doc: update NEWS

sys_linux: allow getrandom in seccomp filter
This fixes commit c5735ebfe9.
2025-12-03 17:45:07 -05:00 · 2017-07-25 17:54:01 +02:00 · 2017-07-25 17:40:35 +02:00 · 2017-07-25 17:40:35 +02:00 · 2017-07-25 17:40:35 +02:00 · 2017-07-25 17:40:35 +02:00
117 changed files with 8386 additions and 3254 deletions
--- a/Makefile.in
+++ b/Makefile.in
@@ -37,7 +37,7 @@ HASH_OBJ = @HASH_OBJ@

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

 EXTRA_OBJS=@EXTRA_OBJECTS@

@@ -63,17 +63,11 @@ chronyd : $(OBJS) $(EXTRA_OBJS)
 chronyc : $(CLI_OBJS)
 	$(CC) $(CFLAGS) -o chronyc $(CLI_OBJS) $(LDFLAGS) $(LIBS) $(EXTRA_CLI_LIBS)

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

 clean :
 	-rm -f *.o *.s chronyc chronyd core *~
@@ -115,10 +109,14 @@ install-docs :
 %.s : %.c
 	$(CC) $(CFLAGS) $(CPPFLAGS) -S $<

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

+check : chronyd chronyc
+	$(MAKE) -C test/unit check
+	cd test/simulation && ./run -i 20 -m 2
+
 Makefile : Makefile.in configure
 	@echo
 	@echo Makefile needs to be regenerated, run ./configure
--- a/78
+++ b/78
@@ -1,3 +1,81 @@
+New in version 3.2
+==================
+
+Enhancements
+------------
+* Improve stability with NTP sources and reference clocks
+* Improve support for NTP interleaved modes
+* Control frequency of system clock on macOS 10.13 and later
+* Set TAI-UTC offset of system clock with leapsectz directive
+* Add support for new HW timestamping options added in Linux 4.13
+* Add rxfilter option to hwtimestamp directive
+* Add extpps option to PHC refclock to timestamp external PPS signal
+* Add pps option to refclock directive to treat any refclock as PPS
+* Add width option to refclock directive to filter wrong pulse edges
+* Add -x option to disable control of system clock
+* Add -l option to log to specified file instead of syslog
+* Allow multiple command-line options to be specified together
+* Allow starting without root privileges with -Q option
+* Update seccomp filter for new glibc versions
+* Dump history on exit by default with dumpdir directive
+* Use hardening compiler options by default
+
+Bug fixes
+---------
+* Don't drop PHC samples with low-resolution system clock
+* Ignore outliers in PHC tracking, RTC tracking, manual input
+* Increase polling interval when peer is not responding
+* Exit with error message when include directive fails
+* Don't allow slash after hostname in allow/deny directive/command
+* Try to connect to all addresses in chronyc before giving up
+
+New in version 3.1
+==================
+
+Enhancements
+------------
+* Add support for precise cross timestamping of PHC on Linux
+* Add minpoll, precision, nocrossts options to hwtimestamp directive
+* Add rawmeasurements option to log directive and modify measurements
+  option to log only valid measurements from synchronised sources
+* Allow sub-second polling interval with NTP sources
+
+Bug fixes
+---------
+* Fix time smoothing in interleaved mode
+
+New in version 3.0
+==================
+
+Enhancements
+------------
+* Add support for software and hardware timestamping on Linux
+* Add support for client/server and symmetric interleaved modes
+* Add support for MS-SNTP authentication in Samba
+* Add support for truncated MACs in NTPv4 packets
+* Estimate and correct for asymmetric network jitter
+* Increase default minsamples and polltarget to improve stability
+  with very low jitter
+* Add maxjitter directive to limit source selection by jitter
+* Add offset option to server/pool/peer directive
+* Add maxlockage option to refclock directive
+* Add -t option to chronyd to exit after specified time
+* Add partial protection against replay attacks on symmetric mode
+* Don't reset polling interval when switching sources to online state
+* Allow rate limiting with very short intervals
+* Improve maximum server throughput on Linux and NetBSD
+* Remove dump files after start
+* Add tab-completion to chronyc with libedit/readline
+* Add ntpdata command to print details about NTP measurements
+* Allow all source options to be set in add server/peer command
+* Indicate truncated addresses/hostnames in chronyc output
+* Print reference IDs as hexadecimal numbers to avoid confusion with
+  IPv4 addresses
+
+Bug fixes
+---------
+* Fix crash with disabled asynchronous name resolving
+
 New in version 2.4.1
 ====================

--- a/48
+++ b/48
@@ -14,10 +14,10 @@ intermittent network connections, heavily congested networks, changing
 temperatures (ordinary computer clocks are sensitive to temperature),
 and systems that do not run continuosly, or run on a virtual machine.

-Typical accuracy between two machines on a LAN is in tens, or a few
-hundreds, of microseconds; over the Internet, accuracy is typically
-within a few milliseconds.  With a good hardware reference clock
-sub-microsecond accuracy is possible.
+Typical accuracy between two machines synchronised over the Internet is
+within a few milliseconds; on a LAN, accuracy is typically in tens of
+microseconds.  With hardware timestamping, or a hardware reference clock,
+sub-microsecond accuracy may be possible.

 Two programs are included in chrony, chronyd is a daemon that can be
 started at boot time and chronyc is a command-line interface program
@@ -27,7 +27,7 @@ operating parameters whilst it is running.
 What will chrony run on?
 ========================

-The software is known to work on Linux, FreeBSD, NetBSD, Mac OS X and
+The software is known to work on Linux, FreeBSD, NetBSD, macOS and
 Solaris.  Closely related systems may work too.  Any other system will
 likely require a porting exercise.  You would need to start from one
 of the existing system-specific drivers and look into the quirks of
@@ -95,19 +95,12 @@ License

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

-
-Author
-======
+Authors
+=======

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

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

@@ -118,6 +111,9 @@ implementation has been used to check the details of the protocol.
 The following people have provided patches and other major contributions
 to the program :

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

@@ -139,7 +135,7 @@ Erik Bryer <ebryer@spots.ab.ca>
    Entries in contrib directory

 Bryan Christianson <bryan@whatroute.net>
-    Support for Mac OS X
+    Support for macOS
    Support for privilege separation
    Entries in contrib directory

@@ -198,18 +194,6 @@ Jim Knoble <jmknoble@pobox.com>
 Antti Jrvinen <costello@iki.fi>
    Advice on configuring for BSD/386

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

@@ -219,6 +203,9 @@ Kalle Olavi Niemitalo  <tosi@stekt.oulu.fi>
 Frank Otto <sandwichmacher@web.de>
    Handling arbitrary HZ values

+Denny Page <dennypage@me.com>
+    Advice on support for hardware timestamping
+
 Gautier PHILIPPON <gautier.philippon@ensimag.grenoble-inp.fr>
    Patch to add refresh command to chronyc

@@ -228,6 +215,9 @@ Andreas Piesk <apiesk@virbus.de>
 Timo Teras <timo.teras@iki.fi>
    Patch to reply correctly on multihomed hosts

+Bill Unruh <unruh@physics.ubc.ca>
+    Advice on statistics
+
 Stephen Wadeley <swadeley@redhat.com>
    Improvements to man pages

@@ -244,5 +234,5 @@ Ulrich Windl <ulrich.windl@rz.uni-regensburg.de> for the
 Doug Woodward <dougw@whistler.com>
    Advice on configuring for Solaris 2.8 on x86

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

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

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

--- a/candm.h
+++ b/candm.h
@@ -94,14 +94,17 @@
 #define REQ_SERVER_STATS 54
 #define REQ_CLIENT_ACCESSES_BY_INDEX2 55
 #define REQ_LOCAL2 56
-#define N_REQUEST_TYPES 57
+#define REQ_NTP_DATA 57
+#define REQ_ADD_SERVER2 58
+#define REQ_ADD_PEER2 59
+#define N_REQUEST_TYPES 60

-/* Structure used to exchange timevals independent on size of time_t */
+/* Structure used to exchange timespecs independent of time_t size */
 typedef struct {
  uint32_t tv_sec_high;
  uint32_t tv_sec_low;
  uint32_t tv_nsec;
-} Timeval;
+} Timespec;

 /* This is used in tv_sec_high for 32-bit timestamps */
 #define TV_NOHIGHSEC 0x7fffffff
@@ -200,12 +203,12 @@ typedef struct {
 } REQ_Modify_Makestep;

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

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

@@ -246,6 +249,7 @@ typedef struct {
 #define REQ_ADDSRC_NOSELECT 0x10
 #define REQ_ADDSRC_TRUST 0x20
 #define REQ_ADDSRC_REQUIRE 0x40
+#define REQ_ADDSRC_INTERLEAVED 0x80

 typedef struct {
  IPAddr ip_addr;
@@ -253,9 +257,17 @@ typedef struct {
  int32_t minpoll;
  int32_t maxpoll;
  int32_t presend_minpoll;
+  uint32_t min_stratum;
+  uint32_t poll_target;
+  uint32_t version;
+  uint32_t max_sources;
+  int32_t min_samples;
+  int32_t max_samples;
  uint32_t authkey;
  Float max_delay;
  Float max_delay_ratio;
+  Float max_delay_dev_ratio;
+  Float offset;
  uint32_t flags;
  int32_t EOR;
 } REQ_NTP_Source;
@@ -309,6 +321,11 @@ typedef struct {
  int32_t EOR;
 } REQ_SmoothTime;

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

 #define PKT_TYPE_CMD_REQUEST 1
@@ -345,8 +362,9 @@ typedef struct {
   domain socket.

   Version 6 (no authentication) : changed format of client accesses by index
-   (using new request/reply types), new flags in NTP source request and report,
-   new commands: refresh, serverstats
+   (using new request/reply types) and manual timestamp, new fields and flags
+   in NTP source request and report, new commands: ntpdata, refresh,
+   serverstats
 */

 #define PROTO_VERSION_NUMBER 6
@@ -409,6 +427,7 @@ typedef struct {
    REQ_ManualDelete manual_delete;
    REQ_ReselectDistance reselect_distance;
    REQ_SmoothTime smoothtime;
+    REQ_NTPData ntp_data;
  } data; /* Command specific parameters */

  /* Padding used to prevent traffic amplification.  It only defines the
@@ -442,7 +461,9 @@ typedef struct {
 #define RPY_SMOOTHING 13
 #define RPY_SERVER_STATS 14
 #define RPY_CLIENT_ACCESSES_BY_INDEX2 15
-#define N_REPLY_TYPES 16
+#define RPY_NTP_DATA 16
+#define RPY_MANUAL_TIMESTAMP2 17
+#define N_REPLY_TYPES 18

 /* Status codes */
 #define STT_SUCCESS 0
@@ -512,7 +533,7 @@ typedef struct {
  IPAddr ip_addr;
  uint16_t stratum;
  uint16_t leap_status;
-  Timeval ref_time;
+  Timespec ref_time;
  Float current_correction;
  Float last_offset;
  Float rms_offset;
@@ -540,7 +561,7 @@ typedef struct {
 } RPY_Sourcestats;

 typedef struct {
-  Timeval ref_time;
+  Timespec ref_time;
  uint16_t n_samples;
  uint16_t n_runs;
  uint32_t span_seconds;
@@ -550,7 +571,7 @@ typedef struct {
 } RPY_Rtc;

 typedef struct {
-  uint32_t centiseconds;
+  Float offset;
  Float dfreq_ppm;
  Float new_afreq_ppm;
  int32_t EOR;
@@ -590,7 +611,7 @@ typedef struct {
 #define MAX_MANUAL_LIST_SAMPLES 16

 typedef struct {
-  Timeval when;
+  Timespec when;
  Float slewed_offset;
  Float orig_offset;
  Float residual;
@@ -624,6 +645,39 @@ typedef struct {
  int32_t EOR;
 } RPY_Smoothing;

+#define RPY_NTP_FLAGS_TESTS 0x3ff
+#define RPY_NTP_FLAG_INTERLEAVED 0x4000
+#define RPY_NTP_FLAG_AUTHENTICATED 0x8000
+
+typedef struct {
+  IPAddr remote_addr;
+  IPAddr local_addr;
+  uint16_t remote_port;
+  uint8_t leap;
+  uint8_t version;
+  uint8_t mode;
+  uint8_t stratum;
+  int8_t poll;
+  int8_t precision;
+  Float root_delay;
+  Float root_dispersion;
+  uint32_t ref_id;
+  Timespec ref_time;
+  Float offset;
+  Float peer_delay;
+  Float peer_dispersion;
+  Float response_time;
+  Float jitter_asymmetry;
+  uint16_t flags;
+  uint8_t tx_tss_char;
+  uint8_t rx_tss_char;
+  uint32_t total_tx_count;
+  uint32_t total_rx_count;
+  uint32_t total_valid_count;
+  uint32_t reserved[4];
+  int32_t EOR;
+} RPY_NTPData;
+
 typedef struct {
  uint8_t version;
  uint8_t pkt_type;
@@ -652,6 +706,7 @@ typedef struct {
    RPY_ManualList manual_list;
    RPY_Activity activity;
    RPY_Smoothing smoothing;
+    RPY_NTPData ntp_data;
  } data; /* Reply specific parameters */

 } CMD_Reply;
--- a/client.c
+++ b/client.c
--- a/clientlog.c
+++ b/clientlog.c
@@ -39,6 +39,7 @@
 #include "clientlog.h"
 #include "conf.h"
 #include "memory.h"
+#include "ntp.h"
 #include "reports.h"
 #include "util.h"
 #include "logging.h"
@@ -57,6 +58,8 @@ typedef struct {
  int8_t cmd_rate;
  int8_t ntp_timeout_rate;
  uint8_t flags;
+  NTP_int64 ntp_rx_ts;
+  NTP_int64 ntp_tx_ts;
 } Record;

 /* Hash table of records, there is a fixed number of records per slot */
@@ -83,6 +86,10 @@ static unsigned int max_slots;
 #define TS_FRAC 4
 #define INVALID_TS 0

+/* Static offset included in conversion to the fixed-point timestamps to
+   randomise their alignment */
+static uint32_t ts_offset;
+
 /* Request rates are saved in the record as 8-bit scaled log2 values */
 #define RATE_SCALE 4
 #define MIN_RATE (-14 * RATE_SCALE)
@@ -92,7 +99,7 @@ static unsigned int max_slots;
   number of tokens spent on response are determined from configured
   minimum inverval between responses (in log2) and burst length. */

-#define MIN_LIMIT_INTERVAL (-TS_FRAC)
+#define MIN_LIMIT_INTERVAL (-15 - TS_FRAC)
 #define MAX_LIMIT_INTERVAL 12
 #define MIN_LIMIT_BURST 1
 #define MAX_LIMIT_BURST 255
@@ -102,7 +109,8 @@ static uint16_t max_cmd_tokens;
 static uint16_t ntp_tokens_per_packet;
 static uint16_t cmd_tokens_per_packet;

-/* Reduction of token rates to avoid overflow of 16-bit counters */
+/* Reduction of token rates to avoid overflow of 16-bit counters.  Negative
+   shift is used for coarse limiting with intervals shorter than -TS_FRAC. */
 static int ntp_token_shift;
 static int cmd_token_shift;

@@ -120,6 +128,9 @@ static int cmd_leak_rate;
 /* Flag indicating whether the last response was dropped */
 #define FLAG_NTP_DROPPED 0x1

+/* NTP limit interval in log2 */
+static int ntp_limit_interval;
+
 /* Flag indicating whether facility is turned on or not */
 static int active;

@@ -130,6 +141,8 @@ static uint32_t total_ntp_drops;
 static uint32_t total_cmd_drops;
 static uint32_t total_record_drops;

+#define NSEC_PER_SEC 1000000000U
+
 /* ================================================== */

 static int expand_hashtable(void);
@@ -155,7 +168,7 @@ get_record(IPAddr *ip)
  time_t last_hit, oldest_hit = 0;
  Record *record, *oldest_record;

-  if (ip->family != IPADDR_INET4 && ip->family != IPADDR_INET6)
+  if (!active || (ip->family != IPADDR_INET4 && ip->family != IPADDR_INET6))
    return NULL;

  while (1) {
@@ -206,6 +219,8 @@ get_record(IPAddr *ip)
  record->ntp_rate = record->cmd_rate = INVALID_RATE;
  record->ntp_timeout_rate = INVALID_RATE;
  record->flags = 0;
+  UTI_ZeroNtp64(&record->ntp_rx_ts);
+  UTI_ZeroNtp64(&record->ntp_tx_ts);

  return record;
 }
@@ -266,16 +281,23 @@ set_bucket_params(int interval, int burst, uint16_t *max_tokens,
  interval = CLAMP(MIN_LIMIT_INTERVAL, interval, MAX_LIMIT_INTERVAL);
  burst = CLAMP(MIN_LIMIT_BURST, burst, MAX_LIMIT_BURST);

-  /* Find smallest shift with which the maximum number fits in 16 bits */
-  for (*token_shift = 0; *token_shift < interval + TS_FRAC; (*token_shift)++) {
-    if (burst << (TS_FRAC + interval - *token_shift) < 1U << 16)
-      break;
+  if (interval >= -TS_FRAC) {
+    /* Find the smallest shift with which the maximum number fits in 16 bits */
+    for (*token_shift = 0; *token_shift < interval + TS_FRAC; (*token_shift)++) {
+      if (burst << (TS_FRAC + interval - *token_shift) < 1U << 16)
+        break;
+    }
+  } else {
+    /* Coarse rate limiting */
+    *token_shift = interval + TS_FRAC;
+    *tokens_per_packet = 1;
+    burst = MAX(1U << -*token_shift, burst);
  }

  *tokens_per_packet = 1U << (TS_FRAC + interval - *token_shift);
  *max_tokens = *tokens_per_packet * burst;

-  DEBUG_LOG(LOGF_ClientLog, "Tokens max %d packet %d shift %d",
+  DEBUG_LOG("Tokens max %d packet %d shift %d",
            *max_tokens, *tokens_per_packet, *token_shift);
 }

@@ -290,11 +312,13 @@ CLG_Initialise(void)
  ntp_tokens_per_packet = cmd_tokens_per_packet = 0;
  ntp_token_shift = cmd_token_shift = 0;
  ntp_leak_rate = cmd_leak_rate = 0;
+  ntp_limit_interval = MIN_LIMIT_INTERVAL;

  if (CNF_GetNTPRateLimit(&interval, &burst, &leak_rate)) {
    set_bucket_params(interval, burst, &max_ntp_tokens, &ntp_tokens_per_packet,
                      &ntp_token_shift);
    ntp_leak_rate = CLAMP(MIN_LEAK_RATE, leak_rate, MAX_LEAK_RATE);
+    ntp_limit_interval = CLAMP(MIN_LIMIT_INTERVAL, interval, MAX_LIMIT_INTERVAL);
  }

  if (CNF_GetCommandRateLimit(&interval, &burst, &leak_rate)) {
@@ -306,7 +330,7 @@ CLG_Initialise(void)
  active = !CNF_GetNoClientLog();
  if (!active) {
    if (ntp_leak_rate || cmd_leak_rate)
-      LOG_FATAL(LOGF_ClientLog, "ratelimit cannot be used with noclientlog");
+      LOG_FATAL("ratelimit cannot be used with noclientlog");
    return;
  }

@@ -320,6 +344,9 @@ CLG_Initialise(void)
  records = NULL;

  expand_hashtable();
+
+  UTI_GetRandomBytes(&ts_offset, sizeof (ts_offset));
+  ts_offset %= NSEC_PER_SEC / (1U << TS_FRAC);
 }

 /* ================================================== */
@@ -336,23 +363,30 @@ CLG_Finalise(void)
 /* ================================================== */

 static uint32_t
-get_ts_from_timeval(struct timeval *tv)
+get_ts_from_timespec(struct timespec *ts)
 {
-  uint32_t sec = tv->tv_sec, usec = tv->tv_usec;
+  uint32_t sec = ts->tv_sec, nsec = ts->tv_nsec;

-  return sec << TS_FRAC | (4295U * usec - (usec >> 5)) >> (32 - TS_FRAC);
+  nsec += ts_offset;
+  if (nsec >= NSEC_PER_SEC) {
+    nsec -= NSEC_PER_SEC;
+    sec++;
+  }
+
+  /* This is fast and accurate enough */
+  return sec << TS_FRAC | (140740U * (nsec >> 15)) >> (32 - TS_FRAC);
 }

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

 static void
-update_record(struct timeval *now, uint32_t *last_hit, uint32_t *hits,
+update_record(struct timespec *now, uint32_t *last_hit, uint32_t *hits,
              uint16_t *tokens, uint32_t max_tokens, int token_shift, int8_t *rate)
 {
  uint32_t interval, now_ts, prev_hit, new_tokens;
  int interval2;

-  now_ts = get_ts_from_timeval(now);
+  now_ts = get_ts_from_timespec(now);

  prev_hit = *last_hit;
  *last_hit = now_ts;
@@ -363,7 +397,12 @@ update_record(struct timeval *now, uint32_t *last_hit, uint32_t *hits,
  if (prev_hit == INVALID_TS || (int32_t)interval < 0)
    return;

-  new_tokens = (now_ts >> token_shift) - (prev_hit >> token_shift);
+  if (token_shift >= 0)
+    new_tokens = (now_ts >> token_shift) - (prev_hit >> token_shift);
+  else if (now_ts - prev_hit > max_tokens)
+    new_tokens = max_tokens;
+  else
+    new_tokens = (now_ts - prev_hit) << -token_shift;
  *tokens = MIN(*tokens + new_tokens, max_tokens);

  /* Convert the interval to scaled and rounded log2 */
@@ -405,15 +444,26 @@ get_index(Record *record)
 /* ================================================== */

 int
-CLG_LogNTPAccess(IPAddr *client, struct timeval *now)
+CLG_GetClientIndex(IPAddr *client)
+{
+  Record *record;
+
+  record = get_record(client);
+  if (record == NULL)
+    return -1;
+
+  return get_index(record);
+}
+
+/* ================================================== */
+
+int
+CLG_LogNTPAccess(IPAddr *client, struct timespec *now)
 {
  Record *record;

  total_ntp_hits++;

-  if (!active)
-    return -1;
-
  record = get_record(client);
  if (record == NULL)
    return -1;
@@ -425,7 +475,7 @@ CLG_LogNTPAccess(IPAddr *client, struct timeval *now)
                record->flags & FLAG_NTP_DROPPED ?
                &record->ntp_timeout_rate : &record->ntp_rate);

-  DEBUG_LOG(LOGF_ClientLog, "NTP hits %"PRIu32" rate %d trate %d tokens %d",
+  DEBUG_LOG("NTP hits %"PRIu32" rate %d trate %d tokens %d",
            record->ntp_hits, record->ntp_rate, record->ntp_timeout_rate,
            record->ntp_tokens);

@@ -435,15 +485,12 @@ CLG_LogNTPAccess(IPAddr *client, struct timeval *now)
 /* ================================================== */

 int
-CLG_LogCommandAccess(IPAddr *client, struct timeval *now)
+CLG_LogCommandAccess(IPAddr *client, struct timespec *now)
 {
  Record *record;

  total_cmd_hits++;

-  if (!active)
-    return -1;
-
  record = get_record(client);
  if (record == NULL)
    return -1;
@@ -452,7 +499,7 @@ CLG_LogCommandAccess(IPAddr *client, struct timeval *now)
                &record->cmd_tokens, max_cmd_tokens, cmd_token_shift,
                &record->cmd_rate);

-  DEBUG_LOG(LOGF_ClientLog, "Cmd hits %"PRIu32" rate %d tokens %d",
+  DEBUG_LOG("Cmd hits %"PRIu32" rate %d tokens %d",
            record->cmd_hits, record->cmd_rate, record->cmd_tokens);

  return get_index(record);
@@ -552,7 +599,27 @@ CLG_LimitCommandResponseRate(int index)

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

-extern int
+void CLG_GetNtpTimestamps(int index, NTP_int64 **rx_ts, NTP_int64 **tx_ts)
+{
+  Record *record;
+
+  record = ARR_GetElement(records, index);
+
+  *rx_ts = &record->ntp_rx_ts;
+  *tx_ts = &record->ntp_tx_ts;
+}
+
+/* ================================================== */
+
+int
+CLG_GetNtpMinPoll(void)
+{
+  return ntp_limit_interval;
+}
+
+/* ================================================== */
+
+int
 CLG_GetNumberOfIndices(void)
 {
  if (!active)
@@ -586,7 +653,7 @@ static uint32_t get_last_ago(uint32_t x, uint32_t y)
 /* ================================================== */

 int
-CLG_GetClientAccessReportByIndex(int index, RPT_ClientAccessByIndex_Report *report, struct timeval *now)
+CLG_GetClientAccessReportByIndex(int index, RPT_ClientAccessByIndex_Report *report, struct timespec *now)
 {
  Record *record;
  uint32_t now_ts;
@@ -599,7 +666,7 @@ CLG_GetClientAccessReportByIndex(int index, RPT_ClientAccessByIndex_Report *repo
  if (record->ip_addr.family == IPADDR_UNSPEC)
    return 0;

-  now_ts = get_ts_from_timeval(now);
+  now_ts = get_ts_from_timespec(now);

  report->ip_addr = record->ip_addr;
  report->ntp_hits = record->ntp_hits;
--- a/clientlog.h
+++ b/clientlog.h
@@ -33,15 +33,18 @@

 extern void CLG_Initialise(void);
 extern void CLG_Finalise(void);
-extern int CLG_LogNTPAccess(IPAddr *client, struct timeval *now);
-extern int CLG_LogCommandAccess(IPAddr *client, struct timeval *now);
+extern int CLG_GetClientIndex(IPAddr *client);
+extern int CLG_LogNTPAccess(IPAddr *client, struct timespec *now);
+extern int CLG_LogCommandAccess(IPAddr *client, struct timespec *now);
 extern int CLG_LimitNTPResponseRate(int index);
 extern int CLG_LimitCommandResponseRate(int index);
+extern void CLG_GetNtpTimestamps(int index, NTP_int64 **rx_ts, NTP_int64 **tx_ts);
+extern int CLG_GetNtpMinPoll(void);

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

 extern int CLG_GetNumberOfIndices(void);
-extern int CLG_GetClientAccessReportByIndex(int index, RPT_ClientAccessByIndex_Report *report, struct timeval *now);
+extern int CLG_GetClientAccessReportByIndex(int index, RPT_ClientAccessByIndex_Report *report, struct timespec *now);
 extern void CLG_GetServerStatsReport(RPT_ServerStatsReport *report);

 #endif /* GOT_CLIENTLOG_H */
--- a/cmdmon.c
+++ b/cmdmon.c
@@ -133,6 +133,9 @@ static const char permissions[] = {
  PERMIT_AUTH, /* SERVER_STATS */
  PERMIT_AUTH, /* CLIENT_ACCESSES_BY_INDEX2 */
  PERMIT_AUTH, /* LOCAL2 */
+  PERMIT_AUTH, /* NTP_DATA */
+  PERMIT_AUTH, /* ADD_SERVER2 */
+  PERMIT_AUTH, /* ADD_PEER2 */
 };

 /* ================================================== */
@@ -143,7 +146,7 @@ static ADF_AuthTable access_auth_table;

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

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

@@ -158,7 +161,7 @@ prepare_socket(int family, int port_number)

  sock_fd = socket(family, SOCK_DGRAM, 0);
  if (sock_fd < 0) {
-    LOG(LOGS_ERR, LOGF_CmdMon, "Could not open %s command socket : %s",
+    LOG(LOGS_ERR, "Could not open %s command socket : %s",
        UTI_SockaddrFamilyToString(family), strerror(errno));
    return -1;
  }
@@ -169,14 +172,14 @@ prepare_socket(int family, int port_number)
  if (family != AF_UNIX) {
    /* Allow reuse of port number */
    if (setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, (char *) &on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_CmdMon, "Could not set reuseaddr socket options");
+      LOG(LOGS_ERR, "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");
+      LOG(LOGS_ERR, "Could not set free bind socket option");
    }
 #endif

@@ -185,7 +188,7 @@ prepare_socket(int family, int port_number)
 #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_CmdMon, "Could not request IPV6_V6ONLY socket option");
+        LOG(LOGS_ERR, "Could not request IPV6_V6ONLY socket option");
      }
 #endif
    }
@@ -227,7 +230,7 @@ prepare_socket(int family, int port_number)
      my_addr.un.sun_family = family;
      if (snprintf(my_addr.un.sun_path, sizeof (my_addr.un.sun_path), "%s",
                   CNF_GetBindCommandPath()) >= sizeof (my_addr.un.sun_path))
-        LOG_FATAL(LOGF_CmdMon, "Unix socket path too long");
+        LOG_FATAL("Unix socket path too long");
      unlink(my_addr.un.sun_path);
      break;
    default:
@@ -235,14 +238,14 @@ prepare_socket(int family, int port_number)
  }

  if (bind(sock_fd, &my_addr.sa, my_addr_len) < 0) {
-    LOG(LOGS_ERR, LOGF_CmdMon, "Could not bind %s command socket : %s",
+    LOG(LOGS_ERR, "Could not bind %s command socket : %s",
        UTI_SockaddrFamilyToString(family), strerror(errno));
    close(sock_fd);
    return -1;
  }

  /* Register handler for read events on the socket */
-  SCH_AddInputFileHandler(sock_fd, read_from_cmd_socket, (void *)(long)sock_fd);
+  SCH_AddFileHandler(sock_fd, SCH_FILE_INPUT, read_from_cmd_socket, NULL);

  return sock_fd;
 }
@@ -312,7 +315,7 @@ CAM_Initialise(int family)
      && sock_fd6 < 0
 #endif
      ) {
-    LOG_FATAL(LOGF_CmdMon, "Could not open any command socket");
+    LOG_FATAL("Could not open any command socket");
  }

  access_auth_table = ADF_CreateTable();
@@ -325,19 +328,19 @@ void
 CAM_Finalise(void)
 {
  if (sock_fdu >= 0) {
-    SCH_RemoveInputFileHandler(sock_fdu);
+    SCH_RemoveFileHandler(sock_fdu);
    close(sock_fdu);
    unlink(CNF_GetBindCommandPath());
  }
  sock_fdu = -1;
  if (sock_fd4 >= 0) {
-    SCH_RemoveInputFileHandler(sock_fd4);
+    SCH_RemoveFileHandler(sock_fd4);
    close(sock_fd4);
  }
  sock_fd4 = -1;
 #ifdef FEAT_IPV6
  if (sock_fd6 >= 0) {
-    SCH_RemoveInputFileHandler(sock_fd6);
+    SCH_RemoveFileHandler(sock_fd6);
    close(sock_fd6);
  }
  sock_fd6 = -1;
@@ -393,12 +396,12 @@ transmit_reply(CMD_Reply *msg, union sockaddr_all *where_to)
                  &where_to->sa, addrlen);

  if (status < 0) {
-    DEBUG_LOG(LOGF_CmdMon, "Could not send to %s fd %d : %s",
+    DEBUG_LOG("Could not send to %s fd %d : %s",
              UTI_SockaddrToString(&where_to->sa), sock_fd, strerror(errno));
    return;
  }

-  DEBUG_LOG(LOGF_CmdMon, "Sent %d bytes to %s fd %d", status,
+  DEBUG_LOG("Sent %d bytes to %s fd %d", status,
            UTI_SockaddrToString(&where_to->sa), sock_fd);
 }
  
@@ -564,15 +567,14 @@ handle_modify_makestep(CMD_Request *rx_message, CMD_Reply *tx_message)
 static void
 handle_settime(CMD_Request *rx_message, CMD_Reply *tx_message)
 {
-  struct timeval ts;
-  long offset_cs;
-  double dfreq_ppm, new_afreq_ppm;
-  UTI_TimevalNetworkToHost(&rx_message->data.settime.ts, &ts);
+  struct timespec ts;
+  double offset, dfreq_ppm, new_afreq_ppm;
+  UTI_TimespecNetworkToHost(&rx_message->data.settime.ts, &ts);
  if (!MNL_IsEnabled()) {
    tx_message->status = htons(STT_NOTENABLED);
-  } else if (MNL_AcceptTimestamp(&ts, &offset_cs, &dfreq_ppm, &new_afreq_ppm)) {
-    tx_message->reply = htons(RPY_MANUAL_TIMESTAMP);
-    tx_message->data.manual_timestamp.centiseconds = htonl((int32_t)offset_cs);
+  } else if (MNL_AcceptTimestamp(&ts, &offset, &dfreq_ppm, &new_afreq_ppm)) {
+    tx_message->reply = htons(RPY_MANUAL_TIMESTAMP2);
+    tx_message->data.manual_timestamp.offset = UTI_FloatHostToNetwork(offset);
    tx_message->data.manual_timestamp.dfreq_ppm = UTI_FloatHostToNetwork(dfreq_ppm);
    tx_message->data.manual_timestamp.new_afreq_ppm = UTI_FloatHostToNetwork(new_afreq_ppm);
  } else {
@@ -634,7 +636,7 @@ static void
 handle_source_data(CMD_Request *rx_message, CMD_Reply *tx_message)
 {
  RPT_SourceReport report;
-  struct timeval now_corr;
+  struct timespec now_corr;

  /* Get data */
  SCH_GetLastEventTime(&now_corr, NULL, NULL);
@@ -777,26 +779,29 @@ handle_add_source(NTP_Source_Type type, CMD_Request *rx_message, CMD_Reply *tx_m
  params.minpoll = ntohl(rx_message->data.ntp_source.minpoll);
  params.maxpoll = ntohl(rx_message->data.ntp_source.maxpoll);
  params.presend_minpoll = ntohl(rx_message->data.ntp_source.presend_minpoll);
+  params.min_stratum = ntohl(rx_message->data.ntp_source.min_stratum);
+  params.poll_target = ntohl(rx_message->data.ntp_source.poll_target);
+  params.version = ntohl(rx_message->data.ntp_source.version);
+  params.max_sources = ntohl(rx_message->data.ntp_source.max_sources);
+  params.min_samples = ntohl(rx_message->data.ntp_source.min_samples);
+  params.max_samples = ntohl(rx_message->data.ntp_source.max_samples);
  params.authkey = ntohl(rx_message->data.ntp_source.authkey);
+  params.max_delay = UTI_FloatNetworkToHost(rx_message->data.ntp_source.max_delay);
+  params.max_delay_ratio =
+    UTI_FloatNetworkToHost(rx_message->data.ntp_source.max_delay_ratio);
+  params.max_delay_dev_ratio =
+    UTI_FloatNetworkToHost(rx_message->data.ntp_source.max_delay_dev_ratio);
+  params.offset = UTI_FloatNetworkToHost(rx_message->data.ntp_source.offset);
+
  params.online  = ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_ONLINE ? 1 : 0;
  params.auto_offline = ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_AUTOOFFLINE ? 1 : 0;
  params.iburst = ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_IBURST ? 1 : 0;
+  params.interleaved = ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_INTERLEAVED ? 1 : 0;
  params.sel_options =
    (ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_PREFER ? SRC_SELECT_PREFER : 0) |
    (ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_NOSELECT ? SRC_SELECT_NOSELECT : 0) |
    (ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_TRUST ? SRC_SELECT_TRUST : 0) |
    (ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_REQUIRE ? SRC_SELECT_REQUIRE : 0);
-  params.max_delay = UTI_FloatNetworkToHost(rx_message->data.ntp_source.max_delay);
-  params.max_delay_ratio = UTI_FloatNetworkToHost(rx_message->data.ntp_source.max_delay_ratio);
-
- /* not transmitted in cmdmon protocol yet */
-  params.min_stratum = SRC_DEFAULT_MINSTRATUM;       
-  params.poll_target = SRC_DEFAULT_POLLTARGET;
-  params.max_delay_dev_ratio = SRC_DEFAULT_MAXDELAYDEVRATIO;
-  params.version = NTP_VERSION;
-  params.max_sources = SRC_DEFAULT_MAXSOURCES;
-  params.min_samples = SRC_DEFAULT_MINSAMPLES;
-  params.max_samples = SRC_DEFAULT_MAXSAMPLES;

  status = NSR_AddSource(&rem_addr, type, &params);
  switch (status) {
@@ -868,7 +873,7 @@ handle_dfreq(CMD_Request *rx_message, CMD_Reply *tx_message)
  double dfreq;
  dfreq = UTI_FloatNetworkToHost(rx_message->data.dfreq.dfreq);
  LCL_AccumulateDeltaFrequency(dfreq * 1.0e-6);
-  LOG(LOGS_INFO, LOGF_CmdMon, "Accumulated delta freq of %.3fppm", dfreq);
+  LOG(LOGS_INFO, "Accumulated delta freq of %.3fppm", dfreq);
 }

 /* ================================================== */
@@ -881,7 +886,7 @@ handle_doffset(CMD_Request *rx_message, CMD_Reply *tx_message)
  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);
+  LOG(LOGS_INFO, "Accumulated delta offset of %.6f seconds", doffset);
  LCL_AccumulateOffset(doffset, 0.0);
 }

@@ -898,7 +903,7 @@ handle_tracking(CMD_Request *rx_message, CMD_Reply *tx_message)
  UTI_IPHostToNetwork(&rpt.ip_addr, &tx_message->data.tracking.ip_addr);
  tx_message->data.tracking.stratum = htons(rpt.stratum);
  tx_message->data.tracking.leap_status = htons(rpt.leap_status);
-  UTI_TimevalHostToNetwork(&rpt.ref_time, &tx_message->data.tracking.ref_time);
+  UTI_TimespecHostToNetwork(&rpt.ref_time, &tx_message->data.tracking.ref_time);
  tx_message->data.tracking.current_correction = UTI_FloatHostToNetwork(rpt.current_correction);
  tx_message->data.tracking.last_offset = UTI_FloatHostToNetwork(rpt.last_offset);
  tx_message->data.tracking.rms_offset = UTI_FloatHostToNetwork(rpt.rms_offset);
@@ -916,7 +921,7 @@ static void
 handle_smoothing(CMD_Request *rx_message, CMD_Reply *tx_message)
 {
  RPT_SmoothingReport report;
-  struct timeval now;
+  struct timespec now;

  SCH_GetLastEventTime(&now, NULL, NULL);

@@ -940,7 +945,7 @@ handle_smoothing(CMD_Request *rx_message, CMD_Reply *tx_message)
 static void
 handle_smoothtime(CMD_Request *rx_message, CMD_Reply *tx_message)
 {
-  struct timeval now;
+  struct timespec now;
  int option;

  if (!SMT_IsEnabled()) {
@@ -971,7 +976,7 @@ handle_sourcestats(CMD_Request *rx_message, CMD_Reply *tx_message)
 {
  int status;
  RPT_SourcestatsReport report;
-  struct timeval now_corr;
+  struct timespec now_corr;

  SCH_GetLastEventTime(&now_corr, NULL, NULL);
  status = SRC_ReportSourcestats(ntohl(rx_message->data.sourcestats.index),
@@ -1004,7 +1009,7 @@ handle_rtcreport(CMD_Request *rx_message, CMD_Reply *tx_message)
  status = RTC_GetReport(&report);
  if (status) {
    tx_message->reply  = htons(RPY_RTC);
-    UTI_TimevalHostToNetwork(&report.ref_time, &tx_message->data.rtc.ref_time);
+    UTI_TimespecHostToNetwork(&report.ref_time, &tx_message->data.rtc.ref_time);
    tx_message->data.rtc.n_samples = htons(report.n_samples);
    tx_message->data.rtc.n_runs = htons(report.n_runs);
    tx_message->data.rtc.span_seconds = htonl(report.span_seconds);
@@ -1041,7 +1046,7 @@ handle_client_accesses_by_index(CMD_Request *rx_message, CMD_Reply *tx_message)
  RPY_ClientAccesses_Client *client;
  int n_indices;
  uint32_t i, j, req_first_index, req_n_clients;
-  struct timeval now;
+  struct timespec now;

  SCH_GetLastEventTime(&now, NULL, NULL);

@@ -1100,7 +1105,7 @@ handle_manual_list(CMD_Request *rx_message, CMD_Reply *tx_message)
  tx_message->data.manual_list.n_samples = htonl(n_samples);
  for (i=0; i<n_samples; i++) {
    sample = &tx_message->data.manual_list.samples[i];
-    UTI_TimevalHostToNetwork(&report[i].when, &sample->when);
+    UTI_TimespecHostToNetwork(&report[i].when, &sample->when);
    sample->slewed_offset = UTI_FloatHostToNetwork(report[i].slewed_offset);
    sample->orig_offset = UTI_FloatHostToNetwork(report[i].orig_offset);
    sample->residual = UTI_FloatHostToNetwork(report[i].residual);
@@ -1185,38 +1190,81 @@ handle_server_stats(CMD_Request *rx_message, CMD_Reply *tx_message)
  tx_message->data.server_stats.log_drops = htonl(report.log_drops);
 }

+/* ================================================== */
+
+static void
+handle_ntp_data(CMD_Request *rx_message, CMD_Reply *tx_message)
+{
+  RPT_NTPReport report;
+
+  UTI_IPNetworkToHost(&rx_message->data.ntp_data.ip_addr, &report.remote_addr);
+
+  if (!NSR_GetNTPReport(&report)) {
+    tx_message->status = htons(STT_NOSUCHSOURCE);
+    return;
+  }
+
+  tx_message->reply = htons(RPY_NTP_DATA);
+  UTI_IPHostToNetwork(&report.remote_addr, &tx_message->data.ntp_data.remote_addr);
+  UTI_IPHostToNetwork(&report.local_addr, &tx_message->data.ntp_data.local_addr);
+  tx_message->data.ntp_data.remote_port = htons(report.remote_port);
+  tx_message->data.ntp_data.leap = report.leap;
+  tx_message->data.ntp_data.version = report.version;
+  tx_message->data.ntp_data.mode = report.mode;
+  tx_message->data.ntp_data.stratum = report.stratum;
+  tx_message->data.ntp_data.poll = report.poll;
+  tx_message->data.ntp_data.precision = report.precision;
+  tx_message->data.ntp_data.root_delay = UTI_FloatHostToNetwork(report.root_delay);
+  tx_message->data.ntp_data.root_dispersion = UTI_FloatHostToNetwork(report.root_dispersion);
+  tx_message->data.ntp_data.ref_id = htonl(report.ref_id);
+  UTI_TimespecHostToNetwork(&report.ref_time, &tx_message->data.ntp_data.ref_time);
+  tx_message->data.ntp_data.offset = UTI_FloatHostToNetwork(report.offset);
+  tx_message->data.ntp_data.peer_delay = UTI_FloatHostToNetwork(report.peer_delay);
+  tx_message->data.ntp_data.peer_dispersion = UTI_FloatHostToNetwork(report.peer_dispersion);
+  tx_message->data.ntp_data.response_time = UTI_FloatHostToNetwork(report.response_time);
+  tx_message->data.ntp_data.jitter_asymmetry = UTI_FloatHostToNetwork(report.jitter_asymmetry);
+  tx_message->data.ntp_data.flags = htons((report.tests & RPY_NTP_FLAGS_TESTS) |
+                                          (report.interleaved ? RPY_NTP_FLAG_INTERLEAVED : 0) |
+                                          (report.authenticated ? RPY_NTP_FLAG_AUTHENTICATED : 0));
+  tx_message->data.ntp_data.tx_tss_char = report.tx_tss_char;
+  tx_message->data.ntp_data.rx_tss_char = report.rx_tss_char;
+  tx_message->data.ntp_data.total_tx_count = htonl(report.total_tx_count);
+  tx_message->data.ntp_data.total_rx_count = htonl(report.total_rx_count);
+  tx_message->data.ntp_data.total_valid_count = htonl(report.total_valid_count);
+  memset(tx_message->data.ntp_data.reserved, 0xff, sizeof (tx_message->data.ntp_data.reserved));
+}
+
 /* ================================================== */
 /* Read a packet and process it */

 static void
-read_from_cmd_socket(void *anything)
+read_from_cmd_socket(int sock_fd, int event, void *anything)
 {
  CMD_Request rx_message;
  CMD_Reply tx_message;
  int status, read_length, expected_length, rx_message_length;
-  int localhost, allowed, sock_fd, log_index;
+  int localhost, allowed, log_index;
  union sockaddr_all where_from;
  socklen_t from_length;
  IPAddr remote_ip;
  unsigned short remote_port, rx_command;
-  struct timeval now, cooked_now;
+  struct timespec now, cooked_now;

  rx_message_length = sizeof(rx_message);
  from_length = sizeof(where_from);

-  sock_fd = (long)anything;
  status = recvfrom(sock_fd, (char *)&rx_message, rx_message_length, 0,
                    &where_from.sa, &from_length);

  if (status < 0) {
-    LOG(LOGS_WARN, LOGF_CmdMon, "Error [%s] reading from control socket %d",
+    LOG(LOGS_WARN, "Error [%s] reading from control socket %d",
        strerror(errno), sock_fd);
    return;
  }

  if (from_length > sizeof (where_from) ||
      from_length <= sizeof (where_from.sa.sa_family)) {
-    DEBUG_LOG(LOGF_CmdMon, "Read command packet without source address");
+    DEBUG_LOG("Read command packet without source address");
    return;
  }

@@ -1251,7 +1299,7 @@ read_from_cmd_socket(void *anything)
      assert(0);
  }

-  DEBUG_LOG(LOGF_CmdMon, "Received %d bytes from %s fd %d",
+  DEBUG_LOG("Received %d bytes from %s fd %d",
            status, UTI_SockaddrToString(&where_from.sa), sock_fd);

  if (!(localhost || ADF_IsAllowed(access_auth_table, &remote_ip))) {
@@ -1270,7 +1318,7 @@ read_from_cmd_socket(void *anything)

    /* We don't know how to process anything like this or an error reply
       would be larger than the request */
-    DEBUG_LOG(LOGF_CmdMon, "Command packet dropped");
+    DEBUG_LOG("Command packet dropped");
    return;
  }

@@ -1292,7 +1340,7 @@ read_from_cmd_socket(void *anything)
  tx_message.pad5 = 0;

  if (rx_message.version != PROTO_VERSION_NUMBER) {
-    DEBUG_LOG(LOGF_CmdMon, "Command packet has invalid version (%d != %d)",
+    DEBUG_LOG("Command packet has invalid version (%d != %d)",
              rx_message.version, PROTO_VERSION_NUMBER);

    if (rx_message.version >= PROTO_VERSION_MISMATCH_COMPAT_SERVER) {
@@ -1304,7 +1352,7 @@ read_from_cmd_socket(void *anything)

  if (rx_command >= N_REQUEST_TYPES ||
      expected_length < (int)offsetof(CMD_Request, data)) {
-    DEBUG_LOG(LOGF_CmdMon, "Command packet has invalid command %d", rx_command);
+    DEBUG_LOG("Command packet has invalid command %d", rx_command);

    tx_message.status = htons(STT_INVALID);
    transmit_reply(&tx_message, &where_from);
@@ -1312,7 +1360,7 @@ read_from_cmd_socket(void *anything)
  }

  if (read_length < expected_length) {
-    DEBUG_LOG(LOGF_CmdMon, "Command packet is too short (%d < %d)", read_length,
+    DEBUG_LOG("Command packet is too short (%d < %d)", read_length,
              expected_length);

    tx_message.status = htons(STT_BADPKTLENGTH);
@@ -1327,7 +1375,7 @@ read_from_cmd_socket(void *anything)
  /* Don't reply to all requests from hosts other than localhost if the rate
     is excessive */
  if (!localhost && log_index >= 0 && CLG_LimitCommandResponseRate(log_index)) {
-      DEBUG_LOG(LOGF_CmdMon, "Command packet discarded to limit response rate");
+      DEBUG_LOG("Command packet discarded to limit response rate");
      return;
  }

@@ -1477,11 +1525,11 @@ read_from_cmd_socket(void *anything)
          handle_cmdaccheck(&rx_message, &tx_message);
          break;

-        case REQ_ADD_SERVER:
+        case REQ_ADD_SERVER2:
          handle_add_source(NTP_SERVER, &rx_message, &tx_message);
          break;

-        case REQ_ADD_PEER:
+        case REQ_ADD_PEER2:
          handle_add_source(NTP_PEER, &rx_message, &tx_message);
          break;

@@ -1573,8 +1621,12 @@ read_from_cmd_socket(void *anything)
          handle_server_stats(&rx_message, &tx_message);
          break;

+        case REQ_NTP_DATA:
+          handle_ntp_data(&rx_message, &tx_message);
+          break;
+
        default:
-          DEBUG_LOG(LOGF_CmdMon, "Unhandled command %d", rx_command);
+          DEBUG_LOG("Unhandled command %d", rx_command);
          tx_message.status = htons(STT_FAILED);
          break;
      }
--- a/cmdparse.c
+++ b/cmdparse.c
@@ -39,186 +39,115 @@

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

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

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

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

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

-      if (*cmd) {
-        if (!strcasecmp(cmd, "port")) {
-          if (sscanf(line, "%hu%n", &src->port, &n) != 1) {
-            result = CPS_BadPort;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "minpoll")) {
-          if (sscanf(line, "%d%n", &src->params.minpoll, &n) != 1) {
-            result = CPS_BadMinpoll;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "maxpoll")) {
-          if (sscanf(line, "%d%n", &src->params.maxpoll, &n) != 1) {
-            result = CPS_BadMaxpoll;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "presend")) {
-          if (sscanf(line, "%d%n", &src->params.presend_minpoll, &n) != 1) {
-            result = CPS_BadPresend;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "maxdelaydevratio")) {
-          if (sscanf(line, "%lf%n", &src->params.max_delay_dev_ratio, &n) != 1) {
-            result = CPS_BadMaxdelaydevratio;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "maxdelayratio")) {
-          if (sscanf(line, "%lf%n", &src->params.max_delay_ratio, &n) != 1) {
-            result = CPS_BadMaxdelayratio;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "maxdelay")) {
-          if (sscanf(line, "%lf%n", &src->params.max_delay, &n) != 1) {
-            result = CPS_BadMaxdelay;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "key")) {
-          if (sscanf(line, "%"SCNu32"%n", &src->params.authkey, &n) != 1 ||
-              src->params.authkey == INACTIVE_AUTHKEY) {
-            result = CPS_BadKey;
-            done = 1;
-          } else {
-            line += n;
-          }
-        } else if (!strcasecmp(cmd, "offline")) {
-          src->params.online = 0;
+  /* Parse options */
+  for (; *line; line += n) {
+    cmd = line;
+    line = CPS_SplitWord(line);
+    n = 0;

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

-  return result;
+  return 1;
 }

 /* ================================================== */
@@ -256,71 +185,6 @@ CPS_ParseLocal(char *line, int *stratum, int *orphan, double *distance)

  return 1;
 }
-/* ================================================== */
-
-void
-CPS_StatusToString(CPS_Status status, char *dest, int len)
-{
-  const char *s = NULL;
-
-  if (len > 0)
-    dest[0] = '\0';
-
-  switch (status) {
-    case CPS_Success:
-      return;
-    case CPS_BadOption:
-      s = "server/peer/pool option";
-      break;
-    case CPS_BadHost:
-      s = "address";
-      break;
-    case CPS_BadPort:
-      s = "port";
-      break;
-    case CPS_BadMinpoll:
-      s = "minpoll";
-      break;
-    case CPS_BadMaxpoll:
-      s = "maxpoll";
-      break;
-    case CPS_BadPresend:
-      s = "presend";
-      break;
-    case CPS_BadMaxdelaydevratio:
-      s = "maxdelaydevratio";
-      break;
-    case CPS_BadMaxdelayratio:
-      s = "maxdelayratio";
-      break;
-    case CPS_BadMaxdelay:
-      s = "maxdelay";
-      break;
-    case CPS_BadKey:
-      s = "key";
-      break;
-    case CPS_BadMinstratum:
-      s = "minstratum";
-      break;
-    case CPS_BadPolltarget:
-      s = "polltarget";
-      break;
-    case CPS_BadVersion:
-      s = "version";
-      break;
-    case CPS_BadMaxsources:
-      s = "maxsources";
-      break;
-    case CPS_BadMinsamples:
-      s = "minsamples";
-      break;
-    case CPS_BadMaxsamples:
-      s = "maxsamples";
-      break;
-  }
-
-  snprintf(dest, len, "Invalid %s", s);
-}

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

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

-typedef enum {
-  CPS_Success,
-  CPS_BadOption,
-  CPS_BadHost,
-  CPS_BadPort,
-  CPS_BadMinpoll,
-  CPS_BadMaxpoll,
-  CPS_BadPresend,
-  CPS_BadMaxdelaydevratio,
-  CPS_BadMaxdelayratio,
-  CPS_BadMaxdelay,
-  CPS_BadKey,
-  CPS_BadMinstratum,
-  CPS_BadPolltarget,
-  CPS_BadVersion,
-  CPS_BadMaxsources,
-  CPS_BadMinsamples,
-  CPS_BadMaxsamples,
-} CPS_Status;
-
 typedef struct {
  char *name;
  unsigned short port;
@@ -57,14 +37,11 @@ typedef struct {
 } CPS_NTP_Source;

 /* Parse a command to add an NTP server or peer */
-extern CPS_Status CPS_ParseNTPSourceAdd(char *line, CPS_NTP_Source *src);
+extern int CPS_ParseNTPSourceAdd(char *line, CPS_NTP_Source *src);
  
 /* Parse a command to enable local reference */
 extern int CPS_ParseLocal(char *line, int *stratum, int *orphan, double *distance);

-/* Get a string describing error status */
-extern void CPS_StatusToString(CPS_Status status, char *dest, int len);
-
 /* Remove extra white-space and comments */
 extern void CPS_NormalizeLine(char *line);

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

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2016
+ * Copyright (C) Miroslav Lichvar  2009-2017
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -57,6 +57,7 @@ static void parse_bindcmdaddress(char *);
 static void parse_broadcast(char *);
 static void parse_clientloglimit(char *);
 static void parse_fallbackdrift(char *);
+static void parse_hwtimestamp(char *);
 static void parse_include(char *);
 static void parse_initstepslew(char *);
 static void parse_leapsecmode(char *);
@@ -78,7 +79,7 @@ static void parse_tempcomp(char *);
 static int restarted = 0;
 static char *rtc_device;
 static int acquisition_port = -1;
-static int ntp_port = 123;
+static int ntp_port = NTP_PORT;
 static char *keys_file = NULL;
 static char *drift_file = NULL;
 static char *rtc_file = NULL;
@@ -89,19 +90,20 @@ static double max_drift = 500000.0; /* in ppm */
 static double max_slew_rate = 1e6 / 12.0; /* in ppm */

 static double max_distance = 3.0;
+static double max_jitter = 1.0;
 static double reselect_distance = 1e-4;
 static double stratum_weight = 1e-3;
 static double combine_limit = 3.0;

 static int cmd_port = DEFAULT_CANDM_PORT;

+static int raw_measurements = 0;
 static int do_log_measurements = 0;
 static int do_log_statistics = 0;
 static int do_log_tracking = 0;
 static int do_log_rtc = 0;
 static int do_log_refclocks = 0;
 static int do_log_tempcomp = 0;
-static int do_dump_on_exit = 0;
 static int log_banner = 32;
 static char *logdir;
 static char *dumpdir;
@@ -147,7 +149,7 @@ static double max_offset;

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

 /* Threshold for a time adjustment to be logged to syslog */
 static double log_change_threshold = 1.0;
@@ -181,6 +183,9 @@ static IPAddr bind_cmd_address4, bind_cmd_address6;
 /* Path to the Unix domain command socket. */
 static char *bind_cmd_path;

+/* Path to Samba (ntp_signd) socket. */
+static char *ntp_signd_socket = NULL;
+
 /* Filename to use for storing pid of running chronyd, to prevent multiple
 * chronyds being started. */
 static char *pidfile;
@@ -189,10 +194,10 @@ static char *pidfile;
 static int ntp_ratelimit_enabled = 0;
 static int ntp_ratelimit_interval = 3;
 static int ntp_ratelimit_burst = 8;
-static int ntp_ratelimit_leak = 3;
+static int ntp_ratelimit_leak = 2;
 static int cmd_ratelimit_enabled = 0;
-static int cmd_ratelimit_interval = 1;
-static int cmd_ratelimit_burst = 16;
+static int cmd_ratelimit_interval = -4;
+static int cmd_ratelimit_burst = 8;
 static int cmd_ratelimit_leak = 2;

 /* Smoothing constants */
@@ -218,6 +223,9 @@ static char *leapsec_tz = NULL;
 /* Name of the user to which will be dropped root privileges. */
 static char *user;

+/* Array of CNF_HwTsInterface */
+static ARR_Instance hwts_interfaces;
+
 typedef struct {
  NTP_Source_Type type;
  int pool;
@@ -262,7 +270,7 @@ static const char *processed_command;
 static void
 command_parse_error(void)
 {
-    LOG_FATAL(LOGF_Configure, "Could not parse %s directive at line %d%s%s",
+    LOG_FATAL("Could not parse %s directive at line %d%s%s",
        processed_command, line_number, processed_file ? " in file " : "",
        processed_file ? processed_file : "");
 }
@@ -272,7 +280,7 @@ command_parse_error(void)
 static void
 other_parse_error(const char *message)
 {
-    LOG_FATAL(LOGF_Configure, "%s at line %d%s%s",
+    LOG_FATAL("%s at line %d%s%s",
        message, line_number, processed_file ? " in file " : "",
        processed_file ? processed_file : "");
 }
@@ -305,7 +313,7 @@ check_number_of_args(char *line, int num)
  num -= get_number_of_args(line);

  if (num) {
-    LOG_FATAL(LOGF_Configure, "%s arguments for %s directive at line %d%s%s",
+    LOG_FATAL("%s arguments for %s directive at line %d%s%s",
        num > 0 ? "Missing" : "Too many",
        processed_command, line_number, processed_file ? " in file " : "",
        processed_file ? processed_file : "");
@@ -315,10 +323,12 @@ check_number_of_args(char *line, int num)
 /* ================================================== */

 void
-CNF_Initialise(int r)
+CNF_Initialise(int r, int client_only)
 {
  restarted = r;

+  hwts_interfaces = ARR_CreateInstance(sizeof (CNF_HwTsInterface));
+
  init_sources = ARR_CreateInstance(sizeof (IPAddr));
  ntp_sources = ARR_CreateInstance(sizeof (NTP_Source));
  refclock_sources = ARR_CreateInstance(sizeof (RefclockParameters));
@@ -327,13 +337,20 @@ CNF_Initialise(int r)
  ntp_restrictions = ARR_CreateInstance(sizeof (AllowDeny));
  cmd_restrictions = ARR_CreateInstance(sizeof (AllowDeny));

-  dumpdir = Strdup(".");
-  logdir = Strdup(".");
-  bind_cmd_path = Strdup(DEFAULT_COMMAND_SOCKET);
-  pidfile = Strdup("/var/run/chronyd.pid");
-  rtc_device = Strdup("/dev/rtc");
+  dumpdir = Strdup("");
+  logdir = Strdup("");
+  rtc_device = Strdup(DEFAULT_RTC_DEVICE);
  hwclock_file = Strdup(DEFAULT_HWCLOCK_FILE);
  user = Strdup(DEFAULT_USER);
+
+  if (client_only) {
+    cmd_port = ntp_port = 0;
+    bind_cmd_path = Strdup("");
+    pidfile = Strdup("");
+  } else {
+    bind_cmd_path = Strdup(DEFAULT_COMMAND_SOCKET);
+    pidfile = Strdup(DEFAULT_PID_FILE);
+  }
 }

 /* ================================================== */
@@ -343,6 +360,10 @@ CNF_Finalise(void)
 {
  unsigned int i;

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

@@ -361,6 +382,7 @@ CNF_Finalise(void)
  Free(leapsec_tz);
  Free(logdir);
  Free(bind_cmd_path);
+  Free(ntp_signd_socket);
  Free(pidfile);
  Free(rtc_device);
  Free(rtc_file);
@@ -382,12 +404,12 @@ CNF_ReadFile(const char *filename)

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

-  DEBUG_LOG(LOGF_Configure, "Reading %s", filename);
+  DEBUG_LOG("Reading %s", filename);

  for (i = 1; fgets(line, sizeof(line), in); i++) {
    CNF_ParseLine(filename, i, line);
@@ -453,11 +475,13 @@ CNF_ParseLine(const char *filename, int number, char *line)
  } else if (!strcasecmp(command, "dumpdir")) {
    parse_string(p, &dumpdir);
  } else if (!strcasecmp(command, "dumponexit")) {
-    do_dump_on_exit = parse_null(p);
+    /* Silently ignored */
  } else if (!strcasecmp(command, "fallbackdrift")) {
    parse_fallbackdrift(p);
  } else if (!strcasecmp(command, "hwclockfile")) {
    parse_string(p, &hwclock_file);
+  } else if (!strcasecmp(command, "hwtimestamp")) {
+    parse_hwtimestamp(p);
  } else if (!strcasecmp(command, "include")) {
    parse_include(p);
  } else if (!strcasecmp(command, "initstepslew")) {
@@ -494,6 +518,8 @@ CNF_ParseLine(const char *filename, int number, char *line)
    parse_double(p, &max_distance);
  } else if (!strcasecmp(command, "maxdrift")) {
    parse_double(p, &max_drift);
+  } else if (!strcasecmp(command, "maxjitter")) {
+    parse_double(p, &max_jitter);
  } else if (!strcasecmp(command, "maxsamples")) {
    parse_int(p, &max_samples);
  } else if (!strcasecmp(command, "maxslewrate")) {
@@ -506,6 +532,8 @@ CNF_ParseLine(const char *filename, int number, char *line)
    parse_int(p, &min_sources);
  } else if (!strcasecmp(command, "noclientlog")) {
    no_client_log = parse_null(p);
+  } else if (!strcasecmp(command, "ntpsigndsocket")) {
+    parse_string(p, &ntp_signd_socket);
  } else if (!strcasecmp(command, "peer")) {
    parse_source(p, NTP_PEER, 0);
  } else if (!strcasecmp(command, "pidfile")) {
@@ -547,7 +575,7 @@ CNF_ParseLine(const char *filename, int number, char *line)
             !strcasecmp(command, "generatecommandkey") ||
             !strcasecmp(command, "linux_freq_scale") ||
             !strcasecmp(command, "linux_hz")) {
-    LOG(LOGS_WARN, LOGF_Configure, "%s directive is no longer supported", command);
+    LOG(LOGS_WARN, "%s directive is no longer supported", command);
  } else {
    other_parse_error("Invalid command");
  }
@@ -604,17 +632,13 @@ parse_null(char *line)
 static void
 parse_source(char *line, NTP_Source_Type type, int pool)
 {
-  CPS_Status status;
  NTP_Source source;
-  char str[64];

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

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

@@ -657,8 +681,9 @@ static void
 parse_refclock(char *line)
 {
  int n, poll, dpoll, filter_length, pps_rate, min_samples, max_samples, sel_options;
+  int max_lock_age, pps_forced;
  uint32_t ref_id, lock_ref_id;
-  double offset, delay, precision, max_dispersion;
+  double offset, delay, precision, max_dispersion, pulse_width;
  char *p, *cmd, *name, *param;
  unsigned char ref[5];
  RefclockParameters *refclock;
@@ -666,6 +691,7 @@ parse_refclock(char *line)
  poll = 4;
  dpoll = 0;
  filter_length = 64;
+  pps_forced = 0;
  pps_rate = 0;
  min_samples = SRC_DEFAULT_MINSAMPLES;
  max_samples = SRC_DEFAULT_MAXSAMPLES;
@@ -674,7 +700,9 @@ parse_refclock(char *line)
  delay = 1e-9;
  precision = 0.0;
  max_dispersion = 0.0;
+  pulse_width = 0.0;
  ref_id = 0;
+  max_lock_age = 2;
  lock_ref_id = 0;

  if (!*line) {
@@ -725,6 +753,9 @@ parse_refclock(char *line)
    } else if (!strcasecmp(cmd, "minsamples")) {
      if (sscanf(line, "%d%n", &min_samples, &n) != 1)
        break;
+    } else if (!strcasecmp(cmd, "maxlockage")) {
+      if (sscanf(line, "%d%n", &max_lock_age, &n) != 1)
+        break;
    } else if (!strcasecmp(cmd, "maxsamples")) {
      if (sscanf(line, "%d%n", &max_samples, &n) != 1)
        break;
@@ -734,12 +765,18 @@ parse_refclock(char *line)
    } else if (!strcasecmp(cmd, "delay")) {
      if (sscanf(line, "%lf%n", &delay, &n) != 1)
        break;
+    } else if (!strcasecmp(cmd, "pps")) {
+      n = 0;
+      pps_forced = 1;
    } else if (!strcasecmp(cmd, "precision")) {
      if (sscanf(line, "%lf%n", &precision, &n) != 1)
        break;
    } else if (!strcasecmp(cmd, "maxdispersion")) {
      if (sscanf(line, "%lf%n", &max_dispersion, &n) != 1)
        break;
+    } else if (!strcasecmp(cmd, "width")) {
+      if (sscanf(line, "%lf%n", &pulse_width, &n) != 1)
+        break;
    } else if (!strcasecmp(cmd, "noselect")) {
      n = 0;
      sel_options |= SRC_SELECT_NOSELECT;
@@ -769,6 +806,7 @@ parse_refclock(char *line)
  refclock->driver_poll = dpoll;
  refclock->poll = poll;
  refclock->filter_length = filter_length;
+  refclock->pps_forced = pps_forced;
  refclock->pps_rate = pps_rate;
  refclock->min_samples = min_samples;
  refclock->max_samples = max_samples;
@@ -777,7 +815,9 @@ parse_refclock(char *line)
  refclock->delay = delay;
  refclock->precision = precision;
  refclock->max_dispersion = max_dispersion;
+  refclock->pulse_width = pulse_width;
  refclock->ref_id = ref_id;
+  refclock->max_lock_age = max_lock_age;
  refclock->lock_ref_id = lock_ref_id;
 }

@@ -791,7 +831,10 @@ parse_log(char *line)
    log_name = line;
    line = CPS_SplitWord(line);
    if (*log_name) {
-      if (!strcmp(log_name, "measurements")) {
+      if (!strcmp(log_name, "rawmeasurements")) {
+        do_log_measurements = 1;
+        raw_measurements = 1;
+      } else if (!strcmp(log_name, "measurements")) {
        do_log_measurements = 1;
      } else if (!strcmp(log_name, "statistics")) {
        do_log_statistics = 1;
@@ -851,7 +894,7 @@ parse_initstepslew(char *line)
      if (DNS_Name2IPAddress(hostname, &ip_addr, 1) == DNS_Success) {
        ARR_AppendElement(init_sources, &ip_addr);
      } else {
-        LOG(LOGS_WARN, LOGF_Configure, "Could not resolve address of initstepslew server %s", hostname);
+        LOG(LOGS_WARN, "Could not resolve address of initstepslew server %s", hostname);
      }
    }
  }
@@ -1028,7 +1071,7 @@ parse_allow_deny(char *line, ARR_Instance restrictions, int allow)
      }

    } else {
-      if (DNS_Name2IPAddress(p, &ip_addr, 1) == DNS_Success) {
+      if (!slashpos && DNS_Name2IPAddress(p, &ip_addr, 1) == DNS_Success) {
        new_node = (AllowDeny *)ARR_GetNewElement(restrictions);
        new_node->allow = allow;
        new_node->all = all;
@@ -1143,7 +1186,7 @@ parse_broadcast(char *line)
    }
  } else {
    /* default port */
-    port = 123;
+    port = NTP_PORT;
  }

  destination = (NTP_Broadcast_Destination *)ARR_GetNewElement(broadcasts);
@@ -1219,16 +1262,84 @@ parse_tempcomp(char *line)

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

+static void
+parse_hwtimestamp(char *line)
+{
+  CNF_HwTsInterface *iface;
+  char *p, filter[5];
+  int n;
+
+  if (!*line) {
+    command_parse_error();
+    return;
+  }
+
+  p = line;
+  line = CPS_SplitWord(line);
+
+  iface = ARR_GetNewElement(hwts_interfaces);
+  iface->name = Strdup(p);
+  iface->minpoll = 0;
+  iface->nocrossts = 0;
+  iface->rxfilter = CNF_HWTS_RXFILTER_NTP;
+  iface->precision = 100.0e-9;
+  iface->tx_comp = 0.0;
+  iface->rx_comp = 0.0;
+
+  for (p = line; *p; line += n, p = line) {
+    line = CPS_SplitWord(line);
+
+    if (!strcasecmp(p, "minpoll")) {
+      if (sscanf(line, "%d%n", &iface->minpoll, &n) != 1)
+        break;
+    } else if (!strcasecmp(p, "precision")) {
+      if (sscanf(line, "%lf%n", &iface->precision, &n) != 1)
+        break;
+    } else if (!strcasecmp(p, "rxcomp")) {
+      if (sscanf(line, "%lf%n", &iface->rx_comp, &n) != 1)
+        break;
+    } else if (!strcasecmp(p, "txcomp")) {
+      if (sscanf(line, "%lf%n", &iface->tx_comp, &n) != 1)
+        break;
+    } else if (!strcasecmp(p, "rxfilter")) {
+      if (sscanf(line, "%4s%n", filter, &n) != 1)
+        break;
+      if (!strcasecmp(filter, "none"))
+        iface->rxfilter = CNF_HWTS_RXFILTER_NONE;
+      else if (!strcasecmp(filter, "ntp"))
+        iface->rxfilter = CNF_HWTS_RXFILTER_NTP;
+      else if (!strcasecmp(filter, "all"))
+        iface->rxfilter = CNF_HWTS_RXFILTER_ALL;
+      else
+        break;
+    } else if (!strcasecmp(p, "nocrossts")) {
+      n = 0;
+      iface->nocrossts = 1;
+    } else {
+      break;
+    }
+  }
+
+  if (*p)
+    command_parse_error();
+}
+
+/* ================================================== */
+
 static void
 parse_include(char *line)
 {
  glob_t gl;
  size_t i;
+  int r;

  check_number_of_args(line, 1);

-  if (glob(line, 0, NULL, &gl)) {
-    DEBUG_LOG(LOGF_Configure, "glob of %s failed", line);
+  if ((r = glob(line, GLOB_ERR | GLOB_NOMAGIC, NULL, &gl)) != 0) {
+    if (r != GLOB_NOMATCH)
+      LOG_FATAL("Could not search for files matching %s", line);
+
+    DEBUG_LOG("glob of %s failed", line);
    return;
  }

@@ -1245,9 +1356,6 @@ CNF_CreateDirs(uid_t uid, gid_t gid)
 {
  char *dir;

-  UTI_CreateDirAndParents(logdir, 0755, uid, gid);
-  UTI_CreateDirAndParents(dumpdir, 0755, uid, gid);
-
  /* Create a directory for the Unix domain command socket */
  if (bind_cmd_path[0]) {
    dir = UTI_PathToDir(bind_cmd_path);
@@ -1257,12 +1365,17 @@ CNF_CreateDirs(uid_t uid, gid_t gid)
       existed.  It MUST NOT be accessible by others as permissions on Unix
       domain sockets are ignored on some systems (e.g. Solaris). */
    if (!UTI_CheckDirPermissions(dir, 0770, uid, gid)) {
-      LOG(LOGS_WARN, LOGF_Configure, "Disabled command socket %s", bind_cmd_path);
+      LOG(LOGS_WARN, "Disabled command socket %s", bind_cmd_path);
      bind_cmd_path[0] = '\0';
    }

    Free(dir);
  }
+
+  if (logdir[0])
+    UTI_CreateDirAndParents(logdir, 0755, uid, gid);
+  if (dumpdir[0])
+    UTI_CreateDirAndParents(dumpdir, 0755, uid, gid);
 }

 /* ================================================== */
@@ -1391,8 +1504,9 @@ CNF_GetDumpDir(void)
 /* ================================================== */

 int
-CNF_GetLogMeasurements(void)
+CNF_GetLogMeasurements(int *raw)
 {
+  *raw = raw_measurements;
  return do_log_measurements;
 }

@@ -1470,14 +1584,6 @@ CNF_GetRtcDevice(void)

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

-int
-CNF_GetDumpOnExit(void)
-{
-  return do_dump_on_exit;
-}
-
-/* ================================================== */
-
 double
 CNF_GetMaxUpdateSkew(void)
 {
@@ -1526,6 +1632,14 @@ CNF_GetMaxDistance(void)

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

+double
+CNF_GetMaxJitter(void)
+{
+  return max_jitter;
+}
+
+/* ================================================== */
+
 double
 CNF_GetReselectDistance(void)
 {
@@ -1650,7 +1764,7 @@ CNF_SetupAccessRestrictions(void)
    node = ARR_GetElement(ntp_restrictions, i);
    status = NCR_AddAccessRestriction(&node->ip, node->subnet_bits, node->allow, node->all);
    if (!status) {
-      LOG_FATAL(LOGF_Configure, "Bad subnet in %s/%d", UTI_IPToString(&node->ip), node->subnet_bits);
+      LOG_FATAL("Bad subnet in %s/%d", UTI_IPToString(&node->ip), node->subnet_bits);
    }
  }

@@ -1658,7 +1772,7 @@ CNF_SetupAccessRestrictions(void)
    node = ARR_GetElement(cmd_restrictions, i);
    status = CAM_AddAccessRestriction(&node->ip, node->subnet_bits, node->allow, node->all);
    if (!status) {
-      LOG_FATAL(LOGF_Configure, "Bad subnet in %s/%d", UTI_IPToString(&node->ip), node->subnet_bits);
+      LOG_FATAL("Bad subnet in %s/%d", UTI_IPToString(&node->ip), node->subnet_bits);
    }
  }

@@ -1740,6 +1854,14 @@ CNF_GetBindCommandAddress(int family, IPAddr *addr)

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

+char *
+CNF_GetNtpSigndSocket(void)
+{
+  return ntp_signd_socket;
+}
+
+/* ================================================== */
+
 char *
 CNF_GetPidFile(void)
 {
@@ -1877,3 +1999,15 @@ CNF_GetInitStepThreshold(void)
 {
  return init_slew_threshold;
 }
+
+/* ================================================== */
+
+int
+CNF_GetHwTsInterface(unsigned int index, CNF_HwTsInterface **iface)
+{
+  if (index >= ARR_GetSize(hwts_interfaces))
+    return 0;
+
+  *iface = (CNF_HwTsInterface *)ARR_GetElement(hwts_interfaces, index);
+  return 1;
+}
--- a/conf.h
+++ b/conf.h
@@ -31,7 +31,7 @@
 #include "addressing.h"
 #include "reference.h"

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

 extern char *CNF_GetRtcDevice(void);
@@ -52,7 +52,7 @@ extern char *CNF_GetDriftFile(void);
 extern char *CNF_GetLogDir(void);
 extern char *CNF_GetDumpDir(void);
 extern int CNF_GetLogBanner(void);
-extern int CNF_GetLogMeasurements(void);
+extern int CNF_GetLogMeasurements(int *raw);
 extern int CNF_GetLogStatistics(void);
 extern int CNF_GetLogTracking(void);
 extern int CNF_GetLogRtc(void);
@@ -60,7 +60,6 @@ extern int CNF_GetLogRefclocks(void);
 extern int CNF_GetLogTempComp(void);
 extern char *CNF_GetKeysFile(void);
 extern char *CNF_GetRtcFile(void);
-extern int CNF_GetDumpOnExit(void);
 extern int CNF_GetManualEnabled(void);
 extern int CNF_GetCommandPort(void);
 extern int CNF_GetRtcOnUtc(void);
@@ -76,6 +75,7 @@ extern void CNF_GetBindAddress(int family, IPAddr *addr);
 extern void CNF_GetBindAcquisitionAddress(int family, IPAddr *addr);
 extern void CNF_GetBindCommandAddress(int family, IPAddr *addr);
 extern char *CNF_GetBindCommandPath(void);
+extern char *CNF_GetNtpSigndSocket(void);
 extern char *CNF_GetPidFile(void);
 extern REF_LeapMode CNF_GetLeapSecMode(void);
 extern char *CNF_GetLeapSecTimezone(void);
@@ -88,6 +88,7 @@ extern double CNF_GetCorrectionTimeRatio(void);
 extern double CNF_GetMaxSlewRate(void);

 extern double CNF_GetMaxDistance(void);
+extern double CNF_GetMaxJitter(void);
 extern double CNF_GetReselectDistance(void);
 extern double CNF_GetStratumWeight(void);
 extern double CNF_GetCombineLimit(void);
@@ -117,4 +118,20 @@ extern char *CNF_GetHwclockFile(void);
 extern int CNF_GetInitSources(void);
 extern double CNF_GetInitStepThreshold(void);

+#define CNF_HWTS_RXFILTER_NONE 0
+#define CNF_HWTS_RXFILTER_NTP 1
+#define CNF_HWTS_RXFILTER_ALL 2
+
+typedef struct {
+  char *name;
+  int minpoll;
+  int nocrossts;
+  int rxfilter;
+  double precision;
+  double tx_comp;
+  double rx_comp;
+} CNF_HwTsInterface;
+
+extern int CNF_GetHwTsInterface(unsigned int index, CNF_HwTsInterface **iface);
+
 #endif /* GOT_CONF_H */
--- a/200
+++ b/200
@@ -4,7 +4,8 @@
 # chronyd/chronyc - Programs for keeping computer clocks accurate.
 #
 # Copyright (C) Richard P. Curnow  1997-2003
-# Copyright (C) Miroslav Lichvar  2009, 2012-2015
+# Copyright (C) Bryan Christianson  2016
+# Copyright (C) Miroslav Lichvar  2009, 2012-2016
 #
 # =======================================================================

@@ -24,6 +25,7 @@ test_code () {
  printf "%s" "Checking for $name : "

  (
+    echo "#include \"config.h\""
    for h in $headers; do
      echo "#include <$h>"
    done
@@ -79,9 +81,8 @@ For better control, use the options below.
  --disable-readline     Disable line editing support
  --without-readline     Don't use GNU readline even if it is available
  --without-editline     Don't use editline even if it is available
-  --readline-dir=DIR     Specify parent of readline include and lib directories
-  --readline-inc-dir=DIR Specify where readline include directory is
-  --readline-lib-dir=DIR Specify where readline lib directory is
+  --with-readline-includes=DIR Specify where readline include directory is
+  --with-readline-library=DIR Specify where readline lib directory is
  --with-ncurses-library=DIR Specify where ncurses lib directory is
  --disable-sechash      Disable support for hashes other than MD5
  --without-nss          Don't use NSS even if it is available
@@ -99,10 +100,15 @@ For better control, use the options below.
  --without-seccomp      Don't use seccomp even if it is available
  --disable-asyncdns     Disable asynchronous name resolving
  --disable-forcednsretry Don't retry on permanent DNS error
+  --without-clock-gettime Don't use clock_gettime() even if it is available
+  --disable-timestamping Disable support for SW/HW timestamping
+  --enable-ntp-signd     Enable support for MS-SNTP authentication in Samba
  --with-ntp-era=SECONDS Specify earliest assumed NTP time in seconds
                         since 1970-01-01 [50*365 days ago]
  --with-user=USER       Specify default chronyd user [root]
  --with-hwclockfile=PATH Specify default path to hwclock(8) adjtime file
+  --with-pidfile=PATH    Specify default pidfile [/var/run/chronyd.pid]
+  --with-rtcdevice=PATH  Specify default path to RTC device [/dev/rtc]
  --with-sendmail=PATH   Path to sendmail binary [/usr/lib/sendmail]
  --enable-debug         Enable debugging support

@@ -114,7 +120,7 @@ Fine tuning of the installation directories:
  --mandir=DIR           man documentation [DATAROOTDIR/man]
  --docdir=DIR           documentation root [DATAROOTDIR/doc/chrony]
  --localstatedir=DIR    modifiable single-machine data [/var]
-  --chronysockdir=DIR    location for chrony sockets [LOCALSTATEDIR/run/chrony]
+  --chronyrundir=DIR     location for chrony sockets [LOCALSTATEDIR/run/chrony]
  --chronyvardir=DIR     location for chrony data [LOCALSTATEDIR/lib/chrony]

 Overriding system detection when cross-compiling:
@@ -213,9 +219,16 @@ try_setsched=0
 try_lockmem=0
 feat_asyncdns=1
 feat_forcednsretry=1
+try_clock_gettime=1
+try_recvmmsg=1
+feat_timestamping=1
+try_timestamping=0
+feat_ntp_signd=0
 ntp_era_split=""
 default_user="root"
 default_hwclockfile=""
+default_pidfile="/var/run/chronyd.pid"
+default_rtcdevice="/dev/rtc"
 mail_program="/usr/lib/sendmail"

 for option
@@ -269,8 +282,8 @@ do
    --localstatedir=* )
      SETLOCALSTATEDIR=`echo $option | sed -e 's/^.*=//;'`
    ;;
-    --chronysockdir=* )
-      SETCHRONYSOCKDIR=`echo $option | sed -e 's/^.*=//;'`
+    --chronyrundir=* | --chronysockdir=* )
+      SETCHRONYRUNDIR=`echo $option | sed -e 's/^.*=//;'`
    ;;
    --chronyvardir=* )
      SETCHRONYVARDIR=`echo $option | sed -e 's/^.*=//;'`
@@ -317,6 +330,15 @@ do
    --disable-forcednsretry)
      feat_forcednsretry=0
    ;;
+    --without-clock-gettime)
+      try_clock_gettime=0
+    ;;
+    --disable-timestamping)
+      feat_timestamping=0
+    ;;
+    --enable-ntp-signd)
+      feat_ntp_signd=1
+    ;;
    --with-ntp-era=* )
      ntp_era_split=`echo $option | sed -e 's/^.*=//;'`
    ;;
@@ -326,6 +348,12 @@ do
    --with-hwclockfile=* )
      default_hwclockfile=`echo $option | sed -e 's/^.*=//;'`
    ;;
+    --with-pidfile=* )
+      default_pidfile=`echo $option | sed -e 's/^.*=//;'`
+    ;;
+    --with-rtcdevice=* )
+      default_rtcdevice=`echo $option | sed -e 's/^.*=//;'`
+    ;;
    --with-sendmail=* )
      mail_program=`echo $option | sed -e 's/^.*=//;'`
    ;;
@@ -366,6 +394,7 @@ case $OPERATINGSYSTEM in
        [ $try_libcap != "0" ] && try_libcap=1
        try_rtc=1
        [ $try_seccomp != "0" ] && try_seccomp=1
+        try_timestamping=1
        try_setsched=1
        try_lockmem=1
        try_phc=1
@@ -373,6 +402,9 @@ case $OPERATINGSYSTEM in
        echo "Configuring for " $SYSTEM
    ;;
    FreeBSD)
+        # recvmmsg() seems to be broken on FreeBSD 11.0 and it's just
+        # a wrapper around recvmsg()
+        try_recvmmsg=0
        EXTRA_OBJECTS="sys_generic.o sys_netbsd.o sys_timex.o"
        add_def FREEBSD
        if [ $feat_droproot = "1" ]; then
@@ -396,7 +428,16 @@ case $OPERATINGSYSTEM in
          add_def FEAT_PRIVDROP
          priv_ops="ADJUSTTIME SETTIME BINDSOCKET"
        fi
-        echo "Configuring for MacOS X (" $SYSTEM "MacOS X version" $VERSION ")"
+        major=`echo $VERSION | cut -d. -f1`
+        # ntp_adjtime is not available in macOS 10.12 (Darwin 16.x.x) and earlier
+        if [ $major -gt "16" ]; then
+          add_def HAVE_MACOS_SYS_TIMEX
+          EXTRA_OBJECTS="$EXTRA_OBJECTS sys_generic.o sys_netbsd.o sys_timex.o"
+          if [ $feat_droproot = "1" ]; then
+            priv_ops="$priv_ops ADJUSTTIMEX"
+          fi
+        fi
+        echo "Configuring for macOS (" $SYSTEM "macOS version" $VERSION ")"
    ;;
    SunOS)
        EXTRA_OBJECTS="sys_generic.o sys_solaris.o sys_timex.o"
@@ -432,8 +473,13 @@ fi
 if [ $feat_ntp = "1" ]; then
  add_def FEAT_NTP
  EXTRA_OBJECTS="$EXTRA_OBJECTS ntp_core.o ntp_io.o ntp_sources.o"
+  if [ $feat_ntp_signd = "1" ]; then
+    add_def FEAT_SIGND
+    EXTRA_OBJECTS="$EXTRA_OBJECTS ntp_signd.o"
+  fi
 else
  feat_asyncdns=0
+  feat_timestamping=0
 fi

 if [ "$feat_cmdmon" = "1" ] || [ $feat_ntp = "1" ]; then
@@ -453,14 +499,16 @@ MYCPPFLAGS="$CPPFLAGS"
 MYLDFLAGS="$LDFLAGS"

 if [ "x$MYCC" = "x" ]; then
-  MYCC=gcc
-  if ! test_code "$MYCC" '' '' '' ''; then
-    MYCC=cc
-    if ! test_code "$MYCC" '' '' '' ''; then
+  for cc in gcc clang cc ""; do
+    if [ "x$cc" = "x" ]; then
      echo "error: no C compiler found"
      exit 1
    fi
-  fi
+    MYCC=$cc
+    if test_code "$MYCC" '' '' '' ''; then
+      break
+    fi
+  done
 else
  if ! test_code "$MYCC" '' '' '' ''; then
    echo "error: C compiler $MYCC cannot create executables"
@@ -470,9 +518,25 @@ fi

 if [ "x$MYCFLAGS" = "x" ]; then
  MYCFLAGS="-O2 -g"
+
+  TESTCFLAGS="-D_FORTIFY_SOURCE=2 -fPIE"
+  TESTLDFLAGS="-pie -Wl,-z,relro,-z,now"
+  if test_code 'hardening compiler options' '' "$TESTCFLAGS" "$TESTLDFLAGS" ''; then
+    MYCFLAGS="$MYCFLAGS $TESTCFLAGS"
+    MYLDFLAGS="$MYLDFLAGS $TESTLDFLAGS"
+  fi
+  TESTCFLAGS="-fstack-protector-strong --param=ssp-buffer-size=4"
+  if test_code '-fstack-protector-strong' '' "$TESTCFLAGS" '' ''; then
+    MYCFLAGS="$MYCFLAGS $TESTCFLAGS"
+  else
+    TESTCFLAGS="-fstack-protector --param=ssp-buffer-size=4"
+    if test_code '-fstack-protector' '' "$TESTCFLAGS" '' ''; then
+      MYCFLAGS="$MYCFLAGS $TESTCFLAGS"
+    fi
+  fi
 fi

-if [ "x$MYCC" = "xgcc" ]; then
+if [ "x$MYCC" = "xgcc" ] || [ "x$MYCC" = "xclang" ]; then
  MYCFLAGS="$MYCFLAGS -Wmissing-prototypes -Wall"
 fi

@@ -559,6 +623,21 @@ then
  fi
 fi

+if [ $try_clock_gettime = "1" ]; then
+  if test_code 'clock_gettime()' 'time.h' '' '' \
+    'clock_gettime(CLOCK_REALTIME, NULL);'
+  then
+    add_def HAVE_CLOCK_GETTIME
+  else
+    if test_code 'clock_gettime() in -lrt' 'time.h' '' '-lrt' \
+      'clock_gettime(CLOCK_REALTIME, NULL);'
+    then
+      add_def HAVE_CLOCK_GETTIME
+      EXTRA_LIBS="$EXTRA_LIBS -lrt"
+    fi
+  fi
+fi
+
 if test_code 'getaddrinfo()' 'sys/types.h sys/socket.h netdb.h' '' "$EXTRA_LIBS" \
  'return getaddrinfo(0, 0, 0, 0);'
 then
@@ -579,6 +658,51 @@ if test_code 'arc4random_buf()' 'stdlib.h' '' '' 'arc4random_buf(NULL, 0);'; the
  add_def HAVE_ARC4RANDOM
 fi

+if test_code 'getrandom()' 'stdlib.h sys/random.h' '' '' \
+    'return getrandom(NULL, 256, 0);'; then
+  add_def HAVE_GETRANDOM
+fi
+
+RECVMMSG_CODE='
+  struct mmsghdr hdr;
+  return !recvmmsg(0, &hdr, 1, MSG_DONTWAIT, 0);'
+if [ $try_recvmmsg = "1" ]; then
+  if test_code 'recvmmsg()' 'sys/socket.h' '' "$EXTRA_LIBS" "$RECVMMSG_CODE"; then
+    add_def HAVE_RECVMMSG
+  else
+    if test_code 'recvmmsg() with _GNU_SOURCE' 'sys/socket.h' '-D_GNU_SOURCE' \
+      "$EXTRA_LIBS" "$RECVMMSG_CODE"
+    then
+      add_def _GNU_SOURCE
+      add_def HAVE_RECVMMSG
+    fi
+  fi
+fi
+
+if [ $feat_timestamping = "1" ] && [ $try_timestamping = "1" ] &&
+  test_code 'SW/HW timestamping' 'sys/types.h sys/socket.h linux/net_tstamp.h
+                                  linux/errqueue.h linux/ptp_clock.h' '' '' '
+    int val = SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_RX_SOFTWARE |
+              SOF_TIMESTAMPING_RAW_HARDWARE | SOF_TIMESTAMPING_OPT_CMSG;
+    return sizeof (struct scm_timestamping) + SCM_TSTAMP_SND + PTP_SYS_OFFSET +
+           setsockopt(0, SOL_SOCKET, SO_SELECT_ERR_QUEUE + SO_TIMESTAMPING,
+                      &val, sizeof (val));'
+then
+  add_def HAVE_LINUX_TIMESTAMPING
+  EXTRA_OBJECTS="$EXTRA_OBJECTS hwclock.o ntp_io_linux.o"
+
+  if test_code 'other timestamping options' \
+    'sys/types.h sys/socket.h linux/net_tstamp.h' '' '' '
+    struct scm_ts_pktinfo pktinfo;
+    pktinfo.if_index = pktinfo.pkt_length = 0;
+    return pktinfo.if_index + pktinfo.pkt_length + HWTSTAMP_FILTER_NTP_ALL +
+           SOF_TIMESTAMPING_OPT_PKTINFO + SOF_TIMESTAMPING_OPT_TX_SWHW;'; then
+    add_def HAVE_LINUX_TIMESTAMPING_RXFILTER_NTP 1
+    add_def HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO 1
+    add_def HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW 1
+  fi
+fi
+
 timepps_h=""
 if [ $feat_refclock = "1" ] && [ $feat_pps = "1" ]; then
  if test_code '<sys/timepps.h>' 'sys/timepps.h' '' '' ''; then
@@ -628,7 +752,7 @@ then
  # NAME2IPADDRESS shouldn't be enabled with other operations as the helper
  # process works on one request at the time and the async resolver could
  # block the main thread
-  priv_ops="NAME2IPADDRESS"
+  priv_ops="NAME2IPADDRESS RELOADDNS"
  EXTRA_LIBS="$EXTRA_LIBS -lseccomp"
 fi

@@ -649,19 +773,13 @@ then
 fi

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

 if [ $try_setsched = "1" ] && \
@@ -691,7 +809,6 @@ then
  add_def FORCE_DNSRETRY
 fi

-READLINE_COMPILE=""
 READLINE_LINK=""
 if [ $feat_readline = "1" ]; then
  if [ $try_editline = "1" ]; then
@@ -701,7 +818,7 @@ if [ $feat_readline = "1" ]; then
    then
      add_def FEAT_READLINE
      add_def USE_EDITLINE
-      READLINE_COMPILE="$readline_inc"
+      MYCPPFLAGS="$MYCPPFLAGS $readline_inc"
      READLINE_LINK="$readline_lib -ledit"
    fi
  fi
@@ -712,7 +829,7 @@ if [ $feat_readline = "1" ]; then
      'add_history(readline("prompt"));'
    then
      add_def FEAT_READLINE
-      READLINE_COMPILE="$readline_inc"
+      MYCPPFLAGS="$MYCPPFLAGS $readline_inc"
      READLINE_LINK="$readline_lib -lreadline"
    fi
  fi
@@ -724,7 +841,7 @@ if [ $feat_readline = "1" ]; then
      'add_history(readline("prompt"));'
    then
      add_def FEAT_READLINE
-      READLINE_COMPILE="$readline_inc"
+      MYCPPFLAGS="$MYCPPFLAGS $readline_inc"
      READLINE_LINK="$readline_lib $ncurses_lib -lreadline -lncurses"
    fi
  fi
@@ -733,7 +850,6 @@ if [ $feat_readline = "1" ]; then
 fi

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

 if [ $feat_sechash = "1" ] && [ $try_nss = "1" ]; then
@@ -744,9 +860,9 @@ if [ $feat_sechash = "1" ] && [ $try_nss = "1" ]; then
    'NSSLOWHASH_Begin(NSSLOWHASH_NewContext(NSSLOW_Init(), HASH_AlgSHA512));'
  then
    HASH_OBJ="hash_nss.o"
-    HASH_COMPILE="$test_cflags"
    HASH_LINK="$test_link"
    LIBS="$LIBS $HASH_LINK"
+    MYCPPFLAGS="$MYCPPFLAGS $test_cflags"
    add_def FEAT_SECHASH
  fi
 fi
@@ -756,9 +872,9 @@ if [ $feat_sechash = "1" ] && [ "x$HASH_LINK" = "x" ] && [ $try_tomcrypt = "1" ]
    'hash_memory_multi(find_hash("md5"), NULL, NULL, NULL, 0, NULL, 0);'
  then
    HASH_OBJ="hash_tomcrypt.o"
-    HASH_COMPILE="-I/usr/include/tomcrypt"
    HASH_LINK="-ltomcrypt"
    LIBS="$LIBS $HASH_LINK"
+    MYCPPFLAGS="$MYCPPFLAGS -I/usr/include/tomcrypt"
    add_def FEAT_SECHASH
  fi
 fi
@@ -808,9 +924,9 @@ if [ "x$SETLOCALSTATEDIR" != "x" ]; then
  LOCALSTATEDIR=$SETLOCALSTATEDIR
 fi

-CHRONYSOCKDIR=${LOCALSTATEDIR}/run/chrony
-if [ "x$SETCHRONYSOCKDIR" != "x" ]; then
-  CHRONYSOCKDIR=$SETCHRONYSOCKDIR
+CHRONYRUNDIR=${LOCALSTATEDIR}/run/chrony
+if [ "x$SETCHRONYRUNDIR" != "x" ]; then
+  CHRONYRUNDIR=$SETCHRONYRUNDIR
 fi

 CHRONYVARDIR=${LOCALSTATEDIR}/lib/chrony
@@ -820,13 +936,15 @@ fi

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

 common_features="`get_features IPV6 DEBUG`"
 chronyc_features="`get_features READLINE`"
-chronyd_features="`get_features CMDMON NTP REFCLOCK RTC PRIVDROP SCFILTER SECHASH ASYNCDNS`"
+chronyd_features="`get_features CMDMON NTP REFCLOCK RTC PRIVDROP SCFILTER SECHASH SIGND ASYNCDNS`"
 add_def CHRONYC_FEATURES "\"$chronyc_features $common_features\""
 add_def CHRONYD_FEATURES "\"$chronyd_features $common_features\""
 echo "Features : $chronyd_features $chronyc_features $common_features"
@@ -850,18 +968,18 @@ do
          s%@LDFLAGS@%${MYLDFLAGS}%;\
          s%@EXTRA_LIBS@%${EXTRA_LIBS}%;\
          s%@EXTRA_CLI_LIBS@%${EXTRA_CLI_LIBS}%;\
-          s%@READLINE_COMPILE@%${READLINE_COMPILE}%;\
          s%@HASH_OBJ@%${HASH_OBJ}%;\
-          s%@HASH_COMPILE@%${HASH_COMPILE}%;\
          s%@SYSCONFDIR@%${SYSCONFDIR}%;\
          s%@BINDIR@%${BINDIR}%;\
          s%@SBINDIR@%${SBINDIR}%;\
          s%@DOCDIR@%${DOCDIR}%;\
          s%@MANDIR@%${MANDIR}%;\
          s%@LOCALSTATEDIR@%${LOCALSTATEDIR}%;\
-          s%@CHRONYSOCKDIR@%${CHRONYSOCKDIR}%;\
+          s%@CHRONYRUNDIR@%${CHRONYRUNDIR}%;\
          s%@CHRONYVARDIR@%${CHRONYVARDIR}%;\
          s%@DEFAULT_HWCLOCK_FILE@%${default_hwclockfile}%;\
+          s%@DEFAULT_PID_FILE@%${default_pidfile}%;\
+          s%@DEFAULT_RTC_DEVICE@%${default_rtcdevice}%;\
          s%@DEFAULT_USER@%${default_user}%;\
          s%@CHRONY_VERSION@%${CHRONY_VERSION}%;" \
          < ${f}.in > $f
--- a/contrib/bryan_christianson_1/README.txt
+++ b/contrib/bryan_christianson_1/README.txt
@@ -1,16 +1,16 @@
-Notes for installing chrony on MacOS X
+Notes for installing chrony on macOS
 Author: Bryan Christianson (bryan@whatroute.net)
 ------------------------------------------------

 These files are for those admins/users who would prefer to install chrony
 from the source distribution and are intended as guidelines rather than
 being definitive. They can be edited with a plain text editor, such as
-vi, emacs or your favourite IDE (xcode)
+vi, emacs or your favourite IDE (Xcode)

 It is assumed you are comfortable with installing software from the
 terminal command line and know how to use sudo to acquire root access.

-If you are not familiar with the MacOS X command line then
+If you are not familiar with the macOS command line then
 please consider using ChronyControl from http://whatroute.net/chronycontrol.html

 ChronyControl provides a gui wrapper for installing these files and sets the
@@ -72,7 +72,7 @@ Installing the support files

 1. chronylogrotate.sh
 This is a simple shell script that deletes old log files. Unfortunately because
-of the need to run chronyc, the standard MacOS X logrotation does not work with
+of the need to run chronyc, the standard macOS logrotation does not work with
 chrony logs.

 This script runs on a daily basis under control of launchd and should be
--- a/doc/Makefile.in
+++ b/doc/Makefile.in
@@ -13,19 +13,23 @@ BINDIR = @BINDIR@
 SBINDIR = @SBINDIR@
 MANDIR = @MANDIR@
 DOCDIR = @DOCDIR@
-CHRONYSOCKDIR = @CHRONYSOCKDIR@
+CHRONYRUNDIR = @CHRONYRUNDIR@
 CHRONYVARDIR = @CHRONYVARDIR@
 CHRONY_VERSION = @CHRONY_VERSION@
 DEFAULT_USER = @DEFAULT_USER@
 DEFAULT_HWCLOCK_FILE = @DEFAULT_HWCLOCK_FILE@
+DEFAULT_PID_FILE = @DEFAULT_PID_FILE@
+DEFAULT_RTC_DEVICE = @DEFAULT_RTC_DEVICE@

 SED_COMMANDS = "s%\@SYSCONFDIR\@%$(SYSCONFDIR)%g;\
 	       s%\@BINDIR\@%$(BINDIR)%g;\
 	       s%\@SBINDIR\@%$(SBINDIR)%g;\
 	       s%\@CHRONY_VERSION\@%$(CHRONY_VERSION)%g;\
 	       s%\@DEFAULT_HWCLOCK_FILE\@%$(DEFAULT_HWCLOCK_FILE)%g;\
+	       s%\@DEFAULT_PID_FILE\@%$(DEFAULT_PID_FILE)%g;\
+	       s%\@DEFAULT_RTC_DEVICE\@%$(DEFAULT_RTC_DEVICE)%g;\
 	       s%\@DEFAULT_USER\@%$(DEFAULT_USER)%g;\
-	       s%\@CHRONYSOCKDIR\@%$(CHRONYSOCKDIR)%g;\
+	       s%\@CHRONYRUNDIR\@%$(CHRONYRUNDIR)%g;\
 	       s%\@CHRONYVARDIR\@%$(CHRONYVARDIR)%g;"

 man: $(MAN_FILES) $(MAN_IN_FILES)
--- a/doc/chrony.conf.adoc
+++ b/doc/chrony.conf.adoc
@@ -1,7 +1,8 @@
 // This file is part of chrony
 //
 // Copyright (C) Richard P. Curnow  1997-2003
-// Copyright (C) Miroslav Lichvar  2009-2016
+// Copyright (C) Stephen Wadeley  2016
+// Copyright (C) Miroslav Lichvar  2009-2017
 //
 // This program is free software; you can redistribute it and/or modify
 // it under the terms of version 2 of the GNU General Public License as
@@ -67,11 +68,15 @@ options:
 Although *chronyd* will trim the rate at which it samples the server during
 normal operation, the user might want to constrain the minimum polling interval.
 This is always defined as a power of 2, so *minpoll 5* would mean that the
-polling interval cannot drop below 32 seconds. The default is 6 (64 seconds).
+polling interval cannot drop below 32 seconds. The default is 6 (64 seconds),
+the minimum is -4 (1/16th of a second), and the maximum is 24 (6 months). Note
+that intervals shorter than 6 (64 seconds) should generally not be used with
+public servers on the Internet, because it might be considered abuse.
 *maxpoll* _poll_:::
 In a similar way, the user might want to constrain the maximum polling interval.
 Again this is specified as a power of 2, *maxpoll 9* indicates that the polling
-interval must stay at or below 512 seconds. The default is 10 (1024 seconds).
+interval must stay at or below 512 seconds. The default is 10 (1024 seconds),
+the minimum is 0 (1 second), and the maximum is 24 (6 months).
 *iburst*:::
 If this option is set, the interval between the first four polls will be 2
 seconds instead of _minpoll_. This is useful to quickly get the first update of
@@ -105,17 +110,25 @@ If the user knows that round trip delays above a certain level should cause the
 measurement to be ignored, this level can be defined with the *maxdelay*
 option. For example, *maxdelay 0.3* would indicate that measurements with a
 round-trip delay of 0.3 seconds or more should be ignored. The default value is
-3 seconds.
+3 seconds and the maximum value is 1000 seconds.
 *maxdelayratio* _ratio_:::
 This option is similar to the maxdelay option above. *chronyd* keeps a record
 of the minimum round-trip delay amongst the previous measurements that it has
 buffered. If a measurement has a round trip delay that is greater than the
-maxdelayratio times the minimum delay, it will be rejected.
+maxdelayratio times the minimum delay, it will be rejected. This option works
+only in the *server* directive when not in the interleaved mode.
 *maxdelaydevratio* _ratio_:::
 If a measurement has a ratio of the increase in the round-trip delay from the
 minimum delay amongst the previous measurements to the standard deviation of
 the previous measurements that is greater than the specified ratio, it will be
 rejected. The default is 10.0.
+*offset* _offset_:::
+This option specifies a correction (in seconds) which will be applied to
+offsets measured with this source. It's particularly useful to compensate for a
+known asymmetry in network delay or timestamping errors. For example, if
+packets sent to the source were on average delayed by 100 microseconds more
+than packets sent from the source back, the correction would be -0.00005 (-50
+microseconds). The default is 0.0.
 *minsamples* _samples_:::
 Set the minimum number of samples kept for this source. This overrides the
 <<minsamples,*minsamples*>> directive.
@@ -149,11 +162,31 @@ clock. Together with the *trust* option this might be useful to allow a trusted
 authenticated source to be safely combined with unauthenticated sources in
 order to improve the accuracy of the clock. They can be selected and used for
 synchronisation only if they agree with the trusted and required source.
+*xleave*:::
+This option enables an interleaved mode which allows the server or the peer to
+send transmit timestamps captured after the actual transmission (e.g. when the
+server or the peer is running *chronyd* with software (kernel) or hardware
+timestamping). This can significantly improve the accuracy of the measurements.
+
+The interleaved mode is compatible with servers that support only the basic
+mode, but peers must both support and have enabled the interleaved mode,
+otherwise the synchronisation will work only in one direction. Note that even
+servers that support the interleaved mode might respond in the basic mode as
+the interleaved mode requires the servers to keep some state for each client
+and the state might be dropped when there are too many clients (e.g.
+<<clientloglimit,*clientloglimit*>> is too small), or it might be overwritten
+by other clients that have the same IP address (e.g. computers behind NAT or
+someone sending requests with a spoofed source address).
+
+With longer polling intervals, it is recommended to combine the *xleave* option
+with the *presend* option in order to shorten the interval in which the server
+has to keep the state to be able to respond in the interleaved mode. The
+shorter interval also improves accuracy of the measured offset and delay.
 *polltarget* _target_:::
 Target number of measurements to use for the regression algorithm which
 *chronyd* will try to maintain by adjusting the polling interval between
 *minpoll* and *maxpoll*. A higher target makes *chronyd* prefer shorter polling
-intervals. The default is 6 and a useful range is from 6 to 60.
+intervals. The default is 8 and a useful range is from 6 to 60.
 *port* _port_:::
 This option allows the UDP port on which the server understands NTP requests to
 be specified. For normal servers this option should not be required (the
@@ -177,8 +210,11 @@ presend 9
 ----
 +
 when the polling interval is 512 seconds or more, an extra NTP client packet
-will be sent to the server a short time (4 seconds) before making the actual
+will be sent to the server a short time (2 seconds) before making the actual
 measurement.
+
+The *presend* option cannot be used in the *peer* directive. If it is used
+with the *xleave* option, *chronyd* will send two extra packets instead of one.
 *minstratum* _stratum_:::
 When the synchronisation source is selected from available sources, sources
 with lower stratum are normally slightly preferred. This option can be used to
@@ -187,9 +223,13 @@ avoid selecting that source. This is useful with low stratum sources that are
 known to be unreliable or inaccurate and which should be used only when other
 sources are unreachable.
 *version* _version_:::
-This option sets the NTP version number used in packets sent to the server.
-This can be useful when the server runs an old NTP implementation that does not
-respond to newer versions. The default version number is 4.
+This option sets the NTP version of packets sent to the server. This can be
+useful when the server runs an old NTP implementation that does not respond to
+requests using a newer version. The default version depends on whether a key is
+specified by the *key* option and which authentication hash function the key
+is using. If the output size of the hash function is longer than 160 bits, the
+default version is 3 for compatibility with older *chronyd* servers. Otherwise,
+the default version is 4.

 [[pool]]*pool* _name_ [_option_]...::
 The syntax of this directive is similar to that for the <<server,*server*>>
@@ -218,26 +258,33 @@ pool pool.ntp.org iburst maxsources 3

 [[peer]]*peer* _hostname_ [_option_]...::
 The syntax of this directive is identical to that for the <<server,*server*>>
-directive, except that it is used to specify an NTP peer rather than an NTP
-server.
+directive, except that it specifies a symmetric association with an NTP peer
+instead of a client/server association with an NTP server. A single symmetric
+association allows the peers to be both servers and clients to each other. This
+is mainly useful when the NTP implementation of the peer (e.g. *ntpd*) supports
+ephemeral symmetric associations and does not need to be configured with an
+address of this host. *chronyd* does not support ephemeral associations.
 +
 When a key is specified by the *key* option to enable authentication, both
-peers must be configured to use the same key and the same key number.
+peers must use the same key and the same key number.
 +
-Please note that NTP peers that are not configured with a key to enable
-authentication are vulnerable to a denial-of-service attack. An attacker
-knowing that NTP hosts A and B are peering with each other can send a packet
-with random timestamps to host A with source address of B which will set the
-NTP state variables on A to the values sent by the attacker. Host A will then
-send on its next poll to B a packet with an origin timestamp that does not match
-the transmit timestamp of B and the packet will be dropped. If the attacker
-does this periodically for both hosts, they will not be able to synchronise to
-each other.
-+
-This attack can be prevented by enabling authentication with the *key* option,
-or by using the <<server,*server*>> directive on both sides to specify the other
-host as a server instead of a peer. The disadvantage of the *server* directive
-is that it will double the network traffic between the two hosts.
+Note that the symmetric mode is less secure than the client/server mode. A
+denial-of-service attack is possible on unauthenticated symmetric associations,
+i.e. when the peer was specified without the *key* option. An attacker who does
+not see network traffic between two hosts, but knows that they are peering with
+each other, can periodically send them unauthenticated packets with spoofed
+source addresses in order to disrupt their NTP state and prevent them from
+synchronising to each other. When the association is authenticated, an attacker
+who does see the network traffic, but cannot prevent the packets from reaching
+the other host, can still disrupt the state by replaying old packets. The
+attacker has effectively the same power as a man-in-the-middle attacker. A
+partial protection against this attack is implemented in *chronyd*, which can
+protect the peers if they are using the same polling interval and they never
+sent an authenticated packet with a timestamp from future, but it should not be
+relied on as it is difficult to ensure the conditions are met. If two hosts
+should be able to synchronise to each other in both directions, it is
+recommended to use two separate client/server associations (specified by the
+<<server,*server*>> directive on both hosts) instead.

 [[initstepslew]]*initstepslew* _step-threshold_ [_hostname_]...::
 In normal operation, *chronyd* slews the time when it needs to adjust the
@@ -297,47 +344,56 @@ for *initstepslew* to finish before exiting. This is useful to prevent programs
 started in the boot sequence after *chronyd* from reading the clock before it
 has been stepped.

-[[refclock]]*refclock* _driver_ _parameter_ [_option_]...::
+[[refclock]]*refclock* _driver_ _parameter_[:__option__,...] [_option_]...::
 The *refclock* directive specifies a hardware reference clock to be used as a
 time source. It has two mandatory parameters, a driver name and a
-driver-specific parameter.
+driver-specific parameter. The two parameters are followed by zero or more
+refclock options. Some drivers have special options, which can be appended to
+the driver-specific parameter (separated by the *:* and *,* characters).
 +
-There are currently four drivers included:
+There are four drivers included in *chronyd*:
 +
 *PPS*:::
 Driver for the kernel PPS (pulse per second) API. The parameter is the path to
-the PPS device (typically _/dev/pps?_). The assert events are used for
-synchronisation by default. String *:clear* can be appended to the path to use
-the clear events instead.
+the PPS device (typically _/dev/pps?_). As PPS refclocks do not supply full
+time, another time source (e.g. NTP server or non-PPS refclock) is needed to
+complete samples from the PPS refclock. An alternative is to enable the
+<<local,*local*>> directive to allow synchronisation with some unknown but
+constant offset. The driver supports the following option:
 +
-As PPS refclocks don't supply full time, *chronyd* needs to be configured with
-another time source (NTP or non-PPS refclock) in order to complete samples from
-the PPS refclock. An alternative is to enable the <<local,*local*>> directive
-to allow synchronisation with some unknown but constant offset.
-For example:
+*clear*::::
+By default, the PPS refclock uses assert events (rising edge) for
+synchronisation. With this option, it will use clear events (falling edge)
+instead.
+
+:::
+Examples:
 +
 ----
-refclock PPS /dev/pps0 lock NMEA
+refclock PPS /dev/pps0 lock NMEA refid GPS
 refclock SHM 0 offset 0.5 delay 0.2 refid NMEA noselect
+refclock PPS /dev/pps1:clear refid GPS2
 ----
 +
 *SHM*:::
 NTP shared memory driver. This driver uses a shared memory segment to receive
-samples from another process. The parameter is the number of the shared memory
-segment, typically 0, 1, 2 or 3. For example:
+samples from another process (e.g. *gpsd*). The parameter is the number of the
+shared memory segment, typically a small number like 0, 1, 2, or 3. The driver
+supports the following option:
+
+*perm*=_mode_::::
+This option specifies the permissions of the shared memory segment created by
+*chronyd*. They are specified as a numeric mode. The default value is 0600
+(read-write access for owner only).
+:::
+
+Examples:
 +
 ----
-refclock SHM 1 poll 3 refid GPS1
+refclock SHM 0 poll 3 refid GPS1
+refclock SHM 1:perm=0644 refid GPS2
 ----
 +
-A driver option in form of *:perm=NNN* can be appended to the segment number to
-create the segment with permissions other than the default 0600.
-+
-Examples of applications that can be used as SHM refclocks are
-http://www.catb.org/gpsd/[*gpsd*],
-http://www.buzzard.me.uk/jonathan/radioclock.html[*radioclk*], and
-https://www.vanheusden.com/time/omnisync/[*omnisync*].
-+
 *SOCK*:::
 Unix domain socket driver. It is similar to the SHM driver, but samples are
 received from a Unix domain socket instead of shared memory and the messages
@@ -357,17 +413,44 @@ refclock SOCK /var/run/chrony.ttyS0.sock
 +
 *PHC*:::
 PTP hardware clock (PHC) driver. The parameter is the path to the device of
-the PTP clock, which for example can be synchronised by *ptp4l* from
-http://linuxptp.sourceforge.net[*linuxptp*]. PTP clocks are typically kept in
-TAI instead of UTC, so the *offset* option should be used to compensate for the
-current UTC-TAI offset. For example:
+the PTP clock which should be used as a time source. If the clock is kept in
+TAI instead of UTC (e.g. it is synchronised by a PTP daemon), the current
+UTC-TAI offset needs to be specified by the *offset* option. Alternatively, the
+*pps* refclock option can be enabled to treat the PHC as a PPS refclock, using
+only the sub-second offset for synchronisation. The driver supports the
+following options:
+
+*nocrossts*::::
+This option disables use of precise cross timestamping.
+*extpps*::::
+This option enables a PPS mode in which the PTP clock is timestamping pulses
+of an external PPS signal connected to the clock. The clock does not need to be
+synchronised, but another time source is needed to complete the PPS samples.
+Note that some PTP clocks cannot be configured to timestamp only assert or
+clear events, and it is necessary to use the *width* option to filter wrong
+PPS samples.
+*pin*=_index_::::
+This option specifies the index of the pin to which is connected the PPS
+signal. The default value is 0.
+*channel*=_index_::::
+This option specifies the index of the channel for the PPS mode. The default
+value is 0.
+*clear*::::
+This option enables timestamping of clear events (falling edge) instead of
+assert events (rising edge) in the PPS mode. This may not work with some
+clocks.
+:::
+
+Examples:
 +
 ----
-refclock PHC /dev/ptp0 poll 3 dpoll -2 offset -36
+refclock PHC /dev/ptp0 poll 0 dpoll -2 offset -37
+refclock PHC /dev/ptp1:nocrossts poll 3 pps
+refclock PHC /dev/ptp2:extpps,pin=1 width 0.2 poll 2
 ----
 +
 ::
-The *refclock* directive also supports a number of options:
+The *refclock* directive supports the following options:
 +
 *poll* _poll_:::
 Timestamps produced by refclock drivers are not used immediately, but they are
@@ -395,6 +478,22 @@ This option sets the rate of the pulses in the PPS signal (in Hz). This option
 controls how the pulses will be completed with real time. To actually receive
 more than one pulse per second, a negative *dpoll* has to be specified (-3 for
 a 5Hz signal). The default is 1.
+*maxlockage* _pulses_:::
+This option specifies in number of pulses how old can be samples from the
+refclock specified by the *lock* option to be paired with the pulses.
+Increasing this value is useful when the samples are produced at a lower rate
+than the pulses. The default is 2.
+*width* _width_:::
+This option specifies the width of the pulses (in seconds). It is used to
+filter PPS samples when the driver provides samples for both rising and falling
+edges. Note that it reduces the maximum allowed error of the time source which
+completes the PPS samples. If the duty cycle is configurable, 50% should be
+prefered in order to maximise the allowed error.
+*pps*:::
+This options forces *chronyd* to treat any refclock (e.g. SHM or PHC) as a PPS
+refclock. This can be useful when the refclock provides time with a variable
+offset of a whole number of seconds (e.g. it uses TAI instead of UTC). Another
+time source is needed to complete samples from the refclock.
 *offset* _offset_:::
 This option can be used to compensate for a constant error. The specified
 offset (in seconds) is applied to all samples produced by the reference clock.
@@ -406,9 +505,8 @@ algorithm. Increasing the delay is useful to avoid having no majority in the
 source selection or to make it prefer other sources. The default is 1e-9 (1
 nanosecond).
 *precision* _precision_:::
-This option sets the refclock precision (in seconds). The default is 1e-6 (1
-microsecond) for SHM refclock, and 1e-9 (1 nanosecond) for SOCK, PPS and PHC
-refclocks.
+This option sets the precision of the reference clock (in seconds). The default
+value is the estimated precision of the system clock.
 *maxdispersion* _dispersion_:::
 Maximum allowed dispersion for filtered samples (in seconds). Samples with
 larger estimated dispersion are ignored. By default, this limit is disabled.
@@ -489,34 +587,28 @@ can be specified.
 To compute the rate of gain or loss of time, *chronyd* has to store a
 measurement history for each of the time sources it uses.
 +
-Certain systems (Linux, FreeBSD, NetBSD, Solaris) have operating system support
-for setting the rate of gain or loss to compensate for known errors. (On Mac OS
-X, *chronyd* must simulate such a capability by periodically slewing the system
-clock forwards or backwards by a suitable amount to compensate for the error
-built up since the previous slew.)
+All supported systems, with the exception of macOS 10.12 and earlier, have
+operating system support for setting the rate of gain or loss to compensate for
+known errors.
+(On macOS 10.12 and earlier, *chronyd* must simulate such a capability by
+periodically slewing the system clock forwards or backwards by a suitable amount
+to compensate for the error built up since the previous slew.)
 +
 For such systems, it is possible to save the measurement history across
 restarts of *chronyd* (assuming no changes are made to the system clock
-behaviour whilst it is not running). If this capability is to be used (via the
-*dumponexit* directive in the configuration file, or the
-<<chronyc.adoc#dump,*dump*>> command in *chronyc*), the *dumpdir* directive
-should be used to define the directory where the measurement histories are
-saved.
+behaviour whilst it is not running). The *dumpdir* directive defines the
+directory where the measurement histories are saved when *chronyd* exits,
+or the <<chronyc.adoc#dump,*dump*>> command in *chronyc* is issued.
 +
 An example of the directive is:
 +
 ----
-dumpdir @CHRONYVARDIR@
+dumpdir @CHRONYRUNDIR@
 ----
 +
-A source whose reference ID (the IP address for IPv4 sources) is _1.2.3.4_
-would have its measurement history saved in the file
-_/var/lib/chrony/1.2.3.4.dat_.
-
-[[dumponexit]]*dumponexit*::
-If this directive is present, it indicates that *chronyd* should save the
-measurement history for each of its time sources recorded whenever the program
-exits. (See the <<dumpdir,*dumpdir*>> directive above.)
+A source whose IP address is _1.2.3.4_ would have its measurement history saved
+in the file _@CHRONYRUNDIR@/1.2.3.4.dat_. History of reference clocks is saved
+to files named by their reference ID in form of _refid:XXXXXXXX.dat_.

 [[maxsamples]]*maxsamples* _samples_::
 The *maxsamples* directive sets the default maximum number of samples that
@@ -529,7 +621,7 @@ useful range is 4 to 64.
 The *minsamples* directive sets the default minimum number of samples that
 *chronyd* should keep for each source. This setting can be overridden for
 individual sources in the <<server,*server*>> and <<refclock,*refclock*>>
-directives. The default value is 0. The useful range is 4 to 64.
+directives. The default value is 6. The useful range is 4 to 64.

 === Source selection

@@ -561,6 +653,13 @@ Setting *maxdistance* to a larger value can be useful to allow synchronisation
 with a server that only has a very infrequent connection to its sources and can
 accumulate a large dispersion between updates of its clock.

+[[maxjitter]]*maxjitter* _jitter_::
+The *maxjitter* directive sets the maximum allowed jitter of the sources to not
+be rejected by the source selection algorithm. This prevents synchronisation
+with sources that have a small root distance, but their time is too variable.
+
+By default, the maximum jitter is 1 second.
+
 [[minsources]]*minsources* _sources_::
 The *minsources* directive sets the minimum number of sources that need to be
 considered as selectable in the source selection algorithm before the local
@@ -592,8 +691,9 @@ distances are in milliseconds.

 [[corrtimeratio]]*corrtimeratio* _ratio_::
 When *chronyd* is slewing the system clock to correct an offset, the rate at
-which it is slewing adds to the frequency error of the clock. On Linux,
-FreeBSD, NetBSD and Solaris this rate can be controlled.
+which it is slewing adds to the frequency error of the clock. On all supported
+systems, with the exception of macOS 12 and earlier, this rate can be
+controlled.
 +
 The *corrtimeratio* directive sets the ratio between the duration in which the
 clock is slewed for an average correction according to the source history and
@@ -676,8 +776,8 @@ that error is corrected. There are four options:
 When inserting a leap second, the kernel steps the system clock backwards by
 one second when the clock gets to 00:00:00 UTC. When deleting a leap second, it
 steps forward by one second when the clock gets to 23:59:59 UTC. This is the
-default mode when the system driver supports leap seconds (i.e. on Linux,
-FreeBSD, NetBSD and Solaris).
+default mode when the system driver supports leap seconds (i.e. all supported
+systems with the exception of macOS 12 and earlier).
 *step*:::
 This is similar to the *system* mode, except the clock is stepped by
 *chronyd* instead of the kernel. It can be useful to avoid bugs in the kernel
@@ -732,15 +832,23 @@ clients to safely synchronise with multiple identically configured leap
 smearing servers.

 [[leapsectz]]*leapsectz* _timezone_::
-This directive is used to set the name of the timezone in the system tz
-database which *chronyd* can use to find out when will the next leap second
-occur. It will periodically check if the times 23:59:59 and 23:59:60 are valid
-on Jun 30 and Dec 31 in the timezone. This typically works with the *right/UTC*
-timezone.
+This directive specifies a timezone in the system tz database which *chronyd*
+can use to determine when will the next leap second occur and what is the
+current offset between TAI and UTC. It will periodically check if 23:59:59 and
+23:59:60 are valid times in the timezone. This typically works with the
+_right/UTC_ timezone.
 +
-This directive is mainly useful with reference clocks which do not provide
-leap second information. It is not necessary to restart *chronyd* if the tz
-database is updated with a new leap second at least 12 hours before the event.
+When a leap second is announced, the timezone needs to be updated at least 12
+hours before the leap second. It is not necessary to restart *chronyd*.
+
+This directive is useful with reference clocks and other time sources which do
+not announce leap seconds, or announce them too late for an NTP server to
+forward them to its own clients. Clients of leap smearing servers must not
+use this directive.
+
+It is also useful when the system clock is required to have correct TAI-UTC
+offset. Note that the offset is set only when leap seconds are handled by the
+kernel, i.e. <<leapsecmode,*leapsecmode*>> is set to *system*.
 +
 An example of the directive is:
 +
@@ -812,7 +920,7 @@ This directive specifies the maximum assumed drift (frequency error) of the
 system clock. It limits the frequency adjustment that *chronyd* is allowed to
 use to correct the measured drift. It is an additional limit to the maximum
 adjustment that can be set by the system driver (100000 ppm on Linux, 500 ppm
-on FreeBSD and NetBSD, 32500 ppm on Solaris).
+on FreeBSD, NetBSD, and macOS 10.13+, 32500 ppm on Solaris).
 +
 By default, the maximum assumed drift is 500000 ppm, i.e. the adjustment is
 limited by the system driver rather than this directive.
@@ -847,14 +955,18 @@ The *maxslewrate* directive sets the maximum rate at which *chronyd* is allowed
 to slew the time. It limits the slew rate controlled by the correction time
 ratio (which can be set by the <<corrtimeratio,*corrtimeratio*>> directive) and
 is effective only on systems where *chronyd* is able to control the rate (i.e.
-Linux, FreeBSD, NetBSD, Solaris).
+all supported systems with the exception of macOS 12 or earlier).
 +
-For each system there is a maximum frequency offset of the clock that
-can be set by the driver. On Linux it is 100000 ppm, on FreeBSD and NetBSD
-it is 5000 ppm, and on Solaris it is 32500 ppm. Also, due to a kernel
-limitation, setting *maxslewrate* on FreeBSD and NetBSD to a value between 500
+For each system there is a maximum frequency offset of the clock that can be set
+by the driver. On Linux it is 100000 ppm, on FreeBSD, NetBSD and macOS 10.13+ it
+is 5000 ppm, and on Solaris it is 32500 ppm. Also, due to a kernel limitation,
+setting *maxslewrate* on FreeBSD, NetBSD, macOS 10.13+ to a value between 500
 ppm and 5000 ppm will effectively set it to 500 ppm.
 +
+In early beta releases of macOS 13 this capability is disabled because of a
+system kernel bug. When the kernel bug is fixed, chronyd will detect this and
+re-enable the capability (see above limitations) with no recompilation required.
+
 By default, the maximum slew rate is set to 83333.333 ppm (one twelfth).

 [[tempcomp]]
@@ -942,7 +1054,7 @@ both a client of its servers, and a server to other clients.
 Examples of the use of the directive are as follows:
 +
 ----
-allow foo.example.net
+allow 1.2.3.4
 allow 1.2
 allow 3.4.5
 allow 6.7.8/22
@@ -953,7 +1065,8 @@ allow ::/0
 allow
 ----
 +
-The first directive allows the named node to be an NTP client of this computer.
+The first directive allows a node with IPv4 address _1.2.3.4_ to be an NTP
+client of this computer.
 The second directive allows any node with an IPv4 address of the form _1.2.x.y_
 (with _x_ and _y_ arbitrary) to be an NTP client of this computer. Likewise,
 the third directive allows any node with an IPv4 address of the form _3.4.5.x_
@@ -994,6 +1107,10 @@ Within a configuration file this capability is probably rather moot; however,
 it is of greater use for reconfiguration at run-time via *chronyc* with the
 <<chronyc.adoc#allow,*allow all*>> command.
 +
+The directive allows a hostname to be specified instead of an IP address, but
+the name must be resolvable when *chronyd* is started (i.e. *chronyd* needs
+to be started when the network is already up and DNS is working).
+
 Note, if the <<initstepslew,*initstepslew*>> directive is used in the
 configuration file, each of the computers listed in that directive must allow
 client access by this computer for it to work.
@@ -1008,25 +1125,20 @@ There is also a *deny all* directive with similar behaviour to the *allow all*
 directive.

 [[bindaddress]]*bindaddress* _address_::
-The *bindaddress* directive allows you to restrict the network interface to
-which *chronyd* will listen for NTP requests. This provides an additional level
-of access restriction above that available through the <<deny,*deny*>>
-mechanism.
+The *bindaddress* directive binds the socket on which *chronyd* listens for NTP
+requests to a local address of the computer. On systems other than Linux, the
+address of the computer needs to be already configured when *chronyd* is
+started.
 +
-Suppose you have a local network with addresses in the _192.168.1.0_
-subnet together with an Internet connection. The network interface's IP
-address is _192.168.1.1_. Suppose you want to block all access through the
-Internet connection. You could add the line:
+An example of the use of the directive is:
 +
 ----
 bindaddress 192.168.1.1
 ----
 +
-to the configuration file.
-+
-For each of the IPv4 and IPv6 protocols, only one *bindaddress* directive can be
-specified. Therefore, it is not useful on computers which should serve NTP on
-multiple network interfaces.
+Currently, for each of the IPv4 and IPv6 protocols, only one *bindaddress*
+directive can be specified. Therefore, it is not useful on computers which
+should serve NTP on multiple network interfaces.

 [[broadcast]]*broadcast* _interval_ _address_ [_port_]::
 The *broadcast* directive is used to declare a broadcast address to which
@@ -1065,8 +1177,10 @@ directive.

 [[clientloglimit]]*clientloglimit* _limit_::
 This directive specifies the maximum amount of memory that *chronyd* is allowed
-to allocate for logging of client accesses. The default limit is 524288 bytes,
-which allows monitoring of several thousands of addresses at the same time.
+to allocate for logging of client accesses and the state that *chronyd* as an
+NTP server needs to support the interleaved mode for its clients. The default
+limit is 524288 bytes, which is sufficient for monitoring about four thousand
+clients at the same time.
 +
 In older *chrony* versions if the limit was set to 0, the memory allocation was
 unlimited.
@@ -1080,7 +1194,8 @@ clientloglimit 1048576
 [[noclientlog]]*noclientlog*::
 This directive, which takes no arguments, specifies that client accesses are
 not to be logged. Normally they are logged, allowing statistics to be reported
-using the <<chronyc.adoc#clients,*clients*>> command in *chronyc*.
+using the <<chronyc.adoc#clients,*clients*>> command in *chronyc*. This option
+also effectively disables server support for the NTP interleaved mode.

 [[local]]*local* [_option_]...::
 The *local* directive enables a local reference mode, which allows *chronyd*
@@ -1142,6 +1257,23 @@ An example of the directive is:
 local stratum 10 orphan
 ----

+[[ntpsigndsocket]]*ntpsigndsocket* _directory_::
+This directive specifies the location of the Samba *ntp_signd* socket when it
+is running as a Domain Controller (DC). If *chronyd* is compiled with this
+feature, responses to MS-SNTP clients will be signed by the *smbd* daemon.
+
+Note that MS-SNTP requests are not authenticated and any client that is allowed
+to access the server by the <<allow,*allow*>> directive, or the
+<<chronyc.adoc#allow,*allow*>> command in *chronyc*, can get an MS-SNTP
+response signed with a trust account's password and try to crack the password
+in a brute-force attack. Access to the server should be carefully controlled.
+
+An example of the directive is:
+
+----
+ntpsigndsocket /var/lib/samba/ntp_signd
+----
+
 [[port]]*port* _port_::
 This option allows you to configure the port on which *chronyd* will listen for
 NTP requests. The port will be open only when an address is allowed by the
@@ -1171,7 +1303,10 @@ in any order):
 *interval*:::
 This option sets the minimum interval between responses. It is defined as a
 power of 2 in seconds. The default value is 3 (8 seconds). The minimum value
-is -4 and the maximum value is 12.
+is -19 (524288 packets per second) and the maximum value is 12 (one packet per
+4096 seconds). Note that with values below -4 the rate limiting is coarse
+(responses are allowed in bursts, even if the interval between them is shorter
+than the specified interval).
 *burst*:::
 This option sets the maximum number of responses that can be sent in a burst,
 temporarily exceeding the limit specified by the *interval* option. This is
@@ -1183,20 +1318,20 @@ This option sets the rate at which responses are randomly allowed even if the
 limits specified by the *interval* and *burst* options are exceeded. This is
 necessary to prevent an attacker who is sending requests with a spoofed
 source address from completely blocking responses to that address. The leak
-rate is defined as a power of 1/2 and it is 3 by default, i.e. on average at
-least every eighth request has a response. The minimum value is 1 and the
+rate is defined as a power of 1/2 and it is 2 by default, i.e. on average at
+least every fourth request has a response. The minimum value is 1 and the
 maximum value is 4.
 ::
 +
 An example use of the directive is:
 +
 ----
-ratelimit interval 4 burst 4
+ratelimit interval 1 burst 16
 ----
 +
-This would reduce the response rate for IP addresses that send packets on
-average more frequently than once per 16 seconds or send packets in bursts
-of more than 4 packets.
+This would reduce the response rate for IP addresses sending packets on average
+more than once per 2 seconds, or sending packets in bursts of more than 16
+packets, by up to 75% (with default *leak* of 2).

 [[smoothtime]]*smoothtime* _max-freq_ _max-wander_ [*leaponly*]::
 The *smoothtime* directive can be used to enable smoothing of the time that
@@ -1251,16 +1386,17 @@ smoothtime 50000 0.01
 === Command and monitoring access

 [[bindcmdaddress]]*bindcmdaddress* _address_::
-The *bindcmdaddress* directive allows you to specify the network interface on
-which *chronyd* will listen for monitoring command packets (issued by
-*chronyc*). This provides an additional level of access restriction above that
-available through the <<cmddeny,*cmddeny*>> mechanism.
+The *bindcmdaddress* directive allows you to specify an IP address of an
+interface on which *chronyd* will listen for monitoring command packets (issued
+by *chronyc*). On systems other than Linux, the address of the interface needs
+to be already configured when *chronyd* is started.
 +
 This directive can also change the path of the Unix domain command socket,
 which is used by *chronyc* to send configuration commands. The socket must be
 in a directory that is accessible only by the root or _chrony_ user. The
 directory will be created on start if it does not exist. The compiled-in default
-path of the socket is _@CHRONYSOCKDIR@/chronyd.sock_.
+path of the socket is _@CHRONYRUNDIR@/chronyd.sock_. The socket can be
+disabled by setting the path to _/_.
 +
 By default, *chronyd* binds to the loopback interface (with addresses
 _127.0.0.1_ and _::1_). This blocks all access except from localhost. To listen
@@ -1273,8 +1409,8 @@ bindcmdaddress ::
 +
 to the configuration file.
 +
-For each of the IPv4 and IPv6 protocols, only one *bindcmdaddress* directive can be
-specified.
+For each of the IPv4, IPv6, and Unix domain protocols, only one
+*bindcmdaddress* directive can be specified.
 +
 An example that sets the path of the Unix domain command socket is:
 +
@@ -1324,8 +1460,8 @@ need to be run with the *-p 257* switch to inter-operate correctly.)
 [[cmdratelimit]]*cmdratelimit* [_option_]...::
 This directive enables response rate limiting for command packets. It is
 similar to the <<ratelimit,*ratelimit*>> directive, except responses to
-localhost are never limited and the default interval is 1 (2 seconds), the default
-burst is 16, and the default leak rate is 2.
+localhost are never limited and the default interval is -4 (16 packets per
+second).
 +
 An example of the use of the directive is:
 +
@@ -1368,7 +1504,7 @@ This would set the threshold error to 30 seconds.

 [[rtcdevice]]*rtcdevice* _device_::
 The *rtcdevice* directive sets the path to the device file for accessing the
-RTC. The default path is _/dev/rtc_.
+RTC. The default path is _@DEFAULT_RTC_DEVICE@_.

 [[rtcfile]]*rtcfile* _file_::
 The *rtcfile* directive defines the name of the file in which *chronyd* can
@@ -1421,7 +1557,7 @@ cannot be used with the <<rtcfile,*rtcfile*>> directive.
 +
 On Linux, the RTC copy is performed by the kernel every 11 minutes.
 +
-On Mac OS X, <<chronyd,*chronyd*>> will perform the RTC copy every 60 minutes
+On macOS, <<chronyd,*chronyd*>> will perform the RTC copy every 60 minutes
 when the system clock is in a synchronised state.
 +
 On other systems this directive does nothing.
@@ -1434,14 +1570,16 @@ The log files are written to the directory specified by the <<logdir,*logdir*>>
 directive. A banner is periodically written to the files to indicate the
 meanings of the columns.
 +
-*measurements*:::
+*rawmeasurements*:::
 This option logs the raw NTP measurements and related information to a file
-called _measurements.log_. An example line (which actually appears as a single
-line in the file) from the log file is shown below.
+called _measurements.log_. An entry is made for each packet received from the
+source. This can be useful when debugging a problem. An example line (which
+actually appears as a single line in the file) from the log file is shown
+below.
 +
 ----
-2015-10-13 05:40:50 203.0.113.15    N  2 111 111 1111  10 10 1.0 \
-   -4.966e-03  2.296e-01  1.577e-05  1.615e-01  7.446e-03
+2016-11-09 05:40:50 203.0.113.15    N  2 111 111 1111  10 10 1.0 \
+   -4.966e-03  2.296e-01  1.577e-05  1.615e-01  7.446e-03 CB00717B 4B D K
 ----
 +
 The columns are as follows (the quantities in square brackets are the values
@@ -1471,6 +1609,19 @@ from the example line above):
 . The peer dispersion (_epsilon_ in RFC 5905). [1.577e-05]
 . The root delay (_DELTA_ in RFC 5905). [1.615e-01]
 . The root dispersion (_EPSILON_ in RFC 5905). [7.446e-03]
+. Reference ID of the server's source as a hexadecimal number. [CB00717B]
+. NTP mode of the received packet (_1_=active peer, _2_=passive peer,
+  _3_=server, _B_=basic, _I_=interleaved). [4B]
+. Source of the local transmit timestamp
+  (_D_=daemon, _K_=kernel, _H_=hardware). [D]
+. Source of the local receive timestamp
+  (_D_=daemon, _K_=kernel, _H_=hardware). [K]
+
+*measurements*:::
+This option is identical to the *rawmeasurements* option, except it logs only
+valid measurements from synchronised sources, i.e. measurements which passed
+the RFC 5905 tests 1 through 7. This can be useful for producing graphs of the
+source's performance.
 +
 *statistics*:::
 This option logs information about the regression processing to a file called
@@ -1478,8 +1629,8 @@ _statistics.log_. An example line (which actually appears as a single line in
 the file) from the log file is shown below.
 +
 ----
-2015-07-22 05:40:50 203.0.113.15     6.261e-03 -3.247e-03 \
-     2.220e-03  1.874e-06  1.080e-06 7.8e-02  16   0   8
+2016-08-10 05:40:50 203.0.113.15     6.261e-03 -3.247e-03 \
+     2.220e-03  1.874e-06  1.080e-06 7.8e-02  16   0   8  0.00
 ----
 +
 The columns are as follows (the quantities in square brackets are the values
@@ -1514,6 +1665,11 @@ from the example line above):
  to be discarded. The number of runs for the data that is being retained is
  tabulated. Values of approximately half the number of samples are expected.
  [8]
+. The estimated asymmetry of network jitter on the path to the source which was
+  used to correct the measured offsets. The asymmetry can be between -0.5 and
+  0.5. A negative value means the delay of packets sent to the source is
+  more variable than the delay of packets sent from the source back. [0.00,
+  i.e. no correction for asymmetry]
 +
 *tracking*:::
 This option logs changes to the estimate of the system's gain or loss rate, and
@@ -1693,6 +1849,83 @@ sendmail binary.

 === Miscellaneous

+[[hwtimestamp]]*hwtimestamp* _interface_ [_option_]...::
+This directive enables hardware timestamping of NTP packets sent to and
+received from the specified network interface. The network interface controller
+(NIC) uses its own clock to accurately timestamp the actual transmissions and
+receptions, avoiding processing and queueing delays in the kernel, network
+driver, and hardware. This can significantly improve the accuracy of the
+timestamps and the measured offset, which is used for synchronisation of the
+system clock. In order to get the best results, both sides receiving and
+sending NTP packets (i.e. server and client, or two peers) need to use HW
+timestamping. If the server or peer supports the interleaved mode, it needs to
+be enabled by the *xleave* option in the <<server,*server*>> or the
+<<peer,*peer*>> directive.
+
+This directive is supported on Linux 3.19 and newer. The NIC must support HW
+timestamping, which can be verified with the *ethtool -T* command. The list of
+capabilities should include _SOF_TIMESTAMPING_RAW_HARDWARE_,
+_SOF_TIMESTAMPING_TX_HARDWARE_, _SOF_TIMESTAMPING_RX_HARDWARE_, and the filter
+modes should include _HWTSTAMP_FILTER_ALL_ or _HWTSTAMP_FILTER_NTP_ALL_. When
+*chronyd* is running, no other process (e.g. a PTP daemon) should be working
+with the NIC clock.
+
+If the kernel supports software timestamping, it will be enabled for all
+interfaces. With both hardware and software timestamping there are some
+limitations on which timestamps can be actually used, e.g. transmit
+timestamping does not currently work with IPv6 packets using IP options and
+hardware timestamping of packets received from bridges, bonds, and other
+virtual interfaces, works only on Linux 4.13 and newer. The source of
+timestamps (i.e. hardware, kernel, or daemon) is indicated in the
+_measurements.log_ file if enabled by the <<log,*log measurements*>> directive,
+and the <<chronyc.adoc#ntpdata,*ntpdata*>> report in *chronyc*.
+
+If the specified interface is _*_, *chronyd* will try to enable HW timestamping
+on all available interfaces.
+
+The *hwtimestamp* directive has the following options:
+
+*minpoll* _poll_:::
+This option specifies the minimum interval between readings of the NIC clock.
+It's defined as a power of two. It should correspond to the minimum polling
+interval of all NTP sources and the minimum expected polling interval of NTP
+clients. The default value is 0 (1 second) and the minimum value is -6 (1/64th
+of a second).
+*precision* _precision_:::
+This option specifies the assumed precision of reading of the NIC clock. The
+default value is 100e-9 (100 nanoseconds).
+*txcomp* _compensation_:::
+This option specifies the difference in seconds between the actual transmission
+time at the physical layer and the reported transmit timestamp. This value will
+be added to transmit timestamps obtained from the NIC. The default value is 0.
+*rxcomp* _compensation_:::
+This option specifies the difference in seconds between the reported receive
+timestamp and the actual reception time at the physical layer. This value will
+be subtracted from receive timestamps obtained from the NIC. The default value
+is 0.
+*nocrossts*:::
+Some hardware can precisely cross timestamp the NIC clock with the system
+clock. This option disables the use of the cross timestamping.
+*rxfilter* _filter_:::
+This option selects the receive timestamping filter. Possible values are:
+_all_, _ntp_, and _none_. The default value is _ntp_, which enables
+timestamping of NTP packets (_HWTSTAMP_FILTER_NTP_ALL_) if it is supported, or
+timestamping of all packets (_HWTSTAMP_FILTER_ALL_). Setting *rxfilter* to
+_all_ forces timestamping of all packets, which can be useful when the NIC
+supports both filters and NTP packets are received from or on a non-standard
+UDP port (e.g. specified by the *port* directive). Setting *rxfilter* to _none_
+disables receive HW timestamping and allows transmit HW timestamping to be
+enabled when the NIC supports only PTP-specific receive filters.
+::
+
+Examples of the directive are:
+
+----
+hwtimestamp eth0
+hwtimestamp eth1 txcomp 300e-9 rxcomp 645e-9
+hwtimestamp *
+----
+
 [[include]]*include* _pattern_::
 The *include* directive includes a configuration file or multiple configuration
 files if a wildcard pattern is specified. This can be useful when maintaining
@@ -1755,8 +1988,8 @@ significant impact on performance as *chronyd's* memory usage is modest. The

 [[pidfile]]*pidfile* _file_::
 *chronyd* always writes its process ID (PID) to a file, and checks this file on
-startup to see if another *chronyd* may already be running on the system. By
-default, the file used is _/var/run/chronyd.pid_. The *pidfile* directive
+startup to see if another *chronyd* might already be running on the system. By
+default, the file used is _@DEFAULT_PID_FILE@_. The *pidfile* directive
 allows the name to be changed, e.g.:
 +
 ----
@@ -1765,8 +1998,8 @@ pidfile /run/chronyd.pid

 [[sched_priority]]*sched_priority* _priority_::
 On Linux, the *sched_priority* directive will select the SCHED_FIFO real-time
-scheduler at the specified priority (which must be between 0 and 100). On Mac
-OS X, this option must have either a value of 0 (the default) to disable the
+scheduler at the specified priority (which must be between 0 and 100). On
+macOS, this option must have either a value of 0 (the default) to disable the
 thread time constraint policy or 1 for the policy to be enabled. Other systems
 do not support this option.
 +
@@ -1781,7 +2014,7 @@ wait for the scheduler to get around to running it. You should not use this
 unless you really need it. The *sched_setscheduler(2)* man page has more
 details.
 +
-On Mac OS X, this directive uses the *thread_policy_set()* kernel call to
+On macOS, this directive uses the *thread_policy_set()* kernel call to
 specify real-time scheduling. As noted for Linux, you should not use this
 directive unless you really need it.

@@ -1790,7 +2023,7 @@ The *user* directive sets the name of the system user to which *chronyd* will
 switch after start in order to drop root privileges.
 +
 On Linux, *chronyd* needs to be compiled with support for the *libcap* library.
-On Mac OS X, FreeBSD, NetBSD and Solaris *chronyd* forks into two processes.
+On macOS, FreeBSD, NetBSD and Solaris *chronyd* forks into two processes.
 The child process retains root privileges, but can only perform a very limited
 range of privileged system calls on behalf of the parent.
 +
@@ -2010,8 +2243,7 @@ is made of the RTC error at a particular RTC second, and the rate at which the
 RTC gains or loses time relative to true time.

 When the computer is powered down, the measurement histories for all the NTP
-servers are saved to files (if the <<dumponexit,*dumponexit*>> directive is
-specified in the configuration file), and the RTC tracking information is also
+servers are saved to files, and the RTC tracking information is also
 saved to a file (if the <<rtcfile,*rtcfile*>> directive has been specified).
 These pieces of information are also saved if the <<chronyc.adoc#dump,*dump*>>
 and <<chronyc.adoc#writertc,*writertc*>> commands respectively are issued
@@ -2064,7 +2296,6 @@ log statistics measurements tracking
 driftfile @CHRONYVARDIR@/drift
 makestep 1.0 3
 maxupdateskew 100.0
-dumponexit
 dumpdir @CHRONYVARDIR@
 rtcfile @CHRONYVARDIR@/rtc
 ----
@@ -2094,6 +2325,43 @@ For the system shutdown, *chronyd* should receive a SIGTERM several seconds
 before the final SIGKILL; the SIGTERM causes the measurement histories and RTC
 information to be saved.

+=== Public NTP server
+
+*chronyd* can be configured to operate as a public NTP server, e.g. to join the
+http://www.pool.ntp.org/en/join.html[pool.ntp.org] project. The configuration
+is similar to the NTP client with permanent connection, except it needs to
+allow client access from all addresses. It is recommended to find at least four
+good servers (e.g. from the pool, or on the NTP homepage). If the server has a
+hardware reference clock (e.g. a GPS receiver), it can be specified by the
+<<refclock,*refclock*>> directive.
+
+The amount of memory used for logging client accesses can be increased in order
+to enable clients to use the interleaved mode even when the server has a large
+number of clients, and better support rate limiting if it is enabled by the
+<<ratelimit,*ratelimit*>> directive. The system timezone database, if it is
+kept up to date and includes the _right/UTC_ timezone, can be used as a
+reliable source to determine when a leap second will be applied to UTC. The
+*-r* option with the <<dumpdir,*dumpdir*>> directive shortens the time in which
+*chronyd* will not be able to serve time to its clients when it needs to be
+restarted (e.g. after upgrading to a newer version, or a change in the
+configuration).
+
+The configuration file could look like:
+
+----
+server foo.example.net iburst
+server bar.example.net iburst
+server baz.example.net iburst
+server qux.example.net iburst
+makestep 1.0 3
+rtcsync
+allow
+clientloglimit 100000000
+leapsectz right/UTC
+driftfile @CHRONYVARDIR@/drift
+dumpdir @CHRONYRUNDIR@
+----
+
 == SEE ALSO

 <<chronyc.adoc#,*chronyc(1)*>>, <<chronyd.adoc#,*chronyd(8)*>>
--- a/doc/chronyc.adoc
+++ b/doc/chronyc.adoc
@@ -1,6 +1,7 @@
 // This file is part of chrony
 //
 // Copyright (C) Richard P. Curnow  1997-2003
+// Copyright (C) Stephen Wadeley  2016
 // Copyright (C) Miroslav Lichvar  2009-2016
 //
 // This program is free software; you can redistribute it and/or modify
@@ -44,7 +45,7 @@ There are two ways *chronyc* can access *chronyd*. One is the Internet
 Protocol (IPv4 or IPv6) and the other is a Unix domain socket, which is
 accessible locally by the root or _chrony_ user. By default, *chronyc* first
 tries to connect to the Unix domain socket. The compiled-in default path is
-_@CHRONYSOCKDIR@/chronyd.sock_. If that fails (e.g. because *chronyc* is
+_@CHRONYRUNDIR@/chronyd.sock_. If that fails (e.g. because *chronyc* is
 running under a non-root user), it will try to connect to 127.0.0.1 and then
 ::1.

@@ -74,8 +75,8 @@ With this option hostnames will be resolved only to IPv4 addresses.
 With this option hostnames will be resolved only to IPv6 addresses.

 *-n*::
-This option disables resolving of IP addresses to hostnames (e.g. to avoid slow
-DNS lookups).
+This option disables resolving of IP addresses to hostnames, e.g. to avoid slow
+DNS lookups. Long addresses will not be truncated to fit into the column.

 *-c*::
 This option enables printing of reports in a comma-separated values (CSV)
@@ -127,17 +128,17 @@ The *tracking* command displays parameters about the system's clock
 performance. An example of the output is shown below.
 +
 ----
-Reference ID    : 203.0.113.15 (foo.example.net)
+Reference ID    : CB00710F (foo.example.net)
 Stratum         : 3
-Ref time (UTC)  : Fri Feb  3 15:00:29 2012
-System time     : 0.000001501 seconds slow of NTP time
-Last offset     : -0.000001632 seconds
-RMS offset      : 0.000002360 seconds
-Frequency       : 331.898 ppm fast
-Residual freq   : 0.004 ppm
-Skew            : 0.154 ppm
-Root delay      : 0.373169 seconds
-Root dispersion : 0.024780 seconds
+Ref time (UTC)  : Fri Jan 27 09:49:17 2017
+System time     : 0.000006523 seconds slow of NTP time
+Last offset     : -0.000006747 seconds
+RMS offset      : 0.000035822 seconds
+Frequency       : 3.225 ppm slow
+Residual freq   : -0.000 ppm
+Skew            : 0.129 ppm
+Root delay      : 0.013639022 seconds
+Root dispersion : 0.001100737 seconds
 Update interval : 64.2 seconds
 Leap status     : Normal
 ----
@@ -150,10 +151,14 @@ computer is currently synchronised. For IPv4 addresses, the reference ID is
 equal to the address and for IPv6 addresses it is the first 32 bits of the MD5
 sum of the address.
 +
-If it is _127.127.1.1_ it means the computer is not synchronised to any
-external source and that you have the _local_ mode operating (via the
-<<local,*local*>> command in *chronyc*, or the
+If the reference ID is _7F7F0101_ and there is no name or IP address, it means
+the computer is not synchronised to any external source and that you have the
+_local_ mode operating (via the <<local,*local*>> command in *chronyc*, or the
 <<chrony.conf.adoc#local,*local*>> directive in the configuration file).
+
+The reference ID is printed as a hexadecimal number. Note that in older
+versions it used to be printed in quad-dotted notation and could be confused
+with an IPv4 address.
 *Stratum*:::
 The stratum indicates how many hops away from a computer with an attached
 reference clock we are. Such a computer is a stratum-1 computer, so the
@@ -182,9 +187,6 @@ The '`frequency`' is the rate by which the system's clock would be wrong if
 For example, a value of 1 ppm would mean that when the system's clock thinks it
 has advanced 1 second, it has actually advanced by 1.000001 seconds relative to
 true time.
-+
-As you can see in the example, the clock in the computer is not a very
-good one; it would gain about 30 seconds per day if it was not corrected!
 *Residual freq*:::
 This shows the '`residual frequency`' for the currently selected reference
 source. This reflects any difference between what the measurements from the
@@ -437,6 +439,92 @@ the offline state.
 the name of the server or peer was not resolved to an address yet; this source is
 not visible in the *sources* and *sourcestats* reports.

+[[ntpdata]]*ntpdata* [_address_]::
+The *ntpdata* command displays the last valid measurement and other
+NTP-specific information about the specified NTP source, or all NTP sources if
+no address was specified. An example of the output is shown below.
+
+----
+Remote address  : 203.0.113.15 (CB00710F)
+Remote port     : 123
+Local address   : 203.0.113.74 (CB00714A)
+Leap status     : Normal
+Version         : 4
+Mode            : Server
+Stratum         : 1
+Poll interval   : 10 (1024 seconds)
+Precision       : -24 (0.000000060 seconds)
+Root delay      : 0.000015 seconds
+Root dispersion : 0.000015 seconds
+Reference ID    : 47505300 (GPS)
+Reference time  : Fri Nov 25 15:22:12 2016
+Offset          : -0.000060878 seconds
+Peer delay      : 0.000175634 seconds
+Peer dispersion : 0.000000681 seconds
+Response time   : 0.000053050 seconds
+Jitter asymmetry: +0.00
+NTP tests       : 111 111 1111
+Interleaved     : No
+Authenticated   : No
+TX timestamping : Kernel
+RX timestamping : Kernel
+Total TX        : 24
+Total RX        : 24
+Total valid RX  : 24
+----
+
+The fields are explained as follows:
+
+*Remote address*:::
+The IP address of the NTP server or peer, and the corresponding reference ID.
+*Remote port*:::
+The UDP port number to which the request was sent. The standard NTP port is
+123.
+*Local address*:::
+The local IP address which received the response, and the corresponding
+reference ID.
+*Leap status*:::
+*Version*:::
+*Mode*:::
+*Stratum*:::
+*Poll interval*:::
+*Precision*:::
+*Root delay*:::
+*Root dispersion*:::
+*Reference ID*:::
+*Reference time*:::
+The NTP values from the last valid response.
+*Offset*:::
+*Peer delay*:::
+*Peer dispersion*:::
+The measured values.
+*Response time*:::
+The time the server or peer spent in processing of the request and waiting
+before sending the response.
+*Jitter asymmetry*:::
+The estimated asymmetry of network jitter on the path to the source. The
+asymmetry can be between -0.5 and 0.5. A negative value means the delay of
+packets sent to the source is more variable than the delay of packets sent
+from the source back.
+*NTP tests*:::
+Results of RFC 5905 tests 1 through 3, 5 through 7, and tests for maximum
+delay, delay ratio, delay dev ratio, and synchronisation loop.
+*Interleaved*:::
+This shows if the response was in the interleaved mode.
+*Authenticated*:::
+This shows if the response was authenticated.
+*TX timestamping*:::
+The source of the local transmit timestamp. Valid values are _Daemon_,
+_Kernel_, and _Hardware_.
+*RX timestamping*:::
+The source of the local receive timestamp.
+*Total TX*:::
+The number of packets sent to the source.
+*Total RX*:::
+The number of all packets received from the source.
+*Total valid RX*:::
+The number of valid packets received from the source.
+
 [[add_peer]]*add peer* _address_ [_option_]...::
 The *add peer* command allows a new NTP peer to be added whilst
 *chronyd* is running.
@@ -1030,17 +1118,15 @@ purged. An example of how to do this is shown below.

 [[dump]]*dump*::
 The *dump* command causes *chronyd* to write its current history of
-measurements for each of its sources to dump files, either for inspection or to
-support the *-r* option when *chronyd* is restarted.
-+
-The *dump* command is somewhat equivalent to the
-<<chrony.conf.adoc#dumponexit,*dumponexit*>> directive in the configuration
-file.
-+
-To use the *dump* command, you might want to configure the name of the
-directory into which the dump files will be written. This can only be
-done in the configuration file with the <<chrony.conf.adoc#dumpdir,*dumpdir*>>
-directive.
+measurements for each of its sources to dump files in the directory specified
+in the configuration file by the <<chrony.conf.adoc#dumpdir,*dumpdir*>>
+directive. Note that *chronyd* does this automatically when it exits. This
+command is mainly useful for inspection of the history whilst *chronyd* is
+running.
+
+[[rekey]]*rekey*::
+The *rekey* command causes *chronyd* to re-read the key file specified in the
+configuration file by the <<chrony.conf.adoc#keyfile,*keyfile*>> directive.

 === Client commands

--- a/doc/chronyd.adoc
+++ b/doc/chronyd.adoc
@@ -62,27 +62,33 @@ When run in this mode, the program will not detach itself from the terminal.

 *-d*::
 When run in this mode, the program will not detach itself from the terminal,
-and all messages will be sent to the terminal instead of to syslog. When
+and all messages will be written to the terminal instead of syslog. When
 *chronyd* was compiled with debugging support, this option can be used twice to
 print also debugging messages.

+*-l* _file_::
+This option specifies a file which should be used for logging instead of syslog
+or terminal.
+
 *-q*::
 When run in this mode, *chronyd* will set the system clock once and exit. It
 will not detach from the terminal.

 *-Q*::
-This option is similar to *-q*, but it will only print the offset without any
-corrections of the clock.
+This option is similar to the *-q* option, except it only prints the offset
+without making any corrections of the clock and it allows *chronyd* to be
+started without root privileges.

 *-r*::
-This option will reload sample histories for each of the servers and refclocks
-being used. These histories are created by using the
-<<chronyc.adoc#dump,*dump*>> command in *chronyc*, or by setting the
-<<chrony.conf.adoc#dumponexit,*dumponexit*>> directive in the configuration
-file. This option is useful if you want to stop and restart *chronyd* briefly
-for any reason, e.g. to install a new version. However, it should be used only
-on systems where the kernel can maintain clock compensation whilst not under
-*chronyd*'s control (i.e. Linux, FreeBSD, NetBSD and Solaris).
+This option will try to reload and then delete files containing sample
+histories for each of the servers and reference clocks being used. These
+histories are created by using the <<chronyc.adoc#dump,*dump*>> command in
+*chronyc*, or by setting the <<chrony.conf.adoc#dumponexit,*dumponexit*>>
+directive in the configuration file. This option is useful if you want to stop
+and restart *chronyd* briefly for any reason, e.g. to install a new version.
+However, it should be used only on systems where the kernel can maintain clock
+compensation whilst not under *chronyd*'s control (i.e. Linux, FreeBSD, NetBSD,
+Solaris, and macOS 10.13 or later).

 *-R*::
 When this option is used, the <<chrony.conf.adoc#initstepslew,*initstepslew*>>
@@ -109,13 +115,20 @@ time and the RTC time, the system time will be set to it to restore the time
 when *chronyd* was previously stopped. This is useful on computers that have no
 RTC or the RTC is broken (e.g. it has no battery).

+*-t* _timeout_::
+This option sets a timeout (in seconds) after which *chronyd* will exit. If the
+clock is not synchronised, it will exit with a non-zero status. This is useful
+with the *-q* or *-Q* option to shorten the maximum time waiting for
+measurements, or with the *-r* option to limit the time when *chronyd* is
+running, but still allow it to adjust the frequency of the system clock.
+
 *-u* _user_::
 This option sets the name of the system user to which *chronyd* will switch
 after start in order to drop root privileges. It overrides the
 <<chrony.conf.adoc#user,*user*>> directive (default _@DEFAULT_USER@_).
 +
 On Linux, *chronyd* needs to be compiled with support for the *libcap* library.
-On Mac OS X, FreeBSD, NetBSD and Solaris *chronyd* forks into two processes.
+On macOS, FreeBSD, NetBSD and Solaris *chronyd* forks into two processes.
 The child process retains root privileges, but can only perform a very limited
 range of privileged system calls on behalf of the parent.

@@ -134,7 +147,7 @@ killed even in normal operation.

 *-P* _priority_::
 On Linux, this option will select the SCHED_FIFO real-time scheduler at the
-specified priority (which must be between 0 and 100). On Mac OS X, this option
+specified priority (which must be between 0 and 100). On macOS, this option
 must have either a value of 0 (the default) to disable the thread time
 constraint policy or 1 for the policy to be enabled. Other systems do not
 support this option.
@@ -143,6 +156,13 @@ support this option.
 This option will lock *chronyd* into RAM so that it will never be paged out.
 This mode is only supported on Linux.

+*-x*::
+This option disables the control of the system clock. *chronyd* will not make
+any adjustments of the clock, but it will still track its offset and frequency
+relative to the estimated true time, and be able to operate as an NTP server.
+This allows *chronyd* to run without the capability to adjust or set the system
+clock (e.g. in some containers).
+
 *-v*::
 With this option *chronyd* will print version number to the terminal and exit.

@@ -161,4 +181,4 @@ https://chrony.tuxfamily.org/.

 == AUTHORS

-chrony was written by Richard Curnow, Miroslav Lichvar and others.
+chrony was written by Richard Curnow, Miroslav Lichvar, and others.
--- a/doc/faq.adoc
+++ b/doc/faq.adoc
@@ -61,8 +61,8 @@ that.
 In order to keep the real-time clock (RTC) close to the true time, so the
 system time is reasonably close to the true time when it's initialized on the
 next boot from the RTC, the `rtcsync` directive enables a mode in which the
-system time is periodically copied to the RTC. It is supported on Linux and Mac
-OS X.
+system time is periodically copied to the RTC. It is supported on Linux and
+macOS.

 If you want to use public NTP servers from the
 http://www.pool.ntp.org/[pool.ntp.org] project, the minimal _chrony.conf_ file
@@ -79,7 +79,7 @@ rtcsync

 You need to add an `allow` directive to the _chrony.conf_ file in order to open
 the NTP port and allow `chronyd` to reply to client requests. `allow` with no
-specified subnet allows all IPv4 and IPv6 addresses.
+specified subnet allows access from all IPv4 and IPv6 addresses.

 === I have several computers on a LAN. Should be all clients of an external server?

@@ -97,7 +97,7 @@ _chrony.conf_ file. This configuration will be better because
 No. Starting from version 1.25, `chronyd` will keep trying to resolve
 the names specified by the `server`, `pool`, and `peer` directives in an
 increasing interval until it succeeds. The `online` command can be issued from
-`chronyc` to try to resolve them immediately.
+`chronyc` to force `chronyd` to try to resolve the names immediately.

 === How can I make `chronyd` more secure?

@@ -148,15 +148,20 @@ network. It's better to use more than one server, three or four is usually
 recommended as the minimum, so `chronyd` can detect servers that serve false
 time and combine measurements from multiple sources.

+If you have a network card with hardware timestamping supported on Linux, it
+can be enabled by the *hwtimestamp* directive in the _chrony.conf_ file. It
+should make local receive and transmit timestamps of NTP packets much more
+accurate.
+
 There are also useful options which can be set in the `server` directive, they
-are `minpoll`, `maxpoll`, `polltarget`, `maxdelay`, `maxdelayratio` and
-`maxdelaydevratio`.
+are `minpoll`, `maxpoll`, `polltarget`, `maxdelay`, `maxdelayratio`,
+`maxdelaydevratio`, and `xleave`.

 The first three options set the minimum and maximum allowed polling interval,
 and how should be the actual interval adjusted in the specified range. Their
 default values are 6 (64 seconds) for `minpoll`, 10 (1024 seconds) for
-`maxpoll` and 6 (samples) for `polltarget`. The default values should be used
-for general servers on the Internet. With your own NTP servers or if have
+`maxpoll` and 8 (samples) for `polltarget`. The default values should be used
+for general servers on the Internet. With your own NTP servers, or if you have
 permission to poll some servers more frequently, setting these options for
 shorter polling intervals may significantly improve the accuracy of the system
 clock.
@@ -189,6 +194,28 @@ with local NTP server
 server ntp.local minpoll 2 maxpoll 4 polltarget 30 maxdelaydevratio 2
 ----

+If your server supports the interleaved mode, the `xleave` option should be
+added to the `server` directive in order to allow the server to send the
+client more accurate hardware or kernel transmit timestamps. When combined with
+local hardware timestamping, sub-microsecond accuracy may be possible. An
+example could be
+
+----
+server ntp.local minpoll 2 maxpoll 2 xleave
+hwtimestamp eth0
+----
+
+=== Does `chronyd` have an ntpdate mode?
+
+Yes. With the `-q` option `chronyd` will set the system clock once and exit.
+With the `-Q` option it will print the measured offset without setting the
+clock. If you don't want to use a configuration file, NTP servers can be
+specified on the command line. For example:
+
+----
+# chronyd -q 'pool pool.ntp.org iburst'
+----
+
 === What happened to the `commandkey` and `generatecommandkey` directives?

 They were removed in version 2.2. Authentication is no longer supported in the
@@ -227,8 +254,17 @@ MS Name/IP address         Stratum Poll Reach LastRx Last sample
 === Are NTP servers specified with the `offline` option?

 Check that you're using ``chronyc``'s `online` and `offline` commands
-appropriately. Again, check in _measurements.log_ to see if you're getting any
-data back from the server.
+appropriately. The `activity` command prints the number of sources that are
+currently online and offline. For example:
+
+----
+200 OK
+3 sources online
+0 sources offline
+0 sources doing burst (return to online)
+0 sources doing burst (return to offline)
+0 sources with unknown address
+----

 === Is `chronyd` allowed to step the system clock?

@@ -287,12 +323,15 @@ authentication (`commandkey` directive).

 === Why does `chronyc tracking` always print an IPv4 address as reference ID?

-The reference ID is a 32-bit value and is always printed in quad-dotted
-notation, even if the reference source doesn't have an IPv4 address. For IPv4
-addresses, the reference ID is equal to the address, but for IPv6 addresses it
-is the first 32 bits of the MD5 sum of the address. For reference clocks, the
-reference ID is the value specified with the `refid` option in the `refclock`
-directive.
+The reference ID is a 32-bit value and in versions before 3.0 it was printed in
+quad-dotted notation, even if the reference source did not actually have an
+IPv4 address. For IPv4 addresses, the reference ID is equal to the address, but
+for IPv6 addresses it is the first 32 bits of the MD5 sum of the address. For
+reference clocks, the reference ID is the value specified with the `refid`
+option in the `refclock` directive.
+
+Since version 3.0, the reference ID is printed as a hexadecimal number to avoid
+confusion with IPv4 addresses.

 If you need to get the IP address of the current reference source, use the `-n`
 option to disable resolving of IP addresses and read the second field (printed
@@ -373,19 +412,20 @@ to serve time to clients in the network which support the broadcast client mode

 === Can `chronyd` keep the system clock a fixed offset away from real time?

-This is not possible as the program currently stands.
+Yes. Starting from version 3.0, an offset can be specified by the `offset`
+option for all time sources in the _chrony.conf_ file.

 === What happens if the network connection is dropped without using ``chronyc``'s `offline` command first?

-`chronyd` will keep trying to access the server(s) that it thinks are online.
-When the network is connected again, it will take some time (on average half of
-the maximum polling interval) before new measurements are made and the clock is
-corrected. If the servers were set to offline and the `online` command was
-issued when the network was connected, `chronyd` would make new measurements
-immediately.
+`chronyd` will keep trying to access the sources that it thinks are online, and
+it will take longer before new measurements are actually made and the clock is
+corrected when the network is connected again. If the sources were set to
+offline, `chronyd` would make new measurements immediately after issuing the
+`online` command.

-The `auto_offline` option to the `server` entry in the _chrony.conf_ file may
-be useful to switch the servers to the offline state automatically.
+Unless the network connection lasts only few minutes (less than the maximum
+polling interval), the delay is usually not a problem, and it may be acceptable
+to keep all sources online all the time.

 == Operating systems

--- a/examples/chrony-wait.service
+++ b/examples/chrony-wait.service
@@ -1,5 +1,6 @@
 [Unit]
 Description=Wait for chrony to synchronize system clock
+Documentation=man:chronyc(1)
 After=chronyd.service
 Requires=chronyd.service
 Before=time-sync.target
@@ -9,7 +10,7 @@ Wants=time-sync.target
 Type=oneshot
 # Wait up to ~10 minutes for chronyd to synchronize and the remaining
 # clock correction to be less than 0.1 seconds
-ExecStart=/usr/bin/chronyc waitsync 600 0.1 0.0 1
+ExecStart=/usr/bin/chronyc -h 127.0.0.1,::1 waitsync 600 0.1 0.0 1
 RemainAfterExit=yes
 StandardOutput=null

--- a/examples/chrony.conf.example1
+++ b/examples/chrony.conf.example1
@@ -4,8 +4,8 @@ pool pool.ntp.org iburst
 # Record the rate at which the system clock gains/losses time.
 driftfile /var/lib/chrony/drift

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

 # Enable kernel synchronization of the real-time clock (RTC).
--- a/examples/chrony.conf.example2
+++ b/examples/chrony.conf.example2
@@ -5,17 +5,24 @@ pool pool.ntp.org iburst
 # Record the rate at which the system clock gains/losses time.
 driftfile /var/lib/chrony/drift

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

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

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

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

 # Specify file containing keys for NTP authentication.
--- a/examples/chrony.conf.example3
+++ b/examples/chrony.conf.example3
@@ -33,42 +33,30 @@

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

 ! maxupdateskew 100
 ! maxupdateskew 5

+# If you want to increase the minimum number of selectable sources
+# required to update the system clock in order to make the
+# synchronisation more reliable, uncomment (and edit) the following
+# line.
+
+! minsources 2
+
+# If your computer has a good stable clock (e.g. it is not a virtual
+# machine), you might also want to reduce the maximum assumed drift
+# (frequency error) of the clock (the value is specified in ppm).
+
+! maxdrift 100
+
 #######################################################################
 ### FILENAMES ETC
 # Chrony likes to keep information about your computer's clock in files.
@@ -181,13 +169,12 @@ driftfile /var/lib/chrony/drift
 # machine accesses it.  The information can be accessed by the 'clients'
 # command of chronyc.  You can disable this facility by uncommenting the
 # following line.  This will save a bit of memory if you have many
-# clients.
+# clients and it will also disable support for the interleaved mode.

 ! noclientlog

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

 ! clientloglimit 4194304

@@ -196,7 +183,7 @@ driftfile /var/lib/chrony/drift
 # clients that are sending requests too frequently, uncomment and edit
 # the following line.

-! limitrate interval 3 burst 8
+! ratelimit interval 3 burst 8

 #######################################################################
 ### REPORTING BIG CLOCK CHANGES
@@ -243,7 +230,17 @@ driftfile /var/lib/chrony/drift
 # Rate limiting can be enabled also for command packets.  (Note,
 # commands from localhost are never limited.)

-! cmdratelimit interval 1 burst 16
+! cmdratelimit interval -4 burst 16
+
+#######################################################################
+### HARDWARE TIMESTAMPING
+# On Linux, if the network interface controller and its driver support
+# hardware timestamping, it can significantly improve the accuracy of
+# synchronisation. It can be enabled on specified interfaces only, or it
+# can be enabled on all interfaces that support it.
+
+! hwtimestamp eth0
+! hwtimestamp *

 #######################################################################
 ### REAL TIME CLOCK
@@ -274,6 +271,12 @@ driftfile /var/lib/chrony/drift

 ! rtcdevice /dev/misc/rtc

+# Alternatively, if not using the -s option, this directive can be used
+# to enable a mode in which the RTC is periodically set to the system
+# time, with no tracking of its drift.
+
+! rtcsync
+
 #######################################################################
 ### REAL TIME SCHEDULER
 # This directive tells chronyd to use the real-time FIFO scheduler with the
--- a/examples/chronyd.service
+++ b/examples/chronyd.service
@@ -1,13 +1,18 @@
 [Unit]
 Description=NTP client/server
+Documentation=man:chronyd(8) man:chrony.conf(5)
 After=ntpdate.service sntp.service ntpd.service
 Conflicts=ntpd.service systemd-timesyncd.service
+ConditionCapability=CAP_SYS_TIME

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

 [Install]
 WantedBy=multi-user.target
--- a/hwclock.c
+++ b/hwclock.c
@@ -0,0 +1,209 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Tracking of hardware clocks (e.g. RTC, PHC)
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "array.h"
+#include "hwclock.h"
+#include "local.h"
+#include "logging.h"
+#include "memory.h"
+#include "regress.h"
+#include "util.h"
+
+/* Maximum number of samples per clock */
+#define MAX_SAMPLES 16
+
+struct HCL_Instance_Record {
+  /* HW and local reference timestamp */
+  struct timespec hw_ref;
+  struct timespec local_ref;
+
+  /* Samples stored as intervals (uncorrected for frequency error)
+     relative to local_ref and hw_ref */
+  double x_data[MAX_SAMPLES];
+  double y_data[MAX_SAMPLES];
+
+  /* Number of samples */
+  int n_samples;
+
+  /* Maximum error of the last sample */
+  double last_err;
+
+  /* Minimum interval between samples */
+  double min_separation;
+
+  /* Flag indicating the offset and frequency values are valid */
+  int valid_coefs;
+
+  /* Estimated offset and frequency of HW clock relative to local clock */
+  double offset;
+  double frequency;
+};
+
+/* ================================================== */
+
+static void
+handle_slew(struct timespec *raw, struct timespec *cooked, double dfreq,
+            double doffset, LCL_ChangeType change_type, void *anything)
+{
+  HCL_Instance clock;
+  double delta;
+
+  clock = anything;
+
+  if (clock->n_samples)
+    UTI_AdjustTimespec(&clock->local_ref, cooked, &clock->local_ref, &delta, dfreq, doffset);
+  if (clock->valid_coefs)
+    clock->frequency /= 1.0 - dfreq;
+}
+
+/* ================================================== */
+
+HCL_Instance
+HCL_CreateInstance(double min_separation)
+{
+  HCL_Instance clock;
+
+  clock = MallocNew(struct HCL_Instance_Record);
+  clock->x_data[MAX_SAMPLES - 1] = 0.0;
+  clock->y_data[MAX_SAMPLES - 1] = 0.0;
+  clock->n_samples = 0;
+  clock->valid_coefs = 0;
+  clock->min_separation = min_separation;
+
+  LCL_AddParameterChangeHandler(handle_slew, clock);
+
+  return clock;
+}
+
+/* ================================================== */
+
+void HCL_DestroyInstance(HCL_Instance clock)
+{
+  LCL_RemoveParameterChangeHandler(handle_slew, clock);
+  Free(clock);
+}
+
+/* ================================================== */
+
+int
+HCL_NeedsNewSample(HCL_Instance clock, struct timespec *now)
+{
+  if (!clock->n_samples ||
+      fabs(UTI_DiffTimespecsToDouble(now, &clock->local_ref)) >= clock->min_separation)
+    return 1;
+
+  return 0;
+}
+
+/* ================================================== */
+
+void
+HCL_AccumulateSample(HCL_Instance clock, struct timespec *hw_ts,
+                     struct timespec *local_ts, double err)
+{
+  double hw_delta, local_delta, local_freq, raw_freq;
+  int i, n_runs, best_start;
+
+  local_freq = 1.0 - LCL_ReadAbsoluteFrequency() / 1.0e6;
+
+  /* Shift old samples */
+  if (clock->n_samples) {
+    if (clock->n_samples >= MAX_SAMPLES)
+      clock->n_samples--;
+
+    hw_delta = UTI_DiffTimespecsToDouble(hw_ts, &clock->hw_ref);
+    local_delta = UTI_DiffTimespecsToDouble(local_ts, &clock->local_ref) / local_freq;
+
+    if (hw_delta <= 0.0 || local_delta < clock->min_separation / 2.0) {
+      clock->n_samples = 0;
+      DEBUG_LOG("HW clock reset interval=%f", local_delta);
+    }
+
+    for (i = MAX_SAMPLES - clock->n_samples; i < MAX_SAMPLES; i++) {
+      clock->y_data[i - 1] = clock->y_data[i] - hw_delta;
+      clock->x_data[i - 1] = clock->x_data[i] - local_delta;
+    }
+  }
+
+  clock->n_samples++;
+  clock->hw_ref = *hw_ts;
+  clock->local_ref = *local_ts;
+  clock->last_err = err;
+
+  /* Get new coefficients */
+  clock->valid_coefs =
+    RGR_FindBestRobustRegression(clock->x_data + MAX_SAMPLES - clock->n_samples,
+                                 clock->y_data + MAX_SAMPLES - clock->n_samples,
+                                 clock->n_samples, 1.0e-10, &clock->offset, &raw_freq,
+                                 &n_runs, &best_start);
+
+  if (!clock->valid_coefs) {
+    DEBUG_LOG("HW clock needs more samples");
+    return;
+  }
+
+  clock->frequency = raw_freq / local_freq;
+
+  /* Drop unneeded samples */
+  clock->n_samples -= best_start;
+
+  /* If the fit doesn't cross the error interval of the last sample, throw away
+     all previous samples and keep only the frequency estimate */
+  if (fabs(clock->offset) > err) {
+    DEBUG_LOG("HW clock reset offset=%e", clock->offset);
+    clock->offset = 0.0;
+    clock->n_samples = 1;
+  }
+
+  DEBUG_LOG("HW clock samples=%d offset=%e freq=%.9e raw_freq=%.9e err=%e ref_diff=%e",
+            clock->n_samples, clock->offset, clock->frequency, raw_freq, err,
+            UTI_DiffTimespecsToDouble(&clock->hw_ref, &clock->local_ref));
+}
+
+/* ================================================== */
+
+int
+HCL_CookTime(HCL_Instance clock, struct timespec *raw, struct timespec *cooked, double *err)
+{
+  double offset, elapsed;
+
+  if (!clock->valid_coefs)
+    return 0;
+
+  elapsed = UTI_DiffTimespecsToDouble(raw, &clock->hw_ref);
+  offset = clock->offset + elapsed / clock->frequency;
+  UTI_AddDoubleToTimespec(&clock->local_ref, offset, cooked);
+
+  /* Fow now, just return the error of the last sample */
+  if (err)
+    *err = clock->last_err;
+
+  return 1;
+}
--- a/hwclock.h
+++ b/hwclock.h
@@ -0,0 +1,48 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Header for tracking of hardware clocks */
+
+#ifndef GOT_HWCLOCK_H
+#define GOT_HWCLOCK_H
+
+typedef struct HCL_Instance_Record *HCL_Instance;
+
+/* Create a new HW clock instance */
+extern HCL_Instance HCL_CreateInstance(double min_separation);
+
+/* Destroy a HW clock instance */
+extern void HCL_DestroyInstance(HCL_Instance clock);
+
+/* Check if a new sample should be accumulated at this time */
+extern int HCL_NeedsNewSample(HCL_Instance clock, struct timespec *now);
+
+/* Accumulate a new sample */
+extern void HCL_AccumulateSample(HCL_Instance clock, struct timespec *hw_ts,
+                                 struct timespec *local_ts, double err);
+
+/* Convert raw hardware time to cooked local time */
+extern int HCL_CookTime(HCL_Instance clock, struct timespec *raw, struct timespec *cooked,
+                        double *err);
+
+#endif
--- a/keys.c
+++ b/keys.c
@@ -103,9 +103,9 @@ static int
 determine_hash_delay(uint32_t key_id)
 {
  NTP_Packet pkt;
-  struct timeval before, after;
-  unsigned long usecs, min_usecs=0;
-  int i;
+  struct timespec before, after;
+  double diff, min_diff;
+  int i, nsecs;

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

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

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

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

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

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

 /* ================================================== */
@@ -170,7 +200,7 @@ KEY_Reload(void)

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

@@ -182,19 +212,19 @@ KEY_Reload(void)
      continue;

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

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

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

@@ -214,7 +244,7 @@ KEY_Reload(void)
  /* Check for duplicates */
  for (i = 1; i < ARR_GetSize(keys); i++) {
    if (get_key(i - 1)->id == get_key(i)->id)
-      LOG(LOGS_WARN, LOGF_Keys, "Detected duplicate key %"PRIu32, get_key(i - 1)->id);
+      LOG(LOGS_WARN, "Detected duplicate key %"PRIu32, get_key(i - 1)->id);
  }

  /* Erase any passwords from stack */
@@ -292,6 +322,22 @@ KEY_GetAuthDelay(uint32_t key_id)

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

+int
+KEY_GetAuthLength(uint32_t key_id)
+{
+  unsigned char buf[MAX_HASH_LENGTH];
+  Key *key;
+
+  key = get_key_by_id(key_id);
+
+  if (!key)
+    return 0;
+
+  return HSH_Hash(key->hash_id, buf, 0, buf, 0, buf, sizeof (buf));
+}
+
+/* ================================================== */
+
 int
 KEY_CheckKeyLength(uint32_t key_id)
 {
@@ -307,6 +353,31 @@ KEY_CheckKeyLength(uint32_t key_id)

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

+static int
+generate_ntp_auth(int hash_id, const unsigned char *key, int key_len,
+                  const unsigned char *data, int data_len,
+                  unsigned char *auth, int auth_len)
+{
+  return HSH_Hash(hash_id, key, key_len, data, data_len, auth, auth_len);
+}
+
+/* ================================================== */
+
+static int
+check_ntp_auth(int hash_id, const unsigned char *key, int key_len,
+               const unsigned char *data, int data_len,
+               const unsigned char *auth, int auth_len, int trunc_len)
+{
+  unsigned char buf[MAX_HASH_LENGTH];
+  int hash_len;
+
+  hash_len = generate_ntp_auth(hash_id, key, key_len, data, data_len, buf, sizeof (buf));
+
+  return MIN(hash_len, trunc_len) == auth_len && !memcmp(buf, auth, auth_len);
+}
+
+/* ================================================== */
+
 int
 KEY_GenerateAuth(uint32_t key_id, const unsigned char *data, int data_len,
    unsigned char *auth, int auth_len)
@@ -318,15 +389,15 @@ KEY_GenerateAuth(uint32_t key_id, const unsigned char *data, int data_len,
  if (!key)
    return 0;

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

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

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

@@ -335,6 +406,6 @@ KEY_CheckAuth(uint32_t key_id, const unsigned char *data, int data_len,
  if (!key)
    return 0;

-  return UTI_CheckNTPAuth(key->hash_id, (unsigned char *)key->val,
-                          key->len, data, data_len, auth, auth_len);
+  return check_ntp_auth(key->hash_id, (unsigned char *)key->val, key->len,
+                        data, data_len, auth, auth_len, trunc_len);
 }
--- a/keys.h
+++ b/keys.h
@@ -37,11 +37,12 @@ extern void KEY_Reload(void);
 extern int KEY_GetKey(uint32_t key_id, char **key, int *len);
 extern int KEY_KeyKnown(uint32_t key_id);
 extern int KEY_GetAuthDelay(uint32_t key_id);
+extern int KEY_GetAuthLength(uint32_t key_id);
 extern int KEY_CheckKeyLength(uint32_t key_id);

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

 #endif /* GOT_KEYS_H */
--- a/local.c
+++ b/local.c
@@ -106,40 +106,47 @@ static double max_clock_error;
   under 1s of busy waiting. */
 #define NITERS 100

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

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

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

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

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

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

 /* ================================================== */
@@ -278,7 +285,7 @@ LCL_IsFirstParameterChangeHandler(LCL_ParameterChangeHandler handler)
 /* ================================================== */

 static void
-invoke_parameter_change_handlers(struct timeval *raw, struct timeval *cooked,
+invoke_parameter_change_handlers(struct timespec *raw, struct timespec *cooked,
                                 double dfreq, double doffset,
                                 LCL_ChangeType change_type)
 {
@@ -345,23 +352,29 @@ void LCL_RemoveDispersionNotifyHandler(LCL_DispersionNotifyHandler handler, void
 }

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

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

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

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

  LCL_ReadRawTime(&raw);
  LCL_CookTime(&raw, result, err);
@@ -370,18 +383,18 @@ LCL_ReadCookedTime(struct timeval *result, double *err)
 /* ================================================== */

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

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

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

 void
-LCL_GetOffsetCorrection(struct timeval *raw, double *correction, double *err)
+LCL_GetOffsetCorrection(struct timespec *raw, double *correction, double *err)
 {
  /* Call system specific driver to get correction */
  (*drv_offset_convert)(raw, correction, err);
@@ -413,7 +426,7 @@ clamp_freq(double freq)
  if (freq <= max_freq_ppm && freq >= -max_freq_ppm)
    return freq;

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

  return CLAMP(-max_freq_ppm, freq, max_freq_ppm);
 }
@@ -421,13 +434,13 @@ clamp_freq(double freq)
 /* ================================================== */

 static int
-check_offset(struct timeval *now, double offset)
+check_offset(struct timespec *now, double offset)
 {
  /* Check if the time will be still sane with accumulated offset */
  if (UTI_IsTimeOffsetSane(now, -offset))
      return 1;

-  LOG(LOGS_WARN, LOGF_Local, "Adjustment of %.1f seconds is invalid", -offset);
+  LOG(LOGS_WARN, "Adjustment of %.1f seconds is invalid", -offset);
  return 0;
 }

@@ -439,7 +452,7 @@ check_offset(struct timeval *now, double offset)
 void
 LCL_SetAbsoluteFrequency(double afreq_ppm)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;
  double dfreq;
  
  afreq_ppm = clamp_freq(afreq_ppm);
@@ -470,7 +483,7 @@ LCL_SetAbsoluteFrequency(double afreq_ppm)
 void
 LCL_AccumulateDeltaFrequency(double dfreq)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;
  double old_freq_ppm;

  old_freq_ppm = current_freq_ppm;
@@ -499,7 +512,7 @@ LCL_AccumulateDeltaFrequency(double dfreq)
 void
 LCL_AccumulateOffset(double offset, double corr_rate)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;

  /* In this case, the cooked time to be passed to the notify clients
     has to be the cooked time BEFORE the change was made */
@@ -521,7 +534,7 @@ LCL_AccumulateOffset(double offset, double corr_rate)
 int
 LCL_ApplyStepOffset(double offset)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;

  /* In this case, the cooked time to be passed to the notify clients
     has to be the cooked time BEFORE the change was made */
@@ -533,7 +546,7 @@ LCL_ApplyStepOffset(double offset)
      return 0;

  if (!(*drv_apply_step_offset)(offset)) {
-    LOG(LOGS_ERR, LOGF_Local, "Could not step clock");
+    LOG(LOGS_ERR, "Could not step system clock");
    return 0;
  }

@@ -549,7 +562,7 @@ LCL_ApplyStepOffset(double offset)
 /* ================================================== */

 void
-LCL_NotifyExternalTimeStep(struct timeval *raw, struct timeval *cooked,
+LCL_NotifyExternalTimeStep(struct timespec *raw, struct timespec *cooked,
    double offset, double dispersion)
 {
  /* Dispatch to all handlers */
@@ -563,7 +576,7 @@ LCL_NotifyExternalTimeStep(struct timeval *raw, struct timeval *cooked,
 void
 LCL_NotifyLeap(int leap)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;

  LCL_ReadRawTime(&raw);
  LCL_CookTime(&raw, &cooked, NULL);
@@ -580,7 +593,7 @@ LCL_NotifyLeap(int leap)
 void
 LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate)
 {
-  struct timeval raw, cooked;
+  struct timespec raw, cooked;
  double old_freq_ppm;

  LCL_ReadRawTime(&raw);
@@ -600,7 +613,7 @@ LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate)

  current_freq_ppm = clamp_freq(current_freq_ppm);

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

  /* Call the system-specific driver for setting the frequency */
@@ -647,7 +660,7 @@ lcl_RegisterSystemDrivers(lcl_ReadFrequencyDriver read_freq,

  current_freq_ppm = (*drv_read_freq)();

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

 /* ================================================== */
@@ -657,7 +670,7 @@ lcl_RegisterSystemDrivers(lcl_ReadFrequencyDriver read_freq,
 int
 LCL_MakeStep(void)
 {
-  struct timeval raw;
+  struct timespec raw;
  double correction;

  LCL_ReadRawTime(&raw);
@@ -671,7 +684,7 @@ LCL_MakeStep(void)
  if (!LCL_ApplyStepOffset(-correction))
    return 0;

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

  return 1;
 }
@@ -687,10 +700,10 @@ LCL_CanSystemLeap(void)
 /* ================================================== */

 void
-LCL_SetSystemLeap(int leap)
+LCL_SetSystemLeap(int leap, int tai_offset)
 {
  if (drv_set_leap) {
-    (drv_set_leap)(leap);
+    (drv_set_leap)(leap, tai_offset);
  }
 }

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

 #include "sysincl.h"

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

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

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

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

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

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

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

 typedef void (*LCL_ParameterChangeHandler)
-     (struct timeval *raw, struct timeval *cooked,
+     (struct timespec *raw, struct timespec *cooked,
      double dfreq,
      double doffset,
      LCL_ChangeType change_type,
@@ -163,7 +162,7 @@ extern int LCL_ApplyStepOffset(double offset);

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

 /* Routine to invoke notify handlers on leap second when the system clock
@@ -202,10 +201,11 @@ extern int LCL_MakeStep(void);
   does something */
 extern int LCL_CanSystemLeap(void);

-/* Routine to set the system clock to correct itself for a leap second if
-   supported.  Leap second will be inserted at the end of the day if the
-   argument is positive, deleted if negative, and zero resets the setting. */
-extern void LCL_SetSystemLeap(int leap);
+/* Routine to set the system clock to correct itself for a leap second and also
+   set its TAI-UTC offset.  If supported, leap second will be inserted at the
+   end of the day if the argument is positive, deleted if negative, and zero
+   resets the setting. */
+extern void LCL_SetSystemLeap(int leap, int tai_offset);

 /* Routine to set a frequency correction (in ppm) that should be applied
   to local clock to compensate for temperature changes.  A positive
--- a/localp.h
+++ b/localp.h
@@ -52,10 +52,10 @@ typedef int (*lcl_ApplyStepOffsetDriver)(double offset);
 /* System driver to convert a raw time to an adjusted (cooked) time.
   The number of seconds returned in 'corr' have to be added to the
   raw time to get the corrected time */
-typedef void (*lcl_OffsetCorrectionDriver)(struct timeval *raw, double *corr, double *err);
+typedef void (*lcl_OffsetCorrectionDriver)(struct timespec *raw, double *corr, double *err);

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

 /* System driver to set the synchronisation status */
 typedef void (*lcl_SetSyncStatusDriver)(int synchronised, double est_error, double max_error);
--- a/logging.c
+++ b/logging.c
@@ -40,6 +40,7 @@ int log_debug_enabled = 0;
 /* Flag indicating we have initialised */
 static int initialised = 0;

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

 static int parent_fd = 0;
@@ -69,6 +70,7 @@ void
 LOG_Initialise(void)
 {
  initialised = 1;
+  file_log = stderr;
 }

 /* ================================================== */
@@ -79,6 +81,8 @@ LOG_Finalise(void)
 {
  if (system_log) {
    closelog();
+  } else {
+    fclose(file_log);
  }

  LOG_CycleLogFiles();
@@ -113,7 +117,7 @@ static void log_message(int fatal, LOG_Severity severity, const char *message)
    }
    syslog(priority, fatal ? "Fatal error : %s" : "%s", message);
  } else {
-    fprintf(stderr, fatal ? "Fatal error : %s\n" : "%s\n", message);
+    fprintf(file_log, fatal ? "Fatal error : %s\n" : "%s\n", message);
  }
 }

@@ -121,8 +125,7 @@ static void log_message(int fatal, LOG_Severity severity, const char *message)

 void LOG_Message(LOG_Severity severity,
 #if DEBUG > 0
-                 LOG_Facility facility, int line_number,
-                 const char *filename, const char *function_name,
+                 int line_number, const char *filename, const char *function_name,
 #endif
                 const char *format, ...)
 {
@@ -136,10 +139,10 @@ void LOG_Message(LOG_Severity severity,
    time(&t);
    stm = *gmtime(&t);
    strftime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%SZ", &stm);
-    fprintf(stderr, "%s ", buf);
+    fprintf(file_log, "%s ", buf);
 #if DEBUG > 0
    if (debug_level >= DEBUG_LEVEL_PRINT_FUNCTION)
-      fprintf(stderr, "%s:%d:(%s) ", filename, line_number, function_name);
+      fprintf(file_log, "%s:%d:(%s) ", filename, line_number, function_name);
 #endif
  }

@@ -174,6 +177,21 @@ void LOG_Message(LOG_Severity severity,
  }
 }

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

 void
@@ -238,12 +256,18 @@ LOG_FileWrite(LOG_FileID id, const char *format, ...)
    return;

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

    if (snprintf(filename, sizeof(filename), "%s/%s.log",
-          CNF_GetLogDir(), logfiles[id].name) >= sizeof(filename) ||
+                 logdir, logfiles[id].name) >= sizeof (filename) ||
        !(logfiles[id].file = fopen(filename, "a"))) {
-      LOG(LOGS_WARN, LOGF_Refclock, "Couldn't open logfile %s for update", filename);
+      LOG(LOGS_WARN, "Could not open log file %s", filename);
      logfiles[id].name = NULL;
      return;
    }
--- a/logging.h
+++ b/logging.h
@@ -46,26 +46,26 @@ extern int log_debug_enabled;
 #endif

 #if DEBUG > 0
-#define LOG_MESSAGE(severity, facility, ...) \
-  LOG_Message(severity, facility, __LINE__, __FILE__, FUNCTION_NAME, __VA_ARGS__);
+#define LOG_MESSAGE(severity, ...) \
+  LOG_Message(severity, __LINE__, __FILE__, FUNCTION_NAME, __VA_ARGS__)
 #else
-#define LOG_MESSAGE(severity, facility, ...) \
-  LOG_Message(severity, __VA_ARGS__);
+#define LOG_MESSAGE(severity, ...) \
+  LOG_Message(severity, __VA_ARGS__)
 #endif

-#define DEBUG_LOG(facility, ...) \
+#define DEBUG_LOG(...) \
  do { \
    if (DEBUG && log_debug_enabled) \
-      LOG_MESSAGE(LOGS_DEBUG, facility, __VA_ARGS__); \
+      LOG_MESSAGE(LOGS_DEBUG, __VA_ARGS__); \
  } while (0)

-#define LOG_FATAL(facility, ...) \
+#define LOG_FATAL(...) \
  do { \
-    LOG_MESSAGE(LOGS_FATAL, facility, __VA_ARGS__); \
+    LOG_MESSAGE(LOGS_FATAL, __VA_ARGS__); \
    exit(1); \
  } while (0)

-#define LOG(severity, facility, ...) LOG_MESSAGE(severity, facility, __VA_ARGS__)
+#define LOG(severity, ...) LOG_MESSAGE(severity, __VA_ARGS__)

 /* Definition of severity */
 typedef enum {
@@ -76,47 +76,6 @@ typedef enum {
  LOGS_DEBUG
 } LOG_Severity;

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

@@ -125,9 +84,8 @@ extern void LOG_Finalise(void);

 /* Line logging function */
 #if DEBUG > 0
-FORMAT_ATTRIBUTE_PRINTF(6, 7)
-extern void LOG_Message(LOG_Severity severity, LOG_Facility facility,
-                        int line_number, const char *filename,
+FORMAT_ATTRIBUTE_PRINTF(5, 6)
+extern void LOG_Message(LOG_Severity severity, int line_number, const char *filename,
                        const char *function_name, const char *format, ...);
 #else
 FORMAT_ATTRIBUTE_PRINTF(2, 3)
@@ -141,6 +99,9 @@ extern void LOG_Message(LOG_Severity severity, const char *format, ...);
   */
 extern void LOG_SetDebugLevel(int level);

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

--- 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  2012-2015
+ * Copyright (C) Miroslav Lichvar  2012-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -35,6 +35,7 @@
 #include "local.h"
 #include "sys.h"
 #include "ntp_io.h"
+#include "ntp_signd.h"
 #include "ntp_sources.h"
 #include "ntp_core.h"
 #include "sources.h"
@@ -85,6 +86,10 @@ static void
 delete_pidfile(void)
 {
  const char *pidfile = CNF_GetPidFile();
+
+  if (!pidfile[0])
+    return;
+
  /* Don't care if this fails, there's not a lot we can do */
  unlink(pidfile);
 }
@@ -96,7 +101,7 @@ MAI_CleanupAndExit(void)
 {
  if (!initialised) exit(exit_status);
  
-  if (CNF_GetDumpOnExit()) {
+  if (CNF_GetDumpDir()[0] != '\0') {
    SRC_DumpSources();
  }

@@ -107,6 +112,7 @@ MAI_CleanupAndExit(void)
  TMC_Finalise();
  MNL_Finalise();
  CLG_Finalise();
+  NSD_Finalise();
  NSR_Finalise();
  SST_Finalise();
  NCR_Finalise();
@@ -125,9 +131,8 @@ MAI_CleanupAndExit(void)
  delete_pidfile();
  
  CNF_Finalise();
-  LOG_Finalise();
-
  HSH_Finalise();
+  LOG_Finalise();

  exit(exit_status);
 }
@@ -143,6 +148,16 @@ signal_cleanup(int x)

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

+static void
+quit_timeout(void *arg)
+{
+  /* Return with non-zero status if the clock is not synchronised */
+  exit_status = REF_GetOurStratum() >= NTP_MAX_STRATUM;
+  SCH_QuitProgram();
+}
+
+/* ================================================== */
+
 static void
 ntp_source_resolving_end(void)
 {
@@ -156,6 +171,7 @@ ntp_source_resolving_end(void)
    SRC_ReloadSources();
  }

+  SRC_RemoveDumpFiles();
  RTC_StartMeasurements();
  RCL_StartRefclocks();
  NSR_StartSources();
@@ -229,55 +245,45 @@ post_init_rtc_hook(void *anything)
 }

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

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

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

-  *other_pid = pid;
-  return does_process_exist(pid);
-  
+  if (getsid(pid) < 0)
+    return;
+
+  LOG_FATAL("Another chronyd may already be running (pid=%d), check %s",
+            pid, pidfile);
 }

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

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

+  if (!pidfile[0])
+    return;
+
  out = fopen(pidfile, "w");
  if (!out) {
-    LOG_FATAL(LOGF_Main, "could not open lockfile %s for writing", pidfile);
+    LOG_FATAL("Could not open %s : %s", pidfile, strerror(errno));
  } else {
    fprintf(out, "%d\n", (int)getpid());
    fclose(out);
@@ -294,14 +300,14 @@ 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_FATAL(LOGF_Logging, "Could not detach, pipe failed : %s", strerror(errno));
+    LOG_FATAL("pipe() failed : %s", strerror(errno));
  }

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

  if (pid < 0) {
-    LOG_FATAL(LOGF_Logging, "Could not detach, fork failed : %s", strerror(errno));
+    LOG_FATAL("fork() failed : %s", strerror(errno));
  } else if (pid > 0) {
    /* In the 'grandparent' */
    char message[1024];
@@ -312,7 +318,8 @@ go_daemon(void)
    if (r) {
      if (r > 0) {
        /* Print the error message from the child */
-        fprintf(stderr, "%.1024s\n", message);
+        message[sizeof (message) - 1] = '\0';
+        fprintf(stderr, "%s\n", message);
      }
      exit(1);
    } else
@@ -326,7 +333,7 @@ go_daemon(void)
    pid = fork();

    if (pid < 0) {
-      LOG_FATAL(LOGF_Logging, "Could not detach, fork failed : %s", strerror(errno));
+      LOG_FATAL("fork() failed : %s", strerror(errno));
    } else if (pid > 0) {
      exit(0); /* In the 'parent' */
    } else {
@@ -334,7 +341,7 @@ go_daemon(void)

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

      /* Don't keep stdin/out/err from before. But don't close
@@ -351,138 +358,171 @@ go_daemon(void)

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

+static void
+print_help(const char *progname)
+{
+      printf("Usage: %s [-4|-6] [-n|-d] [-q|-Q] [-r] [-R] [-s] [-t TIMEOUT] [-f FILE|COMMAND...]\n",
+             progname);
+}
+
+/* ================================================== */
+
+static void
+print_version(void)
+{
+  printf("chronyd (chrony) version %s (%s)\n", CHRONY_VERSION, CHRONYD_FEATURES);
+}
+
+/* ================================================== */
+
+static int
+parse_int_arg(const char *arg)
+{
+  int i;
+
+  if (sscanf(arg, "%d", &i) != 1)
+    LOG_FATAL("Invalid argument %s", arg);
+  return i;
+}
+
+/* ================================================== */
+
 int main
 (int argc, char **argv)
 {
  const char *conf_file = DEFAULT_CONF_FILE;
  const char *progname = argv[0];
-  char *user = NULL;
+  char *user = NULL, *log_file = NULL;
  struct passwd *pw;
-  int debug = 0, nofork = 0, address_family = IPADDR_UNSPEC;
-  int do_init_rtc = 0, restarted = 0;
-  int other_pid;
+  int opt, debug = 0, nofork = 0, address_family = IPADDR_UNSPEC;
+  int do_init_rtc = 0, restarted = 0, client_only = 0, timeout = 0;
  int scfilter_level = 0, lock_memory = 0, sched_priority = 0;
-  int system_log = 1;
+  int clock_control = 1, system_log = 1;
  int config_args = 0;

  do_platform_checks();

  LOG_Initialise();

-  /* Parse command line options */
-  while (++argv, (--argc)>0) {
-
-    if (!strcmp("-f", *argv)) {
-      ++argv, --argc;
-      conf_file = *argv;
-    } else if (!strcmp("-P", *argv)) {
-      ++argv, --argc;
-      if (argc == 0 || sscanf(*argv, "%d", &sched_priority) != 1) {
-        LOG_FATAL(LOGF_Main, "Bad scheduler priority");
-      }
-    } else if (!strcmp("-m", *argv)) {
-      lock_memory = 1;
-    } else if (!strcmp("-r", *argv)) {
-      reload = 1;
-    } else if (!strcmp("-R", *argv)) {
-      restarted = 1;
-    } else if (!strcmp("-u", *argv)) {
-      ++argv, --argc;
-      if (argc == 0) {
-        LOG_FATAL(LOGF_Main, "Missing user name");
-      } else {
-        user = *argv;
-      }
-    } else if (!strcmp("-F", *argv)) {
-      ++argv, --argc;
-      if (argc == 0 || sscanf(*argv, "%d", &scfilter_level) != 1)
-        LOG_FATAL(LOGF_Main, "Bad syscall filter level");
-    } else if (!strcmp("-s", *argv)) {
-      do_init_rtc = 1;
-    } else if (!strcmp("-v", *argv) || !strcmp("--version",*argv)) {
-      /* This write to the terminal is OK, it comes before we turn into a daemon */
-      printf("chronyd (chrony) version %s (%s)\n", CHRONY_VERSION, CHRONYD_FEATURES);
+  /* Parse (undocumented) long command-line options */
+  for (optind = 1; optind < argc; optind++) {
+    if (!strcmp("--help", argv[optind])) {
+      print_help(progname);
      return 0;
-    } else if (!strcmp("-n", *argv)) {
-      nofork = 1;
-    } else if (!strcmp("-d", *argv)) {
-      debug++;
-      nofork = 1;
-      system_log = 0;
-    } else if (!strcmp("-q", *argv)) {
-      ref_mode = REF_ModeUpdateOnce;
-      nofork = 1;
-      system_log = 0;
-    } else if (!strcmp("-Q", *argv)) {
-      ref_mode = REF_ModePrintOnce;
-      nofork = 1;
-      system_log = 0;
-    } else if (!strcmp("-4", *argv)) {
-      address_family = IPADDR_INET4;
-    } else if (!strcmp("-6", *argv)) {
-      address_family = IPADDR_INET6;
-    } else if (!strcmp("-h", *argv) || !strcmp("--help", *argv)) {
-      printf("Usage: %s [-4|-6] [-n|-d] [-q|-Q] [-r] [-R] [-s] [-f FILE|COMMAND...]\n",
-             progname);
+    } else if (!strcmp("--version", argv[optind])) {
+      print_version();
      return 0;
-    } 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;
    }
  }

-  if (getuid() != 0) {
-    /* This write to the terminal is OK, it comes before we turn into a daemon */
-    fprintf(stderr,"Not superuser\n");
-    return 1;
+  optind = 1;
+
+  /* Parse short command-line options */
+  while ((opt = getopt(argc, argv, "46df:F:hl:mnP:qQrRst:u:vx")) != -1) {
+    switch (opt) {
+      case '4':
+      case '6':
+        address_family = opt == '4' ? IPADDR_INET4 : IPADDR_INET6;
+        break;
+      case 'd':
+        debug++;
+        nofork = 1;
+        system_log = 0;
+        break;
+      case 'f':
+        conf_file = optarg;
+        break;
+      case 'F':
+        scfilter_level = parse_int_arg(optarg);
+        break;
+      case 'l':
+        log_file = optarg;
+        break;
+      case 'm':
+        lock_memory = 1;
+        break;
+      case 'n':
+        nofork = 1;
+        break;
+      case 'P':
+        sched_priority = parse_int_arg(optarg);
+        break;
+      case 'q':
+      case 'Q':
+        ref_mode = opt == 'q' ? REF_ModeUpdateOnce : REF_ModePrintOnce;
+        nofork = 1;
+        client_only = 1;
+        clock_control = 0;
+        system_log = 0;
+        break;
+      case 'r':
+        reload = 1;
+        break;
+      case 'R':
+        restarted = 1;
+        break;
+      case 's':
+        do_init_rtc = 1;
+        break;
+      case 't':
+        timeout = parse_int_arg(optarg);
+        break;
+      case 'u':
+        user = optarg;
+        break;
+      case 'v':
+        print_version();
+        return 0;
+      case 'x':
+        clock_control = 0;
+        break;
+      default:
+        print_help(progname);
+        return opt != 'h';
+    }
  }

+  if (getuid() && !client_only)
+    LOG_FATAL("Not superuser");
+
  /* Turn into a daemon */
  if (!nofork) {
    go_daemon();
  }

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

  DNS_SetAddressFamily(address_family);

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

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

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

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

  PRV_Initialise();
  LCL_Initialise();
  SCH_Initialise();
-  SYS_Initialise();
+  SYS_Initialise(clock_control);
  RTC_Initialise(do_init_rtc);
  SRC_Initialise();
  RCL_Initialise();
@@ -511,18 +551,19 @@ int main
  }

  if ((pw = getpwnam(user)) == NULL)
-    LOG_FATAL(LOGF_Main, "Could not get %s uid/gid", user);
+    LOG_FATAL("Could not get %s uid/gid", user);

  /* Create all directories before dropping root */
  CNF_CreateDirs(pw->pw_uid, pw->pw_gid);

-  /* Drop root privileges if the user has non-zero uid or gid */
-  if (pw->pw_uid || pw->pw_gid)
+  /* Drop root privileges if the specified user has a non-zero UID */
+  if (!geteuid() && (pw->pw_uid || pw->pw_gid))
    SYS_DropRoot(pw->pw_uid, pw->pw_gid);

  REF_Initialise();
  SST_Initialise();
  NSR_Initialise();
+  NSD_Initialise();
  CLG_Initialise();
  MNL_Initialise();
  TMC_Initialise();
@@ -545,6 +586,9 @@ int main
  REF_SetModeEndHandler(reference_mode_end);
  REF_SetMode(ref_mode);

+  if (timeout > 0)
+    SCH_AddTimeoutByDelay(timeout, quit_timeout, NULL);
+
  if (do_init_rtc) {
    RTC_TimeInit(post_init_rtc_hook, NULL);
  } else {
@@ -555,7 +599,7 @@ int main
     the scheduler. */
  SCH_MainLoop();

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

  MAI_CleanupAndExit();

--- a/manual.c
+++ b/manual.c
@@ -47,7 +47,7 @@ static int enabled = 0;

 /* More recent samples at highest indices */
 typedef struct {
-  struct timeval when; /* This is our 'cooked' time */
+  struct timespec when; /* This is our 'cooked' time */
  double orig_offset; /*+ Not modified by slew samples */
  double offset; /*+ if we are fast of the supplied reference */
  double residual; /*+ regression residual (sign convention given by
@@ -64,8 +64,8 @@ static int n_samples;
 /* ================================================== */

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

 static void
-estimate_and_set_system(struct timeval *now, int offset_provided, double offset, long *offset_cs, double *dfreq_ppm, double *new_afreq_ppm)
+estimate_and_set_system(struct timespec *now, int offset_provided, double offset,
+                        double *reg_offset, double *dfreq_ppm, double *new_afreq_ppm)
 {
  double agos[MAX_SAMPLES], offsets[MAX_SAMPLES];
  double b0, b1;
@@ -108,32 +109,26 @@ estimate_and_set_system(struct timeval *now, int offset_provided, double offset,
  int found_freq;
  double slew_by;

+  b0 = offset_provided ? offset : 0.0;
+  b1 = freq = 0.0;
+  found_freq = 0;
+
  if (n_samples > 1) {
    for (i=0; i<n_samples; i++) {
-      UTI_DiffTimevalsToDouble(&agos[i], &samples[n_samples-1].when, &samples[i].when);
+      agos[i] = UTI_DiffTimespecsToDouble(&samples[n_samples - 1].when, &samples[i].when);
      offsets[i] = samples[i].offset;
    }
    
-    RGR_FindBestRobustRegression(agos, offsets, n_samples,
-                                 1.0e-8, /* 0.01ppm easily good enough for this! */
-                                 &b0, &b1, &n_runs, &best_start);
-    
-    
-    /* Ignore b0 from regression; treat offset as being the most
-       recently entered value.  (If the administrator knows he's put
-       an outlier in, he will rerun the settime operation.)   However,
-       the frequency estimate comes from the regression. */
-    
-    freq = -b1;
-    found_freq = 1;
-  } else {
-    if (offset_provided) {
-      b0 = offset;
-    } else {
-      b0 = 0.0;
+    if (RGR_FindBestRobustRegression(agos, offsets, n_samples, 1.0e-8,
+                                     &b0, &b1, &n_runs, &best_start)) {
+      /* Ignore b0 from regression; treat offset as being the most
+         recently entered value.  (If the administrator knows he's put
+         an outlier in, he will rerun the settime operation.)   However,
+         the frequency estimate comes from the regression. */
+      freq = -b1;
+      found_freq = 1;
    }
-    b1 = freq = 0.0;
-    found_freq = 0;
+  } else {
    agos[0] = 0.0;
    offsets[0] = b0;
  }
@@ -145,21 +140,20 @@ estimate_and_set_system(struct timeval *now, int offset_provided, double offset,
  }
  
  if (found_freq) {
-    LOG(LOGS_INFO, LOGF_Manual,
-        "Making a frequency change of %.3f ppm and a slew of %.6f",
+    LOG(LOGS_INFO, "Making a frequency change of %.3f ppm and a slew of %.6f",
        1.0e6 * freq, slew_by);
    
    REF_SetManualReference(now,
                           slew_by,
                           freq, skew);
  } else {
-    LOG(LOGS_INFO, LOGF_Manual, "Making a slew of %.6f", slew_by);
+    LOG(LOGS_INFO, "Making a slew of %.6f", slew_by);
    REF_SetManualReference(now,
                           slew_by,
                           0.0, skew);
  }
  
-  if (offset_cs) *offset_cs = (long)(0.5 + 100.0 * b0);
+  if (reg_offset) *reg_offset = b0;
  if (dfreq_ppm) *dfreq_ppm = 1.0e6 * freq;
  if (new_afreq_ppm) *new_afreq_ppm = LCL_ReadAbsoluteFrequency();
  
@@ -173,9 +167,9 @@ estimate_and_set_system(struct timeval *now, int offset_provided, double offset,
 /* ================================================== */

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

@@ -189,12 +183,12 @@ MNL_AcceptTimestamp(struct timeval *ts, long *offset_cs, double *dfreq_ppm, doub
     return 0;

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

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

    /* Check if buffer full up */
    if (n_samples == MAX_SAMPLES) {
@@ -210,7 +204,7 @@ MNL_AcceptTimestamp(struct timeval *ts, long *offset_cs, double *dfreq_ppm, doub
    samples[n_samples].orig_offset = offset;
    ++n_samples;

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

    return 1;

@@ -224,8 +218,8 @@ MNL_AcceptTimestamp(struct timeval *ts, long *offset_cs, double *dfreq_ppm, doub
 /* ================================================== */

 static void
-slew_samples(struct timeval *raw,
-             struct timeval *cooked, 
+slew_samples(struct timespec *raw,
+             struct timespec *cooked,
             double dfreq,
             double doffset,
             LCL_ChangeType change_type,
@@ -239,7 +233,7 @@ slew_samples(struct timeval *raw,
  }

  for (i=0; i<n_samples; i++) {
-    UTI_AdjustTimeval(&samples[i].when, cooked, &samples[i].when, &delta_time,
+    UTI_AdjustTimespec(&samples[i].when, cooked, &samples[i].when, &delta_time,
        dfreq, doffset);
    samples[i].offset += delta_time;
  }
@@ -309,7 +303,7 @@ int
 MNL_DeleteSample(int index)
 {
  int i;
-  struct timeval now;
+  struct timespec now;

  if ((index < 0) || (index >= n_samples)) {
    return 0;
--- a/manual.h
+++ b/manual.h
@@ -33,7 +33,7 @@

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

 extern void MNL_Enable(void);
 extern void MNL_Disable(void);
--- a/memory.c
+++ b/memory.c
@@ -37,7 +37,7 @@ Malloc(size_t size)

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

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

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

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

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

  return r;
 }
--- a/nameserv_async.c
+++ b/nameserv_async.c
@@ -72,18 +72,18 @@ start_resolving(void *anything)
 /* ================================================== */

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

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

  resolving_threads--;

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

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

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

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

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

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

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

 typedef uint32_t NTP_int32;

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

@@ -56,6 +59,10 @@ typedef uint32_t NTP_int32;
 #define NTP_MIN_MAC_LENGTH (4 + 16)
 #define NTP_MAX_MAC_LENGTH (4 + MAX_HASH_LENGTH)

+/* The maximum length of MAC in NTPv4 packets which allows deterministic
+   parsing of extension fields (RFC 7822) */
+#define NTP_MAX_V4_MAC_LENGTH (4 + 20)
+
 /* Type definition for leap bits */
 typedef enum {
  LEAP_Normal = 0,
--- a/ntp_core.c
+++ b/ntp_core.c
--- a/ntp_core.h
+++ b/ntp_core.h
@@ -38,6 +38,18 @@ typedef enum {
  NTP_SERVER, NTP_PEER
 } NTP_Source_Type;

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

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

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

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

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

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

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

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

 extern int NCR_AddAccessRestriction(IPAddr *ip_addr, int subnet_bits, int allow, int all);
 extern int NCR_CheckAccessRestriction(IPAddr *ip_addr);
--- a/ntp_io.c
+++ b/ntp_io.c
@@ -4,7 +4,7 @@
 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
 * Copyright (C) Timo Teras  2009
- * Copyright (C) Miroslav Lichvar  2009, 2013-2015
+ * Copyright (C) Miroslav Lichvar  2009, 2013-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -30,6 +30,7 @@

 #include "sysincl.h"

+#include "array.h"
 #include "ntp_io.h"
 #include "ntp_core.h"
 #include "ntp_sources.h"
@@ -40,7 +41,12 @@
 #include "privops.h"
 #include "util.h"

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

 union sockaddr_in46 {
  struct sockaddr_in in4;
@@ -50,6 +56,31 @@ union sockaddr_in46 {
  struct sockaddr u;
 };

+struct Message {
+  union sockaddr_in46 name;
+  struct iovec iov;
+  NTP_Receive_Buffer buf;
+  /* Aligned buffer for control messages */
+  struct cmsghdr cmsgbuf[CMSGBUF_SIZE / sizeof (struct cmsghdr)];
+};
+
+#ifdef HAVE_RECVMMSG
+#define MAX_RECV_MESSAGES 4
+#define MessageHeader mmsghdr
+#else
+/* Compatible with mmsghdr */
+struct MessageHeader {
+  struct msghdr msg_hdr;
+  unsigned int msg_len;
+};
+
+#define MAX_RECV_MESSAGES 1
+#endif
+
+/* Arrays of Message and MessageHeader */
+static ARR_Instance recv_messages;
+static ARR_Instance recv_headers;
+
 /* The server/peer and client sockets for IPv4 and IPv6 */
 static int server_sock_fd4;
 static int client_sock_fd4;
@@ -80,7 +111,7 @@ static int initialised=0;
 /* ================================================== */

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

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

@@ -91,18 +122,18 @@ prepare_socket(int family, int port_number, int client_only)
  socklen_t my_addr_len;
  int sock_fd;
  IPAddr bind_address;
-  int on_off = 1;
-  
+  int events = SCH_FILE_INPUT, on_off = 1;
+
  /* Open Internet domain UDP socket for NTP message transmissions */

  sock_fd = socket(family, SOCK_DGRAM, 0);

  if (sock_fd < 0) {
    if (!client_only) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not open %s NTP socket : %s",
+      LOG(LOGS_ERR, "Could not open %s NTP socket : %s",
          UTI_SockaddrFamilyToString(family), strerror(errno));
    } else {
-      DEBUG_LOG(LOGF_NtpIO, "Could not open %s NTP socket : %s",
+      DEBUG_LOG("Could not open %s NTP socket : %s",
                UTI_SockaddrFamilyToString(family), strerror(errno));
    }
    return INVALID_SOCK_FD;
@@ -162,30 +193,35 @@ prepare_socket(int family, int port_number, int client_only)
  /* Make the socket capable of re-using an old address if binding to a specific port */
  if (port_number &&
      setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, (char *)&on_off, sizeof(on_off)) < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not set %s socket option", "SO_REUSEADDR");
+    LOG(LOGS_ERR, "Could not set %s socket option", "SO_REUSEADDR");
    /* Don't quit - we might survive anyway */
  }
  
  /* Make the socket capable of sending broadcast pkts - needed for NTP broadcast mode */
  if (!client_only &&
      setsockopt(sock_fd, SOL_SOCKET, SO_BROADCAST, (char *)&on_off, sizeof(on_off)) < 0) {
-    LOG(LOGS_ERR, LOGF_NtpIO, "Could not set %s socket option", "SO_BROADCAST");
+    LOG(LOGS_ERR, "Could not set %s socket option", "SO_BROADCAST");
    /* Don't quit - we might survive anyway */
  }

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

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

@@ -193,7 +229,7 @@ prepare_socket(int family, int port_number, int client_only)
 #ifdef HAVE_IN_PKTINFO
    /* We want the local IP info on server sockets */
    if (setsockopt(sock_fd, IPPROTO_IP, IP_PKTINFO, (char *)&on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not set %s socket option", "IP_PKTINFO");
+      LOG(LOGS_ERR, "Could not set %s socket option", "IP_PKTINFO");
      /* Don't quit - we might survive anyway */
    }
 #endif
@@ -203,18 +239,18 @@ prepare_socket(int family, int port_number, int client_only)
 #ifdef IPV6_V6ONLY
    /* Receive IPv6 packets only */
    if (setsockopt(sock_fd, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not set %s socket option", "IPV6_V6ONLY");
+      LOG(LOGS_ERR, "Could not set %s socket option", "IPV6_V6ONLY");
    }
 #endif

 #ifdef HAVE_IN6_PKTINFO
 #ifdef IPV6_RECVPKTINFO
    if (setsockopt(sock_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, (char *)&on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not set %s socket option", "IPV6_RECVPKTINFO");
+      LOG(LOGS_ERR, "Could not set %s socket option", "IPV6_RECVPKTINFO");
    }
 #else
    if (setsockopt(sock_fd, IPPROTO_IPV6, IPV6_PKTINFO, (char *)&on_off, sizeof(on_off)) < 0) {
-      LOG(LOGS_ERR, LOGF_NtpIO, "Could not set %s socket option", "IPV6_PKTINFO");
+      LOG(LOGS_ERR, "Could not set %s socket option", "IPV6_PKTINFO");
    }
 #endif
 #endif
@@ -223,14 +259,14 @@ prepare_socket(int family, int port_number, int client_only)

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

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

  return sock_fd;
 }
@@ -265,7 +301,7 @@ connect_socket(int sock_fd, NTP_Remote_Address *remote_addr)
  assert(addr_len);

  if (connect(sock_fd, &addr.u, addr_len) < 0) {
-    DEBUG_LOG(LOGF_NtpIO, "Could not connect NTP socket to %s:%d : %s",
+    DEBUG_LOG("Could not connect NTP socket to %s:%d : %s",
        UTI_IPToString(&remote_addr->ip_addr), remote_addr->port,
        strerror(errno));
    return 0;
@@ -282,11 +318,38 @@ close_socket(int sock_fd)
  if (sock_fd == INVALID_SOCK_FD)
    return;

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

 /* ================================================== */
+
+static void
+prepare_buffers(unsigned int n)
+{
+  struct MessageHeader *hdr;
+  struct Message *msg;
+  unsigned int i;
+
+  for (i = 0; i < n; i++) {
+    msg = ARR_GetElement(recv_messages, i);
+    hdr = ARR_GetElement(recv_headers, i);
+
+    msg->iov.iov_base = &msg->buf;
+    msg->iov.iov_len = sizeof (msg->buf);
+    hdr->msg_hdr.msg_name = &msg->name;
+    hdr->msg_hdr.msg_namelen = sizeof (msg->name);
+    hdr->msg_hdr.msg_iov = &msg->iov;
+    hdr->msg_hdr.msg_iovlen = 1;
+    hdr->msg_hdr.msg_control = &msg->cmsgbuf;
+    hdr->msg_hdr.msg_controllen = sizeof (msg->cmsgbuf);
+    hdr->msg_hdr.msg_flags = 0;
+    hdr->msg_len = 0;
+  }
+}
+
+/* ================================================== */
+
 void
 NIO_Initialise(int family)
 {
@@ -295,6 +358,22 @@ NIO_Initialise(int family)
  assert(!initialised);
  initialised = 1;

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

@@ -348,7 +427,7 @@ NIO_Initialise(int family)
       && client_sock_fd6 == INVALID_SOCK_FD
 #endif
      )) {
-    LOG_FATAL(LOGF_NtpIO, "Could not open NTP sockets");
+    LOG_FATAL("Could not open NTP sockets");
  }
 }

@@ -367,6 +446,13 @@ NIO_Finalise(void)
  close_socket(server_sock_fd6);
  server_sock_fd6 = client_sock_fd6 = INVALID_SOCK_FD;
 #endif
+  ARR_DestroyInstance(recv_headers);
+  ARR_DestroyInstance(recv_messages);
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+  NIO_Linux_Finalise();
+#endif
+
  initialised = 0;
 }

@@ -482,133 +568,185 @@ NIO_IsServerSocket(int sock_fd)
 /* ================================================== */

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

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

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

-  iov.iov_base = &message.ntp_pkt;
-  iov.iov_len = sizeof(message);
-  msg.msg_name = &where_from;
-  msg.msg_namelen = sizeof(where_from);
-  msg.msg_iov = &iov;
-  msg.msg_iovlen = 1;
-  msg.msg_control = (void *) cmsgbuf;
-  msg.msg_controllen = sizeof(cmsgbuf);
-  msg.msg_flags = 0;
+  if (hdr->msg_namelen >= sizeof (((struct sockaddr *)hdr->msg_name)->sa_family)) {
+    UTI_SockaddrToIPAndPort((struct sockaddr *)hdr->msg_name,
+                            &remote_addr.ip_addr, &remote_addr.port);
+  } else {
+    remote_addr.ip_addr.family = IPADDR_UNSPEC;
+    remote_addr.port = 0;
+  }

-  sock_fd = (long)anything;
-  status = recvmsg(sock_fd, &msg, flags);
+  local_addr.ip_addr.family = IPADDR_UNSPEC;
+  local_addr.if_index = INVALID_IF_INDEX;
+  local_addr.sock_fd = sock_fd;

-  /* Don't bother checking if read failed or why if it did.  More
-     likely than not, it will be connection refused, resulting from a
-     previous sendto() directing a datagram at a port that is not
-     listening (which appears to generate an ICMP response, and on
-     some architectures e.g. Linux this is translated into an error
-     reponse on a subsequent recvfrom). */
+  if (hdr->msg_flags & MSG_TRUNC) {
+    DEBUG_LOG("Received truncated message from %s:%d",
+              UTI_IPToString(&remote_addr.ip_addr), remote_addr.port);
+    return;
+  }

-  if (status > 0) {
-    if (msg.msg_namelen > sizeof (where_from))
-      LOG_FATAL(LOGF_NtpIO, "Truncated source address");
+  if (hdr->msg_flags & MSG_CTRUNC) {
+    DEBUG_LOG("Truncated control message");
+    /* Continue */
+  }

-    UTI_SockaddrToIPAndPort(&where_from.u, &remote_addr.ip_addr, &remote_addr.port);
-
-    local_addr.ip_addr.family = IPADDR_UNSPEC;
-    local_addr.sock_fd = sock_fd;
-
-    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+  for (cmsg = CMSG_FIRSTHDR(hdr); cmsg; cmsg = CMSG_NXTHDR(hdr, cmsg)) {
 #ifdef HAVE_IN_PKTINFO
-      if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO) {
-        struct in_pktinfo ipi;
+    if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO) {
+      struct in_pktinfo ipi;

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

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

-        memcpy(&ipi, CMSG_DATA(cmsg), sizeof(ipi));
-        memcpy(&local_addr.ip_addr.addr.in6, &ipi.ipi6_addr.s6_addr,
-            sizeof (local_addr.ip_addr.addr.in6));
-        local_addr.ip_addr.family = IPADDR_INET6;
-      }
+      memcpy(&ipi, CMSG_DATA(cmsg), sizeof(ipi));
+      memcpy(&local_addr.ip_addr.addr.in6, &ipi.ipi6_addr.s6_addr,
+             sizeof (local_addr.ip_addr.addr.in6));
+      local_addr.ip_addr.family = IPADDR_INET6;
+      local_addr.if_index = ipi.ipi6_ifindex;
+    }
 #endif

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

-        memcpy(&tv, CMSG_DATA(cmsg), sizeof(tv));
-        LCL_CookTime(&tv, &now, &now_err);
-      }
+      memcpy(&tv, CMSG_DATA(cmsg), sizeof(tv));
+      UTI_TimevalToTimespec(&tv, &ts);
+      LCL_CookTime(&ts, &local_ts.ts, &local_ts.err);
+      local_ts.source = NTP_TS_KERNEL;
+    }
 #endif
+
+#ifdef SCM_TIMESTAMPNS
+    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPNS) {
+      struct timespec ts;
+
+      memcpy(&ts, CMSG_DATA(cmsg), sizeof (ts));
+      LCL_CookTime(&ts, &local_ts.ts, &local_ts.err);
+      local_ts.source = NTP_TS_KERNEL;
    }
-
-    DEBUG_LOG(LOGF_NtpIO, "Received %d bytes from %s:%d to %s fd %d",
-              status, UTI_IPToString(&remote_addr.ip_addr), remote_addr.port,
-              UTI_IPToString(&local_addr.ip_addr), local_addr.sock_fd);
-
-    if (status >= NTP_NORMAL_PACKET_LENGTH) {
-
-      NSR_ProcessReceive((NTP_Packet *) &message.ntp_pkt, &now, now_err,
-                         &remote_addr, &local_addr, status);
-
-    } else {
-
-      /* Just ignore the packet if it's not of a recognized length */
-
-    }
+#endif
  }
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+  if (NIO_Linux_ProcessMessage(&remote_addr, &local_addr, &local_ts, hdr, length))
+    return;
+#endif
+
+  DEBUG_LOG("Received %d bytes from %s:%d to %s fd=%d if=%d tss=%d delay=%.9f",
+            length, UTI_IPToString(&remote_addr.ip_addr), remote_addr.port,
+            UTI_IPToString(&local_addr.ip_addr), local_addr.sock_fd, local_addr.if_index,
+            local_ts.source, UTI_DiffTimespecsToDouble(&sched_ts, &local_ts.ts));
+
+  /* Just ignore the packet if it's not of a recognized length */
+  if (length < NTP_NORMAL_PACKET_LENGTH || length > sizeof (NTP_Receive_Buffer))
+    return;
+
+  NSR_ProcessRx(&remote_addr, &local_addr, &local_ts,
+                (NTP_Packet *)hdr->msg_iov[0].iov_base, length);
+}
+
+/* ================================================== */
+
+static void
+read_from_socket(int sock_fd, int event, void *anything)
+{
+  /* This should only be called when there is something
+     to read, otherwise it may block */
+
+  struct MessageHeader *hdr;
+  unsigned int i, n;
+  int status, flags = 0;
+
+  hdr = ARR_GetElements(recv_headers);
+  n = ARR_GetSize(recv_headers);
+  assert(n >= 1);
+
+  if (event == SCH_FILE_EXCEPTION) {
+#ifdef HAVE_LINUX_TIMESTAMPING
+    flags |= MSG_ERRQUEUE;
+#else
+    assert(0);
+#endif
+  }
+
+#ifdef HAVE_RECVMMSG
+  status = recvmmsg(sock_fd, hdr, n, flags | MSG_DONTWAIT, NULL);
+  if (status >= 0)
+    n = status;
+#else
+  n = 1;
+  status = recvmsg(sock_fd, &hdr[0].msg_hdr, flags);
+  if (status >= 0)
+    hdr[0].msg_len = status;
+#endif
+
+  if (status < 0) {
+    DEBUG_LOG("Could not receive from fd %d : %s", sock_fd,
+              strerror(errno));
+    return;
+  }
+
+  for (i = 0; i < n; i++) {
+    hdr = ARR_GetElement(recv_headers, i);
+    process_message(&hdr->msg_hdr, hdr->msg_len, sock_fd);
+  }
+
+  /* Restore the buffers to their original state */
+  prepare_buffers(n);
 }

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

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

  assert(initialised);

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

  /* Don't set address with connected socket */
-  if (local_addr->sock_fd == server_sock_fd4 ||
-#ifdef FEAT_IPV6
-      local_addr->sock_fd == server_sock_fd6 ||
-#endif
-      !separate_client_sockets) {
+  if (NIO_IsServerSocket(local_addr->sock_fd) || !separate_client_sockets) {
    addrlen = UTI_IPAndPortToSockaddr(&remote_addr->ip_addr, remote_addr->port,
                                      &remote.u);
    if (!addrlen)
@@ -624,7 +762,7 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Lo
  }

  iov.iov_base = packet;
-  iov.iov_len = packetlen;
+  iov.iov_len = length;
  msg.msg_iov = &iov;
  msg.msg_iovlen = 1;
  msg.msg_control = cmsgbuf;
@@ -634,7 +772,6 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Lo

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

    cmsg = CMSG_FIRSTHDR(&msg);
@@ -652,7 +789,6 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Lo

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

    cmsg = CMSG_FIRSTHDR(&msg);
@@ -669,31 +805,27 @@ send_packet(void *packet, int packetlen, NTP_Remote_Address *remote_addr, NTP_Lo
  }
 #endif

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

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

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

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

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

 #endif /* GOT_NTP_IO_H */
--- a/ntp_io_linux.c
+++ b/ntp_io_linux.c
@@ -0,0 +1,665 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016-2017
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Functions for NTP I/O specific to Linux
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include <ifaddrs.h>
+#include <linux/errqueue.h>
+#include <linux/ethtool.h>
+#include <linux/net_tstamp.h>
+#include <linux/sockios.h>
+#include <net/if.h>
+
+#include "array.h"
+#include "conf.h"
+#include "hwclock.h"
+#include "local.h"
+#include "logging.h"
+#include "ntp_core.h"
+#include "ntp_io.h"
+#include "ntp_io_linux.h"
+#include "ntp_sources.h"
+#include "sched.h"
+#include "sys_linux.h"
+#include "util.h"
+
+union sockaddr_in46 {
+  struct sockaddr_in in4;
+#ifdef FEAT_IPV6
+  struct sockaddr_in6 in6;
+#endif
+  struct sockaddr u;
+};
+
+struct Interface {
+  char name[IF_NAMESIZE];
+  int if_index;
+  int phc_fd;
+  int phc_mode;
+  int phc_nocrossts;
+  /* Link speed in mbit/s */
+  int link_speed;
+  /* Start of UDP data at layer 2 for IPv4 and IPv6 */
+  int l2_udp4_ntp_start;
+  int l2_udp6_ntp_start;
+  /* Precision of PHC readings */
+  double precision;
+  /* Compensation of errors in TX and RX timestamping */
+  double tx_comp;
+  double rx_comp;
+  HCL_Instance clock;
+};
+
+/* Number of PHC readings per HW clock sample */
+#define PHC_READINGS 10
+
+/* Minimum interval between PHC readings */
+#define MIN_PHC_POLL -6
+
+/* Maximum acceptable offset between HW and daemon/kernel timestamp */
+#define MAX_TS_DELAY 1.0
+
+/* Array of Interfaces */
+static ARR_Instance interfaces;
+
+/* RX/TX and TX-specific timestamping socket options */
+static int ts_flags;
+static int ts_tx_flags;
+
+/* Flag indicating the socket options can't be changed in control messages */
+static int permanent_ts_options;
+
+/* ================================================== */
+
+static int
+add_interface(CNF_HwTsInterface *conf_iface)
+{
+  struct ethtool_ts_info ts_info;
+  struct hwtstamp_config ts_config;
+  struct ifreq req;
+  int sock_fd, if_index, phc_fd, req_hwts_flags;
+  unsigned int i;
+  struct Interface *iface;
+
+  /* Check if the interface was not already added */
+  for (i = 0; i < ARR_GetSize(interfaces); i++) {
+    if (!strcmp(conf_iface->name, ((struct Interface *)ARR_GetElement(interfaces, i))->name))
+      return 1;
+  }
+
+  sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (sock_fd < 0)
+    return 0;
+
+  memset(&req, 0, sizeof (req));
+  memset(&ts_info, 0, sizeof (ts_info));
+
+  if (snprintf(req.ifr_name, sizeof (req.ifr_name), "%s", conf_iface->name) >=
+      sizeof (req.ifr_name)) {
+    close(sock_fd);
+    return 0;
+  }
+
+  if (ioctl(sock_fd, SIOCGIFINDEX, &req)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "SIOCGIFINDEX", strerror(errno));
+    close(sock_fd);
+    return 0;
+  }
+
+  if_index = req.ifr_ifindex;
+
+  ts_info.cmd = ETHTOOL_GET_TS_INFO;
+  req.ifr_data = (char *)&ts_info;
+
+  if (ioctl(sock_fd, SIOCETHTOOL, &req)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "SIOCETHTOOL", strerror(errno));
+    close(sock_fd);
+    return 0;
+  }
+
+  req_hwts_flags = SOF_TIMESTAMPING_RX_HARDWARE | SOF_TIMESTAMPING_TX_HARDWARE |
+                   SOF_TIMESTAMPING_RAW_HARDWARE;
+  if ((ts_info.so_timestamping & req_hwts_flags) != req_hwts_flags) {
+    DEBUG_LOG("HW timestamping not supported on %s", req.ifr_name);
+    close(sock_fd);
+    return 0;
+  }
+
+  ts_config.flags = 0;
+  ts_config.tx_type = HWTSTAMP_TX_ON;
+
+  switch (conf_iface->rxfilter) {
+    case CNF_HWTS_RXFILTER_NONE:
+      ts_config.rx_filter = HWTSTAMP_FILTER_NONE;
+      break;
+    case CNF_HWTS_RXFILTER_NTP:
+#ifdef HAVE_LINUX_TIMESTAMPING_RXFILTER_NTP
+      if (ts_info.rx_filters & (1 << HWTSTAMP_FILTER_NTP_ALL)) {
+        ts_config.rx_filter = HWTSTAMP_FILTER_NTP_ALL;
+        break;
+      }
+#endif
+      /* Fall through */
+    default:
+      ts_config.rx_filter = HWTSTAMP_FILTER_ALL;
+      break;
+  }
+
+  req.ifr_data = (char *)&ts_config;
+
+  if (ioctl(sock_fd, SIOCSHWTSTAMP, &req)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "SIOCSHWTSTAMP", strerror(errno));
+    close(sock_fd);
+    return 0;
+  }
+
+  close(sock_fd);
+
+  phc_fd = SYS_Linux_OpenPHC(NULL, ts_info.phc_index);
+  if (phc_fd < 0)
+    return 0;
+
+  iface = ARR_GetNewElement(interfaces);
+
+  snprintf(iface->name, sizeof (iface->name), "%s", conf_iface->name);
+  iface->if_index = if_index;
+  iface->phc_fd = phc_fd;
+  iface->phc_mode = 0;
+  iface->phc_nocrossts = conf_iface->nocrossts;
+
+  /* Start with 1 gbit and no VLANs or IPv4/IPv6 options */
+  iface->link_speed = 1000;
+  iface->l2_udp4_ntp_start = 42;
+  iface->l2_udp6_ntp_start = 62;
+
+  iface->precision = conf_iface->precision;
+  iface->tx_comp = conf_iface->tx_comp;
+  iface->rx_comp = conf_iface->rx_comp;
+
+  iface->clock = HCL_CreateInstance(UTI_Log2ToDouble(MAX(conf_iface->minpoll, MIN_PHC_POLL)));
+
+  LOG(LOGS_INFO, "Enabled HW timestamping on %s", iface->name);
+
+  return 1;
+}
+
+/* ================================================== */
+
+static int
+add_all_interfaces(CNF_HwTsInterface *conf_iface_all)
+{
+  CNF_HwTsInterface conf_iface;
+  struct ifaddrs *ifaddr, *ifa;
+  int r;
+
+  conf_iface = *conf_iface_all;
+
+  if (getifaddrs(&ifaddr)) {
+    DEBUG_LOG("getifaddrs() failed : %s", strerror(errno));
+    return 0;
+  }
+
+  for (r = 0, ifa = ifaddr; ifa; ifa = ifa->ifa_next) {
+    conf_iface.name = ifa->ifa_name;
+    if (add_interface(&conf_iface))
+      r = 1;
+  }
+  
+  freeifaddrs(ifaddr);
+
+  /* Return success if at least one interface was added */
+  return r;
+}
+
+/* ================================================== */
+
+static void
+update_interface_speed(struct Interface *iface)
+{
+  struct ethtool_cmd cmd;
+  struct ifreq req;
+  int sock_fd;
+
+  sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (sock_fd < 0)
+    return;
+
+  memset(&req, 0, sizeof (req));
+  memset(&cmd, 0, sizeof (cmd));
+
+  snprintf(req.ifr_name, sizeof (req.ifr_name), "%s", iface->name);
+  cmd.cmd = ETHTOOL_GSET;
+  req.ifr_data = (char *)&cmd;
+
+  if (ioctl(sock_fd, SIOCETHTOOL, &req)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "SIOCETHTOOL", strerror(errno));
+    close(sock_fd);
+    return;
+  }
+
+  close(sock_fd);
+
+  iface->link_speed = ethtool_cmd_speed(&cmd);
+}
+
+/* ================================================== */
+
+#if defined(HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO) || defined(HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW)
+static int
+check_timestamping_option(int option)
+{
+  int sock_fd;
+
+  sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (sock_fd < 0)
+    return 0;
+
+  if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMPING, &option, sizeof (option)) < 0) {
+    DEBUG_LOG("Could not enable timestamping option %x", option);
+    close(sock_fd);
+    return 0;
+  }
+
+  close(sock_fd);
+  return 1;
+}
+#endif
+
+/* ================================================== */
+
+void
+NIO_Linux_Initialise(void)
+{
+  CNF_HwTsInterface *conf_iface;
+  unsigned int i;
+  int hwts;
+
+  interfaces = ARR_CreateInstance(sizeof (struct Interface));
+
+  /* Enable HW timestamping on specified interfaces.  If "*" was specified, try
+     all interfaces.  If no interface was specified, enable SW timestamping. */
+
+  for (i = hwts = 0; CNF_GetHwTsInterface(i, &conf_iface); i++) {
+    if (!strcmp("*", conf_iface->name))
+      continue;
+    if (!add_interface(conf_iface))
+      LOG_FATAL("Could not enable HW timestamping on %s", conf_iface->name);
+    hwts = 1;
+  }
+
+  for (i = 0; CNF_GetHwTsInterface(i, &conf_iface); i++) {
+    if (strcmp("*", conf_iface->name))
+      continue;
+    if (add_all_interfaces(conf_iface))
+      hwts = 1;
+    break;
+  }
+
+  ts_flags = SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_RX_SOFTWARE;
+  ts_tx_flags = SOF_TIMESTAMPING_TX_SOFTWARE;
+
+  if (hwts) {
+    ts_flags |= SOF_TIMESTAMPING_RAW_HARDWARE | SOF_TIMESTAMPING_RX_HARDWARE;
+    ts_tx_flags |= SOF_TIMESTAMPING_TX_HARDWARE;
+#ifdef HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO
+    if (check_timestamping_option(SOF_TIMESTAMPING_OPT_PKTINFO))
+      ts_flags |= SOF_TIMESTAMPING_OPT_PKTINFO;
+#endif
+#ifdef HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW
+    if (check_timestamping_option(SOF_TIMESTAMPING_OPT_TX_SWHW))
+      ts_flags |= SOF_TIMESTAMPING_OPT_TX_SWHW;
+#endif
+  }
+
+  /* Enable IP_PKTINFO in messages looped back to the error queue */
+  ts_flags |= SOF_TIMESTAMPING_OPT_CMSG;
+
+  /* Kernels before 4.7 ignore timestamping flags set in control messages */
+  permanent_ts_options = !SYS_Linux_CheckKernelVersion(4, 7);
+}
+
+/* ================================================== */
+
+void
+NIO_Linux_Finalise(void)
+{
+  struct Interface *iface;
+  unsigned int i;
+
+  for (i = 0; i < ARR_GetSize(interfaces); i++) {
+    iface = ARR_GetElement(interfaces, i);
+    HCL_DestroyInstance(iface->clock);
+    close(iface->phc_fd);
+  }
+
+  ARR_DestroyInstance(interfaces);
+}
+
+/* ================================================== */
+
+int
+NIO_Linux_SetTimestampSocketOptions(int sock_fd, int client_only, int *events)
+{
+  int val, flags;
+
+  if (!ts_flags)
+    return 0;
+
+  /* Enable SCM_TIMESTAMPING control messages and the socket's error queue in
+     order to receive our transmitted packets with more accurate timestamps */
+
+  val = 1;
+  flags = ts_flags;
+
+  if (client_only || permanent_ts_options)
+    flags |= ts_tx_flags;
+
+  if (setsockopt(sock_fd, SOL_SOCKET, SO_SELECT_ERR_QUEUE, &val, sizeof (val)) < 0) {
+    LOG(LOGS_ERR, "Could not set %s socket option", "SO_SELECT_ERR_QUEUE");
+    ts_flags = 0;
+    return 0;
+  }
+
+  if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMPING, &flags, sizeof (flags)) < 0) {
+    LOG(LOGS_ERR, "Could not set %s socket option", "SO_TIMESTAMPING");
+    ts_flags = 0;
+    return 0;
+  }
+
+  *events |= SCH_FILE_EXCEPTION;
+  return 1;
+}
+
+/* ================================================== */
+
+static struct Interface *
+get_interface(int if_index)
+{
+  struct Interface *iface;
+  unsigned int i;
+
+  for (i = 0; i < ARR_GetSize(interfaces); i++) {
+    iface = ARR_GetElement(interfaces, i);
+    if (iface->if_index != if_index)
+      continue;
+
+    return iface;
+  }
+
+  return NULL;
+}
+
+/* ================================================== */
+
+static void
+process_hw_timestamp(struct Interface *iface, struct timespec *hw_ts,
+                     NTP_Local_Timestamp *local_ts, int rx_ntp_length, int family,
+                     int l2_length)
+{
+  struct timespec sample_phc_ts, sample_sys_ts, sample_local_ts, ts;
+  double rx_correction, ts_delay, phc_err, local_err;
+
+  if (HCL_NeedsNewSample(iface->clock, &local_ts->ts)) {
+    if (!SYS_Linux_GetPHCSample(iface->phc_fd, iface->phc_nocrossts, iface->precision,
+                                &iface->phc_mode, &sample_phc_ts, &sample_sys_ts,
+                                &phc_err))
+      return;
+
+    LCL_CookTime(&sample_sys_ts, &sample_local_ts, &local_err);
+    HCL_AccumulateSample(iface->clock, &sample_phc_ts, &sample_local_ts,
+                         phc_err + local_err);
+
+    update_interface_speed(iface);
+  }
+
+  /* We need to transpose RX timestamps as hardware timestamps are normally
+     preamble timestamps and RX timestamps in NTP are supposed to be trailer
+     timestamps.  If we don't know the length of the packet at layer 2, we
+     make an assumption that UDP data start at the same position as in the
+     last transmitted packet which had a HW TX timestamp. */
+  if (rx_ntp_length && iface->link_speed) {
+    if (!l2_length)
+      l2_length = (family == IPADDR_INET4 ? iface->l2_udp4_ntp_start :
+                   iface->l2_udp6_ntp_start) + rx_ntp_length + 4;
+    rx_correction = l2_length / (1.0e6 / 8 * iface->link_speed);
+
+    UTI_AddDoubleToTimespec(hw_ts, rx_correction, hw_ts);
+  }
+
+  if (!HCL_CookTime(iface->clock, hw_ts, &ts, &local_err))
+    return;
+
+  if (!rx_ntp_length && iface->tx_comp)
+    UTI_AddDoubleToTimespec(&ts, iface->tx_comp, &ts);
+  else if (rx_ntp_length && iface->rx_comp)
+    UTI_AddDoubleToTimespec(&ts, -iface->rx_comp, &ts);
+
+  ts_delay = UTI_DiffTimespecsToDouble(&local_ts->ts, &ts);
+
+  if (fabs(ts_delay) > MAX_TS_DELAY) {
+    DEBUG_LOG("Unacceptable timestamp delay %.9f", ts_delay);
+    return;
+  }
+
+  local_ts->ts = ts;
+  local_ts->err = local_err;
+  local_ts->source = NTP_TS_HARDWARE;
+}
+
+/* ================================================== */
+/* Extract UDP data from a layer 2 message.  Supported is Ethernet
+   with optional VLAN tags. */
+
+static int
+extract_udp_data(unsigned char *msg, NTP_Remote_Address *remote_addr, int len)
+{
+  unsigned char *msg_start = msg;
+  union sockaddr_in46 addr;
+
+  remote_addr->ip_addr.family = IPADDR_UNSPEC;
+  remote_addr->port = 0;
+
+  /* Skip MACs */
+  if (len < 12)
+    return 0;
+  len -= 12, msg += 12;
+
+  /* Skip VLAN tag(s) if present */
+  while (len >= 4 && msg[0] == 0x81 && msg[1] == 0x00)
+    len -= 4, msg += 4;
+
+  /* Skip IPv4 or IPv6 ethertype */
+  if (len < 2 || !((msg[0] == 0x08 && msg[1] == 0x00) ||
+                   (msg[0] == 0x86 && msg[1] == 0xdd)))
+    return 0;
+  len -= 2, msg += 2;
+
+  /* Parse destination address and port from IPv4/IPv6 and UDP headers */
+  if (len >= 20 && msg[0] >> 4 == 4) {
+    int ihl = (msg[0] & 0xf) * 4;
+
+    if (len < ihl + 8 || msg[9] != 17)
+      return 0;
+
+    memcpy(&addr.in4.sin_addr.s_addr, msg + 16, sizeof (uint32_t));
+    addr.in4.sin_port = *(uint16_t *)(msg + ihl + 2);
+    addr.in4.sin_family = AF_INET;
+    len -= ihl + 8, msg += ihl + 8;
+#ifdef FEAT_IPV6
+  } else if (len >= 48 && msg[0] >> 4 == 6) {
+    /* IPv6 extension headers are not supported */
+    if (msg[6] != 17)
+      return 0;
+
+    memcpy(&addr.in6.sin6_addr.s6_addr, msg + 24, 16);
+    addr.in6.sin6_port = *(uint16_t *)(msg + 40 + 2);
+    addr.in6.sin6_family = AF_INET6;
+    len -= 48, msg += 48;
+#endif
+  } else {
+    return 0;
+  }
+
+  UTI_SockaddrToIPAndPort(&addr.u, &remote_addr->ip_addr, &remote_addr->port);
+
+  /* Move the message to fix alignment of its fields */
+  if (len > 0)
+    memmove(msg_start, msg, len);
+
+  return len;
+}
+
+/* ================================================== */
+
+int
+NIO_Linux_ProcessMessage(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+                         NTP_Local_Timestamp *local_ts, struct msghdr *hdr, int length)
+{
+  struct Interface *iface;
+  struct cmsghdr *cmsg;
+  int is_tx, ts_if_index, l2_length;
+
+  is_tx = hdr->msg_flags & MSG_ERRQUEUE;
+  iface = NULL;
+  ts_if_index = local_addr->if_index;
+  l2_length = 0;
+
+  for (cmsg = CMSG_FIRSTHDR(hdr); cmsg; cmsg = CMSG_NXTHDR(hdr, cmsg)) {
+#ifdef HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO
+    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPING_PKTINFO) {
+      struct scm_ts_pktinfo ts_pktinfo;
+
+      memcpy(&ts_pktinfo, CMSG_DATA(cmsg), sizeof (ts_pktinfo));
+
+      ts_if_index = ts_pktinfo.if_index;
+      l2_length = ts_pktinfo.pkt_length;
+
+      DEBUG_LOG("Received HW timestamp info if=%d length=%d", ts_if_index, l2_length);
+    }
+#endif
+
+    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPING) {
+      struct scm_timestamping ts3;
+
+      memcpy(&ts3, CMSG_DATA(cmsg), sizeof (ts3));
+
+      if (!UTI_IsZeroTimespec(&ts3.ts[2])) {
+        iface = get_interface(ts_if_index);
+        if (iface) {
+          process_hw_timestamp(iface, &ts3.ts[2], local_ts, !is_tx ? length : 0,
+                               remote_addr->ip_addr.family, l2_length);
+        } else {
+          DEBUG_LOG("HW clock not found for interface %d", ts_if_index);
+        }
+      }
+
+      if (local_ts->source == NTP_TS_DAEMON && !UTI_IsZeroTimespec(&ts3.ts[0]) &&
+          (!is_tx || UTI_IsZeroTimespec(&ts3.ts[2]))) {
+        LCL_CookTime(&ts3.ts[0], &local_ts->ts, &local_ts->err);
+        local_ts->source = NTP_TS_KERNEL;
+      }
+    }
+
+    if ((cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR) ||
+        (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_RECVERR)) {
+      struct sock_extended_err err;
+
+      memcpy(&err, CMSG_DATA(cmsg), sizeof (err));
+
+      if (err.ee_errno != ENOMSG || err.ee_info != SCM_TSTAMP_SND ||
+          err.ee_origin != SO_EE_ORIGIN_TIMESTAMPING) {
+        DEBUG_LOG("Unknown extended error");
+        /* Drop the message */
+        return 1;
+      }
+    }
+  }
+
+  /* Return the message if it's not received from the error queue */
+  if (!is_tx)
+    return 0;
+
+  /* The data from the error queue includes all layers up to UDP.  We have to
+     extract the UDP data and also the destination address with port as there
+     currently doesn't seem to be a better way to get them both. */
+  l2_length = length;
+  length = extract_udp_data(hdr->msg_iov[0].iov_base, remote_addr, length);
+
+  DEBUG_LOG("Received %d (%d) bytes from error queue for %s:%d fd=%d if=%d tss=%d",
+            l2_length, length, UTI_IPToString(&remote_addr->ip_addr), remote_addr->port,
+            local_addr->sock_fd, local_addr->if_index, local_ts->source);
+
+  /* Update assumed position of UDP data at layer 2 for next received packet */
+  if (iface && length) {
+    if (remote_addr->ip_addr.family == IPADDR_INET4)
+      iface->l2_udp4_ntp_start = l2_length - length;
+    else if (remote_addr->ip_addr.family == IPADDR_INET6)
+      iface->l2_udp6_ntp_start = l2_length - length;
+  }
+
+  /* Drop the message if it has no timestamp or its processing failed */
+  if (local_ts->source == NTP_TS_DAEMON) {
+    DEBUG_LOG("Missing TX timestamp");
+    return 1;
+  }
+
+  if (length < NTP_NORMAL_PACKET_LENGTH)
+    return 1;
+
+  NSR_ProcessTx(remote_addr, local_addr, local_ts,
+                (NTP_Packet *)hdr->msg_iov[0].iov_base, length);
+
+  return 1;
+}
+
+/* ================================================== */
+
+int
+NIO_Linux_RequestTxTimestamp(struct msghdr *msg, int cmsglen, int sock_fd)
+{
+  struct cmsghdr *cmsg;
+
+  /* Check if TX timestamping is disabled on this socket */
+  if (permanent_ts_options || !NIO_IsServerSocket(sock_fd))
+    return cmsglen;
+
+  /* Add control message that will enable TX timestamping for this message.
+     Don't use CMSG_NXTHDR as the one in glibc is buggy for creating new
+     control messages. */
+  cmsg = (struct cmsghdr *)((char *)CMSG_FIRSTHDR(msg) + cmsglen);
+  memset(cmsg, 0, CMSG_SPACE(sizeof (ts_tx_flags)));
+  cmsglen += CMSG_SPACE(sizeof (ts_tx_flags));
+
+  cmsg->cmsg_level = SOL_SOCKET;
+  cmsg->cmsg_type = SO_TIMESTAMPING;
+  cmsg->cmsg_len = CMSG_LEN(sizeof (ts_tx_flags));
+
+  memcpy(CMSG_DATA(cmsg), &ts_tx_flags, sizeof (ts_tx_flags));
+
+  return cmsglen;
+}
--- a/ntp_io_linux.h
+++ b/ntp_io_linux.h
@@ -0,0 +1,36 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  This is the header file for the Linux-specific NTP socket I/O bits.
+  */
+
+extern void NIO_Linux_Initialise(void);
+
+extern void NIO_Linux_Finalise(void);
+
+extern int NIO_Linux_SetTimestampSocketOptions(int sock_fd, int client_only, int *events);
+
+extern int NIO_Linux_ProcessMessage(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+                                    NTP_Local_Timestamp *local_ts, struct msghdr *hdr, int length);
+
+extern int NIO_Linux_RequestTxTimestamp(struct msghdr *msg, int cmsglen, int sock_fd);
--- a/ntp_signd.c
+++ b/ntp_signd.c
@@ -0,0 +1,379 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Support for MS-SNTP authentication in Samba (ntp_signd)
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "array.h"
+#include "conf.h"
+#include "logging.h"
+#include "ntp_io.h"
+#include "ntp_signd.h"
+#include "sched.h"
+#include "util.h"
+
+/* Declarations per samba/source4/librpc/idl/ntp_signd.idl */
+
+#define SIGND_VERSION 0
+
+typedef enum {
+  SIGN_TO_CLIENT = 0,
+  ASK_SERVER_TO_SIGN = 1,
+  CHECK_SERVER_SIGNATURE = 2,
+  SIGNING_SUCCESS = 3,
+  SIGNING_FAILURE = 4,
+} SigndOp;
+
+typedef struct {
+  uint32_t length;
+  uint32_t version;
+  uint32_t op;
+  uint16_t packet_id;
+  uint16_t _pad;
+  uint32_t key_id;
+  NTP_Packet packet_to_sign;
+} SigndRequest;
+
+typedef struct {
+  uint32_t length;
+  uint32_t version;
+  uint32_t op;
+  uint32_t packet_id;
+  NTP_Packet signed_packet;
+} SigndResponse;
+
+typedef struct {
+  NTP_Remote_Address remote_addr;
+  NTP_Local_Address local_addr;
+
+  int sent;
+  int received;
+  int request_length;
+  struct timespec request_ts;
+  SigndRequest request;
+  SigndResponse response;
+} SignInstance;
+
+/* As the communication with ntp_signd is asynchronous, incoming packets are
+   saved in a queue in order to avoid loss when they come in bursts */
+
+#define MAX_QUEUE_LENGTH 16U
+#define NEXT_QUEUE_INDEX(index) (((index) + 1) % MAX_QUEUE_LENGTH)
+#define IS_QUEUE_EMPTY() (queue_head == queue_tail)
+
+/* Fixed-size array of SignInstance */
+static ARR_Instance queue;
+static unsigned int queue_head;
+static unsigned int queue_tail;
+
+#define INVALID_SOCK_FD -1
+
+/* Unix domain socket connected to ntp_signd */
+static int sock_fd;
+
+#define MIN_AUTH_DELAY 1.0e-5
+#define MAX_AUTH_DELAY 1.0e-2
+
+/* Average time needed for signing one packet.  This is used to adjust the
+   transmit timestamp in NTP packets.  The timestamp won't be very accurate as
+   the delay is variable, but it should be good enough for MS-SNTP clients. */
+static double auth_delay;
+
+/* Flag indicating if the MS-SNTP authentication is enabled */
+static int enabled;
+
+/* ================================================== */
+
+static void read_write_socket(int sock_fd, int event, void *anything);
+
+/* ================================================== */
+
+static void
+close_socket(void)
+{
+  SCH_RemoveFileHandler(sock_fd);
+  close(sock_fd);
+  sock_fd = INVALID_SOCK_FD;
+
+  /* Empty the queue */
+  queue_head = queue_tail = 0;
+}
+
+/* ================================================== */
+
+static int
+open_socket(void)
+{
+  struct sockaddr_un s;
+
+  if (sock_fd >= 0)
+    return 1;
+
+  sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
+  if (sock_fd < 0) {
+    DEBUG_LOG("Could not open signd socket : %s", strerror(errno));
+    return 0;
+  }
+
+  UTI_FdSetCloexec(sock_fd);
+  SCH_AddFileHandler(sock_fd, SCH_FILE_INPUT, read_write_socket, NULL);
+
+  s.sun_family = AF_UNIX;
+  if (snprintf(s.sun_path, sizeof (s.sun_path), "%s/socket",
+               CNF_GetNtpSigndSocket()) >= sizeof (s.sun_path)) {
+    DEBUG_LOG("signd socket path too long");
+    close_socket();
+    return 0;
+  }
+
+  if (connect(sock_fd, (struct sockaddr *)&s, sizeof (s)) < 0) {
+    DEBUG_LOG("Could not connect to signd : %s", strerror(errno));
+    close_socket();
+    return 0;
+  }
+
+  DEBUG_LOG("Connected to signd");
+
+  return 1;
+}
+
+/* ================================================== */
+
+static void
+process_response(SignInstance *inst)
+{
+  struct timespec ts;
+  double delay;
+
+  if (ntohs(inst->request.packet_id) != ntohl(inst->response.packet_id)) {
+    DEBUG_LOG("Invalid response ID");
+    return;
+  }
+
+  if (ntohl(inst->response.op) != SIGNING_SUCCESS) {
+    DEBUG_LOG("Signing failed");
+    return;
+  }
+
+  /* Check if the file descriptor is still valid */
+  if (!NIO_IsServerSocket(inst->local_addr.sock_fd)) {
+    DEBUG_LOG("Invalid NTP socket");
+    return;
+  }
+
+  SCH_GetLastEventTime(NULL, NULL, &ts);
+  delay = UTI_DiffTimespecsToDouble(&ts, &inst->request_ts);
+
+  DEBUG_LOG("Signing succeeded (delay %f)", delay);
+
+  /* Send the signed NTP packet */
+  NIO_SendPacket(&inst->response.signed_packet, &inst->remote_addr, &inst->local_addr,
+                 ntohl(inst->response.length) + sizeof (inst->response.length) -
+                 offsetof(SigndResponse, signed_packet), 0);
+
+  /* Update exponential moving average of the authentication delay */
+  delay = CLAMP(MIN_AUTH_DELAY, delay, MAX_AUTH_DELAY);
+  auth_delay += 0.1 * (delay - auth_delay);
+}
+
+/* ================================================== */
+
+static void
+read_write_socket(int sock_fd, int event, void *anything)
+{
+  SignInstance *inst;
+  uint32_t response_length;
+  int s;
+
+  inst = ARR_GetElement(queue, queue_head);
+
+  if (event == SCH_FILE_OUTPUT) {
+    assert(!IS_QUEUE_EMPTY());
+    assert(inst->sent < inst->request_length);
+
+    if (!inst->sent)
+      SCH_GetLastEventTime(NULL, NULL, &inst->request_ts);
+
+    s = send(sock_fd, (char *)&inst->request + inst->sent,
+             inst->request_length - inst->sent, 0);
+
+    if (s < 0) {
+      DEBUG_LOG("signd socket error: %s", strerror(errno));
+      close_socket();
+      return;
+    }
+
+    DEBUG_LOG("Sent %d bytes to signd", s);
+    inst->sent += s;
+
+    /* Try again later if the request is not complete yet */
+    if (inst->sent < inst->request_length)
+      return;
+
+    /* Disable output and wait for a response */
+    SCH_SetFileHandlerEvents(sock_fd, SCH_FILE_INPUT);
+  }
+
+  if (event == SCH_FILE_INPUT) {
+    if (IS_QUEUE_EMPTY()) {
+        DEBUG_LOG("Unexpected signd response");
+        close_socket();
+        return;
+    }
+
+    assert(inst->received < sizeof (inst->response));
+    s = recv(sock_fd, (char *)&inst->response + inst->received,
+             sizeof (inst->response) - inst->received, 0);
+
+    if (s <= 0) {
+      if (s < 0)
+        DEBUG_LOG("signd socket error: %s", strerror(errno));
+      else
+        DEBUG_LOG("signd socket closed");
+
+      close_socket();
+      return;
+    }
+
+    DEBUG_LOG("Received %d bytes from signd", s);
+    inst->received += s;
+
+    if (inst->received < sizeof (inst->response.length))
+      return;
+
+    response_length = ntohl(inst->response.length) + sizeof (inst->response.length);
+
+    if (response_length < offsetof(SigndResponse, signed_packet) ||
+        response_length > sizeof (SigndResponse)) {
+      DEBUG_LOG("Invalid response length");
+      close_socket();
+      return;
+    }
+
+    /* Wait for more data if not complete yet */
+    if (inst->received < response_length)
+      return;
+
+    process_response(inst);
+
+    /* Move the head and enable output for the next packet */
+    queue_head = NEXT_QUEUE_INDEX(queue_head);
+    if (!IS_QUEUE_EMPTY())
+      SCH_SetFileHandlerEvents(sock_fd, SCH_FILE_INPUT | SCH_FILE_OUTPUT);
+  }
+}
+
+/* ================================================== */
+
+void
+NSD_Initialise()
+{
+  sock_fd = INVALID_SOCK_FD;
+  auth_delay = MIN_AUTH_DELAY;
+  enabled = CNF_GetNtpSigndSocket() && CNF_GetNtpSigndSocket()[0];
+
+  if (!enabled)
+    return;
+
+  queue = ARR_CreateInstance(sizeof (SignInstance));
+  ARR_SetSize(queue, MAX_QUEUE_LENGTH);
+  queue_head = queue_tail = 0;
+
+  LOG(LOGS_INFO, "MS-SNTP authentication enabled");
+}
+
+/* ================================================== */
+
+void
+NSD_Finalise()
+{
+  if (!enabled)
+    return;
+  if (sock_fd != INVALID_SOCK_FD)
+    close_socket();
+  ARR_DestroyInstance(queue);
+}
+
+/* ================================================== */
+
+extern int NSD_GetAuthDelay(uint32_t key_id)
+{
+  return 1.0e9 * auth_delay;
+}
+
+/* ================================================== */
+
+int
+NSD_SignAndSendPacket(uint32_t key_id, NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
+{
+  SignInstance *inst;
+
+  if (!enabled) {
+    DEBUG_LOG("signd disabled");
+    return 0;
+  }
+
+  if (queue_head == NEXT_QUEUE_INDEX(queue_tail)) {
+    DEBUG_LOG("signd queue full");
+    return 0;
+  }
+
+  if (length != NTP_NORMAL_PACKET_LENGTH) {
+    DEBUG_LOG("Invalid packet length");
+    return 0;
+  }
+
+  if (!open_socket())
+    return 0;
+
+  inst = ARR_GetElement(queue, queue_tail);
+  inst->remote_addr = *remote_addr;
+  inst->local_addr = *local_addr;
+  inst->sent = 0;
+  inst->received = 0;
+  inst->request_length = offsetof(SigndRequest, packet_to_sign) + length;
+
+  /* The length field doesn't include itself */
+  inst->request.length = htonl(inst->request_length - sizeof (inst->request.length));
+  inst->request.version = htonl(SIGND_VERSION);
+  inst->request.op = htonl(SIGN_TO_CLIENT);
+  inst->request.packet_id = htons(queue_tail);
+  inst->request._pad = 0;
+  inst->request.key_id = htonl(key_id);
+
+  memcpy(&inst->request.packet_to_sign, packet, length);
+
+  /* Enable output if there was no pending request */
+  if (IS_QUEUE_EMPTY())
+    SCH_SetFileHandlerEvents(sock_fd, SCH_FILE_INPUT | SCH_FILE_OUTPUT);
+
+  queue_tail = NEXT_QUEUE_INDEX(queue_tail);
+
+  DEBUG_LOG("Packet added to signd queue (%u:%u)", queue_head, queue_tail);
+
+  return 1;
+}
--- a/ntp_signd.h
+++ b/ntp_signd.h
@@ -0,0 +1,44 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Header for MS-SNTP authentication via Samba (ntp_signd) */
+
+#ifndef GOT_NTP_SIGND_H
+#define GOT_NTP_SIGND_H
+
+#include "addressing.h"
+#include "ntp.h"
+
+/* Initialisation function */
+extern void NSD_Initialise(void);
+
+/* Finalisation function */
+extern void NSD_Finalise(void);
+
+/* Function to get an estimate of delay due to signing */
+extern int NSD_GetAuthDelay(uint32_t key_id);
+
+/* Function to sign an NTP packet and send it */
+extern int NSD_SignAndSendPacket(uint32_t key_id, NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
+
+#endif
--- a/ntp_sources.c
+++ b/ntp_sources.c
@@ -39,6 +39,7 @@
 #include "local.h"
 #include "memory.h"
 #include "nameserv_async.h"
+#include "privops.h"
 #include "sched.h"

 /* ================================================== */
@@ -117,8 +118,8 @@ static void rehash_records(void);
 static void clean_source_record(SourceRecord *record);

 static void
-slew_sources(struct timeval *raw,
-             struct timeval *cooked,
+slew_sources(struct timespec *raw,
+             struct timespec *cooked,
             double dfreq,
             double doffset,
             LCL_ChangeType change_type,
@@ -354,7 +355,7 @@ replace_source(NTP_Remote_Address *old_addr, NTP_Remote_Address *new_addr)
  /* The hash table must be rebuilt for the new address */
  rehash_records();

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

@@ -377,7 +378,7 @@ process_resolved_name(struct UnresolvedSource *us, IPAddr *ip_addrs, int n_addrs
    address.ip_addr = ip_addrs[((unsigned int)i + first) % n_addrs];
    address.port = us->port;

-    DEBUG_LOG(LOGF_NtpSources, "(%d) %s", i + 1, UTI_IPToString(&address.ip_addr));
+    DEBUG_LOG("(%d) %s", i + 1, UTI_IPToString(&address.ip_addr));

    if (us->replacement) {
      if (replace_source(&us->replace_source, &address) != NSR_AlreadyInUse)
@@ -404,7 +405,7 @@ name_resolve_handler(DNS_Status status, int n_addrs, IPAddr *ip_addrs, void *any

  assert(us == resolving_source);

-  DEBUG_LOG(LOGF_NtpSources, "%s resolved to %d addrs", us->name, n_addrs);
+  DEBUG_LOG("%s resolved to %d addrs", us->name, n_addrs);

  switch (status) {
    case DNS_TryAgain:
@@ -413,7 +414,7 @@ name_resolve_handler(DNS_Status status, int n_addrs, IPAddr *ip_addrs, void *any
      process_resolved_name(us, ip_addrs, n_addrs);
      break;
    case DNS_Failure:
-      LOG(LOGS_WARN, LOGF_NtpSources, "Invalid host %s", us->name);
+      LOG(LOGS_WARN, "Invalid host %s", us->name);
      break;
    default:
      assert(0);
@@ -438,7 +439,7 @@ name_resolve_handler(DNS_Status status, int n_addrs, IPAddr *ip_addrs, void *any

  if (next) {
    /* Continue with the next source in the list */
-    DEBUG_LOG(LOGF_NtpSources, "resolving %s", next->name);
+    DEBUG_LOG("resolving %s", next->name);
    DNS_Name2IPAddressAsync(next->name, name_resolve_handler, next);
  } else {
    /* This was the last source in the list. If some sources couldn't
@@ -469,14 +470,14 @@ resolve_sources(void *arg)

  assert(!resolving_source);

-  DNS_Reload();
+  PRV_ReloadDNS();

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

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

@@ -657,8 +658,7 @@ resolve_source_replacement(SourceRecord *record)
 {
  struct UnresolvedSource *us;

-  DEBUG_LOG(LOGF_NtpSources, "trying to replace %s",
-            UTI_IPToString(&record->remote_addr->ip_addr));
+  DEBUG_LOG("trying to replace %s", UTI_IPToString(&record->remote_addr->ip_addr));

  us = MallocNew(struct UnresolvedSource);
  us->name = Strdup(record->name);
@@ -680,8 +680,8 @@ resolve_source_replacement(SourceRecord *record)
 void
 NSR_HandleBadSource(IPAddr *address)
 {
-  static struct timeval last_replacement;
-  struct timeval now;
+  static struct timespec last_replacement;
+  struct timespec now;
  NTP_Remote_Address remote_addr;
  SourceRecord *record;
  int slot, found;
@@ -702,9 +702,9 @@ NSR_HandleBadSource(IPAddr *address)

  /* Don't resolve names too frequently */
  SCH_GetLastEventTime(NULL, NULL, &now);
-  UTI_DiffTimevalsToDouble(&diff, &now, &last_replacement);
+  diff = UTI_DiffTimespecsToDouble(&now, &last_replacement);
  if (fabs(diff) < RESOLVE_INTERVAL_UNIT * (1 << MIN_REPLACEMENT_INTERVAL)) {
-    DEBUG_LOG(LOGF_NtpSources, "replacement postponed");
+    DEBUG_LOG("replacement postponed");
    return;
  }
  last_replacement = now;
@@ -742,7 +742,7 @@ static void remove_tentative_pool_sources(int pool)
    if (!record->remote_addr || record->pool != pool || !record->tentative)
      continue;

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

    clean_source_record(record);
@@ -776,7 +776,8 @@ NSR_GetLocalRefid(IPAddr *address)
 /* This routine is called by ntp_io when a new packet arrives off the network,
   possibly with an authentication tail */
 void
-NSR_ProcessReceive(NTP_Packet *message, struct timeval *now, double now_err, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
+NSR_ProcessRx(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+              NTP_Local_Timestamp *rx_ts, NTP_Packet *message, int length)
 {
  SourceRecord *record;
  struct SourcePool *pool;
@@ -788,19 +789,18 @@ NSR_ProcessReceive(NTP_Packet *message, struct timeval *now, double now_err, NTP
  if (found == 2) { /* Must match IP address AND port number */
    record = get_record(slot);

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

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

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

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

        /* If the number of sources from the pool reached the configured
           maximum, remove the remaining tentative sources */
@@ -809,15 +809,34 @@ NSR_ProcessReceive(NTP_Packet *message, struct timeval *now, double now_err, NTP
      }
    }
  } else {
-    NCR_ProcessUnknown(message, now, now_err, remote_addr, local_addr, length);
+    NCR_ProcessRxUnknown(remote_addr, local_addr, rx_ts, message, length);
+  }
+}
+
+/* ================================================== */
+
+void
+NSR_ProcessTx(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+              NTP_Local_Timestamp *tx_ts, NTP_Packet *message, int length)
+{
+  SourceRecord *record;
+  int slot, found;
+
+  find_slot(remote_addr, &slot, &found);
+
+  if (found == 2) { /* Must match IP address AND port number */
+    record = get_record(slot);
+    NCR_ProcessTxKnown(record->data, local_addr, tx_ts, message, length);
+  } else {
+    NCR_ProcessTxUnknown(remote_addr, local_addr, tx_ts, message, length);
  }
 }

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

 static void
-slew_sources(struct timeval *raw,
-             struct timeval *cooked,
+slew_sources(struct timespec *raw,
+             struct timespec *cooked,
             double dfreq,
             double doffset,
             LCL_ChangeType change_type,
@@ -831,6 +850,7 @@ slew_sources(struct timeval *raw,
    if (record->remote_addr) {
      if (change_type == LCL_ChangeUnknownStep) {
        NCR_ResetInstance(record->data);
+        NCR_ResetPoll(record->data);
      } else {
        NCR_SlewTimes(record->data, cooked, dfreq, doffset);
      }
@@ -1083,7 +1103,7 @@ NSR_InitiateSampleBurst(int n_good_samples, int n_total_samples,
   identify the source record. */

 void
-NSR_ReportSource(RPT_SourceReport *report, struct timeval *now)
+NSR_ReportSource(RPT_SourceReport *report, struct timespec *now)
 {
  NTP_Remote_Address rem_addr;
  int slot, found;
@@ -1099,6 +1119,26 @@ NSR_ReportSource(RPT_SourceReport *report, struct timeval *now)
  }
 }

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

 void
--- a/ntp_sources.h
+++ b/ntp_sources.h
@@ -87,7 +87,13 @@ extern void NSR_RefreshAddresses(void);
 extern uint32_t NSR_GetLocalRefid(IPAddr *address);

 /* This routine is called by ntp_io when a new packet arrives off the network */
-extern void NSR_ProcessReceive(NTP_Packet *message, struct timeval *now, double now_err, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
+extern void NSR_ProcessRx(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+                          NTP_Local_Timestamp *rx_ts, NTP_Packet *message, int length);
+
+/* This routine is called by ntp_io when a packet was sent to the network and
+   an accurate transmit timestamp was captured */
+extern void NSR_ProcessTx(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
+                          NTP_Local_Timestamp *tx_ts, NTP_Packet *message, int length);

 /* Initialisation function */
 extern void NSR_Initialise(void);
@@ -121,7 +127,9 @@ extern int NSR_ModifyPolltarget(IPAddr *address, int new_poll_target);

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

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

 extern void NSR_GetActivityReport(RPT_ActivityReport *report);

--- a/pktlength.c
+++ b/pktlength.c
@@ -82,8 +82,8 @@ static const struct request_length request_lengths[] = {
  REQ_LENGTH_ENTRY(allow_deny, null),           /* CMDDENYALL */
  REQ_LENGTH_ENTRY(ac_check, null),             /* ACCHECK */
  REQ_LENGTH_ENTRY(ac_check, null),             /* CMDACCHECK */
-  REQ_LENGTH_ENTRY(ntp_source, null),           /* ADD_SERVER */
-  REQ_LENGTH_ENTRY(ntp_source, null),           /* ADD_PEER */
+  { 0, 0 },                                     /* ADD_SERVER */
+  { 0, 0 },                                     /* ADD_PEER */
  REQ_LENGTH_ENTRY(del_source, null),           /* DEL_SOURCE */
  REQ_LENGTH_ENTRY(null, null),                 /* WRITERTC */
  REQ_LENGTH_ENTRY(dfreq, null),                /* DFREQ */
@@ -113,6 +113,9 @@ static const struct request_length request_lengths[] = {
  REQ_LENGTH_ENTRY(client_accesses_by_index,
                   client_accesses_by_index),   /* CLIENT_ACCESSES_BY_INDEX2 */
  REQ_LENGTH_ENTRY(local, null),                /* LOCAL2 */
+  REQ_LENGTH_ENTRY(ntp_data, ntp_data),         /* NTP_DATA */
+  REQ_LENGTH_ENTRY(ntp_source, null),           /* ADD_SERVER2 */
+  REQ_LENGTH_ENTRY(ntp_source, null),           /* ADD_PEER2 */
 };

 static const uint16_t reply_lengths[] = {
@@ -120,7 +123,7 @@ static const uint16_t reply_lengths[] = {
  RPY_LENGTH_ENTRY(null),                       /* NULL */
  RPY_LENGTH_ENTRY(n_sources),                  /* N_SOURCES */
  RPY_LENGTH_ENTRY(source_data),                /* SOURCE_DATA */
-  RPY_LENGTH_ENTRY(manual_timestamp),           /* MANUAL_TIMESTAMP */
+  0,                                            /* MANUAL_TIMESTAMP */
  RPY_LENGTH_ENTRY(tracking),                   /* TRACKING */
  RPY_LENGTH_ENTRY(sourcestats),                /* SOURCESTATS */
  RPY_LENGTH_ENTRY(rtc),                        /* RTC */
@@ -132,6 +135,8 @@ static const uint16_t reply_lengths[] = {
  RPY_LENGTH_ENTRY(smoothing),                  /* SMOOTHING */
  RPY_LENGTH_ENTRY(server_stats),               /* SERVER_STATS */
  RPY_LENGTH_ENTRY(client_accesses_by_index),   /* CLIENT_ACCESSES_BY_INDEX2 */
+  RPY_LENGTH_ENTRY(ntp_data),                   /* NTP_DATA */
+  RPY_LENGTH_ENTRY(manual_timestamp),           /* MANUAL_TIMESTAMP2 */
 };

 /* ================================================== */
--- a/privops.c
+++ b/privops.c
@@ -40,6 +40,7 @@
 #define OP_SETTIME        1026
 #define OP_BINDSOCKET     1027
 #define OP_NAME2IPADDRESS 1028
+#define OP_RELOADDNS      1029
 #define OP_QUIT           1099

 union sockaddr_in46 {
@@ -293,8 +294,6 @@ do_name_to_ipaddress(ReqName2IPAddress *req, PrvResponse *res)
  /* make sure the string is terminated */
  req->name[sizeof (req->name) - 1] = '\0';

-  DNS_Reload();
-
  res->rc = DNS_Name2IPAddress(req->name, res->data.name_to_ipaddress.addresses,
                               DNS_MAX_ADDRESSES);
 }
@@ -302,6 +301,19 @@ do_name_to_ipaddress(ReqName2IPAddress *req, PrvResponse *res)

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

+/* HELPER - perform DNS_Reload() */
+
+#ifdef PRIVOPS_RELOADDNS
+static void
+do_reload_dns(PrvResponse *res)
+{
+  DNS_Reload();
+  res->rc = 0;
+}
+#endif
+
+/* ======================================================================= */
+
 /* HELPER - main loop - action requests from the daemon */

 static void
@@ -343,6 +355,11 @@ helper_main(int fd)
      case OP_NAME2IPADDRESS:
        do_name_to_ipaddress(&req.data.name_to_ipaddress, &res);
        break;
+#endif
+#ifdef PRIVOPS_RELOADDNS
+      case OP_RELOADDNS:
+        do_reload_dns(&res);
+        break;
 #endif
      case OP_QUIT:
        quit = 1;
@@ -371,14 +388,14 @@ receive_response(PrvResponse *res)

  resp_len = recv(helper_fd, res, sizeof (*res), 0);
  if (resp_len < 0)
-    LOG_FATAL(LOGF_PrivOps, "Could not read from helper : %s", strerror(errno));
+    LOG_FATAL("Could not read from helper : %s", strerror(errno));
  if (resp_len != sizeof (*res))
-    LOG_FATAL(LOGF_PrivOps, "Invalid helper response");
+    LOG_FATAL("Invalid helper response");

  if (res->fatal_error)
-    LOG_FATAL(LOGF_PrivOps, "Error in helper : %s", res->data.fatal_msg.msg);
+    LOG_FATAL("Error in helper : %s", res->data.fatal_msg.msg);

-  DEBUG_LOG(LOGF_PrivOps, "Received response rc=%d", res->rc);
+  DEBUG_LOG("Received response rc=%d", res->rc);

  /* if operation failed in the helper, set errno so daemon can print log message */
  if (res->res_errno)
@@ -429,10 +446,10 @@ send_request(PrvRequest *req)
  if (sendmsg(helper_fd, &msg, 0) < 0) {
    /* don't try to send another request from exit() */
    helper_fd = -1;
-    LOG_FATAL(LOGF_PrivOps, "Could not send to helper : %s", strerror(errno));
+    LOG_FATAL("Could not send to helper : %s", strerror(errno));
  }

-  DEBUG_LOG(LOGF_PrivOps, "Sent request op=%d", req->op);
+  DEBUG_LOG("Sent request op=%d", req->op);
 }

 /* ======================================================================= */
@@ -598,7 +615,7 @@ PRV_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs)
  req.op = OP_NAME2IPADDRESS;
  if (snprintf(req.data.name_to_ipaddress.name, sizeof (req.data.name_to_ipaddress.name),
               "%s", name) >= sizeof (req.data.name_to_ipaddress.name)) {
-    DEBUG_LOG(LOGF_PrivOps, "Name too long");
+    DEBUG_LOG("Name too long");
    return DNS_Failure;
  }

@@ -613,6 +630,30 @@ PRV_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs)

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

+/* DAEMON - request res_init() */
+
+#ifdef PRIVOPS_RELOADDNS
+void
+PRV_ReloadDNS(void)
+{
+  PrvRequest req;
+  PrvResponse res;
+
+  if (!have_helper()) {
+    DNS_Reload();
+    return;
+  }
+
+  memset(&req, 0, sizeof (req));
+  req.op = OP_RELOADDNS;
+
+  submit_request(&req, &res);
+  assert(!res.rc);
+}
+#endif
+
+/* ======================================================================= */
+
 void
 PRV_Initialise(void)
 {
@@ -631,21 +672,21 @@ PRV_StartHelper(void)
  int fd, sock_pair[2];

  if (have_helper())
-    LOG_FATAL(LOGF_PrivOps, "Helper already running");
+    LOG_FATAL("Helper already running");

  if (
 #ifdef SOCK_SEQPACKET
      socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sock_pair) &&
 #endif
      socketpair(AF_UNIX, SOCK_DGRAM, 0, sock_pair))
-    LOG_FATAL(LOGF_PrivOps, "socketpair() failed : %s", strerror(errno));
+    LOG_FATAL("socketpair() failed : %s", strerror(errno));

  UTI_FdSetCloexec(sock_pair[0]);
  UTI_FdSetCloexec(sock_pair[1]);

  pid = fork();
  if (pid < 0)
-    LOG_FATAL(LOGF_PrivOps, "fork() failed : %s", strerror(errno));
+    LOG_FATAL("fork() failed : %s", strerror(errno));

  if (pid == 0) {
    /* child process */
--- a/privops.h
+++ b/privops.h
@@ -58,6 +58,12 @@ int PRV_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs);
 #define PRV_Name2IPAddress DNS_Name2IPAddress
 #endif

+#ifdef PRIVOPS_RELOADDNS
+void PRV_ReloadDNS(void);
+#else
+#define PRV_ReloadDNS DNS_Reload
+#endif
+
 #ifdef PRIVOPS_HELPER
 void PRV_Initialise(void);
 void PRV_StartHelper(void);
--- a/refclock.c
+++ b/refclock.c
@@ -2,7 +2,7 @@
  chronyd/chronyc - Programs for keeping computer clocks accurate.

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

 struct MedianFilter {
@@ -75,14 +75,17 @@ struct RCL_Instance_Record {
  int driver_polled;
  int poll;
  int leap_status;
+  int pps_forced;
  int pps_rate;
  int pps_active;
+  int max_lock_age;
  struct MedianFilter filter;
  uint32_t ref_id;
  uint32_t lock_ref;
  double offset;
  double delay;
  double precision;
+  double pulse_width;
  SCH_TimeoutID timeout_id;
  SRC_Instance source;
 };
@@ -92,24 +95,24 @@ static ARR_Instance refclocks;

 static LOG_FileID logfileid;

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

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

 static RCL_Instance
@@ -163,7 +166,6 @@ RCL_Finalise(void)
 int
 RCL_AddRefclock(RefclockParameters *params)
 {
-  int pps_source = 0;
  RCL_Instance inst;

  inst = MallocNew(struct RCL_Instance_Record);
@@ -171,25 +173,19 @@ RCL_AddRefclock(RefclockParameters *params)

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

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

@@ -200,13 +196,16 @@ RCL_AddRefclock(RefclockParameters *params)
  inst->poll = params->poll;
  inst->driver_polled = 0;
  inst->leap_status = LEAP_Normal;
+  inst->pps_forced = params->pps_forced;
  inst->pps_rate = params->pps_rate;
  inst->pps_active = 0;
+  inst->max_lock_age = params->max_lock_age;
  inst->lock_ref = params->lock_ref_id;
  inst->offset = params->offset;
  inst->delay = params->delay;
-  if (params->precision > 0.0)
-    inst->precision = params->precision;
+  inst->precision = LCL_GetSysPrecisionAsQuantum();
+  inst->precision = MAX(inst->precision, params->precision);
+  inst->pulse_width = params->pulse_width;
  inst->timeout_id = -1;
  inst->source = NULL;

@@ -219,12 +218,8 @@ RCL_AddRefclock(RefclockParameters *params)
        inst->driver_parameter[i] = '\0';
  }

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

  if (params->ref_id)
    inst->ref_id = params->ref_id;
@@ -249,7 +244,7 @@ RCL_AddRefclock(RefclockParameters *params)
    max_samples = 1 << (inst->poll - inst->driver_poll);
    if (max_samples < params->filter_length) {
      if (max_samples < 4) {
-        LOG(LOGS_WARN, LOGF_Refclock, "Setting filter length for %s to %d",
+        LOG(LOGS_WARN, "Setting filter length for %s to %d",
            UTI_RefidToString(inst->ref_id), max_samples);
      }
      params->filter_length = max_samples;
@@ -258,7 +253,7 @@ RCL_AddRefclock(RefclockParameters *params)

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

@@ -267,7 +262,7 @@ RCL_AddRefclock(RefclockParameters *params)
  inst->source = SRC_CreateNewInstance(inst->ref_id, SRC_REFCLOCK, params->sel_options, NULL,
                                       params->min_samples, params->max_samples);

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

@@ -300,7 +295,7 @@ RCL_StartRefclocks(void)
 }

 void
-RCL_ReportSource(RPT_SourceReport *report, struct timeval *now)
+RCL_ReportSource(RPT_SourceReport *report, struct timespec *now)
 {
  unsigned int i;
  uint32_t ref_id;
@@ -362,18 +357,21 @@ RCL_GetDriverOption(RCL_Instance instance, char *name)
 }

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

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

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

  switch (leap) {
@@ -383,7 +381,7 @@ RCL_AddSample(RCL_Instance instance, struct timeval *sample_time, double offset,
      instance->leap_status = leap;
      break;
    default:
-      DEBUG_LOG(LOGF_Refclock, "refclock sample ignored bad leap %d", leap);
+      DEBUG_LOG("refclock sample ignored bad leap %d", leap);
      return 0;
  }

@@ -400,26 +398,59 @@ RCL_AddSample(RCL_Instance instance, struct timeval *sample_time, double offset,
 }

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

-  leap = LEAP_Normal;
-  LCL_GetOffsetCorrection(pulse_time, &correction, &dispersion);
-  UTI_AddDoubleToTimeval(pulse_time, correction, &cooked_time);
-  dispersion += instance->precision;
-
-  if (!UTI_IsTimeOffsetSane(pulse_time, 0.0) ||
-      !valid_sample_time(instance, pulse_time, &cooked_time))
+  if (!UTI_IsTimeOffsetSane(cooked_time, second) ||
+      !valid_sample_time(instance, cooked_time))
    return 0;

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

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

  /* Adjust the offset to [-0.5/rate, 0.5/rate) interval */
  offset -= (long)(offset * rate) / (double)rate;
@@ -430,22 +461,22 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)

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

    lock_refclock = get_refclock(instance->lock_ref);

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

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

-    UTI_DiffTimevalsToDouble(&sample_diff, &cooked_time, &ref_sample_time);
-    if (fabs(sample_diff) >= 2.0 / rate) {
-      DEBUG_LOG(LOGF_Refclock, "refclock pulse ignored samplediff=%.9f",
+    sample_diff = UTI_DiffTimespecsToDouble(cooked_time, &ref_sample_time);
+    if (fabs(sample_diff) >= (double)instance->max_lock_age / rate) {
+      DEBUG_LOG("refclock pulse ignored samplediff=%.9f",
          sample_diff);
      return 0;
    }
@@ -459,17 +490,20 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
    offset += shift;

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

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

-    DEBUG_LOG(LOGF_Refclock, "refclock pulse second=%.9f offset=%.9f offdiff=%.9f samplediff=%.9f",
-        second, offset, ref_offset - offset, sample_diff);
+    DEBUG_LOG("refclock pulse offset=%.9f offdiff=%.9f samplediff=%.9f",
+              offset, ref_offset - offset, sample_diff);
  } else {
-    struct timeval ref_time;
+    struct timespec ref_time;
    int is_synchronised, stratum;
    double root_delay, root_dispersion, distance;
    uint32_t ref_id;
@@ -477,24 +511,28 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
    /* Ignore the pulse if we are not well synchronized and the local
       reference is not active */

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

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

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

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

  /* for logging purposes */
  if (!instance->driver->poll)
@@ -503,23 +541,35 @@ RCL_AddPulse(RCL_Instance instance, struct timeval *pulse_time, double second)
  return 1;
 }

-static int
-valid_sample_time(RCL_Instance instance, struct timeval *raw, struct timeval *cooked)
+double
+RCL_GetPrecision(RCL_Instance instance)
 {
-  struct timeval raw_time, last_sample_time;
+  return instance->precision;
+}
+
+int
+RCL_GetDriverPoll(RCL_Instance instance)
+{
+  return instance->driver_poll;
+}
+
+static int
+valid_sample_time(RCL_Instance instance, struct timespec *sample_time)
+{
+  struct timespec now, last_sample_time;
  double diff, last_offset, last_dispersion;

-  LCL_ReadRawTime(&raw_time);
-  UTI_DiffTimevalsToDouble(&diff, &raw_time, raw);
+  LCL_ReadCookedTime(&now, NULL);
+  diff = UTI_DiffTimespecsToDouble(&now, sample_time);

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

@@ -527,9 +577,9 @@ valid_sample_time(RCL_Instance instance, struct timeval *raw, struct timeval *co
 }

 static int
-pps_stratum(RCL_Instance instance, struct timeval *tv)
+pps_stratum(RCL_Instance instance, struct timespec *ts)
 {
-  struct timeval ref_time;
+  struct timespec ref_time;
  int is_synchronised, stratum;
  unsigned int i;
  double root_delay, root_dispersion;
@@ -537,7 +587,7 @@ pps_stratum(RCL_Instance instance, struct timeval *tv)
  uint32_t ref_id;
  RCL_Instance refclock;

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

  /* Don't change our stratum if the local reference is active
@@ -574,7 +624,7 @@ poll_timeout(void *arg)
  
  if (!(inst->driver->poll && inst->driver_polled < (1 << (inst->poll - inst->driver_poll)))) {
    double offset, dispersion;
-    struct timeval sample_time;
+    struct timespec sample_time;
    int sample_ok, stratum;

    sample_ok = filter_get_sample(&inst->filter, &sample_time, &offset, &dispersion);
@@ -602,7 +652,7 @@ poll_timeout(void *arg)
 }

 static void
-slew_samples(struct timeval *raw, struct timeval *cooked, double dfreq,
+slew_samples(struct timespec *raw, struct timespec *cooked, double dfreq,
             double doffset, LCL_ChangeType change_type, void *anything)
 {
  unsigned int i;
@@ -625,7 +675,7 @@ add_dispersion(double dispersion, void *anything)
 }

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

@@ -635,7 +685,7 @@ log_sample(RCL_Instance instance, struct timeval *sample_time, int filtered, int
  if (!filtered) {
    LOG_FileWrite(logfileid, "%s.%06d %-5s %3d %1c %1d %13.6e %13.6e %10.3e",
      UTI_TimeToLogForm(sample_time->tv_sec),
-      (int)sample_time->tv_usec,
+      (int)sample_time->tv_nsec / 1000,
      UTI_RefidToString(instance->ref_id),
      instance->driver_polled,
      sync_stats[instance->leap_status],
@@ -646,7 +696,7 @@ log_sample(RCL_Instance instance, struct timeval *sample_time, int filtered, int
  } else {
    LOG_FileWrite(logfileid, "%s.%06d %-5s   - %1c -       -       %13.6e %10.3e",
      UTI_TimeToLogForm(sample_time->tv_sec),
-      (int)sample_time->tv_usec,
+      (int)sample_time->tv_nsec / 1000,
      UTI_RefidToString(instance->ref_id),
      sync_stats[instance->leap_status],
      cooked_offset,
@@ -699,7 +749,7 @@ filter_get_avg_sample_dispersion(struct MedianFilter *filter)
 }

 static void
-filter_add_sample(struct MedianFilter *filter, struct timeval *sample_time, double offset, double dispersion)
+filter_add_sample(struct MedianFilter *filter, struct timespec *sample_time, double offset, double dispersion)
 {
  filter->index++;
  filter->index %= filter->length;
@@ -711,12 +761,12 @@ filter_add_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
  filter->samples[filter->index].offset = offset;
  filter->samples[filter->index].dispersion = dispersion;

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

 static int
-filter_get_last_sample(struct MedianFilter *filter, struct timeval *sample_time, double *offset, double *dispersion)
+filter_get_last_sample(struct MedianFilter *filter, struct timespec *sample_time, double *offset, double *dispersion)
 {
  if (filter->last < 0)
    return 0;
@@ -835,7 +885,7 @@ filter_select_samples(struct MedianFilter *filter)
 }

 static int
-filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, double *offset, double *dispersion)
+filter_get_sample(struct MedianFilter *filter, struct timespec *sample_time, double *offset, double *dispersion)
 {
  struct FilterSample *s, *ls;
  int i, n, dof;
@@ -852,7 +902,7 @@ filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
  for (i = 0; i < n; i++) {
    s = &filter->samples[filter->selected[i]];

-    UTI_DiffTimevalsToDouble(&filter->x_data[i], &s->sample_time, &ls->sample_time);
+    filter->x_data[i] = UTI_DiffTimespecsToDouble(&s->sample_time, &ls->sample_time);
    filter->y_data[i] = s->offset;
    filter->w_data[i] = s->dispersion;
  }
@@ -901,7 +951,7 @@ filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, doub

  /* drop the sample if variance is larger than allowed maximum */
  if (filter->max_var > 0.0 && var > filter->max_var) {
-    DEBUG_LOG(LOGF_Refclock, "filter dispersion too large disp=%.9f max=%.9f",
+    DEBUG_LOG("filter dispersion too large disp=%.9f max=%.9f",
        sqrt(var), sqrt(filter->max_var));
    return 0;
  }
@@ -927,7 +977,7 @@ filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
  if (d < e)
    d = e;

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

@@ -937,15 +987,26 @@ filter_get_sample(struct MedianFilter *filter, struct timeval *sample_time, doub
 }

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

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

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

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

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

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

 #include "sysincl.h"

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

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

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

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

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

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

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

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

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

-  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;
+  phc = (struct phc_instance *)RCL_GetDriverData(instance);
+
+  if (!SYS_Linux_GetPHCSample(phc->fd, phc->nocrossts, RCL_GetPrecision(instance),
+                              &phc->mode, &phc_ts, &sys_ts, &phc_err))
+    return 0;
+
+  if (phc->extpps) {
+    LCL_CookTime(&sys_ts, &local_ts, &local_err);
+    HCL_AccumulateSample(phc->clock, &phc_ts, &local_ts, phc_err + local_err);
+    return 0;
  }

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

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

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

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

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

  UTI_FdSetCloexec(fd);

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  shm->valid = 0;

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

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

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

 RefclockDriver RCL_SHM_driver = {
--- a/refclock_sock.c
+++ b/refclock_sock.c
@@ -57,39 +57,42 @@ struct sock_sample {
  int magic;
 };

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

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

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

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

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

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

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

@@ -103,13 +106,13 @@ static int sock_initialise(RCL_Instance instance)
 
  s.sun_family = AF_UNIX;
  if (snprintf(s.sun_path, sizeof (s.sun_path), "%s", path) >= sizeof (s.sun_path)) {
-    LOG_FATAL(LOGF_Refclock, "path %s is too long", path);
+    LOG_FATAL("path %s is too long", path);
    return 0;
  }

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

@@ -117,12 +120,12 @@ static int sock_initialise(RCL_Instance instance)

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

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

@@ -131,7 +134,7 @@ static void sock_finalise(RCL_Instance instance)
  int sockfd;

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

--- a/reference.c
+++ b/reference.c
@@ -49,10 +49,11 @@ static int local_orphan;
 static double local_distance;
 static NTP_Leap our_leap_status;
 static int our_leap_sec;
+static int our_tai_offset;
 static int our_stratum;
 static uint32_t our_ref_id;
 static IPAddr our_ref_ip;
-struct timeval our_ref_time;
+static struct timespec our_ref_time;
 static double our_skew;
 static double our_residual_freq;
 static double our_root_delay;
@@ -111,8 +112,6 @@ static SCH_TimeoutID leap_timeout_id;

 /* Name of a system timezone containing leap seconds occuring at midnight */
 static char *leap_tzname;
-static time_t last_tz_leap_check;
-static NTP_Leap tz_leap;

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

@@ -136,34 +135,33 @@ static int next_fb_drift;
 static SCH_TimeoutID fb_drift_timeout_id;

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

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

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

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

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

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

  if (change_type == LCL_ChangeUnknownStep) {
-    last_ref_update.tv_sec = 0;
-    last_ref_update.tv_usec = 0;
+    UTI_ZeroTimespec(&last_ref_update);
  } else if (last_ref_update.tv_sec) {
-    UTI_AdjustTimeval(&last_ref_update, cooked, &last_ref_update, &delta, dfreq, doffset);
+    UTI_AdjustTimespec(&last_ref_update, cooked, &last_ref_update, &delta, dfreq, doffset);
  }

  /* When the clock was stepped, check if that doesn't change our leap status
@@ -182,11 +180,13 @@ REF_Initialise(void)
  FILE *in;
  double file_freq_ppm, file_skew_ppm;
  double our_frequency_ppm;
+  int tai_offset;

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

@@ -244,11 +244,11 @@ REF_Initialise(void)
  leap_tzname = CNF_GetLeapSecTimezone();
  if (leap_tzname) {
    /* Check that the timezone has good data for Jun 30 2012 and Dec 31 2012 */
-    if (get_tz_leap(1341014400) == LEAP_InsertSecond &&
-        get_tz_leap(1356912000) == LEAP_Normal) {
-      LOG(LOGS_INFO, LOGF_Reference, "Using %s timezone to obtain leap second data", leap_tzname);
+    if (get_tz_leap(1341014400, &tai_offset) == LEAP_InsertSecond && tai_offset == 34 &&
+        get_tz_leap(1356912000, &tai_offset) == LEAP_Normal && tai_offset == 35) {
+      LOG(LOGS_INFO, "Using %s timezone to obtain leap second data", leap_tzname);
    } else {
-      LOG(LOGS_WARN, LOGF_Reference, "Timezone %s failed leap second check, ignoring", leap_tzname);
+      LOG(LOGS_WARN, "Timezone %s failed leap second check, ignoring", leap_tzname);
      leap_tzname = NULL;
    }
  }
@@ -267,8 +267,7 @@ REF_Initialise(void)
    fb_drift_timeout_id = 0;
  }

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

  LCL_AddParameterChangeHandler(handle_slew, NULL);
@@ -366,7 +365,7 @@ update_drift_file(double freq_ppm, double skew)
  out = fopen(temp_drift_file, "w");
  if (!out) {
    Free(temp_drift_file);
-    LOG(LOGS_WARN, LOGF_Reference, "Could not open temporary driftfile %s.tmp for writing",
+    LOG(LOGS_WARN, "Could not open temporary driftfile %s.tmp for writing",
        drift_file);
    return;
  }
@@ -376,7 +375,7 @@ update_drift_file(double freq_ppm, double skew)
  r2 = fclose(out);
  if (r1 < 0 || r2) {
    Free(temp_drift_file);
-    LOG(LOGS_WARN, LOGF_Reference, "Could not write to temporary driftfile %s.tmp",
+    LOG(LOGS_WARN, "Could not write to temporary driftfile %s.tmp",
        drift_file);
    return;
  }
@@ -386,8 +385,7 @@ update_drift_file(double freq_ppm, double skew)
  if (!stat(drift_file,&buf)) {
    if (chown(temp_drift_file,buf.st_uid,buf.st_gid) ||
        chmod(temp_drift_file,buf.st_mode & 0777)) {
-      LOG(LOGS_WARN, LOGF_Reference,
-          "Could not change ownership or permissions of temporary driftfile %s.tmp",
+      LOG(LOGS_WARN, "Could not change ownership or permissions of temporary driftfile %s.tmp",
          drift_file);
    }
  }
@@ -397,7 +395,7 @@ update_drift_file(double freq_ppm, double skew)
  if (rename(temp_drift_file,drift_file)) {
    unlink(temp_drift_file);
    Free(temp_drift_file);
-    LOG(LOGS_WARN, LOGF_Reference, "Could not replace old driftfile %s with new one %s.tmp",
+    LOG(LOGS_WARN, "Could not replace old driftfile %s with new one %s.tmp",
        drift_file,drift_file);
    return;
  }
@@ -445,8 +443,8 @@ update_fb_drifts(double freq_ppm, double update_interval)
        (freq_ppm - fb_drifts[i].freq);
    }

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

@@ -459,7 +457,7 @@ fb_drift_timeout(void *arg)

  fb_drift_timeout_id = 0;

-  DEBUG_LOG(LOGF_Reference, "Fallback drift %d active: %f ppm",
+  DEBUG_LOG("Fallback drift %d active: %f ppm",
            next_fb_drift, fb_drifts[next_fb_drift - fb_drift_min].freq);
  LCL_SetAbsoluteFrequency(fb_drifts[next_fb_drift - fb_drift_min].freq);
  REF_SetUnsynchronised();
@@ -468,16 +466,16 @@ fb_drift_timeout(void *arg)
 /* ================================================== */

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

  if (fb_drift_timeout_id)
    return; /* already scheduled */

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

  for (c = secs = 0, i = fb_drift_min; i <= fb_drift_max; i++) {
    secs = 1 << i;
@@ -494,14 +492,14 @@ schedule_fb_drift(struct timeval *now)
  if (c > next_fb_drift) {
    LCL_SetAbsoluteFrequency(fb_drifts[c - fb_drift_min].freq);
    next_fb_drift = c;
-    DEBUG_LOG(LOGF_Reference, "Fallback drift %d set", c);
+    DEBUG_LOG("Fallback drift %d set", c);
  }

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

@@ -533,8 +531,7 @@ maybe_log_offset(double offset, time_t now)
  abs_offset = fabs(offset);

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

@@ -560,8 +557,7 @@ maybe_log_offset(double offset, time_t now)
              -offset, mail_change_threshold);
      pclose(p);
    } else {
-      LOG(LOGS_ERR, LOGF_Reference,
-          "Could not send mail notification to user %s\n",
+      LOG(LOGS_ERR, "Could not send mail notification to user %s\n",
          mail_change_user);
    }
  }
@@ -596,7 +592,7 @@ is_offset_ok(double offset)

  offset = fabs(offset);
  if (offset > max_offset) {
-    LOG(LOGS_WARN, LOGF_Reference,
+    LOG(LOGS_WARN, 
        "Adjustment of %.3f seconds exceeds the allowed maximum of %.3f seconds (%s) ",
        -offset, max_offset, !max_offset_ignore ? "exiting" : "ignored");
    if (!max_offset_ignore)
@@ -620,12 +616,18 @@ is_leap_second_day(struct tm *stm) {
 /* ================================================== */

 static NTP_Leap
-get_tz_leap(time_t when)
+get_tz_leap(time_t when, int *tai_offset)
 {
+  static time_t last_tz_leap_check;
+  static NTP_Leap tz_leap;
+  static int tz_tai_offset;
+
  struct tm stm;
  time_t t;
  char *tz_env, tz_orig[128];

+  *tai_offset = tz_tai_offset;
+
  /* Do this check at most twice a day */
  when = when / (12 * 3600) * (12 * 3600);
  if (last_tz_leap_check == when)
@@ -633,12 +635,10 @@ get_tz_leap(time_t when)

  last_tz_leap_check = when;
  tz_leap = LEAP_Normal;
+  tz_tai_offset = 0;

  stm = *gmtime(&when);

-  if (!is_leap_second_day(&stm))
-    return tz_leap;
-
  /* Temporarily switch to the timezone containing leap seconds */
  tz_env = getenv("TZ");
  if (tz_env) {
@@ -649,6 +649,11 @@ get_tz_leap(time_t when)
  setenv("TZ", leap_tzname, 1);
  tzset();

+  /* Get the TAI-UTC offset, which started at the epoch at 10 seconds */
+  t = mktime(&stm);
+  if (t != -1)
+    tz_tai_offset = t - when + 10;
+
  /* Set the time to 23:59:60 and see how it overflows in mktime() */
  stm.tm_sec = 60;
  stm.tm_min = 59;
@@ -670,6 +675,8 @@ get_tz_leap(time_t when)
  else if (stm.tm_sec == 1)
    tz_leap = LEAP_DeleteSecond;

+  *tai_offset = tz_tai_offset;
+
  return tz_leap;
 }

@@ -680,10 +687,13 @@ leap_end_timeout(void *arg)
 {
  leap_timeout_id = 0;
  leap_in_progress = 0;
+
+  if (our_tai_offset)
+    our_tai_offset += our_leap_sec;
  our_leap_sec = 0;

  if (leap_mode == REF_LeapModeSystem)
-    LCL_SetSystemLeap(0);
+    LCL_SetSystemLeap(our_leap_sec, our_tai_offset);

  if (our_leap_status == LEAP_InsertSecond ||
      our_leap_status == LEAP_DeleteSecond)
@@ -699,20 +709,20 @@ leap_start_timeout(void *arg)

  switch (leap_mode) {
    case REF_LeapModeSystem:
-      DEBUG_LOG(LOGF_Reference, "Waiting for system clock leap second correction");
+      DEBUG_LOG("Waiting for system clock leap second correction");
      break;
    case REF_LeapModeSlew:
      LCL_NotifyLeap(our_leap_sec);
      LCL_AccumulateOffset(our_leap_sec, 0.0);
-      LOG(LOGS_WARN, LOGF_Reference, "Adjusting system clock for leap second");
+      LOG(LOGS_WARN, "Adjusting system clock for leap second");
      break;
    case REF_LeapModeStep:
      LCL_NotifyLeap(our_leap_sec);
      LCL_ApplyStepOffset(our_leap_sec);
-      LOG(LOGS_WARN, LOGF_Reference, "System clock was stepped for leap second");
+      LOG(LOGS_WARN, "System clock was stepped for leap second");
      break;
    case REF_LeapModeIgnore:
-      LOG(LOGS_WARN, LOGF_Reference, "Ignoring leap second");
+      LOG(LOGS_WARN, "Ignoring leap second");
      break;
    default:
      break;
@@ -727,7 +737,7 @@ leap_start_timeout(void *arg)
 static void
 set_leap_timeout(time_t now)
 {
-  struct timeval when;
+  struct timespec when;

  /* Stop old timer if there is one */
  SCH_RemoveTimeout(leap_timeout_id);
@@ -741,12 +751,12 @@ set_leap_timeout(time_t now)
     will be corrected by the system, timeout slightly sooner to be sure it
     will happen before the system correction. */
  when.tv_sec = (now / (24 * 3600) + 1) * (24 * 3600);
-  when.tv_usec = 0;
+  when.tv_nsec = 0;
  if (our_leap_sec < 0)
    when.tv_sec--;
  if (leap_mode == REF_LeapModeSystem) {
    when.tv_sec--;
-    when.tv_usec = 500000;
+    when.tv_nsec = 500000000;
  }

  leap_timeout_id = SCH_AddTimeout(&when, leap_start_timeout, NULL);
@@ -757,12 +767,17 @@ set_leap_timeout(time_t now)
 static void
 update_leap_status(NTP_Leap leap, time_t now, int reset)
 {
-  int leap_sec;
+  NTP_Leap tz_leap;
+  int leap_sec, tai_offset;

  leap_sec = 0;
+  tai_offset = 0;

-  if (leap_tzname && now && leap == LEAP_Normal)
-    leap = get_tz_leap(now);
+  if (leap_tzname && now) {
+    tz_leap = get_tz_leap(now, &tai_offset);
+    if (leap == LEAP_Normal)
+      leap = tz_leap;
+  }

  if (leap == LEAP_InsertSecond || leap == LEAP_DeleteSecond) {
    /* Check that leap second is allowed today */
@@ -778,12 +793,14 @@ update_leap_status(NTP_Leap leap, time_t now, int reset)
    }
  }
  
-  if (leap_sec != our_leap_sec && !REF_IsLeapSecondClose()) {
+  if ((leap_sec != our_leap_sec || tai_offset != our_tai_offset)
+      && !REF_IsLeapSecondClose()) {
    our_leap_sec = leap_sec;
+    our_tai_offset = tai_offset;

    switch (leap_mode) {
      case REF_LeapModeSystem:
-        LCL_SetSystemLeap(our_leap_sec);
+        LCL_SetSystemLeap(our_leap_sec, our_tai_offset);
        /* Fall through */
      case REF_LeapModeSlew:
      case REF_LeapModeStep:
@@ -804,7 +821,7 @@ update_leap_status(NTP_Leap leap, time_t now, int reset)
 /* ================================================== */

 static void
-write_log(struct timeval *ref_time, char *ref, int stratum, NTP_Leap leap,
+write_log(struct timespec *ref_time, char *ref, int stratum, NTP_Leap leap,
    double freq, double skew, double offset, int combined_sources,
    double offset_sd, double uncorrected_offset)
 {
@@ -827,15 +844,14 @@ special_mode_sync(int valid, double offset)
  switch (mode) {
    case REF_ModeInitStepSlew:
      if (!valid) {
-        LOG(LOGS_WARN, LOGF_Reference, "No suitable source for initstepslew");
+        LOG(LOGS_WARN, "No suitable source for initstepslew");
        end_ref_mode(0);
        break;
      }

      step = fabs(offset) >= CNF_GetInitStepThreshold();

-      LOG(LOGS_INFO, LOGF_Reference,
-          "System's initial offset : %.6f seconds %s of true (%s)",
+      LOG(LOGS_INFO, "System's initial offset : %.6f seconds %s of true (%s)",
          fabs(offset), offset >= 0 ? "fast" : "slow", step ? "step" : "slew");

      if (step)
@@ -849,14 +865,14 @@ special_mode_sync(int valid, double offset)
    case REF_ModeUpdateOnce:
    case REF_ModePrintOnce:
      if (!valid) {
-        LOG(LOGS_WARN, LOGF_Reference, "No suitable source for synchronisation");
+        LOG(LOGS_WARN, "No suitable source for synchronisation");
        end_ref_mode(0);
        break;
      }

      step = mode == REF_ModeUpdateOnce;

-      LOG(LOGS_INFO, LOGF_Reference, "System clock wrong by %.6f seconds (%s)",
+      LOG(LOGS_INFO, "System clock wrong by %.6f seconds (%s)",
          -offset, step ? "step" : "ignored");

      if (step)
@@ -881,7 +897,7 @@ REF_SetReference(int stratum,
                 int combined_sources,
                 uint32_t ref_id,
                 IPAddr *ref_ip,
-                 struct timeval *ref_time,
+                 struct timespec *ref_time,
                 double offset,
                 double offset_sd,
                 double frequency,
@@ -902,7 +918,8 @@ REF_SetReference(int stratum,
  double elapsed;
  double correction_rate;
  double uncorrected_offset, accumulate_offset, step_offset;
-  struct timeval now, raw_now;
+  struct timespec now, raw_now;
+  NTP_int64 ref_fuzz;

  assert(initialised);

@@ -929,16 +946,16 @@ REF_SetReference(int stratum,
    double t;
    t = (skew + skew) / skew; /* Skew shouldn't be zero either */
    if ((t < 1.9) || (t > 2.1)) {
-      LOG(LOGS_WARN, LOGF_Reference, "Bogus skew value encountered");
+      LOG(LOGS_WARN, "Bogus skew value encountered");
      return;
    }
  }
    
  LCL_ReadRawTime(&raw_now);
  LCL_GetOffsetCorrection(&raw_now, &uncorrected_offset, NULL);
-  UTI_AddDoubleToTimeval(&raw_now, uncorrected_offset, &now);
+  UTI_AddDoubleToTimespec(&raw_now, uncorrected_offset, &now);

-  UTI_DiffTimevalsToDouble(&elapsed, &now, ref_time);
+  elapsed = UTI_DiffTimespecsToDouble(&now, ref_time);
  our_offset = offset + elapsed * frequency;

  if (!is_offset_ok(our_offset))
@@ -956,7 +973,7 @@ REF_SetReference(int stratum,
  our_root_dispersion = root_dispersion;

  if (last_ref_update.tv_sec) {
-    UTI_DiffTimevalsToDouble(&update_interval, &now, &last_ref_update);
+    update_interval = UTI_DiffTimespecsToDouble(&now, &last_ref_update);
    if (update_interval < 0.0)
      update_interval = 0.0;
  } else {
@@ -1026,7 +1043,7 @@ REF_SetReference(int stratum,
    LCL_AccumulateFrequencyAndOffset(our_frequency, accumulate_offset, correction_rate);
    
  } else {
-    DEBUG_LOG(LOGF_Reference, "Skew %f too large to track, offset=%f", skew, accumulate_offset);
+    DEBUG_LOG("Skew %f too large to track, offset=%f", skew, accumulate_offset);

    LCL_AccumulateOffset(accumulate_offset, correction_rate);

@@ -1038,11 +1055,20 @@ REF_SetReference(int stratum,

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

  LCL_SetSyncStatus(are_we_synchronised, offset_sd, offset_sd + root_delay / 2.0 + root_dispersion);

+  /* Add a random error of up to one second to the reference time to make it
+     less useful when disclosed to NTP and cmdmon clients for estimating
+     receive timestamps in the interleaved symmetric NTP mode */
+  UTI_GetNtp64Fuzz(&ref_fuzz, 0);
+  UTI_TimespecToNtp64(&our_ref_time, &ref_fuzz, &ref_fuzz);
+  UTI_Ntp64ToTimespec(&ref_fuzz, &our_ref_time);
+  if (UTI_CompareTimespecs(&our_ref_time, ref_time) >= 0)
+    our_ref_time.tv_sec--;
+
  abs_freq_ppm = LCL_ReadAbsoluteFrequency();

  write_log(&now,
@@ -1089,7 +1115,7 @@ REF_SetReference(int stratum,
 void
 REF_SetManualReference
 (
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double offset,
 double frequency,
 double skew
@@ -1108,7 +1134,7 @@ void
 REF_SetUnsynchronised(void)
 {
  /* Variables required for logging to statistics log */
-  struct timeval now, now_raw;
+  struct timespec now, now_raw;
  double uncorrected_offset;

  assert(initialised);
@@ -1121,7 +1147,7 @@ REF_SetUnsynchronised(void)

  LCL_ReadRawTime(&now_raw);
  LCL_GetOffsetCorrection(&now_raw, &uncorrected_offset, NULL);
-  UTI_AddDoubleToTimeval(&now_raw, uncorrected_offset, &now);
+  UTI_AddDoubleToTimespec(&now_raw, uncorrected_offset, &now);

  if (fb_drifts) {
    schedule_fb_drift(&now);
@@ -1149,12 +1175,12 @@ REF_SetUnsynchronised(void)
 void
 REF_GetReferenceParams
 (
- struct timeval *local_time,
+ struct timespec *local_time,
 int *is_synchronised,
 NTP_Leap *leap_status,
 int *stratum,
 uint32_t *ref_id,
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double *root_delay,
 double *root_dispersion
 )
@@ -1164,7 +1190,7 @@ REF_GetReferenceParams
  assert(initialised);

  if (are_we_synchronised) {
-    UTI_DiffTimevalsToDouble(&elapsed, local_time, &our_ref_time);
+    elapsed = UTI_DiffTimespecsToDouble(local_time, &our_ref_time);
    dispersion = our_root_dispersion +
      (our_skew + fabs(our_residual_freq) + LCL_GetMaxClockError()) * elapsed;
  } else {
@@ -1206,7 +1232,7 @@ REF_GetReferenceParams
    *leap_status = LEAP_Normal;
    
    *root_delay = 0.0;
-    *root_dispersion = LCL_GetSysPrecisionAsQuantum();
+    *root_dispersion = 0.0;
    
  } else {

@@ -1215,7 +1241,7 @@ REF_GetReferenceParams
    *leap_status = LEAP_Unsynchronised;
    *stratum = NTP_MAX_STRATUM;
    *ref_id = NTP_REFID_UNSYNC;
-    ref_time->tv_sec = ref_time->tv_usec = 0;
+    UTI_ZeroTimespec(ref_time);
    /* These values seem to be standard for a client, and
       any peer or client of ours will ignore them anyway because
       we don't claim to be synchronised */
@@ -1230,7 +1256,7 @@ REF_GetReferenceParams
 int
 REF_GetOurStratum(void)
 {
-  struct timeval now_cooked, ref_time;
+  struct timespec now_cooked, ref_time;
  int synchronised, stratum;
  NTP_Leap leap_status;
  uint32_t ref_id;
@@ -1303,7 +1329,7 @@ REF_DisableLocal(void)

 int REF_IsLeapSecondClose(void)
 {
-  struct timeval now, now_raw;
+  struct timespec now, now_raw;
  time_t t;

  if (!our_leap_sec)
@@ -1327,20 +1353,20 @@ int REF_IsLeapSecondClose(void)
 void
 REF_GetTrackingReport(RPT_TrackingReport *rep)
 {
-  struct timeval now_raw, now_cooked;
+  struct timespec now_raw, now_cooked;
  double correction;
  int synchronised;

  LCL_ReadRawTime(&now_raw);
  LCL_GetOffsetCorrection(&now_raw, &correction, NULL);
-  UTI_AddDoubleToTimeval(&now_raw, correction, &now_cooked);
+  UTI_AddDoubleToTimespec(&now_raw, correction, &now_cooked);

  REF_GetReferenceParams(&now_cooked, &synchronised,
                         &rep->leap_status, &rep->stratum,
                         &rep->ref_id, &rep->ref_time,
                         &rep->root_delay, &rep->root_dispersion);

-  if (rep->stratum == NTP_MAX_STRATUM)
+  if (rep->stratum == NTP_MAX_STRATUM && !synchronised)
    rep->stratum = 0;

  rep->ip_addr.family = IPADDR_UNSPEC;
--- a/reference.h
+++ b/reference.h
@@ -99,12 +99,12 @@ extern REF_LeapMode REF_GetLeapMode(void);

 extern void REF_GetReferenceParams
 (
- struct timeval *local_time,
+ struct timespec *local_time,
 int *is_synchronised,
 NTP_Leap *leap,
 int *stratum,
 uint32_t *ref_id,
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double *root_delay,
 double *root_dispersion
 );
@@ -140,7 +140,7 @@ extern void REF_SetReference
 int combined_sources,
 uint32_t ref_id,
 IPAddr *ref_ip,
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double offset,
 double offset_sd,
 double frequency,
@@ -151,7 +151,7 @@ extern void REF_SetReference

 extern void REF_SetManualReference
 (
- struct timeval *ref_time,
+ struct timespec *ref_time,
 double offset,
 double frequency,
 double skew
--- a/regress.c
+++ b/regress.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011
+ * Copyright (C) Miroslav Lichvar  2011, 2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -34,7 +34,7 @@
 #include "logging.h"
 #include "util.h"

-#define MAX_POINTS 128
+#define MAX_POINTS 64

 void
 RGR_WeightedRegression
@@ -109,7 +109,7 @@ double
 RGR_GetTCoef(int dof)
 {
  /* Assuming now the 99.95% quantile */
-  static double coefs[] =
+  static const float coefs[] =
  { 636.6, 31.6, 12.92, 8.61, 6.869,
    5.959, 5.408, 5.041, 4.781, 4.587,
    4.437, 4.318, 4.221, 4.140, 4.073,
@@ -132,7 +132,7 @@ RGR_GetTCoef(int dof)
 double
 RGR_GetChi2Coef(int dof)
 {
-  static double coefs[] = {
+  static const float coefs[] = {
    2.706, 4.605, 6.251, 7.779, 9.236, 10.645, 12.017, 13.362,
    14.684, 15.987, 17.275, 18.549, 19.812, 21.064, 22.307, 23.542,
    24.769, 25.989, 27.204, 28.412, 29.615, 30.813, 32.007, 33.196,
@@ -150,20 +150,6 @@ RGR_GetChi2Coef(int dof)
  }
 }

-/* ================================================== */
-/* Structure used for holding results of each regression */
-
-typedef struct {
-  double variance;
-  double slope_sd;
-  double slope;
-  double offset;
-  double offset_sd;
-  double K2; /* Variance / slope_var */
-  int n; /* Number of points */
-  int dof; /* Number of degrees of freedom */
-} RegressionResult;
-
 /* ================================================== */
 /* Critical value for number of runs of residuals with same sign.
   5% critical region for now. */
@@ -299,7 +285,7 @@ RGR_FindBestRegression
        n - start <= min_samples) {
      if (start != resid_start) {
        /* Ignore extra samples in returned nruns */
-        nruns = n_runs_from_residuals(resid - resid_start + start, n - start);
+        nruns = n_runs_from_residuals(resid + (start - resid_start), n - start);
      }
      break;
    } else {
@@ -354,7 +340,7 @@ RGR_FindBestRegression
   0-521-43108-5). */

 static double
-find_ordered_entry_with_flags(double *x, int n, int index, int *flags)
+find_ordered_entry_with_flags(double *x, int n, int index, char *flags)
 {
  int u, v, l, r;
  double temp;
@@ -417,9 +403,9 @@ find_ordered_entry_with_flags(double *x, int n, int index, int *flags)
 static double
 find_ordered_entry(double *x, int n, int index)
 {
-  int flags[MAX_POINTS];
+  char flags[MAX_POINTS];

-  memset(flags, 0, n * sizeof(int));
+  memset(flags, 0, n * sizeof (flags[0]));
  return find_ordered_entry_with_flags(x, n, index, flags);
 }
 #endif
@@ -431,9 +417,9 @@ static double
 find_median(double *x, int n)
 {
  int k;
-  int flags[MAX_POINTS];
+  char flags[MAX_POINTS];

-  memset(flags, 0, n*sizeof(int));
+  memset(flags, 0, n * sizeof (flags[0]));
  k = n>>1;
  if (n&1) {
    return find_ordered_entry_with_flags(x, n, k, flags);
@@ -443,6 +429,19 @@ find_median(double *x, int n)
  }
 }

+/* ================================================== */
+
+double
+RGR_FindMedian(double *x, int n)
+{
+  double tmp[MAX_POINTS];
+
+  assert(n > 0 && n <= MAX_POINTS);
+  memcpy(tmp, x, n * sizeof (tmp[0]));
+
+  return find_median(tmp, n);
+}
+
 /* ================================================== */
 /* This function evaluates the equation

@@ -523,7 +522,7 @@ RGR_FindBestRobustRegression
  double mx, dx, my, dy;
  int nruns = 0;

-  assert(n < MAX_POINTS);
+  assert(n <= MAX_POINTS);

  if (n < 2) {
    return 0;
@@ -580,24 +579,18 @@ RGR_FindBestRobustRegression
       Estimate standard deviation of b and expand range about b based
       on that. */
    sb = sqrt(s2 * W/V);
-    if (sb > tol) {
-      incr = 3.0 * sb;
-    } else {
-      incr = 3.0 * tol;
-    }
+    incr = MAX(sb, tol);
  
-    blo = b;
-    bhi = b;
-
    do {
-      /* Make sure incr is significant to blo and bhi */
-      while (bhi + incr == bhi || blo - incr == blo) {
-        incr *= 2;
-      }
+      incr *= 2.0;
+
+      /* Give up if the interval is too large */
+      if (incr > 100.0)
+        return 0;
+
+      blo = b - incr;
+      bhi = b + incr;

-      blo -= incr;
-      bhi += incr;
-      
      /* We don't want 'a' yet */
      eval_robust_residual(x + start, y + start, n_points, blo, &a, &rlo);
      eval_robust_residual(x + start, y + start, n_points, bhi, &a, &rhi);
@@ -608,6 +601,8 @@ RGR_FindBestRobustRegression
    /* OK, so the root for b lies in (blo, bhi). Start bisecting */
    do {
      bmid = 0.5 * (blo + bhi);
+      if (!(blo < bmid && bmid < bhi))
+        break;
      eval_robust_residual(x + start, y + start, n_points, bmid, &a, &rmid);
      if (rmid == 0.0) {
        break;
@@ -620,7 +615,7 @@ RGR_FindBestRobustRegression
      } else {
        assert(0);
      }
-    } while ((bhi - blo) > tol && (bmid - blo) * (bhi - bmid) > 0.0);
+    } while (bhi - blo > tol);

    *b0 = a;
    *b1 = bmid;
@@ -653,3 +648,57 @@ RGR_FindBestRobustRegression
 }

 /* ================================================== */
+/* This routine performs linear regression with two independent variables.
+   It returns non-zero status if there were enough data points and there
+   was a solution. */
+
+int
+RGR_MultipleRegress
+(double *x1,                    /* first independent variable */
+ double *x2,                    /* second independent variable */
+ double *y,                     /* measured data */
+
+ int n,                         /* number of data points */
+
+ /* The results */
+ double *b2                     /* estimated second slope */
+                                /* other values are not needed yet */
+)
+{
+  double Sx1, Sx2, Sx1x1, Sx1x2, Sx2x2, Sx1y, Sx2y, Sy;
+  double U, V, V1, V2, V3;
+  int i;
+
+  if (n < 4)
+    return 0;
+
+  Sx1 = Sx2 = Sx1x1 = Sx1x2 = Sx2x2 = Sx1y = Sx2y = Sy = 0.0;
+
+  for (i = 0; i < n; i++) {
+    Sx1 += x1[i];
+    Sx2 += x2[i];
+    Sx1x1 += x1[i] * x1[i];
+    Sx1x2 += x1[i] * x2[i];
+    Sx2x2 += x2[i] * x2[i];
+    Sx1y += x1[i] * y[i];
+    Sx2y += x2[i] * y[i];
+    Sy += y[i];
+  }
+
+  U = n * (Sx1x2 * Sx1y - Sx1x1 * Sx2y) +
+      Sx1 * Sx1 * Sx2y - Sx1 * Sx2 * Sx1y +
+      Sy * (Sx2 * Sx1x1 - Sx1 * Sx1x2);
+
+  V1 = n * (Sx1x2 * Sx1x2 - Sx1x1 * Sx2x2);
+  V2 = Sx1 * Sx1 * Sx2x2 + Sx2 * Sx2 * Sx1x1;
+  V3 = -2.0 * Sx1 * Sx2 * Sx1x2;
+  V = V1 + V2 + V3;
+
+  /* Check if there is a (numerically stable) solution */
+  if (fabs(V) * 1.0e10 <= -V1 + V2 + fabs(V3))
+    return 0;
+
+  *b2 = U / V;
+
+  return 1;
+}
--- a/regress.h
+++ b/regress.h
@@ -119,4 +119,19 @@ RGR_FindBestRobustRegression
 int *n_runs,
 int *best_start);

+int
+RGR_MultipleRegress
+(double *x1,                    /* first independent variable */
+ double *x2,                    /* second independent variable */
+ double *y,                     /* measured data */
+
+ int n,                         /* number of data points */
+
+ /* The results */
+ double *b2                     /* estimated second slope */
+);
+
+/* Return the median value from an array */
+extern double RGR_FindMedian(double *x, int n);
+
 #endif /* GOT_REGRESS_H */
--- a/reports.h
+++ b/reports.h
@@ -31,8 +31,6 @@
 #include "addressing.h"
 #include "ntp.h"

-#define REPORT_INVALID_OFFSET 0x80000000
-
 typedef struct {
  IPAddr ip_addr;
  int stratum;
@@ -53,7 +51,7 @@ typedef struct {
  IPAddr ip_addr;
  int stratum;
  NTP_Leap leap_status;
-  struct timeval ref_time;
+  struct timespec ref_time;
  double current_correction;
  double last_offset;
  double rms_offset;
@@ -79,7 +77,7 @@ typedef struct {
 } RPT_SourcestatsReport;

 typedef struct {
-  struct timeval ref_time;
+  struct timespec ref_time;
  unsigned short n_samples;
  unsigned short n_runs;
  unsigned long span_seconds;
@@ -109,7 +107,7 @@ typedef struct {
 } RPT_ServerStatsReport;

 typedef struct {
-  struct timeval when;
+  struct timespec when;
  double slewed_offset;
  double orig_offset;
  double residual;
@@ -133,4 +131,33 @@ typedef struct {
  double remaining_time;
 } RPT_SmoothingReport;

+typedef struct {
+  IPAddr remote_addr;
+  IPAddr local_addr;
+  uint16_t remote_port;
+  uint8_t leap;
+  uint8_t version;
+  uint8_t mode;
+  uint8_t stratum;
+  int8_t poll;
+  int8_t precision;
+  double root_delay;
+  double root_dispersion;
+  uint32_t ref_id;
+  struct timespec ref_time;
+  double offset;
+  double peer_delay;
+  double peer_dispersion;
+  double response_time;
+  double jitter_asymmetry;
+  uint16_t tests;
+  int interleaved;
+  int authenticated;
+  char tx_tss_char;
+  char rx_tss_char;
+  uint32_t total_tx_count;
+  uint32_t total_rx_count;
+  uint32_t total_valid_count;
+} RPT_NTPReport;
+
 #endif /* GOT_REPORTS_H */
--- a/rtc.c
+++ b/rtc.c
@@ -98,13 +98,13 @@ get_driftfile_time(void)
 static void
 apply_driftfile_time(time_t t)
 {
-  struct timeval now;
+  struct timespec now;

  LCL_ReadCookedTime(&now, NULL);

  if (now.tv_sec < t) {
    if (LCL_ApplyStepOffset(now.tv_sec - t))
-      LOG(LOGS_INFO, LOGF_Rtc, "System time restored from driftfile");
+      LOG(LOGS_INFO, "System time restored from driftfile");
  }
 }

@@ -142,7 +142,7 @@ RTC_Initialise(int initial_set)

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

    if (driver.init) {
@@ -150,7 +150,7 @@ RTC_Initialise(int initial_set)
        driver_initialised = 1;
      }
    } else {
-      LOG(LOGS_ERR, LOGF_Rtc, "RTC not supported on this operating system");
+      LOG(LOGS_ERR, "RTC not supported on this operating system");
    }
  }
 }
--- a/rtc_linux.c
+++ b/rtc_linux.c
@@ -50,7 +50,7 @@

 static void measurement_timeout(void *any);

-static void read_from_device(void *any);
+static void read_from_device(int fd_, int event, void *any);

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

@@ -92,9 +92,8 @@ static double *rtc_trim = NULL;
 static time_t rtc_ref;


-/* System clock (gettimeofday) samples associated with the above
-   samples. */
-static struct timeval *system_times = NULL;
+/* System clock samples associated with the above samples. */
+static struct timespec *system_times = NULL;

 /* Number of samples currently stored. */
 static int n_samples;   
@@ -170,7 +169,7 @@ discard_samples(int new_first)

  memmove(rtc_sec, rtc_sec + new_first, n_to_save * sizeof(time_t));
  memmove(rtc_trim, rtc_trim + new_first, n_to_save * sizeof(double));
-  memmove(system_times, system_times + new_first, n_to_save * sizeof(struct timeval));
+  memmove(system_times, system_times + new_first, n_to_save * sizeof(struct timespec));

  n_samples = n_to_save;
 }
@@ -180,7 +179,7 @@ discard_samples(int new_first)
 #define NEW_FIRST_WHEN_FULL 4

 static void
-accumulate_sample(time_t rtc, struct timeval *sys)
+accumulate_sample(time_t rtc, struct timespec *sys)
 {

  if (n_samples == MAX_SAMPLES) {
@@ -188,6 +187,11 @@ accumulate_sample(time_t rtc, struct timeval *sys)
    discard_samples(NEW_FIRST_WHEN_FULL);
  }

+  /* Discard all samples if the RTC was stepped back (not our trim) */
+  if (n_samples > 0 && rtc_sec[n_samples - 1] - rtc >= rtc_trim[n_samples - 1]) {
+    DEBUG_LOG("RTC samples discarded");
+    n_samples = 0;
+  }

  /* Always use most recent sample as reference */
  /* use sample only if n_sample is not negative*/
@@ -225,7 +229,7 @@ run_regression(int new_sample,
    for (i=0; i<n_samples; i++) {
      rtc_rel[i] = rtc_trim[i] + (double)(rtc_sec[i] - rtc_ref);
      offsets[i] = ((double) (rtc_ref - system_times[i].tv_sec) -
-                    (1.0e-6 * (double) system_times[i].tv_usec) +
+                    (1.0e-9 * system_times[i].tv_nsec) +
                    rtc_rel[i]);

    }
@@ -262,7 +266,7 @@ run_regression(int new_sample,

 static void
 slew_samples
-(struct timeval *raw, struct timeval *cooked,
+(struct timespec *raw, struct timespec *cooked,
 double dfreq,
 double doffset,
 LCL_ChangeType change_type,
@@ -278,7 +282,7 @@ slew_samples
  }

  for (i=0; i<n_samples; i++) {
-    UTI_AdjustTimeval(system_times + i, cooked, system_times + i, &delta_time,
+    UTI_AdjustTimespec(system_times + i, cooked, system_times + i, &delta_time,
        dfreq, doffset);
  }

@@ -290,7 +294,7 @@ slew_samples
    coef_gain_rate += dfreq * (1.0 - coef_gain_rate);
  }

-  DEBUG_LOG(LOGF_RtcLinux, "dfreq=%.8f doffset=%.6f old_fast=%.6f old_rate=%.3f new_fast=%.6f new_rate=%.3f",
+  DEBUG_LOG("dfreq=%.8f doffset=%.6f old_fast=%.6f old_rate=%.3f new_fast=%.6f new_rate=%.3f",
      dfreq, doffset,
      old_seconds_fast, 1.0e6 * old_gain_rate,
      coef_seconds_fast, 1.0e6 * coef_gain_rate);
@@ -367,7 +371,7 @@ t_from_rtc(struct tm *stm) {
  diff = t2 - t1;

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

  return t1 - diff;
 }
@@ -386,7 +390,7 @@ read_hwclock_file(const char *hwclock_file)

  in = fopen(hwclock_file, "r");
  if (!in) {
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not open %s : %s",
+    LOG(LOGS_WARN, "Could not open %s : %s",
        hwclock_file, strerror(errno));
    return;
  }
@@ -404,8 +408,7 @@ read_hwclock_file(const char *hwclock_file)
  } else if (i == 3 && !strncmp(line, "UTC", 3)) {
    rtc_on_utc = 1;
  } else {
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not read RTC LOCAL/UTC setting from %s",
-        hwclock_file);
+    LOG(LOGS_WARN, "Could not read RTC LOCAL/UTC setting from %s", hwclock_file);
  }
 }

@@ -447,8 +450,7 @@ read_coefs_from_file(void)
                 &file_ref_offset,
                 &file_rate_ppm) == 4) {
      } else {
-        LOG(LOGS_WARN, LOGF_RtcLinux, "Could not read coefficients from %s",
-            coefs_file_name);
+        LOG(LOGS_WARN, "Could not read coefficients from %s", coefs_file_name);
      }
      fclose(in);
    }
@@ -481,7 +483,7 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  out = fopen(temp_coefs_file_name, "w");
  if (!out) {
    Free(temp_coefs_file_name);
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not open temporary RTC file %s.tmp for writing",
+    LOG(LOGS_WARN, "Could not open temporary RTC file %s.tmp for writing",
        coefs_file_name);
    return RTC_ST_BADFILE;
  }
@@ -492,7 +494,7 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  r2 = fclose(out);
  if (r1 < 0 || r2) {
    Free(temp_coefs_file_name);
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not write to temporary RTC file %s.tmp",
+    LOG(LOGS_WARN, "Could not write to temporary RTC file %s.tmp",
        coefs_file_name);
    return RTC_ST_BADFILE;
  }
@@ -502,7 +504,7 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  if (!stat(coefs_file_name,&buf)) {
    if (chown(temp_coefs_file_name,buf.st_uid,buf.st_gid) ||
        chmod(temp_coefs_file_name,buf.st_mode & 0777)) {
-      LOG(LOGS_WARN, LOGF_RtcLinux,
+      LOG(LOGS_WARN,
          "Could not change ownership or permissions of temporary RTC file %s.tmp",
          coefs_file_name);
    }
@@ -513,7 +515,7 @@ write_coefs_to_file(int valid,time_t ref_time,double offset,double rate)
  if (rename(temp_coefs_file_name,coefs_file_name)) {
    unlink(temp_coefs_file_name);
    Free(temp_coefs_file_name);
-    LOG(LOGS_WARN, LOGF_RtcLinux, "Could not replace old RTC file %s.tmp with new one %s",
+    LOG(LOGS_WARN, "Could not replace old RTC file %s.tmp with new one %s",
        coefs_file_name, coefs_file_name);
    return RTC_ST_BADFILE;
  }
@@ -534,7 +536,7 @@ RTC_Linux_Initialise(void)
 {
  rtc_sec = MallocArray(time_t, MAX_SAMPLES);
  rtc_trim = MallocArray(double, MAX_SAMPLES);
-  system_times = MallocArray(struct timeval, MAX_SAMPLES);
+  system_times = MallocArray(struct timespec, MAX_SAMPLES);

  /* Setup details depending on configuration options */
  setup_config();
@@ -546,7 +548,7 @@ RTC_Linux_Initialise(void)

  fd = open (CNF_GetRtcDevice(), O_RDWR);
  if (fd < 0) {
-    LOG(LOGS_ERR, LOGF_RtcLinux, "Could not open RTC device %s : %s",
+    LOG(LOGS_ERR, "Could not open RTC device %s : %s",
        CNF_GetRtcDevice(), strerror(errno));
    return 0;
  }
@@ -564,7 +566,7 @@ RTC_Linux_Initialise(void)
  operating_mode = OM_NORMAL;

  /* Register file handler */
-  SCH_AddInputFileHandler(fd, read_from_device, NULL);
+  SCH_AddFileHandler(fd, SCH_FILE_INPUT, read_from_device, NULL);

  /* Register slew handler */
  LCL_AddParameterChangeHandler(slew_samples, NULL);
@@ -585,7 +587,7 @@ RTC_Linux_Finalise(void)

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

    /* Save the RTC data */
@@ -607,16 +609,14 @@ switch_interrupts(int onoff)
  if (onoff) {
    status = ioctl(fd, RTC_UIE_ON, 0);
    if (status < 0) {
-      LOG(LOGS_ERR, LOGF_RtcLinux, "Could not %s RTC interrupt : %s",
-          "enable", strerror(errno));
+      LOG(LOGS_ERR, "Could not %s RTC interrupt : %s", "enable", strerror(errno));
      return;
    }
    skip_interrupts = 1;
  } else {
    status = ioctl(fd, RTC_UIE_OFF, 0);
    if (status < 0) {
-      LOG(LOGS_ERR, LOGF_RtcLinux, "Could not %s RTC interrupt : %s",
-          "disable", strerror(errno));
+      LOG(LOGS_ERR, "Could not %s RTC interrupt : %s", "disable", strerror(errno));
      return;
    }
  }
@@ -654,7 +654,7 @@ set_rtc(time_t new_rtc_time)

  status = ioctl(fd, RTC_SET_TIME, &rtc_raw);
  if (status < 0) {
-    LOG(LOGS_ERR, LOGF_RtcLinux, "Could not set RTC time");
+    LOG(LOGS_ERR, "Could not set RTC time");
  }

 }
@@ -697,10 +697,10 @@ handle_initial_trim(void)
    sys_error_now = rtc_error_now - coef_seconds_fast;
          
    LCL_AccumulateOffset(sys_error_now, 0.0);
-    LOG(LOGS_INFO, LOGF_RtcLinux, "System clock off from RTC by %f seconds (slew)",
+    LOG(LOGS_INFO, "System clock off from RTC by %f seconds (slew)",
        sys_error_now);
  } else {
-    LOG(LOGS_WARN, LOGF_RtcLinux, "No valid rtcfile coefficients");
+    LOG(LOGS_WARN, "No valid rtcfile coefficients");
  }
  
  coefs_valid = 0;
@@ -725,7 +725,7 @@ handle_relock_after_trim(void)
  if (valid) {
    write_coefs_to_file(1,ref,fast,saved_coef_gain_rate);
  } else {
-    DEBUG_LOG(LOGF_RtcLinux, "Could not do regression after trim");
+    DEBUG_LOG("Could not do regression after trim");
  }

  coefs_valid = 0;
@@ -758,7 +758,7 @@ maybe_autotrim(void)
 /* ================================================== */

 static void
-process_reading(time_t rtc_time, struct timeval *system_time)
+process_reading(time_t rtc_time, struct timespec *system_time)
 {
  double rtc_fast;

@@ -791,7 +791,7 @@ process_reading(time_t rtc_time, struct timeval *system_time)


  if (logfileid != -1) {
-    rtc_fast = (double)(rtc_time - system_time->tv_sec) - 1.0e-6 * (double) system_time->tv_usec;
+    rtc_fast = (rtc_time - system_time->tv_sec) - 1.0e-9 * system_time->tv_nsec;

    LOG_FileWrite(logfileid, "%s %14.6f %1d  %14.6f  %12.3f  %2d  %2d %4d",
            UTI_TimeToLogForm(system_time->tv_sec),
@@ -805,11 +805,11 @@ process_reading(time_t rtc_time, struct timeval *system_time)
 /* ================================================== */

 static void
-read_from_device(void *any)
+read_from_device(int fd_, int event, void *any)
 {
  int status;
  unsigned long data;
-  struct timeval sys_time;
+  struct timespec sys_time;
  struct rtc_time rtc_raw;
  struct tm rtc_tm;
  time_t rtc_t;
@@ -820,8 +820,8 @@ read_from_device(void *any)
  if (status < 0) {
    /* This looks like a bad error : the file descriptor was indicating it was
     * ready to read but we couldn't read anything.  Give up. */
-    LOG(LOGS_ERR, LOGF_RtcLinux, "Could not read flags %s : %s", CNF_GetRtcDevice(), strerror(errno));
-    SCH_RemoveInputFileHandler(fd);
+    LOG(LOGS_ERR, "Could not read flags %s : %s", CNF_GetRtcDevice(), strerror(errno));
+    SCH_RemoveFileHandler(fd);
    switch_interrupts(0); /* Likely to raise error too, but just to be sure... */
    close(fd);
    fd = -1;
@@ -844,12 +844,12 @@ read_from_device(void *any)

    status = ioctl(fd, RTC_RD_TIME, &rtc_raw);
    if (status < 0) {
-      LOG(LOGS_ERR, LOGF_RtcLinux, "Could not read time from %s : %s", CNF_GetRtcDevice(), strerror(errno));
+      LOG(LOGS_ERR, "Could not read time from %s : %s", CNF_GetRtcDevice(), strerror(errno));
      error = 1;
      goto turn_off_interrupt;
    }

-    /* Convert RTC time into a struct timeval */
+    /* Convert RTC time into a struct timespec */
    rtc_tm.tm_sec = rtc_raw.tm_sec;
    rtc_tm.tm_min = rtc_raw.tm_min;
    rtc_tm.tm_hour = rtc_raw.tm_hour;
@@ -885,7 +885,7 @@ turn_off_interrupt:
  switch (operating_mode) {
    case OM_INITIAL:
      if (error) {
-        DEBUG_LOG(LOGF_RtcLinux, "Could not complete initial step due to errors");
+        DEBUG_LOG("Could not complete initial step due to errors");
        operating_mode = OM_NORMAL;
        (after_init_hook)(after_init_hook_arg);

@@ -898,7 +898,7 @@ turn_off_interrupt:

    case OM_AFTERTRIM:
      if (error) {
-        DEBUG_LOG(LOGF_RtcLinux, "Could not complete after trim relock due to errors");
+        DEBUG_LOG("Could not complete after trim relock due to errors");
        operating_mode = OM_NORMAL;

        switch_interrupts(0);
@@ -978,7 +978,7 @@ RTC_Linux_TimePreInit(time_t driftfile_time)
  struct tm rtc_tm;
  time_t rtc_t;
  double accumulated_error, sys_offset;
-  struct timeval new_sys_time, old_sys_time;
+  struct timespec new_sys_time, old_sys_time;

  coefs_file_name = CNF_GetRtcFile();

@@ -1032,21 +1032,21 @@ RTC_Linux_TimePreInit(time_t driftfile_time)

      new_sys_time.tv_sec = rtc_t;
      /* Average error in the RTC reading */
-      new_sys_time.tv_usec = 500000;
+      new_sys_time.tv_nsec = 500000000;

-      UTI_AddDoubleToTimeval(&new_sys_time, -accumulated_error, &new_sys_time);
+      UTI_AddDoubleToTimespec(&new_sys_time, -accumulated_error, &new_sys_time);

      if (new_sys_time.tv_sec < driftfile_time) {
-        LOG(LOGS_WARN, LOGF_RtcLinux, "RTC time before last driftfile modification (ignored)");
+        LOG(LOGS_WARN, "RTC time before last driftfile modification (ignored)");
        return 0;
      }

-      UTI_DiffTimevalsToDouble(&sys_offset, &old_sys_time, &new_sys_time);
+      sys_offset = UTI_DiffTimespecsToDouble(&old_sys_time, &new_sys_time);

      /* Set system time only if the step is larger than 1 second */
      if (fabs(sys_offset) >= 1.0) {
        if (LCL_ApplyStepOffset(sys_offset))
-          LOG(LOGS_INFO, LOGF_RtcLinux, "System time set from RTC");
+          LOG(LOGS_INFO, "System time set from RTC");
      }
    } else {
      return 0;
@@ -1064,7 +1064,7 @@ int
 RTC_Linux_GetReport(RPT_RTC_Report *report)
 {
  report->ref_time.tv_sec = coef_ref_time;
-  report->ref_time.tv_usec = 0;
+  report->ref_time.tv_nsec = 0;
  report->n_samples = n_samples;
  report->n_runs = n_runs;
  if (n_samples > 1) {
@@ -1083,8 +1083,7 @@ RTC_Linux_GetReport(RPT_RTC_Report *report)
 int
 RTC_Linux_Trim(void)
 {
-  struct timeval now;
-
+  struct timespec now;

  /* Remember the slope coefficient - we won't be able to determine a
     good one in a few seconds when we determine the new offset! */
@@ -1092,7 +1091,7 @@ RTC_Linux_Trim(void)

  if (fabs(coef_seconds_fast) > 1.0) {

-    LOG(LOGS_INFO, LOGF_RtcLinux, "RTC wrong by %.3f seconds (step)",
+    LOG(LOGS_INFO, "RTC wrong by %.3f seconds (step)",
        coef_seconds_fast);

    /* Do processing to set clock.  Let R be the value we set the
@@ -1114,7 +1113,7 @@ RTC_Linux_Trim(void)

    /* Estimate the offset in case writertc is called or chronyd
       is terminated during rapid sampling */
-    coef_seconds_fast = -now.tv_usec / 1e6 + 0.5;
+    coef_seconds_fast = -now.tv_nsec / 1.0e9 + 0.5;
    coef_ref_time = now.tv_sec;

    /* And start rapid sampling, interrupts on now */
--- a/sched.c
+++ b/sched.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011, 2013-2015
+ * Copyright (C) Miroslav Lichvar  2011, 2013-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -44,17 +44,6 @@ static int initialised = 0;

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

-/* Variables to handle the capability to dispatch on particular file
-   handles becoming readable */
-
-/* Each bit set in this fd set corresponds to a read descriptor that
-   we are watching and with which we have a handler associated in the
-   file_handlers array */
-static fd_set read_fds;
-
-/* This is the number of bits that we have set in read_fds */
-static unsigned int n_read_fds;
-
 /* One more than the highest file descriptor that is registered */
 static unsigned int one_highest_fd;

@@ -67,12 +56,13 @@ static unsigned int one_highest_fd;
 typedef struct {
  SCH_FileHandler       handler;
  SCH_ArbitraryArgument arg;
+  int                   events;
 } FileHandlerEntry;

 static ARR_Instance file_handlers;

 /* Timestamp when last select() returned */
-static struct timeval last_select_ts, last_select_ts_raw;
+static struct timespec last_select_ts, last_select_ts_raw;
 static double last_select_ts_err;

 /* ================================================== */
@@ -83,7 +73,7 @@ typedef struct _TimerQueueEntry
 {
  struct _TimerQueueEntry *next; /* Forward and back links in the list */
  struct _TimerQueueEntry *prev;
-  struct timeval tv;            /* Local system time at which the
+  struct timespec ts;           /* Local system time at which the
                                   timeout is to expire.  Clearly this
                                   must be in terms of what the
                                   operating system thinks of as
@@ -111,7 +101,7 @@ static SCH_TimeoutID next_tqe_id;
 static TimerQueueEntry *tqe_free_list = NULL;

 /* Timestamp when was last timeout dispatched for each class */
-static struct timeval last_class_dispatch[SCH_NumberOfClasses];
+static struct timespec last_class_dispatch[SCH_NumberOfClasses];

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

@@ -120,8 +110,8 @@ static int need_to_exit;
 /* ================================================== */

 static void
-handle_slew(struct timeval *raw,
-            struct timeval *cooked,
+handle_slew(struct timespec *raw,
+            struct timespec *cooked,
            double dfreq,
            double doffset,
            LCL_ChangeType change_type,
@@ -132,9 +122,6 @@ handle_slew(struct timeval *raw,
 void
 SCH_Initialise(void)
 {
-  FD_ZERO(&read_fds);
-  n_read_fds = 0;
-
  file_handlers = ARR_CreateInstance(sizeof (FileHandlerEntry));

  n_timer_queue_entries = 0;
@@ -166,73 +153,85 @@ SCH_Finalise(void) {
 /* ================================================== */

 void
-SCH_AddInputFileHandler
-(int fd, SCH_FileHandler handler, SCH_ArbitraryArgument arg)
+SCH_AddFileHandler
+(int fd, int events, SCH_FileHandler handler, SCH_ArbitraryArgument arg)
 {
  FileHandlerEntry *ptr;

  assert(initialised);
+  assert(events);
+  assert(fd >= 0);
  
  if (fd >= FD_SETSIZE)
-    LOG_FATAL(LOGF_Scheduler, "Too many file descriptors");
+    LOG_FATAL("Too many file descriptors");
+
+  /* Resize the array if the descriptor is highest so far */
+  while (ARR_GetSize(file_handlers) <= fd) {
+    ptr = ARR_GetNewElement(file_handlers);
+    ptr->handler = NULL;
+    ptr->arg = NULL;
+    ptr->events = 0;
+  }
+
+  ptr = ARR_GetElement(file_handlers, fd);

  /* Don't want to allow the same fd to register a handler more than
     once without deleting a previous association - this suggests
     a bug somewhere else in the program. */
-  if (FD_ISSET(fd, &read_fds))
-    assert(0);
+  assert(!ptr->handler);

-  ++n_read_fds;
-  
-  if (ARR_GetSize(file_handlers) < fd + 1)
-    ARR_SetSize(file_handlers, fd + 1);
-
-  ptr = (FileHandlerEntry *)ARR_GetElement(file_handlers, fd);
  ptr->handler = handler;
  ptr->arg = arg;
+  ptr->events = events;

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


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

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

  assert(initialised);

+  ptr = ARR_GetElement(file_handlers, fd);
+
  /* Check that a handler was registered for the fd in question */
-  if (!FD_ISSET(fd, &read_fds))
-    assert(0);
+  assert(ptr->handler);

-  --n_read_fds;
-
-  FD_CLR(fd, &read_fds);
+  ptr->handler = NULL;
+  ptr->arg = NULL;
+  ptr->events = 0;

  /* Find new highest file descriptor */
-  fds_left = n_read_fds;
-  fd_to_check = 0;
-  while (fds_left > 0) {
-    if (FD_ISSET(fd_to_check, &read_fds)) {
-      --fds_left;
-    }
-    ++fd_to_check;
+  while (one_highest_fd > 0) {
+    ptr = ARR_GetElement(file_handlers, one_highest_fd - 1);
+    if (ptr->handler)
+      break;
+    one_highest_fd--;
  }
-
-  one_highest_fd = fd_to_check;
 }

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

 void
-SCH_GetLastEventTime(struct timeval *cooked, double *err, struct timeval *raw)
+SCH_SetFileHandlerEvents(int fd, int events)
+{
+  FileHandlerEntry *ptr;
+
+  assert(events);
+  ptr = ARR_GetElement(file_handlers, fd);
+  ptr->events = events;
+}
+
+/* ================================================== */
+
+void
+SCH_GetLastEventTime(struct timespec *cooked, double *err, struct timespec *raw)
 {
  if (cooked) {
    *cooked = last_select_ts;
@@ -299,7 +298,7 @@ try_again:
 /* ================================================== */

 SCH_TimeoutID
-SCH_AddTimeout(struct timeval *tv, SCH_TimeoutHandler handler, SCH_ArbitraryArgument arg)
+SCH_AddTimeout(struct timespec *ts, SCH_TimeoutHandler handler, SCH_ArbitraryArgument arg)
 {
  TimerQueueEntry *new_tqe;
  TimerQueueEntry *ptr;
@@ -311,12 +310,12 @@ SCH_AddTimeout(struct timeval *tv, SCH_TimeoutHandler handler, SCH_ArbitraryArgu
  new_tqe->id = get_new_tqe_id();
  new_tqe->handler = handler;
  new_tqe->arg = arg;
-  new_tqe->tv = *tv;
+  new_tqe->ts = *ts;
  new_tqe->class = SCH_ReservedTimeoutValue;

  /* Now work out where to insert the new entry in the list */
  for (ptr = timer_queue.next; ptr != &timer_queue; ptr = ptr->next) {
-    if (UTI_CompareTimevals(&new_tqe->tv, &ptr->tv) == -1) {
+    if (UTI_CompareTimespecs(&new_tqe->ts, &ptr->ts) == -1) {
      /* If the new entry comes before the current pointer location in
         the list, we want to insert the new entry just before ptr. */
      break;
@@ -343,15 +342,15 @@ SCH_AddTimeout(struct timeval *tv, SCH_TimeoutHandler handler, SCH_ArbitraryArgu
 SCH_TimeoutID
 SCH_AddTimeoutByDelay(double delay, SCH_TimeoutHandler handler, SCH_ArbitraryArgument arg)
 {
-  struct timeval now, then;
+  struct timespec now, then;

  assert(initialised);
  assert(delay >= 0.0);

  LCL_ReadRawTime(&now);
-  UTI_AddDoubleToTimeval(&now, delay, &then);
-  if (UTI_CompareTimevals(&now, &then) > 0) {
-    LOG_FATAL(LOGF_Scheduler, "Timeout overflow");
+  UTI_AddDoubleToTimespec(&now, delay, &then);
+  if (UTI_CompareTimespecs(&now, &then) > 0) {
+    LOG_FATAL("Timeout overflow");
  }

  return SCH_AddTimeout(&then, handler, arg);
@@ -367,7 +366,7 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
 {
  TimerQueueEntry *new_tqe;
  TimerQueueEntry *ptr;
-  struct timeval now;
+  struct timespec now;
  double diff, r;
  double new_min_delay;

@@ -376,10 +375,10 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
  assert(class < SCH_NumberOfClasses);

  if (randomness > 0.0) {
-    uint16_t rnd;
+    uint32_t rnd;

    UTI_GetRandomBytes(&rnd, sizeof (rnd));
-    r = rnd / (double)0xffff * randomness + 1.0;
+    r = rnd * (randomness / (uint32_t)-1) + 1.0;
    min_delay *= r;
    separation *= r;
  }
@@ -388,7 +387,7 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
  new_min_delay = min_delay;

  /* Check the separation from the last dispatched timeout */
-  UTI_DiffTimevalsToDouble(&diff, &now, &last_class_dispatch[class]);
+  diff = UTI_DiffTimespecsToDouble(&now, &last_class_dispatch[class]);
  if (diff < separation && diff >= 0.0 && diff + new_min_delay < separation) {
    new_min_delay = separation - diff;
  }
@@ -397,7 +396,7 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
     if necessary to keep at least the separation away */
  for (ptr = timer_queue.next; ptr != &timer_queue; ptr = ptr->next) {
    if (ptr->class == class) {
-      UTI_DiffTimevalsToDouble(&diff, &ptr->tv, &now);
+      diff = UTI_DiffTimespecsToDouble(&ptr->ts, &now);
      if (new_min_delay > diff) {
        if (new_min_delay - diff < separation) {
          new_min_delay = diff + separation;
@@ -411,7 +410,7 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
  }

  for (ptr = timer_queue.next; ptr != &timer_queue; ptr = ptr->next) {
-    UTI_DiffTimevalsToDouble(&diff, &ptr->tv, &now);
+    diff = UTI_DiffTimespecsToDouble(&ptr->ts, &now);
    if (diff > new_min_delay) {
      break;
    }
@@ -423,7 +422,7 @@ SCH_AddTimeoutInClass(double min_delay, double separation, double randomness,
  new_tqe->id = get_new_tqe_id();
  new_tqe->handler = handler;
  new_tqe->arg = arg;
-  UTI_AddDoubleToTimeval(&now, new_min_delay, &new_tqe->tv);
+  UTI_AddDoubleToTimespec(&now, new_min_delay, &new_tqe->ts);
  new_tqe->class = class;

  new_tqe->next = ptr;
@@ -477,7 +476,7 @@ SCH_RemoveTimeout(SCH_TimeoutID id)
   completed). */

 static void
-dispatch_timeouts(struct timeval *now) {
+dispatch_timeouts(struct timespec *now) {
  TimerQueueEntry *ptr;
  SCH_TimeoutHandler handler;
  SCH_ArbitraryArgument arg;
@@ -487,7 +486,7 @@ dispatch_timeouts(struct timeval *now) {
    LCL_ReadRawTime(now);

    if (!(n_timer_queue_entries > 0 &&
-          UTI_CompareTimevals(now, &(timer_queue.next->tv)) >= 0)) {
+          UTI_CompareTimespecs(now, &timer_queue.next->ts) >= 0)) {
      break;
    }

@@ -513,42 +512,56 @@ dispatch_timeouts(struct timeval *now) {
       more time than was delay of a scheduled timeout. */
    if (n_done > n_timer_queue_entries * 4 &&
        n_done > n_entries_on_start * 4) {
-      LOG_FATAL(LOGF_Scheduler, "Possible infinite loop in scheduling");
+      LOG_FATAL("Possible infinite loop in scheduling");
    }
  }
 }

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

-/* nfh is the number of bits set in fhs */
+/* nfd is the number of bits set in all fd_sets */

 static void
-dispatch_filehandlers(int nfh, fd_set *fhs)
+dispatch_filehandlers(int nfd, fd_set *read_fds, fd_set *write_fds, fd_set *except_fds)
 {
  FileHandlerEntry *ptr;
-  int fh = 0;
+  int fd;
  
-  while (nfh > 0) {
-    if (FD_ISSET(fh, fhs)) {
+  for (fd = 0; nfd && fd < one_highest_fd; fd++) {
+    if (except_fds && FD_ISSET(fd, except_fds)) {
+      /* This descriptor has an exception, dispatch its handler */
+      ptr = (FileHandlerEntry *)ARR_GetElement(file_handlers, fd);
+      (ptr->handler)(fd, SCH_FILE_EXCEPTION, ptr->arg);
+      nfd--;

-      /* This descriptor can be read from, dispatch its handler */
-      ptr = (FileHandlerEntry *)ARR_GetElement(file_handlers, fh);
-      (ptr->handler)(ptr->arg);
-
-      /* Decrement number of readable files still to find */
-      --nfh;
+      /* Don't try to read from it now */
+      if (read_fds && FD_ISSET(fd, read_fds)) {
+        FD_CLR(fd, read_fds);
+        nfd--;
+      }
    }

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

+    if (write_fds && FD_ISSET(fd, write_fds)) {
+      /* This descriptor can be written to, dispatch its handler */
+      ptr = (FileHandlerEntry *)ARR_GetElement(file_handlers, fd);
+      (ptr->handler)(fd, SCH_FILE_OUTPUT, ptr->arg);
+      nfd--;
+    }
+  }
 }

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

 static void
-handle_slew(struct timeval *raw,
-            struct timeval *cooked,
+handle_slew(struct timespec *raw,
+            struct timespec *cooked,
            double dfreq,
            double doffset,
            LCL_ChangeType change_type,
@@ -566,17 +579,69 @@ handle_slew(struct timeval *raw,
    /* If a step change occurs, just shift all raw time stamps by the offset */
    
    for (ptr = timer_queue.next; ptr != &timer_queue; ptr = ptr->next) {
-      UTI_AddDoubleToTimeval(&ptr->tv, -doffset, &ptr->tv);
+      UTI_AddDoubleToTimespec(&ptr->ts, -doffset, &ptr->ts);
    }

    for (i = 0; i < SCH_NumberOfClasses; i++) {
-      UTI_AddDoubleToTimeval(&last_class_dispatch[i], -doffset, &last_class_dispatch[i]);
+      UTI_AddDoubleToTimespec(&last_class_dispatch[i], -doffset, &last_class_dispatch[i]);
    }

-    UTI_AddDoubleToTimeval(&last_select_ts_raw, -doffset, &last_select_ts_raw);
+    UTI_AddDoubleToTimespec(&last_select_ts_raw, -doffset, &last_select_ts_raw);
  }

-  UTI_AdjustTimeval(&last_select_ts, cooked, &last_select_ts, &delta, dfreq, doffset);
+  UTI_AdjustTimespec(&last_select_ts, cooked, &last_select_ts, &delta, dfreq, doffset);
+}
+
+/* ================================================== */
+
+static void
+fill_fd_sets(fd_set **read_fds, fd_set **write_fds, fd_set **except_fds)
+{
+  FileHandlerEntry *handlers;
+  fd_set *rd, *wr, *ex;
+  int i, n, events;
+
+  n = ARR_GetSize(file_handlers);
+  handlers = ARR_GetElements(file_handlers);
+  rd = wr = ex = NULL;
+
+  for (i = 0; i < n; i++) {
+    events = handlers[i].events;
+
+    if (!events)
+      continue;
+
+    if (events & SCH_FILE_INPUT) {
+      if (!rd) {
+        rd = *read_fds;
+        FD_ZERO(rd);
+      }
+      FD_SET(i, rd);
+    }
+
+    if (events & SCH_FILE_OUTPUT) {
+      if (!wr) {
+        wr = *write_fds;
+        FD_ZERO(wr);
+      }
+      FD_SET(i, wr);
+    }
+
+    if (events & SCH_FILE_EXCEPTION) {
+      if (!ex) {
+        ex = *except_fds;
+        FD_ZERO(ex);
+      }
+      FD_SET(i, ex);
+    }
+  }
+
+  if (!rd)
+    *read_fds = NULL;
+  if (!wr)
+    *write_fds = NULL;
+  if (!ex)
+    *except_fds = NULL;
 }

 /* ================================================== */
@@ -584,45 +649,47 @@ handle_slew(struct timeval *raw,
 #define JUMP_DETECT_THRESHOLD 10

 static int
-check_current_time(struct timeval *prev_raw, struct timeval *raw, int timeout,
+check_current_time(struct timespec *prev_raw, struct timespec *raw, int timeout,
                   struct timeval *orig_select_tv,
                   struct timeval *rem_select_tv)
 {
-  struct timeval elapsed_min, elapsed_max;
+  struct timespec elapsed_min, elapsed_max, orig_select_ts, rem_select_ts;
  double step, elapsed;

+  UTI_TimevalToTimespec(orig_select_tv, &orig_select_ts);
+
  /* Get an estimate of the time spent waiting in the select() call. On some
     systems (e.g. Linux) the timeout timeval is modified to return the
     remaining time, use that information. */
  if (timeout) {
-    elapsed_max = elapsed_min = *orig_select_tv;
+    elapsed_max = elapsed_min = orig_select_ts;
  } else if (rem_select_tv && rem_select_tv->tv_sec >= 0 &&
             rem_select_tv->tv_sec <= orig_select_tv->tv_sec &&
             (rem_select_tv->tv_sec != orig_select_tv->tv_sec ||
              rem_select_tv->tv_usec != orig_select_tv->tv_usec)) {
-    UTI_DiffTimevals(&elapsed_min, orig_select_tv, rem_select_tv);
+    UTI_TimevalToTimespec(rem_select_tv, &rem_select_ts);
+    UTI_DiffTimespecs(&elapsed_min, &orig_select_ts, &rem_select_ts);
    elapsed_max = elapsed_min;
  } else {
    if (rem_select_tv)
-      elapsed_max = *orig_select_tv;
+      elapsed_max = orig_select_ts;
    else
-      UTI_DiffTimevals(&elapsed_max, raw, prev_raw);
-    elapsed_min.tv_sec = 0;
-    elapsed_min.tv_usec = 0;
+      UTI_DiffTimespecs(&elapsed_max, raw, prev_raw);
+    UTI_ZeroTimespec(&elapsed_min);
  }

  if (last_select_ts_raw.tv_sec + elapsed_min.tv_sec >
      raw->tv_sec + JUMP_DETECT_THRESHOLD) {
-    LOG(LOGS_WARN, LOGF_Scheduler, "Backward time jump detected!");
+    LOG(LOGS_WARN, "Backward time jump detected!");
  } else if (prev_raw->tv_sec + elapsed_max.tv_sec + JUMP_DETECT_THRESHOLD <
             raw->tv_sec) {
-    LOG(LOGS_WARN, LOGF_Scheduler, "Forward time jump detected!");
+    LOG(LOGS_WARN, "Forward time jump detected!");
  } else {
    return 1;
  }

-  UTI_DiffTimevalsToDouble(&step, &last_select_ts_raw, raw);
-  UTI_TimevalToDouble(&elapsed_min, &elapsed);
+  step = UTI_DiffTimespecsToDouble(&last_select_ts_raw, raw);
+  elapsed = UTI_TimespecToDouble(&elapsed_min);
  step += elapsed;

  /* Cooked time may no longer be valid after dispatching the handlers */
@@ -636,10 +703,11 @@ check_current_time(struct timeval *prev_raw, struct timeval *raw, int timeout,
 void
 SCH_MainLoop(void)
 {
-  fd_set rd;
+  fd_set read_fds, write_fds, except_fds;
+  fd_set *p_read_fds, *p_write_fds, *p_except_fds;
  int status, errsv;
  struct timeval tv, saved_tv, *ptv;
-  struct timeval now, saved_now, cooked;
+  struct timespec ts, now, saved_now, cooked;
  double err;

  assert(initialised);
@@ -655,28 +723,28 @@ SCH_MainLoop(void)

    /* Check whether there is a timeout and set it up */
    if (n_timer_queue_entries > 0) {
+      UTI_DiffTimespecs(&ts, &timer_queue.next->ts, &now);
+      assert(ts.tv_sec > 0 || ts.tv_nsec > 0);

-      UTI_DiffTimevals(&tv, &(timer_queue.next->tv), &now);
+      UTI_TimespecToTimeval(&ts, &tv);
      ptv = &tv;
-      assert(tv.tv_sec > 0 || tv.tv_usec > 0);
      saved_tv = tv;
-
    } else {
      ptv = NULL;
-      /* This is needed to fix a compiler warning */
-      saved_tv.tv_sec = 0;
+      saved_tv.tv_sec = saved_tv.tv_usec = 0;
    }

+    p_read_fds = &read_fds;
+    p_write_fds = &write_fds;
+    p_except_fds = &except_fds;
+    fill_fd_sets(&p_read_fds, &p_write_fds, &p_except_fds);
+
    /* if there are no file descriptors being waited on and no
       timeout set, this is clearly ridiculous, so stop the run */
-    if (!ptv && !n_read_fds) {
-      LOG_FATAL(LOGF_Scheduler, "Nothing to do");
-    }
+    if (!ptv && !p_read_fds && !p_write_fds)
+      LOG_FATAL("Nothing to do");

-    /* Copy current set of read file descriptors */
-    memcpy((void *) &rd, (void *) &read_fds, sizeof(fd_set));
-
-    status = select(one_highest_fd, &rd, NULL, NULL, ptv);
+    status = select(one_highest_fd, p_read_fds, p_write_fds, p_except_fds, ptv);
    errsv = errno;

    LCL_ReadRawTime(&now);
@@ -694,13 +762,11 @@ SCH_MainLoop(void)

    if (status < 0) {
      if (!need_to_exit && errsv != EINTR) {
-        LOG_FATAL(LOGF_Scheduler, "select() failed : %s", strerror(errsv));
+        LOG_FATAL("select() failed : %s", strerror(errsv));
      }
    } else if (status > 0) {
-      /* A file descriptor is ready to read */
-
-      dispatch_filehandlers(status, &rd);
-
+      /* A file descriptor is ready for input or output */
+      dispatch_filehandlers(status, p_read_fds, p_write_fds, p_except_fds);
    } else {
      /* No descriptors readable, timeout must have elapsed.
       Therefore, tv must be non-null */
--- a/sched.h
+++ b/sched.h
@@ -40,7 +40,7 @@ typedef enum {
 } SCH_TimeoutClass;

 typedef void* SCH_ArbitraryArgument;
-typedef void (*SCH_FileHandler)(SCH_ArbitraryArgument);
+typedef void (*SCH_FileHandler)(int fd, int event, SCH_ArbitraryArgument);
 typedef void (*SCH_TimeoutHandler)(SCH_ArbitraryArgument);

 /* Exported functions */
@@ -51,19 +51,21 @@ extern void SCH_Initialise(void);
 /* Finalisation function for the module */
 extern void SCH_Finalise(void);

+/* File events */
+#define SCH_FILE_INPUT 1
+#define SCH_FILE_OUTPUT 2
+#define SCH_FILE_EXCEPTION 4
+
 /* Register a handler for when select goes true on a file descriptor */
-extern void SCH_AddInputFileHandler
-(int fd,                        /* The file descriptor */
- SCH_FileHandler,               /* The handler routine */
- SCH_ArbitraryArgument          /* An arbitrary passthrough argument to the handler */
-);
-extern void SCH_RemoveInputFileHandler(int fd);
+extern void SCH_AddFileHandler(int fd, int events, SCH_FileHandler handler, SCH_ArbitraryArgument arg);
+extern void SCH_RemoveFileHandler(int fd);
+extern void SCH_SetFileHandlerEvents(int fd, int events);

 /* Get the time stamp taken after a file descriptor became ready or a timeout expired */
-extern void SCH_GetLastEventTime(struct timeval *cooked, double *err, struct timeval *raw);
+extern void SCH_GetLastEventTime(struct timespec *cooked, double *err, struct timespec *raw);

 /* This queues a timeout to elapse at a given (raw) local time */
-extern SCH_TimeoutID SCH_AddTimeout(struct timeval *tv, SCH_TimeoutHandler, SCH_ArbitraryArgument);
+extern SCH_TimeoutID SCH_AddTimeout(struct timespec *ts, SCH_TimeoutHandler handler, SCH_ArbitraryArgument arg);

 /* This queues a timeout to elapse at a given delta time relative to the current (raw) time */
 extern SCH_TimeoutID SCH_AddTimeoutByDelay(double delay, SCH_TimeoutHandler, SCH_ArbitraryArgument);
--- a/smooth.c
+++ b/smooth.c
@@ -93,17 +93,17 @@ static double max_freq;
 /* Frequency offset, time offset and the time of the last smoothing update */
 static double smooth_freq;
 static double smooth_offset;
-static struct timeval last_update;
+static struct timespec last_update;


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

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

  offset = smooth_offset;
  freq = smooth_freq;
@@ -208,13 +208,13 @@ update_stages(void)
  stages[2].length = l3;

  for (i = 0; i < NUM_STAGES; i++) {
-    DEBUG_LOG(LOGF_Smooth, "Smooth stage %d wander %e length %f",
+    DEBUG_LOG("Smooth stage %d wander %e length %f",
              i + 1, stages[i].wander, stages[i].length);
  }
 }

 static void
-update_smoothing(struct timeval *now, double offset, double freq)
+update_smoothing(struct timespec *now, double offset, double freq)
 {
  /* Don't accept offset/frequency until the clock has stabilized */
  if (locked) {
@@ -230,11 +230,11 @@ update_smoothing(struct timeval *now, double offset, double freq)

  update_stages();

-  DEBUG_LOG(LOGF_Smooth, "Smooth offset %e freq %e", smooth_offset, smooth_freq);
+  DEBUG_LOG("Smooth offset %e freq %e", smooth_offset, smooth_freq);
 }

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

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

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

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

@@ -290,19 +290,19 @@ SMT_GetOffset(struct timeval *now)
 }

 void
-SMT_Activate(struct timeval *now)
+SMT_Activate(struct timespec *now)
 {
  if (!enabled || !locked)
    return;

-  LOG(LOGS_INFO, LOGF_Smooth, "Time smoothing activated%s", leap_only_mode ?
+  LOG(LOGS_INFO, "Time smoothing activated%s", leap_only_mode ?
      " (leap seconds only)" : "");
  locked = 0;
  last_update = *now;
 }

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

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

 void
-SMT_Leap(struct timeval *now, int leap)
+SMT_Leap(struct timespec *now, int leap)
 {
  /* When the leap-only mode is disabled, the leap second will be accumulated
     in handle_slew() as a normal offset */
@@ -329,7 +329,7 @@ SMT_Leap(struct timeval *now, int leap)
 }

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

-  UTI_DiffTimevalsToDouble(&elapsed, now, &last_update);
+  elapsed = UTI_DiffTimespecsToDouble(now, &last_update);
  if (!locked && elapsed >= 0.0) {
    for (i = 0, length = 0.0; i < NUM_STAGES; i++)
      length += stages[i].length;
--- a/smooth.h
+++ b/smooth.h
@@ -35,14 +35,14 @@ extern void SMT_Finalise(void);

 extern int SMT_IsEnabled(void);

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

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

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

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

-extern int SMT_GetSmoothingReport(RPT_SmoothingReport *report, struct timeval *now);
+extern int SMT_GetSmoothingReport(RPT_SmoothingReport *report, struct timespec *now);

 #endif
--- a/sources.c
+++ b/sources.c
@@ -56,7 +56,7 @@ static int initialised = 0;
 struct SelectInfo {
  int stratum;
  int select_ok;
-  double variance;
+  double std_dev;
  double root_distance;
  double lo_limit;
  double hi_limit;
@@ -71,12 +71,12 @@ typedef enum {
  SRC_UNSELECTABLE,     /* Has noselect option set */
  SRC_BAD_STATS,        /* Doesn't have valid stats data */
  SRC_BAD_DISTANCE,     /* Has root distance longer than allowed maximum */
+  SRC_JITTERY,          /* Had std dev larger than allowed maximum */
  SRC_WAITS_STATS,      /* Others have bad stats, selection postponed */
  SRC_STALE,            /* Has older samples than others */
  SRC_ORPHAN,           /* Has stratum equal or larger than orphan stratum */
  SRC_UNTRUSTED,        /* Overlaps trusted sources */
  SRC_FALSETICKER,      /* Doesn't agree with others */
-  SRC_JITTERY,          /* Scatter worse than other's dispersion (not used) */
  SRC_WAITS_SOURCES,    /* Not enough sources, selection postponed */
  SRC_NONPREFERRED,     /* Others have prefer option */
  SRC_WAITS_UPDATE,     /* No updates, selection postponed */
@@ -159,6 +159,7 @@ static int selected_source_index; /* Which source index is currently
 #define DISTANT_PENALTY 32

 static double max_distance;
+static double max_jitter;
 static double reselect_distance;
 static double stratum_weight;
 static double combine_limit;
@@ -167,7 +168,7 @@ static double combine_limit;
 /* Forward prototype */

 static void
-slew_sources(struct timeval *raw, struct timeval *cooked, double dfreq,
+slew_sources(struct timespec *raw, struct timespec *cooked, double dfreq,
             double doffset, LCL_ChangeType change_type, void *anything);
 static void
 add_dispersion(double dispersion, void *anything);
@@ -184,6 +185,7 @@ void SRC_Initialise(void) {
  max_n_sources = 0;
  selected_source_index = INVALID_SOURCE;
  max_distance = CNF_GetMaxDistance();
+  max_jitter = CNF_GetMaxJitter();
  reselect_distance = CNF_GetReselectDistance();
  stratum_weight = CNF_GetStratumWeight();
  combine_limit = CNF_GetCombineLimit();
@@ -309,22 +311,12 @@ SRC_SetRefid(SRC_Instance instance, uint32_t ref_id, IPAddr *addr)
 }

 /* ================================================== */
-/* Function to get the range of frequencies, relative to the given
-   source, that we believe the local clock lies within.  The return
-   values are in terms of the number of seconds fast (+ve) or slow
-   (-ve) relative to the source that the local clock becomes after a
-   given amount of local time has elapsed.

-   Suppose the initial offset relative to the source is U (fast +ve,
-   slow -ve) and a time interval T elapses measured in terms of the
-   local clock.  Then the error relative to the source at the end of
-   the interval should lie in the interval [U+T*lo, U+T*hi]. */
-
-void SRC_GetFrequencyRange(SRC_Instance instance, double *lo, double *hi)
+SST_Stats
+SRC_GetSourcestats(SRC_Instance instance)
 {
  assert(initialised);
-
-  SST_GetFrequencyRange(instance->stats, lo, hi);
+  return instance->stats;
 }

 /* ================================================== */
@@ -342,7 +334,7 @@ void SRC_GetFrequencyRange(SRC_Instance instance, double *lo, double *hi)

 void SRC_AccumulateSample
 (SRC_Instance inst, 
- struct timeval *sample_time, 
+ struct timespec *sample_time,
 double offset, 
 double peer_delay,
 double peer_dispersion,
@@ -356,11 +348,12 @@ void SRC_AccumulateSample

  inst->leap_status = leap_status;

-  DEBUG_LOG(LOGF_Sources, "ip=[%s] t=%s ofs=%f del=%f disp=%f str=%d",
-      source_to_string(inst), UTI_TimevalToString(sample_time), -offset, root_delay, root_dispersion, stratum);
+  DEBUG_LOG("ip=[%s] t=%s ofs=%f del=%f disp=%f str=%d",
+            source_to_string(inst), UTI_TimespecToString(sample_time), -offset,
+            root_delay, root_dispersion, stratum);

  if (REF_IsLeapSecondClose()) {
-    LOG(LOGS_INFO, LOGF_Sources, "Dropping sample around leap second");
+    LOG(LOGS_INFO, "Dropping sample around leap second");
    return;
  }

@@ -404,7 +397,7 @@ special_mode_end(void)

      /* Check if the source could still have enough samples to be selectable */
      if (SOURCE_REACH_BITS - 1 - sources[i]->reachability_size +
-            SRC_Samples(sources[i]) >= MIN_SAMPLES_FOR_REGRESS)
+            SST_Samples(sources[i]->stats) >= MIN_SAMPLES_FOR_REGRESS)
        return 0;
    }

@@ -432,10 +425,11 @@ SRC_UpdateReachability(SRC_Instance inst, int reachable)
  }

  /* Try to replace NTP sources that are unreachable, falsetickers, or
-     have root distance larger than the allowed maximum */
+     have root distance or jitter larger than the allowed maximums */
  if (inst->type == SRC_NTP &&
      ((!inst->reachability && inst->reachability_size == SOURCE_REACH_BITS) ||
-       inst->status == SRC_FALSETICKER || inst->status == SRC_BAD_DISTANCE)) {
+       inst->status == SRC_BAD_DISTANCE || inst->status == SRC_JITTERY ||
+       inst->status == SRC_FALSETICKER)) {
    NSR_HandleBadSource(inst->ip_addr);
  }
 }
@@ -457,7 +451,7 @@ log_selection_message(char *format, char *arg)
 {
  if (REF_GetMode() != REF_ModeNormal)
    return;
-  LOG(LOGS_INFO, LOGF_Sources, format, arg);
+  LOG(LOGS_INFO, format, arg);
 }

 /* ================================================== */
@@ -514,10 +508,10 @@ mark_ok_sources(SRC_Status status)
 /* ================================================== */

 static int
-combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
+combine_sources(int n_sel_sources, struct timespec *ref_time, double *offset,
                double *offset_sd, double *frequency, double *skew)
 {
-  struct timeval src_ref_time;
+  struct timespec src_ref_time;
  double src_offset, src_offset_sd, src_frequency, src_skew;
  double src_root_delay, src_root_dispersion, sel_src_distance, elapsed;
  double offset_weight, sum_offset_weight, sum_offset, sum2_offset_sd;
@@ -564,12 +558,12 @@ combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
    if (sources[index]->status == SRC_OK)
      sources[index]->status = SRC_UNSELECTED;

-    UTI_DiffTimevalsToDouble(&elapsed, ref_time, &src_ref_time);
+    elapsed = UTI_DiffTimespecsToDouble(ref_time, &src_ref_time);
    src_offset += elapsed * src_frequency;
    offset_weight = 1.0 / sources[index]->sel_info.root_distance;
    frequency_weight = 1.0 / src_skew;

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

    sum_offset_weight += offset_weight;
@@ -590,7 +584,7 @@ combine_sources(int n_sel_sources, struct timeval *ref_time, double *offset,
  *frequency = sum_frequency / sum_frequency_weight;
  *skew = 1.0 / sqrt(inv_sum2_skew);

-  DEBUG_LOG(LOGF_Sources, "combined result offset=%e sd=%e freq=%e skew=%e",
+  DEBUG_LOG("combined result offset=%e sd=%e freq=%e skew=%e",
      *offset, *offset_sd, *frequency, *skew);

  return combined;
@@ -604,12 +598,12 @@ void
 SRC_SelectSource(SRC_Instance updated_inst)
 {
  struct SelectInfo *si;
-  struct timeval now, ref_time;
+  struct timespec now, ref_time;
  int i, j, j1, j2, index, sel_prefer, n_endpoints, n_sel_sources;
  int n_badstats_sources, max_sel_reach, max_badstat_reach, sel_req_source;
  int depth, best_depth, trust_depth, best_trust_depth;
  int combined, stratum, min_stratum, max_score_index;
-  int orphan_stratum, orphan_source;
+  int orphan_stratum, orphan_source, leap_votes, leap_ins, leap_del;
  double src_offset, src_offset_sd, src_frequency, src_skew;
  double src_root_delay, src_root_dispersion;
  double best_lo, best_hi, distance, sel_src_distance, max_score;
@@ -657,7 +651,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
    si = &sources[i]->sel_info;
    SST_GetSelectionData(sources[i]->stats, &now, &si->stratum,
                         &si->lo_limit, &si->hi_limit, &si->root_distance,
-                         &si->variance, &first_sample_ago,
+                         &si->std_dev, &first_sample_ago,
                         &si->last_sample_ago, &si->select_ok);

    if (!si->select_ok) {
@@ -674,6 +668,12 @@ SRC_SelectSource(SRC_Instance updated_inst)
      continue;
    }

+    /* And the same applies for the estimated standard deviation */
+    if (si->std_dev > max_jitter) {
+      sources[i]->status = SRC_JITTERY;
+      continue;
+    }
+
    sources[i]->status = SRC_OK; /* For now */

    if (sources[i]->reachability && max_reach_sample_ago < first_sample_ago)
@@ -736,12 +736,11 @@ SRC_SelectSource(SRC_Instance updated_inst)
    uint32_t local_ref_id = NSR_GetLocalRefid(sources[orphan_source]->ip_addr);

    if (!local_ref_id) {
-      LOG(LOGS_ERR, LOGF_Sources, "Unknown local refid in orphan mode");
+      LOG(LOGS_ERR, "Unknown local refid in orphan mode");
    } else if (sources[orphan_source]->ref_id < local_ref_id) {
      sources[orphan_source]->status = SRC_OK;
      n_sel_sources = 1;
-      DEBUG_LOG(LOGF_Sources, "selecting orphan refid=%"PRIx32,
-                sources[orphan_source]->ref_id);
+      DEBUG_LOG("selecting orphan refid=%"PRIx32, sources[orphan_source]->ref_id);
    }
  }

@@ -765,7 +764,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
    n_endpoints += 2;
  }

-  DEBUG_LOG(LOGF_Sources, "badstat=%d sel=%d badstat_reach=%x sel_reach=%x max_reach_ago=%f",
+  DEBUG_LOG("badstat=%d sel=%d badstat_reach=%x sel_reach=%x max_reach_ago=%f",
            n_badstats_sources, n_sel_sources, max_badstat_reach,
            max_sel_reach, max_reach_sample_ago);

@@ -910,18 +909,22 @@ SRC_SelectSource(SRC_Instance updated_inst)
    return;
  }

-  /* Accept leap second status if more than half of selectable sources agree */
-  for (i = j1 = j2 = 0; i < n_sel_sources; i++) {
+  /* Accept leap second status if more than half of selectable (and trusted
+     if there are any) sources agree */
+  for (i = leap_ins = leap_del = leap_votes = 0; i < n_sel_sources; i++) {
    index = sel_sources[i];
+    if (best_trust_depth && !(sources[index]->sel_options & SRC_SELECT_TRUST))
+      continue;
+    leap_votes++;
    if (sources[index]->leap_status == LEAP_InsertSecond)
-      j1++;
+      leap_ins++;
    else if (sources[index]->leap_status == LEAP_DeleteSecond)
-      j2++;
+      leap_del++;
  }

-  if (j1 > n_sel_sources / 2)
+  if (leap_ins > leap_votes / 2)
    leap_status = LEAP_InsertSecond;
-  else if (j2 > n_sel_sources / 2)
+  else if (leap_del > leap_votes / 2)
    leap_status = LEAP_DeleteSecond;
  else
    leap_status = LEAP_Normal;
@@ -999,7 +1002,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
      sources[i]->sel_score = 1.0 / distance;
    }

-    DEBUG_LOG(LOGF_Sources, "select score=%f refid=%"PRIx32" match_refid=%"PRIx32" status=%d dist=%f",
+    DEBUG_LOG("select score=%f refid=%"PRIx32" match_refid=%"PRIx32" status=%d dist=%f",
              sources[i]->sel_score, sources[i]->ref_id,
              updated_inst ? updated_inst->ref_id : 0,
              sources[i]->status, distance);
@@ -1023,7 +1026,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
    if (sources[max_score_index]->updates == 0) {
      selected_source_index = INVALID_SOURCE;
      mark_ok_sources(SRC_WAITS_UPDATE);
-      DEBUG_LOG(LOGF_Sources, "best source has no updates");
+      DEBUG_LOG("best source has no updates");
      return;
    }

@@ -1094,36 +1097,10 @@ SRC_SetReselectDistance(double distance)
 {
  if (reselect_distance != distance) {
    reselect_distance = distance;
-    LOG(LOGS_INFO, LOGF_Sources, "New reselect distance %f", distance);
+    LOG(LOGS_INFO, "New reselect distance %f", distance);
  }
 }

-/* ================================================== */
-
-double
-SRC_PredictOffset(SRC_Instance inst, struct timeval *when)
-{
-  return SST_PredictOffset(inst->stats, when);
-}
-
-/* ================================================== */
-
-double
-SRC_MinRoundTripDelay(SRC_Instance inst)
-{
-  return SST_MinRoundTripDelay(inst->stats);
-}
-
-/* ================================================== */
-
-int
-SRC_IsGoodSample(SRC_Instance inst, double offset, double delay,
-   double max_delay_dev_ratio, double clock_error, struct timeval *when)
-{
-  return SST_IsGoodSample(inst->stats, offset, delay, max_delay_dev_ratio,
-      clock_error, when);
-}
-
 /* ================================================== */
 /* This routine is registered as a callback with the local clock
   module, to be called whenever the local clock changes frequency or
@@ -1132,12 +1109,8 @@ SRC_IsGoodSample(SRC_Instance inst, double offset, double delay,
   the new regime. */

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

@@ -1169,6 +1142,39 @@ add_dispersion(double dispersion, void *anything)
  }
 }

+/* ================================================== */
+
+static
+FILE *open_dumpfile(SRC_Instance inst, const char *mode)
+{
+  FILE *f;
+  char filename[1024], *dumpdir;
+
+  dumpdir = CNF_GetDumpDir();
+  if (dumpdir[0] == '\0') {
+    LOG(LOGS_WARN, "dumpdir not specified");
+    return NULL;
+  }
+
+  /* Include IP address in the name for NTP sources, or reference ID in hex */
+  if ((inst->type == SRC_NTP &&
+       snprintf(filename, sizeof (filename), "%s/%s.dat", dumpdir,
+                source_to_string(inst)) >= sizeof (filename)) ||
+      (inst->type != SRC_NTP &&
+       snprintf(filename, sizeof (filename), "%s/refid:%08"PRIx32".dat",
+                dumpdir, inst->ref_id) >= sizeof (filename))) {
+    LOG(LOGS_WARN, "dumpdir too long");
+    return NULL;
+  }
+
+  f = fopen(filename, mode);
+  if (!f && mode[0] != 'r')
+    LOG(LOGS_WARN, "Could not open dump file for %s",
+        source_to_string(inst));
+
+  return f;
+}
+
 /* ================================================== */
 /* This is called to dump out the source measurement registers */

@@ -1176,34 +1182,15 @@ void
 SRC_DumpSources(void)
 {
  FILE *out;
-  int direc_len, file_len;
-  char *filename;
-  unsigned int a, b, c, d;
  int i;
-  char *direc;
-
-  direc = CNF_GetDumpDir();
-  direc_len = strlen(direc);
-  file_len = direc_len + 24;
-  filename = MallocArray(char, file_len); /* a bit of slack */

  for (i = 0; i < n_sources; i++) {
-    a = (sources[i]->ref_id) >> 24;
-    b = ((sources[i]->ref_id) >> 16) & 0xff;
-    c = ((sources[i]->ref_id) >> 8) & 0xff;
-    d = ((sources[i]->ref_id)) & 0xff;
-
-    snprintf(filename, file_len - 1, "%s/%d.%d.%d.%d.dat", direc, a, b, c, d);
-    out = fopen(filename, "w");
-    if (!out) {
-      LOG(LOGS_WARN, LOGF_Sources, "Could not open dump file %s", filename);
-    } else {
-      SST_SaveToFile(sources[i]->stats, out);
-      fclose(out);
-    }
+    out = open_dumpfile(sources[i], "w");
+    if (!out)
+      continue;
+    SST_SaveToFile(sources[i]->stats, out);
+    fclose(out);
  }
-
-  Free(filename);
 }

 /* ================================================== */
@@ -1212,40 +1199,63 @@ void
 SRC_ReloadSources(void)
 {
  FILE *in;
-  char *filename;
-  unsigned int a, b, c, d;
  int i;
-  char *dumpdir;
-  int dumpdirlen, filelen;

-  for (i=0; i<n_sources; i++) {
-    a = (sources[i]->ref_id) >> 24;
-    b = ((sources[i]->ref_id) >> 16) & 0xff;
-    c = ((sources[i]->ref_id) >> 8) & 0xff;
-    d = ((sources[i]->ref_id)) & 0xff;
-
-    dumpdir = CNF_GetDumpDir();
-    dumpdirlen = strlen(dumpdir);
-    filelen = dumpdirlen + 24;
-    filename = MallocArray(char, filelen);
-    snprintf(filename, filelen-1, "%s/%d.%d.%d.%d.dat", dumpdir, a, b, c, d);
-    in = fopen(filename, "r");
-    if (!in) {
-      LOG(LOGS_WARN, LOGF_Sources, "Could not open dump file %s", filename);
-    } else {
-      if (SST_LoadFromFile(sources[i]->stats, in)) {
-        SST_DoNewRegression(sources[i]->stats);
-      } else {
-        LOG(LOGS_WARN, LOGF_Sources, "Problem loading from file %s", filename);
-      }
-      fclose(in);
-    }
-    Free(filename);
+  for (i = 0; i < n_sources; i++) {
+    in = open_dumpfile(sources[i], "r");
+    if (!in)
+      continue;
+    if (!SST_LoadFromFile(sources[i]->stats, in))
+      LOG(LOGS_WARN, "Could not load dump file for %s",
+          source_to_string(sources[i]));
+    else
+      LOG(LOGS_INFO, "Loaded dump file for %s",
+          source_to_string(sources[i]));
+    fclose(in);
  }
 }

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

+void
+SRC_RemoveDumpFiles(void)
+{
+  char pattern[1024], name[64], *dumpdir, *s;
+  IPAddr ip_addr;
+  glob_t gl;
+  size_t i;
+
+  dumpdir = CNF_GetDumpDir();
+  if (dumpdir[0] == '\0' ||
+      snprintf(pattern, sizeof (pattern), "%s/*.dat", dumpdir) >= sizeof (pattern))
+    return;
+
+  if (glob(pattern, 0, NULL, &gl))
+    return;
+
+  for (i = 0; i < gl.gl_pathc; i++) {
+    s = strrchr(gl.gl_pathv[i], '/');
+    if (!s || snprintf(name, sizeof (name), "%s", s + 1) >= sizeof (name))
+      continue;
+
+    /* Remove .dat extension */
+    if (strlen(name) < 4)
+      continue;
+    name[strlen(name) - 4] = '\0';
+
+    /* Check if it looks like name of an actual dump file */
+    if (strncmp(name, "refid:", 6) && !UTI_StringToIP(name, &ip_addr))
+      continue;
+
+    DEBUG_LOG("Removing %s", gl.gl_pathv[i]);
+    unlink(gl.gl_pathv[i]);
+  }
+
+  globfree(&gl);
+}
+
+/* ================================================== */
+
 int
 SRC_IsSyncPeer(SRC_Instance inst)
 {
@@ -1290,7 +1300,7 @@ SRC_ActiveSources(void)
 /* ================================================== */

 int
-SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
+SRC_ReportSource(int index, RPT_SourceReport *report, struct timespec *now)
 {
  SRC_Instance src;
  if ((index >= n_sources) || (index < 0)) {
@@ -1298,7 +1308,6 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
  } else {
    src = sources[index];

-    memset(&report->ip_addr, 0, sizeof (report->ip_addr));
    if (src->ip_addr)
      report->ip_addr = *src->ip_addr;
    else {
@@ -1308,14 +1317,6 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
    }

    switch (src->status) {
-      case SRC_UNSELECTABLE:
-      case SRC_BAD_STATS:
-      case SRC_BAD_DISTANCE:
-      case SRC_STALE:
-      case SRC_ORPHAN:
-      case SRC_WAITS_STATS:
-        report->state = RPT_UNREACH;
-        break;
      case SRC_FALSETICKER:
        report->state = RPT_FALSETICKER;
        break;
@@ -1336,9 +1337,8 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
      case SRC_SELECTED:
        report->state = RPT_SYNC;
        break;
-      case SRC_OK:
      default:
-        assert(0);
+        report->state = RPT_UNREACH;
        break;
    }

@@ -1356,7 +1356,7 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
 /* ================================================== */

 int
-SRC_ReportSourcestats(int index, RPT_SourcestatsReport *report, struct timeval *now)
+SRC_ReportSourcestats(int index, RPT_SourcestatsReport *report, struct timespec *now)
 { 
  SRC_Instance src;

@@ -1385,11 +1385,3 @@ SRC_GetType(int index)
 }

 /* ================================================== */
-
-int
-SRC_Samples(SRC_Instance inst)
-{
-  return SST_Samples(inst->stats);
-}
-
-/* ================================================== */
--- a/sources.h
+++ b/sources.h
@@ -34,6 +34,7 @@

 #include "ntp.h"
 #include "reports.h"
+#include "sourcestats.h"

 /* Size of the source reachability register */
 #define SOURCE_REACH_BITS 8
@@ -73,18 +74,8 @@ extern void SRC_ResetInstance(SRC_Instance instance);
 /* Function to change the sources's reference ID and IP address */
 extern void SRC_SetRefid(SRC_Instance instance, uint32_t ref_id, IPAddr *addr);

-/* Function to get the range of frequencies, relative to the given
-   source, that we believe the local clock lies within.  The return
-   values are in terms of the number of seconds fast (+ve) or slow
-   (-ve) relative to the source that the local clock becomes after a
-   given amount of local time has elapsed.
-
-   Suppose the initial offset relative to the source is U (fast +ve,
-   slow -ve) and a time interval T elapses measured in terms of the
-   local clock.  Then the error relative to the source at the end of
-   the interval should lie in the interval [U+T*lo, U+T*hi]. */
-
-extern void SRC_GetFrequencyRange(SRC_Instance instance, double *lo, double *hi);
+/* Function to get access to the sourcestats instance */
+extern SST_Stats SRC_GetSourcestats(SRC_Instance instance);

 /* This function is called by one of the source drivers when it has
   a new sample that is to be accumulated.
@@ -114,7 +105,7 @@ extern void SRC_GetFrequencyRange(SRC_Instance instance, double *lo, double *hi)

   */

-extern void SRC_AccumulateSample(SRC_Instance instance, struct timeval *sample_time, double offset, double peer_delay, double peer_dispersion, double root_delay, double root_dispersion, int stratum, NTP_Leap leap_status);
+extern void SRC_AccumulateSample(SRC_Instance instance, struct timespec *sample_time, double offset, double peer_delay, double peer_dispersion, double root_delay, double root_dispersion, int stratum, NTP_Leap leap_status);

 /* This routine sets the source as receiving reachability updates */
 extern void SRC_SetActive(SRC_Instance inst);
@@ -143,34 +134,18 @@ extern void SRC_ReselectSource(void);
 /* Set reselect distance */
 extern void SRC_SetReselectDistance(double distance);

-/* Predict the offset of the local clock relative to a given source at
-   a given local cooked time. Positive indicates local clock is FAST
-   relative to reference. */
-extern double SRC_PredictOffset(SRC_Instance inst, struct timeval *when);
-
-/* Return the minimum peer delay amongst the previous samples
-   currently held in the register */
-extern double SRC_MinRoundTripDelay(SRC_Instance inst);
-
-/* This routine determines if a new sample is good enough that it should be
-   accumulated */
-extern int SRC_IsGoodSample(SRC_Instance inst, double offset, double delay, double max_delay_dev_ratio, double clock_error, struct timeval *when);
-
 extern void SRC_DumpSources(void);
-
 extern void SRC_ReloadSources(void);
+extern void SRC_RemoveDumpFiles(void);

 extern int SRC_IsSyncPeer(SRC_Instance inst);
 extern int SRC_IsReachable(SRC_Instance inst);
 extern int SRC_ReadNumberOfSources(void);
 extern int SRC_ActiveSources(void);
-extern int SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now);
+extern int SRC_ReportSource(int index, RPT_SourceReport *report, struct timespec *now);

-extern int SRC_ReportSourcestats(int index, RPT_SourcestatsReport *report, struct timeval *now);
+extern int SRC_ReportSourcestats(int index, RPT_SourcestatsReport *report, struct timespec *now);

 extern SRC_Type SRC_GetType(int index);

-extern int SRC_Samples(SRC_Instance inst);
-
 #endif /* GOT_SOURCES_H */
-
--- a/sourcestats.c
+++ b/sourcestats.c
@@ -3,7 +3,7 @@

 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2014
+ * Copyright (C) Miroslav Lichvar  2011-2014, 2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -47,8 +47,22 @@
   2000ppm, which would be pretty bad */
 #define WORST_CASE_FREQ_BOUND (2000.0/1.0e6)

-/* The minimum allowed skew */
+/* The minimum and maximum assumed skew */
 #define MIN_SKEW 1.0e-12
+#define MAX_SKEW 1.0e+02
+
+/* The asymmetry of network jitter when all jitter is in one direction */
+#define MAX_ASYMMETRY 0.5
+
+/* The minimum estimated asymmetry that can activate the offset correction */
+#define MIN_ASYMMETRY 0.45
+
+/* The minimum number of consecutive asymmetries with the same sign needed
+   to activate the offset correction */
+#define MIN_ASYMMETRY_RUN 10
+
+/* The maximum value of the counter */
+#define MAX_ASYMMETRY_RUN 1000

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

@@ -72,8 +86,8 @@ struct SST_Stats_Record {
     buffer. */
  int n_samples;

-  /* Number of extra samples stored in sample_times and offsets arrays that are
-     used to extend runs test */
+  /* Number of extra samples stored in sample_times, offsets and peer_delays
+     arrays that are used to extend the runs test */
  int runs_samples;

  /* The index of the newest sample */
@@ -92,11 +106,18 @@ struct SST_Stats_Record {
  /* This is the estimated offset (+ve => local fast) at a particular time */
  double estimated_offset;
  double estimated_offset_sd;
-  struct timeval offset_time;
+  struct timespec offset_time;

  /* Number of runs of the same sign amongst the residuals */
  int nruns;

+  /* Number of consecutive estimated asymmetries with the same sign.
+     The sign of the number encodes the sign of the asymmetry. */
+  int asymmetry_run;
+
+  /* This is the latest estimated asymmetry of network jitter */
+  double asymmetry;
+
  /* This value contains the estimated frequency.  This is the number
     of seconds that the local clock gains relative to the reference
     source per unit local time.  (Positive => local clock fast,
@@ -108,12 +129,12 @@ struct SST_Stats_Record {
     about estimated_frequency */
  double skew;

-  /* This is the estimated residual variance of the data points */
-  double variance;
+  /* This is the estimated standard deviation of the data points */
+  double std_dev;

  /* This array contains the sample epochs, in terms of the local
     clock. */
-  struct timeval sample_times[MAX_SAMPLES * REGRESS_RUNS_RATIO];
+  struct timespec sample_times[MAX_SAMPLES * REGRESS_RUNS_RATIO];

  /* This is an array of offsets, in seconds, corresponding to the
     sample times.  In this module, we use the convention that
@@ -131,7 +152,7 @@ struct SST_Stats_Record {

  /* This is an array of peer delays, in seconds, being the roundtrip
     measurement delay to the peer */
-  double peer_delays[MAX_SAMPLES];
+  double peer_delays[MAX_SAMPLES * REGRESS_RUNS_RATIO];

  /* This is an array of peer dispersions, being the skew and local
     precision dispersion terms from sampling the peer */
@@ -161,7 +182,7 @@ void
 SST_Initialise(void)
 {
  logfileid = CNF_GetLogStatistics() ? LOG_FileOpen("statistics",
-      "   Date (UTC) Time     IP Address    Std dev'n Est offset  Offset sd  Diff freq   Est skew  Stress  Ns  Bs  Nr")
+      "   Date (UTC) Time     IP Address    Std dev'n Est offset  Offset sd  Diff freq   Est skew  Stress  Ns  Bs  Nr  Asym")
    : -1;
 }

@@ -214,10 +235,11 @@ SST_ResetInstance(SST_Stats inst)
  inst->skew = 2000.0e-6;
  inst->estimated_offset = 0.0;
  inst->estimated_offset_sd = 86400.0; /* Assume it's at least within a day! */
-  inst->offset_time.tv_sec = 0;
-  inst->offset_time.tv_usec = 0;
-  inst->variance = 16.0;
+  UTI_ZeroTimespec(&inst->offset_time);
+  inst->std_dev = 4.0;
  inst->nruns = 0;
+  inst->asymmetry_run = 0;
+  inst->asymmetry = 0.0;
 }

 /* ================================================== */
@@ -253,7 +275,7 @@ prune_register(SST_Stats inst, int new_oldest)
 /* ================================================== */

 void
-SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time,
+SST_AccumulateSample(SST_Stats inst, struct timespec *sample_time,
                     double offset,
                     double peer_delay, double peer_dispersion,
                     double root_delay, double root_dispersion,
@@ -269,8 +291,8 @@ SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time,

  /* Make sure it's newer than the last sample */
  if (inst->n_samples &&
-      UTI_CompareTimevals(&inst->sample_times[inst->last_sample], sample_time) >= 0) {
-    LOG(LOGS_WARN, LOGF_SourceStats, "Out of order sample detected, discarding history for %s",
+      UTI_CompareTimespecs(&inst->sample_times[inst->last_sample], sample_time) >= 0) {
+    LOG(LOGS_WARN, "Out of order sample detected, discarding history for %s",
        inst->ip_addr ? UTI_IPToString(inst->ip_addr) : UTI_RefidToString(inst->refid));
    SST_ResetInstance(inst);
  }
@@ -282,14 +304,14 @@ SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time,
  inst->sample_times[n] = *sample_time;
  inst->offsets[n] = offset;
  inst->orig_offsets[m] = offset;
-  inst->peer_delays[m] = peer_delay;
+  inst->peer_delays[n] = peer_delay;
  inst->peer_dispersions[m] = peer_dispersion;
  inst->root_delays[m] = root_delay;
  inst->root_dispersions[m] = root_dispersion;
  inst->strata[m] = stratum;
 
-  if (!inst->n_samples || inst->peer_delays[m] < inst->peer_delays[inst->min_delay_sample])
-    inst->min_delay_sample = m;
+  if (!inst->n_samples || inst->peer_delays[n] < inst->peer_delays[inst->min_delay_sample])
+    inst->min_delay_sample = n;

  ++inst->n_samples;
 }
@@ -323,14 +345,13 @@ get_buf_index(SST_Stats inst, int i)
 static void
 convert_to_intervals(SST_Stats inst, double *times_back)
 {
-  struct timeval *newest_tv;
+  struct timespec *ts;
  int i;

-  newest_tv = &(inst->sample_times[inst->last_sample]);
+  ts = &inst->sample_times[inst->last_sample];
  for (i = -inst->runs_samples; i < inst->n_samples; i++) {
    /* The entries in times_back[] should end up negative */
-    UTI_DiffTimevalsToDouble(&times_back[i],
-        &inst->sample_times[get_runsbuf_index(inst, i)], newest_tv);
+    times_back[i] = UTI_DiffTimespecsToDouble(&inst->sample_times[get_runsbuf_index(inst, i)], ts);
  }
 }

@@ -376,15 +397,65 @@ find_min_delay_sample(SST_Stats inst)
 {
  int i, index;

-  inst->min_delay_sample = get_buf_index(inst, 0);
+  inst->min_delay_sample = get_runsbuf_index(inst, -inst->runs_samples);

-  for (i = 1; i < inst->n_samples; i++) {
-    index = get_buf_index(inst, i);
+  for (i = -inst->runs_samples + 1; i < inst->n_samples; i++) {
+    index = get_runsbuf_index(inst, i);
    if (inst->peer_delays[index] < inst->peer_delays[inst->min_delay_sample])
      inst->min_delay_sample = index;
  }
 }

+/* ================================================== */
+/* This function estimates asymmetry of network jitter on the path to the
+   source as a slope of offset against network delay in multiple linear
+   regression.  If the asymmetry is significant and its sign doesn't change
+   frequently, the measured offsets (which are used later to estimate the
+   offset and frequency of the clock) are corrected to correspond to the
+   minimum network delay.  This can significantly improve the accuracy and
+   stability of the estimated offset and frequency. */
+
+static void
+correct_asymmetry(SST_Stats inst, double *times_back, double *offsets)
+{
+  double asymmetry, delays[MAX_SAMPLES * REGRESS_RUNS_RATIO];
+  int i, n;
+
+  /* Don't try to estimate the asymmetry with reference clocks */
+  if (!inst->ip_addr)
+    return;
+
+  n = inst->runs_samples + inst->n_samples;
+
+  for (i = 0; i < n; i++)
+    delays[i] = inst->peer_delays[get_runsbuf_index(inst, i - inst->runs_samples)] -
+                inst->peer_delays[inst->min_delay_sample];
+
+  /* Reset the counter when the regression fails or the sign changes */
+  if (!RGR_MultipleRegress(times_back, delays, offsets, n, &asymmetry) ||
+      asymmetry * inst->asymmetry_run < 0.0) {
+    inst->asymmetry_run = 0;
+    inst->asymmetry = 0.0;
+    return;
+  }
+
+  asymmetry = CLAMP(-MAX_ASYMMETRY, asymmetry, MAX_ASYMMETRY);
+
+  if (asymmetry <= -MIN_ASYMMETRY && inst->asymmetry_run > -MAX_ASYMMETRY_RUN)
+    inst->asymmetry_run--;
+  else if (asymmetry >= MIN_ASYMMETRY && inst->asymmetry_run < MAX_ASYMMETRY_RUN)
+    inst->asymmetry_run++;
+
+  if (abs(inst->asymmetry_run) < MIN_ASYMMETRY_RUN)
+    return;
+
+  /* Correct the offsets */
+  for (i = 0; i < n; i++)
+    offsets[i] -= asymmetry * delays[i];
+
+  inst->asymmetry = asymmetry;
+}
+
 /* ================================================== */

 /* This defines the assumed ratio between the standard deviation of
@@ -392,7 +463,7 @@ find_min_delay_sample(SST_Stats inst)
   time.  E.g. a value of 4 means that we think the standard deviation
   is four times the fluctuation  of the peer distance */

-#define SD_TO_DIST_RATIO 1.0
+#define SD_TO_DIST_RATIO 0.7

 /* ================================================== */
 /* This function runs the linear regression operation on the data.  It
@@ -412,9 +483,10 @@ SST_DoNewRegression(SST_Stats inst)
  int best_start, times_back_start;
  double est_intercept, est_slope, est_var, est_intercept_sd, est_slope_sd;
  int i, j, nruns;
-  double min_distance, mean_distance;
+  double min_distance, median_distance;
  double sd_weight, sd;
  double old_skew, old_freq, stress;
+  double precision;

  convert_to_intervals(inst, times_back + inst->runs_samples);

@@ -423,28 +495,34 @@ SST_DoNewRegression(SST_Stats inst)
      offsets[i + inst->runs_samples] = inst->offsets[get_runsbuf_index(inst, i)];
    }
  
-    for (i = 0, mean_distance = 0.0, min_distance = DBL_MAX; i < inst->n_samples; i++) {
+    for (i = 0, min_distance = DBL_MAX; i < inst->n_samples; i++) {
      j = get_buf_index(inst, i);
-      peer_distances[i] = 0.5 * inst->peer_delays[j] + inst->peer_dispersions[j];
-      mean_distance += peer_distances[i];
+      peer_distances[i] = 0.5 * inst->peer_delays[get_runsbuf_index(inst, i)] +
+                          inst->peer_dispersions[j];
      if (peer_distances[i] < min_distance) {
        min_distance = peer_distances[i];
      }
    }
-    mean_distance /= inst->n_samples;

    /* And now, work out the weight vector */

-    sd = mean_distance - min_distance;
-    if (sd > min_distance || sd <= 0.0)
-      sd = min_distance;
+    precision = LCL_GetSysPrecisionAsQuantum();
+    median_distance = RGR_FindMedian(peer_distances, inst->n_samples);
+
+    sd = (median_distance - min_distance) / SD_TO_DIST_RATIO;
+    sd = CLAMP(precision, sd, min_distance);
+    min_distance += precision;

    for (i=0; i<inst->n_samples; i++) {
-      sd_weight = 1.0 + SD_TO_DIST_RATIO * (peer_distances[i] - min_distance) / sd;
+      sd_weight = 1.0;
+      if (peer_distances[i] > min_distance)
+        sd_weight += (peer_distances[i] - min_distance) / sd;
      weights[i] = sd_weight * sd_weight;
    }
  }

+  correct_asymmetry(inst, times_back, offsets);
+
  inst->regression_ok = RGR_FindBestRegression(times_back + inst->runs_samples,
                                         offsets + inst->runs_samples, weights,
                                         inst->n_samples, inst->runs_samples,
@@ -463,26 +541,26 @@ SST_DoNewRegression(SST_Stats inst)
    inst->estimated_offset = est_intercept;
    inst->offset_time = inst->sample_times[inst->last_sample];
    inst->estimated_offset_sd = est_intercept_sd;
-    inst->variance = est_var;
+    inst->std_dev = sqrt(est_var);
    inst->nruns = nruns;

-    if (inst->skew < MIN_SKEW)
-      inst->skew = MIN_SKEW;
-
+    inst->skew = CLAMP(MIN_SKEW, inst->skew, MAX_SKEW);
    stress = fabs(old_freq - inst->estimated_frequency) / old_skew;

+    DEBUG_LOG("off=%e freq=%e skew=%e n=%d bs=%d runs=%d asym=%f arun=%d",
+              inst->estimated_offset, inst->estimated_frequency, inst->skew,
+              inst->n_samples, best_start, inst->nruns,
+              inst->asymmetry, inst->asymmetry_run);
+
    if (logfileid != -1) {
-      LOG_FileWrite(logfileid, "%s %-15s %10.3e %10.3e %10.3e %10.3e %10.3e %7.1e %3d %3d %3d",
+      LOG_FileWrite(logfileid, "%s %-15s %10.3e %10.3e %10.3e %10.3e %10.3e %7.1e %3d %3d %3d %5.2f",
              UTI_TimeToLogForm(inst->offset_time.tv_sec),
              inst->ip_addr ? UTI_IPToString(inst->ip_addr) : UTI_RefidToString(inst->refid),
-              sqrt(inst->variance),
-              inst->estimated_offset,
-              inst->estimated_offset_sd,
-              inst->estimated_frequency,
-              inst->skew,
-              stress,
-              inst->n_samples,
-              best_start, nruns);
+              inst->std_dev,
+              inst->estimated_offset, inst->estimated_offset_sd,
+              inst->estimated_frequency, inst->skew, stress,
+              inst->n_samples, best_start, inst->nruns,
+              inst->asymmetry);
    }

    times_back_start = inst->runs_samples + best_start;
@@ -524,12 +602,12 @@ SST_GetFrequencyRange(SST_Stats inst,
 /* ================================================== */

 void
-SST_GetSelectionData(SST_Stats inst, struct timeval *now,
+SST_GetSelectionData(SST_Stats inst, struct timespec *now,
                     int *stratum,
                     double *offset_lo_limit,
                     double *offset_hi_limit,
                     double *root_distance,
-                     double *variance,
+                     double *std_dev,
                     double *first_sample_ago,
                     double *last_sample_ago,
                     int *select_ok)
@@ -546,9 +624,9 @@ SST_GetSelectionData(SST_Stats inst, struct timeval *now,
  j = get_buf_index(inst, inst->best_single_sample);

  *stratum = inst->strata[get_buf_index(inst, inst->n_samples - 1)];
-  *variance = inst->variance;
+  *std_dev = inst->std_dev;

-  UTI_DiffTimevalsToDouble(&sample_elapsed, now, &inst->sample_times[i]);
+  sample_elapsed = fabs(UTI_DiffTimespecsToDouble(now, &inst->sample_times[i]));
  offset = inst->offsets[i] + sample_elapsed * inst->estimated_frequency;
  *root_distance = 0.5 * inst->root_delays[j] +
    inst->root_dispersions[j] + sample_elapsed * inst->skew;
@@ -560,10 +638,10 @@ SST_GetSelectionData(SST_Stats inst, struct timeval *now,
  double average_offset, elapsed;
  int average_ok;
  /* average_ok ignored for now */
-  UTI_DiffTimevalsToDouble(&elapsed, now, &(inst->offset_time));
+  elapsed = UTI_DiffTimespecsToDouble(now, &inst->offset_time);
  average_offset = inst->estimated_offset + inst->estimated_frequency * elapsed;
  if (fabs(average_offset - offset) <=
-      inst->peer_dispersions[j] + 0.5 * inst->peer_delays[j]) {
+      inst->peer_dispersions[j] + 0.5 * inst->peer_delays[i]) {
    average_ok = 1;
  } else {
    average_ok = 0;
@@ -571,21 +649,21 @@ SST_GetSelectionData(SST_Stats inst, struct timeval *now,
 #endif

  i = get_runsbuf_index(inst, 0);
-  UTI_DiffTimevalsToDouble(first_sample_ago, now, &inst->sample_times[i]);
+  *first_sample_ago = UTI_DiffTimespecsToDouble(now, &inst->sample_times[i]);
  i = get_runsbuf_index(inst, inst->n_samples - 1);
-  UTI_DiffTimevalsToDouble(last_sample_ago, now, &inst->sample_times[i]);
+  *last_sample_ago = UTI_DiffTimespecsToDouble(now, &inst->sample_times[i]);

  *select_ok = inst->regression_ok;

-  DEBUG_LOG(LOGF_SourceStats, "n=%d off=%f dist=%f var=%f first_ago=%f last_ago=%f selok=%d",
-            inst->n_samples, offset, *root_distance, *variance,
+  DEBUG_LOG("n=%d off=%f dist=%f sd=%f first_ago=%f last_ago=%f selok=%d",
+            inst->n_samples, offset, *root_distance, *std_dev,
            *first_sample_ago, *last_sample_ago, *select_ok);
 }

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

 void
-SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,
+SST_GetTrackingData(SST_Stats inst, struct timespec *ref_time,
                    double *average_offset, double *offset_sd,
                    double *frequency, double *skew,
                    double *root_delay, double *root_dispersion)
@@ -605,22 +683,23 @@ SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,
  *skew = inst->skew;
  *root_delay = inst->root_delays[j];

-  UTI_DiffTimevalsToDouble(&elapsed_sample, &inst->offset_time, &inst->sample_times[i]);
+  elapsed_sample = UTI_DiffTimespecsToDouble(&inst->offset_time, &inst->sample_times[i]);
  *root_dispersion = inst->root_dispersions[j] + inst->skew * elapsed_sample;

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

 }

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

 void
-SST_SlewSamples(SST_Stats inst, struct timeval *when, double dfreq, double doffset)
+SST_SlewSamples(SST_Stats inst, struct timespec *when, double dfreq, double doffset)
 {
  int m, i;
  double delta_time;
-  struct timeval *sample, prev;
+  struct timespec *sample, prev;
  double prev_offset, prev_freq;

  if (!inst->n_samples)
@@ -628,9 +707,9 @@ SST_SlewSamples(SST_Stats inst, struct timeval *when, double dfreq, double doffs

  for (m = -inst->runs_samples; m < inst->n_samples; m++) {
    i = get_runsbuf_index(inst, m);
-    sample = &(inst->sample_times[i]);
+    sample = &inst->sample_times[i];
    prev = *sample;
-    UTI_AdjustTimeval(sample, when, sample, &delta_time, dfreq, doffset);
+    UTI_AdjustTimespec(sample, when, sample, &delta_time, dfreq, doffset);
    inst->offsets[i] += delta_time;
  }

@@ -638,14 +717,14 @@ SST_SlewSamples(SST_Stats inst, struct timeval *when, double dfreq, double doffs
  prev = inst->offset_time;
  prev_offset = inst->estimated_offset;
  prev_freq = inst->estimated_frequency;
-  UTI_AdjustTimeval(&(inst->offset_time), when, &(inst->offset_time),
+  UTI_AdjustTimespec(&inst->offset_time, when, &inst->offset_time,
      &delta_time, dfreq, doffset);
  inst->estimated_offset += delta_time;
  inst->estimated_frequency = (inst->estimated_frequency - dfreq) / (1.0 - dfreq);

-  DEBUG_LOG(LOGF_SourceStats, "n=%d m=%d old_off_time=%s new=%s old_off=%f new_off=%f old_freq=%.3f new_freq=%.3f",
+  DEBUG_LOG("n=%d m=%d old_off_time=%s new=%s old_off=%f new_off=%f old_freq=%.3f new_freq=%.3f",
            inst->n_samples, inst->runs_samples,
-            UTI_TimevalToString(&prev), UTI_TimevalToString(&(inst->offset_time)),
+            UTI_TimespecToString(&prev), UTI_TimespecToString(&inst->offset_time),
            prev_offset, inst->estimated_offset,
            1.0e6 * prev_freq, 1.0e6 * inst->estimated_frequency);
 }
@@ -667,7 +746,7 @@ SST_AddDispersion(SST_Stats inst, double dispersion)
 /* ================================================== */

 double
-SST_PredictOffset(SST_Stats inst, struct timeval *when)
+SST_PredictOffset(SST_Stats inst, struct timespec *when)
 {
  double elapsed;
  
@@ -681,7 +760,7 @@ SST_PredictOffset(SST_Stats inst, struct timeval *when)
      return 0.0;
    }
  } else {
-    UTI_DiffTimevalsToDouble(&elapsed, when, &inst->offset_time);
+    elapsed = UTI_DiffTimespecsToDouble(when, &inst->offset_time);
    return inst->estimated_offset + elapsed * inst->estimated_frequency;
  }

@@ -701,20 +780,20 @@ SST_MinRoundTripDelay(SST_Stats inst)

 int
 SST_IsGoodSample(SST_Stats inst, double offset, double delay,
-    double max_delay_dev_ratio, double clock_error, struct timeval *when)
+    double max_delay_dev_ratio, double clock_error, struct timespec *when)
 {
  double elapsed, allowed_increase, delay_increase;

-  if (inst->n_samples < 3)
+  if (inst->n_samples < 6)
    return 1;

-  UTI_DiffTimevalsToDouble(&elapsed, when, &inst->offset_time);
+  elapsed = UTI_DiffTimespecsToDouble(when, &inst->offset_time);

  /* Require that the ratio of the increase in delay from the minimum to the
     standard deviation is less than max_delay_dev_ratio. In the allowed
     increase in delay include also skew and clock_error. */
    
-  allowed_increase = sqrt(inst->variance) * max_delay_dev_ratio +
+  allowed_increase = inst->std_dev * max_delay_dev_ratio +
    elapsed * (inst->skew + clock_error);
  delay_increase = (delay - SST_MinRoundTripDelay(inst)) / 2.0;

@@ -729,8 +808,8 @@ SST_IsGoodSample(SST_Stats inst, double offset, double delay,
  if (fabs(offset) - delay_increase > allowed_increase)
    return 1;

-  DEBUG_LOG(LOGF_SourceStats, "Bad sample: offset=%f delay=%f incr_delay=%f allowed=%f",
-      offset, delay, allowed_increase, delay_increase);
+  DEBUG_LOG("Bad sample: offset=%f delay=%f incr_delay=%f allowed=%f",
+            offset, delay, delay_increase, allowed_increase);

  return 0;
 }
@@ -750,12 +829,18 @@ SST_SaveToFile(SST_Stats inst, FILE *out)
    i = get_runsbuf_index(inst, m);
    j = get_buf_index(inst, m);

-    fprintf(out, "%08lx %08lx %.6e %.6e %.6e %.6e %.6e %.6e %.6e %d\n",
-            (unsigned long) inst->sample_times[i].tv_sec,
-            (unsigned long) inst->sample_times[i].tv_usec,
+    fprintf(out,
+#ifdef HAVE_LONG_TIME_T
+            "%08"PRIx64" %08lx %.6e %.6e %.6e %.6e %.6e %.6e %.6e %d\n",
+            (uint64_t)inst->sample_times[i].tv_sec,
+#else
+            "%08lx %08lx %.6e %.6e %.6e %.6e %.6e %.6e %.6e %d\n",
+            (unsigned long)inst->sample_times[i].tv_sec,
+#endif
+            (unsigned long)inst->sample_times[i].tv_nsec / 1000,
            inst->offsets[i],
            inst->orig_offsets[j],
-            inst->peer_delays[j],
+            inst->peer_delays[i],
            inst->peer_dispersions[j],
            inst->root_delays[j],
            inst->root_dispersions[j],
@@ -763,6 +848,8 @@ SST_SaveToFile(SST_Stats inst, FILE *out)
            inst->strata[j]);

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

 /* ================================================== */
@@ -771,22 +858,30 @@ SST_SaveToFile(SST_Stats inst, FILE *out)
 int
 SST_LoadFromFile(SST_Stats inst, FILE *in)
 {
-  int i, line_number;
+#ifdef HAVE_LONG_TIME_T
+  uint64_t sec;
+#else
+  unsigned long sec;
+#endif
+  unsigned long usec;
+  int i;
  char line[1024];
-  unsigned long sec, usec;
  double weight;

  assert(!inst->n_samples);

  if (fgets(line, sizeof(line), in) &&
      sscanf(line, "%d", &inst->n_samples) == 1 &&
-      inst->n_samples > 0 && inst->n_samples <= MAX_SAMPLES) {
-
-    line_number = 2;
+      inst->n_samples >= 0 && inst->n_samples <= MAX_SAMPLES) {

    for (i=0; i<inst->n_samples; i++) {
      if (!fgets(line, sizeof(line), in) ||
-          (sscanf(line, "%lx%lx%lf%lf%lf%lf%lf%lf%lf%d\n",
+          (sscanf(line,
+#ifdef HAVE_LONG_TIME_T
+                  "%"SCNx64"%lx%lf%lf%lf%lf%lf%lf%lf%d\n",
+#else
+                  "%lx%lx%lf%lf%lf%lf%lf%lf%lf%d\n",
+#endif
                  &(sec), &(usec),
                  &(inst->offsets[i]),
                  &(inst->orig_offsets[i]),
@@ -799,40 +894,44 @@ SST_LoadFromFile(SST_Stats inst, FILE *in)

        /* This is the branch taken if the read FAILED */

-        LOG(LOGS_WARN, LOGF_SourceStats, "Failed to read data from line %d of dump file", line_number);
        inst->n_samples = 0; /* Load abandoned if any sign of corruption */
        return 0;
      } else {

        /* This is the branch taken if the read is SUCCESSFUL */
        inst->sample_times[i].tv_sec = sec;
-        inst->sample_times[i].tv_usec = usec;
-
-        line_number++;
+        inst->sample_times[i].tv_nsec = 1000 * usec;
+        UTI_NormaliseTimespec(&inst->sample_times[i]);
      }
    }
+
+    /* This field was not saved in older versions */
+    if (!fgets(line, sizeof(line), in) || sscanf(line, "%d\n", &inst->asymmetry_run) != 1)
+      inst->asymmetry_run = 0;
  } else {
-    LOG(LOGS_WARN, LOGF_SourceStats, "Could not read number of samples from dump file");
    inst->n_samples = 0; /* Load abandoned if any sign of corruption */
    return 0;
  }

+  if (!inst->n_samples)
+    return 1;
+
  inst->last_sample = inst->n_samples - 1;
  inst->runs_samples = 0;

  find_min_delay_sample(inst);
+  SST_DoNewRegression(inst);

  return 1;
-
 }

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

 void
-SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timeval *now)
+SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timespec *now)
 {
  int i, j;
-  struct timeval ago;
+  struct timespec last_sample_time;

  if (inst->n_samples > 0) {
    i = get_runsbuf_index(inst, inst->n_samples - 1);
@@ -842,8 +941,10 @@ SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timeval *now
    report->latest_meas_err = 0.5*inst->root_delays[j] + inst->root_dispersions[j];
    report->stratum = inst->strata[j];

-    UTI_DiffTimevals(&ago, now, &inst->sample_times[i]);
-    report->latest_meas_ago = ago.tv_sec;
+    /* Align the sample time to reduce the leak of the receive timestamp */
+    last_sample_time = inst->sample_times[i];
+    last_sample_time.tv_nsec = 0;
+    report->latest_meas_ago = UTI_DiffTimespecsToDouble(now, &last_sample_time);
  } else {
    report->latest_meas_ago = (uint32_t)-1;
    report->orig_latest_meas = 0;
@@ -864,7 +965,7 @@ SST_Samples(SST_Stats inst)
 /* ================================================== */

 void
-SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct timeval *now)
+SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct timespec *now)
 {
  double dspan;
  double elapsed, sample_elapsed;
@@ -876,15 +977,15 @@ SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct ti
  if (inst->n_samples > 1) {
    li = get_runsbuf_index(inst, inst->n_samples - 1);
    lj = get_buf_index(inst, inst->n_samples - 1);
-    UTI_DiffTimevalsToDouble(&dspan, &inst->sample_times[li],
+    dspan = UTI_DiffTimespecsToDouble(&inst->sample_times[li],
        &inst->sample_times[get_runsbuf_index(inst, 0)]);
    report->span_seconds = (unsigned long) (dspan + 0.5);

    if (inst->n_samples > 3) {
-      UTI_DiffTimevalsToDouble(&elapsed, now, &inst->offset_time);
+      elapsed = UTI_DiffTimespecsToDouble(now, &inst->offset_time);
      bi = get_runsbuf_index(inst, inst->best_single_sample);
      bj = get_buf_index(inst, inst->best_single_sample);
-      UTI_DiffTimevalsToDouble(&sample_elapsed, now, &inst->sample_times[bi]);
+      sample_elapsed = UTI_DiffTimespecsToDouble(now, &inst->sample_times[bi]);
      report->est_offset = inst->estimated_offset + elapsed * inst->estimated_frequency;
      report->est_offset_err = (inst->estimated_offset_sd +
                 sample_elapsed * inst->skew +
@@ -901,7 +1002,15 @@ SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct ti

  report->resid_freq_ppm = 1.0e6 * inst->estimated_frequency;
  report->skew_ppm = 1.0e6 * inst->skew;
-  report->sd = sqrt(inst->variance);
+  report->sd = inst->std_dev;
+}
+
+/* ================================================== */
+
+double
+SST_GetJitterAsymmetry(SST_Stats inst)
+{
+  return inst->asymmetry;
 }

 /* ================================================== */
--- a/sourcestats.h
+++ b/sourcestats.h
@@ -61,7 +61,7 @@ extern void SST_SetRefid(SST_Stats inst, uint32_t refid, IPAddr *addr);
   stratum is the stratum of the source from which the sample came.
  */

-extern void SST_AccumulateSample(SST_Stats inst, struct timeval *sample_time, double offset, double peer_delay, double peer_dispersion, double root_delay, double root_dispersion, int stratum);
+extern void SST_AccumulateSample(SST_Stats inst, struct timespec *sample_time, double offset, double peer_delay, double peer_dispersion, double root_delay, double root_dispersion, int stratum);

 /* This function runs the linear regression operation on the data.  It
   finds the set of most recent samples that give the tightest
@@ -77,7 +77,7 @@ extern void SST_GetFrequencyRange(SST_Stats inst, double *lo, double *hi);

 /* Get data needed for selection */
 extern void
-SST_GetSelectionData(SST_Stats inst, struct timeval *now,
+SST_GetSelectionData(SST_Stats inst, struct timespec *now,
                     int *stratum,
                     double *offset_lo_limit,
                     double *offset_hi_limit,
@@ -89,7 +89,7 @@ SST_GetSelectionData(SST_Stats inst, struct timeval *now,

 /* Get data needed when setting up tracking on this source */
 extern void
-SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,
+SST_GetTrackingData(SST_Stats inst, struct timespec *ref_time,
                    double *average_offset, double *offset_sd,
                    double *frequency, double *skew,
                    double *root_delay, double *root_dispersion);
@@ -110,7 +110,7 @@ SST_GetTrackingData(SST_Stats inst, struct timeval *ref_time,

 */

-extern void SST_SlewSamples(SST_Stats inst, struct timeval *when, double dfreq, double doffset);
+extern void SST_SlewSamples(SST_Stats inst, struct timespec *when, double dfreq, double doffset);

 /* This routine is called when an indeterminate offset is introduced
   into the local time. */
@@ -119,7 +119,7 @@ extern void SST_AddDispersion(SST_Stats inst, double dispersion);
 /* Predict the offset of the local clock relative to a given source at
   a given local cooked time. Positive indicates local clock is FAST
   relative to reference. */
-extern double SST_PredictOffset(SST_Stats inst, struct timeval *when);
+extern double SST_PredictOffset(SST_Stats inst, struct timespec *when);

 /* Find the minimum round trip delay in the register */
 extern double SST_MinRoundTripDelay(SST_Stats inst);
@@ -127,17 +127,19 @@ extern double SST_MinRoundTripDelay(SST_Stats inst);
 /* This routine determines if a new sample is good enough that it should be
   accumulated */
 extern int SST_IsGoodSample(SST_Stats inst, double offset, double delay,
-   double max_delay_dev_ratio, double clock_error, struct timeval *when);
+   double max_delay_dev_ratio, double clock_error, struct timespec *when);

 extern void SST_SaveToFile(SST_Stats inst, FILE *out);

 extern int SST_LoadFromFile(SST_Stats inst, FILE *in);

-extern void SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timeval *now);
+extern void SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timespec *now);

-extern void SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct timeval *now);
+extern void SST_DoSourcestatsReport(SST_Stats inst, RPT_SourcestatsReport *report, struct timespec *now);

 extern int SST_Samples(SST_Stats inst);

+extern double SST_GetJitterAsymmetry(SST_Stats inst);
+
 #endif /* GOT_SOURCESTATS_H */

--- a/srcparams.h
+++ b/srcparams.h
@@ -42,22 +42,24 @@ typedef struct {
  int max_sources;
  int min_samples;
  int max_samples;
+  int interleaved;
  int sel_options;
  uint32_t authkey;
  double max_delay;
  double max_delay_ratio;
  double max_delay_dev_ratio;
+  double offset;
 } SourceParameters;

 #define SRC_DEFAULT_PORT 123
 #define SRC_DEFAULT_MINPOLL 6
 #define SRC_DEFAULT_MAXPOLL 10
-#define SRC_DEFAULT_PRESEND_MINPOLL 0
+#define SRC_DEFAULT_PRESEND_MINPOLL 100
 #define SRC_DEFAULT_MAXDELAY 3.0
 #define SRC_DEFAULT_MAXDELAYRATIO 0.0
 #define SRC_DEFAULT_MAXDELAYDEVRATIO 10.0
 #define SRC_DEFAULT_MINSTRATUM 0
-#define SRC_DEFAULT_POLLTARGET 6
+#define SRC_DEFAULT_POLLTARGET 8
 #define SRC_DEFAULT_MAXSOURCES 4
 #define SRC_DEFAULT_MINSAMPLES (-1)
 #define SRC_DEFAULT_MAXSAMPLES (-1)
--- a/stubs.c
+++ b/stubs.c
@@ -2,7 +2,7 @@
  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************
- * Copyright (C) Miroslav Lichvar  2014-2015
+ * Copyright (C) Miroslav Lichvar  2014-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -38,9 +38,11 @@
 #include "ntp_core.h"
 #include "ntp_io.h"
 #include "ntp_sources.h"
+#include "ntp_signd.h"
 #include "privops.h"
 #include "refclock.h"
 #include "sched.h"
+#include "util.h"

 #ifndef FEAT_ASYNCDNS

@@ -50,10 +52,11 @@ struct DNS_Async_Instance {
  const char *name;
  DNS_NameResolveHandler handler;
  void *arg;
+  int pipe[2];
 };

 static void
-resolve_name(void *anything)
+resolve_name(int fd, int event, void *anything)
 {
  struct DNS_Async_Instance *inst;
  IPAddr addrs[DNS_MAX_ADDRESSES];
@@ -61,6 +64,11 @@ resolve_name(void *anything)
  int i;

  inst = (struct DNS_Async_Instance *)anything;
+
+  SCH_RemoveFileHandler(inst->pipe[0]);
+  close(inst->pipe[0]);
+  close(inst->pipe[1]);
+
  status = PRV_Name2IPAddress(inst->name, addrs, DNS_MAX_ADDRESSES);

  for (i = 0; status == DNS_Success && i < DNS_MAX_ADDRESSES &&
@@ -82,7 +90,16 @@ DNS_Name2IPAddressAsync(const char *name, DNS_NameResolveHandler handler, void *
  inst->handler = handler;
  inst->arg = anything;

-  SCH_AddTimeoutByDelay(0.0, resolve_name, inst);
+  if (pipe(inst->pipe))
+    LOG_FATAL("pipe() failed");
+
+  UTI_FdSetCloexec(inst->pipe[0]);
+  UTI_FdSetCloexec(inst->pipe[1]);
+
+  SCH_AddFileHandler(inst->pipe[0], SCH_FILE_INPUT, resolve_name, inst);
+
+  if (write(inst->pipe[1], "", 1) < 0)
+    ;
 }

 #endif /* !FEAT_ASYNCDNS */
@@ -291,11 +308,17 @@ NSR_ModifyPolltarget(IPAddr *address, int new_poll_target)
 }

 void
-NSR_ReportSource(RPT_SourceReport *report, struct timeval *now)
+NSR_ReportSource(RPT_SourceReport *report, struct timespec *now)
 {
  memset(report, 0, sizeof (*report));
 }
  
+int
+NSR_GetNTPReport(RPT_NTPReport *report)
+{
+  return 0;
+}
+
 void
 NSR_GetActivityReport(RPT_ActivityReport *report)
 {
@@ -361,9 +384,35 @@ RCL_StartRefclocks(void)
 }

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

 #endif /* !FEAT_REFCLOCK */
+
+#ifndef FEAT_SIGND
+
+void
+NSD_Initialise(void)
+{
+}
+
+void
+NSD_Finalise(void)
+{
+}
+
+int
+NSD_GetAuthDelay(uint32_t key_id)
+{
+  return 0;
+}
+
+int
+NSD_SignAndSendPacket(uint32_t key_id, NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
+{
+  return 0;
+}
+
+#endif /* !FEAT_SIGND */
--- a/sys.c
+++ b/sys.c
@@ -30,6 +30,7 @@
 #include "sysincl.h"

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

 #if defined(LINUX)
@@ -44,9 +45,18 @@

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

+static int null_driver;
+
+/* ================================================== */
+
 void
-SYS_Initialise(void)
+SYS_Initialise(int clock_control)
 {
+  null_driver = !clock_control;
+  if (null_driver) {
+    SYS_Null_Initialise();
+    return;
+  }
 #if defined(LINUX)
  SYS_Linux_Initialise();
 #elif defined(SOLARIS)
@@ -65,6 +75,10 @@ SYS_Initialise(void)
 void
 SYS_Finalise(void)
 {
+  if (null_driver) {
+    SYS_Null_Finalise();
+    return;
+  }
 #if defined(LINUX)
  SYS_Linux_Finalise();
 #elif defined(SOLARIS)
@@ -91,7 +105,7 @@ void SYS_DropRoot(uid_t uid, gid_t gid)
 #elif defined(MACOSX) && defined(FEAT_PRIVDROP)
  SYS_MacOSX_DropRoot(uid, gid);
 #else
-  LOG_FATAL(LOGF_Sys, "dropping root privileges not supported");
+  LOG_FATAL("dropping root privileges not supported");
 #endif
 }

@@ -102,7 +116,7 @@ void SYS_EnableSystemCallFilter(int level)
 #if defined(LINUX) && defined(FEAT_SCFILTER)
  SYS_Linux_EnableSystemCallFilter(level);
 #else
-  LOG_FATAL(LOGF_Sys, "system call filter not supported");
+  LOG_FATAL("system call filter not supported");
 #endif
 }

@@ -115,7 +129,7 @@ void SYS_SetScheduler(int SchedPriority)
 #elif defined(MACOSX)
  SYS_MacOSX_SetScheduler(SchedPriority);
 #else
-  LOG_FATAL(LOGF_Sys, "scheduler priority setting not supported");
+  LOG_FATAL("scheduler priority setting not supported");
 #endif
 }

@@ -126,7 +140,7 @@ void SYS_LockMemory(void)
 #if defined(LINUX) && defined(HAVE_MLOCKALL)
  SYS_Linux_MemLockAll(1);
 #else
-  LOG_FATAL(LOGF_Sys, "memory locking not supported");
+  LOG_FATAL("memory locking not supported");
 #endif
 }

--- a/sys.h
+++ b/sys.h
@@ -30,7 +30,7 @@
 #define GOT_SYS_H

 /* Called at the start of the run to do initialisation */
-extern void SYS_Initialise(void);
+extern void SYS_Initialise(int clock_control);

 /* Called at the end of the run to do final clean-up */
 extern void SYS_Finalise(void);
--- a/sys_generic.c
+++ b/sys_generic.c
@@ -71,7 +71,7 @@ static double offset_register;
 static double slew_freq;

 /* Time (raw) of last update of slewing frequency and offset */
-static struct timeval slew_start;
+static struct timespec slew_start;

 /* Limits for the slew timeout */
 #define MIN_SLEW_TIMEOUT 1.0
@@ -106,7 +106,7 @@ static void update_slew(void);
 /* Adjust slew_start on clock step */

 static void
-handle_step(struct timeval *raw, struct timeval *cooked, double dfreq,
+handle_step(struct timespec *raw, struct timespec *cooked, double dfreq,
            double doffset, LCL_ChangeType change_type, void *anything)
 {
  if (change_type == LCL_ChangeUnknownStep) {
@@ -115,7 +115,7 @@ handle_step(struct timeval *raw, struct timeval *cooked, double dfreq,
    offset_register = 0.0;
    update_slew();
  } else if (change_type == LCL_ChangeStep) {
-    UTI_AddDoubleToTimeval(&slew_start, -doffset, &slew_start);
+    UTI_AddDoubleToTimespec(&slew_start, -doffset, &slew_start);
  }
 }

@@ -129,7 +129,7 @@ start_fastslew(void)

  drv_accrue_offset(offset_register, 0.0);

-  DEBUG_LOG(LOGF_SysGeneric, "fastslew offset=%e", offset_register);
+  DEBUG_LOG("fastslew offset=%e", offset_register);

  offset_register = 0.0;
  fastslew_active = 1;
@@ -138,7 +138,7 @@ start_fastslew(void)
 /* ================================================== */

 static void
-stop_fastslew(struct timeval *now)
+stop_fastslew(struct timespec *now)
 {
  double corr;

@@ -169,7 +169,7 @@ clamp_freq(double freq)
 static void
 update_slew(void)
 {
-  struct timeval now, end_of_slew;
+  struct timespec now, end_of_slew;
  double old_slew_freq, total_freq, corr_freq, duration;

  /* Remove currently running timeout */
@@ -178,7 +178,7 @@ update_slew(void)
  LCL_ReadRawTime(&now);

  /* Adjust the offset register by achieved slew */
-  UTI_DiffTimevalsToDouble(&duration, &now, &slew_start);
+  duration = UTI_DiffTimespecsToDouble(&now, &slew_start);
  offset_register -= slew_freq * duration;

  stop_fastslew(&now);
@@ -242,11 +242,11 @@ update_slew(void)
  }

  /* Restart timer for the next update */
-  UTI_AddDoubleToTimeval(&now, duration, &end_of_slew);
+  UTI_AddDoubleToTimespec(&now, duration, &end_of_slew);
  slew_timeout_id = SCH_AddTimeout(&end_of_slew, handle_end_of_slew, NULL);
  slew_start = now;

-  DEBUG_LOG(LOGF_SysGeneric, "slew offset=%e corr_rate=%e base_freq=%f total_freq=%f slew_freq=%e duration=%f slew_error=%e",
+  DEBUG_LOG("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);
 }
@@ -294,12 +294,12 @@ accrue_offset(double offset, double corr_rate)
 /* Determine the correction to generate the cooked time for given raw time */

 static void
-offset_convert(struct timeval *raw,
+offset_convert(struct timespec *raw,
               double *corr, double *err)
 {
  double duration, fastslew_corr, fastslew_err;

-  UTI_DiffTimevalsToDouble(&duration, raw, &slew_start);
+  duration = UTI_DiffTimespecsToDouble(raw, &slew_start);

  if (drv_get_offset_correction && fastslew_active) {
    drv_get_offset_correction(raw, &fastslew_corr, &fastslew_err);
@@ -324,19 +324,21 @@ offset_convert(struct timeval *raw,
 static int
 apply_step_offset(double offset)
 {
-  struct timeval old_time, new_time;
+  struct timespec old_time, new_time;
+  struct timeval new_time_tv;
  double err;

  LCL_ReadRawTime(&old_time);
-  UTI_AddDoubleToTimeval(&old_time, -offset, &new_time);
+  UTI_AddDoubleToTimespec(&old_time, -offset, &new_time);
+  UTI_TimespecToTimeval(&new_time, &new_time_tv);

-  if (PRV_SetTime(&new_time, NULL) < 0) {
-    DEBUG_LOG(LOGF_SysGeneric, "settimeofday() failed");
+  if (PRV_SetTime(&new_time_tv, NULL) < 0) {
+    DEBUG_LOG("settimeofday() failed");
    return 0;
  }

  LCL_ReadRawTime(&old_time);
-  UTI_DiffTimevalsToDouble(&err, &old_time, &new_time);
+  err = UTI_DiffTimespecsToDouble(&old_time, &new_time);

  lcl_InvokeDispersionNotifyHandlers(fabs(err));

@@ -403,7 +405,7 @@ SYS_Generic_CompleteFreqDriver(double max_set_freq_ppm, double max_set_freq_dela
 void
 SYS_Generic_Finalise(void)
 {
-  struct timeval now;
+  struct timespec now;

  /* Must *NOT* leave a slew running - clock could drift way off
     if the daemon is not restarted */
--- a/sys_linux.c
+++ b/sys_linux.c
@@ -4,7 +4,7 @@
 **********************************************************************
 * Copyright (C) Richard P. Curnow  1997-2003
 * Copyright (C) John G. Hasler  2009
- * Copyright (C) Miroslav Lichvar  2009-2012, 2014-2015
+ * Copyright (C) Miroslav Lichvar  2009-2012, 2014-2016
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
@@ -47,24 +47,29 @@
 #include <sys/capability.h>
 #endif

+#if defined(FEAT_PHC) || defined(HAVE_LINUX_TIMESTAMPING)
+#include <linux/ptp_clock.h>
+#endif
+
 #ifdef FEAT_SCFILTER
 #include <sys/prctl.h>
 #include <seccomp.h>
 #include <termios.h>
-#ifdef FEAT_PHC
-#include <linux/ptp_clock.h>
-#endif
 #ifdef FEAT_PPS
 #include <linux/pps.h>
 #endif
 #ifdef FEAT_RTC
 #include <linux/rtc.h>
 #endif
+#ifdef HAVE_LINUX_TIMESTAMPING
+#include <linux/sockios.h>
+#endif
 #endif

 #include "sys_linux.h"
 #include "sys_timex.h"
 #include "conf.h"
+#include "local.h"
 #include "logging.h"
 #include "privops.h"
 #include "util.h"
@@ -235,7 +240,7 @@ guess_hz(void)
  }

  /* oh dear.  doomed. */
-  LOG_FATAL(LOGF_SysLinux, "Can't determine hz from tick %d", tick);
+  LOG_FATAL("Can't determine hz from tick %d", tick);

  return 0;
 }
@@ -271,6 +276,22 @@ kernelvercmp(int major1, int minor1, int patch1,
 }

 /* ================================================== */
+
+static void
+get_kernel_version(int *major, int *minor, int *patch)
+{
+  struct utsname uts;
+
+  if (uname(&uts) < 0)
+    LOG_FATAL("uname() failed");
+
+  *patch = 0;
+  if (sscanf(uts.release, "%d.%d.%d", major, minor, patch) < 2)
+    LOG_FATAL("Could not parse kernel version");
+}
+
+/* ================================================== */
+
 /* Compute the scaling to use on any frequency we set, according to
   the vintage of the Linux kernel being used. */

@@ -278,7 +299,6 @@ static void
 get_version_specific_details(void)
 {
  int major, minor, patch;
-  struct utsname uts;
  
  hz = get_hz();

@@ -293,19 +313,11 @@ get_version_specific_details(void)
     (CONFIG_NO_HZ aka tickless), assume the lowest commonly used fixed rate */
  tick_update_hz = 100;

-  if (uname(&uts) < 0) {
-    LOG_FATAL(LOGF_SysLinux, "Cannot uname(2) to get kernel version, sorry.");
-  }
-
-  patch = 0;
-  if (sscanf(uts.release, "%d.%d.%d", &major, &minor, &patch) < 2) {
-    LOG_FATAL(LOGF_SysLinux, "Cannot read information from uname, sorry");
-  }
-
-  DEBUG_LOG(LOGF_SysLinux, "Linux kernel major=%d minor=%d patch=%d", major, minor, patch);
+  get_kernel_version(&major, &minor, &patch);
+  DEBUG_LOG("Linux kernel major=%d minor=%d patch=%d", major, minor, patch);

  if (kernelvercmp(major, minor, patch, 2, 2, 0) < 0) {
-    LOG_FATAL(LOGF_SysLinux, "Kernel version not supported, sorry.");
+    LOG_FATAL("Kernel version not supported, sorry.");
  }

  if (kernelvercmp(major, minor, patch, 2, 6, 27) >= 0 &&
@@ -322,7 +334,7 @@ get_version_specific_details(void)
    have_setoffset = 1;
  }

-  DEBUG_LOG(LOGF_SysLinux, "hz=%d nominal_tick=%d max_tick_bias=%d",
+  DEBUG_LOG("hz=%d nominal_tick=%d max_tick_bias=%d",
      hz, nominal_tick, max_tick_bias);
 }

@@ -379,7 +391,7 @@ SYS_Linux_Initialise(void)
  reset_adjtime_offset();

  if (have_setoffset && !test_step_offset()) {
-    LOG(LOGS_INFO, LOGF_SysLinux, "adjtimex() doesn't support ADJ_SETOFFSET");
+    LOG(LOGS_INFO, "adjtimex() doesn't support ADJ_SETOFFSET");
    have_setoffset = 0;
  }

@@ -409,7 +421,7 @@ SYS_Linux_DropRoot(uid_t uid, gid_t gid)
  cap_t cap;

  if (prctl(PR_SET_KEEPCAPS, 1)) {
-    LOG_FATAL(LOGF_SysLinux, "prctl() failed");
+    LOG_FATAL("prctl() failed");
  }
  
  UTI_DropRoot(uid, gid);
@@ -419,11 +431,11 @@ SYS_Linux_DropRoot(uid_t uid, gid_t gid)
             "cap_net_bind_service,cap_sys_time=ep" : "cap_sys_time=ep";

  if ((cap = cap_from_text(cap_text)) == NULL) {
-    LOG_FATAL(LOGF_SysLinux, "cap_from_text() failed");
+    LOG_FATAL("cap_from_text() failed");
  }

  if (cap_set_proc(cap)) {
-    LOG_FATAL(LOGF_SysLinux, "cap_set_proc() failed");
+    LOG_FATAL("cap_set_proc() failed");
  }

  cap_free(cap);
@@ -442,7 +454,7 @@ void check_seccomp_applicability(void)

  CNF_GetMailOnChange(&mail_enabled, &mail_threshold, &mail_user);
  if (mail_enabled)
-    LOG_FATAL(LOGF_SysLinux, "mailonchange directive cannot be used with -F enabled");
+    LOG_FATAL("mailonchange directive cannot be used with -F enabled");
 }

 /* ================================================== */
@@ -452,32 +464,33 @@ SYS_Linux_EnableSystemCallFilter(int level)
 {
  const int syscalls[] = {
    /* Clock */
-    SCMP_SYS(adjtimex), SCMP_SYS(gettimeofday), SCMP_SYS(settimeofday),
-    SCMP_SYS(time),
+    SCMP_SYS(adjtimex), SCMP_SYS(clock_gettime), SCMP_SYS(gettimeofday),
+    SCMP_SYS(settimeofday), SCMP_SYS(time),
    /* Process */
-    SCMP_SYS(clone), SCMP_SYS(exit), SCMP_SYS(exit_group), SCMP_SYS(getrlimit),
-    SCMP_SYS(rt_sigaction), SCMP_SYS(rt_sigreturn), SCMP_SYS(rt_sigprocmask),
-    SCMP_SYS(set_tid_address), SCMP_SYS(sigreturn), SCMP_SYS(wait4),
+    SCMP_SYS(clone), SCMP_SYS(exit), SCMP_SYS(exit_group), SCMP_SYS(getpid),
+    SCMP_SYS(getrlimit), SCMP_SYS(rt_sigaction), SCMP_SYS(rt_sigreturn),
+    SCMP_SYS(rt_sigprocmask), SCMP_SYS(set_tid_address), SCMP_SYS(sigreturn),
+    SCMP_SYS(wait4),
    /* Memory */
    SCMP_SYS(brk), SCMP_SYS(madvise), SCMP_SYS(mmap), SCMP_SYS(mmap2),
    SCMP_SYS(mprotect), SCMP_SYS(mremap), SCMP_SYS(munmap), SCMP_SYS(shmdt),
    /* Filesystem */
    SCMP_SYS(access), SCMP_SYS(chmod), SCMP_SYS(chown), SCMP_SYS(chown32),
-    SCMP_SYS(fstat), SCMP_SYS(fstat64), SCMP_SYS(lseek), SCMP_SYS(rename),
-    SCMP_SYS(stat), SCMP_SYS(stat64), SCMP_SYS(statfs), SCMP_SYS(statfs64),
-    SCMP_SYS(unlink),
+    SCMP_SYS(fstat), SCMP_SYS(fstat64), SCMP_SYS(getdents), SCMP_SYS(getdents64),
+    SCMP_SYS(lseek), SCMP_SYS(rename), SCMP_SYS(stat), SCMP_SYS(stat64),
+    SCMP_SYS(statfs), SCMP_SYS(statfs64), SCMP_SYS(unlink),
    /* Socket */
    SCMP_SYS(bind), SCMP_SYS(connect), SCMP_SYS(getsockname),
-    SCMP_SYS(recvfrom), SCMP_SYS(recvmsg), SCMP_SYS(sendmmsg),
-    SCMP_SYS(sendmsg), SCMP_SYS(sendto),
+    SCMP_SYS(recvfrom), SCMP_SYS(recvmmsg), SCMP_SYS(recvmsg),
+    SCMP_SYS(sendmmsg), SCMP_SYS(sendmsg), SCMP_SYS(sendto),
    /* TODO: check socketcall arguments */
    SCMP_SYS(socketcall),
    /* General I/O */
-    SCMP_SYS(_newselect), SCMP_SYS(close), SCMP_SYS(open), SCMP_SYS(pipe),
+    SCMP_SYS(_newselect), SCMP_SYS(close), SCMP_SYS(open), SCMP_SYS(openat), SCMP_SYS(pipe),
    SCMP_SYS(poll), SCMP_SYS(read), SCMP_SYS(futex), SCMP_SYS(select),
    SCMP_SYS(set_robust_list), SCMP_SYS(write),
    /* Miscellaneous */
-    SCMP_SYS(uname),
+    SCMP_SYS(getrandom), SCMP_SYS(sysinfo), SCMP_SYS(uname),
  };

  const int socket_domains[] = {
@@ -493,21 +506,30 @@ SYS_Linux_EnableSystemCallFilter(int level)
    { SOL_IPV6, IPV6_V6ONLY }, { SOL_IPV6, IPV6_RECVPKTINFO },
 #endif
    { SOL_SOCKET, SO_BROADCAST }, { SOL_SOCKET, SO_REUSEADDR },
-    { SOL_SOCKET, SO_TIMESTAMP },
+    { SOL_SOCKET, SO_TIMESTAMP }, { SOL_SOCKET, SO_TIMESTAMPNS },
+#ifdef HAVE_LINUX_TIMESTAMPING
+    { SOL_SOCKET, SO_SELECT_ERR_QUEUE }, { SOL_SOCKET, SO_TIMESTAMPING },
+#endif
  };

  const static int fcntls[] = { F_GETFD, F_SETFD };

  const static unsigned long ioctls[] = {
    FIONREAD, TCGETS,
-#ifdef FEAT_PPS
-    PTP_SYS_OFFSET,
+#if defined(FEAT_PHC) || defined(HAVE_LINUX_TIMESTAMPING)
+    PTP_EXTTS_REQUEST, PTP_PIN_SETFUNC, PTP_SYS_OFFSET,
+#ifdef PTP_SYS_OFFSET_PRECISE
+    PTP_SYS_OFFSET_PRECISE,
+#endif
 #endif
 #ifdef FEAT_PPS
    PPS_FETCH,
 #endif
 #ifdef FEAT_RTC
    RTC_RD_TIME, RTC_SET_TIME, RTC_UIE_ON, RTC_UIE_OFF,
+#endif
+#ifdef HAVE_LINUX_TIMESTAMPING
+    SIOCETHTOOL,
 #endif
  };

@@ -525,7 +547,7 @@ SYS_Linux_EnableSystemCallFilter(int level)

  ctx = seccomp_init(level > 0 ? SCMP_ACT_KILL : SCMP_ACT_TRAP);
  if (ctx == NULL)
-      LOG_FATAL(LOGF_SysLinux, "Failed to initialize seccomp");
+      LOG_FATAL("Failed to initialize seccomp");

  /* Add system calls that are always allowed */
  for (i = 0; i < (sizeof (syscalls) / sizeof (*syscalls)); i++) {
@@ -566,14 +588,14 @@ SYS_Linux_EnableSystemCallFilter(int level)
  }

  if (seccomp_load(ctx) < 0)
-    LOG_FATAL(LOGF_SysLinux, "Failed to load seccomp rules");
+    LOG_FATAL("Failed to load seccomp rules");

-  LOG(LOGS_INFO, LOGF_SysLinux, "Loaded seccomp filter");
+  LOG(LOGS_INFO, "Loaded seccomp filter");
  seccomp_release(ctx);
  return;

 add_failed:
-  LOG_FATAL(LOGF_SysLinux, "Failed to add seccomp rules");
+  LOG_FATAL("Failed to add seccomp rules");
 }
 #endif

@@ -587,7 +609,7 @@ void SYS_Linux_SetScheduler(int SchedPriority)
  struct sched_param sched;

  if (SchedPriority < 1 || SchedPriority > 99) {
-    LOG_FATAL(LOGF_SysLinux, "Bad scheduler priority: %d", SchedPriority);
+    LOG_FATAL("Bad scheduler priority: %d", SchedPriority);
  } else {
    sched.sched_priority = SchedPriority;
    pmax = sched_get_priority_max(SCHED_FIFO);
@@ -599,10 +621,10 @@ void SYS_Linux_SetScheduler(int SchedPriority)
      sched.sched_priority = pmin;
    }
    if ( sched_setscheduler(0, SCHED_FIFO, &sched) == -1 ) {
-      LOG(LOGS_ERR, LOGF_SysLinux, "sched_setscheduler() failed");
+      LOG(LOGS_ERR, "sched_setscheduler() failed");
    }
    else {
-      DEBUG_LOG(LOGF_SysLinux, "Enabled SCHED_FIFO with priority %d",
+      DEBUG_LOG("Enabled SCHED_FIFO with priority %d",
          sched.sched_priority);
    }
  }
@@ -620,16 +642,230 @@ void SYS_Linux_MemLockAll(int LockAll)
    rlim.rlim_max = RLIM_INFINITY;
    rlim.rlim_cur = RLIM_INFINITY;
    if (setrlimit(RLIMIT_MEMLOCK, &rlim) < 0) {
-      LOG(LOGS_ERR, LOGF_SysLinux, "setrlimit() failed: not locking into RAM");
+      LOG(LOGS_ERR, "setrlimit() failed: not locking into RAM");
    }
    else {
      if (mlockall(MCL_CURRENT|MCL_FUTURE) < 0) {
-	LOG(LOGS_ERR, LOGF_SysLinux, "mlockall() failed");
+	LOG(LOGS_ERR, "mlockall() failed");
      }
      else {
-	DEBUG_LOG(LOGF_SysLinux, "Successfully locked into RAM");
+	DEBUG_LOG("Successfully locked into RAM");
      }
    }
  }
 }
 #endif /* HAVE_MLOCKALL */
+
+/* ================================================== */
+
+int
+SYS_Linux_CheckKernelVersion(int req_major, int req_minor)
+{
+  int major, minor, patch;
+
+  get_kernel_version(&major, &minor, &patch);
+
+  return kernelvercmp(req_major, req_minor, 0, major, minor, patch) <= 0;
+}
+
+/* ================================================== */
+
+#if defined(FEAT_PHC) || defined(HAVE_LINUX_TIMESTAMPING)
+
+#define PHC_READINGS 10
+
+static int
+get_phc_sample(int phc_fd, double precision, struct timespec *phc_ts,
+               struct timespec *sys_ts, double *err)
+{
+  struct ptp_sys_offset sys_off;
+  struct timespec ts1, ts2, ts3, phc_tss[PHC_READINGS], sys_tss[PHC_READINGS];
+  double min_delay = 0.0, delays[PHC_READINGS], phc_sum, sys_sum, sys_prec;
+  int i, n;
+
+  /* Silence valgrind */
+  memset(&sys_off, 0, sizeof (sys_off));
+
+  sys_off.n_samples = PHC_READINGS;
+
+  if (ioctl(phc_fd, PTP_SYS_OFFSET, &sys_off)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "PTP_SYS_OFFSET", strerror(errno));
+    return 0;
+  }
+
+  for (i = 0; i < PHC_READINGS; i++) {
+    ts1.tv_sec = sys_off.ts[i * 2].sec;
+    ts1.tv_nsec = sys_off.ts[i * 2].nsec;
+    ts2.tv_sec = sys_off.ts[i * 2 + 1].sec;
+    ts2.tv_nsec = sys_off.ts[i * 2 + 1].nsec;
+    ts3.tv_sec = sys_off.ts[i * 2 + 2].sec;
+    ts3.tv_nsec = sys_off.ts[i * 2 + 2].nsec;
+
+    sys_tss[i] = ts1;
+    phc_tss[i] = ts2;
+    delays[i] = UTI_DiffTimespecsToDouble(&ts3, &ts1);
+
+    if (delays[i] < 0.0) {
+      /* Step in the middle of a PHC reading? */
+      DEBUG_LOG("Bad PTP_SYS_OFFSET sample delay=%e", delays[i]);
+      return 0;
+    }
+
+    if (!i || delays[i] < min_delay)
+      min_delay = delays[i];
+  }
+
+  sys_prec = LCL_GetSysPrecisionAsQuantum();
+
+  /* Combine best readings */
+  for (i = n = 0, phc_sum = sys_sum = 0.0; i < PHC_READINGS; i++) {
+    if (delays[i] > min_delay + MAX(sys_prec, precision))
+      continue;
+
+    phc_sum += UTI_DiffTimespecsToDouble(&phc_tss[i], &phc_tss[0]);
+    sys_sum += UTI_DiffTimespecsToDouble(&sys_tss[i], &sys_tss[0]) + delays[i] / 2.0;
+    n++;
+  }
+
+  assert(n);
+
+  UTI_AddDoubleToTimespec(&phc_tss[0], phc_sum / n, phc_ts);
+  UTI_AddDoubleToTimespec(&sys_tss[0], sys_sum / n, sys_ts);
+  *err = MAX(min_delay / 2.0, precision);
+
+  return 1;
+}
+/* ================================================== */
+
+static int
+get_precise_phc_sample(int phc_fd, double precision, struct timespec *phc_ts,
+		       struct timespec *sys_ts, double *err)
+{
+#ifdef PTP_SYS_OFFSET_PRECISE
+  struct ptp_sys_offset_precise sys_off;
+
+  /* Silence valgrind */
+  memset(&sys_off, 0, sizeof (sys_off));
+
+  if (ioctl(phc_fd, PTP_SYS_OFFSET_PRECISE, &sys_off)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "PTP_SYS_OFFSET_PRECISE",
+              strerror(errno));
+    return 0;
+  }
+
+  phc_ts->tv_sec = sys_off.device.sec;
+  phc_ts->tv_nsec = sys_off.device.nsec;
+  sys_ts->tv_sec = sys_off.sys_realtime.sec;
+  sys_ts->tv_nsec = sys_off.sys_realtime.nsec;
+  *err = MAX(LCL_GetSysPrecisionAsQuantum(), precision);
+
+  return 1;
+#else
+  return 0;
+#endif
+}
+
+/* ================================================== */
+
+int
+SYS_Linux_OpenPHC(const char *path, int phc_index)
+{
+  struct ptp_clock_caps caps;
+  char phc_path[64];
+  int phc_fd;
+
+  if (!path) {
+    if (snprintf(phc_path, sizeof (phc_path), "/dev/ptp%d", phc_index) >= sizeof (phc_path))
+      return -1;
+    path = phc_path;
+  }
+
+  phc_fd = open(path, O_RDONLY);
+  if (phc_fd < 0) {
+    LOG(LOGS_ERR, "Could not open %s : %s", path, strerror(errno));
+    return -1;
+  }
+
+  /* Make sure it is a PHC */
+  if (ioctl(phc_fd, PTP_CLOCK_GETCAPS, &caps)) {
+    LOG(LOGS_ERR, "ioctl(%s) failed : %s", "PTP_CLOCK_GETCAPS", strerror(errno));
+    close(phc_fd);
+    return -1;
+  }
+
+  UTI_FdSetCloexec(phc_fd);
+
+  return phc_fd;
+}
+
+/* ================================================== */
+
+int
+SYS_Linux_GetPHCSample(int fd, int nocrossts, double precision, int *reading_mode,
+                       struct timespec *phc_ts, struct timespec *sys_ts, double *err)
+{
+  if ((*reading_mode == 2 || !*reading_mode) && !nocrossts &&
+      get_precise_phc_sample(fd, precision, phc_ts, sys_ts, err)) {
+    *reading_mode = 2;
+    return 1;
+  } else if ((*reading_mode == 1 || !*reading_mode) &&
+      get_phc_sample(fd, precision, phc_ts, sys_ts, err)) {
+    *reading_mode = 1;
+    return 1;
+  }
+  return 0;
+}
+
+/* ================================================== */
+
+int
+SYS_Linux_SetPHCExtTimestamping(int fd, int pin, int channel,
+                                int rising, int falling, int enable)
+{
+  struct ptp_pin_desc pin_desc;
+  struct ptp_extts_request extts_req;
+
+  memset(&pin_desc, 0, sizeof (pin_desc));
+  pin_desc.index = pin;
+  pin_desc.func = enable ? PTP_PF_EXTTS : PTP_PF_NONE;
+  pin_desc.chan = channel;
+
+  if (ioctl(fd, PTP_PIN_SETFUNC, &pin_desc)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "PTP_PIN_SETFUNC", strerror(errno));
+    return 0;
+  }
+
+  memset(&extts_req, 0, sizeof (extts_req));
+  extts_req.index = channel;
+  extts_req.flags = (enable ? PTP_ENABLE_FEATURE : 0) |
+                    (rising ? PTP_RISING_EDGE : 0) |
+                    (falling ? PTP_FALLING_EDGE : 0);
+
+  if (ioctl(fd, PTP_EXTTS_REQUEST, &extts_req)) {
+    DEBUG_LOG("ioctl(%s) failed : %s", "PTP_EXTTS_REQUEST", strerror(errno));
+    return 0;
+  }
+
+  return 1;
+}
+
+/* ================================================== */
+
+int
+SYS_Linux_ReadPHCExtTimestamp(int fd, struct timespec *phc_ts, int *channel)
+{
+  struct ptp_extts_event extts_event;
+
+  if (read(fd, &extts_event, sizeof (extts_event)) != sizeof (extts_event)) {
+    DEBUG_LOG("Could not read PHC extts event");
+    return 0;
+  }
+
+  phc_ts->tv_sec = extts_event.t.sec;
+  phc_ts->tv_nsec = extts_event.t.nsec;
+  *channel = extts_event.index;
+
+  return 1;
+}
+
+#endif
--- a/sys_linux.h
+++ b/sys_linux.h
@@ -39,4 +39,16 @@ extern void SYS_Linux_MemLockAll(int LockAll);

 extern void SYS_Linux_SetScheduler(int SchedPriority);

+extern int SYS_Linux_CheckKernelVersion(int req_major, int req_minor);
+
+extern int SYS_Linux_OpenPHC(const char *path, int phc_index);
+
+extern int SYS_Linux_GetPHCSample(int fd, int nocrossts, double precision, int *reading_mode,
+                                  struct timespec *phc_ts, struct timespec *sys_ts, double *err);
+
+extern int SYS_Linux_SetPHCExtTimestamping(int fd, int pin, int channel,
+                                           int rising, int falling, int enable);
+
+extern int SYS_Linux_ReadPHCExtTimestamp(int fd, struct timespec *phc_ts, int *channel);
+
 #endif  /* GOT_SYS_LINUX_H */
--- a/sys_macosx.c
+++ b/sys_macosx.c
@@ -23,7 +23,7 @@

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

-  Driver file for the MacOS X operating system.
+  Driver file for the macOS operating system.

  */

@@ -39,23 +39,33 @@

 #include "sys_macosx.h"
 #include "conf.h"
+#include "local.h"
 #include "localp.h"
 #include "logging.h"
 #include "sched.h"
 #include "privops.h"
 #include "util.h"

+#ifdef HAVE_MACOS_SYS_TIMEX
+#include <dlfcn.h>
+#include "sys_netbsd.h"
+#include "sys_timex.h"
+
+static int have_ntp_adjtime = 0;
+static int have_bad_adjtime = 0;
+#endif
+
 /* ================================================== */

 /* This register contains the number of seconds by which the local
   clock was estimated to be fast of reference time at the epoch when
-   gettimeofday() returned T0 */
+   LCL_ReadRawTime() returned T0 */

 static double offset_register;

 /* This register contains the epoch to which the offset is referenced */

-static struct timeval T0;
+static struct timespec T0;

 /* This register contains the current estimate of the system
   frequency, in absolute (NOT ppm) */
@@ -79,7 +89,7 @@ static double adjustment_requested;

 static double drift_removal_interval;
 static double current_drift_removal_interval;
-static struct timeval Tdrift;
+static struct timespec Tdrift;

 /* weighting applied to error in calculating drift_removal_interval */
 #define ERROR_WEIGHT (0.5)
@@ -91,7 +101,7 @@ static struct timeval Tdrift;

 /* RTC synchronisation - once an hour */

-static struct timeval last_rtc_sync;
+static struct timespec last_rtc_sync;
 #define RTC_SYNC_INTERVAL (60 * 60.0)

 /* ================================================== */
@@ -107,9 +117,7 @@ clock_initialise(void)
  drift_removal_interval = DRIFT_REMOVAL_INTERVAL;
  current_drift_removal_interval = DRIFT_REMOVAL_INTERVAL;

-  if (gettimeofday(&T0, NULL) < 0) {
-    LOG_FATAL(LOGF_SysMacOSX, "gettimeofday() failed");
-  }
+  LCL_ReadRawTime(&T0);
  Tdrift = T0;
  last_rtc_sync = T0;

@@ -117,7 +125,7 @@ clock_initialise(void)
  newadj.tv_usec = 0;

  if (PRV_AdjustTime(&newadj, &oldadj) < 0) {
-    LOG_FATAL(LOGF_SysMacOSX, "adjtime() failed");
+    LOG_FATAL("adjtime() failed");
  }
 }

@@ -135,21 +143,19 @@ static void
 start_adjust(void)
 {
  struct timeval newadj, oldadj;
-  struct timeval T1;
+  struct timespec T1;
  double elapsed, accrued_error, predicted_error, drift_removal_elapsed;
  double adjust_required;
  double rounding_error;
  double old_adjust_remaining;

  /* Determine the amount of error built up since the last adjustment */
-  if (gettimeofday(&T1, NULL) < 0) {
-    LOG_FATAL(LOGF_SysMacOSX, "gettimeofday() failed");
-  }
+  LCL_ReadRawTime(&T1);

-  UTI_DiffTimevalsToDouble(&elapsed, &T1, &T0);
+  elapsed = UTI_DiffTimespecsToDouble(&T1, &T0);
  accrued_error = elapsed * current_freq;

-  UTI_DiffTimevalsToDouble(&drift_removal_elapsed, &T1, &Tdrift);
+  drift_removal_elapsed = UTI_DiffTimespecsToDouble(&T1, &Tdrift);

  /* To allow for the clock being stepped either forward or backwards, clamp
     the elapsed time to bounds [ 0.0, current_drift_removal_interval ] */
@@ -157,22 +163,21 @@ start_adjust(void)

  predicted_error = (current_drift_removal_interval - drift_removal_elapsed) / 2.0 * current_freq;

-  DEBUG_LOG(LOGF_SysMacOSX, "drift_removal_elapsed: %.3f current_drift_removal_interval: %.3f predicted_error: %.3f",
-                            1.0e6 * drift_removal_elapsed,
-                            1.0e6 * current_drift_removal_interval,
-                            1.0e6 * predicted_error);
+  DEBUG_LOG("drift_removal_elapsed: %.3f current_drift_removal_interval: %.3f predicted_error: %.3f",
+            1.0e6 * drift_removal_elapsed, 1.0e6 * current_drift_removal_interval,
+            1.0e6 * predicted_error);

  adjust_required = - (accrued_error + offset_register + predicted_error);

  UTI_DoubleToTimeval(adjust_required, &newadj);
-  UTI_TimevalToDouble(&newadj, &adjustment_requested);
+  adjustment_requested = UTI_TimevalToDouble(&newadj);
  rounding_error = adjust_required - adjustment_requested;

  if (PRV_AdjustTime(&newadj, &oldadj) < 0) {
-    LOG_FATAL(LOGF_SysMacOSX, "adjtime() failed");
+    LOG_FATAL("adjtime() failed");
  }

-  UTI_TimevalToDouble(&oldadj, &old_adjust_remaining);
+  old_adjust_remaining = UTI_TimevalToDouble(&oldadj);

  offset_register = rounding_error - old_adjust_remaining - predicted_error;

@@ -184,7 +189,7 @@ start_adjust(void)
 static void
 stop_adjust(void)
 {
-  struct timeval T1;
+  struct timespec T1;
  struct timeval zeroadj, remadj;
  double adjustment_remaining, adjustment_achieved;
  double elapsed, elapsed_plus_adjust;
@@ -193,15 +198,13 @@ stop_adjust(void)
  zeroadj.tv_usec = 0;

  if (PRV_AdjustTime(&zeroadj, &remadj) < 0) {
-    LOG_FATAL(LOGF_SysMacOSX, "adjtime() failed");
+    LOG_FATAL("adjtime() failed");
  }

-  if (gettimeofday(&T1, NULL) < 0) {
-    LOG_FATAL(LOGF_SysMacOSX, "gettimeofday() failed");
-  }
+  LCL_ReadRawTime(&T1);

-  UTI_DiffTimevalsToDouble(&elapsed, &T1, &T0);
-  UTI_TimevalToDouble(&remadj, &adjustment_remaining);
+  elapsed = UTI_DiffTimespecsToDouble(&T1, &T0);
+  adjustment_remaining = UTI_TimevalToDouble(&remadj);

  adjustment_achieved = adjustment_requested - adjustment_remaining;
  elapsed_plus_adjust = elapsed - adjustment_achieved;
@@ -233,22 +236,22 @@ accrue_offset(double offset, double corr_rate)
 static int
 apply_step_offset(double offset)
 {
-  struct timeval old_time, new_time, T1;
+  struct timespec old_time, new_time, T1;
+  struct timeval new_time_tv;

  stop_adjust();

-  if (gettimeofday(&old_time, NULL) < 0) {
-    LOG_FATAL(LOGF_SysMacOSX, "gettimeofday() failed");
-  }
+  LCL_ReadRawTime(&old_time);

-  UTI_AddDoubleToTimeval(&old_time, -offset, &new_time);
+  UTI_AddDoubleToTimespec(&old_time, -offset, &new_time);
+  UTI_TimespecToTimeval(&new_time, &new_time_tv);

-  if (PRV_SetTime(&new_time, NULL) < 0) {
-    DEBUG_LOG(LOGF_SysMacOSX, "settimeofday() failed");
+  if (PRV_SetTime(&new_time_tv, NULL) < 0) {
+    DEBUG_LOG("settimeofday() failed");
    return 0;
  }

-  UTI_AddDoubleToTimeval(&T0, -offset, &T1);
+  UTI_AddDoubleToTimespec(&T0, -offset, &T1);
  T0 = T1;

  start_adjust();
@@ -279,7 +282,7 @@ read_frequency(void)
 /* ================================================== */

 static void
-get_offset_correction(struct timeval *raw,
+get_offset_correction(struct timespec *raw,
                      double *corr, double *err)
 {
  stop_adjust();
@@ -311,9 +314,7 @@ drift_removal_timeout(SCH_ArbitraryArgument not_used)

  stop_adjust();

-  if (gettimeofday(&Tdrift, NULL) < 0) {
-    LOG_FATAL(LOGF_SysMacOSX, "gettimeofday() failed");
-  }
+  LCL_ReadRawTime(&Tdrift);

  current_drift_removal_interval = drift_removal_interval;

@@ -336,23 +337,23 @@ set_sync_status(int synchronised, double est_error, double max_error)
    drift_removal_interval = MAX(drift_removal_interval, DRIFT_REMOVAL_INTERVAL);
  } else {
    if (CNF_GetRtcSync()) {
-      struct timeval now;
+      struct timespec now;
      double rtc_sync_elapsed;

      SCH_GetLastEventTime(NULL, NULL, &now);
-      UTI_DiffTimevalsToDouble(&rtc_sync_elapsed, &now, &last_rtc_sync);
+      rtc_sync_elapsed = UTI_DiffTimespecsToDouble(&now, &last_rtc_sync);
      if (fabs(rtc_sync_elapsed) >= RTC_SYNC_INTERVAL) {
        /* update the RTC by applying a step of 0.0 secs */
        apply_step_offset(0.0);
        last_rtc_sync = now;
-        DEBUG_LOG(LOGF_SysMacOSX, "rtc synchronised");
+        DEBUG_LOG("rtc synchronised");
      }
    }

    interval = ERROR_WEIGHT * est_error / (fabs(current_freq) + FREQUENCY_RES);
    drift_removal_interval = MAX(interval, DRIFT_REMOVAL_INTERVAL_MIN);

-    DEBUG_LOG(LOGF_SysMacOSX, "est_error: %.3f current_freq: %.3f est drift_removal_interval: %.3f act drift_removal_interval: %.3f",
+    DEBUG_LOG("est_error: %.3f current_freq: %.3f est drift_removal_interval: %.3f act drift_removal_interval: %.3f",
                est_error * 1.0e6, current_freq * 1.0e6, interval, drift_removal_interval);
  }

@@ -396,7 +397,7 @@ set_realtime(void)
          THREAD_TIME_CONSTRAINT_POLICY_COUNT);

  if (kr != KERN_SUCCESS) {
-    LOG(LOGS_WARN, LOGF_SysMacOSX, "Cannot set real-time priority: %d", kr);
+    LOG(LOGS_WARN, "Cannot set real-time priority: %d", kr);
    return -1;
  }
  return 0;
@@ -425,8 +426,8 @@ void SYS_MacOSX_DropRoot(uid_t uid, gid_t gid)

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

-void
-SYS_MacOSX_Initialise(void)
+static void
+legacy_MacOSX_Initialise(void)
 {
  clock_initialise();

@@ -442,8 +443,8 @@ SYS_MacOSX_Initialise(void)

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

-void
-SYS_MacOSX_Finalise(void)
+static void
+legacy_MacOSX_Finalise(void)
 {
  SCH_RemoveTimeout(drift_removal_id);

@@ -452,4 +453,67 @@ SYS_MacOSX_Finalise(void)

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

+#ifdef HAVE_MACOS_SYS_TIMEX
+/*
+    Test adjtime() to see if Apple have fixed the signed/unsigned bug
+*/
+static int
+test_adjtime()
+{
+  struct timeval tv1 = {-1, 0};
+  struct timeval tv2 = {0, 0};
+  struct timeval tv;
+
+  if (PRV_AdjustTime(&tv1, &tv) != 0) {
+    return 0;
+  }
+  if (PRV_AdjustTime(&tv2, &tv) != 0) {
+    return 0;
+  }
+  if (tv.tv_sec < -1 || tv.tv_sec > 1) {
+    return 0;
+  }
+  return 1;
+}
+#endif
+
+/* ================================================== */
+
+void
+SYS_MacOSX_Initialise(void)
+{
+#ifdef HAVE_MACOS_SYS_TIMEX
+  have_ntp_adjtime = (dlsym(RTLD_NEXT, "ntp_adjtime") != NULL);
+  if (have_ntp_adjtime) {
+    have_bad_adjtime = !test_adjtime();
+    if (have_bad_adjtime) {
+      LOG(LOGS_WARN, "adjtime() is buggy - using timex driver");
+      SYS_Timex_Initialise();
+    } else {
+      SYS_NetBSD_Initialise();
+    }
+    return;
+  }
+#endif
+  legacy_MacOSX_Initialise();
+}
+
+/* ================================================== */
+
+void
+SYS_MacOSX_Finalise(void)
+{
+#ifdef HAVE_MACOS_SYS_TIMEX
+  if (have_ntp_adjtime) {
+    if (have_bad_adjtime) {
+      SYS_Timex_Finalise();
+    } else {
+      SYS_NetBSD_Finalise();
+    }
+    return;
+  }
+#endif
+  legacy_MacOSX_Finalise();
+}
+
 #endif
--- a/sys_macosx.h
+++ b/sys_macosx.h
@@ -23,7 +23,7 @@

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

-  Header file for MacOS X driver
+  Header file for macOS driver

  */

--- a/sys_netbsd.c
+++ b/sys_netbsd.c
@@ -60,34 +60,35 @@ static void
 accrue_offset(double offset, double corr_rate)
 {
  struct timeval newadj, oldadj;
+  double doldadj;

  UTI_DoubleToTimeval(-offset, &newadj);

  if (PRV_AdjustTime(&newadj, &oldadj) < 0)
-    LOG_FATAL(LOGF_SysNetBSD, "adjtime() failed");
+    LOG_FATAL("adjtime() failed");

  /* Add the old remaining adjustment if not zero */
-  UTI_TimevalToDouble(&oldadj, &offset);
-  if (offset != 0.0) {
-    UTI_AddDoubleToTimeval(&newadj, offset, &newadj);
+  doldadj = UTI_TimevalToDouble(&oldadj);
+  if (doldadj != 0.0) {
+    UTI_DoubleToTimeval(-offset + doldadj, &newadj);
    if (PRV_AdjustTime(&newadj, NULL) < 0)
-      LOG_FATAL(LOGF_SysNetBSD, "adjtime() failed");
+      LOG_FATAL("adjtime() failed");
  }
 }

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

 static void
-get_offset_correction(struct timeval *raw,
+get_offset_correction(struct timespec *raw,
                      double *corr, double *err)
 {
  struct timeval remadj;
  double adjustment_remaining;

  if (PRV_AdjustTime(NULL, &remadj) < 0)
-    LOG_FATAL(LOGF_SysNetBSD, "adjtime() failed");
+    LOG_FATAL("adjtime() failed");

-  UTI_TimevalToDouble(&remadj, &adjustment_remaining);
+  adjustment_remaining = UTI_TimevalToDouble(&remadj);

  *corr = adjustment_remaining;
  if (err) {
@@ -137,7 +138,7 @@ SYS_NetBSD_DropRoot(uid_t uid, gid_t gid)
  /* Check if we have write access to /dev/clockctl */
  fd = open("/dev/clockctl", O_WRONLY);
  if (fd < 0)
-    LOG_FATAL(LOGF_SysNetBSD, "Can't write to /dev/clockctl");
+    LOG_FATAL("Can't write to /dev/clockctl");
  close(fd);
 #endif
 }
--- a/sys_null.c
+++ b/sys_null.c
@@ -0,0 +1,140 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2017
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Null clock driver for operation with no clock control.
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "sys_null.h"
+
+#include "local.h"
+#include "localp.h"
+#include "logging.h"
+#include "util.h"
+
+/* Current frequency offset of the system clock (in ppm) */
+static double freq;
+
+/* Offset of the system clock at the last update */
+static double offset_register;
+
+/* Time of the last update */
+static struct timespec last_update;
+
+/* Minimum interval between updates when frequency is constant */
+#define MIN_UPDATE_INTERVAL 1000.0
+
+/* ================================================== */
+
+static void
+update_offset(void)
+{
+  struct timespec now;
+  double duration;
+
+  LCL_ReadRawTime(&now);
+  duration = UTI_DiffTimespecsToDouble(&now, &last_update);
+  offset_register += 1.0e-6 * freq * duration;
+  last_update = now;
+
+  DEBUG_LOG("System clock offset=%e freq=%f", offset_register, freq);
+}
+
+/* ================================================== */
+
+static double
+read_frequency(void)
+{
+  return freq;
+}
+
+/* ================================================== */
+
+static double
+set_frequency(double freq_ppm)
+{
+  update_offset();
+  freq = freq_ppm;
+
+  return freq;
+}
+
+/* ================================================== */
+
+static void
+accrue_offset(double offset, double corr_rate)
+{
+  offset_register += offset;
+}
+
+/* ================================================== */
+
+static int
+apply_step_offset(double offset)
+{
+  return 0;
+}
+
+/* ================================================== */
+
+static void
+offset_convert(struct timespec *raw, double *corr, double *err)
+{
+  double duration;
+
+  duration = UTI_DiffTimespecsToDouble(raw, &last_update);
+
+  if (duration > MIN_UPDATE_INTERVAL) {
+    update_offset();
+    duration = 0.0;
+  }
+
+  *corr = -1.0e-6 * freq * duration - offset_register;
+
+  if (err)
+    *err = 0.0;
+}
+
+/* ================================================== */
+
+void
+SYS_Null_Initialise(void)
+{
+  offset_register = 0.0;
+  LCL_ReadRawTime(&last_update);
+
+  lcl_RegisterSystemDrivers(read_frequency, set_frequency, accrue_offset,
+                            apply_step_offset, offset_convert, NULL, NULL);
+
+  LOG(LOGS_INFO, "Disabled control of system clock");
+}
+
+/* ================================================== */
+
+void
+SYS_Null_Finalise(void)
+{
+}
--- a/sys_null.h
+++ b/sys_null.h
@@ -0,0 +1,34 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2017
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Header file for null clock driver
+  */
+
+#ifndef GOT_SYS_NULL_H
+#define GOT_SYS_NULL_H
+
+extern void SYS_Null_Initialise(void);
+
+extern void SYS_Null_Finalise(void);
+
+#endif
--- a/sys_timex.c
+++ b/sys_timex.c
@@ -61,7 +61,10 @@
 #define MIN_TICK_RATE 100

 /* Saved timex status */
-static int status;
+static int sys_status;
+
+/* Saved TAI-UTC offset */
+static int sys_tai_offset;

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

@@ -95,33 +98,47 @@ set_frequency(double freq_ppm)
 /* ================================================== */

 static void
-set_leap(int leap)
+set_leap(int leap, int tai_offset)
 {
  struct timex txc;
-  int applied;
+  int applied, prev_status;

-  applied = 0;
-  if (!leap) {
-    txc.modes = 0;
-    if (SYS_Timex_Adjust(&txc, 1) == TIME_WAIT)
-      applied = 1;
-  }
+  txc.modes = 0;
+  applied = SYS_Timex_Adjust(&txc, 0) == TIME_WAIT;

-  status &= ~(STA_INS | STA_DEL);
+  prev_status = sys_status;
+  sys_status &= ~(STA_INS | STA_DEL);

  if (leap > 0)
-    status |= STA_INS;
+    sys_status |= STA_INS;
  else if (leap < 0)
-    status |= STA_DEL;
+    sys_status |= STA_DEL;

  txc.modes = MOD_STATUS;
-  txc.status = status;
+  txc.status = sys_status;
+
+#ifdef MOD_TAI
+  if (tai_offset) {
+    txc.modes |= MOD_TAI;
+    txc.constant = tai_offset;
+
+    if (applied && !(sys_status & (STA_INS | STA_DEL)))
+      sys_tai_offset += prev_status & STA_INS ? 1 : -1;
+
+    if (sys_tai_offset != tai_offset) {
+      sys_tai_offset = tai_offset;
+      LOG(LOGS_INFO, "System clock TAI offset set to %d seconds", tai_offset);
+    }
+  }
+#endif

  SYS_Timex_Adjust(&txc, 0);

-  LOG(LOGS_INFO, LOGF_SysTimex, "System clock status %s leap second",
-      leap ? (leap > 0 ? "set to insert" : "set to delete") :
-      (applied ? "reset after" : "set to not insert/delete"));
+  if (prev_status != sys_status) {
+    LOG(LOGS_INFO, "System clock status %s leap second",
+        leap ? (leap > 0 ? "set to insert" : "set to delete") :
+        (applied ? "reset after" : "set to not insert/delete"));
+  }
 }

 /* ================================================== */
@@ -149,16 +166,17 @@ set_sync_status(int synchronised, double est_error, double max_error)
 #endif

  if (synchronised)
-    status &= ~STA_UNSYNC;
+    sys_status &= ~STA_UNSYNC;
  else
-    status |= STA_UNSYNC;
+    sys_status |= STA_UNSYNC;

  txc.modes = MOD_STATUS | MOD_ESTERROR | MOD_MAXERROR;
-  txc.status = status;
+  txc.status = sys_status;
  txc.esterror = est_error * 1.0e6;
  txc.maxerror = max_error * 1.0e6;

-  SYS_Timex_Adjust(&txc, 1);
+  if (SYS_Timex_Adjust(&txc, 1) < 0)
+    ;
 }

 /* ================================================== */
@@ -168,17 +186,18 @@ initialise_timex(void)
 {
  struct timex txc;

-  status = STA_UNSYNC;
+  sys_status = STA_UNSYNC;
+  sys_tai_offset = 0;

  /* Reset PLL offset */
  txc.modes = MOD_OFFSET | MOD_STATUS;
-  txc.status = STA_PLL | status;
+  txc.status = STA_PLL | sys_status;
  txc.offset = 0;
  SYS_Timex_Adjust(&txc, 0);

  /* Turn PLL off */
  txc.modes = MOD_STATUS;
-  txc.status = status;
+  txc.status = sys_status;
  SYS_Timex_Adjust(&txc, 0);
 }

@@ -238,11 +257,9 @@ SYS_Timex_Adjust(struct timex *txc, int ignore_error)

  if (state < 0) {
    if (!ignore_error)
-      LOG_FATAL(LOGF_SysTimex, NTP_ADJTIME_NAME"(0x%x) failed : %s",
-                txc->modes, strerror(errno));
+      LOG_FATAL(NTP_ADJTIME_NAME"(0x%x) failed : %s", txc->modes, strerror(errno));
    else
-      DEBUG_LOG(LOGF_SysTimex, NTP_ADJTIME_NAME"(0x%x) failed : %s",
-                txc->modes, strerror(errno));
+      DEBUG_LOG(NTP_ADJTIME_NAME"(0x%x) failed : %s", txc->modes, strerror(errno));
  }

  return state;
--- a/sysincl.h
+++ b/sysincl.h
@@ -59,7 +59,7 @@
 #include <time.h>
 #include <unistd.h>

-#if defined(LINUX) || defined(FREEBSD) || defined(NETBSD) || defined(SOLARIS)
+#if defined(LINUX) || defined(FREEBSD) || defined(NETBSD) || defined(SOLARIS) || defined(HAVE_MACOS_SYS_TIMEX)
 #include <sys/timex.h>
 #endif

@@ -76,4 +76,8 @@
 #include <arpa/inet.h>
 #endif

+#ifdef HAVE_GETRANDOM
+#include <sys/random.h>
+#endif
+
 #endif /* GOT_SYSINCL_H */
--- a/tempcomp.c
+++ b/tempcomp.c
@@ -92,23 +92,21 @@ read_timeout(void *arg)
    if (fabs(comp) <= MAX_COMP) {
      comp = LCL_SetTempComp(comp);

-      DEBUG_LOG(LOGF_TempComp, "tempcomp updated to %f for %f", comp, temp);
+      DEBUG_LOG("tempcomp updated to %f for %f", comp, temp);

      if (logfileid != -1) {
-        struct timeval now;
+        struct timespec now;

        LCL_ReadCookedTime(&now, NULL);
        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",
+      LOG(LOGS_WARN, "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);
+    LOG(LOGS_WARN, "Could not read temperature from %s", filename);
  }

  if (f)
@@ -126,7 +124,7 @@ read_points(const char *filename)

  f = fopen(filename, "r");
  if (!f) {
-    LOG_FATAL(LOGF_TempComp, "Could not open tempcomp point file %s", filename);
+    LOG_FATAL("Could not open tempcomp point file %s", filename);
    return;
  }

@@ -135,7 +133,7 @@ read_points(const char *filename)
  while (fgets(line, sizeof (line), f)) {
    p = (struct Point *)ARR_GetNewElement(points);
    if (sscanf(line, "%lf %lf", &p->temp, &p->comp) != 2) {
-      LOG_FATAL(LOGF_Configure, "Could not read tempcomp point from %s", filename);
+      LOG_FATAL("Could not read tempcomp point from %s", filename);
      break;
    }
  }
@@ -143,7 +141,7 @@ read_points(const char *filename)
  fclose(f);

  if (ARR_GetSize(points) < 2)
-    LOG_FATAL(LOGF_Configure, "Not enough points in %s", filename);
+    LOG_FATAL("Not enough points in %s", filename);
 }

 void
--- a/test/compilation/001-features
+++ b/test/compilation/001-features
@@ -6,6 +6,7 @@ cd ../..

 for opts in \
 	"--enable-debug" \
+	"--enable-ntp-signd" \
 	"--enable-scfilter" \
 	"--disable-asyncdns" \
 	"--disable-ipv6" \
@@ -16,6 +17,8 @@ for opts in \
 	"--disable-cmdmon" \
 	"--disable-ntp" \
 	"--disable-refclock" \
+	"--disable-timestamping" \
+	"--disable-timestamping --disable-ntp" \
 	"--disable-cmdmon --disable-ntp" \
 	"--disable-cmdmon --disable-refclock" \
 	"--disable-cmdmon --disable-ntp --disable-refclock"
--- a/test/compilation/002-scanbuild
+++ b/test/compilation/002-scanbuild
@@ -0,0 +1,14 @@
+#!/bin/sh
+
+cd ../..
+
+for opts in \
+	"--host-system=Linux" \
+	"--host-system=NetBSD" \
+	"--host-system=FreeBSD" \
+	"--without-nss" \
+	"--without-tomcrypt --without-nss"
+do
+	./configure $opts
+	scan-build make "$@" || exit 1
+done
--- a/test/simulation/010-multrecv
+++ b/test/simulation/010-multrecv
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+. ./test.common
+
+export CLKNETSIM_RECV_MULTIPLY=4
+
+test_start "multiple received packets"
+
+limit=50000
+client_server_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/011-asymjitter
+++ b/test/simulation/011-asymjitter
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "asymmetric jitter"
+
+jitter=5e-4
+jitter_asymmetry=0.47
+limit=100000
+max_sync_time=2000
+
+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/105-ntpauth
+++ b/test/simulation/105-ntpauth
@@ -37,13 +37,15 @@ for hash in $hashes; do
 	echo "$key" >> tmp/client.keys
 done

-for key in $(seq $keys); 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
+for version in 3 4; do
+	for key in $(seq $keys); do
+		client_server_options="version $version 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
 done

 server_conf=""
--- a/test/simulation/110-chronyc
+++ b/test/simulation/110-chronyc
@@ -11,7 +11,7 @@ sourcestats"
 run_test || test_fail
 check_chronyd_exit || test_fail

-check_chronyc_output "^Reference ID    : 192\.168\.123\.1 \(192\.168\.123\.1\)
+check_chronyc_output "^Reference ID    : C0A87B01 \(192\.168\.123\.1\)
 Stratum         : 2
 Ref time \(UTC\)  : Fri Jan 01 00:1.:.. 2010
 System time     : 0\.0000..... seconds (slow|fast) of NTP time
@@ -20,8 +20,8 @@ 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
+Root delay      : 0\.000...... seconds
+Root dispersion : 0\.000...... seconds
 Update interval : [0-9]+\.. seconds
 Leap status     : Normal
 210 Number of sources = 1
--- a/test/simulation/113-leapsecond
+++ b/test/simulation/113-leapsecond
@@ -7,6 +7,7 @@ export CLKNETSIM_START_DATE=$(TZ=UTC date -d 'Dec 30 2008 0:00:00' +'%s')

 leap=$[2 * 24 * 3600]
 limit=$[4 * 24 * 3600]
+client_start=$[2 * 3600]
 server_conf="refclock SHM 0 dpoll 10 poll 10
 leapsectz right/UTC"
 refclock_jitter=1e-9
@@ -27,14 +28,25 @@ for leapmode in system step slew; do
 	check_sync || test_fail
 done

+client_server_options="trust"
+client_conf="refclock SHM 0 dpoll 10 poll 10 delay 1e-3"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+client_server_options=""
+client_conf="leapsecmode system"
+min_sync_time=230000
+max_sync_time=240000
+
 for smoothmode in "" "leaponly"; do
 	server_conf="refclock SHM 0 dpoll 10 poll 10
 	leapsectz right/UTC
 	leapsecmode slew
 	smoothtime 400 0.001 $smoothmode"
-	client_conf="leapsecmode system"
-	min_sync_time=230000
-	max_sync_time=240000

 	run_test || test_fail
 	check_chronyd_exit || test_fail
--- a/test/simulation/114-presend
+++ b/test/simulation/114-presend
@@ -3,7 +3,7 @@
 . ./test.common
 test_start "presend option"

-min_sync_time=140
+min_sync_time=136
 max_sync_time=260
 client_server_options="presend 6 maxdelay 16"
 client_conf="maxdistance 10"
--- a/test/simulation/117-fallbackdrift
+++ b/test/simulation/117-fallbackdrift
@@ -11,10 +11,11 @@ freq_offset="(* 1e-4 (sine 1000))"
 base_delay="(* -1.0 (equal 0.1 (min time 4250) 4250))"
 client_server_options="minpoll 4 maxpoll 4"
 client_conf="fallbackdrift 6 10"
+max_sync_time=4500
 time_max_limit=1e0
 time_rms_limit=1e0
-freq_max_limit=5e-4
-freq_rms_limit=5e-4
+freq_max_limit=2e-4
+freq_rms_limit=1e-4

 run_test || test_fail
 check_chronyd_exit || test_fail
--- a/test/simulation/118-maxdelay
+++ b/test/simulation/118-maxdelay
@@ -10,7 +10,7 @@ wander=0.0
 freq_offset="(sum 1e-10)"
 time_rms_limit=2e-4

-client_server_options="maxdelay 3e-5 maxdelayratio 2.0 maxdelaydevratio 2.0"
+client_server_options="maxpoll 6 maxdelay 3e-5 maxdelayratio 2.0 maxdelaydevratio 2.0"

 run_test || test_fail
 check_chronyd_exit || test_fail
@@ -18,7 +18,7 @@ check_source_selection || test_fail
 check_packet_interval || test_fail
 check_sync || test_fail

-for client_server_options in "maxdelay 2e-5" \ "maxdelayratio 1.001"; do
+for client_server_options in "maxpoll 6 maxdelay 2e-5" "maxpoll 6 maxdelayratio 1.001"; do
 	run_test || test_fail
 	check_chronyd_exit || test_fail
 	check_packet_interval || test_fail
--- a/test/simulation/119-smoothtime
+++ b/test/simulation/119-smoothtime
@@ -19,18 +19,27 @@ refclock_offset="(* 10.0 (equal 0.1 (max (sum 1.0) 1000) 1000))"
 server_step="(* -10.0 (equal 0.1 (sum 1.0) 1))"
 server_strata=1
 server_conf="refclock SHM 0 dpoll 4 poll 6
-smoothtime 2000 1"
+smoothtime 2000 1
+maxjitter 10.0"
 time_offset=-10
 client_server_options="minpoll 6 maxpoll 6"
 client_conf="corrtimeratio 100"
 min_sync_time=8000
-max_sync_time=8500
+max_sync_time=9000

 run_test || test_fail
 check_chronyd_exit || test_fail
 check_source_selection || test_fail
 check_sync || test_fail

+client_server_options="minpoll 6 maxpoll 6 xleave maxdelay 1e-1"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+client_server_options="minpoll 6 maxpoll 6"
 min_sync_time=$default_min_sync_time
 max_sync_time=$default_max_sync_time
 time_max_limit=11
--- a/Show More
+++ b/Show More