ims_qos, ima_registrar_pcscf: fixes for de-registration and adding a flow to registration

[vingarzan]

ims_qos: create a proper flow description for the SIP signaling

• before there was just an empty one in the AAR
• re-using the function typically used for the RTP media
• fixing then that function to not just hard-code protocol 17 (UDP) for everything
• now supporting also 6 (TCP) and IP (IP has no protocol number, we use just the
  magic word "ip" (see RFC 3588 IPFilterRule for more details)
• adding the IP of the P-CSCF as a parameter to the module, as this is required
  in the flow (UE IP <-> P-CSCF IP)
• also some inline/static fixes to function for avoiding warnings on gcc >=5

ims_registrar_pcscf: fixed removal of contacts on de-registration

• the code was there, but I guess some API changes resulted in temporary
  commented-out code; this uses the new parameters and seems to fix the
  issue.

[ngvoice]

Hi Dragos,

looks okay to me, waiting for @jaybeepee or @richardgood to approve, too.
Can you add the new parameter to the docs, too?

Thanks,
Carsten

[vingarzan]

Hi Carsten,

fixed the missing doc. I also changed the name to something hopefully more relevant. "rx_" was for parameters related to the Diameter interface.

Cheers,
-Dragos

[richardgood]

Thanks @vingarzan

All looks good - just want to check one thing with @jaybeepee on ims_registrar_pcscf: fixed removal of contacts on de-registration

I have a sneaking suspicion this was removed on purpose and the contact removal is done through NOTIFY from S-CSCF.

Though I don't think this would cause any issues having it here as well (and could be useful in the event of P-CSCF not implementing subscribe to reg event)

[vingarzan]

That's what I thought also, that reginfo would save the day. Then spent a long time tracking down structure of pua, etc, just to find out that the NOTIFY is not doing it unfortunately. Or maybe we missed something...

Anyway: my recommendation is to do both really, to make sure that you catch it even if the configuration has the SUBSCRIBE disabled or some strange S-CSCFs would reject the SUBSCRIBE.

[richardgood]

Hi

Have a look at ims_registrar_pcscf/notify.c line 205.

If the contact is in usrloc and a NOTIFY is received for terminate it should remove it.

But agreed we should do both - just in case. Give me a day or two I just want to double confirm with @jaybeepee why it was removed in the first place to ensure it doesn't have any unintended consequences.

[richardgood]

Ahh I see the confusion - we call reginfo_handle_notify from cfg file - which might not be the case for all P-CSCF cfg files. I think we still need to do quite a bit of polishing on this code and config.

[vingarzan]

Can i haz the pcscf example file plz :) ?

[richardgood]

I see the reginfo_handle_notify is actually in the example pcscf config file in git:

examples/pcscf/kamailio.cfg line 1184.