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Date: Thu, 13 Jun 2002 17:28:51 +0200
From: Guillaume Morin <guillaume@morinfr.org>
To: "Shipman, Jeffrey E" <jeshipm@sandia.gov>
Cc: "'linux-kernel@vger.kernel.org'" <linux-kernel@vger.kernel.org>
Subject: Re: TCP checksum?
Message-ID: <20020613152851.GA3442@morinfr.org>
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Dans un message du 13 jun ?  9:10, Shipman, Jeffrey E ?crivait :
>
> I'm looking for a function similar to skb_checksum(), but
> for the tcphdr->check field. I'm playing around with a module
> I've written for netfilter and I would like to modify options of
> the IP and TCP headers. For example, right now I'm trying
> to set the destination IP to the source IP, but the TCP checksum
> is coming out incorrectly. How can I calculate this checksum?

There is a netfilter function for that. Look at
ip_nat_core.c:ip_nat_cheat_check.

-- 
Guillaume Morin <guillaume@morinfr.org>

          5 years from now everyone will be running free GNU on their
           200 MIPS, 64M SPARCstation-5 (Andy Tanenbaum, 30 Jan 1992)
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