Currently, I have a particular dissector for a proprietary protocol
whose payload is XML. The operation is simple: I parse the proprietary
protocol header and then pass off the payload to the XML dissector.
Everything's great. However, there is an option in the protocol that
the payload can be in "Fast Infoset" format instead of XML. I am not
that familiar with "Fast Infoset", but in a nutshell, and I quote
Wikipedia, it "specifies a binary encoding format for the XML
Information Set as an alternative to the XML document format. It aims
to provide more efficient serialization than the text-based XML format."
So, is there a Wireshark dissector for "Fast Infoset" already? I have
not found one, but there are so many, I could have missed it. "Fast
Infoset" apparently uses ASN.1 formalisms, so I tried looking in both
the asn1/ and epan/dissectors/ directories, but didn't find anything.
The ITU-T recommendation is X.891 (ISO/IEC 24824-1).
Assuming there isn't one, would it be a dissector worth adding? I have
not written an ASN.1-based dissector yet, so apart from looking through
the various existing ones, are there any "getting started" tips, tricks,
pitfalls to avoid, etc. for someone writing his 1st one? Which of the
numerous existing ASN.1 dissectors are probably the simplest to start
looking at, for example? Depending on the amount of work involved, I
may not be able to afford the time to add it now, but I'd at least like
to know what I'm in for.
Thanks for any advice,
Chris
P.S. A couple of "Fast Infoset" links for curious readers:
http://asn1.elibel.tm.fr/en/xml/finf.htm
http://en.wikipedia.org/wiki/Fast_Infoset