User Guide

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D.10. idl2wrs: Creating dissectors from CORBA
IDL files
In an ideal world idl2wrs would be mentioned in the users guide in passing and documented in the
developers guide. As the developers guide has not yet been completed it will be documented here.
D.10.1. What is it?
As you have probably guessed from the name, idl2wrs takes a user specified IDL file and attempts to
build a dissector that can decode the IDL traffic over GIOP. The resulting file is "C" code, that should
compile okay as a Wireshark dissector.
idl2wrs basically parses the data struct given to it by the omniidl compiler, and using the GIOP API
available in packet-giop.[ch], generates get_CDR_xxx calls to decode the CORBA traffic on the wire.
It consists of 4 main files.
README.idl2wrs This document
wireshark_be.py The main compiler backend
wireshark_gen.py A helper class, that generates the C code.
idl2wrs A simple shell script wrapper that the end user should use to generate the
dissector from the IDL file(s).
D.10.2. Why do this?
It is important to understand what CORBA traffic looks like over GIOP/IIOP, and to help build a tool
that can assist in troubleshooting CORBA interworking. This was especially the case after seeing a lot of
discussions about how particular IDL types are represented inside an octet stream.
I have also had comments/feedback that this tool would be good for say a CORBA class when teaching
students what CORBA traffic looks like "on the wire".
It is also COOL to work on a great Open Source project such as the case with "Wireshark" ( http://
www.wireshark.org )
D.10.3. How to use idl2wrs
To use the idl2wrs to generate Wireshark dissectors, you need the following:
Prerequisites to using idl2wrs
1. Python must be installed. See http://python.org/
2. omniidl from the omniORB package must be available. See http://omniorb.sourceforge.net/
3. Of course you need Wireshark installed to compile the code and tweak it if required. idl2wrs is part
of the standard Wireshark distribution
To use idl2wrs to generate an Wireshark dissector from an idl file use the following procedure: