From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ang Way Chuang Subject: [PATCH] bridge: Pseudo-header required for the checksum of ICMP6 header of MLD Date: Wed, 24 Aug 2011 15:10:50 +0900 Message-ID: <4E5495EA.1080906@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Eric Dumazet To: netdev@vger.kernel.org Return-path: Received: from mail-gy0-f174.google.com ([209.85.160.174]:46809 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750795Ab1HXGKy (ORCPT ); Wed, 24 Aug 2011 02:10:54 -0400 Received: by gya6 with SMTP id 6so645554gya.19 for ; Tue, 23 Aug 2011 23:10:53 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Just saw Eric's patch for icmp6_type. Suspect this patch may have issue for reference of ip6h after pskb_trim_rcsum()? Checksum of ICMPv6 is not properly computed because the pseudo header is not used. Thus, the MLD packet gets dropped by the bridge. This patch fixes the problem for my testbed. This bug was made visible by commit ff9a57a62afbbe2d0f3a09af321f1fd7645f38a. This patch has been tested on 3.0.3. Due to lack of understanding on the checksum optimization and multicast snooping of the kernel stack, can someone please verify the correctness of this patch? Signed-off-by: Ang Way Chuang --- index 2d85ca7..bbf361b 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1528,9 +1528,12 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, break; /*FALLTHROUGH*/ case CHECKSUM_NONE: - skb2->csum = 0; - if (skb_checksum_complete(skb2)) + if (!skb_csum_unnecessary(skb2) && csum_ipv6_magic(&ip6h->saddr, + &ip6h->daddr, skb2->len, IPPROTO_ICMPV6, + skb_checksum(skb2, 0, skb2->len, 0))) { + err = -EINVAL; goto out; + } } err = 0; ---