Hi, The following will disregard the routing table for multicast packets when the application chose the interface with IP_MULTICAST_IF, if not, normal lookup will take place.
Ripd now no longer needs to explicitly add the mcast host route to bypass the default reject to 224/4, follows the diff to remove it. Regarding the normal lookup when IP_MULTICAST_IF wan't set, UNP regards it as a BSD descendant behaviour, I really don't know anything else. I've tested it in a small setup, if someone could confirm it in a scarier environment would be nice. Index: netinet/in_pcb.c =================================================================== RCS file: /cvs/src/sys/netinet/in_pcb.c,v retrieving revision 1.112 diff -d -u -p -w netinet/in_pcb.c --- netinet/in_pcb.c 7 May 2010 13:33:16 -0000 1.112 +++ netinet/in_pcb.c 12 Jun 2010 19:18:49 -0000 @@ -819,7 +819,9 @@ in_selectsrc(struct sockaddr_in *sin, struct route *ro } if ((soopts & SO_DONTROUTE) == 0 && /*XXX*/ (ro->ro_rt == (struct rtentry *)0 || - ro->ro_rt->rt_ifp == (struct ifnet *)0)) { + ro->ro_rt->rt_ifp == (struct ifnet *)0) && + !(IN_MULTICAST(sin->sin_addr.s_addr) && + mopts && (mopts->imo_multicast_ifp != NULL))) { /* No route yet, so try to acquire one */ ro->ro_dst.sa_family = AF_INET; ro->ro_dst.sa_len = sizeof(struct sockaddr_in); Index: kroute.c =================================================================== RCS file: /cvs/src/usr.sbin/ripd/kroute.c,v retrieving revision 1.21 diff -d -u -p -w kroute.c --- kroute.c 2 Jan 2009 14:40:54 -0000 1.21 +++ kroute.c 12 Jun 2010 19:19:51 -0000 @@ -97,9 +97,6 @@ RB_HEAD(kif_tree, kif_node) kit; RB_PROTOTYPE(kif_tree, kif_node, entry, kif_compare) RB_GENERATE(kif_tree, kif_node, entry, kif_compare) -struct kroute kr_all_rip_routers; -int flag_all_rip_routers = 0; - int kif_init(void) { @@ -151,14 +148,6 @@ kr_init(int fs, u_int rdomain) if (protect_lo() == -1) return (-1); - kr_all_rip_routers.prefix.s_addr = inet_addr(ALL_RIP_ROUTERS); - kr_all_rip_routers.netmask.s_addr = htonl(INADDR_BROADCAST); - kr_all_rip_routers.nexthop.s_addr = htonl(INADDR_LOOPBACK); - - kr_state.fib_sync = 1; /* force addition of multicast route */ - if (send_rtmsg(kr_state.fd, RTM_ADD, &kr_all_rip_routers) != -1) - flag_all_rip_routers = 1; - kr_state.fib_sync = fs; /* now set correct sync mode */ kr_state.rdomain = rdomain; @@ -243,11 +232,6 @@ void kr_shutdown(void) { kr_fib_decouple(); - - if (flag_all_rip_routers) { - kr_state.fib_sync = 1; /* force removal of mulitcast route */ - (void)send_rtmsg(kr_state.fd, RTM_DELETE, &kr_all_rip_routers); - } kroute_clear(); kif_clear();