Change the algorithm by which /var/db/leap-seconds is updated.

1. Use the leap-seconds version number (update time) to determine
   whether to update the file or not.

2. If the version numbers of the files is the same, use the later
   expiry date to determine which file to use.

Suggested by:	ian@
MFC after:	1 day

1 files changed, 12 insertions, 3 deletions

diff --git a/etc/rc.d/ntpd b/etc/rc.d/ntpd
index a6d0bab3dbef..2b68665d7059 100755
--- a/etc/rc.d/ntpd
+++ b/etc/rc.d/ntpd
@@ -67,11 +67,13 @@ current_ntp_ts() {
 }
 	
 get_ntp_leapfile_ver() {
+	# Leapfile update date (version number).
 	expr "$(awk '$1 == "#$" { print $2 }' "$1" 2>/dev/null)" : \
 		'^\([1-9][0-9]*\)$' \| 0
 }
 
 get_ntp_leapfile_expiry() {
+	# Leapfile expiry date.
 	expr "$(awk '$1 == "#@" { print $2 }' "$1" 2>/dev/null)" : \
 		'^\([1-9][0-9]*\)$' \| 0
 }
@@ -88,19 +90,23 @@ ntpd_fetch_leapfile() {
 	ntp_tmp_leapfile="/var/run/ntpd.leap-seconds.list"
 
 	ntp_ver_no_src=$(get_ntp_leapfile_ver $ntp_src_leapfile)
+	ntp_expiry_src=$(get_ntp_leapfile_expiry $ntp_src_leapfile)
 	ntp_ver_no_db=$(get_ntp_leapfile_ver $ntp_db_leapfile)
+	ntp_expiry_db=$(get_ntp_leapfile_expiry $ntp_db_leapfile)
 	$verbose ntp_src_leapfile version is $ntp_ver_no_src
 	$verbose ntp_db_leapfile version is $ntp_ver_no_db
 
-	if [ "$ntp_ver_no_src" -gt "$ntp_ver_no_db" ]; then
+	if [ "$ntp_ver_no_src" -gt "$ntp_ver_no_db" -o \
+	     "$ntp_ver_no_src" -eq "$ntp_ver_no_db" -a \
+	     "$ntp_expiry_src" -gt "$ntp_expiry_db" ]; then
 		$verbose replacing $ntp_db_leapfile with $ntp_src_leapfile 
 		cp -p $ntp_src_leapfile $ntp_db_leapfile
 		ntp_ver_no_db=$ntp_ver_no_src
 	else
 		$verbose not replacing $ntp_db_leapfile with $ntp_src_leapfile 
 	fi
-	ntp_leap_expiry=$(get_ntp_leapfile_expiry $ntp_db_leapfile)
 	ntp_leapfile_expiry_seconds=$((ntp_leapfile_expiry_days*86400))
+	ntp_leap_expiry=$(get_ntp_leapfile_expiry $ntp_db_leapfile)
 	ntp_leap_fetch_date=$((ntp_leap_expiry-ntp_leapfile_expiry_seconds))
 	if [ $(current_ntp_ts) -ge $ntp_leap_fetch_date ]; then
 		$verbose Within ntp leapfile expiry limit, initiating fetch
@@ -108,8 +114,11 @@ ntpd_fetch_leapfile() {
 			$verbose fetching $url
 			fetch $ntp_leapfile_fetch_opts -o $ntp_tmp_leapfile $url && break
 		done
+		ntp_ver_no_tmp=$(get_ntp_leapfile_ver $ntp_tmp_leapfile)
 		ntp_expiry_tmp=$(get_ntp_leapfile_expiry $ntp_tmp_leapfile)
-		if [ "$ntp_expiry_tmp" -gt "$ntp_leap_expiry" ]; then
+		if [ "$ntp_ver_no_tmp" -gt "$ntp_ver_no_db" -o \
+		     "$ntp_ver_no_tmp" -eq "$ntp_ver_no_db" -a \
+		     "$ntp_expiry_tmp" -gt "$ntp_expiry_db" ]; then
 			$verbose using $url as $ntp_db_leapfile
 			mv $ntp_tmp_leapfile $ntp_db_leapfile
 		else