From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754103Ab1G1Bxj (ORCPT ); Wed, 27 Jul 2011 21:53:39 -0400 Received: from serv2.oss.ntt.co.jp ([222.151.198.100]:51608 "EHLO serv2.oss.ntt.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751878Ab1G1Bxd (ORCPT ); Wed, 27 Jul 2011 21:53:33 -0400 Subject: [STABLE] [PATCH] IGMP snooping: set mrouters_only flag for IPv4 traffic properly From: Fernando Luis Vazquez Cao To: Andi Kleen Cc: pablo@netfilter.org, gregkh@suse.de, ak@linux.intel.com, linux-kernel@vger.kernel.org, stable@kernel.org, tim.bird@am.sony.com In-Reply-To: <1311817873.2707.5.camel@nausicaa> References: <20110727247.325703029@firstfloor.org> <20110727214858.5FECE2403FF@tassilo.jf.intel.com> <1311817873.2707.5.camel@nausicaa> Content-Type: text/plain; charset="UTF-8" Date: Thu, 28 Jul 2011 10:53:30 +0900 Message-ID: <1311818010.2707.7.camel@nausicaa> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Fernando Luis Vázquez Cao commit 62b2bcb49cca72f6d3f39f831127a6ab315a475d upstream. 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 --- 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 2011-04-29 00:21:24.000000000 +0900 +++ linux-2.6.35.13/net/bridge/br_multicast.c 2011-07-28 10:28:08.505872639 +0900 @@ -1403,7 +1403,7 @@ static int br_multicast_ipv4_rcv(struct 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: