Wireshark · Wireshark-dev: Re: [Wireshark-dev] WiMAX ASN Control Protocol dissector submission status?

[Stephen Croll <croll@xxxxxxxxxxxxxxxxx>]

Martin Mathieson wrote:
> This dissector has already been useful to us, thanks again for posting it.
>   
You're welcome.
> (2) I'd probably add more expert items to report more things like:
>     - length fields not being consistent with that implied by type of TLV
>     - unknown tlv codes
>   

Yes, that was something I left for future work.  To facilitate the
addition of expert items, I made all functions accept the packet_info
pointer, regardless of whether it used it or not.

Regarding unknown/TBD TLVs, there is a preference for enabling
debug output that will emit a debug statement to the console when one
of these TLVs is encountered.  It's a rather convenient way of
identifying such TLVs found in captures.

> (3) I notice that the field of the tlv parent is wimaxasncp.tlv_type.  I'd
> rather it were just a byte-string field, e.g. wimaxasncp.tlv, then maybe have
> the child nodes be e,g, wimaxasncp.tlv.length, etc.  This is probably just a
> matter of taste.  There are some other little prettifications that I'd want to
> make.
>   

Matter of taste?  No, not that complicated.  This was my first
dissector, so I would simply say inexperience (on my part).

> (5) Its not possible to set a filter to do a comparison with the value of a
> certain tlv, e.g. you can't do 'wimaxasncp.avp.ms_nai == "base_station_w3"
>   
True.  It's related to the following point:

> Points (1), (3) and (5) remind me strongly of Diameter dissector issues, and I
> wonder if this dissector should (eventually) be done in a similar way, i.e.
> - read the tlv definitions in from one or more XML files at run-time
> - dynamically register filters such as described in (5)
>   

I actually did recommend that the dissector use XML files for TLV
definitions when I did my initial analysis.  Unfortunately that did
not happen in the initial release.

--
Steve Croll