From: Harlan Stenn <stenn@ntp.org>
Date: Thu, 14 Jun 2007 05:40:14 +0000 (-0400)
Subject: Leap file fixes from Dave Mills
X-Git-Tag: NTP_4_2_5P49~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0e909aaa22a8b2eb97611ec59df657b253052afe;p=thirdparty%2Fntp.git

Leap file fixes from Dave Mills

bk: 4670d4beZKM2hDQD3TySou_OCkk35g
---

diff --git a/ChangeLog b/ChangeLog
index b03cae2d9..d7d5b2730 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,4 @@
+* Leap file fixes from Dave Mills.
 * [Bug 858] Recent leapfile changes broke without OPENSSL.
 * Use a char for DIR_SEP, not a string.
 * [Bug 850] driftfile parsing changes.
diff --git a/include/ntpd.h b/include/ntpd.h
index 83e146dc4..4d0771ab3 100644
--- a/include/ntpd.h
+++ b/include/ntpd.h
@@ -122,7 +122,6 @@ extern	void	loop_config (int, double);
 extern	void	huffpuff	(void);
 extern	u_long	sys_clocktime;
 extern	u_int	sys_tai;
-extern	u_long	sys_leapin;
 
 /* ntp_monitor.c */
 extern	void	init_mon	(void);
@@ -183,6 +182,8 @@ extern	void	peer_clear	(struct peer *, char *);
 extern	void 	process_packet	(struct peer *, struct pkt *);
 extern	void	clock_select	(void);
 extern	void	kod_proto	(void);
+extern	u_long	leap_ins;
+extern	u_long	leap_sec;
 
 /*
  * there seems to be a bug in the IRIX 4 compiler which prevents
@@ -238,6 +239,7 @@ extern	void	record_loop_stats (double, double, double, double, int);
 extern	void	record_clock_stats (struct sockaddr_storage *, const char *);
 extern	void	record_raw_stats (struct sockaddr_storage *, struct sockaddr_storage *, l_fp *, l_fp *, l_fp *, l_fp *);
 extern	void	record_sys_stats (void);
+extern	u_long	leap_month(u_long);
 extern	void	record_crypto_stats (struct sockaddr_storage *, const char *);
 #ifdef DEBUG
 extern	void	record_timing_stats (const char *);
diff --git a/ntpd/ntp_proto.c b/ntpd/ntp_proto.c
index 1ab9200a2..9f387a53d 100644
--- a/ntpd/ntp_proto.c
+++ b/ntpd/ntp_proto.c
@@ -67,6 +67,8 @@ double	sys_jitter;		/* system jitter (s) */
 static	int sys_hopper;		/* anticlockhop counter */
 static	int sys_maxhop = MAXHOP; /* anticlockhop counter threshold */
 int	leap_next;		/* leap consensus */
+u_long	leap_ins;		/* seconds ar next leap */
+u_long	leap_sec;		/* leap countdown */
 keyid_t	sys_private;		/* private value for session seed */
 int	sys_manycastserver;	/* respond to manycast client pkts */
 int	peer_ntpdate;		/* active peers in ntpdate mode */
@@ -1261,6 +1263,7 @@ clock_update(void)
 	u_char	oleap;
 	u_char	ostratum;
 	double	dtemp;
+	l_fp	now;
 
 	/*
 	 * There must be a system peer at this point. If we just changed
@@ -1308,16 +1311,36 @@ clock_update(void)
 
 	/*
 	 * Clock was slewed. Update the system stratum, leap bits, root
-	 * delay, root dispersion, reference ID and reference time. If
-	 * the leap changes, we gotta reroll the keys. Except for
-	 * reference clocks, the minimum dispersion increment is not
-	 * less than sys_mindisp.
+	 * delay, root dispersion, reference ID and reference time.
+	 * Except for reference clocks, the minimum dispersion increment
+	 * is not less than sys_mindisp. If a leap is anticipated, read
+	 * the system clock because the time now might not be the time
+	 * at the last offset measurement.
 	 */
 	case 1:
-		sys_leap = leap_next;
+
 		sys_stratum = min(sys_peer->stratum + 1,
 		    STRATUM_UNSPEC);
 		sys_reftime = sys_peer->rec;
+		get_systime(&now);
+
+		/*
+		 * If no leap is scheduled and the number of upstream
+		 * leap bits is at least the sanity threshold, schedule
+		 * a leap for the end of the current month. If from the
+		 * leapseconds file schedule a leap for the last entry
+		 * in the file, but only if it is in the future. 
+		 */
+		if (leap_sec == 0) {
+			if (leap_next >= sys_minsane) {
+				leap_sec = leap_month(now.l_ui);
+			} else if (leap_ins != 0) {
+				if (now.l_ui < leap_ins) {
+					leap_sec = leap_ins - now.l_ui;
+					sys_tai--;
+				}
+			}
+		}
 
 		/*
 		 * In orphan mode the stratum defaults to the orphan
@@ -2166,18 +2189,18 @@ clock_select(void)
 	 * What remains is a list usually not greater than sys_minclock
 	 * peers. We want only a peer at the lowest stratum to become
 	 * the system peer, although all survivors are eligible for the
-	 * combining algorithm. Consider each peer in turn and OR the
-	 * leap bits on the assumption that, if some of them honk
-	 * nonzero bits, they must know what they are doing. Check for
-	 * prefer and pps peers at any stratum. Note that the head of
-	 * the list is at the lowest stratum and that unsynchronized
-	 * peers cannot survive this far.
+	 * combining algorithm. Consider each peer in turn and compute
+	 * the total number of leap bits. Check for prefer and pps peers
+	 * at any stratum. Note that the head of the list is at the
+	 * lowest stratum and that unsynchronized peers cannot survive
+	 * this far.
 	 */
 	leap_next = 0;
 	for (i = 0; i < nlist; i++) {
 		peer = peer_list[i];
 		sys_survivors++;
-		leap_next |= peer->leap;
+		if (peer->leap == LEAP_ADDSECOND)
+			leap_next++;
 		peer->status = CTL_PST_SEL_SYNCCAND;
 		if (peer->flags & FLAG_PREFER)
 			sys_prefer = peer;
diff --git a/ntpd/ntp_timer.c b/ntpd/ntp_timer.c
index 54a5be21b..e29db71cf 100644
--- a/ntpd/ntp_timer.c
+++ b/ntpd/ntp_timer.c
@@ -310,8 +310,15 @@ timer(void)
 	/*
 	 * Leapseconds.
 	 */
-	if (sys_tai > 0 && current_time == sys_leapin)
-		loop_config(LOOP_LEAP, sys_tai);
+	if (leap_sec > 0) {
+		if (leap_sec < 86400 * 28)
+			sys_leap = LEAP_ADDSECOND;
+		if (leap_sec < 86400)
+			loop_config(LOOP_LEAP, sys_tai);
+		leap_sec--;
+	} else {
+		sys_leap = LEAP_NOWARNING;
+	}
 
 	/*
 	 * Garbage collect expired keys.
diff --git a/ntpd/ntp_util.c b/ntpd/ntp_util.c
index f7da0cb80..9a5484333 100644
--- a/ntpd/ntp_util.c
+++ b/ntpd/ntp_util.c
@@ -755,12 +755,62 @@ leap_file(
 		msyslog(LOG_INFO, "Leapseconds format error in %s", cp);
 	} else {
 		sys_tai = offset;
-		sys_leapin = leapsec;
+		leap_ins = leapsec;
 		msyslog(LOG_INFO, "TAI offset %d s at %lu from %s",
-		    sys_tai, sys_leapin, cp);
+		    sys_tai, leap_ins, cp);
 	}
 }
 
+/*
+ * leap_month - returns the number of seconds until the end of the month
+ */
+#define	L_DAY	86400			/* seconds per day */
+#define	L_YEAR	L_DAY * 365		/* days per year */
+#define	L_LYEAR	L_YEAR + 1		/* days per leap year */
+#define	L_4YEAR	L_LYEAR + 3 * L_YEAR	/* days per leap cycle */
+#define	L_CENT	(u_long)L_4YEAR * 25	/* days per century */
+
+u_long
+leap_month(
+	u_long	sec		/* current NTP second */
+	)
+{
+	u_long	ltemp;
+	u_long	*ptr;
+	u_long	year[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30,
+		    31}; 
+	u_long	lyear[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30,
+		    31}; 
+
+	/*
+	 * Find current leap cycle
+	 */
+	ltemp = sec;
+	while (ltemp > L_CENT)
+		ltemp -= L_CENT;
+	while (ltemp > L_4YEAR)
+		ltemp -= L_4YEAR;
+
+	/*
+	 * If in leap year, use leap table
+	 */
+	if (ltemp < L_LYEAR) {
+		ptr = lyear;
+	} else {
+		ptr = year;
+		ltemp -= L_LYEAR;
+		while (ltemp > L_YEAR)
+			ltemp -= L_YEAR;
+	}
+	while (ltemp > *ptr)
+		ltemp -= *ptr++;
+
+	/* The result is the number of seconds until the end of the
+	 * month when the leap is to occur.
+	 */
+	return (ltemp);
+}
+
 
 #ifdef DEBUG_TIMING
 /*