[asterisk-users] Adding Subscribe Handlers in PJSIP

[Joshua Colp]

On Wed, Mar 1, 2017, at 04:02 PM, Trey Hilyard wrote:
> Is there any "easy" way to add a custom subscribe handler? I have a set
> of
> users with Polycom phones that attempt to Events that Asterisk/PJSIP
> doesn't recognize, "call-info" and "as-feature-event". It just generates
> a
> warning, but it got me wondering if I could add my own handlers for those
> that didn't actually do anything but simply responded with a 200 OK.
> 
> Yes, I can probably stop the phones from subscribing, but this is more
> academic at this point. I assume there are things that I could do if I
> wanted to make changes and recompile, but is there an easier way to add a
> handler? I am a little confused about whether there is a subscribe
> handler
> in front of res_pjsip_pubsub, or if that is the first place that a
> SUBSCRIBE could get caught.

The res_pjsip_pubsub module itself provides a framework for registering
support for event types (ast_sip_register_subscription_handler) and
handles the subscription lifetime. Callbacks are invoked on the various
things. Subscription requested, terminated, etc. There are also
functions for sending a NOTIFY and such.

There's also another framework for handling PUBLISH.

This all does require writing a C module though and building it with
Asterisk. There's no external mechanism to implement such things.

-- 
Joshua Colp
Digium, Inc. | Senior Software Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - US
Check us out at: www.digium.com & www.asterisk.org