Wireshark-dev: Re: [Wireshark-dev] Sub_dissectors assertion failed

From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Sat, 22 May 2010 13:39:16 -0700
On May 21, 2010, at 6:42 PM, Scott wrote:

> On Fri, May 21, 2010 at 3:18 PM, Guy Harris <guy@xxxxxxxxxxxx> wrote:
>> So what protocols does your custom protocol run on top of?
> 
> For now the custom protocol is a dummy protocol that only contains a 32-bit int and rides on top of the IP protocol rider (*it*).

So presumably the IP protocol rider protocol has fields of its own.

Does the IP protocol rider have an IP protocol number assigned to it, so that you have:

	link-layer protocol

	IP, with the IP protocol number having the value for the IP protocol rider protocol

	IP protocol rider protocol

	custom protocol

	some protocol that normally runs directly atop IP

or is this a non-standard encapsulation where you have:

	link-layer protocol

	IP, with the IP protocol number having the value for the protocol that's above the custom protocol

	IP protocol rider protocol

	custom protocol

	some protocol that normally runs directly atop IP

The former can be done without modifying Wireshark, but not the way you're doing it.

The latter *CANNOT* be done without Wireshark's IP dissector to directly call the dissector for the IP protocol rider protocol.