summaryrefslogtreecommitdiffstats
path: root/extcap/wifidump.c
blob: 489118eb9734f3278417de8de395b5699c01e493 (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
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
/* wifidump.c
 * wifidump is an extcap tool used to capture Wi-Fi frames using a remote ssh host
 *
 * Adapted from sshdump.
 *
 * Copyright 2022, Adrian Granados <adrian@intuitibits.com>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"
#define WS_LOG_DOMAIN "wifidump"

#include <extcap/extcap-base.h>
#include <extcap/ssh-base.h>
#include <wsutil/interface.h>
#include <wsutil/file_util.h>
#include <wsutil/strtoi.h>
#include <wsutil/filesystem.h>
#include <wsutil/privileges.h>
#include <wsutil/please_report_bug.h>
#include <wsutil/wslog.h>

#include <errno.h>
#include <string.h>
#include <fcntl.h>

#include <cli_main.h>

static char* wifidump_extcap_interface;
#ifdef _WIN32
#define DEFAULT_WIFIDUMP_EXTCAP_INTERFACE "wifidump.exe"
#else
#define DEFAULT_WIFIDUMP_EXTCAP_INTERFACE "wifidump"
#endif

#define WIFIDUMP_VERSION_MAJOR "1"
#define WIFIDUMP_VERSION_MINOR "0"
#define WIFIDUMP_VERSION_RELEASE "0"

#define SSH_READ_BLOCK_SIZE 256

enum {
	EXTCAP_BASE_OPTIONS_ENUM,
	OPT_HELP,
	OPT_VERSION,
	OPT_REMOTE_HOST,
	OPT_REMOTE_PORT,
	OPT_REMOTE_USERNAME,
	OPT_REMOTE_PASSWORD,
	OPT_REMOTE_INTERFACE,
	OPT_REMOTE_CHANNEL_FREQUENCY,
	OPT_REMOTE_CHANNEL_WIDTH,
	OPT_REMOTE_FILTER,
	OPT_SSHKEY,
	OPT_SSHKEY_PASSPHRASE,
	OPT_PROXYCOMMAND,
	OPT_REMOTE_COUNT
};

static struct ws_option longopts[] = {
	EXTCAP_BASE_OPTIONS,
	{ "help", ws_no_argument, NULL, OPT_HELP},
	{ "version", ws_no_argument, NULL, OPT_VERSION},
	SSH_BASE_OPTIONS,
	{ "remote-channel-frequency", ws_required_argument, NULL, OPT_REMOTE_CHANNEL_FREQUENCY},
	{ "remote-channel-width", ws_required_argument, NULL, OPT_REMOTE_CHANNEL_WIDTH},
	{ 0, 0, 0, 0}
};

static const char * remote_capture_functions =
"\n"
"function iface_down {\n"
"  local iface=$1\n"
"  sudo ip link set $iface down > /dev/null 2>&1\n"
"}\n"
"\n"
"function iface_up {\n"
"  local iface=$1\n"
"  sudo ip link set $iface up > /dev/null 2>&1\n"
"}\n"
"\n"
"function iface_monitor {\n"
"  local iface=$1\n"
"  sudo iw dev $iface set monitor control otherbss > /dev/null 2>&1 ||\n"
"  sudo iw dev $iface set type monitor control otherbss > /dev/null 2>&1\n"
"}\n"
"\n"
"function iface_scan {\n"
"  local iface=$1\n"
"  iface_down $iface &&\n"
"  sudo iw dev $iface set type managed > /dev/null 2>&1 &&\n"
"  iface_up $iface &&\n"
"  sudo iw dev $iface scan > /dev/null 2>&1\n"
"}\n"
"\n"
"function iface_config {\n"
"  local iface=$1\n"
"  local freq=$2\n"
"  local ch_width=$3\n"
"  local center_freq=$4\n"
"  if [ $freq -eq $center_freq ]; then\n"
"    sudo iw dev $1 set freq $freq $ch_width 2>&1\n"
"  else\n"
"    sudo iw dev $1 set freq $freq $ch_width $center_freq 2>&1\n"
"  fi\n"
"}\n"
"\n"
"function iface_start {\n"
"  local iface=$1\n"
"  local count=$2\n"
"  local filter=\"${@:3}\"\n"
"  if [ $count -gt 0 ]; then\n"
"    sudo tcpdump -i $iface -U -w - -c $count $filter\n"
"  else\n"
"    sudo tcpdump -i $iface -U -w - $filter\n"
"  fi\n"
"}\n"
"\n"
"function capture_generic {\n"
"  local iface=$1\n"
"  local freq=$2\n"
"  local ch_width=$3\n"
"  local center_freq=$4\n"
"  local count=$5\n"
"  local filter=\"${@:6}\"\n"
"  if ! { iwconfig $iface | grep Monitor > /dev/null 2>&1; }; then\n"
"    iface_down    $iface &&\n"
"    iface_monitor $iface &&\n"
"    iface_up      $iface\n"
"  else\n"
"    iface_monitor $iface\n"
"  fi\n"
"  iface_config  $iface $freq $ch_width $center_freq &&\n"
"  iface_start   $iface $count $filter\n"
"}\n"
"\n"
"function capture_iwlwifi {\n"
"  local iface=$1\n"
"  local freq=$2\n"
"  local ch_width=$3\n"
"  local center_freq=$4\n"
"  local count=$5\n"
"  local filter=\"${@:6}\"\n"
"  INDEX=`sudo iw dev $iface info | grep wiphy | grep -Eo '[0-9]+'`\n"
"  sudo iw phy phy${INDEX} channels | grep $freq | grep -i disabled > /dev/null 2>&1 &&\n"
"  iface_scan $iface\n"
"  MON=${iface}mon\n"
"  sudo iw $iface interface add $MON type monitor flags none > /dev/null 2>&1\n"
"  iface_up $MON &&\n"
"  iface_down $iface &&\n"
"  iface_config $MON $freq $ch_width $center_freq &&\n"
"  iface_start $MON $count $filter\n"
"}\n"
"\n"
"function capture {\n"
"  local iface=$1\n"
"  local freq=$2\n"
"  local ch_width=$3\n"
"  local center_freq=$4\n"
"  local count=$5\n"
"  local filter=\"${@:6}\"\n"
"  if [ \"$iface\" == \"auto\" ]; then\n"
"    iface=`sudo iw dev | grep -i interface | awk '{ print $2 }' | sort | head -n 1`\n"
"  fi\n"
"  local driver=`/usr/sbin/ethtool -i $iface | grep driver | awk '{ print $2 }'`\n"
"  if [ $driver = \"iwlwifi\" ]; then\n"
"    capture_iwlwifi $iface $freq $ch_width $center_freq $count $filter\n"
"  else\n"
"    capture_generic $iface $freq $ch_width $center_freq $count $filter\n"
"  fi\n"
"}\n"
"\n";

static unsigned int wifi_freqs_2dot4_5ghz[] = {
	2412, 2417, 2422, 2427, 2432, 2437, 2442, 2447, 2452, 2457, 2462,
	2467, 2472, 2484,
	5180, 5200, 5220, 5240, 5260, 5280, 5300, 5320, 5500, 5520, 5540, 5560, 5580,
  5600, 5620, 5640, 5660, 5680, 5700, 5720, 5745, 5765, 5785, 5805, 5825,
	0
};

static unsigned int freq_to_channel(unsigned int freq_mhz) {
	if (freq_mhz == 2484)
		return 14;
	else if (freq_mhz >= 2412 && freq_mhz <= 2484)
		return ((freq_mhz - 2412) / 5) + 1;
	else if (freq_mhz >= 5160 && freq_mhz <= 5885)
		return ((freq_mhz - 5180) / 5) + 36;
	else if (freq_mhz >= 5955 && freq_mhz <= 7115)
		return ((freq_mhz - 5955) / 5) + 1;
	else
		return 0;
}

static const char *freq_to_band(unsigned int freq_mhz)
{
	if (freq_mhz >= 2412 && freq_mhz <= 2484)
		return "2.4 GHz";
	else if (freq_mhz >= 5160 && freq_mhz <= 5885)
		return "5 GHz";
	else if (freq_mhz >= 5955 && freq_mhz <= 7115)
		return "6 GHz";
	else
	 return NULL;
}

static unsigned int center_freq(unsigned int freq_mhz, unsigned int ch_width_mhz) {

	unsigned int start_freq;

	if (ch_width_mhz == 20) {
		return freq_mhz;
	}
  else if (ch_width_mhz == 40) {
    if (freq_mhz >= 5180 && freq_mhz <= 5720) {
			for (start_freq = 5180; start_freq <= 5700; start_freq += ch_width_mhz) {
      	if (freq_mhz >= start_freq && freq_mhz <= (start_freq + 20))
        	return ((start_freq * 2) + 20) / 2;
			}
		}
    else if (freq_mhz >= 5745 && freq_mhz <= 5765)
      return 5755;
    else if (freq_mhz >= 5785 && freq_mhz <= 5805)
      return 5795;
    else if (freq_mhz >= 5955 && freq_mhz <= 7095) {
			for (start_freq = 5955; start_freq <= 7075; start_freq += ch_width_mhz) {
        if (freq_mhz >= start_freq && freq_mhz <= (start_freq + 20))
          return ((start_freq * 2) + 20) / 2;
			}
		}
	}
  else if (ch_width_mhz == 80) {
    if (freq_mhz >= 5180 && freq_mhz <= 5660) {
			for (start_freq = 5180; start_freq <= 5660; start_freq += ch_width_mhz) {
      	if (freq_mhz >= start_freq && freq_mhz <= (start_freq + 60))
        	return ((start_freq * 2) + 60) / 2;
			}
		}
    else if (freq_mhz >= 5745 && freq_mhz <= 5805)
      return 5775;
    else if (freq_mhz >= 5955 && freq_mhz <= 7055) {
			for (start_freq = 5955; start_freq <= 6995; start_freq += ch_width_mhz) {
        if (freq_mhz >= start_freq && freq_mhz <= (start_freq + 60))
        	return ((start_freq * 2) + 60) / 2;
			}
		}
	}
  else if (ch_width_mhz == 160) {
    if (freq_mhz >= 5180 && freq_mhz <= 5640) {
			for (start_freq = 5180; start_freq <= 5500; start_freq += ch_width_mhz) {
        if (freq_mhz >= start_freq && freq_mhz <= (start_freq + 140))
          return ((start_freq * 2) + 140) / 2;
			}
		}
    else if (freq_mhz >= 5955 && freq_mhz <= 7055) {
			for (start_freq = 5955; start_freq <= 6915; start_freq += ch_width_mhz) {
      	if (freq_mhz >= start_freq && freq_mhz <= (start_freq + 140))
        	return ((start_freq * 2) + 140) / 2;
			}
		}
	}

  return -1;
}

static int ssh_loop_read(ssh_channel channel, FILE* fp)
{
	int nbytes;
	int ret = EXIT_SUCCESS;
	char buffer[SSH_READ_BLOCK_SIZE];

	/* read from stdin until data are available */
	while (ssh_channel_is_open(channel) && !ssh_channel_is_eof(channel)) {
		nbytes = ssh_channel_read(channel, buffer, SSH_READ_BLOCK_SIZE, 0);
		if (nbytes < 0) {
			ws_warning("Error reading from channel");
			goto end;
		}
		if (nbytes == 0) {
			break;
		}
		if (fwrite(buffer, 1, nbytes, fp) != (unsigned)nbytes) {
			ws_warning("Error writing to fifo");
			ret = EXIT_FAILURE;
			goto end;
		}
		fflush(fp);
	}

	/* read loop finished... maybe something wrong happened. Read from stderr */
	while (ssh_channel_is_open(channel) && !ssh_channel_is_eof(channel)) {
		nbytes = ssh_channel_read(channel, buffer, SSH_READ_BLOCK_SIZE, 1);
		if (nbytes < 0) {
			ws_warning("Error reading from channel");
			goto end;
		}
		if (fwrite(buffer, 1, nbytes, stderr) != (unsigned)nbytes) {
			ws_warning("Error writing to stderr");
			break;
		}
	}

end:
	if (ssh_channel_send_eof(channel) != SSH_OK) {
		ws_warning("Error sending EOF in ssh channel");
		ret = EXIT_FAILURE;
	}
	return ret;
}

static ssh_channel run_ssh_command(ssh_session sshs, const char* capture_functions,
	const char* iface, const uint16_t channel_frequency, const uint16_t channel_width,
	const uint16_t center_frequency, const char* cfilter, const uint32_t count)
{
	char* cmdline;
	ssh_channel channel;
	char* quoted_iface = NULL;
	char* quoted_filter = NULL;
	char* count_str = NULL;
	unsigned int remote_port = 22;

	channel = ssh_channel_new(sshs);
	if (!channel) {
		ws_warning("Can't create channel");
		return NULL;
	}

	if (ssh_channel_open_session(channel) != SSH_OK) {
		ws_warning("Can't open session");
		ssh_channel_free(channel);
		return NULL;
	}

	ssh_options_get_port(sshs, &remote_port);

	quoted_iface = iface ? g_shell_quote(iface) : NULL;
	quoted_filter = g_shell_quote(cfilter ? cfilter : "");
	cmdline = ws_strdup_printf("%s capture %s %u %u %u %u %s",
		capture_functions,
		quoted_iface ? quoted_iface : "auto",
		channel_frequency,
		channel_width,
		center_frequency,
		count,
		quoted_filter);

	ws_debug("Running: %s", cmdline);
	if (ssh_channel_request_exec(channel, cmdline) != SSH_OK) {
		ws_warning("Can't request exec");
		ssh_channel_close(channel);
		ssh_channel_free(channel);
		channel = NULL;
	}

	g_free(quoted_iface);
	g_free(quoted_filter);
	g_free(cmdline);
	g_free(count_str);

	return channel;
}

static int ssh_open_remote_connection(const ssh_params_t* params, const char* capture_functions,
	const char* iface, const uint16_t channel_frequency, const uint16_t channel_width,
	const uint16_t center_frequency, const char* cfilter, const uint32_t count, const char* fifo)
{
	ssh_session sshs = NULL;
	ssh_channel channel = NULL;
	FILE* fp = stdout;
	int ret = EXIT_FAILURE;
	char* err_info = NULL;

	if (g_strcmp0(fifo, "-")) {
		/* Open or create the output file */
		fp = fopen(fifo, "wb");
		if (fp == NULL) {
			ws_warning("Error creating output file: %s (%s)", fifo, g_strerror(errno));
			return EXIT_FAILURE;
		}
	}

	sshs = create_ssh_connection(params, &err_info);

	if (!sshs) {
		ws_warning("Error creating connection.");
		goto cleanup;
	}

	channel = run_ssh_command(sshs, capture_functions, iface, channel_frequency,
		channel_width, center_frequency, cfilter, count);

	if (!channel) {
		ws_warning("Can't run ssh command.");
		goto cleanup;
	}

	/* read from channel and write into fp */
	if (ssh_loop_read(channel, fp) != EXIT_SUCCESS) {
		ws_warning("Error in read loop.");
		ret = EXIT_FAILURE;
		goto cleanup;
	}

	ret = EXIT_SUCCESS;
cleanup:
	if (err_info)
		ws_warning("%s", err_info);
	g_free(err_info);

	/* clean up and exit */
	ssh_cleanup(&sshs, &channel);

	if (g_strcmp0(fifo, "-"))
		fclose(fp);
	return ret;
}

static int list_config(char *interface)
{
	unsigned inc = 0;
	int i, psc;

	if (!interface) {
		ws_warning("ERROR: No interface specified.");
		return EXIT_FAILURE;
	}

	if (g_strcmp0(interface, wifidump_extcap_interface)) {
		ws_warning("ERROR: interface must be %s", wifidump_extcap_interface);
		return EXIT_FAILURE;
	}

	// Server tab
	printf("arg {number=%u}{call=--remote-host}{display=Remote SSH server address}"
		"{type=string}{tooltip=The remote SSH host. It can be both "
		"an IP address or a hostname}{required=true}{group=Server}\n", inc++);
	printf("arg {number=%u}{call=--remote-port}{display=Remote SSH server port}"
		"{type=unsigned}{tooltip=The remote SSH host port (1-65535)}"
		"{range=1,65535}{group=Server}\n", inc++);

	// Authentication tab
	printf("arg {number=%u}{call=--remote-username}{display=Remote SSH server username}"
		"{type=string}{tooltip=The remote SSH username. If not provided, "
		"the current user will be used}{group=Authentication}\n", inc++);
	printf("arg {number=%u}{call=--remote-password}{display=Remote SSH server password}"
		"{type=password}{tooltip=The SSH password, used when other methods (SSH agent "
		"or key files) are unavailable.}{group=Authentication}\n", inc++);
	printf("arg {number=%u}{call=--sshkey}{display=Path to SSH private key}"
		"{type=fileselect}{tooltip=The path on the local filesystem of the private ssh key}"
		"{mustexist=true}{group=Authentication}\n", inc++);
	printf("arg {number=%u}{call=--sshkey-passphrase}{display=SSH key passphrase}"
		"{type=password}{tooltip=Passphrase to unlock the SSH private key}{group=Authentication}\n",
		inc++);

	// Capture tab
	printf("arg {number=%u}{call=--remote-interface}{display=Remote interface}"
		"{type=string}{tooltip=The remote network interface used to capture"
		"}{default=auto}{group=Capture}\n", inc++);
	printf("arg {number=%u}{call=--remote-channel-frequency}{display=Remote channel}"
		"{type=selector}{tooltip=The remote channel used to capture}{group=Capture}\n", inc);

	unsigned int freq = 0;
	for (i = 0; (freq = wifi_freqs_2dot4_5ghz[i]); i++) {
		printf("value {arg=%u}{value=%u}{display=%s, Channel %u}\n", inc, freq, freq_to_band(freq), freq_to_channel(freq));
	}

	for (freq = 5955, psc = 3; freq <= 7115; freq += 20, psc++) {
		printf("value {arg=%u}{value=%u}{display=%s, Channel %u%s}\n", inc, freq,
			freq_to_band(freq), freq_to_channel(freq), (psc % 4 == 0) ? " (PSC)" : "");
	}
	inc++;

	printf("arg {number=%u}{call=--remote-channel-width}{display=Remote channel width}"
		"{type=selector}{tooltip=The remote channel width used to capture}"
		"{group=Capture}\n", inc);
	printf("value {arg=%u}{value=20}{display=20 MHz}\n", inc);
	printf("value {arg=%u}{value=40}{display=40 MHz}\n", inc);
	printf("value {arg=%u}{value=80}{display=80 MHz}\n", inc);
	printf("value {arg=%u}{value=160}{display=160 MHz}\n", inc);
	inc++;

	printf("arg {number=%u}{call=--remote-filter}{display=Remote capture filter}{type=string}"
		"{tooltip=The remote capture filter}{group=Capture}\n", inc++);
	printf("arg {number=%u}{call=--remote-count}{display=Frames to capture}"
		"{type=unsigned}{tooltip=The number of remote frames to capture.}"
		"{group=Capture}\n", inc++);

	extcap_config_debug(&inc);

	return EXIT_SUCCESS;
}

static char* concat_filters(const char* extcap_filter, const char* remote_filter)
{
	if (!extcap_filter && remote_filter)
		return g_strdup(remote_filter);

	if (!remote_filter && extcap_filter)
		return g_strdup(extcap_filter);

	if (!remote_filter && !extcap_filter)
		return NULL;

	return ws_strdup_printf("(%s) and (%s)", extcap_filter, remote_filter);
}

int main(int argc, char *argv[])
{
	char* err_msg;
	int result;
	int option_idx = 0;
	ssh_params_t* ssh_params = ssh_params_new();
	char* remote_interface = NULL;
	uint16_t remote_channel_frequency = 0;
	uint16_t remote_channel_width = 0;
	uint16_t remote_center_frequency = 0;
	char* remote_filter = NULL;
	uint32_t count = 0;
	int ret = EXIT_FAILURE;
	extcap_parameters* extcap_conf = g_new0(extcap_parameters, 1);
	char* help_url;
	char* help_header = NULL;
	char* interface_description = g_strdup("Wi-Fi remote capture");

	/* Initialize log handler early so we can have proper logging during startup. */
	extcap_log_init("wifidump");

	wifidump_extcap_interface = g_path_get_basename(argv[0]);

	/*
	 * Get credential information for later use.
	 */
	init_process_policies();

	/*
	 * Attempt to get the pathname of the directory containing the
	 * executable file.
	 */
	err_msg = configuration_init(argv[0], NULL);
	if (err_msg != NULL) {
		ws_warning("Can't get pathname of directory containing the extcap program: %s.",
			err_msg);
		g_free(err_msg);
	}

	help_url = data_file_url("wifidump.html");
	extcap_base_set_util_info(extcap_conf, argv[0], WIFIDUMP_VERSION_MAJOR, WIFIDUMP_VERSION_MINOR,
		WIFIDUMP_VERSION_RELEASE, help_url);
	g_free(help_url);
	add_libssh_info(extcap_conf);
	if (g_strcmp0(wifidump_extcap_interface, DEFAULT_WIFIDUMP_EXTCAP_INTERFACE)) {
		char* temp = interface_description;
		interface_description = ws_strdup_printf("%s, custom version", interface_description);
		g_free(temp);
	}
	extcap_base_register_interface(extcap_conf, wifidump_extcap_interface, interface_description, 147, "Remote capture dependent DLT");
	g_free(interface_description);

	help_header = ws_strdup_printf(
		" %s --extcap-interfaces\n"
		" %s --extcap-interface=%s --extcap-dlts\n"
		" %s --extcap-interface=%s --extcap-config\n"
		" %s --extcap-interface=%s --remote-host myhost --remote-port 22222 "
		"--remote-username myuser --remote-interface wlan0 --remote-channel-frequency 5180 "
		"--remote-channel-width 40 --fifo=FILENAME --capture\n", argv[0], argv[0], wifidump_extcap_interface, argv[0],
		wifidump_extcap_interface, argv[0], wifidump_extcap_interface);
	extcap_help_add_header(extcap_conf, help_header);
	g_free(help_header);
	extcap_help_add_option(extcap_conf, "--help", "print this help");
	extcap_help_add_option(extcap_conf, "--version", "print the version");
	extcap_help_add_option(extcap_conf, "--remote-host <host>", "the remote SSH host");
	extcap_help_add_option(extcap_conf, "--remote-port <port>", "the remote SSH port");
	extcap_help_add_option(extcap_conf, "--remote-username <username>", "the remote SSH username");
	extcap_help_add_option(extcap_conf, "--remote-password <password>", "the remote SSH password. If not specified, ssh-agent and ssh-key are used");
	extcap_help_add_option(extcap_conf, "--sshkey <public key path>", "the path of the ssh key");
	extcap_help_add_option(extcap_conf, "--sshkey-passphrase <public key passphrase>", "the passphrase to unlock public ssh");
	extcap_help_add_option(extcap_conf, "--remote-interface <iface>", "the remote capture interface");
	extcap_help_add_option(extcap_conf, "--remote-channel-frequency <channel_frequency>", "the remote channel frequency in MHz");
	extcap_help_add_option(extcap_conf, "--remote-channel-width <channel_width>", "the remote channel width in MHz");
	extcap_help_add_option(extcap_conf, "--remote-filter <filter>", "a filter for remote capture");
	extcap_help_add_option(extcap_conf, "--remote-count <count>", "the number of frames to capture");

	ws_opterr = 0;
	ws_optind = 0;

	if (argc == 1) {
		extcap_help_print(extcap_conf);
		goto end;
	}

	while ((result = ws_getopt_long(argc, argv, ":", longopts, &option_idx)) != -1) {

		switch (result) {

		case OPT_HELP:
			extcap_help_print(extcap_conf);
			ret = EXIT_SUCCESS;
			goto end;

		case OPT_VERSION:
			extcap_version_print(extcap_conf);
			ret = EXIT_SUCCESS;
			goto end;

		case OPT_REMOTE_HOST:
			g_free(ssh_params->host);
			ssh_params->host = g_strdup(ws_optarg);
			break;

		case OPT_REMOTE_PORT:
			if (!ws_strtou16(ws_optarg, NULL, &ssh_params->port) || ssh_params->port == 0) {
				ws_warning("Invalid port: %s", ws_optarg);
				goto end;
			}
			break;

		case OPT_REMOTE_USERNAME:
			g_free(ssh_params->username);
			ssh_params->username = g_strdup(ws_optarg);
			break;

		case OPT_REMOTE_PASSWORD:
			g_free(ssh_params->password);
			ssh_params->password = g_strdup(ws_optarg);
			memset(ws_optarg, 'X', strlen(ws_optarg));
			break;

		case OPT_SSHKEY:
			g_free(ssh_params->sshkey_path);
			ssh_params->sshkey_path = g_strdup(ws_optarg);
			break;

		case OPT_SSHKEY_PASSPHRASE:
			g_free(ssh_params->sshkey_passphrase);
			ssh_params->sshkey_passphrase = g_strdup(ws_optarg);
			memset(ws_optarg, 'X', strlen(ws_optarg));
			break;

		case OPT_REMOTE_INTERFACE:
			g_free(remote_interface);
			remote_interface = g_strdup(ws_optarg);
			break;

		case OPT_REMOTE_CHANNEL_FREQUENCY:
			if (!ws_strtou16(ws_optarg, NULL, &remote_channel_frequency)) {
				ws_warning("Invalid channel frequency: %s", ws_optarg);
				goto end;
			}
			break;

		case OPT_REMOTE_CHANNEL_WIDTH:
			if (!ws_strtou16(ws_optarg, NULL, &remote_channel_width)) {
				ws_warning("Invalid channel width: %s", ws_optarg);
				goto end;
			}
			break;

		case OPT_REMOTE_FILTER:
			g_free(remote_filter);
			remote_filter = g_strdup(ws_optarg);
			break;

		case OPT_REMOTE_COUNT:
			if (!ws_strtou32(ws_optarg, NULL, &count)) {
				ws_warning("Invalid value for count: %s", ws_optarg);
				goto end;
			}
			break;

		case ':':
			/* missing option argument */
			ws_warning("Option '%s' requires an argument", argv[ws_optind - 1]);
			break;

		default:
			if (!extcap_base_parse_options(extcap_conf, result - EXTCAP_OPT_LIST_INTERFACES, ws_optarg)) {
				ws_warning("Invalid option: %s", argv[ws_optind - 1]);
				goto end;
			}
		}
	}

	extcap_cmdline_debug(argv, argc);

	if (extcap_base_handle_interface(extcap_conf)) {
		ret = EXIT_SUCCESS;
		goto end;
	}

	if (extcap_conf->show_config) {
		ret = list_config(extcap_conf->interface);
		goto end;
	}

	err_msg = ws_init_sockets();
	if (err_msg != NULL) {
		ws_warning("ERROR: %s", err_msg);
		g_free(err_msg);
		ws_warning("%s", please_report_bug());
		goto end;
	}

	if (extcap_conf->capture) {
		char* filter;

		if (!ssh_params->host) {
			ws_warning("Missing parameter: --remote-host");
			goto end;
		}
		remote_center_frequency = center_freq(remote_channel_frequency, remote_channel_width);
		filter = concat_filters(extcap_conf->capture_filter, remote_filter);
		ssh_params->debug = extcap_conf->debug;
		ret = ssh_open_remote_connection(ssh_params, remote_capture_functions,
			remote_interface, remote_channel_frequency, remote_channel_width, remote_center_frequency,
			filter, count, extcap_conf->fifo);
		g_free(filter);
	} else {
		ws_debug("You should not come here... maybe some parameter missing?");
		ret = EXIT_FAILURE;
	}

end:
	/* clean up stuff */
	ssh_params_free(ssh_params);
	g_free(remote_interface);
	g_free(remote_filter);
	extcap_base_cleanup(&extcap_conf);
	return ret;
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: t
 * End:
 *
 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 * :indentSize=8:tabSize=8:noTabs=false:
 */