initial import of Osmocom TETRA phy and lower MAC code

src/tetra_gsmtap.c

@@ -0,0 +1,134 @@
+
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#include <osmocore/msgb.h>
+#include <osmocore/gsmtap.h>
+#include <osmocore/bits.h>
+#include <netinet/in.h>
+
+#include "tetra_common.h"
+#include "tetra_tdma.h"
+
+static int gsmtap_fd = -1;
+
+static const uint8_t lchan2gsmtap[] = {
+	[TETRA_LC_SCH_F]	= GSMTAP_TETRA_SCH_F,
+	[TETRA_LC_SCH_HD]	= GSMTAP_TETRA_SCH_HD,
+	[TETRA_LC_SCH_HU]	= GSMTAP_TETRA_SCH_HU,
+	[TETRA_LC_STCH]		= GSMTAP_TETRA_STCH,
+	[TETRA_LC_AACH]		= GSMTAP_TETRA_AACH,
+	[TETRA_LC_TCH]		= GSMTAP_TETRA_TCH_F,
+	[TETRA_LC_BSCH]		= GSMTAP_TETRA_BSCH,
+	[TETRA_LC_BNCH]		= GSMTAP_TETRA_BNCH,
+};
+
+
+struct msgb *tetra_gsmtap_makemsg(struct tetra_tdma_time *tm, enum tetra_log_chan lchan,
+				  uint8_t ts, uint8_t ss, int8_t signal_dbm,
+				  uint8_t snr, const ubit_t *bitdata, unsigned int bitlen)
+{
+	struct msgb *msg;
+	struct gsmtap_hdr *gh;
+	uint32_t fn = tetra_tdma_time2fn(tm);
+	unsigned int packed_len = osmo_pbit_bytesize(bitlen);
+	uint8_t *dst;
+
+	msg = msgb_alloc(sizeof(*gh) + packed_len, "tetra_gsmtap_tx");
+	if (!msg)
+		return NULL;
+
+	gh = (struct gsmtap_hdr *) msgb_put(msg, sizeof(*gh));
+	gh->version = GSMTAP_VERSION;
+	gh->hdr_len = sizeof(*gh)/4;
+	gh->type = GSMTAP_TYPE_TETRA_I1;
+	gh->timeslot = ts;
+	gh->sub_slot = ss;
+	gh->snr_db = snr;
+	gh->signal_dbm = signal_dbm;
+	gh->frame_number = htonl(fn);
+	gh->sub_type = lchan2gsmtap[lchan];
+	gh->antenna_nr = 0;
+
+	/* convert from 1bit-per-byte to compressed bits!!! */
+	dst = msgb_put(msg, packed_len);
+	osmo_ubit2pbit(dst, bitdata, bitlen);
+
+	return msg;
+}
+
+int tetra_gsmtap_sendmsg(struct msgb *msg)
+{
+	if (gsmtap_fd != -1)
+		return write(gsmtap_fd, msg->data, msg->len);
+	else
+		return 0;
+}
+
+/* this block should move to libosmocore */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <errno.h>
+
+int gsmtap_init(const char *host, uint16_t port)
+{
+	struct addrinfo hints, *result, *rp;
+	int sfd, rc;
+	char portbuf[16];
+
+	if (port == 0)
+		port = GSMTAP_UDP_PORT;
+	if (host == NULL)
+		host = "localhost";
+
+	sprintf(portbuf, "%u", port);
+	memset(&hints, 0, sizeof(struct addrinfo));
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_flags = 0;
+	hints.ai_protocol = IPPROTO_UDP;
+
+	rc = getaddrinfo(host, portbuf, &hints, &result);
+	if (rc != 0) {
+		perror("getaddrinfo returned NULL");
+		return -EINVAL;
+	}
+
+	for (rp = result; rp != NULL; rp = rp->ai_next) {
+		printf("creating socket %u, %u, %u\n", rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+		sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+		if (sfd == -1)
+			continue;
+		if (connect(sfd, rp->ai_addr, rp->ai_addrlen) != -1)
+			break;
+		close(sfd);
+	}
+	freeaddrinfo(result);
+
+	if (rp == NULL) {
+		perror("unable to bind to socket");
+		return -ENODEV;
+	}
+
+	/* FIXME: if host == localhost, bind to another socket and discard data */
+
+	return sfd;
+}
+/* end block for libosmocore */
+
+int tetra_gsmtap_init(const char *host, uint16_t port)
+{
+	int fd;
+
+	fd = gsmtap_init(host, port);
+	if (fd < 0)
+		return fd;
+
+	gsmtap_fd = fd;
+
+	return 0;
+}