ip: add support for multicast rules

commit 44a5293c1c47b8c32d9bb0756660ea5d4802acf2
Author: Patrick McHardy <kaber@trash.net>
Date:   Tue Apr 13 17:03:47 2010 +0200

    ip: add support for multicast rules
Signed-off-by: Patrick McHardy <kaber@trash.net>

ip/ip.c

@@ -42,7 +42,7 @@ static void usage(void)
 "Usage: ip [ OPTIONS ] OBJECT { COMMAND | help }\n"
 "       ip [ -force ] -batch filename\n"
 "where  OBJECT := { link | addr | addrlabel | route | rule | neigh | ntable |\n"
-"                   tunnel | tuntap | maddr | mroute | monitor | xfrm }\n"
+"                   tunnel | tuntap | maddr | mroute | mrule | monitor | xfrm }\n"
 "       OPTIONS := { -V[ersion] | -s[tatistics] | -d[etails] | -r[esolve] |\n"
 "                    -f[amily] { inet | inet6 | ipx | dnet | link } |\n"
 "                    -o[neline] | -t[imestamp] | -b[atch] [filename] |\n"
@@ -76,6 +76,7 @@ static const struct cmd {
 	{ "monitor",	do_ipmonitor },
 	{ "xfrm",	do_xfrm },
 	{ "mroute",	do_multiroute },
+	{ "mrule",	do_multirule },
 	{ "help",	do_help },
 	{ 0 }
 };

ip/ip_common.h

@@ -37,6 +37,7 @@ extern int do_iplink(int argc, char **argv);
 extern int do_ipmonitor(int argc, char **argv);
 extern int do_multiaddr(int argc, char **argv);
 extern int do_multiroute(int argc, char **argv);
+extern int do_multirule(int argc, char **argv);
 extern int do_xfrm(int argc, char **argv);
 
 static inline int rtm_get_table(struct rtmsg *r, struct rtattr **tb)

ip/iprule.c

@@ -436,3 +436,20 @@ int do_iprule(int argc, char **argv)
 	exit(-1);
 }
 
+int do_multirule(int argc, char **argv)
+{
+	switch (preferred_family) {
+	case AF_UNSPEC:
+	case AF_INET:
+		preferred_family = RTNL_FAMILY_IPMR;
+		break;
+	case AF_INET6:
+		preferred_family = RTNL_FAMILY_IP6MR;
+		break;
+	default:
+		fprintf(stderr, "Multicast rules are only supported for IPv4/IPv6\n");
+		exit(-1);
+	}
+
+	return do_iprule(argc, argv);
+}