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From: David Miller <davem@davemloft.net>
To: fw@strlen.de
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH] net: core: don't account for udp header size when computing seglen
Date: Tue, 08 Apr 2014 22:06:00 -0400 (EDT)	[thread overview]
Message-ID: <20140408.220600.925628398524560053.davem@davemloft.net> (raw)
In-Reply-To: <1396990288-10692-1-git-send-email-fw@strlen.de>

From: Florian Westphal <fw@strlen.de>
Date: Tue,  8 Apr 2014 22:51:28 +0200

> In case of tcp, gso_size contains the tcpmss.
> 
> For UFO (udp fragmentation offloading) skbs, gso_size is the fragment
> payload size, i.e. we must not account for udp header size.
> 
> Otherwise, when using virtio drivers, a to-be-forwarded UFO GSO packet
> will be needlessly fragmented in the forward path, because we think its
> individual segments are too large for the outgoing link.
> 
> Fixes: de960aa9ab4d ("net: add and use skb_gso_transport_seglen()")
> Cc: Eric Dumazet <eric.dumazet@gmail.com>
> Reported-by: Tobias Brunner <tobias@strongswan.org>
> Signed-off-by: Florian Westphal <fw@strlen.de>

I agree completely with the fix, but not necessarily with the Fixes:
tag.

All that commit did was move the code to a common location, it
always had this bug.

I suppose you could list the subsequent commit, the one that started
using this helper in the IP forwarding code, as what this "Fixes".

Thanks Florian.

      reply	other threads:[~2014-04-09  2:06 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-08 20:51 [PATCH] net: core: don't account for udp header size when computing seglen Florian Westphal
2014-04-09  2:06 ` David Miller [this message]

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