From: Fernando Luis Vázquez Cao <[email protected]>
commit fc2af6c73fc9449cd5894a36bb76b8f8c0e49fd8 upstream.
Upon reception of a MGM report packet the kernel sets the mrouters_only flag
in a skb that is a clone of the original skb, which means that the bridge
loses track of MGM packets (cb buffers are tied to a specific skb and not
shared) and it ends up forwading join requests to the bridge interface.
This can cause unexpected membership timeouts and intermitent/permanent loss
of connectivity as described in RFC 4541 [2.1.1. IGMP Forwarding Rules]:
A snooping switch should forward IGMP Membership Reports only to
those ports where multicast routers are attached.
[...]
Sending membership reports to other hosts can result, for IGMPv1
and IGMPv2, in unintentionally preventing a host from joining a
specific multicast group.
Signed-off-by: Fernando Luis Vazquez Cao <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
---
diff -urNp linux-2.6.35.13-orig/net/bridge/br_multicast.c
linux-2.6.35.13/net/bridge/br_multicast.c
--- linux-2.6.35.13-orig/net/bridge/br_multicast.c 2011-07-28
10:29:17.818721561 +0900
+++ linux-2.6.35.13/net/bridge/br_multicast.c 2011-07-28 10:35:14.959083129
+0900
@@ -1517,7 +1517,7 @@ static int br_multicast_ipv6_rcv(struct
case ICMPV6_MGM_REPORT:
{
struct mld_msg *mld = (struct mld_msg *)icmp6h;
- BR_INPUT_SKB_CB(skb2)->mrouters_only = 1;
+ BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
err = br_ip6_multicast_add_group(br, port, &mld->mld_mca);
break;
}
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