[Serusers] How does $f.did work?

[Martin Hoffmann]

x-ser at sidell.org wrote:
> In ser-oob.cfg, the route[AUTHENTICATION] function has this code:
> 
> 
>   # Requests from non-local to local domains should be permitted.
>   # Remove this if you want a walled garden.
>   if (!$f.did) {
> 	break;
>   }
> 
> 
> I'm guessing that the code is permitting all invites that are
> addressed to a local destination, regardless of the source of the
> invite, so that the source is not required to authenticate itself.  Is
> that right?

Not quite. If the from domain (usually the domain mentioned in the hostport
part of the From URI) is known, the attribute $f.did is set otherwise it
isn't. The code breaks out of the route for all requests with a unknown
from domain -- more specifically, a from domain that is not processed by
this proxy.

> Also, what is the tersely named $f variable, how does it get
> initialized, and what is the meaning of the .did member?

I did write a short explanation a couple of days ago. It is split into
two postings:

   o  http://lists.iptel.org/pipermail/serusers/2008-June/035035.html

   o  http://lists.iptel.org/pipermail/serusers/2008-June/035037.html

If I have some time, I will write this all up properly.

Regards,
Martin