[gsm-receiver] Update to new GSMTAP version

In wireshark mainline, there is a UDP-based GSMTAP version which
is much different from our pcap-file / link-type based one.

This commit updates the gsmtap support in gsm-receiver to use
the same format as understood by wireshark mainline.

However, it introduces a build and runtime dependency to
libosmocore (git://git.osmocom.org/libosmocore.git).

7 files changed, 92 insertions, 155 deletions

diff --git a/gsm-receiver/configure.ac b/gsm-receiver/configure.ac
index e309304..0c4cb7a 100644
--- a/gsm-receiver/configure.ac
+++ b/gsm-receiver/configure.ac
@@ -25,7 +25,7 @@ AC_CONFIG_SRCDIR([src/lib/gsm.i])
 AM_CONFIG_HEADER(config.h)
 AC_CANONICAL_TARGET([])
 AC_CONFIG_AUX_DIR([.])
-AM_INIT_AUTOMAKE(gsm-receiver,0.0.1)
+AM_INIT_AUTOMAKE(gsm-receiver,0.0.2)
 AC_CONFIG_MACRO_DIR([config])
 
 GR_X86_64
@@ -93,14 +93,14 @@ GR_PWIN32
 PKG_CHECK_MODULES(GNURADIO_CORE, gnuradio-core >= 3)
 dnl LIBS="$LIBS $GNURADIO_CORE_LIBS"
 
-dnl Check for boost, version 1.35 (or higher I guess - this was taken from GNU Radio's configure.ac)
-AX_BOOST_BASE([1.35])
-CXXFLAGS="$CXXFLAGS $BOOST_CXXFLAGS" 
-CFLAGS="$CFLAGS $BOOST_CXXFLAGS"     
+dnl Define where to find boost includes
+GR_REQUIRE_BOOST_INCLUDES
 
 STD_DEFINES_AND_INCLUDES="$GNURADIO_CORE_CFLAGS $BOOST_CFLAGS"
 AC_SUBST(STD_DEFINES_AND_INCLUDES)
 
+dnl Check for libosmocore (gsmtap support)
+PKG_CHECK_MODULES(LIBOSMOCORE, libosmocore >= 0.1.13)
 
 AC_CONFIG_FILES([\
 	  Makefile \
diff --git a/gsm-receiver/src/lib/Makefile.am b/gsm-receiver/src/lib/Makefile.am
index 925eaca..71ea8fe 100644
--- a/gsm-receiver/src/lib/Makefile.am
+++ b/gsm-receiver/src/lib/Makefile.am
@@ -79,6 +79,7 @@ _gsm_la_LDFLAGS = $(NO_UNDEFINED) -module -avoid-version
 _gsm_la_LIBADD =		\
 	$(PYTHON_LDFLAGS)	\
 	libgsmdemod.la		\
+	$(LIBOSMOCORE_LIBS)	\
 	-lstdc++		\
 	$(DECODER_LA)
 
diff --git a/gsm-receiver/src/lib/decoder/Makefile.am b/gsm-receiver/src/lib/decoder/Makefile.am
index 1726d68..2fcadbb 100644
--- a/gsm-receiver/src/lib/decoder/Makefile.am
+++ b/gsm-receiver/src/lib/decoder/Makefile.am
@@ -36,7 +36,6 @@ libdecoder_la_SOURCES = \
 	fire_crc.c	\
 	gsmstack.c	\
 	interleave.c	\
-	out_pcap.c	\
 	tun.c		
 #	tch.c		\
 #	conv.c
@@ -47,7 +46,6 @@ noinst_HEADERS = 	\
 	fire_crc.h	\
 	gsmstack.h	\
 	interleave.h	\
-	out_pcap.h	\
 	tun.h		\
 	system.h	\
 	gsmtap.h	\
diff --git a/gsm-receiver/src/lib/decoder/gsmstack.c b/gsm-receiver/src/lib/decoder/gsmstack.c
index c3f1921..6c91395 100644
--- a/gsm-receiver/src/lib/decoder/gsmstack.c
+++ b/gsm-receiver/src/lib/decoder/gsmstack.c
@@ -6,6 +6,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <errno.h>
+#include <unistd.h>
 #include <string.h>
 #include "gsmstack.h"
 //#include "gsm_constants.h"
@@ -13,9 +14,16 @@
 //#include "sch.h"
 #include "cch.h"
 
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <osmocore/msgb.h>
+#include <osmocore/gsmtap.h>
+#include <osmocore/gsmtap_util.h>
+
 static const int USEFUL_BITS = 142;
 
-//#include "out_pcap.h"
 enum BURST_TYPE {
         UNKNOWN,
         FCCH, 
@@ -79,22 +87,31 @@ diff_decode(char *dst, char *src, int len)
 int
 GS_new(GS_CTX *ctx)
 {
+	int rc;
+	struct sockaddr_in sin;
+
+	sin.sin_family = AF_INET;
+	sin.sin_port = htons(GSMTAP_UDP_PORT);
+	inet_aton("127.0.0.1", &sin.sin_addr);
+
 	memset(ctx, 0, sizeof *ctx);
 	interleave_init(&ctx->interleave_ctx, 456, 114);
 	ctx->fn = -1;
 	ctx->bsic = -1;
+	ctx->gsmtap_fd = -1;
 
-	ctx->tun_fd = mktun("gsm", ctx->ether_addr);
-	if (ctx->tun_fd < 0)
-		fprintf(stderr, "cannot open 'gsm' tun device, did you create it?\n");
-
-	ctx->pcap_fd = open_pcap_file("gsm-receiver.pcap");
-	if (ctx->pcap_fd < 0)
-		fprintf(stderr, "cannot open PCAP file: %s\n", strerror(errno));
-
-	ctx->burst_pcap_fd = open_pcap_file("gsm-receiver-burst.pcap");
-	if (ctx->burst_pcap_fd < 0)
-		fprintf(stderr, "cannot open burst PCAP file: %s\n", strerror(errno));
+	rc = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	if (rc < 0) {
+		perror("creating UDP socket\n");
+		return rc;
+	}
+	ctx->gsmtap_fd = rc;
+	rc = connect(rc, (struct sockaddr *)&sin, sizeof(sin));
+	if (rc < 0) {
+		perror("connectiong UDP socket");
+		close(ctx->gsmtap_fd);
+		return rc;
+	}
 
 	return 0;
 }
@@ -112,15 +129,9 @@ GS_process(GS_CTX *ctx, int ts, int type, const unsigned char *src, int fn)
 	unsigned char *data;
 	int len;
 	struct gs_ts_ctx *ts_ctx = &ctx->ts_ctx[ts];
-	unsigned char octified[BURST_BYTES];
 
 	memset(ctx->msg, 0, sizeof(ctx->msg));
 
-	/* write burst to burst PCAP file */
-	burst_octify(octified, src, USEFUL_BITS);
-	write_pcap_packet(ctx->burst_pcap_fd, 0 /* arfcn */, ts, ctx->fn,
-			  1, type, octified, BURST_BYTES);
-	
 #if 0
 	if (ts != 0) {
 		/* non-0 timeslots should end up in PCAP */
@@ -177,9 +188,17 @@ GS_process(GS_CTX *ctx, int ts, int type, const unsigned char *src, int fn)
 		//DEBUGF("OK TS %d, len %d\n", ts, len);
 
 		out_gsmdecode(0, 0, ts, ctx->fn - 4, data, len);
-		write_interface(ctx->tun_fd, data+1, len-1, ctx->ether_addr);
-		write_pcap_packet(ctx->pcap_fd, 0 /* arfcn */, ts, ctx->fn,
-				  0, NORMAL, data, len);
+
+		if (ctx->gsmtap_fd >= 0) {
+			struct msgb *msg;
+			/* arfcn, ts, chan_type, ss, fn, signal, snr, data, len */
+			msg = gsmtap_makemsg(0, ts, GSMTAP_CHANNEL_BCCH, 0,
+					     ctx->fn-4, 0, 0, data, len);
+			if (msg)
+				write(ctx->gsmtap_fd, msg->data,
+				      msg->len);
+		}
+
 #if 0
 		if (ctx->fn % 51 != 0) && ( (((ctx->fn % 51 + 5) % 10 == 0) || (((ctx->fn % 51) + 1) % 10 ==0) ) )
 			ready = 1;
diff --git a/gsm-receiver/src/lib/decoder/gsmstack.h b/gsm-receiver/src/lib/decoder/gsmstack.h
index 9355785..d02440c 100644
--- a/gsm-receiver/src/lib/decoder/gsmstack.h
+++ b/gsm-receiver/src/lib/decoder/gsmstack.h
@@ -29,8 +29,7 @@ typedef struct
 	int tun_fd;
 	unsigned char ether_addr[ETH_ALEN];
 
-	int pcap_fd;
-	int burst_pcap_fd;
+	int gsmtap_fd;
 } GS_CTX;
 
 int GS_new(GS_CTX *ctx);
diff --git a/gsm-receiver/src/lib/decoder/gsmtap.h b/gsm-receiver/src/lib/decoder/gsmtap.h
index 1022194..dcd64bd 100644
--- a/gsm-receiver/src/lib/decoder/gsmtap.h
+++ b/gsm-receiver/src/lib/decoder/gsmtap.h
@@ -1,11 +1,20 @@
 #ifndef _GSMTAP_H
 #define _GSMTAP_H
 
-/* gsmtap header, pseudo-header in front of the actua GSM payload*/
+/* gsmtap header, pseudo-header in front of the actua GSM payload */
 
-#include <sys/types.h>
+/* GSMTAP is a generic header format for GSM protocol captures,
+ * it uses the IANA-assigned UDP port number 4729 and carries
+ * payload in various formats of GSM interfaces such as Um MAC
+ * blocks or Um bursts.
+ *
+ * Example programs generating GSMTAP data are airprobe
+ * (http://airprobe.org/) or OsmocomBB (http://bb.osmocom.org/)
+ */
 
-#define GSMTAP_VERSION		0x01
+#include <stdint.h>
+
+#define GSMTAP_VERSION		0x02
 
 #define GSMTAP_TYPE_UM		0x01
 #define GSMTAP_TYPE_ABIS	0x02
@@ -20,22 +29,44 @@
 #define GSMTAP_BURST_NORMAL		0x06
 #define GSMTAP_BURST_DUMMY		0x07
 #define GSMTAP_BURST_ACCESS		0x08
+#define GSMTAP_BURST_NONE		0x09
+
+#define GSMTAP_CHANNEL_UNKNOWN	0x00
+#define GSMTAP_CHANNEL_BCCH	0x01
+#define GSMTAP_CHANNEL_CCCH	0x02
+#define GSMTAP_CHANNEL_RACH	0x03
+#define GSMTAP_CHANNEL_AGCH	0x04
+#define GSMTAP_CHANNEL_PCH	0x05
+#define GSMTAP_CHANNEL_SDCCH	0x06
+#define GSMTAP_CHANNEL_SDCCH4	0x07
+#define GSMTAP_CHANNEL_SDCCH8	0x08
+#define GSMTAP_CHANNEL_TCH_F	0x09
+#define GSMTAP_CHANNEL_TCH_H	0x0a
+#define GSMTAP_CHANNEL_ACCH	0x80
+
+#define GSMTAP_ARFCN_F_PCS	0x8000
+#define GSMTAP_ARFCN_F_UPLINK	0x4000
+#define GSMTAP_ARFCN_MASK	0x3fff
+
+#define GSMTAP_UDP_PORT			4729
 
 struct gsmtap_hdr {
-	u_int8_t version;		/* version, set to 0x01 currently */
-	u_int8_t hdr_len;		/* length in number of 32bit words */
-	u_int8_t type;			/* see GSMTAP_TYPE_* */
-	u_int8_t timeslot;		/* timeslot (0..7 on Um) */
+	uint8_t version;	/* version, set to 0x01 currently */
+	uint8_t hdr_len;	/* length in number of 32bit words */
+	uint8_t type;		/* see GSMTAP_TYPE_* */
+	uint8_t timeslot;	/* timeslot (0..7 on Um) */
 
-	u_int16_t arfcn;		/* ARFCN (frequency) */
-	u_int8_t noise_db;		/* noise figure in dB */
-	u_int8_t signal_db;		/* signal level in dB */
+	uint16_t arfcn;		/* ARFCN (frequency) */
+	int8_t signal_dbm;	/* signal level in dBm */
+	int8_t snr_db;		/* signal/noise ratio in dB */
 
-	u_int32_t frame_number;		/* GSM Frame Number (FN) */
+	uint32_t frame_number;	/* GSM Frame Number (FN) */
 
-	u_int8_t burst_type;		/* Type of burst, see above */
-	u_int8_t antenna_nr;		/* Antenna Number */
-	u_int16_t res;			/* reserved for future use (RFU) */
+	uint8_t sub_type;	/* Type of burst/channel, see above */
+	uint8_t antenna_nr;	/* Antenna Number */
+	uint8_t sub_slot;	/* sub-slot within timeslot */
+	uint8_t res;		/* reserved for future use (RFU) */
 
 } __attribute__((packed));
+
 #endif /* _GSMTAP_H */
diff --git a/gsm-receiver/src/lib/decoder/out_pcap.c b/gsm-receiver/src/lib/decoder/out_pcap.c
deleted file mode 100644
index 4da5fd6..0000000
--- a/gsm-receiver/src/lib/decoder/out_pcap.c
+++ /dev/null
@@ -1,111 +0,0 @@
-/* PCAP support for gsm-tvoid
- * (C) 2008 by Harald Welte <laforge@gnumonks.org>
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <pcap.h>
-#include <errno.h>
-#include <time.h>
-
-#include "out_pcap.h"
-#include "gsmtap.h"
-
-#ifndef LINKTYPE_GSMTAP
-#define LINKTYPE_GSMTAP		2342
-#endif
-
-#define TCPDUMP_MAGIC   0xa1b2c3d4
-
-struct pcap_timeval {
-	int32_t tv_sec;
-	int32_t tv_usec;
-};
-	
-struct pcap_sf_pkthdr {
-	struct pcap_timeval ts;		/* time stamp */
-	u_int32_t caplen;		/* lenght of portion present */
-	u_int32_t len;			/* length of this packet */
-};
-
-static int write_pcap_file_header(int fd)
-{
-	struct pcap_file_header pfh;
-
-	pfh.magic = TCPDUMP_MAGIC;
-	pfh.version_major = PCAP_VERSION_MAJOR;
-	pfh.version_minor = PCAP_VERSION_MINOR;
-	pfh.thiszone = timezone;
-	pfh.sigfigs = 0;
-	pfh.snaplen = 1024; /* FIXME */ 
-	pfh.linktype = LINKTYPE_GSMTAP;
-
-	if (write(fd, &pfh, sizeof(pfh)) < sizeof(pfh))
-		return -1;
-
-	return 0;
-}
-
-/* open pcap file and write header */
-int open_pcap_file(char *fname)
-{
-	int fd;
-	int rc;
-
- 	fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0660);
-	if (fd < 0)
-		return fd;
-
-	rc = write_pcap_file_header(fd);
-	if (rc < 0) {
-		close(fd);
-		fd = -EIO;
-	}
-
-	return fd;
-}
-
-int write_pcap_packet(int fd, int arfcn, int ts, int fn,
-		      int burst, int burst_type,
-		      const unsigned char *data, unsigned int len)
-{
-	unsigned char buf[8192];
-	struct pcap_sf_pkthdr *ph;
-	struct gsmtap_hdr *gh;
-	struct timeval tv;
-	int rc;
-
-	if (fd < 0)
-		return -EINVAL;
-
-	ph = (struct pcap_sf_pkthdr *) &buf[0];
-	gh = (struct gsmtap_hdr *) &buf[sizeof(struct pcap_sf_pkthdr)];
-
-	gettimeofday(&tv, NULL);
-
-	ph->ts.tv_sec = tv.tv_sec;
-	ph->ts.tv_usec = tv.tv_usec;
-	ph->caplen = ph->len = len + sizeof(struct gsmtap_hdr);
-
-	gh->version = GSMTAP_VERSION;
-	gh->hdr_len = sizeof(struct gsmtap_hdr)>>2;
-	if (burst)
-		gh->type = GSMTAP_TYPE_UM_BURST;
-	else
-		gh->type = GSMTAP_TYPE_UM;
-	gh->timeslot = ts;
-	gh->arfcn = htons(arfcn);
-	/* we don't support signal/noise yet */
-	gh->noise_db = gh->signal_db = 0;
-	gh->frame_number = htonl(fn);
-	gh->burst_type = burst_type & 0xff;
-
-	memcpy(buf + sizeof(*ph) + sizeof(*gh), data, len);
-	
-	rc = write(fd, buf, sizeof(*ph) + sizeof(*gh) + len);
-
-	//fsync(fd);
-
-	return rc;
-}