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From: Florian Westphal <fw@strlen.de>
To: Ulrich Weber <uweber.linux@gmail.com>
Cc: Florian Westphal <fw@strlen.de>,
	netfilter-devel@vger.kernel.org,
	Patrick McHardy <kaber@trash.net>
Subject: Re: [RFC] SIP conntrack handler and TCP fragmentation
Date: Wed, 12 Oct 2016 13:41:40 +0200	[thread overview]
Message-ID: <20161012114140.GB26177@breakpoint.cc> (raw)
In-Reply-To: <1e3ffb89-2c24-526a-01aa-53794d554202@gmail.com>

Ulrich Weber <uweber.linux@gmail.com> wrote:
> From reading the code this fixed the problem when Content-Length
> points to one of the next TCP fragments.

Right.

> In our case Content-Length is always 0 with a couple of SUBSCRIBE calls.
> E.g. a TCP packet starting with this will break the SIP connection tracking:
> 
> INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE,SUBSCRIBE
> Content-Length: 0

Ugh.

I guess it makes sense to detect this and then accept for this case too.

> The previous TCP packet was accepted by SIP connection tracking
> because it had no Content-Length field.

Perhaps we should treat Content-length of 0 like "no Conent-Length
field".

  reply	other threads:[~2016-10-12 11:42 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-12  7:38 [RFC] SIP conntrack handler and TCP fragmentation Ulrich Weber
2016-10-12  7:52 ` Florian Westphal
2016-10-12  8:52   ` Ulrich Weber
2016-10-12 11:41     ` Florian Westphal [this message]
2016-10-12 12:27       ` Ulrich Weber

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