In an ideal world idl2eth 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.
As you have probably guessed from the name, idl2eth 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 an ethereal dissector.
idl2eth 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.idl2eth
This document
ethereal_be.py
The main compiler backend
ethereal_gen.py
A helper class, that generates the C code.
idl2eth
A simple shell script wrapper that the end user should use to generate the dissector from the IDL file(s).
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 "Ethereal" ( http://www.ethereal.com )
To use the idl2eth to generate ethereal dissectors, you need the following:
Prerequisites to using idl2eth
Python must be installed. See http://python.org/
omniidl from the the omniORB package must be available. See http://omniorb.sourceforge.net/
Of course you need ethereal installed to compile the code and tweak it if required. idl2eth is part of the standard Ethereal distribution
To use idl2eth to generate an ethereal dissector from an idl file use the following procedure:
Procedure for converting a Corba idl file into an ethereal dissector
To write the C code to stdout.
idl2eth <your file.idl>
eg:
idl2eth echo.idl
To write to a file, just redirect the output.
idl2eth echo.idl > packet-test-idl.c
You may wish to comment out the register_giop_user_module() code and that will leave you with heuristic dissection.
If you don't want to use the shell script wrapper, then try steps 3 or 4 instead.
To write the C code to stdout.
Usage: omniidl -p ./ -b ethereal_be <your file.idl>
eg:
omniidl -p ./ -b ethereal_be echo.idl
To write to a file, just redirect the output.
omniidl -p ./ -b ethereal_be echo.idl > packet-test-idl.c
You may wish to comment out the register_giop_user_module() code and that will leave you with heuristic dissection.
Copy the resulting C code to your ethereal src directory, edit the 2 make files to include the packet-test-idl.c
cp packet-test-idl.c /dir/where/ethereal/lives/ edit Makefile.am edit Makefile.nmake
Run configure
./configure (or ./autogen.sh)
Compile the code
make
Good Luck !!
Exception code not generated (yet), but can be added manually.
Enums not converted to symbolic values (yet), but can be added manually.
Add command line options etc
More I am sure :-)
The "-p ./" option passed to omniidl indicates that the ethereal_be.py and ethereal_gen.py are residing in the current directory. This may need tweaking if you place these files somewhere else.
If it complains about being unable to find some modules (eg tempfile.py), you may want to check if PYTHONPATH is set correctly. On my Linux box, it is PYTHONPATH=/usr/lib/python1.5/