From: James Morris <jmorris@namei.org>
To: Adam Langley <agl@imperialviolet.org>
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: Re: [PATCH] Fix corrupt TCP packets when options space overflows with MD5SIG enabled
Date: Mon, 2 Jun 2008 09:40:15 +1000 (EST) [thread overview]
Message-ID: <Xine.LNX.4.64.0806020938240.8594@us.intercode.com.au> (raw)
In-Reply-To: <396556a20805301217k293e5718h6bbf02bfe0683143@europa>
On Sat, 31 May 2008, Adam Langley wrote:
> When MD5 signatures are turned on we can end up with syntactically invalid
> packets with a header length < 20 bytes. This is because tcp_header_size
> overflows with 12 bytes of timestamp, 20 bytes of signature and > 8 bytes of
> SACK option.
>
> Since we can't fit any SACK blocks in the final 8 bytes of options space, and
> the MD5 signature is more important, we disable including SACK, or even
> advertising it, when MD5 is enabled.
>
> Signed-off-by: Adam Langley <agl@imperialviolet.org>
Reviewed-by: James Morris <jmorris@namei.org>
(FYI, the upcoming replacement for this, TCP-AO, is designed to be SACK
compatible)
--
James Morris
<jmorris@namei.org>
next prev parent reply other threads:[~2008-06-01 23:40 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-30 18:40 [PATCH] Fix corrupt TCP packets when options space overflows with MD5SIG enabled Adam Langley
2008-05-30 19:02 ` Ben Hutchings
2008-05-30 19:11 ` Adam Langley
2008-05-30 19:17 ` Adam Langley
2008-05-30 20:32 ` Stephen Hemminger
2008-05-31 22:01 ` Adam Langley
2008-05-31 21:57 ` Adam Langley
2008-06-01 23:40 ` James Morris [this message]
2008-06-02 6:56 ` David Miller
2008-06-03 16:31 ` Adam Langley
2008-06-03 16:44 ` David Miller
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