mncc: make external mncc work

The external mncc currently does not work properly since the
MNCC_RTP_CREATE commands are removed due to the MSC-Split. It
is possible to operate without these commands, but then it is
not possible to route the RTP streams to an outside leg. Only
internal bridging is currenlty possible. This method is used
when the internal MNCC is enabled.

Add the missing MNCC_RTP_CREATE implementation.
Add logic to keep the old bridging mode working.

1 files changed, 51 insertions, 0 deletions

diff --git a/openbsc/src/libmsc/msc_ifaces.c b/openbsc/src/libmsc/msc_ifaces.c
index 021885ec4..27f644e5f 100644
--- a/openbsc/src/libmsc/msc_ifaces.c
+++ b/openbsc/src/libmsc/msc_ifaces.c
@@ -204,6 +204,12 @@ static void mgcp_response_rab_act_cs_crcx(struct mgcp_response *r, void *priv)
 	} else
 		goto rab_act_cs_error;
 
+	/* Respond back to MNCC (if requested) */
+	if (trans->tch_rtp_create) {
+		if (gsm48_tch_rtp_create(trans))
+			goto rab_act_cs_error;
+	}
+
 rab_act_cs_error:
 	/* FIXME abort call, invalidate conn, ... */
 	return;
@@ -361,6 +367,51 @@ static void mgcp_response_bridge_mdcx(struct mgcp_response *r, void *priv)
 	}
 }
 
+int msc_call_connect(struct gsm_trans *trans, uint16_t port, uint32_t ip)
+{
+	/* With this function we inform the MGCP-GW  where (ip/port) it
+	 * has to send its outgoing voic traffic. The receiving end will
+	 * usually be a PBX (e.g. Asterisk). The IP-Address we tell, will
+	 * not only be used to direct the traffic, it will also be used
+	 * as a filter to make sure only RTP packets from the right
+	 * remote end will reach the BSS. This is also the reason why
+	 * inbound audio will not work until this step is performed */
+
+	/* NOTE: This function is used when msc_call_bridge(), is not
+	 * applicable. This is usually the case when an external MNCC
+	 * is in use */
+
+	struct gsm_subscriber_connection *conn;
+	struct mgcpgw_client *mgcp;
+	struct msgb *msg;
+
+	if (!trans)
+		return -EINVAL;
+	if (!trans->conn)
+		return -EINVAL;
+	if (!trans->conn->network)
+		return -EINVAL;
+	if (!trans->conn->network->mgcpgw.client)
+		return -EINVAL;
+
+	mgcp = trans->conn->network->mgcpgw.client;
+
+	struct in_addr ip_addr;
+	ip_addr.s_addr = ntohl(ip);
+
+	conn = trans->conn;
+
+	msg = mgcp_msg_mdcx(mgcp,
+			    conn->iu.mgcp_rtp_endpoint,
+			    inet_ntoa(ip_addr), port, MGCP_CONN_RECV_SEND);
+	if (mgcpgw_client_tx(mgcp, msg, NULL, trans))
+		LOGP(DMGCP, LOGL_ERROR,
+		     "Failed to send MDCX message for %s\n",
+		     vlr_subscr_name(trans->vsub));
+
+	return 0;
+}
+
 int msc_call_bridge(struct gsm_trans *trans1, struct gsm_trans *trans2)
 {
 	if (!trans1)