res_pjsip: Fix infinite recursion when loading transports from realtime

Attempting to load a transport from realtime was forcing asterisk into an
infinite recursion loop.  The first thing transport_apply did was to do a
sorcery retrieve by id for an existing transport of the same name. For files,
this just returns the previous object from res_sorcery_config's internal
container, if any.  For realtime, the res_sourcery_realtime driver looks in the
database and finds the existing row but now it has to rehydrate it into a
sorcery object which means calling... transport_apply.  And so it goes.

The main issue with loading from realtime (apart from the loop) was that
transport stores structures and pointers directly in the ast_sip_transport
structure instead of the separate ast_transport_state structure.  This patch
separates those items into the ast_sip_transport_state structure.  The pattern
is roughly the same as res_pjsip_outbound_registration.

Although all current usages of ast_sip_transport and ast_sip_transport_state
were modified to use the new ast_sip_get_transport_state API, the original
items are left in ast_sip_transport and kept updated to maintain ABI
compatability for third-party modules.  They are marked as deprecated and
noted that they're now in ast_sip_transport_state.

ASTERISK-25606 #close
Reported-by: Martin Moučka

Change-Id: Ic7a836ea8e786e8def51fe3f8cce855ea54f5f19

1 files changed, 3 insertions, 2 deletions

diff --git a/res/res_pjsip_sdp_rtp.c b/res/res_pjsip_sdp_rtp.c
index 2a1f56ed4..08e80a38c 100644
--- a/res/res_pjsip_sdp_rtp.c
+++ b/res/res_pjsip_sdp_rtp.c
@@ -1360,11 +1360,12 @@ static int apply_negotiated_sdp_stream(struct ast_sip_session *session, struct a
 /*! \brief Function which updates the media stream with external media address, if applicable */
 static void change_outgoing_sdp_stream_media_address(pjsip_tx_data *tdata, struct pjmedia_sdp_media *stream, struct ast_sip_transport *transport)
 {
+	RAII_VAR(struct ast_sip_transport_state *, transport_state, ast_sip_get_transport_state(ast_sorcery_object_get_id(transport)), ao2_cleanup);
 	char host[NI_MAXHOST];
 	struct ast_sockaddr addr = { { 0, } };
 
 	/* If the stream has been rejected there will be no connection line */
-	if (!stream->conn) {
+	if (!stream->conn || !transport_state) {
 		return;
 	}
 
@@ -1372,7 +1373,7 @@ 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->localnet, &addr) == AST_SENSE_ALLOW) {
+	if (ast_apply_ha(transport_state->localnet, &addr) == AST_SENSE_ALLOW) {
 		return;
 	}