Handle accounting stop with zero session length

[Alan DeKok]

On Apr 22, 2020, at 2:38 AM, Stefan Möding <s.moeding at gmail.com> wrote:
> I think I pretty much got the config changes done on the old version
> into the new setup and the system works mostly as expected. But there
> seems to be a change from version 2 to version 3 that creates additional
> accounting records with zero session length.

  Yeah, that used to be suppressed by the SQL module.  In the interest of making things more configurable, we remove many hard-coded rules.

> We used radsniff to observe that our NAS does send an accounting request
> stop after receiving an access reject from Freeradius:

  Which is technically allowed by the specs.  However, it's entirely a stupid thing to do.

> Looking a the source code I got the impression that this is where things
> changed from version 2 to version 3. In version 2 the log message
> indicates the the zero length stop message was ignores. In version 3 the
> code changed and the accounting recored is written to the database.

  Yes.

> Can we do anything about this?

  Yes.  The unlang policy you posted will work.

> Does this look reasonable? Do I miss anything?

  Yes, and no.  :)

  Alan DeKok.