1 files changed, 111 insertions, 0 deletions
diff --git a/gsm-receiver/src/lib/decoder/out_pcap.c b/gsm-receiver/src/lib/decoder/out_pcap.c
new file mode 100644
index 0000000..4da5fd6
--- /dev/null
+++ b/gsm-receiver/src/lib/decoder/out_pcap.c
@@ -0,0 +1,111 @@
+/* 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;
+}