On Dec 15, 2022, at 2:21 PM, Alex Balashov <abalashov@evaristesys.com> wrote:

Adding further to this, it seems to me the real problem is that I can't use t_release() in an async resume route, because it's internally structured to take place inside a failure_route context. If I could, I think that would rid me of the first transaction after I send the challenge and call 'exit'.

On Dec 15, 2022, at 12:42 PM, Alex Balashov <abalashov@evaristesys.com> wrote:

As a test, I tried to put the auth_challenge() in the request_route before any async suspension, and in that case works fine.

The issue is definitely with the way auth_challenge() issued from _within_ an async resume route (failure_route context) bears upon transaction state.

-- Alex

On Dec 15, 2022, at 12:23 PM, Alex Balashov <abalashov@evaristesys.com> wrote:

Well, the difference seems pretty clear. In a scenario with an auth challenge and no subsequent INVITE+credentials, the negative ACK is matched:

4(54) DEBUG: <core> [core/receive.c:389]: receive_msg(): --- received sip message - request - call-id: [01eed151-4234-4518-9a0e-9b9168f21a3f] - cseq: [288439 ACK]
4(54) DEBUG: <core> [core/receive.c:261]: ksr_evrt_pre_routing(): event route core:pre-routing not defined
4(54) DEBUG: <core> [core/receive.c:471]: receive_msg(): preparing to run routing scripts...
4(54) DEBUG: sl [sl_funcs.c:447]: sl_filter_ACK(): too late to be a local ACK!
4(54) DEBUG: <core> [core/parser/parse_hname2.c:301]: parse_sip_header_name(): parsed header name [Content-Length] type 12
4(54) DEBUG: <core> [core/parser/msg_parser.c:187]: get_hdr_field(): content_length=0
4(54) DEBUG: <core> [core/parser/msg_parser.c:91]: get_hdr_field(): found end of header
4(54) DEBUG: maxfwd [mf_funcs.c:55]: is_maxfwd_present(): max_forwards header not found!
4(54) DEBUG: siputils [checks.c:123]: has_totag(): totag found
4(54) DEBUG: rr [loose.c:108]: find_first_route(): No Route headers found
4(54) DEBUG: rr [loose.c:1006]: loose_route_mode(): There is no Route HF
4(54) DEBUG: tm [t_lookup.c:1053]: t_check_msg(): msg (0xffffa72f7088) id=14/54 global id=13/54 T start=0
4(54) DEBUG: tm [t_lookup.c:497]: t_lookup_request(): start searching: hash=42311, isACK=1
4(54) DEBUG: tm [t_lookup.c:439]: matching_3261(): RFC3261 transaction matched, tid=SG.ceb57d44-7388-4739-9a86-d44ea04d974d
4(54) DEBUG: tm [t_lookup.c:692]: t_lookup_request(): transaction found (T=0xffffa2f428a8)
4(54) DEBUG: tm [t_lookup.c:1122]: t_check_msg(): msg (0xffffa72f7088) id=14/54 global id=14/54 T end=0xffffa2f428a8
4(54) DEBUG: tm [t_reply.c:1763]: cleanup_uac_timers(): RETR/FR timers reset
4(54) DEBUG: tm [t_funcs.c:120]: put_on_wait(): put T [0xffffa2f428a8] on wait
4(54) DEBUG: <core> [core/timer.c:557]: timer_add_safe(): timer_add called on an active timer 0xffffa2f42930 (0xffffa2d05d08, 0xffffa2d05d08), flags 201
4(54) DEBUG: tm [t_funcs.c:143]: put_on_wait(): transaction 0xffffa2f428a8 already on wait

However, in a scenario with an auth challenge with subsequent INVITE+credentials, the same negative ACK is not matched to a known transaction.

2(52) DEBUG: <core> [core/receive.c:389]: receive_msg(): --- received sip message - request - call-id: [895a7051-3e0c-410a-88ea-4bad7a1c21b6] - cseq: [939189 ACK]
2(52) DEBUG: <core> [core/receive.c:261]: ksr_evrt_pre_routing(): event route core:pre-routing not defined
2(52) DEBUG: <core> [core/receive.c:471]: receive_msg(): preparing to run routing scripts...
2(52) DEBUG: sl [sl_funcs.c:447]: sl_filter_ACK(): too late to be a local ACK!
2(52) DEBUG: <core> [core/parser/parse_hname2.c:301]: parse_sip_header_name(): parsed header name [Content-Length] type 12
2(52) DEBUG: <core> [core/parser/msg_parser.c:187]: get_hdr_field(): content_length=0
2(52) DEBUG: <core> [core/parser/msg_parser.c:91]: get_hdr_field(): found end of header
2(52) DEBUG: maxfwd [mf_funcs.c:55]: is_maxfwd_present(): max_forwards header not found!
2(52) DEBUG: siputils [checks.c:123]: has_totag(): totag found
2(52) DEBUG: rr [loose.c:108]: find_first_route(): No Route headers found
2(52) DEBUG: rr [loose.c:1006]: loose_route_mode(): There is no Route HF
2(52) DEBUG: tm [t_lookup.c:1053]: t_check_msg(): msg (0xffffa72f7088) id=19/52 global id=18/52 T start=0
2(52) DEBUG: tm [t_lookup.c:497]: t_lookup_request(): start searching: hash=21251, isACK=1
2(52) DEBUG: tm [t_lookup.c:455]: matching_3261(): RFC3261 transaction matching failed - via branch [z9hG4bKSG.c52861b7-2535-4080-84f5-2819c4169843]
2(52) DEBUG: tm [t_lookup.c:675]: t_lookup_request(): no transaction found

This makes sense intuitively; the auth_challenge(), and resulting 407 challenge, should have ended the old transaction, so the negative ACK should just be absorbed.

But in that case, why does the 407 keep being retransmitted?

-- Alex

On Dec 15, 2022, at 12:00 PM, Alex Balashov <abalashov@evaristesys.com> wrote:

Hi Henning,

On Dec 15, 2022, at 11:51 AM, Henning Westerholt <hw@gilawa.com> wrote:

Hi Alex,
it might not help you much, but recently I was implementing a similar structure in one larger migration project, and it seems to work fine.
I am not using any special flags for the challenge etc..
It’s basically like this (pseudo-code)
route{
if no auth user -> auth_challenge()
else -> http_async_query(API, AUTH)
}
route[AUTH] {
get API result for password
if API failure -> auth_challenge()
else -> pv_auth_check(..)
route(next steps)
}

Yeah, that's more or less what I've got, except the first part.

I don't auth_challenge() every request because some requests are allowed by static IP, and I don't know whether to auth_challenge() them unless I am already in the async resume context.

I have eliminated the independent credentials query. At this point my process is more:

request_route {
  ...

  http_async_query(API, RESUME)
}

route[RESUME] {
  if(method == "INVITE") {
     if(has_auth_attrib()) {
        if(!pv_auth_check(...)) {
           auth_challenge("realm", "1");
           exit;
        }
     }

     # Get more routing info.
     http_async_query(API, RESUME2)
     return;
  }
}

route[RESUME2} {
  t_relay() etc
}

-- Alex

--
Alex Balashov | Principal | Evariste Systems LLC

Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free)
Web: http://www.evaristesys.com/, http://www.csrpswitch.com/

--
Alex Balashov | Principal | Evariste Systems LLC

Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free)
Web: http://www.evaristesys.com/, http://www.csrpswitch.com/

--
Alex Balashov | Principal | Evariste Systems LLC

Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free)
Web: http://www.evaristesys.com/, http://www.csrpswitch.com/

--
Alex Balashov | Principal | Evariste Systems LLC

Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free)
Web: http://www.evaristesys.com/, http://www.csrpswitch.com/