res_pjsip/config_transport: Allow reloading transports.

The 'reload' mechanism actually involves closing the underlying
socket and calling the appropriate udp, tcp or tls start functions
again.  Only outbound_registration, pubsub and session needed work
to reset the transport before sending requests to insure that the
pjsip transport didn't get pulled out from under them.

In my testing, no calls were dropped when a transport was changed
for any of the 3 transport types even if ip addresses or ports were
changed. To be on the safe side however, a new transport option was
added (allow_reload) which defaults to 'no'.  Unless it's explicitly
set to 'yes' for a transport, changes to that transport will be ignored
on a reload of res_pjsip.  This should preserve the current behavior.

Change-Id: I5e759850e25958117d4c02f62ceb7244d7ec9edf

1 files changed, 28 insertions, 5 deletions

diff --git a/res/res_pjsip_session.c b/res/res_pjsip_session.c
index e7dd5b91d..983687174 100644
--- a/res/res_pjsip_session.c
+++ b/res/res_pjsip_session.c
@@ -888,10 +888,32 @@ int ast_sip_session_refresh(struct ast_sip_session *session,
 	return 0;
 }
 
+/*!
+ * \internal
+ * \brief Wrapper for pjsip_inv_send_msg
+ *
+ * This function (re)sets the transport before sending to catch cases
+ * where the transport might have changed.
+ *
+ * If pjproject gives us the ability to resend, we'll only reset the transport
+ * if PJSIP_ETPNOTAVAIL is returned from send.
+ *
+ * \returns pj_status_t
+ */
+static pj_status_t internal_pjsip_inv_send_msg(pjsip_inv_session *inv, const char *transport_name, pjsip_tx_data *tdata)
+{
+	pjsip_tpselector selector = { .type = PJSIP_TPSELECTOR_NONE, };
+
+	ast_sip_set_tpselector_from_transport_name(transport_name, &selector);
+	pjsip_dlg_set_transport(inv->dlg, &selector);
+
+	return pjsip_inv_send_msg(inv, tdata);
+}
+
 void ast_sip_session_send_response(struct ast_sip_session *session, pjsip_tx_data *tdata)
 {
 	handle_outgoing_response(session, tdata);
-	pjsip_inv_send_msg(session->inv_session, tdata);
+	internal_pjsip_inv_send_msg(session->inv_session, session->endpoint->transport, tdata);
 	return;
 }
 
@@ -1087,7 +1109,8 @@ void ast_sip_session_send_request_with_cb(struct ast_sip_session *session, pjsip
 	}
 
 	handle_outgoing_request(session, tdata);
-	pjsip_inv_send_msg(session->inv_session, tdata);
+	internal_pjsip_inv_send_msg(session->inv_session, session->endpoint->transport, tdata);
+
 	return;
 }
 
@@ -1852,7 +1875,7 @@ static pjsip_inv_session *pre_session_setup(pjsip_rx_data *rdata, const struct a
 		if (pjsip_inv_initial_answer(inv_session, rdata, 500, NULL, NULL, &tdata) != PJ_SUCCESS) {
 			pjsip_inv_terminate(inv_session, 500, PJ_FALSE);
 		}
-		pjsip_inv_send_msg(inv_session, tdata);
+		internal_pjsip_inv_send_msg(inv_session, endpoint->transport, tdata);
 		return NULL;
 	}
 	return inv_session;
@@ -2005,7 +2028,7 @@ static void handle_new_invite_request(pjsip_rx_data *rdata)
 		if (pjsip_inv_initial_answer(inv_session, rdata, 500, NULL, NULL, &tdata) == PJ_SUCCESS) {
 			pjsip_inv_terminate(inv_session, 500, PJ_FALSE);
 		} else {
-			pjsip_inv_send_msg(inv_session, tdata);
+			internal_pjsip_inv_send_msg(inv_session, endpoint->transport, tdata);
 		}
 		return;
 	}
@@ -2015,7 +2038,7 @@ static void handle_new_invite_request(pjsip_rx_data *rdata)
 		if (pjsip_inv_initial_answer(inv_session, rdata, 500, NULL, NULL, &tdata) == PJ_SUCCESS) {
 			pjsip_inv_terminate(inv_session, 500, PJ_FALSE);
 		} else {
-			pjsip_inv_send_msg(inv_session, tdata);
+			internal_pjsip_inv_send_msg(inv_session, endpoint->transport, tdata);
 		}
 		ao2_cleanup(invite);
 	}