Fix #279: allow restart:always, restart:-1, of crashing services

This change allows endless restarts, similar to `respawn` but honors
`restart_sec`.  There is no upper limit on the number of times Finit
tries to restart a crashing service.  Same as `restart:-1`

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

doc/config.md

@@ -450,6 +450,8 @@ configurable with the following options:
     a crashing service, default: 2 seconds for the first five retries,
 	then back-off to 5 seconds.  The maximum of this configured value
 	and the above (2 and 5) will be used
+  * `restart:always` -- no upper limit on the number of times Finit
+    tries to restart a crashing service.  Same as `restart:-1`
   * `norestart` -- dont restart on failures, same as `restart:0`
   * `respawn` -- bypasses the `restart` mechanism completely, allows
     endless restarts.  Useful in many use-cases, but not what `service`

man/finit.conf.5

@@ -304,6 +304,10 @@ number of seconds before Finit tries to restart
 a crashing service, default: 2 seconds for the first five retries,
 then back-off to 5 seconds.  The maximum of this configured value
 and the above (2 and 5) will be used
+.It Cm restart:always
+no upper limit on the number of times Finit tries to restart a crashing
+service.  Same as
+.Cm restart:-1
 .It Cm norestart
 dont restart on failures, same as
 .Cm restart:0

src/service.c

@@ -1274,6 +1274,8 @@ int service_register(int type, char *cfg, struct rlimit rlimit[], char *file)
 			forking = 1;
 		else if (!strncasecmp(cmd, "manual:yes", 10))
 			manual = 1;
+		else if (!strncasecmp(cmd, "restart:always", 14))
+			restart_max = -1;
 		else if (!strncasecmp(cmd, "restart:", 8))
 			restart_max = atoi(&cmd[8]);
 		else if (!strncasecmp(cmd, "restarttmo:", 11)) /* compat alias */
@@ -1759,7 +1761,7 @@ static void service_retry(svc_t *svc)
 	}
 
 	/* Peak instability index */
-	if (*restart_cnt >= svc->restart_max) {
+	if (svc->restart_max != -1 && *restart_cnt >= svc->restart_max) {
 		logit(LOG_CONSOLE | LOG_WARNING, "Service %s keeps crashing, not restarting.",
 		      svc_ident(svc, NULL, 0));
 		svc_crashing(svc);

src/svc.h

@@ -139,7 +139,7 @@ typedef struct svc {
 	/* Counters */
 	char           once;	       /* run/task, (at least) once per runlevel */
 	unsigned int   restart_tot;    /* Total restarts ever, summarized, including `initctl restart` */
-	unsigned char  restart_max;    /* Maximum number of restarts allowed */
+	int            restart_max;    /* Maximum number of restarts allowed */
 	int            restart_tmo;    /* Time required for the service to start. */
 	unsigned char  oncrash_action; /* Action to perform in crashed state. */
 	char           respawn;	       /* ttys, or services with `respawn`, never increment restart_cnt */