From Duncan Salerno:

Added LAPDm protocol dissector, GSM Um layer, and wiretap support for dct3trace
captures, generated by gammu (many available at http://wiki.thc.org/gsm).

svn path=/trunk/; revision=27176

1 files changed, 390 insertions, 0 deletions

diff --git a/wiretap/dct3trace.c b/wiretap/dct3trace.c
new file mode 100644
index 0000000000..2697609696
--- /dev/null
+++ b/wiretap/dct3trace.c
@@ -0,0 +1,390 @@
+/* dct3trace.c
+ * Routines for reading signalling traces generated by Gammu (www.gammu.org)
+ * from Nokia DCT3 phones in Netmonitor mode.
+ *
+ * gammu --nokiadebug nhm5_587.txt v20-25,v18-19
+ *
+ * Duncan Salerno <duncan.salerno@googlemail.com>
+ *
+ * $Id$
+ *
+ * Wiretap Library
+ * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include "wtap-int.h"
+#include "buffer.h"
+#include "dct3trace.h"
+#include "file_wrappers.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+
+/*
+   Example downlink data:
+
+<?xml version="1.0"?>
+<dump>
+<l1 direction="down" logicalchannel="96" physicalchannel="19" sequence="268116" error="0" timeshift="2992" bsic="22" data="31063F100DD0297A53E1020103C802398E0B2B2B2B2B2B" >
+<l2 data="063F100DD0297A53E1020103" rest="C802398E0B2B2B2B2B2B" >
+</l2>
+</l1>
+</dump>
+
+   Example uplink data (no raw L1):
+
+<?xml version="1.0"?>
+<dump>
+<l1 direction="up" logicalchannel="112" >
+<l2 type="U" subtype="Unknown" p="0" data="061500400000000000000000000000000000" >
+</l2>
+</l1>
+</dump>
+
+ */
+
+
+/* Magic text to check */
+static const char dct3trace_magic_line1[] = "<?xml version=\"1.0\"?>";
+static const char dct3trace_magic_line2[] = "<dump>";
+static const char dct3trace_magic_record_start[]  = "<l1 ";
+static const char dct3trace_magic_record_end[]  = "</l1>";
+static const char dct3trace_magic_l2_start[]  = "<l2 ";
+static const char dct3trace_magic_l2_end[]  = "</l2>";
+static const char dct3trace_magic_end[]  = "</dump>";
+
+
+static gboolean dct3trace_read(wtap *wth, int *err, gchar **err_info,
+	gint64 *data_offset);
+static gboolean dct3trace_seek_read(wtap *wth, gint64 seek_off,
+	union wtap_pseudo_header *pseudo_header, guint8 *pd, int len,
+	int *err, gchar **err_info);
+
+/*
+ * Following 3 functions taken from gsmdecode-0.7bis, with permission - http://wiki.thc.org/gsm
+ */
+
+static int
+hc2b(unsigned char hex)
+{
+	hex = tolower(hex);
+	if ((hex >= '0') && (hex <= '9'))
+		return hex - '0';
+	if ((hex >= 'a') && (hex <= 'f'))
+		return hex - 'a' + 10;
+	return -1;
+}
+
+static int
+hex2bin(unsigned char *out, unsigned char *in)
+{
+	unsigned char *out_start = out;
+	unsigned char *end = in + strlen((char *)in);
+	int is_low = 0;
+	int c;
+
+	while (in < end)
+	{
+		c = hc2b(in[0]);
+		if (c < 0)
+		{
+			in++;
+			continue;
+		}
+		if (is_low == 0)
+		{
+			out[0] = c << 4;
+			is_low = 1;
+		} else {
+			out[0] |= (c & 0x0f);
+			is_low = 0;
+			out++;
+		}
+		in++;
+	}
+
+	return out - out_start;
+}
+
+static int
+xml_get_int(int *val, const unsigned char *str, const unsigned char *pattern)
+{
+	char *ptr;
+	char *start, *end;
+	char buf[32];
+
+	ptr = strstr((char *)str, (char *)pattern);
+	if (ptr == NULL)
+		return -1;
+	start = strchr(ptr, '"');
+	if (start == NULL)
+		return -2;
+	start++;
+	end = strchr(start, '"');
+	if (end == NULL)
+		return -3;
+
+	memcpy(buf, start, end - start);
+	buf[end - start] = '\0';
+	*val = atoi(buf);
+	return 0;
+}
+
+
+/* Look through the first part of a file to see if this is
+ * a DCT3 trace file.
+ *
+ * Returns TRUE if it is, FALSE if it isn't or if we get an I/O error;
+ * if we get an I/O error, "*err" will be set to a non-zero value.
+ */
+static gboolean dct3trace_check_file_type(wtap *wth, int *err)
+{
+	char line1[64], line2[64];
+
+	if (file_gets(line1, sizeof(line1), wth->fh) != NULL &&
+		file_gets(line2, sizeof(line2), wth->fh) != NULL)
+	{
+		/* Don't compare line endings */
+		if( strncmp(dct3trace_magic_line1, line1, strlen(dct3trace_magic_line1)) == 0 &&
+			strncmp(dct3trace_magic_line2, line2, strlen(dct3trace_magic_line2)) == 0)
+		{
+			return TRUE;
+		}
+	}
+	/* EOF or error. */
+	else
+	{
+		if (file_eof(wth->fh))
+			*err = 0;
+		else
+			*err = file_error(wth->fh);
+	}
+
+	return FALSE;
+}
+
+
+int dct3trace_open(wtap *wth, int *err, gchar **err_info _U_)
+{
+	/* Look for Gammu DCT3 trace header */
+	if (!dct3trace_check_file_type(wth, err))
+	{
+		if (*err == 0)
+			return 0;
+		else
+			return -1;
+	}
+
+	wth->data_offset = 0;
+	wth->file_encap = WTAP_ENCAP_GSM_UM;
+	wth->file_type = WTAP_FILE_DCT3TRACE;
+	wth->snapshot_length = 0; /* not known */
+	wth->subtype_read = dct3trace_read;
+	wth->subtype_seek_read = dct3trace_seek_read;
+	wth->tsprecision = WTAP_FILE_TSPREC_SEC;
+
+	return 1;
+}
+
+
+static gboolean dct3trace_get_packet(FILE *fh, union wtap_pseudo_header *pseudo_header,
+	unsigned char *buf, int *len, int *err, gchar **err_info)
+{
+	unsigned char line[1024];
+	gboolean have_data = FALSE;
+
+	while (file_gets(line, sizeof(line), fh) != NULL)
+	{
+		if( memcmp(dct3trace_magic_end, line, strlen(dct3trace_magic_end)) == 0 )
+		{
+			/* Return on end of file </dump> */
+			*err = 0;
+			return FALSE;
+		}
+		else if( memcmp(dct3trace_magic_record_end, line, strlen(dct3trace_magic_record_end)) == 0 )
+		{
+			/* Return on end of record </l1> */
+			if( have_data )
+			{
+				*err = 0;
+				return TRUE;
+			}
+			else
+			{
+				/* If not got any data return error */
+				*err = WTAP_ERR_BAD_RECORD;
+				*err_info = g_strdup_printf("dct3trace: record without data");
+				return FALSE;
+			}
+		}
+		else if( memcmp(dct3trace_magic_record_start, line, strlen(dct3trace_magic_record_start)) == 0 )
+		{
+			/* Parse L1 header <l1 ...>*/
+			int channel, tmp, ret = 0;
+			char *ptr;
+
+			pseudo_header->gsm_um.uplink = !strstr(line, "direction=\"down\"");
+			ret |= xml_get_int(&channel, line, "logicalchannel");
+
+			/* Parse downlink only fields */
+			if( !pseudo_header->gsm_um.uplink )
+			{
+				ret |= xml_get_int(&tmp, line, "physicalchannel");
+				pseudo_header->gsm_um.arfcn = tmp;
+				ret |= xml_get_int(&tmp, line, "sequence");
+				pseudo_header->gsm_um.tdma_frame = tmp;
+				ret |= xml_get_int(&tmp, line, "bsic");
+				pseudo_header->gsm_um.bsic = tmp;
+				ret |= xml_get_int(&tmp, line, "error");
+				pseudo_header->gsm_um.error = tmp;
+				ret |= xml_get_int(&tmp, line, "timeshift");
+				pseudo_header->gsm_um.timeshift = tmp;
+			}
+
+			if( ret != 0 )
+			{
+				*err = WTAP_ERR_BAD_RECORD;
+				*err_info = g_strdup_printf("dct3trace: record missing mandatory attributes");
+				return FALSE;
+			}
+
+			switch( channel )
+			{
+				case 128: pseudo_header->gsm_um.channel = GSM_UM_CHANNEL_SDCCH; break;
+				case 112: pseudo_header->gsm_um.channel = GSM_UM_CHANNEL_SACCH; break;
+				case 176: pseudo_header->gsm_um.channel = GSM_UM_CHANNEL_FACCH; break;
+				case 96: pseudo_header->gsm_um.channel = GSM_UM_CHANNEL_CCCH; break;
+				case 80: pseudo_header->gsm_um.channel = GSM_UM_CHANNEL_BCCH; break;
+				default: pseudo_header->gsm_um.channel = GSM_UM_CHANNEL_UNKNOWN; break;
+			}
+
+			/* Read data (if have it) into buf */
+			ptr = strstr(line, "data=\"");
+			if( ptr )
+			{
+				have_data = TRUE; /* If has data... */
+				*len = hex2bin(buf, ptr+6);
+			}
+		}
+		else if( !have_data && memcmp(dct3trace_magic_l2_start, line, strlen(dct3trace_magic_l2_start)) == 0 )
+		{
+			/* For uplink packets we don't get the raw L1, so have to recreate it from the L2 */
+			/* Parse L2 header if didn't get data from L1 <l2 ...> */
+			int data_len = 0;
+			char *ptr = strstr(line, "data=\"");
+
+			if( !ptr )
+			{
+				continue;
+			}
+
+			have_data = TRUE;
+
+			if( pseudo_header->gsm_um.channel == GSM_UM_CHANNEL_SACCH || pseudo_header->gsm_um.channel == GSM_UM_CHANNEL_FACCH || pseudo_header->gsm_um.channel == GSM_UM_CHANNEL_SDCCH )
+			{
+				/* Add LAPDm B header */
+				memset(buf, 0x1, 2);
+				*len = 3;
+			}
+			else
+			{
+				/* Add LAPDm Bbis header */
+				*len = 1;
+			}
+			buf += *len;
+
+			data_len = hex2bin(buf, ptr+6);
+			*len += data_len;
+
+			/* Add LAPDm length byte */
+			*(buf - 1) = data_len << 2 | 0x1;
+		}
+	}
+
+	*err = file_error(fh);
+	if (*err == 0)
+	{
+		*err = WTAP_ERR_SHORT_READ;
+	}
+	return FALSE;
+}
+
+
+/* Find the next packet and parse it; called from wtap_read(). */
+static gboolean dct3trace_read(wtap *wth, int *err, gchar **err_info,
+    gint64 *data_offset)
+{
+	guint64 offset = file_tell(wth->fh);
+	int buf_len;
+	char buf[23];
+
+	if( !dct3trace_get_packet(wth->fh, &wth->pseudo_header, buf, &buf_len, err, err_info) )
+	{
+		return FALSE;
+	}
+
+	/* We've got a full packet! */
+	wth->phdr.ts.secs = 0;
+	wth->phdr.ts.nsecs = 0;
+	wth->phdr.caplen = buf_len;
+	wth->phdr.len = buf_len;
+
+	/* Make sure we have enough room for the packet */
+	buffer_assure_space(wth->frame_buffer, buf_len);
+	memcpy( buffer_start_ptr(wth->frame_buffer), buf, buf_len );
+
+	wth->data_offset = *data_offset = offset;
+
+	return TRUE;
+}
+
+
+/* Used to read packets in random-access fashion */
+static gboolean dct3trace_seek_read (wtap *wth, gint64 seek_off,
+	union wtap_pseudo_header *pseudo_header, guint8 *pd, int len,
+	int *err, gchar **err_info)
+{
+	int buf_len;
+	char buf[23];
+
+	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
+	{
+		return FALSE;
+	}
+
+	if( !dct3trace_get_packet(wth->random_fh, pseudo_header, buf, &buf_len, err, err_info) )
+	{
+		return FALSE;
+	}
+
+	if( len != buf_len && len != -1 )
+	{
+		*err = WTAP_ERR_BAD_RECORD;
+		*err_info = g_strdup_printf("dct3trace: requested length %d doesn't match record length %d",
+		    len, buf_len);
+		return FALSE;
+	}
+
+	memcpy( pd, buf, buf_len );
+	return TRUE;
+}