osmo-bts-virtual: implement GSMTAP_CHANNEL_VOICE

Change-Id: I1cd9a251ce0b87181a0822d7940bbfc9f1428543

src/osmo-bts-virtual/l1_if.c

@@ -87,6 +87,7 @@ static void virt_um_rcv_cb(struct virt_um_inst *vui, struct msgb *msg)
 	uint8_t link_id;			/* rsl link id tells if this is an ssociated or dedicated link */
 	uint8_t chan_nr;			/* encoded rsl channel type, timeslot and mf subslot */
 	struct osmo_phsap_prim l1sap;
+	struct msgb *msg_tch;
 
 	memset(&l1sap, 0, sizeof(l1sap));
 	/* get rid of l1 gsmtap hdr */
@@ -128,12 +129,7 @@ static void virt_um_rcv_cb(struct virt_um_inst *vui, struct msgb *msg)
 		break;
 	case GSMTAP_CHANNEL_TCH_F:
 	case GSMTAP_CHANNEL_TCH_H:
-#if 0
+		/* This is TCH signalling, for voice frames see GSMTAP_CHANNEL_VOICE */
-		/* TODO: handle voice messages */
-		if (!facch && ! tch_acch) {
-			osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_TCH, PRIM_OP_INDICATION, msg);
-		}
-#endif
 	case GSMTAP_CHANNEL_SDCCH4:
 	case GSMTAP_CHANNEL_SDCCH8:
 	case GSMTAP_CHANNEL_PACCH:
@@ -151,6 +147,14 @@ static void virt_um_rcv_cb(struct virt_um_inst *vui, struct msgb *msg)
 		l1sap.u.data.pdch_presence_info = PRES_INFO_BOTH;
 		l1if_process_meas_res(pinst->trx, timeslot, fn, chan_nr, 0, 0, 0, 0);
 		break;
+	case GSMTAP_CHANNEL_VOICE:
+		msg_tch = msgb_alloc_headroom(sizeof(l1sap) + msg->len, sizeof(l1sap),
+					      "virtphy-voice-frame-from-GSMTAP-to-Um");
+		msgb_put(msg_tch, msg->len);
+		memcpy(msg_tch->data, msg->data, msg->len);
+		add_l1sap_header(pinst->trx, msg_tch, NULL, chan_nr, fn,
+				 0, 10 * signal_dbm, 0, 0, 0);
+		return;
 	case GSMTAP_CHANNEL_AGCH:
 	case GSMTAP_CHANNEL_PCH:
 	case GSMTAP_CHANNEL_BCCH:

src/osmo-bts-virtual/scheduler_virtbts.c

@@ -51,8 +51,8 @@
  * This will at first wrap the msg with a GSMTAP header and then write it to the declared multicast socket.
  * TODO: we might want to remove unused argument uint8_t tn
  */
-static void tx_to_virt_um(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+static void _tx_to_virt_um(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
-			  enum trx_chan_type chan, struct msgb *msg)
+			   enum trx_chan_type chan, struct msgb *msg, bool is_voice_frame)
 {
 	const struct trx_chan_desc *chdesc = &trx_chan_desc[chan];
 	struct msgb *outmsg;			/* msg to send with gsmtap header prepended */
@@ -69,9 +69,11 @@ static void tx_to_virt_um(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
 	rsl_dec_chan_nr(chdesc->chan_nr, &rsl_chantype, &subslot, &timeslot);
 	/* the timeslot is not encoded in the chan_nr of the chdesc, and so has to be overwritten */
 	timeslot = tn;
+	if (is_voice_frame)
+		gsmtap_chantype = GSMTAP_CHANNEL_VOICE;
 	/* in Osmocom, AGCH is only sent on ccch block 0. no idea why. this seems to cause false GSMTAP channel
 	 * types for agch and pch. */
-	if (rsl_chantype == RSL_CHAN_PCH_AGCH &&
+	else if (rsl_chantype == RSL_CHAN_PCH_AGCH &&
 	    l1sap_fn2ccch_block(fn) >= num_agch(l1t->trx, "PH-DATA-REQ"))
 		gsmtap_chantype = GSMTAP_CHANNEL_PCH;
 	else
@@ -104,6 +106,18 @@ static void tx_to_virt_um(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
 	msgb_free(msg);
 }
 
+static void tx_to_virt_um(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+			  enum trx_chan_type chan, struct msgb *msg)
+{
+	_tx_to_virt_um(l1t, tn, fn, chan, msg, false);
+}
+
+static void tx_to_virt_um_voice_frame(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+				      enum trx_chan_type chan, struct msgb *msg)
+{
+	_tx_to_virt_um(l1t, tn, fn, chan, msg, true);
+}
+
 /*
  * TX on downlink
  */
@@ -410,11 +424,10 @@ ubit_t *tx_tchf_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
 		goto send_burst;
 	}
 
-	if (msg_facch) {
+	if (msg_facch)
 		tx_to_virt_um(l1t, tn, fn, chan, msg_facch);
-		msgb_free(msg_tch);
+	if (msg_tch)
-	} else
+		tx_to_virt_um_voice_frame(l1t, tn, fn, chan, msg_tch);
-		tx_to_virt_um(l1t, tn, fn, chan, msg_tch);
 
 send_burst:
 
@@ -451,11 +464,10 @@ ubit_t *tx_tchh_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
 		goto send_burst;
 	}
 
-	if (msg_facch) {
+	if (msg_facch)
 		tx_to_virt_um(l1t, tn, fn, chan, msg_facch);
-		msgb_free(msg_tch);
+	if (msg_tch)
-	} else if (msg_tch)
+		tx_to_virt_um_voice_frame(l1t, tn, fn, chan, msg_tch);
-		tx_to_virt_um(l1t, tn, fn, chan, msg_tch);
 
 send_burst:
 	return NULL;