Wireshark · Ethereal-dev: Re: [Ethereal-dev] Re: New dissectors: H.223 and friends

[Richard van der Hoff <richardv@xxxxxxxxxxxxx>]

Richard van der Hoff wrote:
> Guy Harris wrote:
>
> > Are those higher-level PDUs always in order, so that there's no 
> > sequence number in them?  If so, then you should be using 
> > "fragment_add_seq_next()".
>
> You may well be right - I'm not entirely sure why Jeff chose 
> fragment_add(), but I imagine it was because he based the code on the 
> TCP dissector.

Ah no, I see the problem with that. The issue is that the iax2 dissector 
must first mark a pdu as complete, then pass it to a higher-level 
dissector, which may in turn decide that the pdu was incomplete; so we 
must have the ability to unmark a pdu as complete.

You can't do this with fragment_add_seq_next(), because it moves 
complete PDUs to a separate hash table.

I'll work on a fix for the existing logic.

Richard


--
Richard van der Hoff <richardv@xxxxxxxxxxxxx>
Systems Analyst
Tel: +44 (0) 845 666 7778
http://www.mxtelecom.com