Wireshark-dev: [Wireshark-dev] Help with dissector_add and h248 protocol

From: Alex Lindberg <alindber@xxxxxxxxx>
Date: Wed, 8 Jul 2009 09:25:54 -0700 (PDT)
I am creating a plugin that is intended to decode custom h248 packages.

I would like to register my protocol to h248.propertyName, but the "dissector_add" function continues abort with "assertion failed" messages in protocol.c, line 709.  My intent is register all of my custom package IDs to this field

I looking at the back trace, in packet.c, link 707 thefunction "find_dissector_table(name)" where name==h248.propertyName, returns Zero.  Hence the error is created on packet.c, line 709 where the sanity check is called.

I have listed the registered fields (tshark -G) looking for a field name that would work but I have and no success.

Here is the code in my plugin that fails:

for ( i = 0; package_name_ext_vals[i].strptr!=NULL; i++ )
{
  dissector_add("h248.<Field>", \ /* tried many field values */
    package_name_ext_vals[i].value,\
    h248ext_handle);

}

The value_string array "package_name_ext_vals[]" lists all of the custom packageIDs and their names that I would like to decode.

I would prefer to create a plugin and not modify the current h248 code base.

Thanks as always for your help.

Alex Lindberg