Merge ntpd & friends 4.2.4p5 from vendor/ntp/dist into head. Next commit

will update usr.sbin/ntp to match this.

MFC after:	2 weeks

1 files changed, 73 insertions, 9 deletions

diff --git a/contrib/ntp/libntp/prettydate.c b/contrib/ntp/libntp/prettydate.c
index 9710c84..55adf64 100644
--- a/contrib/ntp/libntp/prettydate.c
+++ b/contrib/ntp/libntp/prettydate.c
@@ -17,6 +17,60 @@ static const char *days[] = {
   "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
 };
 
+/* Helper function to handle possible wraparound of the ntp epoch.
+
+   Works by assuming that the localtime/gmtime library functions 
+   have been updated so that they work
+*/
+
+#define MAX_EPOCH_NR 1000
+
+struct tm *
+ntp2unix_tm(
+	u_long ntp, int local
+	)
+{
+	time_t t, curr;
+	struct tm *tm;
+	int curr_year, epoch_nr;
+
+	/* First get the current year: */
+	curr = time(NULL);
+	tm = local ? localtime(&curr) : gmtime(&curr);
+	if (!tm) return NULL;
+
+	curr_year = 1900 + tm->tm_year;
+
+	/* Convert the ntp timestamp to a unix utc seconds count: */
+	t = (time_t) ntp - JAN_1970;
+
+	/* Check that the ntp timestamp is not before a 136 year window centered
+	   around the current year:
+
+	   Failsafe in case of an infinite loop:
+       Allow up to 1000 epochs of 136 years each!
+	*/
+    for (epoch_nr = 0; epoch_nr < MAX_EPOCH_NR; epoch_nr++) {
+		tm = local ? localtime(&t) : gmtime(&t);
+
+#if SIZEOF_TIME_T < 4
+# include "Bletch: sizeof(time_t) < 4!"
+#endif
+
+#if SIZEOF_TIME_T == 4
+		/* If 32 bits, then year is 1970-2038, so no sense looking */
+		epoch_nr = MAX_EPOCH_NR;
+#else	/* SIZEOF_TIME_T > 4 */
+		/* Check that the resulting year is in the correct epoch: */
+		if (1900 + tm->tm_year > curr_year - 68) break;
+
+		/* Epoch wraparound: Add 2^32 seconds! */
+		t += (time_t) 65536 << 16;
+#endif /* SIZEOF_TIME_T > 4 */
+	}
+	return tm;
+}
+
 char *
 prettydate(
 	l_fp *ts
@@ -29,15 +83,20 @@ prettydate(
 
 	LIB_GETBUF(bp);
 	
-	sec = ts->l_ui - JAN_1970;
+	sec = ts->l_ui;
 	msec = ts->l_uf / 4294967;	/* fract / (2 ** 32 / 1000) */
 
-	tm = localtime(&sec);
-
-	(void) sprintf(bp, "%08lx.%08lx  %s, %s %2d %4d %2d:%02d:%02d.%03lu",
+	tm = ntp2unix_tm(sec, 1);
+	if (!tm) {
+		(void) sprintf(bp, "%08lx.%08lx  --- --- -- ---- --:--:--",
+		       (u_long)ts->l_ui, (u_long)ts->l_uf);
+	}
+	else {
+		(void) sprintf(bp, "%08lx.%08lx  %s, %s %2d %4d %2d:%02d:%02d.%03lu",
 		       (u_long)ts->l_ui, (u_long)ts->l_uf, days[tm->tm_wday],
 		       months[tm->tm_mon], tm->tm_mday, 1900 + tm->tm_year,
 		       tm->tm_hour,tm->tm_min, tm->tm_sec, msec);
+	}
 	
 	return bp;
 }
@@ -54,15 +113,20 @@ gmprettydate(
 
 	LIB_GETBUF(bp);
 	
-	sec = ts->l_ui - JAN_1970;
+	sec = ts->l_ui;
 	msec = ts->l_uf / 4294967;	/* fract / (2 ** 32 / 1000) */
 
-	tm = gmtime(&sec);
-
-	(void) sprintf(bp, "%08lx.%08lx  %s, %s %2d %4d %2d:%02d:%02d.%03lu UTC",
+	tm = ntp2unix_tm(sec, 0);
+	if (!tm) {
+		(void) sprintf(bp, "%08lx.%08lx  --- --- -- ---- --:--:--",
+		       (u_long)ts->l_ui, (u_long)ts->l_uf);
+	}
+	else {
+		(void) sprintf(bp, "%08lx.%08lx  %s, %s %2d %4d %2d:%02d:%02d.%03lu",
 		       (u_long)ts->l_ui, (u_long)ts->l_uf, days[tm->tm_wday],
 		       months[tm->tm_mon], tm->tm_mday, 1900 + tm->tm_year,
 		       tm->tm_hour,tm->tm_min, tm->tm_sec, msec);
-	
+	}
+
 	return bp;
 }