Wireshark-dev: Re: [Wireshark-dev] [PATCH] Dissector hooks: Small and Simple additions
From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Tue, 27 Feb 2007 17:22:18 -0800

On Feb 21, 2007, at 6:53 PM, Shehjar Tikoo wrote:

It brings in the dissector hooks feature discussed here a few weeks back. Its a small patch that includes basic infra for hooks and a sample hook for the NFS dissector.

Right now, the hook gets called(..using call_dissector_hooks()..) only for NFSv3 setattr call/reply but the intention is to call them in every message dissector function.

If so, perhaps the hooks should be attached to fields, rather than inserted into the code of particular dissectors. Having to change *every* dissector would be a lot of work.

My inclination would be to have a list of fields with callback hooks - most of the time, the list would be empty, so this would, I think, minimize the added overhead in the usual case - with an entry in the list having the field's hf_ value, the callback routine, and the private data pointer to be passed to the callback. Whenever a field is added to the protocol tree, the list would be checked, and the hook called if the field in question is being added.

There would be routines to register and unregister hooks.