[hackers] [scron] [PATCH 3/3] Keep existing crontab entries if loading new entries fails

From: Michael Forney <mforney_AT_mforney.org>
Date: Mon, 10 Jul 2017 21:55:42 -0700

Also, don't bother unloading entries right before we exit.

---
 crond.c | 40 +++++++++++-----------------------------
 1 file changed, 11 insertions(+), 29 deletions(-)
diff --git a/crond.c b/crond.c
index 7974b1f..ca339ea 100644
--- a/crond.c
+++ b/crond.c
_AT_@ -73,18 +73,6 @@ loginfo(const char *fmt, ...)
 }
 
 static void
-logwarn(const char *fmt, ...)
-{
-	va_list ap;
-	va_start(ap, fmt);
-	if (nflag == 0)
-		vsyslog(LOG_WARNING, fmt, ap);
-	else
-		vfprintf(stderr, fmt, ap);
-	va_end(ap);
-}
-
-static void
 logerr(const char *fmt, ...)
 {
 	va_list ap;
_AT_@ -391,7 +379,7 @@ freecte(struct ctabentry *cte, int nfields)
 }
 
 static void
-unloadentries(void)
+unloadentries(struct ctabentry *ctab)
 {
 	struct ctabentry *cte, *tmp;
 
_AT_@ -399,13 +387,12 @@ unloadentries(void)
 		tmp = cte->next;
 		freecte(cte, 6);
 	}
-	ctab = NULL;
 }
 
 static int
 loadentries(void)
 {
-	struct ctabentry *cte;
+	struct ctabentry *cte, *newctab = NULL;
 	FILE *fp;
 	char *line = NULL, *p, *col;
 	int r = 0, y;
_AT_@ -478,12 +465,16 @@ loadentries(void)
 			r = -1;
 			break;
 		}
-		cte->next = ctab;
-		ctab = cte;
+		cte->next = newctab;
+		newctab = cte;
 	}
 
-	if (r < 0)
-		unloadentries();
+	if (r < 0) {
+		unloadentries(newctab);
+	} else {
+		unloadentries(ctab);
+		ctab = newctab;
+	}
 
 	free(line);
 	fclose(fp);
_AT_@ -492,14 +483,6 @@ loadentries(void)
 }
 
 static void
-reloadentries(void)
-{
-	unloadentries();
-	if (loadentries() < 0)
-		logwarn("warning: discarding old crontab entries\n");
-}
-
-static void
 sighandler(int sig)
 {
 	switch (sig) {
_AT_@ -576,14 +559,13 @@ main(int argc, char *argv[])
 		if (quit == 1) {
 			if (nflag == 0)
 				unlink(pidfile);
-			unloadentries();
 			/* Don't wait or kill forked processes, just exit */
 			break;
 		}
 
 		if (reload == 1 || chldreap == 1) {
 			if (reload == 1) {
-				reloadentries();
+				loadentries();
 				reload = 0;
 			}
 			if (chldreap == 1) {
-- 
2.13.2

Received on Tue Jul 11 2017 - 06:55:42 CEST