Wireshark-dev: Re: [Wireshark-dev] Adding data parameter to dissector handler

From: Jakub Zawadzki <darkjames-ws@xxxxxxxxxxxx>
Date: Tue, 4 Sep 2012 11:19:09 +0200
On Mon, Sep 03, 2012 at 06:00:06PM -0700, Guy Harris wrote:
> 
> On Sep 3, 2012, at 4:35 PM, Jakub Zawadzki wrote:
> 
> > I plan to replace:
> >  typedef void (*dissector_t)(tvbuff_t *, packet_info *, proto_tree *);
> >  typedef int (*new_dissector_t)(tvbuff_t *, packet_info *, proto_tree *);
> > 
> > with:
> >  typedef int (*real_dissector_t)(tvbuff_t *, packet_info *, proto_tree *, void *data);
> 
> "Replace"?  That means changing *all* dissectors to have the new function signature (not that doing so is the wrong thing to do; it's just going to be a lot of work, even if it's work with a shell script or something such as that).
> 
> Did you mean "I plan to add to ... this", i.e. keep dissector_t and new_dissector_t around, and add real_dissector_t and have new routines with which "new new style" dissectors can register themselves, with older dissectors not being passed the additional argument when called through call_dissector(), etc.?

I want to have one API, so yes, replace. I know it's monkey job ;-)

> Don't forget to change heur_dissector_t - or add real_heur_dissector_t - and the calls to invoke a heuristic dissector.

Ok, good point, what about another try[1] of merging heur_dissector_t into real_dissector_t,
heuristic dissectors which haven't accept tvb just return -1.

[1] http://www.wireshark.org/lists/wireshark-dev/201207/msg00197.html