Final response 2xx not retransmitted when transport is closed

[trengginas]

When transport is closed before sending 2xx final response, the message will fail to be sent.
However, it is not retransmitted.

15:18:01.361       sip_endpoint.c  Processing incoming message: Request msg INVITE/cseq=1 (rdata0xd6da70)
15:18:01.361          tsx0xd75a38  ..Transaction created for Request msg INVITE/cseq=1 (rdata0xd70518)
15:18:01.361          tsx0xd75a38  .Incoming Request msg INVITE/cseq=1 (rdata0xd70518) in state Null
15:18:01.361          tsx0xd75a38  ..State changed from Null to Trying, event=RX_MSG
15:18:01.361          dlg0xd747d8  ...Transaction tsx0xd75a38 state changed to Trying
15:18:01.361          dlg0xd747d8  .UAS dialog created
...
15:18:01.361          tsx0xd75a38  ....State changed from Trying to Proceeding, event=TX_MSG
15:18:01.361          dlg0xd747d8  .....Transaction tsx0xd75a38 state changed to Proceeding
15:18:01.361          inv0xd747d8  ......State changed from NULL to INCOMING, event=TSX_STATE
...
15:18:01.367         tcps0xd6d788 !TCP connection closed
15:18:01.367      sip_transport.c  Transport tcps0xd6d788 shutting down, force=0
15:18:01.368      sip_transport.c  Transport tcps0xd6d788 is being destroyed due to timeout in idle timer
15:18:01.368         tcps0xd6d788  TCP transport destroyed with reason 70016: End of file (PJ_EEOF)
...
15:18:01.368          inv0xd747d8  .Sending Response msg 200/INVITE/cseq=1 (tdta0x7fec84008738)
15:18:01.368      sip_transport.c  .Tx data Response msg 200/INVITE/cseq=1 (tdta0x7fec84001478) cloned
15:18:01.368          dlg0xd747d8  ..Sending Response msg 200/INVITE/cseq=1 (tdta0x7fec84001478)
15:18:01.368          tsx0xd75a38  ..Sending Response msg 200/INVITE/cseq=1 (tdta0x7fec84001478) in state Proceeding
...
15:18:01.378   tcpc0x7fec8400e178 !TCP connect() error: [code=120111]: Connection refused
15:18:01.378          tsx0xd75a38  Failed to send Response msg 200/INVITE/cseq=1 (tdta0x7fec84001478)! err=120111 (Connection refused)
15:18:01.378   tcpc0x7fec8400e178  TCP send() error, sent=-120111
15:18:01.378      sip_transport.c  Transport tcpc0x7fec8400e178 shutting down, force=0
15:18:01.378      sip_transport.c  Transport tcpc0x7fec8400e178 is being destroyed due to timeout in idle timer
15:18:01.378   tcpc0x7fec8400e178  TCP transport destroyed with reason 120111: Connection refused
15:18:33.369          tsx0xd75a38  Timeout timer event
15:18:33.369          tsx0xd75a38  .State changed from Completed to Terminated, event=TIMER
15:18:33.369          dlg0xd747d8  ..Transaction tsx0xd75a38 state changed to Terminated
15:18:33.369           sip_util.c  ...Request msg BYE/cseq=16412 (tdta0xd7a8b8) created.

When the transport is closed, the response will be sent using pjsip_endpt_send_response()

pjproject/pjsip/src/pjsip/sip_transaction.c

Line 2532 in e9771e2

tsx->transport_flag |= TSX_HAS_PENDING_TRANSPORT;

with TSX_HAS_PENDING_TRANSPORT set and later will prevent the retransmit timer from being scheduled and instead setting TSX_HAS_PENDING_RESCHED.

pjproject/pjsip/src/pjsip/sip_transaction.c

Line 3086 in e9771e2

tsx->transport_flag |= TSX_HAS_PENDING_RESCHED;

This patch will check if TSX_HAS_PENDING_RESCHED is set, and schedule the timer in the case that the send failed.

[sauwming]

The CI tests failed.

[trengginas]

restarted the registrar, and now it's fine