From: Fernando Luis Vázquez Cao Date: Mon, 13 Jun 2011 15:06:58 +0000 (+0000) Subject: IGMP snooping: set mrouters_only flag for IPv6 traffic X-Git-Tag: v2.6.35.14~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef0c3e7d6e082b7f3cf41546525c84f4477a76d3;p=thirdparty%2Fkernel%2Fstable.git IGMP snooping: set mrouters_only flag for IPv6 traffic [ upstream commit fc2af6c73fc9449cd5894a36bb76b8f8c0e49fd8 ] properly 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 Signed-off-by: David S. Miller Signed-off-by: Andi Kleen --- diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 7ab8ad30adcd3..382a4288c5186 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1517,7 +1517,7 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, 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; }