Wireshark-dev: Re: [Wireshark-dev] how to access lower level packet information
From: Guy Harris <[email protected]>
Date: Tue, 15 Aug 2006 02:40:29 -0700
Motonori Shindo wrote:

Is there any way for a dissector to access the information that has
already been dissected by lower level dissector?
If the dissector supplies that information, yes.

For example, suppose
I'm writing a dissector for a certain protocol atop UDP and I need the
source IP address of the packet. How would I get such information in
the dissector I'm writing?
pinfo->net_src would contain that address - the type field would be 
AT_IPv4 or AT_IPv6 for UDP over IP.