Wireshark · Ethereal-dev: Re: [Ethereal-dev] dissector_add problem

[Ulf Lamping <ulf.lamping@xxxxxx>]

Helge Kruse wrote:

> Hello,
>
> I write a dissector for a protocol on UDP. In the plugin_init function 
> I call
>
> myProtocol = proto_register_protocol("My Genial Protocol", 
> "MyProtocol", "myproto");
>
> I also register the subtree_array, and the subtree_arrays. In the 
> plugin_reg_handoff function, I call this:
>
> hDissector = create_dissector_handle(DissectorFunc, myProtocol); 
> dissector_add("udp.port", 2002, hDissector); dissector_add("udp.port", 
> 2001, hDissector);
>
> The DissectorFunc is called for all UDP packets from/to UDP port 2001 
> but for none UDP packet from/to port 2002. This does not change, when 
> I exchange the two dissector_add calls or remove the first call.
>
> When I select “Decode As” and assign the protocol to the UDP port 
> 2002, the DissectorFunc is called and the packet is displayed as expected.
>
> I have no clue, what is wrong. Can you give advise?
It seems to be ok what you are doing, some other dissectors are doing it 
the same way.

I would think you have a bug somewhere at registering the stuff in your 
proto_register_... function, so Ethereal's internal data gets a bit 
confused.

You may try to reduce the stuff in your registering function to a 
minimum and see if the problem still remains.

Regards, ULFL