common: Add RTP related rate counters

Let's add some rate counters to add visibility to the BTS on what is
happening in terms of received and/or transmitted RTP packets.

This should help during debugging any RTP related issues.

Change-Id: Ide674bde10b0e4b501d6a48947b983090342dfec

3 files changed, 34 insertions, 4 deletions

diff --git a/src/common/bts.c b/src/common/bts.c
index b6b84d1b..56765eca 100644
--- a/src/common/bts.c
+++ b/src/common/bts.c
@@ -104,6 +104,15 @@ static const struct rate_ctr_desc bts_ctr_desc[] = {
 	[BTS_CTR_AGCH_RCVD] =		{"agch:rcvd", "Received AGCH requests (Abis)"},
 	[BTS_CTR_AGCH_SENT] =		{"agch:sent", "Sent AGCH requests (Abis)"},
 	[BTS_CTR_AGCH_DELETED] =	{"agch:delete", "Sent AGCH DELETE IND (Abis)"},
+
+	[BTS_CTR_RTP_RX_TOTAL] =	{"rtp:rx:total", "Total number of received RTP packets"},
+	[BTS_CTR_RTP_RX_MARKER] =	{"rtp:rx:marker", "Number of received RTP packets with marker bit set"},
+	[BTS_CTR_RTP_RX_DROP_PREEN] =	{"rtp:rx:drop:preen", "Total number of received RTP packets dropped during preening"},
+	[BTS_CTR_RTP_RX_DROP_LOOPBACK] = {"rtp:rx:drop:loopback", "Total number of received RTP packets dropped during loopback"},
+	[BTS_CTR_RTP_RX_DROP_OVERFLOW] = {"rtp:rx:drop:overflow", "Total number of received RTP packets dropped during DL queue overflow"},
+	[BTS_CTR_RTP_RX_DROP_V110_DEC] = {"rtp:rx:drop:v110_dec", "Total number of received RTP packets dropped during V.110 decode"},
+	[BTS_CTR_RTP_TX_TOTAL] =	{"rtp:tx:total", "Total number of transmitted RTP packets"},
+	[BTS_CTR_RTP_TX_MARKER] =	{"rtp:tx:marker", "Number of transmitted RTP packets with marker bit set"},
 };
 static const struct rate_ctr_group_desc bts_ctrg_desc = {
 	"bts",
diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index 7cbedd47..5f275cd8 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -1930,6 +1930,7 @@ static void gsmtap_csd_rlp_process(struct gsm_lchan *lchan, bool is_uplink,
 static void send_ul_rtp_packet_data(struct gsm_lchan *lchan, const struct ph_tch_param *tch_ind,
 				    const uint8_t *data, uint16_t data_len)
 {
+	struct gsm_bts *bts = lchan->ts->trx->bts;
 	uint8_t rtp_pl[RFC4040_RTP_PLEN];
 	int rc;
 
@@ -1939,6 +1940,10 @@ static void send_ul_rtp_packet_data(struct gsm_lchan *lchan, const struct ph_tch
 	if (rc < 0)
 		return;
 
+	rate_ctr_inc2(bts->ctrs, BTS_CTR_RTP_TX_TOTAL);
+	if (lchan->rtp_tx_marker)
+		rate_ctr_inc2(bts->ctrs, BTS_CTR_RTP_TX_MARKER);
+
 	osmo_rtp_send_frame_ext(lchan->abis_ip.rtp_socket,
 				&rtp_pl[0], sizeof(rtp_pl),
 				fn_ms_adj(tch_ind->fn, lchan),
@@ -1951,12 +1956,17 @@ static void send_ul_rtp_packet_data(struct gsm_lchan *lchan, const struct ph_tch
 static void send_ul_rtp_packet_speech(struct gsm_lchan *lchan, uint32_t fn,
 				      const uint8_t *rtp_pl, uint16_t rtp_pl_len)
 {
+	struct gsm_bts *bts = lchan->ts->trx->bts;
+
 	if (lchan->abis_ip.osmux.use) {
 		lchan_osmux_send_frame(lchan, rtp_pl, rtp_pl_len,
 				       fn_ms_adj(fn, lchan), lchan->rtp_tx_marker);
 	} else if (lchan->abis_ip.rtp_socket) {
 		osmo_rtp_send_frame_ext(lchan->abis_ip.rtp_socket,
 			rtp_pl, rtp_pl_len, fn_ms_adj(fn, lchan), lchan->rtp_tx_marker);
+		rate_ctr_inc2(bts->ctrs, BTS_CTR_RTP_TX_TOTAL);
+		if (lchan->rtp_tx_marker)
+			rate_ctr_inc2(bts->ctrs, BTS_CTR_RTP_TX_MARKER);
 	}
 	/* Only clear the marker bit once we have sent a RTP packet with it */
 	lchan->rtp_tx_marker = false;
@@ -2360,17 +2370,25 @@ void l1sap_rtp_rx_cb(struct osmo_rtp_socket *rs, const uint8_t *rtp_pl,
 		     uint32_t timestamp, bool marker)
 {
 	struct gsm_lchan *lchan = rs->priv;
+	struct gsm_bts *bts = lchan->ts->trx->bts;
 	struct msgb *msg;
 	bool rfc5993_sid = false;
 
+	rate_ctr_inc2(bts->ctrs, BTS_CTR_RTP_RX_TOTAL);
+	if (marker)
+		rate_ctr_inc2(bts->ctrs, BTS_CTR_RTP_RX_MARKER);
+
 	/* if we're in loopback mode, we don't accept frames from the
 	 * RTP socket anymore */
-	if (lchan->loopback)
+	if (lchan->loopback) {
+		rate_ctr_inc2(bts->ctrs, BTS_CTR_RTP_RX_DROP_LOOPBACK);
 		return;
+	}
 
 	/* initial preen */
 	switch (rtp_payload_input_preen(lchan, rtp_pl, rtp_pl_len, &rfc5993_sid)) {
 	case PL_DECISION_DROP:
+		rate_ctr_inc2(bts->ctrs, BTS_CTR_RTP_RX_DROP_PREEN);
 		return;
 	case PL_DECISION_ACCEPT:
 		break;
@@ -2396,6 +2414,7 @@ void l1sap_rtp_rx_cb(struct osmo_rtp_socket *rs, const uint8_t *rtp_pl,
 			gsmtap_csd_rlp_process(lchan, false, &fake_tch_ind, msg->tail, rc);
 			msgb_put(msg, rc);
 		} else {
+			rate_ctr_inc2(bts->ctrs, BTS_CTR_RTP_RX_DROP_V110_DEC);
 			msgb_free(msg);
 			return;
 		}
diff --git a/src/common/lchan.c b/src/common/lchan.c
index f4ed5033..5b41a158 100644
--- a/src/common/lchan.c
+++ b/src/common/lchan.c
@@ -652,9 +652,11 @@ void lchan_rtp_socket_free(struct gsm_lchan *lchan)
 /*! limit number of queue entries to %u; drops any surplus messages */
 void lchan_dl_tch_queue_enqueue(struct gsm_lchan *lchan, struct msgb *msg, unsigned int limit)
 {
-	if (lchan->dl_tch_queue_len > limit)
-		LOGPLCHAN(lchan, DL1P, LOGL_NOTICE, "freeing %d queued frames\n",
-			  lchan->dl_tch_queue_len - limit);
+	if (lchan->dl_tch_queue_len > limit) {
+		unsigned int excess = lchan->dl_tch_queue_len - limit;
+		LOGPLCHAN(lchan, DL1P, LOGL_NOTICE, "freeing %d queued frames\n", excess);
+		rate_ctr_add2(lchan->ts->trx->bts->ctrs, BTS_CTR_RTP_RX_DROP_OVERFLOW, excess);
+	}
 	while (lchan->dl_tch_queue_len > limit) {
 		struct msgb *tmp = msgb_dequeue_count(&lchan->dl_tch_queue, &lchan->dl_tch_queue_len);
 		msgb_free(tmp);