zebra: When shutting down actually close the socket

When shutting down and we have a very large table to shutdown
and after we've intentionally closed all the client connections
close the zebra zserv client socket.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

zebra/main.c

@@ -153,7 +153,9 @@ static void sigint(void)
 	for (ALL_LIST_ELEMENTS(zrouter.client_list, ln, nn, client))
 		zserv_close_client(client);
 
+	zserv_close();
 	list_delete_all_node(zrouter.client_list);
+
 	zebra_ptm_finish();
 
 	if (retain_mode)

zebra/zserv.c

@@ -773,6 +773,18 @@ static int zserv_accept(struct thread *thread)
 	return 0;
 }
 
+void zserv_close(void)
+{
+	/*
+	 * On shutdown, let's close the socket down
+	 * so that long running processes of killing the
+	 * routing table doesn't leave us in a bad
+	 * state where a client tries to reconnect
+	 */
+	close(zsock);
+	zsock = -1;
+}
+
 void zserv_start(char *path)
 {
 	int ret;

zebra/zserv.h

@@ -183,6 +183,13 @@ extern unsigned int multipath_num;
  */
 extern void zserv_init(void);
 
+/*
+ * Stop the Zebra API server.
+ *
+ * closes the socket
+ */
+extern void zserv_close(void);
+
 /*
  * Start Zebra API server.
  *