Message-ID: <493423D7.5030203@myri.com>
Date: Mon, 01 Dec 2008 12:50:15 -0500
From: Andrew Gallatin <gallatin@myri.com>
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To: Jan-Bernd Themann <ossthema@de.ibm.com>
CC: David Miller <davem@davemloft.net>, netdev@vger.kernel.org,
       linux-kernel <linux-kernel@vger.kernel.org>, tklein@de.ibm.com,
       Christoph Raisch <raisch@de.ibm.com>, jb.billaud@gmail.com,
       hering2@de.ibm.com
Subject: Re: [PATCH] lro: IP fragment checking
References: <4933A74F.3050809@de.ibm.com>
In-Reply-To: <4933A74F.3050809@de.ibm.com>
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Jan-Bernd Themann wrote:
> This patch prevents that ip fragmented TCP packets are considered vaild
> for aggregation

<...>

> +	if (iph->frag_off & IP_MF)
> +		return -1;
> +

I think there is an endian bug, and that you should also check
IP_OFFSET.  What about:

	if (iph->frag_off & htons(IP_MF|IP_OFFSET))

As to whether or not to do it in the drivers/hardware or in the
LRO code, I favor doing it in the LRO code just so that it is not
missed in some driver.

Drew
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