From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexander Nasonov <alnsn-mycop@yandex.ru>
Subject: ASN.1 decoder for h323-conntrack-nat
Date: Thu, 16 Oct 2003 15:25:06 +0200
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Hi!
Sorry, I don't have enough time right now to understand how current 
version of h323-conntrack-nat works. Probably, what I'm going to 
announce here is already implemented.
Anyway, here is what I have. I've implemented callback-based decoder of 
ASN.1 PER rules. With a help of this decoder it's possible to analyze 
H323 packet and to call user-defined function when the code came across 
an interesting type. For example, it's easy to jump from fastStart 
element to OpenLogicalChannel or to detect OpenLogicalChannel -> 
reverseLogicalChannelParameters -> mediaChannel -> ipAddress sequence.
Generated code doesn't have dynamic memory allocations and other 
undeterministic stuff. It just easts bits :))) In it's current state the 
code is ugly (due to deadline) and it is C++. If there is an interest, I 
can rewrite it later.
--
Alexander Nasonov