RTP-enable MNCC API for LCR + ip.access

Instead of passing TRAU frames down the MNCC API to the call control
application like MNCC, we now decode the TRAU frame into the actual codec
frame.  We do the same with the RTP packets in case of ip.access and
thus have a unified format of passing codec data from the BTS to
an application, independent of the BTS type.

This is only implemented for V1 full-rate at the moment, and needs
to be fixed.

1 files changed, 83 insertions, 34 deletions

diff --git a/openbsc/src/gsm_04_08.c b/openbsc/src/gsm_04_08.c
index d59d7d7ca..f36723937 100644
--- a/openbsc/src/gsm_04_08.c
+++ b/openbsc/src/gsm_04_08.c
@@ -1864,12 +1864,16 @@ static int setup_trig_pag_evt(unsigned int hooknum, unsigned int event,
 	return 0;
 }
 
+static int tch_recv_mncc(struct gsm_network *net, u_int32_t callref, int enable);
+
 /* some other part of the code sends us a signal */
 static int handle_abisip_signal(unsigned int subsys, unsigned int signal,
 				 void *handler_data, void *signal_data)
 {
 	struct gsm_lchan *lchan = signal_data;
 	int rc;
+	struct gsm_network *net;
+	struct gsm_trans *trans;
 
 	if (subsys != SS_ABISIP)
 		return 0;
@@ -1896,6 +1900,15 @@ static int handle_abisip_signal(unsigned int subsys, unsigned int signal,
 				   lchan->abis_ip.bound_port);
 		if (rc < 0)
 			goto out_err;
+		/* check if any transactions on this lchan still have
+		 * a tch_recv_mncc request pending */
+		net = lchan->ts->trx->bts->network;
+		llist_for_each_entry(trans, &net->trans_list, entry) {
+			if (trans->lchan == lchan && trans->tch_recv) {
+				DEBUGP(DCC, "pending tch_recv_mncc request\n");
+				tch_recv_mncc(net, trans->callref, 1);
+			}
+		}
 		break;
 	case S_ABISIP_DLCX_IND:
 		/* the BTS tells us a RTP stream has been disconnected */
@@ -1941,7 +1954,8 @@ static int tch_map(struct gsm_lchan *lchan, struct gsm_lchan *remote_lchan)
 		DEBUGP(DCC, "Cannot switch calls between different BTS types yet\n");
 		return -EINVAL;
 	}
-	
+
+	// todo: map between different bts types
 	switch (bts->type) {
 	case GSM_BTS_TYPE_NANOBTS:
 		if (!ipacc_rtp_direct) {
@@ -1950,6 +1964,7 @@ static int tch_map(struct gsm_lchan *lchan, struct gsm_lchan *remote_lchan)
 			if (rc < 0)
 				return rc;
 			rc = ipacc_connect_proxy_bind(remote_lchan);
+#warning do we need a check of rc here?
 
 			/* connect them with each other */
 			rtp_socket_proxy(lchan->abis_ip.rtp_socket,
@@ -1971,8 +1986,7 @@ static int tch_map(struct gsm_lchan *lchan, struct gsm_lchan *remote_lchan)
 		break;
 	default:
 		DEBUGP(DCC, "Unknown BTS type %u\n", bts->type);
-		rc = -EINVAL;
-		break;
+		return -EINVAL;
 	}
 
 	return 0;
@@ -1994,45 +2008,61 @@ static int tch_bridge(struct gsm_network *net, u_int32_t *refs)
 	return tch_map(trans1->lchan, trans2->lchan);
 }
 
-/* enable receive of channels to upqueue */
-static int tch_recv(struct gsm_network *net, struct gsm_mncc *data, int enable)
+/* enable receive of channels to MNCC upqueue */
+static int tch_recv_mncc(struct gsm_network *net, u_int32_t callref, int enable)
 {
 	struct gsm_trans *trans;
+	struct gsm_lchan *lchan;
+	struct gsm_bts *bts;
+	int rc;
 
 	/* Find callref */
-	trans = trans_find_by_callref(net, data->callref);
+	trans = trans_find_by_callref(net, callref);
 	if (!trans)
 		return -EIO;
 	if (!trans->lchan)
 		return 0;
+	lchan = trans->lchan;
+	bts = lchan->ts->trx->bts;
 
-	// todo IPACCESS
-	if (enable)
-		return trau_recv_lchan(trans->lchan, data->callref);
-	return trau_mux_unmap(NULL, data->callref);
-}
-
-/* send a frame to channel */
-static int tch_frame(struct gsm_network *net, struct gsm_trau_frame *frame)
-{
-	struct gsm_trans *trans;
-
-	/* Find callref */
-	trans = trans_find_by_callref(net, frame->callref);
-	if (!trans)
-		return -EIO;
-	if (!trans->lchan)
-		return 0;
-	if (trans->lchan->type != GSM_LCHAN_TCH_F &&
-	    trans->lchan->type != GSM_LCHAN_TCH_H)
-		return 0;
+	switch (bts->type) {
+	case GSM_BTS_TYPE_NANOBTS:
+		if (ipacc_rtp_direct) {
+			DEBUGP(DCC, "Error: RTP proxy is disabled\n");
+			return -EINVAL;
+		}
+		/* in case, we don't have a RTP socket yet, we note this
+		 * in the transaction and try later */
+		if (!lchan->abis_ip.rtp_socket) {
+			trans->tch_recv = enable;
+			DEBUGP(DCC, "queue tch_recv_mncc request (%d)\n", enable);
+			return 0;
+		}
+		if (enable) {
+			/* connect the TCH's to our RTP proxy */
+			rc = ipacc_connect_proxy_bind(lchan);
+			if (rc < 0)
+				return rc;
+			/* assign socket to application interface */
+			rtp_socket_upstream(lchan->abis_ip.rtp_socket,
+				net, callref);
+		} else
+			rtp_socket_upstream(lchan->abis_ip.rtp_socket,
+				net, 0);
+		break;
+	case GSM_BTS_TYPE_BS11:
+		if (enable)
+			return trau_recv_lchan(lchan, callref);
+		return trau_mux_unmap(NULL, callref);
+		break;
+	default:
+		DEBUGP(DCC, "Unknown BTS type %u\n", bts->type);
+		return -EINVAL;
+	}
 
-	// todo IPACCESS
-	return trau_send_lchan(trans->lchan, 
-				(struct decoded_trau_frame *)frame->data);
+	return 0;
 }
 
-
 static int gsm48_cc_rx_status_enq(struct gsm_trans *trans, struct msgb *msg)
 {
 	DEBUGP(DCC, "-> STATUS ENQ\n");
@@ -3262,11 +3292,30 @@ int mncc_send(struct gsm_network *net, int msg_type, void *arg)
 	case MNCC_BRIDGE:
 		return tch_bridge(net, arg);
 	case MNCC_FRAME_DROP:
-		return tch_recv(net, arg, 0);
+		return tch_recv_mncc(net, data->callref, 0);
 	case MNCC_FRAME_RECV:
-		return tch_recv(net, arg, 1);
-	case GSM_TRAU_FRAME:
-		return tch_frame(net, arg);
+		return tch_recv_mncc(net, data->callref, 1);
+	case GSM_TCHF_FRAME:
+		/* Find callref */
+		trans = trans_find_by_callref(net, data->callref);
+		if (!trans)
+			return -EIO;
+		if (!trans->lchan)
+			return 0;
+		if (trans->lchan->type != GSM_LCHAN_TCH_F)
+			return 0;
+		bts = trans->lchan->ts->trx->bts;
+		switch (bts->type) {
+		case GSM_BTS_TYPE_NANOBTS:
+			if (!trans->lchan->abis_ip.rtp_socket)
+				return 0;
+			return rtp_send_frame(trans->lchan->abis_ip.rtp_socket, arg);
+		case GSM_BTS_TYPE_BS11:
+			return trau_send_frame(trans->lchan, arg);
+		default:
+			DEBUGP(DCC, "Unknown BTS type %u\n", bts->type);
+		}
+		return -EINVAL;
 	}
 
 	memset(&rel, 0, sizeof(struct gsm_mncc));