aboutsummaryrefslogtreecommitdiffstats
path: root/wiretap/radcom.c
blob: a81d72ccf07ae38ea77ac6ddd0363c3feee5e90d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
/* radcom.c
 *
 * $Id$
 *
 * 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 <errno.h>
#include <string.h>
#include "wtap-int.h"
#include "file_wrappers.h"
#include "buffer.h"
#include "radcom.h"

struct frame_date {
	guint16	year;
	guint8	month;
	guint8	day;
	guint32	sec;		/* seconds since midnight */
	guint32	usec;
};

struct unaligned_frame_date {
	char	year[2];
	char	month;
	char	day;
	char	sec[4];		/* seconds since midnight */
	char	usec[4];
};

/* Found at the beginning of the file. Bytes 2 and 3 (D2:00) seem to be
 * different in some captures */
static const guint8 radcom_magic[8] = {
	0x42, 0xD2, 0x00, 0x34, 0x12, 0x66, 0x22, 0x88
};

static const guint8 encap_magic[4] = {
	0x00, 0x42, 0x43, 0x09
};

static const guint8 active_time_magic[11] = {
	0x41, 0x63, 0x74, 0x69, 0x76, 0x65, 0x20, 0x54, 0x69, 0x6d, 0x65
};

/* RADCOM record header - followed by frame data (perhaps including FCS).

   "data_length" appears to be the length of packet data following
   the record header.  It's 0 in the last record.

   "length" appears to be the amount of captured packet data, and
   "real_length" might be the actual length of the frame on the wire -
   in some captures, it's the same as "length", and, in others,
   it's greater than "length".  In the last record, however, those
   may have bogus values (or is that some kind of trailer record?).

   "xxx" appears to be all-zero in all but the last record in one
   capture; if so, perhaps this indicates that the last record is,
   in fact, a trailer of some sort, and some field in the header
   is a record type. */
struct radcomrec_hdr {
	char	xxx[4];		/* unknown */
	char	data_length[2];	/* packet length? */
	char	xxy[5];		/* unknown */
	struct unaligned_frame_date date; /* date/time stamp of packet */
	char	real_length[2];	/* actual length of packet */
	char	length[2];	/* captured length of packet */
	char	xxz[2];		/* unknown */
	char	dce;		/* DCE/DTE flag (and other flags?) */
	char	xxw[9];		/* unknown */
};

static gboolean radcom_read(wtap *wth, int *err, gchar **err_info,
	gint64 *data_offset);
static gboolean radcom_seek_read(wtap *wth, gint64 seek_off,
	union wtap_pseudo_header *pseudo_header, guint8 *pd, int length,
	int *err, gchar **err_info);
static int radcom_read_rec_header(FILE_T fh, struct radcomrec_hdr *hdr,
	int *err, gchar **err_info);
static gboolean radcom_read_rec_data(FILE_T fh, guint8 *pd, int length,
	int *err, gchar **err_info);

int radcom_open(wtap *wth, int *err, gchar **err_info)
{
	int bytes_read;
	guint8 r_magic[8], t_magic[11], search_encap[7];
	struct frame_date start_date;
#if 0
	guint32 sec;
	struct tm tm;
#endif

	/* Read in the string that should be at the start of a RADCOM file */
	errno = WTAP_ERR_CANT_READ;
	bytes_read = file_read(r_magic, 8, wth->fh);
	if (bytes_read != 8) {
		*err = file_error(wth->fh, err_info);
		if (*err != 0)
			return -1;
		return 0;
	}

	/* XXX: bytes 2 and 3 of the "magic" header seem to be different in some
	 * captures. We force them to our standard value so that the test
	 * succeeds (until we find if they have a special meaning, perhaps a
	 * version number ?) */
	r_magic[1] = 0xD2;
	r_magic[2] = 0x00;
	if (memcmp(r_magic, radcom_magic, 8) != 0) {
		return 0;
	}

	/* Look for the "Active Time" string. The "frame_date" structure should
	 * be located 32 bytes before the beginning of this string */
	wth->data_offset = 8;
	errno = WTAP_ERR_CANT_READ;
	bytes_read = file_read(t_magic, 11, wth->fh);
	if (bytes_read != 11) {
		*err = file_error(wth->fh, err_info);
		if (*err != 0)
			return -1;
		return 0;
	}
	while (memcmp(t_magic, active_time_magic, 11) != 0)
	{
		if (file_seek(wth->fh, -10, SEEK_CUR, err) == -1)
			return -1;
		wth->data_offset += 1;
		errno = WTAP_ERR_CANT_READ;
		bytes_read = file_read(t_magic, 11, wth->fh);
		if (bytes_read != 11) {
			*err = file_error(wth->fh, err_info);
			if (*err != 0)
				return -1;
			return 0;
		}
	}
	if (file_seek(wth->fh, -43, SEEK_CUR, err) == -1) return -1;
	wth->data_offset -= 32;

	/* Get capture start time */
	errno = WTAP_ERR_CANT_READ;
	bytes_read = file_read(&start_date, sizeof(struct frame_date),
			       wth->fh);
	if (bytes_read != sizeof(struct frame_date)) {
		*err = file_error(wth->fh, err_info);
		if (*err != 0)
			return -1;
		return 0;
	}
	wth->data_offset += sizeof(struct frame_date);

	/* This is a radcom file */
	wth->file_type = WTAP_FILE_RADCOM;
	wth->subtype_read = radcom_read;
	wth->subtype_seek_read = radcom_seek_read;
	wth->snapshot_length = 0; /* not available in header, only in frame */
	wth->tsprecision = WTAP_FILE_TSPREC_USEC;

#if 0
	tm.tm_year = pletohs(&start_date.year)-1900;
	tm.tm_mon = start_date.month-1;
	tm.tm_mday = start_date.day;
	sec = pletohl(&start_date.sec);
	tm.tm_hour = sec/3600;
	tm.tm_min = (sec%3600)/60;
	tm.tm_sec = sec%60;
	tm.tm_isdst = -1;
#endif
	if (file_seek(wth->fh, sizeof(struct frame_date), SEEK_CUR, err) == -1)
		return -1;
	wth->data_offset += sizeof(struct frame_date);

	errno = WTAP_ERR_CANT_READ;
	bytes_read = file_read(search_encap, 4, wth->fh);
	if (bytes_read != 4) {
		goto read_error;
	}
	wth->data_offset += 4;
	while (memcmp(encap_magic, search_encap, 4)) {
		if (file_seek(wth->fh, -3, SEEK_CUR, err) == -1)
			return -1;
		wth->data_offset -= 3;
		errno = WTAP_ERR_CANT_READ;
		bytes_read = file_read(search_encap, 4, wth->fh);
		if (bytes_read != 4) {
			goto read_error;
		}
		wth->data_offset += 4;
	}
	if (file_seek(wth->fh, 12, SEEK_CUR, err) == -1)
		return -1;
	wth->data_offset += 12;
	errno = WTAP_ERR_CANT_READ;
	bytes_read = file_read(search_encap, 4, wth->fh);
	if (bytes_read != 4) {
		goto read_error;
	}
	wth->data_offset += 4;
	if (memcmp(search_encap, "LAPB", 4) == 0)
		wth->file_encap = WTAP_ENCAP_LAPB;
	else if (memcmp(search_encap, "Ethe", 4) == 0)
		wth->file_encap = WTAP_ENCAP_ETHERNET;
	else if (memcmp(search_encap, "ATM/", 4) == 0)
		wth->file_encap = WTAP_ENCAP_ATM_RFC1483;
	else {
		*err = WTAP_ERR_UNSUPPORTED_ENCAP;
		*err_info = g_strdup_printf("radcom: network type \"%.4s\" unknown", search_encap);
		return -1;
	}

#if 0
	bytes_read = file_read(&next_date, sizeof(struct frame_date), wth->fh);
	errno = WTAP_ERR_CANT_READ;
	if (bytes_read != sizeof(struct frame_date)) {
		goto read_error;
	}

	while (memcmp(&start_date, &next_date, 4)) {
		if (file_seek(wth->fh, 1-sizeof(struct frame_date), SEEK_CUR, err) == -1)
			return -1;
		errno = WTAP_ERR_CANT_READ;
		bytes_read = file_read(&next_date, sizeof(struct frame_date),
				   wth->fh);
		if (bytes_read != sizeof(struct frame_date)) {
			goto read_error;
		}
	}
#endif

	if (wth->file_encap == WTAP_ENCAP_ETHERNET) {
		if (file_seek(wth->fh, 294, SEEK_CUR, err) == -1)
			return -1;
		wth->data_offset += 294;
	} else if (wth->file_encap == WTAP_ENCAP_LAPB) {
		if (file_seek(wth->fh, 297, SEEK_CUR, err) == -1)
			return -1;
		wth->data_offset += 297;
	} else if (wth->file_encap == WTAP_ENCAP_ATM_RFC1483) {
		if (file_seek(wth->fh, 504, SEEK_CUR, err) == -1)
			return -1;
		wth->data_offset += 504;
	}

	return 1;

read_error:
	*err = file_error(wth->fh, err_info);
	if (*err != 0)
		return -1;
	return 0;
}

/* Read the next packet */
static gboolean radcom_read(wtap *wth, int *err, gchar **err_info,
			    gint64 *data_offset)
{
	int	ret;
	struct radcomrec_hdr hdr;
	guint16 data_length, real_length, length;
	guint32 sec;
	int	bytes_read;
	struct tm tm;
	guint8	phdr[8];
	char	fcs[2];

	/* Read record header. */
	*data_offset = wth->data_offset;
	ret = radcom_read_rec_header(wth->fh, &hdr, err, err_info);
	if (ret <= 0) {
		/* Read error or EOF */
		return FALSE;
	}
	wth->data_offset += sizeof hdr;
	data_length = pletohs(&hdr.data_length);
	if (data_length == 0) {
		/*
		 * The last record appears to have 0 in its "data_length"
		 * field, but non-zero values in other fields, so we
		 * check for that and treat it as an EOF indication.
		 */
		*err = 0;
		return FALSE;
	}
	length = pletohs(&hdr.length);
	real_length = pletohs(&hdr.real_length);

	if (wth->file_encap == WTAP_ENCAP_LAPB) {
		length -= 2; /* FCS */
		real_length -= 2;
	}

	wth->phdr.presence_flags = WTAP_HAS_TS|WTAP_HAS_CAP_LEN;

	wth->phdr.len = real_length;
	wth->phdr.caplen = length;

	tm.tm_year = pletohs(&hdr.date.year)-1900;
	tm.tm_mon = (hdr.date.month&0x0f)-1;
	tm.tm_mday = hdr.date.day;
	sec = pletohl(&hdr.date.sec);
	tm.tm_hour = sec/3600;
	tm.tm_min = (sec%3600)/60;
	tm.tm_sec = sec%60;
	tm.tm_isdst = -1;
	wth->phdr.ts.secs = mktime(&tm);
	wth->phdr.ts.nsecs = pletohl(&hdr.date.usec) * 1000;

	switch (wth->file_encap) {

	case WTAP_ENCAP_ETHERNET:
		/* XXX - is there an FCS? */
		wth->pseudo_header.eth.fcs_len = -1;
		break;

	case WTAP_ENCAP_LAPB:
		wth->pseudo_header.x25.flags = (hdr.dce & 0x1) ?
		    0x00 : FROM_DCE;
		break;

	case WTAP_ENCAP_ATM_RFC1483:
		/*
		 * XXX - is this stuff a pseudo-header?
		 * The direction appears to be in the "hdr.dce" field.
		 */
		if (!radcom_read_rec_data(wth->fh, phdr, sizeof phdr, err,
		    err_info))
			return FALSE;	/* Read error */
		wth->data_offset += 8;
		length -= 8;
		wth->phdr.len -= 8;
		wth->phdr.caplen -= 8;
		break;
	}

	/*
	 * Read the packet data.
	 */
	buffer_assure_space(wth->frame_buffer, length);
	if (!radcom_read_rec_data(wth->fh,
	    buffer_start_ptr(wth->frame_buffer), length, err, err_info))
		return FALSE;	/* Read error */
	wth->data_offset += length;

	if (wth->file_encap == WTAP_ENCAP_LAPB) {
		/* Read the FCS.
		   XXX - should we have some way of indicating the
		   presence and size of an FCS to our caller?
		   That'd let us handle other file types as well. */
		errno = WTAP_ERR_CANT_READ;
		bytes_read = file_read(&fcs, sizeof fcs, wth->fh);
		if (bytes_read != sizeof fcs) {
			*err = file_error(wth->fh, err_info);
			if (*err == 0)
				*err = WTAP_ERR_SHORT_READ;
			return FALSE;
		}
		wth->data_offset += sizeof fcs;
	}

	return TRUE;
}

static gboolean
radcom_seek_read(wtap *wth, gint64 seek_off,
		 union wtap_pseudo_header *pseudo_header, guint8 *pd, int length,
		 int *err, gchar **err_info)
{
	int	ret;
	struct radcomrec_hdr hdr;
	guint8	phdr[8];

	if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
		return FALSE;

	/* Read record header. */
	ret = radcom_read_rec_header(wth->random_fh, &hdr, err, err_info);
	if (ret <= 0) {
		/* Read error or EOF */
		if (ret == 0) {
			/* EOF means "short read" in random-access mode */
			*err = WTAP_ERR_SHORT_READ;
		}
		return FALSE;
	}

	switch (wth->file_encap) {

	case WTAP_ENCAP_ETHERNET:
		/* XXX - is there an FCS? */
		pseudo_header->eth.fcs_len = -1;
		break;

	case WTAP_ENCAP_LAPB:
		pseudo_header->x25.flags = (hdr.dce & 0x1) ? 0x00 : FROM_DCE;
		break;

	case WTAP_ENCAP_ATM_RFC1483:
		/*
		 * XXX - is this stuff a pseudo-header?
		 * The direction appears to be in the "hdr.dce" field.
		 */
		if (!radcom_read_rec_data(wth->random_fh, phdr, sizeof phdr,
		    err, err_info))
			return FALSE;	/* Read error */
		break;
	}

	/*
	 * Read the packet data.
	 */
	return radcom_read_rec_data(wth->random_fh, pd, length, err, err_info);
}

static int
radcom_read_rec_header(FILE_T fh, struct radcomrec_hdr *hdr, int *err,
		       gchar **err_info)
{
	int	bytes_read;

	errno = WTAP_ERR_CANT_READ;
	bytes_read = file_read(hdr, sizeof *hdr, fh);
	if (bytes_read != sizeof *hdr) {
		*err = file_error(fh, err_info);
		if (*err != 0)
			return -1;
		if (bytes_read != 0) {
			*err = WTAP_ERR_SHORT_READ;
			return -1;
		}
		return 0;
	}
	return 1;
}

static gboolean
radcom_read_rec_data(FILE_T fh, guint8 *pd, int length, int *err,
		     gchar **err_info)
{
	int	bytes_read;

	errno = WTAP_ERR_CANT_READ;
	bytes_read = file_read(pd, length, fh);

	if (bytes_read != length) {
		*err = file_error(fh, err_info);
		if (*err == 0)
			*err = WTAP_ERR_SHORT_READ;
		return FALSE;
	}
	return TRUE;
}