Update routed to use the RFC 3678 protocol-independent multicast API. Use
IP_MULTICAST_IF with struct ip_mreqn (obtained from Linux) to tell the
stack which interface index to use for sending IPv4 datagrams.

diff -uNr routed.orig/defs.h routed/defs.h
--- routed.orig/defs.h	Thu Nov 11 17:34:53 2004
+++ routed/defs.h	Sun Apr  8 02:43:06 2007
@@ -123,21 +123,6 @@
 #define _HAVE_SIN_LEN
 #endif
 
-/* Turn on if IP_{ADD,DROP}_MEMBERSHIP and IP_MULTICAST_IF considers address
- * within 0.0.0.0/8 as interface index.
- */
-#ifdef __NetBSD__
-#define MCAST_IFINDEX
-#endif
-
-/* Turn on if IP_DROP_MEMBERSHIP and IP_ADD_MEMBERSHIP do not look at
- * the dstaddr of point-to-point interfaces.
- * #define MCAST_PPP_BUG
- */
-#ifdef MCAST_IFINDEX
-#undef MCAST_PPP_BUG
-#endif
-
 #define DAY (24*60*60)
 #define NEVER DAY			/* a long time */
 #define EPOCH NEVER			/* bias time by this to avoid <0 */
diff -uNr routed.orig/if.c routed/if.c
--- routed.orig/if.c	Thu Nov 11 17:34:22 2004
+++ routed/if.c	Sun Apr  8 02:51:35 2007
@@ -454,7 +454,6 @@
 static void
 ifdel(struct interface *ifp)
 {
-	struct ip_mreq m;
 	struct interface *ifp1;
 
 
@@ -493,25 +492,23 @@
 				ifdel(ifp1);
 		}
 
-		if ((ifp->int_if_flags & IFF_MULTICAST)
-#ifdef MCAST_PPP_BUG
-		    && !(ifp->int_if_flags & IFF_POINTOPOINT)
+		if ((ifp->int_if_flags & IFF_MULTICAST) && rip_sock >= 0) {
+			struct group_req gr;
+			struct sockaddr_in *sin;
+
+			memset(&gr, 0, sizeof(gr));
+			gr.gr_interface = ifp->int_index;
+			sin = (struct sockaddr_in *)&gr.gr_group;
+			sin->sin_family = AF_INET;
+#ifdef _HAVE_SIN_LEN
+			sin->sin_len = sizeof(struct sockaddr_in);
 #endif
-		    && rip_sock >= 0) {
-			m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
-#ifdef MCAST_IFINDEX
-			m.imr_interface.s_addr = htonl(ifp->int_index);
-#else
-			m.imr_interface.s_addr = ((ifp->int_if_flags
-						   & IFF_POINTOPOINT)
-						  ? ifp->int_dstaddr
-						  : ifp->int_addr);
-#endif
-			if (setsockopt(rip_sock,IPPROTO_IP,IP_DROP_MEMBERSHIP,
-				       &m, sizeof(m)) < 0
+			sin->sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
+			if (setsockopt(rip_sock, IPPROTO_IP, MCAST_LEAVE_GROUP,
+				       &gr, sizeof(gr)) < 0
 			    && errno != EADDRNOTAVAIL
 			    && !TRACEACTIONS)
-				LOGERR("setsockopt(IP_DROP_MEMBERSHIP RIP)");
+				LOGERR("setsockopt(MCAST_LEAVE_GROUP RIP)");
 			if (rip_sock_mcast == ifp)
 				rip_sock_mcast = 0;
 		}
diff -uNr routed.orig/main.c routed/main.c
--- routed.orig/main.c	Thu Nov 11 17:34:22 2004
+++ routed/main.c	Sun Apr  8 02:51:49 2007
@@ -717,25 +717,23 @@
 static void
 rip_mcast_on(struct interface *ifp)
 {
-	struct ip_mreq m;
+	struct group_req gr;
+	struct sockaddr_in *sin;
 
 	if (!IS_RIP_IN_OFF(ifp->int_state)
 	    && (ifp->int_if_flags & IFF_MULTICAST)
-#ifdef MCAST_PPP_BUG
-	    && !(ifp->int_if_flags & IFF_POINTOPOINT)
-#endif
 	    && !(ifp->int_state & IS_ALIAS)) {
-		m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);
-#ifdef MCAST_IFINDEX
-		m.imr_interface.s_addr = htonl(ifp->int_index);
-#else
-		m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
-					  ? ifp->int_dstaddr
-					  : ifp->int_addr);
+		memset(&gr, 0, sizeof(gr));
+		gr.gr_interface = ifp->int_index;
+		sin = (struct sockaddr_in *)&gr.gr_group;
+		sin->sin_family = AF_INET;
+#ifdef _HAVE_SIN_LEN
+		sin->sin_len = sizeof(struct sockaddr_in);
 #endif
-		if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,
-			       &m, sizeof(m)) < 0)
-			LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");
+		sin->sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
+		if (setsockopt(rip_sock, IPPROTO_IP, MCAST_JOIN_GROUP,
+			       &gr, sizeof(gr)) < 0)
+			LOGERR("setsockopt(MCAST_JOIN_GROUP RIP)");
 	}
 }
 
diff -uNr routed.orig/output.c routed/output.c
--- routed.orig/output.c	Thu Nov 11 17:34:52 2004
+++ routed/output.c	Mon Apr  9 05:09:24 2007
@@ -106,7 +106,6 @@
 	int flags;
 	const char *msg;
 	int res;
-	naddr tgt_mcast;
 	int soc;
 	int serrno;
 
@@ -152,31 +151,17 @@
 		} else {
 			msg = "Send mcast";
 			if (rip_sock_mcast != ifp) {
-#ifdef MCAST_IFINDEX
-				/* specify ifindex */
-				tgt_mcast = htonl(ifp->int_index);
-#else
-#ifdef MCAST_PPP_BUG
-				/* Do not specify the primary interface
-				 * explicitly if we have the multicast
-				 * point-to-point kernel bug, since the
-				 * kernel will do the wrong thing if the
-				 * local address of a point-to-point link
-				 * is the same as the address of an ordinary
-				 * interface.
-				 */
-				if (ifp->int_addr == myaddr) {
-					tgt_mcast = 0;
-				} else
-#endif
-				tgt_mcast = ifp->int_addr;
-#endif
+				struct ip_mreqn mreqn;
+
+				memset(&mreqn, 0, sizeof(struct ip_mreqn));
+				mreqn.imr_ifindex = ifp->int_index;
 				if (0 > setsockopt(rip_sock,
-						   IPPROTO_IP, IP_MULTICAST_IF,
-						   &tgt_mcast,
-						   sizeof(tgt_mcast))) {
+						   IPPROTO_IP,
+						   IP_MULTICAST_IF,
+						   &mreqn,
+						   sizeof(mreqn))) {
 					serrno = errno;
-					LOGERR("setsockopt(rip_sock,"
+					LOGERR("setsockopt(rip_sock, "
 					       "IP_MULTICAST_IF)");
 					errno = serrno;
 					ifp = 0;
diff -uNr routed.orig/rdisc.c routed/rdisc.c
--- routed.orig/rdisc.c	Sat Mar 27 14:52:01 2004
+++ routed/rdisc.c	Mon Apr  9 05:09:32 2007
@@ -171,7 +171,8 @@
 set_rdisc_mg(struct interface *ifp,
 	     int on)			/* 0=turn it off */
 {
-	struct ip_mreq m;
+	struct group_req gr;
+	struct sockaddr_in *sin;
 
 	if (rdisc_sock < 0) {
 		/* Create the raw socket so that we can hear at least
@@ -188,39 +189,35 @@
 		return;
 	}
 
-#ifdef MCAST_PPP_BUG
-	if (ifp->int_if_flags & IFF_POINTOPOINT)
-		return;
-#endif
-	memset(&m, 0, sizeof(m));
-#ifdef MCAST_IFINDEX
-	m.imr_interface.s_addr = htonl(ifp->int_index);
-#else
-	m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
-				  ? ifp->int_dstaddr
-				  : ifp->int_addr);
+	memset(&gr, 0, sizeof(gr));
+	gr.gr_interface = ifp->int_index;
+	sin = (struct sockaddr_in *)&gr.gr_group;
+	sin->sin_family = AF_INET;
+#ifdef _HAVE_SIN_LEN
+	sin->sin_len = sizeof(struct sockaddr_in);
 #endif
+
 	if (supplier
 	    || (ifp->int_state & IS_NO_ADV_IN)
 	    || !on) {
 		/* stop listening to advertisements
 		 */
 		if (ifp->int_state & IS_ALL_HOSTS) {
-			m.imr_multiaddr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
+			sin->sin_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
 			if (setsockopt(rdisc_sock, IPPROTO_IP,
-				       IP_DROP_MEMBERSHIP,
-				       &m, sizeof(m)) < 0)
-				LOGERR("IP_DROP_MEMBERSHIP ALLHOSTS");
+				       MCAST_LEAVE_GROUP,
+				       &gr, sizeof(gr)) < 0)
+				LOGERR("MCAST_LEAVE_GROUP ALLHOSTS");
 			ifp->int_state &= ~IS_ALL_HOSTS;
 		}
 
 	} else if (!(ifp->int_state & IS_ALL_HOSTS)) {
 		/* start listening to advertisements
 		 */
-		m.imr_multiaddr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
-		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
-			       &m, sizeof(m)) < 0) {
-			LOGERR("IP_ADD_MEMBERSHIP ALLHOSTS");
+		sin->sin_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
+		if (setsockopt(rdisc_sock, IPPROTO_IP, MCAST_JOIN_GROUP,
+			       &gr, sizeof(gr)) < 0) {
+			LOGERR("MCAST_JOIN_GROUP ALLHOSTS");
 		} else {
 			ifp->int_state |= IS_ALL_HOSTS;
 		}
@@ -232,21 +229,21 @@
 		/* stop listening to solicitations
 		 */
 		if (ifp->int_state & IS_ALL_ROUTERS) {
-			m.imr_multiaddr.s_addr=htonl(INADDR_ALLROUTERS_GROUP);
+			sin->sin_addr.s_addr = htonl(INADDR_ALLROUTERS_GROUP);
 			if (setsockopt(rdisc_sock, IPPROTO_IP,
-				       IP_DROP_MEMBERSHIP,
-				       &m, sizeof(m)) < 0)
-				LOGERR("IP_DROP_MEMBERSHIP ALLROUTERS");
+				       MCAST_LEAVE_GROUP,
+				       &gr, sizeof(gr)) < 0)
+				LOGERR("MCAST_LEAVE_GROUP ALLROUTERS");
 			ifp->int_state &= ~IS_ALL_ROUTERS;
 		}
 
 	} else if (!(ifp->int_state & IS_ALL_ROUTERS)) {
 		/* start hearing solicitations
 		 */
-		m.imr_multiaddr.s_addr=htonl(INADDR_ALLROUTERS_GROUP);
-		if (setsockopt(rdisc_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
-			       &m, sizeof(m)) < 0) {
-			LOGERR("IP_ADD_MEMBERSHIP ALLROUTERS");
+		sin->sin_addr.s_addr = htonl(INADDR_ALLROUTERS_GROUP);
+		if (setsockopt(rdisc_sock, IPPROTO_IP, MCAST_JOIN_GROUP,
+			       &gr, sizeof(gr)) < 0) {
+			LOGERR("MCAST_JOIN_GROUP ALLROUTERS");
 		} else {
 			ifp->int_state |= IS_ALL_ROUTERS;
 		}
@@ -702,7 +699,6 @@
 	struct sockaddr_in rsin;
 	int flags;
 	const char *msg;
-	naddr tgt_mcast;
 
 
 	memset(&rsin, 0, sizeof(rsin));
@@ -739,27 +735,14 @@
 		}
 		if (rdisc_sock_mcast != ifp) {
 			/* select the right interface. */
-#ifdef MCAST_IFINDEX
-			/* specify ifindex */
-			tgt_mcast = htonl(ifp->int_index);
-#else
-#ifdef MCAST_PPP_BUG
-			/* Do not specify the primary interface explicitly
-			 * if we have the multicast point-to-point kernel
-			 * bug, since the kernel will do the wrong thing
-			 * if the local address of a point-to-point link
-			 * is the same as the address of an ordinary
-			 * interface.
-			 */
-			if (ifp->int_addr == myaddr) {
-				tgt_mcast = 0;
-			} else
-#endif
-			tgt_mcast = ifp->int_addr;
-#endif
+			struct ip_mreqn mreqn;
+
+			memset(&mreqn, 0, sizeof(struct ip_mreqn));
+			mreqn.imr_ifindex = ifp->int_index;
 			if (0 > setsockopt(rdisc_sock,
 					   IPPROTO_IP, IP_MULTICAST_IF,
-					   &tgt_mcast, sizeof(tgt_mcast))) {
+					   &mreqn,
+					   sizeof(mreqn))) {
 				LOGERR("setsockopt(rdisc_sock,"
 				       "IP_MULTICAST_IF)");
 				rdisc_sock_mcast = 0;