[asterisk-dev] supported: timers though deactivated

[Michael Maier]

On 06.06.21 at 22:19 Joshua C. Colp wrote:
> On Sun, Jun 6, 2021 at 3:57 PM Michael Maier <m1278468 at mailbox.org> wrote:
> 
>> Hello!
>>
>> Using Asterisk 18.4 / pjisp, timers are advertised as supported though
>> disabled in config with timers=no.
>>
>> This does not happen initially (during the Invite sequence) but later on
>> in 200 Ok as answer to a reInvite or as the answer to an Update methode.
>>
>> Is there any reason why it's suddenly activated later on though it's
>> deactivated? From my point of view, this smells like a bug.
>>
> 
> It'd be a bug in PJSIP itself, probably in the INVITE session[1] code as
> that is what responsible for this.

Thanks for your hint!

They are using a function to clean up the supported header (cleanup_allow_sup_hdr).

Let's take a look at the creation of the 200 Ok answer of the received update - I could find this path (there is no SDP in the received Update):

inv_respond_incoming_update
	pjsip_dlg_create_response
		pjsip_endpt_create_response
			pjsip_msg_create
				pj_list_init

	pjsip_timer_update_resp
	pjsip_dlg_send_response

If I didn't oversee anything, I couldn't find the usage of cleanup_allow_sup_hdr - but I couldn't find either where the supported header should have been added. Do you have an idea?



Greetings
Micahel

> 
> [1]
> https://github.com/pjsip/pjproject/blob/master/pjsip/src/pjsip-ua/sip_inv.c#L1819
> 
> 
>