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Date: Thu, 02 Apr 2009 14:09:00 +0200
From: Paolo Pisati <p.pisati@oltrelinux.com>
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To: Luigi Rizzo <rizzo@iet.unipi.it>
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Cc: freebsd-ipfw@FreeBSD.org, Dmitriy Demidov <dima_bsd@inbox.lv>,
	Alex Dupre <ale@FreeBSD.org>
Subject: Re: keep-state rules inadequately handles big UDP packets
 or	fragmented IP packets?
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Luigi Rizzo wrote:
> Can you put a description in the manpage especially on the
> assumptions and side effects of the reass option ?
>
> E.g. as i read it,
> + you need to make sure that the fragments are not dropped before
>   the 'reass' (so you cannot rely on port numbers to decide
>   accept or deny). This is obvious but a very common mistake;
> + reass silently queues the fragment if it does not reass, so it
>   opens up a bit of vulnerability. Again obvious, but people
>   won't realise if they don't see the code.
>   
someone else already pointed out that i should mention 
net.inet.ip.maxfrag*, i'll come up
with an updated man page later today.

-- 

bye,
P.