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, 13 insertions, 19 deletions

diff --git a/res/res_pjsip_outbound_registration.c b/res/res_pjsip_outbound_registration.c
index 0ff609a63..dd69ff20e 100644
--- a/res/res_pjsip_outbound_registration.c
+++ b/res/res_pjsip_outbound_registration.c
@@ -346,6 +346,8 @@ struct sip_outbound_registration_client_state {
 	unsigned int destroy:1;
 	/*! \brief Non-zero if we have attempted sending a REGISTER with authentication */
 	unsigned int auth_attempted:1;
+	/*! \brief The name of the transport to be used for the registration */
+	char *transport_name;
 };
 
 /*! \brief Outbound registration state information (persists for lifetime that registration should exist) */
@@ -508,6 +510,7 @@ static pj_status_t registration_client_send(struct sip_outbound_registration_cli
 {
 	pj_status_t status;
 	int *callback_invoked;
+	pjsip_tpselector selector = { .type = PJSIP_TPSELECTOR_NONE, };
 
 	callback_invoked = ast_threadstorage_get(&register_callback_invoked, sizeof(int));
 	if (!callback_invoked) {
@@ -517,6 +520,13 @@ static pj_status_t registration_client_send(struct sip_outbound_registration_cli
 
 	/* Due to the message going out the callback may now be invoked, so bump the count */
 	ao2_ref(client_state, +1);
+	/*
+	 * Set the transport in case transports were reloaded.
+	 * When pjproject removes the extraneous error messages produced,
+	 * we can check status and only set the transport and resend if there was an error
+	 */
+	ast_sip_set_tpselector_from_transport_name(client_state->transport_name, &selector);
+	pjsip_regc_set_transport(client_state->client, &selector);
 	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
@@ -966,6 +976,7 @@ static void sip_outbound_registration_client_state_destroy(void *obj)
 {
 	struct sip_outbound_registration_client_state *client_state = obj;
 
+	ast_free(client_state->transport_name);
 	ast_statsd_log_string("PJSIP.registrations.count", AST_STATSD_GAUGE, "-1", 1.0);
 	ast_statsd_log_string_va("PJSIP.registrations.state.%s", AST_STATSD_GAUGE, "-1", 1.0,
 		sip_outbound_registration_status_str(client_state->status));
@@ -1003,6 +1014,7 @@ static struct sip_outbound_registration_state *sip_outbound_registration_state_a
 	state->client_state->status = SIP_REGISTRATION_UNREGISTERED;
 	state->client_state->timer.user_data = state->client_state;
 	state->client_state->timer.cb = sip_outbound_registration_timer_cb;
+	state->client_state->transport_name = ast_strdup(registration->transport);
 
 	ast_statsd_log_string("PJSIP.registrations.count", AST_STATSD_GAUGE, "+1", 1.0);
 	ast_statsd_log_string_va("PJSIP.registrations.state.%s", AST_STATSD_GAUGE, "+1", 1.0,
@@ -1171,25 +1183,6 @@ static int sip_outbound_registration_regc_alloc(void *data)
 
 	pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), pool);
 
-	if (!ast_strlen_zero(registration->transport)) {
-		RAII_VAR(struct ast_sip_transport_state *, transport_state, ast_sip_get_transport_state(registration->transport), ao2_cleanup);
-
-		if (!transport_state) {
-			ast_log(LOG_ERROR, "Unable to retrieve PJSIP transport '%s' "
-				" for outbound registration", registration->transport);
-			return -1;
-		}
-
-		if (transport_state->transport) {
-			selector.type = PJSIP_TPSELECTOR_TRANSPORT;
-			selector.u.transport = transport_state->transport;
-		} else if (transport_state->factory) {
-			selector.type = PJSIP_TPSELECTOR_LISTENER;
-			selector.u.listener = transport_state->factory;
-		} else {
-			return -1;
-		}
-	}
 
 	ast_assert(state->client_state->client == NULL);
 	if (pjsip_regc_create(ast_sip_get_pjsip_endpoint(), state->client_state,
@@ -1198,6 +1191,7 @@ static int sip_outbound_registration_regc_alloc(void *data)
 		return -1;
 	}
 
+	ast_sip_set_tpselector_from_transport_name(registration->transport, &selector);
 	pjsip_regc_set_transport(state->client_state->client, &selector);
 
 	if (!ast_strlen_zero(registration->outbound_proxy)) {