res_pjsip: Record the serializer earlier on the tdata.

When PJPROJECT needs to do a DNS resolution and there is not a cached
entry available, the SIP request message goes out on the PJSIP monitor
thread instead of the original serializer thread.  Thus when the response
comes back it does not get processed by the original sending serializer.

This patch records the serializer on tdata before passing a request
message to PJPROJECT where it can in Asterisk code.  There are several
places in PJPROJECT for outbound registration and publishing support that
would need to record the serializer.  Unfortunately, without replacing the
PJPROJECT DNS resolver as was done in v14 we cannot fix those without
modifying PJPROJECT.

Even if we backported the DNS resolver from v14, the outbound registration
refresh timer does not go out on a serializer thread but the PJSIP monitor
thread.  Fortunately, Asterisk's outbound publish support doesn't use the
auto refresh timer that would also not go out under the serializer thread.

This patch is v13 only.

ASTERISK-26669
ASTERISK-26738

Change-Id: I9997b9ed6dbcebd2c37d6a67dc6dcee9c78914a4

4 files changed, 8 insertions, 12 deletions

diff --git a/res/res_pjsip.c b/res/res_pjsip.c
index 9b9905826..a167150f6 100644
--- a/res/res_pjsip.c
+++ b/res/res_pjsip.c
@@ -3603,6 +3603,8 @@ static pj_status_t endpt_send_request(struct ast_sip_endpoint *endpoint,
 		}
 	}
 
+	ast_sip_record_request_serializer(tdata);
+
 	/* We need to insure that the wrapper and tdata are available when the
 	 * transaction callback is executed.
 	 */
diff --git a/res/res_pjsip/pjsip_distributor.c b/res/res_pjsip/pjsip_distributor.c
index 82ca184d3..e076db3b8 100644
--- a/res/res_pjsip/pjsip_distributor.c
+++ b/res/res_pjsip/pjsip_distributor.c
@@ -29,12 +29,11 @@
 
 static int distribute(void *data);
 static pj_bool_t distributor(pjsip_rx_data *rdata);
-static pj_status_t record_serializer(pjsip_tx_data *tdata);
 
 static pjsip_module distributor_mod = {
 	.name = {"Request Distributor", 19},
 	.priority = PJSIP_MOD_PRIORITY_TSX_LAYER - 6,
-	.on_tx_request = record_serializer,
+	.on_tx_request = ast_sip_record_request_serializer,
 	.on_rx_request = distributor,
 	.on_rx_response = distributor,
 };
@@ -65,16 +64,7 @@ struct unidentified_request{
 /*! Pool of serializers to use if not supplied. */
 static struct ast_taskprocessor *distributor_pool[DISTRIBUTOR_POOL_SIZE];
 
-/*!
- * \internal
- * \brief Record the task's serializer name on the tdata structure.
- * \since 14.0.0
- *
- * \param tdata The outgoing message.
- *
- * \retval PJ_SUCCESS.
- */
-static pj_status_t record_serializer(pjsip_tx_data *tdata)
+pj_status_t ast_sip_record_request_serializer(pjsip_tx_data *tdata)
 {
 	struct ast_taskprocessor *serializer;
 
diff --git a/res/res_pjsip_outbound_publish.c b/res/res_pjsip_outbound_publish.c
index 35eedf0d2..7c0b64b4d 100644
--- a/res/res_pjsip_outbound_publish.c
+++ b/res/res_pjsip_outbound_publish.c
@@ -349,6 +349,7 @@ static int send_unpublish_task(void *data)
 			pjsip_tx_data_set_transport(tdata, &selector);
 		}
 
+		ast_sip_record_request_serializer(tdata);
 		pjsip_publishc_send(client->client, tdata);
 	}
 
@@ -598,6 +599,7 @@ static int sip_publish_client_service_queue(void *data)
 		pjsip_tx_data_set_transport(tdata, &selector);
 	}
 
+	ast_sip_record_request_serializer(tdata);
 	status = pjsip_publishc_send(client->client, tdata);
 	if (status == PJ_EBUSY) {
 		/* We attempted to send the message but something else got there first */
@@ -910,6 +912,7 @@ static void sip_outbound_publish_callback(struct pjsip_publishc_cbparam *param)
 				pjsip_tx_data_set_transport(tdata, &selector);
 			}
 
+			ast_sip_record_request_serializer(tdata);
 			pjsip_publishc_send(client->client, tdata);
 		}
 		client->auth_attempts++;
diff --git a/res/res_pjsip_outbound_registration.c b/res/res_pjsip_outbound_registration.c
index da15f19f5..6c615f0a4 100644
--- a/res/res_pjsip_outbound_registration.c
+++ b/res/res_pjsip_outbound_registration.c
@@ -528,6 +528,7 @@ static pj_status_t registration_client_send(struct sip_outbound_registration_cli
 	 */
 	ast_sip_set_tpselector_from_transport_name(client_state->transport_name, &selector);
 	pjsip_regc_set_transport(client_state->client, &selector);
+	ast_sip_record_request_serializer(tdata);
 	status = pjsip_regc_send(client_state->client, tdata);
 
 	/* If the attempt to send the message failed and the callback was not invoked we need to