netdev - Re: Disable tcp MSS option in three way handshake?

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Message-ID: <alpine.LNX.2.01.1211040124370.30066@nerf07.vanv.qr>
Date:	Sun, 4 Nov 2012 01:25:13 +0100 (CET)
From:	Jan Engelhardt <jengelh@...i.de>
To:	Eric Dumazet <eric.dumazet@...il.com>
cc:	Vincent Li <vincent.mc.li@...il.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: Disable tcp MSS option in three way handshake?


On Friday 2012-10-26 00:42, Eric Dumazet wrote:
>On Thu, 2012-10-25 at 15:27 -0700, Vincent Li wrote:
>> 
>> this sounds crazy, we have a weird situation that an unknown tcp
>> implementation not putting tcp MSS option in the SYN/ACK which caused
>> us some issue. I am tasked to mimic the unknown tcp immplementation on
>> not sending MSS in tcp SYN/ACK, I am wondering if I can achieve that
>> by modifying linux kernel tcp code,  there is socket option
>> TCP_MAXSEG, but that seems only affecting the size of MSS, not
>> removing the MSS option. do you have any pointer on how to do that in
>> kernel tcp code?
>
>You'll have to patch the code.
>
>Or else, you could add a new feature to net/netfilter/xt_TCPMSS.c

Or you could just use -j TCPOPTSTRIP.
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