From: John Hughes <john@atlantech•com>
To: Vlad Yasevich <vyasevich@gmail•com>
Cc: John Hughes <john@atlantech•com>, netdev@vger•kernel.org
Subject: Re: When a TCP segment is split up (to be sent through a TUN device with a small MTU) who should recalculate the checksum?
Date: Fri, 15 Nov 2013 15:31:59 +0100 [thread overview]
Message-ID: <5286305F.5060903@atlantech.com> (raw)
In-Reply-To: <52862DBF.2060801@gmail.com>
On 15/11/13 15:20, Vlad Yasevich wrote:
>
> Can you check to see if you have the following patch in your kernel
> commit: 1cdbcb7957cf9e5f841dbcde9b38fd18a804208b
> Author: Simon Horman <horms@verge•net.au>
> Date: Sun May 19 15:46:49 2013 +0000
>
> net: Loosen constraints for recalculating checksum in skb_segment()
>
>
> This commit help if the forwarding system has to re-segment the data
> before transition. Especially if the receiving interface had GRO
> enabled with checksum offloading and the transmitting interface does
> not support checksum offloading.
No, the Debian 3.10 kernel doesn't seem to have that commit:
Around line 2859 in skbuff.c I see:
if (fskb != skb_shinfo(skb)->frag_list)
continue;
next prev parent reply other threads:[~2013-11-15 14:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-15 8:52 When a TCP segment is split up (to be sent through a TUN device with a small MTU) who should recalculate the checksum? John Hughes
2013-11-15 13:06 ` Eric Dumazet
2013-11-15 14:02 ` John Hughes
2013-11-15 14:20 ` Vlad Yasevich
2013-11-15 14:31 ` John Hughes [this message]
2013-11-15 14:41 ` Vlad Yasevich
2013-11-15 14:55 ` John Hughes
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