aboutsummaryrefslogtreecommitdiffstats
path: root/wiretap/nettl.c
blob: e5f159ef8900e7278ace3942d5b206be980a6b36 (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
/* nettl.c
 *
 * Wiretap Library
 * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
 *
 * Enhancements by Mark C. Brown <mbrown@hp.com>
 * Copyright (C) 2003, 2005 Hewlett-Packard Development Company, L.P.
 *
 * 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>
#include <string.h>
#include "wtap-int.h"
#include "file_wrappers.h"
#include "buffer.h"
#include "nettl.h"

/* HP nettl file header */

/* Magic number size */
#define MAGIC_SIZE	12

/* HP-UX 9.x */
static const guint8 nettl_magic_hpux9[MAGIC_SIZE] = {
    0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0xD0, 0x00
};
/* HP-UX 10.x and 11.x */
static const guint8 nettl_magic_hpux10[MAGIC_SIZE] = {
    0x54, 0x52, 0x00, 0x64, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80
};

#define FILE_HDR_SIZE	128
#define NETTL_FILENAME_SIZE 56

struct nettl_file_hdr {
    guint8	magic[MAGIC_SIZE];
    gchar	file_name[NETTL_FILENAME_SIZE];
    gchar	tz[20];
    gchar	host_name[9];
    gchar	os_vers[9];
    guint8	os_v;
    guint8	xxa[8];
    gchar	model[11];
    guint16	unknown;	/* just padding to 128 bytes? */
};

/* HP nettl record header */
/* see /usr/include/sys/netdiag1.h for hints */
struct nettlrec_hdr {
    guint16	hdr_len;
    guint16	subsys;
    guint32	devid;
    guint8	xxa[4];
    guint32	kind;
    guint8	xxb[16];
    guint32	caplen;
    guint32	length;
    guint32	sec;
    guint32	usec;
    guint32	pid;
    guint8	xxc[10];
    guint16	uid;
};

/*
 * This is what we treat as the minimum size of a record header.
 * It is *not* necessarily the same as sizeof(struct nettlrec_hdr),
 * because it doesn't include any padding added to the structure.
 */
#define NETTL_REC_HDR_LEN	64

/* HP nettl record header for the SX25L2 subsystem - The FCS is not included
   in the file. */
struct nettlrec_sx25l2_hdr {
    guint8	xxa[8];
    guint8	from_dce;
    guint8	xxb[55];
    guint8	caplen[2];
    guint8	length[2];
    guint8	xxc[4];
    guint8	sec[4];
    guint8	usec[4];
    guint8	xxd[4];
};

/* NL_LS_DRIVER :
The following shows what the header and subheader looks like for NS_LS_DRIVER
The capture was taken on HPUX11 and for a 100baseT interface.

000080 00 44 00 0b 00 00 00 02 00 00 00 00 20 00 00 00
000090 00 00 00 00 00 00 04 06 00 00 00 00 00 00 00 00
0000a0 00 00 00 74 00 00 00 74 3c e3 76 19 00 06 34 63
0000b0 ff ff ff ff 00 00 00 00 00 00 00 00 ff ff ff ff
0000c0 00 00 00 00 00 00 01 02 00 5c 00 5c ff ff ff ff
0000d0 3c e3 76 19 00 06 34 5a 00 0b 00 14 <here starts the MAC header>

Each entry starts with 0x0044000b

The values 0x005c at position 0x0000c8 and 0x0000ca matches the number of
bytes in the packet up to the next entry, which starts with 0x00440b again.
These are the captured and real and captured length of the packet.

The values 0x00000074 at positions 0x0000a0 and 0x0000a4 seems to indicate
the same number as positions 0x0000c8 and 0x0000ca but added with 24.
Perhaps we have here two layers of headers.
The first layer is fixed and consists of all the bytes from 0x000084 up to and
including 0x0000c3 which is a generic header for all packets captured from any
device. This header might be of fixed size 64 bytes (although the first two
bytes appear to be the length of that header, in big-endian format) and there
might be something in it which indicates the type of the next header which is
link type specific. Following this header there is another header for the
100baseT interface which in this case is 24 bytes long spanning positions
0x0000c4 to 0x0000db.

In another capture, claimed to be taken on an HP-UX 8 box, but with a
file header suggesting it was taken on HP-UX 10.20, the header for
NS_LS_DRIVER looks like:

000080   00 40 00 0b ff ff ff ff 00 00 00 00 00 00 00 00
000090   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000a0   00 00 00 51 00 00 00 51 42 02 5e bf 00 0e ab 7c
0000b0   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000c0   00 02 01 00 00 3b 00 3b ff ff ff ff 42 02 5e bf
0000d0   00 0e 8e 44 00 0b <here starts the MAC header>

When someone reports that the loading of the captures breaks, we can
compare this header above with what he/she got to learn how to
distinguish between different types of link specific headers.


For now, the subheader for 100baseT seems to be
	4-5	captured length
	6-7	actual length
	8-11	unknown
	12-15	secs
	16-19	usecs
	20-21	unknown
*/
struct nettlrec_ns_ls_drv_eth_hdr {
    guint8	xxa[4];
    guint8      caplen[2];
    guint8      length[2];
    guint8	xxb[4];
    guint8	sec[4];
    guint8	usec[4];
    guint8	xxc[2];
};

/*
 * This is the size of an NS_LS_DRV_ETH header; it is *not* necessarily
 * the same as sizeof(struct nettlrec_ns_ls_drv_eth_hdr), because it
 * doesn't include any padding added to the structure.
 */
#define NS_LS_DRV_ETH_HDR_LEN	22

/* header is followed by data and once again the total length (2 bytes) ! */

typedef struct {
	gboolean is_hpux_11;
} nettl_t;

static gboolean nettl_read(wtap *wth, int *err, gchar **err_info,
		gint64 *data_offset);
static gboolean nettl_seek_read(wtap *wth, gint64 seek_off,
		struct wtap_pkthdr *phdr, Buffer *buf,
		int *err, gchar **err_info);
static gboolean nettl_read_rec(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr,
		Buffer *buf, int *err, gchar **err_info);
static gboolean nettl_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
    const guint8 *pd, int *err);

int nettl_open(wtap *wth, int *err, gchar **err_info)
{
    struct nettl_file_hdr file_hdr;
    guint16 dummy[2];
    int subsys;
    int bytes_read;
    nettl_t *nettl;

    memset(&file_hdr, 0, sizeof(file_hdr));

    /* Read in the string that should be at the start of a HP file */
    errno = WTAP_ERR_CANT_READ;
    bytes_read = file_read(file_hdr.magic, MAGIC_SIZE, wth->fh);
    if (bytes_read != MAGIC_SIZE) {
    	*err = file_error(wth->fh, err_info);
	if (*err != 0 && *err != WTAP_ERR_SHORT_READ)
	    return -1;
	return 0;
    }

    if (memcmp(file_hdr.magic, nettl_magic_hpux9, MAGIC_SIZE) &&
        memcmp(file_hdr.magic, nettl_magic_hpux10, MAGIC_SIZE)) {
	return 0;
    }

    /* Read the rest of the file header */
    bytes_read = file_read(file_hdr.file_name, FILE_HDR_SIZE - MAGIC_SIZE,
			   wth->fh);
    if (bytes_read != FILE_HDR_SIZE - MAGIC_SIZE) {
	*err = file_error(wth->fh, err_info);
	if (*err == 0)
	    *err = WTAP_ERR_SHORT_READ;
	return -1;
    }

    /* This is an nettl file */
    wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_NETTL;
    nettl = g_new(nettl_t,1);
    wth->priv = (void *)nettl;
    if (file_hdr.os_vers[2] == '1' && file_hdr.os_vers[3] == '1')
	nettl->is_hpux_11 = TRUE;
    else
	nettl->is_hpux_11 = FALSE;
    wth->subtype_read = nettl_read;
    wth->subtype_seek_read = nettl_seek_read;
    wth->snapshot_length = 0;	/* not available */

    /* read the first header to take a guess at the file encap */
    bytes_read = file_read(dummy, 4, wth->fh);
    if (bytes_read != 4) {
        if (*err != 0) {
            return -1;
        }
        if (bytes_read != 0) {
            *err = WTAP_ERR_SHORT_READ;
            return -1;
        }
        return 0;
    }

    subsys = g_ntohs(dummy[1]);
    switch (subsys) {
        case NETTL_SUBSYS_HPPB_FDDI :
        case NETTL_SUBSYS_EISA_FDDI :
        case NETTL_SUBSYS_PCI_FDDI :
        case NETTL_SUBSYS_HSC_FDDI :
		wth->file_encap = WTAP_ENCAP_NETTL_FDDI;
		break;
        case NETTL_SUBSYS_TOKEN :
        case NETTL_SUBSYS_PCI_TR :
		wth->file_encap = WTAP_ENCAP_NETTL_TOKEN_RING;
		break;
        case NETTL_SUBSYS_NS_LS_IP :
        case NETTL_SUBSYS_NS_LS_LOOPBACK :
        case NETTL_SUBSYS_NS_LS_TCP :
        case NETTL_SUBSYS_NS_LS_UDP :
        case NETTL_SUBSYS_NS_LS_IPV6 :
		wth->file_encap = WTAP_ENCAP_NETTL_RAW_IP;
		break;
        case NETTL_SUBSYS_NS_LS_ICMP :
		wth->file_encap = WTAP_ENCAP_NETTL_RAW_ICMP;
		break;
        case NETTL_SUBSYS_NS_LS_ICMPV6 :
		wth->file_encap = WTAP_ENCAP_NETTL_RAW_ICMPV6;
		break;
        case NETTL_SUBSYS_NS_LS_TELNET :
		wth->file_encap = WTAP_ENCAP_NETTL_RAW_TELNET;
		break;
	default:
		/* If this assumption is bad, the read will catch it */
		wth->file_encap = WTAP_ENCAP_NETTL_ETHERNET;
    }

    if (file_seek(wth->fh, FILE_HDR_SIZE, SEEK_SET, err) == -1) {
	return -1;
    }
    wth->tsprecision = WTAP_FILE_TSPREC_USEC;

    return 1;
}

/* Read the next packet */
static gboolean nettl_read(wtap *wth, int *err, gchar **err_info,
    gint64 *data_offset)
{
    /* Read record. */
    *data_offset = file_tell(wth->fh);
    if (!nettl_read_rec(wth, wth->fh, &wth->phdr, wth->frame_buffer,
        err, err_info)) {
	/* Read error or EOF */
	return FALSE;
    }

    /*
     * If the per-file encapsulation isn't known, set it to this
     * packet's encapsulation.
     *
     * If it *is* known, and it isn't this packet's encapsulation,
     * set it to WTAP_ENCAP_PER_PACKET, as this file doesn't
     * have a single encapsulation for all packets in the file.
     */
    if (wth->file_encap == WTAP_ENCAP_UNKNOWN)
	wth->file_encap = wth->phdr.pkt_encap;
    else {
	if (wth->file_encap != wth->phdr.pkt_encap)
	    wth->file_encap = WTAP_ENCAP_PER_PACKET;
    }

    return TRUE;
}

static gboolean
nettl_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
		Buffer *buf, int *err, gchar **err_info)
{
    if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
	return FALSE;

    /* Read record header. */
    if (!nettl_read_rec(wth, wth->random_fh, phdr, buf, err, err_info)) {
	/* Read error or EOF */
	if (*err == 0) {
	    /* EOF means "short read" in random-access mode */
	    *err = WTAP_ERR_SHORT_READ;
	}
	return FALSE;
    }
    return TRUE;
}

static gboolean
nettl_read_rec(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr, Buffer *buf,
		int *err, gchar **err_info)
{
    union wtap_pseudo_header *pseudo_header = &phdr->pseudo_header;
    nettl_t *nettl = (nettl_t *)wth->priv;
    gboolean fddihack = FALSE;
    int bytes_read;
    struct nettlrec_hdr rec_hdr;
    guint16 hdr_len;
    struct nettlrec_ns_ls_drv_eth_hdr drv_eth_hdr;
    guint32 length, caplen;
    int subsys;
    guint padlen;
    int datalen;
    guint8 dummyc[16];
    int bytes_to_read;
    guint8 *pd;
    guint8 dummy[3];

    errno = WTAP_ERR_CANT_READ;
    bytes_read = file_read(&rec_hdr.hdr_len, sizeof rec_hdr.hdr_len, fh);
    if (bytes_read != sizeof rec_hdr.hdr_len) {
	*err = file_error(fh, err_info);
	if (*err == 0 && bytes_read != 0)
	    *err = WTAP_ERR_SHORT_READ;
	return FALSE;
    }
    hdr_len = g_ntohs(rec_hdr.hdr_len);
    if (hdr_len < NETTL_REC_HDR_LEN) {
    	*err = WTAP_ERR_BAD_FILE;
	*err_info = g_strdup_printf("nettl: record header length %u too short",
	    hdr_len);
	return FALSE;
    }
    bytes_read = file_read(&rec_hdr.subsys, NETTL_REC_HDR_LEN - 2, fh);
    if (bytes_read != NETTL_REC_HDR_LEN - 2) {
	*err = file_error(fh, err_info);
	if (*err == 0)
	    *err = WTAP_ERR_SHORT_READ;
	return FALSE;
    }
    subsys = g_ntohs(rec_hdr.subsys);
    hdr_len -= NETTL_REC_HDR_LEN;
    if (file_seek(fh, hdr_len, SEEK_CUR, err) == -1)
	return FALSE;

    if ( (pntoh32(&rec_hdr.kind) & NETTL_HDR_PDU_MASK) == 0 ) {
        /* not actually a data packet (PDU) trace record */
        phdr->pkt_encap = WTAP_ENCAP_NETTL_RAW_IP;
        length = pntoh32(&rec_hdr.length);
        caplen = pntoh32(&rec_hdr.caplen);
        padlen = 0;
    } else switch (subsys) {
	case NETTL_SUBSYS_LAN100 :
	case NETTL_SUBSYS_EISA100BT :
	case NETTL_SUBSYS_BASE100 :
	case NETTL_SUBSYS_GSC100BT :
	case NETTL_SUBSYS_PCI100BT :
	case NETTL_SUBSYS_SPP100BT :
	case NETTL_SUBSYS_100VG :
	case NETTL_SUBSYS_GELAN :
	case NETTL_SUBSYS_BTLAN :
	case NETTL_SUBSYS_INTL100 :
	case NETTL_SUBSYS_IGELAN :
	case NETTL_SUBSYS_IETHER :
	case NETTL_SUBSYS_IXGBE :
	case NETTL_SUBSYS_HSSN :
	case NETTL_SUBSYS_IGSSN :
	case NETTL_SUBSYS_ICXGBE :
	case NETTL_SUBSYS_IEXGBE :
	case NETTL_SUBSYS_IOCXGBE :
	case NETTL_SUBSYS_IQXGBE :
	case NETTL_SUBSYS_HPPB_FDDI :
	case NETTL_SUBSYS_EISA_FDDI :
        case NETTL_SUBSYS_PCI_FDDI :
        case NETTL_SUBSYS_HSC_FDDI :
        case NETTL_SUBSYS_TOKEN :
        case NETTL_SUBSYS_PCI_TR :
	case NETTL_SUBSYS_NS_LS_IP :
	case NETTL_SUBSYS_NS_LS_LOOPBACK :
	case NETTL_SUBSYS_NS_LS_TCP :
	case NETTL_SUBSYS_NS_LS_UDP :
	case NETTL_SUBSYS_HP_APAPORT :
	case NETTL_SUBSYS_HP_APALACP :
	case NETTL_SUBSYS_NS_LS_IPV6 :
	case NETTL_SUBSYS_NS_LS_ICMPV6 :
	case NETTL_SUBSYS_NS_LS_ICMP :
	case NETTL_SUBSYS_NS_LS_TELNET :
	case NETTL_SUBSYS_NS_LS_SCTP :
	    if( (subsys == NETTL_SUBSYS_NS_LS_IP)
	     || (subsys == NETTL_SUBSYS_NS_LS_LOOPBACK)
	     || (subsys == NETTL_SUBSYS_NS_LS_UDP)
	     || (subsys == NETTL_SUBSYS_NS_LS_TCP)
	     || (subsys == NETTL_SUBSYS_NS_LS_SCTP)
	     || (subsys == NETTL_SUBSYS_NS_LS_IPV6)) {
		phdr->pkt_encap = WTAP_ENCAP_NETTL_RAW_IP;
	    } else if (subsys == NETTL_SUBSYS_NS_LS_ICMP) {
		phdr->pkt_encap = WTAP_ENCAP_NETTL_RAW_ICMP;
	    } else if (subsys == NETTL_SUBSYS_NS_LS_ICMPV6) {
		phdr->pkt_encap = WTAP_ENCAP_NETTL_RAW_ICMPV6;
	    } else if (subsys == NETTL_SUBSYS_NS_LS_TELNET) {
		phdr->pkt_encap = WTAP_ENCAP_NETTL_RAW_TELNET;
	    } else if( (subsys == NETTL_SUBSYS_HPPB_FDDI)
		    || (subsys == NETTL_SUBSYS_EISA_FDDI)
		    || (subsys == NETTL_SUBSYS_PCI_FDDI)
		    || (subsys == NETTL_SUBSYS_HSC_FDDI) ) {
		phdr->pkt_encap = WTAP_ENCAP_NETTL_FDDI;
	    } else if( (subsys == NETTL_SUBSYS_PCI_TR)
		    || (subsys == NETTL_SUBSYS_TOKEN) ) {
		phdr->pkt_encap = WTAP_ENCAP_NETTL_TOKEN_RING;
	    } else {
		phdr->pkt_encap = WTAP_ENCAP_NETTL_ETHERNET;
	    }

	    length = pntoh32(&rec_hdr.length);
	    caplen = pntoh32(&rec_hdr.caplen);

	    /* HPPB FDDI has different inbound vs outbound trace records */
	    if (subsys == NETTL_SUBSYS_HPPB_FDDI) {
                if (pntoh32(&rec_hdr.kind) == NETTL_HDR_PDUIN) {
                    /* inbound is very strange...
                       there are an extra 3 bytes after the DSAP and SSAP
                       for SNAP frames ???
                    */
                    fddihack=TRUE;
                    padlen = 0;
                } else {
	            /* outbound appears to have variable padding */
		    bytes_read = file_read(dummyc, 9, fh);
		    if (bytes_read != 9) {
			*err = file_error(fh, err_info);
			if (*err == 0)
			    *err = WTAP_ERR_SHORT_READ;
			return FALSE;
		    }
                    /* padding is usually either a total 11 or 16 bytes??? */
		    padlen = (int)dummyc[8];
		    if (file_seek(fh, padlen, SEEK_CUR, err) == -1)
			return FALSE;
		    padlen += 9;
		}
	    } else if ( (subsys == NETTL_SUBSYS_PCI_FDDI)
	             || (subsys == NETTL_SUBSYS_EISA_FDDI)
	             || (subsys == NETTL_SUBSYS_HSC_FDDI) ) {
	        /* other flavor FDDI cards have an extra 3 bytes of padding */
                if (file_seek(fh, 3, SEEK_CUR, err) == -1)
                    return FALSE;
                padlen = 3;
	    } else if (subsys == NETTL_SUBSYS_NS_LS_LOOPBACK) {
	        /* LOOPBACK has an extra 26 bytes of padding */
                if (file_seek(fh, 26, SEEK_CUR, err) == -1)
                    return FALSE;
                padlen = 26;
            } else if (subsys == NETTL_SUBSYS_NS_LS_SCTP) {
                /*
                 * SCTP 8 byte header that we will ignore...
                 * 32 bit integer defines format
                 *   1 = Log
                 *   2 = ASCII
                 *   3 = Binary (PDUs should be Binary format)
                 * 32 bit integer defines type
                 *   1 = Inbound
                 *   2 = Outbound
                 */
                if (file_seek(fh, 8, SEEK_CUR, err) == -1)
                    return FALSE;
                padlen = 8;
	    } else {
	    	padlen = 0;
	    }
	    break;

	case NETTL_SUBSYS_NS_LS_DRIVER :
	    /* XXX we dont know how to identify this as ethernet frames, so
	       we assumes everything is. We will crash and burn for anything else */
	    /* for encapsulated 100baseT we do this */
	    phdr->pkt_encap = WTAP_ENCAP_NETTL_ETHERNET;
	    bytes_read = file_read(&drv_eth_hdr, NS_LS_DRV_ETH_HDR_LEN, fh);
	    if (bytes_read != NS_LS_DRV_ETH_HDR_LEN) {
		*err = file_error(fh, err_info);
		if (*err == 0)
		    *err = WTAP_ERR_SHORT_READ;
		return FALSE;
	    }

	    length = pntoh16(&drv_eth_hdr.length);
	    caplen = pntoh16(&drv_eth_hdr.caplen);
	    /*
	     * XXX - is there a length field that would give the length
	     * of this header, so that we don't have to check for
	     * nettl files from HP-UX 11?
	     *
	     * And what are the extra two bytes?
	     */
            if (nettl->is_hpux_11) {
                if (file_seek(fh, 2, SEEK_CUR, err) == -1) return FALSE;
            }
	    padlen = 0;
	    break;

	case NETTL_SUBSYS_SX25L2:
	case NETTL_SUBSYS_SX25L3:
	    /*
	     * XXX - is the 24-byte padding actually a header with
	     * packet lengths, time stamps, etc., just as is the case
	     * for NETTL_SUBSYS_NS_LS_DRIVER?  It might be
	     *
	     *    guint8	caplen[2];
	     *    guint8	length[2];
	     *    guint8	xxc[4];
	     *    guint8	sec[4];
	     *    guint8	usec[4];
	     *    guint8	xxd[4];
	     *
	     * or something such as that - if it has 4 bytes before that
	     * (making it 24 bytes), it'd be like struct
	     * nettlrec_ns_ls_drv_eth_hdr but with 2 more bytes at the end.
	     *
	     * And is "from_dce" at xxa[0] in the nettlrec_hdr structure?
	     */
	    phdr->pkt_encap = WTAP_ENCAP_NETTL_X25;
	    length = pntoh32(&rec_hdr.length);
	    caplen = pntoh32(&rec_hdr.caplen);
	    padlen = 24;	/* sizeof (struct nettlrec_sx25l2_hdr) - NETTL_REC_HDR_LEN + 4 */
	    if (file_seek(fh, padlen, SEEK_CUR, err) == -1)
		return FALSE;
	    break;

	default:
            /* We're going to assume it's ethernet if we don't recognize the
               subsystem -- We'll probably spew junks and core if it isn't... */
	    wth->file_encap = WTAP_ENCAP_PER_PACKET;
	    phdr->pkt_encap = WTAP_ENCAP_NETTL_ETHERNET;
            length = pntoh32(&rec_hdr.length);
            caplen = pntoh32(&rec_hdr.caplen);
            padlen = 0;
            break;
    }

    if (length < padlen) {
	*err = WTAP_ERR_BAD_FILE;
	*err_info = g_strdup_printf("nettl: packet length %u in record header too short, less than %u",
	    length, padlen);
	return FALSE;
    }
    phdr->presence_flags = WTAP_HAS_TS|WTAP_HAS_CAP_LEN;
    phdr->len = length - padlen;
    if (caplen < padlen) {
	*err = WTAP_ERR_BAD_FILE;
	*err_info = g_strdup_printf("nettl: captured length %u in record header too short, less than %u",
	    caplen, padlen);
	return FALSE;
    }
    datalen = caplen - padlen;
    phdr->caplen = datalen;
    phdr->ts.secs = pntoh32(&rec_hdr.sec);
    phdr->ts.nsecs = pntoh32(&rec_hdr.usec) * 1000;

    pseudo_header->nettl.subsys   = subsys;
    pseudo_header->nettl.devid    = pntoh32(&rec_hdr.devid);
    pseudo_header->nettl.kind     = pntoh32(&rec_hdr.kind);
    pseudo_header->nettl.pid      = pntoh32(&rec_hdr.pid);
    pseudo_header->nettl.uid      = pntoh16(&rec_hdr.uid);

    if (phdr->caplen > WTAP_MAX_PACKET_SIZE) {
	/*
	 * Probably a corrupt capture file; don't blow up trying
	 * to allocate space for an immensely-large packet.
	 */
	*err = WTAP_ERR_BAD_FILE;
	*err_info = g_strdup_printf("nettl: File has %u-byte packet, bigger than maximum of %u",
	    phdr->caplen, WTAP_MAX_PACKET_SIZE);
	return FALSE;
    }

    /*
     * Read the packet data.
     */
    buffer_assure_space(buf, datalen);
    pd = buffer_start_ptr(buf);
    errno = WTAP_ERR_CANT_READ;
    if (fddihack) {
        /* read in FC, dest, src, DSAP and SSAP */
        bytes_to_read = 15;
        if (bytes_to_read > datalen)
            bytes_to_read = datalen;
        bytes_read = file_read(pd, bytes_to_read, fh);
        if (bytes_read != bytes_to_read) {
            if (*err == 0)
                *err = WTAP_ERR_SHORT_READ;
            return FALSE;
        }
        datalen -= bytes_read;
        if (datalen == 0) {
            /* There's nothing past the FC, dest, src, DSAP and SSAP */
            return TRUE;
        }
        if (pd[13] == 0xAA) {
            /* it's SNAP, have to eat 3 bytes??? */
            bytes_to_read = 3;
            if (bytes_to_read > datalen)
                bytes_to_read = datalen;
            bytes_read = file_read(dummy, bytes_to_read, fh);
            if (bytes_read != bytes_to_read) {
                if (*err == 0)
                    *err = WTAP_ERR_SHORT_READ;
                return FALSE;
            }
            datalen -= bytes_read;
            if (datalen == 0) {
                /* There's nothing past the FC, dest, src, DSAP, SSAP, and 3 bytes to eat */
		return TRUE;
	    }
        }
        bytes_read = file_read(pd + 15, datalen, fh);
    } else
        bytes_read = file_read(pd, datalen, fh);

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

/* Returns 0 if we could write the specified encapsulation type,
   an error indication otherwise.  nettl files are WTAP_ENCAP_UNKNOWN
   when they are first opened, so we allow that for tshark read/write.
 */

int nettl_dump_can_write_encap(int encap)
{

	switch (encap) {
		case WTAP_ENCAP_ETHERNET:
		case WTAP_ENCAP_FDDI_BITSWAPPED:
		case WTAP_ENCAP_TOKEN_RING:
		case WTAP_ENCAP_NETTL_ETHERNET:
		case WTAP_ENCAP_NETTL_FDDI:
		case WTAP_ENCAP_NETTL_TOKEN_RING:
		case WTAP_ENCAP_NETTL_RAW_IP:
		case WTAP_ENCAP_NETTL_RAW_ICMP:
		case WTAP_ENCAP_NETTL_RAW_ICMPV6:
		case WTAP_ENCAP_NETTL_RAW_TELNET:
/*
		case WTAP_ENCAP_NETTL_X25:
*/
		case WTAP_ENCAP_PER_PACKET:
		case WTAP_ENCAP_UNKNOWN:
		case WTAP_ENCAP_NETTL_UNKNOWN:
			return 0;
		default:
			return WTAP_ERR_UNSUPPORTED_ENCAP;
	}
}


/* Returns TRUE on success, FALSE on failure;
   sets "*err" to an error code on failure */
gboolean nettl_dump_open(wtap_dumper *wdh, int *err)
{
	struct nettl_file_hdr file_hdr;

	/* This is a nettl file */
	wdh->subtype_write = nettl_dump;
	wdh->subtype_close = NULL;

	/* Write the file header. */
	memset(&file_hdr,0,sizeof(file_hdr));
	memcpy(file_hdr.magic,nettl_magic_hpux10,sizeof(file_hdr.magic));
	g_strlcpy(file_hdr.file_name,"/tmp/wireshark.TRC000",NETTL_FILENAME_SIZE);
	g_strlcpy(file_hdr.tz,"UTC",20);
	g_strlcpy(file_hdr.host_name,"",9);
	g_strlcpy(file_hdr.os_vers,"B.11.11",9);
	file_hdr.os_v=0x55;
	g_strlcpy(file_hdr.model,"9000/800",11);
	file_hdr.unknown=g_htons(0x406);
	if (!wtap_dump_file_write(wdh, &file_hdr, sizeof file_hdr, err))
		return FALSE;
	wdh->bytes_dumped += sizeof(file_hdr);

	return TRUE;
}

/* Write a record for a packet to a dump file.
   Returns TRUE on success, FALSE on failure. */
static gboolean nettl_dump(wtap_dumper *wdh,
	const struct wtap_pkthdr *phdr,
	const guint8 *pd, int *err)
{
	const union wtap_pseudo_header *pseudo_header = &phdr->pseudo_header;
	struct nettlrec_hdr rec_hdr;
	guint8 dummyc[24];

	/* Don't write anything we're not willing to read. */
	if (phdr->caplen > WTAP_MAX_PACKET_SIZE) {
		*err = WTAP_ERR_PACKET_TOO_LARGE;
		return FALSE;
	}

	memset(&rec_hdr,0,sizeof(rec_hdr));
        /* HP-UX 11.X header should be 68 bytes */
	rec_hdr.hdr_len = g_htons(sizeof(rec_hdr) + 4);
	rec_hdr.kind = g_htonl(NETTL_HDR_PDUIN);
	rec_hdr.sec = g_htonl(phdr->ts.secs);
	rec_hdr.usec = g_htonl(phdr->ts.nsecs/1000);
	rec_hdr.caplen = g_htonl(phdr->caplen);
	rec_hdr.length = g_htonl(phdr->len);
	rec_hdr.devid = -1;
	rec_hdr.pid = -1;
	rec_hdr.uid = -1;

	switch (phdr->pkt_encap) {

		case WTAP_ENCAP_NETTL_FDDI:
			/* account for pad bytes */
			rec_hdr.caplen = g_htonl(phdr->caplen + 3);
			rec_hdr.length = g_htonl(phdr->len + 3);
                        /* fall through and fill the rest of the fields */
		case WTAP_ENCAP_NETTL_ETHERNET:
		case WTAP_ENCAP_NETTL_TOKEN_RING:
		case WTAP_ENCAP_NETTL_RAW_IP:
		case WTAP_ENCAP_NETTL_RAW_ICMP:
		case WTAP_ENCAP_NETTL_RAW_ICMPV6:
		case WTAP_ENCAP_NETTL_RAW_TELNET:
		case WTAP_ENCAP_NETTL_UNKNOWN:
			rec_hdr.subsys = g_htons(pseudo_header->nettl.subsys);
			rec_hdr.devid = g_htonl(pseudo_header->nettl.devid);
			rec_hdr.kind = g_htonl(pseudo_header->nettl.kind);
			rec_hdr.pid = g_htonl(pseudo_header->nettl.pid);
			rec_hdr.uid = g_htons(pseudo_header->nettl.uid);
			break;

		case WTAP_ENCAP_RAW_IP:
			rec_hdr.subsys = g_htons(NETTL_SUBSYS_NS_LS_IP);
			break;

		case WTAP_ENCAP_ETHERNET:
			rec_hdr.subsys = g_htons(NETTL_SUBSYS_BTLAN);
			break;

		case WTAP_ENCAP_FDDI_BITSWAPPED:
			rec_hdr.subsys = g_htons(NETTL_SUBSYS_PCI_FDDI);
			/* account for pad bytes */
			rec_hdr.caplen = g_htonl(phdr->caplen + 3);
			rec_hdr.length = g_htonl(phdr->len + 3);
			break;

		case WTAP_ENCAP_TOKEN_RING:
			rec_hdr.subsys = g_htons(NETTL_SUBSYS_PCI_TR);
			break;
#if 0
		case WTAP_ENCAP_NETTL_X25:
			rec_hdr.caplen = g_htonl(phdr->caplen + 24);
			rec_hdr.length = g_htonl(phdr->len + 24);
			rec_hdr.subsys = g_htons(pseudo_header->nettl.subsys);
			rec_hdr.devid = g_htonl(pseudo_header->nettl.devid);
			rec_hdr.kind = g_htonl(pseudo_header->nettl.kind);
			rec_hdr.pid = g_htonl(pseudo_header->nettl.pid);
			rec_hdr.uid = g_htons(pseudo_header->nettl.uid);
			break;
#endif
		default:
			/* found one we don't support */
			*err = WTAP_ERR_UNSUPPORTED_ENCAP;
			return FALSE;
	}

	if (!wtap_dump_file_write(wdh, &rec_hdr, sizeof(rec_hdr), err))
		return FALSE;
	wdh->bytes_dumped += sizeof(rec_hdr);

	/* Write out 4 extra bytes of unknown stuff for HP-UX11
	 * header format.
	 */
	memset(dummyc, 0, sizeof dummyc);
	if (!wtap_dump_file_write(wdh, dummyc, 4, err))
		return FALSE;
	wdh->bytes_dumped += 4;

	if ((phdr->pkt_encap == WTAP_ENCAP_FDDI_BITSWAPPED) ||
	    (phdr->pkt_encap == WTAP_ENCAP_NETTL_FDDI)) {
		/* add those weird 3 bytes of padding */
		if (!wtap_dump_file_write(wdh, dummyc, 3, err))
			return FALSE;
        	wdh->bytes_dumped += 3;
	}
/*
	} else if (phdr->pkt_encap == WTAP_ENCAP_NETTL_X25) {
		if (!wtap_dump_file_write(wdh, dummyc, 24, err))
			return FALSE;
		wdh->bytes_dumped += 24;
	}
*/

	/* write actual PDU data */

	if (!wtap_dump_file_write(wdh, pd, phdr->caplen, err))
		return FALSE;
        wdh->bytes_dumped += phdr->caplen;

	return TRUE;
}