doc: update NEWS

cmdmon: fix initialization of allocated reply slots
When allocating memory to save unacknowledged replies to authenticated command requests, the last "next" pointer was not initialized to NULL. When all allocated reply slots were used, the next reply could be written to an invalid memory instead of allocating a new slot for it. An attacker that has the command key and is allowed to access cmdmon (only localhost is allowed by default) could exploit this to crash chronyd or possibly execute arbitrary code with the privileges of the chronyd process.
2025-12-03 17:45:07 -05:00 · 2015-04-07 16:35:16 +02:00 · 2015-04-07 16:35:16 +02:00 · 2015-04-07 16:35:16 +02:00 · 2015-04-07 16:34:42 +02:00 · 2014-09-10 17:00:54 +02:00
106 changed files with 6000 additions and 5106 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,5 @@ config.h
 config.log
 tags
 version.h
+/test/simulation/clknetsim
+/test/simulation/tmp
--- a/95
+++ b/95
@@ -1,95 +0,0 @@
-The software is distributed as source code which has to be compiled.
-
-PARTS OF THE SOFTWARE ARE HIGHLY SYSTEM-SPECIFIC AND NON-PORTABLE.
-UNLESS YOU ARE RUNNING A SUPPORTED SYSTEM, BE PREPARED FOR SOME
-PROGRAMMING!
-
-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.
-
-If editline or readline library is available, chronyc will be built
-with line editing support.  If you don't want this, specify the
--disable-readline flag to configure.  Please refer to the chrony.txt
-file for more information.
-
-If a `timepps.h' header is available, 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 CPPFLAGS variable to -I/path/to/timepps.
-
-Now type
-
-    make
-
-to build the programs.
-
-If you want to build the manual in plain text, HTML and info versions, 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, plain text manual and manpages.
-
-To install the HTML and info versions of the manual as well, enter the command
-
-    make install-docs
-
-If you want chrony to appear in the top level info directory listing, you need
-to run the install-info command manually after this step.  install-info takes 2
-arguments.  The first is the path to the chrony.info file you have just
-installed.  This will be the argument you gave to --prefix when you configured
-(/usr/local by default), with /share/info/chrony.info on the end.  The second
-argument is the location of the file called 'dir'.  This will typically be
-/usr/share/info/dir.  So the typical command line would be
-
-    install-info /usr/local/share/info/chrony.info /usr/share/info/dir
-
-Now that the software is successfully installed, the next step is to
-set up a configuration file.  The contents of this depend on the
-network environment in which the computer operates.  Typical scenarios
-are described in the manual.  The simplest case is for a computer with
-a permanent Internet connection - suppose you want to use public NTP
-servers from the pool.ntp.org project as your time reference.  You would
-create an /etc/chrony.conf file containing
-
-    server 0.pool.ntp.org
-    server 1.pool.ntp.org
-    server 2.pool.ntp.org
-    driftfile /var/lib/chrony/drift
-
-and then run /usr/local/sbin/chronyd.
-
-
--- a/Makefile.in
+++ b/Makefile.in
@@ -42,10 +42,10 @@ OBJS = util.o sched.o regress.o local.o \
 	sys.o main.o ntp_io.o ntp_core.o ntp_sources.o \
 	sources.o sourcestats.o reference.o \
 	logging.o conf.o cmdmon.o keys.o \
-	nameserv.o acquire.o manual.o addrfilt.o \
+	nameserv.o nameserv_async.o manual.o addrfilt.o \
 	cmdparse.o mkdirpp.o rtc.o pktlength.o clientlog.o \
-	broadcast.o refclock.o refclock_shm.o refclock_sock.o \
-	refclock_pps.o tempcomp.o $(HASH_OBJ)
+	broadcast.o refclock.o refclock_phc.o refclock_pps.o \
+	refclock_shm.o refclock_sock.o tempcomp.o $(HASH_OBJ)

 EXTRA_OBJS=@EXTRA_OBJECTS@

@@ -66,10 +66,10 @@ EXTRA_CLI_LIBS=@EXTRA_CLI_LIBS@
 all : chronyd chronyc

 chronyd : $(OBJS) $(EXTRA_OBJS)
-	$(CC) $(CFLAGS) -o chronyd $(OBJS) $(EXTRA_OBJS) $(LDFLAGS) @HASH_LINK@ $(LIBS) $(EXTRA_LIBS)
+	$(CC) $(CFLAGS) -o chronyd $(OBJS) $(EXTRA_OBJS) $(LDFLAGS) $(LIBS) $(EXTRA_LIBS)

 chronyc : $(CLI_OBJS)
-	$(CC) $(CFLAGS) -o chronyc $(CLI_OBJS) $(LDFLAGS) @READLINE_LINK@ @HASH_LINK@ $(LIBS) $(EXTRA_CLI_LIBS)
+	$(CC) $(CFLAGS) -o chronyc $(CLI_OBJS) $(LDFLAGS) $(LIBS) $(EXTRA_CLI_LIBS)

 client.o : client.c
 	$(CC) $(CFLAGS) $(CPPFLAGS) @READLINE_COMPILE@ -c $<
@@ -85,14 +85,17 @@ clean :
 	-rm -f *.o *.s chronyc chronyd core *~ chrony.info chrony.html chrony.txt
 	-rm -rf .deps

-getdate.c : ;
+getdate.c :
+	bison -o getdate.c getdate.y
+
+# This can be used to force regeneration of getdate.c
 getdate :
 	bison -o getdate.c getdate.y

 # For install, don't use the install command, because its switches
 # seem to vary between systems.

-install: chronyd chronyc
+install: chronyd chronyc chrony.txt
 	[ -d $(DESTDIR)$(SYSCONFDIR) ] || mkdir -p $(DESTDIR)$(SYSCONFDIR)
 	[ -d $(DESTDIR)$(SBINDIR) ] || mkdir -p $(DESTDIR)$(SBINDIR)
 	[ -d $(DESTDIR)$(BINDIR) ] || mkdir -p $(DESTDIR)$(BINDIR)
@@ -129,6 +132,9 @@ install: chronyd chronyc
 %.s : %.c
 	$(CC) $(CFLAGS) $(CPPFLAGS) -S $<

+check : chronyd chronyc
+	cd test/simulation && ./run
+
 install-docs : docs
 	[ -d $(DESTDIR)$(DOCDIR) ] || mkdir -p $(DESTDIR)$(DOCDIR)
 	cp chrony.txt $(DESTDIR)$(DOCDIR)/chrony.txt
@@ -151,10 +157,6 @@ chrony.html : chrony.texi
 chrony.info : chrony.texi
 	makeinfo chrony.texi

-# This is only relevant if you're maintaining the website!
-faq.php : faq.txt faqgen.pl
-	perl faqgen.pl < faq.txt > faq.php
-
 .deps:
 	@mkdir .deps

--- a/85
+++ b/85
@@ -1,3 +1,88 @@
+New in version 1.31.1
+=====================
+
+Security fixes
+--------------
+* Protect authenticated symmetric NTP associations against DoS attacks
+  (CVE-2015-1799)
+* Fix access configuration with subnet size indivisible by 4 (CVE-2015-1821)
+* Fix initialization of reply slots for authenticated commands (CVE-2015-1822)
+
+New in version 1.31
+===================
+
+Enhancements
+------------
+* Support operation in other NTP eras (next era begins in 2036),
+  NTP time is mapped to [-50, +86] years around build date by default
+* Restore time from driftfile with -s when RTC is missing/unsupported
+* Close connected client sockets when not waiting for reply
+* Use one client socket with random port when acquisitionport is 0
+* Use NTP packets instead of UDP echo for presend
+* Don't adjust polling interval when sending fails
+* Allow binding to addresses that don't exist yet
+* Ignore measurements around leap second
+* Improve detection of unexpected time jumps
+* Include example of logrotate configuration, systemd services and
+  NetworkManager dispatcher script
+
+Bug fixes
+---------
+* Reconnect client sockets for each request to follow changes
+  in network configuration automatically
+* Restart timer when polling interval is changed on reset
+
+New in version 1.30
+===================
+
+Enhancements
+------------
+* Add asynchronous name resolving with POSIX threads
+* Add PTP hardware clock (PHC) refclock driver
+* Add new generic clock driver to slew by adjusting frequency only
+  (without kernel PLL or adjtime) and use it on Linux
+* Add rtcautotrim directive to trim RTC automatically
+* Add hwclockfile directive to share RTC LOCAL/UTC setting with hwclock
+* Add maxslewrate directive to set maximum allowed slew rate
+* Add maxdispersion option for refclocks
+* Add -q/-Q options to set clock/print offset once and exit
+* Allow directives to be specified on chronyd command line
+* Replace frequency scaling in Linux driver with retaining of tick
+* Try to detect unexpected forward time jumps and reset state
+* Exit with non-zero code when maxchange limit is reached
+* Improve makestep to not start and stop slew unnecessarily
+* Change default corrtimeratio to 3.0 to improve frequency accuracy
+* Announce leap second only on last day of June and December
+* Use separate connected client sockets for each NTP server
+* Remove separate NTP implementation used for initstepslew
+* Limit maximum minpoll set by KoD RATE to default maxpoll
+* Don't send NTP requests with unknown key
+* Print warning when source is added with unknown key
+* Take leap second in PPS refclock from locked source
+* Make reading of RTC for initial trim more reliable
+* Don't create cmdmon sockets when cmdport is 0
+* Add configure option to set default user to drop root privileges
+* Add configure option to compile with debug messages
+* Print debug messages when -d is used more than once
+* Change format of messages written to terminal with -d
+* Write fatal messages also to stderr with -n
+* Use IP_RECVERR socket option in chronyc to not wait unnecessarily
+* Shorten default chronyc timeout for localhost
+* Change default hostname in chronyc from localhost to 127.0.0.1
+* Print error message on invalid syntax with all chronyc commands
+* Include simulation test suite using clknetsim
+
+Bug fixes
+---------
+* Fix crash when selecting with multiple preferred sources
+* Fix frequency calculation with large frequency offsets
+* Fix code writing drift and RTC files to compile correctly
+* Fix -4/-6 options in chronyc to not reset hostname set by -h
+* Fix refclock sample validation with sub-second polling interval
+* Set stratum correctly with non-PPS SOCK refclock and local stratum
+* Modify dispersion accounting in refclocks to prevent PPS getting
+  stuck with large dispersion and not accepting new samples
+
 New in version 1.29.1
 =====================

--- a/13
+++ b/13
@@ -2,6 +2,7 @@ This is the README for chrony.

 What is chrony?
 ===============
+
 Chrony is a pair of programs for maintaining the accuracy of computer
 clocks.

@@ -61,7 +62,7 @@ Chrony can be successfully built and run on
 Any other system will require a porting exercise.  You would need to
 start from one of the existing system-specific drivers and look into
 the quirks of certain system calls and the kernel on your target
-system.  (This is described in the manual).
+system.

 How do I set it up?
 ===================
@@ -94,8 +95,7 @@ by sending mail with the subject "subscribe" to

 chrony-announce-request@chrony.tuxfamily.org

-These messages will be copied to chrony-users (see below).  New versions
-are announced also on Freshmeat (http://freshmeat.net/).
+These messages will be copied to chrony-users (see below).

 How can I get support for chrony?
 and where can I discuss new features, possible bugs etc?
@@ -125,7 +125,6 @@ Richard P. Curnow <rc@rc0.org.uk>
 Maintainers
 ===========

-John Hasler <john@dhh.gt.org>
 Miroslav Lichvar <mlichvar@redhat.com>


@@ -179,6 +178,7 @@ Juergen Hannken-Illjes <hannken@eis.cs.tu-bs.de>
    Port to NetBSD

 John Hasler <john@dhh.gt.org>
+    Project and website at tuxfamily.org
    Changes to support 64 bit machines (i.e. those where
      sizeof(unsigned long) > 4)
    Bug fix to initstepslew directive
@@ -186,6 +186,11 @@ John Hasler <john@dhh.gt.org>
    Memory locking and real-time scheduler support
    Fix fault where chronyd enters an endless loop

+Tjalling Hattink <t.hattink@fugro.nl>
+    Fix scheduler to allow stepping clock from timeout handler
+    Patch to take leap second in PPS refclock from locked source
+    Patch to make reading of RTC for initial trim more reliable
+
 Liam Hatton <me@liamhatton.com>
    Advice on configuring for Linux on PPC

--- a/acquire.c
+++ b/acquire.c
@@ -1,796 +0,0 @@
-/*
-  chronyd/chronyc - Programs for keeping computer clocks accurate.
-
- **********************************************************************
- * Copyright (C) Richard P. Curnow  1997-2003
- * 
- * 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.
- * 
- **********************************************************************
-
-  =======================================================================
-
-  Processing to perform the equivalent of what ntpdate does.  That is,
-  make a rapid-fire set of measurements to a designated set of
-  sources, and step or slew the local clock to bring it into line with
-  the result.
-
-  This is kept completely separate of the main chronyd processing, by
-  using a separate socket for sending/receiving the measurement
-  packets.  That way, ntp_core.c can be kept completely independent of
-  this functionality.
-  
-  A few of the finer points of how to construct valid RFC1305 packets
-  and validate responses for this case have been cribbed from the
-  ntpdate source.
-
-  */
-
-#include "config.h"
-
-#include "sysincl.h"
-
-#include "acquire.h"
-#include "memory.h"
-#include "sched.h"
-#include "local.h"
-#include "logging.h"
-#include "ntp.h"
-#include "util.h"
-#include "main.h"
-#include "conf.h"
-
-/* ================================================== */
-
-/* Interval between firing off the first sample to successive sources */
-#define INTER_SOURCE_START (0.2)
-
-#define MAX_SAMPLES 8
-
-#define MAX_DEAD_PROBES 4
-#define N_GOOD_SAMPLES 4
-
-#define RETRANSMISSION_TIMEOUT (1.0)
-
-#define NTP_VERSION 3
-#define NTP_MAX_COMPAT_VERSION 4
-#define NTP_MIN_COMPAT_VERSION 2
-
-typedef struct {
-  IPAddr ip_addr;               /* Address of the server */
-  int sanity;                   /* Flag indicating whether source
-                                   looks sane or not */
-  int n_dead_probes;            /* Number of probes sent to the server
-                                   since a good one */
-  int n_samples;                /* Number of samples accumulated */
-  int n_total_samples;          /* Total number of samples received
-                                   including useless ones */
-  double offsets[MAX_SAMPLES];  /* In seconds, positive means local
-                                   clock is fast of reference */
-  double root_distances[MAX_SAMPLES]; /* in seconds */
-  double inter_lo;              /* Low end of estimated range of offset */
-  double inter_hi;              /* High end of estimated range of offset */
-
-  NTP_int64 last_tx;            /* Transmit timestamp in last packet
-                                   transmitted to source. */
-
-  int timer_running;
-  SCH_TimeoutID timeout_id;
-} SourceRecord;
-
-static SourceRecord *sources;
-static int n_sources;
-static int n_started_sources;
-static int n_completed_sources;
-
-static double init_slew_threshold;
-
-union sockaddr_in46 {
-  struct sockaddr_in in4;
-#ifdef HAVE_IPV6
-  struct sockaddr_in6 in6;
-#endif
-  struct sockaddr u;
-};
-
-static int sock_fd4 = -1;
-#ifdef HAVE_IPV6
-static int sock_fd6 = -1;
-#endif
-
-/* ================================================== */
-
-static void (*saved_after_hook)(void *) = NULL;
-static void *saved_after_hook_anything = NULL;
-
-/* ================================================== */
-
-typedef struct {
-  double offset;
-  enum {LO, HIGH} type;
-  int index;
-} Endpoint;
-
-typedef struct {
-  double lo;
-  double hi;
-} Interval;
-
-/* ================================================== */
-
-static void read_from_socket(void *anything);
-static void transmit_timeout(void *x);
-static void wind_up_acquisition(void);
-static void start_source_timeout_handler(void *not_used);
-
-/* ================================================== */
-
-static SCH_TimeoutID source_start_timeout_id;
-
-/* ================================================== */
-
-void
-ACQ_Initialise(void)
-{
-}
-
-
-/* ================================================== */
-
-void
-ACQ_Finalise(void)
-{
-}
-
-/* ================================================== */
-
-static int
-prepare_socket(int family)
-{
-  unsigned short port_number = CNF_GetAcquisitionPort();
-  int sock_fd;
-  socklen_t addrlen;
-
-  sock_fd = socket(family, SOCK_DGRAM, 0);
-
-  if (sock_fd < 0) {
-    LOG_FATAL(LOGF_Acquire, "Could not open socket : %s", strerror(errno));
-  }
-
-  /* Close on exec */
-  UTI_FdSetCloexec(sock_fd);
-
-  if (port_number == 0) {
-    /* Don't bother binding this socket - we're not fussed what port
-       number it gets */
-  } else {
-    union sockaddr_in46 my_addr;
-
-    memset(&my_addr, 0, sizeof (my_addr));
-
-    switch (family) {
-      case AF_INET:
-        my_addr.in4.sin_family = family;
-        my_addr.in4.sin_port = htons(port_number);
-        my_addr.in4.sin_addr.s_addr = htonl(INADDR_ANY);
-        addrlen = sizeof (my_addr.in4);
-        break;
-#ifdef HAVE_IPV6
-      case AF_INET6:
-        my_addr.in6.sin6_family = family;
-        my_addr.in6.sin6_port = htons(port_number);
-        my_addr.in6.sin6_addr = in6addr_any;
-        addrlen = sizeof (my_addr.in6);
-        break;
-#endif
-      default:
-        assert(0);
-    }
-
-    if (bind(sock_fd, &my_addr.u, addrlen) < 0) {
-      LOG(LOGS_ERR, LOGF_Acquire, "Could not bind socket : %s", strerror(errno));
-      /* but keep running */
-    }
-  }
-
-  SCH_AddInputFileHandler(sock_fd, read_from_socket, (void *)(long)sock_fd);
-
-  return sock_fd;
-}
-/* ================================================== */
-
-static void
-initialise_io(int family)
-{
-  if (family == IPADDR_INET4 || family == IPADDR_UNSPEC)
-    sock_fd4 = prepare_socket(AF_INET);
-#ifdef HAVE_IPV6
-  if (family == IPADDR_INET6 || family == IPADDR_UNSPEC)
-    sock_fd6 = prepare_socket(AF_INET6);
-#endif
-}
-
-/* ================================================== */
-
-static void
-finalise_io(void)
-{
-  if (sock_fd4 >= 0) {
-    SCH_RemoveInputFileHandler(sock_fd4);
-    close(sock_fd4);
-  }
-  sock_fd4 = -1;
-#ifdef HAVE_IPV6
-  if (sock_fd6 >= 0) {
-    SCH_RemoveInputFileHandler(sock_fd6);
-    close(sock_fd6);
-  }
-  sock_fd6 = -1;
-#endif
-}
-
-/* ================================================== */
-
-static void
-probe_source(SourceRecord *src)
-{
-  NTP_Packet pkt;
-  int version = NTP_VERSION;
-  NTP_Mode my_mode = MODE_CLIENT;
-  struct timeval cooked;
-  union sockaddr_in46 his_addr;
-  int sock_fd;
-  socklen_t addrlen;
-  uint32_t ts_fuzz;
-
-#if 0
-  printf("Sending probe to %s sent=%d samples=%d\n", UTI_IPToString(&src->ip_addr), src->n_probes_sent, src->n_samples);
-#endif
-
-  pkt.lvm = (((LEAP_Unsynchronised << 6) & 0xc0) |
-             ((version << 3) & 0x38) |
-             ((my_mode) & 0x7));
-
-  pkt.stratum = 0;
-  pkt.poll = 4;
-  pkt.precision = -6; /* as ntpdate */
-  pkt.root_delay = UTI_DoubleToInt32(1.0); /* 1 second */
-  pkt.root_dispersion = UTI_DoubleToInt32(1.0); /* likewise */
-  pkt.reference_id = 0;
-  pkt.reference_ts.hi = 0; /* Set to 0 */
-  pkt.reference_ts.lo = 0; /* Set to 0 */
-  pkt.originate_ts.hi = 0; /* Set to 0 */
-  pkt.originate_ts.lo = 0; /* Set to 0 */
-  pkt.receive_ts.hi = 0;   /* Set to 0 */
-  pkt.receive_ts.lo = 0;   /* Set to 0 */
-
-  /* And do transmission */
-
-  memset(&his_addr, 0, sizeof (his_addr));
-  switch (src->ip_addr.family) {
-    case IPADDR_INET4:
-      his_addr.in4.sin_addr.s_addr = htonl(src->ip_addr.addr.in4);
-      his_addr.in4.sin_port = htons(123); /* Fixed for now */
-      his_addr.in4.sin_family = AF_INET;
-      addrlen = sizeof (his_addr.in4);
-      sock_fd = sock_fd4;
-      break;
-#ifdef HAVE_IPV6
-    case IPADDR_INET6:
-      memcpy(&his_addr.in6.sin6_addr.s6_addr, &src->ip_addr.addr.in6,
-          sizeof (his_addr.in6.sin6_addr.s6_addr));
-      his_addr.in6.sin6_port = htons(123); /* Fixed for now */
-      his_addr.in6.sin6_family = AF_INET6;
-      addrlen = sizeof (his_addr.in6);
-      sock_fd = sock_fd6;
-      break;
-#endif
-    default:
-      assert(0);
-  }
-
-
-  ts_fuzz = UTI_GetNTPTsFuzz(LCL_GetSysPrecisionAsLog());
-  LCL_ReadCookedTime(&cooked, NULL);
-  UTI_TimevalToInt64(&cooked, &pkt.transmit_ts, ts_fuzz);
-
-  if (sendto(sock_fd, (void *) &pkt, NTP_NORMAL_PACKET_SIZE,
-             0,
-             &his_addr.u, addrlen) < 0) {
-    LOG(LOGS_WARN, LOGF_Acquire, "Could not send to %s : %s",
-        UTI_IPToString(&src->ip_addr),
-        strerror(errno));
-  }
-
-  src->last_tx = pkt.transmit_ts;
-
-  ++(src->n_dead_probes);
-  src->timer_running = 1;
-  src->timeout_id = SCH_AddTimeoutByDelay(RETRANSMISSION_TIMEOUT, transmit_timeout, (void *) src);
-}
-
-/* ================================================== */
-
-static void
-transmit_timeout(void *x)
-{
-  SourceRecord *src = (SourceRecord *) x;
-
-  src->timer_running = 0;
-
-#if 0
-  printf("Timeout expired for server %s\n", UTI_IPToString(&src->ip_addr));
-#endif
-
-  if (src->n_dead_probes < MAX_DEAD_PROBES) {
-    probe_source(src);
-  } else {
-    /* Source has croaked or is taking too long to respond */
-    ++n_completed_sources;
-    if (n_completed_sources == n_sources) {
-      wind_up_acquisition();
-    }
-  }
-}
-
-/* ================================================== */
-
-#define MAX_STRATUM 15
-
-static void
-process_receive(NTP_Packet *msg, SourceRecord *src, struct timeval *now)
-{
-
-  unsigned long lvm;
-  int leap, version, mode;
-  double root_delay, root_dispersion;
-  double total_root_delay, total_root_dispersion, total_root_distance;
-
-  struct timeval local_orig, local_average, remote_rx, remote_tx, remote_average;
-  double remote_interval, local_interval;
-  double delta, theta, epsilon;
-  int n;
-  
-  /* Most of the checks are from ntpdate */
-
-  /* Need to do something about authentication */
-
-  lvm = msg->lvm;
-  leap = (lvm >> 6) & 0x3;
-  version = (lvm >> 3) & 0x7;
-  mode = lvm & 0x7;
-
-  if ((leap == LEAP_Unsynchronised) ||
-      (version  < NTP_MIN_COMPAT_VERSION || version > NTP_MAX_COMPAT_VERSION) ||
-      (mode != MODE_SERVER && mode != MODE_PASSIVE)) {
-    return;
-  }
-
-  if (msg->stratum > MAX_STRATUM) {
-    return;
-  }
-
-  /* Check whether server is responding to our last request */
-  if ((msg->originate_ts.hi != src->last_tx.hi) ||
-      (msg->originate_ts.lo != src->last_tx.lo)) {
-    return;
-  }
-
-  /* Check that the server is sane */
-  if (((msg->originate_ts.hi == 0) && (msg->originate_ts.lo == 0)) ||
-      ((msg->receive_ts.hi == 0) && (msg->receive_ts.lo) == 0)) {
-    return;
-  }
-
-  root_delay = UTI_Int32ToDouble(msg->root_delay);
-  root_dispersion = UTI_Int32ToDouble(msg->root_dispersion);
-
-  UTI_Int64ToTimeval(&src->last_tx, &local_orig);
-  UTI_Int64ToTimeval(&msg->receive_ts, &remote_rx);
-  UTI_Int64ToTimeval(&msg->transmit_ts, &remote_tx);
-  UTI_AverageDiffTimevals(&remote_rx, &remote_tx, &remote_average, &remote_interval);
-  UTI_AverageDiffTimevals(&local_orig, now, &local_average, &local_interval);
-
-  delta = local_interval - remote_interval;
-
-  /* Defined as positive if we are fast.  Note this sign convention is
-     opposite to that used in ntp_core.c */
-
-  UTI_DiffTimevalsToDouble(&theta, &local_average, &remote_average);
-  
-  /* Could work out epsilon - leave till later */
-  epsilon = 0.0;
-
-  total_root_delay = fabs(delta) + root_delay;
-  total_root_dispersion = epsilon + root_dispersion;
-  total_root_distance = 0.5 * fabs(total_root_delay) + total_root_dispersion;
-
-  n = src->n_samples;
-#if 0
-  printf("Sample %d theta=%.6f delta=%.6f root_del=%.6f root_disp=%.6f root_dist=%.6f\n",
-         n, theta, delta, total_root_delay, total_root_dispersion, total_root_distance);
-#endif
-  src->offsets[n] = theta;
-  src->root_distances[n] = total_root_distance;
-  ++(src->n_samples);
-
-}
-
-/* ================================================== */
-
-static void
-read_from_socket(void *anything)
-{
-  int status;
-  ReceiveBuffer msg;
-  union sockaddr_in46 his_addr;
-  int sock_fd;
-  socklen_t his_addr_len;
-  int flags;
-  int message_length;
-  IPAddr remote_ip;
-  int i, ok;
-  struct timeval now;
-  SourceRecord *src;
-
-  flags = 0;
-  message_length = sizeof(msg);
-  his_addr_len = sizeof(his_addr);
-
-  /* Get timestamp */
-  SCH_GetLastEventTime(&now, NULL, NULL);
-
-  sock_fd = (long)anything;
-  status = recvfrom (sock_fd, (char *)&msg, message_length, flags,
-                     &his_addr.u, &his_addr_len);
-
-  if (status < 0) {
-    LOG(LOGS_WARN, LOGF_Acquire, "Error reading from socket, %s", strerror(errno));
-    return;
-  }
-  
-  switch (his_addr.u.sa_family) {
-    case AF_INET:
-      remote_ip.family = IPADDR_INET4;
-      remote_ip.addr.in4 = ntohl(his_addr.in4.sin_addr.s_addr);
-      break;
-#ifdef HAVE_IPV6
-    case AF_INET6:
-      remote_ip.family = IPADDR_INET6;
-      memcpy(&remote_ip.addr.in6, his_addr.in6.sin6_addr.s6_addr,
-          sizeof (remote_ip.addr.in6));
-      break;
-#endif
-    default:
-      assert(0);
-  }
-
-#if 0
-  printf("Got message from %s\n", UTI_IPToString(&remote_ip));
-#endif
-  
-  /* Find matching host */
-  ok = 0;
-  for (i=0; i<n_sources; i++) {
-    if (UTI_CompareIPs(&remote_ip, &sources[i].ip_addr, NULL) == 0) {
-      ok = 1;
-      break;
-    }
-  }
-
-  if (ok) {
-
-    src = sources + i;
-    ++src->n_total_samples;
-
-    src->n_dead_probes = 0; /* reset this when we actually receive something */
-
-    /* If we got into this function, we know the retransmission timeout has not
-       expired for the source */
-    if (src->timer_running) {
-      SCH_RemoveTimeout(src->timeout_id);
-      src->timer_running = 0;
-    }
-
-    process_receive(&msg.ntp_pkt, src, &now);
-
-    /* Check if server done and requeue timeout */
-    if ((src->n_samples >= N_GOOD_SAMPLES) ||
-        (src->n_total_samples >= MAX_SAMPLES)) {
-      ++n_completed_sources;
-#if 0
-      printf("Source %s completed\n", UTI_IPToString(&src->ip_addr));
-#endif
-      if (n_completed_sources == n_sources) {
-        wind_up_acquisition();
-      }
-    } else {
-      
-      /* Send the next probe */
-      probe_source(src);
-
-    }
-  }
-
-}
-
-/* ================================================== */
-
-static void
-start_next_source(void)
-{
-  probe_source(sources + n_started_sources);
-#if 0
-  printf("Trying to start source %s\n", UTI_IPToString(&sources[n_started_sources].ip_addr));
-#endif
-  n_started_sources++;
-  
-  if (n_started_sources < n_sources) {
-    source_start_timeout_id = SCH_AddTimeoutByDelay(INTER_SOURCE_START, start_source_timeout_handler, NULL);
-  }
-}
-
-/* ================================================== */
-
-static int
-endpoint_compare(const void *a, const void *b)
-{
-  const Endpoint *aa = (const Endpoint *) a;
-  const Endpoint *bb = (const Endpoint *) b;
-
-  if (aa->offset < bb->offset) {
-    return -1;
-  } else if (aa->offset > bb->offset) {
-    return +1;
-  } else {
-    return 0;
-  }
-}
-
-/* ================================================== */
-
-static void
-process_measurements(void)
-{
-
-  SourceRecord *s;
-  Endpoint *eps;
-  int i, j;
-  int n_sane_sources;
-  double lo, hi;
-  double inter_lo, inter_hi;
-
-  int depth;
-  int best_depth;
-  int n_at_best_depth;
-  Interval *intervals;
-  double estimated_offset;
-  int index1, index2;
-
-  n_sane_sources = 0;
-
-  /* First, get a consistent interval for each source.  Those for
-     which this is not possible are considered to be insane. */
-
-  for (i=0; i<n_sources; i++) {
-    s = sources + i;
-    /* If we got no measurements, the source is insane */
-    if (s->n_samples == 0) {
-      s->sanity = 0;
-    } else {
-      s->sanity = 1; /* so far ... */
-      lo = s->offsets[0] - s->root_distances[0];
-      hi = s->offsets[0] + s->root_distances[0];
-      inter_lo = lo;
-      inter_hi = hi;
-      for (j=1; j<s->n_samples; j++) {
-        lo = s->offsets[j] - s->root_distances[j];
-        hi = s->offsets[j] + s->root_distances[j];
-        if ((inter_hi <= lo) || (inter_lo >= hi)) {
-          /* Oh dear, we won't get an interval for this source */
-          s->sanity = 0;
-          break;
-        } else {
-          inter_lo = (lo < inter_lo) ? inter_lo : lo;
-          inter_hi = (hi > inter_hi) ? inter_hi : hi;
-        }
-      }
-      if (s->sanity) {
-        s->inter_lo = inter_lo;
-        s->inter_hi = inter_hi;
-      }
-    }
-
-    if (s->sanity) {
-      ++n_sane_sources;
-    }
-
-  }
-
-  /* Now build the endpoint list, similar to the RFC1305 clock
-     selection algorithm. */
-  eps = MallocArray(Endpoint, 2*n_sane_sources);
-  intervals = MallocArray(Interval, n_sane_sources);
-
-  j = 0;
-  for (i=0; i<n_sources; i++) {
-    s = sources + i;
-    if (s->sanity) {
-      eps[j].offset = s->inter_lo;
-      eps[j].type = LO;
-      eps[j].index = i;
-      eps[j+1].offset = s->inter_hi;
-      eps[j+1].type = HIGH;
-      eps[j+1].index = i;
-      j += 2;
-    }
-  }
-
-  qsort(eps, 2*n_sane_sources, sizeof(Endpoint), endpoint_compare);
-
-  /* Now do depth searching algorithm */
-  n_at_best_depth = best_depth = depth = 0;
-  for (i=0; i<2*n_sane_sources; i++) {
-
-#if 0
-    fprintf(stderr, "Endpoint type %s source index %d [ip=%s] offset=%.6f\n",
-            (eps[i].type == LO) ? "LO" : "HIGH",
-            eps[i].index,
-            UTI_IPToString(&sources[eps[i].index].ip_addr),
-            eps[i].offset);
-#endif
-
-    switch (eps[i].type) {
-      case LO:
-        depth++;
-        if (depth > best_depth) {
-          best_depth = depth;
-          n_at_best_depth = 0;
-          intervals[0].lo = eps[i].offset;
-        } else if (depth == best_depth) {
-          intervals[n_at_best_depth].lo = eps[i].offset;
-        } else {
-          /* Nothing to do */
-        }
-
-        break;
-
-      case HIGH:
-        if (depth == best_depth) {
-          intervals[n_at_best_depth].hi = eps[i].offset;
-          n_at_best_depth++;
-        }
-
-        depth--;
-
-        break;
-
-    }
-  }
-
-  if (best_depth > 0) {
-    if ((n_at_best_depth % 2) == 1) {
-      index1 = (n_at_best_depth - 1) / 2;
-      estimated_offset = 0.5 * (intervals[index1].lo + intervals[index1].hi);
-    } else {
-      index2 = (n_at_best_depth / 2);
-      index1 = index2 - 1;
-      estimated_offset = 0.5 * (intervals[index1].lo + intervals[index2].hi);
-    }
-
-
-    /* Apply a step change to the system clock.  As per sign
-       convention in local.c and its children, a positive offset means
-       the system clock is fast of the reference, i.e. it needs to be
-       stepped backwards. */
-
-    if (fabs(estimated_offset) > init_slew_threshold) {
-      LOG(LOGS_INFO, LOGF_Acquire, "System's initial offset : %.6f seconds %s of true (step)",
-          fabs(estimated_offset),
-          (estimated_offset >= 0) ? "fast" : "slow");
-      LCL_ApplyStepOffset(estimated_offset);
-    } else {
-      LOG(LOGS_INFO, LOGF_Acquire, "System's initial offset : %.6f seconds %s of true (slew)",
-          fabs(estimated_offset),
-          (estimated_offset >= 0) ? "fast" : "slow");
-      LCL_AccumulateOffset(estimated_offset, 0.0);
-    }
-
-  } else {
-    LOG(LOGS_WARN, LOGF_Acquire, "No intersecting endpoints found");
-  }  
-
-  Free(intervals);
-  Free(eps);
-        
-}
-
-/* ================================================== */
-
-static void
-wind_up_acquisition(void)
-{
-
-  /* Now process measurements */
-  process_measurements();
-
-  Free(sources);
-
-  finalise_io();
-
-  if (saved_after_hook) {
-    (saved_after_hook)(saved_after_hook_anything);
-  }
-
-}
-
-/* ================================================== */
-
-static void
-start_source_timeout_handler(void *not_used)
-{
-
-  start_next_source();
-}
-
-/* ================================================== */
-
-void
-ACQ_StartAcquisition(int n, IPAddr *ip_addrs, double threshold, void (*after_hook)(void *), void *anything)
-{
-
-  int i, ip4, ip6;
-  int k, duplicate_ip;
-
-  saved_after_hook = after_hook;
-  saved_after_hook_anything = anything;
-
-  init_slew_threshold = threshold;
-
-  n_started_sources = 0;
-  n_completed_sources = 0;
-  n_sources = 0;
-  sources = MallocArray(SourceRecord, n);
-
-  for (i = ip4 = ip6 = 0; i < n; i++) {
-    /* check for duplicate IP addresses and ignore them */
-    duplicate_ip = 0;
-    for (k = 0; k < i; k++) {
-      duplicate_ip |= UTI_CompareIPs(&(sources[k].ip_addr),
-                                     &ip_addrs[i],
-                                     NULL) == 0;
-    }
-    if (!duplicate_ip) {
-      sources[n_sources].ip_addr = ip_addrs[i];
-      sources[n_sources].n_samples = 0;
-      sources[n_sources].n_total_samples = 0;
-      sources[n_sources].n_dead_probes = 0;
-      if (ip_addrs[i].family == IPADDR_INET4)
-        ip4++;
-      else if (ip_addrs[i].family == IPADDR_INET6)
-        ip6++;
-      n_sources++;
-    } else {
-      LOG(LOGS_WARN, LOGF_Acquire, "Ignoring duplicate source: %s",
-          UTI_IPToString(&ip_addrs[i]));
-    }
-  }
-
-  initialise_io((ip4 && ip6) ? IPADDR_UNSPEC : (ip4 ? IPADDR_INET4 : IPADDR_INET6));
-
-  /* Start sampling first source */
-  start_next_source();
-}
-
-/* ================================================== */
--- a/addressing.h
+++ b/addressing.h
@@ -46,9 +46,13 @@ typedef struct {

 typedef struct {
  IPAddr ip_addr;
-  IPAddr local_ip_addr;
  unsigned short port;
 } NTP_Remote_Address;

+typedef struct {
+  IPAddr ip_addr;
+  int sock_fd;
+} NTP_Local_Address;
+
 #endif /* GOT_ADDRESSING_H */

--- a/addrfilt.c
+++ b/addrfilt.c
@@ -199,7 +199,10 @@ set_subnet(TableNode *start_node,

      /* How many subnet entries to set : 1->8, 2->4, 3->2 */
      N = 1 << (NBITS-bits_to_go);
-      subnet = get_subnet(ip, bits_consumed);
+
+      subnet = get_subnet(ip, bits_consumed) & ~(N - 1);
+      assert(subnet + N <= TABLE_SIZE);
+
      if (!(node->extended)) {
        open_node(node);
      }
--- a/broadcast.c
+++ b/broadcast.c
@@ -40,6 +40,7 @@

 typedef struct {
  NTP_Remote_Address addr;
+  NTP_Local_Address local_addr;
  int interval;
 } Destination;
 static Destination *destinations = 0;
@@ -114,7 +115,7 @@ timeout_handler(void *arbitrary)
  ts_fuzz = UTI_GetNTPTsFuzz(message.precision);
  LCL_ReadCookedTime(&local_transmit, NULL);
  UTI_TimevalToInt64(&local_transmit, &message.transmit_ts, ts_fuzz);
-  NIO_SendNormalPacket(&message, &d->addr);
+  NIO_SendNormalPacket(&message, &d->addr, &d->local_addr);

  /* Requeue timeout.  Don't care if interval drifts gradually, so just do it
   * at the end. */
@@ -141,8 +142,10 @@ BRD_AddDestination(IPAddr *addr, unsigned short port, int interval)
  }

  destinations[n_destinations].addr.ip_addr = *addr;
-  destinations[n_destinations].addr.local_ip_addr.family = IPADDR_UNSPEC;
  destinations[n_destinations].addr.port = port;
+  destinations[n_destinations].local_addr.ip_addr.family = IPADDR_UNSPEC;
+  destinations[n_destinations].local_addr.sock_fd =
+    NIO_GetServerSocket(&destinations[n_destinations].addr);
  destinations[n_destinations].interval = interval;

  SCH_AddTimeoutInClass((double) interval, 1.0, 0.0,
--- a/candm.h
+++ b/candm.h
@@ -518,7 +518,7 @@ typedef struct {

 typedef struct {
  IPAddr ip_addr;
-  uint16_t poll;
+  int16_t poll;
  uint16_t stratum;
  uint16_t state;
  uint16_t mode;
@@ -637,9 +637,9 @@ typedef struct {
  uint16_t command; /* Which command is being replied to */
  uint16_t reply; /* Which format of reply this is */
  uint16_t status; /* Status of command processing */
-  uint16_t number; /* Which packet this is in reply sequence */
-  uint16_t total; /* Number of replies to expect in this sequence */
-  uint16_t pad1; /* Get up to 4 byte alignment */
+  uint16_t pad1; /* Padding for compatibility and 4 byte alignment */
+  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
--- a/chrony.1
+++ b/chrony.1
@@ -55,7 +55,8 @@ With a good reference clock the accuracy can reach one microsecond.

 .SH "SEE ALSO"
 .BR chronyc(1),
-.BR chrony(1)
+.BR chrony.conf(5),
+.BR chronyd(8)

 .I http://chrony.tuxfamily.org/

--- a/chrony.conf.5.in
+++ b/chrony.conf.5.in
@@ -22,16 +22,19 @@ as a minimum

 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 will be
-particularly useful : `driftfile', `commandkey', `keyfile'.  The smallest
-useful configuration file would look something like
+(\fIchrony.txt\fR and \fIchrony.texi\fR). The following directives may be
+particularly useful : `driftfile', `generatecommandkey', `keyfile', `makestep'.
+Also, the `iburst' server option is useful to speed up the initial
+synchronization. The smallest useful configuration file would look something
+like

-     server a.b.c
-     server d.e.f
-     server g.h.i
+     server a.b.c iburst
+     server d.e.f iburst
+     server g.h.i iburst
     keyfile @SYSCONFDIR@/chrony.keys
-     commandkey 1
+     generatecommandkey
     driftfile @CHRONYVARDIR@/drift
+     makestep 10 3


 .SH "SEE ALSO"
--- a/chrony.texi.in
+++ b/chrony.texi.in
--- a/chronyc.1.in
+++ b/chronyc.1.in
@@ -24,7 +24,7 @@ A summary of the options supported by \fBchronyc\fR is included below.

 .TP
 \fB\-h\fR \fIhostname\fR
-specify hostname
+specify hostname (default 127.0.0.1)
 .TP
 \fB\-p\fR \fIport-number\fR
 specify port-number
--- a/chronyd.8.in
+++ b/chronyd.8.in
@@ -4,7 +4,7 @@ chronyd \- chrony background daemon

 .SH SYNOPSIS
 .B chronyd
-[\fIOPTIONS\fR]
+[\fIOPTIONS\fR] [\fIconfiguration commands\fR]

 .SH DESCRIPTION
 \fIchrony\fR is a pair of programs for maintaining the accuracy of computer
@@ -31,6 +31,9 @@ command:

 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.
@@ -52,7 +55,8 @@ terminal.
 .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.
+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
@@ -72,35 +76,45 @@ should not be used.
 .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 conjuction
+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/clock\fR program during the Linux boot sequence.
+\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 \fBchronyd\fR cannot support the real time clock on your computer,
-this option cannot be used and a warning message will be logged to
-the syslog.
-
 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.  This can be used to allow \fBchronyd\fR to
+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 real time clock and system clock last time the
-computer was on.
+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
-When this option is used, chronyd will drop root privileges to the specified
-user.  So far, it works only on Linux when compiled with capabilities support.
+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
@@ -119,8 +133,7 @@ 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) and is also available
-from \fIhttp://go.to/chrony\fR
+distribution (\fIchrony.txt\fR and \fIchrony.texi\fR).

 .BR chrony(1),
 .BR chronyc(1),
@@ -128,6 +141,8 @@ from \fIhttp://go.to/chrony\fR
 .BR hwclock(8),
 .BR ntpd(8)

+.I http://chrony.tuxfamily.org/
+
 .SH AUTHOR
 Richard Curnow <rc@rc0.org.uk>

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

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2013
+ * Copyright (C) Miroslav Lichvar  2009-2014
 * 
 * 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
@@ -66,6 +66,8 @@ static int on_terminal = 0;

 static int no_dns = 0;

+static int recv_errqueue = 0;
+
 /* ================================================== */
 /* Ought to extract some code from util.c to make
   a new set of utilities that can be linked into either
@@ -139,6 +141,7 @@ static void
 open_io(const char *hostname, int port)
 {
  IPAddr ip;
+  int on_off = 1;

  /* Note, this call could block for a while */
  if (DNS_Name2IPAddress(hostname, &ip) != DNS_Success) {
@@ -176,6 +179,22 @@ open_io(const char *hostname, int port)
    perror("Can't create socket");
    exit(1);
  }
+
+  /* Enable extended error reporting (e.g. ECONNREFUSED on ICMP unreachable) */
+#ifdef IP_RECVERR
+  if (ip.family == IPADDR_INET4 &&
+      !setsockopt(sock_fd, IPPROTO_IP, IP_RECVERR, &on_off, sizeof(on_off))) {
+    recv_errqueue = 1;
+  }
+#endif
+#ifdef HAVE_IPV6
+#ifdef IPV6_RECVERR
+  if (ip.family == IPADDR_INET6 &&
+      !setsockopt(sock_fd, IPPROTO_IPV6, IPV6_RECVERR, &on_off, sizeof(on_off))) {
+    recv_errqueue = 1;
+  }
+#endif
+#endif
 }

 /* ================================================== */
@@ -613,9 +632,7 @@ process_cmd_local(CMD_Request *msg, const char *line)

  p = line;
  
-  if (!*p) {
-    return 0;
-  } else if (!strcmp(p, "off")) {
+  if (!strcmp(p, "off")) {
    msg->data.local.on_off = htonl(0);
    msg->data.local.stratum = htonl(0);
  } else if (sscanf(p, "stratum%d", &stratum) == 1) {
@@ -639,15 +656,14 @@ process_cmd_manual(CMD_Request *msg, const char *line)

  p = line;

-  if (!*p) {
-    return 0;
-  } else if (!strcmp(p, "off")) {
+  if (!strcmp(p, "off")) {
    msg->data.manual.option = htonl(0);
  } else if (!strcmp(p, "on")) {
    msg->data.manual.option = htonl(1);
  } else if (!strcmp(p, "reset")) {
    msg->data.manual.option = htonl(2);
  } else {
+    fprintf(stderr, "Invalid syntax for manual command\n");
    return 0;
  }
  msg->command = htons(REQ_MANUAL);
@@ -1368,6 +1384,15 @@ submit_request(CMD_Request *request, CMD_Reply *reply, int *reply_auth_ok)
        /* If we get connrefused here, it suggests the sendto is
           going to a dead port - but only if the daemon machine is
           running Linux (Solaris doesn't return anything) */
+
+#ifdef IP_RECVERR
+        /* Fetch the message from the error queue */
+        if (recv_errqueue &&
+            recvfrom(sock_fd, (void *)reply, sizeof(CMD_Reply), MSG_ERRQUEUE,
+                     &where_from.u, &where_from_len) < 0)
+          ;
+#endif
+
        n_attempts++;
        if (n_attempts > max_retries) {
          return 0;
@@ -1375,7 +1400,11 @@ submit_request(CMD_Request *request, CMD_Reply *reply, int *reply_auth_ok)
      } else {
        
        read_length = recvfrom_status;
-        expected_length = PKL_ReplyLength(reply);
+        if (read_length >= offsetof(CMD_Reply, data)) {
+          expected_length = PKL_ReplyLength(reply);
+        } else {
+          expected_length = 0;
+        }

        bad_length = (read_length < expected_length ||
                      expected_length < offsetof(CMD_Reply, data));
@@ -1436,10 +1465,9 @@ submit_request(CMD_Request *request, CMD_Reply *reply, int *reply_auth_ok)

        /* Good packet received, print out results */
 #if 0
-        printf("Reply cmd=%d reply=%d stat=%d num=%d tot=%d seq=%d utok=%08lx tok=%d\n",
+        printf("Reply cmd=%d reply=%d stat=%d seq=%d utok=%08lx tok=%d\n",
               ntohs(reply->command), ntohs(reply->reply),
-               ntohs(reply->status), ntohs(reply->number),
-               ntohs(reply->total),
+               ntohs(reply->status),
               ntohl(reply->sequence),
               ntohl(reply->utoken),
               ntohl(reply->token));
@@ -1669,6 +1697,18 @@ print_freq_ppm(double f)

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

+static void
+print_signed_freq_ppm(double f)
+{
+  if (fabs(f) < 99999.5) {
+    printf("%+10.3f", f);
+  } else {
+    printf("%+10.0f", f);
+  }
+}
+
+/* ================================================== */
+
 static int
 check_for_verbose_flag(char *line)
 {
@@ -1693,8 +1733,8 @@ process_cmd_sources(char *line)
  double orig_latest_meas, latest_meas, latest_meas_err;
  IPAddr ip_addr;
  uint32_t latest_meas_ago;
-  uint16_t poll, stratum;
-  uint16_t state, mode, flags, reachability;
+  int16_t poll;
+  uint16_t stratum, state, mode, flags, reachability;
  char hostname_buf[50];

  /* Check whether to output verbose headers */
@@ -1863,7 +1903,7 @@ process_cmd_sourcestats(char *line)
          printf("%-25s %3lu %3lu  ", hostname_buf, n_samples, n_runs);
          print_seconds(span_seconds);
          printf(" ");
-          print_freq_ppm(resid_freq_ppm);
+          print_signed_freq_ppm(resid_freq_ppm);
          printf(" ");
          print_freq_ppm(skew_ppm);
          printf("  ");
@@ -1952,7 +1992,7 @@ process_cmd_tracking(char *line)
    rms_offset = UTI_FloatNetworkToHost(reply.data.tracking.rms_offset);
    printf("System time     : %.9f seconds %s of NTP time\n", fabs(correction),
           (correction > 0.0) ? "slow" : "fast");
-    printf("Last offset     : %.9f seconds\n", last_offset);
+    printf("Last offset     : %+.9f seconds\n", last_offset);
    printf("RMS offset      : %.9f seconds\n", rms_offset);
    freq_ppm = UTI_FloatNetworkToHost(reply.data.tracking.freq_ppm);
    resid_freq_ppm = UTI_FloatNetworkToHost(reply.data.tracking.resid_freq_ppm);
@@ -1961,7 +2001,7 @@ process_cmd_tracking(char *line)
    root_dispersion = UTI_FloatNetworkToHost(reply.data.tracking.root_dispersion);
    last_update_interval = UTI_FloatNetworkToHost(reply.data.tracking.last_update_interval);
    printf("Frequency       : %.3f ppm %s\n", fabs(freq_ppm), (freq_ppm < 0.0) ? "slow" : "fast"); 
-    printf("Residual freq   : %.3f ppm\n", resid_freq_ppm);
+    printf("Residual freq   : %+.3f ppm\n", resid_freq_ppm);
    printf("Skew            : %.3f ppm\n", skew_ppm);
    printf("Root delay      : %.6f seconds\n", root_delay);
    printf("Root dispersion : %.6f seconds\n", root_dispersion);
@@ -2576,7 +2616,7 @@ authenticate_from_config(const char *filename)

  in = fopen(filename, "r");
  if (!in) {
-    fprintf(stderr, "Could not open file %s\n", filename);
+    fprintf(stderr, "Could not open file %s : %s\n", filename, strerror(errno));
    return 0;
  }

@@ -2601,7 +2641,7 @@ authenticate_from_config(const char *filename)

  in = fopen(keyfile, "r");
  if (!in) {
-    fprintf(stderr, "Could not open keyfile %s\n", filename);
+    fprintf(stderr, "Could not open keyfile %s : %s\n", keyfile, strerror(errno));
    return 0;
  }

@@ -2675,7 +2715,7 @@ static void
 display_gpl(void)
 {
    printf("chrony version %s\n"
-           "Copyright (C) 1997-2003, 2007, 2009-2013 Richard P. Curnow and others\n"
+           "Copyright (C) 1997-2003, 2007, 2009-2014 Richard P. Curnow and others\n"
           "chrony comes with ABSOLUTELY NO WARRANTY.  This is free software, and\n"
           "you are welcome to redistribute it under certain conditions.  See the\n"
           "GNU General Public License version 2 for details.\n\n",
@@ -2689,9 +2729,9 @@ main(int argc, char **argv)
 {
  char *line;
  const char *progname = argv[0];
-  const char *hostname = "localhost";
+  const char *hostname = NULL;
  const char *conf_file = DEFAULT_CONF_FILE;
-  int quit = 0, ret = 1, multi = 0, auto_auth = 0;
+  int quit = 0, ret = 1, multi = 0, auto_auth = 0, family = IPADDR_UNSPEC;
  int port = DEFAULT_CANDM_PORT;

  /* Parse command line options */
@@ -2718,11 +2758,9 @@ main(int argc, char **argv)
    } else if (!strcmp(*argv, "-n")) {
      no_dns = 1;
    } else if (!strcmp(*argv, "-4")) {
-      DNS_SetAddressFamily(IPADDR_INET4);
-      hostname = "127.0.0.1";
+      family = IPADDR_INET4;
    } else if (!strcmp(*argv, "-6")) {
-      DNS_SetAddressFamily(IPADDR_INET6);
-      hostname = "::1";
+      family = IPADDR_INET6;
    } else if (!strcmp("-v", *argv) || !strcmp("--version",*argv)) {
      printf("chronyc (chrony) version %s\n", CHRONY_VERSION);
      exit(0);
@@ -2749,6 +2787,15 @@ main(int argc, char **argv)
    return 1;
  }
  
+  DNS_SetAddressFamily(family);
+
+  if (!hostname) {
+    hostname = family == IPADDR_INET6 ? "::1" : "127.0.0.1";
+#ifdef FEAT_ASYNCDNS
+    initial_timeout /= 10;
+#endif
+  }
+
  open_io(hostname, port);

  if (auto_auth) {
--- a/cmdmon.c
+++ b/cmdmon.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2012
+ * Copyright (C) Miroslav Lichvar  2009-2014
 * 
 * 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
@@ -171,22 +171,19 @@ static ADF_AuthTable access_auth_table;

 /* ================================================== */
 /* Forward prototypes */
-static int prepare_socket(int family);
 static void read_from_cmd_socket(void *anything);

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

 static int
-prepare_socket(int family)
+prepare_socket(int family, int port_number)
 {
-  int port_number, sock_fd;
+  int sock_fd;
  socklen_t my_addr_len;
  union sockaddr_in46 my_addr;
  IPAddr bind_address;
  int on_off = 1;

-  port_number = CNF_GetCommandPort();
-
  sock_fd = socket(family, SOCK_DGRAM, 0);
  if (sock_fd < 0) {
    LOG(LOGS_ERR, LOGF_CmdMon, "Could not open %s command socket : %s",
@@ -202,6 +199,14 @@ prepare_socket(int family)
    LOG(LOGS_ERR, LOGF_CmdMon, "Could not set reuseaddr socket options");
    /* Don't quit - we might survive anyway */
  }
+
+#ifdef IP_FREEBIND
+  /* Allow binding to address that doesn't exist yet */
+  if (setsockopt(sock_fd, IPPROTO_IP, IP_FREEBIND, (char *)&on_off, sizeof(on_off)) < 0) {
+    LOG(LOGS_ERR, LOGF_CmdMon, "Could not set free bind socket option");
+  }
+#endif
+
 #ifdef HAVE_IPV6
  if (family == AF_INET6) {
 #ifdef IPV6_V6ONLY
@@ -265,7 +270,7 @@ prepare_socket(int family)
 void
 CAM_Initialise(int family)
 {
-  int i;
+  int i, port_number;

  assert(!initialised);
  initialised = 1;
@@ -293,18 +298,20 @@ CAM_Initialise(int family)
  free_replies = NULL;
  kept_replies.next = NULL;

-  if (family == IPADDR_UNSPEC || family == IPADDR_INET4)
-    sock_fd4 = prepare_socket(AF_INET);
+  port_number = CNF_GetCommandPort();
+
+  if (port_number && (family == IPADDR_UNSPEC || family == IPADDR_INET4))
+    sock_fd4 = prepare_socket(AF_INET, port_number);
  else
    sock_fd4 = -1;
 #ifdef HAVE_IPV6
-  if (family == IPADDR_UNSPEC || family == IPADDR_INET6)
-    sock_fd6 = prepare_socket(AF_INET6);
+  if (port_number && (family == IPADDR_UNSPEC || family == IPADDR_INET6))
+    sock_fd6 = prepare_socket(AF_INET6, port_number);
  else
    sock_fd6 = -1;
 #endif

-  if (sock_fd4 < 0
+  if (port_number && sock_fd4 < 0
 #ifdef HAVE_IPV6
      && sock_fd6 < 0
 #endif
@@ -559,6 +566,7 @@ get_more_replies(void)
    for (i=1; i<REPLY_EXTEND_QUANTUM; i++) {
      new_replies[i-1].next = new_replies + i;
    }
+    new_replies[REPLY_EXTEND_QUANTUM - 1].next = NULL;
    free_replies = new_replies;
  }
 }
@@ -667,46 +675,6 @@ token_acknowledged(unsigned long token, struct timeval *now)

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

-#if 0
-/* These two routines are not legal if the program is operating as a daemon, since
-   stderr is no longer open */
-
-static void
-print_command_packet(CMD_Request *pkt, int length)
-{
-  unsigned char *x;
-  int i;
-  x = (unsigned char *) pkt;
-  for (i=0; i<length; i++) {
-    fprintf(stderr, "%02x ", x[i]);
-    if (i%16 == 15) {
-      fprintf(stderr, "\n");
-    }
-  }
-  fprintf(stderr, "\n");
-}
-
-/* ================================================== */
-
-static void
-print_reply_packet(CMD_Reply *pkt)
-{
-  unsigned char *x;
-  int i;
-  x = (unsigned char *) pkt;
-  for (i=0; i<sizeof(CMD_Reply); i++) {
-    fprintf(stderr, "%02x ", x[i]);
-    if (i%16 == 15) {
-      fprintf(stderr, "\n");
-    }
-  }
-  fprintf(stderr, "\n");
-}
-
-#endif 
-
-/* ================================================== */
-
 static void
 transmit_reply(CMD_Reply *msg, union sockaddr_in46 *where_to, int auth_len)
 {
@@ -734,7 +702,7 @@ transmit_reply(CMD_Reply *msg, union sockaddr_in46 *where_to, int auth_len)
  status = sendto(sock_fd, (void *) msg, tx_message_length, 0,
                  &where_to->u, addrlen);

-  if (status < 0 && !LOG_RateLimited()) {
+  if (status < 0) {
    unsigned short port;
    IPAddr ip;

@@ -755,7 +723,7 @@ transmit_reply(CMD_Reply *msg, union sockaddr_in46 *where_to, int auth_len)
        assert(0);
    }

-    LOG(LOGS_WARN, LOGF_CmdMon, "Could not send response to %s:%hu", UTI_IPToString(&ip), port);
+    DEBUG_LOG(LOGF_CmdMon, "Could not send response to %s:%hu", UTI_IPToString(&ip), port);
  }
 }
  
@@ -1276,7 +1244,6 @@ handle_add_source(NTP_Source_Type type, CMD_Request *rx_message, CMD_Reply *tx_m
  NSR_Status status;
  
  UTI_IPNetworkToHost(&rx_message->data.ntp_source.ip_addr, &rem_addr.ip_addr);
-  rem_addr.local_ip_addr.family = IPADDR_UNSPEC;
  rem_addr.port = (unsigned short)(ntohl(rx_message->data.ntp_source.port));
  params.minpoll = ntohl(rx_message->data.ntp_source.minpoll);
  params.maxpoll = ntohl(rx_message->data.ntp_source.maxpoll);
@@ -1324,7 +1291,6 @@ handle_del_source(CMD_Request *rx_message, CMD_Reply *tx_message)
  NSR_Status status;
  
  UTI_IPNetworkToHost(&rx_message->data.del_source.ip_addr, &rem_addr.ip_addr);
-  rem_addr.local_ip_addr.family = IPADDR_UNSPEC;
  rem_addr.port = 0;
  
  status = NSR_RemoveSource(&rem_addr);
@@ -1380,8 +1346,8 @@ handle_doffset(CMD_Request *rx_message, CMD_Reply *tx_message)
 {
  long sec, usec;
  double doffset;
-  sec = (long)(ntohl(rx_message->data.doffset.sec));
-  usec = (long)(ntohl(rx_message->data.doffset.usec));
+  sec = (int32_t)ntohl(rx_message->data.doffset.sec);
+  usec = (int32_t)ntohl(rx_message->data.doffset.usec);
  doffset = (double) sec + 1.0e-6 * (double) usec;
  LOG(LOGS_INFO, LOGF_CmdMon, "Accumulated delta offset of %.6f seconds", doffset);
  LCL_AccumulateOffset(doffset, 0.0);
@@ -1591,7 +1557,7 @@ handle_manual_delete(CMD_Request *rx_message, CMD_Reply *tx_message)
 static void
 handle_make_step(CMD_Request *rx_message, CMD_Reply *tx_message)
 {
-  LCL_MakeStep(0.0);
+  LCL_MakeStep();
  tx_message->status = htons(STT_SUCCESS);
 }

@@ -1631,20 +1597,6 @@ handle_reselect(CMD_Request *rx_message, CMD_Reply *tx_message)
  tx_message->status = htons(STT_SUCCESS);
 }

-/* ================================================== */
-
-#if 0
-/* ================================================== */
-
-static void
-handle_(CMD_Request *rx_message, CMD_Reply *tx_message)
-{
-  int status;
-}
-
-
-#endif
-
 /* ================================================== */
 /* Read a packet and process it */

@@ -1693,6 +1645,9 @@ read_from_cmd_socket(void *anything)
    return;
  }

+  if (from_length > sizeof (where_from))
+    LOG_FATAL(LOGF_CmdMon, "Truncated source address");
+
  read_length = status;

  LCL_ReadRawTime(&now);
@@ -1758,9 +1713,9 @@ read_from_cmd_socket(void *anything)
  tx_message.command = rx_message.command;
  tx_message.sequence = rx_message.sequence;
  tx_message.reply = htons(RPY_NULL);
-  tx_message.number = htons(1);
-  tx_message.total = htons(1);
  tx_message.pad1 = 0;
+  tx_message.pad2 = 0;
+  tx_message.pad3 = 0;
  tx_message.utoken = htonl(utoken);
  /* Set this to a default (invalid) value.  This protects against the
     token field being set to an arbitrary value if we reject the
@@ -1769,10 +1724,7 @@ read_from_cmd_socket(void *anything)
  memset(&tx_message.auth, 0, sizeof(tx_message.auth));

  if (rx_message.version != PROTO_VERSION_NUMBER) {
-    tx_message.status = htons(STT_NOHOSTACCESS);
-    if (!LOG_RateLimited()) {
-      LOG(LOGS_WARN, LOGF_CmdMon, "Read command packet with protocol version %d (expected %d) from %s:%hu", rx_message.version, PROTO_VERSION_NUMBER, UTI_IPToString(&remote_ip), remote_port);
-    }
+    DEBUG_LOG(LOGF_CmdMon, "Read command packet with protocol version %d (expected %d) from %s:%hu", rx_message.version, PROTO_VERSION_NUMBER, UTI_IPToString(&remote_ip), remote_port);

    CLG_LogCommandAccess(&remote_ip, CLG_CMD_BAD_PKT, cooked_now.tv_sec);

@@ -1784,9 +1736,7 @@ read_from_cmd_socket(void *anything)
  }

  if (rx_command >= N_REQUEST_TYPES) {
-    if (!LOG_RateLimited()) {
-      LOG(LOGS_WARN, LOGF_CmdMon, "Read command packet with invalid command %d from %s:%hu", rx_command, UTI_IPToString(&remote_ip), remote_port);
-    }
+    DEBUG_LOG(LOGF_CmdMon, "Read command packet with invalid command %d from %s:%hu", rx_command, UTI_IPToString(&remote_ip), remote_port);

    CLG_LogCommandAccess(&remote_ip, CLG_CMD_BAD_PKT, cooked_now.tv_sec);

@@ -1796,9 +1746,7 @@ read_from_cmd_socket(void *anything)
  }

  if (read_length < expected_length) {
-    if (!LOG_RateLimited()) {
-      LOG(LOGS_WARN, LOGF_CmdMon, "Read incorrectly sized command packet from %s:%hu", UTI_IPToString(&remote_ip), remote_port);
-    }
+    DEBUG_LOG(LOGF_CmdMon, "Read incorrectly sized command packet from %s:%hu", UTI_IPToString(&remote_ip), remote_port);

    CLG_LogCommandAccess(&remote_ip, CLG_CMD_BAD_PKT, cooked_now.tv_sec);

@@ -1881,8 +1829,8 @@ read_from_cmd_socket(void *anything)
      tx_message_length = PKL_ReplyLength(prev_tx_message);
      status = sendto(sock_fd, (void *) prev_tx_message, tx_message_length, 0,
                      &where_from.u, from_length);
-      if (status < 0 && !LOG_RateLimited()) {
-        LOG(LOGS_WARN, LOGF_CmdMon, "Could not send response to %s:%hu", UTI_IPToString(&remote_ip), remote_port);
+      if (status < 0) {
+        DEBUG_LOG(LOGF_CmdMon, "Could not send response to %s:%hu", UTI_IPToString(&remote_ip), remote_port);
      }
      return;
    }
@@ -1896,20 +1844,22 @@ read_from_cmd_socket(void *anything)
  }

  valid_ts = 0;
+  issue_token = 0;

  if (auth_ok) {
-    struct timeval ts;
-
-    UTI_TimevalNetworkToHost(&rx_message.data.logon.ts, &ts);
-    if ((utoken_ok && token_ok) ||
-        ((ntohl(rx_message.utoken) == SPECIAL_UTOKEN) &&
-         (rx_command == REQ_LOGON) &&
-         (valid_ts = ts_is_unique_and_not_stale(&ts, &now))))
+    if (utoken_ok && token_ok) {
      issue_token = 1;
-    else 
-      issue_token = 0;
-  } else {
-    issue_token = 0;
+    } else if (rx_command == REQ_LOGON &&
+               ntohl(rx_message.utoken) == SPECIAL_UTOKEN) {
+      struct timeval ts;
+
+      UTI_TimevalNetworkToHost(&rx_message.data.logon.ts, &ts);
+      valid_ts = ts_is_unique_and_not_stale(&ts, &now);
+
+      if (valid_ts) {
+        issue_token = 1;
+      }
+    }
  }

  authenticated = auth_ok & utoken_ok & token_ok;
@@ -1936,8 +1886,6 @@ read_from_cmd_socket(void *anything)
    /* This should be already handled */
    assert(0);
  } else {
-    allowed = 0;
-
    /* Check level of authority required to issue the command */
    switch(permissions[rx_command]) {
      case PERMIT_AUTH:
@@ -1959,6 +1907,7 @@ read_from_cmd_socket(void *anything)
        break;
      default:
        assert(0);
+        allowed = 0;
    }

    if (allowed) {
@@ -2010,8 +1959,8 @@ read_from_cmd_socket(void *anything)

        case REQ_LOGON:
          /* If the log-on fails, record the reason why */
-          if (!issue_token && !LOG_RateLimited()) {
-            LOG(LOGS_WARN, LOGF_CmdMon,
+          if (!issue_token) {
+            DEBUG_LOG(LOGF_CmdMon,
                "Bad command logon from %s port %d (auth_ok=%d valid_ts=%d)",
                UTI_IPToString(&remote_ip),
                remote_port,
--- a/cmdparse.c
+++ b/cmdparse.c
@@ -134,7 +134,8 @@ CPS_ParseNTPSourceAdd(char *line, CPS_NTP_Source *src)
            line += n;
          }
        } else if (!strcasecmp(cmd, "key")) {
-          if (sscanf(line, "%lu%n", &src->params.authkey, &n) != 1) {
+          if (sscanf(line, "%lu%n", &src->params.authkey, &n) != 1 ||
+              src->params.authkey == INACTIVE_AUTHKEY) {
            result = CPS_BadKey;
            ok = 0;
            done = 1;
@@ -203,7 +204,7 @@ CPS_NormalizeLine(char *line)

  /* Remove white-space at beginning and replace white-spaces with space char */
  for (p = q = line; *p; p++) {
-    if (isspace(*p)) {
+    if (isspace((unsigned char)*p)) {
      if (!space)
        *q++ = ' ';
      space = 1;
@@ -233,15 +234,15 @@ CPS_SplitWord(char *line)
  char *p = line, *q = line;

  /* Skip white-space before the word */
-  while (*q && isspace(*q))
+  while (*q && isspace((unsigned char)*q))
    q++;

  /* Move the word to the beginning */
-  while (*q && !isspace(*q))
+  while (*q && !isspace((unsigned char)*q))
    *p++ = *q++;

  /* Find the next word */
-  while (*q && isspace(*q))
+  while (*q && isspace((unsigned char)*q))
    q++;

  *p = '\0';
--- a/conf.c
+++ b/conf.c
--- a/conf.h
+++ b/conf.h
@@ -3,6 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
+ * Copyright (C) Miroslav Lichvar  2013-2014
 * 
 * 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
@@ -34,15 +35,15 @@ extern void CNF_SetRestarted(int);
 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_AddInitSources(void);
 extern void CNF_AddSources(void);
 extern void CNF_AddBroadcasts(void);
 extern void CNF_AddRefclocks(void);

-extern void CNF_ProcessInitStepSlew(void (*after_hook)(void *), void *anything);
-
-extern unsigned short CNF_GetAcquisitionPort(void);
-extern unsigned short CNF_GetNTPPort(void);
+extern int CNF_GetAcquisitionPort(void);
+extern int CNF_GetNTPPort(void);
 extern char *CNF_GetDriftFile(void);
 extern char *CNF_GetLogDir(void);
 extern char *CNF_GetDumpDir(void);
@@ -60,8 +61,8 @@ extern int CNF_GetGenerateCommandKey(void);
 extern int CNF_GetDumpOnExit(void);
 extern int CNF_GetManualEnabled(void);
 extern int CNF_GetCommandPort(void);
-extern int CNF_GetRTCOnUTC(void);
-extern int CNF_GetRTCSync(void);
+extern 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);
@@ -70,16 +71,16 @@ extern int CNF_GetNoClientLog(void);
 extern unsigned long CNF_GetClientLogLimit(void);
 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_GetPidFile(void);
 extern char *CNF_GetLeapSecTimezone(void);
-extern void CNF_GetLinuxHz(int *set, int *hz);
-extern void CNF_GetLinuxFreqScale(int *set, double *freq_scale);

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

 extern double CNF_GetReselectDistance(void);
 extern double CNF_GetStratumWeight(void);
@@ -99,4 +100,10 @@ extern char *CNF_GetUser(void);
 extern int CNF_GetMaxSamples(void);
 extern int CNF_GetMinSamples(void);

+extern double CNF_GetRtcAutotrim(void);
+extern char *CNF_GetHwclockFile(void);
+
+extern int CNF_GetInitSources(void);
+extern double CNF_GetInitStepThreshold(void);
+
 #endif /* GOT_CONF_H */
--- a/132
+++ b/132
@@ -4,7 +4,7 @@
 # chronyd/chronyc - Programs for keeping computer clocks accurate.
 #
 # Copyright (C) Richard P. Curnow  1997-2003
-# Copyright (C) Miroslav Lichvar  2009, 2012
+# Copyright (C) Miroslav Lichvar  2009, 2012-2014
 #
 # =======================================================================

@@ -108,12 +108,17 @@ For better control, use the options below.
  --without-nss          Don't use NSS even if it is available
  --without-tomcrypt     Don't use libtomcrypt even if it is available
  --disable-ipv6         Disable IPv6 support
+  --disable-phc          Disable PHC support
  --disable-pps          Disable PPS API support
  --disable-rtc          Don't include RTC even on Linux
  --disable-linuxcaps    Disable Linux capabilities support
+  --disable-asyncdns     Disable asynchronous name resolving
  --disable-forcednsretry Don't retry on permanent DNS error
+  --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-sendmail=PATH   Path to sendmail binary [/usr/lib/sendmail]
-  --enable-trace         Enable tracing
+  --enable-debug         Enable debugging support

 Fine tuning of the installation directories:
  --sysconfdir=DIR       chrony.conf location [/etc]
@@ -155,6 +160,13 @@ add_def () {
  fi
 }
 #}}}
+#{{{ pkg_config
+pkg_config () {
+  type pkg-config > /dev/null 2> /dev/null || return 1
+
+  pkg-config $@ 2> /dev/null
+}
+#}}}

 # ======================================================================

@@ -170,7 +182,7 @@ EXTRA_OBJECTS=""
 EXTRA_DEFS=""
 SYSDEFS=""

-# Support for readline (on by default)
+debug=0
 feat_readline=1
 try_readline=1
 try_editline=1
@@ -184,17 +196,22 @@ readline_lib=""
 readline_inc=""
 ncurses_lib=""
 feat_ipv6=1
+feat_phc=1
+try_phc=0
 feat_pps=1
 try_setsched=0
 try_lockmem=0
+feat_asyncdns=1
 feat_forcednsretry=1
+ntp_era_split=""
+default_user="root"
 mail_program="/usr/lib/sendmail"

 for option
 do
    case "$option" in
-    --enable-trace )
-      add_def TRACEON
+    --enable-debug )
+      debug=1
    ;;
    --disable-readline )
      feat_readline=0
@@ -253,15 +270,27 @@ do
    --disable-ipv6)
      feat_ipv6=0
    ;;
+    --disable-phc)
+      feat_phc=0
+    ;;
    --disable-pps)
      feat_pps=0
    ;;
    --disable-linuxcaps)
      feat_linuxcaps=0
    ;;
+    --disable-asyncdns)
+      feat_asyncdns=0
+    ;;
    --disable-forcednsretry)
      feat_forcednsretry=0
    ;;
+    --with-ntp-era=* )
+      ntp_era_split=`echo $option | sed -e 's/^.*=//;'`
+    ;;
+    --with-user=* )
+      default_user=`echo $option | sed -e 's/^.*=//;'`
+    ;;
    --with-sendmail=* )
      mail_program=`echo $option | sed -e 's/^.*=//;'`
    ;;
@@ -310,11 +339,12 @@ case $SYSTEM in
    esac
    ;;
    Linux* )
-        EXTRA_OBJECTS="sys_linux.o wrap_adjtimex.o"
+        EXTRA_OBJECTS="sys_generic.o sys_linux.o wrap_adjtimex.o"
        try_linuxcaps=1
        try_rtc=1
        try_setsched=1
        try_lockmem=1
+        try_phc=1
        add_def LINUX
        echo "Configuring for " $SYSTEM
        if [ "${MACHINE}" = "alpha" ]; then
@@ -359,6 +389,40 @@ case $SYSTEM in
    ;;
 esac

+if test_code '64-bit time_t' 'time.h' '' '' '
+  char x[sizeof(time_t) > 4 ? 1 : -1] = {0};
+  return x[0];'
+then
+  add_def HAVE_LONG_TIME_T 1
+
+  if [ "x$ntp_era_split" != "x" ]; then
+    split_seconds=$ntp_era_split
+    split_days=0
+  else
+    split_seconds=`date '+%s'`
+    if [ "x$split_seconds" = "" ]; then
+      echo "Could not get current time, --with-ntp-era option is needed"
+      exit 1
+    fi
+    split_days=$((50 * 365))
+  fi
+
+  add_def NTP_ERA_SPLIT "(${split_seconds}LL - $split_days * 24 * 3600)"
+
+  date_format='+%Y-%m-%dT%H:%M:%SZ'
+
+  # Print the full NTP interval if a suitable date is found
+  if [ "x`date -u -d '1970-01-01 UTC 9 days ago 5 seconds 3 seconds' \
+    $date_format 2> /dev/null`" = "x1969-12-23T00:00:08Z" ]
+  then
+    time1="`date -u -d "1970-01-01 UTC $split_days days ago $split_seconds seconds" \
+      $date_format`"
+    time2="`date -u -d "1970-01-01 UTC $split_days days ago $split_seconds seconds 4294967296 seconds" \
+      $date_format`"
+    echo "NTP time mapped to $time1/$time2"
+  fi
+fi
+
 MATHCODE='return (int) pow(2.0, log(sqrt((double)argc)));'
 if test_code 'math' 'math.h' '' '' "$MATHCODE"; then
  LIBS=""
@@ -401,6 +465,21 @@ then
  fi
 fi

+if test_code 'getaddrinfo()' 'sys/types.h sys/socket.h netdb.h' '' '' \
+  'return getaddrinfo(0, 0, 0, 0);'
+then
+  add_def HAVE_GETADDRINFO
+fi
+
+if [ $feat_asyncdns = "1" ] && \
+  test_code 'pthread' 'pthread.h' '-pthread' '' \
+    'return pthread_create((void *)1, NULL, (void *)1, NULL);'
+then
+  add_def FEAT_ASYNCDNS
+  add_def USE_PTHREAD_ASYNCDNS
+  MYCFLAGS="$MYCFLAGS -pthread"
+fi
+
 timepps_h=""
 if [ $feat_pps = "1" ]; then
  if test_code '<sys/timepps.h>' 'sys/timepps.h' '' '' ''; then
@@ -416,7 +495,7 @@ fi

 if [ "x$timepps_h" != "x" ] && \
  test_code 'PPSAPI' "string.h $timepps_h" '' '' '
-    pps_handle_t h;
+    pps_handle_t h = 0;
    pps_info_t i;
    struct timespec ts;
    return time_pps_fetch(h, PPS_TSFMT_TSPEC, &i, &ts);'
@@ -432,7 +511,7 @@ if [ $feat_linuxcaps = "1" ] && [ $try_linuxcaps = "1" ] && \
    'prctl(PR_SET_KEEPCAPS, 1);cap_set_proc(cap_from_text("cap_sys_time=ep"));'
 then
    add_def FEAT_LINUXCAPS
-    EXTRA_LIBS="-lcap"
+    EXTRA_LIBS="$EXTRA_LIBS -lcap"
 fi

 if [ $feat_rtc = "1" ] && [ $try_rtc = "1" ] && \
@@ -443,6 +522,22 @@ then
    add_def FEAT_RTC
 fi

+if [ $feat_phc = "1" ] && [ $try_phc = "1" ] && \
+  test_code '<linux/ptp_clock.h>' 'sys/ioctl.h linux/ptp_clock.h' '' '' \
+    'ioctl(1, PTP_CLOCK_GETCAPS, 0);'
+then
+  if test_code 'clock_gettime()' 'time.h' '' '' 'clock_gettime(0, NULL);'; then
+    add_def FEAT_PHC
+  else
+    if test_code 'clock_gettime() in -lrt' 'time.h' '' '-lrt' \
+      'clock_gettime(0, NULL);'
+    then
+      EXTRA_LIBS="$EXTRA_LIBS -lrt"
+      add_def FEAT_PHC
+    fi
+  fi
+fi
+
 if [ $try_setsched = "1" ] && \
  test_code \
    'sched_setscheduler()' \
@@ -487,12 +582,12 @@ if [ $feat_readline = "1" ]; then

  if [ "x$READLINE_LINK" = "x" ] && [ $try_readline = "1" ]; then
    if test_code readline 'stdio.h readline/readline.h readline/history.h' \
-      "$readline_inc" "$readline_lib $ncurses_lib -lreadline" \
+      "$readline_inc" "$readline_lib -lreadline" \
      'add_history(readline("prompt"));'
    then
      add_def FEAT_READLINE
      READLINE_COMPILE="$readline_inc"
-      READLINE_LINK="$readline_lib $ncurses_lib -lreadline"
+      READLINE_LINK="$readline_lib -lreadline"
    fi
  fi

@@ -507,6 +602,8 @@ if [ $feat_readline = "1" ]; then
      READLINE_LINK="$readline_lib $ncurses_lib -lreadline -lncurses"
    fi
  fi
+
+  EXTRA_CLI_LIBS="$EXTRA_CLI_LIBS $READLINE_LINK"
 fi

 HASH_OBJ="hash_intmd5.o"
@@ -514,8 +611,8 @@ HASH_COMPILE=""
 HASH_LINK=""

 if [ $try_nss = "1" ]; then
-  test_cflags="`pkg-config --cflags nss`"
-  test_link="`pkg-config --libs-only-L nss` -lfreebl3"
+  test_cflags="`pkg_config --cflags nss`"
+  test_link="`pkg_config --libs-only-L nss` -lfreebl3"
  if test_code 'NSS' 'nss.h hasht.h nsslowhash.h' \
    "$test_cflags" "$test_link" \
    'NSSLOWHASH_Begin(NSSLOWHASH_NewContext(NSSLOW_Init(), HASH_AlgSHA512));'
@@ -523,6 +620,7 @@ if [ $try_nss = "1" ]; then
    HASH_OBJ="hash_nss.o"
    HASH_COMPILE="$test_cflags"
    HASH_LINK="$test_link"
+    LIBS="$LIBS $HASH_LINK"
    add_def GENERATE_SHA1_KEY
  fi
 fi
@@ -534,6 +632,7 @@ if [ "x$HASH_LINK" = "x" ] && [ $try_tomcrypt = "1" ]; then
    HASH_OBJ="hash_tomcrypt.o"
    HASH_COMPILE="-I/usr/include/tomcrypt"
    HASH_LINK="-ltomcrypt"
+    LIBS="$LIBS $HASH_LINK"
    add_def GENERATE_SHA1_KEY
  fi
 fi
@@ -593,7 +692,9 @@ if [ "x$SETCHRONYVARDIR" != "x" ]; then
  CHRONYVARDIR=$SETCHRONYVARDIR
 fi

+add_def DEBUG $debug
 add_def DEFAULT_CONF_FILE "\"$SYSCONFDIR/chrony.conf\""
+add_def DEFAULT_USER "\"$default_user\""
 add_def MAIL_PROGRAM "\"$mail_program\""

 if [ -f version.txt ]; then
@@ -608,15 +709,13 @@ do
  sed -e "s%@EXTRA_OBJECTS@%${EXTRA_OBJECTS}%;\
          s%@CC@%${MYCC}%;\
          s%@CFLAGS@%${MYCFLAGS}%;\
-          s%@CPPFLAGS@%${CPPFLAGS}%;\
+          s%@CPPFLAGS@%${MYCPPFLAGS}%;\
          s%@LIBS@%${LIBS}%;\
          s%@LDFLAGS@%${MYLDFLAGS}%;\
          s%@EXTRA_LIBS@%${EXTRA_LIBS}%;\
          s%@EXTRA_CLI_LIBS@%${EXTRA_CLI_LIBS}%;\
          s%@READLINE_COMPILE@%${READLINE_COMPILE}%;\
-          s%@READLINE_LINK@%${READLINE_LINK}%;\
          s%@HASH_OBJ@%${HASH_OBJ}%;\
-          s%@HASH_LINK@%${HASH_LINK}%;\
          s%@HASH_COMPILE@%${HASH_COMPILE}%;\
          s%@SYSCONFDIR@%${SYSCONFDIR}%;\
          s%@BINDIR@%${BINDIR}%;\
@@ -625,7 +724,8 @@ do
          s%@MANDIR@%${MANDIR}%;\
          s%@INFODIR@%${INFODIR}%;\
          s%@LOCALSTATEDIR@%${LOCALSTATEDIR}%;\
-          s%@CHRONYVARDIR@%${CHRONYVARDIR}%;"\
+          s%@CHRONYVARDIR@%${CHRONYVARDIR}%;\
+          s%@DEFAULT_USER@%${default_user}%;"\
          < ${f}.in > $f
 done

--- a/examples/chrony-wait.service
+++ b/examples/chrony-wait.service
@@ -0,0 +1,17 @@
+[Unit]
+Description=Wait for chrony to synchronize system clock
+After=chronyd.service
+Requires=chronyd.service
+Before=time-sync.target
+Wants=time-sync.target
+
+[Service]
+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
+RemainAfterExit=yes
+StandardOutput=null
+
+[Install]
+WantedBy=multi-user.target
--- a/examples/chrony.conf.example
+++ b/examples/chrony.conf.example
@@ -106,6 +106,9 @@ keyfile /etc/chrony.keys

 commandkey 1

+# With this directive a random password will be generated automatically.
+generatecommandkey
+
 # chronyd can save the measurement history for the servers to files when
 # it it exits.  This is useful in 2 situations:
 #
--- a/examples/chrony.logrotate
+++ b/examples/chrony.logrotate
@@ -0,0 +1,8 @@
+/var/log/chrony/*.log {
+    missingok
+    nocreate
+    sharedscripts
+    postrotate
+        /usr/bin/chronyc -a cyclelogs > /dev/null 2>&1 || true
+    endscript
+}
--- a/examples/chrony.nm-dispatcher
+++ b/examples/chrony.nm-dispatcher
@@ -0,0 +1,17 @@
+#!/bin/sh
+# This is a NetworkManager dispatcher script for chronyd to set its NTP sources
+# online/offline when a default route is configured/removed on the system.
+
+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
+fi
+
+if [ "$2" = "down" ]; then
+	/sbin/ip route list | grep -q '^default' ||
+		/usr/bin/chronyc -a offline > /dev/null 2>&1
+fi
+
+exit 0
--- a/examples/chrony.spec
+++ b/examples/chrony.spec
--- a/examples/chronyd.service
+++ b/examples/chronyd.service
@@ -0,0 +1,13 @@
+[Unit]
+Description=NTP client/server
+After=ntpdate.service sntp.service ntpd.service
+Conflicts=ntpd.service systemd-timesyncd.service
+
+[Service]
+Type=forking
+PIDFile=/var/run/chronyd.pid
+EnvironmentFile=-/etc/sysconfig/chronyd
+ExecStart=/usr/sbin/chronyd $OPTIONS
+
+[Install]
+WantedBy=multi-user.target
--- a/faq.txt
+++ b/faq.txt
@@ -1,286 +0,0 @@
-@@PROLOGUE
-<html>
-<head>
-<title>Frequently asked questions</title>
-<meta name="description" content="Chrony FAQ (frequently asked questions)">
-<meta name="keywords" content="chrony,network time protocol,NTP,RFC 1305,dial-up connection,real time clock,RTC,Linux,FAQ,frequently asked questns">
-<?php
-  $root = ".";
-  include "$root/styles.php";
-?>
-</head>
-
-<body>
-<?php
-  include 'main_banner.php';
-  include 'header.php';
-?>
-<?php pretty_h1("Introduction") ?>
-<p>
-This is a set of questions and answers to common problems and issues.
-<p>
-As we receive more emails about the software, we will add new questions
-to this page.
-<hr>
-<p>
-The developers can be reached via the chrony-dev mailing list.  See 
-<a href="#question_1.4">question 1.4.</a> for details.
-<hr>
-
-<br clear=all>
-@@ENDPROLOGUE
-S: Administrative issues
-
-Q: Where can I get chrony source code?
-Tarballs are available via the <b>Download</b> link on the Chrony
-Web site.  For the current development from the developers' version control
-system see the <b>Git</b> link on the Web site.
-
-Q: Are there any packaged versions of chrony?
-We are aware of packages for Debian, Fedora, Gentoo, Mandriva, Slackware,
-and Ubuntu.  We are not involved with how these are built or distributed.
-
-Q: Where is the home page?
-It is currently at <a href="http://chrony.tuxfamily.org/">http://chrony.tuxfamily.org/</a>. 
-
-Q: Is there a mailing list?
-Yes, it's currently at chrony-users@chrony.tuxfamily.org. There is a low-volume
-list called chrony-announce which is just for announcements of new releases or
-similar matters of high importance.  You can join the lists by sending a
-message with the subject subscribe to <a href="mailto:chrony-users-request@chrony.tuxfamily.org">chrony-users-request@chrony.tuxfamily.org</a> or
-<a href="mailto:chrony-announce-request@chrony.tuxfamily.org">chrony-announce-request@chrony.tuxfamily.org</a> respectively.
-
-For those who want to contribute to the development of chrony, there is a
-developers' mailing list.  You can subscribe by sending mail with the
-subject subscribe to
-<a href="mailto:chrony-dev-request@chrony.tuxfamily.org">chrony-dev-request@chrony.tuxfamily.org</a>.
-
-Q: What licence is applied to chrony?
-Starting from version 1.15, chrony is licensed under the GNU General Public
-License, Version 2.  Versions prior to 1.15 were licensed under a custom BSD-like
-license.
-
-S: Chrony compared to other programs
-Q: How does chrony compare to xntpd?
-If your computer is permenently connected, or connected for long periods (that
-is, for the several hours it takes xntpd to settle down), or you need to
-support hardware reference clocks to your computer, then xntpd will work fine.
-Apart from not supporting hardware clocks, chrony will work fine too.
-
-If your computer connects to the 'net for 5 minutes once a day (or something
-like that), or you turn your Linux computer off when you're not using
-it, or you want to use NTP on an isolated network with no hardware clocks in
-sight, chrony will work much better for you.
-
-The reason I wrote chrony was that I could not get xntpd to do
-anything sensible on my PC at home, which is connected to the 'net for
-about 5 minutes once or twice a day, mainly to upload/download email
-and news.  Nowadays it is also turned off for 22-23 hours a day, when
-not in use.  I wanted a program which would :
-
- slew the time to correct it when I go 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. (In the last few months, it became impossible for
-  me to leave my computer powered permanently.)
-
-Also, when working with isolated networks with no true time references
-at all, I found xntpd gave me no help with managing the local clock's
-gain/loss rate on the NTP master node (which I set from my watch).  I
-added some automated support in chrony to deal with this.
-
-S: Selection of NTP servers
-Q: I have several computers on a LAN.  Should I make one the master, or make them all clients of an external server?
-I think the best configuration is 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 load on the external connection is less
-* the load on the external NTP server(s) is less
-* if your external connection goes down, the computers on the LAN will maintain
-  a common time with each other.
-
-S: Addressing issues
-Q: I get the following error message : "Could not get IP adress for localhost"
-Add a line like the following to your /etc/hosts file
-    127.0.0.1   localhost
-
-Q: I have problems if I put the names of my NTP servers in the chrony.conf file.
-If you have no connection to the Internet at boot time, chrony won't be able to
-turn the names into IP addresses when it starts.  There seem to be 2 solutions:
-
-1. Put the numeric IP addresses in the chrony.conf file
-or
-2. Put the server->IP address mappings in your /etc/hosts file and ensure that
-   /etc/host.conf reads 'order hosts,bind'.
-
-The problem is that chronyd (currently) isn't designed in a way that allows
-hostname->IP address lookups during normal operation.  I hope to work on this
-problem very soon.
-
-S: My computer is not synchronising.
-This is the most common problem.  There are a number of reasons, see the
-following questions.
-
-Q: 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 etherfind 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.
-
-Most people run chronyd on the firewall itself, to avoid all issues of UDP
-packet forwarding and/or masquerading.
-
-Q: Do you have a non-permanant (i.e. intermittent) Internet connection?
-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.
-
-Q: In measurements.log, do the '7' and '8' flag columns always show zero?
-Do you have a 'local stratum X' directive in the chrony.conf file?  If X is
-lower than the stratum of the server you're trying to use, this situation will
-arise.  You should always make X quite high (e.g. 10) in this directive.
-
-S: Issues with chronyc
-
-Q: I keep getting the error '506 Cannot talk to daemon'.
-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.  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.
-
-Q: Is the chronyc&lt;-&gt;chronyd protocol documented anywhere?
-Only by the source code :-)  See cmdmon.c (chronyd side) and client.c (chronyc
-side).
-
-S: Real-time clock issues.
-Q: 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.
-
-Q: I want to use chronyd's real-time clock support.  Must I disable hwclock?
-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 <b>shutdown</b>
-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.
-
-There is no need to remove hwclock from the boot process, as long as chronyd is
-started after it has run.
-
-Q: I just keep getting the '513 RTC driver not running' message
-For the real time clock support to work, you need the following three things:
-                                                                                                                                    
-* 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.                                                                                  
-
-S: Microsoft Windows
-
-Q: 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 an NT service.
-
-Q: Are there any plans to support Windows?
-We have no plans to do this.  Anyone is welcome to pick this work up and
-contribute it back to the project.
-
-Q: What alternative NTP clients are there for Windows?
-Some of the names we've seen mentioned are 
-   - Automachron
-   - NetTime (nettime.sourceforge.net)
-
-S: NTP-specific issues
-Q: Can chrony be driven from broadcast NTP servers?
-No.  I remember looking at how they worked when I was first writing chrony.
-Since the 'target market' then was dial-up systems, broadcast packets were not
-relevant so I didn't bother working out how to deal with the complexities of
-doing the delay estimation.
-
-I no longer have root access to a LAN environment to develop and test broadcast
-server support.  Neither have I the time to work on this.  I would be very
-happy to accept a patch from anyone who can develop, test and debug the
-necessary changes!
-
-Q: 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.
-
-Q: Can chrony keep the system clock a fixed offset away from real time?
-I have not experimented much, but I don't believe this would be possible as
-the program currently stands.
-
-Q: What happens if the network connection is dropped without using chronyc's 'offline' command first?
-In this case chronyd will keep trying to access the server(s) that it thinks
-are online.  Eventually it will decide that they are unreachable and no longer
-consider itself synchronised to them.  If you have other computers on your LAN
-accessing the computer that is affected this way, they too will become
-'unsynchronised', unless you have the 'local' directive set up on the master
-computer.
-
-The 'auto_offline' option to the 'server' entry in the chrony.conf file may be
-useful to avoid this situation.
-
-S: Development
-
-Q: Can I get the source via git from anywhere?
-Yes.  See the Git link at <a
-href="http://chrony.tuxfamily.org/">http://chrony.tuxfamily.org</a> for
-information.
-
-S: Linux-specific issues
-
-Q: Why does the source code include kernel header files?
-The program needs to see the definitions of structures used to interact with
-the real time clock (via /dev/rtc) and with the adjtimex() system call.  Sadly
-this has led to a number of compilation problems with newer kernels which have
-been increasingly hard to fix in a way that makes the code compilable on all
-Linux kernel versions.  Hopefully
-the situation will not deteriorate further with future kernel versions.
-
-Q: I get "Could not open /dev/rtc, Device or resource busy" in my syslog file.
-Check that you haven't accidentally got two copies of chronyd running (perhaps
-defined in different start-up scripts.)
-
-S: Solaris-specific issues
-Q: On Solaris 2.8, 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.  I no longer have root
-access to any Solaris machines to work on this, and am reliant on somebody
-developing the patch and testing it.  A good starting point would be to see if
-xntpd has been modified to work for Solaris 2.8.
-
-@@EPILOGUE
-<hr>
-
-Back to
-<a href="mailto:rc@rc0.org.uk?subject=chrony">the author</a>'s
-<a href="http://www.rc0.org.uk/">main page</a>
-</body>
-</html>
-@@ENDEPILOGUE
--- a/faqgen.pl
+++ b/faqgen.pl
@@ -1,140 +0,0 @@
-#!/usr/bin/env perl
-
-# $Header
-
-# Copyright 2001 Richard P. Curnow
-# LICENCE
-
-# A script to generate an HTML FAQ page from a text input file.  The input is assumed to consist of the following:
-# Lines starting with 'S:'.  These introduce sections.
-# Lines starting with 'Q:'.  These are the topics of questions.
-# Body text (either as an introduction to the sections, or as answers to the questions.
-# The body text is set as pre-formatted.
-
-$| = 1;
-
-@prologue = ();
-@epilogue = ();
-
-@sections=();  # section titles
-@sect_text=(); # introductory text in sections
-
-@questions=(); # questions in sections
-@answers=();   # answers to questions
-
-$sn = -1;
-$had_q = 0;
-
-#{{{ Parse input 
-while (<>) {
-    if (m/\@\@PROLOG/o) {
-        while (<>) {
-            last if (m/^\@\@ENDPROLOG/);
-            push (@prologue, $_);
-        }
-    } elsif (m/\@\@EPILOG/o) {
-        while (<>) {
-            last if (m/^\@\@ENDEPILOG/);
-            push (@epilogue, $_);
-        }
-    } elsif (m/^[sS]:[ \t]*(.*)$/) {
-        chomp;
-        $qn = -1;
-        ++$sn;
-        $sections[$sn] = &guard($1);
-        $sect_text[$sn] = "";
-        $questions[$sn] = [ ];
-        $answers[$sn] = [ ];
-        $had_q = 0;
-    } elsif (/^[qQ]:[ \t]*(.*)$/) {
-        chomp;
-        die unless ($sn >= 0);
-        ++$qn;
-        $questions[$sn]->[$qn] = &guard($1);
-        $had_q = 1;
-    } else {
-        if ($had_q) {
-            if ($qn >= 0) {
-                $answers[$sn]->[$qn] .= $_;
-            }
-        } else {
-            if ($sect_text[$sn] ne "" || $_ !~ /^\s*$/) {
-                $sect_text[$sn] .= $_;
-            }
-        }
-    }
-}
-#}}}
-
-# Emit file header
-if ($#prologue >= 0) {
-    print @prologue;
-} else {
-print <<EOF;
-<html>
-<head>
-<title>
-Chrony Frequently Asked Questions
-</title>
-</head>
-<body>
-<font face=\"arial,helvetica\" size=+4><b>Table of contents</b></font>
-EOF
-}
-
-# Emit table of contents
-print "<ul>\n";
-for $sn (0 .. $#sections) {
-    print "<b><li> <a href=\"#section_".($sn+1)."\">".($sn+1).".</a> ".$sections[$sn]."</b>\n";
-    print "  <ul>\n";
-    for $qn (0 .. $#{$questions[$sn]}) {
-        $sq = ($sn+1).".".($qn+1);
-        print "  <li> <a href=\"#question_".$sq."\">".$sq.".</a> ".$questions[$sn]->[$qn]."\n";
-        #print "  <li> ".$sq.". ".$questions[$sn]->[$qn]."\n";
-    }
-    print "  </ul>\n";
-}
-print "</ul>\n";
-
-# Emit main sections
-for $sn (0 .. $#sections) {
-    print "<hr>\n";
-    print "<a name=section_".($sn+1).">\n";
-    #print "<b><font size=+2 face=\"arial,helvetica\">".($sn+1).". ".$sections[$sn]."</font></b>\n";
-    print "<?php pretty_h2(\"".($sn+1).". ".$sections[$sn]."\"); ?>\n";
-    if ($sect_text[$sn] ne "") {
-        print "<pre>\n";
-        print $sect_text[$sn];
-        print "</pre>\n";
-    }
-    for $qn (0 .. $#{$questions[$sn]}) {
-        $sq = ($sn+1).".".($qn+1);
-        print "<p>\n";
-        print "<a name=question_".$sq.">\n";
-        print "<font size=+1 face=\"arial,helvetica\">".$sq.". ".$questions[$sn]->[$qn]."</font>\n";
-        print "<pre>\n";
-        print $answers[$sn]->[$qn];
-        print "</pre>\n";
-    }
-}
-
-# Print footer
-if ($#epilogue >= 0) {
-    print @epilogue;
-} else {
-print <<EOF;
-</body>
-</html>
-EOF
-}
-
-
-#{{{  sub guard {
-sub guard {
-# Hide wierd tags etc
-    my ($x) = @_;
-    return $x;
-}
-#}}}
-
-
--- a/getdate.c
+++ b/getdate.c
--- a/getdate.y
+++ b/getdate.y
@@ -711,7 +711,7 @@ LookupWord (buff)
  /* Make it lowercase. */
  for (p = buff; *p; p++)
    if (ISUPPER ((unsigned char) *p))
-      *p = tolower (*p);
+      *p = tolower ((unsigned char) *p);

  if (strcmp (buff, "am") == 0 || strcmp (buff, "a.m.") == 0)
    {
--- a/keys.c
+++ b/keys.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2012-2013
+ * Copyright (C) Miroslav Lichvar  2012-2014
 * 
 * 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
@@ -142,7 +142,7 @@ KEY_Finalise(void)
 /* ================================================== */

 static int
-determine_hash_delay(int key_id)
+determine_hash_delay(unsigned long key_id)
 {
  NTP_Packet pkt;
  struct timeval before, after;
@@ -162,12 +162,12 @@ determine_hash_delay(int key_id)
    }
  }

-#if 0
-  LOG(LOGS_INFO, LOGF_Keys, "authentication delay for key %lu: %d useconds", key_id, min_usecs);
-#endif
-
  /* Add on a bit extra to allow for copying, conversions etc */
-  return min_usecs + (min_usecs >> 4);
+  min_usecs += min_usecs >> 4;
+
+  DEBUG_LOG(LOGF_Keys, "authentication delay for key %lu: %ld useconds", key_id, min_usecs);
+
+  return min_usecs;
 }

 /* ================================================== */
@@ -260,7 +260,7 @@ KEY_Reload(void)
  /* Check for duplicates */
  for (i = 1; i < n_keys; i++) {
    if (keys[i - 1].id == keys[i].id) {
-      LOG(LOGS_WARN, LOGF_Keys, "Detected duplicate key %lu", key_id);
+      LOG(LOGS_WARN, LOGF_Keys, "Detected duplicate key %lu", keys[i].id);
    }
  }

@@ -295,13 +295,20 @@ lookup_key(unsigned long id)
 static int
 get_key_pos(unsigned long key_id)
 {
-  if (!cache_valid || key_id != cache_key_id) {
+  int position;
+
+  if (cache_valid && key_id == cache_key_id)
+    return cache_key_pos;
+
+  position = lookup_key(key_id);
+
+  if (position >= 0) {
    cache_valid = 1;
-    cache_key_pos = lookup_key(key_id);
+    cache_key_pos = position;
    cache_key_id = key_id;
  }

-  return cache_key_pos;
+  return position;
 }

 /* ================================================== */
@@ -321,25 +328,7 @@ KEY_GetCommandKey(void)
 int
 KEY_KeyKnown(unsigned long key_id)
 {
-  int position;
-
-  if (cache_valid && (key_id == cache_key_id)) {
-    return 1;
-  } else {
-
-    position = lookup_key(key_id);
-
-    if (position >= 0) {
-      /* Store key in cache, we will probably be using it in a
-         minute... */
-      cache_valid = 1;
-      cache_key_pos = position;
-      cache_key_id = key_id;
-      return 1;
-    } else {
-      return 0;
-    }
-  }
+  return get_key_pos(key_id) >= 0;
 }

 /* ================================================== */
--- a/local.c
+++ b/local.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011
+ * Copyright (C) Miroslav Lichvar  2011, 2014
 * 
 * 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
@@ -126,11 +126,15 @@ calculate_sys_precision(void)
  assert(best_dusec > 0);

  precision_quantum = best_dusec * 1.0e-6;
+
+  /* Get rounded log2 value of the measured precision */
  precision_log = 0;
-  while (best_dusec < 500000) {
+  while (best_dusec < 707107) {
    precision_log--;
    best_dusec *= 2;
  }
+
+  DEBUG_LOG(LOGF_Local, "Clock precision %.9f (%d)", precision_quantum, precision_log);
 }

 /* ================================================== */
@@ -248,6 +252,28 @@ void LCL_RemoveParameterChangeHandler(LCL_ParameterChangeHandler handler, void *

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

+int
+LCL_IsFirstParameterChangeHandler(LCL_ParameterChangeHandler handler)
+{
+  return change_list.next->handler == handler;
+}
+
+/* ================================================== */
+
+static void
+invoke_parameter_change_handlers(struct timeval *raw, struct timeval *cooked,
+                                 double dfreq, double doffset,
+                                 LCL_ChangeType change_type)
+{
+  ChangeListEntry *ptr;
+
+  for (ptr = change_list.next; ptr != &change_list; ptr = ptr->next) {
+    (ptr->handler)(raw, cooked, dfreq, doffset, change_type, ptr->anything);
+  }
+}
+
+/* ================================================== */
+
 void
 LCL_AddDispersionNotifyHandler(LCL_DispersionNotifyHandler handler, void *anything)
 {
@@ -369,7 +395,6 @@ LCL_ReadAbsoluteFrequency(void)
 void
 LCL_SetAbsoluteFrequency(double afreq_ppm)
 {
-  ChangeListEntry *ptr;
  struct timeval raw, cooked;
  double dfreq;
  
@@ -382,15 +407,13 @@ LCL_SetAbsoluteFrequency(double afreq_ppm)
  
  afreq_ppm = (*drv_set_freq)(afreq_ppm);

-  dfreq = (afreq_ppm - current_freq_ppm) / (1.0e6 + current_freq_ppm);
+  dfreq = (afreq_ppm - current_freq_ppm) / (1.0e6 - current_freq_ppm);

  LCL_ReadRawTime(&raw);
  LCL_CookTime(&raw, &cooked, NULL);

  /* Dispatch to all handlers */
-  for (ptr = change_list.next; ptr != &change_list; ptr = ptr->next) {
-    (ptr->handler)(&raw, &cooked, dfreq, 0.0, 0, ptr->anything);
-  }
+  invoke_parameter_change_handlers(&raw, &cooked, dfreq, 0.0, LCL_ChangeAdjust);

  current_freq_ppm = afreq_ppm;

@@ -401,7 +424,6 @@ LCL_SetAbsoluteFrequency(double afreq_ppm)
 void
 LCL_AccumulateDeltaFrequency(double dfreq)
 {
-  ChangeListEntry *ptr;
  struct timeval raw, cooked;
  double old_freq_ppm;

@@ -411,20 +433,17 @@ LCL_AccumulateDeltaFrequency(double dfreq)
   are handled in units of ppm, whereas the 'dfreq' argument is in
   terms of the gradient of the (offset) v (local time) function. */

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

  /* Call the system-specific driver for setting the frequency */
  current_freq_ppm = (*drv_set_freq)(current_freq_ppm);
-  dfreq = (current_freq_ppm - old_freq_ppm) / (1.0e6 + old_freq_ppm);
+  dfreq = (current_freq_ppm - old_freq_ppm) / (1.0e6 - old_freq_ppm);

  LCL_ReadRawTime(&raw);
  LCL_CookTime(&raw, &cooked, NULL);

  /* Dispatch to all handlers */
-  for (ptr = change_list.next; ptr != &change_list; ptr = ptr->next) {
-    (ptr->handler)(&raw, &cooked, dfreq, 0.0, 0, ptr->anything);
-  }
-
+  invoke_parameter_change_handlers(&raw, &cooked, dfreq, 0.0, LCL_ChangeAdjust);
 }

 /* ================================================== */
@@ -432,7 +451,6 @@ LCL_AccumulateDeltaFrequency(double dfreq)
 void
 LCL_AccumulateOffset(double offset, double corr_rate)
 {
-  ChangeListEntry *ptr;
  struct timeval raw, cooked;

  /* In this case, the cooked time to be passed to the notify clients
@@ -444,10 +462,7 @@ LCL_AccumulateOffset(double offset, double corr_rate)
  (*drv_accrue_offset)(offset, corr_rate);

  /* Dispatch to all handlers */
-  for (ptr = change_list.next; ptr != &change_list; ptr = ptr->next) {
-    (ptr->handler)(&raw, &cooked, 0.0, offset, 0, ptr->anything);
-  }
-
+  invoke_parameter_change_handlers(&raw, &cooked, 0.0, offset, LCL_ChangeAdjust);
 }

 /* ================================================== */
@@ -455,7 +470,6 @@ LCL_AccumulateOffset(double offset, double corr_rate)
 void
 LCL_ApplyStepOffset(double offset)
 {
-  ChangeListEntry *ptr;
  struct timeval raw, cooked;

  /* In this case, the cooked time to be passed to the notify clients
@@ -467,10 +481,7 @@ LCL_ApplyStepOffset(double offset)
  (*drv_apply_step_offset)(offset);

  /* Dispatch to all handlers */
-  for (ptr = change_list.next; ptr != &change_list; ptr = ptr->next) {
-    (ptr->handler)(&raw, &cooked, 0.0, offset, 1, ptr->anything);
-  }
-
+  invoke_parameter_change_handlers(&raw, &cooked, 0.0, offset, LCL_ChangeStep);
 }

 /* ================================================== */
@@ -479,12 +490,8 @@ void
 LCL_NotifyExternalTimeStep(struct timeval *raw, struct timeval *cooked,
    double offset, double dispersion)
 {
-  ChangeListEntry *ptr;
-
  /* Dispatch to all handlers */
-  for (ptr = change_list.next; ptr != &change_list; ptr = ptr->next) {
-    (ptr->handler)(raw, cooked, 0.0, offset, 1, ptr->anything);
-  }
+  invoke_parameter_change_handlers(raw, cooked, 0.0, offset, LCL_ChangeUnknownStep);

  lcl_InvokeDispersionNotifyHandlers(dispersion);
 }
@@ -494,7 +501,6 @@ LCL_NotifyExternalTimeStep(struct timeval *raw, struct timeval *cooked,
 void
 LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate)
 {
-  ChangeListEntry *ptr;
  struct timeval raw, cooked;
  double old_freq_ppm;

@@ -508,25 +514,19 @@ LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate)
  /* Work out new absolute frequency.  Note that absolute frequencies
   are handled in units of ppm, whereas the 'dfreq' argument is in
   terms of the gradient of the (offset) v (local time) function. */
-  current_freq_ppm = (1.0 + dfreq) * old_freq_ppm + 1.0e6 * dfreq;
+  current_freq_ppm += dfreq * (1.0e6 - current_freq_ppm);

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_Local, "old_freq=%.3fppm new_freq=%.3fppm offset=%.6fsec",
+  DEBUG_LOG(LOGF_Local, "old_freq=%.3fppm new_freq=%.3fppm offset=%.6fsec",
      old_freq_ppm, current_freq_ppm, doffset);
-#endif

  /* Call the system-specific driver for setting the frequency */
  current_freq_ppm = (*drv_set_freq)(current_freq_ppm);
-  dfreq = (current_freq_ppm - old_freq_ppm) / (1.0e6 + old_freq_ppm);
+  dfreq = (current_freq_ppm - old_freq_ppm) / (1.0e6 - old_freq_ppm);

  (*drv_accrue_offset)(doffset, corr_rate);

  /* Dispatch to all handlers */
-  for (ptr = change_list.next; ptr != &change_list; ptr = ptr->next) {
-    (ptr->handler)(&raw, &cooked, dfreq, doffset, 0, ptr->anything);
-  }
-
-
+  invoke_parameter_change_handlers(&raw, &cooked, dfreq, doffset, LCL_ChangeAdjust);
 }

 /* ================================================== */
@@ -561,17 +561,15 @@ lcl_RegisterSystemDrivers(lcl_ReadFrequencyDriver read_freq,

  current_freq_ppm = (*drv_read_freq)();

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_Local, "Local freq=%.3fppm", current_freq_ppm);
-#endif
+  DEBUG_LOG(LOGF_Local, "Local freq=%.3fppm", current_freq_ppm);
 }

 /* ================================================== */
 /* Look at the current difference between the system time and the NTP
-   time, and make a step to cancel it if it's larger than the threshold. */
+   time, and make a step to cancel it. */

 int
-LCL_MakeStep(double threshold)
+LCL_MakeStep(void)
 {
  struct timeval raw;
  double correction;
@@ -579,14 +577,11 @@ LCL_MakeStep(double threshold)
  LCL_ReadRawTime(&raw);
  LCL_GetOffsetCorrection(&raw, &correction, NULL);

-  if (fabs(correction) <= threshold)
-    return 0;
-
  /* Cancel remaining slew and make the step */
  LCL_AccumulateOffset(correction, 0.0);
  LCL_ApplyStepOffset(-correction);

-  LOG(LOGS_WARN, LOGF_Local, "System clock was stepped by %.3f seconds", correction);
+  LOG(LOGS_WARN, LOGF_Local, "System clock was stepped by %.6f seconds", correction);

  return 1;
 }
--- a/local.h
+++ b/local.h
@@ -67,16 +67,22 @@ extern void LCL_GetOffsetCorrection(struct timeval *raw, double *correction, dou
   doffset : delta offset applied (positive => make local system fast
   by that amount, negative => make it slow by that amount)

-   is_step_change : true if change is being applied as a jump (using
-   settimeofday rather than adjtime)
+   change_type : what type of change is being applied
   
   anything : Passthrough argument from call to registration routine */


+typedef enum {
+  LCL_ChangeAdjust,
+  LCL_ChangeStep,
+  LCL_ChangeUnknownStep
+} LCL_ChangeType;
+
 typedef void (*LCL_ParameterChangeHandler)
     (struct timeval *raw, struct timeval *cooked,
      double dfreq,
-      double doffset, int is_step_change,
+      double doffset,
+      LCL_ChangeType change_type,
      void *anything
      );

@@ -86,6 +92,9 @@ extern void LCL_AddParameterChangeHandler(LCL_ParameterChangeHandler handler, vo
 /* Remove a handler */
 extern void LCL_RemoveParameterChangeHandler(LCL_ParameterChangeHandler, void *anything);

+/* Check if a handler is invoked first when dispatching */
+extern int LCL_IsFirstParameterChangeHandler(LCL_ParameterChangeHandler handler);
+
 /* Function type for handlers to be called back when an indeterminate
   offset is introduced into the local time.  This situation occurs
   when the frequency must be adjusted to effect a clock slew and
@@ -183,7 +192,7 @@ extern void LCL_Finalise(void);
 /* Routine to convert the outstanding system clock error to a step and
   apply it, e.g. if the system clock has ended up an hour wrong due
   to a timezone problem. */
-extern int LCL_MakeStep(double threshold);
+extern int LCL_MakeStep(void);

 /* Routine to schedule a leap second. Leap second will be inserted
   at the end of the day if argument is positive, deleted if negative,
--- a/logging.c
+++ b/logging.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2012
+ * Copyright (C) Miroslav Lichvar  2011-2014
 * 
 * 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
@@ -34,6 +34,9 @@
 #include "mkdirpp.h"
 #include "util.h"

+/* This is used by DEBUG_LOG macro */
+int log_debug_enabled = 0;
+
 /* ================================================== */
 /* Flag indicating we have initialised */
 static int initialised = 0;
@@ -42,7 +45,9 @@ static int system_log = 0;

 static int parent_fd = 0;

-static time_t last_limited = 0;
+#define DEBUG_LEVEL_PRINT_FUNCTION 2
+#define DEBUG_LEVEL_PRINT_DEBUG 2
+static int debug_level = 0;

 #ifdef WINNT
 static FILE *logfile;
@@ -98,86 +103,94 @@ LOG_Finalise(void)

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

-void
-LOG_Line_Function(LOG_Severity severity, LOG_Facility facility, const char *format, ...)
+static void log_message(int fatal, LOG_Severity severity, const char *message)
 {
-  char buf[2048];
-  va_list other_args;
-  va_start(other_args, format);
-  vsnprintf(buf, sizeof(buf), format, other_args);
-  va_end(other_args);
 #ifdef WINNT
  if (logfile) {
-    fprintf(logfile, "%s\n", buf);
+    fprintf(logfile, fatal ? "Fatal error : %s\n" : "%s\n", message);
  }
 #else
  if (system_log) {
+    int priority;
    switch (severity) {
+      case LOGS_DEBUG:
+        priority = LOG_DEBUG;
+        break;
      case LOGS_INFO:
-        syslog(LOG_INFO, "%s", buf);
+        priority = LOG_INFO;
        break;
      case LOGS_WARN:
-        syslog(LOG_WARNING, "%s", buf);
+        priority = LOG_WARNING;
        break;
      case LOGS_ERR:
-      default:
-        syslog(LOG_ERR, "%s", buf);
+        priority = LOG_ERR;
        break;
+      case LOGS_FATAL:
+        priority = LOG_CRIT;
+        break;
+      default:
+        assert(0);
    }
+    syslog(priority, fatal ? "Fatal error : %s" : "%s", message);
  } else {
-    fprintf(stderr, "%s\n", buf);
+    fprintf(stderr, fatal ? "Fatal error : %s\n" : "%s\n", message);
  }
 #endif
 }

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

-void
-LOG_Fatal_Function(LOG_Facility facility, const char *format, ...)
+void LOG_Message(LOG_Severity severity, LOG_Facility facility,
+                 int line_number, const char *filename,
+                 const char *function_name, 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_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);
  va_end(other_args);

-#ifdef WINNT
-  if (logfile) {
-    fprintf(logfile, "Fatal error : %s\n", buf);
-  }
-#else
-  if (system_log) {
-    syslog(LOG_CRIT, "Fatal error : %s", buf);
-  } else {
-    fprintf(stderr, "Fatal error : %s\n", buf);
-  }
-  if (parent_fd) {
-    if (write(parent_fd, buf, strlen(buf) + 1) < 0)
-      ; /* Not much we can do here */
-  }
-#endif
+  switch (severity) {
+    case LOGS_DEBUG:
+    case LOGS_INFO:
+    case LOGS_WARN:
+    case LOGS_ERR:
+      log_message(0, severity, buf);
+      break;
+    case LOGS_FATAL:
+      log_message(1, severity, buf);

-  exit(1);
-}
-
-/* ================================================== */
-
-void
-LOG_Position(const char *filename, int line_number, const char *function_name)
-{
-#ifdef WINNT
-#else
-  time_t t;
-  struct tm stm;
-  char buf[64];
-  if (!system_log) {
-    /* Don't clutter up syslog with internal debugging info */
-    time(&t);
-    stm = *gmtime(&t);
-    strftime(buf, sizeof(buf), "%d-%H:%M:%S", &stm);
-    fprintf(stderr, "%s:%d:(%s)[%s] ", filename, line_number, function_name, buf);
+      /* With syslog, send the message also to the grandparent
+         process or write it to stderr if not detached */
+      if (system_log) {
+        if (parent_fd > 0) {
+          if (write(parent_fd, buf, strlen(buf) + 1) < 0)
+            ; /* Not much we can do here */
+        } else if (parent_fd == 0) {
+          system_log = 0;
+          log_message(1, severity, buf);
+        }
+      }
+      break;
+    default:
+      assert(0);
  }
-#endif
 }

 /* ================================================== */
@@ -194,6 +207,18 @@ LOG_OpenSystemLog(void)

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

+void LOG_SetDebugLevel(int level)
+{
+  debug_level = level;
+  if (level >= DEBUG_LEVEL_PRINT_DEBUG) {
+    if (!DEBUG)
+      LOG(LOGS_WARN, LOGF_Logging, "Not compiled with full debugging support");
+    log_debug_enabled = 1;
+  }
+}
+
+/* ================================================== */
+
 void
 LOG_SetParentFd(int fd)
 {
@@ -207,22 +232,7 @@ LOG_CloseParentFd()
 {
  if (parent_fd > 0)
    close(parent_fd);
-}
-
-/* ================================================== */
-
-int
-LOG_RateLimited(void)
-{
-  time_t now;
-
-  now = time(NULL);
-
-  if (last_limited + 10 > now && last_limited <= now)
-    return 1;
-
-  last_limited = now;
-  return 0;
+  parent_fd = -1;
 }

 /* ================================================== */
--- a/logging.h
+++ b/logging.h
@@ -3,6 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2002
+ * Copyright (C) Miroslav Lichvar  2013-2014
 * 
 * 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
@@ -28,11 +29,41 @@
 #ifndef GOT_LOGGING_H
 #define GOT_LOGGING_H

+#include "sysincl.h"
+
+/* Flag indicating whether debug messages are logged */
+extern int log_debug_enabled;
+
+/* Line logging macros.  If the compiler is GNU C, we take advantage of
+   being able to get the function name also. */
+
+#ifdef __GNUC__
+#define FUNCTION_NAME __FUNCTION__
+#define FORMAT_ATTRIBUTE_PRINTF(str, first) __attribute__ ((format (printf, str, first)))
+#else
+#define FUNCTION_NAME ""
+#define FORMAT_ATTRIBUTE_PRINTF(str, first)
+#endif
+
+#define DEBUG_LOG(facility, ...) \
+  do { \
+    if (DEBUG && log_debug_enabled) \
+      LOG_Message(LOGS_DEBUG, facility, __LINE__, __FILE__, FUNCTION_NAME, __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__); \
+    exit(1); \
+  } while (0)
+
 /* Definition of severity */
 typedef enum {
  LOGS_INFO,
  LOGS_WARN,
-  LOGS_ERR
+  LOGS_ERR,
+  LOGS_FATAL,
+  LOGS_DEBUG
 } LOG_Severity;

 /* Definition of facility.  Each message is tagged with who generated
@@ -56,14 +87,17 @@ typedef enum {
  LOGF_Manual,
  LOGF_Keys,
  LOGF_Logging,
+  LOGF_Nameserv,
  LOGF_Rtc,
  LOGF_Regress,
  LOGF_Sys,
+  LOGF_SysGeneric,
  LOGF_SysLinux,
  LOGF_SysNetBSD,
  LOGF_SysSolaris,
  LOGF_SysSunOS,
  LOGF_SysWinnt,
+  LOGF_TempComp,
  LOGF_RtcLinux,
  LOGF_Refclock
 } LOG_Facility;
@@ -75,13 +109,17 @@ extern void LOG_Initialise(void);
 extern void LOG_Finalise(void);

 /* Line logging function */
-extern void LOG_Line_Function(LOG_Severity severity, LOG_Facility facility, const char *format, ...);
+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, ...);

-/* Logging function for fatal errors */
-extern void LOG_Fatal_Function(LOG_Facility facility, const char *format, ...);
-
-/* Position in code reporting function */
-extern void LOG_Position(const char *filename, int line_number, const char *function_name);
+/* Set debug level:
+   0, 1 - only non-debug messages are logged
+   2    - debug messages are logged too, all messages are prefixed with
+          filename, line, and function name
+   */
+extern void LOG_SetDebugLevel(int level);

 /* Log messages to syslog instead of stderr */
 extern void LOG_OpenSystemLog(void);
@@ -92,24 +130,13 @@ extern void LOG_SetParentFd(int fd);
 /* Close the pipe to the foreground process so it can exit */
 extern void LOG_CloseParentFd(void);

-/* Return zero once per 10 seconds */
-extern int LOG_RateLimited(void);
-
-/* Line logging macro.  If the compiler is GNU C, we take advantage of
-   being able to get the function name also. */
-#if defined(__GNUC__)
-#define LOG LOG_Position(__FILE__, __LINE__, __FUNCTION__); LOG_Line_Function
-#define LOG_FATAL LOG_Position(__FILE__, __LINE__, __FUNCTION__); LOG_Fatal_Function
-#else
-#define LOG LOG_Position(__FILE__, __LINE__, ""); LOG_Line_Function
-#define LOG_FATAL LOG_Position(__FILE__, __LINE__, ""); LOG_Fatal_Function
-#endif /* defined (__GNUC__) */
-
 /* File logging functions */

 typedef int LOG_FileID;

 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);
--- 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
+ * Copyright (C) Miroslav Lichvar  2012-2014
 * 
 * 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 "conf.h"
 #include "cmdmon.h"
 #include "keys.h"
-#include "acquire.h"
 #include "manual.h"
 #include "rtc.h"
 #include "refclock.h"
@@ -60,10 +59,12 @@

 static int initialised = 0;

-/* ================================================== */
+static int exit_status = 0;

 static int reload = 0;

+static REF_Mode ref_mode = REF_ModeNormal;
+
 /* ================================================== */

 static void
@@ -79,7 +80,7 @@ delete_pidfile(void)
 void
 MAI_CleanupAndExit(void)
 {
-  if (!initialised) exit(0);
+  if (!initialised) exit(exit_status);
  
  if (CNF_GetDumpOnExit()) {
    SRC_DumpSources();
@@ -87,7 +88,6 @@ MAI_CleanupAndExit(void)

  TMC_Finalise();
  MNL_Finalise();
-  ACQ_Finalise();
  CLG_Finalise();
  NSR_Finalise();
  NCR_Finalise();
@@ -108,7 +108,7 @@ MAI_CleanupAndExit(void)
  
  LOG_Finalise();

-  exit(0);
+  exit(exit_status);
 }

 /* ================================================== */
@@ -123,13 +123,10 @@ signal_cleanup(int x)
 /* ================================================== */

 static void
-post_acquire_hook(void *anything)
+ntp_source_resolving_end(void)
 {
-  /* Close the pipe to the foreground process so it can exit */
-  LOG_CloseParentFd();
+  NSR_SetSourceResolvingEndHandler(NULL);

-  CNF_AddSources();
-  CNF_AddBroadcasts();
  if (reload) {
    /* Note, we want reload to come well after the initialisation from
       the real time clock - this gives us a fighting chance that the
@@ -137,10 +134,62 @@ post_acquire_hook(void *anything)
       semblence of validity about it. */
    SRC_ReloadSources();
  }
-  CNF_SetupAccessRestrictions();

  RTC_StartMeasurements();
  RCL_StartRefclocks();
+  NSR_StartSources();
+  NSR_AutoStartSources();
+
+  /* Special modes can end only when sources update their reachability.
+     Give up immediatelly if there are no active sources. */
+  if (ref_mode != REF_ModeNormal && !SRC_ActiveSources()) {
+    REF_SetUnsynchronised();
+  }
+}
+
+/* ================================================== */
+
+static void
+post_init_ntp_hook(void *anything)
+{
+  if (ref_mode == REF_ModeInitStepSlew) {
+    /* Remove the initstepslew sources and set normal mode */
+    NSR_RemoveAllSources();
+    ref_mode = REF_ModeNormal;
+    REF_SetMode(ref_mode);
+  }
+
+  /* Close the pipe to the foreground process so it can exit */
+  LOG_CloseParentFd();
+
+  CNF_AddSources();
+  CNF_AddBroadcasts();
+
+  NSR_SetSourceResolvingEndHandler(ntp_source_resolving_end);
+  NSR_ResolveSources();
+}
+
+/* ================================================== */
+
+static void
+reference_mode_end(int result)
+{
+  switch (ref_mode) {
+    case REF_ModeNormal:
+    case REF_ModeUpdateOnce:
+    case REF_ModePrintOnce:
+      exit_status = !result;
+      SCH_QuitProgram();
+      break;
+    case REF_ModeInitStepSlew:
+      /* Switch to the normal mode, the delay is used to prevent polling
+         interval shorter than the burst interval if some configured servers
+         were used also for initstepslew */
+      SCH_AddTimeoutByDelay(2.0, post_init_ntp_hook, NULL);
+      break;
+    default:
+      assert(0);
+  }
 }

 /* ================================================== */
@@ -148,7 +197,14 @@ post_acquire_hook(void *anything)
 static void
 post_init_rtc_hook(void *anything)
 {
-  CNF_ProcessInitStepSlew(post_acquire_hook, NULL);
+  if (CNF_GetInitSources() > 0) {
+    CNF_AddInitSources();
+    NSR_StartSources();
+    assert(REF_GetMode() != REF_ModeNormal);
+    /* Wait for mode end notification */
+  } else {
+    (post_init_ntp_hook)(NULL);
+  }
 }

 /* ================================================== */
@@ -200,7 +256,7 @@ write_lockfile(void)

  out = fopen(pidfile, "w");
  if (!out) {
-    LOG(LOGS_ERR, LOGF_Main, "could not open lockfile %s for writing", pidfile);
+    LOG_FATAL(LOGF_Main, "could not open lockfile %s for writing", pidfile);
  } else {
    fprintf(out, "%d\n", getpid());
    fclose(out);
@@ -222,14 +278,14 @@ go_daemon(void)
  /* Create pipe which will the daemon use to notify the grandparent
     when it's initialised or send an error message */
  if (pipe(pipefd)) {
-    LOG(LOGS_ERR, LOGF_Logging, "Could not detach, pipe failed : %s", strerror(errno));
+    LOG_FATAL(LOGF_Logging, "Could not detach, pipe failed : %s", strerror(errno));
  }

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

  if (pid < 0) {
-    LOG(LOGS_ERR, LOGF_Logging, "Could not detach, fork failed : %s", strerror(errno));
+    LOG_FATAL(LOGF_Logging, "Could not detach, fork failed : %s", strerror(errno));
  } else if (pid > 0) {
    /* In the 'grandparent' */
    char message[1024];
@@ -254,7 +310,7 @@ go_daemon(void)
    pid = fork();

    if (pid < 0) {
-      LOG(LOGS_ERR, LOGF_Logging, "Could not detach, fork failed : %s", strerror(errno));
+      LOG_FATAL(LOGF_Logging, "Could not detach, fork failed : %s", strerror(errno));
    } else if (pid > 0) {
      exit(0); /* In the 'parent' */
    } else {
@@ -262,7 +318,7 @@ go_daemon(void)

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

      /* Don't keep stdin/out/err from before. But don't close
@@ -290,6 +346,8 @@ int main
  int do_init_rtc = 0, restarted = 0;
  int other_pid;
  int lock_memory = 0, sched_priority = 0;
+  int system_log = 1;
+  int config_args = 0;

  LOG_Initialise();

@@ -326,14 +384,27 @@ int main
    } else if (!strcmp("-n", *argv)) {
      nofork = 1;
    } else if (!strcmp("-d", *argv)) {
-      debug = 1;
+      debug++;
      nofork = 1;
+      system_log = 0;
+    } else if (!strcmp("-q", *argv)) {
+      ref_mode = REF_ModeUpdateOnce;
+      nofork = 1;
+      system_log = 0;
+    } else if (!strcmp("-Q", *argv)) {
+      ref_mode = REF_ModePrintOnce;
+      nofork = 1;
+      system_log = 0;
    } else if (!strcmp("-4", *argv)) {
      address_family = IPADDR_INET4;
    } else if (!strcmp("-6", *argv)) {
      address_family = IPADDR_INET6;
-    } else {
+    } else if (*argv[0] == '-') {
      LOG_FATAL(LOGF_Main, "Unrecognized command line option [%s]", *argv);
+    } else {
+      /* Process remaining arguments and configuration lines */
+      config_args = argc;
+      break;
    }
  }

@@ -348,16 +419,26 @@ int main
    go_daemon();
  }

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

  DNS_SetAddressFamily(address_family);

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

  /* Check whether another chronyd may already be running.  Do this after
   * forking, so that message logging goes to the right place (i.e. syslog), in
@@ -371,16 +452,12 @@ int main
   * be done *AFTER* the daemon-creation fork() */
  write_lockfile();

-  if (do_init_rtc) {
-    RTC_TimePreInit();
-  }
-
  LCL_Initialise();
  SCH_Initialise();
  SYS_Initialise();
  NIO_Initialise(address_family);
  CAM_Initialise(address_family);
-  RTC_Initialise();
+  RTC_Initialise(do_init_rtc);
  SRC_Initialise();
  RCL_Initialise();
  KEY_Initialise();
@@ -400,7 +477,7 @@ int main
  if (!user) {
    user = CNF_GetUser();
  }
-  if (user) {
+  if (user && strcmp(user, "root")) {
    SYS_DropRoot(user);
  }

@@ -412,13 +489,21 @@ int main
  NCR_Initialise();
  NSR_Initialise();
  CLG_Initialise();
-  ACQ_Initialise();
  MNL_Initialise();
  TMC_Initialise();

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

+  CNF_SetupAccessRestrictions();
+
+  if (ref_mode == REF_ModeNormal && CNF_GetInitSources() > 0) {
+    ref_mode = REF_ModeInitStepSlew;
+  }
+
+  REF_SetModeEndHandler(reference_mode_end);
+  REF_SetMode(ref_mode);
+
  if (do_init_rtc) {
    RTC_TimeInit(post_init_rtc_hook, NULL);
  } else {
--- a/42
+++ b/42
@@ -9,6 +9,7 @@ if [ $# -ne 1 ]; then
 fi

 version=$1
+tag=$version
 subdir=chrony-${version}
 mandate=$(date +'%B %Y')

@@ -21,20 +22,24 @@ fi

 [ -d RELEASES ] || mkdir RELEASES

-git tag -s $version || exit 1
-
 rm -rf RELEASES/$subdir

-git archive --format=tar --prefix=RELEASES/${subdir}/ $version | \
+if [ $version != test ]; then
+  git tag -s $tag || exit 1
+else
+  tag=HEAD
+fi
+
+git archive --format=tar --prefix=RELEASES/${subdir}/ $tag | \
  tar xf - || exit 1

 cd RELEASES/$subdir || exit 1

 echo $version > version.txt

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

-for m in chrony.1.in chronyc.1.in chrony.conf.5.in chronyd.8.in; do
+for m in chrony.1 chronyc.1.in chrony.conf.5.in chronyd.8.in; do
  sed -e "s%@VERSION@%${version}%;s%@MAN_DATE@%${mandate}%" \
    < $m > ${m}_
  mv -f ${m}_ $m
@@ -45,10 +50,29 @@ mv chrony.txt chrony.txt_
 make distclean
 mv chrony.txt_ chrony.txt

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

 cd ..
-tar cvf - $subdir | gzip -9 > ${subdir}.tar.gz
-gpg -b -a -o ${subdir}-tar-gz-asc.txt ${subdir}.tar.gz
-
+tar cv --owner root --group root $subdir | gzip -9 > ${subdir}.tar.gz

+[ $version != test ] && \
+  gpg -b -a -o ${subdir}-tar-gz-asc.txt ${subdir}.tar.gz
--- a/manual.c
+++ b/manual.c
@@ -59,13 +59,6 @@ typedef struct {
 static Sample samples[16];
 static int n_samples;

-static int replace_margin;
-static int error;
-
-/* Eventually these constants need to be user-defined in conf file */
-#define REPLACE_MARGIN 300
-#define ERROR_MARGIN 0.2
-
 /* ================================================== */

 static void
@@ -73,7 +66,7 @@ slew_samples(struct timeval *raw,
             struct timeval *cooked, 
             double dfreq,
             double doffset,
-             int is_step_change,
+             LCL_ChangeType change_type,
             void *not_used);

 /* ================================================== */
@@ -89,9 +82,6 @@ MNL_Initialise(void)

  n_samples = 0;

-  replace_margin = REPLACE_MARGIN;
-  error = ERROR_MARGIN;
-
  LCL_AddParameterChangeHandler(slew_samples, NULL);
 }

@@ -226,11 +216,16 @@ slew_samples(struct timeval *raw,
             struct timeval *cooked, 
             double dfreq,
             double doffset,
-             int is_step_change,
+             LCL_ChangeType change_type,
             void *not_used)
 {
  double delta_time;
  int i;
+
+  if (change_type == LCL_ChangeUnknownStep) {
+    MNL_Reset();
+  }
+
  for (i=0; i<n_samples; i++) {
    UTI_AdjustTimeval(&samples[i].when, cooked, &samples[i].when, &delta_time,
        dfreq, doffset);
--- a/nameserv.c
+++ b/nameserv.c
@@ -46,7 +46,7 @@ DNS_SetAddressFamily(int family)
 DNS_Status 
 DNS_Name2IPAddress(const char *name, IPAddr *addr)
 {
-#ifdef HAVE_IPV6
+#ifdef HAVE_GETADDRINFO
  struct addrinfo hints, *res, *ai;
  int result;
  
--- a/nameserv_async.c
+++ b/nameserv_async.c
@@ -0,0 +1,144 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2014
+ * 
+ * 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 to asynchronously convert name to IP address
+
+  */
+
+#include "config.h"
+#include "sysincl.h"
+
+#include "nameserv_async.h"
+#include "logging.h"
+#include "memory.h"
+#include "sched.h"
+#include "util.h"
+
+#ifdef FEAT_ASYNCDNS
+
+#ifdef USE_PTHREAD_ASYNCDNS
+#include <pthread.h>
+
+/* ================================================== */
+
+struct DNS_Async_Instance {
+  const char *name;
+  DNS_Status status;
+  IPAddr addr;
+  DNS_NameResolveHandler handler;
+  void *arg;
+
+  pthread_t thread;
+  int pipe[2];
+};
+
+static int resolving_threads = 0;
+
+/* ================================================== */
+
+static void *
+start_resolving(void *anything)
+{
+  struct DNS_Async_Instance *inst = (struct DNS_Async_Instance *)anything;
+
+  inst->status = DNS_Name2IPAddress(inst->name, &inst->addr);
+
+  /* Notify the main thread that the result is ready */
+  if (write(inst->pipe[1], "", 1) < 0)
+    ;
+
+  return NULL;
+}
+
+/* ================================================== */
+
+static void
+end_resolving(void *anything)
+{
+  struct DNS_Async_Instance *inst = (struct DNS_Async_Instance *)anything;
+
+  if (pthread_join(inst->thread, NULL)) {
+    LOG_FATAL(LOGF_Nameserv, "pthread_join() failed");
+  }
+
+  resolving_threads--;
+
+  SCH_RemoveInputFileHandler(inst->pipe[0]);
+  close(inst->pipe[0]);
+  close(inst->pipe[1]);
+
+  (inst->handler)(inst->status, &inst->addr, inst->arg);
+
+  Free(inst);
+}
+
+/* ================================================== */
+
+void
+DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *anything)
+{
+  struct DNS_Async_Instance *inst;
+
+  inst = MallocNew(struct DNS_Async_Instance);
+  inst->name = name;
+  inst->handler = handler;
+  inst->arg = anything;
+  inst->status = DNS_Failure;
+
+  if (pipe(inst->pipe)) {
+    LOG_FATAL(LOGF_Nameserv, "pipe() failed");
+  }
+
+  resolving_threads++;
+  assert(resolving_threads <= 1);
+
+  if (pthread_create(&inst->thread, NULL, start_resolving, inst)) {
+    LOG_FATAL(LOGF_Nameserv, "pthread_create() failed");
+  }
+
+  SCH_AddInputFileHandler(inst->pipe[0], end_resolving, inst);
+}
+
+/* ================================================== */
+
+#else
+#error
+#endif
+
+#else
+
+/* This is a blocking implementation used when nothing else is available */
+
+void
+DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *anything)
+{
+  IPAddr addr;
+  DNS_Status status;
+
+  status = DNS_Name2IPAddress(name, &addr);
+  (handler)(status, &addr, anything);
+}
+
+/* ================================================== */
+
+#endif
--- a/nameserv_async.h
+++ b/nameserv_async.h
@@ -2,7 +2,7 @@
  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************
- * Copyright (C) Richard P. Curnow  1997-2002
+ * Copyright (C) Miroslav Lichvar  2014
 * 
 * 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
@@ -21,25 +21,21 @@

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

-  Header file for acquisition module
+  Header for asynchronous nameserver functions
  */

-#ifndef GOT_ACQUIRE_H
-#define GOT_ACQUIRE_H

-#include "addressing.h"
+#ifndef GOT_NAMESERV_ASYNC_H
+#define GOT_NAMESERV_ASYNC_H

-typedef struct ACQ_SourceRecord *ACQ_Source;
+#include "nameserv.h"

-extern void ACQ_Initialise(void);
+/* Function type for callback to process the result */
+typedef void (*DNS_NameResolveHandler)(DNS_Status status, IPAddr *ip_addr, void *anything);

-extern void ACQ_Finalise(void);
+/* 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. */
+extern void DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *anything);

-extern void ACQ_StartAcquisition(int n, IPAddr *ip_addrs, double init_slew_threshold,
-                                 void (*after_hook)(void *), void *anything);
-
-extern void ACQ_AccumulateSample(ACQ_Source acq_source, double offset, double root_distance);
-
-extern void ACQ_MissedSample(ACQ_Source acq_source);
-
-#endif /* GOT_ACQUIRE_H */
+#endif
--- a/ntp_core.c
+++ b/ntp_core.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2013
+ * Copyright (C) Miroslav Lichvar  2009-2014
 * 
 * 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
@@ -47,11 +47,6 @@

 static LOG_FileID logfileid;

-/* ================================================== */
-
-/* Day number of 1 Jan 1970 */
-#define MJD_1970 40587
-
 /* ================================================== */
 /* Enumeration used for remembering the operating mode of one of the
   sources */
@@ -69,6 +64,7 @@ typedef enum {

 struct NCR_Instance_Record {
  NTP_Remote_Address remote_addr; /* Needed for routing transmit packets */
+  NTP_Local_Address local_addr; /* Local address/socket used to send packets */
  NTP_Mode mode;                /* The source's NTP mode
                                   (client/server or symmetric active peer) */
  OperatingMode opmode;         /* Whether we are sampling this source
@@ -77,6 +73,7 @@ struct NCR_Instance_Record {
                                   pending to transmit to the source */
  SCH_TimeoutID timeout_id;     /* Scheduler's timeout ID, if we are
                                   running on a timer. */
+  int tx_suspended;             /* Boolean indicating we can't transmit yet */

  int auto_offline;             /* If 1, automatically go offline if server/peer
                                   isn't responding */
@@ -88,8 +85,8 @@ struct NCR_Instance_Record {
                                   received packets) */

  int presend_minpoll;           /* If the current polling interval is
-                                    at least this, an echo datagram
-                                    will be send some time before every
+                                    at least this, an extra client packet
+                                    will be send some time before normal
                                    transmit.  This ensures that both
                                    us and the server/peer have an ARP
                                    entry for each other ready, which
@@ -188,9 +185,13 @@ struct NCR_Instance_Record {

 /* Time to wait before retransmitting in burst mode, if we did not get
   a reply to the previous probe */
-#define BURST_TIMEOUT 8.0
+#define BURST_TIMEOUT 2.0

-/* Time to wait after sending echo to 'warm up' link */
+/* Number of samples in initial burst */
+#define IBURST_GOOD_SAMPLES 4
+#define IBURST_TOTAL_SAMPLES SOURCE_REACH_BITS
+
+/* Time to wait after sending packet to 'warm up' link */
 #define WARM_UP_DELAY 4.0

 /* The NTP protocol version that we support */
@@ -212,6 +213,14 @@ struct NCR_Instance_Record {
 /* INVALID or Unkown  stratum from external server  as per the NTP 4 docs */
 #define NTP_INVALID_STRATUM 0

+/* Minimum allowed poll interval */
+#define MIN_POLL 0
+
+/* Maximum poll interval set by KoD RATE */
+#define MAX_KOD_RATE_POLL SRC_DEFAULT_MAXPOLL
+
+#define INVALID_SOCK_FD -1
+
 /* ================================================== */

 static ADF_AuthTable access_auth_table;
@@ -220,12 +229,79 @@ static ADF_AuthTable access_auth_table;
 /* Forward prototypes */

 static void transmit_timeout(void *arg);
+static double get_transmit_delay(NCR_Instance inst, int on_tx, double last_tx);
+
+/* ================================================== */
+
+static void
+do_size_checks(void)
+{
+  /* Assertions to check the sizes of certain data types
+     and the positions of certain record fields */
+
+  /* Check that certain invariants are true */
+  assert(sizeof(NTP_int32) == 4);
+  assert(sizeof(NTP_int64) == 8);
+
+  /* Check offsets of all fields in the NTP packet format */
+  assert(offsetof(NTP_Packet, lvm)             ==  0);
+  assert(offsetof(NTP_Packet, stratum)         ==  1);
+  assert(offsetof(NTP_Packet, poll)            ==  2);
+  assert(offsetof(NTP_Packet, precision)       ==  3);
+  assert(offsetof(NTP_Packet, root_delay)      ==  4);
+  assert(offsetof(NTP_Packet, root_dispersion) ==  8);
+  assert(offsetof(NTP_Packet, reference_id)    == 12);
+  assert(offsetof(NTP_Packet, reference_ts)    == 16);
+  assert(offsetof(NTP_Packet, originate_ts)    == 24);
+  assert(offsetof(NTP_Packet, receive_ts)      == 32);
+  assert(offsetof(NTP_Packet, transmit_ts)     == 40);
+}
+
+/* ================================================== */
+
+static void
+do_time_checks(void)
+{
+  struct timeval now;
+  time_t warning_advance = 3600 * 24 * 365 * 10; /* 10 years */
+
+#ifdef HAVE_LONG_TIME_T
+  /* Check that time before NTP_ERA_SPLIT underflows correctly */
+
+  struct timeval tv1 = {NTP_ERA_SPLIT, 1}, tv2 = {NTP_ERA_SPLIT - 1, 1};
+  NTP_int64 ntv1, ntv2;
+  int r;
+
+  UTI_TimevalToInt64(&tv1, &ntv1, 0);
+  UTI_TimevalToInt64(&tv2, &ntv2, 0);
+  UTI_Int64ToTimeval(&ntv1, &tv1);
+  UTI_Int64ToTimeval(&ntv2, &tv2);
+
+  r = tv1.tv_sec == NTP_ERA_SPLIT &&
+      tv1.tv_sec + (1ULL << 32) - 1 == tv2.tv_sec;
+
+  assert(r);
+
+  LCL_ReadRawTime(&now);
+  if (tv2.tv_sec - now.tv_sec < warning_advance)
+    LOG(LOGS_WARN, LOGF_NtpCore, "Assumed NTP time ends at %s!",
+        UTI_TimeToLogForm(tv2.tv_sec));
+#else
+  LCL_ReadRawTime(&now);
+  if (now.tv_sec > 0x7fffffff - warning_advance)
+    LOG(LOGS_WARN, LOGF_NtpCore, "System time ends at %s!",
+        UTI_TimeToLogForm(0x7fffffff));
+#endif
+}

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

 void
 NCR_Initialise(void)
 {
+  do_size_checks();
+  do_time_checks();
+
  logfileid = CNF_GetLogMeasurements() ? LOG_FileOpen("measurements",
      "   Date (UTC) Time     IP Address   L St 1234 abc 5678 LP RP Score Offset     Peer del. Peer disp. Root del.  Root disp.")
    : -1;
@@ -245,11 +321,20 @@ NCR_Finalise(void)
 /* ================================================== */

 static void
-start_initial_timeout(NCR_Instance inst)
+restart_timeout(NCR_Instance inst, double delay)
 {
+  /* Check if we can transmit */
+  if (inst->tx_suspended) {
+    assert(!inst->timer_running);
+    return;
+  }

-  /* Start timer for first transmission */
-  inst->timeout_id = SCH_AddTimeoutInClass(INITIAL_DELAY, SAMPLING_SEPARATION,
+  /* Stop old timer if running */
+  if (inst->timer_running)
+    SCH_RemoveTimeout(inst->timeout_id);
+
+  /* Start new timer for transmission */
+  inst->timeout_id = SCH_AddTimeoutInClass(delay, SAMPLING_SEPARATION,
                                           SAMPLING_RANDOMNESS,
                                           SCH_NtpSamplingClass,
                                           transmit_timeout, (void *)inst);
@@ -258,6 +343,32 @@ start_initial_timeout(NCR_Instance inst)

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

+static void
+start_initial_timeout(NCR_Instance inst)
+{
+  if (!inst->timer_running) {
+    /* This will be the first transmission after mode change */
+
+    /* Mark source active */
+    SRC_SetActive(inst->source);
+  }
+
+  restart_timeout(inst, INITIAL_DELAY);
+}
+
+/* ================================================== */
+
+static void
+close_client_socket(NCR_Instance inst)
+{
+  if (inst->mode == MODE_CLIENT && inst->local_addr.sock_fd != INVALID_SOCK_FD) {
+    NIO_CloseClientSocket(inst->local_addr.sock_fd);
+    inst->local_addr.sock_fd = INVALID_SOCK_FD;
+  }
+}
+
+/* ================================================== */
+
 static void
 take_offline(NCR_Instance inst)
 {
@@ -269,6 +380,13 @@ take_offline(NCR_Instance inst)

  /* Mark source unreachable */
  SRC_ResetReachability(inst->source);
+
+  /* And inactive */
+  SRC_UnsetActive(inst->source);
+
+  close_client_socket(inst);
+
+  NCR_ResetInstance(inst);
 }

 /* ================================================== */
@@ -281,11 +399,16 @@ NCR_GetInstance(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourcePar
  result = MallocNew(struct NCR_Instance_Record);

  result->remote_addr = *remote_addr;
+  result->local_addr.ip_addr.family = IPADDR_UNSPEC;
+
  switch (type) {
    case NTP_SERVER:
+      /* Client socket will be obtained when sending request */
+      result->local_addr.sock_fd = INVALID_SOCK_FD;
      result->mode = MODE_CLIENT;
      break;
    case NTP_PEER:
+      result->local_addr.sock_fd = NIO_GetServerSocket(remote_addr);
      result->mode = MODE_ACTIVE;
      break;
    default:
@@ -293,11 +416,22 @@ NCR_GetInstance(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourcePar
  }

  result->minpoll = params->minpoll;
+  if (result->minpoll < MIN_POLL)
+    result->minpoll = SRC_DEFAULT_MINPOLL;
  result->maxpoll = params->maxpoll;
-  result->min_stratum = params->min_stratum;
+  if (result->maxpoll < MIN_POLL)
+    result->maxpoll = SRC_DEFAULT_MAXPOLL;
+  if (result->maxpoll < result->minpoll)
+    result->maxpoll = result->minpoll;

+  result->min_stratum = params->min_stratum;
  result->presend_minpoll = params->presend_minpoll;
-  result->presend_done = 0;
+
+  result->max_delay = params->max_delay;
+  result->max_delay_ratio = params->max_delay_ratio;
+  result->max_delay_dev_ratio = params->max_delay_dev_ratio;
+  result->auto_offline = params->auto_offline;
+  result->poll_target = params->poll_target;

  if (params->authkey == INACTIVE_AUTHKEY) {
    result->do_auth = 0;
@@ -305,51 +439,28 @@ NCR_GetInstance(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourcePar
  } else {
    result->do_auth = 1;
    result->auth_key_id = params->authkey;
+    if (!KEY_KeyKnown(result->auth_key_id)) {
+      LOG(LOGS_WARN, LOGF_NtpCore, "Source %s added with unknown key %lu",
+          UTI_IPToString(&result->remote_addr.ip_addr), result->auth_key_id);
+    }
  }

-  result->max_delay = params->max_delay;
-  result->max_delay_ratio = params->max_delay_ratio;
-  result->max_delay_dev_ratio = params->max_delay_dev_ratio;
-
-  result->tx_count = 0;
-
-  result->remote_orig.hi = 0;
-  result->remote_orig.lo = 0;
-
-  result->poll_target = params->poll_target;
-  result->poll_score = 0.0;
-
-  if (params->online) {
-    start_initial_timeout(result);
-    result->opmode = MD_ONLINE;
-  } else {
-    result->timer_running = 0;
-    result->timeout_id = 0;
-    result->opmode = MD_OFFLINE;
-  }
-  
-  if (params->iburst) {
-    NCR_InitiateSampleBurst(result, 4, 8);
-  }
-
-  result->auto_offline = params->auto_offline;
-  
-  result->local_poll = params->minpoll;
-  result->remote_poll = 0;
-  result->remote_stratum = 0;
-
  /* Create a source instance for this NTP source */
  result->source = SRC_CreateNewInstance(UTI_IPToRefid(&remote_addr->ip_addr), SRC_NTP, params->sel_option, &result->remote_addr.ip_addr);

-  result->local_rx.tv_sec = 0;
-  result->local_rx.tv_usec = 0;
-  result->local_tx.tv_sec = 0;
-  result->local_tx.tv_usec = 0;
-  result->local_ntp_tx.hi = 0;
-  result->local_ntp_tx.lo = 0;
+  result->timer_running = 0;
+  result->timeout_id = 0;
+  result->tx_suspended = 1;
+  result->opmode = params->online ? MD_ONLINE : MD_OFFLINE;
+  result->local_poll = result->minpoll;
+  
+  NCR_ResetInstance(result);
+
+  if (params->iburst) {
+    NCR_InitiateSampleBurst(result, IBURST_GOOD_SAMPLES, IBURST_TOTAL_SAMPLES);
+  }

  return result;
-
 }

 /* ================================================== */
@@ -358,23 +469,60 @@ NCR_GetInstance(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourcePar
 void
 NCR_DestroyInstance(NCR_Instance instance)
 {
+  if (instance->opmode != MD_OFFLINE)
+    take_offline(instance);
+
  /* This will destroy the source instance inside the
     structure, which will cause reselection if this was the
     synchronising source etc. */
  SRC_DestroyInstance(instance->source);

-  /* Cancel any pending timeouts */
-  if (instance->timer_running) {
-    SCH_RemoveTimeout(instance->timeout_id);
-    instance->timer_running = 0;
-  }
-
  /* Free the data structure */
  Free(instance);
 }

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

+void
+NCR_StartInstance(NCR_Instance instance)
+{
+  instance->tx_suspended = 0;
+  if (instance->opmode != MD_OFFLINE)
+    start_initial_timeout(instance);
+}
+
+/* ================================================== */
+
+void
+NCR_ResetInstance(NCR_Instance instance)
+{
+  instance->tx_count = 0;
+  instance->presend_done = 0;
+
+  instance->poll_score = 0.0;
+  instance->remote_poll = 0;
+  instance->remote_stratum = 0;
+
+  instance->remote_orig.hi = 0;
+  instance->remote_orig.lo = 0;
+  instance->local_rx.tv_sec = 0;
+  instance->local_rx.tv_usec = 0;
+  instance->local_tx.tv_sec = 0;
+  instance->local_tx.tv_usec = 0;
+  instance->local_ntp_tx.hi = 0;
+  instance->local_ntp_tx.lo = 0;
+
+  if (instance->local_poll != instance->minpoll) {
+    instance->local_poll = instance->minpoll;
+
+    /* The timer was set with a longer poll interval, restart it */
+    if (instance->timer_running)
+      restart_timeout(instance, get_transmit_delay(instance, 0, 0.0));
+  }
+}
+
+/* ================================================== */
+
 static int
 check_packet_auth(NTP_Packet *pkt, unsigned long keyid, int auth_len)
 {
@@ -520,8 +668,7 @@ get_transmit_delay(NCR_Instance inst, int on_tx, double last_tx)

    case MD_BURST_WAS_ONLINE:
    case MD_BURST_WAS_OFFLINE:
-      /* With burst, the timeout for new transmit after valid reply is shorter
-         than the timeout without reply */
+      /* Burst modes */
      delay_time = on_tx ? BURST_TIMEOUT : BURST_INTERVAL;
      break;
    default:
@@ -534,7 +681,7 @@ get_transmit_delay(NCR_Instance inst, int on_tx, double last_tx)

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

-static void
+static int
 transmit_packet(NTP_Mode my_mode, /* The mode this machine wants to be */
                int my_poll, /* The log2 of the local poll interval */
                int version, /* The NTP version to be set in the packet */
@@ -551,11 +698,12 @@ transmit_packet(NTP_Mode my_mode, /* The mode this machine wants to be */
                                            (including adjustment to
                                            reference), ignored if
                                            NULL */
-                NTP_Remote_Address *where_to /* Where to address the reponse to */
+                NTP_Remote_Address *where_to, /* Where to address the reponse to */
+                NTP_Local_Address *from /* From what address to send it */
                )
 {
  NTP_Packet message;
-  int leap;
+  int leap, ret;
  struct timeval local_transmit;

  /* Parameters read from reference module */
@@ -639,12 +787,17 @@ transmit_packet(NTP_Mode my_mode, /* The mode this machine wants to be */
        (unsigned char *)&message.auth_data, sizeof (message.auth_data));
    if (auth_len > 0) {
      message.auth_keyid = htonl(key_id);
-      NIO_SendAuthenticatedPacket(&message, where_to,
+      ret = NIO_SendAuthenticatedPacket(&message, where_to, from,
          sizeof (message.auth_keyid) + auth_len);
+    } else {
+      DEBUG_LOG(LOGF_NtpCore,
+                "Could not generate auth data with key %lu to send packet",
+                key_id);
+      return 0;
    }
  } else {
    UTI_TimevalToInt64(&local_transmit, &message.transmit_ts, ts_fuzz);
-    NIO_SendNormalPacket(&message, where_to);
+    ret = NIO_SendNormalPacket(&message, where_to, from);
  }

  if (local_tx) {
@@ -655,6 +808,7 @@ transmit_packet(NTP_Mode my_mode, /* The mode this machine wants to be */
    *local_ntp_tx = message.transmit_ts;
  }

+  return ret;
 }

 /* ================================================== */
@@ -664,8 +818,7 @@ static void
 transmit_timeout(void *arg)
 {
  NCR_Instance inst = (NCR_Instance) arg;
-  double timeout_delay;
-  int do_auth;
+  int sent;

  inst->timer_running = 0;

@@ -686,13 +839,18 @@ transmit_timeout(void *arg)
    return;
  }

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_NtpCore, "Transmit timeout for [%s:%d]",
+  DEBUG_LOG(LOGF_NtpCore, "Transmit timeout for [%s:%d]",
      UTI_IPToString(&inst->remote_addr.ip_addr), inst->remote_addr.port);
-#endif
+
+  /* Open new client socket */
+  if (inst->mode == MODE_CLIENT) {
+    close_client_socket(inst);
+    assert(inst->local_addr.sock_fd == INVALID_SOCK_FD);
+    inst->local_addr.sock_fd = NIO_GetClientSocket(&inst->remote_addr);
+  }

  /* Check whether we need to 'warm up' the link to the other end by
-     sending an echo exchange to ensure both ends' ARP caches are
+     sending an NTP exchange to ensure both ends' ARP caches are
     primed.  On loaded systems this might also help ensure that bits
     of the program are paged in properly before we start. */

@@ -700,33 +858,42 @@ transmit_timeout(void *arg)
      (inst->presend_minpoll <= inst->local_poll) &&
      !inst->presend_done) {
    
-    /* Send */
-    NIO_SendEcho(&inst->remote_addr);
+    /* Send a client packet, don't store the local tx values
+       as the reply will be ignored */
+    transmit_packet(MODE_CLIENT, inst->local_poll, NTP_VERSION, 0, 0,
+                    &inst->remote_orig, &inst->local_rx, NULL, NULL,
+                    &inst->remote_addr, &inst->local_addr);

    inst->presend_done = 1;

    /* Requeue timeout */
-    inst->timer_running = 1;
-    inst->timeout_id = SCH_AddTimeoutInClass(WARM_UP_DELAY, SAMPLING_SEPARATION,
-                                             SAMPLING_RANDOMNESS,
-                                             SCH_NtpSamplingClass,
-                                             transmit_timeout, (void *)inst);
+    restart_timeout(inst, WARM_UP_DELAY);

    return;
  }

  inst->presend_done = 0; /* Reset for next time */

+  sent = transmit_packet(inst->mode, inst->local_poll,
+                         NTP_VERSION,
+                         inst->do_auth, inst->auth_key_id,
+                         &inst->remote_orig,
+                         &inst->local_rx, &inst->local_tx, &inst->local_ntp_tx,
+                         &inst->remote_addr,
+                         &inst->local_addr);
+
  ++inst->tx_count;

-  /* If the source loses connectivity, back off the sampling rate to reduce
-     wasted sampling. If it's the source to which we are currently locked,
-     back off slower. */
+  /* If the source loses connectivity and our packets are still being sent,
+     back off the sampling rate to reduce the network traffic.  If it's the
+     source to which we are currently locked, back off slowly. */

  if (inst->tx_count >= 2) {
    /* Implies we have missed at least one transmission */

-    adjust_poll(inst, SRC_IsSyncPeer(inst->source) ? 0.1 : 0.25);
+    if (sent) {
+      adjust_poll(inst, SRC_IsSyncPeer(inst->source) ? 0.1 : 0.25);
+    }

    SRC_UpdateReachability(inst->source, 0);

@@ -735,21 +902,12 @@ transmit_timeout(void *arg)
    }
  }

-  if (inst->do_auth && KEY_KeyKnown(inst->auth_key_id)) {
-    do_auth = 1;
-  } else {
-    do_auth = 0;
-  }
-
-  transmit_packet(inst->mode, inst->local_poll,
-                  NTP_VERSION,
-                  do_auth, inst->auth_key_id,
-                  &inst->remote_orig,
-                  &inst->local_rx, &inst->local_tx, &inst->local_ntp_tx,
-                  &inst->remote_addr);
-
  switch (inst->opmode) {
    case MD_BURST_WAS_ONLINE:
+      /* When not reachable, don't stop online burst until sending succeeds */
+      if (!sent && !SRC_IsReachable(inst->source))
+        break;
+      /* Fall through */
    case MD_BURST_WAS_OFFLINE:
      --inst->burst_total_samples_to_go;
      break;
@@ -758,12 +916,7 @@ transmit_timeout(void *arg)
  }

  /* Restart timer for this message */
-  timeout_delay = get_transmit_delay(inst, 1, 0.0);
-  inst->timer_running = 1;
-  inst->timeout_id = SCH_AddTimeoutInClass(timeout_delay, SAMPLING_SEPARATION,
-                                           SAMPLING_RANDOMNESS,
-                                           SCH_NtpSamplingClass,
-                                           transmit_timeout, (void *)inst);
+  restart_timeout(inst, get_transmit_delay(inst, 1, 0.0));
 }


@@ -852,9 +1005,6 @@ receive_packet(NTP_Packet *message, struct timeval *now, double now_err, NCR_Ins

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

-  /* Save local receive timestamp */
-  inst->local_rx = *now;
-
  pkt_leap = (message->lvm >> 6) & 0x3;
  if (pkt_leap == 0x3) {
    source_is_synchronized = 0;
@@ -886,14 +1036,6 @@ receive_packet(NTP_Packet *message, struct timeval *now, double now_err, NCR_Ins
    test2 = 1; /* Success */
  }

-  /* Regardless of any validity checks we apply, we are required to
-     save this field from the packet into the ntp source
-     instance record.  See RFC1305 section 3.4.4, peer.org <- pkt.xmt
-     & peer.peerpoll <- pkt.poll.  Note we can't do this assignment
-     before test1 has been carried out!! */
-
-  inst->remote_orig = message->transmit_ts;
-
  /* Test 3 requires that pkt.org != 0 and pkt.rec != 0.  If
     either of these are true it means the association is not properly
     'up'. */
@@ -998,11 +1140,7 @@ receive_packet(NTP_Packet *message, struct timeval *now, double now_err, NCR_Ins
  if (inst->do_auth) {
    if (auth_len > 0) {
      auth_key_id = ntohl(message->auth_keyid);
-      if (!KEY_KeyKnown(auth_key_id)) {
-        test5 = 0;
-      } else {
-        test5 = check_packet_auth(message, auth_key_id, auth_len);
-      }
+      test5 = check_packet_auth(message, auth_key_id, auth_len);
    } else {
      /* If we expect authenticated info from this peer/server and the packet
         doesn't have it, it's got to fail */
@@ -1070,6 +1208,14 @@ receive_packet(NTP_Packet *message, struct timeval *now, double now_err, NCR_Ins
        kod_rate = 1;
  }

+  /* The transmit timestamp and local receive timestamp must not be saved when
+     the authentication test failed to prevent denial-of-service attacks on
+     symmetric associations using authentication */
+  if (test5) {
+    inst->remote_orig = message->transmit_ts;
+    inst->local_rx = *now;
+  }
+
  valid_kod = test1 && test2 && test5;

  valid_data = test1 && test2 && test3 && test4 && test4a && test4b;
@@ -1080,55 +1226,61 @@ receive_packet(NTP_Packet *message, struct timeval *now, double now_err, NCR_Ins
  root_delay = pkt_root_delay + fabs(delta);
  root_dispersion = pkt_root_dispersion + epsilon;

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_NtpCore, "lvm=%o stratum=%d poll=%d prec=%d",
+  DEBUG_LOG(LOGF_NtpCore, "lvm=%o stratum=%d poll=%d prec=%d",
      message->lvm, message->stratum, message->poll, message->precision);
-  LOG(LOGS_INFO, LOGF_NtpCore, "Root delay=%08lx (%f), dispersion=%08lx (%f)",
+  DEBUG_LOG(LOGF_NtpCore, "Root delay=%08x (%f), dispersion=%08x (%f)",
      message->root_delay, pkt_root_delay, message->root_dispersion, pkt_root_dispersion);
-  LOG(LOGS_INFO, LOGF_NtpCore, "Ref id=[%lx], ref_time=%08lx.%08lx [%s]",
+  DEBUG_LOG(LOGF_NtpCore, "Ref id=[%x], ref_time=%08x.%08x [%s]",
      ntohl(message->reference_id),
      message->reference_ts.hi, message->reference_ts.lo,
      UTI_TimestampToString(&message->reference_ts));
-  LOG(LOGS_INFO, LOGF_NtpCore, "Originate=%08lx.%08lx [%s]",
+  DEBUG_LOG(LOGF_NtpCore, "Originate=%08x.%08x [%s]",
      message->originate_ts.hi, message->originate_ts.lo,
      UTI_TimestampToString(&message->originate_ts));
-  LOG(LOGS_INFO, LOGF_NtpCore, "Message receive=%08lx.%08lx [%s]",
+  DEBUG_LOG(LOGF_NtpCore, "Message receive=%08x.%08x [%s]",
      message->receive_ts.hi, message->receive_ts.lo,
      UTI_TimestampToString(&message->receive_ts));

-  LOG(LOGS_INFO, LOGF_NtpCore, "Transmit=%08lx.%08lx [%s]",
+  DEBUG_LOG(LOGF_NtpCore, "Transmit=%08x.%08x [%s]",
      message->transmit_ts.hi, message->transmit_ts.lo,
      UTI_TimestampToString(&message->transmit_ts));

-  LOG(LOGS_INFO, LOGF_NtpCore, "theta=%f delta=%f epsilon=%f root_delay=%f root_dispersion=%f",
+  DEBUG_LOG(LOGF_NtpCore, "theta=%f delta=%f epsilon=%f root_delay=%f root_dispersion=%f",
      theta, delta, epsilon, root_delay, root_dispersion);

-  LOG(LOGS_INFO, LOGF_NtpCore, "test1=%d test2=%d test3=%d test4=%d valid_data=%d good_data=%d",
+  DEBUG_LOG(LOGF_NtpCore, "test1=%d test2=%d test3=%d test4=%d valid_data=%d good_data=%d",
      test1, test2, test3, test4, valid_data, good_data);

-  LOG(LOGS_INFO, LOGF_NtpCore, "test5=%d test6=%d test7=%d test8=%d valid_header=%d good_header=%d",
+  DEBUG_LOG(LOGF_NtpCore, "test5=%d test6=%d test7=%d test8=%d valid_header=%d good_header=%d",
      test5, test6, test7, test8, valid_header, good_header);

-  LOG(LOGS_INFO, LOGF_NtpCore, "kod_rate=%d valid_kod=%d", kod_rate, valid_kod);
-#endif
+  DEBUG_LOG(LOGF_NtpCore, "kod_rate=%d valid_kod=%d", kod_rate, valid_kod);

  /* Reduce polling rate if KoD RATE was received */
  if (kod_rate && valid_kod) {
    if (message->poll > inst->minpoll) {
-      inst->minpoll = message->poll;
+      /* Set our minpoll to message poll, but use a reasonable maximum */
+      if (message->poll <= MAX_KOD_RATE_POLL)
+        inst->minpoll = message->poll;
+      else if (inst->minpoll < MAX_KOD_RATE_POLL)
+        inst->minpoll = MAX_KOD_RATE_POLL;
+
      if (inst->minpoll > inst->maxpoll)
        inst->maxpoll = inst->minpoll;
      if (inst->minpoll > inst->local_poll)
        inst->local_poll = inst->minpoll;
-      LOG(LOGS_WARN, LOGF_NtpCore, "Received KoD RATE from %s, minpoll set to %d",
-          UTI_IPToString(&inst->remote_addr.ip_addr), inst->minpoll);
+
+      LOG(LOGS_WARN, LOGF_NtpCore,
+          "Received KoD RATE with poll %d from %s, minpoll set to %d",
+          message->poll, UTI_IPToString(&inst->remote_addr.ip_addr),
+          inst->minpoll);
    }

    /* Stop ongoing burst */
    if (inst->opmode == MD_BURST_WAS_OFFLINE || inst->opmode == MD_BURST_WAS_ONLINE) {
      inst->burst_good_samples_to_go = 0;
      LOG(LOGS_WARN, LOGF_NtpCore, "Received KoD RATE from %s, burst sampling stopped",
-          UTI_IPToString(&inst->remote_addr.ip_addr), inst->minpoll);
+          UTI_IPToString(&inst->remote_addr.ip_addr));
    }

    requeue_transmit = 1;
@@ -1161,6 +1313,8 @@ receive_packet(NTP_Packet *message, struct timeval *now, double now_err, NCR_Ins
                           root_delay, root_dispersion,
                           message->stratum, (NTP_Leap) pkt_leap);

+      SRC_SelectSource(inst->source);
+
      /* Now examine the registers.  First though, if the prediction is
         not even within +/- the peer distance of the peer, we are clearly
         not tracking the peer at all well, so we back off the sampling
@@ -1191,6 +1345,10 @@ receive_packet(NTP_Packet *message, struct timeval *now, double now_err, NCR_Ins
      adjust_poll(inst, 0.1);
    }

+    /* If in client mode, no more packets are expected to be coming from the
+       server and the socket can be closed */
+    close_client_socket(inst);
+
    requeue_transmit = 1;
  }

@@ -1205,11 +1363,7 @@ receive_packet(NTP_Packet *message, struct timeval *now, double now_err, NCR_Ins

    /* Get rid of old timeout and start a new one */
    assert(inst->timer_running);
-    SCH_RemoveTimeout(inst->timeout_id);
-    inst->timeout_id = SCH_AddTimeoutInClass(delay_time, SAMPLING_SEPARATION,
-                                             SAMPLING_RANDOMNESS,
-                                             SCH_NtpSamplingClass,
-                                             transmit_timeout, (void *)inst);
+    restart_timeout(inst, delay_time);
  }

  /* Do measurement logging */
@@ -1259,18 +1413,24 @@ NCR_ProcessKnown
 struct timeval *now,           /* timestamp at time of receipt */
 double now_err,
 NCR_Instance inst,             /* the instance record for this peer/server */
+ int sock_fd,                   /* the receiving socket */
 int length                     /* the length of the received packet */
 )
 {
  int pkt_mode;
  int version;
-  int valid_auth, valid_key;
-  int authenticate_reply, auth_len;
-  unsigned long auth_key_id;
-  unsigned long reply_auth_key_id;
+  int auth_len;
+
+  /* Make sure the packet was received by the sending socket */
+  if (sock_fd != inst->local_addr.sock_fd) {
+    DEBUG_LOG(LOGF_NtpCore,
+              "Packet received by wrong socket %d (expected %d)",
+              sock_fd, inst->local_addr.sock_fd);
+    return;
+  }

  /* Ignore packets from offline sources */
-  if (inst->opmode == MD_OFFLINE) {
+  if (inst->opmode == MD_OFFLINE || inst->tx_suspended) {
    return;
  }

@@ -1309,45 +1469,8 @@ NCR_ProcessKnown
         one of the secondaries to flywheel it. The behaviour coded here
         is required in the secondaries to make this possible. */

-      if (ADF_IsAllowed(access_auth_table, &inst->remote_addr.ip_addr)) {
-
-        CLG_LogNTPClientAccess(&inst->remote_addr.ip_addr, (time_t) now->tv_sec);
-
-        if (auth_len > 0) {
-          auth_key_id = ntohl(message->auth_keyid);
-          valid_key = KEY_KeyKnown(auth_key_id);
-          if (valid_key) {
-            valid_auth = check_packet_auth(message, auth_key_id, auth_len);
-          } else {
-            valid_auth = 0;
-          }
-          
-          if (valid_key && valid_auth) {
-            authenticate_reply = 1;
-            reply_auth_key_id = auth_key_id;
-          } else {
-            authenticate_reply = 0;
-            reply_auth_key_id = 0UL;
-          }
-        } else {
-          authenticate_reply = 0;
-          reply_auth_key_id = 0UL;
-        }
-        
-        transmit_packet(MODE_SERVER, inst->local_poll,
-                        version,
-                        authenticate_reply, reply_auth_key_id,
-                        &message->transmit_ts,
-                        now,
-                        &inst->local_tx,
-                        &inst->local_ntp_tx,
-                        &inst->remote_addr);
-
-      } else if (!LOG_RateLimited()) {
-        LOG(LOGS_WARN, LOGF_NtpCore, "NTP packet received from unauthorised host %s port %d",
-            UTI_IPToString(&inst->remote_addr.ip_addr),
-            inst->remote_addr.port);
-      }
+      NCR_ProcessUnknown(message, now, now_err,
+                         &inst->remote_addr, &inst->local_addr, length);

      break;

@@ -1383,6 +1506,9 @@ NCR_ProcessKnown
      break;

    case MODE_SERVER:
+      /* Ignore presend reply */
+      if (inst->presend_done)
+        break;

      switch(inst->mode) {
        case MODE_ACTIVE:
@@ -1452,7 +1578,7 @@ NCR_ProcessKnown

 /* ================================================== */
 /* 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 */
+   and it relates to a source we don't know (not our server or peer) */

 void
 NCR_ProcessUnknown
@@ -1460,15 +1586,23 @@ NCR_ProcessUnknown
 struct timeval *now,           /* timestamp at time of receipt */
 double now_err,                /* assumed error in the timestamp */
 NTP_Remote_Address *remote_addr,
+ NTP_Local_Address *local_addr,
 int length                     /* the length of the received packet */
 )
 {
  NTP_Mode his_mode;
  NTP_Mode my_mode;
  int my_poll, version;
-  int valid_key, valid_auth, auth_len;
+  int valid_auth, auth_len;
  unsigned long key_id;

+  /* Ignore the packet if it wasn't received by server socket */
+  if (!NIO_IsServerSocket(local_addr->sock_fd)) {
+    DEBUG_LOG(LOGF_NtpCore, "NTP request packet received by client socket %d",
+              local_addr->sock_fd);
+    return;
+  }
+
  /* Check version */
  version = (message->lvm >> 3) & 0x7;
  if (version < NTP_MIN_COMPAT_VERSION || version > NTP_MAX_COMPAT_VERSION) {
@@ -1505,18 +1639,13 @@ NCR_ProcessUnknown
        /* Only reply if we know the key and the packet authenticates
           properly. */
        key_id = ntohl(message->auth_keyid);
-        valid_key = KEY_KeyKnown(key_id);
        do_auth = 1;
-
-        if (valid_key) {
-          valid_auth = check_packet_auth(message, key_id, auth_len);
-        } else {
-          valid_auth = 0;
-        }
+        valid_auth = check_packet_auth(message, key_id, auth_len);
      }

-      if (!do_auth || (valid_key && valid_auth)) {
-        my_poll = message->poll; /* What should this be set to?  Does the client actually care? */
+      if (!do_auth || valid_auth) {
+        /* Reply with the same poll, the client may use it to control its poll */
+        my_poll = message->poll;

        transmit_packet(my_mode, my_poll,
                        version,
@@ -1525,11 +1654,12 @@ NCR_ProcessUnknown
                        now, /* Time we received the packet */
                        NULL, /* Don't care when we send reply, we aren't maintaining state about this client */
                        NULL, /* Ditto */
-                        remote_addr);
+                        remote_addr,
+                        local_addr);
      }
    }
-  } else if (!LOG_RateLimited()) {
-    LOG(LOGS_WARN, LOGF_NtpCore, "NTP packet received from unauthorised host %s port %d",
+  } else {
+    DEBUG_LOG(LOGF_NtpCore, "NTP packet received from unauthorised host %s port %d",
        UTI_IPToString(&remote_addr->ip_addr),
        remote_addr->port);
  }
@@ -1545,19 +1675,13 @@ NCR_SlewTimes(NCR_Instance inst, struct timeval *when, double dfreq, double doff
  prev = inst->local_rx;
  if (inst->local_rx.tv_sec || inst->local_rx.tv_usec)
    UTI_AdjustTimeval(&inst->local_rx, when, &inst->local_rx, &delta, dfreq, doffset);
-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_NtpCore, "rx prev=[%s] new=[%s]",
+  DEBUG_LOG(LOGF_NtpCore, "rx prev=[%s] new=[%s]",
      UTI_TimevalToString(&prev), UTI_TimevalToString(&inst->local_rx));
-#endif
  prev = inst->local_tx;
  if (inst->local_tx.tv_sec || inst->local_tx.tv_usec)
    UTI_AdjustTimeval(&inst->local_tx, when, &inst->local_tx, &delta, dfreq, doffset);
-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_NtpCore, "tx prev=[%s] new=[%s]",
+  DEBUG_LOG(LOGF_NtpCore, "tx prev=[%s] new=[%s]",
      UTI_TimevalToString(&prev), UTI_TimevalToString(&inst->local_tx));
-#else
-  (void)prev;
-#endif
 }

 /* ================================================== */
@@ -1570,15 +1694,10 @@ NCR_TakeSourceOnline(NCR_Instance inst)
      /* Nothing to do */
      break;
    case MD_OFFLINE:
-      if (!inst->timer_running) {
-        /* We are not already actively polling it */
-        LOG(LOGS_INFO, LOGF_NtpCore, "Source %s online", UTI_IPToString(&inst->remote_addr.ip_addr));
-        inst->tx_count = 0;
-        inst->local_poll = inst->minpoll;
-        inst->poll_score = 0.5;
-        inst->opmode = MD_ONLINE;
-        start_initial_timeout(inst);
-      }
+      LOG(LOGS_INFO, LOGF_NtpCore, "Source %s online", UTI_IPToString(&inst->remote_addr.ip_addr));
+      inst->opmode = MD_ONLINE;
+      NCR_ResetInstance(inst);
+      start_initial_timeout(inst);
      break;
    case MD_BURST_WAS_ONLINE:
      /* Will revert */
@@ -1597,10 +1716,8 @@ NCR_TakeSourceOffline(NCR_Instance inst)
 {
  switch (inst->opmode) {
    case MD_ONLINE:
-      if (inst->timer_running) {
-        LOG(LOGS_INFO, LOGF_NtpCore, "Source %s offline", UTI_IPToString(&inst->remote_addr.ip_addr));
-        take_offline(inst);
-      }
+      LOG(LOGS_INFO, LOGF_NtpCore, "Source %s offline", UTI_IPToString(&inst->remote_addr.ip_addr));
+      take_offline(inst);
      break;
    case MD_OFFLINE:
      break;
@@ -1619,8 +1736,12 @@ NCR_TakeSourceOffline(NCR_Instance inst)
 void
 NCR_ModifyMinpoll(NCR_Instance inst, int new_minpoll)
 {
+  if (new_minpoll < MIN_POLL)
+    return;
  inst->minpoll = new_minpoll;
  LOG(LOGS_INFO, LOGF_NtpCore, "Source %s new minpoll %d", UTI_IPToString(&inst->remote_addr.ip_addr), new_minpoll);
+  if (inst->maxpoll < inst->minpoll)
+    NCR_ModifyMaxpoll(inst, inst->minpoll);
 }

 /* ================================================== */
@@ -1628,8 +1749,12 @@ NCR_ModifyMinpoll(NCR_Instance inst, int new_minpoll)
 void
 NCR_ModifyMaxpoll(NCR_Instance inst, int new_maxpoll)
 {
+  if (new_maxpoll < MIN_POLL)
+    return;
  inst->maxpoll = new_maxpoll;
  LOG(LOGS_INFO, LOGF_NtpCore, "Source %s new maxpoll %d", UTI_IPToString(&inst->remote_addr.ip_addr), new_maxpoll);
+  if (inst->minpoll > inst->maxpoll)
+    NCR_ModifyMinpoll(inst, inst->maxpoll);
 }

 /* ================================================== */
@@ -1704,20 +1829,11 @@ NCR_InitiateSampleBurst(NCR_Instance inst, int n_good_samples, int n_total_sampl

      case MD_ONLINE:
      case MD_OFFLINE:
-        if (inst->opmode == MD_ONLINE)
-          inst->opmode = MD_BURST_WAS_ONLINE;
-        else
-          inst->opmode = MD_BURST_WAS_OFFLINE;
+        inst->opmode = inst->opmode == MD_ONLINE ?
+          MD_BURST_WAS_ONLINE : MD_BURST_WAS_OFFLINE;
        inst->burst_good_samples_to_go = n_good_samples;
        inst->burst_total_samples_to_go = n_total_samples;
-        if (inst->timer_running) {
-          SCH_RemoveTimeout(inst->timeout_id);
-        }
-        inst->timer_running = 1;
-        inst->timeout_id = SCH_AddTimeoutInClass(INITIAL_DELAY, SAMPLING_SEPARATION,
-                                                 SAMPLING_RANDOMNESS,
-                                                 SCH_NtpSamplingClass,
-                                                 transmit_timeout, (void *) inst);
+        start_initial_timeout(inst);
        break;
      default:
        assert(0);
--- a/ntp_core.h
+++ b/ntp_core.h
@@ -52,13 +52,19 @@ extern NCR_Instance NCR_GetInstance(NTP_Remote_Address *remote_addr, NTP_Source_
 /* Destroy an instance */
 extern void NCR_DestroyInstance(NCR_Instance instance);

+/* Start an instance */
+extern void NCR_StartInstance(NCR_Instance instance);
+
+/* Reset an instance */
+extern void NCR_ResetInstance(NCR_Instance inst);
+
 /* 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 void NCR_ProcessKnown(NTP_Packet *message, struct timeval *now, double now_err, NCR_Instance data, int length);
+extern void NCR_ProcessKnown(NTP_Packet *message, struct timeval *now, double now_err, NCR_Instance data, int sock_fd, 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, int length);
+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);

 /* Slew receive and transmit times in instance records */
 extern void NCR_SlewTimes(NCR_Instance inst, struct timeval *when, double dfreq, double doffset);
--- a/ntp_io.c
+++ b/ntp_io.c
@@ -4,7 +4,7 @@
 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
 * Copyright (C) Timo Teras  2009
- * Copyright (C) Miroslav Lichvar  2009
+ * Copyright (C) Miroslav Lichvar  2009, 2013-2014
 * 
 * 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 "conf.h"
 #include "util.h"

+#define INVALID_SOCK_FD -1
+
 union sockaddr_in46 {
  struct sockaddr_in in4;
 #ifdef HAVE_IPV6
@@ -47,87 +49,108 @@ union sockaddr_in46 {
  struct sockaddr u;
 };

-/* The file descriptors for the IPv4 and IPv6 sockets */
-static int sock_fd4;
+/* The server/peer and client sockets for IPv4 and IPv6 */
+static int server_sock_fd4;
+static int client_sock_fd4;
 #ifdef HAVE_IPV6
-static int sock_fd6;
+static int server_sock_fd6;
+static int client_sock_fd6;
 #endif

+/* Flag indicating we create a new connected client socket for each
+   server instead of sharing client_sock_fd4 and client_sock_fd6 */
+static int separate_client_sockets;
+
 /* Flag indicating that we have been initialised */
 static int initialised=0;

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

 /* Forward prototypes */
-static int prepare_socket(int family);
 static void read_from_socket(void *anything);

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

-static void
-do_size_checks(void)
-{
-  /* Assertions to check the sizes of certain data types
-     and the positions of certain record fields */
-
-  /* Check that certain invariants are true */
-  assert(sizeof(NTP_int32) == 4);
-  assert(sizeof(NTP_int64) == 8);
-
-  /* Check offsets of all fields in the NTP packet format */
-  assert(offsetof(NTP_Packet, lvm)             ==  0);
-  assert(offsetof(NTP_Packet, stratum)         ==  1);
-  assert(offsetof(NTP_Packet, poll)            ==  2);
-  assert(offsetof(NTP_Packet, precision)       ==  3);
-  assert(offsetof(NTP_Packet, root_delay)      ==  4);
-  assert(offsetof(NTP_Packet, root_dispersion) ==  8);
-  assert(offsetof(NTP_Packet, reference_id)    == 12);
-  assert(offsetof(NTP_Packet, reference_ts)    == 16);
-  assert(offsetof(NTP_Packet, originate_ts)    == 24);
-  assert(offsetof(NTP_Packet, receive_ts)      == 32);
-  assert(offsetof(NTP_Packet, transmit_ts)     == 40);
-
-}
-
-/* ================================================== */
-
 static int
-prepare_socket(int family)
+prepare_socket(int family, int port_number, int client_only)
 {
  union sockaddr_in46 my_addr;
  socklen_t my_addr_len;
  int sock_fd;
-  unsigned short port_number;
  IPAddr bind_address;
  int on_off = 1;
  
-  port_number = CNF_GetNTPPort();
-
  /* Open Internet domain UDP socket for NTP message transmissions */

-#if 0
-  sock_fd = socket(family, SOCK_DGRAM, IPPROTO_UDP);
-#else
  sock_fd = socket(family, SOCK_DGRAM, 0);
-#endif 

  if (sock_fd < 0) {
    LOG(LOGS_ERR, LOGF_NtpIO, "Could not open %s NTP socket : %s",
        family == AF_INET ? "IPv4" : "IPv6", strerror(errno));
-    return -1;
+    return INVALID_SOCK_FD;
  }

  /* Close on exec */
  UTI_FdSetCloexec(sock_fd);

-  /* Make the socket capable of re-using an old address */
-  if (setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, (char *)&on_off, sizeof(on_off)) < 0) {
+  /* Prepare local address */
+  memset(&my_addr, 0, sizeof (my_addr));
+  my_addr_len = 0;
+
+  switch (family) {
+    case AF_INET:
+      if (!client_only)
+        CNF_GetBindAddress(IPADDR_INET4, &bind_address);
+      else
+        CNF_GetBindAcquisitionAddress(IPADDR_INET4, &bind_address);
+
+      if (bind_address.family == IPADDR_INET4)
+        my_addr.in4.sin_addr.s_addr = htonl(bind_address.addr.in4);
+      else if (port_number)
+        my_addr.in4.sin_addr.s_addr = htonl(INADDR_ANY);
+      else
+        break;
+
+      my_addr.in4.sin_family = family;
+      my_addr.in4.sin_port = htons(port_number);
+      my_addr_len = sizeof (my_addr.in4);
+
+      break;
+#ifdef HAVE_IPV6
+    case AF_INET6:
+      if (!client_only)
+        CNF_GetBindAddress(IPADDR_INET6, &bind_address);
+      else
+        CNF_GetBindAcquisitionAddress(IPADDR_INET6, &bind_address);
+
+      if (bind_address.family == IPADDR_INET6)
+        memcpy(my_addr.in6.sin6_addr.s6_addr, bind_address.addr.in6,
+            sizeof (my_addr.in6.sin6_addr.s6_addr));
+      else if (port_number)
+        my_addr.in6.sin6_addr = in6addr_any;
+      else
+        break;
+
+      my_addr.in6.sin6_family = family;
+      my_addr.in6.sin6_port = htons(port_number);
+      my_addr_len = sizeof (my_addr.in6);
+
+      break;
+#endif
+    default:
+      assert(0);
+  }
+
+  /* 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");
    /* Don't quit - we might survive anyway */
  }
  
  /* Make the socket capable of sending broadcast pkts - needed for NTP broadcast mode */
-  if (setsockopt(sock_fd, SOL_SOCKET, SO_BROADCAST, (char *)&on_off, sizeof(on_off)) < 0) {
+  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");
    /* Don't quit - we might survive anyway */
  }
@@ -140,11 +163,20 @@ prepare_socket(int family)
  }
 #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");
+  }
+#endif
+
  if (family == AF_INET) {
 #ifdef IP_PKTINFO
-    /* We want the local IP info too */
-    if (setsockopt(sock_fd, IPPROTO_IP, IP_PKTINFO, (char *)&on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not request packet info using socket option");
+    /* We want the local IP info on server sockets */
+    if (!client_only &&
+        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");
      /* Don't quit - we might survive anyway */
    }
 #endif
@@ -154,110 +186,164 @@ prepare_socket(int family)
 #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 request IPV6_V6ONLY socket option");
+      LOG(LOGS_ERR, LOGF_NtpIO, "Could not set IPV6_V6ONLY socket option");
    }
 #endif

+    if (!client_only) {
 #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 request IPv6 packet info socket option");
-    }
+      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");
+      }
 #elif defined(IPV6_PKTINFO)
-    if (setsockopt(sock_fd, IPPROTO_IPV6, IPV6_PKTINFO, (char *)&on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not request IPv6 packet info socket option");
-    }
+      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");
+      }
 #endif
+    }
  }
 #endif

-  /* Bind the port */
-  memset(&my_addr, 0, sizeof (my_addr));
+  /* Bind the socket if a port or address was specified */
+  if (my_addr_len > 0 && bind(sock_fd, &my_addr.u, my_addr_len) < 0) {
+    LOG(LOGS_ERR, LOGF_NtpIO, "Could not bind %s NTP socket : %s",
+        family == AF_INET ? "IPv4" : "IPv6", strerror(errno));
+    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);
+
+  return sock_fd;
+}
+
+/* ================================================== */
+
+static int
+prepare_separate_client_socket(int family)
+{
  switch (family) {
-    case AF_INET:
-      my_addr_len = sizeof (my_addr.in4);
-      my_addr.in4.sin_family = family;
-      my_addr.in4.sin_port = htons(port_number);
+    case IPADDR_INET4:
+      return prepare_socket(AF_INET, 0, 1);
+#ifdef HAVE_IPV6
+    case IPADDR_INET6:
+      return prepare_socket(AF_INET6, 0, 1);
+#endif
+    default:
+      return INVALID_SOCK_FD;
+  }
+}

-      CNF_GetBindAddress(IPADDR_INET4, &bind_address);
+/* ================================================== */

-      if (bind_address.family == IPADDR_INET4)
-        my_addr.in4.sin_addr.s_addr = htonl(bind_address.addr.in4);
-      else
-        my_addr.in4.sin_addr.s_addr = htonl(INADDR_ANY);
+static int
+connect_socket(int sock_fd, NTP_Remote_Address *remote_addr)
+{
+  union sockaddr_in46 addr;
+  socklen_t addr_len;
+
+  memset(&addr, 0, sizeof (addr));
+
+  switch (remote_addr->ip_addr.family) {
+    case IPADDR_INET4:
+      addr_len = sizeof (addr.in4);
+      addr.in4.sin_family = AF_INET;
+      addr.in4.sin_addr.s_addr = htonl(remote_addr->ip_addr.addr.in4);
+      addr.in4.sin_port = htons(remote_addr->port);
      break;
 #ifdef HAVE_IPV6
-    case AF_INET6:
-      my_addr_len = sizeof (my_addr.in6);
-      my_addr.in6.sin6_family = family;
-      my_addr.in6.sin6_port = htons(port_number);
-
-      CNF_GetBindAddress(IPADDR_INET6, &bind_address);
-
-      if (bind_address.family == IPADDR_INET6)
-        memcpy(my_addr.in6.sin6_addr.s6_addr, bind_address.addr.in6,
-            sizeof (my_addr.in6.sin6_addr.s6_addr));
-      else
-        my_addr.in6.sin6_addr = in6addr_any;
+    case IPADDR_INET6:
+      addr_len = sizeof (addr.in6);
+      addr.in6.sin6_family = AF_INET6;
+      memcpy(addr.in6.sin6_addr.s6_addr, remote_addr->ip_addr.addr.in6,
+             sizeof (addr.in6.sin6_addr.s6_addr));
+      addr.in6.sin6_port = htons(remote_addr->port);
      break;
 #endif
    default:
      assert(0);
  }

-#if 0
-  LOG(LOGS_INFO, LOGF_NtpIO, "Initialising, socket fd=%d", sock_fd);
-#endif
-
-  if (bind(sock_fd, &my_addr.u, my_addr_len) < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not bind %s NTP socket : %s",
-        family == AF_INET ? "IPv4" : "IPv6", strerror(errno));
-    close(sock_fd);
-    return -1;
+  if (connect(sock_fd, &addr.u, addr_len) < 0) {
+    DEBUG_LOG(LOGF_NtpIO, "Could not connect NTP socket to %s:%d : %s",
+        UTI_IPToString(&remote_addr->ip_addr), remote_addr->port,
+        strerror(errno));
+    return 0;
  }

-  /* Register handler for read events on the socket */
-  SCH_AddInputFileHandler(sock_fd, read_from_socket, (void *)(long)sock_fd);
-
-#if 0
-  if (fcntl(sock_fd, F_SETFL, O_NONBLOCK | O_NDELAY) < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not make socket non-blocking");
-  }
-
-  if (ioctl(sock_fd, I_SETSIG, S_INPUT) < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not enable signal");
-  }
-#endif
-  return sock_fd;
+  return 1;
 }

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

+static void
+close_socket(int sock_fd)
+{
+  if (sock_fd == INVALID_SOCK_FD)
+    return;
+
+  SCH_RemoveInputFileHandler(sock_fd);
+  close(sock_fd);
+}
+
+/* ================================================== */
 void
 NIO_Initialise(int family)
 {
+  int server_port, client_port;
+
  assert(!initialised);
  initialised = 1;

-  do_size_checks();
+  server_port = CNF_GetNTPPort();
+  client_port = CNF_GetAcquisitionPort();

-  if (family == IPADDR_UNSPEC || family == IPADDR_INET4)
-    sock_fd4 = prepare_socket(AF_INET);
-  else
-    sock_fd4 = -1;
+  /* Use separate connected sockets if client port is negative */
+  separate_client_sockets = client_port < 0;
+  if (client_port < 0)
+    client_port = 0;
+
+  server_sock_fd4 = INVALID_SOCK_FD;
+  client_sock_fd4 = INVALID_SOCK_FD;
 #ifdef HAVE_IPV6
-  if (family == IPADDR_UNSPEC || family == IPADDR_INET6)
-    sock_fd6 = prepare_socket(AF_INET6);
-  else
-    sock_fd6 = -1;
+  server_sock_fd6 = INVALID_SOCK_FD;
+  client_sock_fd6 = INVALID_SOCK_FD;
 #endif

-  if (sock_fd4 < 0
+  if (family == IPADDR_UNSPEC || family == IPADDR_INET4) {
+    if (server_port)
+      server_sock_fd4 = prepare_socket(AF_INET, server_port, 0);
+    if (!separate_client_sockets) {
+      if (client_port != server_port || !server_port)
+        client_sock_fd4 = prepare_socket(AF_INET, client_port, 1);
+      else
+        client_sock_fd4 = server_sock_fd4;
+    }
+  }
 #ifdef HAVE_IPV6
-      && sock_fd6 < 0
+  if (family == IPADDR_UNSPEC || family == IPADDR_INET6) {
+    if (server_port)
+      server_sock_fd6 = prepare_socket(AF_INET6, server_port, 0);
+    if (!separate_client_sockets) {
+      if (client_port != server_port || !server_port)
+        client_sock_fd6 = prepare_socket(AF_INET6, client_port, 1);
+      else
+        client_sock_fd6 = server_sock_fd6;
+    }
+  }
 #endif
-      ) {
-    LOG_FATAL(LOGF_NtpIO, "Could not open any NTP socket");
+
+  if ((server_port && server_sock_fd4 == INVALID_SOCK_FD
+#ifdef HAVE_IPV6
+       && server_sock_fd6 == INVALID_SOCK_FD
+#endif
+      ) || (!separate_client_sockets && client_sock_fd4 == INVALID_SOCK_FD
+#ifdef HAVE_IPV6
+       && client_sock_fd6 == INVALID_SOCK_FD
+#endif
+      )) {
+    LOG_FATAL(LOGF_NtpIO, "Could not open NTP sockets");
  }
 }

@@ -266,23 +352,88 @@ NIO_Initialise(int family)
 void
 NIO_Finalise(void)
 {
-  if (sock_fd4 >= 0) {
-    SCH_RemoveInputFileHandler(sock_fd4);
-    close(sock_fd4);
-  }
-  sock_fd4 = -1;
+  if (server_sock_fd4 != client_sock_fd4)
+    close_socket(client_sock_fd4);
+  close_socket(server_sock_fd4);
+  server_sock_fd4 = client_sock_fd4 = INVALID_SOCK_FD;
 #ifdef HAVE_IPV6
-  if (sock_fd6 >= 0) {
-    SCH_RemoveInputFileHandler(sock_fd6);
-    close(sock_fd6);
-  }
-  sock_fd6 = -1;
+  if (server_sock_fd6 != client_sock_fd6)
+    close_socket(client_sock_fd6);
+  close_socket(server_sock_fd6);
+  server_sock_fd6 = client_sock_fd6 = INVALID_SOCK_FD;
 #endif
  initialised = 0;
 }

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

+int
+NIO_GetClientSocket(NTP_Remote_Address *remote_addr)
+{
+  if (separate_client_sockets) {
+    int sock_fd = prepare_separate_client_socket(remote_addr->ip_addr.family);
+
+    if (sock_fd == INVALID_SOCK_FD)
+      return INVALID_SOCK_FD;
+
+    if (!connect_socket(sock_fd, remote_addr)) {
+      close_socket(sock_fd);
+      return INVALID_SOCK_FD;
+    }
+
+    return sock_fd;
+  } else {
+    switch (remote_addr->ip_addr.family) {
+      case IPADDR_INET4:
+        return client_sock_fd4;
+#ifdef HAVE_IPV6
+      case IPADDR_INET6:
+        return client_sock_fd6;
+#endif
+      default:
+        return INVALID_SOCK_FD;
+    }
+  }
+}
+
+/* ================================================== */
+
+int
+NIO_GetServerSocket(NTP_Remote_Address *remote_addr)
+{
+  switch (remote_addr->ip_addr.family) {
+    case IPADDR_INET4:
+      return server_sock_fd4;
+#ifdef HAVE_IPV6
+    case IPADDR_INET6:
+      return server_sock_fd6;
+#endif
+    default:
+      return INVALID_SOCK_FD;
+  }
+}
+
+/* ================================================== */
+
+void
+NIO_CloseClientSocket(int sock_fd)
+{
+  if (separate_client_sockets)
+    close_socket(sock_fd);
+}
+
+/* ================================================== */
+
+int
+NIO_IsServerSocket(int sock_fd)
+{
+  return sock_fd != INVALID_SOCK_FD &&
+    (sock_fd == server_sock_fd4
+#ifdef HAVE_IPV6
+     || sock_fd == server_sock_fd6
+#endif
+    );
+}

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

@@ -296,9 +447,10 @@ read_from_socket(void *anything)
  ReceiveBuffer message;
  union sockaddr_in46 where_from;
  unsigned int flags = 0;
-  struct timeval now, now_raw;
+  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;
@@ -306,7 +458,7 @@ read_from_socket(void *anything)

  assert(initialised);

-  SCH_GetLastEventTime(&now, &now_err, &now_raw);
+  SCH_GetLastEventTime(&now, &now_err, NULL);

  iov.iov_base = message.arbitrary;
  iov.iov_len = sizeof(message);
@@ -329,7 +481,8 @@ read_from_socket(void *anything)
     reponse on a subsequent recvfrom). */

  if (status > 0) {
-    memset(&remote_addr, 0, sizeof (remote_addr));
+    if (msg.msg_namelen > sizeof (where_from))
+      LOG_FATAL(LOGF_NtpIO, "Truncated source address");

    switch (where_from.u.sa_family) {
      case AF_INET:
@@ -349,14 +502,17 @@ read_from_socket(void *anything)
        assert(0);
    }

+    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));
-        remote_addr.local_ip_addr.addr.in4 = ntohl(ipi.ipi_spec_dst.s_addr);
-        remote_addr.local_ip_addr.family = IPADDR_INET4;
+        local_addr.ip_addr.addr.in4 = ntohl(ipi.ipi_spec_dst.s_addr);
+        local_addr.ip_addr.family = IPADDR_INET4;
      }
 #endif

@@ -365,9 +521,9 @@ read_from_socket(void *anything)
        struct in6_pktinfo ipi;

        memcpy(&ipi, CMSG_DATA(cmsg), sizeof(ipi));
-        memcpy(&remote_addr.local_ip_addr.addr.in6, &ipi.ipi6_addr.s6_addr,
-            sizeof (remote_addr.local_ip_addr.addr.in6));
-        remote_addr.local_ip_addr.family = IPADDR_INET6;
+        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

@@ -376,16 +532,22 @@ read_from_socket(void *anything)
        struct timeval tv;

        memcpy(&tv, CMSG_DATA(cmsg), sizeof(tv));
-
-        /* This should be more accurate than LCL_CookTime(&now_raw,...) */
-        UTI_AddDiffToTimeval(&now, &now_raw, &tv, &now);
+        LCL_CookTime(&tv, &now, &now_err);
      }
 #endif
    }

+    if (status > 0) {
+      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_SIZE && status <= sizeof(NTP_Packet)) {

-      NSR_ProcessReceive((NTP_Packet *) &message.ntp_pkt, &now, now_err, &remote_addr, status);
+      NSR_ProcessReceive((NTP_Packet *) &message.ntp_pkt, &now, now_err,
+                         &remote_addr, &local_addr, status);

    } else {

@@ -398,50 +560,62 @@ read_from_socket(void *anything)
 /* ================================================== */
 /* Send a packet to given address */

-static void
-send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr)
+static int
+send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr)
 {
  union sockaddr_in46 remote;
  struct msghdr msg;
  struct iovec iov;
  char cmsgbuf[256];
  int cmsglen;
-  int sock_fd;
-  socklen_t addrlen;
+  socklen_t addrlen = 0;

  assert(initialised);

+  if (local_addr->sock_fd == INVALID_SOCK_FD) {
+    DEBUG_LOG(LOGF_NtpIO, "No socket to send to %s:%d",
+              UTI_IPToString(&remote_addr->ip_addr), remote_addr->port);
+    return 0;
+  }
+
  switch (remote_addr->ip_addr.family) {
    case IPADDR_INET4:
+      /* Don't set address with connected socket */
+      if (local_addr->sock_fd != server_sock_fd4 && separate_client_sockets)
+        break;
      memset(&remote.in4, 0, sizeof (remote.in4));
      addrlen = sizeof (remote.in4);
      remote.in4.sin_family = AF_INET;
      remote.in4.sin_port = htons(remote_addr->port);
      remote.in4.sin_addr.s_addr = htonl(remote_addr->ip_addr.addr.in4);
-      sock_fd = sock_fd4;
      break;
 #ifdef HAVE_IPV6
    case IPADDR_INET6:
+      /* Don't set address with connected socket */
+      if (local_addr->sock_fd != server_sock_fd6 && separate_client_sockets)
+        break;
      memset(&remote.in6, 0, sizeof (remote.in6));
      addrlen = sizeof (remote.in6);
      remote.in6.sin6_family = AF_INET6;
      remote.in6.sin6_port = htons(remote_addr->port);
      memcpy(&remote.in6.sin6_addr.s6_addr, &remote_addr->ip_addr.addr.in6,
          sizeof (remote.in6.sin6_addr.s6_addr));
-      sock_fd = sock_fd6;
      break;
 #endif
    default:
-      return;
+      return 0;
  }

-  if (sock_fd < 0)
-    return;
+  if (addrlen) {
+    msg.msg_name = &remote.u;
+    msg.msg_namelen = addrlen;
+  } else {
+    msg.msg_name = NULL;
+    msg.msg_namelen = 0;
+  }

  iov.iov_base = packet;
  iov.iov_len = packetlen;
-  msg.msg_name = &remote.u;
-  msg.msg_namelen = addrlen;
  msg.msg_iov = &iov;
  msg.msg_iovlen = 1;
  msg.msg_control = cmsgbuf;
@@ -450,7 +624,7 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr)
  cmsglen = 0;

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

@@ -463,12 +637,12 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr)
    cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));

    ipi = (struct in_pktinfo *) CMSG_DATA(cmsg);
-    ipi->ipi_spec_dst.s_addr = htonl(remote_addr->local_ip_addr.addr.in4);
+    ipi->ipi_spec_dst.s_addr = htonl(local_addr->ip_addr.addr.in4);
  }
 #endif

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

@@ -481,65 +655,45 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr)
    cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));

    ipi = (struct in6_pktinfo *) CMSG_DATA(cmsg);
-    memcpy(&ipi->ipi6_addr.s6_addr, &remote_addr->local_ip_addr.addr.in6,
+    memcpy(&ipi->ipi6_addr.s6_addr, &local_addr->ip_addr.addr.in6,
        sizeof(ipi->ipi6_addr.s6_addr));
  }
 #endif

-#if 0
-    LOG(LOGS_INFO, LOGF_NtpIO, "sending to %s:%d from %s",
-        UTI_IPToString(&remote_addr->ip_addr), remote_addr->port, UTI_IPToString(&remote_addr->local_ip_addr));
-#endif
-
  msg.msg_controllen = cmsglen;
  /* This is apparently required on some systems */
  if (!cmsglen)
    msg.msg_control = NULL;

-  if (sendmsg(sock_fd, &msg, 0) < 0 &&
-#ifdef ENETUNREACH
-      errno != ENETUNREACH &&
-#endif
-#ifdef ENETDOWN
-      errno != ENETDOWN &&
-#endif
-      !LOG_RateLimited()) {
-    LOG(LOGS_WARN, LOGF_NtpIO, "Could not send to %s:%d : %s",
-        UTI_IPToString(&remote_addr->ip_addr), remote_addr->port, strerror(errno));
+  if (sendmsg(local_addr->sock_fd, &msg, 0) < 0) {
+    DEBUG_LOG(LOGF_NtpIO, "Could not send to %s:%d from %s fd %d : %s",
+        UTI_IPToString(&remote_addr->ip_addr), remote_addr->port,
+        UTI_IPToString(&local_addr->ip_addr), local_addr->sock_fd,
+        strerror(errno));
+    return 0;
  }
+
+  DEBUG_LOG(LOGF_NtpIO, "Sent to %s:%d from %s fd %d",
+      UTI_IPToString(&remote_addr->ip_addr), remote_addr->port,
+      UTI_IPToString(&local_addr->ip_addr), local_addr->sock_fd);
+
+  return 1;
 }

 /* ================================================== */
 /* Send an unauthenticated packet to a given address */

-void
-NIO_SendNormalPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr)
+int
+NIO_SendNormalPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr)
 {
-  send_packet((void *) packet, NTP_NORMAL_PACKET_SIZE, remote_addr);
+  return send_packet((void *) packet, NTP_NORMAL_PACKET_SIZE, remote_addr, local_addr);
 }

 /* ================================================== */
 /* Send an authenticated packet to a given address */

-void
-NIO_SendAuthenticatedPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr, int auth_len)
+int
+NIO_SendAuthenticatedPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int auth_len)
 {
-  send_packet((void *) packet, NTP_NORMAL_PACKET_SIZE + auth_len, remote_addr);
-}
-
-/* ================================================== */
-
-/* We ought to use getservbyname, but I can't really see this changing */
-#define ECHO_PORT 7
-
-void
-NIO_SendEcho(NTP_Remote_Address *remote_addr)
-{
-  unsigned long magic_message = 0xbe7ab1e7UL;
-  NTP_Remote_Address addr;
-
-  addr = *remote_addr;
-  addr.port = ECHO_PORT;
-
-  send_packet((void *) &magic_message, sizeof(unsigned long), &addr);
+  return send_packet((void *) packet, NTP_NORMAL_PACKET_SIZE + auth_len, remote_addr, local_addr);
 }
--- a/ntp_io.h
+++ b/ntp_io.h
@@ -3,6 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2002
+ * Copyright (C) Miroslav Lichvar  2014
 * 
 * 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
@@ -37,13 +38,22 @@ extern void NIO_Initialise(int family);
 /* Function to finalise the module */
 extern void NIO_Finalise(void);

+/* Function to obtain a socket for sending client packets */
+extern int NIO_GetClientSocket(NTP_Remote_Address *remote_addr);
+
+/* Function to obtain a socket for sending server/peer packets */
+extern int NIO_GetServerSocket(NTP_Remote_Address *remote_addr);
+
+/* Function to close a socket returned by NIO_GetClientSocket() */
+extern void NIO_CloseClientSocket(int sock_fd);
+
+/* Function to check if socket is a server socket */
+extern int NIO_IsServerSocket(int sock_fd);
+
 /* Function to transmit a packet */
-extern void NIO_SendNormalPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr);
+extern int NIO_SendNormalPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr);

 /* Function to transmit an authenticated packet */
-extern void NIO_SendAuthenticatedPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr, int auth_len);
-
-/* Function to send a datagram to a remote machine's UDP echo port. */
-extern void NIO_SendEcho(NTP_Remote_Address *remote_addr);
+extern int NIO_SendAuthenticatedPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int auth_len);

 #endif /* GOT_NTP_IO_H */
--- 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
+ * Copyright (C) Miroslav Lichvar  2011-2012, 2014
 * 
 * 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
@@ -37,7 +37,7 @@
 #include "logging.h"
 #include "local.h"
 #include "memory.h"
-#include "nameserv.h"
+#include "nameserv_async.h"
 #include "sched.h"

 /* ================================================== */
@@ -62,6 +62,9 @@ static int n_sources;
 /* The largest number of sources we want to have stored in the hash table */
 #define MAX_SOURCES 64

+/* Flag indicating new sources will be started automatically when added */
+static int auto_start_sources = 0;
+
 /* Source with unknown address (which may be resolved later) */
 struct UnresolvedSource {
  char *name;
@@ -71,18 +74,27 @@ struct UnresolvedSource {
  struct UnresolvedSource *next;
 };

+#define RESOLVE_INTERVAL_UNIT 7
+#define MIN_RESOLVE_INTERVAL 2
+#define MAX_RESOLVE_INTERVAL 9
+
 static struct UnresolvedSource *unresolved_sources = NULL;
 static int resolving_interval = 0;
 static SCH_TimeoutID resolving_id;
+static struct UnresolvedSource *resolving_source = NULL;
+static NSR_SourceResolvingEndHandler resolving_end_handler = NULL;

 /* ================================================== */
 /* Forward prototypes */
+
+static void resolve_sources(void *arg);
+
 static void
 slew_sources(struct timeval *raw,
             struct timeval *cooked,
             double dfreq,
             double doffset,
-             int is_step_change,
+             LCL_ChangeType change_type,
             void *anything);

 /* ================================================== */
@@ -188,10 +200,6 @@ NSR_AddSource(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourceParam

  assert(initialised);

-#if 0
-  LOG(LOGS_INFO, LOGF_NtpSources, "IP=%s port=%d", UTI_IPToString(&remote_addr->ip_addr), remote_addr->port);
-#endif
-
  /* Find empty bin & check that we don't have the address already */
  find_slot(remote_addr, &slot, &found);
  if (found) {
@@ -206,6 +214,8 @@ NSR_AddSource(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourceParam
      n_sources++;
      records[slot].data = NCR_GetInstance(remote_addr, type, params); /* Will need params passing through */
      records[slot].remote_addr = NCR_GetRemoteAddress(records[slot].data);
+      if (auto_start_sources)
+        NCR_StartInstance(records[slot].data);
      return NSR_Success;
    }
  }
@@ -213,44 +223,90 @@ NSR_AddSource(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourceParam

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

+static void
+name_resolve_handler(DNS_Status status, IPAddr *ip_addr, void *anything)
+{
+  struct UnresolvedSource *us, **i, *next;
+  NTP_Remote_Address address;
+
+  us = (struct UnresolvedSource *)anything;
+
+  assert(us == resolving_source);
+
+  switch (status) {
+    case DNS_TryAgain:
+      break;
+    case DNS_Success:
+      DEBUG_LOG(LOGF_NtpSources, "%s resolved to %s", us->name, UTI_IPToString(ip_addr));
+      address.ip_addr = *ip_addr;
+      address.port = us->port;
+      NSR_AddSource(&address, us->type, &us->params);
+      break;
+    case DNS_Failure:
+      LOG(LOGS_WARN, LOGF_NtpSources, "Invalid host %s", us->name);
+      break;
+    default:
+      assert(0);
+  }
+
+  next = us->next;
+
+  if (status != DNS_TryAgain) {
+    /* Remove the source from the list */
+    for (i = &unresolved_sources; *i; i = &(*i)->next) {
+      if (*i == us) {
+        *i = us->next;
+        Free(us->name);
+        Free(us);
+        break;
+      }
+    }
+  }
+
+  resolving_source = next;
+
+  if (next) {
+    /* Continue with the next source in the list */
+    DEBUG_LOG(LOGF_NtpSources, "resolving %s", next->name);
+    DNS_Name2IPAddressAsync(next->name, name_resolve_handler, next);
+  } else {
+    /* This was the last source in the list. If some sources couldn't
+       be resolved, try again in exponentially increasing interval. */
+    if (unresolved_sources) {
+      if (resolving_interval < MIN_RESOLVE_INTERVAL)
+        resolving_interval = MIN_RESOLVE_INTERVAL;
+      else if (resolving_interval < MAX_RESOLVE_INTERVAL)
+        resolving_interval++;
+      resolving_id = SCH_AddTimeoutByDelay(RESOLVE_INTERVAL_UNIT *
+          (1 << resolving_interval), resolve_sources, NULL);
+    } else {
+      resolving_interval = 0;
+    }
+
+    /* This round of resolving is done */
+    if (resolving_end_handler)
+      (resolving_end_handler)();
+  }
+}
+
+/* ================================================== */
+
 static void
 resolve_sources(void *arg)
 {
-  NTP_Remote_Address address;
-  struct UnresolvedSource *us, **i;
-  DNS_Status s;
+  struct UnresolvedSource *us;

-  memset(&address.local_ip_addr, 0, sizeof (address.local_ip_addr));
+  assert(!resolving_source);

  DNS_Reload();

-  for (i = &unresolved_sources; *i; ) {
-    us = *i;
-    s = DNS_Name2IPAddress(us->name, &address.ip_addr);
-    if (s == DNS_TryAgain) {
-      i = &(*i)->next;
-      continue;
-    } else if (s == DNS_Success) {
-      address.port = us->port;
-      NSR_AddSource(&address, us->type, &us->params);
-    } else {
-      LOG(LOGS_WARN, LOGF_NtpSources, "Invalid host %s", us->name);
-    }
-    
-    *i = us->next;
+  /* Start with the first source in the list, name_resolve_handler
+     will iterate over the rest */
+  us = unresolved_sources;

-    Free(us->name);
-    Free(us);
-  }
-
-  if (unresolved_sources) {
-    /* Try again later */
-    if (resolving_interval < 9)
-      resolving_interval++;
-    resolving_id = SCH_AddTimeoutByDelay(7 * (1 << resolving_interval), resolve_sources, NULL);
-  } else {
-    resolving_interval = 0;
-  }
+  resolving_source = us;
+  DEBUG_LOG(LOGF_NtpSources, "resolving %s", us->name);
+  DNS_Name2IPAddressAsync(us->name, name_resolve_handler, us);
 }

 /* ================================================== */
@@ -273,11 +329,14 @@ NSR_AddUnresolvedSource(char *name, int port, NTP_Source_Type type, SourceParame
  for (i = &unresolved_sources; *i; i = &(*i)->next)
    ;
  *i = us;
+}

-  if (!resolving_interval) {
-    resolving_interval = 2;
-    resolving_id = SCH_AddTimeoutByDelay(7 * (1 << resolving_interval), resolve_sources, NULL);
-  }
+/* ================================================== */
+
+void
+NSR_SetSourceResolvingEndHandler(NSR_SourceResolvingEndHandler handler)
+{
+  resolving_end_handler = handler;
 }

 /* ================================================== */
@@ -286,15 +345,44 @@ void
 NSR_ResolveSources(void)
 {
  /* Try to resolve unresolved sources now */
-  if (resolving_interval) {
-    SCH_RemoveTimeout(resolving_id);
-    resolving_interval--;
-    resolve_sources(NULL);
+  if (unresolved_sources) {
+    /* Make sure no resolving is currently running */
+    if (!resolving_source) {
+      if (resolving_interval) {
+        SCH_RemoveTimeout(resolving_id);
+        resolving_interval--;
+      }
+      resolve_sources(NULL);
+    }
+  } else {
+    /* No unresolved sources, we are done */
+    if (resolving_end_handler)
+      (resolving_end_handler)();
  }
 }

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

+void NSR_StartSources(void)
+{
+  int i;
+
+  for (i = 0; i < N_RECORDS; i++) {
+    if (!records[i].remote_addr)
+      continue;
+    NCR_StartInstance(records[i].data);
+  }
+}
+
+/* ================================================== */
+
+void NSR_AutoStartSources(void)
+{
+  auto_start_sources = 1;
+}
+
+/* ================================================== */
+
 /* Procedure to remove a source.  We don't bother whether the port
   address is matched - we're only interested in removing a record for
   the right IP address.  Thus the caller can specify the port number
@@ -341,26 +429,36 @@ NSR_RemoveSource(NTP_Remote_Address *remote_addr)

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

+void
+NSR_RemoveAllSources(void)
+{
+  int i;
+
+  for (i = 0; i < N_RECORDS; i++) {
+    if (!records[i].remote_addr)
+      continue;
+    NCR_DestroyInstance(records[i].data);
+    records[i].remote_addr = NULL;
+  }
+}
+
+/* ================================================== */
+
 /* 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, int length)
+NSR_ProcessReceive(NTP_Packet *message, struct timeval *now, double now_err, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
 {
  int slot, found;

  assert(initialised);

-#if 0
-  LOG(LOGS_INFO, LOGF_NtpSources, "from (%s,%d) at %s",
-      UTI_IPToString(&remote_addr->ip_addr),
-      remote_addr->port, UTI_TimevalToString(now));
-#endif
-  
  find_slot(remote_addr, &slot, &found);
  if (found == 2) { /* Must match IP address AND port number */
-    NCR_ProcessKnown(message, now, now_err, records[slot].data, length);
+    NCR_ProcessKnown(message, now, now_err, records[slot].data,
+                     local_addr->sock_fd, length);
  } else {
-    NCR_ProcessUnknown(message, now, now_err, remote_addr, length);
+    NCR_ProcessUnknown(message, now, now_err, remote_addr, local_addr, length);
  }
 }

@@ -371,22 +469,20 @@ slew_sources(struct timeval *raw,
             struct timeval *cooked,
             double dfreq,
             double doffset,
-             int is_step_change,
+             LCL_ChangeType change_type,
             void *anything)
 {
  int i;

  for (i=0; i<N_RECORDS; i++) {
    if (records[i].remote_addr) {
-#if 0
-      LOG(LOGS_INFO, LOGF_Sources, "IP=%s dfreq=%f doff=%f",
-          UTI_IPToString(&records[i].remote_addr->ip_addr), dfreq, doffset);
-#endif
-
-      NCR_SlewTimes(records[i].data, cooked, dfreq, doffset);
+      if (change_type == LCL_ChangeUnknownStep) {
+        NCR_ResetInstance(records[i].data);
+      } else {
+        NCR_SlewTimes(records[i].data, cooked, dfreq, doffset);
+      }
    }
  }
-
 }

 /* ================================================== */
--- a/ntp_sources.h
+++ b/ntp_sources.h
@@ -3,6 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2002
+ * Copyright (C) Miroslav Lichvar  2014
 * 
 * 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
@@ -54,14 +55,30 @@ extern NSR_Status NSR_AddSource(NTP_Remote_Address *remote_addr, NTP_Source_Type
   until it succeeds or fails with a non-temporary error. */
 extern void NSR_AddUnresolvedSource(char *name, int port, NTP_Source_Type type, SourceParameters *params);

-/* Procedure to try resolve unresolved sources immediately. */
+/* Function type for handlers to be called back when an attempt
+ * (possibly unsuccessful) to resolve unresolved sources ends */
+typedef void (*NSR_SourceResolvingEndHandler)(void);
+
+/* Set the handler, or NULL to disable the notification */
+extern void NSR_SetSourceResolvingEndHandler(NSR_SourceResolvingEndHandler handler);
+
+/* Procedure to start resolving unresolved sources */
 extern void NSR_ResolveSources(void);

+/* Procedure to start all sources */
+extern void NSR_StartSources(void);
+
+/* Start new sources automatically */
+extern void NSR_AutoStartSources(void);
+
 /* Procedure to remove a source */
 extern NSR_Status NSR_RemoveSource(NTP_Remote_Address *remote_addr);

+/* Procedure to remove all sources */
+extern void NSR_RemoveAllSources(void);
+
 /* 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, int length);
+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);

 /* Initialisation function */
 extern void NSR_Initialise(void);
--- a/refclock.c
+++ b/refclock.c
@@ -2,7 +2,7 @@
  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************
- * Copyright (C) Miroslav Lichvar  2009-2011
+ * Copyright (C) Miroslav Lichvar  2009-2011, 2013-2014
 * 
 * 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
@@ -42,6 +42,7 @@
 extern RefclockDriver RCL_SHM_driver;
 extern RefclockDriver RCL_SOCK_driver;
 extern RefclockDriver RCL_PPS_driver;
+extern RefclockDriver RCL_PHC_driver;

 struct FilterSample {
  double offset;
@@ -56,6 +57,7 @@ struct MedianFilter {
  int last;
  int avg_var_n;
  double avg_var;
+  double max_var;
  struct FilterSample *samples;
  int *selected;
  double *x_data;
@@ -73,6 +75,7 @@ struct RCL_Instance_Record {
  int poll;
  int leap_status;
  int pps_rate;
+  int pps_active;
  struct MedianFilter filter;
  uint32_t ref_id;
  uint32_t lock_ref;
@@ -94,11 +97,11 @@ static int valid_sample_time(RCL_Instance instance, struct timeval *tv);
 static int pps_stratum(RCL_Instance instance, struct timeval *tv);
 static void poll_timeout(void *arg);
 static void slew_samples(struct timeval *raw, struct timeval *cooked, double dfreq,
-             double doffset, int is_step_change, void *anything);
+             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 filter_init(struct MedianFilter *filter, int length);
+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);
@@ -166,6 +169,9 @@ RCL_AddRefclock(RefclockParameters *params)
    inst->driver = &RCL_PPS_driver;
    inst->precision = 1e-9;
    pps_source = 1;
+  } else if (strcmp(params->driver_name, "PHC") == 0) {
+    inst->driver = &RCL_PHC_driver;
+    inst->precision = 1e-9;
  } else {
    LOG_FATAL(LOGF_Refclock, "unknown refclock driver %s", params->driver_name);
    return 0;
@@ -184,6 +190,7 @@ RCL_AddRefclock(RefclockParameters *params)
  inst->driver_polled = 0;
  inst->leap_status = LEAP_Normal;
  inst->pps_rate = params->pps_rate;
+  inst->pps_active = 0;
  inst->lock_ref = params->lock_ref_id;
  inst->offset = params->offset;
  inst->delay = params->delay;
@@ -239,14 +246,12 @@ RCL_AddRefclock(RefclockParameters *params)
      return 0;
    }

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

  inst->source = SRC_CreateNewInstance(inst->ref_id, SRC_REFCLOCK, params->sel_option, NULL);

-#if 0
-  LOG(LOGS_INFO, LOGF_Refclock, "refclock added poll=%d dpoll=%d filter=%d",
-		  inst->poll, inst->driver_poll, params->filter_length);
-#endif
+  DEBUG_LOG(LOGF_Refclock, "refclock %s added poll=%d dpoll=%d filter=%d",
+      params->driver_name, inst->poll, inst->driver_poll, params->filter_length);
  n_sources++;

  Free(params->driver_name);
@@ -263,6 +268,7 @@ RCL_StartRefclocks(void)
    RCL_Instance inst = &refclocks[i];

    SRC_SetSelectable(inst->source);
+    SRC_SetActive(inst->source);
    inst->timeout_id = SCH_AddTimeoutByDelay(0.0, poll_timeout, (void *)inst);

    if (inst->lock_ref) {
@@ -345,7 +351,7 @@ RCL_AddSample(RCL_Instance instance, struct timeval *sample_time, double offset,

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

  if (!valid_sample_time(instance, sample_time))
    return 0;
@@ -363,6 +369,8 @@ RCL_AddSample(RCL_Instance instance, struct timeval *sample_time, double offset,
      break;
  }

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

  /* for logging purposes */
@@ -378,10 +386,12 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
  double correction, dispersion, offset;
  struct timeval cooked_time;
  int rate;
+  NTP_Leap leap;

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

  if (!valid_sample_time(instance, pulse_time))
    return 0;
@@ -403,12 +413,19 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
    double sample_diff, ref_offset, ref_dispersion, shift;

    if (!filter_get_last_sample(&refclocks[instance->lock_ref].filter,
-          &ref_sample_time, &ref_offset, &ref_dispersion))
+          &ref_sample_time, &ref_offset, &ref_dispersion)) {
+      DEBUG_LOG(LOGF_Refclock, "refclock pulse ignored no ref sample");
      return 0;
+    }
+
+    ref_dispersion += filter_get_avg_sample_dispersion(&refclocks[instance->lock_ref].filter);

    UTI_DiffTimevalsToDouble(&sample_diff, &cooked_time, &ref_sample_time);
-    if (fabs(sample_diff) >= 2.0 / rate)
+    if (fabs(sample_diff) >= 2.0 / rate) {
+      DEBUG_LOG(LOGF_Refclock, "refclock pulse ignored samplediff=%.9f",
+          sample_diff);
      return 0;
+    }

    /* Align the offset to the reference sample */
    if ((ref_offset - offset) >= 0.0)
@@ -418,18 +435,20 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)

    offset += shift;

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

-#if 0
-    LOG(LOGS_INFO, LOGF_Refclock, "refclock pulse second=%.9f offset=%.9f offdiff=%.9f samplediff=%.9f",
+    leap = refclocks[instance->lock_ref].leap_status;
+
+    DEBUG_LOG(LOGF_Refclock, "refclock pulse second=%.9f offset=%.9f offdiff=%.9f samplediff=%.9f",
        second, offset, ref_offset - offset, sample_diff);
-#endif
  } else {
    struct timeval ref_time;
    int is_synchronised, stratum;
    double root_delay, root_dispersion, distance;
-    NTP_Leap leap;
    uint32_t ref_id;

    /* Ignore the pulse if we are not well synchronized */
@@ -439,10 +458,8 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
    distance = fabs(root_delay) / 2 + root_dispersion;

    if (!is_synchronised || distance >= 0.5 / rate) {
-#if 0
-      LOG(LOGS_INFO, LOGF_Refclock, "refclock pulse dropped second=%.9f sync=%d dist=%.9f",
+      DEBUG_LOG(LOGF_Refclock, "refclock pulse ignored second=%.9f sync=%d dist=%.9f",
          second, is_synchronised, distance);
-#endif
      /* Drop also all stored samples */
      filter_reset(&instance->filter);
      return 0;
@@ -450,7 +467,8 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
  }

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

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

@@ -461,6 +479,15 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
  return 1;
 }

+static double
+poll_interval(int poll)
+{
+  if (poll >= 0)
+    return 1 << poll;
+  else
+    return 1.0 / (1 << -poll);
+}
+
 static int
 valid_sample_time(RCL_Instance instance, struct timeval *tv)
 {
@@ -469,8 +496,11 @@ valid_sample_time(RCL_Instance instance, struct timeval *tv)

  LCL_ReadRawTime(&raw_time);
  UTI_DiffTimevalsToDouble(&diff, &raw_time, tv);
-  if (diff < 0.0 || diff > 1 << (instance->poll + 1))
+  if (diff < 0.0 || diff > poll_interval(instance->poll + 1)) {
+    DEBUG_LOG(LOGF_Refclock, "refclock sample not valid age=%.6f tv=%s",
+        diff, UTI_TimevalToString(tv));
    return 0;
+  }
  return 1;
 }

@@ -494,7 +524,7 @@ pps_stratum(RCL_Instance instance, struct timeval *tv)
  /* Or the current source is another PPS refclock */ 
  for (i = 0; i < n_sources; i++) {
    if (refclocks[i].ref_id == ref_id &&
-        refclocks[i].pps_rate && refclocks[i].lock_ref == -1)
+        refclocks[i].pps_active && refclocks[i].lock_ref == -1)
      return stratum - 1;
  }

@@ -504,7 +534,6 @@ pps_stratum(RCL_Instance instance, struct timeval *tv)
 static void
 poll_timeout(void *arg)
 {
-  double next;
  int poll;

  RCL_Instance inst = (RCL_Instance)arg;
@@ -526,7 +555,7 @@ poll_timeout(void *arg)
    inst->driver_polled = 0;

    if (sample_ok) {
-      if (inst->pps_rate && inst->lock_ref == -1)
+      if (inst->pps_active && inst->lock_ref == -1)
        /* Handle special case when PPS is used with local stratum */
        stratum = pps_stratum(inst, &sample_time);
      else
@@ -535,6 +564,7 @@ poll_timeout(void *arg)
      SRC_UpdateReachability(inst->source, 1);
      SRC_AccumulateSample(inst->source, &sample_time, offset,
          inst->delay, dispersion, inst->delay, dispersion, stratum, inst->leap_status);
+      SRC_SelectSource(inst->source);

      log_sample(inst, &sample_time, 1, 0, 0.0, offset, dispersion);
    } else {
@@ -542,22 +572,21 @@ poll_timeout(void *arg)
    }
  }

-  if (poll >= 0)
-    next = 1 << poll;
-  else
-    next = 1.0 / (1 << -poll);
-
-  inst->timeout_id = SCH_AddTimeoutByDelay(next, poll_timeout, arg);
+  inst->timeout_id = SCH_AddTimeoutByDelay(poll_interval(poll), poll_timeout, arg);
 }

 static void
 slew_samples(struct timeval *raw, struct timeval *cooked, double dfreq,
-             double doffset, int is_step_change, void *anything)
+             double doffset, LCL_ChangeType change_type, void *anything)
 {
  int i;

-  for (i = 0; i < n_sources; i++)
-    filter_slew_samples(&refclocks[i].filter, cooked, dfreq, doffset);
+  for (i = 0; i < n_sources; i++) {
+    if (change_type == LCL_ChangeUnknownStep)
+      filter_reset(&refclocks[i].filter);
+    else
+      filter_slew_samples(&refclocks[i].filter, cooked, dfreq, doffset);
+  }
 }

 static void
@@ -600,7 +629,7 @@ log_sample(RCL_Instance instance, struct timeval *sample_time, int filtered, int
 }

 static void
-filter_init(struct MedianFilter *filter, int length)
+filter_init(struct MedianFilter *filter, int length, double max_dispersion)
 {
  if (length < 1)
    length = 1;
@@ -612,6 +641,7 @@ filter_init(struct MedianFilter *filter, int length)
  /* set first estimate to system precision */
  filter->avg_var_n = 0;
  filter->avg_var = LCL_GetSysPrecisionAsQuantum() * LCL_GetSysPrecisionAsQuantum();
+  filter->max_var = max_dispersion * max_dispersion;
  filter->samples = MallocArray(struct FilterSample, filter->length);
  filter->selected = MallocArray(int, filter->length);
  filter->x_data = MallocArray(double, filter->length);
@@ -654,6 +684,9 @@ filter_add_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
  filter->samples[filter->index].sample_time = *sample_time;
  filter->samples[filter->index].offset = offset;
  filter->samples[filter->index].dispersion = dispersion;
+
+  DEBUG_LOG(LOGF_Refclock, "filter sample %d t=%s offset=%.9f dispersion=%.9f",
+      filter->index, UTI_TimevalToString(sample_time), offset, dispersion);
 }

 static int
@@ -802,8 +835,6 @@ filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
  y /= n;
  e /= n;

-  e -= sqrt(filter->avg_var);
-
  if (n >= 4) {
    double b0, b1, s2, sb0, sb1;

@@ -836,6 +867,13 @@ filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
    d = sqrt(var);
  }

+  /* drop the sample if variance is larger than allowed maximum */
+  if (filter->max_var > 0.0 && var > filter->max_var) {
+    DEBUG_LOG(LOGF_Refclock, "filter dispersion too large disp=%.9f max=%.9f",
+        sqrt(var), sqrt(filter->max_var));
+    return 0;
+  }
+
  prev_avg_var = filter->avg_var;

  /* update exponential moving average of the variance */
@@ -870,20 +908,13 @@ static void
 filter_slew_samples(struct MedianFilter *filter, struct timeval *when, double dfreq, double doffset)
 {
  int i;
-  double delta_time, prev_offset;
+  double delta_time;
  struct timeval *sample;

  for (i = 0; i < filter->used; i++) {
    sample = &filter->samples[i].sample_time;
    UTI_AdjustTimeval(sample, when, sample, &delta_time, dfreq, doffset);
-    prev_offset = filter->samples[i].offset;
    filter->samples[i].offset -= delta_time;
-#if 0
-    LOG(LOGS_INFO, LOGF_Refclock, "i=%d old_off=%.9f new_off=%.9f",
-        i, prev_offset, filter->samples[i].offset);
-#else
-    (void)prev_offset;
-#endif
  }
 }

--- a/refclock.h
+++ b/refclock.h
@@ -43,6 +43,7 @@ typedef struct {
  double offset;
  double delay;
  double precision;
+  double max_dispersion;
  SRC_SelectOption sel_option;
 } RefclockParameters;

@@ -58,7 +59,6 @@ extern void RCL_Initialise(void);
 extern void RCL_Finalise(void);
 extern int RCL_AddRefclock(RefclockParameters *params);
 extern void RCL_StartRefclocks(void);
-extern void RCL_StartRefclocks(void);
 extern void RCL_ReportSource(RPT_SourceReport *report, struct timeval *now);

 /* functions used by drivers */
--- a/refclock_phc.c
+++ b/refclock_phc.c
@@ -0,0 +1,193 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2013
+ * 
+ * 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.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  PTP hardware clock (PHC) refclock driver.
+
+  */
+
+#include "config.h"
+
+#include "refclock.h"
+
+#ifdef FEAT_PHC
+
+#include "sysincl.h"
+
+#include <linux/ptp_clock.h>
+
+#include "refclock.h"
+#include "logging.h"
+#include "util.h"
+
+/* From linux/include/linux/posix-timers.h */
+#define CPUCLOCK_MAX            3
+#define CLOCKFD                 CPUCLOCK_MAX
+#define CLOCKFD_MASK            (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)
+
+#define FD_TO_CLOCKID(fd)       ((~(clockid_t) (fd) << 3) | CLOCKFD)
+
+#define NUM_READINGS 10
+
+static int no_sys_offset_ioctl = 0;
+
+struct phc_reading {
+  struct timespec sys_ts1;
+  struct timespec phc_ts;;
+  struct timespec sys_ts2;
+};
+
+static double diff_ts(struct timespec *ts1, struct timespec *ts2)
+{
+  return (ts1->tv_sec - ts2->tv_sec) + (ts1->tv_nsec - ts2->tv_nsec) / 1e9;
+}
+
+static int read_phc_ioctl(struct phc_reading *readings, int phc_fd, int n)
+{
+#if defined(PTP_SYS_OFFSET) && NUM_READINGS <= PTP_MAX_SAMPLES
+  struct ptp_sys_offset sys_off;
+  int i;
+
+  /* Silence valgrind */
+  memset(&sys_off, 0, sizeof (sys_off));
+
+  sys_off.n_samples = n;
+  if (ioctl(phc_fd, PTP_SYS_OFFSET, &sys_off)) {
+    LOG(LOGS_ERR, LOGF_Refclock, "ioctl(PTP_SYS_OFFSET) failed : %s", strerror(errno));
+    return 0;
+  }
+
+  for (i = 0; i < n; i++) {
+    readings[i].sys_ts1.tv_sec = sys_off.ts[i * 2].sec;
+    readings[i].sys_ts1.tv_nsec = sys_off.ts[i * 2].nsec;
+    readings[i].phc_ts.tv_sec = sys_off.ts[i * 2 + 1].sec;
+    readings[i].phc_ts.tv_nsec = sys_off.ts[i * 2 + 1].nsec;
+    readings[i].sys_ts2.tv_sec = sys_off.ts[i * 2 + 2].sec;
+    readings[i].sys_ts2.tv_nsec = sys_off.ts[i * 2 + 2].nsec;
+  }
+
+  return 1;
+#else
+  /* Not available */
+  return 0;
+#endif
+}
+
+static int read_phc_user(struct phc_reading *readings, int phc_fd, int n)
+{
+  clockid_t phc_id;
+  int i;
+
+  phc_id = FD_TO_CLOCKID(phc_fd);
+
+  for (i = 0; i < n; i++) {
+    if (clock_gettime(CLOCK_REALTIME, &readings[i].sys_ts1) ||
+        clock_gettime(phc_id, &readings[i].phc_ts) ||
+        clock_gettime(CLOCK_REALTIME, &readings[i].sys_ts2)) {
+      LOG(LOGS_ERR, LOGF_Refclock, "clock_gettime() failed : %s", strerror(errno));
+      return 0;
+    }
+  }
+
+  return 1;
+}
+
+static int phc_initialise(RCL_Instance instance)
+{
+  struct ptp_clock_caps caps;
+  int phc_fd;
+  char *path;
+
+  path = RCL_GetDriverParameter(instance);
+ 
+  phc_fd = open(path, O_RDONLY);
+  if (phc_fd < 0) {
+    LOG_FATAL(LOGF_Refclock, "open() failed on %s", path);
+    return 0;
+  }
+
+  /* Make sure it is a PHC */
+  if (ioctl(phc_fd, PTP_CLOCK_GETCAPS, &caps)) {
+    LOG_FATAL(LOGF_Refclock, "ioctl(PTP_CLOCK_GETCAPS) failed : %s", strerror(errno));
+    return 0;
+  }
+
+  UTI_FdSetCloexec(phc_fd);
+
+  RCL_SetDriverData(instance, (void *)(long)phc_fd);
+  return 1;
+}
+
+static void phc_finalise(RCL_Instance instance)
+{
+  close((long)RCL_GetDriverData(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;
+ 
+  phc_fd = (long)RCL_GetDriverData(instance);
+
+  if (!no_sys_offset_ioctl) {
+    if (!read_phc_ioctl(readings, phc_fd, NUM_READINGS)) {
+      no_sys_offset_ioctl = 1;
+      return 0;
+    }
+  } else {
+    if (!read_phc_user(readings, phc_fd, NUM_READINGS))
+      return 0;
+  }
+
+  /* Find the fastest reading */
+  for (i = 0; i < NUM_READINGS; i++) {
+    delay = diff_ts(&readings[i].sys_ts2, &readings[i].sys_ts1);
+
+    if (!i || best_delay > delay) {
+      best = i;
+      best_delay = delay;
+    }
+  }
+
+  offset = diff_ts(&readings[best].phc_ts, &readings[best].sys_ts2) + best_delay / 2.0;
+  tv.tv_sec = readings[best].sys_ts2.tv_sec;
+  tv.tv_usec = readings[best].sys_ts2.tv_nsec / 1000;
+
+  DEBUG_LOG(LOGF_Refclock, "PHC offset: %+.9f delay: %.9f", offset, best_delay);
+
+  return RCL_AddSample(instance, &tv, offset, LEAP_Normal);
+}
+
+RefclockDriver RCL_PHC_driver = {
+  phc_initialise,
+  phc_finalise,
+  phc_poll
+};
+
+#else
+
+RefclockDriver RCL_PHC_driver = { NULL, NULL, NULL };
+
+#endif
--- a/refclock_pps.c
+++ b/refclock_pps.c
@@ -134,9 +134,7 @@ static int pps_poll(RCL_Instance instance)
  ts.tv_nsec = 0;

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

@@ -149,6 +147,8 @@ static int pps_poll(RCL_Instance instance)
  }

  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);
    return 0;
  }

--- a/refclock_shm.c
+++ b/refclock_shm.c
@@ -100,9 +100,8 @@ static int shm_poll(RCL_Instance instance)
  
  if ((t.mode == 1 && t.count != shm->count) ||
    !(t.mode == 0 || t.mode == 1) || !t.valid) {
-#if 0
-    LOG(LOGS_INFO, LOGF_Refclock, "sample ignored mode: %d count: %d valid: %d", t.mode, t.count, t.valid);
-#endif
+    DEBUG_LOG(LOGF_Refclock, "SHM sample ignored mode=%d count=%d valid=%d",
+        t.mode, t.count, t.valid);
    return 0;
  }

--- a/refclock_sock.c
+++ b/refclock_sock.c
@@ -57,23 +57,20 @@ static void read_sample(void *anything)
  s = recv(sockfd, &sample, sizeof (sample), 0);

  if (s < 0) {
-#if 0
-    LOG(LOGS_INFO, LOGF_Refclock, "Error reading from SOCK socket : %s", strerror(errno));
-#endif
+    LOG(LOGS_ERR, LOGF_Refclock, "Could not read SOCK sample : %s",
+        strerror(errno));
    return;
  }

  if (s != sizeof (sample)) {
-#if 0
-    LOG(LOGS_INFO, LOGF_Refclock, "Unexpected length of SOCK sample : %d != %d", s, sizeof (sample));
-#endif
+    LOG(LOGS_WARN, LOGF_Refclock, "Unexpected length of SOCK sample : %d != %ld",
+        s, (long)sizeof (sample));
    return;
  }

  if (sample.magic != SOCK_MAGIC) {
-#if 0
-    LOG(LOGS_INFO, LOGF_Refclock, "Unexpected magic number in SOCK sample : %x != %x", sample.magic, SOCK_MAGIC);
-#endif
+    LOG(LOGS_WARN, LOGF_Refclock, "Unexpected magic number in SOCK sample : %x != %x",
+        sample.magic, SOCK_MAGIC);
    return;
  }

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

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2013
+ * Copyright (C) Miroslav Lichvar  2009-2014
 * 
 * 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
@@ -67,6 +67,9 @@ static double correction_time_ratio;
 /* Flag indicating that we are initialised */
 static int initialised = 0;

+/* Current operating mode */
+static REF_Mode mode;
+
 /* Threshold and update limit for stepping clock */
 static int make_step_limit;
 static double make_step_threshold;
@@ -86,6 +89,9 @@ static int do_mail_change;
 static double mail_change_threshold;
 static char *mail_change_user;

+/* Handler for mode ending */
+static REF_ModeEndHandler mode_end_handler = NULL;
+
 /* Filename of the drift file. */
 static char *drift_file=NULL;
 static double drift_file_age;
@@ -138,11 +144,16 @@ handle_slew(struct timeval *raw,
            struct timeval *cooked,
            double dfreq,
            double doffset,
-            int is_step_change,
+            LCL_ChangeType change_type,
            void *anything)
 {
-  if (is_step_change) {
-    UTI_AddDoubleToTimeval(&last_ref_update, -doffset, &last_ref_update);
+  double delta;
+
+  if (change_type == LCL_ChangeUnknownStep) {
+    last_ref_update.tv_sec = 0;
+    last_ref_update.tv_usec = 0;
+  } else if (last_ref_update.tv_sec) {
+    UTI_AdjustTimeval(&last_ref_update, cooked, &last_ref_update, &delta, dfreq, doffset);
  }
 }

@@ -155,6 +166,7 @@ REF_Initialise(void)
  double file_freq_ppm, file_skew_ppm;
  double our_frequency_ppm;

+  mode = REF_ModeNormal;
  are_we_synchronised = 0;
  our_leap_status = LEAP_Unsynchronised;
  our_leap_sec = 0;
@@ -255,7 +267,7 @@ REF_Finalise(void)
    LCL_SetLeap(0);
  }

-  if (drift_file && drift_file_age > 0.0) {
+  if (drift_file) {
    update_drift_file(LCL_ReadAbsoluteFrequency(), our_skew);
  }

@@ -266,6 +278,29 @@ REF_Finalise(void)

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

+void REF_SetMode(REF_Mode new_mode)
+{
+  mode = new_mode;
+}
+
+/* ================================================== */
+
+REF_Mode
+REF_GetMode(void)
+{
+  return mode;
+}
+
+/* ================================================== */
+
+void
+REF_SetModeEndHandler(REF_ModeEndHandler handler)
+{
+  mode_end_handler = handler;
+}
+
+/* ================================================== */
+
 static double
 Sqr(double x)
 {
@@ -290,6 +325,7 @@ update_drift_file(double freq_ppm, double skew)
  struct stat buf;
  char *temp_drift_file;
  FILE *out;
+  int r1, r2;

  /* Create a temporary file with a '.tmp' extension. */

@@ -311,8 +347,9 @@ update_drift_file(double freq_ppm, double skew)
  }

  /* Write the frequency and skew parameters in ppm */
-  if ((fprintf(out, "%20.6f %20.6f\n", freq_ppm, 1.0e6 * skew) < 0) |
-      fclose(out)) {
+  r1 = fprintf(out, "%20.6f %20.6f\n", freq_ppm, 1.0e6 * skew);
+  r2 = fclose(out);
+  if (r1 < 0 || r2) {
    Free(temp_drift_file);
    LOG(LOGS_WARN, LOGF_Reference, "Could not write to temporary driftfile %s.tmp",
        drift_file);
@@ -322,10 +359,12 @@ update_drift_file(double freq_ppm, double skew)
  /* Clone the file attributes from the existing file if there is one. */

  if (!stat(drift_file,&buf)) {
-    if (chown(temp_drift_file,buf.st_uid,buf.st_gid)) {
-      LOG(LOGS_WARN, LOGF_Reference, "Could not change ownership of temporary driftfile %s.tmp", drift_file);
+    if (chown(temp_drift_file,buf.st_uid,buf.st_gid) ||
+        chmod(temp_drift_file,buf.st_mode & 0777)) {
+      LOG(LOGS_WARN, LOGF_Reference,
+          "Could not change ownership or permissions of temporary driftfile %s.tmp",
+          drift_file);
    }
-    chmod(temp_drift_file,buf.st_mode&0777);
  }

  /* Rename the temporary file to the correct location (see rename(2) for details). */
@@ -387,10 +426,8 @@ update_fb_drifts(double freq_ppm, double update_interval)
        (freq_ppm - fb_drifts[i].freq);
    }

-#if 0
-    LOG(LOGS_INFO, LOGF_Reference, "Fallback drift %d updated: %f ppm %f seconds",
+    DEBUG_LOG(LOGF_Reference, "Fallback drift %d updated: %f ppm %f seconds",
        i + fb_drift_min, fb_drifts[i].freq, fb_drifts[i].secs);
-#endif
  }
 }

@@ -437,23 +474,31 @@ schedule_fb_drift(struct timeval *now)
  if (c > next_fb_drift) {
    LCL_SetAbsoluteFrequency(fb_drifts[c - fb_drift_min].freq);
    next_fb_drift = c;
-#if 0
-    LOG(LOGS_INFO, LOGF_Reference, "Fallback drift %d set", c);
-#endif
+    DEBUG_LOG(LOGF_Reference, "Fallback drift %d set", c);
  }

  if (i <= fb_drift_max) {
    next_fb_drift = i;
    UTI_AddDoubleToTimeval(now, secs - unsynchronised, &when);
    fb_drift_timeout_id = SCH_AddTimeout(&when, fb_drift_timeout, NULL);
-#if 0
-    LOG(LOGS_INFO, LOGF_Reference, "Fallback drift %d scheduled", i);
-#endif
+    DEBUG_LOG(LOGF_Reference, "Fallback drift %d scheduled", i);
  }
 }

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

+static void
+end_ref_mode(int result)
+{
+  mode = REF_ModeIgnore;
+
+  /* Dispatch the handler */
+  if (mode_end_handler)
+    (mode_end_handler)(result);
+}
+
+/* ================================================== */
+
 #define BUFLEN 255
 #define S_MAX_USER_LEN "128"

@@ -506,15 +551,15 @@ maybe_log_offset(double offset, time_t now)

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

-static void
-maybe_make_step()
+static int
+is_step_limit_reached(double offset, double offset_correction)
 {
  if (make_step_limit == 0) {
-    return;
+    return 0;
  } else if (make_step_limit > 0) {
    make_step_limit--;
  }
-  LCL_MakeStep(make_step_threshold);
+  return fabs(offset - offset_correction) > make_step_threshold;
 }

 /* ================================================== */
@@ -534,9 +579,9 @@ is_offset_ok(double offset)
  if (offset > max_offset) {
    LOG(LOGS_WARN, LOGF_Reference,
        "Adjustment of %.3f seconds exceeds the allowed maximum of %.3f seconds (%s) ",
-        offset, max_offset, !max_offset_ignore ? "exiting" : "ignored");
+        -offset, max_offset, !max_offset_ignore ? "exiting" : "ignored");
    if (!max_offset_ignore)
-      SCH_QuitProgram();
+      end_ref_mode(0);
    else if (max_offset_ignore > 0)
      max_offset_ignore--;
    return 0;
@@ -546,6 +591,15 @@ is_offset_ok(double offset)

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

+static int
+is_leap_second_day(struct tm *stm) {
+  /* Allow leap second only on the last day of June and December */
+  return (stm->tm_mon == 5 && stm->tm_mday == 30) ||
+         (stm->tm_mon == 11 && stm->tm_mday == 31);
+}
+
+/* ================================================== */
+
 static NTP_Leap
 get_tz_leap(time_t when)
 {
@@ -563,12 +617,7 @@ get_tz_leap(time_t when)

  stm = *gmtime(&when);

-  /* Check for leap second only in the latter half of June and December */
-  if (stm.tm_mon == 5 && stm.tm_mday > 14)
-    stm.tm_mday = 30;
-  else if (stm.tm_mon == 11 && stm.tm_mday > 14)
-    stm.tm_mday = 31;
-  else
+  if (!is_leap_second_day(&stm))
    return tz_leap;

  /* Temporarily switch to the timezone containing leap seconds */
@@ -610,7 +659,6 @@ get_tz_leap(time_t when)
 static void
 update_leap_status(NTP_Leap leap, time_t now)
 {
-  struct tm stm;
  int leap_sec;

  leap_sec = 0;
@@ -619,24 +667,20 @@ update_leap_status(NTP_Leap leap, time_t now)
    leap = get_tz_leap(now);

  if (leap == LEAP_InsertSecond || leap == LEAP_DeleteSecond) {
-    /* Insert/delete leap second only on June 30 or December 31
-       and in other months ignore the leap status completely */
+    /* Check that leap second is allowed today */

-    stm = *gmtime(&now);
-
-    if (stm.tm_mon != 5 && stm.tm_mon != 11) {
-      leap = LEAP_Normal;
-    } else if ((stm.tm_mon == 5 && stm.tm_mday == 30) ||
-        (stm.tm_mon == 11 && stm.tm_mday == 31)) {
+    if (is_leap_second_day(gmtime(&now))) {
      if (leap == LEAP_InsertSecond) {
        leap_sec = 1;
      } else {
        leap_sec = -1;
      }
+    } else {
+      leap = LEAP_Normal;
    }
  }
  
-  if (leap_sec != our_leap_sec) {
+  if (leap_sec != our_leap_sec && !REF_IsLeapSecondClose()) {
    LCL_SetLeap(leap_sec);
    our_leap_sec = leap_sec;
  }
@@ -662,6 +706,62 @@ write_log(struct timeval *ref_time, char *ref, int stratum, NTP_Leap leap,

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

+static void
+special_mode_sync(int valid, double offset)
+{
+  int step;
+
+  switch (mode) {
+    case REF_ModeInitStepSlew:
+      if (!valid) {
+        LOG(LOGS_WARN, LOGF_Reference, "No suitable source for initstepslew");
+        end_ref_mode(0);
+        break;
+      }
+
+      step = fabs(offset) >= CNF_GetInitStepThreshold();
+
+      LOG(LOGS_INFO, LOGF_Reference,
+          "System's initial offset : %.6f seconds %s of true (%s)",
+          fabs(offset), offset >= 0 ? "fast" : "slow", step ? "step" : "slew");
+
+      if (step)
+        LCL_ApplyStepOffset(offset);
+      else
+        LCL_AccumulateOffset(offset, 0.0);
+
+      end_ref_mode(1);
+
+      break;
+    case REF_ModeUpdateOnce:
+    case REF_ModePrintOnce:
+      if (!valid) {
+        LOG(LOGS_WARN, LOGF_Reference, "No suitable source for synchronisation");
+        end_ref_mode(0);
+        break;
+      }
+
+      step = mode == REF_ModeUpdateOnce;
+
+      LOG(LOGS_INFO, LOGF_Reference, "System clock wrong by %.6f seconds (%s)",
+          -offset, step ? "step" : "ignored");
+
+      if (step)
+        LCL_ApplyStepOffset(offset);
+
+      end_ref_mode(1);
+
+      break;
+    case REF_ModeIgnore:
+      /* Do nothing until the mode is changed */
+      break;
+    default:
+      assert(0);
+  }
+}
+
+/* ================================================== */
+
 void
 REF_SetReference(int stratum,
                 NTP_Leap leap,
@@ -688,11 +788,17 @@ REF_SetReference(int stratum,
  double update_interval;
  double elapsed;
  double correction_rate;
-  double uncorrected_offset;
-  struct timeval now, raw_now, ev_now, ev_raw_now;
+  double uncorrected_offset, accumulate_offset, step_offset;
+  struct timeval now, raw_now;

  assert(initialised);

+  /* Special modes are implemented elsewhere */
+  if (mode != REF_ModeNormal) {
+    special_mode_sync(1, offset);
+    return;
+  }
+
  /* Guard against dividing by zero */
  if (skew < MIN_SKEW)
    skew = MIN_SKEW;
@@ -716,10 +822,7 @@ REF_SetReference(int stratum,
  }
    
  LCL_ReadRawTime(&raw_now);
-
-  /* This is cheaper than calling LCL_CookTime */
-  SCH_GetLastEventTime(&ev_now, NULL, &ev_raw_now);
-  UTI_DiffTimevalsToDouble(&uncorrected_offset, &ev_now, &ev_raw_now);
+  LCL_GetOffsetCorrection(&raw_now, &uncorrected_offset, NULL);
  UTI_AddDoubleToTimeval(&raw_now, uncorrected_offset, &now);

  UTI_DiffTimevalsToDouble(&elapsed, &now, ref_time);
@@ -763,6 +866,16 @@ REF_SetReference(int stratum,

  correction_rate = correction_time_ratio * 0.5 * offset_sd * update_interval;

+  /* Check if the clock should be stepped */
+  if (is_step_limit_reached(our_offset, uncorrected_offset)) {
+    /* Cancel the uncorrected offset and correct the total offset by step */
+    accumulate_offset = uncorrected_offset;
+    step_offset = our_offset - uncorrected_offset;
+  } else {
+    accumulate_offset = our_offset;
+    step_offset = 0.0;
+  }
+
  /* Eliminate updates that are based on totally unreliable frequency
     information. Ignore this limit with manual reference. */

@@ -797,21 +910,23 @@ REF_SetReference(int stratum,

    our_residual_freq = new_freq - our_frequency;

-    LCL_AccumulateFrequencyAndOffset(our_frequency, our_offset, correction_rate);
+    LCL_AccumulateFrequencyAndOffset(our_frequency, accumulate_offset, correction_rate);
    
  } else {
+    DEBUG_LOG(LOGF_Reference, "Skew %f too large to track, offset=%f", skew, accumulate_offset);

-#if 0    
-    LOG(LOGS_INFO, LOGF_Reference, "Skew %f too large to track, offset=%f", skew, our_offset);
-#endif
-    LCL_AccumulateOffset(our_offset, correction_rate);
+    LCL_AccumulateOffset(accumulate_offset, correction_rate);

    our_residual_freq = frequency;
  }

  update_leap_status(leap, raw_now.tv_sec);
  maybe_log_offset(our_offset, raw_now.tv_sec);
-  maybe_make_step();
+
+  if (step_offset != 0.0) {
+    LCL_ApplyStepOffset(step_offset);
+    LOG(LOGS_WARN, LOGF_Reference, "System clock was stepped by %.6f seconds", -step_offset);
+  }

  abs_freq_ppm = LCL_ReadAbsoluteFrequency();

@@ -884,9 +999,15 @@ REF_SetUnsynchronised(void)

  assert(initialised);

-  /* This is cheaper than calling LCL_CookTime */
-  SCH_GetLastEventTime(&now, NULL, &now_raw);
-  UTI_DiffTimevalsToDouble(&uncorrected_offset, &now, &now_raw);
+  /* Special modes are implemented elsewhere */
+  if (mode != REF_ModeNormal) {
+    special_mode_sync(0, 0.0);
+    return;
+  }
+
+  LCL_ReadRawTime(&now_raw);
+  LCL_GetOffsetCorrection(&now_raw, &uncorrected_offset, NULL);
+  UTI_AddDoubleToTimeval(&now_raw, uncorrected_offset, &now);

  if (fb_drifts) {
    schedule_fb_drift(&now);
@@ -1000,9 +1121,6 @@ void
 REF_ModifyMaxupdateskew(double new_max_update_skew)
 {
  max_update_skew = new_max_update_skew * 1.0e-6;
-#if 0
-  LOG(LOGS_INFO, LOGF_Reference, "New max update skew = %.3fppm", new_max_update_skew);
-#endif
 }

 /* ================================================== */
@@ -1032,6 +1150,31 @@ REF_IsLocalActive(void)

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

+#define LEAP_SECOND_CLOSE 5
+
+int REF_IsLeapSecondClose(void)
+{
+  struct timeval now, now_raw;
+  time_t t;
+
+  if (!our_leap_sec)
+    return 0;
+
+  SCH_GetLastEventTime(&now, NULL, &now_raw);
+
+  t = now.tv_sec > 0 ? now.tv_sec : -now.tv_sec;
+  if ((t + LEAP_SECOND_CLOSE) % (24 * 3600) < 2 * LEAP_SECOND_CLOSE)
+    return 1;
+
+  t = now_raw.tv_sec > 0 ? now_raw.tv_sec : -now_raw.tv_sec;
+  if ((t + LEAP_SECOND_CLOSE) % (24 * 3600) < 2 * LEAP_SECOND_CLOSE)
+    return 1;
+
+  return 0;
+}
+
+/* ================================================== */
+
 void
 REF_GetTrackingReport(RPT_TrackingReport *rep)
 {
@@ -1084,5 +1227,3 @@ REF_GetTrackingReport(RPT_TrackingReport *rep)
  }

 }
-
-/* ================================================== */
--- a/reference.h
+++ b/reference.h
@@ -3,6 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2002
+ * Copyright (C) Miroslav Lichvar  2014
 * 
 * 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
@@ -40,6 +41,26 @@ extern void REF_Initialise(void);
 /* Fini function */
 extern void REF_Finalise(void);

+typedef enum {
+  REF_ModeNormal,
+  REF_ModeInitStepSlew,
+  REF_ModeUpdateOnce,
+  REF_ModePrintOnce,
+  REF_ModeIgnore,
+} REF_Mode;
+
+/* Set reference update mode */
+extern void REF_SetMode(REF_Mode mode);
+
+/* Get reference update mode */
+extern REF_Mode REF_GetMode(void);
+
+/* Function type for handlers to be called back when mode ends */
+typedef void (*REF_ModeEndHandler)(int result);
+
+/* Set the handler for being notified of mode ending */
+extern void REF_SetModeEndHandler(REF_ModeEndHandler handler);
+
 /* Function which takes a local cooked time and returns the estimated
   time of the reference.  It also returns the other parameters
   required for forming the outgoing NTP packet.
@@ -129,7 +150,7 @@ extern void REF_SetManualReference
 extern void
 REF_SetUnsynchronised(void);

-/* Return the current stratum of this host or zero if the host is not
+/* Return the current stratum of this host or 16 if the host is not
   synchronised */
 extern int REF_GetOurStratum(void);

@@ -140,6 +161,10 @@ extern void REF_EnableLocal(int stratum);
 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 */
+extern int REF_IsLeapSecondClose(void);
+
 extern void REF_GetTrackingReport(RPT_TrackingReport *rep);

 #endif /* GOT_REFERENCE_H */
--- a/regress.c
+++ b/regress.c
@@ -209,8 +209,6 @@ n_runs_from_residuals(double *resid, int n)
 /* Return a boolean indicating whether we had enough points for
   regression */

-#define MIN_SAMPLES_FOR_REGRESS 3
-
 int
 RGR_FindBestRegression 
 (double *x,                     /* independent variable */
@@ -255,7 +253,7 @@ RGR_FindBestRegression
  int start, resid_start, nruns, npoints;
  int i;

-  assert(n <= MAX_POINTS);
+  assert(n <= MAX_POINTS && m >= 0);
  assert(n * REGRESS_RUNS_RATIO < sizeof (critical_runs) / sizeof (critical_runs[0]));

  if (n < MIN_SAMPLES_FOR_REGRESS) {
@@ -392,7 +390,7 @@ find_ordered_entry_with_flags(double *x, int n, int index, int *flags)
      l = u + 1;
      r = v;
      do {
-        while (x[l] < piv && l < v) l++;
+        while (l < v && x[l] < piv) l++;
        while (x[r] > piv) r--;
        if (r <= l) break;
        EXCH(x[l], x[r]);
@@ -572,11 +570,6 @@ RGR_FindBestRobustRegression
    b = X / V;
    a = my - b*mx;

-
-#if 0
-    printf("my=%20.12f mx=%20.12f a=%20.12f b=%20.12f\n", my, mx, a, b);
-#endif
-
    s2 = 0.0;
    for (i=start; i<n; i++) {
      resid = y[i] - a - b * x[i];
--- a/regress.h
+++ b/regress.h
@@ -66,6 +66,9 @@ extern double RGR_GetChi2Coef(int dof);
   points */
 #define REGRESS_RUNS_RATIO 2

+/* Minimum number of samples for regression */
+#define MIN_SAMPLES_FOR_REGRESS 3
+
 /* Return a status indicating whether there were enough points to
   carry out the regression */

--- a/rtc.c
+++ b/rtc.c
@@ -28,6 +28,7 @@
 #include "sysincl.h"

 #include "rtc.h"
+#include "local.h"
 #include "logging.h"
 #include "conf.h"

@@ -42,7 +43,7 @@ static int driver_initialised = 0;
 static struct {
  int  (*init)(void);
  void (*fini)(void);
-  void (*time_pre_init)(void);
+  int  (*time_pre_init)(void);
  void (*time_init)(void (*after_hook)(void*), void *anything);
  void (*start_measurements)(void);
  int  (*write_parameters)(void);
@@ -71,42 +72,68 @@ static struct {
 #endif 
 };
     
+/* ================================================== */
+/* Set the system clock to the time of last modification of driftfile
+   if it's in the future */
+
+static void
+fallback_time_init(void)
+{
+  struct timeval now;
+  struct stat buf;
+  char *drift_file;
+
+  drift_file = CNF_GetDriftFile();
+  if (!drift_file)
+    return;
+
+  if (stat(drift_file, &buf))
+    return;
+
+  LCL_ReadCookedTime(&now, NULL);
+
+  if (now.tv_sec < buf.st_mtime) {
+    LCL_ApplyStepOffset(now.tv_sec - buf.st_mtime);
+    LOG(LOGS_INFO, LOGF_Rtc,
+        "System clock set from driftfile %s", drift_file);
+  }
+}
+
 /* ================================================== */

 void
-RTC_Initialise(void)
+RTC_Initialise(int initial_set)
 {
  char *file_name;
-  int ok;
+
+  /* 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 (initial_set) {
+    if (!driver.time_pre_init || !driver.time_pre_init()) {
+      fallback_time_init();
+    }
+  }
+
+  driver_initialised = 0;

  /* This is how we tell whether the user wants to load the RTC
     driver, if he is on a machine where it is an option. */
  file_name = CNF_GetRtcFile();

  if (file_name) {
-    if (CNF_GetRTCSync()) {
+    if (CNF_GetRtcSync()) {
      LOG_FATAL(LOGF_Rtc, "rtcfile directive cannot be used with rtcsync");
    }

    if (driver.init) {
      if ((driver.init)()) {
-        ok = 1;
-      } else {
-        ok = 0;
+        driver_initialised = 1;
      }
    } else {
-      ok = 0;
+      LOG(LOGS_ERR, LOGF_Rtc, "RTC not supported on this operating system");
    }
-
-    if (ok) {
-      driver_initialised = 1;
-    } else {
-      driver_initialised = 0;
-      LOG(LOGS_ERR, LOGF_Rtc, "Real time clock not supported on this operating system");
-    }
-
-  } else {
-    driver_initialised = 0;
  }
 }

@@ -137,23 +164,10 @@ RTC_TimeInit(void (*after_hook)(void *), void *anything)
  if (driver_initialised) {
    (driver.time_init)(after_hook, anything);
  } else {
-    LOG(LOGS_ERR, LOGF_Rtc, "Can't initialise from real time clock, driver not loaded");
    (after_hook)(anything);
  }
 }

-/* ================================================== */
-/* Do an initial read of the RTC and set the system time to it.  This
-   is analogous to what /sbin/clock -s -u would do on Linux. */
-
-void
-RTC_TimePreInit(void)
-{
-  if (driver.time_pre_init) {
-    (driver.time_pre_init)();
-  }
-}
-
 /* ================================================== */
 /* Start the RTC measurement process */

--- a/rtc.h
+++ b/rtc.h
@@ -28,9 +28,8 @@

 #include "reports.h"

-extern void RTC_Initialise(void);
+extern void RTC_Initialise(int initial_set);
 extern void RTC_Finalise(void);
-extern void RTC_TimePreInit(void);
 extern void RTC_TimeInit(void (*after_hook)(void *), void *anything);
 extern void RTC_StartMeasurements(void);
 extern int  RTC_GetReport(RPT_RTC_Report *report);
--- a/rtc_linux.c
+++ b/rtc_linux.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2012
+ * Copyright (C) Miroslav Lichvar  2012-2014
 * 
 * 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
@@ -38,6 +38,7 @@
 #include "local.h"
 #include "util.h"
 #include "sys_linux.h"
+#include "reference.h"
 #include "regress.h"
 #include "rtc.h"
 #include "rtc_linux.h"
@@ -67,9 +68,7 @@ static int fd = -1;

 #define LOWEST_MEASUREMENT_PERIOD 15
 #define HIGHEST_MEASUREMENT_PERIOD 480
-
-/* Try to avoid doing regression after _every_ sample we accumulate */
-#define N_SAMPLES_PER_REGRESSION 4
+#define N_SAMPLES_PER_REGRESSION 1

 static int measurement_period = LOWEST_MEASUREMENT_PERIOD;

@@ -125,6 +124,9 @@ static double coef_gain_rate;
   RTC data file once we have reacquired its offset after the step */
 static double saved_coef_gain_rate;

+/* Threshold for automatic RTC trimming in seconds, zero when disabled */
+static double autotrim_threshold;
+
 /* Filename supplied by config file where RTC coefficients are
   stored. */
 static char *coefs_file_name;
@@ -263,13 +265,19 @@ static void
 slew_samples
 (struct timeval *raw, struct timeval *cooked,
 double dfreq,
- double doffset, int is_step_change,
+ double doffset,
+ LCL_ChangeType change_type,
 void *anything)
 {
  int i;
  double delta_time;
  double old_seconds_fast, old_gain_rate;

+  if (change_type == LCL_ChangeUnknownStep) {
+    /* Drop all samples. */
+    n_samples = 0;
+  }
+
  for (i=0; i<n_samples; i++) {
    UTI_AdjustTimeval(system_times + i, cooked, system_times + i, &delta_time,
        dfreq, doffset);
@@ -280,18 +288,13 @@ slew_samples

  if (coefs_valid) {
    coef_seconds_fast += doffset;
-    coef_gain_rate = (1.0 + dfreq) * (1.0 + coef_gain_rate) - 1.0;
+    coef_gain_rate += dfreq * (1.0 - coef_gain_rate);
  }

-#if 0
-  LOG(LOGS_INFO, LOGF_RtcLinux, "dfreq=%.8f doffset=%.6f old_fast=%.6f old_rate=%.3f new_fast=%.6f new_rate=%.3f",
+  DEBUG_LOG(LOGF_RtcLinux, "dfreq=%.8f doffset=%.6f old_fast=%.6f old_rate=%.3f new_fast=%.6f new_rate=%.3f",
      dfreq, doffset,
      old_seconds_fast, 1.0e6 * old_gain_rate,
      coef_seconds_fast, 1.0e6 * coef_gain_rate);
-#else
-  (void)old_seconds_fast; (void)old_gain_rate;
-#endif
-
 }

 /* ================================================== */
@@ -369,14 +372,55 @@ t_from_rtc(struct tm *stm) {

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

+static void
+read_hwclock_file(const char *hwclock_file)
+{
+  FILE *in;
+  char line[256];
+  int i;
+
+  if (!hwclock_file)
+    return;
+
+  in = fopen(hwclock_file, "r");
+  if (!in) {
+    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not open hwclockfile %s",
+        hwclock_file);
+    return;
+  }
+
+  /* Read third line from the file. */
+  for (i = 0; i < 3; i++) {
+    if (!fgets(line, sizeof(line), in))
+      break;
+  }
+
+  fclose(in);
+
+  if (i == 3 && !strncmp(line, "LOCAL", 5)) {
+    rtc_on_utc = 0;
+  } else if (i == 3 && !strncmp(line, "UTC", 3)) {
+    rtc_on_utc = 1;
+  } else {
+    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not read LOCAL/UTC setting from hwclockfile %s",
+        hwclock_file);
+  }
+}
+
+/* ================================================== */
+
 static void
 setup_config(void)
 {
-  if (CNF_GetRTCOnUTC()) {
+  if (CNF_GetRtcOnUtc()) {
    rtc_on_utc = 1;
  } else {
    rtc_on_utc = 0;
  }
+
+  read_hwclock_file(CNF_GetHwclockFile());
+
+  autotrim_threshold = CNF_GetRtcAutotrim();
 }

 /* ================================================== */
@@ -387,7 +431,6 @@ static void
 read_coefs_from_file(void)
 {
  FILE *in;
-  char line[256];

  if (!tried_to_load_coefs) {

@@ -395,26 +438,17 @@ read_coefs_from_file(void)

    tried_to_load_coefs = 1;

-    in = fopen(coefs_file_name, "r");
-    if (in) {
-      if (fgets(line, sizeof(line), in)) {
-        if (sscanf(line, "%d%ld%lf%lf",
-                   &valid_coefs_from_file,
-                   &file_ref_time,
-                   &file_ref_offset,
-                   &file_rate_ppm) == 4) {
-        } else {
-          LOG(LOGS_WARN, LOGF_RtcLinux, "Could not parse coefficients line from RTC file %s",
-              coefs_file_name);
-        }
+    if (coefs_file_name && (in = fopen(coefs_file_name, "r"))) {
+      if (fscanf(in, "%d%ld%lf%lf",
+                 &valid_coefs_from_file,
+                 &file_ref_time,
+                 &file_ref_offset,
+                 &file_rate_ppm) == 4) {
      } else {
-        LOG(LOGS_WARN, LOGF_RtcLinux, "Could not read first line from RTC file %s",
+        LOG(LOGS_WARN, LOGF_RtcLinux, "Could not read coefficients from RTC file %s",
            coefs_file_name);
      }
      fclose(in);
-    } else {
-      LOG(LOGS_WARN, LOGF_RtcLinux, "Could not open RTC file %s for reading",
-          coefs_file_name);
    }
  }
 }
@@ -429,6 +463,7 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  struct stat buf;
  char *temp_coefs_file_name;
  FILE *out;
+  int r1, r2;

  /* Create a temporary file with a '.tmp' extension. */

@@ -450,9 +485,10 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  }

  /* Gain rate is written out in ppm */
-  if ((fprintf(out, "%1d %ld %.6f %.3f\n",
-          valid,ref_time, offset, 1.0e6 * rate) < 0) |
-      fclose(out)) {
+  r1 = fprintf(out, "%1d %ld %.6f %.3f\n",
+               valid, ref_time, offset, 1.0e6 * rate);
+  r2 = fclose(out);
+  if (r1 < 0 || r2) {
    Free(temp_coefs_file_name);
    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not write to temporary RTC file %s.tmp",
        coefs_file_name);
@@ -462,10 +498,12 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  /* Clone the file attributes from the existing file if there is one. */

  if (!stat(coefs_file_name,&buf)) {
-    if (chown(temp_coefs_file_name,buf.st_uid,buf.st_gid)) {
-      LOG(LOGS_WARN, LOGF_RtcLinux, "Could not change ownership of temporary RTC file %s.tmp", coefs_file_name);
+    if (chown(temp_coefs_file_name,buf.st_uid,buf.st_gid) ||
+        chmod(temp_coefs_file_name,buf.st_mode & 0777)) {
+      LOG(LOGS_WARN, LOGF_RtcLinux,
+          "Could not change ownership or permissions of temporary RTC file %s.tmp",
+          coefs_file_name);
    }
-    chmod(temp_coefs_file_name,buf.st_mode&0777);
  }

  /* Rename the temporary file to the correct location (see rename(2) for details). */
@@ -502,7 +540,8 @@ RTC_Linux_Initialise(void)

  fd = open (CNF_GetRtcDevice(), O_RDWR);
  if (fd < 0) {
-    LOG(LOGS_ERR, LOGF_RtcLinux, "Could not open %s, %s", CNF_GetRtcDevice(), strerror(errno));
+    LOG(LOGS_ERR, LOGF_RtcLinux, "Could not open RTC device %s : %s",
+        CNF_GetRtcDevice(), strerror(errno));
    return 0;
  }

@@ -670,6 +709,7 @@ handle_relock_after_trim(void)
  time_t ref;
  double fast, slope;

+  valid = 0;
  run_regression(1, &valid, &ref, &fast, &slope);

  if (valid) {
@@ -687,8 +727,25 @@ handle_relock_after_trim(void)

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

-/* Day number of 1 Jan 1970 */
-#define MJD_1970 40587
+static void
+maybe_autotrim(void)
+{
+  /* Trim only when in normal mode, the coefficients are fresh, the current
+     offset is above the threshold and the system clock is synchronized */
+
+  if (operating_mode != OM_NORMAL || !coefs_valid || n_samples_since_regression)
+    return;
+  
+  if (autotrim_threshold <= 0.0 || fabs(coef_seconds_fast) < autotrim_threshold)
+    return;
+
+  if (REF_GetOurStratum() >= 16)
+    return;
+
+  RTC_Linux_Trim();
+}
+
+/* ================================================== */

 static void
 process_reading(time_t rtc_time, struct timeval *system_time)
@@ -700,9 +757,10 @@ process_reading(time_t rtc_time, struct timeval *system_time)
  switch (operating_mode) {
    case OM_NORMAL:

-      if (n_samples_since_regression >= /* 4 */ 1 ) {
+      if (n_samples_since_regression >= N_SAMPLES_PER_REGRESSION) {
        run_regression(1, &coefs_valid, &coef_ref_time, &coef_seconds_fast, &coef_gain_rate);
        n_samples_since_regression = 0;
+        maybe_autotrim();
      }
      
      break;
@@ -753,7 +811,6 @@ 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));
-    error = 1;
    SCH_RemoveInputFileHandler(fd);
    switch_interrupts(0); /* Likely to raise error too, but just to be sure... */
    close(fd);
@@ -905,19 +962,18 @@ RTC_Linux_WriteParameters(void)

 /* ================================================== */
 /* Try to set the system clock from the RTC, in the same manner as
-   /sbin/clock -s -u would do.  We're not as picky about OS version
+   /sbin/hwclock -s would do.  We're not as picky about OS version
   etc in this case, since we have fewer requirements regarding the
   RTC behaviour than we do for the rest of the module. */

-void
+int
 RTC_Linux_TimePreInit(void)
 {
  int fd, status;
-  struct rtc_time rtc_raw;
+  struct rtc_time rtc_raw, rtc_raw_retry;
  struct tm rtc_tm;
-  time_t rtc_t, estimated_correct_rtc_t;
-  long interval;
-  double accumulated_error = 0.0;
+  time_t rtc_t;
+  double accumulated_error, sys_offset;
  struct timeval new_sys_time, old_sys_time;

  coefs_file_name = CNF_GetRtcFile();
@@ -928,10 +984,23 @@ RTC_Linux_TimePreInit(void)
  fd = open(CNF_GetRtcDevice(), O_RDONLY);

  if (fd < 0) {
-    return; /* Can't open it, and won't be able to later */
+    return 0; /* Can't open it, and won't be able to later */
  }

-  status = ioctl(fd, RTC_RD_TIME, &rtc_raw);
+  /* Retry reading the rtc until both read attempts give the same sec value.
+     This way the race condition is prevented that the RTC has updated itself
+     during the first read operation. */
+  do {
+    status = ioctl(fd, RTC_RD_TIME, &rtc_raw);
+    if (status >= 0) {
+      status = ioctl(fd, RTC_RD_TIME, &rtc_raw_retry);
+    }
+  } while (status >= 0 && rtc_raw.tm_sec != rtc_raw_retry.tm_sec);
+
+  /* Read system clock */
+  LCL_ReadCookedTime(&old_sys_time, NULL);
+
+  close(fd);

  if (status >= 0) {
    /* Convert to seconds since 1970 */
@@ -949,37 +1018,35 @@ RTC_Linux_TimePreInit(void)
      /* Work out approximatation to correct time (to about the
         nearest second) */
      if (valid_coefs_from_file) {
-        interval = rtc_t - file_ref_time;
-        accumulated_error = file_ref_offset + (double)(interval) * 1.0e-6 * file_rate_ppm;
-
-        /* Correct time */
-        estimated_correct_rtc_t = rtc_t - (long)(0.5 + accumulated_error);
+        accumulated_error = file_ref_offset +
+          (rtc_t - file_ref_time) * 1.0e-6 * file_rate_ppm;
      } else {
-        estimated_correct_rtc_t = rtc_t - (long)(0.5 + accumulated_error);
+        accumulated_error = 0.0;
      }

-      new_sys_time.tv_sec = estimated_correct_rtc_t;
-      new_sys_time.tv_usec = 0;
+      /* Correct time */
+
+      new_sys_time.tv_sec = rtc_t;
+      /* Average error in the RTC reading */
+      new_sys_time.tv_usec = 500000;
+
+      UTI_AddDoubleToTimeval(&new_sys_time, -accumulated_error, &new_sys_time);
+
+      UTI_DiffTimevalsToDouble(&sys_offset, &old_sys_time, &new_sys_time);

      /* Set system time only if the step is larger than 1 second */
-      if (!(gettimeofday(&old_sys_time, NULL) < 0) &&
-          (old_sys_time.tv_sec - new_sys_time.tv_sec > 1 ||
-           old_sys_time.tv_sec - new_sys_time.tv_sec < -1)) {
-
+      if (fabs(sys_offset) >= 1.0) {
        LOG(LOGS_INFO, LOGF_RtcLinux, "Set system time, error in RTC = %f",
            accumulated_error);
-
-        /* Tough luck if this fails */
-        if (settimeofday(&new_sys_time, NULL) < 0) {
-          LOG(LOGS_WARN, LOGF_RtcLinux, "Could not settimeofday");
-        }
+        LCL_ApplyStepOffset(sys_offset);
      }
    } else {
      LOG(LOGS_WARN, LOGF_RtcLinux, "Could not convert RTC reading to seconds since 1/1/1970");
+      return 0;
    }
  }

-  close(fd);
+  return 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 void RTC_Linux_TimePreInit(void);
+extern int RTC_Linux_TimePreInit(void);
 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
+ * Copyright (C) Miroslav Lichvar  2011, 2013-2014
 * 
 * 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
@@ -57,18 +57,18 @@ static unsigned int n_read_fds;
 /* One more than the highest file descriptor that is registered */
 static unsigned int one_highest_fd;

-/* This assumes that fd_set is implemented as a fixed size array of
-   bits, possibly embedded inside a record.  It might therefore
-   somewhat non-portable. */
-
-#define FD_SET_SIZE (sizeof(fd_set) * 8)
+#ifndef FD_SETSIZE
+/* If FD_SETSIZE is not defined, assume that fd_set is implemented
+   as a fixed size array of bits, possibly embedded inside a record */
+#define FD_SETSIZE (sizeof(fd_set) * 8)
+#endif

 typedef struct {
  SCH_FileHandler       handler;
  SCH_ArbitraryArgument arg;
 } FileHandlerEntry;

-static FileHandlerEntry file_handlers[FD_SET_SIZE];
+static FileHandlerEntry file_handlers[FD_SETSIZE];

 /* Timestamp when last select() returned */
 static struct timeval last_select_ts, last_select_ts_raw;
@@ -123,7 +123,7 @@ handle_slew(struct timeval *raw,
            struct timeval *cooked,
            double dfreq,
            double doffset,
-            int is_step_change,
+            LCL_ChangeType change_type,
            void *anything);

 /* ================================================== */
@@ -169,6 +169,9 @@ SCH_AddInputFileHandler

  assert(initialised);
  
+  if (fd >= FD_SETSIZE)
+    LOG_FATAL(LOGF_Scheduler, "Too many file descriptors");
+
  /* Don't want to allow the same fd to register a handler more than
     once without deleting a previous association - this suggests
     a bug somewhere else in the program. */
@@ -503,14 +506,18 @@ handle_slew(struct timeval *raw,
            struct timeval *cooked,
            double dfreq,
            double doffset,
-            int is_step_change,
+            LCL_ChangeType change_type,
            void *anything)
 {
  TimerQueueEntry *ptr;
  double delta;
  int i;

-  if (is_step_change) {
+  if (change_type != LCL_ChangeAdjust) {
+    /* Make sure this handler is invoked first in order to not shift new timers
+       added from other handlers */
+    assert(LCL_IsFirstParameterChangeHandler(handle_slew));
+
    /* 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) {
@@ -529,30 +536,54 @@ handle_slew(struct timeval *raw,

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

-/* Try to handle unexpected backward time jump */
+#define JUMP_DETECT_THRESHOLD 10

-static void
-recover_backjump(struct timeval *raw, struct timeval *cooked, int timeout)
+static int
+check_current_time(struct timeval *prev_raw, struct timeval *raw, int timeout,
+                   struct timeval *orig_select_tv,
+                   struct timeval *rem_select_tv)
 {
-      double diff, err;
+  struct timeval elapsed_min, elapsed_max;
+  double step, elapsed;

-      UTI_DiffTimevalsToDouble(&diff, &last_select_ts_raw, raw);
+  /* 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;
+  } 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);
+    elapsed_max = elapsed_min;
+  } else {
+    if (rem_select_tv)
+      elapsed_max = *orig_select_tv;
+    else
+      UTI_DiffTimevals(&elapsed_max, raw, prev_raw);
+    elapsed_min.tv_sec = 0;
+    elapsed_min.tv_usec = 0;
+  }

-      if (n_timer_queue_entries > 0) {
-        UTI_DiffTimevalsToDouble(&err, &(timer_queue.next->tv), &last_select_ts_raw);
-      } else {
-        err = 0.0;
-      }
+  if (last_select_ts_raw.tv_sec + elapsed_min.tv_sec >
+      raw->tv_sec + JUMP_DETECT_THRESHOLD) {
+    LOG(LOGS_WARN, LOGF_Scheduler, "Backward time jump detected!");
+  } else if (prev_raw->tv_sec + elapsed_max.tv_sec + JUMP_DETECT_THRESHOLD <
+             raw->tv_sec) {
+    LOG(LOGS_WARN, LOGF_Scheduler, "Forward time jump detected!");
+  } else {
+    return 1;
+  }

-      diff += err;
+  UTI_DiffTimevalsToDouble(&step, &last_select_ts_raw, raw);
+  UTI_TimevalToDouble(&elapsed_min, &elapsed);
+  step += elapsed;

-      if (timeout) {
-        err = 1.0;
-      }
+  /* Cooked time may no longer be valid after dispatching the handlers */
+  LCL_NotifyExternalTimeStep(raw, raw, step, fabs(step));

-      LOG(LOGS_WARN, LOGF_Scheduler, "Backward time jump detected! (correction %.1f +- %.1f seconds)", diff, err);
-
-      LCL_NotifyExternalTimeStep(raw, cooked, diff, err);
+  return 0;
 }

 /* ================================================== */
@@ -562,34 +593,43 @@ SCH_MainLoop(void)
 {
  fd_set rd;
  int status, errsv;
-  struct timeval tv, *ptv;
-  struct timeval now, cooked;
+  struct timeval tv, saved_tv, *ptv;
+  struct timeval now, saved_now, cooked;
  double err;

  assert(initialised);

  while (!need_to_exit) {
-
-    /* Copy current set of read file descriptors */
-    memcpy((void *) &rd, (void *) &read_fds, sizeof(fd_set));
-    
    /* Dispatch timeouts and fill now with current raw time */
    dispatch_timeouts(&now);
+    saved_now = now;
    
+    /* The timeout handlers may request quit */
+    if (need_to_exit)
+      break;
+
    /* Check whether there is a timeout and set it up */
    if (n_timer_queue_entries > 0) {

      UTI_DiffTimevals(&tv, &(timer_queue.next->tv), &now);
      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;
    }

    /* if there are no file descriptors being waited on and no
       timeout set, this is clearly ridiculous, so stop the run */
-    assert(ptv || n_read_fds);
+    if (!ptv && !n_read_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);
    errsv = errno;
@@ -597,9 +637,10 @@ SCH_MainLoop(void)
    LCL_ReadRawTime(&now);
    LCL_CookTime(&now, &cooked, &err);

-    /* Check if time didn't jump backwards */
-    if (last_select_ts_raw.tv_sec > now.tv_sec + 1) {
-      recover_backjump(&now, &cooked, status == 0);
+    /* Check if the time didn't jump unexpectedly */
+    if (!check_current_time(&saved_now, &now, status == 0, &saved_tv, ptv)) {
+      /* Cook the time again after handling the step */
+      LCL_CookTime(&now, &cooked, &err);
    }

    last_select_ts_raw = now;
--- a/sources.c
+++ b/sources.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2013
+ * Copyright (C) Miroslav Lichvar  2011-2014
 * 
 * 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
@@ -45,6 +45,7 @@
 #include "nameserv.h"
 #include "mkdirpp.h"
 #include "sched.h"
+#include "regress.h"

 /* ================================================== */
 /* Flag indicating that we are initialised */
@@ -90,11 +91,14 @@ struct SRC_Instance_Record {
  /* Flag indicating that we can use this source as a reference */
  int selectable;

+  /* Flag indicating that the source is updating reachability */
+  int active;
+
  /* Reachability register */
  int reachability;

-  /* Flag indicating that only few samples were accumulated so far */
-  int beginning;
+  /* Number of set bits in the reachability register */
+  int reachability_size;

  /* Updates left before allowing combining */
  int outlier;
@@ -135,9 +139,6 @@ static int selected_source_index; /* Which source index is currently
                                     selected (set to INVALID_SOURCE
                                     if no current valid reference) */

-/* Keep reachability status for last 8 samples */
-#define REACH_BITS 8
-
 /* Score needed to replace the currently selected source */
 #define SCORE_LIMIT 10.0

@@ -153,7 +154,7 @@ static double combine_limit;

 static void
 slew_sources(struct timeval *raw, struct timeval *cooked, double dfreq,
-             double doffset, int is_step_change, void *anything);
+             double doffset, LCL_ChangeType change_type, void *anything);
 static void
 add_dispersion(double dispersion, void *anything);
 static char *
@@ -217,9 +218,10 @@ SRC_Instance SRC_CreateNewInstance(uint32_t ref_id, SRC_Type type, SRC_SelectOpt
  result->leap_status = LEAP_Normal;
  result->ref_id = ref_id;
  result->ip_addr = addr;
+  result->active = 0;
  result->selectable = 0;
  result->reachability = 0;
-  result->beginning = 1;
+  result->reachability_size = 0;
  result->outlier = 0;
  result->status = SRC_BAD_STATS;
  result->type = type;
@@ -307,17 +309,34 @@ void SRC_AccumulateSample

  inst->leap_status = leap_status;

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_Sources, "ip=[%s] t=%s ofs=%f del=%f disp=%f str=%d",
+  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);
-#endif
+
+  if (REF_IsLeapSecondClose()) {
+    LOG(LOGS_INFO, LOGF_Sources, "Dropping sample around leap second");
+    return;
+  }

  /* WE HAVE TO NEGATE OFFSET IN THIS CALL, IT IS HERE THAT THE SENSE OF OFFSET
     IS FLIPPED */
  SST_AccumulateSample(inst->stats, sample_time, -offset, peer_delay, peer_dispersion, root_delay, root_dispersion, stratum);
  SST_DoNewRegression(inst->stats);
-  /* And redo clock selection */
-  SRC_SelectSource(inst->ref_id);
+}
+
+/* ================================================== */
+
+void
+SRC_SetActive(SRC_Instance inst)
+{
+  inst->active = 1;
+}
+
+/* ================================================== */
+
+void
+SRC_UnsetActive(SRC_Instance inst)
+{
+  inst->active = 0;
 }

 /* ================================================== */
@@ -327,9 +346,7 @@ SRC_SetSelectable(SRC_Instance inst)
 {
  inst->selectable = 1;

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_Sources, "%s", source_to_string(inst));
-#endif
+  DEBUG_LOG(LOGF_Sources, "%s", source_to_string(inst));

  /* Don't do selection at this point, though - that will come about
     in due course when we get some useful data from the source */
@@ -342,35 +359,60 @@ SRC_UnsetSelectable(SRC_Instance inst)
 {
  inst->selectable = 0;

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_Sources, "%s%s", source_to_string(inst),
+  DEBUG_LOG(LOGF_Sources, "%s%s", source_to_string(inst),
      (inst->index == selected_source_index) ? "(REF)":"");
-#endif

  /* If this was the previous reference source, we have to reselect!  */

  if (inst->index == selected_source_index) {
-    SRC_SelectSource(0);
+    SRC_SelectSource(NULL);
  }

 }

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

+static int
+special_mode_end(void)
+{
+    int i;
+
+    for (i = 0; i < n_sources; i++) {
+      /* No updates from inactive sources */
+      if (!sources[i]->active)
+        continue;
+
+      /* Don't expect more updates than from an offline iburst NTP source */
+      if (sources[i]->reachability_size >= SOURCE_REACH_BITS - 1)
+        continue;
+
+      /* 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)
+        return 0;
+    }
+
+    return 1;
+}
+
 void
 SRC_UpdateReachability(SRC_Instance inst, int reachable)
 {
  inst->reachability <<= 1;
  inst->reachability |= !!reachable;
-  inst->reachability &= ~(-1 << REACH_BITS);
+  inst->reachability &= ~(-1 << SOURCE_REACH_BITS);

-  /* The beginning is over when the first sample is at the end of the register */
-  if (inst->reachability & (1 << (REACH_BITS - 1)))
-      inst->beginning = 0;
+  if (inst->reachability_size < SOURCE_REACH_BITS)
+      inst->reachability_size++;

  if (!reachable && inst->index == selected_source_index) {
    /* Try to select a better source */
-    SRC_SelectSource(0);
+    SRC_SelectSource(NULL);
+  }
+
+  /* Check if special reference update mode failed */
+  if (REF_GetMode() != REF_ModeNormal && special_mode_end()) {
+    REF_SetUnsynchronised();
  }
 }

@@ -383,12 +425,23 @@ SRC_ResetReachability(SRC_Instance inst)
     a peer selected even when not reachable */
 #if 0
  inst->reachability = 0;
+  inst->reachability_size = 0;
  SRC_UpdateReachability(inst, 0);
 #endif
 }

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

+static void
+log_selection_message(char *format, char *arg)
+{
+  if (REF_GetMode() != REF_ModeNormal)
+    return;
+  LOG(LOGS_INFO, LOGF_Sources, format, arg);
+}
+
+/* ================================================== */
+
 static int
 compare_sort_elements(const void *a, const void *b)
 {
@@ -459,7 +512,9 @@ combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
           (reselect_distance + sources[selected_source_index]->sel_info.root_distance) ||
         fabs(*frequency - src_frequency) >
           combine_limit * (*skew + src_skew + LCL_GetMaxClockError()))) {
-      sources[index]->outlier = !sources[index]->beginning ? OUTLIER_PENALTY : 1;
+      /* Use a smaller penalty in first few updates */
+      sources[index]->outlier = sources[index]->reachability_size >= SOURCE_REACH_BITS ?
+                                OUTLIER_PENALTY : 1;
    } else if (sources[index]->outlier) {
      sources[index]->outlier--;
    }
@@ -472,10 +527,8 @@ combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
    offset_weight = 1.0 / sources[index]->sel_info.root_distance;
    frequency_weight = 1.0 / src_skew;

-#ifdef TRACEON
-    LOG(LOGS_INFO, LOGF_Sources, "combining index=%d oweight=%e offset=%e sd=%e fweight=%e freq=%e skew=%e",
+    DEBUG_LOG(LOGF_Sources, "combining index=%d oweight=%e offset=%e sd=%e fweight=%e freq=%e skew=%e",
        index, offset_weight, src_offset, src_offset_sd, frequency_weight, src_frequency, src_skew);
-#endif

    sum_offset_weight += offset_weight;
    sum_offset += offset_weight * src_offset;
@@ -495,10 +548,8 @@ combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
  *frequency = sum_frequency / sum_frequency_weight;
  *skew = 1.0 / sqrt(inv_sum2_skew);

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_Sources, "combined result offset=%e sd=%e freq=%e skew=%e",
+  DEBUG_LOG(LOGF_Sources, "combined result offset=%e sd=%e freq=%e skew=%e",
      *offset, *offset_sd, *frequency, *skew);
-#endif

  return combined;
 }
@@ -511,9 +562,9 @@ combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
   or match_refid is equal to the selected reference source refid */

 void
-SRC_SelectSource(uint32_t match_refid)
+SRC_SelectSource(SRC_Instance updated_inst)
 {
-  int i, j, index, old_selected_index;
+  int i, j, index, old_selected_index, sel_prefer;
  struct timeval now, ref_time;
  double src_offset, src_offset_sd, src_frequency, src_skew;
  double src_root_delay, src_root_dispersion;
@@ -535,7 +586,7 @@ SRC_SelectSource(uint32_t match_refid)
  if (n_sources == 0) {
    /* In this case, we clearly cannot synchronise to anything */
    if (selected_source_index != INVALID_SOURCE) {
-      LOG(LOGS_INFO, LOGF_Sources, "Can't synchronise: no sources");
+      log_selection_message("Can't synchronise: no sources", NULL);
      selected_source_index = INVALID_SOURCE;
      REF_SetUnsynchronised();
    }
@@ -564,13 +615,6 @@ SRC_SelectSource(uint32_t match_refid)
                           &(si->variance),
                           &(si->select_ok));

-#if 0
-      LOG(LOGS_INFO, LOGF_Sources, "%s dist=%f lo=%f hi=%f",
-          source_to_string(sources[i]),
-          si->root_distance,
-          si->lo_limit, si->hi_limit);
-#endif
-      
      if (si->select_ok) {
        ++n_sel_sources;

@@ -609,10 +653,8 @@ SRC_SelectSource(uint32_t match_refid)
    }
  }

-#if 0
-  LOG(LOGS_INFO, LOGF_Sources, "badstat_sources=%d sel_sources=%d badstat_reach=%x sel_reach=%x",
+  DEBUG_LOG(LOGF_Sources, "badstat_sources=%d sel_sources=%d badstat_reach=%x sel_reach=%x",
      n_badstats_sources, n_sel_sources, max_badstat_reach, max_sel_reach);
-#endif

  /* Wait for the next call if we have no source selected and there is
     a source with bad stats (has less than 3 samples) with reachability
@@ -626,10 +668,6 @@ SRC_SelectSource(uint32_t match_refid)
    return;
  }

-#if 0
-  LOG(LOGS_INFO, LOGF_Sources, "n_endpoints=%d", n_endpoints);
-#endif
-
  /* Now sort the endpoint list */
  if (n_endpoints > 0) {

@@ -663,10 +701,6 @@ SRC_SelectSource(uint32_t match_refid)
    best_lo = best_hi = 0.0;

    for (i=0; i<n_endpoints; i++) {
-#if 0
-      LOG(LOGS_INFO, LOGF_Sources, "i=%d t=%f tag=%d addr=%s", i, sort_list[i].offset, sort_list[i].tag,
-          source_to_string(sources[sort_list[i].index]));
-#endif
      switch(sort_list[i].tag) {
        case LOW:
          depth++;
@@ -690,11 +724,6 @@ SRC_SelectSource(uint32_t match_refid)
      }
    }

-#if 0
-    LOG(LOGS_INFO, LOGF_Sources, "best_depth=%d best_lo=%f best_hi=%f",
-        best_depth, best_lo, best_hi);
-#endif
-
    if (best_depth <= n_sel_sources/2) {
      /* Could not even get half the reachable sources to agree -
         clearly we can't synchronise.
@@ -708,7 +737,7 @@ SRC_SelectSource(uint32_t match_refid)
           */

      if (selected_source_index != INVALID_SOURCE) {
-        LOG(LOGS_INFO, LOGF_Sources, "Can't synchronise: no majority");
+        log_selection_message("Can't synchronise: no majority", NULL);
      }
      selected_source_index = INVALID_SOURCE;

@@ -737,14 +766,8 @@ SRC_SelectSource(uint32_t match_refid)
               (sources[i]->sel_info.hi_limit <= best_hi))) {

            sel_sources[n_sel_sources++] = i;
-#if 0
-            LOG(LOGS_INFO, LOGF_Sources, "i=%d addr=%s is valid", i, source_to_string(sources[i]));
-#endif
          } else {
            sources[i]->status = SRC_FALSETICKER;
-#if 0
-            LOG(LOGS_INFO, LOGF_Sources, "i=%d addr=%s is a falseticker", i, source_to_string(sources[i]));
-#endif
          }
        }
      }
@@ -765,10 +788,6 @@ SRC_SelectSource(uint32_t match_refid)
        }
      }

-#if 0
-      LOG(LOGS_INFO, LOGF_Sources, "min_distance=%f", min_distance);
-#endif
-
      /* Now go through and prune any NTP sources that have excessive
         variance */
      for (i=0; i<n_sel_sources; i++) {
@@ -777,9 +796,6 @@ SRC_SelectSource(uint32_t match_refid)
            sqrt(sources[index]->sel_info.variance) > min_distance) {
          sel_sources[i] = INVALID_SOURCE;
          sources[index]->status = SRC_JITTERY;
-#if 0
-          LOG(LOGS_INFO, LOGF_Sources, "i=%d addr=%s has too much variance", i, source_to_string(sources[i]));
-#endif
        }
      }
 #endif
@@ -790,7 +806,6 @@ SRC_SelectSource(uint32_t match_refid)
        if (index != INVALID_SOURCE) {
          sources[index]->status = SRC_SELECTABLE;
          sel_sources[j++] = sel_sources[i];
-          index++;
        }
      }
      n_sel_sources = j;
@@ -822,6 +837,9 @@ SRC_SelectSource(uint32_t match_refid)
        }
        if (j > 0) {
          n_sel_sources = j;
+          sel_prefer = 1;
+        } else {
+          sel_prefer = 0;
        }

        /* Now find minimum stratum.  If none are left now,
@@ -836,10 +854,6 @@ SRC_SelectSource(uint32_t match_refid)
          if (stratum < min_stratum) min_stratum = stratum;
        }

-#if 0
-        LOG(LOGS_INFO, LOGF_Sources, "min_stratum=%d", min_stratum);
-#endif
-
        /* Update scores and find source with maximum score */

        max_score_index = INVALID_SOURCE;
@@ -854,7 +868,8 @@ SRC_SelectSource(uint32_t match_refid)
        for (i = 0; i < n_sources; i++) {

          /* Reset score for non-selectable sources */
-          if (sources[i]->status != SRC_SELECTABLE) {
+          if (sources[i]->status != SRC_SELECTABLE ||
+              (sel_prefer && sources[i]->sel_option != SRC_SelectPrefer)) {
            sources[i]->sel_score = 1.0;
            sources[i]->outlier = OUTLIER_PENALTY;
            continue;
@@ -869,8 +884,8 @@ SRC_SelectSource(uint32_t match_refid)

            /* Update score, but only for source pairs where one source
               has a new sample */
-            if (sources[i]->ref_id == match_refid ||
-                sources[selected_source_index]->ref_id == match_refid) {
+            if (sources[i] == updated_inst ||
+                sources[selected_source_index] == updated_inst) {

              sources[i]->sel_score *= sel_src_distance / distance;

@@ -887,10 +902,9 @@ SRC_SelectSource(uint32_t match_refid)
            sources[i]->sel_score = 1.0 / distance; 
          }

-#if 0
-          LOG(LOGS_INFO, LOGF_Sources, "select score=%f refid=%lx match_refid=%lx status=%d dist=%f",
-              sources[i]->sel_score, sources[i]->ref_id, match_refid, sources[i]->status, distance);
-#endif
+          DEBUG_LOG(LOGF_Sources, "select score=%f refid=%x match_refid=%x status=%d dist=%f",
+              sources[i]->sel_score, sources[i]->ref_id, updated_inst ? updated_inst->ref_id : 0,
+              sources[i]->status, distance);
        
          if (max_score < sources[i]->sel_score) {
            max_score = sources[i]->sel_score;
@@ -910,13 +924,9 @@ SRC_SelectSource(uint32_t match_refid)
          /* We have to elect a new synchronisation source */

          selected_source_index = max_score_index;
-          LOG(LOGS_INFO, LOGF_Sources, "Selected source %s",
+          log_selection_message("Selected source %s",
                source_to_string(sources[selected_source_index]));
                                 
-#if 0
-          LOG(LOGS_INFO, LOGF_Sources, "new_sel_index=%d", selected_source_index);
-#endif
-
          /* New source has been selected, reset all scores */
          for (i=0; i < n_sources; i++) {
            sources[i]->sel_score = 1.0;
@@ -926,10 +936,10 @@ SRC_SelectSource(uint32_t match_refid)

        sources[selected_source_index]->status = SRC_SYNC;

-        /* Update local reference only when a new source was selected or a new
-           sample was received (i.e. match_refid is equal to selected refid) */
+        /* Update local reference only when a new source was selected
+           or the selected source has a new sample */
        if (selected_source_index != old_selected_index ||
-            match_refid == sources[selected_source_index]->ref_id) {
+            updated_inst == sources[selected_source_index]) {

          /* Now just use the statistics of the selected source combined with
             the other selectable sources for trimming the local clock */
@@ -958,7 +968,7 @@ SRC_SelectSource(uint32_t match_refid)

      } else {
        if (selected_source_index != INVALID_SOURCE) {
-          LOG(LOGS_INFO, LOGF_Sources, "Can't synchronise: no selectable sources");
+          log_selection_message("Can't synchronise: no selectable sources", NULL);
        }
        selected_source_index = INVALID_SOURCE;
      }
@@ -967,7 +977,7 @@ SRC_SelectSource(uint32_t match_refid)
  } else {
    /* No sources provided valid endpoints */
    if (selected_source_index != INVALID_SOURCE) {
-      LOG(LOGS_INFO, LOGF_Sources, "Can't synchronise: no reachable sources");
+      log_selection_message("Can't synchronise: no reachable sources", NULL);
    }
    selected_source_index = INVALID_SOURCE;
  }
@@ -985,7 +995,7 @@ void
 SRC_ReselectSource(void)
 {
  selected_source_index = INVALID_SOURCE;
-  SRC_SelectSource(0);
+  SRC_SelectSource(NULL);
 }

 /* ================================================== */
@@ -1037,15 +1047,23 @@ slew_sources(struct timeval *raw,
             struct timeval *cooked,
             double dfreq,
             double doffset,
-             int is_step_change,
+             LCL_ChangeType change_type,
             void *anything)
 {
  int i;

  for (i=0; i<n_sources; i++) {
-    SST_SlewSamples(sources[i]->stats, cooked, dfreq, doffset);
+    if (change_type == LCL_ChangeUnknownStep) {
+      SST_ResetInstance(sources[i]->stats);
+    } else {
+      SST_SlewSamples(sources[i]->stats, cooked, dfreq, doffset);
+    }
+  }
+
+  if (change_type == LCL_ChangeUnknownStep) {
+    /* After resetting no source is selectable, set reference unsynchronised */
+    SRC_SelectSource(NULL);
  }
-  
 }

 /* ================================================== */
@@ -1154,6 +1172,14 @@ SRC_IsSyncPeer(SRC_Instance inst)

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

+int
+SRC_IsReachable(SRC_Instance inst)
+{
+  return inst->reachability != 0;
+}
+
+/* ================================================== */
+
 int
 SRC_ReadNumberOfSources(void)
 {
@@ -1162,6 +1188,20 @@ SRC_ReadNumberOfSources(void)

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

+int
+SRC_ActiveSources(void)
+{
+  int i, r;
+
+  for (i = r = 0; i < n_sources; i++)
+    if (sources[i]->active)
+      r++;
+
+  return r;
+}
+
+/* ================================================== */
+
 int
 SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
 {
--- a/sources.h
+++ b/sources.h
@@ -3,6 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2002
+ * Copyright (C) Miroslav Lichvar  2014
 * 
 * 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
@@ -34,6 +35,9 @@
 #include "ntp.h"
 #include "reports.h"

+/* Size of the source reachability register */
+#define SOURCE_REACH_BITS 8
+
 /* This datatype is used to hold information about sources.  The
   instance must be passed when calling many of the interface
   functions */
@@ -114,6 +118,12 @@ 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);

+/* This routine sets the source as receiving reachability updates */
+extern void SRC_SetActive(SRC_Instance inst);
+
+/* This routine sets the source as not receiving reachability updates */
+extern void SRC_UnsetActive(SRC_Instance inst);
+
 /* This routine indicates that packets with valid headers are being
   received from the designated source */
 extern void SRC_SetSelectable(SRC_Instance instance);
@@ -131,11 +141,11 @@ extern void SRC_ResetReachability(SRC_Instance inst);
 /* This routine is used to select the best source from amongst those
   we currently have valid data on, and use it as the tracking base
   for the local time.  Updates are only made to the local reference
-   if a new source is selected or match_addr is equal to the selected
-   reference source address. (This avoids updating the frequency
+   if a new source is selected or updated_inst is the selected
+   reference source. (This avoids updating the frequency
   tracking for every sample from other sources - only the ones from
   the selected reference make a difference) */
-extern void SRC_SelectSource(uint32_t match_refid);
+extern void SRC_SelectSource(SRC_Instance updated_inst);

 /* Force reselecting the best source */
 extern void SRC_ReselectSource(void);
@@ -161,7 +171,9 @@ extern void SRC_DumpSources(void);
 extern void SRC_ReloadSources(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_ReportSourcestats(int index, RPT_SourcestatsReport *report, struct timeval *now);
--- a/sourcestats.c
+++ b/sourcestats.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2012
+ * Copyright (C) Miroslav Lichvar  2011-2014
 * 
 * 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
@@ -188,6 +188,26 @@ SST_CreateInstance(uint32_t refid, IPAddr *addr)
  inst = MallocNew(struct SST_Stats_Record);
  inst->refid = refid;
  inst->ip_addr = addr;
+
+  SST_ResetInstance(inst);
+
+  return inst;
+}
+
+/* ================================================== */
+/* This function deletes an instance of the statistics handler. */
+
+void
+SST_DeleteInstance(SST_Stats inst)
+{
+  Free(inst);
+}
+
+/* ================================================== */
+
+void
+SST_ResetInstance(SST_Stats inst)
+{
  inst->n_samples = 0;
  inst->runs_samples = 0;
  inst->last_sample = 0;
@@ -203,16 +223,6 @@ SST_CreateInstance(uint32_t refid, IPAddr *addr)
  inst->offset_time.tv_usec = 0;
  inst->variance = 16.0;
  inst->nruns = 0;
-  return inst;
-}
-
-/* ================================================== */
-/* This function deletes an instance of the statistics handler. */
-
-void
-SST_DeleteInstance(SST_Stats inst)
-{
-  Free(inst);
 }

 /* ================================================== */
@@ -258,7 +268,7 @@ SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time,
      UTI_CompareTimevals(&inst->sample_times[inst->last_sample], sample_time) >= 0) {
    LOG(LOGS_WARN, LOGF_SourceStats, "Out of order sample detected, discarding history for %s",
        inst->ip_addr ? UTI_IPToString(inst->ip_addr) : UTI_RefidToString(inst->refid));
-    prune_register(inst, inst->n_samples);
+    SST_ResetInstance(inst);
  }

  n = inst->last_sample = (inst->last_sample + 1) %
@@ -353,10 +363,6 @@ find_best_sample_index(SST_Stats inst, double *times_back)

  assert(best_index >= 0);
  inst->best_single_sample = best_index;
-
-#if 0
-  LOG(LOGS_INFO, LOGF_SourceStats, "n=%d best_index=%d", n, best_index);
-#endif
 }

 /* ================================================== */
@@ -490,9 +496,6 @@ SST_DoNewRegression(SST_Stats inst)
    times_back_start = inst->runs_samples + best_start;
    prune_register(inst, best_start);
  } else {
-#if 0
-    LOG(LOGS_INFO, LOGF_SourceStats, "too few points (%d) for regression", inst->n_samples);
-#endif
    inst->estimated_frequency = 0.0;
    inst->skew = WORST_CASE_FREQ_BOUND;
    times_back_start = 0;
@@ -569,10 +572,8 @@ SST_GetSelectionData(SST_Stats inst, struct timeval *now,

  *select_ok = inst->regression_ok;

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_SourceStats, "n=%d off=%f dist=%f var=%f selok=%d",
+  DEBUG_LOG(LOGF_SourceStats, "n=%d off=%f dist=%f var=%f selok=%d",
      inst->n_samples, offset, *root_distance, *variance, *select_ok);
-#endif
 }

 /* ================================================== */
@@ -586,6 +587,8 @@ SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,
  int i, j;
  double elapsed_sample;

+  assert(inst->n_samples > 0);
+
  i = get_runsbuf_index(inst, inst->best_single_sample);
  j = get_buf_index(inst, inst->best_single_sample);

@@ -599,10 +602,8 @@ SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,
  UTI_DiffTimevalsToDouble(&elapsed_sample, &inst->offset_time, &inst->sample_times[i]);
  *root_dispersion = inst->root_dispersions[j] + inst->skew * elapsed_sample;

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_SourceStats, "n=%d freq=%f (%.3fppm) skew=%f (%.3fppm) avoff=%f offsd=%f disp=%f",
+  DEBUG_LOG(LOGF_SourceStats, "n=%d freq=%f (%.3fppm) skew=%f (%.3fppm) avoff=%f offsd=%f disp=%f",
      inst->n_samples, *frequency, 1.0e6* *frequency, *skew, 1.0e6* *skew, *average_offset, *offset_sd, *root_dispersion);
-#endif

 }

@@ -626,13 +627,10 @@ SST_SlewSamples(SST_Stats inst, struct timeval *when, double dfreq, double doffs
    UTI_AdjustTimeval(sample, when, sample, &delta_time, dfreq, doffset);
    prev_offset = inst->offsets[i];
    inst->offsets[i] += delta_time;
-#ifdef TRACEON
-    LOG(LOGS_INFO, LOGF_SourceStats, "i=%d old_st=[%s] new_st=[%s] old_off=%f new_off=%f",
+
+    DEBUG_LOG(LOGF_SourceStats, "i=%d old_st=[%s] new_st=[%s] old_off=%f new_off=%f",
        i, UTI_TimevalToString(&prev), UTI_TimevalToString(sample),
        prev_offset, inst->offsets[i]);
-#else
-    (void)prev_offset;
-#endif
  }

  /* Do a half-baked update to the regression estimates */
@@ -644,14 +642,10 @@ SST_SlewSamples(SST_Stats inst, struct timeval *when, double dfreq, double doffs
  inst->estimated_offset += delta_time;
  inst->estimated_frequency -= dfreq;

-#ifdef TRACEON
-  LOG(LOGS_INFO, LOGF_SourceStats, "old_off_time=[%s] new=[%s] old_off=%f new_off=%f old_freq=%.3fppm new_freq=%.3fppm",
+  DEBUG_LOG(LOGF_SourceStats, "old_off_time=[%s] new=[%s] old_off=%f new_off=%f old_freq=%.3fppm new_freq=%.3fppm",
      UTI_TimevalToString(&prev), UTI_TimevalToString(&(inst->offset_time)),
      prev_offset, inst->estimated_offset,
      1.0e6*prev_freq, 1.0e6*inst->estimated_frequency);
-#else
-  (void)prev; (void)prev_freq;
-#endif
 }

 /* ================================================== */
@@ -733,9 +727,8 @@ SST_IsGoodSample(SST_Stats inst, double offset, double delay,
  if (fabs(offset) - delay_increase > allowed_increase)
    return 1;

-#if 0
-  LOG(LOGS_INFO, LOGF_SourceStats, "bad sample: offset=%f delay=%f incr_delay=%f allowed=%f", offset, delay, allowed_increase, delay_increase);
-#endif
+  DEBUG_LOG(LOGF_SourceStats, "Bad sample: offset=%f delay=%f incr_delay=%f allowed=%f",
+      offset, delay, allowed_increase, delay_increase);

  return 0;
 }
@@ -781,8 +774,11 @@ SST_LoadFromFile(SST_Stats inst, FILE *in)
  unsigned long sec, usec;
  double weight;

+  assert(!inst->n_samples);
+
  if (fgets(line, sizeof(line), in) &&
-      (sscanf(line, "%u", &inst->n_samples) == 1) && inst->n_samples <= MAX_SAMPLES) {
+      sscanf(line, "%d", &inst->n_samples) == 1 &&
+      inst->n_samples > 0 && inst->n_samples <= MAX_SAMPLES) {

    line_number = 2;

--- a/sourcestats.h
+++ b/sourcestats.h
@@ -43,6 +43,9 @@ extern SST_Stats SST_CreateInstance(uint32_t refid, IPAddr *addr);
 /* This function deletes an instance of the statistics handler. */
 extern void SST_DeleteInstance(SST_Stats inst);

+/* This function resets an instance */
+extern void SST_ResetInstance(SST_Stats inst);
+
 /* This function accumulates a single sample into the statistics handler

   sample_time is the epoch at which the sample is to be considered to
@@ -67,11 +70,6 @@ extern void SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time, do
   down to that number of samples. */
 extern void SST_DoNewRegression(SST_Stats inst);

-/* This function does a simple regression on what is in the register,
-   without trying to optimise the error bounds on the frequency by
-   deleting old samples */
-extern void SST_DoUpdateRegression(SST_Stats inst);
-
 /* Return the assumed worst case range of values that this source's
   frequency lies within.  Frequency is defined as the amount of time
   the local clock gains relative to the source per unit local clock
--- a/sys_generic.c
+++ b/sys_generic.c
@@ -0,0 +1,314 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2014
+ * 
+ * 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.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Generic driver functions to complete system-specific drivers
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "sys_generic.h"
+
+#include "conf.h"
+#include "local.h"
+#include "localp.h"
+#include "logging.h"
+#include "sched.h"
+#include "util.h"
+
+/* ================================================== */
+
+/* System clock frequency drivers */
+static lcl_ReadFrequencyDriver drv_read_freq;
+static lcl_SetFrequencyDriver drv_set_freq;
+
+/* Current frequency as requested by the local module (in ppm) */
+static double base_freq;
+
+/* Maximum frequency that can be set by drv_set_freq (in ppm) */
+static double max_freq;
+
+/* Maximum expected delay in the actual frequency change (e.g. kernel ticks)
+   in local time */
+static double max_freq_change_delay;
+
+/* Maximum allowed frequency offset relative to the base frequency */
+static double max_corr_freq;
+
+/* Amount of outstanding offset to process */
+static double offset_register;
+
+/* Minimum offset to correct */
+#define MIN_OFFSET_CORRECTION 1.0e-9
+
+/* Current frequency offset between base_freq and the real clock frequency
+   as set by drv_set_freq (not in ppm) */
+static double slew_freq;
+
+/* Time (raw) of last update of slewing frequency and offset */
+static struct timeval slew_start;
+
+/* Limits for the slew timeout */
+#define MIN_SLEW_TIMEOUT 1.0
+#define MAX_SLEW_TIMEOUT 1.0e4
+
+/* Scheduler timeout ID and flag if the timer is currently running */
+static SCH_TimeoutID slew_timeout_id;
+static int slew_timer_running;
+
+/* Suggested offset correction rate (correction time * offset) */
+static double correction_rate;
+
+/* Maximum expected offset correction error caused by delayed change in the
+   real frequency of the clock */
+static double slew_error;
+
+/* ================================================== */
+
+static void handle_end_of_slew(void *anything);
+static void update_slew(void);
+
+/* ================================================== */
+/* Adjust slew_start on clock step */
+
+static void
+handle_step(struct timeval *raw, struct timeval *cooked, double dfreq,
+            double doffset, LCL_ChangeType change_type, void *anything)
+{
+  if (change_type == LCL_ChangeUnknownStep) {
+    /* Reset offset and slewing */
+    slew_start = *raw;
+    offset_register = 0.0;
+    update_slew();
+  } else if (change_type == LCL_ChangeStep) {
+    UTI_AddDoubleToTimeval(&slew_start, -doffset, &slew_start);
+  }
+}
+
+/* ================================================== */
+/* End currently running slew and start a new one */
+
+static void
+update_slew(void)
+{
+  struct timeval now, end_of_slew;
+  double old_slew_freq, total_freq, corr_freq, duration;
+
+  /* Remove currently running timeout */
+  if (slew_timer_running)
+    SCH_RemoveTimeout(slew_timeout_id);
+
+  LCL_ReadRawTime(&now);
+
+  /* Adjust the offset register by achieved slew */
+  UTI_DiffTimevalsToDouble(&duration, &now, &slew_start);
+  offset_register -= slew_freq * duration;
+
+  /* Estimate how long should the next slew take */
+  if (fabs(offset_register) < MIN_OFFSET_CORRECTION) {
+    duration = MAX_SLEW_TIMEOUT;
+  } else {
+    duration = correction_rate / fabs(offset_register);
+    if (duration < MIN_SLEW_TIMEOUT)
+      duration = MIN_SLEW_TIMEOUT;
+  }
+
+  /* Get frequency offset needed to slew the offset in the duration
+     and clamp it to the allowed maximum */
+  corr_freq = offset_register / duration;
+  if (corr_freq < -max_corr_freq)
+    corr_freq = -max_corr_freq;
+  else if (corr_freq > max_corr_freq)
+    corr_freq = max_corr_freq;
+
+  /* Get the new real frequency and clamp it */
+  total_freq = base_freq + corr_freq * (1.0e6 - base_freq);
+  if (total_freq > max_freq)
+    total_freq = max_freq;
+  else if (total_freq < -max_freq)
+    total_freq = -max_freq;
+
+  /* Set the new frequency (the actual frequency returned by the call may be
+     slightly different from the requested frequency due to rounding) */
+  total_freq = (*drv_set_freq)(total_freq);
+
+  /* Compute the new slewing frequency, it's relative to the real frequency to
+     make the calculation in offset_convert() cheaper */
+  old_slew_freq = slew_freq;
+  slew_freq = (total_freq - base_freq) / (1.0e6 - total_freq);
+
+  /* Compute the dispersion introduced by changing frequency and add it
+     to all statistics held at higher levels in the system */
+  slew_error = fabs((old_slew_freq - slew_freq) * max_freq_change_delay);
+  if (slew_error >= MIN_OFFSET_CORRECTION)
+    lcl_InvokeDispersionNotifyHandlers(slew_error);
+
+  /* Compute the duration of the slew and clamp it.  If the slewing frequency
+     is zero or has wrong sign (e.g. due to rounding in the frequency driver or
+     when base_freq is larger than max_freq), use maximum timeout and try again
+     on the next update. */
+  if (fabs(offset_register) < MIN_OFFSET_CORRECTION ||
+      offset_register * slew_freq <= 0.0) {
+    duration = MAX_SLEW_TIMEOUT;
+  } else {
+    duration = offset_register / slew_freq;
+    if (duration < MIN_SLEW_TIMEOUT)
+      duration = MIN_SLEW_TIMEOUT;
+    else if (duration > MAX_SLEW_TIMEOUT)
+      duration = MAX_SLEW_TIMEOUT;
+  }
+
+  /* Restart timer for the next update */
+  UTI_AddDoubleToTimeval(&now, duration, &end_of_slew);
+  slew_timeout_id = SCH_AddTimeout(&end_of_slew, handle_end_of_slew, NULL);
+
+  slew_start = now;
+  slew_timer_running = 1;
+
+  DEBUG_LOG(LOGF_SysGeneric, "slew offset=%e corr_rate=%e base_freq=%f total_freq=%f slew_freq=%e duration=%f slew_error=%e",
+      offset_register, correction_rate, base_freq, total_freq, slew_freq,
+      duration, slew_error);
+}
+
+/* ================================================== */
+
+static void
+handle_end_of_slew(void *anything)
+{
+  slew_timer_running = 0;
+  update_slew();
+}
+
+/* ================================================== */
+
+static double
+read_frequency(void)
+{
+  return base_freq;
+}
+
+/* ================================================== */
+
+static double
+set_frequency(double freq_ppm)
+{
+  base_freq = freq_ppm;
+  update_slew();
+
+  return base_freq;
+}
+
+/* ================================================== */
+
+static void
+accrue_offset(double offset, double corr_rate)
+{
+  offset_register += offset;
+  correction_rate = corr_rate;
+
+  update_slew();
+}
+
+/* ================================================== */
+/* Determine the correction to generate the cooked time for given raw time */
+
+static void
+offset_convert(struct timeval *raw,
+               double *corr, double *err)
+{
+  double duration;
+
+  UTI_DiffTimevalsToDouble(&duration, raw, &slew_start);
+
+  *corr = slew_freq * duration - offset_register;
+  if (err)
+    *err = fabs(duration) <= max_freq_change_delay ? slew_error : 0.0;
+}
+
+/* ================================================== */
+/* Positive means currently fast of true time, i.e. jump backwards */
+
+static void
+apply_step_offset(double offset)
+{
+  struct timeval old_time, new_time;
+  double err;
+
+  LCL_ReadRawTime(&old_time);
+  UTI_AddDoubleToTimeval(&old_time, -offset, &new_time);
+
+  if (settimeofday(&new_time, NULL) < 0) {
+    LOG_FATAL(LOGF_SysGeneric, "settimeofday() failed");
+  }
+
+  LCL_ReadRawTime(&old_time);
+  UTI_DiffTimevalsToDouble(&err, &old_time, &new_time);
+
+  lcl_InvokeDispersionNotifyHandlers(fabs(err));
+}
+
+/* ================================================== */
+
+void
+SYS_Generic_CompleteFreqDriver(double max_set_freq_ppm, double max_set_freq_delay,
+                               lcl_ReadFrequencyDriver sys_read_freq,
+                               lcl_SetFrequencyDriver sys_set_freq,
+                               lcl_ApplyStepOffsetDriver sys_apply_step_offset,
+                               lcl_SetLeapDriver sys_set_leap)
+{
+  max_freq = max_set_freq_ppm;
+  max_freq_change_delay = max_set_freq_delay * (1.0 + max_freq / 1.0e6);
+  drv_read_freq = sys_read_freq;
+  drv_set_freq = sys_set_freq;
+
+  base_freq = (*drv_read_freq)();
+  slew_freq = 0.0;
+  offset_register = 0.0;
+
+  max_corr_freq = CNF_GetMaxSlewRate() / 1.0e6;
+
+  lcl_RegisterSystemDrivers(read_frequency, set_frequency,
+                            accrue_offset, sys_apply_step_offset ?
+                              sys_apply_step_offset : apply_step_offset,
+                            offset_convert, sys_set_leap);
+
+  LCL_AddParameterChangeHandler(handle_step, NULL);
+}
+
+/* ================================================== */
+
+void
+SYS_Generic_Finalise(void)
+{
+  /* Must *NOT* leave a slew running - clock could drift way off
+     if the daemon is not restarted */
+  if (slew_timer_running) {
+    SCH_RemoveTimeout(slew_timeout_id);
+    slew_timer_running = 0;
+  }
+
+  (*drv_set_freq)(base_freq);
+}
+
+/* ================================================== */
--- a/sys_generic.h
+++ b/sys_generic.h
@@ -0,0 +1,42 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2014
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Header file for generic driver
+  */
+
+#ifndef GOT_SYS_GENERIC_H
+#define GOT_SYS_GENERIC_H
+
+#include "localp.h"
+
+/* Register a completed driver that implements offset functions on top of
+   provided frequency functions */
+extern void SYS_Generic_CompleteFreqDriver(double max_set_freq_ppm, double max_set_freq_delay,
+                                           lcl_ReadFrequencyDriver sys_read_freq,
+                                           lcl_SetFrequencyDriver sys_set_freq,
+                                           lcl_ApplyStepOffsetDriver sys_apply_step_offset,
+                                           lcl_SetLeapDriver sys_set_leap);
+
+extern void SYS_Generic_Finalise(void);
+
+#endif  /* GOT_SYS_GENERIC_H */
--- a/sys_linux.c
+++ b/sys_linux.c
--- a/sys_netbsd.c
+++ b/sys_netbsd.c
@@ -281,7 +281,6 @@ SYS_NetBSD_Initialise(void)
  };

  kvm_t *kt;
-  FILE *fp;

  kt = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL);
  if (!kt) {
--- a/sys_solaris.c
+++ b/sys_solaris.c
@@ -409,11 +409,6 @@ set_dosynctodr(unsigned long on_off)
  kvm_close(kt);

  assert(read_back == on_off);
-
-#if 0
-  LOG(LOGS_INFO, LOGF_SysSolaris, "Set value of dosynctodr to %d", on_off);
-#endif
-
 }

 /* ================================================== */
--- a/sys_sunos.c
+++ b/sys_sunos.c
@@ -364,11 +364,6 @@ setup_kernel(unsigned long on_off)
  }

  kvm_close(kt);
-
-#if 0
-  LOG(LOGS_INFO, LOGF_SysSunOS, "Set value of _dosynctodr to %d", on_off);
-#endif
-
 }

 /* ================================================== */
--- a/sysincl.h
+++ b/sysincl.h
@@ -62,10 +62,10 @@
 #include <syslog.h>
 #include <time.h>

-#if HAS_STDINT_H
-#include <stdint.h>
-#elif defined(HAS_INTTYPES_H)
+#ifdef HAS_INTTYPES_H
 #include <inttypes.h>
+#elif HAS_STDINT_H
+#include <stdint.h>
 #else
 /* Tough */
 #endif
--- a/tempcomp.c
+++ b/tempcomp.c
@@ -2,7 +2,7 @@
  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************
- * Copyright (C) Miroslav Lichvar  2011
+ * Copyright (C) Miroslav Lichvar  2011, 2014
 * 
 * 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 +35,9 @@
 #include "sched.h"
 #include "tempcomp.h"

+/* Sanity limit (in ppm) */
+#define MAX_COMP 10.0
+
 static SCH_TimeoutID timeout_id;

 static LOG_FileID logfileid;
@@ -54,8 +57,7 @@ read_timeout(void *arg)
  if (f && fscanf(f, "%lf", &temp) == 1) {
    comp = k0 + (temp - T0) * k1 + (temp - T0) * (temp - T0) * k2;

-    /* Don't allow corrections above 10 ppm */
-    if (fabs(comp) < 10.0) {
+    if (fabs(comp) <= MAX_COMP) {
      comp = LCL_SetTempComp(comp);

      if (logfileid != -1) {
@@ -65,7 +67,14 @@ read_timeout(void *arg)
        LOG_FileWrite(logfileid, "%s %11.4e %11.4e",
            UTI_TimeToLogForm(now.tv_sec), temp, comp);
      }
+    } else {
+      LOG(LOGS_WARN, LOGF_TempComp,
+          "Temperature compensation of %.3f ppm exceeds sanity limit of %.1f",
+          comp, MAX_COMP);
    }
+  } else {
+    LOG(LOGS_WARN, LOGF_TempComp, "Could not read temperature from %s",
+        filename);
  }

  if (f)
--- a/test/simulation/001-defaults
+++ b/test/simulation/001-defaults
@@ -0,0 +1,13 @@
+#!/bin/bash
+
+. test.common
+
+test_start "default test settings"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
--- a/test/simulation/002-largenetwork
+++ b/test/simulation/002-largenetwork
@@ -0,0 +1,22 @@
+#!/bin/bash
+
+. test.common
+
+test_start "large network"
+
+time_rms_limit=5e-4
+
+server_strata=3
+servers=4
+clients=5
+
+client_start=2000
+min_sync_time=2100
+max_sync_time=2300
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
--- a/test/simulation/003-largefreqoffset
+++ b/test/simulation/003-largefreqoffset
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+. test.common
+
+test_start "large frequency offset"
+
+max_sync_time=1000
+
+for freq_offset in -5e-2 -5e-3 5e-3 5e-2; do
+	# Adjust offset so it's close to 0 on first clock update
+	time_offset=$(awk "BEGIN {print -($freq_offset * 130)}")
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
--- a/test/simulation/004-largetimeoffset
+++ b/test/simulation/004-largetimeoffset
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+. test.common
+
+test_start "large time offset"
+
+min_sync_time=1300
+max_sync_time=1400
+
+for time_offset in -1e2 1e2; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
--- a/test/simulation/005-externalstep
+++ b/test/simulation/005-externalstep
@@ -0,0 +1,46 @@
+#!/bin/bash
+
+. test.common
+
+test_start "external time step"
+
+min_sync_time=1500
+max_sync_time=1550
+
+for step in -1e2 1e2; do
+	# Make one step in 150th second
+	client_step="(* $step (equal 0.1 (sum 1.0) 150))"
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+min_sync_time=5120
+max_sync_time=6200
+client_conf="makestep 1 -1"
+
+for step in -1e8 -1e5 1e5 1e8; do
+	# Make one step in 5000th second
+	client_step="(* $step (equal 0.1 (sum 1.0) 5000))"
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+min_sync_time=$default_min_sync_time
+max_sync_time=$default_max_sync_time
+time_max_limit=2e4
+time_rms_limit=8e3
+
+for step in -1e4 1e4; do
+	# Make a step every 500 seconds
+	client_step="(* $step (equal 0.1 (% (sum 1.0) 500) 0))"
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
--- a/test/simulation/006-largejitter
+++ b/test/simulation/006-largejitter
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+. test.common
+
+test_start "large jitter"
+
+time_offset=1e0
+jitter=1e-1
+
+time_max_limit=5e-1
+freq_max_limit=2e-1
+time_rms_limit=1e-1
+freq_rms_limit=5e-3
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
--- a/test/simulation/007-largewander
+++ b/test/simulation/007-largewander
@@ -0,0 +1,20 @@
+#!/bin/bash
+
+. test.common
+
+test_start "large wander"
+
+wander=1e-7
+
+time_max_limit=5e-3
+freq_max_limit=5e-3
+time_rms_limit=1e-3
+freq_rms_limit=1e-4
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
--- a/test/simulation/008-ntpera
+++ b/test/simulation/008-ntpera
@@ -0,0 +1,40 @@
+#!/bin/bash
+
+. test.common
+test_start "NTP eras"
+
+# Assume NTP_ERA_SPLIT is between years 1960 and 1990
+
+# Set date to 500 seconds before NTP second overflows, this should
+# work correctly with both 32-bit and 64-bit time_t
+export CLKNETSIM_START_DATE=$(date -d 'Feb  7 06:19:56 UTC 2036' +'%s')
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+# The following tests need 64-bit time_t
+grep -q 'HAVE_LONG_TIME_T 1' ../../config.h || test_skip
+
+for year in 1990 2090; do
+	export CLKNETSIM_START_DATE=$(date -d "Jan  1 00:00:00 UTC $year" +'%s')
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+for year in 1950 2130; do
+	export CLKNETSIM_START_DATE=$(date -d "Jan  1 00:00:00 UTC $year" +'%s')
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	# This check is expected to fail
+	check_sync && test_fail
+done
+
+test_pass
--- a/test/simulation/101-poll
+++ b/test/simulation/101-poll
@@ -0,0 +1,28 @@
+#!/bin/bash
+
+. test.common
+test_start "minpoll/maxpoll options"
+
+wander=0.0
+jitter=1e-6
+
+time_max_limit=1e-5
+freq_max_limit=1e-5
+time_rms_limit=5e-6
+freq_rms_limit=5e-6
+client_conf="makestep 1e-2 1"
+
+for poll in $(seq 2 14); do
+	client_server_options="minpoll $poll maxpoll $poll"
+	limit=$[2**$poll * 10]
+	min_sync_time=$[2**$poll * 2]
+	max_sync_time=$[2**$poll * 21 / 10 + 1]
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
--- a/test/simulation/102-iburst
+++ b/test/simulation/102-iburst
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+. test.common
+test_start "iburst option"
+
+freq_offset=1e-4
+
+client_conf="makestep 1e-2 1
+driftfile tmp/drift"
+client_server_options="iburst"
+
+min_sync_time=4
+max_sync_time=6
+
+echo "100 1.0" > tmp/drift
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
--- a/test/simulation/103-initstepslew
+++ b/test/simulation/103-initstepslew
@@ -0,0 +1,32 @@
+#!/bin/bash
+
+. test.common
+test_start "initstepslew directive"
+
+freq_offset=0.0
+wander=0.0
+time_rms_limit=1e-3
+limit=100
+
+client_conf="initstepslew 5 192.168.123.1"
+
+min_sync_time=6
+max_sync_time=35
+
+for time_offset in -2.0 -0.2 0.2 2.0; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+min_sync_time=5
+max_sync_time=5
+
+for time_offset in -1e8 -1e2 1e2 1e8; do
+	run_test || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
--- a/test/simulation/104-driftfile
+++ b/test/simulation/104-driftfile
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+. test.common
+test_start "driftfile directive"
+
+servers=0
+time_offset=0.0
+wander=0.0
+limit=10
+freq_max_limit=1e-9
+min_sync_time=1
+max_sync_time=1
+client_conf="driftfile tmp/drift"
+
+for freq_offset in -5e-2 -5e-4 -5e-6 5e-6 5e-4 5e-2; do
+	awk "BEGIN {printf \"%.9e 1\", 1e6 - 1 / (1 + $freq_offset) * 1e6}" > tmp/drift
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
--- a/test/simulation/105-ntpauth
+++ b/test/simulation/105-ntpauth
@@ -0,0 +1,42 @@
+#!/bin/bash
+
+. test.common
+
+test_start "NTP authentication"
+
+server_conf="keyfile tmp/keys"
+client_conf="keyfile tmp/keys"
+
+cat > tmp/keys <<-EOF
+1 $(tr -c -d 'a-zA-Z0-9' < /dev/urandom 2> /dev/null | head -c 24)
+2 ASCII:$(tr -c -d 'a-zA-Z0-9' < /dev/urandom 2> /dev/null | head -c 24)
+3 MD5 ASCII:$(tr -c -d 'a-zA-Z' < /dev/urandom 2> /dev/null | head -c 24)
+4 MD5 HEX:$(tr -c -d '0-9A-F' < /dev/urandom 2> /dev/null | head -c 32)
+EOF
+
+for key in 1 2 3 4; do
+	client_server_options="key $key"
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+server_conf=""
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+# This check must fail as the server doesn't know the key
+check_sync && test_fail
+check_packet_interval || test_fail
+
+server_conf="keyfile tmp/keys"
+client_conf=""
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+# This check must fail as the client doesn't know the key
+check_sync && test_fail
+check_packet_interval || test_fail
+test_pass
--- a/test/simulation/106-refclock
+++ b/test/simulation/106-refclock
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+. test.common
+test_start "SHM refclock"
+
+servers=0
+limit=1000
+refclock_jitter=$jitter
+min_sync_time=45
+max_sync_time=70
+client_conf="refclock SHM 0"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+test_pass
--- a/test/simulation/107-allowdeny
+++ b/test/simulation/107-allowdeny
@@ -0,0 +1,46 @@
+#!/bin/bash
+
+. test.common
+
+test_start "allow/deny directives"
+
+limit=500
+
+# Note that start_client in clknetsim.bash always adds allow to the config
+
+for server_conf in \
+	"deny" \
+	"deny all" \
+	"deny 192.168.0.0/16" \
+	"deny 192.168.123" \
+	"deny 192.168.123.2" \
+	"deny all
+allow 192.168.124.0/24"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	# These checks are expected to fail
+	check_source_selection && test_fail
+	check_sync && test_fail
+done
+
+for server_conf in \
+	"deny all
+allow" \
+	"deny all
+allow all" \
+	"deny all
+allow 192.168.123" \
+	"deny all
+allow 192.168.123/24" \
+	"deny 192.168.124.0/24"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
--- a/test/simulation/108-peer
+++ b/test/simulation/108-peer
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+. test.common
+
+test_start "NTP peers"
+
+# Allow and drop packets to the server in 1000 second intervals, so only one
+# client has access to it and the other is forced to switch to the peer.
+base_delay=$(cat <<-EOF | tr -d '\n'
+  (+ 1e-4
+     (* -1
+        (equal 0.1 from 2)
+        (equal 0.1 to 1)
+        (equal 0.1 (min (% time 2000) 1000) 1000))
+     (* -1
+        (equal 0.1 from 3)
+        (equal 0.1 to 1)
+	(equal 0.1 (max (% time 2000) 1000) 1000)))
+EOF
+)
+
+clients=2
+peers=2
+max_sync_time=1000
+client_server_options="minpoll 6 maxpoll 6"
+client_peer_options="minpoll 6 maxpoll 6"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+test_pass
--- a/test/simulation/109-makestep
+++ b/test/simulation/109-makestep
@@ -0,0 +1,41 @@
+#!/bin/bash
+
+. test.common
+test_start "makestep directive"
+
+client_conf="makestep 0 -1
+corrtimeratio 1e10"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+limit=200
+jitter=1e-5
+client_conf="makestep 2 1"
+
+min_sync_time=130
+max_sync_time=150
+
+for time_offset in -1.0 -0.1 0.1 1.0; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+min_sync_time=120
+max_sync_time=140
+
+for time_offset in -1e8 -1e2 1e2 1e8; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
--- a/test/simulation/110-chronyc
+++ b/test/simulation/110-chronyc
@@ -0,0 +1,37 @@
+#!/bin/bash
+
+. test.common
+
+test_start "chronyc"
+
+chronyc_conf="tracking
+sources
+sourcestats"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+
+check_chronyc_output "^Reference ID    : 192\.168\.123\.1 \(192\.168\.123\.1\)
+Stratum         : 2
+Ref time \(UTC\)  : Fri Jan  1 00:1.:.. 2010
+System time     : 0\.0000..... seconds (slow|fast) of NTP time
+Last offset     : [+-]0\.000...... seconds
+RMS offset      : 0\.000...... seconds
+Frequency       : (99|100)\.... ppm fast
+Residual freq   : [+-][0-9]\.... ppm
+Skew            : [0-9]\.... ppm
+Root delay      : 0\.000... seconds
+Root dispersion : 0\.000... seconds
+Update interval : [0-9]+\.. seconds
+Leap status     : Normal
+210 Number of sources = 1
+MS Name/IP address         Stratum Poll Reach LastRx Last sample
+===============================================================================
+\^\* 192\.168\.123\.1                 1   [67]   377    [0-9]+ [0-9 +-]+[un]s\[[0-9 +-]+[un]s\] \+/-[ 0-9]+[un]s
+210 Number of sources = 1
+Name/IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
+==============================================================================
+192\.168\.123\.1              [0-9 ]+ [0-9 ]+ [0-9 ]+ [ +-][01]\.... [0-9 ]+\....  [0-9 +-]+[un]s [0-9 ]+[un]s$" \
+|| test_fail
+
+test_pass
--- a/test/simulation/111-knownclient
+++ b/test/simulation/111-knownclient
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+. test.common
+
+test_start "reply to client configured as server"
+
+server_conf="server 192.168.123.2
+acquisitionport 123"
+client_conf="acquisitionport 123"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_port || test_fail
+check_sync || test_fail
+
+test_pass
--- a/test/simulation/112-port
+++ b/test/simulation/112-port
@@ -0,0 +1,55 @@
+#!/bin/bash
+
+. test.common
+
+test_start "port and acquisitionport directives"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+# This check is expected to fail
+check_packet_port && test_fail
+
+client_conf="acquisitionport 123"
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_port || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+client_conf=""
+for server_conf in \
+	"port 0" \
+	"acquisitionport 123
+port 0"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_port || test_fail
+	check_packet_interval || test_fail
+	# These checks are expected to fail
+	check_source_selection && test_fail
+	check_sync && test_fail
+done
+
+server_conf="port 124
+acquisitionport 123"
+client_server_options="port 124"
+for client_conf in \
+	"acquisitionport 0" \
+	"acquisitionport 123" \
+	"acquisitionport 124"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+	# This check is expected to fail
+	check_packet_port && test_fail
+done
+
+test_pass
--- a/test/simulation/113-leapsecond
+++ b/test/simulation/113-leapsecond
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+. test.common
+test_start "leap second"
+
+export CLKNETSIM_START_DATE=$(TZ=UTC date -d 'Dec 30 2008 0:00:00' +'%s')
+
+limit=$[4 * 24 * 3600]
+server_conf="refclock SHM 0 dpoll 10 poll 10
+leapsectz right/UTC"
+server_step="(* 1.0 (equal 0.1 (sum 1.0) $[2 * 24 * 3600 + 1]))"
+client_step="(* 1.0 (equal 0.1 (sum 1.0) $[2 * 24 * 3600 + 1]))"
+refclock_jitter=1e-9
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
--- a/test/simulation/114-presend
+++ b/test/simulation/114-presend
@@ -0,0 +1,22 @@
+#!/bin/bash
+
+. test.common
+test_start "presend option"
+
+client_server_options="presend 6"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+base_delay=5
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
--- a/test/simulation/115-cmdmontime
+++ b/test/simulation/115-cmdmontime
@@ -0,0 +1,24 @@
+#!/bin/bash
+
+. test.common
+
+test_start "cmdmon timestamps"
+
+# The following tests need 64-bit time_t
+grep -q 'HAVE_LONG_TIME_T 1' ../../config.h || test_skip
+
+limit=2
+client_server_options="noselect"
+client_conf="local stratum 1"
+chronyc_start="0.5"
+chronyc_conf="tracking"
+
+for year in `seq 1850 100 2300`; do
+	date="Jan  1 00:00:00 $year"
+	export CLKNETSIM_START_DATE=$(date -d "$date UTC" +'%s')
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_chronyc_output "^.*Ref time \(UTC\).*$date.*$" || test_fail
+done
+
+test_pass
--- a/test/simulation/201-freqaccumulation
+++ b/test/simulation/201-freqaccumulation
@@ -0,0 +1,35 @@
+#!/bin/bash
+
+. test.common
+
+# Test fix in commit 60d0fa299307076143da94d36deb7b908fa9bdb7
+
+test_start "frequency accumulation"
+
+time_offset=100.0
+jitter=1e-6
+base_delay=1e-6
+wander=0.0
+
+limit=180
+time_max_limit=1e-5
+freq_max_limit=1e-7
+time_rms_limit=1e-5
+freq_rms_limit=1e-7
+min_sync_time=120
+max_sync_time=140
+
+client_server_options="minpoll 6 maxpoll 6"
+client_conf="driftfile tmp/drift
+makestep 1 1"
+
+for freq_offset in -5e-2 -5e-4 5e-4 5e-2; do
+	for drift in -1e+4 -1e+2 1e+2 1e+4; do
+		echo "$drift 100000" > tmp/drift
+		run_test || test_fail
+		check_chronyd_exit || test_fail
+		check_sync || test_fail
+	done
+done
+
+test_pass
--- a/test/simulation/README
+++ b/test/simulation/README
@@ -0,0 +1,12 @@
+This is a collection of simulation tests. They use clknetsim to simulate
+multiple systems connected in a network. It's available at
+
+https://github.com/mlichvar/clknetsim
+
+If this directory doesn't have a clknetsim subdirectory, a known working
+revision will be downloaded and compiled automatically.
+
+Currently it runs only on Linux.
+
+The tests are written in bash and they can be run directly. The ./run script
+runs all tests.
--- a/Show More
+++ b/Show More