From: Patrick McHardy <kaber@trash.net>
To: Jarek Poplawski <jarkao2@o2.pl>
Cc: Michael Tokarev <mjt@tls.msk.ru>,
netdev@vger.kernel.org, Herbert Xu <herbert@gondor.apana.org.au>
Subject: Re: [PATCH] tcp_output: Re: rare bad TCP checksum with 2.6.19?
Date: Fri, 19 Jan 2007 13:14:52 +0100 [thread overview]
Message-ID: <45B0B63C.3080201@trash.net> (raw)
In-Reply-To: <20070119110641.GA3135@ff.dom.local>
Jarek Poplawski wrote:
> Here is my patch proposal. If I'm not totally wrong,
> there is a possibility that, during collapsing, empty
> skb with FIN is added to "normal" packet and changes
> its ip_summed field to CHECKSUM_NONE.
>
> diff -Nurp linux-2.6.19-/net/ipv4/tcp_output.c linux-2.6.19/net/ipv4/tcp_output.c
> --- linux-2.6.19-/net/ipv4/tcp_output.c 2006-11-29 22:57:37.000000000 +0100
> +++ linux-2.6.19/net/ipv4/tcp_output.c 2007-01-19 07:58:39.000000000 +0100
> @@ -1590,7 +1590,8 @@ static void tcp_retrans_try_collapse(str
>
> memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size);
>
> - skb->ip_summed = next_skb->ip_summed;
> + if (next_skb->ip_summed == CHECKSUM_PARTIAL)
> + skb->ip_summed = CHECKSUM_PARTIAL;
>
> if (skb->ip_summed != CHECKSUM_PARTIAL)
> skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);
>
I noticed this too, but I can't see how it could lead to
a partial checksum on the wire since the checksumming is
done after changing ip_summed to CHECKSUM_NONE. Is this
patch verified to fix Michael's problem?
next prev parent reply other threads:[~2007-01-19 12:14 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-01-14 22:59 rare bad TCP checksum with 2.6.19? Michael Tokarev
2007-01-15 9:39 ` Herbert Xu
2007-01-15 13:34 ` Michael Tokarev
2007-01-15 14:25 ` Michael Tokarev
2007-01-15 18:13 ` Eric Dumazet
2007-01-15 19:33 ` Michael Tokarev
2007-01-15 23:36 ` Eric Dumazet
2007-01-15 20:10 ` Herbert Xu
2007-01-15 21:46 ` Michael Tokarev
2007-01-15 23:35 ` Herbert Xu
2007-01-16 3:27 ` Herbert Xu
2007-01-16 3:38 ` Herbert Xu
2007-01-16 8:08 ` Michael Tokarev
2007-01-16 11:50 ` Herbert Xu
2007-01-16 12:15 ` Patrick McHardy
2007-01-16 14:38 ` Michael Tokarev
2007-01-17 14:12 ` Michael Tokarev
2007-01-19 11:06 ` [PATCH] tcp_output: " Jarek Poplawski
2007-01-19 12:14 ` Patrick McHardy [this message]
2007-01-19 13:23 ` Michael Tokarev
2007-01-19 14:32 ` Jarek Poplawski
2007-01-19 13:20 ` Michael Tokarev
2007-01-19 14:08 ` Jarek Poplawski
2007-01-22 7:13 ` Jarek Poplawski
2007-01-22 7:19 ` Michael Tokarev
2007-01-22 8:03 ` Jarek Poplawski
2007-01-19 21:10 ` Herbert Xu
2007-01-22 6:52 ` Jarek Poplawski
2007-01-22 7:45 ` Herbert Xu
2007-01-22 8:48 ` Jarek Poplawski
2007-01-22 13:46 ` Patrick McHardy
2007-01-24 6:08 ` David Miller
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