Hi Daniel,
thanks for having a look.
There is already a callback for negative ACK, my problem was that I was using t_check_trans (tm api) to check if the ACK was a negative ACK, and t_check_trans was calling this callback internally.
So, if after the sip_trace() call in the script we had a t_check_trans(), the callback itself was called again, thus giving a duplicated message. I've solved using instead t_lookup_request.
I've pushed another commit on the branch and I'm going to open the PR.

Cheers,

Federico



On Sun, Apr 5, 2020 at 9:18 AM Daniel-Constantin Mierla <miconda@gmail.com> wrote:

Hello,

I think it is fine to merge those three commits to master as they solve some of the reported issue. There is also some work planned to be done for a global enable/disable tracing to database, so it makes sense to have all the code in master for combined testing.

Regarding the negative ACK, maybe getting the invite transaction and seeing if it is a failed transaction is an option. Or simply adding in tm module a callback for negative ACK.

Cheers,
Daniel

On 03.04.20 13:48, Federico Cabiddu wrote:
Hi all,
following the feedback I just pushed a branch (https://github.com/kamailio/kamailio/tree/grumvalski/siptrace_flag_fixes), which tries to address the issues discussed.
I've tried to split the commits so that each issue is handled separately.
With the first commit (https://github.com/kamailio/kamailio/commit/b64b3f03a9c6b69587ca360465f091f873f7274b) I fixed the incoming ACK for negative replies tracing: as discussed it makes no sense to check in the callback if tracing is enabled or not.
The second commit (https://github.com/kamailio/kamailio/commit/e28f464457eea47cc606c73cbfe4b30fcc8b542a) refactors the e2e CANCEL handling. With the previous implementation the incoming CANCEL captured would have the ANYADDR set as destination address. This commit also allows to have exactly the same behavior between transaction tracing (sip_trace_mode("t")) and legacy tracing (setflag + sip_trace()) when tracing a specific INVITE.
With the third (https://github.com/kamailio/kamailio/commit/080c6e07708f1964498a43e70c9b6240b5bdebcd) I've tried as much as possible to restore the legacy behavior when tracing all the requests without having duplicated captures for CANCEL and ACK for negative replies. I could achieve this for the CANCEL checking if the INVITE it refers to is already being traced (meaning that the CANCEL will be captured by the callback) but I couldn't for the ACK. I couldn't find a way to check if the ACK is for a negative reply (and thus it belongs to a transaction), without having the tm callbacks for ACK run, since both t_check and t_check_trans tm calls run the E2ECANCEL_IN callbacks.
I've tried different scenarios in both capturing modes (transaction and flag+trace):
1) Successful call (INVITE-200-ACK)
2) Error replied
3) Canceled call
4) locally generated CANCEL (timeout)
All looks good (except for the ACK issue) in both modes.
I would like to have the developers' feedback before opening a PR, there could be other scenarios/use cases I'm not considering here.
Thank you all.

Cheers,

Federico



On Wed, Apr 1, 2020 at 2:45 PM Federico Cabiddu <federico.cabiddu@gmail.com> wrote:
Hi,

OK, indeed, the previous behavior should be preserved in this case. Is sip_trace() without params now doing transaction mode capturing?

Yes and no. Transaction mode is activated but actual behavior is not exactly the same (see case 3) vs case 1)). 

Cheers,

Federico
-- 
Daniel-Constantin Mierla -- www.asipto.com
www.twitter.com/miconda -- www.linkedin.com/in/miconda