[03/11] mgcp: Add a function to get media info for MGCP responses

diff --git a/openbsc/include/openbsc/mgcp.h b/openbsc/include/openbsc/mgcp.h
index 6ba0769..b595aba 100644
--- a/openbsc/include/openbsc/mgcp.h
+++ b/openbsc/include/openbsc/mgcp.h
@@ -92,6 +92,12 @@  typedef int (*mgcp_processing)(struct mgcp_rtp_end *dst_end,
 typedef int (*mgcp_processing_setup)(struct mgcp_endpoint *endp,
 				     struct mgcp_rtp_end *dst_end,
 				     struct mgcp_rtp_end *src_end);
+
+typedef void (*mgcp_get_format)(struct mgcp_endpoint *endp,
+				int *payload_type,
+				const char**subtype_name,
+				const char**fmtp_extra);
+
 #define PORT_ALLOC_STATIC	0
 #define PORT_ALLOC_DYNAMIC	1
 
@@ -166,6 +172,8 @@  struct mgcp_config {
 	mgcp_processing rtp_processing_cb;
 	mgcp_processing_setup setup_rtp_processing_cb;
 
+	mgcp_get_format get_net_downlink_format_cb;
+
 	struct osmo_wqueue gw_fd;
 
 	struct mgcp_port_range bts_ports;
diff --git a/openbsc/include/openbsc/mgcp_internal.h b/openbsc/include/openbsc/mgcp_internal.h
index 72ac8e9..e74b9fa 100644
--- a/openbsc/include/openbsc/mgcp_internal.h
+++ b/openbsc/include/openbsc/mgcp_internal.h
@@ -209,4 +209,9 @@  int mgcp_setup_rtp_processing_default(struct mgcp_endpoint *endp,
 				      struct mgcp_rtp_end *dst_end,
 				      struct mgcp_rtp_end *src_end);
 
+void mgcp_get_net_downlink_format_default(struct mgcp_endpoint *endp,
+					  int *payload_type,
+					  const char**subtype_name,
+					  const char**fmtp_extra);
+
 #endif
diff --git a/openbsc/src/libmgcp/mgcp_network.c b/openbsc/src/libmgcp/mgcp_network.c
index 4d1ad35..dcbb97a 100644
--- a/openbsc/src/libmgcp/mgcp_network.c
+++ b/openbsc/src/libmgcp/mgcp_network.c
@@ -361,6 +361,19 @@  int mgcp_setup_rtp_processing_default(struct mgcp_endpoint *endp,
 	return 0;
 }
 
+void mgcp_get_net_downlink_format_default(struct mgcp_endpoint *endp,
+					  int *payload_type,
+					  const char**audio_name,
+					  const char**fmtp_extra)
+{
+	/* Use the BTS side parameters when passing the SDP data (for
+	 * downlink) to the net peer.
+	 */
+	*payload_type = endp->bts_end.payload_type;
+	*audio_name = endp->bts_end.audio_name;
+	*fmtp_extra = endp->bts_end.fmtp_extra;
+}
+
 /**
  * The RFC 3550 Appendix A assumes there are multiple sources but
  * some of the supported endpoints (e.g. the nanoBTS) can only handle
diff --git a/openbsc/src/libmgcp/mgcp_protocol.c b/openbsc/src/libmgcp/mgcp_protocol.c
index 3960c88..215c2ee 100644
--- a/openbsc/src/libmgcp/mgcp_protocol.c
+++ b/openbsc/src/libmgcp/mgcp_protocol.c
@@ -232,12 +232,15 @@  static struct msgb *create_response_with_sdp(struct mgcp_endpoint *endp,
 					     const char *msg, const char *trans_id)
 {
 	const char *addr = endp->cfg->local_ip;
-	const char *fmtp_extra = endp->bts_end.fmtp_extra;
-	const char *audio_name = endp->bts_end.audio_name;
-	int payload_type = endp->bts_end.payload_type;
+	const char *fmtp_extra;
+	const char *audio_name;
+	int payload_type;
 	char sdp_record[4096];
 	int len;
 
+	endp->cfg->get_net_downlink_format_cb(endp, &payload_type,
+					      &audio_name, &fmtp_extra);
+
 	if (!addr)
 		addr = endp->cfg->source_addr;
 
@@ -1213,6 +1216,8 @@  struct mgcp_config *mgcp_config_alloc(void)
 	cfg->rtp_processing_cb = &mgcp_rtp_processing_default;
 	cfg->setup_rtp_processing_cb = &mgcp_setup_rtp_processing_default;
 
+	cfg->get_net_downlink_format_cb = &mgcp_get_net_downlink_format_default;
+
 	/* default trunk handling */
 	cfg->trunk.cfg = cfg;
 	cfg->trunk.trunk_nr = 0;
@@ -1365,9 +1370,12 @@  static void send_msg(struct mgcp_endpoint *endp, int endpoint, int port,
 {
 	char buf[2096];
 	int len;
-	const char *fmtp_extra = endp->bts_end.fmtp_extra;
-	const char *audio_name = endp->bts_end.audio_name;
-	int payload_type = endp->bts_end.payload_type;
+	const char *fmtp_extra;
+	const char *audio_name;
+	int payload_type;
+
+	endp->cfg->get_net_downlink_format_cb(endp, &payload_type,
+					      &audio_name, &fmtp_extra);
 
 	/* hardcoded to AMR right now, we do not know the real type at this point */
 	len = snprintf(buf, sizeof(buf),