aboutsummaryrefslogtreecommitdiffstats
path: root/extcap.c
blob: df40bd10172f7497b286ef94f113703ac38471e2 (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
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
/* extcap.h
 *
 * Routines for extcap external capture
 * Copyright 2013, Mike Ryan <mikeryan@lacklustre.net>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <config.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef _WIN32
#include <windows.h>
#include <process.h>
#include <time.h>
#else
/* Include for unlink */
#include <unistd.h>
#endif

#include <glib.h>
#include <log.h>

#include <wsutil/file_util.h>
#include <wsutil/filesystem.h>
#include <wsutil/tempfile.h>

#include "capture_opts.h"

#ifdef HAVE_EXTCAP

#include "extcap.h"
#include "extcap_parser.h"

#ifdef _WIN32
static HANDLE pipe_h = NULL;
#endif

/* internal container, for all the extcap interfaces that have been found.
 * will be resetted by every call to extcap_interface_list() and is being
 * used in extcap_get_if_* as well as extcap_init_interfaces to ensure,
 * that only extcap interfaces are being given to underlying extcap programs
 */
static GHashTable *ifaces = NULL;

/* internal container, for all the extcap executables that have been found.
 * will be resetted by every call to extcap_interface_list() and is being
 * used for printing information about all extcap interfaces found
 */
static GHashTable *tools = NULL;

/* Callback definition for extcap_foreach */
typedef gboolean (*extcap_cb_t)(const gchar *extcap, gchar *output, void *data,
        gchar **err_str);

/* #define ARG_DEBUG */
#if ARG_DEBUG
static void extcap_debug_arguments ( extcap_arg *arg_iter );
#endif

static gboolean
extcap_if_exists(const gchar *ifname)
{
    if ( !ifname || !ifaces )
        return FALSE;

    if ( g_hash_table_lookup(ifaces, ifname) )
        return TRUE;

    return FALSE;
}

static gboolean
extcap_if_exists_for_extcap(const gchar *ifname, const gchar *extcap)
{
    gchar *entry = (gchar *)g_hash_table_lookup(ifaces, ifname);

    if ( entry && strcmp(entry, extcap) == 0 )
        return TRUE;

    return FALSE;
}

static gchar *
extcap_if_executable(const gchar *ifname)
{
    return (gchar *)g_hash_table_lookup(ifaces, ifname);
}

static void
extcap_if_add(const gchar *ifname, const gchar *extcap)
{
    if ( !g_hash_table_lookup(ifaces, ifname) )
        g_hash_table_insert(ifaces, g_strdup(ifname), g_strdup(extcap));
}

static void
extcap_tool_add(const gchar *extcap, const extcap_interface *interface)
{
    char *toolname;

    if ( !extcap || !interface )
        return;

    toolname = g_path_get_basename(extcap);

    if ( !g_hash_table_lookup(tools, toolname) ) {
        extcap_info * store = (extcap_info *)g_new0(extcap_info, 1);
        store->version = g_strdup(interface->version);
        store->full_path = g_strdup(extcap);
        store->basename = g_strdup(toolname);

        g_hash_table_insert(tools, g_strdup(toolname), store);
    }

    g_free(toolname);
}

/* Note: args does not need to be NULL-terminated. */
static void extcap_foreach(gint argc, gchar **args, extcap_cb_t cb,
        void *cb_data, char **err_str, const char * ifname _U_) {
    const char *dirname = get_extcap_dir();
    GDir *dir;
    const gchar *file;
    gboolean keep_going;
    gint i;
    gchar **argv;
#ifdef _WIN32
    gchar **dll_search_envp;
    gchar *progfile_dir;
#endif

    keep_going = TRUE;

    argv = (gchar **) g_malloc0(sizeof(gchar *) * (argc + 2));

#ifdef _WIN32
    /*
     * Make sure executables can find dependent DLLs and that they're *our*
     * DLLs: https://msdn.microsoft.com/en-us/library/windows/desktop/ms682586.aspx
     * Alternatively we could create a simple wrapper exe similar to Create
     * Hidden Process (http://www.commandline.co.uk/chp/).
     */
    dll_search_envp = g_get_environ();
    progfile_dir = g_strdup_printf("%s;%s", get_progfile_dir(), g_environ_getenv(dll_search_envp, "Path"));
    dll_search_envp = g_environ_setenv(dll_search_envp, "Path", progfile_dir, TRUE);
    g_free(progfile_dir);
#endif

    if ((dir = g_dir_open(dirname, 0, NULL)) != NULL) {
        GString *extcap_path = NULL;

        extcap_path = g_string_new("");
        while (keep_going && (file = g_dir_read_name(dir)) != NULL ) {
            gchar *command_output = NULL;
            gboolean status = FALSE;
            gint exit_status = 0;
            GError *error = NULL;
            gchar **envp = NULL;

            /* full path to extcap binary */
#ifdef _WIN32
            g_string_printf(extcap_path, "%s\\%s", dirname, file);
            envp = dll_search_envp;
#else
            g_string_printf(extcap_path, "%s/%s", dirname, file);
#endif
            if ( extcap_if_exists(ifname) && !extcap_if_exists_for_extcap(ifname, extcap_path->str ) )
                continue;

#ifdef _WIN32
            argv[0] = g_strescape(extcap_path->str, NULL);
#else
            argv[0] = g_strdup(extcap_path->str);
#endif
            for (i = 0; i < argc; ++i)
                argv[i+1] = args[i];
            argv[argc+1] = NULL;

            status = g_spawn_sync(dirname, argv, envp,
                (GSpawnFlags) 0, NULL, NULL,
                    &command_output, NULL, &exit_status, &error);

            if (status && exit_status == 0)
            keep_going = cb(extcap_path->str, command_output, cb_data, err_str);

            g_free(argv[0]);
            g_free(command_output);
        }

        g_dir_close(dir);
        g_string_free(extcap_path, TRUE);
    }

#ifdef _WIN32
    g_strfreev(dll_search_envp);
#endif
    g_free(argv);
}

static gboolean dlt_cb(const gchar *extcap _U_, gchar *output, void *data,
        char **err_str) {
    extcap_token_sentence *tokens;
    extcap_dlt *dlts, *dlt_iter, *next;
    if_capabilities_t *caps;
    GList *linktype_list = NULL;
    data_link_info_t *data_link_info;

    tokens = extcap_tokenize_sentences(output);
    extcap_parse_dlts(tokens, &dlts);

    extcap_free_tokenized_sentence_list(tokens);

    g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "Extcap pipe %s ", extcap);

    /*
     * Allocate the interface capabilities structure.
     */
    caps = (if_capabilities_t *) g_malloc(sizeof *caps);
    caps->can_set_rfmon = FALSE;

    dlt_iter = dlts;
    while (dlt_iter != NULL ) {
        g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG,
                "  DLT %d name=\"%s\" display=\"%s\" ", dlt_iter->number,
                dlt_iter->name, dlt_iter->display);

        data_link_info = g_new(data_link_info_t, 1);
        data_link_info->dlt = dlt_iter->number;
        data_link_info->name = g_strdup(dlt_iter->name);
        data_link_info->description = g_strdup(dlt_iter->display);
        linktype_list = g_list_append(linktype_list, data_link_info);
        dlt_iter = dlt_iter->next_dlt;
    }

    /* Check to see if we built a list */
    if (linktype_list != NULL && data != NULL) {
        caps->data_link_types = linktype_list;
        *(if_capabilities_t **) data = caps;
    } else {
        if (err_str) {
            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "  returned no DLTs");
            *err_str = g_strdup("Extcap returned no DLTs");
        }
        g_free(caps);
    }

    dlt_iter = dlts;
    while (dlt_iter != NULL ) {
        next = dlt_iter->next_dlt;
        extcap_free_dlt(dlt_iter);
        dlt_iter = next;
    }

    return FALSE;
}

if_capabilities_t *
extcap_get_if_dlts(const gchar *ifname, char **err_str) {
    gchar *argv[3];
    gint i;
    if_capabilities_t *caps = NULL;

    if (ifname != NULL && err_str != NULL)
        *err_str = NULL;

    if ( extcap_if_exists(ifname) )
    {
        argv[0] = g_strdup(EXTCAP_ARGUMENT_LIST_DLTS);
        argv[1] = g_strdup(EXTCAP_ARGUMENT_INTERFACE);
        argv[2] = g_strdup(ifname);

        if (err_str)
            *err_str = NULL;
        extcap_foreach(3, argv, dlt_cb, &caps, err_str, ifname);

        for (i = 0; i < 3; ++i)
            g_free(argv[i]);
    }

    return caps;
}

static gboolean interfaces_cb(const gchar *extcap, gchar *output, void *data,
        char **err_str _U_) {
    GList **il = (GList **) data;
    extcap_token_sentence *tokens;
    extcap_interface *interfaces, *int_iter; /*, *next; */
    if_info_t *if_info;

    tokens = extcap_tokenize_sentences(output);
    extcap_parse_interfaces(tokens, &interfaces);

    extcap_free_tokenized_sentence_list(tokens);

    g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "Extcap pipe %s ", extcap);

    int_iter = interfaces;
    while (int_iter != NULL ) {
        if ( int_iter->if_type == EXTCAP_SENTENCE_INTERFACE && extcap_if_exists(int_iter->call) )
        {
            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_WARNING, "Extcap interface \"%s\" is already provided by \"%s\" ",
                    int_iter->call, (gchar *)extcap_if_executable(int_iter->call) );
            int_iter = int_iter->next_interface;
            continue;
        }

        if ( int_iter->if_type == EXTCAP_SENTENCE_INTERFACE )
            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "  Interface [%s] \"%s\" ",
                    int_iter->call, int_iter->display);
        else if ( int_iter->if_type == EXTCAP_SENTENCE_EXTCAP )
            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "  Extcap [%s] ", int_iter->call);

        if ( int_iter->if_type == EXTCAP_SENTENCE_INTERFACE ) {
            if_info = g_new0(if_info_t, 1);
            if_info->name = g_strdup(int_iter->call);
            if_info->friendly_name = g_strdup(int_iter->display);

            if_info->type = IF_EXTCAP;

            if_info->extcap = g_strdup(extcap);
            *il = g_list_append(*il, if_info);

            extcap_if_add(int_iter->call, extcap);
        }

        /* Call for interfaces and tools alike. Multiple calls (because a tool has multiple
         * interfaces) are handled internally */
        extcap_tool_add(extcap, int_iter);

        int_iter = int_iter->next_interface;
    }
    extcap_free_interface(interfaces);

    return TRUE;
}

static gint
if_info_compare(gconstpointer a, gconstpointer b)
{
    gint comp = 0;
    if_info_t * if_a = (if_info_t *)a;
    if_info_t * if_b = (if_info_t *)b;

    if ( (comp = g_strcmp0(if_a->name, if_b->name)) == 0 )
        return g_strcmp0(if_a->friendly_name, if_b->friendly_name);

    return comp;
}

GHashTable *
extcap_tools_list(void) {
    if ( tools == NULL || g_hash_table_size(tools) == 0 )
        extcap_interface_list(NULL);

    return tools;
}

static void
extcap_free_info (gpointer data) {
    extcap_info * info = (extcap_info *)data;

    g_free (info->basename);
    g_free (info->full_path);
    g_free (info->version);
    g_free (info);
}

GList *
extcap_interface_list(char **err_str) {
    gchar *argv;
    /* gint i; */
    GList *ret = NULL;

    if (err_str != NULL)
    *err_str = NULL;

    /* ifaces is used as cache, do not destroy its contents when
     * returning or no extcap interfaces can be queried for options */
    if (ifaces == NULL)
        ifaces = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, g_free);
    else
        g_hash_table_remove_all(ifaces);

    if (tools == NULL)
        tools = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, extcap_free_info);
    else
        g_hash_table_remove_all(tools);

    argv = g_strdup(EXTCAP_ARGUMENT_LIST_INTERFACES);

    if (err_str)
    *err_str = NULL;
    extcap_foreach(1, &argv, interfaces_cb, &ret, err_str, NULL);

    g_free(argv);

    return g_list_sort ( ret, if_info_compare );
}

static void extcap_free_arg_elem(gpointer data, gpointer user_data _U_) {
    extcap_free_arg((extcap_arg *) data);
    g_free(data);
}

static void extcap_free_if_configuration(GList *list)
{
    GList *elem, *sl;

    for (elem = g_list_first(list); elem; elem = elem->next)
    {
        if (elem->data != NULL) {
            /* g_list_free_full() only exists since 2.28. */
            sl = g_list_first((GList *)elem->data);
            g_list_foreach(sl, (GFunc)extcap_free_arg_elem, NULL);
            g_list_free(sl);
        }
    }
    g_list_free(list);
}

static gboolean search_cb(const gchar *extcap _U_, gchar *output, void *data,
        char **err_str _U_) {
    extcap_token_sentence *tokens = NULL;
    GList *arguments = NULL;
    GList **il = (GList **) data;

    tokens = extcap_tokenize_sentences(output);
    arguments = extcap_parse_args(tokens);

    extcap_free_tokenized_sentence_list(tokens);

#if ARG_DEBUG
    extcap_debug_arguments ( arguments );
#endif

    *il = g_list_append(*il, arguments);

    /* By returning false, extcap_foreach will break on first found */
    return TRUE;
}

GList *
extcap_get_if_configuration(const char * ifname) {
    gchar *argv[3];
    GList *ret = NULL;
    gchar **err_str = NULL;
    int i;

    if ( extcap_if_exists(ifname) )
    {
        g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "Extcap path %s",
                get_extcap_dir());

        argv[0] = g_strdup(EXTCAP_ARGUMENT_CONFIG);
        argv[1] = g_strdup(EXTCAP_ARGUMENT_INTERFACE);
        argv[2] = g_strdup(ifname);

        extcap_foreach(3, argv, search_cb, &ret, err_str, ifname);

        for (i = 0; i < 3; i++)
            g_free(argv[i]);
    }

    return ret;
}

gboolean
extcap_has_configuration(const char * ifname, gboolean is_required) {
    GList * arguments = 0;
    GList * walker = 0, * item = 0;

    gboolean found = FALSE;

    arguments = extcap_get_if_configuration((const char *)( ifname ) );
    walker = g_list_first(arguments);

    while ( walker != NULL && ! found )
    {
        item = g_list_first((GList *)(walker->data));
        while ( item != NULL && ! found )
        {
            if ( (extcap_arg *)(item->data) != NULL )
            {
                /* Should required options be present, or any kind of options */
                if ( ! is_required || ((extcap_arg *)(item->data))->is_required )
                    found = TRUE;
            }

            item = item->next;
        }
        walker = walker->next;
    }
    extcap_free_if_configuration(arguments);

    return found;
}

void extcap_cleanup(capture_options * capture_opts) {
    interface_options interface_opts;
    guint icnt = 0;

    for (icnt = 0; icnt < capture_opts->ifaces->len; icnt++) {
        interface_opts = g_array_index(capture_opts->ifaces, interface_options,
                icnt);

        /* skip native interfaces */
        if (interface_opts.if_type != IF_EXTCAP)
        continue;

        g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG,
                "Extcap [%s] - Cleaning up fifo: %s; PID: %d", interface_opts.name,
                interface_opts.extcap_fifo, interface_opts.extcap_pid);
#ifdef _WIN32
        if (pipe_h)
        {
            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG,
                "Extcap [%s] - Closing pipe", interface_opts.name);
            FlushFileBuffers(pipe_h);
            DisconnectNamedPipe(pipe_h);
            CloseHandle(pipe_h);
        }
#else
        if (interface_opts.extcap_fifo != NULL && file_exists(interface_opts.extcap_fifo))
        {
            /* the fifo will not be freed here, but with the other capture_opts in capture_sync */
            ws_unlink(interface_opts.extcap_fifo);
            interface_opts.extcap_fifo = NULL;
        }
#endif
        /* Maybe the client closed and removed fifo, but ws should check if
         * pid should be closed */
        g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG,
                "Extcap [%s] - Closing spawned PID: %d", interface_opts.name,
                interface_opts.extcap_pid);

        if (interface_opts.extcap_child_watch > 0)
        {
            g_source_remove(interface_opts.extcap_child_watch);
            interface_opts.extcap_child_watch = 0;
        }

        if (interface_opts.extcap_pid != INVALID_EXTCAP_PID)
        {
#ifdef _WIN32
            TerminateProcess(interface_opts.extcap_pid, 0);
#endif
            g_spawn_close_pid(interface_opts.extcap_pid);
            interface_opts.extcap_pid = INVALID_EXTCAP_PID;
        }

        /* Make sure modified interface_opts is saved in capture_opts. */
        capture_opts->ifaces = g_array_remove_index(capture_opts->ifaces, icnt);
        g_array_insert_val(capture_opts->ifaces, icnt, interface_opts);
    }
}

static void
extcap_arg_cb(gpointer key, gpointer value, gpointer data) {
    GPtrArray *args = (GPtrArray *)data;

    if ( key != NULL )
    {
        g_ptr_array_add(args, g_strdup((const gchar*)key));

        if ( value != NULL )
            g_ptr_array_add(args, g_strdup((const gchar*)value));
    }
}

static void extcap_child_watch_cb(GPid pid, gint status _U_, gpointer user_data)
{
    guint i;
    interface_options interface_opts;
    capture_options *capture_opts = (capture_options *)user_data;

    /* Close handle to child process. */
    g_spawn_close_pid(pid);

    /* Update extcap_pid in interface options structure. */
    for (i = 0; i < capture_opts->ifaces->len; i++)
    {
        interface_opts = g_array_index(capture_opts->ifaces, interface_options, i);
        if (interface_opts.extcap_pid == pid)
        {
            interface_opts.extcap_pid = INVALID_EXTCAP_PID;
            interface_opts.extcap_child_watch = 0;
            capture_opts->ifaces = g_array_remove_index(capture_opts->ifaces, i);
            g_array_insert_val(capture_opts->ifaces, i, interface_opts);
            break;
        }
    }
}

/* call mkfifo for each extcap,
 * returns FALSE if there's an error creating a FIFO */
gboolean
extcap_init_interfaces(capture_options *capture_opts)
{
    guint i;
    interface_options interface_opts;

    for (i = 0; i < capture_opts->ifaces->len; i++)
    {
        GPtrArray *args = NULL;
        GPid pid = INVALID_EXTCAP_PID;
        gchar **tmp;
        int tmp_i;

        interface_opts = g_array_index(capture_opts->ifaces, interface_options, i);

        /* skip native interfaces */
        if (interface_opts.if_type != IF_EXTCAP )
            continue;

        /* create pipe for fifo */
        if ( ! extcap_create_pipe ( &interface_opts.extcap_fifo ) )
            return FALSE;

        /* Create extcap call */
        args = g_ptr_array_new();
#define add_arg(X) g_ptr_array_add(args, g_strdup(X))

        add_arg(interface_opts.extcap);
        add_arg(EXTCAP_ARGUMENT_RUN_CAPTURE);
        add_arg(EXTCAP_ARGUMENT_INTERFACE);
        add_arg(interface_opts.name);
        if (interface_opts.cfilter && strlen(interface_opts.cfilter) > 0) {
            add_arg(EXTCAP_ARGUMENT_CAPTURE_FILTER);
            add_arg(interface_opts.cfilter);
        }
        add_arg(EXTCAP_ARGUMENT_RUN_PIPE);
        add_arg(interface_opts.extcap_fifo);
        if (interface_opts.extcap_args == NULL)
        {
            /* User did not perform interface configuration.
             *
             * Check if there are any boolean flags that are set by default
             * and hence their argument should be added.
             */
            GList *arglist;
            GList *elem;

            arglist = extcap_get_if_configuration(interface_opts.name);
            for (elem = g_list_first(arglist); elem; elem = elem->next)
            {
                GList * arg_list;
                extcap_arg *arg_iter;

                if (elem->data == NULL)
                {
                    continue;
                }

                arg_list = g_list_first((GList *)elem->data);
                while (arg_list != NULL)
                {
                    /* In case of boolflags only first element in arg_list is relevant. */
                    arg_iter = (extcap_arg*) (arg_list->data);

                    if  (arg_iter->arg_type == EXTCAP_ARG_BOOLFLAG)
                    {
                        if (arg_iter->default_complex != NULL
                            && extcap_complex_get_bool(arg_iter->default_complex))
                        {
                            add_arg(arg_iter->call);
                        }
                    }

                    arg_list = arg_list->next;
                }
            }

            extcap_free_if_configuration(arglist);
        }
        else
        {
            g_hash_table_foreach(interface_opts.extcap_args, extcap_arg_cb, args);
        }
        add_arg(NULL);
#undef add_arg

        /* Dump commandline parameters sent to extcap. */
        for (tmp = (gchar **)args->pdata, tmp_i = 0; *tmp && **tmp; ++tmp_i, ++tmp)
        {
            g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "argv[%d]: %s", tmp_i, *tmp);
        }

        /* Wireshark for windows crashes here sometimes *
         * Access violation reading location 0x...      */
        g_spawn_async(NULL, (gchar **)args->pdata, NULL,
                    (GSpawnFlags) G_SPAWN_DO_NOT_REAP_CHILD, NULL, NULL,
                    &pid,NULL);

        g_ptr_array_foreach(args, (GFunc)g_free, NULL);
        g_ptr_array_free(args, TRUE);
        interface_opts.extcap_pid = pid;
        interface_opts.extcap_child_watch =
            g_child_watch_add(pid, extcap_child_watch_cb, (gpointer)capture_opts);
        capture_opts->ifaces = g_array_remove_index(capture_opts->ifaces, i);
        g_array_insert_val(capture_opts->ifaces, i, interface_opts);

#ifdef _WIN32
        /* On Windows, wait for extcap to connect to named pipe.
         * Some extcaps will present UAC screen to user.
         * 30 second timeout should be reasonable timeout for extcap to
         * connect to named pipe (including user interaction).
         * Wait on multiple object in case of extcap termination
         * without opening pipe.
         *
         * Minimum supported version of Windows: XP / Server 2003.
         */
        if (pid != INVALID_EXTCAP_PID)
        {
            DWORD dw;
            HANDLE handles[2];
            OVERLAPPED ov;
            ov.Pointer = 0;
            ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

            ConnectNamedPipe(pipe_h, &ov);
            handles[0] = ov.hEvent;
            handles[1] = pid;

            if (GetLastError() == ERROR_PIPE_CONNECTED)
            {
                g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "extcap connected to pipe");
            }
            else
            {
                dw = WaitForMultipleObjects(2, handles, FALSE, 30000);
                if (dw == WAIT_OBJECT_0)
                {
                    /* ConnectNamedPipe finished. */
                    DWORD code;

                    code = GetLastError();
                    if (code == ERROR_IO_PENDING)
                    {
                        DWORD dummy;
                        if (!GetOverlappedResult(ov.hEvent, &ov, &dummy, TRUE))
                        {
                            code = GetLastError();
                        }
                        else
                        {
                            code = ERROR_SUCCESS;
                        }
                    }

                    g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "ConnectNamedPipe code: %d", code);
                }
                else if (dw == (WAIT_OBJECT_0 + 1))
                {
                    /* extcap process terminated. */
                    g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "extcap terminated without connecting to pipe!");
                }
                else if (dw == WAIT_TIMEOUT)
                {
                    g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "extcap didn't connect to pipe within 30 seconds!");
                }
                else
                {
                    g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG, "WaitForMultipleObjects returned 0x%08X. Error %d", dw, GetLastError());
                }
            }

            CloseHandle(ov.hEvent);
        }
#endif
    }

    return TRUE;
}

#ifdef _WIN32
/* called by capture_sync to get the CreatNamedPipe handle*/
HANDLE
extcap_get_win32_handle()
{
    return pipe_h;
}
#endif

gboolean extcap_create_pipe(char ** fifo)
{
#ifdef _WIN32
    gchar timestr[ 14+1 ];
    time_t current_time;

    gchar *pipename = NULL;

    SECURITY_ATTRIBUTES security;
    /* create pipename */
    current_time = time(NULL);
    strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&current_time));
    pipename = g_strconcat ( "\\\\.\\pipe\\", EXTCAP_PIPE_PREFIX, "_", timestr, NULL );

    /* Security struct to enable Inheritable HANDLE */
    memset(&security, 0, sizeof(SECURITY_ATTRIBUTES));
    security.nLength = sizeof(SECURITY_ATTRIBUTES);
    security.bInheritHandle = TRUE;
    security.lpSecurityDescriptor = NULL;

    /* create a namedPipe*/
    pipe_h = CreateNamedPipe(
                utf_8to16(pipename),
                PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED,
                PIPE_TYPE_MESSAGE| PIPE_READMODE_MESSAGE | PIPE_WAIT,
                5, 65536, 65536,
                300,
                &security);

    if (pipe_h == INVALID_HANDLE_VALUE)
    {
        g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG,"\nError creating pipe => (%d)", GetLastError());
        return FALSE;
    }
    else
    {
        g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG,"\nWireshark Created pipe =>(%s)",pipename);
        *fifo = g_strdup(pipename);
    }
#else
    gchar *temp_name = NULL;
    int fd = 0;

    if ((fd = create_tempfile(&temp_name, EXTCAP_PIPE_PREFIX)) < 0 )
        return FALSE;

    ws_close(fd);

    g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG,
            "Extcap - Creating fifo: %s", temp_name);

    if ( file_exists(temp_name) )
        ws_unlink(temp_name);

    if (mkfifo(temp_name, 0600) == 0)
        *fifo = g_strdup(temp_name);
#endif

    return TRUE;
}

#if ARG_DEBUG
void extcap_debug_arguments ( extcap_arg *arg_iter )
{
    extcap_value *v = NULL;
    GList *walker = NULL;

    printf("debug - parser dump\n");
    while (arg_iter != NULL) {
        printf("ARG %d call=%s display=\"%s\" type=", arg_iter->arg_num, arg_iter->call, arg_iter->display);

        switch (arg_iter->arg_type) {
            case EXTCAP_ARG_INTEGER:
            printf("int\n");
            break;
            case EXTCAP_ARG_UNSIGNED:
            printf("unsigned\n");
            break;
            case EXTCAP_ARG_LONG:
            printf("long\n");
            break;
            case EXTCAP_ARG_DOUBLE:
            printf("double\n");
            break;
            case EXTCAP_ARG_BOOLEAN:
            printf("boolean\n");
            break;
            case EXTCAP_ARG_MENU:
            printf("menu\n");
            break;
            case EXTCAP_ARG_RADIO:
            printf("radio\n");
            break;
            case EXTCAP_ARG_SELECTOR:
            printf("selctor\n");
            break;
            case EXTCAP_ARG_STRING:
            printf ( "string\n" );
            break;
            case EXTCAP_ARG_PASSWORD:
            printf ( "PASSWORD\n" );
            break;
            case EXTCAP_ARG_MULTICHECK:
            printf ( "unknown\n" );
            break;
            case EXTCAP_ARG_UNKNOWN:
            printf ( "unknown\n" );
            break;
        }

        if (arg_iter->range_start != NULL && arg_iter->range_end != NULL) {
            printf("\tRange: ");
            extcap_printf_complex(arg_iter->range_start);
            printf(" - ");
            extcap_printf_complex(arg_iter->range_end);
            printf("\n");
        }

        for ( walker = g_list_first ( arg_iter->value_list ); walker; walker = walker->next )
        {
            v = (extcap_value *)walker->data;
            if (v->is_default)
            printf("*");
            printf("\tcall=\"%p\" display=\"%p\"\n", v->call, v->display);
            printf("\tcall=\"%s\" display=\"%s\"\n", v->call, v->display);
        }

        arg_iter = arg_iter->next_arg;
    }
}
#endif
#endif

/*
 * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */