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Ethereal-dev: Re: [Ethereal-dev] updated fakelink dissector + (new) README.fakelink

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From: Navin Anand <navin.anand@xxxxxxxxxxxx>
Date: Wed, 13 Aug 2003 11:05:18 +0530
Hello,


3) How to write a fake link layer PCAP file?
----------------------------------------------

There are 2 methods that you can use to write out a fake link PCAP capture file: by using the Wiretap library (part of Ethereal) or by writing the file out directly from your application. It would make sense that libpcap could be used directly (which could be advantageous since it has a BSD license) but the APIs for libpcap do not seem to allow writing protocol packets to a file
directly (it seems geared more towards capture-and-writing).



You could, with more recent versions of libpcap, probably cheat by calling "pcap_open_dead()" and using the pcap_t * you get back from that as the argument to "pcap_dump_open()".


Okay, yes, that works well, too...  Thanks for the pointer.



Does anybody have any thoughts on what direction to take with this?

I'm leaning towards asking 'tcpdump-workers' for some new LINKTYPE_ definitions:

LINKTYPE_MTP2
LINKTYPE_MTP3
LINKTYPE_SCCP (Navin, I assume you want this one?  I don't need it)

and ditch the "fake link" dissector for now. (But I'd like some level of agreement before doing so.)

Regards,
-Jeff

My requirement extends beyond SCCP, for e.g. I need to be able to decode raw MAP packets. I find it convenient to have a single LINKTYPE_ definition for fake link, and have all other protocols register with it. Perhaps I am biased towards my creation.

Yours truly,
Navin Anand.