shutdown_handler: really shutdown when we are last

If we are a master and we don't have peers, there is no use keeping the
sessions alive, when we'll restart we will have forgotten them all.
Better gracefully close them, so they can be quickly respawn on restart,
instead of having to wait for timeouts.

cluster.c

@@ -754,6 +754,14 @@ void cluster_check_master(void)
 	// should also update.
 }
 
+//
+// Returns whether we have peers.
+//
+int cluster_have_peers(void)
+{
+	return num_peers > 0;
+}
+
 
 //
 // Check that our session table is validly matching what the

cluster.h

@@ -92,6 +92,7 @@ void cluster_send_ping(time_t basetime);
 void cluster_heartbeat(void);
 void cluster_check_master(void);
 void cluster_check_slaves(void);
+int cluster_have_peers(void);
 int cmd_show_cluster(struct cli_def *cli, const char *command, char **argv, int argc);
 int master_forward_pppoe_packet(uint8_t *data, int size, uint8_t codepad);
 

l2tpns.c

@@ -5337,7 +5337,7 @@ static void sighup_handler(int sig)
 
 static void shutdown_handler(int sig)
 {
-	main_quit = (sig == SIGQUIT) ? QUIT_SHUTDOWN : QUIT_FAILOVER;
+	main_quit = (sig == SIGQUIT || (config->cluster_iam_master && !cluster_have_peers())) ? QUIT_SHUTDOWN : QUIT_FAILOVER;
 }
 
 static void sigchild_handler(int sig)