aboutsummaryrefslogtreecommitdiffstats
path: root/wiretap/merge.c
blob: 06dc5db6178bab4c8f3e763f934fb0a5a3b71b6a (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
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
/* Combine multiple dump files, either by appending or by merging by timestamp
 *
 * Written by Scott Renfro <scott@renfro.org> based on
 * editcap by Richard Sharpe and Guy Harris
 *
 * Copyright 2013, Scott Renfro <scott[AT]renfro.org>
 *
 * 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 <stdlib.h>
#include <errno.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <string.h>
#include "merge.h"

#include <wsutil/filesystem.h>
#include "wsutil/os_version_info.h"


#if 0
#define merge_debug(...) g_warning(__VA_ARGS__)
#else
#define merge_debug(...)
#endif


static const char* idb_merge_mode_strings[] = {
    /* IDB_MERGE_MODE_NONE */
    "none",
    /* IDB_MERGE_MODE_ALL_SAME */
    "all",
    /* IDB_MERGE_MODE_ANY_SAME */
    "any",
    /* IDB_MERGE_MODE_MAX */
    "UNKNOWN"
};

idb_merge_mode
merge_string_to_idb_merge_mode(const char *name)
{
    int i;
    for (i = 0; i < IDB_MERGE_MODE_MAX; i++) {
        if (g_strcmp0(name, idb_merge_mode_strings[i]) == 0) {
            return (idb_merge_mode) i;
        }
    }
    return IDB_MERGE_MODE_MAX;
}

const char *
merge_idb_merge_mode_to_string(const int mode)
{
    if (mode >= 0 && mode < IDB_MERGE_MODE_MAX) {
        return idb_merge_mode_strings[mode];
    }
    return idb_merge_mode_strings[(int)IDB_MERGE_MODE_MAX];
}


static void
cleanup_in_file(merge_in_file_t *in_file)
{
    g_assert(in_file != NULL);

    wtap_close(in_file->wth);
    in_file->wth = NULL;

    g_array_free(in_file->idb_index_map, TRUE);
    in_file->idb_index_map = NULL;
}

static void
add_idb_index_map(merge_in_file_t *in_file, const guint orig_index, const guint found_index)
{
    g_assert(in_file != NULL);
    g_assert(in_file->idb_index_map != NULL);

    /*
     * we didn't really need the orig_index, since just appending to the array
     * should result in the orig_index being its location in the array; but we
     * pass it into this function to do a sanity check here
     */
    g_assert(orig_index == in_file->idb_index_map->len);

    g_array_append_val(in_file->idb_index_map, found_index);
}

/** Open a number of input files to merge.
 *
 * @param in_file_count number of entries in in_file_names and in_files
 * @param in_file_names filenames of the input files
 * @param in_files input file array to be filled (>= sizeof(merge_in_file_t) * in_file_count)
 * @param err wiretap error, if failed
 * @param err_info wiretap error string, if failed
 * @param err_fileno file on which open failed, if failed
 * @return TRUE if all files could be opened, FALSE otherwise
 */
static gboolean
merge_open_in_files(int in_file_count, const char *const *in_file_names,
                    merge_in_file_t **in_files, int *err, gchar **err_info,
                    int *err_fileno)
{
    gint i;
    gint j;
    size_t files_size = in_file_count * sizeof(merge_in_file_t);
    merge_in_file_t *files;
    gint64 size;

    files = (merge_in_file_t *)g_malloc0(files_size);
    *in_files = files;

    for (i = 0; i < in_file_count; i++) {
        files[i].filename    = in_file_names[i];
        files[i].wth         = wtap_open_offline(in_file_names[i], WTAP_TYPE_AUTO, err, err_info, FALSE);
        files[i].data_offset = 0;
        files[i].state       = PACKET_NOT_PRESENT;
        files[i].packet_num  = 0;

        if (!files[i].wth) {
            /* Close the files we've already opened. */
            for (j = 0; j < i; j++)
                cleanup_in_file(&files[j]);
            *err_fileno = i;
            return FALSE;
        }
        size = wtap_file_size(files[i].wth, err);
        if (size == -1) {
            for (j = 0; j != G_MAXINT && j <= i; j++)
                cleanup_in_file(&files[j]);
            *err_fileno = i;
            return FALSE;
        }
        files[i].size = size;
        files[i].idb_index_map = g_array_new(FALSE, FALSE, sizeof(guint));
    }
    return TRUE;
}

/** Close the input files again.
 *
 * @param in_file_count number of entries in in_files
 * @param in_files input file array to be closed
 */
static void
merge_close_in_files(int in_file_count, merge_in_file_t in_files[])
{
    int i;
    for (i = 0; i < in_file_count; i++) {
        cleanup_in_file(&in_files[i]);
    }
}

/** Select an output frame type based on the input files
 *
 * If all files have the same frame type, then use that.
 * Otherwise select WTAP_ENCAP_PER_PACKET.  If the selected
 * output file type doesn't support per packet frame types,
 * then the wtap_dump_open call will fail with a reasonable
 * error condition.
 *
 * @param in_file_count number of entries in in_files
 * @param in_files input file array
 * @return the frame type
 */
static int
merge_select_frame_type(int in_file_count, merge_in_file_t in_files[])
{
    int i;
    int selected_frame_type;

    selected_frame_type = wtap_file_encap(in_files[0].wth);

    for (i = 1; i < in_file_count; i++) {
        int this_frame_type = wtap_file_encap(in_files[i].wth);
        if (selected_frame_type != this_frame_type) {
            selected_frame_type = WTAP_ENCAP_PER_PACKET;
            break;
        }
    }

    return selected_frame_type;
}

/*
 * returns TRUE if first argument is earlier than second
 */
static gboolean
is_earlier(nstime_t *l, nstime_t *r) /* XXX, move to nstime.c */
{
    if (l->secs > r->secs) {  /* left is later */
        return FALSE;
    } else if (l->secs < r->secs) { /* left is earlier */
        return TRUE;
    } else if (l->nsecs > r->nsecs) { /* tv_sec equal, l.usec later */
        return FALSE;
    }
    /* either one < two or one == two
     * either way, return one
     */
    return TRUE;
}

/** Read the next packet, in chronological order, from the set of files to
 * be merged.
 *
 * On success, set *err to 0 and return a pointer to the merge_in_file_t
 * for the file from which the packet was read.
 *
 * On a read error, set *err to the error and return a pointer to the
 * merge_in_file_t for the file on which we got an error.
 *
 * On an EOF (meaning all the files are at EOF), set *err to 0 and return
 * NULL.
 *
 * @param in_file_count number of entries in in_files
 * @param in_files input file array
 * @param err wiretap error, if failed
 * @param err_info wiretap error string, if failed
 * @return pointer to merge_in_file_t for file from which that packet
 * came, or NULL on error or EOF
 */
static merge_in_file_t *
merge_read_packet(int in_file_count, merge_in_file_t in_files[],
                  int *err, gchar **err_info)
{
    int i;
    int ei = -1;
    nstime_t tv = { sizeof(time_t) > sizeof(int) ? LONG_MAX : INT_MAX, INT_MAX };
    struct wtap_pkthdr *phdr;

    /*
     * Make sure we have a packet available from each file, if there are any
     * packets left in the file in question, and search for the packet
     * with the earliest time stamp.
     */
    for (i = 0; i < in_file_count; i++) {
        if (in_files[i].state == PACKET_NOT_PRESENT) {
            /*
             * No packet available, and we haven't seen an error or EOF yet,
             * so try to read the next packet.
             */
            if (!wtap_read(in_files[i].wth, err, err_info, &in_files[i].data_offset)) {
                if (*err != 0) {
                    in_files[i].state = GOT_ERROR;
                    return &in_files[i];
                }
                in_files[i].state = AT_EOF;
            } else
                in_files[i].state = PACKET_PRESENT;
        }

        if (in_files[i].state == PACKET_PRESENT) {
            phdr = wtap_phdr(in_files[i].wth);
            if (is_earlier(&phdr->ts, &tv)) {
                tv = phdr->ts;
                ei = i;
            }
        }
    }

    if (ei == -1) {
        /* All the streams are at EOF.  Return an EOF indication. */
        *err = 0;
        return NULL;
    }

    /* We'll need to read another packet from this file. */
    in_files[ei].state = PACKET_NOT_PRESENT;

    /* Count this packet. */
    in_files[ei].packet_num++;

    /*
     * Return a pointer to the merge_in_file_t of the file from which the
     * packet was read.
     */
    *err = 0;
    return &in_files[ei];
}

/** Read the next packet, in file sequence order, from the set of files
 * to be merged.
 *
 * On success, set *err to 0 and return a pointer to the merge_in_file_t
 * for the file from which the packet was read.
 *
 * On a read error, set *err to the error and return a pointer to the
 * merge_in_file_t for the file on which we got an error.
 *
 * On an EOF (meaning all the files are at EOF), set *err to 0 and return
 * NULL.
 *
 * @param in_file_count number of entries in in_files
 * @param in_files input file array
 * @param err wiretap error, if failed
 * @param err_info wiretap error string, if failed
 * @return pointer to merge_in_file_t for file from which that packet
 * came, or NULL on error or EOF
 */
static merge_in_file_t *
merge_append_read_packet(int in_file_count, merge_in_file_t in_files[],
                         int *err, gchar **err_info)
{
    int i;

    /*
     * Find the first file not at EOF, and read the next packet from it.
     */
    for (i = 0; i < in_file_count; i++) {
        if (in_files[i].state == AT_EOF)
            continue; /* This file is already at EOF */
        if (wtap_read(in_files[i].wth, err, err_info, &in_files[i].data_offset))
            break; /* We have a packet */
        if (*err != 0) {
            /* Read error - quit immediately. */
            in_files[i].state = GOT_ERROR;
            return &in_files[i];
        }
        /* EOF - flag this file as being at EOF, and try the next one. */
        in_files[i].state = AT_EOF;
    }
    if (i == in_file_count) {
        /* All the streams are at EOF.  Return an EOF indication. */
        *err = 0;
        return NULL;
    }

    /*
     * Return a pointer to the merge_in_file_t of the file from which the
     * packet was read.
     */
    *err = 0;
    return &in_files[i];
}


/* creates a section header block for the new output file */
static wtapng_section_t*
create_shb_header(const merge_in_file_t *in_files, const guint in_file_count,
                  const gchar *app_name)
{
    wtapng_section_t *shb_hdr = NULL;
    GString *comment_gstr;
    GString *os_info_str;
    guint i;

    shb_hdr = wtap_file_get_shb_for_new_file(in_files[0].wth);

    comment_gstr = g_string_new("");

    /* TODO: merge comments from all files */

    /* very lame way to save comments - does not save them from the other files */
    if (shb_hdr->opt_comment && strlen(shb_hdr->opt_comment) > 0) {
        g_string_append_printf(comment_gstr, "%s \n",shb_hdr->opt_comment);
    }
    g_free(shb_hdr->opt_comment);
    shb_hdr->opt_comment = NULL;

    g_string_append_printf(comment_gstr, "File created by merging: \n");

    for (i = 0; i < in_file_count; i++) {
        g_string_append_printf(comment_gstr, "File%d: %s \n",i+1,in_files[i].filename);
    }

    os_info_str = g_string_new("");
    get_os_version_info(os_info_str);

    shb_hdr->section_length = -1;
    /* TODO: handle comments from each file being merged */
    shb_hdr->opt_comment   = g_string_free(comment_gstr, FALSE);  /* section comment */
    shb_hdr->shb_hardware  = NULL;        /* NULL if not available, UTF-8 string containing the        */
                                          /*  description of the hardware used to create this section. */
    shb_hdr->shb_os        = g_string_free(os_info_str, FALSE); /* UTF-8 string containing the name   */
                                          /*  of the operating system used to create this section.     */
    shb_hdr->shb_user_appl = g_strdup(app_name); /* NULL if not available, UTF-8 string containing the name */
                                          /*  of the application used to create this section.          */

    return shb_hdr;
}

static gboolean
is_duplicate_idb(const wtapng_if_descr_t *idb1, const wtapng_if_descr_t *idb2)
{
    g_assert(idb1 && idb2);

    merge_debug("merge::is_duplicate_idb() called");
    merge_debug("idb1->wtap_encap == idb2->wtap_encap: %s",
                 (idb1->wtap_encap == idb2->wtap_encap) ? "TRUE":"FALSE");
    merge_debug("idb1->time_units_per_second == idb2->time_units_per_second: %s",
                 (idb1->time_units_per_second == idb2->time_units_per_second) ? "TRUE":"FALSE");
    merge_debug("idb1->tsprecision == idb2->tsprecision: %s",
                 (idb1->tsprecision == idb2->tsprecision) ? "TRUE":"FALSE");
    merge_debug("idb1->link_type == idb2->link_type: %s",
                 (idb1->link_type == idb2->link_type) ? "TRUE":"FALSE");
    merge_debug("idb1->snap_len == idb2->snap_len: %s",
                 (idb1->snap_len == idb2->snap_len) ? "TRUE":"FALSE");
    merge_debug("idb1->if_speed == idb2->if_speed: %s",
                 (idb1->if_speed == idb2->if_speed) ? "TRUE":"FALSE");
    merge_debug("idb1->if_tsresol == idb2->if_tsresol: %s",
                 (idb1->if_tsresol == idb2->if_tsresol) ? "TRUE":"FALSE");
    merge_debug("idb1->if_fcslen == idb2->if_fcslen: %s",
                 (idb1->if_fcslen == idb2->if_fcslen) ? "TRUE":"FALSE");
    merge_debug("g_strcmp0(idb1->opt_comment, idb2->opt_comment) == 0: %s",
                 (g_strcmp0(idb1->opt_comment, idb2->opt_comment) == 0) ? "TRUE":"FALSE");
    merge_debug("g_strcmp0(idb1->if_name, idb2->if_name) == 0: %s",
                 (g_strcmp0(idb1->if_name, idb2->if_name) == 0) ? "TRUE":"FALSE");
    merge_debug("g_strcmp0(idb1->if_description, idb2->if_description) == 0: %s",
                 (g_strcmp0(idb1->if_description, idb2->if_description) == 0) ? "TRUE":"FALSE");
    merge_debug("g_strcmp0(idb1->if_os, idb2->if_os) == 0: %s",
                 (g_strcmp0(idb1->if_os, idb2->if_os) == 0) ? "TRUE":"FALSE");
    merge_debug("merge::is_duplicate_idb() returning");

    /* does not compare filters nor interface statistics */
    return (idb1->wtap_encap == idb2->wtap_encap &&
            idb1->time_units_per_second == idb2->time_units_per_second &&
            idb1->tsprecision == idb2->tsprecision &&
            idb1->link_type == idb2->link_type &&
            /* XXX: should snaplen not be compared? */
            idb1->snap_len == idb2->snap_len &&
            idb1->if_speed == idb2->if_speed &&
            idb1->if_tsresol == idb2->if_tsresol &&
            idb1->if_fcslen == idb2->if_fcslen &&
            g_strcmp0(idb1->opt_comment, idb2->opt_comment) == 0 &&
            g_strcmp0(idb1->if_name, idb2->if_name) == 0 &&
            g_strcmp0(idb1->if_description, idb2->if_description) == 0 &&
            g_strcmp0(idb1->if_os, idb2->if_os) == 0);
}

/*
 * Returns true if all of the input files have duplicate IDBs to the other files.
 */
static gboolean
all_idbs_are_duplicates(const merge_in_file_t *in_files, const guint in_file_count)
{
    wtapng_iface_descriptions_t *first_idb_list = NULL;
    wtapng_iface_descriptions_t *other_idb_list = NULL;
    guint first_idb_list_size, other_idb_list_size;
    const wtapng_if_descr_t *first_file_idb, *other_file_idb;
    guint i, j;

    g_assert(in_files != NULL);

    /* get the first file's info */
    first_idb_list = wtap_file_get_idb_info(in_files[0].wth);
    g_assert(first_idb_list->interface_data);

    first_idb_list_size = first_idb_list->interface_data->len;

    /* now compare the other input files with that */
    for (i = 1; i < in_file_count; i++) {
        other_idb_list = wtap_file_get_idb_info(in_files[i].wth);
        g_assert(other_idb_list->interface_data);
        other_idb_list_size = other_idb_list->interface_data->len;

        if (other_idb_list_size != first_idb_list_size) {
            merge_debug("merge::all_idbs_are_duplicates: sizes of IDB lists don't match: first=%u, other=%u",
                         first_idb_list_size, other_idb_list_size);
            g_free(other_idb_list);
            g_free(first_idb_list);
            return FALSE;
        }

        for (j = 0; j < other_idb_list_size; j++) {
            first_file_idb = &g_array_index(first_idb_list->interface_data, wtapng_if_descr_t, j);
            other_file_idb = &g_array_index(other_idb_list->interface_data, wtapng_if_descr_t, j);

            if (!is_duplicate_idb(first_file_idb, other_file_idb)) {
                merge_debug("merge::all_idbs_are_duplicates: IDBs at index %d do not match, returning FALSE", j);
                g_free(other_idb_list);
                g_free(first_idb_list);
                return FALSE;
            }
        }
        g_free(other_idb_list);
    }

    merge_debug("merge::all_idbs_are_duplicates: returning TRUE");

    g_free(first_idb_list);

    return TRUE;
}

/*
 * Returns true if the given input_file_idb is a duplicate of an existing one
 * in the merged_idb_list; it's a duplicate if the interface description data
 * is all identical to a previous one in another input file. For this
 * function, the input file IDB's index does NOT need to match the index
 * location of a previous one to be considered a duplicate; any match is
 * considered a success. That means it will even match another IDB from its
 * own (same) input file.
 */
static gboolean
find_duplicate_idb(const wtapng_if_descr_t *input_file_idb,
               const wtapng_iface_descriptions_t *merged_idb_list,
               guint *found_index)
{
    const wtapng_if_descr_t *merged_idb;
    guint i;

    g_assert(input_file_idb != NULL);
    g_assert(merged_idb_list != NULL);
    g_assert(merged_idb_list->interface_data != NULL);
    g_assert(found_index != NULL);

    for (i = 0; i < merged_idb_list->interface_data->len; i++) {
        merged_idb = &g_array_index(merged_idb_list->interface_data, wtapng_if_descr_t, i);

        if (is_duplicate_idb(input_file_idb, merged_idb)) {
            *found_index = i;
            return TRUE;
        }
    }

    return FALSE;
}

/* adds IDB to merged file info, returns its index */
static guint
add_idb_to_merged_file(wtapng_iface_descriptions_t *merged_idb_list,
                       const wtapng_if_descr_t *input_file_idb)
{
    wtapng_if_descr_t idb;

    g_assert(merged_idb_list != NULL);
    g_assert(merged_idb_list->interface_data != NULL);
    g_assert(input_file_idb != NULL);

    idb.wtap_encap            = input_file_idb->wtap_encap;
    idb.time_units_per_second = input_file_idb->time_units_per_second;
    idb.tsprecision           = input_file_idb->tsprecision;
    idb.link_type             = input_file_idb->link_type;
    idb.snap_len              = input_file_idb->snap_len;
    idb.if_name               = g_strdup(input_file_idb->if_name);
    idb.opt_comment           = g_strdup(input_file_idb->opt_comment);;
    idb.if_description        = g_strdup(input_file_idb->if_description);
    idb.if_speed              = input_file_idb->if_speed;
    idb.if_tsresol            = input_file_idb->if_tsresol;
    idb.if_filter_str         = NULL;
    idb.bpf_filter_len        = 0;
    idb.if_filter_bpf_bytes   = NULL;
    idb.if_os                 = g_strdup(input_file_idb->if_os);
    idb.if_fcslen             = input_file_idb->if_fcslen;
    idb.num_stat_entries      = 0;          /* Number of ISB:s */
    idb.interface_statistics  = NULL;

    g_array_append_val(merged_idb_list->interface_data, idb);

    return merged_idb_list->interface_data->len - 1;
}

/*
 * Create clone IDBs for the merge file, based on the input files and mode.
 */
static wtapng_iface_descriptions_t *
generate_merged_idb(merge_in_file_t *in_files, const guint in_file_count, const idb_merge_mode mode)
{
    wtapng_iface_descriptions_t *merged_idb_list = NULL;
    wtapng_iface_descriptions_t *input_file_idb_list = NULL;
    const wtapng_if_descr_t     *input_file_idb = NULL;
    guint                        itf_count, merged_index;
    guint                        i;

    /* create new IDB info */
    merged_idb_list = g_new(wtapng_iface_descriptions_t,1);
    merged_idb_list->interface_data = g_array_new(FALSE, FALSE, sizeof(wtapng_if_descr_t));

    if (mode == IDB_MERGE_MODE_ALL_SAME && all_idbs_are_duplicates(in_files, in_file_count)) {
        guint num_idbs;

        merge_debug("merge::generate_merged_idb: mode ALL set and all IDBs are duplicates");

        /* they're all the same, so just get the first file's IDBs */
        input_file_idb_list = wtap_file_get_idb_info(in_files[0].wth);
        /* this is really one more than number of IDBs, but that's good for the for-loops */
        num_idbs = input_file_idb_list->interface_data->len;

        /* put them in the merged file */
        for (itf_count = 0; itf_count < num_idbs; itf_count++) {
            input_file_idb = &g_array_index(input_file_idb_list->interface_data,
                                            wtapng_if_descr_t, itf_count);
            merged_index = add_idb_to_merged_file(merged_idb_list, input_file_idb);
            add_idb_index_map(&in_files[0], itf_count, merged_index);
        }

        /* and set all the other file index maps the same way */
        for (i = 1; i < in_file_count; i++) {
            for (itf_count = 0; itf_count < num_idbs; itf_count++) {
                add_idb_index_map(&in_files[i], itf_count, itf_count);
            }
        }

        g_free(input_file_idb_list);
    }
    else {
        for (i = 0; i < in_file_count; i++) {
            input_file_idb_list = wtap_file_get_idb_info(in_files[i].wth);

            for (itf_count = 0; itf_count < input_file_idb_list->interface_data->len; itf_count++) {
                input_file_idb = &g_array_index(input_file_idb_list->interface_data,
                                                wtapng_if_descr_t, itf_count);

                if (mode == IDB_MERGE_MODE_ANY_SAME &&
                    find_duplicate_idb(input_file_idb, merged_idb_list, &merged_index))
                {
                    merge_debug("merge::generate_merged_idb: mode ANY set and found a duplicate");
                    /*
                     * It's the same as a previous IDB, so we're going to "merge"
                     * them into one by adding a map from its old IDB index to the new
                     * one. This will be used later to change the phdr interface_id.
                     */
                    add_idb_index_map(&in_files[i], itf_count, merged_index);
                }
                else {
                    merge_debug("merge::generate_merged_idb: mode NONE set or did not find a duplicate");
                    /*
                     * This IDB does not match a previous (or we want to save all IDBs),
                     * so add the IDB to the merge file, and add a map of the indeces.
                     */
                    merged_index = add_idb_to_merged_file(merged_idb_list, input_file_idb);
                    add_idb_index_map(&in_files[i], itf_count, merged_index);
                }
            }

            g_free(input_file_idb_list);
        }
    }

    return merged_idb_list;
}

static gboolean
map_phdr_interface_id(struct wtap_pkthdr *phdr, const merge_in_file_t *in_file)
{
    guint current_interface_id = 0;
    g_assert(phdr != NULL);
    g_assert(in_file != NULL);
    g_assert(in_file->idb_index_map != NULL);

    if (phdr->presence_flags & WTAP_HAS_INTERFACE_ID) {
        current_interface_id = phdr->interface_id;
    }

    if (current_interface_id >= in_file->idb_index_map->len) {
        /* this shouldn't happen, but in a malformed input file it could */
        merge_debug("merge::map_phdr_interface_id: current_interface_id >= in_file->idb_index_map->len (ERROR?)");
        return FALSE;
    }

    phdr->interface_id = g_array_index(in_file->idb_index_map, guint, current_interface_id);
    phdr->presence_flags |= WTAP_HAS_INTERFACE_ID;

    return TRUE;
}

static gchar*
get_read_error_string(const merge_in_file_t *in_files, const guint in_file_count,
                      const int *err, gchar **err_info)
{
    GString *err_message = g_string_new("");
    gchar   *display_basename = NULL;
    guint    i;

    g_assert(in_files != NULL);
    g_assert(err != NULL);
    g_assert(err_info != NULL);

    if (*err_info == NULL) {
        *err_info = g_strdup("no information supplied");
    }

    /*
     * Find the file on which we got the error, and report the error.
     */
    for (i = 0; i < in_file_count; i++) {
        if (in_files[i].state == GOT_ERROR) {
            display_basename = g_filename_display_basename(in_files[i].filename);

            switch (*err) {

                case WTAP_ERR_SHORT_READ:
                    g_string_printf(err_message,
                         "The capture file %s appears to have been cut short"
                          " in the middle of a packet.", display_basename);
                    break;

                case WTAP_ERR_BAD_FILE:
                    g_string_printf(err_message,
                         "The capture file %s appears to be damaged or corrupt.\n(%s)",
                         display_basename, *err_info);
                    break;

                case WTAP_ERR_DECOMPRESS:
                    g_string_printf(err_message,
                         "The compressed capture file %s appears to be damaged or corrupt.\n"
                         "(%s)", display_basename, *err_info);
                    break;

                default:
                    g_string_printf(err_message,
                         "An error occurred while reading the"
                         " capture file %s: %s.",
                         display_basename,  wtap_strerror(*err));
                    break;
            }

            g_free(display_basename);
            break;
        }
    }

    g_free(*err_info);
    *err_info = g_string_free(err_message, FALSE);

    return *err_info;
}

static gchar*
get_write_error_string(const merge_in_file_t *in_file, const int file_type,
                       const gchar* out_filename, const int *err, gchar **err_info)
{
    GString *err_message = g_string_new("");
    gchar *display_basename = NULL;
    int write_err;

    /* in_file may be NULL */
    g_assert(err != NULL);
    g_assert(err_info != NULL);

    if (*err_info == NULL) {
        *err_info = g_strdup("no information supplied");
    }

    write_err = *err;

    display_basename = g_filename_display_basename(in_file ? in_file->filename : "UNKNOWN");

    if (write_err < 0) {

        switch (write_err) {

            case WTAP_ERR_UNWRITABLE_ENCAP:
                /*
                 * This is a problem with the particular frame we're writing and
                 * the file type and subtype we're wwriting; note that, and
                 * report the frame number and file type/subtype.
                 */
                g_string_printf(err_message,
                    "Frame %u of \"%s\" has a network type that can't be saved in a \"%s\" file.\n",
                    in_file ? in_file->packet_num : 0, display_basename,
                    wtap_file_type_subtype_string(file_type));
                break;

            case WTAP_ERR_PACKET_TOO_LARGE:
                /*
                 * This is a problem with the particular frame we're writing and
                 * the file type and subtype we're writing; note that, and report
                 * the frame number and file type/subtype.
                 */
                g_string_printf(err_message,
                    "Frame %u of \"%s\" is too large for a \"%s\" file.",
                    in_file ? in_file->packet_num : 0, display_basename,
                    wtap_file_type_subtype_string(file_type));
                break;

            case WTAP_ERR_UNWRITABLE_REC_TYPE:
                /*
                 * This is a problem with the particular record we're writing and
                 * the file type and subtype we're writing; note that, and report
                 * the record number and file type/subtype.
                 */
                g_string_printf(err_message,
                    "Record %u of \"%s\" has a record type that can't be saved in a \"%s\" file.",
                    in_file ? in_file->packet_num : 0, display_basename,
                    wtap_file_type_subtype_string(file_type));
                break;

            case WTAP_ERR_UNWRITABLE_REC_DATA:
                /*
                 * This is a problem with the particular record we're writing and
                 * the file type and subtype we're writing; note that, and report
                 * the frame number and file type/subtype.
                 */
                g_string_printf(err_message,
                    "Record %u of \"%s\" has data that can't be saved in a \"%s\" file.\n(%s)",
                    in_file ? in_file->packet_num : 0, display_basename,
                    wtap_file_type_subtype_string(file_type), *err_info);
                break;

            default:
                g_string_printf(err_message,
                    "An error occurred while writing to the file \"%s\": %s.",
                    out_filename, wtap_strerror(write_err));
                break;
        }
    }
    else {
        /* OS error. */
        g_string_printf(err_message, file_write_error_message(write_err), out_filename);
    }

    g_free(display_basename);
    g_free(*err_info);
    *err_info = g_string_free(err_message, FALSE);

    return *err_info;
}


/*
 * Merges the files based on given input, and invokes callback during
 * execution. Returns MERGE_OK on success, or a MERGE_ERR_XXX on failure; note
 * that the passed-in 'err' variable will be more specific to what failed, and
 * err_info will have pretty output.
 */
merge_result
merge_files(int out_fd, const gchar* out_filename, const int file_type,
            const char *const *in_filenames, const guint in_file_count,
            const gboolean do_append, const idb_merge_mode mode,
            guint snaplen, const gchar *app_name, merge_progress_callback_t* cb,
            int *err, gchar **err_info, int *err_fileno)
{
    merge_in_file_t    *in_files = NULL, *in_file = NULL;
    int                 frame_type = WTAP_ENCAP_PER_PACKET;
    merge_result        status = MERGE_OK;
    wtap_dumper        *pdh;
    struct wtap_pkthdr *phdr, snap_phdr;
    int                 count = 0;
    gboolean            stop_flag = FALSE;
    wtapng_section_t            *shb_hdr = NULL;
    wtapng_iface_descriptions_t *idb_inf = NULL;

    g_assert(out_fd > 0);
    g_assert(in_file_count > 0);
    g_assert(in_filenames != NULL);
    g_assert(err != NULL);
    g_assert(err_info != NULL);
    g_assert(err_fileno != NULL);

    /* if a callback was given, it has to have a callback function ptr */
    g_assert((cb != NULL) ? (cb->callback_func != NULL) : TRUE);

    merge_debug("merge_files: begin");

    /* open the input files */
    if (!merge_open_in_files(in_file_count, in_filenames, &in_files,
                             err, err_info, err_fileno)) {
        merge_debug("merge_files: merge_open_in_files() failed with err=%d", *err);
        return MERGE_ERR_CANT_OPEN_INFILE;
    }

    if (cb)
        cb->callback_func(MERGE_EVENT_INPUT_FILES_OPENED, 0, in_files, in_file_count, cb->data);

    if (snaplen == 0) {
        /* Snapshot length not specified - default to the maximum. */
        snaplen = WTAP_MAX_PACKET_SIZE;
    }

    /*
     * This doesn't tell us that much. It tells us what to set the outfile's
     * encap type to, but that's all - for example, it does *not* tells us
     * whether the input files had the same number of IDBs, for the same exact
     * interfaces, and only one IDB each, so it doesn't actually tell us
     * whether we can merge IDBs into one or not.
     */
    frame_type = merge_select_frame_type(in_file_count, in_files);
    merge_debug("merge_files: got frame_type=%d", frame_type);

    if (cb)
        cb->callback_func(MERGE_EVENT_FRAME_TYPE_SELECTED, frame_type, in_files, in_file_count, cb->data);

    /* prepare the outfile */
    if (file_type == WTAP_FILE_TYPE_SUBTYPE_PCAPNG) {
        shb_hdr = create_shb_header(in_files, in_file_count, app_name);
        merge_debug("merge_files: SHB created");

        idb_inf = generate_merged_idb(in_files, in_file_count, mode);
        merge_debug("merge_files: IDB merge operation complete, got %u IDBs", idb_inf ? idb_inf->interface_data->len : 0);

        pdh = wtap_dump_fdopen_ng(out_fd, file_type, frame_type, snaplen,
                                  FALSE /* compressed */, shb_hdr, idb_inf,
                                  NULL, err);
    }
    else {
        pdh = wtap_dump_fdopen(out_fd, file_type, frame_type, snaplen, FALSE /* compressed */, err);
    }

    if (pdh == NULL) {
        merge_close_in_files(in_file_count, in_files);
        g_free(in_files);
        wtap_free_shb(shb_hdr);
        wtap_free_idb_info(idb_inf);
        return MERGE_ERR_CANT_OPEN_OUTFILE;
    }

    if (cb)
        cb->callback_func(MERGE_EVENT_READY_TO_MERGE, 0, in_files, in_file_count, cb->data);

    for (;;) {
        *err = 0;

        if (do_append) {
            in_file = merge_append_read_packet(in_file_count, in_files, err,
                                               err_info);
        }
        else {
            in_file = merge_read_packet(in_file_count, in_files, err,
                                        err_info);
        }

        if (in_file == NULL) {
            /* EOF */
            break;
        }

        if (*err != 0) {
            /* I/O error reading from in_file */
            status = MERGE_ERR_CANT_READ_INFILE;
            break;
        }

        count++;
        if (cb)
            stop_flag = cb->callback_func(MERGE_EVENT_PACKET_WAS_READ, count, in_files, in_file_count, cb->data);

        if (stop_flag) {
            /* The user decided to abort the merge. */
            status = MERGE_USER_ABORTED;
            break;
        }

        phdr = wtap_phdr(in_file->wth);

        if (snaplen != 0 && phdr->caplen > snaplen) {
            /*
             * The dumper will only write up to caplen bytes out, so we only
             * need to change that value, instead of cloning the whole packet
             * with fewer bytes.
             *
             * XXX: but do we need to change the IDBs' snap_len?
             */
            snap_phdr = *phdr;
            snap_phdr.caplen = snaplen;
            phdr = &snap_phdr;
        }

        if (file_type == WTAP_FILE_TYPE_SUBTYPE_PCAPNG) {
            if (!map_phdr_interface_id(phdr, in_file)) {
                status = MERGE_ERR_BAD_PHDR_INTERFACE_ID;
                break;
            }
        }

        if (!wtap_dump(pdh, phdr, wtap_buf_ptr(in_file->wth), err, err_info)) {
            status = MERGE_ERR_CANT_WRITE_OUTFILE;
            break;
        }
    }

    if (cb)
        cb->callback_func(MERGE_EVENT_DONE, count, in_files, in_file_count, cb->data);

    merge_close_in_files(in_file_count, in_files);

    if (status == MERGE_OK || status == MERGE_USER_ABORTED) {
        if (!wtap_dump_close(pdh, err))
            status = MERGE_ERR_CANT_CLOSE_OUTFILE;
    } else {
        /*
         * We already got some error; no need to report another error on
         * close.
         *
         * Don't overwrite the earlier error.
         */
        int close_err = 0;
        (void)wtap_dump_close(pdh, &close_err);
    }

    if (status != MERGE_OK) {
        GString *err_message = NULL;
        gchar   *display_basename = NULL;

        switch(status) {

            case MERGE_ERR_CANT_READ_INFILE:
                *err_info = get_read_error_string(in_files, in_file_count, err, err_info);
                break;

            case MERGE_ERR_CANT_WRITE_OUTFILE: /* fall through */
            case MERGE_ERR_CANT_CLOSE_OUTFILE:
                *err_info = get_write_error_string(in_file, file_type, out_filename, err, err_info);
                break;

            case MERGE_ERR_BAD_PHDR_INTERFACE_ID:
                display_basename = g_filename_display_basename(in_file ? in_file->filename : "UNKNOWN");
                if (*err_info != NULL)
                    g_free(*err_info);
                err_message = g_string_new("");
                g_string_printf(err_message,
                    "Record %u of \"%s\" has an interface ID which does not match any IDB in its file.",
                    in_file ? in_file->packet_num : 0, display_basename);
                g_free(display_basename);
                *err_info = g_string_free(err_message, FALSE);
                break;

            case MERGE_USER_ABORTED: /* not really an error */
            default:
                break;
        }
    }

    g_free(in_files);
    wtap_free_shb(shb_hdr);
    wtap_free_idb_info(idb_inf);

    return status;
}

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