examples: add leapsectz to configuration examples

Although gmtime() is expected to convert any time of the system clock at
least in the next few NTP eras, a correct code should always check the
returned value and this shouldn't be a fatal error in handling of leap
seconds.

conf.c

@@ -1335,7 +1335,11 @@ parse_include(char *line)
 
   check_number_of_args(line, 1);
 
-  if ((r = glob(line, GLOB_ERR | GLOB_NOMAGIC, NULL, &gl)) != 0) {
+  if ((r = glob(line,
+#ifdef GLOB_NOMAGIC
+                GLOB_NOMAGIC |
+#endif
+                GLOB_ERR, NULL, &gl)) != 0) {
     if (r != GLOB_NOMATCH)
       LOG_FATAL("Could not search for files matching %s", line);
 

doc/chrony.conf.adoc

@@ -500,7 +500,7 @@ This option specifies the width of the pulses (in seconds). It is used to
 filter PPS samples when the driver provides samples for both rising and falling
 edges. Note that it reduces the maximum allowed error of the time source which
 completes the PPS samples. If the duty cycle is configurable, 50% should be
-prefered in order to maximise the allowed error.
+preferred in order to maximise the allowed error.
 *pps*:::
 This options forces *chronyd* to treat any refclock (e.g. SHM or PHC) as a PPS
 refclock. This can be useful when the refclock provides time with a variable

examples/chrony.conf.example2

@@ -28,6 +28,9 @@ rtcsync
 # Specify file containing keys for NTP authentication.
 #keyfile /etc/chrony.keys
 
+# Get TAI-UTC offset and leap seconds from the system tz database.
+#leapsectz right/UTC
+
 # Specify directory for log files.
 logdir /var/log/chrony
 

examples/chrony.conf.example3

@@ -97,6 +97,12 @@ driftfile /var/lib/chrony/drift
 
 ! pidfile /var/run/chronyd.pid
 
+# If the system timezone database is kept up to date and includes the
+# right/UTC timezone, chronyd can use it to determine the current
+# TAI-UTC offset and when will the next leap second occur.
+
+! leapsectz right/UTC
+
 #######################################################################
 ### INITIAL CLOCK CORRECTION
 # This option is useful to quickly correct the clock on start if it's

reference.c

@@ -609,7 +609,14 @@ is_offset_ok(double offset)
 /* ================================================== */
 
 static int
-is_leap_second_day(struct tm *stm) {
+is_leap_second_day(time_t when)
+{
+  struct tm *stm;
+
+  stm = gmtime(&when);
+  if (!stm)
+    return 0;
+
   /* Allow leap second only on the last day of June and December */
   return (stm->tm_mon == 5 && stm->tm_mday == 30) ||
          (stm->tm_mon == 11 && stm->tm_mday == 31);
@@ -624,7 +631,7 @@ get_tz_leap(time_t when, int *tai_offset)
   static NTP_Leap tz_leap;
   static int tz_tai_offset;
 
-  struct tm stm;
+  struct tm stm, *tm;
   time_t t;
   char *tz_env, tz_orig[128];
 
@@ -639,7 +646,11 @@ get_tz_leap(time_t when, int *tai_offset)
   tz_leap = LEAP_Normal;
   tz_tai_offset = 0;
 
-  stm = *gmtime(&when);
+  tm = gmtime(&when);
+  if (!tm)
+    return tz_leap;
+
+  stm = *tm;
 
   /* Temporarily switch to the timezone containing leap seconds */
   tz_env = getenv("TZ");
@@ -784,7 +795,7 @@ update_leap_status(NTP_Leap leap, time_t now, int reset)
   if (leap == LEAP_InsertSecond || leap == LEAP_DeleteSecond) {
     /* Check that leap second is allowed today */
 
-    if (is_leap_second_day(gmtime(&now))) {
+    if (is_leap_second_day(now)) {
       if (leap == LEAP_InsertSecond) {
         leap_sec = 1;
       } else {

test/unit/keys.c

@@ -134,8 +134,8 @@ test_unit(void)
       UTI_GetRandomBytes(&key, sizeof (key));
       if (KEY_KeyKnown(key))
         continue;
-      TEST_CHECK(!KEY_GenerateAuth(j, data, data_len, auth, sizeof (auth)));
-      TEST_CHECK(!KEY_CheckAuth(j, data, data_len, auth, auth_len, auth_len));
+      TEST_CHECK(!KEY_GenerateAuth(key, data, data_len, auth, sizeof (auth)));
+      TEST_CHECK(!KEY_CheckAuth(key, data, data_len, auth, auth_len, auth_len));
     }
   }