Please use the following patch to rdate. It is a little improved,
including option '-b'.
diff -ur rdate-1.1.3-old/docs/rdate.8 rdate-1.1.3-new/docs/rdate.8
--- rdate-1.1.3-old/docs/rdate.8 2009-04-10 15:49:34.000000000 -0300
+++ rdate-1.1.3-new/docs/rdate.8 2009-04-10 18:07:00.000000000 -0300
@@ -39,7 +39,9 @@
.Sh SYNOPSIS
.Nm rdate
.Op Fl 46acnpsuv
+.Op Fl b Ar sec
.Op Fl o Ar port
+.Op Fl t Ar msec
.Ar host
.Sh DESCRIPTION
.Nm
@@ -68,6 +70,11 @@
.Xr adjtime 2
call to gradually skew the local time to the
remote time rather than just hopping.
+.It Fl b Ar sec
+Use adjtime if clock difference is at most
+.Ar sec
+seconds or hop if difference is greater. This is the same as including of
+removing the option -a, based on clock difference.
.It Fl c
Correct leap seconds.
Sometimes required when synchronizing to an NTP server.
@@ -88,6 +95,10 @@
Do not print the time.
.It Fl u
Use UDP instead of TCP as transport.
+.It Fl t Ar msec
+Does not set time if it took more than
+.Ar msec
+mili-seconds to fetch time from network.
.It Fl v
Verbose output.
Always show the adjustment.
diff -ur rdate-1.1.3-old/src/rdate.c rdate-1.1.3-new/src/rdate.c
--- rdate-1.1.3-old/src/rdate.c 2009-04-10 15:49:34.000000000 -0300
+++ rdate-1.1.3-new/src/rdate.c 2009-04-10 18:10:48.000000000 -0300
@@ -38,6 +38,7 @@
* Time is returned as the number of seconds since
* midnight January 1st 1900.
*/
+/* options -t and -b implemented by Pedro Zorzenon Neto - 2009-04-10 */
#ifndef lint
#if 0
from: static char rcsid[] = "$NetBSD: rdate.c,v 1.3 1996/02/22 06:59:18 thorpej Exp $";
@@ -77,16 +78,19 @@
void
usage(void)
{
- (void) fprintf(stderr, "Usage: %s [-46acnpsv] [-o port] host\n", __progname);
+ (void) fprintf(stderr, "Usage: %s [-46acnpsv] [ -b sec ] [-o port] [ -t msec ] host\n", __progname);
(void) fprintf(stderr, " -4: use IPv4 only\n");
(void) fprintf(stderr, " -6: use IPv6 only\n");
(void) fprintf(stderr, " -a: use adjtime instead of instant change\n");
+ (void) fprintf(stderr, " -b num: use instant change if difference is greater than\n"
+ " num seconds, or else use adjtime\n");
(void) fprintf(stderr, " -c: correct leap second count\n");
(void) fprintf(stderr, " -n: use SNTP instead of RFC868 time protocol\n");
(void) fprintf(stderr, " -o num: override time port with num\n");
(void) fprintf(stderr, " -p: just print, don't set\n");
(void) fprintf(stderr, " -s: just set, don't print\n");
(void) fprintf(stderr, " -u: use UDP instead of TCP as transport\n");
+ (void) fprintf(stderr, " -t msec: does not set clock if network delay greater than msec\n");
(void) fprintf(stderr, " -v: verbose output\n");
}
@@ -102,8 +106,13 @@
int port = 0;
struct timeval new, adjust;
+ int maxdelay = 0;
+ int netdelay = 0;
+ struct timeval netdelay1, netdelay2;
+ struct timezone tz;
+ int conditionalslide = 0;
- while ((c = getopt(argc, argv, "46psancvuo:")) != -1)
+ while ((c = getopt(argc, argv, "46psancvuo:t:b:")) != -1)
switch (c) {
case '4':
family = PF_INET;
@@ -145,6 +154,14 @@
port = atoi(optarg);
break;
+ case 't':
+ maxdelay = atoi(optarg);
+ break;
+
+ case 'b':
+ conditionalslide = atoi(optarg);
+ break;
+
default:
usage();
return 1;
@@ -156,12 +173,36 @@
}
hname = argv[optind];
+ if (maxdelay) {
+ gettimeofday(&netdelay1, &tz);
+ }
if (ntp)
ntp_client(hname, family, &new, &adjust, corrleaps, port, verbose);
else
rfc868time_client(hname, family, &new, &adjust, corrleaps, useudp, port);
+ if (maxdelay) {
+ gettimeofday(&netdelay2, &tz);
+ netdelay = (netdelay2.tv_sec - netdelay1.tv_sec) * 1000;
+ netdelay += (netdelay2.tv_usec - netdelay1.tv_usec) / 1000;
+ if (netdelay > maxdelay) {
+ fprintf(stderr, "%s: Network delay exceeded (%i msec)\n",
+ __progname, netdelay);
+ exit(2);
+ }
+ }
+
if (!pr) {
+
+ if (conditionalslide) {
+ if (((adjust.tv_sec > 0) && (adjust.tv_sec > conditionalslide)) ||
+ ((adjust.tv_sec < 0) && ((-adjust.tv_sec) > conditionalslide))) {
+ slidetime = 0;
+ } else {
+ slidetime = 1;
+ }
+ }
+
if (!slidetime) {
logwtmp("|", "date", "");
if (settimeofday(&new, NULL) == -1)
@@ -186,15 +227,32 @@
adjsec = adjust.tv_sec + adjust.tv_usec / 1.0e6;
if (slidetime || verbose) {
+ char slidemsg[32];
+ if (conditionalslide) {
+ if (slidetime) {
+ strcpy(slidemsg," (adjtime)");
+ } else {
+ strcpy(slidemsg," (instant change)");
+ }
+ } else {
+ strcpy(slidemsg,"");
+ }
if (ntp)
(void) fprintf(stdout,
- "%s: adjust local clock by %.6f seconds\n",
- __progname, adjsec);
+ "%s: adjust local clock by %.6f seconds%s\n",
+ __progname, adjsec, slidemsg);
else
(void) fprintf(stdout,
- "%s: adjust local clock by %ld seconds\n",
- __progname, adjust.tv_sec);
+ "%s: adjust local clock by %ld seconds%s\n",
+ __progname, adjust.tv_sec, slidemsg);
}
+
+ if (verbose && maxdelay) {
+ (void) fprintf(stdout,
+ "%s: network delay %i msecs\n",
+ __progname, netdelay);
+ }
+
}
return 0;
