doc: update NEWS

Reorder the local off command with respect to offline and online to
prevent the client from getting an unsynchronized response.

NEWS

@@ -1,3 +1,27 @@
+New in version 4.1
+==================
+
+Enhancements
+------------
+* Add support for NTS servers specified by IP address (matching
+  Subject Alternative Name in server certificate)
+* Add source-specific configuration of trusted certificates
+* Allow multiple files and directories with trusted certificates
+* Allow multiple pairs of server keys and certificates
+* Add copy option to server/pool directive
+* Increase PPS lock limit to 40% of pulse interval
+* Perform source selection immediately after loading dump files
+* Reload dump files for addresses negotiated by NTS-KE server
+* Update seccomp filter and add less restrictive level
+* Restart ongoing name resolution on online command
+
+Bug fixes
+---------
+* Fix responding to IPv4 command requests on FreeBSD
+* Fix dump files to not include uncorrected offset
+* Fix initstepslew to accept time from own NTP clients
+* Reset NTP address and port when no longer negotiated by NTS-KE server
+
 New in version 4.0
 ==================
 
@@ -8,11 +32,13 @@ Enhancements
 * Add authselectmode directive to control selection of unauthenticated sources
 * Add binddevice, bindacqdevice, bindcmddevice directives
 * Add confdir directive to better support fragmented configuration
-* Add sourcedir directive and "reload sources" command to support
+* Add sourcedir directive and "reload sources" command to support dynamic
-  dynamic NTP sources specified in files
+  NTP sources specified in files
+* Add clockprecision directive
 * Add dscp directive to set Differentiated Services Code Point (DSCP)
 * Add -L option to limit log messages by severity
 * Add -p option to print whole configuration with included files
+* Add -U option to allow start under non-root user
 * Allow maxsamples to be set to 1 for faster update with -q/-Q option
 * Avoid replacing NTP sources with sources that have unreachable address
 * Improve pools to repeat name resolution to get "maxsources" sources
@@ -38,6 +64,9 @@ Bug fixes
 Removed features
 ----------------
 * Drop support for RIPEMD keys (RMD128, RMD160, RMD256, RMD320)
+* Drop support for long (non-standard) MACs in NTPv4 packets (chrony 2.x
+  clients using non-MD5/SHA1 keys need to use option "version 3")
+* Drop support for line editing with GNU Readline
 
 New in version 3.5.1
 ====================

README

@@ -91,7 +91,7 @@ Acknowledgements
 In writing the chronyd program, extensive use has been made of the NTPv3 (RFC
 1305) and NTPv4 (RFC 5905) specification.  The source code of the xntpd/ntpd
 implementation written by Dennis Fergusson, Lars Mathiesen, David Mills, and
-others, has been used to check the details of the protocol.
+others has been used to check the details of the protocol.
 
 The following people have provided patches and other major contributions
 to chrony:
@@ -108,6 +108,7 @@ Erik Bryer <ebryer@spots.ab.ca>
 Jonathan Cameron <jic23@cam.ac.uk>
 Bryan Christianson <bryan@whatroute.net>
 Juliusz Chroboczek <jch@pps.jussieu.fr>
+Kamil Dudka <kdudka@redhat.com>
 Christian Ehrhardt <christian.ehrhardt@canonical.com>
 Paul Elliott <pelliott@io.com>
 Robert Fairley <rfairley@redhat.com>
@@ -124,6 +125,7 @@ Jachym Holecek <jakym@volny.cz>
 Håkan Johansson <f96hajo@chalmers.se>
 Jim Knoble <jmknoble@pobox.com>
 Antti Jrvinen <costello@iki.fi>
+Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
 Eric Lammerts <eric@lammerts.org>
 Stefan Lucke <stefan@lucke.in-berlin.de>
 Victor Lum <viclum@vanu.com>
@@ -137,6 +139,8 @@ Denny Page <dennypage@me.com>
 Chris Perl <cperl@janestreet.com>
 Gautier PHILIPPON <gautier.philippon@ensimag.grenoble-inp.fr>
 Andreas Piesk <apiesk@virbus.de>
+Baruch Siach <baruch@tkos.co.il>
+Foster Snowhill <forst@forstwoof.ru>
 Andreas Steinmetz <ast@domdv.de>
 NAKAMURA Takumi <takumi@ps.sakura.ne.jp>
 Timo Teras <timo.teras@iki.fi>
@@ -148,6 +152,7 @@ Bernhard M. Wiedemann <bwiedemann@suse.de>
 Joachim Wiedorn <ad_debian@joonet.de>
 Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
 Ulrich Windl <ulrich.windl@rz.uni-regensburg.de>
+Michael Witten <mfwitten@gmail.com>
 Doug Woodward <dougw@whistler.com>
 Thomas Zajic <zlatko@zlatko.fdns.net>
 

candm.h

@@ -108,7 +108,8 @@
 #define REQ_CLIENT_ACCESSES_BY_INDEX3 68
 #define REQ_SELECT_DATA 69
 #define REQ_RELOAD_SOURCES 70
-#define N_REQUEST_TYPES 71
+#define REQ_DOFFSET2 71
+#define N_REQUEST_TYPES 72
 
 /* Structure used to exchange timespecs independent of time_t size */
 typedef struct {
@@ -268,6 +269,7 @@ typedef struct {
 #define REQ_ADDSRC_INTERLEAVED 0x80
 #define REQ_ADDSRC_BURST 0x100
 #define REQ_ADDSRC_NTS 0x200
+#define REQ_ADDSRC_COPY 0x400
 
 typedef struct {
   uint32_t type;
@@ -292,7 +294,8 @@ typedef struct {
   Float offset;
   uint32_t flags;
   int32_t filter_length;
-  uint32_t reserved[3];
+  uint32_t cert_set;
+  uint32_t reserved[2];
   int32_t EOR;
 } REQ_NTP_Source;
 
@@ -307,8 +310,7 @@ typedef struct {
 } REQ_Dfreq;
 
 typedef struct {
-  int32_t sec;
+  Float doffset;
-  int32_t usec;
   int32_t EOR;
 } REQ_Doffset;
 
@@ -403,7 +405,7 @@ typedef struct {
    domain socket.
 
    Version 6 (no authentication) : changed format of client accesses by index
-   (using new request/reply types) and manual timestamp, added new fields and
+   (two times), delta offset, and manual timestamp, added new fields and
    flags to NTP source request and report, made length of manual list constant,
    added new commands: authdata, ntpdata, onoffline, refresh, reset,
    selectdata, serverstats, shutdown, sourcename
@@ -553,12 +555,12 @@ typedef struct {
 #define RPY_SD_MD_PEER   1
 #define RPY_SD_MD_REF    2
 
-#define RPY_SD_ST_SYNC 0
+#define RPY_SD_ST_SELECTED 0
-#define RPY_SD_ST_UNREACH 1
+#define RPY_SD_ST_NONSELECTABLE 1
 #define RPY_SD_ST_FALSETICKER 2
 #define RPY_SD_ST_JITTERY 3
-#define RPY_SD_ST_CANDIDATE 4
+#define RPY_SD_ST_UNSELECTED 4
-#define RPY_SD_ST_OUTLIER 5
+#define RPY_SD_ST_SELECTABLE 5
 
 typedef struct {
   IPAddr ip_addr;
@@ -764,7 +766,8 @@ typedef struct {
   IPAddr ip_addr;
   uint8_t state_char;
   uint8_t authentication;
-  uint8_t pad[2];
+  uint8_t leap;
+  uint8_t pad;
   uint16_t conf_options;
   uint16_t eff_options;
   uint32_t last_sample_ago;

client.c

@@ -4,7 +4,7 @@
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
  * Copyright (C) Lonnie Abelbeck  2016, 2018
- * Copyright (C) Miroslav Lichvar  2009-2018
+ * Copyright (C) Miroslav Lichvar  2009-2021
  * 
  * 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
@@ -44,12 +44,7 @@
 #include "util.h"
 
 #ifdef FEAT_READLINE
-#ifdef USE_EDITLINE
 #include <editline/readline.h>
-#else
-#include <readline/readline.h>
-#include <readline/history.h>
-#endif
 #endif
 
 /* ================================================== */
@@ -66,7 +61,7 @@ static ARR_Instance server_addresses;
 
 static int sock_fd = -1;
 
-static int quit = 0;
+static volatile int quit = 0;
 
 static int on_terminal = 0;
 
@@ -992,54 +987,38 @@ process_cmd_cmdaccheck(CMD_Request *msg, char *line)
 
 /* ================================================== */
 
-static void
+static int
 process_cmd_dfreq(CMD_Request *msg, char *line)
 {
   double dfreq;
+
   msg->command = htons(REQ_DFREQ);
-  if (sscanf(line, "%lf", &dfreq) == 1) {
+
-    msg->data.dfreq.dfreq = UTI_FloatHostToNetwork(dfreq);
+  if (sscanf(line, "%lf", &dfreq) != 1) {
-  } else {
+    LOG(LOGS_ERR, "Invalid value");
-    msg->data.dfreq.dfreq = UTI_FloatHostToNetwork(0.0);
+    return 0;
   }
+
+  msg->data.dfreq.dfreq = UTI_FloatHostToNetwork(dfreq);
+  return 1;
 }
 
 /* ================================================== */
 
-static void
+static int
-cvt_to_sec_usec(double x, long *sec, long *usec) {
-  long s, us;
-  s = (long) x;
-  us = (long)(0.5 + 1.0e6 * (x - (double) s));
-  while (us >= 1000000) {
-    us -= 1000000;
-    s += 1;
-  }
-  while (us < 0) {
-    us += 1000000;
-    s -= 1;
-  }
-  
-  *sec = s;
-  *usec = us;
-}
-
-/* ================================================== */
-
-static void
 process_cmd_doffset(CMD_Request *msg, char *line)
 {
   double doffset;
-  long sec, usec;
+
-  msg->command = htons(REQ_DOFFSET);
+  msg->command = htons(REQ_DOFFSET2);
-  if (sscanf(line, "%lf", &doffset) == 1) {
+
-    cvt_to_sec_usec(doffset, &sec, &usec);
+  if (sscanf(line, "%lf", &doffset) != 1) {
-    msg->data.doffset.sec = htonl(sec);
+    LOG(LOGS_ERR, "Invalid value");
-    msg->data.doffset.usec = htonl(usec);
+    return 0;
-  } else {
-    msg->data.doffset.sec = htonl(0);
-    msg->data.doffset.usec = htonl(0);
   }
+
+  msg->data.doffset.doffset = UTI_FloatHostToNetwork(doffset);
+  return 1;
 }
 
 /* ================================================== */
@@ -1119,11 +1098,13 @@ process_cmd_add_source(CMD_Request *msg, char *line)
           (data.params.interleaved ? REQ_ADDSRC_INTERLEAVED : 0) |
           (data.params.burst ? REQ_ADDSRC_BURST : 0) |
           (data.params.nts ? REQ_ADDSRC_NTS : 0) |
+          (data.params.copy ? REQ_ADDSRC_COPY : 0) |
           (data.params.sel_options & SRC_SELECT_PREFER ? REQ_ADDSRC_PREFER : 0) |
           (data.params.sel_options & SRC_SELECT_NOSELECT ? REQ_ADDSRC_NOSELECT : 0) |
           (data.params.sel_options & SRC_SELECT_TRUST ? REQ_ADDSRC_TRUST : 0) |
           (data.params.sel_options & SRC_SELECT_REQUIRE ? REQ_ADDSRC_REQUIRE : 0));
       msg->data.ntp_source.filter_length = htonl(data.params.filter_length);
+      msg->data.ntp_source.cert_set = htonl(data.params.cert_set);
       memset(msg->data.ntp_source.reserved, 0, sizeof (msg->data.ntp_source.reserved));
 
       result = 1;
@@ -1267,7 +1248,7 @@ give_help(void)
 }
 
 /* ================================================== */
-/* Tab-completion when editline/readline is available */
+/* Tab-completion when editline is available */
 
 #ifdef FEAT_READLINE
 
@@ -1887,19 +1868,19 @@ print_report(const char *format, ...)
         integer = va_arg(ap, int);
         switch (integer) {
           case LEAP_Normal:
-            string = "Normal";
+            string = width != 1 ? "Normal" : "N";
             break;
           case LEAP_InsertSecond:
-            string = "Insert second";
+            string = width != 1 ? "Insert second" : "+";
             break;
           case LEAP_DeleteSecond:
-            string = "Delete second";
+            string = width != 1 ? "Delete second" : "-";
             break;
           case LEAP_Unsynchronised:
-            string = "Not synchronised";
+            string = width != 1 ? "Not synchronised" : "?";
             break;
           default:
-            string = "Invalid";
+            string = width != 1 ? "Invalid" : "?";
             break;
         }
         printf("%s", string);
@@ -2054,7 +2035,7 @@ get_source_name(IPAddr *ip_addr, char *buf, int size)
 
   /* Make sure the name is printable */
   for (i = 0; i < size && buf[i] != '\0'; i++) {
-    if (!isgraph(buf[i]))
+    if (!isgraph((unsigned char)buf[i]))
       return 0;
   }
 
@@ -2110,7 +2091,7 @@ process_cmd_sourcename(char *line)
   IPAddr ip_addr;
   char name[256];
 
-  if (!UTI_StringToIP(line, &ip_addr)) {
+  if (!parse_source_address(line, &ip_addr)) {
     LOG(LOGS_ERR, "Could not read address");
     return 0;
   }
@@ -2146,8 +2127,8 @@ process_cmd_sources(char *line)
   if (verbose) {
     printf("\n");
     printf("  .-- Source mode  '^' = server, '=' = peer, '#' = local clock.\n");
-    printf(" / .- Source state '*' = current synced, '+' = combined , '-' = not combined,\n");
+    printf(" / .- Source state '*' = current best, '+' = combined, '-' = not combined,\n");
-    printf("| /   '?' = unreachable, 'x' = time may be in error, '~' = time too variable.\n");
+    printf("| /             'x' = may be in error, '~' = too variable, '?' = unusable.\n");
     printf("||                                                 .- xxxx [ yyyy ] +/- zzzz\n");
     printf("||      Reachability register (octal) -.           |  xxxx = adjusted offset,\n");
     printf("||      Log2(Polling interval) --.      |          |  yyyy = measured offset,\n");
@@ -2189,10 +2170,10 @@ process_cmd_sources(char *line)
     }
 
     switch (ntohs(reply.data.source_data.state)) {
-      case RPY_SD_ST_SYNC:
+      case RPY_SD_ST_SELECTED:
         state_ch = '*';
         break;
-      case RPY_SD_ST_UNREACH:
+      case RPY_SD_ST_NONSELECTABLE:
         state_ch = '?';
         break;
       case RPY_SD_ST_FALSETICKER:
@@ -2201,10 +2182,10 @@ process_cmd_sources(char *line)
       case RPY_SD_ST_JITTERY:
         state_ch = '~';
         break;
-      case RPY_SD_ST_CANDIDATE:
+      case RPY_SD_ST_UNSELECTED:
         state_ch = '+';
         break;
-      case RPY_SD_ST_OUTLIER:
+      case RPY_SD_ST_SELECTABLE:
         state_ch = '-';
         break;
       default:
@@ -2581,9 +2562,9 @@ process_cmd_selectdata(char *line)
     printf(    "|                        |    |     |                       |\n");
   }
 
-  print_header("S Name/IP Address        Auth COpts EOpts Last Score     Interval   ");
+  print_header("S Name/IP Address        Auth COpts EOpts Last Score     Interval  Leap");
 
-  /*           "S NNNNNNNNNNNNNNNNNNNNNNNNN A OOOO- OOOO- LLLL SSSSS LLLLLLL LLLLLLL" */
+  /*           "S NNNNNNNNNNNNNNNNNNNNNNNNN A OOOO- OOOO- LLLL SSSSS IIIIIII IIIIIII  L" */
 
   for (i = 0; i < n_sources; i++) {
     request.command = htons(REQ_SELECT_DATA);
@@ -2601,7 +2582,7 @@ process_cmd_selectdata(char *line)
     conf_options = ntohs(reply.data.select_data.conf_options);
     eff_options = ntohs(reply.data.select_data.eff_options);
 
-    print_report("%c %-25s %c %c%c%c%c%c %c%c%c%c%c %I %5.1f %+S %+S\n",
+    print_report("%c %-25s %c %c%c%c%c%c %c%c%c%c%c %I %5.1f %+S %+S  %1L\n",
                  reply.data.select_data.state_char,
                  name,
                  reply.data.select_data.authentication ? 'Y' : 'N',
@@ -2619,6 +2600,7 @@ process_cmd_selectdata(char *line)
                  UTI_FloatNetworkToHost(reply.data.select_data.score),
                  UTI_FloatNetworkToHost(reply.data.select_data.lo_limit),
                  UTI_FloatNetworkToHost(reply.data.select_data.hi_limit),
+                 reply.data.select_data.leap,
                  REPORT_END);
   }
 
@@ -3289,12 +3271,12 @@ process_line(char *line)
       do_normal_submit = process_cmd_deny(&tx_message, line);
     }
   } else if (!strcmp(command, "dfreq")) {
-    process_cmd_dfreq(&tx_message, line);
+    do_normal_submit = process_cmd_dfreq(&tx_message, line);
   } else if (!strcmp(command, "dns")) {
     ret = process_cmd_dns(line);
     do_normal_submit = 0;
   } else if (!strcmp(command, "doffset")) {
-    process_cmd_doffset(&tx_message, line);
+    do_normal_submit = process_cmd_doffset(&tx_message, line);
   } else if (!strcmp(command, "dump")) {
     process_cmd_dump(&tx_message, line);
   } else if (!strcmp(command, "exit")) {
@@ -3476,7 +3458,7 @@ static void
 display_gpl(void)
 {
     printf("chrony version %s\n"
-           "Copyright (C) 1997-2003, 2007, 2009-2019 Richard P. Curnow and others\n"
+           "Copyright (C) 1997-2003, 2007, 2009-2021 Richard P. Curnow and others\n"
            "chrony comes with ABSOLUTELY NO WARRANTY.  This is free software, and\n"
            "you are welcome to redistribute it under certain conditions.  See the\n"
            "GNU General Public License version 2 for details.\n\n",
@@ -3488,8 +3470,22 @@ display_gpl(void)
 static void
 print_help(const char *progname)
 {
-      printf("Usage: %s [-h HOST] [-p PORT] [-n] [-N] [-c] [-d] [-4|-6] [-m] [COMMAND]\n",
+      printf("Usage: %s [OPTION]... [COMMAND]...\n\n"
-             progname);
+             "Options:\n"
+             "  -4\t\tUse IPv4 addresses only\n"
+             "  -6\t\tUse IPv6 addresses only\n"
+             "  -n\t\tDon't resolve hostnames\n"
+             "  -N\t\tPrint original source names\n"
+             "  -c\t\tEnable CSV format\n"
+#if DEBUG > 0
+             "  -d\t\tEnable debug messages\n"
+#endif
+             "  -m\t\tAccept multiple commands\n"
+             "  -h HOST\tSpecify server (%s)\n"
+             "  -p PORT\tSpecify UDP port (%d)\n"
+             "  -v, --version\tPrint version and exit\n"
+             "      --help\tPrint usage and exit\n",
+             progname, DEFAULT_COMMAND_SOCKET",127.0.0.1,::1", DEFAULT_CANDM_PORT);
 }
 
 /* ================================================== */
@@ -3511,7 +3507,7 @@ main(int argc, char **argv)
   int opt, ret = 1, multi = 0, family = IPADDR_UNSPEC;
   int port = DEFAULT_CANDM_PORT;
 
-  /* Parse (undocumented) long command-line options */
+  /* Parse long command-line options */
   for (optind = 1; optind < argc; optind++) {
     if (!strcmp("--help", argv[optind])) {
       print_help(progname);

clientlog.c

@@ -169,7 +169,7 @@ compare_total_hits(Record *x, Record *y)
 static Record *
 get_record(IPAddr *ip)
 {
-  uint32_t last_hit, oldest_hit = 0;
+  uint32_t last_hit = 0, oldest_hit = 0;
   Record *record, *oldest_record;
   unsigned int first, i, j;
 

cmdmon.c

@@ -3,7 +3,7 @@
 
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2016, 2018
+ * Copyright (C) Miroslav Lichvar  2009-2016, 2018-2021
  * 
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -62,6 +62,9 @@ static int sock_fdu;
 static int sock_fd4;
 static int sock_fd6;
 
+/* Flag indicating the IPv4 socket is bound to an address */
+static int bound_sock_fd4;
+
 /* Flag indicating whether this module has been initialised or not */
 static int initialised = 0;
 
@@ -140,6 +143,7 @@ static const char permissions[] = {
   PERMIT_AUTH, /* CLIENT_ACCESSES_BY_INDEX3 */
   PERMIT_AUTH, /* SELECT_DATA */
   PERMIT_AUTH, /* RELOAD_SOURCES */
+  PERMIT_AUTH, /* DOFFSET2 */
 };
 
 /* ================================================== */
@@ -179,6 +183,9 @@ open_socket(int family)
         return INVALID_SOCK_FD;
       }
 
+      if (family == IPADDR_INET4)
+        bound_sock_fd4 = local_addr.ip_addr.addr.in4 != INADDR_ANY;
+
       break;
     case IPADDR_UNSPEC:
       local_path = CNF_GetBindCommandPath();
@@ -244,6 +251,8 @@ CAM_Initialise(void)
 
   initialised = 1;
 
+  bound_sock_fd4 = 0;
+
   sock_fdu = INVALID_SOCK_FD;
   sock_fd4 = open_socket(IPADDR_INET4);
   sock_fd6 = open_socket(IPADDR_INET6);
@@ -294,15 +303,28 @@ CAM_OpenUnixSocket(void)
 /* ================================================== */
 
 static void
-transmit_reply(int sock_fd, SCK_Message *message)
+transmit_reply(int sock_fd, int request_length, SCK_Message *message)
 {
   message->length = PKL_ReplyLength((CMD_Reply *)message->data);
 
+  if (request_length < message->length) {
+    DEBUG_LOG("Response longer than request req_len=%d res_len=%d",
+              request_length, message->length);
+    return;
+  }
+
   /* Don't require responses to non-link-local addresses to use the same
      interface */
-  if (!SCK_IsLinkLocalIPAddress(&message->remote_addr.ip.ip_addr))
+  if (message->addr_type == SCK_ADDR_IP &&
+      !SCK_IsLinkLocalIPAddress(&message->remote_addr.ip.ip_addr))
     message->if_index = INVALID_IF_INDEX;
 
+#if !defined(HAVE_IN_PKTINFO) && defined(IP_SENDSRCADDR)
+  /* On FreeBSD a local IPv4 address cannot be specified on bound socket */
+  if (message->local_addr.ip.family == IPADDR_INET4 && (sock_fd != sock_fd4 || bound_sock_fd4))
+    message->local_addr.ip.family = IPADDR_UNSPEC;
+#endif
+
   if (!SCK_SendMessage(sock_fd, message, 0))
     return;
 }
@@ -572,11 +594,8 @@ handle_source_data(CMD_Request *rx_message, CMD_Reply *tx_message)
     tx_message->data.source_data.stratum = htons(report.stratum);
     tx_message->data.source_data.poll    = htons(report.poll);
     switch (report.state) {
-      case RPT_SYNC:
+      case RPT_NONSELECTABLE:
-        tx_message->data.source_data.state   = htons(RPY_SD_ST_SYNC);
+        tx_message->data.source_data.state   = htons(RPY_SD_ST_NONSELECTABLE);
-        break;
-      case RPT_UNREACH:
-        tx_message->data.source_data.state   = htons(RPY_SD_ST_UNREACH);
         break;
       case RPT_FALSETICKER:
         tx_message->data.source_data.state   = htons(RPY_SD_ST_FALSETICKER);
@@ -584,11 +603,14 @@ handle_source_data(CMD_Request *rx_message, CMD_Reply *tx_message)
       case RPT_JITTERY:
         tx_message->data.source_data.state   = htons(RPY_SD_ST_JITTERY);
         break;
-      case RPT_CANDIDATE:
+      case RPT_SELECTABLE:
-        tx_message->data.source_data.state   = htons(RPY_SD_ST_CANDIDATE);
+        tx_message->data.source_data.state   = htons(RPY_SD_ST_SELECTABLE);
         break;
-      case RPT_OUTLIER:
+      case RPT_UNSELECTED:
-        tx_message->data.source_data.state   = htons(RPY_SD_ST_OUTLIER);
+        tx_message->data.source_data.state   = htons(RPY_SD_ST_UNSELECTED);
+        break;
+      case RPT_SELECTED:
+        tx_message->data.source_data.state   = htons(RPY_SD_ST_SELECTED);
         break;
     }
     switch (report.mode) {
@@ -728,6 +750,7 @@ handle_add_source(CMD_Request *rx_message, CMD_Reply *tx_message)
   params.filter_length = ntohl(rx_message->data.ntp_source.filter_length);
   params.authkey = ntohl(rx_message->data.ntp_source.authkey);
   params.nts_port = ntohl(rx_message->data.ntp_source.nts_port);
+  params.cert_set = ntohl(rx_message->data.ntp_source.cert_set);
   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);
@@ -744,6 +767,7 @@ handle_add_source(CMD_Request *rx_message, CMD_Reply *tx_message)
   params.interleaved = ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_INTERLEAVED ? 1 : 0;
   params.burst = ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_BURST ? 1 : 0;
   params.nts = ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_NTS ? 1 : 0;
+  params.copy = ntohl(rx_message->data.ntp_source.flags) & REQ_ADDSRC_COPY ? 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) |
@@ -834,13 +858,14 @@ handle_dfreq(CMD_Request *rx_message, CMD_Reply *tx_message)
 static void
 handle_doffset(CMD_Request *rx_message, CMD_Reply *tx_message)
 {
-  long sec, usec;
   double doffset;
-  sec = (int32_t)ntohl(rx_message->data.doffset.sec);
+
-  usec = (int32_t)ntohl(rx_message->data.doffset.usec);
+  doffset = UTI_FloatNetworkToHost(rx_message->data.doffset.doffset);
-  doffset = (double) sec + 1.0e-6 * (double) usec;
+  if (!LCL_AccumulateOffset(doffset, 0.0)) {
-  LOG(LOGS_INFO, "Accumulated delta offset of %.6f seconds", doffset);
+    tx_message->status = htons(STT_FAILED);
-  LCL_AccumulateOffset(doffset, 0.0);
+  } else {
+    LOG(LOGS_INFO, "Accumulated delta offset of %.6f seconds", doffset);
+  }
 }
 
 /* ================================================== */
@@ -1320,6 +1345,7 @@ handle_select_data(CMD_Request *rx_message, CMD_Reply *tx_message)
   UTI_IPHostToNetwork(&report.ip_addr, &tx_message->data.select_data.ip_addr);
   tx_message->data.select_data.state_char = report.state_char;
   tx_message->data.select_data.authentication = report.authentication;
+  tx_message->data.select_data.leap = report.leap;
   tx_message->data.select_data.conf_options = htons(convert_select_options(report.conf_options));
   tx_message->data.select_data.eff_options = htons(convert_select_options(report.eff_options));
   tx_message->data.select_data.last_sample_ago = htonl(report.last_sample_ago);
@@ -1427,7 +1453,7 @@ read_from_cmd_socket(int sock_fd, int event, void *anything)
 
     if (rx_message.version >= PROTO_VERSION_MISMATCH_COMPAT_SERVER) {
       tx_message.status = htons(STT_BADPKTVERSION);
-      transmit_reply(sock_fd, sck_message);
+      transmit_reply(sock_fd, read_length, sck_message);
     }
     return;
   }
@@ -1437,7 +1463,7 @@ read_from_cmd_socket(int sock_fd, int event, void *anything)
     DEBUG_LOG("Command packet has invalid command %d", rx_command);
 
     tx_message.status = htons(STT_INVALID);
-    transmit_reply(sock_fd, sck_message);
+    transmit_reply(sock_fd, read_length, sck_message);
     return;
   }
 
@@ -1446,7 +1472,7 @@ read_from_cmd_socket(int sock_fd, int event, void *anything)
               expected_length);
 
     tx_message.status = htons(STT_BADPKTLENGTH);
-    transmit_reply(sock_fd, sck_message);
+    transmit_reply(sock_fd, read_length, sck_message);
     return;
   }
 
@@ -1614,7 +1640,7 @@ read_from_cmd_socket(int sock_fd, int event, void *anything)
           handle_dfreq(&rx_message, &tx_message);
           break;
 
-        case REQ_DOFFSET:
+        case REQ_DOFFSET2:
           handle_doffset(&rx_message, &tx_message);
           break;
 
@@ -1733,19 +1759,7 @@ read_from_cmd_socket(int sock_fd, int event, void *anything)
   }
 
   /* Transmit the response */
-  {
+  transmit_reply(sock_fd, read_length, sck_message);
-    /* Include a simple way to lose one message in three to test resend */
-
-    static int do_it=1;
-
-    if (do_it) {
-      transmit_reply(sock_fd, sck_message);
-    }
-
-#if 0
-    do_it = ((do_it + 1) % 3);
-#endif
-  }
 }
 
 /* ================================================== */

cmdparse.c

@@ -64,7 +64,9 @@ CPS_ParseNTPSourceAdd(char *line, CPS_NTP_Source *src)
   src->params.sel_options = 0;
   src->params.nts = 0;
   src->params.nts_port = SRC_DEFAULT_NTSPORT;
+  src->params.copy = 0;
   src->params.authkey = INACTIVE_AUTHKEY;
+  src->params.cert_set = SRC_DEFAULT_CERTSET;
   src->params.max_delay = SRC_DEFAULT_MAXDELAY;
   src->params.max_delay_ratio = SRC_DEFAULT_MAXDELAYRATIO;
   src->params.max_delay_dev_ratio = SRC_DEFAULT_MAXDELAYDEVRATIO;
@@ -90,6 +92,8 @@ CPS_ParseNTPSourceAdd(char *line, CPS_NTP_Source *src)
       src->params.auto_offline = 1;
     } else if (!strcasecmp(cmd, "burst")) {
       src->params.burst = 1;
+    } else if (!strcasecmp(cmd, "copy")) {
+      src->params.copy = 1;
     } else if (!strcasecmp(cmd, "iburst")) {
       src->params.iburst = 1;
     } else if (!strcasecmp(cmd, "offline")) {
@@ -102,6 +106,9 @@ CPS_ParseNTPSourceAdd(char *line, CPS_NTP_Source *src)
       src->params.sel_options |= SRC_SELECT_REQUIRE;
     } else if (!strcasecmp(cmd, "trust")) {
       src->params.sel_options |= SRC_SELECT_TRUST;
+    } else if (!strcasecmp(cmd, "certset")) {
+      if (sscanf(line, "%"SCNu32"%n", &src->params.cert_set, &n) != 1)
+        return 0;
     } else if (!strcasecmp(cmd, "key")) {
       if (sscanf(line, "%"SCNu32"%n", &src->params.authkey, &n) != 1 ||
           src->params.authkey == INACTIVE_AUTHKEY)

conf.c

@@ -3,7 +3,7 @@
 
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2017
+ * Copyright (C) Miroslav Lichvar  2009-2017, 2020
  * 
  * 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
@@ -76,6 +76,8 @@ static void parse_log(char *);
 static void parse_mailonchange(char *);
 static void parse_makestep(char *);
 static void parse_maxchange(char *);
+static void parse_ntsserver(char *, ARR_Instance files);
+static void parse_ntstrustedcerts(char *);
 static void parse_ratelimit(char *line, int *enabled, int *interval,
                             int *burst, int *leak);
 static void parse_refclock(char *);
@@ -100,6 +102,7 @@ static double correction_time_ratio = 3.0;
 static double max_clock_error = 1.0; /* in ppm */
 static double max_drift = 500000.0; /* in ppm */
 static double max_slew_rate = 1e6 / 12.0; /* in ppm */
+static double clock_precision = 0.0; /* in seconds */
 
 static SRC_AuthSelectMode authselect_mode = SRC_AUTHSELECT_MIX;
 static double max_distance = 3.0;
@@ -251,14 +254,15 @@ static char *user;
 /* NTS server and client configuration */
 static char *nts_dump_dir = NULL;
 static char *nts_ntp_server = NULL;
-static char *nts_server_cert_file = NULL;
+static ARR_Instance nts_server_cert_files; /* array of (char *) */
-static char *nts_server_key_file = NULL;
+static ARR_Instance nts_server_key_files; /* array of (char *) */
 static int nts_server_port = NKE_PORT;
 static int nts_server_processes = 1;
 static int nts_server_connections = 100;
 static int nts_refresh = 2419200; /* 4 weeks */
 static int nts_rotate = 604800; /* 1 week */
-static char *nts_trusted_cert_file = NULL;
+static ARR_Instance nts_trusted_certs_paths; /* array of (char *) */
+static ARR_Instance nts_trusted_certs_ids; /* array of uint32_t */
 
 /* Number of clock updates needed to enable certificate time checks */
 static int no_cert_time_check = 0;
@@ -387,6 +391,11 @@ CNF_Initialise(int r, int client_only)
   ntp_restrictions = ARR_CreateInstance(sizeof (AllowDeny));
   cmd_restrictions = ARR_CreateInstance(sizeof (AllowDeny));
 
+  nts_server_cert_files = ARR_CreateInstance(sizeof (char *));
+  nts_server_key_files = ARR_CreateInstance(sizeof (char *));
+  nts_trusted_certs_paths = ARR_CreateInstance(sizeof (char *));
+  nts_trusted_certs_ids = ARR_CreateInstance(sizeof (uint32_t));
+
   rtc_device = Strdup(DEFAULT_RTC_DEVICE);
   hwclock_file = Strdup(DEFAULT_HWCLOCK_FILE);
   user = Strdup(DEFAULT_USER);
@@ -421,6 +430,16 @@ CNF_Finalise(void)
     Free(((NTP_Source *)ARR_GetElement(ntp_sources, i))->params.name);
   for (i = 0; i < ARR_GetSize(ntp_source_dirs); i++)
     Free(*(char **)ARR_GetElement(ntp_source_dirs, i));
+  for (i = 0; i < ARR_GetSize(refclock_sources); i++) {
+    Free(((RefclockParameters *)ARR_GetElement(refclock_sources, i))->driver_name);
+    Free(((RefclockParameters *)ARR_GetElement(refclock_sources, i))->driver_parameter);
+  }
+  for (i = 0; i < ARR_GetSize(nts_server_cert_files); i++)
+    Free(*(char **)ARR_GetElement(nts_server_cert_files, i));
+  for (i = 0; i < ARR_GetSize(nts_server_key_files); i++)
+    Free(*(char **)ARR_GetElement(nts_server_key_files, i));
+  for (i = 0; i < ARR_GetSize(nts_trusted_certs_paths); i++)
+    Free(*(char **)ARR_GetElement(nts_trusted_certs_paths, i));
 
   ARR_DestroyInstance(init_sources);
   ARR_DestroyInstance(ntp_sources);
@@ -432,6 +451,11 @@ CNF_Finalise(void)
   ARR_DestroyInstance(ntp_restrictions);
   ARR_DestroyInstance(cmd_restrictions);
 
+  ARR_DestroyInstance(nts_server_cert_files);
+  ARR_DestroyInstance(nts_server_key_files);
+  ARR_DestroyInstance(nts_trusted_certs_paths);
+  ARR_DestroyInstance(nts_trusted_certs_ids);
+
   Free(drift_file);
   Free(dumpdir);
   Free(hwclock_file);
@@ -452,9 +476,6 @@ CNF_Finalise(void)
   Free(tempcomp_point_file);
   Free(nts_dump_dir);
   Free(nts_ntp_server);
-  Free(nts_server_cert_file);
-  Free(nts_server_key_file);
-  Free(nts_trusted_cert_file);
 }
 
 /* ================================================== */
@@ -544,6 +565,8 @@ CNF_ParseLine(const char *filename, int number, char *line)
     parse_broadcast(p);
   } else if (!strcasecmp(command, "clientloglimit")) {
     parse_clientloglimit(p);
+  } else if (!strcasecmp(command, "clockprecision")) {
+    parse_double(p, &clock_precision);
   } else if (!strcasecmp(command, "cmdallow")) {
     parse_allow_deny(p, cmd_restrictions, 1);
   } else if (!strcasecmp(command, "cmddeny")) {
@@ -636,8 +659,6 @@ CNF_ParseLine(const char *filename, int number, char *line)
   } else if (!strcasecmp(command, "ntsratelimit")) {
     parse_ratelimit(p, &nts_ratelimit_enabled, &nts_ratelimit_interval,
                     &nts_ratelimit_burst, &nts_ratelimit_leak);
-  } else if (!strcasecmp(command, "ntstrustedcerts")) {
-    parse_string(p, &nts_trusted_cert_file);
   } else if (!strcasecmp(command, "ntscachedir") ||
              !strcasecmp(command, "ntsdumpdir")) {
     parse_string(p, &nts_dump_dir);
@@ -652,9 +673,11 @@ CNF_ParseLine(const char *filename, int number, char *line)
   } else if (!strcasecmp(command, "ntsrotate")) {
     parse_int(p, &nts_rotate);
   } else if (!strcasecmp(command, "ntsservercert")) {
-    parse_string(p, &nts_server_cert_file);
+    parse_ntsserver(p, nts_server_cert_files);
   } else if (!strcasecmp(command, "ntsserverkey")) {
-    parse_string(p, &nts_server_key_file);
+    parse_ntsserver(p, nts_server_key_files);
+  } else if (!strcasecmp(command, "ntstrustedcerts")) {
+    parse_ntstrustedcerts(p);
   } else if (!strcasecmp(command, "peer")) {
     parse_source(p, command, 1);
   } else if (!strcasecmp(command, "pidfile")) {
@@ -1151,6 +1174,41 @@ parse_mailonchange(char *line)
 
 /* ================================================== */
 
+static void
+parse_ntsserver(char *line, ARR_Instance files)
+{
+  char *file = NULL;
+
+  parse_string(line, &file);
+  ARR_AppendElement(files, &file);
+}
+
+/* ================================================== */
+
+static void
+parse_ntstrustedcerts(char *line)
+{
+  uint32_t id;
+  char *path;
+
+  if (get_number_of_args(line) == 2) {
+    path = CPS_SplitWord(line);
+    if (sscanf(line, "%"SCNu32, &id) != 1)
+      command_parse_error();
+  } else {
+    check_number_of_args(line, 1);
+    path = line;
+    id = 0;
+  }
+
+  path = Strdup(path);
+
+  ARR_AppendElement(nts_trusted_certs_paths, &path);
+  ARR_AppendElement(nts_trusted_certs_ids, &id);
+}
+
+/* ================================================== */
+
 static void
 parse_allow_deny(char *line, ARR_Instance restrictions, int allow)
 {
@@ -1636,8 +1694,9 @@ load_source_file(const char *filename)
     return;
 
   while (fgets(line, sizeof (line), f)) {
-    if (strlen(line) >= MAX_LINE_LENGTH)
+    /* Require lines to be terminated */
-      continue;
+    if (line[0] == '\0' || line[strlen(line) - 1] != '\n')
+      break;
 
     CPS_NormalizeLine(line);
     if (line[0] == '\0')
@@ -1734,6 +1793,8 @@ reload_source_dirs(void)
       if (s == NSR_UnresolvedName) {
         unresolved++;
       } else if (s != NSR_Success) {
+        LOG(LOGS_ERR, "Could not add source %s", source->params.name);
+
         /* Mark the source as not present */
         source->params.name[0] = '\0';
       }
@@ -1805,7 +1866,8 @@ CNF_AddInitSources(void)
     ntp_addr.port = cps_source.port;
     cps_source.params.iburst = 1;
 
-    NSR_AddSource(&ntp_addr, NTP_SERVER, &cps_source.params, NULL);
+    if (NSR_AddSource(&ntp_addr, NTP_SERVER, &cps_source.params, NULL) != NSR_Success)
+      LOG(LOGS_ERR, "Could not add source %s", UTI_IPToString(&ntp_addr.ip_addr));
   }
 
   ARR_SetSize(init_sources, 0);
@@ -1818,11 +1880,16 @@ CNF_AddSources(void)
 {
   NTP_Source *source;
   unsigned int i;
+  NSR_Status s;
 
   for (i = 0; i < ARR_GetSize(ntp_sources); i++) {
     source = (NTP_Source *)ARR_GetElement(ntp_sources, i);
-    NSR_AddSourceByName(source->params.name, source->params.port,
+
-                        source->pool, source->type, &source->params.params, NULL);
+    s = NSR_AddSourceByName(source->params.name, source->params.port, source->pool,
+                            source->type, &source->params.params, NULL);
+    if (s != NSR_Success && s != NSR_UnresolvedName)
+      LOG(LOGS_ERR, "Could not add source %s", source->params.name);
+
     Free(source->params.name);
   }
 
@@ -1836,10 +1903,14 @@ CNF_AddSources(void)
 void
 CNF_AddRefclocks(void)
 {
+  RefclockParameters *refclock;
   unsigned int i;
 
   for (i = 0; i < ARR_GetSize(refclock_sources); i++) {
-    RCL_AddRefclock((RefclockParameters *)ARR_GetElement(refclock_sources, i));
+    refclock = ARR_GetElement(refclock_sources, i);
+    RCL_AddRefclock(refclock);
+    Free(refclock->driver_name);
+    Free(refclock->driver_parameter);
   }
 
   ARR_SetSize(refclock_sources, 0);
@@ -2048,6 +2119,14 @@ CNF_GetMaxSlewRate(void)
 
 /* ================================================== */
 
+double
+CNF_GetClockPrecision(void)
+{
+  return clock_precision;
+}
+
+/* ================================================== */
+
 double
 CNF_GetMaxDistance(void)
 {
@@ -2496,18 +2575,16 @@ CNF_GetNtsNtpServer(void)
 
 /* ================================================== */
 
-char *
+int
-CNF_GetNtsServerCertFile(void)
+CNF_GetNtsServerCertAndKeyFiles(const char ***certs, const char ***keys)
 {
-  return nts_server_cert_file;
+  *certs = ARR_GetElements(nts_server_cert_files);
-}
+  *keys = ARR_GetElements(nts_server_key_files);
 
-/* ================================================== */
+  if (ARR_GetSize(nts_server_cert_files) != ARR_GetSize(nts_server_key_files))
+    LOG_FATAL("Uneven number of NTS certs and keys");
 
-char *
+  return ARR_GetSize(nts_server_cert_files);
-CNF_GetNtsServerKeyFile(void)
-{
-  return nts_server_key_file;
 }
 
 /* ================================================== */
@@ -2552,10 +2629,16 @@ CNF_GetNtsRotate(void)
 
 /* ================================================== */
 
-char *
+int
-CNF_GetNtsTrustedCertFile(void)
+CNF_GetNtsTrustedCertsPaths(const char ***paths, uint32_t **ids)
 {
-  return nts_trusted_cert_file;
+  *paths = ARR_GetElements(nts_trusted_certs_paths);
+  *ids = ARR_GetElements(nts_trusted_certs_ids);
+
+  if (ARR_GetSize(nts_trusted_certs_paths) != ARR_GetSize(nts_trusted_certs_ids))
+    assert(0);
+
+  return ARR_GetSize(nts_trusted_certs_paths);
 }
 
 /* ================================================== */

conf.h

@@ -95,6 +95,7 @@ extern double CNF_GetMaxClockError(void);
 extern double CNF_GetMaxDrift(void);
 extern double CNF_GetCorrectionTimeRatio(void);
 extern double CNF_GetMaxSlewRate(void);
+extern double CNF_GetClockPrecision(void);
 
 extern SRC_AuthSelectMode CNF_GetAuthSelectMode(void);
 extern double CNF_GetMaxDistance(void);
@@ -152,14 +153,13 @@ extern int CNF_GetHwTsInterface(unsigned int index, CNF_HwTsInterface **iface);
 
 extern char *CNF_GetNtsDumpDir(void);
 extern char *CNF_GetNtsNtpServer(void);
-extern char *CNF_GetNtsServerCertFile(void);
+extern int CNF_GetNtsServerCertAndKeyFiles(const char ***certs, const char ***keys);
-extern char *CNF_GetNtsServerKeyFile(void);
 extern int CNF_GetNtsServerPort(void);
 extern int CNF_GetNtsServerProcesses(void);
 extern int CNF_GetNtsServerConnections(void);
 extern int CNF_GetNtsRefresh(void);
 extern int CNF_GetNtsRotate(void);
-extern char *CNF_GetNtsTrustedCertFile(void);
+extern int CNF_GetNtsTrustedCertsPaths(const char ***paths, uint32_t **ids);
 extern int CNF_GetNoSystemCert(void);
 extern int CNF_GetNoCertTimeCheck(void);
 

configure

@@ -5,7 +5,7 @@
 #
 # Copyright (C) Richard P. Curnow  1997-2003
 # Copyright (C) Bryan Christianson  2016
-# Copyright (C) Miroslav Lichvar  2009, 2012-2018
+# Copyright (C) Miroslav Lichvar  2009, 2012-2021
 # Copyright (C) Stefan R. Filipek  2019
 #
 # =======================================================================
@@ -33,13 +33,13 @@ test_code () {
     echo "int main(int argc, char **argv) {"
     echo "$code"
     echo "return 0; }"
-  ) > docheck.c
+  ) > conftest.c
 
-  echo "docheck.c:" >> config.log
+  echo "conftest.c:" >> config.log
-  cat docheck.c >> config.log
+  cat conftest.c >> config.log
-  echo $MYCC $MYCFLAGS $MYCPPFLAGS $cflags -o docheck docheck.c $ldflags \
+  echo $MYCC $MYCFLAGS $MYCPPFLAGS $cflags -o conftest conftest.c $ldflags \
     $MYLDFLAGS >> config.log
-  $MYCC $MYCFLAGS $MYCPPFLAGS $cflags -o docheck docheck.c $ldflags \
+  $MYCC $MYCFLAGS $MYCPPFLAGS $cflags -o conftest conftest.c $ldflags \
     $MYLDFLAGS >> config.log 2>&1
 
   if [ $? -eq 0 ]
@@ -50,7 +50,7 @@ test_code () {
     echo "No"
     result=1
   fi
-  rm -f docheck.c docheck
+  rm -f conftest.c conftest
   echo >> config.log
   return $result
 }
@@ -108,11 +108,7 @@ for instance \`--prefix=$HOME'.
 
 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
-  --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-nettle       Don't use nettle even if it is available
   --without-nss          Don't use NSS even if it is available
@@ -225,7 +221,6 @@ feat_cmdmon=1
 feat_ntp=1
 feat_refclock=1
 feat_readline=1
-try_readline=1
 try_editline=1
 feat_sechash=1
 try_nettle=1
@@ -241,9 +236,6 @@ try_clockctl=0
 feat_scfilter=0
 try_seccomp=-1
 priv_ops=""
-readline_lib=""
-readline_inc=""
-ncurses_lib=""
 feat_ipv6=1
 feat_phc=1
 try_phc=0
@@ -274,21 +266,9 @@ do
     --disable-readline )
       feat_readline=0
     ;;
-    --without-readline )
-      try_readline=0
-    ;;
     --without-editline )
       try_editline=0
     ;;
-    --with-readline-library=* )
-      readline_lib=-L`echo $option | sed -e 's/^.*=//;'`
-    ;;
-    --with-readline-includes=* )
-      readline_inc=-I`echo $option | sed -e 's/^.*=//;'`
-    ;;
-    --with-ncurses-library=* )
-      ncurses_lib=-L`echo $option | sed -e 's/^.*=//;'`
-    ;;
     --prefix=* | --install_prefix=* )
       SETPREFIX=`echo $option | sed -e 's/[^=]*=//;'`
     ;;
@@ -675,6 +655,20 @@ then
   fi
 fi
 
+if ! test_code 'O_NOFOLLOW flag' 'sys/types.h sys/stat.h fcntl.h' '' "$LIBS" \
+  'return open("/dev/null", O_NOFOLLOW);'
+then
+  if test_code 'O_NOFOLLOW flag with _GNU_SOURCE' 'sys/types.h sys/stat.h fcntl.h' \
+    '-D_GNU_SOURCE' "$LIBS" \
+    'return open("/dev/null", O_NOFOLLOW);'
+  then
+    add_def _GNU_SOURCE
+  else
+    echo "error: open() does not support O_NOFOLLOW flag"
+    exit 1
+  fi
+fi
+
 if [ $try_clock_gettime = "1" ]; then
   if test_code 'clock_gettime()' 'time.h' '' '' \
     'clock_gettime(CLOCK_REALTIME, NULL);'
@@ -690,10 +684,11 @@ if [ $try_clock_gettime = "1" ]; then
   fi
 fi
 
-if test_code 'getaddrinfo()' 'sys/types.h sys/socket.h netdb.h' '' "$LIBS" \
+if ! test_code 'getaddrinfo()' 'sys/types.h sys/socket.h netdb.h' '' "$LIBS" \
   'return getaddrinfo(0, 0, 0, 0);'
 then
-  add_def HAVE_GETADDRINFO
+  echo "error: getaddrinfo() not found"
+  exit 1
 fi
 
 if [ $feat_asyncdns = "1" ] && \
@@ -709,11 +704,11 @@ fi
 
 if test_code 'arc4random_buf()' 'stdlib.h' '' '' 'arc4random_buf(NULL, 0);'; then
   add_def HAVE_ARC4RANDOM
-fi
+else
-
+  if test_code 'getrandom()' 'stdlib.h sys/random.h' '' '' \
-if test_code 'getrandom()' 'stdlib.h sys/random.h' '' '' \
+      'return getrandom(NULL, 256, 0);'; then
-    'return getrandom(NULL, 256, 0);'; then
+    add_def HAVE_GETRANDOM
-  add_def HAVE_GETRANDOM
+  fi
 fi
 
 RECVMMSG_CODE='
@@ -804,10 +799,12 @@ if [ $feat_scfilter = "1" ] && [ $try_seccomp = "1" ] && \
     'seccomp_init(SCMP_ACT_KILL);'
 then
   add_def FEAT_SCFILTER
-  # NAME2IPADDRESS shouldn't be enabled with other operations as the helper
+  if [ $feat_ntp = "1" ]; then
-  # process works on one request at the time and the async resolver could
+    # NAME2IPADDRESS shouldn't be enabled together with a privops operation
-  # block the main thread
+    # used by the main thread as the helper process works on one request at
-  priv_ops="NAME2IPADDRESS RELOADDNS"
+    # a time and the async resolver would block the main thread
+    priv_ops="NAME2IPADDRESS RELOADDNS"
+  fi
   EXTRA_LIBS="$EXTRA_LIBS -lseccomp"
 fi
 
@@ -876,37 +873,11 @@ fi
 READLINE_LINK=""
 if [ $feat_readline = "1" ]; then
   if [ $try_editline = "1" ]; then
-    if test_code editline 'stdio.h editline/readline.h' \
+    if test_code editline 'stdio.h editline/readline.h' '' '-ledit' \
-      "$readline_inc" "$readline_lib -ledit" \
       'add_history(readline("prompt"));'
     then
       add_def FEAT_READLINE
-      add_def USE_EDITLINE
+      READLINE_LINK="-ledit"
-      MYCPPFLAGS="$MYCPPFLAGS $readline_inc"
-      READLINE_LINK="$readline_lib -ledit"
-    fi
-  fi
-
-  if [ "x$READLINE_LINK" = "x" ] && [ $try_readline = "1" ]; then
-    if test_code readline 'stdio.h readline/readline.h readline/history.h' \
-      "$readline_inc" "$readline_lib -lreadline" \
-      'add_history(readline("prompt"));'
-    then
-      add_def FEAT_READLINE
-      MYCPPFLAGS="$MYCPPFLAGS $readline_inc"
-      READLINE_LINK="$readline_lib -lreadline"
-    fi
-  fi
-
-  if [ "x$READLINE_LINK" = "x" ] && [ $try_readline = "1" ]; then
-    if test_code 'readline with -lncurses' \
-      'stdio.h readline/readline.h readline/history.h' \
-      "$readline_inc" "$readline_lib $ncurses_lib -lreadline -lncurses" \
-      'add_history(readline("prompt"));'
-    then
-      add_def FEAT_READLINE
-      MYCPPFLAGS="$MYCPPFLAGS $readline_inc"
-      READLINE_LINK="$readline_lib $ncurses_lib -lreadline -lncurses"
     fi
   fi
 
@@ -972,7 +943,7 @@ if [ $feat_ntp = "1" ] && [ $feat_nts = "1" ] && [ $try_gnutls = "1" ]; then
   test_link="`pkg_config --libs gnutls`"
   if test_code 'gnutls' 'gnutls/gnutls.h' \
     "$test_cflags" "$test_link" '
-      return gnutls_init(NULL, 0) +
+      return gnutls_init(NULL, 0) + GNUTLS_TLS1_3 +
         gnutls_priority_init2(NULL, "", NULL, GNUTLS_PRIORITY_INIT_DEF_APPEND) +
         gnutls_prf_rfc5705(NULL, 0, "", 0, "", 16, NULL);'
   then

doc/chrony.conf.adoc

@@ -3,7 +3,7 @@
 // Copyright (C) Richard P. Curnow  1997-2003
 // Copyright (C) Stephen Wadeley  2016
 // Copyright (C) Bryan Christianson  2017
-// Copyright (C) Miroslav Lichvar  2009-2017
+// Copyright (C) Miroslav Lichvar  2009-2021
 //
 // This program is free software; you can redistribute it and/or modify
 // it under the terms of version 2 of the GNU General Public License as
@@ -32,12 +32,14 @@ chrony.conf - chronyd configuration file
 == DESCRIPTION
 
 This file configures the *chronyd* daemon. The compiled-in location is
-_@SYSCONFDIR@/chrony.conf_, but other locations can be specified on the
+_@SYSCONFDIR@/chrony.conf_. Other locations can be specified on the
 *chronyd* command line with the *-f* option.
 
 Each directive in the configuration file is placed on a separate line. The
-following sections describe each of the directives in turn. The directives can
+following sections describe each of the directives in turn. The directives are
-occur in any order in the file and they are not case-sensitive.
+not case-sensitive. Generally, the directives can occur in any order in the file
+and if a directive is specified multiple times, only the last one will be
+effective. Exceptions are noted in the descriptions.
 
 The configuration directives can also be specified directly on the *chronyd*
 command line. In this case each argument is parsed as a new line and the
@@ -61,9 +63,10 @@ source. The client-server relationship is strictly hierarchical: a client might
 synchronise its system time to that of the server, but the server's system time
 will never be influenced by that of a client.
 +
-The *server* directive is immediately followed by either the name of the
+This directive can be used multiple times to specify multiple servers.
-server, or its IP address. The *server* directive supports the following
++
-options:
+The directive is immediately followed by either the name of the
+server, or its IP address. It supports the following options:
 +
 *minpoll* _poll_:::
 This option specifies the minimum interval between requests sent to the server
@@ -113,6 +116,12 @@ mechanism. Unlike with the *key* option, the server and client do not need to
 share a key in a key file. NTS has a Key Establishment (NTS-KE) protocol using
 the Transport Layer Security (TLS) protocol to get the keys and cookies
 required by NTS for authentication of NTP packets.
+*certset* _ID_:::
+This option specifies which set of trusted certificates should be used to verify
+the server's certificate when the *nts* option is enabled. Sets of certificates
+can be specified with the <<ntstrustedcerts,*ntstrustedcerts*>> directive. The
+default set is 0, which by default contains certificates of the system's
+default trusted certificate authorities.
 *maxdelay* _delay_:::
 *chronyd* uses the network round-trip delay to the server to determine how
 accurate a particular measurement is likely to be. Long round-trip delays
@@ -122,9 +131,9 @@ of the messages was delayed the measurement error is likely to be substantial.
 For small variations in the round-trip delay, *chronyd* uses a weighting scheme
 when processing the measurements. However, beyond a certain level of delay the
 measurements are likely to be so corrupted as to be useless. (This is
-particularly so on dial-up or other slow links, where a long delay probably
+particularly so on wireless networks and other slow links, where a long delay
-indicates a highly asymmetric delay caused by the response waiting behind a lot
+probably indicates a highly asymmetric delay caused by the response waiting
-of packets related to a download of some sort).
+behind a lot of packets related to a download of some sort).
 +
 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*
@@ -135,7 +144,7 @@ round-trip delay of 0.3 seconds or more should be ignored. The default value is
 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.
+specified ratio times the minimum delay, it will be rejected.
 *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
@@ -258,7 +267,7 @@ will send two extra packets instead of one.
 When the synchronisation source is selected from available sources, sources
 with lower stratum are normally slightly preferred. This option can be used to
 increase stratum of the source to the specified minimum, so *chronyd* will
-avoid selecting that source. This is useful with low stratum sources that are
+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_:::
@@ -269,6 +278,15 @@ 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.
+*copy*:::
+This option specifies that the server and client are closely related, their
+configuration does not allow a synchronisation loop to form between them, and
+the client is allowed to assume the reference ID and stratum of the server.
+This is useful when multiple instances of `chronyd` are running on one computer
+(e.g. for security or performance reasons), one primarily operating as a client
+to synchronise the system clock and other instances started with the *-x*
+option to operate as NTP servers for other computers with their NTP clocks
+synchronised to the first instance.
 
 [[pool]]*pool* _name_ [_option_]...::
 The syntax of this directive is similar to that for the <<server,*server*>>
@@ -276,6 +294,8 @@ directive, except that it is used to specify a pool of NTP servers rather than
 a single NTP server. The pool name is expected to resolve to multiple addresses
 which might change over time.
 +
+This directive can be used multiple times to specify multiple pools.
++
 All options valid in the <<server,*server*>> directive can be used in this
 directive too. There is one option specific to the *pool* directive:
 +
@@ -306,8 +326,10 @@ 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.
 +
+This directive can be used multiple times to specify multiple peers.
++
 The following options of the *server* directive do not work in the *peer*
-directive: *iburst*, *burst*, *nts*, *presend*.
+directive: *iburst*, *burst*, *nts*, *presend*, *copy*.
 +
 When using the *xleave* option, both peers must support and have enabled the
 interleaved mode, otherwise the synchronisation will work in one direction
@@ -334,19 +356,8 @@ 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
+(This directive is deprecated in favour of the <<makestep,*makestep*>>
-system clock. For example, to correct a system clock which is 1 second slow,
+directive.)
-*chronyd* slightly increases the amount by which the system clock is advanced
-on each clock interrupt, until the error is removed. Note that at no time does
-time run backwards with this method.
-+
-On most Unix systems it is not desirable to step the system clock, because many
-programs rely on time advancing monotonically forwards.
-+
-When the *chronyd* daemon is initially started, it is possible that the system
-clock is considerably in error. Attempting to correct such an error by slewing
-might not be sensible, since it might take several hours to correct the error by
-this means.
 +
 The purpose of the *initstepslew* directive is to allow *chronyd* to make a
 rapid measurement of the system clock error at boot time, and to correct the
@@ -367,29 +378,30 @@ error. *chronyd* then enters its normal operating mode.
 An example of the use of the directive is:
 +
 ----
-initstepslew 30 foo.example.net bar.example.net
+initstepslew 30 foo.example.net bar.example.net baz.example.net
 ----
 +
-where 2 NTP servers are used to make the measurement. The _30_ indicates that
+where 3 NTP servers are used to make the measurement. The _30_ indicates that
 if the system's error is found to be 30 seconds or less, a slew will be used to
 correct it; if the error is above 30 seconds, a step will be used.
 +
 The *initstepslew* directive can also be used in an isolated LAN environment,
 where the clocks are set manually. The most stable computer is chosen as the
-master, and the other computers are slaved to it. If each of the slaves is
+primary server and the other computers are its clients. If each of the clients
-configured with the <<local,*local*>> directive, the master can be set up with
+is configured with the <<local,*local*>> directive, the server can be set up
-an *initstepslew* directive which references some or all of the slaves. Then,
+with an *initstepslew* directive which references some or all of the clients.
-if the master machine has to be rebooted, the slaves can be relied on to act
+Then, if the server machine has to be rebooted, the clients can be relied on to
-analogously to a flywheel and preserve the time for a short period while the
+act analogously to a flywheel and preserve the time for a short period while
-master completes its reboot.
+the server completes its reboot.
 +
 The *initstepslew* directive is functionally similar to a combination of the
 <<makestep,*makestep*>> and <<server,*server*>> directives with the *iburst*
 option. The main difference is that the *initstepslew* servers are used only
 before normal operation begins and that the foreground *chronyd* process waits
-for *initstepslew* to finish before exiting. This is useful to prevent programs
+for *initstepslew* to finish before exiting. This prevent programs started in
-started in the boot sequence after *chronyd* from reading the clock before it
+the boot sequence after *chronyd* from reading the clock before it has been
-has been stepped.
+stepped. With the *makestep* directive, the
+<<chronyc.adoc#waitsync,*waitsync*>> command of *chronyc* can be used instead.
 
 [[refclock]]*refclock* _driver_ _parameter_[:__option__]... [_option_]...::
 The *refclock* directive specifies a hardware reference clock to be used as a
@@ -398,6 +410,8 @@ 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 using the *:* character.
 +
+This directive can be used multiple times to specify multiple reference clocks.
++
 There are four drivers included in *chronyd*:
 +
 *PPS*:::
@@ -610,12 +624,13 @@ behaviour, whereas the *settime* command allows samples of manually entered
 time to be provided.)
 
 [[acquisitionport]]*acquisitionport* _port_::
-By default, *chronyd* uses a separate client socket for each configured server
+By default, *chronyd* as an NTP client opens a new socket for each request with
-and their source port is chosen arbitrarily by the operating system. However,
+the source port chosen randomly by the operating system. The *acquisitionport*
-you can use the *acquisitionport* directive to explicitly specify a port and
+directive can be used to specify the source port and use only one socket (per
-use only one socket (per IPv4 or IPv6 address family) for all configured servers.
+IPv4 or IPv6 address family) for all configured servers. This can be useful for
-This can be useful for getting through some firewalls. If set to 0, the source
+getting through some firewalls. It should not be used if not necessary as there
-port of the socket will be chosen arbitrarily.
+is a small impact on security of the client. If set to 0, the source port of
+the permanent socket will be chosen randomly by the operating system.
 +
 It can be set to the same port as is used by the NTP server (which can be
 configured with the <<port,*port*>> directive) to use only one socket for all
@@ -632,8 +647,8 @@ You could then persuade the firewall administrator to open that port.
 
 [[bindacqaddress]]*bindacqaddress* _address_::
 The *bindacqaddress* directive specifies a local IP address to which
-*chronyd* will bind its NTP client sockets. The syntax is similar to the
+*chronyd* will bind its NTP and NTS-KE client sockets. The syntax is similar to
-<<bindaddress,*bindaddress*>> and <<bindcmdaddress,*bindcmdaddress*>>
+the <<bindaddress,*bindaddress*>> and <<bindcmdaddress,*bindcmdaddress*>>
 directives.
 +
 For each of the IPv4 and IPv6 protocols, only one *bindacqaddress* directive
@@ -684,6 +699,10 @@ or the <<chronyc.adoc#dump,*dump*>> command in *chronyc* is issued.
 +
 If the directory does not exist, it will be created automatically.
 +
+The *-r* option of *chronyd* enables loading of the dump files on start. All
+dump files found in the directory will be removed after start, even if the *-r*
+option is not present.
++
 An example of the directive is:
 +
 ----
@@ -738,25 +757,49 @@ This directory is used also by the <<ntsdumpdir2,NTS server>> to save keys.
 [[ntsrefresh]]*ntsrefresh* _interval_::
 This directive specifies the maximum interval between NTS-KE handshakes (in
 seconds) in order to refresh the keys authenticating NTP packets. The default
-value is 2419200 (4 weeks).
+value is 2419200 (4 weeks) and the maximum value is 2^31-1 (68 years).
 
-[[ntstrustedcerts]]*ntstrustedcerts* _file_::
+[[ntstrustedcerts]]*ntstrustedcerts* [_set-ID_] _file_|_directory_::
-This directive specifies a file containing certificates (in the PEM format) of
+This directive specifies a file or directory containing certificates (in the
-trusted certificate authorities (CA) that should be used to verify certificates
+PEM format) of trusted certificate authorities (CA) which can be used to
-of NTS servers in addition to the system's default trusted CAs (if the
+verify certificates of NTS servers.
-*nosystemcert* directive is not present).
++
+The optional _set-ID_ argument is a number in the range 0 through 2^32-1, which
+selects the set of certificates where certificates from the specified file
+or directory are added. The default ID is 0, which is a set containing the
+system's default trusted CAs (unless the *nosystemcert* directive is present).
+All other sets are empty by default. A set of certificates can be selected for
+verification of an NTS server by the *certset* option in the *server* or *pool*
+directive.
++
+This directive can be used multiple times to specify one or more sets of
+trusted certificates, each containing certificates from one or more files
+and/or directories.
++
+It is not necessary to restart *chronyd* in order to reload the certificates if
+they change (e.g. after a renewal).
++
+An example is:
++
+----
+ntstrustedcerts /etc/pki/nts/foo.crt
+ntstrustedcerts 1 /etc/pki/nts/bar.crt
+ntstrustedcerts 1 /etc/pki/nts/baz.crt
+ntstrustedcerts 2 /etc/pki/nts/qux.crt
+----
 
 [[nosystemcert]]*nosystemcert*::
-This directive disables the system's default trusted CAs.
+This directive disables the system's default trusted CAs. Only certificates
+specified by the *ntstrustedcerts* directive will be trusted.
 
 [[nocerttimecheck]]*nocerttimecheck* _limit_::
 This directive disables the checks of the activation and expiration times of
 certificates for the specified number of clock updates. It allows the NTS
 authentication mechanism to be used on computers which start with wrong time
 (e.g. due to not having an RTC or backup battery). Disabling the time checks
-has important security implications, e.g. if an NTP server was ever
+has important security implications and should be used only as a last resort,
-compromised, its certificate could be used in an attack after the expiration
+preferably with a minimal number of trusted certificates. The default value is
-time. The default value is 0, which means the time checks are always enabled.
+0, which means the time checks are always enabled.
 +
 An example of the directive is:
 +
@@ -860,11 +903,11 @@ source combining algorithm and only the selected source will be used to control
 the system clock.
 
 [[maxdistance]]*maxdistance* _distance_::
-The *maxdistance* directive sets the maximum allowed root distance of the
+The *maxdistance* directive sets the maximum root distance of a source to be
-sources to not be rejected by the source selection algorithm. The distance
+acceptable for synchronisation of the clock. Sources that have a distance
-includes the accumulated dispersion, which might be large when the source is no
+larger than the specified distance will be rejected. The distance estimates the
-longer synchronised, and half of the total round-trip delay to the primary
+maximum error of the source. It includes the root dispersion and half of the
-source.
+root delay (round-trip time) accumulated on the path to the primary source.
 +
 By default, the maximum root distance is 3 seconds.
 +
@@ -908,6 +951,27 @@ distances are in milliseconds.
 
 === System clock
 
+[[clockprecision]]*clockprecision* _precision_::
+The *clockprecision* directive specifies the precision of the system clock (in
+seconds). It is used by *chronyd* to estimate the minimum noise in NTP
+measurements and randomise low-order bits of timestamps in NTP responses. By
+default, the precision is measured on start as the minimum time to read the
+clock.
++
+The measured value works well in most cases. However, it generally
+overestimates the precision and it can be sensitive to the CPU speed, which can
+change over time to save power. In some cases with a high-precision clocksource
+(e.g. the Time Stamp Counter of the CPU) and hardware timestamping, setting the
+precision on the server to a smaller value can improve stability of clients'
+NTP measurements. The server's precision is reported on clients by the
+<<chronyc.adoc#ntpdata,*ntpdata*>> command.
++
+An example setting the precision to 8 nanoseconds is:
++
+----
+clockprecision 8e-9
+----
+
 [[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 all supported
@@ -1039,7 +1103,7 @@ A recommended configuration to enable a server leap smear is:
 ----
 leapsecmode slew
 maxslewrate 1000
-smoothtime 400 0.001 leaponly
+smoothtime 400 0.001024 leaponly
 ----
 +
 The first directive is necessary to disable the clock step which would reset
@@ -1047,17 +1111,23 @@ the smoothing process. The second directive limits the slewing rate of the
 local clock to 1000 ppm, which improves the stability of the smoothing process
 when the local correction starts and ends. The third directive enables the
 server time smoothing process. It will start when the clock gets to 00:00:00
-UTC and it will take 17 hours 34 minutes to finish. The frequency offset will
+UTC and it will take 62500 seconds (about 17.36 hours) to finish. The frequency
-be changing by 0.001 ppm per second and will reach a maximum of 31.623 ppm. The
+offset will be changing by 0.001024 ppm per second and will reach a maximum of
-*leaponly* option makes the duration of the leap smear constant and allows the
+32 ppm in 31250 seconds. The *leaponly* option makes the duration of the leap
-clients to safely synchronise with multiple identically configured leap
+smear constant and allows the clients to safely synchronise with multiple
-smearing servers.
+identically configured leap smearing servers.
++
+The duration of the leap smear can be calculated from the specified wander as
++
+----
+duration = sqrt(4 / wander)
+----
 
 [[leapsectz]]*leapsectz* _timezone_::
-This directive specifies a timezone in the system tz database which *chronyd*
+This directive specifies a timezone in the system timezone database which
-can use to determine when will the next leap second occur and what is the
+*chronyd* can use to determine when will the next leap second occur and what is
-current offset between TAI and UTC. It will periodically check if 23:59:59 and
+the current offset between TAI and UTC. It will periodically check if 23:59:59
-23:59:60 are valid times in the timezone. This typically works with the
+and 23:59:60 are valid times in the timezone. This normally works with the
 _right/UTC_ timezone.
 +
 When a leap second is announced, the timezone needs to be updated at least 12
@@ -1094,16 +1164,17 @@ Wed Dec 31 23:59:60 UTC 2008
 [[makestep]]*makestep* _threshold_ _limit_::
 Normally *chronyd* will cause the system to gradually correct any time offset,
 by slowing down or speeding up the clock as required. In certain situations,
-the system clock might be so far adrift that this slewing process would take a
+e.g. when *chronyd* is initially started, the system clock might be so far
-very long time to correct the system clock.
+adrift that this slewing process would take a very long time to correct the
+system clock.
 +
 This directive forces *chronyd* to step the system clock if the adjustment is
 larger than a threshold value, but only if there were no more clock updates
-since *chronyd* was started than a specified limit (a negative value can be
+since *chronyd* was started than the specified limit. A negative value disables
-used to disable the limit).
+the limit.
 +
-This is particularly useful when using reference clocks, because the
+On most systems it is desirable to step the system clock only on boot, before
-<<initstepslew,*initstepslew*>> directive works only with NTP sources.
+starting programs that rely on time advancing monotonically forwards.
 +
 An example of the use of this directive is:
 +
@@ -1165,8 +1236,8 @@ The *maxupdateskew* directive sets the threshold for determining whether an
 estimate might be so unreliable that it should not be used. By default, the
 threshold is 1000 ppm.
 +
-Typical values for _skew-in-ppm_ might be 100 for a dial-up connection to
+Typical values for _skew-in-ppm_ might be 100 for NTP sources polled over a
-servers over a phone line, and 5 or 10 for a computer on a LAN.
+wireless network, and 10 or smaller for sources on a local wired network.
 +
 It should be noted that this is not the only means of protection against using
 unreliable estimates. At all times, *chronyd* keeps track of both the estimated
@@ -1221,7 +1292,7 @@ coefficients _T0_, _k0_, _k1_, _k2_.
 The frequency compensation is calculated (in ppm) as
 +
 ----
-k0 + (T - T0) * k1 + (T - T0)^2 * k2
+comp = k0 + (T - T0) * k1 + (T - T0)^2 * k2
 ----
 +
 The result has to be between -10 ppm and 10 ppm, otherwise the measurement is
@@ -1272,38 +1343,34 @@ _tempcomp.log_ file if enabled by the <<log,*log tempcomp*>> directive.
 
 [[allow]]*allow* [*all*] [_subnet_]::
 The *allow* directive is used to designate a particular subnet from which NTP
-clients are allowed to access the computer as an NTP server.
+clients are allowed to access the computer as an NTP server. It also controls
+access of NTS-KE clients when NTS is enabled on the server.
 +
 The default is that no clients are allowed access, i.e. *chronyd* operates
 purely as an NTP client. If the *allow* directive is used, *chronyd* will be
 both a client of its servers, and a server to other clients.
 +
+This directive can be used multiple times.
++
 Examples of the use of the directive are as follows:
 +
 ----
 allow 1.2.3.4
-allow 1.2
+allow 3.4.5.0/24
 allow 3.4.5
-allow 6.7.8/22
-allow 6.7.8.9/22
 allow 2001:db8::/32
 allow 0/0
 allow ::/0
 allow
 ----
 +
-The first directive allows a node with IPv4 address _1.2.3.4_ to be an NTP
+The first directive allows access from an IPv4 address. The second directive
-client of this computer.
+allows access from all computers in an IPv4 subnet specified in the CIDR
-The second directive allows any node with an IPv4 address of the form _1.2.x.y_
+notation. The third directive specifies the same subnet using a simpler
-(with _x_ and _y_ arbitrary) to be an NTP client of this computer. Likewise,
+notation where the prefix length is determined by the number of dots. The
-the third directive allows any node with an IPv4 address of the form _3.4.5.x_
+fourth directive specifies an IPv6 subnet. The fifth and sixth directives allow
-to have client NTP access. The fourth and fifth forms allow access from any
+access from all IPv4 and IPv6 addresses respectively. The seventh directive
-node with an IPv4 address of the form _6.7.8.x_, _6.7.9.x_, _6.7.10.x_ or
+allows access from all addresses (both IPv4 or IPv6).
-_6.7.11.x_ (with _x_ arbitrary), i.e. the value 22 is the number of bits
-defining the specified subnet. In the fifth form, the final byte is ignored.
-The sixth form is used for IPv6 addresses. The seventh and eighth forms allow
-access by any IPv4 and IPv6 node respectively. The ninth forms allows access by
-any node (IPv4 or IPv6).
 +
 A second form of the directive, *allow all*, has a greater effect, depending on
 the ordering of directives in the configuration file. To illustrate the effect,
@@ -1311,32 +1378,43 @@ consider the two examples:
 +
 ----
 allow 1.2.3.4
-deny 1.2.3
+deny 1.2.3.0/24
-allow 1.2
+allow 1.2.0.0/16
 ----
 +
 and
 +
 ----
 allow 1.2.3.4
-deny 1.2.3
+deny 1.2.3.0/24
-allow all 1.2
+allow all 1.2.0.0/16
 ----
 +
 In the first example, the effect is the same regardless of what order the three
-directives are given in. So the _1.2.x.y_ subnet is allowed access, except for
+directives are given in. So the _1.2.0.0/16_ subnet is allowed access, except
-the _1.2.3.x_ subnet, which is denied access, however the host _1.2.3.4_ is
+for the _1.2.3.0/24_ subnet, which is denied access, however the host _1.2.3.4_
-allowed access.
+is allowed access.
 +
-In the second example, the *allow all 1.2* directives overrides the effect of
+In the second example, the *allow all 1.2.0.0/16* directive overrides the
-_any_ previous directive relating to a subnet within the specified subnet.
+effect of _any_ previous directive relating to a subnet within the specified
-Within a configuration file this capability is probably rather moot; however,
+subnet. Within a configuration file this capability is probably rather moot;
-it is of greater use for reconfiguration at run-time via *chronyc* with the
+however, it is of greater use for reconfiguration at run-time via *chronyc*
-<<chronyc.adoc#allow,*allow all*>> command.
+with the <<chronyc.adoc#allow,*allow all*>> command.
 +
-The directive allows a hostname to be specified instead of an IP address, but
+The rules are internally represented as a tree of tables with one level per
-the name must be resolvable when *chronyd* is started (i.e. *chronyd* needs
+four bits of the IPv4 or IPv6 address. The order of the *allow* and *deny*
-to be started when the network is already up and DNS is working).
+directives matters if they modify the same records of one table, i.e. if one
+subnet is included in the other subnet and their prefix lengths are at the same
+level. For example, _1.2.3.0/28_ and _1.2.3.0/29_ are in different tables, but
+_1.2.3.0/25_ and _1.2.3.0/28_ are in the same table. The configuration can be
+verified for individual addresses with the <<chronyc.adoc#accheck,*accheck*>>
+command in *chronyc*.
++
+A hostname can be specified in the directives instead of the IP address, but
+the name must be resolvable when *chronyd* is started, i.e. the network is
+already up and DNS is working. If the hostname resolves to multiple addresses,
+only the first address (in the order returned by the system resolver) will be
+allowed or denied.
 +
 Note, if the <<initstepslew,*initstepslew*>> directive is used in the
 configuration file, each of the computers listed in that directive must allow
@@ -1344,18 +1422,19 @@ client access by this computer for it to work.
 
 [[deny]]*deny* [*all*] [_subnet_]::
 This is similar to the <<allow,*allow*>> directive, except that it denies NTP
-client access to a particular subnet or host, rather than allowing it.
+and NTS-KE client access to a particular subnet or host, rather than allowing
+it.
 +
-The syntax is identical.
+The syntax is identical and the directive can be used multiple times too.
 +
 There is also a *deny all* directive with similar behaviour to the *allow all*
 directive.
 
 [[bindaddress]]*bindaddress* _address_::
-The *bindaddress* directive binds the socket on which *chronyd* listens for NTP
+The *bindaddress* directive binds the sockets on which *chronyd* listens for
-requests to a local address of the computer. On systems other than Linux, the
+NTP and NTS-KE requests to a local address of the computer. On systems other
-address of the computer needs to be already configured when *chronyd* is
+than Linux, the address of the computer needs to be already configured when
-started.
+*chronyd* is started.
 +
 An example of the use of the directive is:
 +
@@ -1368,9 +1447,9 @@ directive can be specified. Therefore, it is not useful on computers which
 should serve NTP on multiple network interfaces.
 
 [[binddevice]]*binddevice* _interface_::
-The *binddevice* directive binds the NTP server sockets to a network device
+The *binddevice* directive binds the NTP and NTS-KE server sockets to a network
-specified by the interface name. This directive can specify only one interface
+device specified by the interface name. This directive can specify only one
-and it is supported on Linux only.
+interface and it is supported on Linux only.
 +
 An example of the directive is:
 +
@@ -1384,17 +1463,19 @@ chronyd should send packets in the NTP broadcast mode (i.e. make *chronyd* act
 as a broadcast server). Broadcast clients on that subnet will be able to
 synchronise.
 +
+This directive can be used multiple times to specify multiple addresses.
++
 The syntax is as follows:
 +
 ----
-broadcast 30 192.168.1.255
+broadcast 32 192.168.1.255
-broadcast 60 192.168.2.255 12123
+broadcast 64 192.168.2.255 12123
-broadcast 60 ff02::101
+broadcast 64 ff02::101
 ----
 +
 In the first example, the destination port defaults to UDP port 123 (the normal NTP
 port). In the second example, the destination port is specified as 12123. The
-first parameter in each case (30 or 60 respectively) is the interval in seconds
+first parameter in each case (32 or 64 respectively) is the interval in seconds
 between broadcast packets being sent. The second parameter in each case is the
 broadcast address to send the packet to. This should correspond to the
 broadcast address of one of the network interfaces on the computer where
@@ -1418,10 +1499,8 @@ This directive specifies the maximum amount of memory that *chronyd* is allowed
 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.
+clients at the same time. The maximum value is 2^32-1 (4 GB) on 32-bit systems
-+
+and 2^35 (32 GB) on 64-bit systems.
-In older *chrony* versions if the limit was set to 0, the memory allocation was
-unlimited.
 +
 An example of the use of this directive is:
 +
@@ -1483,7 +1562,9 @@ configuration and to be synchronised to one another, without confusing clients
 that poll more than one server. Each server needs to be configured to poll all
 other servers with the *local* directive. This ensures only the server with the
 smallest reference ID has the local reference active and others are
-synchronised to it. When that server fails, another will take over.
+synchronised to it. If that server stops responding, the server with the second
+smallest reference ID will take over when its local reference mode activates
+(root distance reaches the threshold configured by the *distance* option).
 +
 The *orphan* mode is compatible with the *ntpd*'s orphan mode (enabled by the
 *tos orphan* command).
@@ -1492,7 +1573,7 @@ The *orphan* mode is compatible with the *ntpd*'s orphan mode (enabled by the
 An example of the directive is:
 +
 ----
-local stratum 10 orphan
+local stratum 10 orphan distance 0.1
 ----
 
 [[ntpsigndsocket]]*ntpsigndsocket* _directory_::
@@ -1521,11 +1602,25 @@ The port will be open only when a certificate and key is specified by the
 
 [[ntsservercert]]*ntsservercert* _file_::
 This directive specifies a file containing a certificate in the PEM format
-for *chronyd* to operate as an NTS server.
+for *chronyd* to operate as an NTS server. The file should also include
+any intermediate certificates that the clients will need to validate the
+server's certificate.
++
+This directive can be used multiple times to specify multiple certificates for
+different names of the server.
++
+The files are loaded only once. *chronyd* needs to be restarted in order to
+load a renewed certificate. The <<ntsdumpdir,*ntsdumpdir*>> and
+<<dumpdir,*dumpdir*>> directives with the *-r* option of *chronyd* are
+recommended for a near-seamless server operation.
 
 [[ntsserverkey]]*ntsserverkey* _file_::
 This directive specifies a file containing a private key in the PEM format
 for *chronyd* to operate as an NTS server.
++
+This directive can be used multiple times to specify multiple keys. The number
+of keys must be the same as the number of certificates and the corresponding
+files must be specified in the same order.
 
 [[ntsprocesses]]*ntsprocesses* _processes_::
 This directive specifies how many helper processes will *chronyd* operating
@@ -1536,7 +1631,9 @@ process will be started and all NTS-KE requests will be handled by the main
 
 [[maxntsconnections]]*maxntsconnections* _connections_::
 This directive specifies the maximum number of concurrent NTS-KE connections
-per process that the NTS server will accept. The default value is 100.
+per process that the NTS server will accept. The default value is 100. The
+maximum practical value is half of the system *FD_SETSIZE* constant (usually
+1024).
 
 [[ntsdumpdir2]]*ntsdumpdir* _directory_::
 This directive specifies a directory where *chronyd* operating as an NTS server
@@ -1554,7 +1651,8 @@ ntsdumpdir @CHRONYVARDIR@
 This directory is used also by the <<ntsdumpdir1,NTS client>> to save NTS cookies.
 
 [[ntsntpserver]]*ntsntpserver* _hostname_::
-This directive specifies the hostname or address of the NTP server(s) which is
+This directive specifies the hostname (as a fully qualified domain name) or
+address of the NTP server(s) which is
 provided in the NTS-KE response to the clients. It allows the NTS-KE server to
 be separated from the NTP server. However, the servers need to share the keys,
 i.e. external key management needs to be enabled by setting
@@ -1563,9 +1661,12 @@ to the clients, which means they should use the same server for NTS-KE and NTP.
 
 [[ntsrotate]]*ntsrotate* _interval_::
 This directive specifies the rotation interval (in seconds) of the server key
-which encrypts the NTS cookies. New keys are generated automatically. The
+which encrypts the NTS cookies. New keys are generated automatically from the
-server keeps two previous keys to give the clients time to get new cookies
+_/dev/urandom_ device. The server keeps two previous keys to give the clients
-encrypted by the latest key. The default interval is 604800 seconds (1 week).
+time to get new cookies encrypted by the latest key. The interval is measured
+as the server's operating time, i.e. the actual interval can be longer if
+*chronyd* is not running continuously. The default interval is 604800 seconds
+(1 week). The maximum value is 2^31-1 (68 years).
 +
 The automatic rotation of the keys can be disabled by setting *ntsrotate* to 0.
 In this case the keys are assumed to be managed externally. *chronyd* will not
@@ -1574,7 +1675,7 @@ the <<chronyc.adoc#rekey,*rekey*>> command is issued in *chronyc*. The file can
 be periodically copied from another server running *chronyd* (which does
 not have *ntsrotate* set to 0) in order to have one or more servers dedicated
 to NTS-KE. The NTS-KE servers need to be configured with the
-<<ntsntpname,*ntsntpname*>> directive to point the clients to the right NTP
+<<ntsntpserver,*ntsntpserver*>> directive to point the clients to the right NTP
 server.
 +
 An example of the directive is:
@@ -1822,7 +1923,8 @@ The *rtcautotrim* directive is used to keep the RTC close to the system clock
 automatically. When the system clock is synchronised and the estimated error
 between the two clocks is larger than the specified threshold, *chronyd* will
 trim the RTC as if the <<chronyc.adoc#trimrtc,*trimrtc*>> command in *chronyc*
-was issued.
+was issued. The trimming operation is accurate to only about 1 second, which is
+the minimum effective threshold.
 +
 This directive is effective only with the <<rtcfile,*rtcfile*>> directive.
 +
@@ -2202,6 +2304,8 @@ name, only the first file in the order of the specified directories will be
 included. This enables a fragmented configuration where existing fragments can
 be replaced by adding files to a different directory.
 +
+This directive can be used multiple times.
++
 An example of the directive is:
 +
 ----
@@ -2211,12 +2315,15 @@ confdir @SYSCONFDIR@/chrony.d
 [[sourcedir]]*sourcedir* _directory_...::
 The *sourcedir* directive is identical to the *confdir* directive, except the
 configuration files have the _.sources_ suffix, they can only specify NTP
-sources (i.e. use the *server*, *pool*, and *peer* directive), and can be
+sources (i.e. the *server*, *pool*, and *peer* directives), they are expected
+to have all lines terminated by the newline character, and they can be
 reloaded by the <<chronyc.adoc#reload,*reload sources*>> command in
 *chronyc*. It is particularly useful with dynamic sources like NTP servers
 received from a DHCP server, which can be written to a file specific to the
 network interface by a networking script.
 +
+This directive can be used multiple times.
++
 An example of the directive is:
 +
 ----
@@ -2229,6 +2336,8 @@ files if a wildcard pattern is specified. Unlike with the *confdir* directive,
 the full name of the files needs to be specified and at least one file is
 required to exist.
 +
+This directive can be used multiple times.
++
 An example of the directive is:
 +
 ----
@@ -2264,8 +2373,9 @@ 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
+This directive can be used multiple times to enable HW timestamping on multiple
-on all available interfaces.
+interfaces. If the specified interface is _*_, *chronyd* will try to enable HW
+timestamping on all available interfaces.
 +
 The *hwtimestamp* directive has the following options:
 +
@@ -2458,7 +2568,7 @@ the following methods:
   stratum 1 and stratum 2 servers. You should find one or more servers that are
   near to you. Check that their access policy allows you to use their
   facilities.
-* Use public servers from the http://www.pool.ntp.org/[pool.ntp.org] project.
+* Use public servers from the https://www.pool.ntp.org/[pool.ntp.org] project.
 
 Assuming that your NTP servers are called _foo.example.net_, _bar.example.net_
 and _baz.example.net_, your _chrony.conf_ file could contain as a minimum:
@@ -2497,6 +2607,20 @@ makestep 1.0 3
 rtcsync
 ----
 
+If the servers (or pool) support the Network Time Security (NTS)
+authentication mechanism and *chronyd* is compiled with NTS support, the *nts*
+option will enable a secure synchronisation to the servers. The configuration
+file could look like:
+
+----
+server foo.example.net iburst nts
+server bar.example.net iburst nts
+server baz.example.net iburst nts
+driftfile @CHRONYVARDIR@/drift
+makestep 1.0 3
+rtcsync
+----
+
 === NTP client with infrequent connection to NTP servers
 
 This section shows how to configure *chronyd* for computers that have
@@ -2547,22 +2671,22 @@ This section shows how to configure *chronyd* for computers that never have
 network connectivity to any computer which ultimately derives its time from a
 reference clock.
 
-In this situation, one computer is selected to be the master timeserver. The
+In this situation, one computer is selected to be the primary timeserver. The
-other computers are either direct clients of the master, or clients of clients.
+other computers are either direct clients of the server, or clients of clients.
 
 The <<local,*local*>> directive enables a local reference mode, which allows
 *chronyd* to appear synchronised even when it is not.
 
-The rate value in the master's drift file needs to be set to the average rate
+The rate value in the server's drift file needs to be set to the average rate
-at which the master gains or loses time. *chronyd* includes support for this,
+at which the server gains or loses time. *chronyd* includes support for this,
 in the form of the <<manual,*manual*>> directive and the
 <<chronyc.adoc#settime,*settime*>> command in the *chronyc* program.
 
-If the master is rebooted, *chronyd* can re-read the drift rate from the drift
+If the server is rebooted, *chronyd* can re-read the drift rate from the drift
-file. However, the master has no accurate estimate of the current time. To get
+file. However, the server has no accurate estimate of the current time. To get
-around this, the system can be configured so that the master can initially set
+around this, the system can be configured so that the server can initially set
 itself to a '`majority-vote`' of selected clients' times; this allows the
-clients to '`flywheel`' the master while it is rebooting.
+clients to '`flywheel`' the server while it is rebooting.
 
 The <<smoothtime,*smoothtime*>> directive is useful when the clocks of the
 clients need to stay close together when the local time is adjusted by the
@@ -2571,8 +2695,8 @@ activated by the <<chronyc.adoc#smoothtime,*smoothtime activate*>> command when
 the local time is ready to be served. After that point, any adjustments will be
 smoothed out.
 
-A typical configuration file for the master (called _master_) might be
+A typical configuration file for the server (called _ntp.local_) might be
-(assuming the clients and the master are in the _192.168.165.x_ subnet):
+(assuming the clients and the server are in the _192.168.165.x_ subnet):
 
 ----
 initstepslew 1 client1 client3 client6
@@ -2584,11 +2708,11 @@ smoothtime 400 0.01
 rtcsync
 ----
 
-For the clients that have to resynchronise the master when it restarts,
+For the clients that have to resynchronise the server when it restarts,
 the configuration file might be:
 
 ----
-server master iburst
+server ntp.local iburst
 driftfile @CHRONYVARDIR@/drift
 allow 192.168.165.0/24
 makestep 1.0 3
@@ -2598,22 +2722,22 @@ rtcsync
 The rest of the clients would be the same, except that the *allow* directive is
 not required.
 
-If there is no suitable computer to be designated as the master, or there is a
+If there is no suitable computer to be designated as the primary server, or
-requirement to keep the clients synchronised even when it fails, the *orphan*
+there is a requirement to keep the clients synchronised even when it fails, the
-option of the *local* directive enables a special mode where the master is
+*orphan* option of the *local* directive enables a special mode where the
-selected from multiple computers automatically. They all need to use the same
+server is selected from multiple computers automatically. They all need to use
-*local* configuration and poll one another. The server with the smallest
+the same *local* configuration and poll one another. The server with the
-reference ID (which is based on its IP address) will take the role of the
+smallest reference ID (which is based on its IP address) will take the role of
-master and others will be synchronised to it. When it fails, the server with
+the primary server and others will be synchronised to it. When it fails, the
-the second smallest reference ID will take over and so on.
+server with the second smallest reference ID will take over and so on.
 
 A configuration file for the first server might be (assuming there are three
-servers called _master1_, _master2_, and _master3_):
+servers called _ntp1.local_, _ntp2.local_, and _ntp3.local_):
 
 ----
-initstepslew 1 master2 master3
+initstepslew 1 ntp2.local ntp3.local
-server master2
+server ntp2.local
-server master3
+server ntp3.local
 driftfile @CHRONYVARDIR@/drift
 local stratum 8 orphan
 manual
@@ -2736,7 +2860,7 @@ 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
+https://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

doc/chronyc.adoc

@@ -2,7 +2,7 @@
 //
 // Copyright (C) Richard P. Curnow  1997-2003
 // Copyright (C) Stephen Wadeley  2016
-// Copyright (C) Miroslav Lichvar  2009-2017
+// Copyright (C) Miroslav Lichvar  2009-2017, 2019-2020
 //
 // This program is free software; you can redistribute it and/or modify
 // it under the terms of version 2 of the GNU General Public License as
@@ -39,7 +39,7 @@ running.
 If no commands are specified on the command line, *chronyc* will expect input
 from the user. The prompt _chronyc>_ will be displayed when it is being run
 from a terminal. If *chronyc*'s input or output are redirected from or to a file,
-the prompt is not shown.
+the prompt will not be shown.
 
 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
@@ -60,9 +60,7 @@ default, the commands are accepted only from localhost (127.0.0.1 or ::1).
 
 All other commands are allowed only through the Unix domain socket. When sent
 over the network, *chronyd* will respond with a '`Not authorised`' error, even
-if it is from localhost. In chrony versions before 2.2 they were allowed
+if it is from localhost.
-from the network if they were authenticated with a password, but that is no
-longer supported.
 
 Having full access to *chronyd* via *chronyc* is more or less equivalent to
 being able to modify the *chronyd*'s configuration file and restart it.
@@ -80,11 +78,10 @@ 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.
 
 *-N*::
-This option enables printing of the original names of NTP sources that were
+This option enables printing of original hostnames or IP addresses of NTP
-specified in the configuration file, or *chronyc* commands, and are internally
+sources that were specified in the configuration file, or *chronyc* commands.
-used by *chronyd*. Without the *-n* and *-N* option, the names of NTP sources
+Without the *-n* and *-N* option, the printed hostnames are obtained from
-are obtained from reverse DNS lookups and can be different from the original
+reverse DNS lookups and can be different from the specified hostnames.
-names.
 
 *-c*::
 This option enables printing of reports in a comma-separated values (CSV)
@@ -120,10 +117,14 @@ This option is ignored and is provided only for compatibility.
 *-a*::
 This option is ignored and is provided only for compatibility.
 
-*-v*::
+*-v*, *--version*::
 With this option *chronyc* displays its version number on the terminal and
 exits.
 
+*--help*::
+With this option *chronyc* displays a help message on the terminal and
+exits.
+
 == COMMANDS
 
 This section describes each of the commands available within the *chronyc*
@@ -183,10 +184,12 @@ speeding up or slowing down the system clock until the error has been removed,
 and then returning to the system clock's normal speed. A consequence of this is
 that there will be a period when the system clock (as read by other programs)
 will be different from *chronyd*'s estimate of the current true time (which it
-reports to NTP clients when it is operating in server mode). The value reported
+reports to NTP clients when it is operating as a server). The value reported
 on this line is the difference due to this effect.
 *Last offset*:::
-This is the estimated local offset on the last clock update.
+This is the estimated local offset on the last clock update. A positive value
+indicates the local time (as previously estimated true time) was ahead of the
+time sources.
 *RMS offset*:::
 This is a long-term average of the offset value.
 *Frequency*:::
@@ -317,18 +320,23 @@ The columns are as follows:
 This indicates the mode of the source. _^_ means a server, _=_ means a peer
 and _#_ indicates a locally connected reference clock.
 *S*:::
-This column indicates the state of the source.
+This column indicates the selection state of the source.
-* _*_ indicates the source to which *chronyd* is currently synchronised.
+* _*_ indicates the best source which is currently selected for
-* _+_ indicates acceptable sources which are combined with the selected
+  synchronisation.
-  source.
+* _+_ indicates other sources selected for synchronisation, which are combined
-* _-_ indicates acceptable sources which are excluded by the combining
+  with the best source.
-  algorithm.
+* _-_ indicates a source which is considered to be selectable for
-* _?_ indicates sources to which connectivity has been lost or whose packets
+  synchronisation, but not currently selected.
-  do not pass all tests. It is also shown at start-up, until at least 3 samples
+* _x_ indicates a source which *chronyd* thinks is a falseticker (i.e. its
-  have been gathered from it.
+  time is inconsistent with a majority of other sources, or sources specified
-* _x_ indicates a clock which *chronyd* thinks is a falseticker (i.e. its
+  with the *trust* option).
-  time is inconsistent with a majority of other sources).
 * _~_ indicates a source whose time appears to have too much variability.
+* _?_ indicates a source which is not considered to be selectable for
+  synchronisation for other reasons (e.g. unreachable, not synchronised, or
+  does not have enough measurements).
+{blank}:::
+The <<selectdata,*selectdata*>> command can be used to get more details about
+the selection state.
 *Name/IP address*:::
 This shows the name or the IP address of the source, or reference ID for reference
 clocks.
@@ -423,11 +431,11 @@ lines are shown as a reminder of the meanings of the columns.
 An example of the output is shown below.
 +
 ----
-S Name/IP Address        Auth COpts EOpts Last Score     Interval   
+S Name/IP Address        Auth COpts EOpts Last Score     Interval  Leap
-====================================================================
+=======================================================================
-D foo.example.net           Y ----- --TR-    4   1.0   -61ms   +62ms
+D foo.example.net           Y ----- --TR-    4   1.0   -61ms   +62ms  N
-* bar.example.net           N ----- -----    0   1.0 -6846us +7305us
+* bar.example.net           N ----- -----    0   1.0 -6846us +7305us  N
-+ baz.example.net           N ----- -----   10   1.0 -7381us +7355us
++ baz.example.net           N ----- -----   10   1.0 -7381us +7355us  N
 ----
 +
 The columns are as follows:
@@ -499,6 +507,12 @@ be reselected and the scores will be reset to 1.
 This column displays the lower and upper endpoint of the interval which was
 expected to contain the true offset of the local clock considering the root
 distance at the time of the selection.
+*Leap*:::
+This column displays the current leap status of the source.
+* _N_ indicates the normal status (no leap second).
+* _+_ indicates that a leap second will be inserted at the end of the month.
+* _-_ indicates that a leap second will be deleted at the end of the month.
+* _?_ indicates the unknown status (i.e. no valid measurement was made).
 
 [[reselect]]*reselect*::
 To avoid excessive switching between sources, *chronyd* can stay synchronised
@@ -1119,11 +1133,8 @@ The effect of the allow command is identical to the
 The syntax is illustrated in the following examples:
 +
 ----
-allow foo.example.net
+allow 1.2.3.4
-allow all 1.2
+allow all 3.4.5.0/24
-allow 3.4.5
-allow 6.7.8/22
-allow 6.7.8.9/22
 allow 2001:db8:789a::/48
 allow 0/0
 allow ::/0
@@ -1138,11 +1149,8 @@ The effect of the allow command is identical to the
 The syntax is illustrated in the following examples:
 +
 ----
-deny foo.example.net
+deny 1.2.3.4
-deny all 1.2
+deny all 3.4.5.0/24
-deny 3.4.5
-deny 6.7.8/22
-deny 6.7.8.9/22
 deny 2001:db8:789a::/48
 deny 0/0
 deny ::/0
@@ -1328,10 +1336,7 @@ purged. An example of how to do this is shown below.
 ----
 # mv /var/log/chrony/measurements.log /var/log/chrony/measurements1.log
 # chronyc cyclelogs
-# ls -l /var/log/chrony
+# rm /var/log/chrony/measurements1.log
--rw-r--r--   1 root     root            0 Jun  8 18:17 measurements.log
--rw-r--r--   1 root     root        12345 Jun  8 18:17 measurements1.log
-# rm -f measurements1.log
 ----
 
 [[dump]]*dump*::
@@ -1356,7 +1361,9 @@ The *reset sources* command causes *chronyd* to drop all measurements and
 switch to the unsynchronised state. This command can help *chronyd* with
 recovery when the measurements are known to be no longer valid or accurate,
 e.g. due to moving the computer to a different network, or resuming the
-computer from a low-power state (which resets the system clock).
+computer from a low-power state (which resets the system clock). *chronyd* will
+drop the measurements automatically when it detects the clock has made an
+unexpected jump, but the detection is not completely reliable.
 
 [[shutdown]]*shutdown*::
 The *shutdown* command causes *chronyd* to exit. This is equivalent to sending
@@ -1423,7 +1430,13 @@ keygen 73 SHA1 256
 +
 which generates a 256-bit SHA1 key with number 73. The printed line should
 then be securely transferred and added to the key files on both server and
-client, or peers.
+client, or peers. A different key should be generated for each client or peer.
++
+An example using the AES128 cipher is:
++
+----
+keygen 151 AES128
+----
 
 [[exit]]*exit*::
 [[quit]]*quit*::

doc/chronyd.adoc

@@ -55,7 +55,7 @@ IPv6 sockets will be created.
 
 *-f* _file_::
 This option can be used to specify an alternate location for the configuration
-file. The default value is _@SYSCONFDIR@/chrony.conf_.
+file. The compiled-in default value is _@SYSCONFDIR@/chrony.conf_.
 
 *-n*::
 When run in this mode, the program will not detach itself from the terminal.
@@ -137,7 +137,7 @@ 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. The default value is
+<<chrony.conf.adoc#user,*user*>> directive. The compiled-in default value is
 _@DEFAULT_USER@_.
 +
 On Linux, *chronyd* needs to be compiled with support for the *libcap* library.
@@ -145,19 +145,40 @@ 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.
 
+*-U*::
+This option disables a check for root privileges to allow *chronyd* to be
+started under a non-root user, assuming the process will have all capabilities
+(e.g. provided by the service manager) and access to all files, directories,
+and devices, needed to operate correctly in the specified configuration. Note
+that different capabilities might be needed with different configurations and
+different Linux kernel versions. Starting *chronyd* under a non-root user is
+not recommended when the configuration is not known, or at least limited to
+specific directives.
+
 *-F* _level_::
-This option configures a system call filter when *chronyd* is compiled with
+This option configures system call filters loaded by *chronyd* processes if it
-support for the Linux secure computing (seccomp) facility. In level 1 the
+was compiled with support for the Linux secure computing (seccomp) facility.
-process is killed when a forbidden system call is made, in level -1 the SIGSYS
+Three levels are defined: 0, 1, 2. The filters are disabled at level 0. At
-signal is thrown instead and in level 0 the filter is disabled. The default
+levels 1 and 2, *chronyd* will be killed if it makes a system call which is
-value is 0.
+blocked by the filters. The level can be specified as a negative number to
+trigger the SIGSYS signal instead of SIGKILL, which can be useful for
+debugging. The default value is 0.
 +
-It's recommended to enable the filter only when it's known to work on the
+At level 1, the filters allow only selected system calls that are normally
-version of the system where *chrony* is installed as the filter needs to allow
+expected to be made by *chronyd*. Other system calls are blocked. This level is
-also system calls made from libraries that *chronyd* is using (e.g. libc) and
+recommended only if it is known to work on the version of the system where
-different versions or implementations of the libraries may make different
+*chrony* is installed. The filters need to allow also system calls made by
-system calls. If the filter is missing some system call, *chronyd* could be
+libraries that *chronyd* is using (e.g. libc), but different versions or
-killed even in normal operation.
+implementations of the libraries might make different system calls. If the
+filters are missing a system call, *chronyd* could be killed even in normal
+operation.
++
+At level 2, the filters block only a small number of specific system calls
+(e.g. fork and exec). This approach should avoid false positives, but the
+protection of the system against a compromised *chronyd* process is much more
+limited.
++
+The filters cannot be enabled with the *mailonchange* directive.
 
 *-P* _priority_::
 On Linux, this option will select the SCHED_FIFO real-time scheduler at the
@@ -174,14 +195,15 @@ This mode is only supported on Linux.
 This option disables the control of the system clock. *chronyd* will not try to
 make any adjustments of the clock. It will assume the clock is free running and
 still track its offset and frequency relative to the estimated true time. This
-option allows *chronyd* to run without the capability to adjust or set the
+option allows *chronyd* to be started without the capability to adjust or set
-system clock (e.g. in some containers) in order to operate as an NTP server. It
+the system clock (e.g. in some containers) to operate as an NTP server.
-is not recommended to run *chronyd* (with or without *-x*) when another process
-is controlling the system clock.
 
-*-v*::
+*-v*, *--version*::
 With this option *chronyd* will print version number to the terminal and exit.
 
+*-h*, *--help*::
+With this option *chronyd* will print a help message to the terminal and exit.
+
 == FILES
 
 _@SYSCONFDIR@/chrony.conf_

doc/faq.adoc

@@ -1,7 +1,7 @@
 // This file is part of chrony
 //
 // Copyright (C) Richard P. Curnow  1997-2003
-// Copyright (C) Miroslav Lichvar  2014-2016
+// Copyright (C) Miroslav Lichvar  2014-2016, 2020-2021
 //
 // 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
@@ -24,17 +24,20 @@
 
 === How does `chrony` compare to `ntpd`?
 
-`chronyd` was designed to work well in a wide range of conditions and it can
+`chrony` and `ntpd` are two different implementations of the Network Time
-usually synchronise the system clock faster and with better time accuracy. It
+Protocol (NTP).
-doesn't implement some of the less useful NTP modes like broadcast client or
+
-multicast server/client.
+`chrony` is a newer implementation, which was designed to work well in a wider
+range of conditions. It can usually synchronise the system clock faster and
+with better time accuracy. It has many features, but it does not implement some
+of the less useful NTP modes like broadcast client or multicast server/client.
 
 If your computer is connected to the Internet only for few minutes at a time,
 the network connection is often congested, you turn your computer off or
 suspend it frequently, the clock is not very stable (e.g. there are rapid
-changes in the temperature or it's a virtual machine), or you want to use NTP
+changes in the temperature or it is a virtual machine), or you want to use NTP
 on an isolated network with no hardware reference clocks in sight, `chrony`
-will probably work much better for you.
+will probably work better for you.
 
 For a more detailed comparison of features and performance, see the
 https://chrony.tuxfamily.org/comparison.html[comparison page] on the `chrony`
@@ -46,9 +49,11 @@ website.
 
 First, the client needs to know which NTP servers it should ask for the current
 time. They are specified by the `server` or `pool` directive. The `pool`
-directive can be used for names that resolve to multiple addresses. For good
+directive is used with names that resolve to multiple addresses of different
-reliability the client should have at least three servers. The `iburst` option
+servers. For reliable operation, the client should have at least three servers.
-speeds up the initial synchronisation.
+
+The `iburst` option enables a burst of requests to speed up the initial
+synchronisation.
 
 To stabilise the initial synchronisation on the next start, the estimated drift
 of the system clock is saved to a file specified by the `driftfile` directive.
@@ -59,13 +64,13 @@ slewing, which would take a very long time. The `makestep` directive does
 that.
 
 In order to keep the real-time clock (RTC) close to the true time, so the
-system time is reasonably close to the true time when it's initialised on the
+system time is reasonably close to the true time when it is initialised on the
 next boot from the RTC, the `rtcsync` directive enables a mode in which the
 system time is periodically copied to the RTC. It is supported on Linux and
 macOS.
 
-If you want to use public NTP servers from the
+If you wanted to use public NTP servers from the
-http://www.pool.ntp.org/[pool.ntp.org] project, the minimal _chrony.conf_ file
+https://www.pool.ntp.org/[pool.ntp.org] project, the minimal _chrony.conf_ file
 could be:
 
 ----
@@ -75,52 +80,43 @@ makestep 1 3
 rtcsync
 ----
 
-=== How do I make an NTP server from an NTP client?
+=== How do I make an NTP server?
 
-You need to add an `allow` directive to the _chrony.conf_ file in order to open
+By default, `chronyd` does not operate as an NTP server. You need to add an
-the NTP port and allow `chronyd` to reply to client requests. `allow` with no
+`allow` directive to the _chrony.conf_ file in order for `chronyd` to open the
-specified subnet allows access from all IPv4 and IPv6 addresses.
+server NTP port and respond to client requests.
 
-=== I have several computers on a LAN. Should be all clients of an external server?
+----
+allow 192.168.1.0/24
+----
 
-The best configuration is usually to make one computer the server, with
+An `allow` directive with no specified subnet allows access from all IPv4 and
-the others as clients of it. Add a `local` directive to the server's
+IPv6 addresses.
-_chrony.conf_ file. This configuration will be better because
+
+=== Should all computers on a LAN be clients of an external server?
+
+It depends on the requirements. Usually, the best configuration is to make one
+computer the server, with the others as clients of it. Add a `local` directive
+to the server's _chrony.conf_ file. This configuration will be better because
 
 * the load on the external connection is less
 * the load on the external NTP server(s) is less
 * if your external connection goes down, the computers on the LAN
   will maintain a common time with each other.
 
-=== Must I specify servers by IP address if DNS is not available on chronyd start?
+=== Must I specify servers by IP address if DNS is not available on `chronyd` start?
 
-No. Starting from version 1.25, `chronyd` will keep trying to resolve
+No, `chronyd` will keep trying to resolve
 the names specified by the `server`, `pool`, and `peer` directives in an
 increasing interval until it succeeds. The `online` command can be issued from
 `chronyc` to force `chronyd` to try to resolve the names immediately.
 
 === How can I make `chronyd` more secure?
 
-If you don't need to serve time to NTP clients or peers, you can add `port 0`
+If you do not need to use `chronyc`, or you want to run `chronyc` only
-to the _chrony.conf_ file to completely disable the NTP server functionality
-and prevent NTP requests from reaching `chronyd`. Starting from version 2.0,
-the NTP server port is open only when client access is allowed by the `allow`
-directive or command, an NTP peer is configured, or the `broadcast` directive
-is used.
-
-If you don't need to use `chronyc` remotely, you can add the following
-directives to the configuration file to bind the command sockets to the
-loopback interface. This is done by default since version 2.0.
-
-----
-bindcmdaddress 127.0.0.1
-bindcmdaddress ::1
-----
-
-If you don't need to use `chronyc` at all or you need to run `chronyc` only
 under the root or _chrony_ user (which can access `chronyd` through a Unix
-domain socket since version 2.2), you can disable the internet command sockets
+domain socket), you can disable the IPv4 and IPv6 command sockets (by default
-completely by adding `cmdport 0` to the configuration file.
+listening on localhost) by adding `cmdport 0` to the configuration file.
 
 You can specify an unprivileged user with the `-u` option, or the `user`
 directive in the _chrony.conf_ file, to which `chronyd` will switch after start
@@ -133,29 +129,144 @@ a very limited range of privileged system calls on behalf of the parent.
 Also, if `chronyd` is compiled with support for the Linux secure computing
 (seccomp) facility, you can enable a system call filter with the `-F` option.
 It will significantly reduce the kernel attack surface and possibly prevent
-kernel exploits from the `chronyd` process if it's compromised. It's
+kernel exploits from the `chronyd` process if it is compromised. It is
-recommended to enable the filter only when it's known to work on the version of
+recommended to enable the filter only when it is known to work on the version of
 the system where `chrony` is installed as the filter needs to allow also system
 calls made from libraries that `chronyd` is using (e.g. libc) and different
-versions or implementations of the libraries may make different system calls.
+versions or implementations of the libraries might make different system calls.
 If the filter is missing some system call, `chronyd` could be killed even in
 normal operation.
 
+=== How can I make the system clock more secure?
+
+An NTP client synchronising the system clock to an NTP server is susceptible to
+various attacks, which can break applications and network protocols relying on
+accuracy of the clock (e.g. DNSSEC, Kerberos, TLS, WireGuard).
+
+Generally, a man-in-the-middle (MITM) attacker between the client and server
+can
+
+* make fake responses, or modify real responses from the server, to create an
+  arbitrarily large time and frequency offset, make the server appear more
+  accurate, insert a leap second, etc.
+* delay the requests and/or responses to create a limited time offset and
+  temporarily also a limited frequency offset
+* drop the requests or responses to prevent updates of the clock with new
+  measurements
+* redirect the requests to a different server
+
+The attacks can be combined for a greater effect. The attacker can delay
+packets to create a significant frequency offset first and then drop all
+subsequent packets to let the clock quickly drift away from the true time.
+The attacker might also be able to control the server's clock.
+
+Some attacks cannot be prevented. Monitoring is needed for detection, e.g. the
+reachability register in the `sources` report shows missing packets. The extent
+to which the attacker can control the client's clock depends on its
+configuration.
+
+Enable authentication to prevent `chronyd` from accepting modified, fake, or
+redirected packets. It can be enabled with a symmetric key specified by the
+`key` option, or Network Time Security (NTS) by the `nts` option (supported
+since `chrony` version 4.0). The server needs to support the selected
+authentication mechanism. Symmetric keys have to be configured on both client
+and server, and each client must have its own key (one per server).
+
+The maximum offset that the attacker can insert in an NTP measurement by
+delaying packets can be limited by the `maxdelay` option. The default value is
+3 seconds. The measured delay is reported as the peer delay in the `ntpdata`
+report and `measurements` log. Set the `maxdelay` option to a value larger than
+the maximum value that is normally observed. Note that the delay can increase
+significantly even when not under an attack, e.g. when the network is congested
+or the routing has changed.
+
+The maximum accepted change in time offset between clock updates can be limited
+by the `maxchange` directive. Larger changes in the offset will be ignored or
+cause `chronyd` to exit. Note that the attacker can get around this limit by
+splitting the offset into multiple smaller offsets and/or creating a large
+frequency offset. When this directive is used, `chronyd` will have to be
+restarted after a successful attack. It will not be able to recover on its own.
+It must not be restarted automatically (e.g. by the service manager).
+
+The impact of a large accepted time offset can be reduced by disabling clock
+steps, i.e. by not using the `makestep` and `initstepslew` directives. The
+offset will be slowly corrected by speeding up or slowing down the clock at a
+rate which can be limited by the `maxslewrate` directive. Disabling clock steps
+completely is practical only if the clock cannot gain a larger error on its
+own, e.g. when the computer is shut down or suspended, and the `maxslewrate`
+limit is large enough to correct an expected error in an acceptable time. The
+`rtcfile` directive with the `-s` option can be used to compensate for the RTC
+drift.
+
+A more practical approach is to enable `makestep` for a limited number of clock
+updates (the 2nd argument of the directive) and limit the offset change in all
+updates by the `maxchange` directive. The attacker will be able to make only a
+limited step and only if the attack starts in a short window after booting the
+computer, or when `chronyd` is restarted without the `-R` option.
+
+The frequency offset can be limited by the `maxdrift` directive. The measured
+frequency offset is reported in the drift file, `tracking` report, and
+`tracking` log. Set `maxdrift` to a value larger than the maximum absolute
+value that is normally observed. Note that the frequency of the clock can
+change due to aging of the crystal, differences in calibration of the clock
+source between reboots, migrated virtual machine, etc. A typical computer clock
+has a drift smaller than 100 parts per million (ppm), but much larger drifts
+are possible (e.g. in some virtual machines).
+
+Use only trusted servers, which you expect to be well configured and managed,
+using authentication for their own servers, etc. Use multiple servers, ideally
+in different locations. The attacker will have to deal with a majority of the
+servers in order to pass the source selection and update the clock with a large
+offset. Use the `minsources` directive to increase the required number of
+selectable sources to make the selection more robust.
+
+Do not specify servers as peers. The symmetric mode is less secure than the
+client/server mode. If not authenticated, it is vulnerable to off-path
+denial-of-service attacks, and even when it is authenticated, it is still
+susceptible to replay attacks.
+
+Mixing of authenticated and unauthenticated servers should generally be
+avoided. If mixing is necessary (e.g. for a more accurate and stable
+synchronisation to a closer server which does not support authentication), the
+authenticated servers should be configured as trusted and required to not allow
+the unauthenticated servers to override the authenticated servers in the source
+selection. Since `chrony` version 4.0, the selection options are enabled in
+such a case automatically. This behaviour can be disabled or modified by the
+`authselmode` directive.
+
+An example of a client configuration limiting the impact of the attacks could
+be
+
+----
+server foo.example.net iburst nts maxdelay 0.1
+server bar.example.net iburst nts maxdelay 0.2
+server baz.example.net iburst nts maxdelay 0.05
+server qux.example.net iburst nts maxdelay 0.1
+server quux.example.net iburst nts maxdelay 0.1
+minsources 3
+maxchange 100 0 0
+makestep 0.001 1
+maxdrift 100
+maxslewrate 100
+driftfile /var/lib/chrony/drift
+ntsdumpdir /var/lib/chrony
+rtcsync
+----
+
 === How can I improve the accuracy of the system clock with NTP sources?
 
 Select NTP servers that are well synchronised, stable and close to your
-network. It's better to use more than one server, three or four is usually
+network. It is 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
+can be enabled by the `hwtimestamp` directive. It should make local receive and
-should make local receive and transmit timestamps of NTP packets much more
+transmit timestamps of NTP packets much more stable and accurate.
-accurate.
 
-There are also useful options which can be set in the `server` directive, they
+The `server` directive has some useful options: `minpoll`, `maxpoll`,
-are `minpoll`, `maxpoll`, `polltarget`, `maxdelay`, `maxdelayratio`,
+`polltarget`, `maxdelay`, `maxdelayratio`, `maxdelaydevratio`, `xleave`,
-`maxdelaydevratio`, and `xleave`.
+`filter`.
 
 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
@@ -163,8 +274,8 @@ default values are 6 (64 seconds) for `minpoll`, 10 (1024 seconds) for
 `maxpoll` and 8 (samples) for `polltarget`. The default values should be used
 for general servers on the Internet. With your own NTP servers, or if you have
 permission to poll some servers more frequently, setting these options for
-shorter polling intervals may significantly improve the accuracy of the system
+shorter polling intervals might significantly improve the accuracy of the
-clock.
+system clock.
 
 The optimal polling interval depends mainly on two factors, stability of the
 network latency and stability of the system clock (which mainly depends on the
@@ -174,7 +285,7 @@ temperature change).
 Generally, if the `sourcestats` command usually reports a small number of
 samples retained for a source (e.g. fewer than 16), a shorter polling interval
 should be considered. If the number of samples is usually at the maximum of 64,
-a longer polling interval may work better.
+a longer polling interval might work better.
 
 An example of the directive for an NTP server on the Internet that you are
 allowed to poll frequently could be
@@ -190,7 +301,7 @@ LAN could be
 server ntp.local minpoll 2 maxpoll 4 polltarget 30
 ----
 
-The maxdelay options are useful to ignore measurements with an unusally large
+The maxdelay options are useful to ignore measurements with an unusually large
 delay (e.g. due to congestion in the network) and improve the stability of the
 synchronisation. The `maxdelaydevratio` option could be added to the example
 with local NTP server
@@ -200,8 +311,8 @@ server ntp.local minpoll 2 maxpoll 4 polltarget 30 maxdelaydevratio 2
 ----
 
 If your server supports the interleaved mode (e.g. it is running `chronyd`),
-the `xleave` option should be added to the `server` directive in order to allow
+the `xleave` option should be added to the `server` directive to enable the
-the server to send the client more accurate transmit timestamps (kernel or
+server to provide the client with more accurate transmit timestamps (kernel or
 preferably hardware). For example:
 
 ----
@@ -210,7 +321,7 @@ server ntp.local minpoll 2 maxpoll 4 xleave
 
 When combined with local hardware timestamping, good network switches, and even
 shorter polling intervals, a sub-microsecond accuracy and stability of a few
-tens of nanoseconds may be possible. For example:
+tens of nanoseconds might be possible. For example:
 
 ----
 server ntp.local minpoll 0 maxpoll 0 xleave
@@ -221,10 +332,11 @@ For best stability, the CPU should be running at a constant frequency (i.e.
 disabled power saving and performance boosting). Energy-Efficient Ethernet
 (EEE) should be disabled in the network. The switches should be configured to
 prioritize NTP packets, especially if the network is expected to be heavily
-loaded.
+loaded. The `dscp` directive can be used to set the Differentiated Services
+Code Point in transmitted NTP packets if needed.
 
-If it is acceptable for NTP clients in the network to send requests at an
+If it is acceptable for NTP clients in the network to send requests at a high
-excessive rate, a sub-second polling interval may be specified. A median filter
+rate, a sub-second polling interval can be specified. A median filter
 can be enabled in order to update the clock at a reduced rate with more stable
 measurements. For example:
 
@@ -237,7 +349,7 @@ hwtimestamp eth0 minpoll -6
 
 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
+clock. If you do not want to use a configuration file, NTP servers can be
 specified on the command line. For example:
 
 ----
@@ -249,17 +361,28 @@ well synchronised and responding to all requests. If not synchronised or
 responding, it would take about 10 seconds for `chronyd` to give up and exit
 with a non-zero status. A faster configuration is possible. A single server can
 be used instead of four servers, the number of measurements can be reduced with
-the `maxsamples` option, and a timeout can be specified with the `-t` option.
+the `maxsamples` option to one (supported since `chrony` version 4.0), and a
-The following command would take only up to about 1 second.
+timeout can be specified with the `-t` option. The following command would take
+only up to about one second.
 
 ----
 # chronyd -q -t 1 'server pool.ntp.org iburst maxsamples 1'
 ----
 
+It is not recommended to run `chronyd` with the `-q` option periodically (e.g.
+from a cron job) as a replacement for the daemon mode, because it performs
+significantly worse (e.g. the clock is stepped and its frequency is not
+corrected). If you must run it this way and you are using a public NTP server,
+make sure `chronyd` does not always start around the first second of a minute,
+e.g. by adding a random sleep before the `chronyd` command. Public servers
+typically receive large bursts of requests around the first second as there is
+a large number of NTP clients started from cron with no delay.
+
 === Can `chronyd` be configured to control the clock like `ntpd`?
 
 It is not possible to perfectly emulate `ntpd`, but there are some options that
-can configure `chronyd` to behave more like `ntpd`.
+can configure `chronyd` to behave more like `ntpd` if there is a reason to
+prefer that.
 
 In the following example the `minsamples` directive slows down the response to
 changes in the frequency and offset of the clock. The `maxslewrate` and
@@ -279,10 +402,87 @@ maxchange 1000 1 1
 maxclockerror 15
 ----
 
-Note that increasing `minsamples` may cause the offsets in the `tracking` and
+Note that increasing `minsamples` might cause the offsets in the `tracking` and
 `sourcestats` reports/logs to be significantly smaller than the actual offsets
 and be unsuitable for monitoring.
 
+=== Can NTP server be separated from NTP client?
+
+Yes, it is possible to run multiple instances of `chronyd` on a computer at the
+same time. One can operate primarily as an NTP client to synchronise the system
+clock and another as a server for other computers. If they use the same
+filesystem, they need to be configured with different pidfiles, Unix domain
+command sockets, and any other file or directory specified in the configuration
+file. If they run in the same network namespace, they need to use different NTP
+and command ports, or bind the ports to different addresses or interfaces.
+
+The server instance should be started with the `-x` option to prevent it from
+adjusting the system clock and interfering with the client instance. It can be
+configured as a client to synchronise its NTP clock to other servers, or the
+client instance running on the same computer. In the latter case, the `copy`
+option (added in `chrony` version 4.1) can be used to assume the reference ID
+and stratum of the client instance, which enables detection of synchronisation
+loops with its own clients.
+
+On Linux, starting with `chrony` version 4.0, it is possible to run multiple
+server instances sharing a port to better utilise multiple cores of the CPU.
+Note that for rate limiting and client/server interleaved mode to work well
+it is necessary that all packets received from the same address are handled by
+the same server instance.
+
+An example configuration of the client instance could be
+
+----
+pool pool.ntp.org iburst
+allow 127.0.0.1
+port 11123
+driftfile /var/lib/chrony/drift
+makestep 1 3
+rtcsync
+----
+
+and configuration of the first server instance could be
+
+----
+server 127.0.0.1 port 11123 minpoll 0 maxpoll 0 copy
+allow
+cmdport 11323
+bindcmdaddress /var/run/chrony/chronyd-server1.sock
+pidfile /var/run/chronyd-server1.pid
+driftfile /var/lib/chrony/drift-server1
+----
+
+=== Should be a leap smear enabled on NTP server?
+
+With the `smoothtime` and `leapsecmode` directives it is possible to enable a
+server leap smear in order to hide leap seconds from clients and force them to
+follow a slow server's adjustment instead.
+
+This feature should be used only in local networks and only when necessary,
+e.g. when the clients cannot be configured to handle the leap seconds as
+needed, or their number is so large that configuring them all would be
+impractical. The clients should use only one leap-smearing server, or multiple
+identically configured leap-smearing servers. Note that some clients can get
+leap seconds from other sources (e.g. with the `leapsectz` directive in
+`chrony`) and they will not work correctly with a leap smearing server.
+
+=== Does `chrony` support PTP?
+
+No, the Precision Time Protocol (PTP) is not supported and there are no plans
+to support it. It is a complex protocol, which shares some issues with the
+NTP broadcast mode. One of the main differences between NTP and PTP is that PTP
+was designed to be easily supported in hardware (e.g. network switches and
+routers) in order to make more stable and accurate measurements. PTP relies on
+the hardware support. NTP does not rely on any support in the hardware, but if
+it had the same support as PTP, it could perform equally well.
+
+On Linux, `chrony` supports hardware clocks that some NICs have for PTP. They
+are called PTP hardware clocks (PHC). They can be used as reference clocks
+(specified by the `refclock` directive) and for hardware timestamping of NTP
+packets (enabled by the `hwtimestamp` directive) if the NIC can timestamp other
+packets than PTP, which is usually the case at least for transmitted packets.
+The `ethtool -T` command can be used to verify the timestamping support.
+
 === What happened to the `commandkey` and `generatecommandkey` directives?
 
 They were removed in version 2.2. Authentication is no longer supported in the
@@ -299,18 +499,17 @@ following questions.
 
 === Behind a firewall?
 
-Check the `Reach` value printed by the ``chronyc``'s `sources` command. If it's
+Check the `Reach` value printed by the ``chronyc``'s `sources` command. If it
-zero, it means `chronyd` did not get any valid responses from the NTP server
+is zero, it means `chronyd` did not get any valid responses from the NTP server
 you are trying to use. If there is a firewall between you and the server, the
-packets may be blocked. Try using a tool like `wireshark` or `tcpdump` to see
+packets might be blocked. Try using a tool like `wireshark` or `tcpdump` to see
-if you're getting any responses from the server.
+if you are getting any responses from the server.
 
 When `chronyd` is receiving responses from the servers, the output of the
 `sources` command issued few minutes after `chronyd` start might look like
 this:
 
 ----
-210 Number of sources = 3
 MS Name/IP address         Stratum Poll Reach LastRx Last sample
 ===============================================================================
 ^* foo.example.net               2   6   377    34   +484us[ -157us] +/-   30ms
@@ -320,9 +519,10 @@ 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
+Check that the ``chronyc``'s `online` and `offline` commands are used
-appropriately. The `activity` command prints the number of sources that are
+appropriately (e.g. in the system networking scripts). The `activity` command
-currently online and offline. For example:
+prints the number of sources that are currently online and offline. For
+example:
 
 ----
 200 OK
@@ -333,6 +533,19 @@ currently online and offline. For example:
 0 sources with unknown address
 ----
 
+=== Is name resolution working correctly?
+
+NTP servers specified by their hostname (instead of an IP address) have to have
+their names resolved before `chronyd` can send any requests to them. If the
+`activity` command prints a non-zero number of sources with unknown address,
+there is an issue with the resolution. Typically, a DNS server is specified in
+_/etc/resolv.conf_. Make sure it is working correctly.
+
+Since `chrony` version 4.0, you can run `chronyc -N sources -a` command to
+print all sources, even those that do not have a known address yet, with their
+names as they were specified in the configuration. This can be useful to verify
+that the names specified in the configuration are used as expected.
+
 === Is `chronyd` allowed to step the system clock?
 
 By default, `chronyd` adjusts the clock gradually by slowing it down or
@@ -349,9 +562,9 @@ makestep 1 3
 ----
 
 the clock would be stepped in the first three updates if its offset was larger
-than one second. Normally, it's recommended to allow the step only in the first
+than one second. Normally, it is recommended to allow the step only in the first
 few updates, but in some cases (e.g. a computer without an RTC or virtual
-machine which can be suspended and resumed with an incorrect time) it may be
+machine which can be suspended and resumed with an incorrect time) it might be
 necessary to allow the step on any clock update. The example above would change
 to
 
@@ -359,11 +572,55 @@ to
 makestep 1 -1
 ----
 
+=== Using NTS?
+
+The Network Time Security (NTS) mechanism uses Transport Layer Security (TLS)
+to establish the keys needed for authentication of NTP packets.
+
+Run the `authdata` command to check whether the key establishment was
+successful:
+
+----
+# chronyc -N authdata
+Name/IP address             Mode KeyID Type KLen Last Atmp  NAK Cook CLen
+=========================================================================
+foo.example.net              NTS     1   15  256  33m    0    0    8  100
+bar.example.net              NTS     1   15  256  33m    0    0    8  100
+baz.example.net              NTS     1   15  256  33m    0    0    8  100
+----
+
+The KeyID, Type, and KLen columns should have non-zero values. If they are
+zero, check the system log for error messages from `chronyd`. One possible
+cause of failure is a firewall blocking the client's connection to the server's
+TCP port 4460.
+
+Another possible cause of failure is a certificate that is failing to verify
+because the client's clock is wrong. This is a chicken-and-egg problem with NTS.
+You might need to manually correct the date, or temporarily disable NTS, in
+order to get NTS working. If your computer has an RTC and it is backed up by a
+good battery, this operation should be needed only once, assuming the RTC will
+be set periodically with the `rtcsync` directive, or compensated with the
+`rtcfile` directive and the `-s` option.
+
+If the computer does not have an RTC or battery, you can use the `-s` option
+without `rtcfile` directive to restore time of the last shutdown or reboot from
+the drift file. The clock will start behind the true time, but if the computer
+was not shut down for too long and the server's certificate was not renewed too
+close to its expiration, it should be sufficient for the time checks to
+succeed.
+
+As a last resort, you can disable the time checks by the `nocerttimecheck`
+directive. This has some important security implications. To reduce the
+security risk, you can use the `nosystemcert` and `ntstrustedcerts` directives
+to disable the system's default trusted certificate authorities and trust only
+a minimal set of selected authorities needed to validate the certificates of
+used NTP servers.
+
 === Using a Windows NTP server?
 
 A common issue with Windows NTP servers is that they report a very large root
 dispersion (e.g. three seconds or more), which causes `chronyd` to ignore the
-server for being too inaccurate. The `sources` command may show a valid
+server for being too inaccurate. The `sources` command might show a valid
 measurement, but the server is not selected for synchronisation. You can check
 the root dispersion of the server with the ``chronyc``'s `ntpdata` command.
 
@@ -374,6 +631,52 @@ synchronisation to such a server. For example:
 maxdistance 16.0
 ----
 
+=== An unreachable source is selected?
+
+When `chronyd` is configured with multiple time sources, it tries to select the
+most accurate and stable sources for synchronisation of the system clock. They
+are marked with the _*_ or _+_ symbol in the report printed by the `sources`
+command.
+
+When the best source (marked with the _*_ symbol) becomes unreachable (e.g. NTP
+server stops responding), `chronyd` will not immediately switch
+to the second best source in an attempt to minimise the error of the clock. It
+will let the clock run free for as long as its estimated error (in terms of
+root distance) based on previous measurements is smaller than the estimated
+error of the second source, and there is still an interval which contains some
+measurements from both sources.
+
+If the first source was significantly better than the second source, it can
+take many hours before the second source is selected, depending on its polling
+interval. You can force a faster reselection by increasing the clock error rate
+(`maxclockerror` directive), shortening the polling interval (`maxpoll`
+option), or reducing the number of samples (`maxsamples` option).
+
+=== Does selected source drop new measurements?
+
+`chronyd` can drop a large number of successive NTP measurements if they are
+not passing some of the NTP tests. The `sources` command can report for a
+selected source the fully-reachable value of 377 in the Reach column and at the
+same time a LastRx value that is much larger than the current polling interval.
+If the source is online, this indicates that a number of measurements was
+dropped. You can use the `ntpdata` command to check the NTP tests for the last
+measurement. Usually, it is the test C which fails.
+
+This can be an issue when there is a long-lasting increase in the measured
+delay, e.g. due to a routing change in the network. Unfortunately, `chronyd`
+does not know for how long it should wait for the delay to come back to the
+original values, or whether it is a permanent increase and it should start from
+scratch.
+
+The test C is an adaptive filter. It can take many hours before it accepts
+a measurement with the larger delay, and even much longer before it drops all
+measurements with smaller delay, which determine an expected delay used by the
+test. You can use the `reset sources` command to drop all measurements
+immediately (available in chrony 4.0 and later). If this issue happens
+frequently, you can effectively disable the test by setting the
+`maxdelaydevratio` option to a very large value (e.g. 1000000), or speed up the
+recovery by increasing the clock error rate with the `maxclockerror` directive.
+
 === Using a PPS reference clock?
 
 A pulse-per-second (PPS) reference clock requires a non-PPS time source to
@@ -409,15 +712,15 @@ to be used for synchronisation.
 When accessing `chronyd` remotely, make sure that the _chrony.conf_ file (on
 the computer where `chronyd` is running) has a `cmdallow` entry for the
 computer you are running `chronyc` on and an appropriate `bindcmdaddress`
-directive. This isn't necessary for localhost.
+directive. This is not necessary for localhost.
 
 Perhaps `chronyd` is not running. Try using the `ps` command (e.g. on Linux,
-`ps -auxw`) to see if it's running. Or try `netstat -a` and see if the ports
+`ps -auxw`) to see if it is running. Or try `netstat -a` and see if the UDP
-123/udp and 323/udp are listening. If `chronyd` is not running, you may have a
+port 323 is listening. If `chronyd` is not running, you might have a problem
-problem with the way you are trying to start it (e.g. at boot time).
+with the way you are trying to start it (e.g. at boot time).
 
-Perhaps you have a firewall set up in a way that blocks packets on port
+Perhaps you have a firewall set up in a way that blocks packets on the UDP
-323/udp. You need to amend the firewall configuration in this case.
+port 323. You need to amend the firewall configuration in this case.
 
 === I keep getting the error `501 Not authorised`
 
@@ -426,20 +729,16 @@ socket instead of the Unix domain socket (e.g. _/var/run/chrony/chronyd.sock_),
 which is required for some commands. For security reasons, only the root and
 _chrony_ users are allowed to access the socket.
 
-It is also possible that the socket doesn't exist. `chronyd` will not create
+It is also possible that the socket does not exist. `chronyd` will not create
 the socket if the directory has a wrong owner or permissions. In this case
 there should be an error message from `chronyd` in the system log.
 
-With versions older than 2.2, which don't use the Unix domain socket, you need
+=== What is the reference ID reported by the `tracking` command?
-to authenticate with the `password` command first,
-or use the `-a` option to authenticate automatically on start. The
-configuration file needs to specify a file which contains keys (`keyfile`
-directive) and which key in the key file should be used for `chronyc`
-authentication (`commandkey` directive).
 
-=== Why does `chronyc tracking` always print an IPv4 address as reference ID?
+The reference ID is a 32-bit value used in NTP to prevent synchronisation
+loops.
 
-The reference ID is a 32-bit value and in versions before 3.0 it was printed in
+In `chrony` versions before 3.0 it was printed in the
 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
@@ -463,12 +762,12 @@ Only by the source code. See _cmdmon.c_ (`chronyd` side) and _client.c_
 === What is the real-time clock (RTC)?
 
 This is the clock which keeps the time even when your computer is turned off.
-It is used to initialise the system clock on boot. It normally doesn't drift
+It is used to initialise the system clock on boot. It normally does not drift
 more than few seconds per day.
 
 There are two approaches how `chronyd` can work with it. One is to use the
 `rtcsync` directive, which tells `chronyd` to enable a kernel mode which sets
-the RTC from the system clock every 11 minutes. `chronyd` itself won't touch
+the RTC from the system clock every 11 minutes. `chronyd` itself will not touch
 the RTC. If the computer is not turned off for a long time, the RTC should
 still be close to the true time when the system clock will be initialised from
 it on the next boot.
@@ -478,17 +777,17 @@ monitor the rate at which the RTC gains or loses time. When `chronyd` is
 started with the `-s` option on the next boot, it will set the system time from
 the RTC and also compensate for the drift it has measured previously. The
 `rtcautotrim` directive can be used to keep the RTC close to the true time, but
-it's not strictly necessary if its only purpose is to set the system clock when
+it is not strictly necessary if its only purpose is to set the system clock when
 `chronyd` is started on boot. See the documentation for details.
 
-=== I want to use ``chronyd``'s RTC support. Must I disable `hwclock`?
+=== Does `hwclock` have to be disabled?
 
-The `hwclock` program is often set-up by default in the boot and shutdown
+The `hwclock` program is run by default in the boot and/or shutdown
-scripts with many Linux installations. With the kernel RTC synchronisation
+scripts in some Linux installations. With the kernel RTC synchronisation
 (`rtcsync` directive), the RTC will be set also every 11 minutes as long as the
 system clock is synchronised. If you want to use ``chronyd``'s RTC monitoring
-(`rtcfile` directive), it's important to disable `hwclock` in the shutdown
+(`rtcfile` directive), it is important to disable `hwclock` in the shutdown
-procedure. If you don't, it will over-write the RTC with a new value, unknown
+procedure. If you do not do that, it will overwrite the RTC with a new value, unknown
 to `chronyd`. At the next reboot, `chronyd` started with the `-s` option will
 compensate this (wrong) time with its estimate of how far the RTC has drifted
 whilst the power was off, giving a meaningless initial system time.
@@ -507,7 +806,20 @@ things
 
 === I get `Could not open /dev/rtc, Device or resource busy` in my syslog file
 
-Some other program running on the system may be using the device.
+Some other program running on the system might be using the device.
+
+=== When I start `chronyd`, the log says `Could not enable RTC interrupt : Invalid argument` (or it may say `disable`)
+
+Your real-time clock hardware might not support the required ioctl requests:
+
+* `RTC_UIE_ON`
+* `RTC_UIE_OFF`
+
+A possible solution could be to build the Linux kernel with support for software
+emulation instead; try enabling the following configuration option when building
+the Linux kernel:
+
+* `CONFIG_RTC_INTF_DEV_UIE_EMUL`
 
 === What if my computer does not have an RTC or backup battery?
 
@@ -522,7 +834,7 @@ observe backward steps.
 === Can `chronyd` be driven from broadcast/multicast NTP servers?
 
 No, the broadcast/multicast client mode is not supported and there is currently
-no plan to implement it. While the mode may be useful to simplify configuration
+no plan to implement it. While this mode can simplify configuration
 of clients in large networks, it is inherently less accurate and less secure
 (even with authentication) than the ordinary client/server mode.
 
@@ -539,7 +851,8 @@ thousands of clients using the ordinary client/server mode.
 
 Yes, the `broadcast` directive can be used to enable the broadcast server mode
 to serve time to clients in the network which support the broadcast client mode
-(it's not supported in `chronyd`, see the previous question).
+(it is not supported in `chronyd`). Note that this mode should generally be
+avoided. See the previous question.
 
 === Can `chronyd` keep the system clock a fixed offset away from real time?
 
@@ -555,9 +868,21 @@ offline, `chronyd` would make new measurements immediately after issuing the
 `online` command.
 
 Unless the network connection lasts only few minutes (less than the maximum
-polling interval), the delay is usually not a problem, and it may be acceptable
+polling interval), the delay is usually not a problem, and it might be acceptable
 to keep all sources online all the time.
 
+=== Why is an offset measured between two computers synchronised to each another?
+
+When two computers are synchronised to each other using the client/server or
+symmetric NTP mode, there is an expectation that NTP measurements between the
+two computers made on both ends show an average offset close to zero.
+
+With `chronyd` that can be expected only when the interleaved mode is enabled
+by the `xleave` option. Otherwise, `chronyd` will use different transmit
+timestamps (e.g. daemon timestamp vs kernel timestamp) for serving time and
+synchronisation of its own clock, which will cause the other computer to
+measure a significant offset.
+
 == Operating systems
 
 === Does `chrony` support Windows?

doc/installation.adoc

@@ -94,13 +94,13 @@ want to enable the support, specify the `--disable-asyncdns` flag to
 
 If development files for the https://www.lysator.liu.se/~nisse/nettle/[Nettle],
 https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS[NSS], or
-http://www.libtom.net/LibTomCrypt/[libtomcrypt] library are available,
+https://www.libtom.net/LibTomCrypt/[libtomcrypt] library are available,
 `chronyd` will be built with support for other cryptographic hash functions
 than MD5, which can be used for NTP authentication with a symmetric key. If you
 don't want to enable the support, specify the `--disable-sechash` flag to
 `configure`.
 
-If development files for the editline or readline library are available,
+If development files for the editline library are available,
 `chronyc` will be built with line editing support. If you don't want this,
 specify the `--disable-readline` flag to `configure`.
 
@@ -170,43 +170,6 @@ https://github.com/seccomp/libseccomp[libseccomp] library and the
 the kernel attack surface and possibly prevent kernel exploits from `chronyd`
 if it is compromised.
 
-== Support for line editing libraries
-
-`chronyc` can be built with support for line editing, this allows you to use
-the cursor keys to replay and edit old commands. Two libraries are supported
-which provide such functionality, editline and GNU readline.
-
-Please note that readline since version 6.0 is licensed under GPLv3+ which is
-incompatible with chrony's license GPLv2. You should use editline instead if
-you don't want to use older readline versions.
-
-The `configure` script will automatically enable the line editing support if
-one of the supported libraries is available. If they are both available, the
-editline library will be used.
-
-If you don't want to use it (in which case `chronyc` will use a minimal command
-line interface), invoke `configure` like this:
-
-----
-./configure --disable-readline other-options...
-----
-
-If you have editline, readline or ncurses installed in locations that aren't
-normally searched by the compiler and linker, you need to use extra options:
-
-`--with-readline-includes=directory_name`::
-  This defines the name of the directory above the one where `readline.h` is.
-  `readline.h` is assumed to be in `editline` or `readline` subdirectory of the
-  named directory.
-
-`--with-readline-library=directory_name`::
-  This defines the directory containing the `libedit.a` or `libedit.so` file,
-  or `libreadline.a` or `libreadline.so` file.
-
-`--with-ncurses-library=directory_name`::
-  This defines the directory containing the `libncurses.a` or `libncurses.so`
-  file.
-
 == Extra options for package builders
 
 The `configure` and `make` procedures have some extra options that may be

examples/chrony-wait.service

@@ -8,9 +8,11 @@ Wants=time-sync.target
 
 [Service]
 Type=oneshot
-# Wait up to ~10 minutes for chronyd to synchronize and the remaining
+# Wait for chronyd to update the clock and the remaining
-# clock correction to be less than 0.1 seconds
+# correction to be less than 0.1 seconds
-ExecStart=/usr/bin/chronyc -h 127.0.0.1,::1 waitsync 600 0.1 0.0 1
+ExecStart=/usr/bin/chronyc -h 127.0.0.1,::1 waitsync 0 0.1 0.0 1
+# Wait for at most 3 minutes
+TimeoutStartSec=180
 RemainAfterExit=yes
 StandardOutput=null
 

examples/chrony.conf.example2

@@ -1,5 +1,5 @@
 # Use public servers from the pool.ntp.org project.
-# Please consider joining the pool (http://www.pool.ntp.org/join.html).
+# Please consider joining the pool (https://www.pool.ntp.org/join.html).
 pool pool.ntp.org iburst
 
 # Record the rate at which the system clock gains/losses time.

keys.c

@@ -3,7 +3,7 @@
 
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2012-2016
+ * Copyright (C) Miroslav Lichvar  2012-2016, 2019-2020
  * 
  * 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

local.c

@@ -108,8 +108,8 @@ static double max_clock_error;
 
 #define NSEC_PER_SEC 1000000000
 
-static void
+static double
-calculate_sys_precision(void)
+measure_clock_precision(void)
 {
   struct timespec ts, old_ts;
   int iters, diff, best;
@@ -135,18 +135,7 @@ calculate_sys_precision(void)
 
   assert(best > 0);
 
-  precision_quantum = 1.0e-9 * best;
+  return 1.0e-9 * best;
-
-  /* Get rounded log2 value of the measured precision */
-  precision_log = 0;
-  while (best < 707106781) {
-    precision_log--;
-    best *= 2;
-  }
-
-  assert(precision_log >= -30);
-
-  DEBUG_LOG("Clock precision %.9f (%d)", precision_quantum, precision_log);
 }
 
 /* ================================================== */
@@ -170,7 +159,16 @@ LCL_Initialise(void)
   current_freq_ppm = 0.0;
   temp_comp_ppm = 0.0;
 
-  calculate_sys_precision();
+  precision_quantum = CNF_GetClockPrecision();
+  if (precision_quantum <= 0.0)
+    precision_quantum = measure_clock_precision();
+
+  precision_quantum = CLAMP(1.0e-9, precision_quantum, 1.0);
+  precision_log = round(log(precision_quantum) / log(2.0));
+  /* NTP code doesn't support smaller log than -30 */
+  assert(precision_log >= -30);
+
+  DEBUG_LOG("Clock precision %.9f (%d)", precision_quantum, precision_log);
 
   /* This is the maximum allowed frequency offset in ppm, the time must
      never stop or run backwards */
@@ -507,7 +505,7 @@ LCL_AccumulateDeltaFrequency(double dfreq)
 
 /* ================================================== */
 
-void
+int
 LCL_AccumulateOffset(double offset, double corr_rate)
 {
   struct timespec raw, cooked;
@@ -519,12 +517,14 @@ LCL_AccumulateOffset(double offset, double corr_rate)
   LCL_CookTime(&raw, &cooked, NULL);
 
   if (!check_offset(&cooked, offset))
-      return;
+    return 0;
 
   (*drv_accrue_offset)(offset, corr_rate);
 
   /* Dispatch to all handlers */
   invoke_parameter_change_handlers(&raw, &cooked, 0.0, offset, LCL_ChangeAdjust);
+
+  return 1;
 }
 
 /* ================================================== */
@@ -588,7 +588,7 @@ LCL_NotifyLeap(int leap)
 
 /* ================================================== */
 
-void
+int
 LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate)
 {
   struct timespec raw, cooked;
@@ -600,7 +600,7 @@ LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate)
   LCL_CookTime(&raw, &cooked, NULL);
 
   if (!check_offset(&cooked, doffset))
-      return;
+    return 0;
 
   old_freq_ppm = current_freq_ppm;
 
@@ -622,6 +622,8 @@ LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate)
 
   /* Dispatch to all handlers */
   invoke_parameter_change_handlers(&raw, &cooked, dfreq, doffset, LCL_ChangeAdjust);
+
+  return 1;
 }
 
 /* ================================================== */
@@ -689,6 +691,19 @@ LCL_MakeStep(void)
 
 /* ================================================== */
 
+void
+LCL_CancelOffsetCorrection(void)
+{
+  struct timespec raw;
+  double correction;
+
+  LCL_ReadRawTime(&raw);
+  LCL_GetOffsetCorrection(&raw, &correction, NULL);
+  LCL_AccumulateOffset(correction, 0.0);
+}
+
+/* ================================================== */
+
 int
 LCL_CanSystemLeap(void)
 {

local.h

@@ -149,7 +149,7 @@ extern void LCL_AccumulateDeltaFrequency(double dfreq);
    forwards (i.e. it is currently slow of true time).  Provided is also
    a suggested correction rate (correction time * offset). */
 
-extern void LCL_AccumulateOffset(double offset, double corr_rate);
+extern int LCL_AccumulateOffset(double offset, double corr_rate);
 
 /* Routine to apply an immediate offset by doing a sudden step if
    possible. (Intended for use after an initial estimate of offset has
@@ -171,7 +171,7 @@ extern void LCL_NotifyLeap(int leap);
 
 /* Perform the combination of modifying the frequency and applying
    a slew, in one easy step */
-extern void LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate);
+extern int LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate);
 
 /* Routine to read the system precision as a log to base 2 value. */
 extern int LCL_GetSysPrecisionAsLog(void);
@@ -197,6 +197,9 @@ extern void LCL_Finalise(void);
    to a timezone problem. */
 extern int LCL_MakeStep(void);
 
+/* Routine to cancel the outstanding system clock correction */
+extern void LCL_CancelOffsetCorrection(void);
+
 /* Check if the system driver supports leap seconds, i.e. LCL_SetSystemLeap
    does something */
 extern int LCL_CanSystemLeap(void);

logging.c

@@ -3,7 +3,7 @@
 
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2014, 2018
+ * Copyright (C) Miroslav Lichvar  2011-2014, 2018-2020
  * 
  * 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

main.c

@@ -4,7 +4,7 @@
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
  * Copyright (C) John G. Hasler  2009
- * Copyright (C) Miroslav Lichvar  2012-2018
+ * Copyright (C) Miroslav Lichvar  2012-2020
  * 
  * 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
@@ -104,6 +104,7 @@ MAI_CleanupAndExit(void)
 {
   if (!initialised) exit(exit_status);
   
+  LCL_CancelOffsetCorrection();
   SRC_DumpSources();
 
   /* Don't update clock when removing sources */
@@ -183,7 +184,7 @@ ntp_source_resolving_end(void)
   NSR_AutoStartSources();
 
   /* Special modes can end only when sources update their reachability.
-     Give up immediatelly if there are no active sources. */
+     Give up immediately if there are no active sources. */
   if (ref_mode != REF_ModeNormal && !SRC_ActiveSources()) {
     REF_SetUnsynchronised();
   }
@@ -374,8 +375,34 @@ go_daemon(void)
 static void
 print_help(const char *progname)
 {
-      printf("Usage: %s [-4|-6] [-n|-d] [-p|-q|-Q] [-r] [-R] [-s] [-t TIMEOUT] [-f FILE|COMMAND...]\n",
+      printf("Usage: %s [OPTION]... [DIRECTIVE]...\n\n"
-             progname);
+             "Options:\n"
+             "  -4\t\tUse IPv4 addresses only\n"
+             "  -6\t\tUse IPv6 addresses only\n"
+             "  -f FILE\tSpecify configuration file (%s)\n"
+             "  -n\t\tDon't run as daemon\n"
+             "  -d\t\tDon't run as daemon and log to stderr\n"
+#if DEBUG > 0
+             "  -d -d\t\tEnable debug messages\n"
+#endif
+             "  -l FILE\tLog to file\n"
+             "  -L LEVEL\tSet logging threshold (0)\n"
+             "  -p\t\tPrint configuration and exit\n"
+             "  -q\t\tSet clock and exit\n"
+             "  -Q\t\tLog offset and exit\n"
+             "  -r\t\tReload dump files\n"
+             "  -R\t\tAdapt configuration for restart\n"
+             "  -s\t\tSet clock from RTC\n"
+             "  -t SECONDS\tExit after elapsed time\n"
+             "  -u USER\tSpecify user (%s)\n"
+             "  -U\t\tDon't check for root\n"
+             "  -F LEVEL\tSet system call filter level (0)\n"
+             "  -P PRIORITY\tSet process priority (0)\n"
+             "  -m\t\tLock memory\n"
+             "  -x\t\tDon't control clock\n"
+             "  -v, --version\tPrint version and exit\n"
+             "  -h, --help\tPrint usage and exit\n",
+             progname, DEFAULT_CONF_FILE, DEFAULT_USER);
 }
 
 /* ================================================== */
@@ -411,13 +438,13 @@ int main
   int do_init_rtc = 0, restarted = 0, client_only = 0, timeout = -1;
   int scfilter_level = 0, lock_memory = 0, sched_priority = 0;
   int clock_control = 1, system_log = 1, log_severity = LOGS_INFO;
-  int config_args = 0, print_config = 0;
+  int user_check = 1, config_args = 0, print_config = 0;
 
   do_platform_checks();
 
   LOG_Initialise();
 
-  /* Parse (undocumented) long command-line options */
+  /* Parse long command-line options */
   for (optind = 1; optind < argc; optind++) {
     if (!strcmp("--help", argv[optind])) {
       print_help(progname);
@@ -431,7 +458,7 @@ int main
   optind = 1;
 
   /* Parse short command-line options */
-  while ((opt = getopt(argc, argv, "46df:F:hl:L:mnpP:qQrRst:u:vx")) != -1) {
+  while ((opt = getopt(argc, argv, "46df:F:hl:L:mnpP:qQrRst:u:Uvx")) != -1) {
     switch (opt) {
       case '4':
       case '6':
@@ -462,9 +489,10 @@ int main
         break;
       case 'p':
         print_config = 1;
-        client_only = 1;
+        user_check = 0;
         nofork = 1;
         system_log = 0;
+        log_severity = LOGS_WARN;
         break;
       case 'P':
         sched_priority = parse_int_arg(optarg);
@@ -479,6 +507,7 @@ int main
         ref_mode = REF_ModePrintOnce;
         nofork = 1;
         client_only = 1;
+        user_check = 0;
         clock_control = 0;
         system_log = 0;
         break;
@@ -497,6 +526,9 @@ int main
       case 'u':
         user = optarg;
         break;
+      case 'U':
+        user_check = 0;
+        break;
       case 'v':
         print_version();
         return 0;
@@ -509,7 +541,7 @@ int main
     }
   }
 
-  if (getuid() && !client_only)
+  if (user_check && getuid() != 0)
     LOG_FATAL("Not superuser");
 
   /* Turn into a daemon */
@@ -595,7 +627,10 @@ int main
 
   /* 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);
+    SYS_DropRoot(pw->pw_uid, pw->pw_gid, SYS_MAIN_PROCESS);
+
+  if (!geteuid())
+    LOG(LOGS_WARN, "Running with root privileges");
 
   REF_Initialise();
   SST_Initialise();

nameserv.c

@@ -50,12 +50,24 @@ DNS_SetAddressFamily(int family)
 DNS_Status 
 DNS_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs)
 {
-#ifdef HAVE_GETADDRINFO
   struct addrinfo hints, *res, *ai;
   int i, result;
+  IPAddr ip;
 
   max_addrs = MIN(max_addrs, DNS_MAX_ADDRESSES);
 
+  for (i = 0; i < max_addrs; i++)
+    ip_addrs[i].family = IPADDR_UNSPEC;
+
+  /* Avoid calling getaddrinfo() if the name is an IP address */
+  if (UTI_StringToIP(name, &ip)) {
+    if (address_family != IPADDR_UNSPEC && ip.family != address_family)
+      return DNS_Failure;
+    if (max_addrs >= 1)
+      ip_addrs[0] = ip;
+    return DNS_Success;
+  }
+
   memset(&hints, 0, sizeof (hints));
 
   switch (address_family) {
@@ -107,48 +119,9 @@ DNS_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs)
     }
   }
 
-  for (; i < max_addrs; i++)
-        ip_addrs[i].family = IPADDR_UNSPEC;
-
   freeaddrinfo(res);
 
   return !max_addrs || ip_addrs[0].family != IPADDR_UNSPEC ? DNS_Success : DNS_Failure;
-#else
-  struct hostent *host;
-  int i;
-  
-  if (address_family != IPADDR_UNSPEC && address_family != IPADDR_INET4)
-    return DNS_Failure;
-
-  max_addrs = MIN(max_addrs, DNS_MAX_ADDRESSES);
-
-  host = gethostbyname(name);
-
-  if (host == NULL) {
-    if (h_errno == TRY_AGAIN)
-      return DNS_TryAgain;
-  } else {
-    if (host->h_addrtype != AF_INET || !host->h_addr_list[0])
-      return DNS_Failure;
-
-    for (i = 0; host->h_addr_list[i] && i < max_addrs; i++) {
-      ip_addrs[i].family = IPADDR_INET4;
-      ip_addrs[i].addr.in4 = ntohl(*(uint32_t *)host->h_addr_list[i]);
-    }
-
-    for (; i < max_addrs; i++)
-      ip_addrs[i].family = IPADDR_UNSPEC;
-
-    return DNS_Success;
-  }
-
-#ifdef FORCE_DNSRETRY
-  return DNS_TryAgain;
-#else
-  return DNS_Failure;
-#endif
-
-#endif
 }
 
 /* ================================================== */
@@ -157,9 +130,11 @@ int
 DNS_IPAddress2Name(IPAddr *ip_addr, char *name, int len)
 {
   char *result = NULL;
-
 #ifdef FEAT_IPV6
-  struct sockaddr_in6 in6;
+  struct sockaddr_in6 saddr;
+#else
+  struct sockaddr_in saddr;
+#endif
   IPSockAddr ip_saddr;
   socklen_t slen;
   char hbuf[NI_MAXHOST];
@@ -167,29 +142,9 @@ DNS_IPAddress2Name(IPAddr *ip_addr, char *name, int len)
   ip_saddr.ip_addr = *ip_addr;
   ip_saddr.port = 0;
 
-  slen = SCK_IPSockAddrToSockaddr(&ip_saddr, (struct sockaddr *)&in6, sizeof (in6));
+  slen = SCK_IPSockAddrToSockaddr(&ip_saddr, (struct sockaddr *)&saddr, sizeof (saddr));
-  if (!getnameinfo((struct sockaddr *)&in6, slen, hbuf, sizeof (hbuf), NULL, 0, 0))
+  if (!getnameinfo((struct sockaddr *)&saddr, slen, hbuf, sizeof (hbuf), NULL, 0, 0))
     result = hbuf;
-#else
-  struct hostent *host;
-  uint32_t addr;
-
-  switch (ip_addr->family) {
-    case IPADDR_INET4:
-      addr = htonl(ip_addr->addr.in4);
-      host = gethostbyaddr((const char *) &addr, sizeof (ip_addr), AF_INET);
-      break;
-#ifdef FEAT_IPV6
-    case IPADDR_INET6:
-      host = gethostbyaddr((const void *) ip_addr->addr.in6, sizeof (ip_addr->addr.in6), AF_INET6);
-      break;
-#endif
-    default:
-      host = NULL;
-  }
-  if (host)
-    result = host->h_name;
-#endif
 
   if (result == NULL)
     result = UTI_IPToString(ip_addr);

ntp.h

@@ -116,10 +116,11 @@ typedef struct {
 /* Enumeration for authentication modes of NTP packets */
 typedef enum {
   NTP_AUTH_NONE = 0,            /* No authentication */
-  NTP_AUTH_SYMMETRIC,           /* MAC using symmetric key (RFC 1305, RFC 5905) */
+  NTP_AUTH_SYMMETRIC,           /* NTP MAC or CMAC using a symmetric key
+                                   (RFC 1305, RFC 5905, RFC 8573) */
   NTP_AUTH_MSSNTP,              /* MS-SNTP authenticator field */
   NTP_AUTH_MSSNTP_EXT,          /* MS-SNTP extended authenticator field */
-  NTP_AUTH_NTS,                 /* Network Time Security (RFC ????) */
+  NTP_AUTH_NTS,                 /* Network Time Security (RFC 8915) */
 } NTP_AuthMode;
 
 /* Structure describing an NTP packet */
@@ -151,7 +152,6 @@ typedef struct {
   double peer_dispersion;
   double root_delay;
   double root_dispersion;
-  int stratum;
 } NTP_Sample;
 
 #endif /* GOT_NTP_H */

ntp_auth.c

@@ -2,7 +2,7 @@
   chronyd/chronyc - Programs for keeping computer clocks accurate.
 
  **********************************************************************
- * Copyright (C) Miroslav Lichvar  2019
+ * Copyright (C) Miroslav Lichvar  2019-2020
  * 
  * 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
@@ -161,11 +161,12 @@ NAU_CreateSymmetricInstance(uint32_t key_id)
 /* ================================================== */
 
 NAU_Instance
-NAU_CreateNtsInstance(IPSockAddr *nts_address, const char *name, const IPSockAddr *ntp_address)
+NAU_CreateNtsInstance(IPSockAddr *nts_address, const char *name, uint32_t cert_set,
+                      uint16_t ntp_port)
 {
   NAU_Instance instance = create_instance(NTP_AUTH_NTS);
 
-  instance->nts = NNC_CreateInstance(nts_address, name, ntp_address);
+  instance->nts = NNC_CreateInstance(nts_address, name, cert_set, ntp_port);
 
   return instance;
 }
@@ -175,7 +176,7 @@ NAU_CreateNtsInstance(IPSockAddr *nts_address, const char *name, const IPSockAdd
 void
 NAU_DestroyInstance(NAU_Instance instance)
 {
-  if (instance->nts)
+  if (instance->mode == NTP_AUTH_NTS)
     NNC_DestroyInstance(instance->nts);
   Free(instance);
 }
@@ -300,21 +301,9 @@ NAU_ParsePacket(NTP_Packet *packet, NTP_PacketInfo *info)
     if (remainder >= NTP_MIN_MAC_LENGTH && remainder <= NTP_MAX_V4_MAC_LENGTH)
       break;
 
-    /* The NTPv4-specific limit for MAC length enables deterministic parsing of
-       packets with extension fields (RFC 7822), but we support longer MACs in
-       packets with no extension fields for compatibility with older chrony
-       clients.  Check if the longer MAC would authenticate the packet before
-       trying to parse the data as an extension field. */
-    if (parsed == NTP_HEADER_LENGTH &&
-        remainder > NTP_MAX_V4_MAC_LENGTH && remainder <= NTP_MAX_MAC_LENGTH &&
-        KEY_CheckAuth(ntohl(*(uint32_t *)(data + parsed)), data, parsed,
-                      data + parsed + 4, remainder - 4, NTP_MAX_MAC_LENGTH - 4))
-      break;
-
     /* Check if this is a valid NTPv4 extension field and skip it */
     if (!NEF_ParseField(packet, info->length, parsed, &ef_length, &ef_type, NULL, NULL)) {
-      /* Invalid MAC or format error */
+      DEBUG_LOG("Invalid format");
-      DEBUG_LOG("Invalid format or MAC");
       return 0;
     }
 
@@ -340,9 +329,6 @@ NAU_ParsePacket(NTP_Packet *packet, NTP_PacketInfo *info)
     /* No MAC */
     return 1;
   } else if (remainder >= NTP_MIN_MAC_LENGTH) {
-    /* This is not 100% reliable as a MAC could fail to authenticate and could
-       pass as an extension field, leaving reminder smaller than the minimum MAC
-       length */
     info->auth.mode = NTP_AUTH_SYMMETRIC;
     info->auth.mac.start = parsed;
     info->auth.mac.length = remainder;

ntp_auth.h

@@ -37,7 +37,7 @@ typedef struct NAU_Instance_Record *NAU_Instance;
 extern NAU_Instance NAU_CreateNoneInstance(void);
 extern NAU_Instance NAU_CreateSymmetricInstance(uint32_t key_id);
 extern NAU_Instance NAU_CreateNtsInstance(IPSockAddr *nts_address, const char *name,
-                                          const IPSockAddr *ntp_address);
+                                          uint32_t cert_set, uint16_t ntp_port);
 
 /* Destroy an instance */
 extern void NAU_DestroyInstance(NAU_Instance instance);

ntp_core.c

@@ -3,7 +3,7 @@
 
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2018
+ * Copyright (C) Miroslav Lichvar  2009-2020
  * 
  * 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
@@ -107,6 +107,8 @@ struct NCR_Instance_Record {
   int min_stratum;              /* Increase stratum in received packets to the
                                    minimum */
 
+  int copy;                     /* Boolean suppressing own refid and stratum */
+
   int poll_target;              /* Target number of sourcestats samples */
 
   int version;                  /* Version set in packets for server/peer */
@@ -560,6 +562,7 @@ NCR_CreateInstance(NTP_Remote_Address *remote_addr, NTP_Source_Type type,
   result->auto_iburst = params->iburst;
   result->auto_burst = params->burst;
   result->auto_offline = params->auto_offline;
+  result->copy = params->copy && result->mode == MODE_CLIENT;
   result->poll_target = params->poll_target;
 
   if (params->nts) {
@@ -571,7 +574,8 @@ NCR_CreateInstance(NTP_Remote_Address *remote_addr, NTP_Source_Type type,
     nts_address.ip_addr = remote_addr->ip_addr;
     nts_address.port = params->nts_port;
 
-    result->auth = NAU_CreateNtsInstance(&nts_address, name, &result->remote_addr);
+    result->auth = NAU_CreateNtsInstance(&nts_address, name, params->cert_set,
+                                         result->remote_addr.port);
   } else if (params->authkey != INACTIVE_AUTHKEY) {
     result->auth = NAU_CreateSymmetricInstance(params->authkey);
   } else {
@@ -703,7 +707,6 @@ NCR_ChangeRemoteAddress(NCR_Instance inst, NTP_Remote_Address *remote_addr, int
   memset(&inst->report, 0, sizeof (inst->report));
   NCR_ResetInstance(inst);
 
-  /* Update the authentication-specific address before NTP address */
   if (!ntp_only)
     NAU_ChangeAddress(inst->auth, &remote_addr->ip_addr);
 
@@ -1381,9 +1384,8 @@ check_sync_loop(NCR_Instance inst, NTP_Packet *message, NTP_Local_Address *local
   NTP_Leap leap_status;
   uint32_t our_ref_id;
 
-  /* Check if a server socket is open, i.e. a client or peer can actually
+  /* Check if a client or peer can be synchronised to us */
-     be synchronised to us */
+  if (!NIO_IsServerSocketOpen() || REF_GetMode() != REF_ModeNormal)
-  if (!NIO_IsServerSocketOpen())
     return 1;
 
   /* Check if the source indicates that it is synchronised to our address
@@ -1678,7 +1680,6 @@ process_response(NCR_Instance inst, NTP_Local_Address *local_addr,
 
   sample.root_delay = pkt_root_delay + sample.peer_delay;
   sample.root_dispersion = pkt_root_dispersion + sample.peer_dispersion;
-  sample.stratum = MAX(message->stratum, inst->min_stratum);
 
   /* Update the NTP timestamps.  If it's a valid packet from a synchronised
      source, the timestamps may be used later when processing a packet in the
@@ -1761,14 +1762,23 @@ process_response(NCR_Instance inst, NTP_Local_Address *local_addr,
   if (valid_packet) {
     inst->remote_poll = message->poll;
     inst->remote_stratum = message->stratum != NTP_INVALID_STRATUM ?
-                           message->stratum : NTP_MAX_STRATUM;
+                           MIN(message->stratum, NTP_MAX_STRATUM) : NTP_MAX_STRATUM;
 
     inst->prev_local_poll = inst->local_poll;
     inst->prev_tx_count = inst->tx_count;
     inst->tx_count = 0;
 
     SRC_UpdateReachability(inst->source, synced_packet);
-    SRC_SetLeapStatus(inst->source, pkt_leap);
+
+    if (synced_packet) {
+      if (inst->copy && inst->remote_stratum > 0) {
+        /* Assume the reference ID and stratum of the server */
+        inst->remote_stratum--;
+        SRC_SetRefid(inst->source, ntohl(message->reference_id), &inst->remote_addr.ip_addr);
+      }
+
+      SRC_UpdateStatus(inst->source, MAX(inst->remote_stratum, inst->min_stratum), pkt_leap);
+    }
 
     if (good_packet) {
       /* Adjust the polling interval, accumulate the sample, etc. */
@@ -2095,15 +2105,6 @@ NCR_ProcessRxUnknown(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_a
     CLG_LogAuthNtpRequest();
   }
 
-  /* If it is an NTPv4 packet with a long MAC and no extension fields,
-     respond with an NTPv3 packet to avoid breaking RFC 7822 and keep
-     the length symmetric.  Otherwise, respond with the same version. */
-  if (info.version == 4 && info.ext_fields == 0 && info.auth.mode == NTP_AUTH_SYMMETRIC &&
-      info.auth.mac.length > NTP_MAX_V4_MAC_LENGTH)
-    version = 3;
-  else
-    version = info.version;
-
   local_ntp_rx = local_ntp_tx = NULL;
   tx_ts = NULL;
   interleaved = 0;
@@ -2133,6 +2134,9 @@ NCR_ProcessRxUnknown(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_a
   poll = CLG_GetNtpMinPoll();
   poll = MAX(poll, message->poll);
 
+  /* Respond with the same version */
+  version = info.version;
+
   /* Send a reply */
   transmit_packet(my_mode, interleaved, poll, version, kod, NULL,
                   &message->receive_ts, &message->transmit_ts,

ntp_ext.c

@@ -2,7 +2,7 @@
   chronyd/chronyc - Programs for keeping computer clocks accurate.
 
  **********************************************************************
- * Copyright (C) Miroslav Lichvar  2019
+ * Copyright (C) Miroslav Lichvar  2019-2020
  * 
  * 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

ntp_io.c

@@ -4,7 +4,7 @@
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
  * Copyright (C) Timo Teras  2009
- * Copyright (C) Miroslav Lichvar  2009, 2013-2016, 2018
+ * Copyright (C) Miroslav Lichvar  2009, 2013-2016, 2018-2020
  * 
  * 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

ntp_io_linux.c

@@ -200,7 +200,8 @@ add_interface(CNF_HwTsInterface *conf_iface)
   req.ifr_data = (char *)&ts_config;
 
   if (ioctl(sock_fd, SIOCSHWTSTAMP, &req)) {
-    DEBUG_LOG("ioctl(%s) failed : %s", "SIOCSHWTSTAMP", strerror(errno));
+    LOG(errno == EPERM ? LOGS_ERR : LOGS_DEBUG,
+        "ioctl(%s) failed : %s", "SIOCSHWTSTAMP", strerror(errno));
 
     /* Check the current timestamping configuration in case this interface
        allows only reading of the configuration and it was already configured

ntp_sources.c

@@ -3,7 +3,7 @@
 
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2012, 2014, 2016
+ * Copyright (C) Miroslav Lichvar  2011-2012, 2014, 2016, 2020-2021
  * 
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -45,6 +45,9 @@
 
 /* ================================================== */
 
+/* Maximum number of sources */
+#define MAX_SOURCES 65536
+
 /* Record type private to this file, used to store information about
    particular sources */
 typedef struct {
@@ -53,7 +56,8 @@ typedef struct {
                                       (an IPADDR_ID address means the address
                                       is not resolved yet) */
   NCR_Instance data;            /* Data for the protocol engine for this source */
-  char *name;                   /* Name of the source, may be NULL */
+  char *name;                   /* Name of the source as it was specified
+                                   (may be an IP address) */
   int pool_id;                  /* ID of the pool from which was this source
                                    added or INVALID_POOL */
   int tentative;                /* Flag indicating there was no valid response
@@ -72,6 +76,9 @@ static int n_sources;
 /* Flag indicating new sources will be started automatically when added */
 static int auto_start_sources = 0;
 
+/* Flag indicating a record is currently being modified */
+static int record_lock;
+
 /* Last assigned address ID */
 static uint32_t last_address_id = 0;
 
@@ -100,6 +107,7 @@ struct UnresolvedSource {
 
 static struct UnresolvedSource *unresolved_sources = NULL;
 static int resolving_interval = 0;
+static int resolving_restart = 0;
 static SCH_TimeoutID resolving_id;
 static struct UnresolvedSource *resolving_source = NULL;
 static NSR_SourceResolvingEndHandler resolving_end_handler = NULL;
@@ -122,11 +130,21 @@ struct SourcePool {
 /* Array of SourcePool (indexed by their ID) */
 static ARR_Instance pools;
 
+/* Requested update of a source's address */
+struct AddressUpdate {
+  NTP_Remote_Address old_address;
+  NTP_Remote_Address new_address;
+};
+
+/* Update saved when record_lock is true */
+static struct AddressUpdate saved_address_update;
+
 /* ================================================== */
 /* Forward prototypes */
 
 static void resolve_sources(void);
 static void rehash_records(void);
+static void handle_saved_address_update(void);
 static void clean_source_record(SourceRecord *record);
 static void remove_pool_sources(int pool_id, int tentative, int unresolved);
 static void remove_unresolved_source(struct UnresolvedSource *us);
@@ -181,14 +199,7 @@ NSR_Initialise(void)
 void
 NSR_Finalise(void)
 {
-  SourceRecord *record;
+  NSR_RemoveAllSources();
-  unsigned int i;
-
-  for (i = 0; i < ARR_GetSize(records); i++) {
-    record = get_record(i);
-    if (record->remote_addr)
-      clean_source_record(record);
-  }
 
   LCL_RemoveParameterChangeHandler(slew_sources, NULL);
 
@@ -275,6 +286,8 @@ rehash_records(void)
   unsigned int i, old_size, new_size;
   int slot;
 
+  assert(!record_lock);
+
   old_size = ARR_GetSize(records);
 
   temp_records = MallocArray(SourceRecord, old_size);
@@ -317,6 +330,11 @@ add_source(NTP_Remote_Address *remote_addr, char *name, NTP_Source_Type type,
   /* Find empty bin & check that we don't have the address already */
   if (find_slot2(remote_addr, &slot) != 0) {
     return NSR_AlreadyInUse;
+  } else if (!name && !UTI_IsIPReal(&remote_addr->ip_addr)) {
+    /* Name is required for non-real addresses */
+    return NSR_InvalidName;
+  } else if (n_sources >= MAX_SOURCES) {
+    return NSR_TooManySources;
   } else {
     if (remote_addr->ip_addr.family != IPADDR_INET4 &&
         remote_addr->ip_addr.family != IPADDR_INET6 &&
@@ -331,14 +349,20 @@ add_source(NTP_Remote_Address *remote_addr, char *name, NTP_Source_Type type,
           assert(0);
       }
 
+      assert(!record_lock);
+      record_lock = 1;
+
       record = get_record(slot);
-      record->data = NCR_CreateInstance(remote_addr, type, params, name);
+      assert(!name || !UTI_IsStringIP(name));
+      record->name = Strdup(name ? name : UTI_IPToString(&remote_addr->ip_addr));
+      record->data = NCR_CreateInstance(remote_addr, type, params, record->name);
       record->remote_addr = NCR_GetRemoteAddress(record->data);
-      record->name = name ? Strdup(name) : NULL;
       record->pool_id = pool_id;
       record->tentative = 1;
       record->conf_id = conf_id;
 
+      record_lock = 0;
+
       if (record->pool_id != INVALID_POOL) {
         get_pool(record->pool_id)->sources++;
         if (!UTI_IsIPReal(&remote_addr->ip_addr))
@@ -348,6 +372,9 @@ add_source(NTP_Remote_Address *remote_addr, char *name, NTP_Source_Type type,
       if (auto_start_sources && UTI_IsIPReal(&remote_addr->ip_addr))
         NCR_StartInstance(record->data);
 
+      /* The new instance is allowed to change its address immediately */
+      handle_saved_address_update();
+
       return NSR_Success;
     }
   }
@@ -365,7 +392,7 @@ change_source_address(NTP_Remote_Address *old_addr, NTP_Remote_Address *new_addr
   char *name;
 
   found = find_slot2(old_addr, &slot1);
-  if (found == 0)
+  if (found != 2)
     return NSR_NoSuchSource;
 
   /* Make sure there is no other source using the new address (with the same
@@ -374,9 +401,16 @@ change_source_address(NTP_Remote_Address *old_addr, NTP_Remote_Address *new_addr
   if (found == 2 || (found != 0 && slot1 != slot2))
     return NSR_AlreadyInUse;
 
+  assert(!record_lock);
+  record_lock = 1;
+
   record = get_record(slot1);
   NCR_ChangeRemoteAddress(record->data, new_addr, !replacement);
-  record->remote_addr = NCR_GetRemoteAddress(record->data);
+
+  if (record->remote_addr != NCR_GetRemoteAddress(record->data) ||
+      UTI_CompareIPs(&record->remote_addr->ip_addr, &new_addr->ip_addr, NULL) != 0)
+    assert(0);
+
   if (!UTI_IsIPReal(&old_addr->ip_addr) && UTI_IsIPReal(&new_addr->ip_addr)) {
     if (auto_start_sources)
       NCR_StartInstance(record->data);
@@ -391,6 +425,8 @@ change_source_address(NTP_Remote_Address *old_addr, NTP_Remote_Address *new_addr
       get_pool(record->pool_id)->confirmed_sources--;
   }
 
+  record_lock = 0;
+
   name = record->name;
   severity = UTI_IsIPReal(&old_addr->ip_addr) ? LOGS_INFO : LOGS_DEBUG;
 
@@ -400,10 +436,10 @@ change_source_address(NTP_Remote_Address *old_addr, NTP_Remote_Address *new_addr
 
     LOG(severity, "Source %s %s %s (%s)", UTI_IPToString(&old_addr->ip_addr),
         replacement ? "replaced with" : "changed to",
-        UTI_IPToString(&new_addr->ip_addr), name ? name : "");
+        UTI_IPToString(&new_addr->ip_addr), name);
   } else {
     LOG(severity, "Source %s (%s) changed port to %d",
-        UTI_IPToString(&new_addr->ip_addr), name ? name : "", new_addr->port);
+        UTI_IPToString(&new_addr->ip_addr), name, new_addr->port);
   }
 
   return NSR_Success;
@@ -411,6 +447,24 @@ change_source_address(NTP_Remote_Address *old_addr, NTP_Remote_Address *new_addr
 
 /* ================================================== */
 
+static void
+handle_saved_address_update(void)
+{
+  if (!UTI_IsIPReal(&saved_address_update.old_address.ip_addr))
+    return;
+
+  if (change_source_address(&saved_address_update.old_address,
+                            &saved_address_update.new_address, 0) != NSR_Success)
+    /* This is expected to happen only if the old address is wrong */
+    LOG(LOGS_ERR, "Could not change %s to %s",
+        UTI_IPSockAddrToString(&saved_address_update.old_address),
+        UTI_IPSockAddrToString(&saved_address_update.new_address));
+
+  saved_address_update.old_address.ip_addr.family = IPADDR_UNSPEC;
+}
+
+/* ================================================== */
+
 static int
 replace_source_connectable(NTP_Remote_Address *old_addr, NTP_Remote_Address *new_addr)
 {
@@ -422,6 +476,8 @@ replace_source_connectable(NTP_Remote_Address *old_addr, NTP_Remote_Address *new
   if (change_source_address(old_addr, new_addr, 1) == NSR_AlreadyInUse)
     return 0;
 
+  handle_saved_address_update();
+
   return 1;
 }
 
@@ -444,8 +500,8 @@ process_resolved_name(struct UnresolvedSource *us, IPAddr *ip_addrs, int n_addrs
     DEBUG_LOG("(%d) %s", i + 1, UTI_IPToString(&new_addr.ip_addr));
 
     if (us->pool_id != INVALID_POOL) {
-      /* In the pool resolving mode, try to replace all sources from
+      /* In the pool resolving mode, try to replace a source from
-         the pool which don't have a real address yet */
+         the pool which does not have a real address yet */
       for (j = 0; j < ARR_GetSize(records); j++) {
         record = get_record(j);
         if (!record->remote_addr || record->pool_id != us->pool_id ||
@@ -454,7 +510,8 @@ process_resolved_name(struct UnresolvedSource *us, IPAddr *ip_addrs, int n_addrs
         old_addr = *record->remote_addr;
         new_addr.port = old_addr.port;
         if (replace_source_connectable(&old_addr, &new_addr))
-          break;
+          ;
+        break;
       }
     } else {
       new_addr.port = us->address.port;
@@ -523,6 +580,13 @@ name_resolve_handler(DNS_Status status, int n_addrs, IPAddr *ip_addrs, void *any
   if (status == DNS_Failure || UTI_IsIPReal(&us->address.ip_addr) || is_resolved(us))
     remove_unresolved_source(us);
 
+  /* If a restart was requested and this was the last source in the list,
+     start with the first source again (if there still is one) */
+  if (!next && resolving_restart) {
+    next = unresolved_sources;
+    resolving_restart = 0;
+  }
+
   resolving_source = next;
 
   if (next) {
@@ -662,8 +726,7 @@ NSR_AddSourceByName(char *name, int port, int pool, NTP_Source_Type type,
   NTP_Remote_Address remote_addr;
   int i, new_sources, pool_id;
 
-  /* If the name is an IP address, don't bother with full resolving now
+  /* If the name is an IP address, add the source with the address directly */
-     or later when trying to replace the source */
   if (UTI_StringToIP(name, &remote_addr.ip_addr)) {
     remote_addr.port = port;
     return NSR_AddSource(&remote_addr, type, params, conf_id);
@@ -671,7 +734,7 @@ NSR_AddSourceByName(char *name, int port, int pool, NTP_Source_Type type,
 
   /* Make sure the name is at least printable and has no spaces */
   for (i = 0; name[i] != '\0'; i++) {
-    if (!isgraph(name[i]))
+    if (!isgraph((unsigned char)name[i]))
       return NSR_InvalidName;
   }
 
@@ -736,7 +799,7 @@ NSR_ResolveSources(void)
 {
   /* Try to resolve unresolved sources now */
   if (unresolved_sources) {
-    /* Make sure no resolving is currently running */
+    /* Allow only one resolving to be running at a time */
     if (!resolving_source) {
       if (resolving_id != 0) {
         SCH_RemoveTimeout(resolving_id);
@@ -744,6 +807,9 @@ NSR_ResolveSources(void)
         resolving_interval--;
       }
       resolve_sources();
+    } else {
+      /* Try again as soon as the current resolving ends */
+      resolving_restart = 1;
     }
   } else {
     /* No unresolved sources, we are done */
@@ -795,8 +861,7 @@ clean_source_record(SourceRecord *record)
 
   record->remote_addr = NULL;
   NCR_DestroyInstance(record->data);
-  if (record->name)
+  Free(record->name);
-    Free(record->name);
 
   n_sources--;
 }
@@ -869,7 +934,8 @@ resolve_source_replacement(SourceRecord *record)
 {
   struct UnresolvedSource *us;
 
-  DEBUG_LOG("trying to replace %s", UTI_IPToString(&record->remote_addr->ip_addr));
+  DEBUG_LOG("trying to replace %s (%s)",
+            UTI_IPToString(&record->remote_addr->ip_addr), record->name);
 
   us = MallocNew(struct UnresolvedSource);
   us->name = Strdup(record->name);
@@ -893,6 +959,7 @@ NSR_HandleBadSource(IPAddr *address)
   static struct timespec last_replacement;
   struct timespec now;
   SourceRecord *record;
+  IPAddr ip_addr;
   double diff;
   int slot;
 
@@ -901,8 +968,10 @@ NSR_HandleBadSource(IPAddr *address)
 
   record = get_record(slot);
 
-  /* Only sources with a name can be replaced */
+  /* Don't try to replace a source specified by an IP address unless the
-  if (!record->name)
+     address changed since the source was added (e.g. by NTS-KE) */
+  if (UTI_StringToIP(record->name, &ip_addr) &&
+      UTI_CompareIPs(&record->remote_addr->ip_addr, &ip_addr, NULL) == 0)
     return;
 
   /* Don't resolve names too frequently */
@@ -927,7 +996,7 @@ NSR_RefreshAddresses(void)
 
   for (i = 0; i < ARR_GetSize(records); i++) {
     record = get_record(i);
-    if (!record->remote_addr || !record->name)
+    if (!record->remote_addr)
       continue;
 
     resolve_source_replacement(record);
@@ -939,10 +1008,28 @@ NSR_RefreshAddresses(void)
 NSR_Status
 NSR_UpdateSourceNtpAddress(NTP_Remote_Address *old_addr, NTP_Remote_Address *new_addr)
 {
-  if (new_addr->ip_addr.family == IPADDR_UNSPEC)
+  int slot;
+
+  if (!UTI_IsIPReal(&old_addr->ip_addr) || !UTI_IsIPReal(&new_addr->ip_addr))
     return NSR_InvalidAF;
 
-  return change_source_address(old_addr, new_addr, 0);
+  if (UTI_CompareIPs(&old_addr->ip_addr, &new_addr->ip_addr, NULL) != 0 &&
+      find_slot(&new_addr->ip_addr, &slot))
+    return NSR_AlreadyInUse;
+
+  /* If a record is being modified (e.g. by change_source_address(), or the
+     source is just being created), postpone the change to avoid corruption */
+
+  if (!record_lock)
+    return change_source_address(old_addr, new_addr, 0);
+
+  if (UTI_IsIPReal(&saved_address_update.old_address.ip_addr))
+    return NSR_TooManySources;
+
+  saved_address_update.old_address = *old_addr;
+  saved_address_update.new_address = *new_addr;
+
+  return NSR_Success;
 }
 
 /* ================================================== */
@@ -991,17 +1078,12 @@ NSR_GetLocalRefid(IPAddr *address)
 char *
 NSR_GetName(IPAddr *address)
 {
-  SourceRecord *record;
   int slot;
 
   if (!find_slot(address, &slot))
-    return 0;
+    return NULL;
 
-  record = get_record(slot);
+  return get_record(slot)->name;
-  if (record->name)
-    return record->name;
-
-  return UTI_IPToString(&record->remote_addr->ip_addr); 
 }
 
 /* ================================================== */

ntp_sources.h

@@ -91,15 +91,16 @@ extern void NSR_HandleBadSource(IPAddr *address);
 /* Procedure to resolve all names again */
 extern void NSR_RefreshAddresses(void);
 
-/* Procedure to update the address of a source */
+/* Procedure to update the address of a source.  The update may be
+   postponed. */
 extern NSR_Status NSR_UpdateSourceNtpAddress(NTP_Remote_Address *old_addr,
                                              NTP_Remote_Address *new_addr);
 
 /* Procedure to get local reference ID corresponding to a source */
 extern uint32_t NSR_GetLocalRefid(IPAddr *address);
 
-/* Procedure to get the name of a source.  If the source doesn't have a name,
+/* Procedure to get the name of a source as it was specified (it may be
-   it returns a temporary string containing formatted address. */
+   an IP address) */
 extern char *NSR_GetName(IPAddr *address);
 
 /* This routine is called by ntp_io when a new packet arrives off the network */

nts_ke_client.c

@@ -2,7 +2,7 @@
   chronyd/chronyc - Programs for keeping computer clocks accurate.
 
  **********************************************************************
- * Copyright (C) Miroslav Lichvar  2020
+ * Copyright (C) Miroslav Lichvar  2020-2021
  * 
  * 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
@@ -44,6 +44,7 @@
 struct NKC_Instance_Record {
   char *name;
   IPSockAddr address;
+  NKSN_Credentials credentials;
   NKSN_Instance session;
   int destroying;
   int got_response;
@@ -52,14 +53,14 @@ struct NKC_Instance_Record {
   NKE_Context context;
   NKE_Cookie cookies[NKE_MAX_COOKIES];
   int num_cookies;
-  char server_name[NKE_MAX_RECORD_BODY_LENGTH + 1];
+  char server_name[NKE_MAX_RECORD_BODY_LENGTH + 2];
   IPSockAddr ntp_address;
 };
 
 /* ================================================== */
 
-static void *client_credentials = NULL;
+static NKSN_Credentials default_credentials = NULL;
-static int client_credentials_refs = 0;
+static int default_credentials_refs = 0;
 
 /* ================================================== */
 
@@ -126,9 +127,10 @@ process_response(NKC_Instance inst)
 {
   int next_protocol = -1, aead_algorithm = -1, error = 0;
   int i, critical, type, length;
-  uint16_t data[NKE_MAX_COOKIE_LENGTH / sizeof (uint16_t)];
+  uint16_t data[NKE_MAX_RECORD_BODY_LENGTH / sizeof (uint16_t)];
 
-  assert(NKE_MAX_COOKIE_LENGTH % sizeof (uint16_t) == 0);
+  assert(NKE_MAX_COOKIE_LENGTH <= NKE_MAX_RECORD_BODY_LENGTH);
+  assert(sizeof (data) % sizeof (uint16_t) == 0);
   assert(sizeof (uint16_t) == 2);
 
   inst->num_cookies = 0;
@@ -140,6 +142,13 @@ process_response(NKC_Instance inst)
     if (!NKSN_GetRecord(inst->session, &critical, &type, &length, &data, sizeof (data)))
       break;
 
+    if (length > sizeof (data)) {
+      DEBUG_LOG("Record too long type=%d length=%d critical=%d", type, length, critical);
+      if (critical)
+        error = 1;
+      continue;
+    }
+
     switch (type) {
       case NKE_RECORD_NEXT_PROTOCOL:
         if (!critical || length != 2 || ntohs(data[0]) != NKE_NEXT_PROTOCOL_NTPV4) {
@@ -196,7 +205,7 @@ process_response(NKC_Instance inst)
         inst->server_name[length] = '\0';
 
         /* Make sure the name is printable and has no spaces */
-        for (i = 0; i < length && isgraph(inst->server_name[i]); i++)
+        for (i = 0; i < length && isgraph((unsigned char)inst->server_name[i]); i++)
           ;
         if (i != length) {
           DEBUG_LOG("Invalid server name");
@@ -253,6 +262,17 @@ handle_message(void *arg)
     if (inst->resolving_name)
       return 0;
     if (!UTI_StringToIP(inst->server_name, &inst->ntp_address.ip_addr)) {
+      int length = strlen(inst->server_name);
+
+      /* Add a trailing dot if not present to force the name to be
+         resolved as a fully qualified domain name */
+      if (length < 1 || length + 1 >= sizeof (inst->server_name))
+        return 0;
+      if (inst->server_name[length - 1] != '.') {
+        inst->server_name[length] = '.';
+        inst->server_name[length + 1] = '\0';
+      }
+
       DNS_Name2IPAddressAsync(inst->server_name, name_resolve_handler, inst);
       inst->resolving_name = 1;
     }
@@ -266,9 +286,12 @@ handle_message(void *arg)
 /* ================================================== */
 
 NKC_Instance
-NKC_CreateInstance(IPSockAddr *address, const char *name)
+NKC_CreateInstance(IPSockAddr *address, const char *name, uint32_t cert_set)
 {
+  const char **trusted_certs;
+  uint32_t *certs_ids;
   NKC_Instance inst;
+  int n_certs;
 
   inst = MallocNew(struct NKC_Instance_Record);
 
@@ -279,10 +302,21 @@ NKC_CreateInstance(IPSockAddr *address, const char *name)
   inst->destroying = 0;
   inst->got_response = 0;
 
-  /* Share the credentials with other client instances */
+  n_certs = CNF_GetNtsTrustedCertsPaths(&trusted_certs, &certs_ids);
-  if (!client_credentials)
+
-    client_credentials = NKSN_CreateCertCredentials(NULL, NULL, CNF_GetNtsTrustedCertFile());
+  /* Share the credentials among clients using the default set of trusted
-  client_credentials_refs++;
+     certificates, which likely contains most certificates */
+  if (cert_set == 0) {
+    if (!default_credentials)
+      default_credentials = NKSN_CreateClientCertCredentials(trusted_certs, certs_ids,
+                                                             n_certs, cert_set);
+    inst->credentials = default_credentials;
+    if (default_credentials)
+      default_credentials_refs++;
+  } else {
+    inst->credentials = NKSN_CreateClientCertCredentials(trusted_certs, certs_ids,
+                                                         n_certs, cert_set);
+  }
 
   return inst;
 }
@@ -296,10 +330,16 @@ NKC_DestroyInstance(NKC_Instance inst)
 
   Free(inst->name);
 
-  client_credentials_refs--;
+  if (inst->credentials) {
-  if (client_credentials_refs <= 0 && client_credentials) {
+    if (inst->credentials == default_credentials) {
-    NKSN_DestroyCertCredentials(client_credentials);
+      default_credentials_refs--;
-    client_credentials = NULL;
+      if (default_credentials_refs <= 0) {
+        NKSN_DestroyCertCredentials(default_credentials);
+        default_credentials = NULL;
+      }
+    } else {
+      NKSN_DestroyCertCredentials(inst->credentials);
+    }
   }
 
   /* If the asynchronous resolver is running, let the handler free
@@ -325,7 +365,7 @@ NKC_Start(NKC_Instance inst)
 
   inst->got_response = 0;
 
-  if (!client_credentials) {
+  if (!inst->credentials) {
     DEBUG_LOG("Missing client credentials");
     return 0;
   }
@@ -335,17 +375,19 @@ NKC_Start(NKC_Instance inst)
   local_addr.port = 0;
   iface = CNF_GetBindAcquisitionInterface();
 
-  sock_fd = SCK_OpenTcpSocket(&inst->address, &local_addr, iface, 0);
-  if (sock_fd < 0)
-    return 0;
-
   /* Make a label containing both the address and name of the server */
   if (snprintf(label, sizeof (label), "%s (%s)",
                UTI_IPSockAddrToString(&inst->address), inst->name) >= sizeof (label))
     ;
 
+  sock_fd = SCK_OpenTcpSocket(&inst->address, &local_addr, iface, 0);
+  if (sock_fd < 0) {
+    LOG(LOGS_ERR, "Could not connect to %s", label);
+    return 0;
+  }
+
   /* Start an NTS-KE session */
-  if (!NKSN_StartSession(inst->session, sock_fd, label, client_credentials, CLIENT_TIMEOUT)) {
+  if (!NKSN_StartSession(inst->session, sock_fd, label, inst->credentials, CLIENT_TIMEOUT)) {
     SCK_CloseSocket(sock_fd);
     return 0;
   }

nts_ke_client.h

@@ -33,7 +33,7 @@
 typedef struct NKC_Instance_Record *NKC_Instance;
 
 /* Create a client NTS-KE instance */
-extern NKC_Instance NKC_CreateInstance(IPSockAddr *address, const char *name);
+extern NKC_Instance NKC_CreateInstance(IPSockAddr *address, const char *name, uint32_t cert_set);
 
 /* Destroy an instance */
 extern void NKC_DestroyInstance(NKC_Instance inst);

nts_ke_server.c

@@ -95,7 +95,7 @@ static int initialised = 0;
 
 /* Array of NKSN instances */
 static ARR_Instance sessions;
-static void *server_credentials;
+static NKSN_Credentials server_credentials;
 
 /* ================================================== */
 
@@ -556,7 +556,7 @@ error:
 
 #define MAX_WORDS 2
 
-static void
+static int
 load_keys(void)
 {
   char *dump_dir, line[1024], *words[MAX_WORDS];
@@ -568,11 +568,11 @@ load_keys(void)
 
   dump_dir = CNF_GetNtsDumpDir();
   if (!dump_dir)
-    return;
+    return 0;
 
   f = UTI_OpenFile(dump_dir, DUMP_FILENAME, NULL, 'r', 0);
   if (!f)
-    return;
+    return 0;
 
   if (!fgets(line, sizeof (line), f) || strcmp(line, DUMP_IDENTIFIER) != 0 ||
       !fgets(line, sizeof (line), f) || UTI_SplitString(line, words, MAX_WORDS) != 2 ||
@@ -607,11 +607,13 @@ load_keys(void)
 
   fclose(f);
 
-  return;
+  return 1;
 
 error:
   DEBUG_LOG("Could not %s server keys", "load");
   fclose(f);
+
+  return 0;
 }
 
 /* ================================================== */
@@ -646,7 +648,7 @@ run_helper(uid_t uid, gid_t gid, int scfilter_level)
   LOG_SetMinSeverity(log_severity);
 
   if (!geteuid() && (uid || gid))
-    SYS_DropRoot(uid, gid);
+    SYS_DropRoot(uid, gid, SYS_NTSKE_HELPER);
 
   NKS_Initialise();
 
@@ -676,13 +678,14 @@ void
 NKS_PreInitialise(uid_t uid, gid_t gid, int scfilter_level)
 {
   int i, processes, sock_fd1, sock_fd2;
+  const char **certs, **keys;
   char prefix[16];
   pid_t pid;
 
   helper_sock_fd = INVALID_SOCK_FD;
   is_helper = 0;
 
-  if (!CNF_GetNtsServerCertFile() || !CNF_GetNtsServerKeyFile())
+  if (CNF_GetNtsServerCertAndKeyFiles(&certs, &keys) <= 0)
     return;
 
   processes = CNF_GetNtsServerProcesses();
@@ -726,21 +729,19 @@ NKS_PreInitialise(uid_t uid, gid_t gid, int scfilter_level)
 void
 NKS_Initialise(void)
 {
-  char *cert, *key;
+  const char **certs, **keys;
+  int i, n_certs_keys;
   double key_delay;
-  int i;
 
   server_sock_fd4 = INVALID_SOCK_FD;
   server_sock_fd6 = INVALID_SOCK_FD;
 
-  cert = CNF_GetNtsServerCertFile();
+  n_certs_keys = CNF_GetNtsServerCertAndKeyFiles(&certs, &keys);
-  key = CNF_GetNtsServerKeyFile();
+  if (n_certs_keys <= 0)
-
-  if (!cert || !key)
     return;
 
   if (helper_sock_fd == INVALID_SOCK_FD) {
-    server_credentials = NKSN_CreateCertCredentials(cert, key, NULL);
+    server_credentials = NKSN_CreateServerCertCredentials(certs, keys, n_certs_keys);
     if (!server_credentials)
       return;
   } else {
@@ -764,10 +765,12 @@ NKS_Initialise(void)
     server_sock_fd4 = open_socket(IPADDR_INET4);
     server_sock_fd6 = open_socket(IPADDR_INET6);
 
-    load_keys();
-
     key_rotation_interval = MAX(CNF_GetNtsRotate(), 0);
 
+    /* Reload saved keys, or save the new keys */
+    if (!load_keys())
+      save_keys();
+
     if (key_rotation_interval > 0) {
       key_delay = key_rotation_interval - (SCH_GetLastEventMonoTime() - last_server_key_ts);
       SCH_AddTimeoutByDelay(MAX(key_delay, 0.0), key_timeout, NULL);

nts_ke_session.c

@@ -2,7 +2,7 @@
   chronyd/chronyc - Programs for keeping computer clocks accurate.
 
  **********************************************************************
- * Copyright (C) Miroslav Lichvar  2020
+ * Copyright (C) Miroslav Lichvar  2020-2021
  * 
  * 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
@@ -225,9 +225,13 @@ create_tls_session(int server_mode, int sock_fd, const char *server_name,
   }
 
   if (!server_mode) {
-    r = gnutls_server_name_set(session, GNUTLS_NAME_DNS, server_name, strlen(server_name));
+    assert(server_name);
-    if (r < 0)
+
-      goto error;
+    if (!UTI_IsStringIP(server_name)) {
+      r = gnutls_server_name_set(session, GNUTLS_NAME_DNS, server_name, strlen(server_name));
+      if (r < 0)
+        goto error;
+    }
 
     flags = 0;
 
@@ -637,11 +641,13 @@ deinit_gnutls(void)
 
 /* ================================================== */
 
-void *
+static NKSN_Credentials
-NKSN_CreateCertCredentials(char *cert, char *key, char *trusted_certs)
+create_credentials(const char **certs, const char **keys, int n_certs_keys,
+                   const char **trusted_certs, uint32_t *trusted_certs_ids,
+                   int n_trusted_certs, uint32_t trusted_cert_set)
 {
   gnutls_certificate_credentials_t credentials = NULL;
-  int r;
+  int i, r;
 
   init_gnutls();
 
@@ -649,29 +655,50 @@ NKSN_CreateCertCredentials(char *cert, char *key, char *trusted_certs)
   if (r < 0)
     goto error;
 
-  if (cert && key) {
+  if (certs && keys) {
-    r = gnutls_certificate_set_x509_key_file(credentials, cert, key,
+    if (trusted_certs || trusted_certs_ids)
-                                             GNUTLS_X509_FMT_PEM);
+      assert(0);
-    if (r < 0)
+
-      goto error;
+    for (i = 0; i < n_certs_keys; i++) {
+      r = gnutls_certificate_set_x509_key_file(credentials, certs[i], keys[i],
+                                               GNUTLS_X509_FMT_PEM);
+      if (r < 0)
+        goto error;
+    }
   } else {
-    if (!CNF_GetNoSystemCert()) {
+    if (certs || keys || n_certs_keys > 0)
+      assert(0);
+
+    if (trusted_cert_set == 0 && !CNF_GetNoSystemCert()) {
       r = gnutls_certificate_set_x509_system_trust(credentials);
       if (r < 0)
         goto error;
     }
 
-    if (trusted_certs) {
+    if (trusted_certs && trusted_certs_ids) {
-      r = gnutls_certificate_set_x509_trust_file(credentials, trusted_certs,
+      for (i = 0; i < n_trusted_certs; i++) {
-                                                 GNUTLS_X509_FMT_PEM);
+        struct stat buf;
-      if (r < 0)
+
-        goto error;
+        if (trusted_certs_ids[i] != trusted_cert_set)
+          continue;
+
+        if (stat(trusted_certs[i], &buf) == 0 && S_ISDIR(buf.st_mode))
+          r = gnutls_certificate_set_x509_trust_dir(credentials, trusted_certs[i],
+                                                    GNUTLS_X509_FMT_PEM);
+        else
+          r = gnutls_certificate_set_x509_trust_file(credentials, trusted_certs[i],
+                                                     GNUTLS_X509_FMT_PEM);
+        if (r < 0)
+          goto error;
+
+        DEBUG_LOG("Added %d trusted certs from %s", r, trusted_certs[i]);
+      }
     }
   }
 
   credentials_counter++;
 
-  return credentials;
+  return (NKSN_Credentials)credentials;
 
 error:
   LOG(LOGS_ERR, "Could not set credentials : %s", gnutls_strerror(r));
@@ -683,10 +710,27 @@ error:
 
 /* ================================================== */
 
-void
+NKSN_Credentials
-NKSN_DestroyCertCredentials(void *credentials)
+NKSN_CreateServerCertCredentials(const char **certs, const char **keys, int n_certs_keys)
 {
-  gnutls_certificate_free_credentials(credentials);
+  return create_credentials(certs, keys, n_certs_keys, NULL, NULL, 0, 0);
+}
+
+/* ================================================== */
+
+NKSN_Credentials
+NKSN_CreateClientCertCredentials(const char **certs, uint32_t *ids,
+                                 int n_certs_ids, uint32_t trusted_cert_set)
+{
+  return create_credentials(NULL, NULL, 0, certs, ids, n_certs_ids, trusted_cert_set);
+}
+
+/* ================================================== */
+
+void
+NKSN_DestroyCertCredentials(NKSN_Credentials credentials)
+{
+  gnutls_certificate_free_credentials((gnutls_certificate_credentials_t)credentials);
   credentials_counter--;
   deinit_gnutls();
 }
@@ -734,12 +778,13 @@ NKSN_DestroyInstance(NKSN_Instance inst)
 
 int
 NKSN_StartSession(NKSN_Instance inst, int sock_fd, const char *label,
-                  void *credentials, double timeout)
+                  NKSN_Credentials credentials, double timeout)
 {
   assert(inst->state == KE_STOPPED);
 
   inst->tls_session = create_tls_session(inst->server, sock_fd, inst->server_name,
-                                         credentials, priority_cache);
+                                         (gnutls_certificate_credentials_t)credentials,
+                                         priority_cache);
   if (!inst->tls_session)
     return 0;
 
@@ -825,21 +870,27 @@ NKSN_GetRecord(NKSN_Instance inst, int *critical, int *type, int *body_length,
 int
 NKSN_GetKeys(NKSN_Instance inst, SIV_Algorithm siv, NKE_Key *c2s, NKE_Key *s2c)
 {
-  c2s->length = SIV_GetKeyLength(siv);
+  int length = SIV_GetKeyLength(siv);
-  s2c->length = SIV_GetKeyLength(siv);
+
-  assert(c2s->length <= sizeof (c2s->key));
+  if (length <= 0 || length > sizeof (c2s->key) || length > sizeof (s2c->key)) {
-  assert(s2c->length <= sizeof (s2c->key));
+    DEBUG_LOG("Invalid algorithm");
+    return 0;
+  }
 
   if (gnutls_prf_rfc5705(inst->tls_session,
                          sizeof (NKE_EXPORTER_LABEL) - 1, NKE_EXPORTER_LABEL,
                          sizeof (NKE_EXPORTER_CONTEXT_C2S) - 1, NKE_EXPORTER_CONTEXT_C2S,
-                         c2s->length, (char *)c2s->key) < 0)
+                         length, (char *)c2s->key) < 0 ||
-    return 0;
+      gnutls_prf_rfc5705(inst->tls_session,
-  if (gnutls_prf_rfc5705(inst->tls_session,
                          sizeof (NKE_EXPORTER_LABEL) - 1, NKE_EXPORTER_LABEL,
                          sizeof (NKE_EXPORTER_CONTEXT_S2C) - 1, NKE_EXPORTER_CONTEXT_S2C,
-                         s2c->length, (char *)s2c->key) < 0)
+                         length, (char *)s2c->key) < 0) {
+    DEBUG_LOG("Could not export key");
     return 0;
+  }
+
+  c2s->length = length;
+  s2c->length = length;
 
   return 1;
 }

nts_ke_session.h

@@ -30,19 +30,25 @@
 #include "nts_ke.h"
 #include "siv.h"
 
+typedef struct NKSN_Credentials_Record *NKSN_Credentials;
+
 typedef struct NKSN_Instance_Record *NKSN_Instance;
 
 /* Handler for received NTS-KE messages.  A zero return code stops
    the session. */
 typedef int (*NKSN_MessageHandler)(void *arg);
 
-/* Get client or server credentials using certificates of trusted CAs,
+/* Get server or client credentials using a server certificate and key,
-   or a server certificate and key.  The credentials may be shared between
+   or certificates of trusted CAs.  The credentials may be shared between
    different clients or servers. */
-extern void *NKSN_CreateCertCredentials(char *cert, char *key, char *trusted_certs);
+extern NKSN_Credentials NKSN_CreateServerCertCredentials(const char **certs, const char **keys,
+                                                         int n_certs_keys);
+extern NKSN_Credentials NKSN_CreateClientCertCredentials(const char **certs, uint32_t *ids,
+                                                         int n_certs_ids,
+                                                         uint32_t trusted_cert_set);
 
 /* Destroy the credentials */
-extern void NKSN_DestroyCertCredentials(void *credentials);
+extern void NKSN_DestroyCertCredentials(NKSN_Credentials credentials);
 
 /* Create an instance */
 extern NKSN_Instance NKSN_CreateInstance(int server_mode, const char *server_name,
@@ -53,7 +59,7 @@ extern void NKSN_DestroyInstance(NKSN_Instance inst);
 
 /* Start a new NTS-KE session */
 extern int NKSN_StartSession(NKSN_Instance inst, int sock_fd, const char *label,
-                             void *credentials, double timeout);
+                             NKSN_Credentials credentials, double timeout);
 
 /* Begin an NTS-KE message.  A request should be made right after starting
    the session and response should be made in the message handler. */

nts_ntp_auth.c

@@ -112,6 +112,7 @@ NNA_GenerateAuthEF(NTP_Packet *packet, NTP_PacketInfo *info, SIV_Instance siv,
   if (!SIV_Encrypt(siv, nonce, nonce_length, packet, assoc_length,
                    plaintext, plaintext_length, ciphertext, ciphertext_length)) {
     DEBUG_LOG("SIV encrypt failed");
+    info->length = assoc_length;
     return 0;
   }
 

nts_ntp_client.c

@@ -50,13 +50,20 @@
 #define DUMP_IDENTIFIER "NNC0\n"
 
 struct NNC_Instance_Record {
-  const IPSockAddr *ntp_address;
+  /* Address of NTS-KE server */
   IPSockAddr nts_address;
+  /* Hostname or IP address for certificate verification */
   char *name;
+  /* ID of trusted certificates */
+  uint32_t cert_set;
+  /* Configured NTP port */
+  uint16_t default_ntp_port;
+  /* Address of NTP server (can be negotiated in NTS-KE) */
+  IPSockAddr ntp_address;
+
   NKC_Instance nke;
   SIV_Instance siv;
 
-  int load_attempt;
   int nke_attempts;
   double next_nke_attempt;
   double last_nke_success;
@@ -66,6 +73,7 @@ struct NNC_Instance_Record {
   NKE_Cookie cookies[NTS_MAX_COOKIES];
   int num_cookies;
   int cookie_index;
+  int auth_ready;
   int nak_response;
   int ok_response;
   unsigned char nonce[NTS_MIN_UNPADDED_NONCE_LENGTH];
@@ -82,7 +90,13 @@ static void load_cookies(NNC_Instance inst);
 static void
 reset_instance(NNC_Instance inst)
 {
-  inst->load_attempt = 0;
+  if (inst->nke)
+    NKC_DestroyInstance(inst->nke);
+  inst->nke = NULL;
+  if (inst->siv)
+    SIV_DestroyInstance(inst->siv);
+  inst->siv = NULL;
+
   inst->nke_attempts = 0;
   inst->next_nke_attempt = 0.0;
   inst->last_nke_success = 0.0;
@@ -92,6 +106,7 @@ reset_instance(NNC_Instance inst)
   memset(inst->cookies, 0, sizeof (inst->cookies));
   inst->num_cookies = 0;
   inst->cookie_index = 0;
+  inst->auth_ready = 0;
   inst->nak_response = 0;
   inst->ok_response = 1;
   memset(inst->nonce, 0, sizeof (inst->nonce));
@@ -101,20 +116,26 @@ reset_instance(NNC_Instance inst)
 /* ================================================== */
 
 NNC_Instance
-NNC_CreateInstance(IPSockAddr *nts_address, const char *name, const IPSockAddr *ntp_address)
+NNC_CreateInstance(IPSockAddr *nts_address, const char *name, uint32_t cert_set, uint16_t ntp_port)
 {
   NNC_Instance inst;
 
   inst = MallocNew(struct NNC_Instance_Record);
 
-  inst->ntp_address = ntp_address;
   inst->nts_address = *nts_address;
-  inst->name = name ? Strdup(name) : NULL;
+  inst->name = Strdup(name);
+  inst->cert_set = cert_set;
+  inst->default_ntp_port = ntp_port;
+  inst->ntp_address.ip_addr = nts_address->ip_addr;
+  inst->ntp_address.port = ntp_port;
   inst->siv = NULL;
   inst->nke = NULL;
 
   reset_instance(inst);
 
+  /* Try to reload saved keys and cookies */
+  load_cookies(inst);
+
   return inst;
 }
 
@@ -125,10 +146,7 @@ NNC_DestroyInstance(NNC_Instance inst)
 {
   save_cookies(inst);
 
-  if (inst->nke)
+  reset_instance(inst);
-    NKC_DestroyInstance(inst->nke);
-  if (inst->siv)
-    SIV_DestroyInstance(inst->siv);
 
   Free(inst->name);
   Free(inst);
@@ -158,13 +176,13 @@ set_ntp_address(NNC_Instance inst, NTP_Remote_Address *negotiated_address)
 {
   NTP_Remote_Address old_address, new_address;
 
-  old_address = *inst->ntp_address;
+  old_address = inst->ntp_address;
   new_address = *negotiated_address;
 
   if (new_address.ip_addr.family == IPADDR_UNSPEC)
-    new_address.ip_addr = old_address.ip_addr;
+    new_address.ip_addr = inst->nts_address.ip_addr;
   if (new_address.port == 0)
-    new_address.port = old_address.port;
+    new_address.port = inst->default_ntp_port;
 
   if (UTI_CompareIPs(&old_address.ip_addr, &new_address.ip_addr, NULL) == 0 &&
       old_address.port == new_address.port)
@@ -177,6 +195,8 @@ set_ntp_address(NNC_Instance inst, NTP_Remote_Address *negotiated_address)
     return 0;
   }
 
+  inst->ntp_address = new_address;
+
   return 1;
 }
 
@@ -216,13 +236,7 @@ get_cookies(NNC_Instance inst)
       return 0;
     }
 
-    if (!inst->name) {
+    inst->nke = NKC_CreateInstance(&inst->nts_address, inst->name, inst->cert_set);
-      LOG(LOGS_ERR, "Missing name of %s for NTS-KE",
-          UTI_IPToString(&inst->nts_address.ip_addr));
-      return 0;
-    }
-
-    inst->nke = NKC_CreateInstance(&inst->nts_address, inst->name);
 
     inst->nke_attempts++;
     update_next_nke_attempt(inst, now);
@@ -266,8 +280,6 @@ get_cookies(NNC_Instance inst)
   inst->last_nke_success = now;
   inst->cookie_index = 0;
 
-  inst->nak_response = 0;
-
   return 1;
 }
 
@@ -276,11 +288,12 @@ get_cookies(NNC_Instance inst)
 int
 NNC_PrepareForAuth(NNC_Instance inst)
 {
-  /* Try to reload saved keys and cookies (once for the NTS-KE address) */
+  inst->auth_ready = 0;
-  if (!inst->load_attempt) {
+
-    load_cookies(inst);
+  /* Prepare data for the next request and invalidate any responses to the
-    inst->load_attempt = 1;
+     previous request */
-  }
+  UTI_GetRandomBytes(inst->uniq_id, sizeof (inst->uniq_id));
+  UTI_GetRandomBytes(inst->nonce, sizeof (inst->nonce));
 
   /* Get new cookies if there are not any, or they are no longer usable */
   if (!check_cookies(inst)) {
@@ -288,6 +301,8 @@ NNC_PrepareForAuth(NNC_Instance inst)
       return 0;
   }
 
+  inst->nak_response = 0;
+
   if (!inst->siv)
     inst->siv = SIV_CreateInstance(inst->context.algorithm);
 
@@ -297,9 +312,7 @@ NNC_PrepareForAuth(NNC_Instance inst)
     return 0;
   }
 
-  /* Prepare data for NNC_GenerateRequestAuth() */
+  inst->auth_ready = 1;
-  UTI_GetRandomBytes(inst->uniq_id, sizeof (inst->uniq_id));
-  UTI_GetRandomBytes(inst->nonce, sizeof (inst->nonce));
 
   return 1;
 }
@@ -314,14 +327,22 @@ NNC_GenerateRequestAuth(NNC_Instance inst, NTP_Packet *packet,
   int i, req_cookies;
   void *ef_body;
 
-  if (inst->num_cookies == 0 || !inst->siv)
+  if (!inst->auth_ready)
+    return 0;
+
+  inst->auth_ready = 0;
+
+  if (inst->num_cookies <= 0 || !inst->siv)
     return 0;
 
   if (info->mode != MODE_CLIENT)
     return 0;
 
   cookie = &inst->cookies[inst->cookie_index];
-  req_cookies = MIN(NTS_MAX_COOKIES - inst->num_cookies + 1,
+  inst->num_cookies--;
+  inst->cookie_index = (inst->cookie_index + 1) % NTS_MAX_COOKIES;
+
+  req_cookies = MIN(NTS_MAX_COOKIES - inst->num_cookies,
                     MAX_TOTAL_COOKIE_LENGTH / (cookie->length + 4));
 
   if (!NEF_AddField(packet, info, NTP_EF_NTS_UNIQUE_IDENTIFIER,
@@ -343,9 +364,6 @@ NNC_GenerateRequestAuth(NNC_Instance inst, NTP_Packet *packet,
                           (const unsigned char *)"", 0, NTP_MAX_V4_MAC_LENGTH + 4))
     return 0;
 
-  inst->num_cookies--;
-  inst->cookie_index = (inst->cookie_index + 1) % NTS_MAX_COOKIES;
-  inst->nak_response = 0;
   inst->ok_response = 0;
 
   return 1;
@@ -427,7 +445,7 @@ NNC_CheckResponseAuth(NNC_Instance inst, NTP_Packet *packet,
     return 0;
 
   /* Accept at most one response per request */
-  if (inst->ok_response)
+  if (inst->ok_response || inst->auth_ready)
     return 0;
 
   if (!inst->siv ||
@@ -506,16 +524,14 @@ NNC_ChangeAddress(NNC_Instance inst, IPAddr *address)
 {
   save_cookies(inst);
 
-  if (inst->nke)
-    NKC_DestroyInstance(inst->nke);
-
-  inst->nke = NULL;
-  inst->num_cookies = 0;
   inst->nts_address.ip_addr = *address;
+  inst->ntp_address.ip_addr = *address;
 
   reset_instance(inst);
 
   DEBUG_LOG("NTS reset");
+
+  load_cookies(inst);
 }
 
 /* ================================================== */
@@ -546,9 +562,10 @@ save_cookies(NNC_Instance inst)
   context_time = inst->last_nke_success - SCH_GetLastEventMonoTime();
   context_time += UTI_TimespecToDouble(&now);
 
-  if (fprintf(f, "%s%.1f\n%s %d\n%u %d ",
+  if (fprintf(f, "%s%s\n%.1f\n%s %d\n%u %d ",
-              DUMP_IDENTIFIER, context_time, UTI_IPToString(&inst->ntp_address->ip_addr),
+              DUMP_IDENTIFIER, inst->name, context_time,
-              inst->ntp_address->port, inst->context_id, (int)inst->context.algorithm) < 0 ||
+              UTI_IPToString(&inst->ntp_address.ip_addr), inst->ntp_address.port,
+              inst->context_id, (int)inst->context.algorithm) < 0 ||
       !UTI_BytesToHex(inst->context.s2c.key, inst->context.s2c.length, buf, sizeof (buf)) ||
       fprintf(f, "%s ", buf) < 0 ||
       !UTI_BytesToHex(inst->context.c2s.key, inst->context.c2s.length, buf, sizeof (buf)) ||
@@ -609,6 +626,8 @@ load_cookies(NNC_Instance inst)
   inst->siv = NULL;
 
   if (!fgets(line, sizeof (line), f) || strcmp(line, DUMP_IDENTIFIER) != 0 ||
+      !fgets(line, sizeof (line), f) || UTI_SplitString(line, words, MAX_WORDS) != 1 ||
+        strcmp(words[0], inst->name) != 0 ||
       !fgets(line, sizeof (line), f) || UTI_SplitString(line, words, MAX_WORDS) != 1 ||
         sscanf(words[0], "%lf", &context_time) != 1 ||
       !fgets(line, sizeof (line), f) || UTI_SplitString(line, words, MAX_WORDS) != 2 ||
@@ -650,6 +669,8 @@ load_cookies(NNC_Instance inst)
   inst->last_nke_success = context_time + SCH_GetLastEventMonoTime();
   inst->context_id = context_id;
 
+  fclose(f);
+
   DEBUG_LOG("Loaded %d cookies for %s", i, filename);
   return;
 

nts_ntp_client.h

@@ -34,7 +34,7 @@
 typedef struct NNC_Instance_Record *NNC_Instance;
 
 extern NNC_Instance NNC_CreateInstance(IPSockAddr *nts_address, const char *name,
-                                                   const IPSockAddr *ntp_address);
+                                       uint32_t cert_set, uint16_t ntp_port);
 extern void NNC_DestroyInstance(NNC_Instance inst);
 extern int NNC_PrepareForAuth(NNC_Instance inst);
 extern int NNC_GenerateRequestAuth(NNC_Instance inst, NTP_Packet *packet,

nts_ntp_server.c

@@ -59,8 +59,10 @@ struct NtsServer *server;
 void
 NNS_Initialise(void)
 {
+  const char **certs, **keys;
+
   /* Create an NTS-NTP server instance only if NTS-KE server is enabled */
-  if (!CNF_GetNtsServerCertFile() || !CNF_GetNtsServerKeyFile()) {
+  if (CNF_GetNtsServerCertAndKeyFiles(&certs, &keys) <= 0) {
     server = NULL;
     return;
   }
@@ -96,11 +98,11 @@ NNS_CheckRequestAuth(NTP_Packet *packet, NTP_PacketInfo *info, uint32_t *kod)
   NKE_Cookie cookie;
   void *ef_body;
 
+  *kod = 0;
+
   if (!server)
     return 0;
 
-  *kod = 0;
-
   server->num_cookies = 0;
   server->req_tx = packet->transmit_ts;
 

pktlength.c

@@ -87,7 +87,7 @@ static const struct request_length request_lengths[] = {
   REQ_LENGTH_ENTRY(del_source, null),           /* DEL_SOURCE */
   REQ_LENGTH_ENTRY(null, null),                 /* WRITERTC */
   REQ_LENGTH_ENTRY(dfreq, null),                /* DFREQ */
-  REQ_LENGTH_ENTRY(doffset, null),              /* DOFFSET */
+  { 0, 0 },                                     /* DOFFSET - not supported */
   REQ_LENGTH_ENTRY(null, tracking),             /* TRACKING */
   REQ_LENGTH_ENTRY(sourcestats, sourcestats),   /* SOURCESTATS */
   REQ_LENGTH_ENTRY(null, rtc),                  /* RTCREPORT */
@@ -128,6 +128,7 @@ static const struct request_length request_lengths[] = {
                    client_accesses_by_index),   /* CLIENT_ACCESSES_BY_INDEX3 */
   REQ_LENGTH_ENTRY(select_data, select_data),   /* SELECT_DATA */
   REQ_LENGTH_ENTRY(null, null),                 /* RELOAD_SOURCES */
+  REQ_LENGTH_ENTRY(doffset, null),              /* DOFFSET2 */
 };
 
 static const uint16_t reply_lengths[] = {

refclock.c

@@ -40,6 +40,9 @@
 #include "samplefilt.h"
 #include "sched.h"
 
+/* Maximum offset of locked reference as a fraction of the PPS interval */
+#define PPS_LOCK_LIMIT 0.4
+
 /* list of refclock drivers */
 extern RefclockDriver RCL_SHM_driver;
 extern RefclockDriver RCL_SOCK_driver;
@@ -181,7 +184,7 @@ RCL_AddRefclock(RefclockParameters *params)
     LOG_FATAL("refclock tai option requires leapsectz");
 
   inst->data = NULL;
-  inst->driver_parameter = params->driver_parameter;
+  inst->driver_parameter = Strdup(params->driver_parameter);
   inst->driver_parameter_length = 0;
   inst->driver_poll = params->driver_poll;
   inst->poll = params->poll;
@@ -261,15 +264,13 @@ RCL_AddRefclock(RefclockParameters *params)
       params->driver_name, UTI_RefidToString(inst->ref_id),
       inst->poll, inst->driver_poll, params->filter_length);
 
-  Free(params->driver_name);
-
   return 1;
 }
 
 void
 RCL_StartRefclocks(void)
 {
-  unsigned int i, j, n;
+  unsigned int i, j, n, lock_index;
 
   n = ARR_GetSize(refclocks);
 
@@ -279,13 +280,31 @@ RCL_StartRefclocks(void)
     SRC_SetActive(inst->source);
     inst->timeout_id = SCH_AddTimeoutByDelay(0.0, poll_timeout, (void *)inst);
 
-    if (inst->lock_ref) {
+    /* Replace lock refid with the refclock's index, or -1 if not valid */
-      /* Replace lock refid with index to refclocks */
+
-      for (j = 0; j < n && get_refclock(j)->ref_id != inst->lock_ref; j++)
+    lock_index = -1;
-        ;
+
-      inst->lock_ref = j < n ? j : -1;
+    if (inst->lock_ref != 0) {
-    } else
+      for (j = 0; j < n; j++) {
-      inst->lock_ref = -1;
+        RCL_Instance inst2 = get_refclock(j);
+
+        if (inst->lock_ref != inst2->ref_id)
+          continue;
+
+        if (inst->driver->poll && inst2->driver->poll &&
+            (double)inst->max_lock_age / inst->pps_rate < UTI_Log2ToDouble(inst2->driver_poll))
+          LOG(LOGS_WARN, "%s maxlockage too small for %s",
+              UTI_RefidToString(inst->ref_id), UTI_RefidToString(inst2->ref_id));
+
+        lock_index = j;
+        break;
+      }
+
+      if (lock_index == -1 || lock_index == i)
+        LOG(LOGS_WARN, "Invalid lock refid %s", UTI_RefidToString(inst->lock_ref));
+    }
+
+    inst->lock_ref = lock_index;
   }
 }
 
@@ -417,12 +436,6 @@ accumulate_sample(RCL_Instance instance, struct timespec *sample_time, double of
   sample.peer_dispersion = dispersion;
   sample.root_dispersion = dispersion;
 
-  /* Handle special case when PPS is used with the local reference */
-  if (instance->pps_active && instance->lock_ref == -1)
-    sample.stratum = pps_stratum(instance, &sample.time);
-  else
-    sample.stratum = instance->stratum;
-
   return SPF_AccumulateSample(instance->filter, &sample);
 }
 
@@ -567,7 +580,7 @@ RCL_AddCookedPulse(RCL_Instance instance, struct timespec *cooked_time,
     offset += shift;
 
     if (fabs(ref_sample.offset - offset) +
-        ref_sample.root_dispersion + dispersion >= 0.2 / rate) {
+        ref_sample.root_dispersion + dispersion > PPS_LOCK_LIMIT / rate) {
       DEBUG_LOG("refclock pulse ignored offdiff=%.9f refdisp=%.9f disp=%.9f",
                 ref_sample.offset - offset, ref_sample.root_dispersion, dispersion);
       return 0;
@@ -687,7 +700,7 @@ static void
 poll_timeout(void *arg)
 {
   NTP_Sample sample;
-  int poll;
+  int poll, stratum;
 
   RCL_Instance inst = (RCL_Instance)arg;
 
@@ -703,8 +716,14 @@ poll_timeout(void *arg)
     inst->driver_polled = 0;
 
     if (SPF_GetFilteredSample(inst->filter, &sample)) {
+      /* Handle special case when PPS is used with the local reference */
+      if (inst->pps_active && inst->lock_ref == -1)
+        stratum = pps_stratum(inst, &sample.time);
+      else
+        stratum = inst->stratum;
+
       SRC_UpdateReachability(inst->source, 1);
-      SRC_SetLeapStatus(inst->source, inst->leap_status);
+      SRC_UpdateStatus(inst->source, stratum, inst->leap_status);
       SRC_AccumulateSample(inst->source, &sample);
       SRC_SelectSource(inst->source);
 

refclock_phc.c

@@ -66,10 +66,8 @@ static int phc_initialise(RCL_Instance instance)
   path = RCL_GetDriverParameter(instance);
  
   phc_fd = SYS_Linux_OpenPHC(path, 0);
-  if (phc_fd < 0) {
+  if (phc_fd < 0)
     LOG_FATAL("Could not open PHC");
-    return 0;
-  }
 
   phc = MallocNew(struct phc_instance);
   phc->fd = phc_fd;

refclock_pps.c

@@ -61,49 +61,36 @@ static int pps_initialise(RCL_Instance instance) {
   edge_clear = RCL_GetDriverOption(instance, "clear") ? 1 : 0;
 
   fd = open(path, O_RDWR);
-  if (fd < 0) {
+  if (fd < 0)
     LOG_FATAL("Could not open %s : %s", path, strerror(errno));
-    return 0;
-  }
 
   UTI_FdSetCloexec(fd);
 
-  if (time_pps_create(fd, &handle) < 0) {
+  if (time_pps_create(fd, &handle) < 0)
     LOG_FATAL("time_pps_create() failed on %s : %s", path, strerror(errno));
-    return 0;
-  }
 
-  if (time_pps_getcap(handle, &mode) < 0) {
+  if (time_pps_getcap(handle, &mode) < 0)
     LOG_FATAL("time_pps_getcap() failed on %s : %s", path, strerror(errno));
-    return 0;
-  }
 
-  if (time_pps_getparams(handle, &params) < 0) {
+  if (time_pps_getparams(handle, &params) < 0)
     LOG_FATAL("time_pps_getparams() failed on %s : %s", path, strerror(errno));
-    return 0;
-  }
 
   if (!edge_clear) {
-    if (!(mode & PPS_CAPTUREASSERT)) {
+    if (!(mode & PPS_CAPTUREASSERT))
       LOG_FATAL("CAPTUREASSERT not supported on %s", path);
-      return 0;
+
-    }
     params.mode |= PPS_CAPTUREASSERT;
     params.mode &= ~PPS_CAPTURECLEAR;
   } else {
-    if (!(mode & PPS_CAPTURECLEAR)) {
+    if (!(mode & PPS_CAPTURECLEAR))
       LOG_FATAL("CAPTURECLEAR not supported on %s", path);
-      return 0;
+
-    }
     params.mode |= PPS_CAPTURECLEAR;
     params.mode &= ~PPS_CAPTUREASSERT;
   }
 
-  if (time_pps_setparams(handle, &params) < 0) {
+  if (time_pps_setparams(handle, &params) < 0)
     LOG_FATAL("time_pps_setparams() failed on %s : %s", path, strerror(errno));
-    return 0;
-  }
-
 
   pps = MallocNew(struct pps_instance);
   pps->handle = handle;

reference.c

@@ -3,7 +3,7 @@
 
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2009-2018
+ * Copyright (C) Miroslav Lichvar  2009-2018, 2020
  * 
  * 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

reports.h

@@ -36,7 +36,14 @@ typedef struct {
   int stratum;
   int poll;
   enum {RPT_NTP_CLIENT, RPT_NTP_PEER, RPT_LOCAL_REFERENCE} mode;
-  enum {RPT_SYNC, RPT_UNREACH, RPT_FALSETICKER, RPT_JITTERY, RPT_CANDIDATE, RPT_OUTLIER} state;
+  enum {
+    RPT_NONSELECTABLE,
+    RPT_FALSETICKER,
+    RPT_JITTERY,
+    RPT_SELECTABLE,
+    RPT_UNSELECTED,
+    RPT_SELECTED,
+  } state;
 
   int reachability;
   unsigned long latest_meas_ago; /* seconds */
@@ -183,6 +190,7 @@ typedef struct {
   IPAddr ip_addr;
   char state_char;
   int authentication;
+  NTP_Leap leap;
   int conf_options;
   int eff_options;
   uint32_t last_sample_ago;

rtc.c

@@ -148,6 +148,8 @@ RTC_Initialise(int initial_set)
     if (driver.init) {
       if ((driver.init)()) {
         driver_initialised = 1;
+      } else {
+        LOG(LOGS_ERR, "RTC driver could not be initialised");
       }
     } else {
       LOG(LOGS_ERR, "RTC not supported on this operating system");

samplefilt.c

@@ -386,7 +386,6 @@ combine_selected_samples(SPF_Instance filter, int n, NTP_Sample *result)
   result->root_dispersion = MAX(disp, mean_root_dispersion);
   result->peer_delay = mean_peer_delay;
   result->root_delay = mean_root_delay;
-  result->stratum = last_sample->stratum;
 
   return 1;
 }

sched.c

@@ -111,7 +111,8 @@ static struct timespec last_class_dispatch[SCH_NumberOfClasses];
 
 /* ================================================== */
 
-static int need_to_exit;
+/* Flag terminating the main loop, which can be set from a signal handler */
+static volatile int need_to_exit;
 
 /* ================================================== */
 
@@ -498,12 +499,15 @@ SCH_RemoveTimeout(SCH_TimeoutID id)
 
 static void
 dispatch_timeouts(struct timespec *now) {
+  unsigned long n_done, n_entries_on_start;
   TimerQueueEntry *ptr;
   SCH_TimeoutHandler handler;
   SCH_ArbitraryArgument arg;
-  int n_done = 0, n_entries_on_start = n_timer_queue_entries;
 
-  while (1) {
+  n_entries_on_start = n_timer_queue_entries;
+  n_done = 0;
+
+  do {
     LCL_ReadRawTime(now);
 
     if (!(n_timer_queue_entries > 0 &&
@@ -526,16 +530,21 @@ dispatch_timeouts(struct timespec *now) {
     /* Increment count of timeouts handled */
     ++n_done;
 
-    /* If more timeouts were handled than there were in the timer queue on
+    /* If the number of dispatched timeouts is significantly larger than the
-       start and there are now, assume some code is scheduling timeouts with
+       length of the queue on start and now, assume there is a bug causing
-       negative delays and abort.  Make the actual limit higher in case the
+       an infinite loop by constantly adding a timeout with a zero or negative
-       machine is temporarily overloaded and dispatching the handlers takes
+       delay.  Check the actual rate of timeouts to avoid false positives in
-       more time than was delay of a scheduled timeout. */
+       case the execution slowed down so much (e.g. due to memory thrashing)
-    if (n_done > n_timer_queue_entries * 4 &&
+       that it repeatedly takes more time to handle the timeout than is its
-        n_done > n_entries_on_start * 4) {
+       delay.  This is a safety mechanism intended to stop a full-speed flood
+       of NTP requests due to a bug in the NTP polling. */
+
+    if (n_done > 20 &&
+        n_done > 4 * MAX(n_timer_queue_entries, n_entries_on_start) &&
+        fabs(UTI_DiffTimespecsToDouble(now, &last_select_ts_raw)) / n_done < 0.01)
       LOG_FATAL("Possible infinite loop in scheduling");
-    }
+
-  }
+  } while (!need_to_exit);
 }
 
 /* ================================================== */
@@ -799,14 +808,14 @@ SCH_MainLoop(void)
     LCL_ReadRawTime(&now);
     LCL_CookTime(&now, &cooked, &err);
 
+    update_monotonic_time(&now, &last_select_ts_raw);
+
     /* Check if the time didn't jump unexpectedly */
     if (!check_current_time(&saved_now, &now, status == 0, &saved_tv, ptv)) {
       /* Cook the time again after handling the step */
       LCL_CookTime(&now, &cooked, &err);
     }
 
-    update_monotonic_time(&cooked, &last_select_ts);
-
     last_select_ts_raw = now;
     last_select_ts = cooked;
     last_select_ts_err = err;

siv_gnutls.c

@@ -204,6 +204,9 @@ SIV_Encrypt(SIV_Instance instance,
 {
   size_t clen = ciphertext_length;
 
+  if (!instance->cipher)
+    return 0;
+
   if (nonce_length < 1 || assoc_length < 0 ||
       plaintext_length < 0 || ciphertext_length < 0)
     return 0;
@@ -232,6 +235,9 @@ SIV_Decrypt(SIV_Instance instance,
 {
   size_t plen = plaintext_length;
 
+  if (!instance->cipher)
+    return 0;
+
   if (nonce_length < 1 || assoc_length < 0 ||
       plaintext_length < 0 || ciphertext_length < 0)
     return 0;

siv_nettle.c

@@ -39,6 +39,7 @@
 
 struct SIV_Instance_Record {
   struct siv_cmac_aes128_ctx siv;
+  int key_set;
 };
 
 /* ================================================== */
@@ -52,6 +53,7 @@ SIV_CreateInstance(SIV_Algorithm algorithm)
     return NULL;
 
   instance = MallocNew(struct SIV_Instance_Record);
+  instance->key_set = 0;
 
   return instance;
 }
@@ -86,6 +88,8 @@ SIV_SetKey(SIV_Instance instance, const unsigned char *key, int length)
 
   siv_cmac_aes128_set_key(&instance->siv, key);
 
+  instance->key_set = 1;
+
   return 1;
 }
 
@@ -108,6 +112,9 @@ SIV_Encrypt(SIV_Instance instance,
             const void *plaintext, int plaintext_length,
             unsigned char *ciphertext, int ciphertext_length)
 {
+  if (!instance->key_set)
+    return 0;
+
   if (nonce_length < SIV_MIN_NONCE_SIZE || assoc_length < 0 ||
       plaintext_length < 0 || plaintext_length > ciphertext_length ||
       plaintext_length + SIV_DIGEST_SIZE != ciphertext_length)
@@ -130,6 +137,9 @@ SIV_Decrypt(SIV_Instance instance,
             const unsigned char *ciphertext, int ciphertext_length,
             void *plaintext, int plaintext_length)
 {
+  if (!instance->key_set)
+    return 0;
+
   if (nonce_length < SIV_MIN_NONCE_SIZE || assoc_length < 0 ||
       plaintext_length < 0 || plaintext_length > ciphertext_length ||
       plaintext_length + SIV_DIGEST_SIZE != ciphertext_length)

socket.c

@@ -4,7 +4,7 @@
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
  * Copyright (C) Timo Teras  2009
- * Copyright (C) Miroslav Lichvar  2009, 2013-2019
+ * Copyright (C) Miroslav Lichvar  2009, 2013-2020
  * 
  * 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
@@ -737,23 +737,26 @@ init_message_nonaddress(SCK_Message *message)
 
 /* ================================================== */
 
+static int
+match_cmsg(struct cmsghdr *cmsg, int level, int type, size_t length)
+{
+  if (cmsg->cmsg_type == type && cmsg->cmsg_level == level &&
+      (length == 0 || cmsg->cmsg_len == CMSG_LEN(length)))
+    return 1;
+  return 0;
+}
+
+/* ================================================== */
+
 static int
 process_header(struct msghdr *msg, int msg_length, int sock_fd, int flags,
                SCK_Message *message)
 {
   struct cmsghdr *cmsg;
+  int r = 1;
 
-  if (msg->msg_iovlen != 1) {
+  if (msg->msg_namelen <= sizeof (union sockaddr_all) &&
-    DEBUG_LOG("Unexpected iovlen");
+      msg->msg_namelen > sizeof (((struct sockaddr *)msg->msg_name)->sa_family)) {
-    return 0;
-  }
-
-  if (msg->msg_namelen > sizeof (union sockaddr_all)) {
-    DEBUG_LOG("Truncated source address");
-    return 0;
-  }
-
-  if (msg->msg_namelen > sizeof (((struct sockaddr *)msg->msg_name)->sa_family)) {
     switch (((struct sockaddr *)msg->msg_name)->sa_family) {
       case AF_INET:
 #ifdef FEAT_IPV6
@@ -767,31 +770,45 @@ process_header(struct msghdr *msg, int msg_length, int sock_fd, int flags,
         message->remote_addr.path = ((struct sockaddr_un *)msg->msg_name)->sun_path;
         break;
       default:
+        init_message_addresses(message, SCK_ADDR_UNSPEC);
         DEBUG_LOG("Unexpected address");
-        return 0;
+        r = 0;
+        break;
     }
   } else {
     init_message_addresses(message, SCK_ADDR_UNSPEC);
+
+    if (msg->msg_namelen > sizeof (union sockaddr_all)) {
+      DEBUG_LOG("Truncated source address");
+      r = 0;
+    }
   }
 
   init_message_nonaddress(message);
 
-  message->data = msg->msg_iov[0].iov_base;
+  if (msg->msg_iovlen == 1) {
-  message->length = msg_length;
+    message->data = msg->msg_iov[0].iov_base;
+    message->length = msg_length;
+  } else {
+    DEBUG_LOG("Unexpected iovlen");
+    r = 0;
+  }
 
   if (msg->msg_flags & MSG_TRUNC) {
     log_message(sock_fd, 1, message, "Truncated", NULL);
-    return 0;
+    r = 0;
   }
 
   if (msg->msg_flags & MSG_CTRUNC) {
     log_message(sock_fd, 1, message, "Truncated cmsg in", NULL);
-    return 0;
+    r = 0;
   }
 
   for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
+    if (0) {
+    }
 #ifdef HAVE_IN_PKTINFO
-    if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO) {
+    else if (match_cmsg(cmsg, IPPROTO_IP, IP_PKTINFO, sizeof (struct in_pktinfo))) {
       struct in_pktinfo ipi;
 
       if (message->addr_type != SCK_ADDR_IP)
@@ -803,7 +820,7 @@ process_header(struct msghdr *msg, int msg_length, int sock_fd, int flags,
       message->if_index = ipi.ipi_ifindex;
     }
 #elif defined(IP_RECVDSTADDR)
-    if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_RECVDSTADDR) {
+    else if (match_cmsg(cmsg, IPPROTO_IP, IP_RECVDSTADDR, sizeof (struct in_addr))) {
       struct in_addr addr;
 
       if (message->addr_type != SCK_ADDR_IP)
@@ -814,9 +831,8 @@ process_header(struct msghdr *msg, int msg_length, int sock_fd, int flags,
       message->local_addr.ip.family = IPADDR_INET4;
     }
 #endif
-
 #ifdef HAVE_IN6_PKTINFO
-    if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
+    else if (match_cmsg(cmsg, IPPROTO_IPV6, IPV6_PKTINFO, sizeof (struct in6_pktinfo))) {
       struct in6_pktinfo ipi;
 
       if (message->addr_type != SCK_ADDR_IP)
@@ -829,25 +845,23 @@ process_header(struct msghdr *msg, int msg_length, int sock_fd, int flags,
       message->if_index = ipi.ipi6_ifindex;
     }
 #endif
-
 #ifdef SCM_TIMESTAMP
-    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMP) {
+    else if (match_cmsg(cmsg, SOL_SOCKET, SCM_TIMESTAMP, sizeof (struct timeval))) {
       struct timeval tv;
 
       memcpy(&tv, CMSG_DATA(cmsg), sizeof (tv));
       UTI_TimevalToTimespec(&tv, &message->timestamp.kernel);
     }
 #endif
-
 #ifdef SCM_TIMESTAMPNS
-    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPNS) {
+    else if (match_cmsg(cmsg, SOL_SOCKET, SCM_TIMESTAMPNS, sizeof (message->timestamp.kernel))) {
       memcpy(&message->timestamp.kernel, CMSG_DATA(cmsg), sizeof (message->timestamp.kernel));
     }
 #endif
-
 #ifdef HAVE_LINUX_TIMESTAMPING
 #ifdef HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO
-    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPING_PKTINFO) {
+    else if (match_cmsg(cmsg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO,
+                        sizeof (struct scm_ts_pktinfo))) {
       struct scm_ts_pktinfo ts_pktinfo;
 
       memcpy(&ts_pktinfo, CMSG_DATA(cmsg), sizeof (ts_pktinfo));
@@ -855,17 +869,17 @@ process_header(struct msghdr *msg, int msg_length, int sock_fd, int flags,
       message->timestamp.l2_length = ts_pktinfo.pkt_length;
     }
 #endif
-
+    else if (match_cmsg(cmsg, SOL_SOCKET, SCM_TIMESTAMPING,
-    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPING) {
+                        sizeof (struct scm_timestamping))) {
       struct scm_timestamping ts3;
 
       memcpy(&ts3, CMSG_DATA(cmsg), sizeof (ts3));
       message->timestamp.kernel = ts3.ts[0];
       message->timestamp.hw = ts3.ts[2];
     }
-
+    else if ((match_cmsg(cmsg, SOL_IP, IP_RECVERR, 0) ||
-    if ((cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR) ||
+              match_cmsg(cmsg, SOL_IPV6, IPV6_RECVERR, 0)) &&
-        (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_RECVERR)) {
+             cmsg->cmsg_len >= CMSG_LEN(sizeof (struct sock_extended_err))) {
       struct sock_extended_err err;
 
       memcpy(&err, CMSG_DATA(cmsg), sizeof (err));
@@ -873,25 +887,34 @@ process_header(struct msghdr *msg, int msg_length, int sock_fd, int flags,
       if (err.ee_errno != ENOMSG || err.ee_info != SCM_TSTAMP_SND ||
           err.ee_origin != SO_EE_ORIGIN_TIMESTAMPING) {
         log_message(sock_fd, 1, message, "Unexpected extended error in", NULL);
-        return 0;
+        r = 0;
       }
     }
 #endif
-
+    else if (match_cmsg(cmsg, SOL_SOCKET, SCM_RIGHTS, 0)) {
-    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
       if (!(flags & SCK_FLAG_MSG_DESCRIPTOR) || cmsg->cmsg_len != CMSG_LEN(sizeof (int))) {
-        unsigned int i;
+        int i, fd;
 
         DEBUG_LOG("Unexpected SCM_RIGHTS");
-        for (i = 0; CMSG_LEN((i + 1) * sizeof (int)) <= cmsg->cmsg_len; i++)
+        for (i = 0; CMSG_LEN((i + 1) * sizeof (int)) <= cmsg->cmsg_len; i++) {
-          close(((int *)CMSG_DATA(cmsg))[i]);
+          memcpy(&fd, (char *)CMSG_DATA(cmsg) + i * sizeof (int), sizeof (fd));
-        return 0;
+          close(fd);
+        }
+        r = 0;
+      } else {
+        memcpy(&message->descriptor, CMSG_DATA(cmsg), sizeof (message->descriptor));
       }
-      message->descriptor = *(int *)CMSG_DATA(cmsg);
+    }
+    else {
+      DEBUG_LOG("Unexpected control message level=%d type=%d len=%d",
+                cmsg->cmsg_level, cmsg->cmsg_type, (int)cmsg->cmsg_len);
     }
   }
 
-  return 1;
+  if (!r && message->descriptor != INVALID_SOCK_FD)
+    close(message->descriptor);
+
+  return r;
 }
 
 /* ================================================== */
@@ -901,7 +924,7 @@ receive_messages(int sock_fd, int flags, int max_messages, int *num_messages)
 {
   struct MessageHeader *hdr;
   SCK_Message *messages;
-  unsigned int i, n;
+  unsigned int i, n, n_ok;
   int ret, recv_flags = 0;
 
   assert(initialised);
@@ -945,18 +968,20 @@ receive_messages(int sock_fd, int flags, int max_messages, int *num_messages)
 
   received_messages = n;
 
-  for (i = 0; i < n; i++) {
+  for (i = n_ok = 0; i < n; i++) {
     hdr = ARR_GetElement(recv_headers, i);
-    if (!process_header(&hdr->msg_hdr, hdr->msg_len, sock_fd, flags, &messages[i]))
+    if (!process_header(&hdr->msg_hdr, hdr->msg_len, sock_fd, flags, &messages[n_ok]))
-      return NULL;
+      continue;
 
-    log_message(sock_fd, 1, &messages[i],
+    log_message(sock_fd, 1, &messages[n_ok],
                 flags & SCK_FLAG_MSG_ERRQUEUE ? "Received error" : "Received", NULL);
+
+    n_ok++;
   }
 
-  *num_messages = n;
+  *num_messages = n_ok;
 
-  return messages;
+  return n_ok > 0 ? messages : NULL;
 }
 
 /* ================================================== */

sources.c

@@ -3,7 +3,7 @@
 
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2016, 2018
+ * Copyright (C) Miroslav Lichvar  2011-2016, 2018, 2020
  * 
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -54,7 +54,6 @@ static int initialised = 0;
 /* ================================================== */
 /* Structure used to hold info for selecting between sources */
 struct SelectInfo {
-  int stratum;
   int select_ok;
   double std_dev;
   double root_distance;
@@ -132,7 +131,10 @@ struct SRC_Instance_Record {
 
   struct SelectInfo sel_info;
 
-  /* Latest leap status */
+  /* Current stratum */
+  int stratum;
+
+  /* Current leap status */
   NTP_Leap leap;
 
   /* Flag indicating the source has a leap second vote */
@@ -175,6 +177,9 @@ static double reselect_distance;
 static double stratum_weight;
 static double combine_limit;
 
+/* Identifier of the dump file */
+#define DUMP_IDENTIFIER "SRC0\n"
+
 /* ================================================== */
 /* Forward prototype */
 
@@ -313,6 +318,7 @@ SRC_ResetInstance(SRC_Instance instance)
   instance->distant = 0;
   instance->status = SRC_BAD_STATS;
   instance->sel_score = 1.0;
+  instance->stratum = 0;
   instance->leap = LEAP_Unsynchronised;
   instance->leap_vote = 0;
 
@@ -371,8 +377,10 @@ get_leap_status(void)
 /* ================================================== */
 
 void
-SRC_SetLeapStatus(SRC_Instance inst, NTP_Leap leap)
+SRC_UpdateStatus(SRC_Instance inst, int stratum, NTP_Leap leap)
 {
+  inst->stratum = stratum;
+
   if (REF_IsLeapSecondClose(NULL, 0.0))
     return;
 
@@ -398,9 +406,9 @@ SRC_AccumulateSample(SRC_Instance inst, NTP_Sample *sample)
 
   assert(initialised);
 
-  DEBUG_LOG("src=%s ts=%s offset=%e delay=%e disp=%e stratum=%d",
+  DEBUG_LOG("src=%s ts=%s offset=%e delay=%e disp=%e",
             source_to_string(inst), UTI_TimespecToString(&sample->time), -sample->offset,
-            sample->root_delay, sample->root_dispersion, sample->stratum);
+            sample->root_delay, sample->root_dispersion);
 
   if (REF_IsLeapSecondClose(&sample->time, sample->offset)) {
     LOG(LOGS_INFO, "Dropping sample around leap second");
@@ -808,7 +816,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
     }
 
     si = &sources[i]->sel_info;
-    SST_GetSelectionData(sources[i]->stats, &now, &si->stratum,
+    SST_GetSelectionData(sources[i]->stats, &now,
                          &si->lo_limit, &si->hi_limit, &si->root_distance,
                          &si->std_dev, &first_sample_ago,
                          &si->last_sample_ago, &si->select_ok);
@@ -890,10 +898,10 @@ SRC_SelectSource(SRC_Instance updated_inst)
        source can settle down to a state where only one server is serving its
        local unsychronised time and others are synchronised to it. */
 
-    if (si->stratum >= orphan_stratum && sources[i]->type == SRC_NTP) {
+    if (sources[i]->stratum >= orphan_stratum && sources[i]->type == SRC_NTP) {
       mark_source(sources[i], SRC_ORPHAN);
 
-      if (si->stratum == orphan_stratum && sources[i]->reachability &&
+      if (sources[i]->stratum == orphan_stratum && sources[i]->reachability &&
           (orphan_source == INVALID_SOURCE ||
            sources[i]->ref_id < sources[orphan_source]->ref_id))
         orphan_source = i;
@@ -1131,10 +1139,10 @@ SRC_SelectSource(SRC_Instance updated_inst)
   /* Find minimum stratum */
 
   index = sel_sources[0];
-  min_stratum = sources[index]->sel_info.stratum;
+  min_stratum = sources[index]->stratum;
   for (i = 1; i < n_sel_sources; i++) {
     index = sel_sources[i];
-    stratum = sources[index]->sel_info.stratum;
+    stratum = sources[index]->stratum;
     if (stratum < min_stratum)
       min_stratum = stratum;
   }
@@ -1147,7 +1155,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
 
   if (selected_source_index != INVALID_SOURCE)
     sel_src_distance = sources[selected_source_index]->sel_info.root_distance +
-      (sources[selected_source_index]->sel_info.stratum - min_stratum) * stratum_weight;
+      (sources[selected_source_index]->stratum - min_stratum) * stratum_weight;
 
   for (i = 0; i < n_sources; i++) {
     /* Reset score for non-selectable sources */
@@ -1159,7 +1167,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
     }
 
     distance = sources[i]->sel_info.root_distance +
-      (sources[i]->sel_info.stratum - min_stratum) * stratum_weight;
+      (sources[i]->stratum - min_stratum) * stratum_weight;
     if (sources[i]->type == SRC_NTP)
       distance += reselect_distance;
 
@@ -1247,7 +1255,7 @@ SRC_SelectSource(SRC_Instance updated_inst)
   combined = combine_sources(n_sel_sources, &ref_time, &src_offset, &src_offset_sd,
                              &src_frequency, &src_frequency_sd, &src_skew);
 
-  REF_SetReference(sources[selected_source_index]->sel_info.stratum,
+  REF_SetReference(sources[selected_source_index]->stratum,
                    leap_status, combined,
                    sources[selected_source_index]->ref_id,
                    sources[selected_source_index]->ip_addr,
@@ -1320,24 +1328,60 @@ add_dispersion(double dispersion, void *anything)
 
 /* ================================================== */
 
-static
+static int
-FILE *open_dumpfile(SRC_Instance inst, char mode)
+get_dumpfile(SRC_Instance inst, char *filename, size_t len)
 {
-  char filename[64], *dumpdir;
+  /* Use the IP address, or reference ID with reference clocks */
+  switch (inst->type) {
+    case SRC_NTP:
+      if (!UTI_IsIPReal(inst->ip_addr) ||
+          snprintf(filename, len, "%s", source_to_string(inst)) >= len)
+        return 0;
+      break;
+    case SRC_REFCLOCK:
+      if (snprintf(filename, len, "refid:%08"PRIx32, inst->ref_id) >= len)
+        return 0;
+      break;
+    default:
+      assert(0);
+  }
+
+  return 1;
+}
+
+/* ================================================== */
+
+static void
+save_source(SRC_Instance inst)
+{
+  char filename[64], *dumpdir, *ntp_name;
+  FILE *f;
 
   dumpdir = CNF_GetDumpDir();
   if (!dumpdir)
-    return NULL;
+    return;
 
-  /* Include IP address in the name for NTP sources, or reference ID in hex */
+  if (!get_dumpfile(inst, filename, sizeof (filename)))
-  if (inst->type == SRC_NTP && UTI_IsIPReal(inst->ip_addr))
+    return;
-    snprintf(filename, sizeof (filename), "%s", source_to_string(inst));
-  else if (inst->type == SRC_REFCLOCK)
-    snprintf(filename, sizeof (filename), "refid:%08"PRIx32, inst->ref_id);
-  else
-    return NULL;
 
-  return UTI_OpenFile(dumpdir, filename, ".dat", mode, 0644);
+  f = UTI_OpenFile(dumpdir, filename, ".dat", 'w', 0644);
+  if (!f)
+    return;
+
+  ntp_name = inst->type == SRC_NTP ? NSR_GetName(inst->ip_addr) : ".";
+
+  if (fprintf(f, "%s%s\n%d %o %d %d %d\n",
+              DUMP_IDENTIFIER, ntp_name, inst->authenticated,
+              (unsigned int)inst->reachability, inst->reachability_size,
+              inst->stratum, (int)inst->leap) < 0 ||
+      !SST_SaveToFile(inst->stats, f)) {
+    fclose(f);
+    if (!UTI_RemoveFile(dumpdir, filename, ".dat"))
+      ;
+    return;
+  }
+
+  fclose(f);
 }
 
 /* ================================================== */
@@ -1346,16 +1390,60 @@ FILE *open_dumpfile(SRC_Instance inst, char mode)
 void
 SRC_DumpSources(void)
 {
-  FILE *out;
   int i;
 
-  for (i = 0; i < n_sources; i++) {
+  for (i = 0; i < n_sources; i++)
-    out = open_dumpfile(sources[i], 'w');
+    save_source(sources[i]);
-    if (!out)
+}
-      continue;
+
-    SST_SaveToFile(sources[i]->stats, out);
+/* ================================================== */
-    fclose(out);
+
+#define MAX_WORDS 1
+
+static void
+load_source(SRC_Instance inst)
+{
+  char filename[64], line[256], *dumpdir, *ntp_name, *words[MAX_WORDS];
+  int auth, leap, reach_size, stratum;
+  unsigned int reach;
+  FILE *f;
+
+  dumpdir = CNF_GetDumpDir();
+  if (!dumpdir)
+    return;
+
+  if (!get_dumpfile(inst, filename, sizeof (filename)))
+    return;
+
+  f = UTI_OpenFile(dumpdir, filename, ".dat", 'r', 0);
+  if (!f)
+    return;
+
+  ntp_name = inst->type == SRC_NTP ? NSR_GetName(inst->ip_addr) : NULL;
+
+  if (!fgets(line, sizeof (line), f) || strcmp(line, DUMP_IDENTIFIER) != 0 ||
+      !fgets(line, sizeof (line), f) || UTI_SplitString(line, words, MAX_WORDS) != 1 ||
+        (inst->type == SRC_NTP && (!ntp_name || strcmp(words[0], ntp_name) != 0)) ||
+      !fgets(line, sizeof (line), f) ||
+        sscanf(words[0], "%d %o %d %d %d",
+               &auth, &reach, &reach_size, &stratum, &leap) != 5 ||
+        (!auth && inst->authenticated) ||
+        stratum < 0 || stratum >= NTP_MAX_STRATUM ||
+        leap < LEAP_Normal || leap >= LEAP_Unsynchronised ||
+      !SST_LoadFromFile(inst->stats, f)) {
+    LOG(LOGS_WARN, "Could not load dump file for %s", source_to_string(inst));
+    fclose(f);
+    return;
   }
+
+  inst->reachability = reach & ((1U << SOURCE_REACH_BITS) - 1);
+  inst->reachability_size = CLAMP(0, reach_size, SOURCE_REACH_BITS);
+  inst->stratum = stratum;
+  inst->leap = leap;
+
+  LOG(LOGS_INFO, "Loaded dump file for %s", source_to_string(inst));
+
+  fclose(f);
 }
 
 /* ================================================== */
@@ -1363,21 +1451,17 @@ SRC_DumpSources(void)
 void
 SRC_ReloadSources(void)
 {
-  FILE *in;
   int i;
 
   for (i = 0; i < n_sources; i++) {
-    in = open_dumpfile(sources[i], 'r');
+    load_source(sources[i]);
-    if (!in)
+
-      continue;
+    /* Allow an immediate update of the reference */
-    if (!SST_LoadFromFile(sources[i]->stats, in))
+    sources[i]->updates++;
-      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);
   }
+
+  /* Select sources and set the reference */
+  SRC_SelectSource(NULL);
 }
 
 /* ================================================== */
@@ -1492,6 +1576,8 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timespec *now)
       report->ip_addr.family = IPADDR_INET4;
     }
 
+    report->stratum = src->stratum;
+
     switch (src->status) {
       case SRC_FALSETICKER:
         report->state = RPT_FALSETICKER;
@@ -1499,22 +1585,21 @@ SRC_ReportSource(int index, RPT_SourceReport *report, struct timespec *now)
       case SRC_JITTERY:
         report->state = RPT_JITTERY;
         break;
-      case SRC_UNTRUSTED:
       case SRC_WAITS_SOURCES:
       case SRC_NONPREFERRED:
       case SRC_WAITS_UPDATE:
       case SRC_DISTANT:
       case SRC_OUTLIER:
-        report->state = RPT_OUTLIER;
+        report->state = RPT_SELECTABLE;
         break;
       case SRC_UNSELECTED:
-        report->state = RPT_CANDIDATE;
+        report->state = RPT_UNSELECTED;
         break;
       case SRC_SELECTED:
-        report->state = RPT_SYNC;
+        report->state = RPT_SELECTED;
         break;
       default:
-        report->state = RPT_UNREACH;
+        report->state = RPT_NONSELECTABLE;
         break;
     }
 
@@ -1611,6 +1696,7 @@ SRC_GetSelectReport(int index, RPT_SelectReport *report)
     report->ip_addr.family = IPADDR_UNSPEC;
   report->state_char = get_status_char(inst->status);
   report->authentication = inst->authenticated;
+  report->leap = inst->leap;
   report->conf_options = inst->conf_sel_options;
   report->eff_options = inst->sel_options;
   report->last_sample_ago = inst->sel_info.last_sample_ago;

sources.h

@@ -87,8 +87,8 @@ extern void SRC_SetRefid(SRC_Instance instance, uint32_t ref_id, IPAddr *addr);
 /* Function to get access to the sourcestats instance */
 extern SST_Stats SRC_GetSourcestats(SRC_Instance instance);
 
-/* Function to set the current leap status according to the source */
+/* Function to update the stratum and leap status of the source */
-extern void SRC_SetLeapStatus(SRC_Instance instance, NTP_Leap leap);
+extern void SRC_UpdateStatus(SRC_Instance instance, int stratum, NTP_Leap leap);
 
 /* Function to accumulate a new sample from the source */
 extern void SRC_AccumulateSample(SRC_Instance instance, NTP_Sample *sample);

sourcestats.c

@@ -3,7 +3,7 @@
 
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2003
- * Copyright (C) Miroslav Lichvar  2011-2014, 2016-2018
+ * Copyright (C) Miroslav Lichvar  2011-2014, 2016-2018, 2021
  * 
  * 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
@@ -177,9 +177,6 @@ struct SST_Stats_Record {
   /* This array contains the root dispersions of each sample at the
      time of the measurements */
   double root_dispersions[MAX_SAMPLES];
-
-  /* The stratum from the last accumulated sample */
-  int stratum;
 };
 
 /* ================================================== */
@@ -321,7 +318,6 @@ SST_AccumulateSample(SST_Stats inst, NTP_Sample *sample)
   inst->peer_dispersions[m] = sample->peer_dispersion;
   inst->root_delays[m] = sample->root_delay;
   inst->root_dispersions[m] = sample->root_dispersion;
-  inst->stratum = sample->stratum;
  
   if (inst->peer_delays[n] < inst->fixed_min_delay)
     inst->peer_delays[n] = 2.0 * inst->fixed_min_delay - inst->peer_delays[n];
@@ -650,7 +646,6 @@ SST_GetFrequencyRange(SST_Stats inst,
 
 void
 SST_GetSelectionData(SST_Stats inst, struct timespec *now,
-                     int *stratum,
                      double *offset_lo_limit,
                      double *offset_hi_limit,
                      double *root_distance,
@@ -670,7 +665,6 @@ SST_GetSelectionData(SST_Stats inst, struct timespec *now,
   i = get_runsbuf_index(inst, inst->best_single_sample);
   j = get_buf_index(inst, inst->best_single_sample);
 
-  *stratum = inst->stratum;
   *std_dev = inst->std_dev;
 
   sample_elapsed = fabs(UTI_DiffTimespecsToDouble(now, &inst->sample_times[i]));
@@ -858,38 +852,30 @@ SST_GetDelayTestData(SST_Stats inst, struct timespec *sample_time,
 /* This is used to save the register to a file, so that we can reload
    it after restarting the daemon */
 
-void
+int
 SST_SaveToFile(SST_Stats inst, FILE *out)
 {
   int m, i, j;
 
-  fprintf(out, "%d\n", inst->n_samples);
+  if (inst->n_samples < 1)
+    return 0;
+
+  if (fprintf(out, "%d %d\n", inst->n_samples, inst->asymmetry_run) < 0)
+    return 0;
 
   for(m = 0; m < inst->n_samples; m++) {
     i = get_runsbuf_index(inst, m);
     j = get_buf_index(inst, m);
 
-    fprintf(out,
+    if (fprintf(out, "%s %.6e %.6e %.6e %.6e %.6e %.6e\n",
-#ifdef HAVE_LONG_TIME_T
+                UTI_TimespecToString(&inst->sample_times[i]),
-            "%08"PRIx64" %08lx %.6e %.6e %.6e %.6e %.6e %.6e %.6e %d\n",
+                inst->offsets[i], inst->orig_offsets[j],
-            (uint64_t)inst->sample_times[i].tv_sec,
+                inst->peer_delays[i], inst->peer_dispersions[j],
-#else
+                inst->root_delays[j], inst->root_dispersions[j]) < 0)
-            "%08lx %08lx %.6e %.6e %.6e %.6e %.6e %.6e %.6e %d\n",
+      return 0;
-            (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[i],
-            inst->peer_dispersions[j],
-            inst->root_delays[j],
-            inst->root_dispersions[j],
-            1.0, /* used to be inst->weights[i] */
-            inst->stratum /* used to be an array */);
-
   }
 
-  fprintf(out, "%d\n", inst->asymmetry_run);
+  return 1;
 }
 
 /* ================================================== */
@@ -898,65 +884,46 @@ SST_SaveToFile(SST_Stats inst, FILE *out)
 int
 SST_LoadFromFile(SST_Stats inst, FILE *in)
 {
-#ifdef HAVE_LONG_TIME_T
+  int i, n_samples, arun;
-  uint64_t sec;
+  struct timespec now;
-#else
+  double sample_time;
-  unsigned long sec;
+  char line[256];
-#endif
+
-  unsigned long usec;
+  if (!fgets(line, sizeof (line), in) ||
-  int i;
+      sscanf(line, "%d %d", &n_samples, &arun) != 2 ||
-  char line[1024];
+      n_samples < 1 || n_samples > MAX_SAMPLES)
-  double weight;
+    return 0;
 
   SST_ResetInstance(inst);
 
-  if (fgets(line, sizeof(line), in) &&
+  LCL_ReadCookedTime(&now, NULL);
-      sscanf(line, "%d", &inst->n_samples) == 1 &&
-      inst->n_samples >= 0 && inst->n_samples <= MAX_SAMPLES) {
 
-    for (i=0; i<inst->n_samples; i++) {
+  for (i = 0; i < n_samples; i++) {
-      if (!fgets(line, sizeof(line), in) ||
+    if (!fgets(line, sizeof (line), in) ||
-          (sscanf(line,
+        sscanf(line, "%lf %lf %lf %lf %lf %lf %lf",
-#ifdef HAVE_LONG_TIME_T
+               &sample_time, &inst->offsets[i], &inst->orig_offsets[i],
-                  "%"SCNx64"%lx%lf%lf%lf%lf%lf%lf%lf%d\n",
+               &inst->peer_delays[i], &inst->peer_dispersions[i],
-#else
+               &inst->root_delays[i], &inst->root_dispersions[i]) != 7)
-                  "%lx%lx%lf%lf%lf%lf%lf%lf%lf%d\n",
+      return 0;
-#endif
-                  &(sec), &(usec),
-                  &(inst->offsets[i]),
-                  &(inst->orig_offsets[i]),
-                  &(inst->peer_delays[i]),
-                  &(inst->peer_dispersions[i]),
-                  &(inst->root_delays[i]),
-                  &(inst->root_dispersions[i]),
-                  &weight, /* not used anymore */
-                  &inst->stratum) != 10)) {
 
-        /* This is the branch taken if the read FAILED */
+    if (!UTI_IsTimeOffsetSane(&now, sample_time - UTI_TimespecToDouble(&now)))
+      return 0;
 
-        inst->n_samples = 0; /* Load abandoned if any sign of corruption */
+    /* Some resolution is lost in the double format, but that's ok */
-        return 0;
+    UTI_DoubleToTimespec(sample_time, &inst->sample_times[i]);
-      } else {
 
-        /* This is the branch taken if the read is SUCCESSFUL */
+    /* Make sure the samples are sane and they are in order */
-        inst->sample_times[i].tv_sec = sec;
+    if (!UTI_IsTimeOffsetSane(&inst->sample_times[i], -inst->offsets[i]) ||
-        inst->sample_times[i].tv_nsec = 1000 * usec;
+        !(fabs(inst->peer_delays[i]) < 1.0e6 && fabs(inst->peer_dispersions[i]) < 1.0e6 &&
-        UTI_NormaliseTimespec(&inst->sample_times[i]);
+          fabs(inst->root_delays[i]) < 1.0e6 && fabs(inst->root_dispersions[i]) < 1.0e6) ||
-      }
+        (i > 0 && UTI_CompareTimespecs(&inst->sample_times[i],
-    }
+                                       &inst->sample_times[i - 1]) <= 0))
-
+      return 0;
-    /* 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 {
-    inst->n_samples = 0; /* Load abandoned if any sign of corruption */
-    return 0;
   }
 
-  if (!inst->n_samples)
+  inst->n_samples = n_samples;
-    return 1;
-
   inst->last_sample = inst->n_samples - 1;
+  inst->asymmetry_run = CLAMP(-MAX_ASYMMETRY_RUN, arun, MAX_ASYMMETRY_RUN);
 
   find_min_delay_sample(inst);
   SST_DoNewRegression(inst);
@@ -978,7 +945,6 @@ SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timespec *no
     report->orig_latest_meas = inst->orig_offsets[j];
     report->latest_meas = inst->offsets[i];
     report->latest_meas_err = 0.5*inst->root_delays[j] + inst->root_dispersions[j];
-    report->stratum = inst->stratum;
 
     /* Align the sample time to reduce the leak of the receive timestamp */
     last_sample_time = inst->sample_times[i];

sourcestats.h

@@ -69,7 +69,6 @@ extern void SST_GetFrequencyRange(SST_Stats inst, double *lo, double *hi);
 /* Get data needed for selection */
 extern void
 SST_GetSelectionData(SST_Stats inst, struct timespec *now,
-                     int *stratum,
                      double *offset_lo_limit,
                      double *offset_hi_limit,
                      double *root_distance,
@@ -120,7 +119,7 @@ extern int SST_GetDelayTestData(SST_Stats inst, struct timespec *sample_time,
                                 double *last_sample_ago, double *predicted_offset,
                                 double *min_delay, double *skew, double *std_dev);
 
-extern void SST_SaveToFile(SST_Stats inst, FILE *out);
+extern int SST_SaveToFile(SST_Stats inst, FILE *out);
 
 extern int SST_LoadFromFile(SST_Stats inst, FILE *in);
 

srcparams.h

@@ -54,7 +54,9 @@ typedef struct {
   int sel_options;
   int nts;
   int nts_port;
+  int copy;
   uint32_t authkey;
+  uint32_t cert_set;
   double max_delay;
   double max_delay_ratio;
   double max_delay_dev_ratio;
@@ -77,6 +79,7 @@ typedef struct {
 #define SRC_DEFAULT_MAXSAMPLES (-1)
 #define SRC_DEFAULT_ASYMMETRY 1.0
 #define SRC_DEFAULT_NTSPORT 4460
+#define SRC_DEFAULT_CERTSET 0
 #define INACTIVE_AUTHKEY 0
 
 /* Flags for source selection */

stubs.c

@@ -49,7 +49,7 @@
 #include "sched.h"
 #include "util.h"
 
-#ifndef FEAT_ASYNCDNS
+#if defined(FEAT_NTP) && !defined(FEAT_ASYNCDNS)
 
 /* This is a blocking implementation used when asynchronous resolving is not available */
 
@@ -491,7 +491,8 @@ NNS_GenerateResponseAuth(NTP_Packet *request, NTP_PacketInfo *req_info,
 }
 
 NNC_Instance
-NNC_CreateInstance(IPSockAddr *nts_address, const char *name, const IPSockAddr *ntp_address)
+NNC_CreateInstance(IPSockAddr *nts_address, const char *name, uint32_t cert_set,
+                   uint16_t ntp_port)
 {
   return NULL;
 }

sys.c

@@ -97,16 +97,16 @@ SYS_Finalise(void)
 
 /* ================================================== */
 
-void SYS_DropRoot(uid_t uid, gid_t gid)
+void SYS_DropRoot(uid_t uid, gid_t gid, SYS_ProcessContext context)
 {
 #if defined(LINUX) && defined (FEAT_PRIVDROP)
-  SYS_Linux_DropRoot(uid, gid, !null_driver);
+  SYS_Linux_DropRoot(uid, gid, context, !null_driver);
 #elif defined(SOLARIS) && defined(FEAT_PRIVDROP)
-  SYS_Solaris_DropRoot(uid, gid);
+  SYS_Solaris_DropRoot(uid, gid, context);
 #elif (defined(NETBSD) || defined(FREEBSD)) && defined(FEAT_PRIVDROP)
-  SYS_NetBSD_DropRoot(uid, gid);
+  SYS_NetBSD_DropRoot(uid, gid, context, !null_driver);
 #elif defined(MACOSX) && defined(FEAT_PRIVDROP)
-  SYS_MacOSX_DropRoot(uid, gid);
+  SYS_MacOSX_DropRoot(uid, gid, context);
 #else
   LOG_FATAL("dropping root privileges not supported");
 #endif
@@ -114,7 +114,7 @@ void SYS_DropRoot(uid_t uid, gid_t gid)
 
 /* ================================================== */
 
-void SYS_EnableSystemCallFilter(int level, SYS_SystemCallContext context)
+void SYS_EnableSystemCallFilter(int level, SYS_ProcessContext context)
 {
 #if defined(LINUX) && defined(FEAT_SCFILTER)
   SYS_Linux_EnableSystemCallFilter(level, context);

sys.h

@@ -35,17 +35,17 @@ extern void SYS_Initialise(int clock_control);
 /* Called at the end of the run to do final clean-up */
 extern void SYS_Finalise(void);
 
-/* Drop root privileges to the specified user and group */
-extern void SYS_DropRoot(uid_t uid, gid_t gid);
-
 typedef enum {
   SYS_MAIN_PROCESS,
   SYS_NTSKE_HELPER,
-} SYS_SystemCallContext;
+} SYS_ProcessContext;
+
+/* Switch to the specified user and group in given context */
+extern void SYS_DropRoot(uid_t uid, gid_t gid, SYS_ProcessContext context);
 
 /* Enable a system call filter to allow only system calls
    which chronyd normally needs after initialization */
-extern void SYS_EnableSystemCallFilter(int level, SYS_SystemCallContext context);
+extern void SYS_EnableSystemCallFilter(int level, SYS_ProcessContext context);
 
 extern void SYS_SetScheduler(int SchedPriority);
 extern void SYS_LockMemory(void);

sys_linux.c

@@ -426,7 +426,7 @@ SYS_Linux_Finalise(void)
 
 #ifdef FEAT_PRIVDROP
 void
-SYS_Linux_DropRoot(uid_t uid, gid_t gid, int clock_control)
+SYS_Linux_DropRoot(uid_t uid, gid_t gid, SYS_ProcessContext context, int clock_control)
 {
   char cap_text[256];
   cap_t cap;
@@ -437,16 +437,23 @@ SYS_Linux_DropRoot(uid_t uid, gid_t gid, int clock_control)
   
   UTI_DropRoot(uid, gid);
 
-  /* Keep CAP_NET_BIND_SERVICE if the NTP server sockets may need to be bound.
+  /* Keep CAP_NET_BIND_SERVICE if the NTP server sockets may need to be bound
-     Keep CAP_NET_RAW if an NTP socket may need to be bound to a device.
+     to a privileged port.
+     Keep CAP_NET_RAW if an NTP socket may need to be bound to a device on
+     kernels before 5.7.
      Keep CAP_SYS_TIME if the clock control is enabled. */
   if (snprintf(cap_text, sizeof (cap_text), "%s %s %s",
-               CNF_GetNTPPort() ? "cap_net_bind_service=ep" : "",
+               (CNF_GetNTPPort() > 0 && CNF_GetNTPPort() < 1024) ?
-               CNF_GetBindNtpInterface() || CNF_GetBindAcquisitionInterface() ?
+                 "cap_net_bind_service=ep" : "",
-                 "cap_net_raw=ep" : "",
+               (CNF_GetBindNtpInterface() || CNF_GetBindAcquisitionInterface()) &&
+                 !SYS_Linux_CheckKernelVersion(5, 7) ? "cap_net_raw=ep" : "",
                clock_control ? "cap_sys_time=ep" : "") >= sizeof (cap_text))
     assert(0);
 
+  /* Helpers don't need any capabilities */
+  if (context != SYS_MAIN_PROCESS)
+    cap_text[0] = '\0';
+
   if ((cap = cap_from_text(cap_text)) == NULL) {
     LOG_FATAL("cap_from_text() failed");
   }
@@ -477,9 +484,9 @@ void check_seccomp_applicability(void)
 /* ================================================== */
 
 void
-SYS_Linux_EnableSystemCallFilter(int level, SYS_SystemCallContext context)
+SYS_Linux_EnableSystemCallFilter(int level, SYS_ProcessContext context)
 {
-  const int syscalls[] = {
+  const int allowed[] = {
     /* Clock */
     SCMP_SYS(adjtimex),
     SCMP_SYS(clock_adjtime),
@@ -501,6 +508,7 @@ SYS_Linux_EnableSystemCallFilter(int level, SYS_SystemCallContext context)
     SCMP_SYS(getpid),
     SCMP_SYS(getrlimit),
     SCMP_SYS(getuid),
+    SCMP_SYS(getuid32),
     SCMP_SYS(rt_sigaction),
     SCMP_SYS(rt_sigreturn),
     SCMP_SYS(rt_sigprocmask),
@@ -530,17 +538,27 @@ SYS_Linux_EnableSystemCallFilter(int level, SYS_SystemCallContext context)
     SCMP_SYS(fchownat),
     SCMP_SYS(fstat),
     SCMP_SYS(fstat64),
+    SCMP_SYS(fstatat64),
     SCMP_SYS(getdents),
     SCMP_SYS(getdents64),
     SCMP_SYS(lseek),
+    SCMP_SYS(lstat),
+    SCMP_SYS(lstat64),
     SCMP_SYS(newfstatat),
+    SCMP_SYS(readlink),
+    SCMP_SYS(readlinkat),
     SCMP_SYS(rename),
     SCMP_SYS(renameat),
+#ifdef __NR_renameat2
     SCMP_SYS(renameat2),
+#endif
     SCMP_SYS(stat),
     SCMP_SYS(stat64),
     SCMP_SYS(statfs),
     SCMP_SYS(statfs64),
+#ifdef __NR_statx
+    SCMP_SYS(statx),
+#endif
     SCMP_SYS(unlink),
     SCMP_SYS(unlinkat),
 
@@ -596,6 +614,22 @@ SYS_Linux_EnableSystemCallFilter(int level, SYS_SystemCallContext context)
     SCMP_SYS(uname),
   };
 
+  const int denied_any[] = {
+    SCMP_SYS(execve),
+#ifdef __NR_execveat
+    SCMP_SYS(execveat),
+#endif
+    SCMP_SYS(fork),
+    SCMP_SYS(ptrace),
+    SCMP_SYS(vfork),
+  };
+
+  const int denied_ntske[] = {
+    SCMP_SYS(ioctl),
+    SCMP_SYS(setsockopt),
+    SCMP_SYS(socket),
+  };
+
   const int socket_domains[] = {
     AF_NETLINK, AF_UNIX, AF_INET,
 #ifdef FEAT_IPV6
@@ -604,9 +638,12 @@ SYS_Linux_EnableSystemCallFilter(int level, SYS_SystemCallContext context)
   };
 
   const static int socket_options[][2] = {
-    { SOL_IP, IP_PKTINFO }, { SOL_IP, IP_FREEBIND },
+    { SOL_IP, IP_PKTINFO }, { SOL_IP, IP_FREEBIND }, { SOL_IP, IP_TOS },
 #ifdef FEAT_IPV6
     { SOL_IPV6, IPV6_V6ONLY }, { SOL_IPV6, IPV6_RECVPKTINFO },
+#endif
+#ifdef SO_BINDTODEVICE
+    { SOL_SOCKET, SO_BINDTODEVICE },
 #endif
     { SOL_SOCKET, SO_BROADCAST }, { SOL_SOCKET, SO_REUSEADDR },
 #ifdef SO_REUSEPORT
@@ -645,31 +682,65 @@ SYS_Linux_EnableSystemCallFilter(int level, SYS_SystemCallContext context)
 #endif
   };
 
+  unsigned int default_action, deny_action;
   scmp_filter_ctx *ctx;
   int i;
 
+  /* Sign of the level determines the deny action (kill or SIGSYS).
+     At level 1, selected syscalls are allowed, others are denied.
+     At level 2, selected syscalls are denied, others are allowed. */
+
+  deny_action = level > 0 ? SCMP_ACT_KILL : SCMP_ACT_TRAP;
+  if (level < 0)
+    level = -level;
+
+  switch (level) {
+    case 1:
+      default_action = deny_action;
+      break;
+    case 2:
+      default_action = SCMP_ACT_ALLOW;
+      break;
+    default:
+      LOG_FATAL("Unsupported filter level");
+  }
+
   if (context == SYS_MAIN_PROCESS) {
     /* Check if the chronyd configuration is supported */
     check_seccomp_applicability();
 
-    /* Start the helper process, which will run without any seccomp filter.  It
+    /* At level 1, start a helper process which will not have a seccomp filter.
-       will be used for getaddrinfo(), for which it's difficult to maintain a
+       It will be used for getaddrinfo(), for which it is difficult to maintain
-       list of required system calls (with glibc it depends on what NSS modules
+       a list of required system calls (with glibc it depends on what NSS
-       are installed and enabled on the system). */
+       modules are installed and enabled on the system). */
-    PRV_StartHelper();
+    if (default_action != SCMP_ACT_ALLOW)
+      PRV_StartHelper();
   }
 
-  ctx = seccomp_init(level > 0 ? SCMP_ACT_KILL : SCMP_ACT_TRAP);
+  ctx = seccomp_init(default_action);
   if (ctx == NULL)
       LOG_FATAL("Failed to initialize seccomp");
 
-  /* Add system calls that are always allowed */
+  if (default_action != SCMP_ACT_ALLOW) {
-  for (i = 0; i < (sizeof (syscalls) / sizeof (*syscalls)); i++) {
+    for (i = 0; i < sizeof (allowed) / sizeof (*allowed); i++) {
-    if (seccomp_rule_add(ctx, SCMP_ACT_ALLOW, syscalls[i], 0) < 0)
+      if (seccomp_rule_add(ctx, SCMP_ACT_ALLOW, allowed[i], 0) < 0)
-      goto add_failed;
+        goto add_failed;
+    }
+  } else {
+    for (i = 0; i < sizeof (denied_any) / sizeof (*denied_any); i++) {
+      if (seccomp_rule_add(ctx, deny_action, denied_any[i], 0) < 0)
+        goto add_failed;
+    }
+
+    if (context == SYS_NTSKE_HELPER) {
+      for (i = 0; i < sizeof (denied_ntske) / sizeof (*denied_ntske); i++) {
+        if (seccomp_rule_add(ctx, deny_action, denied_ntske[i], 0) < 0)
+          goto add_failed;
+      }
+    }
   }
 
-  if (context == SYS_MAIN_PROCESS) {
+  if (default_action != SCMP_ACT_ALLOW && context == SYS_MAIN_PROCESS) {
     /* Allow opening sockets in selected domains */
     for (i = 0; i < sizeof (socket_domains) / sizeof (*socket_domains); i++) {
       if (seccomp_rule_add(ctx, SCMP_ACT_ALLOW, SCMP_SYS(socket), 1,
@@ -706,7 +777,8 @@ SYS_Linux_EnableSystemCallFilter(int level, SYS_SystemCallContext context)
   if (seccomp_load(ctx) < 0)
     LOG_FATAL("Failed to load seccomp rules");
 
-  LOG(context == SYS_MAIN_PROCESS ? LOGS_INFO : LOGS_DEBUG, "Loaded seccomp filter");
+  LOG(context == SYS_MAIN_PROCESS ? LOGS_INFO : LOGS_DEBUG,
+      "Loaded seccomp filter (level %d)", level);
   seccomp_release(ctx);
   return;
 

sys_linux.h

@@ -33,9 +33,9 @@ extern void SYS_Linux_Initialise(void);
 
 extern void SYS_Linux_Finalise(void);
 
-extern void SYS_Linux_DropRoot(uid_t uid, gid_t gid, int clock_control);
+extern void SYS_Linux_DropRoot(uid_t uid, gid_t gid, SYS_ProcessContext context, int clock_control);
 
-extern void SYS_Linux_EnableSystemCallFilter(int level, SYS_SystemCallContext context);
+extern void SYS_Linux_EnableSystemCallFilter(int level, SYS_ProcessContext context);
 
 extern int SYS_Linux_CheckKernelVersion(int req_major, int req_minor);
 

sys_macosx.c

@@ -4,7 +4,7 @@
  **********************************************************************
  * Copyright (C) Richard P. Curnow  1997-2001
  * Copyright (C) J. Hannken-Illjes  2001
- * Copyright (C) Bryan Christianson  2015, 2017
+ * Copyright (C) Bryan Christianson  2015, 2017, 2020
  *
  * 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
@@ -415,9 +415,10 @@ SYS_MacOSX_SetScheduler(int SchedPriority)
 /* ================================================== */
 
 #ifdef FEAT_PRIVDROP
-void SYS_MacOSX_DropRoot(uid_t uid, gid_t gid)
+void SYS_MacOSX_DropRoot(uid_t uid, gid_t gid, SYS_ProcessContext context)
 {
-  PRV_StartHelper();
+  if (context == SYS_MAIN_PROCESS)
+    PRV_StartHelper();
 
   UTI_DropRoot(uid, gid);
 }

sys_macosx.h

@@ -30,8 +30,10 @@
 #ifndef GOT_SYS_MACOSX_H
 #define GOT_SYS_MACOSX_H
 
+#include "sys.h"
+
 void SYS_MacOSX_SetScheduler(int SchedPriority);
-void SYS_MacOSX_DropRoot(uid_t uid, gid_t gid);
+void SYS_MacOSX_DropRoot(uid_t uid, gid_t gid, SYS_ProcessContext context);
 void SYS_MacOSX_Initialise(void);
 void SYS_MacOSX_Finalise(void);
 

sys_netbsd.c

@@ -131,7 +131,7 @@ SYS_NetBSD_Finalise(void)
 
 #ifdef FEAT_PRIVDROP
 void
-SYS_NetBSD_DropRoot(uid_t uid, gid_t gid)
+SYS_NetBSD_DropRoot(uid_t uid, gid_t gid, SYS_ProcessContext context, int clock_control)
 {
 #ifdef NETBSD
   int fd;
@@ -139,11 +139,15 @@ SYS_NetBSD_DropRoot(uid_t uid, gid_t gid)
 
   /* On NetBSD the helper is used only for socket binding, but on FreeBSD
      it's used also for setting and adjusting the system clock */
-  PRV_StartHelper();
+  if (context == SYS_MAIN_PROCESS)
+    PRV_StartHelper();
 
   UTI_DropRoot(uid, gid);
 
 #ifdef NETBSD
+  if (!clock_control)
+    return;
+
   /* Check if we have write access to /dev/clockctl */
   fd = open("/dev/clockctl", O_WRONLY);
   if (fd < 0)

sys_netbsd.h

@@ -28,10 +28,12 @@
 #ifndef GOT_SYS_NETBSD_H
 #define GOT_SYS_NETBSD_H
 
+#include "sys.h"
+
 void SYS_NetBSD_Initialise(void);
 
 void SYS_NetBSD_Finalise(void);
 
-void SYS_NetBSD_DropRoot(uid_t uid, gid_t gid);
+void SYS_NetBSD_DropRoot(uid_t uid, gid_t gid, SYS_ProcessContext context, int clock_control);
 
 #endif

sys_solaris.c

@@ -55,9 +55,10 @@ SYS_Solaris_Finalise(void)
 
 #ifdef FEAT_PRIVDROP
 void
-SYS_Solaris_DropRoot(uid_t uid, gid_t gid)
+SYS_Solaris_DropRoot(uid_t uid, gid_t gid, SYS_ProcessContext context)
 {
-  PRV_StartHelper();
+  if (context == SYS_MAIN_PROCESS)
+    PRV_StartHelper();
   UTI_DropRoot(uid, gid);
 }
 #endif

sys_solaris.h

@@ -27,10 +27,12 @@
 #ifndef GOT_SYS_SOLARIS_H
 #define GOT_SYS_SOLARIS_H
 
+#include "sys.h"
+
 void SYS_Solaris_Initialise(void);
 
 void SYS_Solaris_Finalise(void);
 
-void SYS_Solaris_DropRoot(uid_t uid, gid_t gid);
+void SYS_Solaris_DropRoot(uid_t uid, gid_t gid, SYS_ProcessContext context);
 
 #endif

sys_timex.c

@@ -68,6 +68,18 @@ static int sys_tai_offset;
 
 /* ================================================== */
 
+static double
+convert_timex_frequency(const struct timex *txc)
+{
+  double freq_ppm;
+
+  freq_ppm = txc->freq / FREQ_SCALE;
+
+  return -freq_ppm;
+}
+
+/* ================================================== */
+
 static double
 read_frequency(void)
 {
@@ -77,7 +89,7 @@ read_frequency(void)
 
   SYS_Timex_Adjust(&txc, 0);
 
-  return txc.freq / -FREQ_SCALE;
+  return convert_timex_frequency(&txc);
 }
 
 /* ================================================== */
@@ -92,7 +104,7 @@ set_frequency(double freq_ppm)
 
   SYS_Timex_Adjust(&txc, 0);
 
-  return txc.freq / -FREQ_SCALE;
+  return convert_timex_frequency(&txc);
 }
 
 /* ================================================== */

sysincl.h

@@ -28,6 +28,7 @@
 #ifndef GOT_SYSINCL_H
 #define GOT_SYSINCL_H
 
+#include <arpa/inet.h>
 #include <assert.h>
 #include <ctype.h>
 #include <errno.h>
@@ -61,11 +62,6 @@
 #include <sys/timex.h>
 #endif
 
-#ifdef FEAT_IPV6
-/* For inet_ntop() */
-#include <arpa/inet.h>
-#endif
-
 #ifdef HAVE_GETRANDOM
 #include <sys/random.h>
 #endif

test/compilation/001-features

@@ -17,12 +17,15 @@ for opts in \
 	"--disable-rtc" \
 	"--disable-sechash" \
 	"--disable-cmdmon" \
+	"--disable-cmdmon --enable-scfilter" \
 	"--disable-ntp" \
+	"--disable-ntp --enable-scfilter" \
 	"--disable-nts" \
 	"--disable-refclock" \
 	"--disable-timestamping" \
 	"--disable-timestamping --disable-ntp" \
 	"--disable-cmdmon --disable-ntp" \
+	"--disable-cmdmon --disable-ntp --enable-scfilter" \
 	"--disable-cmdmon --disable-refclock" \
 	"--disable-cmdmon --disable-ntp --disable-refclock"
 do

test/compilation/003-sanitizers

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Run the unit and simulation tests with different compiler sanitizers
 # and under valgrind
 
@@ -80,7 +80,12 @@ for CC in gcc clang; do
 
         echo
         pushd test/simulation || exit 1
-        CLKNETSIM_RANDOM_SEED=101 ./run -i 1 || exit 1
+        export CLKNETSIM_RANDOM_SEED=101
+        if [ "$arch_opts" = "" -a "$san_options" = "" ]; then
+          CLKNETSIM_CLIENT_WRAPPER=valgrind ./run -i 1 || exit 1
+        else
+          ./run -i 1 || exit 1
+        fi
         popd
       done
     done

test/kernel/ntpadjtime.c

@@ -52,15 +52,15 @@ test_freqrange(void)
 
   printf("freq range:\n");
 
-  for (i = 0; i <= 1000; i += 50) {
+  for (i = -1000; i <= 1000; i += 50) {
     t.modes = MOD_FREQUENCY;
-    t.freq = i << 16;
+    t.freq = i * (1 << 16);
     printf("%4d ppm => ", i);
     if (try_ntpadjtime(&t) < 0)
       continue;
 
     printf("%4ld ppm : ", t.freq / (1 << 16));
-    printf("%s\n", t.freq == i << 16 ? "ok" : "fail");
+    printf("%s\n", t.freq == i * (1 << 16) ? "ok" : "fail");
   }
 }
 

test/simulation/001-defaults

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/002-largenetwork

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/003-largefreqoffset

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/004-largetimeoffset

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/005-externalstep

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/006-largejitter

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/007-largewander

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/008-ntpera

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 test_start "NTP eras"

test/simulation/009-sourceselection

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/010-multrecv

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/011-asymjitter

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/012-daemonts

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/013-nameserv

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/101-poll

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 test_start "minpoll/maxpoll options"

test/simulation/102-iburst

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 test_start "iburst option"

test/simulation/103-initstepslew

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 test_start "initstepslew directive"
@@ -9,6 +9,7 @@ time_rms_limit=1e-3
 limit=100
 
 client_conf="initstepslew 5 192.168.123.1"
+client_server_conf="#"
 
 min_sync_time=6
 max_sync_time=35
@@ -18,6 +19,7 @@ for time_offset in -2.0 -0.2 0.2 2.0; do
 	check_chronyd_exit || test_fail
 	check_packet_interval || test_fail
 	check_sync || test_fail
+	check_log_messages "00:00:0.Z System's initial.*slew" 1 1 || test_fail
 done
 
 min_sync_time=5
@@ -27,6 +29,35 @@ for time_offset in -1e8 -1e2 1e2 1e8; do
 	run_test || test_fail
 	check_packet_interval || test_fail
 	check_sync || test_fail
+	check_log_messages "System's initial.*step" 1 1 || test_fail
 done
 
+time_offset=3
+limit=500
+servers=2
+falsetickers=1
+client_conf="initstepslew 5 192.168.123.1 192.168.123.2"
+client_server_conf="server 192.168.123.2"
+
+min_sync_time=360
+max_sync_time=450
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+check_log_messages "00:03:2.Z No suitable source for initstepslew" 1 1 || test_fail
+
+client_conf="initstepslew 5 192.168.123.1 192.168.123.2"
+
+min_sync_time=1
+max_sync_time=500
+server_conf="deny all"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval || test_fail
+check_sync && test_fail
+check_log_messages "00:00:1.Z No suitable source for initstepslew" 1 1 || test_fail
+
 test_pass

test/simulation/104-driftfile

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 test_start "driftfile directive"

test/simulation/105-ntpauth

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/106-refclock

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 test_start "SHM refclock"
@@ -16,7 +16,9 @@ chronyc_start=70
 chronyc_conf="tracking"
 
 for refclock in "SHM 0" "PHC /dev/ptp0"; do
-	client_conf="refclock $refclock stratum 3 delay 1e-3 refid GPS"
+	client_conf="refclock $refclock stratum 3 delay 1e-3 refid GPS
+logdir tmp
+log refclocks"
 
 	run_test || test_fail
 	check_chronyd_exit || test_fail
@@ -29,6 +31,79 @@ Root delay      : 0.001000000 seconds
 .*
 Update interval : 16\.. seconds
 .*$" || test_fail
+
+	check_file_messages "20.* GPS.*[0-9] N " 997 1001 refclocks.log || test_fail
+	check_file_messages "20.* GPS.*- N " 61 63 refclocks.log || test_fail
+	rm -f tmp/refclocks.log
 done
 
+if check_config_h 'FEAT_PPS 1'; then
+	refclock_offset=0.35
+	refclock_jitter=0.05
+
+	client_conf="
+refclock SHM 0 refid NMEA noselect
+refclock PPS /dev/pps0 lock NMEA
+logdir tmp
+log refclocks"
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
+	check_chronyc_output "^Reference ID.*50505331 \(PPS1\)
+Stratum.*: 1
+.*
+Root delay      : 0\.000000001 seconds
+.*$" || test_fail
+
+	check_file_messages "20.* PPS1.*[0-9] N " 620 740 refclocks.log || test_fail
+	check_file_messages "20.* PPS1.*- N " 60 63 refclocks.log || test_fail
+	rm -f tmp/refclocks.log
+
+	client_conf="
+refclock SHM 0 noselect
+refclock PPS /dev/pps0
+local
+logdir tmp
+log refclocks"
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
+	check_chronyc_output "^Reference ID.*50505331 \(PPS1\)
+Stratum.*: 10
+.*
+Root delay      : 0\.000000001 seconds
+.*$" || test_fail
+
+	check_file_messages "20.* PPS1.*[0-9] N " 997 1001 refclocks.log || test_fail
+	check_file_messages "20.* PPS1.*- N " 60 63 refclocks.log || test_fail
+	rm -f tmp/refclocks.log
+
+	min_sync_time=100
+	max_sync_time=220
+	chronyc_start=220
+	client_conf="
+refclock SHM 0 refid NMEA offset 0.35 delay 0.1
+refclock PPS /dev/pps0
+logdir tmp
+log refclocks"
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
+	check_chronyc_output "^Reference ID.*50505331 \(PPS1\)
+Stratum.*: 1
+.*
+Root delay      : 0\.000000001 seconds
+.*$" || test_fail
+
+	check_file_messages "20.* PPS1.*[0-9] N " 800 940  refclocks.log || test_fail
+	check_file_messages "20.* PPS1.*- N " 50 63 refclocks.log || test_fail
+	rm -f tmp/refclocks.log
+fi
+
 test_pass

test/simulation/107-allowdeny

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/108-peer

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/109-makestep

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 test_start "makestep directive"

test/simulation/110-chronyc

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 
@@ -101,7 +101,7 @@ limit=1
 for chronyc_conf in \
 	"accheck 1.2.3.4" \
 	"add peer 10.0.0.0 minpoll 2 maxpoll 6" \
-	"add server 10.0.0.0 minpoll 6 maxpoll 10 iburst burst key 1 maxdelay 1e-3 maxdelayratio 10.0 maxdelaydevratio 10.0 mindelay 1e-4 asymmetry 0.5 offset 1e-5 minsamples 6 maxsamples 6 filter 3 offline auto_offline prefer noselect trust require xleave polltarget 20 port 123 presend 7 minstratum 3 version 4" \
+	"add server 10.0.0.0 minpoll 6 maxpoll 10 iburst burst key 1 certset 2 maxdelay 1e-3 maxdelayratio 10.0 maxdelaydevratio 10.0 mindelay 1e-4 asymmetry 0.5 offset 1e-5 minsamples 6 maxsamples 6 filter 3 offline auto_offline prefer noselect trust require xleave polltarget 20 port 123 presend 7 minstratum 3 version 4 nts ntsport 4460 copy" \
 	"add server node1.net1.clk" \
 	"allow 1.2.3.4" \
 	"allow 1.2" \
@@ -223,4 +223,23 @@ keygen 7 AES256"
 7 AES256 HEX:................................................................\$" || test_fail
 fi
 
+# Pass every fourth request
+base_delay=$(cat <<-EOF | tr -d '\n'
+  (+ 1e-4
+     (* -1
+        (equal 0.1 from 2)
+        (equal 0.1 (min (% (sum 1) 4) 1) 1)))
+EOF
+)
+limit=15
+
+chronyc_conf="sources"
+run_test || test_fail
+check_chronyc_output "^506 Cannot talk to daemon$" || test_fail
+
+chronyc_conf="retries 3
+sources"
+run_test || test_fail
+check_chronyc_output "^MS.*0ns$" || test_fail
+
 test_pass

test/simulation/111-knownclient

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/112-port

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common
 

test/simulation/113-leapsecond

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . ./test.common