From 08353c7cc596d2d09fd7f22a9bfde4d83bd9ebda Mon Sep 17 00:00:00 2001
From: systemd team <systemd-maint@redhat.com>
Date: Tue, 8 Nov 2016 17:06:01 -0500
Subject: [PATCH 1/1] inject millisec in syslog date

---
 src/journal/journald-syslog.c | 48 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 42 insertions(+), 6 deletions(-)

diff --git a/src/journal/journald-syslog.c b/src/journal/journald-syslog.c
index 4e118aa..85cdeb9 100644
--- a/src/journal/journald-syslog.c
+++ b/src/journal/journald-syslog.c
@@ -35,6 +35,44 @@
 /* Warn once every 30s if we missed syslog message */
 #define WARN_FORWARD_SYSLOG_MISSED_USEC (30 * USEC_PER_SEC)
 
+/*  internal function that builds a formatted time str of the
+ *  tv parameter into the passed buffer. (ie Nov  7 16:28:38.109)
+ *  If tv is NULL, then the clock function is used to build the formatted time
+ *  returns (same as snprintf) - number of characters written to buffer.
+ */
+static int formatSyslogDate(char * buffer, int bufLen, const struct timeval *tv) {
+  struct timeval tv_tmp;
+  long int millisec;
+  char tmpbuf[64];
+  struct tm *tm;
+  time_t t;
+
+  if (!tv) {
+      // no timeval input so get time data from clock
+      usec_t now_usec  = now(CLOCK_REALTIME);
+      time_t now_sec = ((time_t) now_usec / USEC_PER_SEC);
+      long int now_fraction_secs = now_usec % USEC_PER_SEC;
+      tv_tmp.tv_sec = now_sec;
+      tv_tmp.tv_usec = now_fraction_secs;
+      tv = &tv_tmp;
+  }
+
+  t = tv->tv_sec;
+  tm = localtime(&t);
+  if (!tm)
+     return 0;
+
+  // format time to the second granularity - ie Nov  7 16:28:38
+  if (strftime(tmpbuf,sizeof(tmpbuf),"%h %e %T", tm) <= 0)
+     return 0;
+
+  millisec = tv->tv_usec / 1000;
+  // now append millisecond granularity (ie Nov  7 16:28:38.109) to
+  // the formatted string.
+  return snprintf(buffer, bufLen, "%s.%03lu", tmpbuf, millisec);
+}
+
+
 static void forward_syslog_iovec(Server *s, const struct iovec *iovec, unsigned n_iovec, const struct ucred *ucred, const struct timeval *tv) {
 
         static const union sockaddr_union sa = {
@@ -143,13 +181,11 @@ void server_forward_syslog(Server *s, int priority, const char *identifier, cons
         xsprintf(header_priority, "<%i>", priority);
         IOVEC_SET_STRING(iovec[n++], header_priority);
 
+
         /* Second: timestamp */
-        t = tv ? tv->tv_sec : ((time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC));
-        tm = localtime(&t);
-        if (!tm)
-                return;
-        if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
-                return;
+        if (formatSyslogDate(header_time, sizeof(header_time), tv) <=0 )
+           return;
+
         IOVEC_SET_STRING(iovec[n++], header_time);
 
         /* Third: identifier and PID */
-- 
1.9.1