On Sun, Mar 27, 2011 at 08:27:23AM +0200, Linus Lüssing wrote:
> In contrast to IGMP, the MLDv1/2 message checksum needs to include an
> IPv6 "pseudo-header" in the calculations (see RFC2710, section 3.3;
> RFC3810, section 5.1.2).
> 
> The multicast snooping feature of the bridge code however did not take
> this "pseudo-header" into consideration for the checksum validation when
> parsing a snooped IPv6 MLDv1/2 message of another host, leading to
> possibly ignored, though valid MLDv1/2 messages. This commit shall fix
> this issue.
> 
> Signed-off-by: Linus Lüssing <linus.luess...@web.de>
> ---
>  net/bridge/br_multicast.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
> index f61eb2e..47fae4f 100644
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
> @@ -1525,7 +1525,10 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br,
>                       break;
>               /*FALLTHROUGH*/
>       case CHECKSUM_NONE:
> -             skb2->csum = 0;
> +             skb2->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
> +                                                       &ip6h->daddr,
> +                                                       skb2->len,
> +                                                       nexthdr, 0));

You also need to include the pseudo-header for the CHECKSUM_COMPLETE
case, before we've fallen through (which only happens if the
hardware checksum doesn't match).

Thanks,
-- 
Email: Herbert Xu <herb...@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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