utils: add v110_decode for decoding L1CTL TRAFFIC.indfixeria/suart

Change-Id: Id0fd70201d011a4324a0c24fe10d359c69d6c758
Related: OS#4396

2 files changed, 127 insertions, 0 deletions

diff --git a/utils/Makefile.am b/utils/Makefile.am
index 3ec71ea3..f4c84dbe 100644
--- a/utils/Makefile.am
+++ b/utils/Makefile.am
@@ -44,3 +44,7 @@ osmo_ns_dummy_LDADD = $(LDADD) $(TALLOC_LIBS) \
 			$(top_builddir)/src/ctrl/libosmoctrl.la \
 			$(NULL)
 endif
+
+v110_decode_SOURCES = v110_decode.c
+v110_decode_LDADD = $(LDADD) $(top_builddir)/src/isdn/libosmoisdn.la
+noinst_PROGRAMS += v110_decode
diff --git a/utils/v110_decode.c b/utils/v110_decode.c
new file mode 100644
index 00000000..955a7da7
--- /dev/null
+++ b/utils/v110_decode.c
@@ -0,0 +1,123 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <osmocom/core/soft_uart.h>
+#include <osmocom/gsm/gsm44021.h>
+#include <osmocom/isdn/v110.h>
+
+static struct osmo_soft_uart *g_suart;
+
+static void uart_rx_cb(void *priv, struct msgb *rx_data, unsigned int flags)
+{
+	char *data = (char *)msgb_data(rx_data);
+
+	fprintf(stdout, "%s(): %s\n", __func__, msgb_hexdump(rx_data));
+	for (unsigned int i = 0; i < msgb_length(rx_data); i++) {
+		fputc(data[i], stdout);
+		if (data[i] == '\r')
+			fputc('\n', stdout);
+	}
+
+	fputc('\n', stdout);
+	msgb_free(rx_data);
+}
+
+static const struct osmo_soft_uart_cfg suart_cfg = {
+	.num_data_bits = 8,
+	.num_stop_bits = 1,
+	.parity_mode = OSMO_SUART_PARITY_NONE,
+	.rx_buf_size = 1024,
+	.rx_timeout_ms = 100,
+	.priv = NULL,
+	.rx_cb = uart_rx_cb,
+	.status_change_cb = NULL,
+};
+
+static void swap_words(uint8_t *data, size_t data_len)
+{
+	/* swap bytes in words */
+	while (data_len >= 2) {
+		uint8_t tmp = data[0];
+		data[0] = data[1];
+		data[1] = tmp;
+
+		data_len -= 2;
+		data += 2;
+	}
+}
+
+static void decode_record(uint8_t *record)
+{
+	ubit_t data[4 * 60];
+
+	/* XXX: assuming TCH/F9.6 (4 * 60 = 240 bits or 30 bytes) */
+
+	/* the layer1 firmware emits frames with swapped words (LE ordering) */
+	swap_words(record, 30);
+	/* unpack packed bits (MSB goes first) */
+	osmo_pbit2ubit_ext(data, 0, record, 0, sizeof(data), 1);
+
+	for (unsigned int i = 0; i < 4; i++) {
+		struct osmo_v110_decoded_frame df = { 0 };
+
+		osmo_csd_12k_6k_decode_frame(&df, &data[i * 60], 60);
+
+#if 1
+		fprintf(stderr, "S: %s\n", osmo_ubit_dump(df.s_bits, sizeof(df.s_bits)));
+		fprintf(stderr, "X: %s\n", osmo_ubit_dump(df.x_bits, sizeof(df.x_bits)));
+		fprintf(stderr, "E: %s\n", osmo_ubit_dump(df.e_bits, sizeof(df.e_bits)));
+		fprintf(stderr, "D: %s\n", osmo_ubit_dump(df.d_bits, sizeof(df.d_bits)));
+#endif
+
+		/* XXX: what do we do with S-/X-/E-bits? */
+		osmo_soft_uart_rx_ubits(g_suart, &df.d_bits[0], sizeof(df.d_bits));
+	}
+}
+
+/* osmocom-bb/layer1 firmware emits TRAFFIC.ind with len=33 */
+#define RECORD_LEN 33
+
+static int open_and_process(const char *fname)
+{
+	uint8_t buf[RECORD_LEN];
+	int fd;
+
+	fd = open(fname, O_RDONLY);
+	if (fd < 0)
+		return fd;
+
+	while (true) {
+		int rc = read(fd, buf, sizeof(buf));
+		if (rc <= 0)
+			return rc;
+		decode_record(&buf[0]);
+	}
+
+	close(fd);
+}
+
+int main(int argc, char **argv)
+{
+	if (argc < 2) {
+		fprintf(stderr, "Usage: %s FILE\n", argv[0]);
+		return 1;
+	}
+
+	g_suart = osmo_soft_uart_alloc(NULL, "V110_csd_uart");
+	OSMO_ASSERT(g_suart);
+
+	OSMO_ASSERT(osmo_soft_uart_configure(g_suart, &suart_cfg) == 0);
+	OSMO_ASSERT(osmo_soft_uart_enable(g_suart, 1, 0) == 0);
+
+	open_and_process(argv[1]);
+
+	/* disable Rx to flush any pending characters */
+	osmo_soft_uart_enable(g_suart, 0, 0);
+
+	return 0;
+}