Fix ip monitor since it is special and can't reuse

rtnl_open handle.

ip/ip.c

@@ -53,6 +53,11 @@ static void usage(void)
 	exit(-1);
 }
 
+static int do_help(int argc, char **argv)
+{
+	usage();
+}
+
 static const struct cmd {
 	const char *cmd;
 	int (*func)(int argc, char **argv);
@@ -66,6 +71,7 @@ static const struct cmd {
 	{ "tunnel",	do_iptunnel },
 	{ "monitor",	do_ipmonitor },
 	{ "xfrm",	do_xfrm },
+	{ "help",	do_help },
 	{ 0 }
 };
 

ip/ipmonitor.c

@@ -95,6 +95,7 @@ int do_ipmonitor(int argc, char **argv)
 	int lroute=0;
 	int lprefix=0;
 
+	rtnl_close(&rth);
 	ipaddr_reset_filter(1);
 	iproute_reset_filter();
 	ipneigh_reset_filter();
@@ -152,12 +153,14 @@ int do_ipmonitor(int argc, char **argv)
 			perror("Cannot fopen");
 			exit(-1);
 		}
-		return rtnl_from_file(fp, accept_msg, (void*)stdout);
+		return rtnl_from_file(fp, accept_msg, stdout);
 	}
 
+	if (rtnl_open(&rth, groups) < 0)
+		exit(1);
 	ll_init_map(&rth);
 
-	if (rtnl_listen(&rth, accept_msg, (void*)stdout) < 0)
+	if (rtnl_listen(&rth, accept_msg, stdout) < 0)
 		exit(2);
 
 	return 0;