doc: update NEWS

In NIO_Linux_RequestTxTimestamp(), check the returned pointer and the
length of the buffer before adding the control message. This fixes an
issue reported by the Clang static analyzer.

NEWS

@@ -4,6 +4,8 @@ New in version 3.5
 Enhancements
 ------------
 * Add support for more accurate reading of PHC on Linux 5.0
+* Add support for hardware timestamping on interfaces with read-only
+  timestamping configuration
 * Add support for memory locking and real-time priority on FreeBSD,
   NetBSD, Solaris
 * Update seccomp filter to work on more architectures

client.c

@@ -3159,7 +3159,7 @@ static void
 display_gpl(void)
 {
     printf("chrony version %s\n"
-           "Copyright (C) 1997-2003, 2007, 2009-2018 Richard P. Curnow and others\n"
+           "Copyright (C) 1997-2003, 2007, 2009-2019 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",

configure

@@ -6,6 +6,7 @@
 # Copyright (C) Richard P. Curnow  1997-2003
 # Copyright (C) Bryan Christianson  2016
 # Copyright (C) Miroslav Lichvar  2009, 2012-2018
+# Copyright (C) Stefan R. Filipek  2019
 #
 # =======================================================================
 

doc/faq.adoc

@@ -267,6 +267,10 @@ maxchange 1000 1 1
 maxclockerror 15
 ----
 
+Note that increasing `minsamples` may cause the offsets in the `tracking` and
+`sourcestats` reports/logs to be significantly smaller than the actual offsets
+and be unsuitable for monitoring.
+
 === What happened to the `commandkey` and `generatecommandkey` directives?
 
 They were removed in version 2.2. Authentication is no longer supported in the

examples/chronyd.service

@@ -7,7 +7,7 @@ ConditionCapability=CAP_SYS_TIME
 
 [Service]
 Type=forking
-PIDFile=/var/run/chrony/chronyd.pid
+PIDFile=/run/chrony/chronyd.pid
 EnvironmentFile=-/etc/sysconfig/chronyd
 ExecStart=/usr/sbin/chronyd $OPTIONS
 PrivateTmp=yes

ntp_io_linux.c

@@ -2,7 +2,7 @@
   chronyd/chronyc - Programs for keeping computer clocks accurate.
 
  **********************************************************************
- * Copyright (C) Miroslav Lichvar  2016-2018
+ * Copyright (C) Miroslav Lichvar  2016-2019
  * 
  * 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
@@ -123,7 +123,7 @@ add_interface(CNF_HwTsInterface *conf_iface)
   struct ethtool_ts_info ts_info;
   struct hwtstamp_config ts_config;
   struct ifreq req;
-  int sock_fd, if_index, phc_fd, req_hwts_flags;
+  int sock_fd, if_index, phc_fd, req_hwts_flags, rx_filter;
   unsigned int i;
   struct Interface *iface;
 
@@ -177,40 +177,51 @@ add_interface(CNF_HwTsInterface *conf_iface)
     return 0;
   }
 
-  ts_config.flags = 0;
-  ts_config.tx_type = HWTSTAMP_TX_ON;
-
   switch (conf_iface->rxfilter) {
     case CNF_HWTS_RXFILTER_ANY:
 #ifdef HAVE_LINUX_TIMESTAMPING_RXFILTER_NTP
       if (ts_info.rx_filters & (1 << HWTSTAMP_FILTER_NTP_ALL))
-        ts_config.rx_filter = HWTSTAMP_FILTER_NTP_ALL;
+        rx_filter = HWTSTAMP_FILTER_NTP_ALL;
       else
 #endif
       if (ts_info.rx_filters & (1 << HWTSTAMP_FILTER_ALL))
-        ts_config.rx_filter = HWTSTAMP_FILTER_ALL;
+        rx_filter = HWTSTAMP_FILTER_ALL;
       else
-        ts_config.rx_filter = HWTSTAMP_FILTER_NONE;
+        rx_filter = HWTSTAMP_FILTER_NONE;
       break;
     case CNF_HWTS_RXFILTER_NONE:
-      ts_config.rx_filter = HWTSTAMP_FILTER_NONE;
+      rx_filter = HWTSTAMP_FILTER_NONE;
       break;
 #ifdef HAVE_LINUX_TIMESTAMPING_RXFILTER_NTP
     case CNF_HWTS_RXFILTER_NTP:
-      ts_config.rx_filter = HWTSTAMP_FILTER_NTP_ALL;
+      rx_filter = HWTSTAMP_FILTER_NTP_ALL;
       break;
 #endif
     default:
-      ts_config.rx_filter = HWTSTAMP_FILTER_ALL;
+      rx_filter = HWTSTAMP_FILTER_ALL;
       break;
   }
 
+  ts_config.flags = 0;
+  ts_config.tx_type = HWTSTAMP_TX_ON;
+  ts_config.rx_filter = rx_filter;
   req.ifr_data = (char *)&ts_config;
 
   if (ioctl(sock_fd, SIOCSHWTSTAMP, &req)) {
     DEBUG_LOG("ioctl(%s) failed : %s", "SIOCSHWTSTAMP", strerror(errno));
-    close(sock_fd);
-    return 0;
+
+    /* Check the current timestamping configuration in case this interface
+       allows only reading of the configuration and it was already configured
+       as requested */
+    req.ifr_data = (char *)&ts_config;
+#ifdef SIOCGHWTSTAMP
+    if (ioctl(sock_fd, SIOCGHWTSTAMP, &req) ||
+        ts_config.tx_type != HWTSTAMP_TX_ON || ts_config.rx_filter != rx_filter)
+#endif
+    {
+      close(sock_fd);
+      return 0;
+    }
   }
 
   close(sock_fd);
@@ -845,7 +856,12 @@ NIO_Linux_RequestTxTimestamp(struct msghdr *msg, int cmsglen, int sock_fd)
   /* Add control message that will enable TX timestamping for this message.
      Don't use CMSG_NXTHDR as the one in glibc is buggy for creating new
      control messages. */
-  cmsg = (struct cmsghdr *)((char *)CMSG_FIRSTHDR(msg) + cmsglen);
+
+  cmsg = CMSG_FIRSTHDR(msg);
+  if (!cmsg || cmsglen + CMSG_SPACE(sizeof (ts_tx_flags)) > msg->msg_controllen)
+    return cmsglen;
+
+  cmsg = (struct cmsghdr *)((char *)cmsg + cmsglen);
   memset(cmsg, 0, CMSG_SPACE(sizeof (ts_tx_flags)));
   cmsglen += CMSG_SPACE(sizeof (ts_tx_flags));
 

refclock.c

@@ -2,7 +2,7 @@
   chronyd/chronyc - Programs for keeping computer clocks accurate.
 
  **********************************************************************
- * Copyright (C) Miroslav Lichvar  2009-2011, 2013-2014, 2016-2018
+ * Copyright (C) Miroslav Lichvar  2009-2011, 2013-2014, 2016-2019
  * 
  * 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
@@ -350,7 +350,7 @@ RCL_CheckDriverOptions(RCL_Instance instance, const char **options)
        option = get_next_driver_option(instance, option)) {
     for (i = 0; options && options[i]; i++) {
       len = strlen(options[i]);
-      if (!strncmp(options[i], option, strlen(options[i])) &&
+      if (!strncmp(options[i], option, len) &&
           (option[len] == '=' || option[len] == '\0'))
         break;
     }

test/simulation/133-hwtimestamp

@@ -13,22 +13,25 @@ refclock_offset=10.0
 min_sync_time=4
 max_sync_time=20
 limit=200
-client_conf="hwtimestamp eth0"
-client_server_options="minpoll 0 maxpoll 0 minsamples 32"
+server_conf="hwtimestamp eth0"
+client_server_options="minpoll 0 maxpoll 0 minsamples 32 xleave"
 client_chronyd_options="-d"
 
-run_test || test_fail
-check_chronyd_exit || test_fail
-check_source_selection || test_fail
-check_sync || test_fail
+for client_conf in "hwtimestamp eth0" "hwtimestamp eth0
+acquisitionport 123"; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
 
-if check_config_h 'FEAT_DEBUG 1'; then
-	check_log_messages "HW clock samples" 190 200 || test_fail
-	check_log_messages "HW clock reset" 0 0 || test_fail
-	check_log_messages "Received.*tss=1" 1 1 || test_fail
-	check_log_messages "Received.*tss=2" 390 400 || test_fail
-	check_log_messages "update_tx_timestamp.*Updated" 50 140 || test_fail
-	check_log_messages "update_tx_timestamp.*Unacceptable" 50 140 || test_fail
-fi
+	if check_config_h 'FEAT_DEBUG 1'; then
+		check_log_messages "HW clock samples" 190 200 || test_fail
+		check_log_messages "HW clock reset" 0 0 || test_fail
+		check_log_messages "Received.*tss=1" 1 1 || test_fail
+		check_log_messages "Received.*tss=2" 390 400 || test_fail
+		check_log_messages "update_tx_timestamp.*Updated" 50 140 || test_fail
+		check_log_messages "update_tx_timestamp.*Unacceptable" 50 140 || test_fail
+	fi
+done
 
 test_pass