aboutsummaryrefslogtreecommitdiffstats
path: root/wiretap/catapult_dct2000.c
blob: ef6769d99813308a3acdcccf0e431d6636078b45 (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
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
/* catapult_dct2000.c
 *
 * $Id$
 *
 * Wiretap Library
 * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

#include "wtap-int.h"
#include "file_wrappers.h"
#include "buffer.h"

#include "catapult_dct2000.h"

#define MAX_FIRST_LINE_LENGTH      200
#define MAX_TIMESTAMP_LINE_LENGTH  100
#define MAX_LINE_LENGTH            65536
#define MAX_TIMESTAMP_LEN          32
#define MAX_SECONDS_CHARS          16
#define MAX_SUBSECOND_DECIMALS     4
#define MAX_CONTEXT_NAME           64
#define MAX_PROTOCOL_NAME          64
#define MAX_PORT_DIGITS            2
#define MAX_VARIANT_DIGITS         32
#define MAX_OUTHDR_NAME            256
#define AAL_HEADER_CHARS           12

/* TODO:
   - support for FP over AAL0
   - support for IuR interface FP
   - support for x.25?
*/

/* 's' or 'r' of a packet as read from .out file */
typedef enum packet_direction_t
{
    sent,
    received
} packet_direction_t;


/***********************************************************************/
/* For each line, store (in case we need to dump):                     */
/* - String before time field                                          */
/* - String beween time field and data (if NULL assume " l ")          */
typedef struct
{
    gchar *before_time;
    gchar *after_time;
} line_prefix_info_t;


/*******************************************************************/
/* Information stored external to a file (wtap) needed for reading and dumping */
typedef struct dct2000_file_externals
{
    /* Remember the time at the start of capture */
    time_t  start_secs;
    guint32 start_usecs;

    /*
     * The following information is needed only for dumping.
     *
     * XXX - Wiretap is not *supposed* to require that a packet being
     * dumped come from a file of the same type that you currently have
     * open; this should be fixed.
     */

    /* Buffer to hold first line, including magic and format number */
    gchar firstline[MAX_FIRST_LINE_LENGTH];
    gint  firstline_length;

    /* Buffer to hold second line with formatted file creation data/time */
    gchar secondline[MAX_TIMESTAMP_LINE_LENGTH];
    gint  secondline_length;

    /* Hash table to store text prefix data part of displayed packets.
       Records (file offset -> line_prefix_info_t)
    */
    GHashTable *packet_prefix_table;
} dct2000_file_externals_t;

/* 'Magic number' at start of Catapult DCT2000 .out files. */
static const gchar catapult_dct2000_magic[] = "Session Transcript";

/************************************************************/
/* Functions called from wiretap core                       */
static gboolean catapult_dct2000_read(wtap *wth, int *err, gchar **err_info,
                                      gint64 *data_offset);
static gboolean catapult_dct2000_seek_read(wtap *wth, gint64 seek_off,
                                           union wtap_pseudo_header *pseudo_header,
                                           guint8 *pd, int length,
                                           int *err, gchar **err_info);
static void catapult_dct2000_close(wtap *wth);

static gboolean catapult_dct2000_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
                                      const union wtap_pseudo_header *pseudo_header,
                                      const guint8 *pd, int *err);


/************************************************************/
/* Private helper functions                                 */
static gboolean read_new_line(FILE_T fh, gint64 *offset, gint *length,
                              gchar *buf, size_t bufsize);
static gboolean parse_line(char *linebuff, gint line_length,
                           gint *seconds, gint *useconds,
                           long *before_time_offset, long *after_time_offset,
                           long *data_offset,
                           gint *data_chars,
                           packet_direction_t *direction,
                           int *encap, int *is_comment,
                           gchar *aal_header_chars,
                           gchar *context_name, guint8 *context_portp,
                           gchar *protocol_name, gchar *variant_name,
                           gchar *outhdr_name);
static int write_stub_header(guint8 *frame_buffer, char *timestamp_string,
                             packet_direction_t direction, int encap,
                             gchar *context_name, guint8 context_port,
                             gchar *protocol_name, gchar *variant_name,
                             gchar *outhdr_name);
static guint8 hex_from_char(gchar c);
static void   prepare_hex_byte_from_chars_table(void);
static guint8 hex_byte_from_chars(gchar *c);
static gchar char_from_hex(guint8 hex);

static void set_pseudo_header_info(wtap *wth,
                                   int pkt_encap,
                                   gint64 file_offset,
                                   union wtap_pseudo_header *pseudo_header,
                                   packet_direction_t direction,
                                   gchar *aal_header_chars);
static void set_aal_info(union wtap_pseudo_header *pseudo_header,
                         packet_direction_t direction,
                         gchar *aal_header_chars);
static void set_isdn_info(union wtap_pseudo_header *pseudo_header,
                          packet_direction_t direction);
static void set_ppp_info(union wtap_pseudo_header *pseudo_header,
                         packet_direction_t direction);

static gint packet_offset_equal(gconstpointer v, gconstpointer v2);
static guint packet_offset_hash_func(gconstpointer v);

static gboolean get_file_time_stamp(gchar *linebuff, time_t *secs, guint32 *usecs);
static gboolean free_line_prefix_info(gpointer key, gpointer value, gpointer user_data);



/********************************************/
/* Open file (for reading)                 */
/********************************************/
int
catapult_dct2000_open(wtap *wth, int *err, gchar **err_info _U_)
{
    gint64  offset = 0;
    time_t  timestamp;
    guint32 usecs;
    gint firstline_length = 0;
    dct2000_file_externals_t *file_externals;
    static gchar linebuff[MAX_LINE_LENGTH];
    static gboolean hex_byte_table_values_set = FALSE;

    /* Clear errno before reading from the file */
    errno = 0;


    /********************************************************************/
    /* First line needs to contain at least as many characters as magic */

    read_new_line(wth->fh, &offset, &firstline_length, linebuff,
                  sizeof linebuff);
    if (((size_t)firstline_length < strlen(catapult_dct2000_magic)) ||
        firstline_length >= MAX_FIRST_LINE_LENGTH) {

        return 0;
    }

    /* This file is not for us if it doesn't match our signature */
    if (memcmp(catapult_dct2000_magic, linebuff, strlen(catapult_dct2000_magic)) != 0) {
        return 0;
    }

    /* Make sure table is ready for use */
    if (!hex_byte_table_values_set) {
        prepare_hex_byte_from_chars_table();
        hex_byte_table_values_set = TRUE;
    }

    /*********************************************************************/
    /* Need entry in file_externals table                                */

    /* Allocate a new file_externals structure for this file */
    file_externals = g_malloc(sizeof(dct2000_file_externals_t));
    memset((void*)file_externals, '\0', sizeof(dct2000_file_externals_t));

    /* Copy this first line into buffer so could write out later */
    g_strlcpy(file_externals->firstline, linebuff, firstline_length+1);
    file_externals->firstline_length = firstline_length;


    /***********************************************************/
    /* Second line contains file timestamp                     */
    /* Store this offset in in file_externals                  */

    read_new_line(wth->fh, &offset, &(file_externals->secondline_length),
                  linebuff, sizeof linebuff);
    if ((file_externals->secondline_length >= MAX_TIMESTAMP_LINE_LENGTH) ||
        (!get_file_time_stamp(linebuff, &timestamp, &usecs))) {

        /* Give up if file time line wasn't valid */
        g_free(file_externals);
        return 0;
    }

    /* Fill in timestamp */
    file_externals->start_secs = timestamp;
    file_externals->start_usecs = usecs;

    /* Copy this second line into buffer so could write out later */
    g_strlcpy(file_externals->secondline, linebuff, file_externals->secondline_length+1);


    /************************************************************/
    /* File is for us. Fill in details so packets can be read   */

    /* Set our file type */
    wth->file_type = WTAP_FILE_CATAPULT_DCT2000;

    /* Use our own encapsulation to send all packets to our stub dissector */
    wth->file_encap = WTAP_ENCAP_CATAPULT_DCT2000;

    /* Callbacks for reading operations */
    wth->subtype_read = catapult_dct2000_read;
    wth->subtype_seek_read = catapult_dct2000_seek_read;
    wth->subtype_close = catapult_dct2000_close;

    /* Choose microseconds (have 4 decimal places...) */
    wth->tsprecision = WTAP_FILE_TSPREC_USEC;


    /***************************************************************/
    /* Initialise packet_prefix_table (index is offset into file)  */
    file_externals->packet_prefix_table =
        g_hash_table_new(packet_offset_hash_func, packet_offset_equal);

    /* Set this wtap to point to the file_externals */
    wth->priv = (void*)file_externals;

    *err = errno;
    return 1;
}


/**************************************************/
/* Read packet function.                          */
/* Look for and read the next usable packet       */
/* - return TRUE and details if found             */
/**************************************************/
static gboolean
catapult_dct2000_read(wtap *wth, int *err, gchar **err_info _U_,
                               gint64 *data_offset)
{
    gint64 offset = file_tell(wth->fh);
    long dollar_offset, before_time_offset, after_time_offset;
    packet_direction_t direction;
    int encap;

    /* Get wtap external structure for this wtap */
    dct2000_file_externals_t *file_externals =
        (dct2000_file_externals_t*)wth->priv;

    /* There *has* to be an entry for this wth */
    if (!file_externals) {
        return FALSE;
    }

    /* Search for a line containing a usable packet */
    while (1) {
        int line_length, seconds, useconds, data_chars;
        int is_comment = FALSE;
        gint64 this_offset = offset;
        static gchar linebuff[MAX_LINE_LENGTH+1];
        gchar aal_header_chars[AAL_HEADER_CHARS];
        gchar context_name[MAX_CONTEXT_NAME];
        guint8 context_port;
        gchar protocol_name[MAX_PROTOCOL_NAME+1];
        gchar variant_name[MAX_VARIANT_DIGITS+1];
        gchar outhdr_name[MAX_OUTHDR_NAME+1];

        /* Are looking for first packet after 2nd line */
        if (file_tell(wth->fh) == 0) {
            this_offset += (file_externals->firstline_length+1+
                            file_externals->secondline_length+1);
        }

        /* Clear errno before reading from the file */
        errno = 0;

        /* Read a new line from file into linebuff */
        if (read_new_line(wth->fh, &offset, &line_length, linebuff,
                          sizeof linebuff) == FALSE) {
            /* Get out if no more lines can be read */
            break;
        }

        /* Try to parse the line as a frame record */
        if (parse_line(linebuff, line_length, &seconds, &useconds,
                       &before_time_offset, &after_time_offset,
                       &dollar_offset,
                       &data_chars, &direction, &encap, &is_comment,
                       aal_header_chars,
                       context_name, &context_port,
                       protocol_name, variant_name, outhdr_name)) {
            guint8 *frame_buffer;
            int n;
            int stub_offset = 0;
            line_prefix_info_t *line_prefix_info;
            char timestamp_string[MAX_TIMESTAMP_LEN+1];
            gint64 *pkey = NULL;

            g_snprintf(timestamp_string, MAX_TIMESTAMP_LEN, "%d.%04d", seconds, useconds/100);

            wth->phdr.presence_flags = WTAP_HAS_TS;

            /* All packets go to Catapult DCT2000 stub dissector */
            wth->phdr.pkt_encap = WTAP_ENCAP_CATAPULT_DCT2000;

            /* Set data_offset to the beginning of the line we're returning.
               This will be the seek_off parameter when this frame is re-read.
            */
            *data_offset = this_offset;

            /* Fill in timestamp (capture base + packet offset) */
            wth->phdr.ts.secs = file_externals->start_secs + seconds;
            if ((file_externals->start_usecs + useconds) >= 1000000) {
                wth->phdr.ts.secs++;
            }
            wth->phdr.ts.nsecs =
                ((file_externals->start_usecs + useconds) % 1000000) *1000;

            /* Get buffer pointer ready */
            buffer_assure_space(wth->frame_buffer,
                                strlen(context_name)+1 +     /* Context name */
                                1 +                          /* port */
                                strlen(timestamp_string)+1 + /* timestamp */
                                strlen(variant_name)+1 +     /* variant */
                                strlen(outhdr_name)+1 +      /* outhdr */
                                strlen(protocol_name)+1 +    /* Protocol name */
                                1 +                          /* direction */
                                1 +                          /* encap */
                                (is_comment ? data_chars : (data_chars/2)));
            frame_buffer = buffer_start_ptr(wth->frame_buffer);


            /*********************/
            /* Write stub header */
            stub_offset = write_stub_header(frame_buffer, timestamp_string,
                                            direction, encap, context_name,
                                            context_port,
                                            protocol_name, variant_name,
                                            outhdr_name);

            /* Binary data length is half bytestring length + stub header */
            wth->phdr.len = stub_offset + (is_comment ? data_chars : (data_chars/2));
            wth->phdr.caplen = stub_offset + (is_comment ? data_chars : (data_chars/2));


            if (!is_comment) {
                /****************************************************/
                /* Copy data into buffer, converting from ascii hex */
                for (n=0; n <= data_chars; n+=2) {
                    frame_buffer[stub_offset + n/2] =
                        hex_byte_from_chars(linebuff+dollar_offset+n);
                }
            }
            else {
                /***********************************************************/
                /* Copy packet data into buffer, just copying ascii chars  */
                for (n=0; n <= data_chars; n++) {
                    frame_buffer[stub_offset + n] = linebuff[dollar_offset+n];
                }
            }

            /* Store the packet prefix in the hash table */
            line_prefix_info = g_malloc(sizeof(line_prefix_info_t));

            /* Create and use buffer for contents before time */
            line_prefix_info->before_time = g_malloc(before_time_offset+2);
            g_strlcpy(line_prefix_info->before_time, linebuff, before_time_offset+1);
            line_prefix_info->before_time[before_time_offset+1] = '\0';

            /* Create and use buffer for contents before time.
               Do this only if it doesn't correspond to " l ", which is by far the most
               common case. */
            if (((size_t)(dollar_offset - after_time_offset -1) == strlen(" l ")) &&
                (strncmp(linebuff+after_time_offset, " l ", strlen(" l ")) == 0)) {

                line_prefix_info->after_time = NULL;
            }
            else {
                /* Allocate & write buffer for line between timestamp and data */
                line_prefix_info->after_time = g_malloc(dollar_offset - after_time_offset);
                g_strlcpy(line_prefix_info->after_time, linebuff+after_time_offset,
                          dollar_offset - after_time_offset);
                line_prefix_info->after_time[dollar_offset - after_time_offset-1] = '\0';
            }

            /* Add packet entry into table */
            pkey = g_malloc(sizeof(*pkey));
            *pkey = this_offset;
            g_hash_table_insert(file_externals->packet_prefix_table, pkey, line_prefix_info);

            /* Set pseudo-header if necessary */
            set_pseudo_header_info(wth, encap, this_offset, &wth->pseudo_header,
                                   direction, aal_header_chars);

            /* OK, we have packet details to return */
            *err = errno;
            return TRUE;
        }
    }

    /* No packet details to return... */
    *err = errno;
    return FALSE;
}


/**************************************************/
/* Read & seek function.                          */
/**************************************************/
static gboolean
catapult_dct2000_seek_read(wtap *wth, gint64 seek_off,
                           union wtap_pseudo_header *pseudo_header, guint8 *pd,
                           int length, int *err, gchar **err_info)
{
    gint64 offset;
    long dollar_offset, before_time_offset, after_time_offset;
    static gchar linebuff[MAX_LINE_LENGTH+1];
    gchar aal_header_chars[AAL_HEADER_CHARS];
    gchar context_name[MAX_CONTEXT_NAME];
    guint8 context_port;
    gchar protocol_name[MAX_PROTOCOL_NAME+1];
    gchar variant_name[MAX_VARIANT_DIGITS+1];
    gchar outhdr_name[MAX_OUTHDR_NAME+1];
    int  is_comment = FALSE;
    packet_direction_t direction;
    int encap;
    int seconds, useconds, data_chars;

    /* Reset errno */
    *err = errno = 0;

    /* Seek to beginning of packet */
    if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1) {
        return FALSE;
    }

    /* Re-read whole line (this really should succeed) */
    if (read_new_line(wth->random_fh, &offset, &length, linebuff,
                      sizeof linebuff) == FALSE) {
        return FALSE;
    }

    /* Try to parse this line again (should succeed as re-reading...) */
    if (parse_line(linebuff, length, &seconds, &useconds,
                   &before_time_offset, &after_time_offset,
                   &dollar_offset,
                   &data_chars, &direction, &encap, &is_comment,
                   aal_header_chars,
                   context_name, &context_port,
                   protocol_name, variant_name, outhdr_name)) {
        int n;
        int stub_offset = 0;
        char timestamp_string[MAX_TIMESTAMP_LEN+1];
        g_snprintf(timestamp_string, MAX_TIMESTAMP_LEN, "%d.%04d", seconds, useconds/100);

        /* Make sure all packets go to catapult dct2000 dissector */
        wth->phdr.pkt_encap = WTAP_ENCAP_CATAPULT_DCT2000;


        /*********************/
        /* Write stub header */
        stub_offset = write_stub_header(pd, timestamp_string,
                                        direction, encap, context_name,
                                        context_port,
                                        protocol_name, variant_name,
                                        outhdr_name);


        if (!is_comment) {
            /***********************************************************/
            /* Copy packet data into buffer, converting from ascii hex */
            for (n=0; n <= data_chars; n+=2) {
                pd[stub_offset + n/2] = hex_byte_from_chars(linebuff+dollar_offset+n);
            }
        }
        else {
            /***********************************************************/
            /* Copy packet data into buffer, just copying ascii chars  */
            for (n=0; n <= data_chars; n++) {
                pd[stub_offset+n] = linebuff[dollar_offset+n];
            }
        }

        /* Set packet pseudo-header if necessary */
        set_pseudo_header_info(wth, encap, seek_off, pseudo_header, direction,
                               aal_header_chars);

        *err = errno = 0;
        return TRUE;
    }

    /* If get here, must have failed */
    *err = errno;
    *err_info = g_strdup_printf("catapult dct2000: seek_read failed to read/parse "
                                "line at position %" G_GINT64_MODIFIER "d",
                                seek_off);
    return FALSE;
}


/***************************************************************************/
/* Free dct2000-specific capture info from file that was open for reading  */
/***************************************************************************/
static void
catapult_dct2000_close(wtap *wth)
{
    /* Get externals for this file */
    dct2000_file_externals_t *file_externals =
        (dct2000_file_externals_t*)wth->priv;

    /* The entry *has* to be found */
    if (!file_externals) {
        return;
    }

    /* Free up its line prefix values */
    g_hash_table_foreach_remove(file_externals->packet_prefix_table,
                                free_line_prefix_info, NULL);
    /* Free up its line prefix table */
    g_hash_table_destroy(file_externals->packet_prefix_table);
}




/***************************/
/* Dump functions          */
/***************************/

typedef struct {
    gboolean           first_packet_written;
    struct wtap_nstime start_time;
} dct2000_dump_t;

/*****************************************************/
/* The file that we are writing to has been opened.  */
/* Set other dump callbacks.                         */
/*****************************************************/
gboolean
catapult_dct2000_dump_open(wtap_dumper *wdh, int *err _U_)
{
    /* Fill in other dump callbacks */
    wdh->subtype_write = catapult_dct2000_dump;

    return TRUE;
}

/*********************************************************/
/* Respond to queries about which encap types we support */
/* writing to.                                           */
/*********************************************************/
int
catapult_dct2000_dump_can_write_encap(int encap)
{
    switch (encap) {
        case WTAP_ENCAP_CATAPULT_DCT2000:
            /* We support this */
            return 0;

        default:
            /* But don't write to any other formats... */
            return WTAP_ERR_UNSUPPORTED_ENCAP;
    }
}


/*****************************************/
/* Write a single packet out to the file */
/*****************************************/

static gboolean
catapult_dct2000_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
                               const union wtap_pseudo_header *pseudo_header,
                               const guint8 *pd, int *err)
{
    guint32 n;
    line_prefix_info_t *prefix = NULL;
    gchar time_string[16];
    gboolean is_comment;
    dct2000_dump_t *dct2000;

    /******************************************************/
    /* Get the file_externals structure for this file */
    /* Find wtap external structure for this wtap */
    dct2000_file_externals_t *file_externals =
        (dct2000_file_externals_t*)pseudo_header->dct2000.wth->priv;

    dct2000 = (dct2000_dump_t *)wdh->priv;
    if (dct2000 == NULL) {

        /* Write out saved first line */
        if (!wtap_dump_file_write(wdh, file_externals->firstline,
                                  file_externals->firstline_length, err)) {
            return FALSE;
        }
        if (!wtap_dump_file_write(wdh, "\n", 1, err)) {
            return FALSE;
        }

        /* Also write out saved second line with timestamp corresponding to the
           opening time of the log.
        */
        if (!wtap_dump_file_write(wdh, file_externals->secondline,
                                  file_externals->secondline_length, err)) {
            return FALSE;
        }
        if (!wtap_dump_file_write(wdh, "\n", 1, err)) {
            return FALSE;
        }

        /* Allocate the dct2000-specific dump structure */
        dct2000 = (dct2000_dump_t *)g_malloc(sizeof(dct2000_dump_t));
        wdh->priv = (void *)dct2000;

        /* Copy time of beginning of file */
        dct2000->start_time.secs = file_externals->start_secs;
        dct2000->start_time.nsecs =
            (file_externals->start_usecs * 1000);

        /* Set flag do don't write header out again */
        dct2000->first_packet_written = TRUE;
    }


    /******************************************************************/
    /* Write out this packet's prefix, including calculated timestamp */

    /* Look up line data prefix using stored offset */
    prefix = (line_prefix_info_t*)g_hash_table_lookup(file_externals->packet_prefix_table,
                                                      (const void*)&(pseudo_header->dct2000.seek_off));

    /* Write out text before timestamp */
    if (!wtap_dump_file_write(wdh, prefix->before_time,
                              strlen(prefix->before_time), err)) {
        return FALSE;
    }

    /* Can infer from prefix if this is a comment (whose payload is displayed differently) */
    is_comment = (strstr(prefix->before_time, "/////") != NULL);

    /* Calculate time of this packet to write, relative to start of dump */
    if (phdr->ts.nsecs >= dct2000->start_time.nsecs) {
        g_snprintf(time_string, 16, "%ld.%04d",
                  (long)(phdr->ts.secs - dct2000->start_time.secs),
                  (phdr->ts.nsecs - dct2000->start_time.nsecs) / 100000);
    }
    else {
        g_snprintf(time_string, 16, "%ld.%04u",
                  (long)(phdr->ts.secs - dct2000->start_time.secs-1),
                  ((1000000000 + (phdr->ts.nsecs / 100000)) - (dct2000->start_time.nsecs / 100000)) % 10000);
    }

    /* Write out the calculated timestamp */
    if (!wtap_dump_file_write(wdh, time_string, strlen(time_string), err)) {
        return FALSE;
    }

    /* Write out text between timestamp and start of hex data */
    if (prefix->after_time == NULL) {
        if (!wtap_dump_file_write(wdh, " l ", strlen(" l "), err)) {
            return FALSE;
        }
    }
    else {
        if (!wtap_dump_file_write(wdh, prefix->after_time,
                                  strlen(prefix->after_time), err)) {
            return FALSE;
        }
    }


    /****************************************************************/
    /* Need to skip stub header at start of pd before we reach data */

    /* Context name */
    for (n=0; pd[n] != '\0'; n++);
    n++;

    /* Context port number */
    n++;

    /* Timestamp */
    for (; pd[n] != '\0'; n++);
    n++;

    /* Protocol name */
    for (; pd[n] != '\0'; n++);
    n++;

    /* Variant number (as string) */
    for (; pd[n] != '\0'; n++);
    n++;

    /* Outhdr (as string) */
    for (; pd[n] != '\0'; n++);
    n++;

    /* Direction & encap */
    n += 2;


    /**************************************/
    /* Remainder is encapsulated protocol */
    if (!wtap_dump_file_write(wdh, "$", 1, err)) {
        return FALSE;
    }

    if (!is_comment) {
        /* Each binary byte is written out as 2 hex string chars */ 
        for (; n < phdr->len; n++) {
            gchar c[2];
            c[0] = char_from_hex((guint8)(pd[n] >> 4));
            c[1] = char_from_hex((guint8)(pd[n] & 0x0f));

            /* Write both hex chars of byte together */
            if (!wtap_dump_file_write(wdh, c, 2, err)) {
                return FALSE;
            }
        }
    }
    else {
        for (; n < phdr->len; n++) {
            char c[1];
            c[0] = pd[n];

            /* Write both hex chars of byte together */
            if (!wtap_dump_file_write(wdh, c, 1, err)) {
                return FALSE;
            }
        }
    }

    /* End the line */
    if (!wtap_dump_file_write(wdh, "\n", 1, err)) {
        return FALSE;
    }

    return TRUE;
}


/****************************/
/* Private helper functions */
/****************************/

/**********************************************************************/
/* Read a new line from the file, starting at offset.                 */
/* - writes data to its argument linebuff                             */
/* - on return 'offset' will point to the next position to read from  */
/* - return TRUE if this read is successful                           */
/**********************************************************************/
static gboolean
read_new_line(FILE_T fh, gint64 *offset, gint *length,
                       gchar *linebuff, size_t linebuffsize)
{
    /* Read in a line */
    gint64 pos_before = file_tell(fh);
    char *result = file_gets(linebuff, (int)linebuffsize - 1, fh);
    if (result == NULL) {
        /* No characters found, or error */
        return FALSE;
    }

    /* Set length (avoiding strlen()) and offset.. */
    *length = (gint)(file_tell(fh) - pos_before);
    *offset = *offset + *length;

    /* ...but don't want to include newline in line length */
    if (linebuff[*length-1] == '\n') {
        linebuff[*length-1] = '\0';
        *length = *length - 1;
    }

    return TRUE;
}


/**********************************************************************/
/* Parse a line from buffer, by identifying:                          */
/* - context, port and direction of packet                            */
/* - timestamp                                                        */
/* - data position and length                                         */
/* Return TRUE if this packet looks valid and can be displayed        */
/**********************************************************************/
static gboolean
parse_line(gchar *linebuff, gint line_length,
                           gint *seconds, gint *useconds,
                           long *before_time_offset, long *after_time_offset,
                           long *data_offset, gint *data_chars,
                           packet_direction_t *direction,
                           int *encap, int *is_comment,
                           gchar *aal_header_chars,
                           gchar *context_name, guint8 *context_portp,
                           gchar *protocol_name, gchar *variant_name,
                           gchar *outhdr_name)
{
    int  n = 0;
    int  port_digits;
    char port_number_string[MAX_PORT_DIGITS+1];
    int  variant_digits = 0;
    int  variant = 1;
    int  protocol_chars = 0;
    int  outhdr_chars = 0;

    char seconds_buff[MAX_SECONDS_CHARS+1];
    int  seconds_chars;
    char subsecond_decimals_buff[MAX_SUBSECOND_DECIMALS+1];
    int  subsecond_decimals_chars;
    int  skip_first_byte = FALSE;
    gboolean atm_header_present = FALSE;

    *is_comment = FALSE;

    /* Read context name until find '.' */
    for (n=0; (linebuff[n] != '.') && (n < MAX_CONTEXT_NAME) && (n+1 < line_length); n++) {
        if (linebuff[n] == '/') {
            context_name[n] = '\0';

            /* If not a comment (/////), not a valid line */
            if (strncmp(linebuff+n, "/////", 5) != 0) {
                return FALSE;
            }

            /* There is no variant, outhdr, etc.  Set protocol to be a comment */
            g_snprintf(protocol_name, MAX_PROTOCOL_NAME, "comment");
            *is_comment = TRUE;
            break;
        }
        if (!isalnum((guchar)linebuff[n]) && (linebuff[n] != '_') && (linebuff[n] != '-')) {
            return FALSE;
        }
        context_name[n] = linebuff[n];
    }
    if (n == MAX_CONTEXT_NAME || (n+1 >= line_length)) {
        return FALSE;
    }

    /* Reset strings (that won't be set by comments) */
    variant_name[0] = '\0';
    outhdr_name[0] = '\0';
    port_number_string[0] = '\0';

    if (!(*is_comment)) {
        /* '.' must follow context name */
        if (linebuff[n] != '.') {
            return FALSE;
        }
        context_name[n] = '\0';
        /* Skip it */
        n++;

        /* Now read port number */
        for (port_digits = 0;
             (linebuff[n] != '/') && (port_digits <= MAX_PORT_DIGITS) && (n+1 < line_length);
             n++, port_digits++) {

            if (!isdigit((guchar)linebuff[n])) {
                return FALSE;
            }
            port_number_string[port_digits] = linebuff[n];
        }
        if (port_digits > MAX_PORT_DIGITS || (n+1 >= line_length)) {
            return FALSE;
        }

        /* Slash char must follow port number */
        if (linebuff[n] != '/')
        {
            return FALSE;
        }
        port_number_string[port_digits] = '\0';
        *context_portp = atoi(port_number_string);
        /* Skip it */
        n++;

        /* Now for the protocol name */
        for (protocol_chars = 0;
             (linebuff[n] != '/') && (protocol_chars < MAX_PROTOCOL_NAME) && (n < line_length);
             n++, protocol_chars++) {

            if (!isalnum((guchar)linebuff[n]) && linebuff[n] != '_') {
                return FALSE;
            }
            protocol_name[protocol_chars] = linebuff[n];
        }
        if (protocol_chars == MAX_PROTOCOL_NAME || n >= line_length) {
            /* If doesn't fit, fail rather than truncate */
            return FALSE;
        }
        protocol_name[protocol_chars] = '\0';

        /* Slash char must follow protocol name */
        if (linebuff[n] != '/') {
            return FALSE;
        }
        /* Skip it */
        n++;


        /* Following the / is the variant number.  No digits indicate 1 */
        for (variant_digits = 0;
             (isdigit((guchar)linebuff[n])) && (variant_digits <= MAX_VARIANT_DIGITS) && (n+1 < line_length);
             n++, variant_digits++) {

            if (!isdigit((guchar)linebuff[n])) {
                return FALSE;
            }
            variant_name[variant_digits] = linebuff[n];
        }
        if (variant_digits > MAX_VARIANT_DIGITS || (n+1 >= line_length)) {
            return FALSE;
        }
        if (variant_digits > 0) {
            variant_name[variant_digits] = '\0';
            variant = atoi(variant_name);
        }
        else {
            g_strlcpy(variant_name, "1", MAX_VARIANT_DIGITS+1);
        }


        /* Outheader values may follow */
        outhdr_name[0] = '\0';
        if (linebuff[n] == ',') {
            /* Skip , */
            n++;

            for (outhdr_chars = 0;
                 (isdigit((guchar)linebuff[n]) || linebuff[n] == ',') &&
                 (outhdr_chars <= MAX_OUTHDR_NAME) && (n+1 < line_length);
                 n++, outhdr_chars++) {

                if (!isdigit((guchar)linebuff[n]) && (linebuff[n] != ',')) {
                    return FALSE;
                }
                outhdr_name[outhdr_chars] = linebuff[n];
            }
            if (outhdr_chars > MAX_OUTHDR_NAME || (n+1 >= line_length)) {
                return FALSE;
            }
            /* Terminate (possibly empty) string */
            outhdr_name[outhdr_chars] = '\0';
        }
    }


    /******************************************************************/
    /* Now check whether we know how to use a packet of this protocol */

    if ((strcmp(protocol_name, "ip") == 0) ||
        (strcmp(protocol_name, "sctp") == 0) ||
        (strcmp(protocol_name, "gre") == 0) ||
        (strcmp(protocol_name, "mipv6") == 0) ||
        (strcmp(protocol_name, "igmp") == 0)) {

        *encap = WTAP_ENCAP_RAW_IP;
    }
    else

    /* FP may be carried over ATM, which has separate atm header to parse */
    if ((strcmp(protocol_name, "fp") == 0) ||
        (strcmp(protocol_name, "fp_r4") == 0) ||
        (strcmp(protocol_name, "fp_r5") == 0) ||
        (strcmp(protocol_name, "fp_r6") == 0) ||
        (strcmp(protocol_name, "fp_r7") == 0) ||
        (strcmp(protocol_name, "fp_r8") == 0)) {

        if ((variant > 256) && (variant % 256 == 3)) {
            /* FP over udp is contained in IPPrim... */
            *encap = 0;
        }
        else {
            /* FP over AAL0 or AAL2 */
            *encap = WTAP_ENCAP_ATM_PDUS_UNTRUNCATED;
            atm_header_present = TRUE;
        }
    }
    else if (strcmp(protocol_name, "fpiur_r5") == 0) {
        /* FP (IuR) over AAL2 */
        *encap = WTAP_ENCAP_ATM_PDUS_UNTRUNCATED;
        atm_header_present = TRUE;
    }

    else
    if (strcmp(protocol_name, "ppp") == 0) {
        *encap = WTAP_ENCAP_PPP;
    }
    else
    if (strcmp(protocol_name, "isdn_l3") == 0) {
       /* TODO: find out what this byte means... */
        skip_first_byte = TRUE;
        *encap = WTAP_ENCAP_ISDN;
    }
    else
    if (strcmp(protocol_name, "isdn_l2") == 0) {
        *encap = WTAP_ENCAP_ISDN;
    }
    else
    if (strcmp(protocol_name, "ethernet") == 0) {
        *encap = WTAP_ENCAP_ETHERNET;
    }
    else
    if ((strcmp(protocol_name, "saalnni_sscop") == 0) ||
        (strcmp(protocol_name, "saaluni_sscop") == 0)) {

        *encap = DCT2000_ENCAP_SSCOP;
    }
    else
    if (strcmp(protocol_name, "frelay_l2") == 0) {
        *encap = WTAP_ENCAP_FRELAY;
    }
    else
    if (strcmp(protocol_name, "ss7_mtp2") == 0) {
        *encap = DCT2000_ENCAP_MTP2;
    }
    else
    if ((strcmp(protocol_name, "nbap") == 0) ||
        (strcmp(protocol_name, "nbap_r4") == 0) ||
        (strncmp(protocol_name, "nbap_sscfuni", strlen("nbap_sscfuni")) == 0)) {

        /* The entire message in these cases is nbap, so use an encap value. */
        *encap = DCT2000_ENCAP_NBAP;
    }
    else {
        /* Not a supported board port protocol/encap, but can show as raw data or
           in some cases find protocol embedded inside primitive */
        *encap = DCT2000_ENCAP_UNHANDLED;
    }


    /* Find separate ATM header if necessary */
    if (atm_header_present) {
        int header_chars_seen = 0;

        /* Scan ahead to the next $ */
        for (; (linebuff[n] != '$') && (n+1 < line_length); n++);
        /* Skip it */
        n++;
        if (n+1 >= line_length) {
            return FALSE;
        }

        /* Read consecutive hex chars into atm header buffer */
        for (;
             ((linebuff[n] >= '0') && (linebuff[n] <= '?') &&
              (n < line_length) &&
              (header_chars_seen < AAL_HEADER_CHARS));
             n++, header_chars_seen++) {

            aal_header_chars[header_chars_seen] = linebuff[n];
            /* Next 6 characters after '9' are mapped to a->f */
            if (!isdigit((guchar)linebuff[n])) {
                aal_header_chars[header_chars_seen] = 'a' + (linebuff[n] - '9') -1;
            }
        }

        if (header_chars_seen != AAL_HEADER_CHARS || n >= line_length) {
            return FALSE;
        }
    }

    /* Skip next '/' */
    n++;

    /* If there is a number, skip all info to next '/'.
       TODO: for IP encapsulation, should store PDCP ueid, drb in pseudo info
       and display dct2000 dissector... */
    if (isdigit(linebuff[n])) {
        while ((n+1 < line_length) && linebuff[n] != '/') {
            n++;
        }
    }

    /* Skip '/' */
    while ((n+1 < line_length) && linebuff[n] == '/') {
        n++;
    }

    /* Skip a space that may happen here */
    if ((n+1 < line_length) && linebuff[n] == ' ') {
        n++;
    }

    /* Next character gives direction of message (must be 's' or 'r') */
    if (!(*is_comment)) {
        if (linebuff[n] == 's') {
            *direction = sent;
        }
        else
        if (linebuff[n] == 'r') {
            *direction = received;
        }
        else {
            return FALSE;
        }
        /* Skip it */
        n++;
    }
    else {
        *direction = sent;
    }


    /*********************************************************************/
    /* Find and read the timestamp                                       */

    /* Now scan to the next digit, which should be the start of the timestamp */
    /* This will involve skipping " tm "                                      */

    for (; ((linebuff[n] != 't') || (linebuff[n+1] != 'm')) && (n+1 < line_length); n++);
    if (n >= line_length) {
        return FALSE;
    }

    for (; !isdigit((guchar)linebuff[n]) && (n < line_length); n++);
    if (n >= line_length) {
        return FALSE;
    }

    *before_time_offset = n;

    /* Seconds */
    for (seconds_chars = 0;
         (linebuff[n] != '.') &&
         (seconds_chars <= MAX_SECONDS_CHARS) &&
         (n < line_length);
         n++, seconds_chars++) {

        if (!isdigit((guchar)linebuff[n])) {
            /* Found a non-digit before decimal point. Fail */
            return FALSE;
        }
        seconds_buff[seconds_chars] = linebuff[n];
    }
    if (seconds_chars > MAX_SECONDS_CHARS || n >= line_length) {
        /* Didn't fit in buffer.  Fail rather than use truncated */
        return FALSE;
    }

    /* Convert found value into number */
    seconds_buff[seconds_chars] = '\0';
    *seconds = atoi(seconds_buff);

    /* The decimal point must follow the last of the seconds digits */
    if (linebuff[n] != '.') {
        return FALSE;
    }
    /* Skip it */
    n++;

    /* Subsecond decimal digits (expect 4-digit accuracy) */
    for (subsecond_decimals_chars = 0;
         (linebuff[n] != ' ') &&
         (subsecond_decimals_chars <= MAX_SUBSECOND_DECIMALS) &&
         (n < line_length);
         n++, subsecond_decimals_chars++) {

        if (!isdigit((guchar)linebuff[n])) {
            return FALSE;
        }
        subsecond_decimals_buff[subsecond_decimals_chars] = linebuff[n];
    }
    if (subsecond_decimals_chars > MAX_SUBSECOND_DECIMALS || n >= line_length) {
        /* More numbers than expected - give up */
        return FALSE;
    }
    /* Convert found value into microseconds */
    subsecond_decimals_buff[subsecond_decimals_chars] = '\0';
    *useconds = atoi(subsecond_decimals_buff) * 100;

    /* Space character must follow end of timestamp */
    if (linebuff[n] != ' ') {
        return FALSE;
    }

    *after_time_offset = n;

    /* Now skip ahead to find start of data (marked by '$') */
    /* Want to avoid matching with normal sprint command output at the moment... */
    for (; (linebuff[n] != '$') && (linebuff[n] != '\'') && (n+1 < line_length); n++);
    if ((linebuff[n] == '\'') || (n+1 >= line_length)) {
        return FALSE;
    }
    /* Skip it */
    n++;

    /* Set offset to data start within line */
    *data_offset = n;

    /* Set number of chars that comprise the hex string protocol data */
    *data_chars = line_length - n;

    /* May need to skip first byte (2 hex string chars) */
    if (skip_first_byte) {
        *data_offset += 2;
        *data_chars -= 2;
    }

    return TRUE;
}

/*****************************************************************/
/* Write the stub info to the data buffer while reading a packet */
/*****************************************************************/
static int
write_stub_header(guint8 *frame_buffer, char *timestamp_string,
                             packet_direction_t direction, int encap,
                             gchar *context_name, guint8 context_port,
                             gchar *protocol_name, gchar *variant_name,
                             gchar *outhdr_name)
{
    int stub_offset = 0;

    g_strlcpy((char*)frame_buffer, context_name, MAX_CONTEXT_NAME+1);
    stub_offset += (int)(strlen(context_name) + 1);

    /* Context port number */
    frame_buffer[stub_offset] = context_port;
    stub_offset++;

    /* Timestamp within file */
    g_strlcpy((char*)&frame_buffer[stub_offset], timestamp_string, MAX_TIMESTAMP_LEN+1);
    stub_offset += (int)(strlen(timestamp_string) + 1);

    /* Protocol name */
    g_strlcpy((char*)&frame_buffer[stub_offset], protocol_name, MAX_PROTOCOL_NAME+1);
    stub_offset += (int)(strlen(protocol_name) + 1);

    /* Protocol variant number (as string) */
    g_strlcpy((void*)&frame_buffer[stub_offset], variant_name, MAX_VARIANT_DIGITS+1);
    stub_offset += (int)(strlen(variant_name) + 1);

    /* Outhdr */
    g_strlcpy((char*)&frame_buffer[stub_offset], outhdr_name, MAX_OUTHDR_NAME+1);
    stub_offset += (int)(strlen(outhdr_name) + 1);

    /* Direction */
    frame_buffer[stub_offset] = direction;
    stub_offset++;

    /* Encap */
    frame_buffer[stub_offset] = (guint8)encap;
    stub_offset++;

    return stub_offset;
}


/**************************************************************/
/* Set pseudo-header info depending upon packet encapsulation */
/**************************************************************/
static void
set_pseudo_header_info(wtap *wth,
                                   int pkt_encap,
                                   gint64 file_offset,
                                   union wtap_pseudo_header *pseudo_header,
                                   packet_direction_t direction,
                                   gchar *aal_header_chars)
{
    pseudo_header->dct2000.seek_off = file_offset;
    pseudo_header->dct2000.wth = wth;

    switch (pkt_encap) {
        case WTAP_ENCAP_ATM_PDUS_UNTRUNCATED:
            set_aal_info(pseudo_header, direction, aal_header_chars);
            break;
        case WTAP_ENCAP_ISDN:
            set_isdn_info(pseudo_header, direction);
            break;
        case WTAP_ENCAP_PPP:
            set_ppp_info(pseudo_header, direction);
            break;

        default:
            /* Other supported types don't need to set anything here... */
            break;
    }
}


/*********************************************/
/* Fill in atm pseudo-header with known info */
/*********************************************/
static void
set_aal_info(union wtap_pseudo_header *pseudo_header,
                         packet_direction_t direction,
                         gchar *aal_header_chars)
{
    /* 'aal_head_chars' has this format (for AAL2 at least):
       Global Flow Control (4 bits) | VPI (8 bits) | VCI (16 bits) |
       Payload Type (4 bits) | Padding (3 bits?) | Link? (1 bit) |
       Channel Identifier (8 bits) | ...
    */

    /* Indicate that this is a reassembled PDU */
    pseudo_header->dct2000.inner_pseudo_header.atm.flags = 0x00;

    /* Channel 0 is DTE->DCE, 1 is DCE->DTE. Always set 0 for now.
       TODO: Can we infer the correct value here?
       Meanwhile, just use the direction to make them distinguishable...
    */
    pseudo_header->dct2000.inner_pseudo_header.atm.channel = (direction == received);

    /* Assume always AAL2 for FP */
    pseudo_header->dct2000.inner_pseudo_header.atm.aal = AAL_2;

    pseudo_header->dct2000.inner_pseudo_header.atm.type = TRAF_UMTS_FP;
    pseudo_header->dct2000.inner_pseudo_header.atm.subtype = TRAF_ST_UNKNOWN;

    /* vpi is 8 bits (2nd & 3rd nibble) */
    pseudo_header->dct2000.inner_pseudo_header.atm.vpi =
        hex_byte_from_chars(aal_header_chars+1);

    /* vci is next 16 bits */
    pseudo_header->dct2000.inner_pseudo_header.atm.vci =
        ((hex_from_char(aal_header_chars[3]) << 12) |
         (hex_from_char(aal_header_chars[4]) << 8) |
         (hex_from_char(aal_header_chars[5]) << 4) |
         hex_from_char(aal_header_chars[6]));

    /* 0 means we don't know how many cells the frame comprises. */
    pseudo_header->dct2000.inner_pseudo_header.atm.cells = 0;

    /* cid is usually last byte.  Unless last char is not hex digit, in which
       case cid is derived from last char in ascii */
    if (isalnum((guchar)aal_header_chars[11])) {
        pseudo_header->dct2000.inner_pseudo_header.atm.aal2_cid =
            hex_byte_from_chars(aal_header_chars+10);
    }
    else {
        pseudo_header->dct2000.inner_pseudo_header.atm.aal2_cid =
            (int)aal_header_chars[11] - '0';
    }
}


/**********************************************/
/* Fill in isdn pseudo-header with known info */
/**********************************************/
static void
set_isdn_info(union wtap_pseudo_header *pseudo_header,
                   packet_direction_t direction)
{
    /* This field is used to set the 'Source' and 'Destination' columns to
       'User' or 'Network'. If we assume that we're simulating the network,
       treat Received messages as being destined for the network.
    */
    pseudo_header->dct2000.inner_pseudo_header.isdn.uton = (direction == received);

    /* This corresponds to the circuit ID.  0 is treated as LAPD,
       everything else would be treated as a B-channel
    */
    pseudo_header->dct2000.inner_pseudo_header.isdn.channel = 0;
}


/*********************************************/
/* Fill in ppp pseudo-header with known info */
/*********************************************/
static void
set_ppp_info(union wtap_pseudo_header *pseudo_header,
                         packet_direction_t direction)
{
    /* Set direction. */
    pseudo_header->dct2000.inner_pseudo_header.p2p.sent = (direction == sent);
}


/********************************************************/
/* Return hex nibble equivalent of hex string character */
/********************************************************/
static guint8
hex_from_char(gchar c)
{
    if ((c >= '0') && (c <= '9')) {
        return c - '0';
    }

    if ((c >= 'a') && (c <= 'f')) {
        return 0x0a + (c - 'a');
    }

    /* Not a valid hex string character */
    return 0xff;
}



/* Table allowing fast lookup from a pair of ascii hex characters to a guint8 */
static guint8 s_tableValues[255][255];

/* Prepare table values so ready so don't need to check inside hex_byte_from_chars() */
static void  prepare_hex_byte_from_chars_table(void)
{
    guchar hex_char_array[16] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                                  'a', 'b', 'c', 'd', 'e', 'f' };

    gint i, j;
    for (i=0; i < 16; i++) {
        for (j=0; j < 16; j++) {
            s_tableValues[hex_char_array[i]][hex_char_array[j]] = i*16 + j;
        }
    }
}

/* Extract and return a byte value from 2 ascii hex chars, starting from the given pointer */
static guint8 hex_byte_from_chars(gchar *c)
{
    /* Return value from quick table lookup */
    return s_tableValues[(unsigned char)c[0]][(unsigned char)c[1]];
}



/********************************************************/
/* Return character corresponding to hex nibble value   */
/********************************************************/
static gchar
char_from_hex(guint8 hex)
{
    static char hex_lookup[16] =
    { '0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};

    if (hex > 15) {
        return '?';
    }

    return hex_lookup[hex];
}

/***********************************************/
/* Equality test for packet prefix hash tables */
/***********************************************/
static gint
packet_offset_equal(gconstpointer v, gconstpointer v2)
{
    /* Dereferenced pointers must have same gint64 offset value */
    return (*(const gint64*)v == *(const gint64*)v2);
}


/********************************************/
/* Hash function for packet-prefix hash table */
/********************************************/
static guint
packet_offset_hash_func(gconstpointer v)
{
    /* Use low-order bits of gint64 offset value */
    return (guint)(*(const gint64*)v);
}


/************************************************************************/
/* Parse year, month, day, hour, minute, seconds out of formatted line. */
/* Set secs and usecs as output                                         */
/* Return FALSE if no valid time can be read                            */
/************************************************************************/
static gboolean
get_file_time_stamp(gchar *linebuff, time_t *secs, guint32 *usecs)
{
    int n;
    struct tm tm;
    #define MAX_MONTH_LETTERS 9
    char month[MAX_MONTH_LETTERS+1];

    int day, year, hour, minute, second;
    int scan_found;

    /* If line longer than expected, file is probably not correctly formatted */
    if (strlen(linebuff) > MAX_TIMESTAMP_LINE_LENGTH) {
        return FALSE;
    }

    /**************************************************************/
    /* First is month. Read until get a space following the month */
    for (n=0; (linebuff[n] != ' ') && (n < MAX_MONTH_LETTERS); n++) {
        month[n] = linebuff[n];
    }
    month[n] = '\0';

    if      (strcmp(month, "January"  ) == 0)  tm.tm_mon = 0;
    else if (strcmp(month, "February" ) == 0)  tm.tm_mon = 1;
    else if (strcmp(month, "March"    ) == 0)  tm.tm_mon = 2;
    else if (strcmp(month, "April"    ) == 0)  tm.tm_mon = 3;
    else if (strcmp(month, "May"      ) == 0)  tm.tm_mon = 4;
    else if (strcmp(month, "June"     ) == 0)  tm.tm_mon = 5;
    else if (strcmp(month, "July"     ) == 0)  tm.tm_mon = 6;
    else if (strcmp(month, "August"   ) == 0)  tm.tm_mon = 7;
    else if (strcmp(month, "September") == 0)  tm.tm_mon = 8;
    else if (strcmp(month, "October"  ) == 0)  tm.tm_mon = 9;
    else if (strcmp(month, "November" ) == 0)  tm.tm_mon = 10;
    else if (strcmp(month, "December" ) == 0)  tm.tm_mon = 11;
    else {
        /* Give up if not found a properly-formatted date */
        return FALSE;
    }
    /* Skip space char */
    n++;

    /********************************************************/
    /* Scan for remaining numerical fields                  */
    scan_found = sscanf(linebuff+n, "%2d, %4d     %2d:%2d:%2d.%4u",
                        &day, &year, &hour, &minute, &second, usecs);
    if (scan_found != 6) {
        /* Give up if not all found */
        return FALSE;
    }

    /******************************************************/
    /* Fill in remaining fields and return it in a time_t */
    tm.tm_year = year - 1900;
    tm.tm_mday = day;
    tm.tm_hour = hour;
    tm.tm_min = minute;
    tm.tm_sec = second;
    tm.tm_isdst = -1;    /* daylight saving time info not known */

    /* Get seconds from this time */
    *secs = mktime(&tm);

    /* Multiply 4 digits given to get micro-seconds */
    *usecs = *usecs * 100;

    return TRUE;
}

/* Free the data allocated inside a line_prefix_info_t */
static gboolean
free_line_prefix_info(gpointer key, gpointer value,
                               gpointer user_data _U_)
{
    line_prefix_info_t *info = (line_prefix_info_t*)value;

    /* Free the 64-bit key value */
    g_free(key);

    /* Free the strings inside */
    g_free(info->before_time);
    if (info->after_time) {
        g_free(info->after_time);
    }

    /* And the structure itself */
    g_free(info);

    /* Item will always be removed from table */
    return TRUE;
}