[IPV6] MROUTE: Support multicast forwarding.

[net-next-2.6.git] / net / ipv6 / ip6_input.c

diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 7e36269826ba5b1d7c24ce7b2f9e38cd1b790f9d..09a3201e408aa9fd32d78d15d525db49968462d4 100644 (file)
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -29,6 +29,7 @@
 #include <linux/netdevice.h>
 #include <linux/in6.h>
 #include <linux/icmpv6.h>
+#include <linux/mroute6.h>
 
 #include <linux/netfilter.h>
 #include <linux/netfilter_ipv6.h>
@@ -234,39 +235,86 @@ int ip6_mc_input(struct sk_buff *skb)
        IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS);
 
        hdr = ipv6_hdr(skb);
-       deliver = unlikely(skb->dev->flags & (IFF_PROMISC|IFF_ALLMULTI)) ||
-           ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
+       deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
 
+#ifdef CONFIG_IPV6_MROUTE
        /*
-        *      IPv6 multicast router mode isnt currently supported.
+        *      IPv6 multicast router mode is now supported ;)
         */
-#if 0
-       if (ipv6_config.multicast_route) {
-               int addr_type;
-
-               addr_type = ipv6_addr_type(&hdr->daddr);
-
-               if (!(addr_type & (IPV6_ADDR_LOOPBACK | IPV6_ADDR_LINKLOCAL))) {
-                       struct sk_buff *skb2;
-                       struct dst_entry *dst;
+       if (ipv6_devconf.mc_forwarding &&
+           likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
+               /*
+                * Okay, we try to forward - split and duplicate
+                * packets.
+                */
+               struct sk_buff *skb2;
+               struct inet6_skb_parm *opt = IP6CB(skb);
+
+               /* Check for MLD */
+               if (unlikely(opt->ra)) {
+                       /* Check if this is a mld message */
+                       u8 *ptr = skb_network_header(skb) + opt->ra;
+                       struct icmp6hdr *icmp6;
+                       u8 nexthdr = hdr->nexthdr;
+                       int offset;
+
+                       /* Check if the value of Router Alert
+                        * is for MLD (0x0000).
+                        */
+                       if ((ptr[2] | ptr[3]) == 0) {
+                               if (!ipv6_ext_hdr(nexthdr)) {
+                                       /* BUG */
+                                       goto discard;
+                               }
+                               offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
+                                                         &nexthdr);
+                               if (offset < 0)
+                                       goto discard;
+
+                               if (nexthdr != IPPROTO_ICMPV6)
+                                       goto discard;
+
+                               if (!pskb_may_pull(skb, (skb_network_header(skb) +
+                                                  offset + 1 - skb->data)))
+                                       goto discard;
+
+                               icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
+
+                               switch (icmp6->icmp6_type) {
+                               case ICMPV6_MGM_QUERY:
+                               case ICMPV6_MGM_REPORT:
+                               case ICMPV6_MGM_REDUCTION:
+                               case ICMPV6_MLD2_REPORT:
+                                       break;
+                               default:
+                                       /* Bogus */
+                                       goto discard;
+                               }
+                               deliver = 1;
+                               goto out;
+                       }
+                       /* unknown RA - process it normally */
+               }
 
-                       dst = skb->dst;
+               if (deliver)
+                       skb2 = skb_clone(skb, GFP_ATOMIC);
+               else {
+                       skb2 = skb;
+                       skb = NULL;
+               }
 
-                       if (deliver) {
-                               skb2 = skb_clone(skb, GFP_ATOMIC);
-                               dst_output(skb2);
-                       } else {
-                               dst_output(skb);
-                               return 0;
-                       }
+               if (skb2) {
+                       skb2->dev = skb2->dst->dev;
+                       ip6_mr_input(skb2);
                }
        }
 #endif
-
+out:
        if (likely(deliver)) {
                ip6_input(skb);
                return 0;
        }
+discard:
        /* discard */
        kfree_skb(skb);