Cause crontab to send SIGUSR1 when a user's crontab file has changed.

In cron, this interrupts the sleep() in cron_sleep() and causes cron
to check to see what signal woke it up and act appropriately.
This makes crontab changes take effect more or immediately.

3 files changed, 62 insertions, 17 deletions

diff --git a/usr.sbin/cron/cron.8 b/usr.sbin/cron/cron.8
index 7c3d2a2ec17..04b06575cfb 100644
--- a/usr.sbin/cron/cron.8
+++ b/usr.sbin/cron/cron.8
@@ -17,7 +17,7 @@
 .\" ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 .\" SOFTWARE.
 .\"
-.\" $OpenBSD: cron.8,v 1.12 2001/12/13 19:38:42 millert Exp $
+.\" $OpenBSD: cron.8,v 1.13 2001/12/20 23:27:47 millert Exp $
 .\"
 .Dd June 6, 1999
 .Dt CRON 8
@@ -97,14 +97,28 @@ new time immediately.
 Clock changes of more than 3 hours are considered to be corrections to
 the clock, and the new time is used immediately.
 .Sh SIGNALS
-On receipt of a
-.Tn SIGHUP ,
-the cron daemon will close and reopen its log file.
-This is useful in scripts which rotate and age log files.  
-Naturally this is not relevant if cron was built to use
+.Bl -tag -width Ds
+.It Dv SIGHUP
+causes
+.Nm
+to close and reopen its log file.
+This is useful in scripts which rotate and age log files.
+On
+.Ox
+this has no effect because
+.Nm cron
+logs via
 .Xr syslog 3 .
+.It Dv SIGUSR1
+causes
+.Nm
+to check its spool directory's modtime (and the modtime of
+.Pa /etc/crontab )
+at the next possible moment instead of waiting until the next minute.
+.El
 .Sh SEE ALSO
 .Xr crontab 1 ,
+.Xr syslog 3 ,
 .Xr crontab 5
 .Sh AUTHORS
 Paul Vixie <paul@vix.com>
diff --git a/usr.sbin/cron/cron.c b/usr.sbin/cron/cron.c
index 2ed9b52e26f..07b1075bdaf 100644
--- a/usr.sbin/cron/cron.c
+++ b/usr.sbin/cron/cron.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cron.c,v 1.17 2001/12/11 04:14:00 millert Exp $	*/
+/*	$OpenBSD: cron.c,v 1.18 2001/12/20 23:27:47 millert Exp $	*/
 /* Copyright 1988,1990,1993,1994 by Paul Vixie
  * All rights reserved
  */
@@ -21,7 +21,7 @@
  */
 
 #if !defined(lint) && !defined(LINT)
-static char rcsid[] = "$OpenBSD: cron.c,v 1.17 2001/12/11 04:14:00 millert Exp $";
+static char rcsid[] = "$OpenBSD: cron.c,v 1.18 2001/12/20 23:27:47 millert Exp $";
 #endif
 
 #define	MAIN_PROGRAM
@@ -35,13 +35,15 @@ static	void	usage(void),
 		cron_sleep __P((int)),
 		sigchld_handler(int),
 		sighup_handler(int),
+		sigusr1_handler(int),
 		sigchld_reaper(void),
-		check_sigs(void),
+		check_sigs(int),
 		parse_args(int c, char *v[]);
 
-static	volatile sig_atomic_t	got_sighup, got_sigchld;
+static	volatile sig_atomic_t	got_sighup, got_sigchld, got_sigusr1;
 static	int			timeRunning, virtualTime, clockTime;
 static	long			GMToff;
+static	cron_db			database;
 
 static void
 usage(void) {
@@ -56,7 +58,6 @@ usage(void) {
 
 int
 main(int argc, char *argv[]) {
-	cron_db	database;
 	struct sigaction sact;
 	int fd;
 
@@ -144,8 +145,7 @@ main(int argc, char *argv[]) {
 		int timeDiff;
 		int wakeupKind;
 
-		check_sigs();
-		load_database(&database);
+		check_sigs(TRUE);
 		/* ... wait for the time (in minutes) to change ... */
 		do {
 			cron_sleep(timeRunning + 1);
@@ -340,6 +340,16 @@ static void
 cron_sleep(int target) {
 	time_t t1, t2;
 	int seconds_to_wait;
+	struct sigaction sact;
+
+	bzero((char *)&sact, sizeof sact);
+	sigemptyset(&sact.sa_mask);
+	sact.sa_flags = 0;
+#ifdef SA_RESTART
+	sact.sa_flags |= SA_RESTART;
+#endif
+	sact.sa_handler = sigusr1_handler;
+	(void) sigaction(SIGUSR1, &sact, NULL);
 
 	t1 = time(NULL) + GMToff;
 	seconds_to_wait = (int)(target * SECONDS_PER_MINUTE - t1) + 1;
@@ -354,11 +364,14 @@ cron_sleep(int target) {
 		 * If so, service the signal(s) then continue sleeping
 		 * where we left off.
 		 */
-		check_sigs();
+		check_sigs(FALSE);
 		t2 = time(NULL) + GMToff;
 		seconds_to_wait -= (int)(t2 - t1);
 		t1 = t2;
 	}
+
+	sact.sa_handler = SIG_DFL;
+	(void) sigaction(SIGUSR1, &sact, NULL);
 }
 
 static void
@@ -372,6 +385,11 @@ sigchld_handler(int x) {
 }
 
 static void
+sigusr1_handler(int x) {
+	got_sigusr1 = 1;
+}
+
+static void
 sigchld_reaper() {
 	WAIT_T waiter;
 	PID_T pid;
@@ -400,7 +418,7 @@ sigchld_reaper() {
 }
 
 static void
-check_sigs() {
+check_sigs(int force_dbload) {
 	if (got_sighup) {
 		got_sighup = 0;
 		log_close();
@@ -409,6 +427,10 @@ check_sigs() {
 		got_sigchld = 0;
 		sigchld_reaper();
 	}
+	if (got_sigusr1 || force_dbload) {
+		got_sigusr1 = 0;
+		load_database(&database);
+	}
 }
 
 static void
diff --git a/usr.sbin/cron/crontab.c b/usr.sbin/cron/crontab.c
index 08f1c0d9238..2fae5876d30 100644
--- a/usr.sbin/cron/crontab.c
+++ b/usr.sbin/cron/crontab.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: crontab.c,v 1.25 2001/12/07 22:33:09 deraadt Exp $	*/
+/*	$OpenBSD: crontab.c,v 1.26 2001/12/20 23:27:47 millert Exp $	*/
 /* Copyright 1988,1990,1993,1994 by Paul Vixie
  * All rights reserved
  */
@@ -21,7 +21,7 @@
  */
 
 #if !defined(lint) && !defined(LINT)
-static char rcsid[] = "$OpenBSD: crontab.c,v 1.25 2001/12/07 22:33:09 deraadt Exp $";
+static char rcsid[] = "$OpenBSD: crontab.c,v 1.26 2001/12/20 23:27:47 millert Exp $";
 #endif
 
 /* crontab - install and manage per-user crontab files
@@ -675,11 +675,20 @@ done:
 
 static void
 poke_daemon() {
+	char pidfile[MAX_FNAME];
+	PID_T pid;
+	FILE *fp;
+
 	if (utime(SPOOL_DIR, NULL) < OK) {
 		fprintf(stderr, "crontab: can't update mtime on spooldir\n");
 		perror(SPOOL_DIR);
 		return;
 	}
+	if (glue_strings(pidfile, sizeof pidfile, PIDDIR, PIDFILE, '/')) {
+		if ((fp = fopen(pidfile, "r")) &&
+		    fscanf(fp, "%d", &pid) == 1)
+			kill(pid, SIGUSR1);
+	}
 }
 
 static void