res/res_pjsip_session: Only check localnet if it is defined

If local_net is not defined on a transport, transport_state->localnet
will be NULL. ast_apply_ha will, be default, return AST_SENSE_ALLOW in
this case, causing the external_media_address, if set, to be skipped.

This patch causes us to only check if we are sending within a network if
local_net is defined.

ASTERISK-26879 #close

Change-Id: Ib661c31a954cabc9c99f1f25c9c9a5c5b82cbbfb

res/res_pjsip_nat.c

@@ -262,18 +262,18 @@ static pj_status_t nat_on_tx_message(pjsip_tx_data *tdata)
 		return PJ_SUCCESS;
 	}
 
-	if ( !transport_state->localnet || 	ast_sockaddr_isnull(&transport_state->external_address)) {
+	if (transport_state->localnet) {
-		return PJ_SUCCESS;
-	}
-
 		ast_sockaddr_parse(&addr, tdata->tp_info.dst_name, PARSE_PORT_FORBID);
 		ast_sockaddr_set_port(&addr, tdata->tp_info.dst_port);
 
 		/* See if where we are sending this request is local or not, and if not that we can get a Contact URI to modify */
 		if (ast_apply_ha(transport_state->localnet, &addr) != AST_SENSE_ALLOW) {
+			ast_debug(5, "Request is being sent to local address, skipping NAT manipulation\n");
 			return PJ_SUCCESS;
 		}
+	}
 
+	if (!ast_sockaddr_isnull(&transport_state->external_address)) {
 		/* Update the contact header with the external address */
 		if (uri || (uri = nat_get_contact_sip_uri(tdata))) {
 			pj_strdup2(tdata->pool, &uri->host, ast_sockaddr_stringify_host(&transport_state->external_address));
@@ -290,6 +290,7 @@ static pj_status_t nat_on_tx_message(pjsip_tx_data *tdata)
 				via->sent_by.port = transport->external_signaling_port;
 			}
 		}
+	}
 
 	/* Invoke any additional hooks that may be registered */
 	if ((hooks = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "nat_hook", AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL))) {

res/res_pjsip_sdp_rtp.c

@@ -1473,10 +1473,11 @@ static void change_outgoing_sdp_stream_media_address(pjsip_tx_data *tdata, struc
 	ast_sockaddr_parse(&addr, host, PARSE_PORT_FORBID);
 
 	/* Is the address within the SDP inside the same network? */
-	if (ast_apply_ha(transport_state->localnet, &addr) == AST_SENSE_ALLOW) {
+	if (transport_state->localnet
+		&& ast_apply_ha(transport_state->localnet, &addr) == AST_SENSE_ALLOW) {
 		return;
 	}
-
+	ast_debug(5, "Setting media address to %s\n", transport->external_media_address);
 	pj_strdup2(tdata->pool, &stream->conn->addr, transport->external_media_address);
 }
 

res/res_pjsip_session.c

@@ -3148,7 +3148,10 @@ static void session_outgoing_nat_hook(pjsip_tx_data *tdata, struct ast_sip_trans
 		ast_copy_pj_str(host, &sdp->conn->addr, sizeof(host));
 		ast_sockaddr_parse(&addr, host, PARSE_PORT_FORBID);
 
-		if (ast_apply_ha(transport_state->localnet, &addr) != AST_SENSE_ALLOW) {
+		if (!transport_state->localnet
+			|| (transport_state->localnet
+				&& ast_apply_ha(transport_state->localnet, &addr) == AST_SENSE_ALLOW)) {
+			ast_debug(5, "Setting external media address to %s\n", transport->external_media_address);
 			pj_strdup2(tdata->pool, &sdp->conn->addr, transport->external_media_address);
 		}
 	}

res/res_pjsip_t38.c

@@ -867,10 +867,11 @@ static void change_outgoing_sdp_stream_media_address(pjsip_tx_data *tdata, struc
 	ast_sockaddr_parse(&addr, host, PARSE_PORT_FORBID);
 
 	/* Is the address within the SDP inside the same network? */
-	if (ast_apply_ha(transport_state->localnet, &addr) == AST_SENSE_ALLOW) {
+	if (transport_state->localnet
+		&& ast_apply_ha(transport_state->localnet, &addr) == AST_SENSE_ALLOW) {
 		return;
 	}
-
+	ast_debug(5, "Setting media address to %s\n", transport->external_media_address);
 	pj_strdup2(tdata->pool, &stream->conn->addr, transport->external_media_address);
 }