From: Ang Way Chuang <wcang@sfc•wide.ad.jp>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: netdev@vger•kernel.org, "Linus Lüssing" <linus.luessing@web•de>,
"Herbert Xu" <herbert@gondor•apana.org.au>
Subject: Re: IPv6 multicast snooping behaviour on 2.6.39-rc2 and later
Date: Wed, 24 Aug 2011 02:24:07 +0900 [thread overview]
Message-ID: <4E53E237.1060401@sfc.wide.ad.jp> (raw)
In-Reply-To: <4E53B360.8090107@sfc.wide.ad.jp>
This is what I found so far from debugging.
The packet is not forwarded due to the failed checksum at br_multicast.c:1533
case CHECKSUM_NONE:
skb2->csum = 0;
if (skb_checksum_complete(skb2))
goto out;
}
Contrary to description of commit ff9a57a6, when the patch of commit ff9a57a6 is applied,
pskb_trim_rcsum is never called at all on my testbed. When commit ff9a57a6 is reverted,
pskb_trim_rcsum will be called. The difference is:
with commit ff9a57a6,
pskb_trim_rcsum is never called, br_multicast_ipv6_rcv returns -EINVAL which causes
br_handle_frame_finish to drop the packet
without commit ff9a57a6,
pskb_trim_rcsum is called overwriting err with 0. br_multicast_ipv6_rcv still fails on the
same line (skb_checksum_complete). But the difference is err is set to 0 this time. Thereby,
allowing the packet to be forwarded.
Anyway, I don't think the behaviour is correct with or without commit ff9a57a6
On 23/08/11 23:04, Ang Way Chuang wrote:
> Tough luck :( Got no love from bridge. It still doesn't work with your latest patch. Please keep sending those patches.
>
> On 23/08/11 22:10, Eric Dumazet wrote:
>> Le mardi 23 août 2011 à 21:31 +0900, Ang Way Chuang a écrit :
>>> Sorry for the blurb. I hope I've configured thunderbird properly to
>>> send in plain text. Hope you received my reply. I tried your patch on
>>> 3.0.3 and it didn't fix the problem.
>>
>> Thanks for trying !
>>
>> Ok could you please try following patch then ?
>>
>> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
>> index 2d85ca7..e9b32a3 100644
>> --- a/net/bridge/br_multicast.c
>> +++ b/net/bridge/br_multicast.c
>> @@ -1497,7 +1497,7 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br,
>> if (!pskb_may_pull(skb2, offset + sizeof(struct icmp6hdr)))
>> goto out;
>>
>> - len -= offset - skb_network_offset(skb2);
>> + len -= offset;
>>
>> __skb_pull(skb2, offset);
>> skb_reset_transport_header(skb2);
>> @@ -1520,6 +1520,7 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br,
>> err = pskb_trim_rcsum(skb2, len);
>> if (err)
>> goto out;
>> + icmp6h = icmp6_hdr(skb2);
>> }
>>
>> switch (skb2->ip_summed) {
>>
>>
>>
>
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger•kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
next prev parent reply other threads:[~2011-08-23 17:24 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-23 8:41 IPv6 multicast snooping behaviour on 2.6.39-rc2 and later Ang Way Chuang
2011-08-23 9:57 ` Eric Dumazet
2011-08-23 12:31 ` Ang Way Chuang
2011-08-23 13:10 ` Eric Dumazet
2011-08-23 14:04 ` Ang Way Chuang
2011-08-23 17:24 ` Ang Way Chuang [this message]
2011-08-24 4:56 ` [PATCH] bridge: Pseudo-header required for the checksum of ICMP6 header of MLD Ang Way Chuang
2011-08-24 5:06 ` David Miller
2011-08-24 7:04 ` IPv6 multicast snooping behaviour on 2.6.39-rc2 and later Yan, Zheng
2011-08-24 7:22 ` Eric Dumazet
2011-08-24 7:38 ` Ang Way Chuang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4E53E237.1060401@sfc.wide.ad.jp \
--to=wcang@sfc$(echo .)wide.ad.jp \
--cc=eric.dumazet@gmail$(echo .)com \
--cc=herbert@gondor$(echo .)apana.org.au \
--cc=linus.luessing@web$(echo .)de \
--cc=netdev@vger$(echo .)kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox