From fc2af6c73fc9449cd5894a36bb76b8f8c0e49fd8 Mon Sep 17 00:00:00 2001 From: Fernando Luis Vázquez Cao Date: Mon, 13 Jun 2011 15:06:58 +0000 Subject: IGMP snooping: set mrouters_only flag for IPv6 traffic 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 --- net/bridge/br_multicast.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index a6d87c17bb03..29b9812c8da0 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1543,7 +1543,7 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, goto out; } mld = (struct mld_msg *)skb_transport_header(skb2); - 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; } -- cgit v1.2.3-59-g8ed1b