From 62b2bcb49cca72f6d3f39f831127a6ab315a475d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fernando=20Luis=20V=C3=A1zquez=20Cao?= Date: Mon, 13 Jun 2011 15:04:43 +0000 Subject: [PATCH] IGMP snooping: set mrouters_only flag for IPv4 traffic properly Upon reception of a IGMP/IGMPv2 membership report the kernel sets the mrouters_only flag in a skb that may be a clone of the original skb, which means that sometimes the bridge loses track of membership report 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 Tested-by: Hayato Kakuta Signed-off-by: David S. Miller --- net/bridge/br_multicast.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 2f14eafdeeab..a6d87c17bb03 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1424,7 +1424,7 @@ static int br_multicast_ipv4_rcv(struct net_bridge *br, switch (ih->type) { case IGMP_HOST_MEMBERSHIP_REPORT: case IGMPV2_HOST_MEMBERSHIP_REPORT: - BR_INPUT_SKB_CB(skb2)->mrouters_only = 1; + BR_INPUT_SKB_CB(skb)->mrouters_only = 1; err = br_ip4_multicast_add_group(br, port, ih->group); break; case IGMPV3_HOST_MEMBERSHIP_REPORT: