Re: Would it be useful to have preferences for radiotap to allow handling of captures with conflicting presence flags?

Johannes Berg <[email protected]> Fri, 15 Dec 2017 09:24:00 +0100
Newsgroups org.netbsd.radiotap
Message-ID <[email protected]>
On Thu, 2017-12-14 at 17:52 -0800, Guy Harris wrote:

> My inclination is 1) not to add the presence bits for suggested
> fields to any code that processes radiotap headers unless there are
> capture files or devices that use them and 

Absolutely - that's why we got this mailing list and process started in
the first place :-)

> 2) not to add preferences unless there are capture files or devices
> that one interpretation of the presence bit in question *and* capture
> files or devices that use the other interpretation.

Agree with this. We do have conflicts now because the spec historically
evolved in the header files in various *BSD & Linux trees, but that
should be a thing of the past now. At least, if anyone still does that
I'd hope we don't actually encourage it and add preferences for it.

> If you're doing this because you're working on something that
> *generates* radiotap headers, I would suggest that you use only
> defined fields if possible and, if you need to add information that's
> *not* supported by any defined field, try to get a field defined -
> preferably with its own presence bit assigned.

You could also use vendor fields if you really think it's not something
that benefits from proper definition/assignment.

johannes