) {
+    DEBUG_LOG(LOGF_NtpIOLinux, "ioctl(%s) failed : %s", "SIOCSHWTSTAMP", strerror(errno));
+    close(sock_fd);
+    return 0;
+  }
+
+  close(sock_fd);
+  phc_index = ts_info.phc_index;
+
+  if (snprintf(phc_path, sizeof (phc_path), "/dev/ptp%d", phc_index) >= sizeof (phc_path))
+    return 0;
+
+  phc_fd = open(phc_path, O_RDONLY);
+  if (phc_fd < 0) {
+    LOG(LOGS_ERR, LOGF_NtpIOLinux, "Could not open %s : %s", phc_path, strerror(errno));
+    return 0;
+  }
+
+  UTI_FdSetCloexec(phc_fd);
+
+  iface = ARR_GetNewElement(interfaces);
+
+  snprintf(iface->name, sizeof (iface->name), "%s", name);
+  iface->if_index = if_index;
+  iface->phc_fd = phc_fd;
+
+  /* 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->clock = HCL_CreateInstance();
+
+  DEBUG_LOG(LOGF_NtpIOLinux, "Enabled HW timestamping on %s", name);
+
+  return 1;
+}
+
+/* ================================================== */
+
+static int
+add_all_interfaces(void)
+{
+  struct ifaddrs *ifaddr, *ifa;
+  int r;
+
+  if (getifaddrs(&ifaddr)) {
+    DEBUG_LOG(LOGF_NtpIOLinux, "getifaddrs() failed : %s", strerror(errno));
+    return 0;
+  }
+
+  for (r = 0, ifa = ifaddr; ifa; ifa = ifa->ifa_next) {
+    if (add_interface(ifa->ifa_name))
+      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(LOGF_NtpIOLinux, "ioctl(%s) failed : %s", "SIOCETHTOOL", strerror(errno));
+    close(sock_fd);
+    return;
+  }
+
+  close(sock_fd);
+
+  iface->link_speed = ethtool_cmd_speed(&cmd);
+}
+
+/* ================================================== */
+
+void
+NIO_Linux_Initialise(void)
+{
+  ARR_Instance config_hwts_ifaces;
+  char *if_name;
+  unsigned int i;
+  int wildcard, hwts;
+
+  interfaces = ARR_CreateInstance(sizeof (struct Interface));
+
+  config_hwts_ifaces = CNF_GetHwTsInterfaces();
+
+  /* Enable HW timestamping on specified interfaces.  If "*" was specified, try
+     all interfaces.  If no interface was specified, enable SW timestamping. */
+
+  for (i = wildcard = 0; i < ARR_GetSize(config_hwts_ifaces); i++) {
+    if (!strcmp("*", *(char **)ARR_GetElement(config_hwts_ifaces, i)))
+      wildcard = 1;
+  }
+
+  if (!wildcard && ARR_GetSize(config_hwts_ifaces)) {
+    for (i = 0; i < ARR_GetSize(config_hwts_ifaces); i++) {
+      if_name = *(char **)ARR_GetElement(config_hwts_ifaces, i);
+      if (!add_interface(if_name))
+        LOG_FATAL(LOGF_NtpIO, "Could not enable HW timestamping on %s", if_name);
+    }
+    hwts = 1;
+  } else if (wildcard && add_all_interfaces()) {
+    hwts = 1;
+  } else {
+    hwts = 0;
+  }
+
+  if (hwts) {
+    ts_flags = SOF_TIMESTAMPING_RAW_HARDWARE | SOF_TIMESTAMPING_RX_HARDWARE;
+    ts_tx_flags = SOF_TIMESTAMPING_TX_HARDWARE;
+  } else {
+    ts_flags = SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_RX_SOFTWARE;
+    ts_tx_flags = SOF_TIMESTAMPING_TX_SOFTWARE;
+  }
+
+  /* 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, LOGF_NtpIOLinux, "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, LOGF_NtpIOLinux, "Could not set %s socket option", "SO_TIMESTAMPING");
+    ts_flags = 0;
+    return 0;
+  }
+
+  *events |= SCH_FILE_EXCEPTION;
+  return 1;
+}
+
+/* ================================================== */
+
+static int
+get_phc_sample(int phc_fd, struct timespec *phc_ts, struct timespec *local_ts, double *p_delay)
+{
+  struct ptp_sys_offset sys_off;
+  struct timespec ts1, ts2, ts3, phc_tss[PHC_READINGS], sys_tss[PHC_READINGS];
+  double min_delay = 0.0, delays[PHC_READINGS], phc_sum, local_sum, local_prec;
+  int i, n;
+
+  /* Silence valgrind */
+  memset(&sys_off, 0, sizeof (sys_off));
+
+  sys_off.n_samples = PHC_READINGS;
+
+  if (ioctl(phc_fd, PTP_SYS_OFFSET, &sys_off)) {
+    DEBUG_LOG(LOGF_NtpIOLinux, "ioctl(%s) failed : %s", "PTP_SYS_OFFSET", strerror(errno));
+    return 0;
+  }
+
+  for (i = 0; i < PHC_READINGS; i++) {
+    ts1.tv_sec = sys_off.ts[i * 2].sec;
+    ts1.tv_nsec = sys_off.ts[i * 2].nsec;
+    ts2.tv_sec = sys_off.ts[i * 2 + 1].sec;
+    ts2.tv_nsec = sys_off.ts[i * 2 + 1].nsec;
+    ts3.tv_sec = sys_off.ts[i * 2 + 2].sec;
+    ts3.tv_nsec = sys_off.ts[i * 2 + 2].nsec;
+
+    sys_tss[i] = ts1;
+    phc_tss[i] = ts2;
+    delays[i] = UTI_DiffTimespecsToDouble(&ts3, &ts1);
+
+    if (delays[i] <= 0.0)
+      /* Step in the middle of a PHC reading? */
+      return 0;
+
+    if (!i || delays[i] < min_delay)
+      min_delay = delays[i];
+  }
+
+  local_prec = LCL_GetSysPrecisionAsQuantum();
+
+  /* Combine best readings */
+  for (i = n = 0, phc_sum = local_sum = 0.0; i < PHC_READINGS; i++) {
+    if (delays[i] > min_delay + local_prec)
+      continue;
+
+    phc_sum += UTI_DiffTimespecsToDouble(&phc_tss[i], &phc_tss[0]);
+    local_sum += UTI_DiffTimespecsToDouble(&sys_tss[i], &sys_tss[0]) + delays[i] / 2.0;
+    n++;
+  }
+
+  assert(n);
+
+  UTI_AddDoubleToTimespec(&phc_tss[0], phc_sum / n, phc_ts);
+  UTI_AddDoubleToTimespec(&sys_tss[0], local_sum / n, &ts1);
+  LCL_CookTime(&ts1, local_ts, NULL);
+  *p_delay = min_delay;
+
+  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)
+{
+  struct timespec sample_phc_ts, sample_local_ts;
+  double sample_delay, rx_correction;
+  int l2_length;
+
+  if (HCL_NeedsNewSample(iface->clock, &local_ts->ts)) {
+    if (!get_phc_sample(iface->phc_fd, &sample_phc_ts, &sample_local_ts, &sample_delay))
+      return;
+
+    HCL_AccumulateSample(iface->clock, &sample_phc_ts, &sample_local_ts,
+                         sample_delay / 2.0);
+
+    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.  Without raw sockets we don't know the length of the packet
+     at layer 2, so 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) {
+    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, &local_ts->ts, &local_ts->err))
+    return;
+
+  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, int sock_fd, int if_index)
+{
+  struct Interface *iface;
+  struct cmsghdr *cmsg;
+  int is_tx, l2_length;
+
+  is_tx = hdr->msg_flags & MSG_ERRQUEUE;
+  iface = NULL;
+
+  for (cmsg = CMSG_FIRSTHDR(hdr); cmsg; cmsg = CMSG_NXTHDR(hdr, cmsg)) {
+    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[0])) {
+        LCL_CookTime(&ts3.ts[0], &local_ts->ts, &local_ts->err);
+        local_ts->source = NTP_TS_KERNEL;
+      } else {
+        iface = get_interface(if_index);
+        if (iface) {
+          process_hw_timestamp(iface, &ts3.ts[2], local_ts, !is_tx ? length : 0,
+                               remote_addr->ip_addr.family);
+        } else {
+          DEBUG_LOG(LOGF_NtpIOLinux, "HW clock not found for interface %d", if_index);
+        }
+      }
+    }
+
+    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(LOGF_NtpIOLinux, "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(LOGF_NtpIOLinux, "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,
+            sock_fd, 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 HW timestamp is missing or its processing failed */
+  if ((ts_flags & SOF_TIMESTAMPING_RAW_HARDWARE) && local_ts->source != NTP_TS_HARDWARE) {
+    DEBUG_LOG(LOGF_NtpIOLinux, "Missing HW 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
@@ -21,18 +21,17 @@

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

-  Replacement strerror function for systems that don't have it
+  This is the header file for the Linux-specific NTP socket I/O bits.
  */

-#include "config.h"
+extern void NIO_Linux_Initialise(void);

-#ifdef SUNOS
+extern void NIO_Linux_Finalise(void);

-#include <errno.h>
-extern char *sys_errlist[];
+extern int NIO_Linux_SetTimestampSocketOptions(int sock_fd, int client_only, int *events);

-char *strerror(int n) {
-  return sys_errlist[n];
-}
+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,
+                                    int sock_fd, int if_index);

-#endif /* SUNOS */
+extern int NIO_Linux_RequestTxTimestamp(struct msghdr *msg, int cmsglen, int sock_fd);
--- a/ntp_signd.c
+++ b/ntp_signd.c
@@ -0,0 +1,380 @@
+/*
+  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(LOGF_NtpSignd, "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(LOGF_NtpSignd, "signd socket path too long");
+    close_socket();
+    return 0;
+  }
+
+  if (connect(sock_fd, (struct sockaddr *)&s, sizeof (s)) < 0) {
+    DEBUG_LOG(LOGF_NtpSignd, "Could not connect to signd : %s", strerror(errno));
+    close_socket();
+    return 0;
+  }
+
+  DEBUG_LOG(LOGF_NtpSignd, "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(LOGF_NtpSignd, "Invalid response ID");
+    return;
+  }
+
+  if (ntohl(inst->response.op) != SIGNING_SUCCESS) {
+    DEBUG_LOG(LOGF_NtpSignd, "Signing failed");
+    return;
+  }
+
+  /* Check if the file descriptor is still valid */
+  if (!NIO_IsServerSocket(inst->local_addr.sock_fd)) {
+    DEBUG_LOG(LOGF_NtpSignd, "Invalid NTP socket");
+    return;
+  }
+
+  SCH_GetLastEventTime(NULL, NULL, &ts);
+  delay = UTI_DiffTimespecsToDouble(&ts, &inst->request_ts);
+
+  DEBUG_LOG(LOGF_NtpSignd, "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(LOGF_NtpSignd, "signd socket error: %s", strerror(errno));
+      close_socket();
+      return;
+    }
+
+    DEBUG_LOG(LOGF_NtpSignd, "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(LOGF_NtpSignd, "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(LOGF_NtpSignd, "signd socket error: %s", strerror(errno));
+      else
+        DEBUG_LOG(LOGF_NtpSignd, "signd socket closed");
+
+      close_socket();
+      return;
+    }
+
+    DEBUG_LOG(LOGF_NtpSignd, "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(LOGF_NtpSignd, "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, LOGF_NtpSignd, "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(LOGF_NtpSignd, "signd disabled");
+    return 0;
+  }
+
+  if (queue_head == NEXT_QUEUE_INDEX(queue_tail)) {
+    DEBUG_LOG(LOGF_NtpSignd, "signd queue full");
+    return 0;
+  }
+
+  if (length != NTP_NORMAL_PACKET_LENGTH) {
+    DEBUG_LOG(LOGF_NtpSignd, "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(LOGF_NtpSignd, "Packet added to signd queue (%u:%u)",
+            queue_head, queue_tail);
+
+  return 1;
+}
--- a/ntp_signd.h
+++ b/ntp_signd.h
@@ -1,8 +1,8 @@
-/* 
+/*
  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 +21,24 @@

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

-   */
+  Header for MS-SNTP authentication via Samba (ntp_signd) */

-#ifndef GOT_MKDIRPP_H
-#define GOT_MKDIRPP_H
+#ifndef GOT_NTP_SIGND_H
+#define GOT_NTP_SIGND_H

-extern int mkdir_and_parents(const char *path);
+#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
@@ -53,11 +53,11 @@ typedef struct {
  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 */
@@ -70,6 +70,7 @@ static int auto_start_sources = 0;
 struct UnresolvedSource {
  char *name;
  int port;
+  int random_order;
  int replacement;
  union {
    struct {
@@ -116,8 +117,8 @@ 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,
@@ -202,26 +203,16 @@ 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:
-      *found = *slot = 0;
-      return;
+  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++) {
@@ -243,12 +234,12 @@ 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;
 }

 /* ================================================== */
@@ -266,7 +257,7 @@ 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);
@@ -320,7 +311,7 @@ add_source(NTP_Remote_Address *remote_addr, char *name, NTP_Source_Type type, So
      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);
@@ -337,6 +328,7 @@ 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)
@@ -350,6 +342,15 @@ 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();

@@ -367,13 +368,17 @@ 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, "(%d) %s", i + 1, 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(LOGF_NtpSources, "(%d) %s", i + 1, UTI_IPToString(&address.ip_addr));
+
    if (us->replacement) {
      if (replace_source(&us->replace_source, &address) != NSR_AlreadyInUse)
        break;
@@ -516,6 +521,7 @@ NSR_AddSourceByName(char *name, int port, int pool, NTP_Source_Type type, Source
  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;
@@ -657,6 +663,11 @@ resolve_source_replacement(SourceRecord *record)
  us = MallocNew(struct UnresolvedSource);
  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 = *record->remote_addr;

@@ -669,8 +680,8 @@ resolve_source_replacement(SourceRecord *record)
 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;
  SourceRecord *record;
  int slot, found;
@@ -691,7 +702,7 @@ NSR_HandleBadSource(IPAddr *address)

  /* Don't resolve names too frequently */
  SCH_GetLastEventTime(NULL, NULL, &now);
-  UTI_DiffTimevalsToDouble(&diff, &now, &last_replacement);
+  diff = UTI_DiffTimespecsToDouble(&now, &last_replacement);
  if (fabs(diff) < RESOLVE_INTERVAL_UNIT * (1 << MIN_REPLACEMENT_INTERVAL)) {
    DEBUG_LOG(LOGF_NtpSources, "replacement postponed");
    return;
@@ -703,6 +714,23 @@ NSR_HandleBadSource(IPAddr *address)

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

+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);
+  }
+}
+
+/* ================================================== */
+
 static void remove_tentative_pool_sources(int pool)
 {
  SourceRecord *record;
@@ -725,10 +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;
@@ -740,35 +789,55 @@ 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);
-      pool->sources++;
+      if (record->pool != INVALID_POOL) {
+        pool = ARR_GetElement(pools, record->pool);
+        pool->sources++;

-      DEBUG_LOG(LOGF_NtpSources, "pool %s has %d confirmed sources",
-                record->name, pool->sources);
+        DEBUG_LOG(LOGF_NtpSources, "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 (pool->sources >= pool->max_sources)
-        remove_tentative_pool_sources(record->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,
@@ -782,6 +851,7 @@ 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);
      }
@@ -1034,7 +1104,7 @@ 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;
@@ -1050,6 +1120,26 @@ 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
@@ -33,143 +34,125 @@
 #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) {
-      case REQ_NULL:
-        return offsetof(CMD_Request, data.null.EOR);
-      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.null.EOR);
-      case REQ_SOURCE_DATA :
-        return offsetof(CMD_Request, data.source_data.EOR);
-      case REQ_REKEY :
-        return offsetof(CMD_Request, data.null.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.null.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.null.EOR);
-      case REQ_SOURCESTATS :
-        return offsetof(CMD_Request, data.sourcestats.EOR);
-      case REQ_RTCREPORT :
-        return offsetof(CMD_Request, data.null.EOR);
-      case REQ_TRIMRTC :
-        return offsetof(CMD_Request, data.null.EOR);
-      case REQ_CYCLELOGS :
-        return offsetof(CMD_Request, data.null.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.null.EOR);
-      case REQ_MANUAL_DELETE:
-        return offsetof(CMD_Request, data.manual_delete.EOR);
-      case REQ_MAKESTEP:
-        return offsetof(CMD_Request, data.null.EOR);
-      case REQ_ACTIVITY:
-        return offsetof(CMD_Request, data.null.EOR);
-      case REQ_RESELECT:
-        return offsetof(CMD_Request, data.null.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);
-      case REQ_SMOOTHING:
-        return offsetof(CMD_Request, data.null.EOR);
-      case REQ_SMOOTHTIME:
-        return offsetof(CMD_Request, data.smoothtime.EOR);
-      default:
-        /* If we fall through the switch, it most likely means we've forgotten to implement a new case */
-        assert(0);
-    }
-  }
+struct request_length {
+  uint16_t command;
+  uint16_t padding;
+};

-  /* 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 */
+  RPY_LENGTH_ENTRY(manual_timestamp),           /* 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 */
+};

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

 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;

@@ -178,137 +161,20 @@ 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.null.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.null.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.null.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.null.EOR, data.tracking.EOR);
-    case REQ_SOURCESTATS:
-      return PADDING_LENGTH(data.sourcestats.EOR, data.sourcestats.EOR);
-    case REQ_RTCREPORT:
-      return PADDING_LENGTH(data.null.EOR, data.rtc.EOR);
-    case REQ_TRIMRTC:
-      return PADDING_LENGTH(data.null.EOR, data.null.EOR);
-    case REQ_CYCLELOGS:
-      return PADDING_LENGTH(data.null.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.null.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.null.EOR, data.null.EOR);
-    case REQ_ACTIVITY:
-      return PADDING_LENGTH(data.null.EOR, data.activity.EOR);
-    case REQ_RESELECT:
-      return PADDING_LENGTH(data.null.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);
-    case REQ_SMOOTHING:
-      return PADDING_LENGTH(data.null.EOR, data.smoothing.EOR);
-    case REQ_SMOOTHTIME:
-      return PADDING_LENGTH(data.smoothtime.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;
 }

 /* ================================================== */
@@ -316,65 +182,32 @@ 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 {
-            return offsetof(CMD_Reply, data);
-          }
-        }
-      case RPY_MANUAL_LIST:
-        {
-          unsigned long 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);
-      case RPY_SMOOTHING:
-        return offsetof(CMD_Reply, data.smoothing.EOR);
-      default:
-        assert(0);
-    }
+
+  /* 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);
+
+    ns = ntohl(r->data.manual_list.n_samples);
+    if (ns > MAX_MANUAL_LIST_SAMPLES)
+      return 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 +1,689 @@
+/*
+  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_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';
+
+  DNS_Reload();
+
+  res->rc = DNS_Name2IPAddress(req->name, res->data.name_to_ipaddress.addresses,
+                               DNS_MAX_ADDRESSES);
+}
+#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
+      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(LOGF_PrivOps, "Could not read from helper : %s", strerror(errno));
+  if (resp_len != sizeof (*res))
+    LOG_FATAL(LOGF_PrivOps, "Invalid helper response");
+
+  if (res->fatal_error)
+    LOG_FATAL(LOGF_PrivOps, "Error in helper : %s", res->data.fatal_msg.msg);
+
+  DEBUG_LOG(LOGF_PrivOps, "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(LOGF_PrivOps, "Could not send to helper : %s", strerror(errno));
+  }
+
+  DEBUG_LOG(LOGF_PrivOps, "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(LOGF_PrivOps, "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
+
+/* ======================================================================= */
+
+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(LOGF_PrivOps, "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(LOGF_PrivOps, "socketpair() failed : %s", strerror(errno));
+
+  UTI_FdSetCloexec(sock_pair[0]);
+  UTI_FdSetCloexec(sock_pair[1]);
+
+  pid = fork();
+  if (pid < 0)
+    LOG_FATAL(LOGF_PrivOps, "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 +1,71 @@
+/*
+  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_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
@@ -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 {
@@ -77,6 +77,7 @@ struct RCL_Instance_Record {
  int leap_status;
  int pps_rate;
  int pps_active;
+  int max_lock_age;
  struct MedianFilter filter;
  uint32_t ref_id;
  uint32_t lock_ref;
@@ -87,40 +88,41 @@ struct RCL_Instance_Record {
  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 *raw, struct timespec *cooked);
+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 +150,7 @@ RCL_Finalise(void)
    filter_fini(&inst->filter);
    Free(inst->driver_parameter);
    SRC_DestroyInstance(inst->source);
+    Free(inst);
  }

  if (ARR_GetSize(refclocks) > 0) {
@@ -162,8 +165,10 @@ 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;
@@ -198,6 +203,7 @@ RCL_AddRefclock(RefclockParameters *params)
  inst->leap_status = LEAP_Normal;
  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;
@@ -233,7 +239,7 @@ RCL_AddRefclock(RefclockParameters *params)
    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) {
@@ -260,7 +266,7 @@ RCL_AddRefclock(RefclockParameters *params)

  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",
@@ -296,7 +302,7 @@ 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;
@@ -358,22 +364,20 @@ 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;

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

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

-  filter_add_sample(&instance->filter, &cooked_time, offset - correction + instance->offset, dispersion);
-
  switch (leap) {
    case LEAP_Normal:
    case LEAP_InsertSecond:
@@ -381,10 +385,11 @@ 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(LOGF_Refclock, "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);
@@ -397,20 +402,20 @@ 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;
+  struct timespec cooked_time;
  int rate;
  NTP_Leap leap;

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

  if (!UTI_IsTimeOffsetSane(pulse_time, 0.0) ||
-      !valid_sample_time(instance, pulse_time))
+      !valid_sample_time(instance, pulse_time, &cooked_time))
    return 0;

  rate = instance->pps_rate;
@@ -427,7 +432,7 @@ 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);
@@ -440,8 +445,8 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)

    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) {
+    sample_diff = UTI_DiffTimespecsToDouble(&cooked_time, &ref_sample_time);
+    if (fabs(sample_diff) >= (double)instance->max_lock_age / rate) {
      DEBUG_LOG(LOGF_Refclock, "refclock pulse ignored samplediff=%.9f",
          sample_diff);
      return 0;
@@ -466,20 +471,21 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
    DEBUG_LOG(LOGF_Refclock, "refclock pulse second=%.9f offset=%.9f offdiff=%.9f samplediff=%.9f",
        second, 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_id, &ref_time, &root_delay, &root_dispersion);
    distance = fabs(root_delay) / 2 + root_dispersion;

-    if (!is_synchronised || distance >= 0.5 / rate) {
+    if (leap == LEAP_Unsynchronised || distance >= 0.5 / rate) {
      DEBUG_LOG(LOGF_Refclock, "refclock pulse ignored second=%.9f sync=%d dist=%.9f",
-          second, is_synchronised, distance);
+          second, leap != LEAP_Unsynchronised, distance);
      /* Drop also all stored samples */
      filter_reset(&instance->filter);
      return 0;
@@ -500,25 +506,32 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
 }

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

-  LCL_ReadRawTime(&raw_time);
-  UTI_DiffTimevalsToDouble(&diff, &raw_time, tv);
-  if (diff < 0.0 || diff > UTI_Log2ToDouble(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_ReadRawTime(&now_raw);
+  diff = UTI_DiffTimespecsToDouble(&now_raw, raw);
+
+  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, cooked) >= 0)) {
+    DEBUG_LOG(LOGF_Refclock, "%s refclock sample not valid age=%.6f raw=%s cooked=%s",
+              UTI_RefidToString(instance->ref_id), diff,
+              UTI_TimespecToString(raw), UTI_TimespecToString(cooked));
    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;
@@ -526,12 +539,13 @@ 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 */ 
@@ -562,7 +576,7 @@ 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);
@@ -590,7 +604,7 @@ poll_timeout(void *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;
@@ -613,7 +627,7 @@ 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', '+', '-', '?'};

@@ -623,7 +637,7 @@ 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],
@@ -634,7 +648,7 @@ 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,
@@ -687,7 +701,7 @@ 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;
@@ -700,11 +714,11 @@ filter_add_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
  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);
+      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;
@@ -715,6 +729,12 @@ 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
@@ -817,7 +837,7 @@ 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;
@@ -834,7 +854,7 @@ 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;
  }
@@ -909,7 +929,7 @@ 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;

@@ -919,15 +939,26 @@ 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
@@ -40,13 +40,14 @@ typedef struct {
  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;
 } RefclockParameters;

 typedef struct RCL_Instance_Record *RCL_Instance;
@@ -61,14 +62,14 @@ 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);

 #endif
--- a/refclock_phc.c
+++ b/refclock_phc.c
@@ -56,11 +56,6 @@ struct phc_reading {
  struct timespec sys_ts2;
 };

-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
@@ -145,7 +140,6 @@ static void phc_finalise(RCL_Instance instance)
 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;
 
@@ -163,7 +157,7 @@ static int phc_poll(RCL_Instance instance)

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

    if (!i || best_delay > delay) {
      best = i;
@@ -171,13 +165,12 @@ static int phc_poll(RCL_Instance instance)
    }
  }

-  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;
+  offset = UTI_DiffTimespecsToDouble(&readings[best].phc_ts, &readings[best].sys_ts2) +
+           best_delay / 2.0;

  DEBUG_LOG(LOGF_Refclock, "PHC offset: %+.9f delay: %.9f", offset, best_delay);

-  return RCL_AddSample(instance, &tv, offset, LEAP_Normal);
+  return RCL_AddSample(instance, &readings[best].sys_ts2, offset, LEAP_Normal);
 }

 RefclockDriver RCL_PHC_driver = {
--- a/refclock_pps.c
+++ b/refclock_pps.c
@@ -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;

@@ -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(LOGF_Refclock, "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
@@ -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;

@@ -107,17 +107,23 @@ static int shm_poll(RCL_Instance instance)

  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
@@ -37,22 +37,34 @@
 #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);

@@ -74,10 +86,13 @@ static void read_sample(void *anything)
    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);
  }
 }

@@ -110,7 +125,7 @@ static int sock_initialise(RCL_Instance instance)
  }

  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  2009-2015
+ * 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 +45,14 @@
 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_stratum;
 static uint32_t our_ref_id;
 static IPAddr our_ref_ip;
-struct timeval our_ref_time;
+static struct timespec our_ref_time;
 static double our_skew;
 static double our_residual_freq;
 static double our_root_delay;
@@ -80,8 +82,7 @@ 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 */
@@ -106,7 +107,6 @@ static REF_LeapMode leap_mode;
 static int leap_in_progress;

 /* Timer for the leap second handler */
-static int leap_timer_running;
 static SCH_TimeoutID leap_timeout_id;

 /* Name of a system timezone containing leap seconds occuring at midnight */
@@ -136,7 +136,7 @@ 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;

 /* ================================================== */
@@ -147,23 +147,22 @@ 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 timeval now;
+  struct timespec now;

-  UTI_AdjustTimeval(&our_ref_time, cooked, &our_ref_time, &delta, dfreq, doffset);
+  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
@@ -232,9 +231,9 @@ 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_timer_running = 0;
+  leap_timeout_id = 0;
  leap_in_progress = 0;
  leap_mode = CNF_GetLeapSecMode();
  /* Switch to step mode if the system driver doesn't support leap */
@@ -255,8 +254,8 @@ REF_Initialise(void)

  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);

@@ -264,20 +263,14 @@ 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();
 }
@@ -428,10 +421,8 @@ 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;
-  }
+  SCH_RemoveTimeout(fb_drift_timeout_id);
+  fb_drift_timeout_id = 0;

  if (update_interval < 1.0 || update_interval > last_ref_update_interval * 4.0)
    return;
@@ -464,7 +455,7 @@ fb_drift_timeout(void *arg)
 {
  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(LOGF_Reference, "Fallback drift %d active: %f ppm",
            next_fb_drift, fb_drifts[next_fb_drift - fb_drift_min].freq);
@@ -475,16 +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;
@@ -506,7 +497,7 @@ schedule_fb_drift(struct timeval *now)

  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);
  }
@@ -539,8 +530,7 @@ maybe_log_offset(double offset, time_t now)

  abs_offset = fabs(offset);

-  if (do_log_change &&
-      (abs_offset > log_change_threshold)) {
+  if (abs_offset > log_change_threshold) {
    LOG(LOGS_WARN, LOGF_Reference,
        "System clock wrong by %.6f seconds, adjustment started",
        -offset);
@@ -686,7 +676,7 @@ get_tz_leap(time_t when)
 static void
 leap_end_timeout(void *arg)
 {
-  leap_timer_running = 0;
+  leap_timeout_id = 0;
  leap_in_progress = 0;
  our_leap_sec = 0;

@@ -735,14 +725,12 @@ leap_start_timeout(void *arg)
 static void
 set_leap_timeout(time_t now)
 {
-  struct timeval when;
+  struct timespec when;

  /* Stop old timer if there is one */
-  if (leap_timer_running) {
-    SCH_RemoveTimeout(leap_timeout_id);
-    leap_timer_running = 0;
-    leap_in_progress = 0;
-  }
+  SCH_RemoveTimeout(leap_timeout_id);
+  leap_timeout_id = 0;
+  leap_in_progress = 0;

  if (!our_leap_sec)
    return;
@@ -751,16 +739,15 @@ set_leap_timeout(time_t now)
     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_usec = 0;
+  when.tv_nsec = 0;
  if (our_leap_sec < 0)
    when.tv_sec--;
  if (leap_mode == REF_LeapModeSystem) {
    when.tv_sec--;
-    when.tv_usec = 500000;
+    when.tv_nsec = 500000000;
  }

  leap_timeout_id = SCH_AddTimeout(&when, leap_start_timeout, NULL);
-  leap_timer_running = 1;
 }

 /* ================================================== */
@@ -789,7 +776,7 @@ update_leap_status(NTP_Leap leap, time_t now, int reset)
    }
  }
  
-  if (reset || (leap_sec != our_leap_sec && !REF_IsLeapSecondClose())) {
+  if (leap_sec != our_leap_sec && !REF_IsLeapSecondClose()) {
    our_leap_sec = leap_sec;

    switch (leap_mode) {
@@ -805,6 +792,8 @@ update_leap_status(NTP_Leap leap, time_t now, int reset)
        assert(0);
        break;
    }
+  } else if (reset) {
+    set_leap_timeout(now);
  }

  our_leap_status = leap;
@@ -813,7 +802,7 @@ update_leap_status(NTP_Leap leap, time_t now, int reset)
 /* ================================================== */

 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)
 {
@@ -890,7 +879,7 @@ 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,
@@ -911,7 +900,8 @@ 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);

@@ -945,9 +935,9 @@ REF_SetReference(int stratum,
    
  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))
@@ -965,7 +955,7 @@ 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 {
@@ -1052,6 +1042,15 @@ REF_SetReference(int stratum,

  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,
@@ -1098,7 +1097,7 @@ REF_SetReference(int stratum,
 void
 REF_SetManualReference
 (
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double offset,
 double frequency,
 double skew
@@ -1117,7 +1116,7 @@ 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);
@@ -1130,7 +1129,7 @@ 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);
@@ -1158,39 +1157,47 @@ 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 = !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 = NTP_REFID_LOCAL;
@@ -1216,7 +1223,7 @@ REF_GetReferenceParams
    *leap_status = LEAP_Unsynchronised;
    *stratum = NTP_MAX_STRATUM;
    *ref_id = NTP_REFID_UNSYNC;
-    ref_time->tv_sec = ref_time->tv_usec = 0;
+    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 */
@@ -1231,13 +1238,27 @@ REF_GetReferenceParams
 int
 REF_GetOurStratum(void)
 {
-  if (are_we_synchronised) {
-    return our_stratum;
-  } else if (enable_local_stratum) {
-    return local_stratum;
-  } else {
+  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;
 }

 /* ================================================== */
@@ -1268,10 +1289,12 @@ 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;
 }

 /* ================================================== */
@@ -1284,19 +1307,11 @@ 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)
@@ -1320,52 +1335,34 @@ 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);
+
+  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)
+    rep->stratum = 0;

-  rep->ref_id = NTP_REFID_UNSYNC;
  rep->ip_addr.family = IPADDR_UNSPEC;
-  rep->stratum = 0;
-  rep->leap_status = our_leap_status;
-  rep->ref_time.tv_sec = 0;
-  rep->ref_time.tv_usec = 0;
  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 = NTP_REFID_LOCAL;
-    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
@@ -99,12 +99,12 @@ extern REF_LeapMode REF_GetLeapMode(void);

 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
 );
@@ -140,7 +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,
@@ -151,7 +151,7 @@ extern void REF_SetReference

 extern void REF_SetManualReference
 (
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double offset,
 double frequency,
 double skew
@@ -165,6 +165,9 @@ 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);

@@ -174,9 +177,8 @@ 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
@@ -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. */
@@ -653,3 +639,57 @@ 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 +119,16 @@ 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 */
+);
+
 #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;
@@ -122,4 +131,33 @@ typedef struct {
  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) {
-    if (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, LOGF_Rtc, "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);
    }
  }

@@ -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) {
@@ -226,7 +224,7 @@ 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 +261,7 @@ 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 +277,7 @@ 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);
  }

@@ -367,6 +365,9 @@ t_from_rtc(struct tm *stm) {
  t2 = mktime(&temp2);
  diff = t2 - t1;

+  if (t1 - diff == -1)
+    DEBUG_LOG(LOGF_RtcLinux, "Could not convert RTC time");
+
  return t1 - diff;
 }

@@ -379,13 +380,13 @@ 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, LOGF_RtcLinux, "Could not open %s : %s",
+        hwclock_file, strerror(errno));
    return;
  }

@@ -402,7 +403,7 @@ 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",
+    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not read RTC LOCAL/UTC setting from %s",
        hwclock_file);
  }
 }
@@ -445,7 +446,7 @@ 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",
+        LOG(LOGS_WARN, LOGF_RtcLinux, "Could not read coefficients from %s",
            coefs_file_name);
      }
      fclose(in);
@@ -532,7 +533,7 @@ 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();
@@ -562,7 +563,7 @@ 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 +579,12 @@ RTC_Linux_Initialise(void)
 void
 RTC_Linux_Finalise(void)
 {
-  if (timeout_running) {
-    SCH_RemoveTimeout(timeout_id);
-    timeout_running = 0;
-  }
+  SCH_RemoveTimeout(timeout_id);
+  timeout_id = 0;

  /* Remove input file handler */
  if (fd >= 0) {
-    SCH_RemoveInputFileHandler(fd);
+    SCH_RemoveFileHandler(fd);
    close(fd);

    /* Save the RTC data */
@@ -607,14 +606,16 @@ 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, LOGF_RtcLinux, "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, LOGF_RtcLinux, "Could not %s RTC interrupt : %s",
+          "disable", strerror(errno));
      return;
    }
  }
@@ -625,7 +626,7 @@ switch_interrupts(int onoff)
 static void
 measurement_timeout(void *any)
 {
-  timeout_running = 0;
+  timeout_id = 0;
  switch_interrupts(1);
 }

@@ -694,10 +695,11 @@ 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, LOGF_RtcLinux, "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, LOGF_RtcLinux, "No valid rtcfile coefficients");
  }
  
  coefs_valid = 0;
@@ -722,7 +724,7 @@ 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(LOGF_RtcLinux, "Could not do regression after trim");
  }

  coefs_valid = 0;
@@ -755,7 +757,7 @@ 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 +790,7 @@ 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 +804,11 @@ 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;
@@ -818,7 +820,7 @@ read_from_device(void *any)
    /* 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);
+    SCH_RemoveFileHandler(fd);
    switch_interrupts(0); /* Likely to raise error too, but just to be sure... */
    close(fd);
    fd = -1;
@@ -846,7 +848,7 @@ read_from_device(void *any)
      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 +859,6 @@ 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 +884,12 @@ 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(LOGF_RtcLinux, "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 +897,11 @@ turn_off_interrupt:

    case OM_AFTERTRIM:
      if (error) {
-        LOG(LOGS_WARN, LOGF_RtcLinux, "Could not complete after trim relock due to errors");
+        DEBUG_LOG(LOGF_RtcLinux, "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 +910,6 @@ 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 +929,8 @@ 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 +938,6 @@ RTC_Linux_TimeInit(void (*after_hook)(void *), void *anything)
 void
 RTC_Linux_StartMeasurements(void)
 {
-  timeout_running = 0;
  measurement_timeout(NULL);
 }

@@ -974,14 +970,14 @@ 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 +1031,27 @@ 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, LOGF_RtcLinux, "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) {
        if (LCL_ApplyStepOffset(sys_offset))
-          LOG(LOGS_INFO, LOGF_RtcLinux, "Set system time, error in RTC = %f",
-              accumulated_error);
+          LOG(LOGS_INFO, LOGF_RtcLinux, "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 +1063,7 @@ 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 +1082,7 @@ 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 +1090,8 @@ 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, LOGF_RtcLinux, "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 +1112,12 @@ 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;
-    }
+    SCH_RemoveTimeout(timeout_id);
+    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, 2013-2015
 * 
 * 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
@@ -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(LOGF_Scheduler, "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(!FD_ISSET(fd, &read_fds));
+  assert(!ptr->handler);

-  ++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;
+  ptr->events = events;

-  FD_SET(fd, &read_fds);
-
-  if ((fd + 1) > one_highest_fd) {
+  if (one_highest_fd < fd + 1)
    one_highest_fd = fd + 1;
-  }
 }


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

 void
-SCH_RemoveInputFileHandler(int fd)
+SCH_RemoveFileHandler(int fd)
 {
-  int fds_left, fd_to_check;
+  FileHandlerEntry *ptr;

  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;
-    }
-    ++fd_to_check;
+  while (one_highest_fd > 0) {
+    ptr = ARR_GetElement(file_handlers, one_highest_fd - 1);
+    if (ptr->handler)
+      break;
+    one_highest_fd--;
  }
-
-  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;
@@ -323,14 +342,14 @@ 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);
-  if (UTI_CompareTimevals(&now, &then) > 0) {
+  UTI_AddDoubleToTimespec(&now, delay, &then);
+  if (UTI_CompareTimespecs(&now, &then) > 0) {
    LOG_FATAL(LOGF_Scheduler, "Timeout overflow");
  }

@@ -347,7 +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;

@@ -356,7 +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;
  }
@@ -365,7 +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;
  }
@@ -374,7 +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;
@@ -388,7 +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;
    }
@@ -397,10 +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;
@@ -421,6 +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) {
@@ -436,9 +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);
 }

 /* ================================================== */
@@ -448,7 +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;
@@ -458,7 +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;
    }

@@ -491,35 +519,49 @@ dispatch_timeouts(struct timeval *now) {

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

-/* 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--;

-      /* 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;
+      /* Don't try to read from it now */
+      if (read_fds && FD_ISSET(fd, read_fds)) {
+        FD_CLR(fd, read_fds);
+        nfd--;
+      }
    }

-    ++fh;
-  }
+    if (read_fds && FD_ISSET(fd, read_fds)) {
+      /* This descriptor can be read from, dispatch its handler */
+      ptr = (FileHandlerEntry *)ARR_GetElement(file_handlers, fd);
+      (ptr->handler)(fd, SCH_FILE_INPUT, ptr->arg);
+      nfd--;
+    }

+    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,
@@ -537,17 +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;
 }

 /* ================================================== */
@@ -555,31 +649,33 @@ 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 >
@@ -592,8 +688,8 @@ check_current_time(struct timeval *prev_raw, struct timeval *raw, int timeout,
    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 */
@@ -607,10 +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);
@@ -626,28 +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) {
+    if (!ptv && !p_read_fds && !p_write_fds)
      LOG_FATAL(LOGF_Scheduler, "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);
@@ -668,10 +765,8 @@ SCH_MainLoop(void)
        LOG_FATAL(LOGF_Scheduler, "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 */
@@ -690,7 +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
@@ -93,17 +93,17 @@ 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 timeval last_update;
+static struct timespec last_update;


 static void
-get_smoothing(struct timeval *now, double *poffset, double *pfreq,
+get_smoothing(struct timespec *now, double *poffset, double *pfreq,
              double *pwander)
 {
  double elapsed, length, offset, freq, wander;
  int i;

-  UTI_DiffTimevalsToDouble(&elapsed, now, &last_update);
+  elapsed = UTI_DiffTimespecsToDouble(now, &last_update);

  offset = smooth_offset;
  freq = smooth_freq;
@@ -137,7 +137,7 @@ get_smoothing(struct timeval *now, double *poffset, double *pfreq,
 static void
 update_stages(void)
 {
-  double s1, s2, s, l1, l2, l3, lc, f, f2;
+  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
@@ -146,22 +146,41 @@ update_stages(void)
  s1 = smooth_offset / max_wander;
  s2 = smooth_freq * smooth_freq / (2.0 * max_wander * max_wander);
  
-  l1 = l2 = l3 = 0.0;
-
  /* Calculate the lengths of the 1st and 3rd stage assuming there is no
-     frequency limit.  If length of the 1st stage comes out negative, switch
-     its direction. */
-  for (dir = -1; dir <= 1; dir += 2) {
+     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) {
-      l3 = sqrt(s);
-      l1 = l3 - dir * smooth_freq / max_wander;
-      if (l1 >= 0.0)
-        break;
+
+    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;
    }
  }

-  assert(dir <= 1 && l1 >= 0.0 && l3 >= 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;
@@ -195,7 +214,7 @@ update_stages(void)
 }

 static void
-update_smoothing(struct timeval *now, double offset, double freq)
+update_smoothing(struct timespec *now, double offset, double freq)
 {
  /* Don't accept offset/frequency until the clock has stabilized */
  if (locked) {
@@ -215,7 +234,7 @@ update_smoothing(struct timeval *now, double offset, double freq)
 }

 static void
-handle_slew(struct timeval *raw, struct timeval *cooked, double dfreq,
+handle_slew(struct timespec *raw, struct timespec *cooked, double dfreq,
            double doffset, LCL_ChangeType change_type, void *anything)
 {
  double delta;
@@ -227,7 +246,7 @@ handle_slew(struct timeval *raw, struct timeval *cooked, double dfreq,
      update_smoothing(cooked, doffset, dfreq);
  }

-  UTI_AdjustTimeval(&last_update, cooked, &last_update, &delta, dfreq, doffset);
+  UTI_AdjustTimespec(&last_update, cooked, &last_update, &delta, dfreq, doffset);
 }

 void SMT_Initialise(void)
@@ -258,7 +277,7 @@ int SMT_IsEnabled(void)
 }

 double
-SMT_GetOffset(struct timeval *now)
+SMT_GetOffset(struct timespec *now)
 {
  double offset, freq;

@@ -271,7 +290,7 @@ SMT_GetOffset(struct timeval *now)
 }

 void
-SMT_Activate(struct timeval *now)
+SMT_Activate(struct timespec *now)
 {
  if (!enabled || !locked)
    return;
@@ -283,7 +302,7 @@ SMT_Activate(struct timeval *now)
 }

 void
-SMT_Reset(struct timeval *now)
+SMT_Reset(struct timespec *now)
 {
  int i;

@@ -299,7 +318,7 @@ SMT_Reset(struct timeval *now)
 }

 void
-SMT_Leap(struct timeval *now, int leap)
+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 */
@@ -310,7 +329,7 @@ SMT_Leap(struct timeval *now, int leap)
 }

 int
-SMT_GetSmoothingReport(RPT_SmoothingReport *report, struct timeval *now)
+SMT_GetSmoothingReport(RPT_SmoothingReport *report, struct timespec *now)
 {
  double length, elapsed;
  int i;
@@ -327,7 +346,7 @@ SMT_GetSmoothingReport(RPT_SmoothingReport *report, struct timeval *now)
  report->freq_ppm *= -1.0e6;
  report->wander_ppm *= -1.0e6;

-  UTI_DiffTimevalsToDouble(&elapsed, now, &last_update);
+  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;
--- a/smooth.h
+++ b/smooth.h
@@ -35,14 +35,14 @@ extern void SMT_Finalise(void);

 extern int SMT_IsEnabled(void);

-extern double SMT_GetOffset(struct timeval *now);
+extern double SMT_GetOffset(struct timespec *now);

-extern void SMT_Activate(struct timeval *now);
+extern void SMT_Activate(struct timespec *now);

-extern void SMT_Reset(struct timeval *now);
+extern void SMT_Reset(struct timespec *now);

-extern void SMT_Leap(struct timeval *now, int leap);
+extern void SMT_Leap(struct timespec *now, int leap);

-extern int SMT_GetSmoothingReport(RPT_SmoothingReport *report, struct timeval *now);
+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,
@@ -353,7 +349,8 @@ 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);
+            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");
@@ -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 +424,11 @@ 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 larger than the allowed maximum */
+  if (inst->type == SRC_NTP &&
+      ((!inst->reachability && inst->reachability_size == SOURCE_REACH_BITS) ||
+       inst->status == SRC_FALSETICKER || inst->status == SRC_BAD_DISTANCE)) {
    NSR_HandleBadSource(inst->ip_addr);
  }
 }
@@ -508,10 +507,10 @@ 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, sel_src_distance, elapsed;
  double offset_weight, sum_offset_weight, sum_offset, sum2_offset_sd;
@@ -558,7 +557,7 @@ 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;
@@ -598,10 +597,12 @@ 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;
@@ -628,14 +629,20 @@ 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;
    }
@@ -643,7 +650,7 @@ 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) {
@@ -654,6 +661,18 @@ 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)
@@ -663,6 +682,9 @@ 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;
@@ -677,7 +699,56 @@ 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, LOGF_Sources, "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(LOGF_Sources, "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;
@@ -728,22 +799,27 @@ SRC_SelectSource(SRC_Instance updated_inst)
     If we get a case like

     <----------------------->
-     <-->
-     <-->
-     <===========>
+         <-->
+                  <-->
+         <===========>

     we will build the interval as shown with '=', whereas with an extra source we get
+
     <----------------------->
-     <------->
-     <-->
-     <-->
-     <==>
+        <------->
+         <-->
+                  <-->
+         <==>

     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;

@@ -751,14 +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:
@@ -766,9 +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);
@@ -789,46 +871,60 @@ 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 (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;
@@ -836,12 +932,12 @@ SRC_SelectSource(SRC_Instance updated_inst)
  /* 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_option == SRC_SelectPrefer)
+    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];
@@ -877,7 +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;
@@ -1005,32 +1101,6 @@ SRC_SetReselectDistance(double 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
@@ -1039,12 +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;

@@ -1076,6 +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, LOGF_Sources, "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, LOGF_Sources, "dumpdir too long");
+    return NULL;
+  }
+
+  f = fopen(filename, mode);
+  if (!f && mode[0] != 'r')
+    LOG(LOGS_WARN, LOGF_Sources, "Could not open dump file for %s",
+        source_to_string(inst));
+
+  return f;
+}
+
 /* ================================================== */
 /* This is called to dump out the source measurement registers */

@@ -1083,36 +1182,15 @@ 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 {
-        SST_SaveToFile(sources[i]->stats, out);
-        fclose(out);
-      }
-    }
-  } else {
-    LOG(LOGS_ERR, LOGF_Sources, "Could not create directory %s", direc);
+  for (i = 0; i < n_sources; i++) {
+    out = open_dumpfile(sources[i], "w");
+    if (!out)
+      continue;
+    SST_SaveToFile(sources[i]->stats, out);
+    fclose(out);
  }
-  Free(filename);
 }

 /* ================================================== */
@@ -1121,40 +1199,63 @@ 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);
-      }
-      fclose(in);
-    }
-    Free(filename);
+  for (i = 0; i < n_sources; i++) {
+    in = open_dumpfile(sources[i], "r");
+    if (!in)
+      continue;
+    if (!SST_LoadFromFile(sources[i]->stats, in))
+      LOG(LOGS_WARN, LOGF_Sources, "Could not load dump file for %s",
+          source_to_string(sources[i]));
+    else
+      LOG(LOGS_INFO, LOGF_Sources, "Loaded dump file for %s",
+          source_to_string(sources[i]));
+    fclose(in);
  }
 }

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

+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(LOGF_Sources, "Removing %s", gl.gl_pathv[i]);
+    unlink(gl.gl_pathv[i]);
+  }
+
+  globfree(&gl);
+}
+
+/* ================================================== */
+
 int
 SRC_IsSyncPeer(SRC_Instance inst)
 {
@@ -1199,7 +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)) {
@@ -1207,7 +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 {
@@ -1217,18 +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:
@@ -1242,26 +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 */
@@ -1275,7 +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;

@@ -1304,11 +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
@@ -47,8 +47,25 @@
   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 minimum assumed std dev for weighting */
+#define MIN_WEIGHT_SD 1.0e-9
+
+/* 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 +89,8 @@ 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 +109,18 @@ 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 +132,12 @@ 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 +155,7 @@ 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 +185,7 @@ 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 +238,11 @@ 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 +278,7 @@ 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,
@@ -269,7 +294,7 @@ 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) {
+      UTI_CompareTimespecs(&inst->sample_times[inst->last_sample], sample_time) >= 0) {
    LOG(LOGS_WARN, LOGF_SourceStats, "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 +307,14 @@ 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 +348,13 @@ 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 +400,65 @@ 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
@@ -425,7 +499,8 @@ SST_DoNewRegression(SST_Stats inst)
  
    for (i = 0, mean_distance = 0.0, 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];
+      peer_distances[i] = 0.5 * inst->peer_delays[get_runsbuf_index(inst, i)] +
+                          inst->peer_dispersions[j];
      mean_distance += peer_distances[i];
      if (peer_distances[i] < min_distance) {
        min_distance = peer_distances[i];
@@ -436,8 +511,7 @@ SST_DoNewRegression(SST_Stats inst)
    /* And now, work out the weight vector */

    sd = mean_distance - min_distance;
-    if (sd > min_distance || sd <= 0.0)
-      sd = min_distance;
+    sd = CLAMP(MIN_WEIGHT_SD, sd, min_distance);

    for (i=0; i<inst->n_samples; i++) {
      sd_weight = 1.0 + SD_TO_DIST_RATIO * (peer_distances[i] - min_distance) / sd;
@@ -445,6 +519,8 @@ SST_DoNewRegression(SST_Stats inst)
    }
  }

+  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 +539,26 @@ 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(LOGF_SourceStats, "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 +600,12 @@ 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 +622,9 @@ 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 = 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 +636,10 @@ 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 +647,21 @@ 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(LOGF_SourceStats, "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)
@@ -605,7 +681,7 @@ 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",
@@ -616,11 +692,11 @@ SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,
 /* ================================================== */

 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)
@@ -628,9 +704,9 @@ 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;
  }

@@ -638,14 +714,14 @@ SST_SlewSamples(SST_Stats inst, struct timeval *when, double dfreq, double doffs
  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 = (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",
            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 +743,7 @@ 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 +757,7 @@ 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 +777,20 @@ 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)
    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;

@@ -750,12 +826,18 @@ 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",
-            (unsigned long) inst->sample_times[i].tv_sec,
-            (unsigned long) inst->sample_times[i].tv_usec,
+    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,
+#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 +845,8 @@ SST_SaveToFile(SST_Stats inst, FILE *out)
            inst->strata[j]);

  }
+
+  fprintf(out, "%d\n", inst->asymmetry_run);
 }

 /* ================================================== */
@@ -771,22 +855,30 @@ 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 +891,44 @@ 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;
-
-        line_number++;
+        inst->sample_times[i].tv_nsec = 1000 * usec;
+        UTI_NormaliseTimespec(&inst->sample_times[i]);
      }
    }
+
+    /* 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 ago;

  if (inst->n_samples > 0) {
    i = get_runsbuf_index(inst, inst->n_samples - 1);
@@ -842,10 +938,10 @@ 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]);
+    UTI_DiffTimespecs(&ago, now, &inst->sample_times[i]);
    report->latest_meas_ago = ago.tv_sec;
  } 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 +960,7 @@ 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 +972,15 @@ 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 +997,15 @@ 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/srcparams.h
+++ b/srcparams.h
@@ -42,25 +42,33 @@ typedef struct {
  int max_sources;
  int min_samples;
  int max_samples;
+  int interleaved;
+  int sel_options;
  uint32_t authkey;
  double max_delay;
  double max_delay_ratio;
  double max_delay_dev_ratio;
-  SRC_SelectOption sel_option;
+  double offset;
 } SourceParameters;

 #define SRC_DEFAULT_PORT 123
 #define SRC_DEFAULT_MINPOLL 6
 #define SRC_DEFAULT_MAXPOLL 10
-#define SRC_DEFAULT_PRESEND_MINPOLL 0
+#define SRC_DEFAULT_PRESEND_MINPOLL 100
 #define SRC_DEFAULT_MAXDELAY 3.0
 #define SRC_DEFAULT_MAXDELAYRATIO 0.0
 #define SRC_DEFAULT_MAXDELAYDEVRATIO 10.0
 #define SRC_DEFAULT_MINSTRATUM 0
-#define SRC_DEFAULT_POLLTARGET 6
+#define SRC_DEFAULT_POLLTARGET 8
 #define SRC_DEFAULT_MAXSOURCES 4
 #define SRC_DEFAULT_MINSAMPLES (-1)
 #define SRC_DEFAULT_MAXSAMPLES (-1)
 #define INACTIVE_AUTHKEY 0

+/* Flags for source selection */
+#define SRC_SELECT_NOSELECT 0x1
+#define SRC_SELECT_PREFER 0x2
+#define SRC_SELECT_TRUST 0x4
+#define SRC_SELECT_REQUIRE 0x8
+
 #endif /* GOT_SRCPARAMS_H */
--- a/stubs.c
+++ b/stubs.c
@@ -2,7 +2,7 @@
  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************
- * Copyright (C) Miroslav Lichvar  2014
+ * Copyright (C) Miroslav Lichvar  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
@@ -32,33 +32,74 @@
 #include "keys.h"
 #include "logging.h"
 #include "manual.h"
+#include "memory.h"
 #include "nameserv.h"
 #include "nameserv_async.h"
 #include "ntp_core.h"
 #include "ntp_io.h"
 #include "ntp_sources.h"
+#include "ntp_signd.h"
+#include "privops.h"
 #include "refclock.h"
+#include "sched.h"
+#include "util.h"

 #ifndef FEAT_ASYNCDNS

-#define MAX_ADDRESSES 16
-
 /* This is a blocking implementation used when asynchronous resolving is not available */

+struct DNS_Async_Instance {
+  const char *name;
+  DNS_NameResolveHandler handler;
+  void *arg;
+  int pipe[2];
+};
+
+static void
+resolve_name(int fd, int event, void *anything)
+{
+  struct DNS_Async_Instance *inst;
+  IPAddr addrs[DNS_MAX_ADDRESSES];
+  DNS_Status status;
+  int i;
+
+  inst = (struct DNS_Async_Instance *)anything;
+
+  SCH_RemoveFileHandler(inst->pipe[0]);
+  close(inst->pipe[0]);
+  close(inst->pipe[1]);
+
+  status = PRV_Name2IPAddress(inst->name, addrs, DNS_MAX_ADDRESSES);
+
+  for (i = 0; status == DNS_Success && i < DNS_MAX_ADDRESSES &&
+       addrs[i].family != IPADDR_UNSPEC; i++)
+    ;
+
+  (inst->handler)(status, i, addrs, inst->arg);
+
+  Free(inst);
+}
+
 void
 DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *anything)
 {
-  IPAddr addrs[MAX_ADDRESSES];
-  DNS_Status status;
-  int i;
+  struct DNS_Async_Instance *inst;

-  status = DNS_Name2IPAddress(name, addrs, MAX_ADDRESSES);
+  inst = MallocNew(struct DNS_Async_Instance);
+  inst->name = name;
+  inst->handler = handler;
+  inst->arg = anything;

-  for (i = 0; status == DNS_Success && i < MAX_ADDRESSES &&
-              addrs[i].family != IPADDR_UNSPEC; i++)
+  if (pipe(inst->pipe))
+    LOG_FATAL(LOGF_Nameserv, "pipe() failed");
+
+  UTI_FdSetCloexec(inst->pipe[0]);
+  UTI_FdSetCloexec(inst->pipe[1]);
+
+  SCH_AddFileHandler(inst->pipe[0], SCH_FILE_INPUT, resolve_name, inst);
+
+  if (write(inst->pipe[1], "", 1) < 0)
    ;
-
-  (handler)(status, i, addrs, anything);
 }

 #endif /* !FEAT_ASYNCDNS */
@@ -75,6 +116,11 @@ CAM_Finalise(void)
 {
 }

+void
+CAM_OpenUnixSocket(void)
+{
+}
+
 int
 CAM_AddAccessRestriction(IPAddr *ip_addr, int subnet_bits, int allow, int all)
 {
@@ -169,6 +215,11 @@ NSR_HandleBadSource(IPAddr *address)
 {
 }

+void
+NSR_RefreshAddresses(void)
+{
+}
+
 void
 NSR_SetSourceResolvingEndHandler(NSR_SourceResolvingEndHandler handler)
 {
@@ -196,6 +247,12 @@ NSR_InitiateSampleBurst(int n_good_samples, int n_total_samples,
  return 0;
 }

+uint32_t
+NSR_GetLocalRefid(IPAddr *address)
+{
+  return 0;
+}
+
 int
 NSR_TakeSourcesOnline(IPAddr *mask, IPAddr *address)
 {
@@ -251,11 +308,17 @@ NSR_ModifyPolltarget(IPAddr *address, int new_poll_target)
 }

 void
-NSR_ReportSource(RPT_SourceReport *report, struct timeval *now)
+NSR_ReportSource(RPT_SourceReport *report, struct timespec *now)
 {
  memset(report, 0, sizeof (*report));
 }
  
+int
+NSR_GetNTPReport(RPT_NTPReport *report)
+{
+  return 0;
+}
+
 void
 NSR_GetActivityReport(RPT_ActivityReport *report)
 {
@@ -321,9 +384,35 @@ RCL_StartRefclocks(void)
 }

 void
-RCL_ReportSource(RPT_SourceReport *report, struct timeval *now)
+RCL_ReportSource(RPT_SourceReport *report, struct timespec *now)
 {
  memset(report, 0, sizeof (*report));
 }

 #endif /* !FEAT_REFCLOCK */
+
+#ifndef FEAT_SIGND
+
+void
+NSD_Initialise(void)
+{
+}
+
+void
+NSD_Finalise(void)
+{
+}
+
+int
+NSD_GetAuthDelay(uint32_t key_id)
+{
+  return 0;
+}
+
+int
+NSD_SignAndSendPacket(uint32_t key_id, NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
+{
+  return 0;
+}
+
+#endif /* !FEAT_SIGND */
--- a/sys.c
+++ b/sys.c
@@ -27,26 +27,18 @@

 #include "config.h"

+#include "sysincl.h"
+
 #include "sys.h"
 #include "logging.h"

-#if defined (LINUX)
+#if defined(LINUX)
 #include "sys_linux.h"
-#endif
-
-#if defined (SOLARIS)
+#elif defined(SOLARIS)
 #include "sys_solaris.h"
-#endif
-
-#if defined (SUNOS)
-#include "sys_sunos.h"
-#endif
-
-#if defined (__NetBSD__)
+#elif defined(NETBSD) || defined(FREEBSD)
 #include "sys_netbsd.h"
-#endif
-
-#if defined (MACOSX)
+#elif defined(MACOSX)
 #include "sys_macosx.h"
 #endif

@@ -55,27 +47,17 @@
 void
 SYS_Initialise(void)
 {
-
 #if defined(LINUX)
  SYS_Linux_Initialise();
-#endif
-
-#if defined(SOLARIS)
+#elif defined(SOLARIS)
  SYS_Solaris_Initialise();
-#endif
-
-#if defined(SUNOS)
-  SYS_SunOS_Initialise();
-#endif
-
-#if defined(__NetBSD__)
+#elif defined(NETBSD) || defined(FREEBSD)
  SYS_NetBSD_Initialise();
-#endif
-
-#if defined(MACOSX)
+#elif defined(MACOSX)
  SYS_MacOSX_Initialise();
+#else
+#error Unknown system
 #endif
-
 }

 /* ================================================== */
@@ -83,34 +65,31 @@ SYS_Initialise(void)
 void
 SYS_Finalise(void)
 {
-  
 #if defined(LINUX)
  SYS_Linux_Finalise();
-#endif
-
-#if defined(SOLARIS)
+#elif defined(SOLARIS)
  SYS_Solaris_Finalise();
-#endif
-
-#if defined(SUNOS)
-  SYS_SunOS_Finalise();
-#endif
-
-#if defined(__NetBSD__)
+#elif defined(NETBSD) || defined(FREEBSD)
  SYS_NetBSD_Finalise();
-#endif
-
-#if defined(MACOSX)
+#elif defined(MACOSX)
  SYS_MacOSX_Finalise();
+#else
+#error Unknown system
 #endif
 }

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

-void SYS_DropRoot(char *user)
+void SYS_DropRoot(uid_t uid, gid_t gid)
 {
 #if defined(LINUX) && defined (FEAT_PRIVDROP)
-  SYS_Linux_DropRoot(user);
+  SYS_Linux_DropRoot(uid, gid);
+#elif defined(SOLARIS) && defined(FEAT_PRIVDROP)
+  SYS_Solaris_DropRoot(uid, gid);
+#elif (defined(NETBSD) || defined(FREEBSD)) && defined(FEAT_PRIVDROP)
+  SYS_NetBSD_DropRoot(uid, gid);
+#elif defined(MACOSX) && defined(FEAT_PRIVDROP)
+  SYS_MacOSX_DropRoot(uid, gid);
 #else
  LOG_FATAL(LOGF_Sys, "dropping root privileges not supported");
 #endif
@@ -118,10 +97,23 @@ void SYS_DropRoot(char *user)

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

+void SYS_EnableSystemCallFilter(int level)
+{
+#if defined(LINUX) && defined(FEAT_SCFILTER)
+  SYS_Linux_EnableSystemCallFilter(level);
+#else
+  LOG_FATAL(LOGF_Sys, "system call filter not supported");
+#endif
+}
+
+/* ================================================== */
+
 void SYS_SetScheduler(int SchedPriority)
 {
 #if defined(LINUX) && defined(HAVE_SCHED_SETSCHEDULER)
  SYS_Linux_SetScheduler(SchedPriority);
+#elif defined(MACOSX)
+  SYS_MacOSX_SetScheduler(SchedPriority);
 #else
  LOG_FATAL(LOGF_Sys, "scheduler priority setting not supported");
 #endif
--- a/Show More
+++ b/Show More