[IPV6]: Try not to send icmp to anycast address.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 14 insertions, 2 deletions

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 34a332225c17..6ec6a2b549bb 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -328,8 +328,10 @@ void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info,
                 iif = skb->dev->ifindex;
 
         /*
-         *      Must not send if we know that source is Anycast also.
-         *      for now we don't know that.
+         *      Must not send error if the source does not uniquely
+         *      identify a single node (RFC2463 Section 2.4).
+         *      We check unspecified / multicast addresses here,
+         *      and anycast addresses will be checked later.
          */
         if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
                 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n");
@@ -373,6 +375,16 @@ void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info,
         err = ip6_dst_lookup(sk, &dst, &fl);
         if (err)
                 goto out;
+
+        /*
+         * We won't send icmp if the destination is known
+         * anycast.
+         */
+        if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) {
+                LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n");
+                goto out_dst_release;
+        }
+
         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
                 goto out;