contrib: Import BER testing tooltnt/ber

Change-Id: I1cffa0ae959e29ec61775b13185fd1057ed7485a
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>

4 files changed, 628 insertions, 0 deletions

diff --git a/contrib/ber/Makefile b/contrib/ber/Makefile
new file mode 100644
index 00000000..5063107c
--- /dev/null
+++ b/contrib/ber/Makefile
@@ -0,0 +1,14 @@
+CC=gcc
+LD=gcc
+CFLAGS=`pkg-config --cflags libosmocore libosmotrau libosmocodec` -O2 -Wall -ggdb
+LDLIBS=`pkg-config --libs   libosmocore libosmotrau libosmocodec` -ggdb
+
+all: rtp_ber
+
+rtp_ber.o: codec_bit_class.h
+
+codec_bit_class.h: rtp_gen_map
+	./rtp_gen_map > codec_bit_class.h
+
+clean:
+	rm -f rtp_ber rtp_gen_map codec_bit_class.h *.o
diff --git a/contrib/ber/README b/contrib/ber/README
new file mode 100644
index 00000000..07c4a785
--- /dev/null
+++ b/contrib/ber/README
@@ -0,0 +1,26 @@
+BER testing tool
+----------------
+
+* Check all configs (MSC/BSC/BTS) for proper codec support
+  - FR enabled
+  - EFR enabled
+  - AMR 12.2 enabled (and all other modes disabled !)
+  - Use `amr-payload octet-aligned` in BSC config
+
+* Check BTS config
+  - Disable jitter buffer : `bts N / rtp jitter-buffer 0`
+
+* Check BSC config
+  - Disable radio timeout : `network / bts n / radio-link-timeout infinite`
+
+* Start BER testing tool
+  - `./rtp_ber 4000`
+
+* On the MSC CLI, start a silent-call, then request GSM to test loop
+  - `subscriber imsi <XXX> silent-call start tch/f speech-amr`
+  - `subscriber imsi <XXX> ms-test close-loop b`
+
+  Don't forget to terminate the loop and terminate the silent call !
+
+  - `subscriber imsi <XXX> ms-test open-loop`
+  - `subscriber imsi <XXX> silent-call stop`
diff --git a/contrib/ber/rtp_ber.c b/contrib/ber/rtp_ber.c
new file mode 100644
index 00000000..718e247e
--- /dev/null
+++ b/contrib/ber/rtp_ber.c
@@ -0,0 +1,461 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <osmocom/codec/codec.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/prbs.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/trau/osmo_ortp.h>
+
+#include "codec_bit_class.h"
+
+
+struct app_state {
+	struct osmo_rtp_socket *rs;
+
+	enum {
+		WAIT_CONN = 0,	/* Wait for incoming connection */
+		WAIT_LOOP,	/* Wait for a somewhat valid packet to start measuring */
+		RUNNING,	/* Main state */
+	} state;
+
+	int pt;
+
+	int     ref_len;
+	uint8_t ref_bytes[GSM_FR_BYTES];	/* FR is the largest possible one */
+	ubit_t  ref_bits[8*GSM_FR_BYTES];
+
+	struct osmo_timer_list rtp_timer;
+
+	uint16_t rx_last_seq;
+	uint32_t rx_last_ts;
+	uint32_t rx_idx;
+	uint32_t tx_idx;
+
+	const int *err_tbl;	/* Classification table */
+	int err_frames;		/* Number of accumulated frames */
+	int err_cnt[3];		/* Bit error counter */
+	int err_tot[3];		/* Total # bits in that class */
+};
+
+#define FLOW_REG_TX_MAX_ADVANCE		200
+#define FLOW_REG_TX_MIN_ADVANCE		 50
+
+
+const struct log_info log_info;
+
+
+static const uint8_t amr_size_by_ft[] = {
+	[0]	= 12,	/* 4.75 */
+	[1]	= 13,	/* 5.15 */
+	[2]	= 15,	/* 5.9 */
+	[3]	= 17,	/* 6.7 */
+	[4]	= 19,	/* 7.4 */
+	[5]	= 20,	/* 7.95 */
+	[6]	= 26,	/* 10.2 */
+	[7]	= 31,	/* 12.2 */
+	[8]	= 5,	/* SID */
+};
+
+static const char *amr_rate_by_ft[] = {
+	[0]	= "4.75",
+	[1]	= "5.15",
+	[2]	= "5.9",
+	[3]	= "6.7",
+	[4]	= "7.4",
+	[5]	= "7.95",
+	[6]	= "10.2",
+	[7]	= "12.2",
+	[8]	= "SID",
+};
+
+
+static void
+_gsm_fr_gen_ref(struct app_state *as)
+{
+	struct osmo_prbs_state pn9;
+
+	/* Length */
+	as->ref_len = GSM_FR_BYTES;
+
+	/* Marker */
+	as->ref_bits[0] = 1;
+	as->ref_bits[1] = 1;
+	as->ref_bits[2] = 0;
+	as->ref_bits[3] = 1;
+
+	/* PN */
+	osmo_prbs_state_init(&pn9, &osmo_prbs9);
+	pn9.state = 31;
+	osmo_prbs_get_ubits(&as->ref_bits[4], 260, &pn9);
+
+	/* Convert to bytes */
+	osmo_ubit2pbit_ext(as->ref_bytes, 0, as->ref_bits, 0, 8*GSM_FR_BYTES, 0);
+
+	/* Init error classes */
+	as->err_tot[0] =  50;
+	as->err_tot[1] = 132;
+	as->err_tot[2] =  78;
+	as->err_tbl = gsm_fr_bitclass;
+}
+
+static void
+_gsm_efr_gen_ref(struct app_state *as)
+{
+	struct osmo_prbs_state pn9;
+
+	/* Length */
+	as->ref_len = GSM_EFR_BYTES;
+
+	/* Marker */
+	as->ref_bits[0] = 1;
+	as->ref_bits[1] = 1;
+	as->ref_bits[2] = 0;
+	as->ref_bits[3] = 0;
+
+	/* PN */
+	osmo_prbs_state_init(&pn9, &osmo_prbs9);
+	pn9.state = 31;
+	osmo_prbs_get_ubits(&as->ref_bits[4], 244, &pn9);
+
+	/* Convert to bytes */
+	osmo_ubit2pbit_ext(as->ref_bytes, 0, as->ref_bits, 0, 8*GSM_EFR_BYTES, 0);
+
+	/* Init error classes */
+	as->err_tot[0] =  50;
+	as->err_tot[1] = 125;
+	as->err_tot[2] =  73;
+	as->err_tbl = gsm_efr_bitclass;
+}
+
+static void
+_gsm_amr_gen_ref(struct app_state *as)
+{
+	struct osmo_prbs_state pn9;
+	uint8_t hdr[2];
+
+	/* Length */
+	as->ref_len = 33;
+
+	/* Header */
+	hdr[0] = 0x70;
+	hdr[1] = 0x3c;
+	osmo_pbit2ubit_ext(as->ref_bits, 0, hdr, 0, 16, 0);
+
+	/* PN */
+	osmo_prbs_state_init(&pn9, &osmo_prbs9);
+	pn9.state = 31;
+	osmo_prbs_get_ubits(&as->ref_bits[16], 244, &pn9);
+
+	/* Unused bits */
+	as->ref_bits[260] = 0;
+	as->ref_bits[261] = 0;
+	as->ref_bits[262] = 0;
+	as->ref_bits[263] = 0;
+
+	/* Convert to bytes */
+	osmo_ubit2pbit_ext(as->ref_bytes, 0, as->ref_bits, 0, 264, 0);
+
+	/* Init error classes */
+	as->err_tot[0] =  81;
+	as->err_tot[1] = 163;
+	as->err_tot[2] =  -1;
+	as->err_tbl = gsm_amr_12_2_bitclass;
+}
+
+
+static void
+_gsm_gen_ref(struct app_state *as)
+{
+	switch (as->pt) {
+	case RTP_PT_GSM_FULL:
+		_gsm_fr_gen_ref(as);
+		break;
+	case RTP_PT_GSM_EFR:
+		_gsm_efr_gen_ref(as);
+		break;
+	case RTP_PT_AMR:
+		_gsm_amr_gen_ref(as);
+		break;
+	default:
+		fprintf(stderr, "[!] Unsupported payload type for BER measurement\n");
+	}
+}
+
+static int
+_gsm_ber(struct app_state *as, const uint8_t *payload, unsigned int payload_len)
+{
+	ubit_t rx_bits[8*33];
+	int err[3];	/* Class 1a, 1b, 2 */
+	int ones;
+	int i, j;
+
+	if (payload) {
+		/* Process real-payload */
+		osmo_pbit2ubit_ext(rx_bits, 0, payload, 0, 8*payload_len, 0);
+
+		err[0] = err[1] = err[2] = 0;
+		ones = 0;
+
+		for (i=0; i<8*payload_len; i++)
+		{
+			j = as->err_tbl[i];
+			if (j >= 0) {
+				err[j] += rx_bits[i] ^ as->ref_bits[i];
+				ones += rx_bits[i];
+			}
+		}
+
+		if (ones < 32)	// This frames is probably us underrunning Tx, don't use it
+		{
+			fprintf(stderr, "[w] Frame ignored as probably TX underrun %d %d\n", as->tx_idx, as->rx_idx);
+			return 1;
+		}
+	} else {
+		/* No payload -> Lost frame completely */
+		err[0] = as->err_tot[0] / 2;
+		err[1] = as->err_tot[1] / 2;
+		err[2] = as->err_tot[2] / 2;
+	}
+
+	if (as->state == RUNNING)
+	{
+		/* Update records */
+		if (err[0] != 0) {
+			/* Class 1a bits bad -> Frame error */
+			as->err_cnt[0]++;
+		}
+
+		as->err_cnt[1] += err[1];	/* Class 1b */
+		as->err_cnt[2] += err[2];	/* class 2  */
+
+		as->err_frames++;
+
+		/* Enough for a read-out ? */
+		if (as->err_frames == 200) {
+			printf("FBER: %4.2f    C1b RBER: %5.3f    C2 RBER: %5.3f\n",
+				100.0f * as->err_cnt[0] / as->err_frames,
+				100.0f * as->err_cnt[1] / (as->err_tot[1] * as->err_frames),
+				100.0f * as->err_cnt[2] / (as->err_tot[2] * as->err_frames)
+			);
+			memset(as->err_cnt, 0, sizeof(as->err_cnt));
+			as->err_frames = 0;
+		}
+	}
+
+	return err[0] != 0;
+}
+
+static int
+_rtp_check_payload_type(const uint8_t *payload, unsigned int payload_len)
+{
+	uint8_t ft;
+	int pt = -1;
+
+	switch (payload_len) {
+	case GSM_FR_BYTES: /* FR  or AMR 12.2k */
+		/* Check for AMR */
+		ft = (payload[1] >> 3) & 0xf;
+		if (ft == 7)
+			pt = RTP_PT_AMR;
+
+		/* Check for FR */
+		else if ((payload[0] & 0xF0) == 0xD0)
+			pt = RTP_PT_GSM_FULL;
+
+		/* None of the above */
+		else
+			fprintf(stderr, "[!] FR without 0xD0 signature or AMR with unknwon Frame Type ?!?\n");
+
+		break;
+	case GSM_EFR_BYTES: /* EFR */
+		if ((payload[0] & 0xF0) != 0xC0)
+			fprintf(stderr, "[!] EFR without 0xC0 signature ?!?\n");
+		pt = RTP_PT_GSM_EFR;
+		break;
+	case GSM_HR_BYTES: /* HR */
+		pt = RTP_PT_GSM_HALF;
+		break;
+	default: /* AMR */
+		{
+			uint8_t cmr, cmi, sti;
+			cmr = payload[0] >> 4;
+			ft = (payload[1] >> 3) & 0xf;
+
+			if (payload_len != amr_size_by_ft[ft]+2)
+				fprintf(stderr, "AMR FT %u(%s) but size %u\n",
+					ft, amr_rate_by_ft[ft], payload_len);
+
+			switch (ft) {
+			case 0: case 1: case 2: case 3:
+			case 4: case 5: case 6: case 7:
+				cmi = ft;
+				printf("AMR SPEECH with FT/CMI %u(%s), "
+					"CMR %u\n",
+					cmi, amr_rate_by_ft[cmi],
+					cmr);
+				break;
+			case 8: /* SID */
+				cmi = (payload[2+4] >> 1) & 0x7;
+				sti = payload[2+4] & 0x10;
+				printf("AMR SID %s with CMI %u(%s), CMR %u(%s)\n",
+					sti ? "UPDATE" : "FIRST",
+					cmi, amr_rate_by_ft[cmi],
+					cmr, amr_rate_by_ft[cmr]);
+				break;
+			}
+		}
+		break;
+	}
+
+	return pt;
+}
+
+static void
+rtp_timer_cb(void *priv)
+{
+	struct app_state *as = (struct app_state *)priv;
+
+	/* Send at least one frame if we're not too far ahead */
+	if (as->tx_idx < (as->rx_idx + FLOW_REG_TX_MAX_ADVANCE)) {
+		osmo_rtp_send_frame(as->rs, as->ref_bytes, as->ref_len, GSM_RTP_DURATION);
+		as->tx_idx++;
+	}
+	else
+		fprintf(stderr, "Skipped\n");
+
+	/* Then maybe a second one to try and catch up to RX */
+	if (as->tx_idx < (as->rx_idx + FLOW_REG_TX_MIN_ADVANCE)) {
+		osmo_rtp_send_frame(as->rs, as->ref_bytes, as->ref_len, GSM_RTP_DURATION);
+		as->tx_idx++;
+	}
+
+	/* Re-schedule */
+	osmo_timer_schedule(&as->rtp_timer, 0, 20000);
+}
+
+static int
+rtp_seq_num_diff(uint16_t new, uint16_t old)
+{
+	int d = (int)new - (int)old;
+	while (d > 49152)
+		d -= 65536;
+	while (d < -49152)
+		d += 65536;
+	return d;
+}
+
+static void
+rtp_rx_cb(struct osmo_rtp_socket *rs,
+	const uint8_t *payload, unsigned int payload_len,
+	uint16_t seq_number, uint32_t timestamp, bool marker)
+{
+	struct app_state *as = (struct app_state *)rs->priv;
+	int pt, rc, d;
+
+//	printf("Rx(%u, %d, %d, %d): %s\n", payload_len, seq_number, timestamp, marker, osmo_hexdump(payload, payload_len));
+
+	/* Identify payload */
+	pt = _rtp_check_payload_type(payload, payload_len);
+
+	/* First packet ? */
+	if (as->state == WAIT_CONN)
+	{
+		/* Setup for this payload type */
+		as->pt = pt;
+		osmo_rtp_socket_set_pt(as->rs, pt);
+		_gsm_gen_ref(as);
+
+		/* Timer every 20 ms */
+		osmo_timer_setup(&as->rtp_timer, rtp_timer_cb, as);
+		osmo_timer_add(&as->rtp_timer);
+		osmo_timer_schedule(&as->rtp_timer, 0, 20000);
+
+		/* Init our time tracking */
+		as->rx_last_seq = seq_number;
+		as->rx_last_ts  = timestamp;
+
+		/* Now we wait for a loop */
+		as->state = WAIT_LOOP;
+	}
+
+	/* RX sequence & timstamp tracking */
+	if (rtp_seq_num_diff(seq_number, as->rx_last_seq) > 1) {
+		fprintf(stderr, "[!] RTP sequence number discontinuity (%d -> %d)\n", as->rx_last_seq, seq_number);
+	}
+
+	d = (timestamp - as->rx_last_ts) / GSM_RTP_DURATION;
+
+	as->rx_idx += d;
+	as->rx_last_seq = seq_number;
+	as->rx_last_ts  = timestamp;
+
+	/* Account for missing frames in BER tracking */
+	if (d > 1)
+	{
+		fprintf(stderr, "[!] RTP %d missing frames assumed lost @%d\n", d-1, seq_number);
+		while (--d)
+			_gsm_ber(as, NULL, 0);
+	}
+
+	/* BER analysis */
+	rc = _gsm_ber(as, payload, payload_len);
+
+	if ((as->state == WAIT_LOOP) && (rc == 0))
+		as->state = RUNNING;
+}
+
+
+int main(int argc, char **argv)
+{
+	struct app_state _as, *as = &_as;
+	int rc, port;
+
+	/* Args */
+	if (argc < 2)
+		return -1;
+
+	port = atoi(argv[1]);
+
+	/* App init */
+	memset(as, 0x00, sizeof(struct app_state));
+
+	log_init(&log_info, NULL);
+	osmo_rtp_init(NULL);
+
+	/* Start auto-connect RTP socket */
+	as->rs = osmo_rtp_socket_create(NULL, 0);
+
+	as->rs->priv = as;
+	as->rs->rx_cb = rtp_rx_cb;
+
+		/* Jitter buffer gets in the way, we want the raw traffic */
+	osmo_rtp_socket_set_param(as->rs, OSMO_RTP_P_JIT_ADAP, 0);
+	osmo_rtp_socket_set_param(as->rs, OSMO_RTP_P_JITBUF, 0);
+
+		/* Bind to requested port */
+	fprintf(stderr, "[+] Binding RTP socket on port %u...\n", port);
+	rc = osmo_rtp_socket_bind(as->rs, "0.0.0.0", port);
+	if (rc < 0) {
+		fprintf(stderr, "[!] error binding RTP socket: %d\n", rc);
+		return rc;
+	}
+
+		/* We 'connect' to the first source we hear from */
+	osmo_rtp_socket_autoconnect(as->rs);
+
+	/* Main loop */
+	while (1) {
+		osmo_select_main(0);
+	}
+
+	return 0;
+}
diff --git a/contrib/ber/rtp_gen_map.c b/contrib/ber/rtp_gen_map.c
new file mode 100644
index 00000000..cbf1587f
--- /dev/null
+++ b/contrib/ber/rtp_gen_map.c
@@ -0,0 +1,127 @@
+#include <stdio.h>
+
+#include <osmocom/codec/codec.h>
+
+
+static int
+gen_table_fr(int *tbl)
+{
+	int i,j;
+
+	tbl[0] = tbl[1] = tbl[2] = tbl[3] = -1;
+
+	for (i=0; i<260; i++)
+	{
+		j = 4 + gsm610_bitorder[i];
+		if (i < 50)
+			tbl[j] = 0;	/* Class 1a */
+		else if (i < 182)
+			tbl[j] = 1;	/* Class 1b */
+		else
+			tbl[j] = 2;	/* Class 2 */
+	}
+
+	return GSM_FR_BYTES * 8;
+}
+
+static int
+gen_table_efr(int *tbl)
+{
+	int i, j, k;
+
+	tbl[0] = tbl[1] = tbl[2] = tbl[3] = -1;
+
+	for (i=0; i<260; i++)
+	{
+		j = gsm660_bitorder[i];
+
+		if (j < 71)
+			k = j;
+		else if (j < 73)
+			k = 71;
+		else if (j < 123)
+			k = j - 2;
+		else if (j < 125)
+			k = 119;
+		else if (j < 178)
+			k = j - 4;
+		else if (j < 180)
+			k = 172;
+		else if (j < 230)
+			k = j - 6;
+		else if (j < 232)
+			k = 222;
+		else if (j < 252)
+			k = j - 8;
+		else
+			continue;
+
+		if (i < 50)
+			tbl[k] = 0;	/* Class 1a */
+		else if (i < 182)
+			tbl[k] = 1;	/* Class 1b */
+		else
+			tbl[k] = 2;	/* Class 2 */
+	}
+
+	return GSM_EFR_BYTES * 8;
+}
+
+static int
+gen_table_amr_12_2(int *tbl)
+{
+	int i;
+
+	for (i=0; i<16; i++)
+		tbl[i] = -1;
+	
+	for (i=0; i<244; i++)
+		tbl[i+16] = i < 81 ? 0 : 1;
+	
+	for (i=0; i<4; i++)
+		tbl[i+16+244] = -1;
+
+	return 8 * 33;
+}
+
+
+static void
+print_table(const char  *name, int *tbl, int len)
+{
+	int i;
+
+	printf("static const int %s[] = {\n", name);
+
+	for (i=0; i<len; i++)
+	{
+		if ((i & 15) == 0)
+			printf("\t");
+
+		printf("%2d", tbl[i]);
+		
+		if (((i & 15) == 15) || (i == len-1))
+			printf(",\n");
+		else
+			printf(", ");
+	}
+
+	printf("};\n\n");
+}
+
+
+int main(int argc, char *argv[])
+{
+	int tbl[33*8];
+	int rv;
+
+	rv = gen_table_fr(tbl);
+	print_table("gsm_fr_bitclass", tbl, rv);
+
+	rv = gen_table_efr(tbl);
+	print_table("gsm_efr_bitclass", tbl, rv);
+
+	rv = gen_table_amr_12_2(tbl);
+	print_table("gsm_amr_12_2_bitclass", tbl, rv);
+
+	return 0;
+}