This repository has been archived by the owner on Nov 15, 2022. It is now read-only.
/
pcap.c
2029 lines (1824 loc) · 52.6 KB
/
pcap.c
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
/*
* Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Computer Systems
* Engineering Group at Lawrence Berkeley Laboratory.
* 4. Neither the name of the University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef WIN32
#include <pcap-stdinc.h>
#else /* WIN32 */
#if HAVE_INTTYPES_H
#include <inttypes.h>
#elif HAVE_STDINT_H
#include <stdint.h>
#endif
#ifdef HAVE_SYS_BITYPES_H
#include <sys/bitypes.h>
#endif
#include <sys/types.h>
#endif /* WIN32 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if !defined(_MSC_VER) && !defined(__BORLANDC__) && !defined(__MINGW32__)
#include <unistd.h>
#endif
#include <fcntl.h>
#include <errno.h>
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
#ifdef MSDOS
#include "pcap-dos.h"
#endif
#include "pcap-int.h"
#ifdef HAVE_DAG_API
#include "pcap-dag.h"
#endif /* HAVE_DAG_API */
#ifdef HAVE_SEPTEL_API
#include "pcap-septel.h"
#endif /* HAVE_SEPTEL_API */
#ifdef HAVE_SNF_API
#include "pcap-snf.h"
#endif /* HAVE_SNF_API */
#ifdef PCAP_SUPPORT_USB
#include "pcap-usb-linux.h"
#endif
#ifdef PCAP_SUPPORT_BT
#include "pcap-bt-linux.h"
#endif
#ifdef PCAP_SUPPORT_BT_MONITOR
#include "pcap-bt-monitor-linux.h"
#endif
#ifdef PCAP_SUPPORT_CAN
#include "pcap-can-linux.h"
#endif
#ifdef PCAP_SUPPORT_CANUSB
#include "pcap-canusb-linux.h"
#endif
#ifdef PCAP_SUPPORT_NETFILTER
#include "pcap-netfilter-linux.h"
#endif
#ifdef PCAP_SUPPORT_DBUS
#include "pcap-dbus.h"
#endif
int
pcap_not_initialized(pcap_t *pcap _U_)
{
/* this means 'not initialized' */
return (PCAP_ERROR_NOT_ACTIVATED);
}
#ifdef WIN32
Adapter *
pcap_no_adapter(pcap_t *pcap _U_)
{
return (NULL);
}
#endif
/*
* Returns 1 if rfmon mode can be set on the pcap_t, 0 if it can't,
* a PCAP_ERROR value on an error.
*/
int
pcap_can_set_rfmon(pcap_t *p)
{
return (p->can_set_rfmon_op(p));
}
/*
* For systems where rfmon mode is never supported.
*/
static int
pcap_cant_set_rfmon(pcap_t *p _U_)
{
return (0);
}
/*
* Sets *tstamp_typesp to point to an array 1 or more supported time stamp
* types; the return value is the number of supported time stamp types.
* The list should be freed by a call to pcap_free_tstamp_types() when
* you're done with it.
*
* A return value of 0 means "you don't get a choice of time stamp type",
* in which case *tstamp_typesp is set to null.
*
* PCAP_ERROR is returned on error.
*/
int
pcap_list_tstamp_types(pcap_t *p, int **tstamp_typesp)
{
if (p->tstamp_type_count == 0) {
/*
* We don't support multiple time stamp types.
*/
*tstamp_typesp = NULL;
} else {
*tstamp_typesp = (int*)calloc(sizeof(**tstamp_typesp),
p->tstamp_type_count);
if (*tstamp_typesp == NULL) {
(void)snprintf(p->errbuf, sizeof(p->errbuf),
"malloc: %s", pcap_strerror(errno));
return (PCAP_ERROR);
}
(void)memcpy(*tstamp_typesp, p->tstamp_type_list,
sizeof(**tstamp_typesp) * p->tstamp_type_count);
}
return (p->tstamp_type_count);
}
/*
* In Windows, you might have a library built with one version of the
* C runtime library and an application built with another version of
* the C runtime library, which means that the library might use one
* version of malloc() and free() and the application might use another
* version of malloc() and free(). If so, that means something
* allocated by the library cannot be freed by the application, so we
* need to have a pcap_free_tstamp_types() routine to free up the list
* allocated by pcap_list_tstamp_types(), even though it's just a wrapper
* around free().
*/
void
pcap_free_tstamp_types(int *tstamp_type_list)
{
free(tstamp_type_list);
}
/*
* Default one-shot callback; overridden for capture types where the
* packet data cannot be guaranteed to be available after the callback
* returns, so that a copy must be made.
*/
void
pcap_oneshot(u_char *user, const struct pcap_pkthdr *h, const u_char *pkt)
{
struct oneshot_userdata *sp = (struct oneshot_userdata *)user;
*sp->hdr = *h;
*sp->pkt = pkt;
}
const u_char *
pcap_next(pcap_t *p, struct pcap_pkthdr *h)
{
struct oneshot_userdata s;
const u_char *pkt;
s.hdr = h;
s.pkt = &pkt;
s.pd = p;
if (pcap_dispatch(p, 1, p->oneshot_callback, (u_char *)&s) <= 0)
return (0);
return (pkt);
}
int
pcap_next_ex(pcap_t *p, struct pcap_pkthdr **pkt_header,
const u_char **pkt_data)
{
struct oneshot_userdata s;
s.hdr = &p->pcap_header;
s.pkt = pkt_data;
s.pd = p;
/* Saves a pointer to the packet headers */
*pkt_header= &p->pcap_header;
if (p->rfile != NULL) {
int status;
/* We are on an offline capture */
status = pcap_offline_read(p, 1, p->oneshot_callback,
(u_char *)&s);
/*
* Return codes for pcap_offline_read() are:
* - 0: EOF
* - -1: error
* - >1: OK
* The first one ('0') conflicts with the return code of
* 0 from pcap_read() meaning "no packets arrived before
* the timeout expired", so we map it to -2 so you can
* distinguish between an EOF from a savefile and a
* "no packets arrived before the timeout expired, try
* again" from a live capture.
*/
if (status == 0)
return (-2);
else
return (status);
}
/*
* Return codes for pcap_read() are:
* - 0: timeout
* - -1: error
* - -2: loop was broken out of with pcap_breakloop()
* - >1: OK
* The first one ('0') conflicts with the return code of 0 from
* pcap_offline_read() meaning "end of file".
*/
return (p->read_op(p, 1, p->oneshot_callback, (u_char *)&s));
}
#if defined(DAG_ONLY)
int
pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
{
return (dag_findalldevs(alldevsp, errbuf));
}
pcap_t *
pcap_create(const char *source, char *errbuf)
{
int is_ours;
return (dag_create(source, errbuf, &is_ours));
}
#elif defined(SEPTEL_ONLY)
int
pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
{
return (septel_findalldevs(alldevsp, errbuf));
}
pcap_t *
pcap_create(const char *source, char *errbuf)
{
int is_ours;
return (septel_create(source, errbuf, &is_ours));
}
#elif defined(SNF_ONLY)
int
pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
{
return (snf_findalldevs(alldevsp, errbuf));
}
pcap_t *
pcap_create(const char *source, char *errbuf)
{
int is_ours;
return (snf_create(source, errbuf, &is_ours));
}
#else /* regular pcap */
struct capture_source_type {
int (*findalldevs_op)(pcap_if_t **, char *);
pcap_t *(*create_op)(const char *, char *, int *);
} capture_source_types[] = {
#ifdef HAVE_DAG_API
{ dag_findalldevs, dag_create },
#endif
#ifdef HAVE_SEPTEL_API
{ septel_findalldevs, septel_create },
#endif
#ifdef HAVE_SNF_API
{ snf_findalldevs, snf_create },
#endif
#ifdef PCAP_SUPPORT_BT
{ bt_findalldevs, bt_create },
#endif
#ifdef PCAP_SUPPORT_BT_MONITOR
{ bt_monitor_findalldevs, bt_monitor_create },
#endif
#if PCAP_SUPPORT_CANUSB
{ canusb_findalldevs, canusb_create },
#endif
#ifdef PCAP_SUPPORT_CAN
{ can_findalldevs, can_create },
#endif
#ifdef PCAP_SUPPORT_USB
{ usb_findalldevs, usb_create },
#endif
#ifdef PCAP_SUPPORT_NETFILTER
{ netfilter_findalldevs, netfilter_create },
#endif
#ifdef PCAP_SUPPORT_DBUS
{ dbus_findalldevs, dbus_create },
#endif
{ NULL, NULL }
};
/*
* Get a list of all capture sources that are up and that we can open.
* Returns -1 on error, 0 otherwise.
* The list, as returned through "alldevsp", may be null if no interfaces
* were up and could be opened.
*/
int
pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
{
size_t i;
/*
* Get the list of regular interfaces first.
*/
if (pcap_findalldevs_interfaces(alldevsp, errbuf) == -1)
return (-1); /* failure */
/*
* Add any interfaces that need a platform-specific mechanism
* to find.
*/
if (pcap_platform_finddevs(alldevsp, errbuf) == -1) {
/*
* We had an error; free the list we've been
* constructing.
*/
if (*alldevsp != NULL) {
pcap_freealldevs(*alldevsp);
*alldevsp = NULL;
}
return (-1);
}
/*
* Ask each of the non-local-network-interface capture
* source types what interfaces they have.
*/
for (i = 0; capture_source_types[i].findalldevs_op != NULL; i++) {
if (capture_source_types[i].findalldevs_op(alldevsp, errbuf) == -1) {
/*
* We had an error; free the list we've been
* constructing.
*/
if (*alldevsp != NULL) {
pcap_freealldevs(*alldevsp);
*alldevsp = NULL;
}
return (-1);
}
}
return (0);
}
pcap_t *
pcap_create(const char *source, char *errbuf)
{
size_t i;
int is_theirs;
pcap_t *p;
/*
* A null source name is equivalent to the "any" device -
* which might not be supported on this platform, but
* this means that you'll get a "not supported" error
* rather than, say, a crash when we try to dereference
* the null pointer.
*/
if (source == NULL)
source = "any";
/*
* Try each of the non-local-network-interface capture
* source types until we find one that works for this
* device or run out of types.
*/
for (i = 0; capture_source_types[i].create_op != NULL; i++) {
is_theirs = 0;
p = capture_source_types[i].create_op(source, errbuf, &is_theirs);
if (is_theirs) {
/*
* The device name refers to a device of the
* type in question; either it succeeded,
* in which case p refers to a pcap_t to
* later activate for the device, or it
* failed, in which case p is null and we
* should return that to report the failure
* to create.
*/
return (p);
}
}
/*
* OK, try it as a regular network interface.
*/
return (pcap_create_interface(source, errbuf));
}
#endif
static void
initialize_ops(pcap_t *p)
{
/*
* Set operation pointers for operations that only work on
* an activated pcap_t to point to a routine that returns
* a "this isn't activated" error.
*/
p->read_op = (read_op_t)pcap_not_initialized;
p->inject_op = (inject_op_t)pcap_not_initialized;
p->setfilter_op = (setfilter_op_t)pcap_not_initialized;
p->setdirection_op = (setdirection_op_t)pcap_not_initialized;
p->set_datalink_op = (set_datalink_op_t)pcap_not_initialized;
p->getnonblock_op = (getnonblock_op_t)pcap_not_initialized;
p->setnonblock_op = (setnonblock_op_t)pcap_not_initialized;
p->stats_op = (stats_op_t)pcap_not_initialized;
#ifdef WIN32
p->setbuff_op = (setbuff_op_t)pcap_not_initialized;
p->setmode_op = (setmode_op_t)pcap_not_initialized;
p->setmintocopy_op = (setmintocopy_op_t)pcap_not_initialized;
p->getadapter_op = pcap_no_adapter;
#endif
/*
* Default cleanup operation - implementations can override
* this, but should call pcap_cleanup_live_common() after
* doing their own additional cleanup.
*/
p->cleanup_op = pcap_cleanup_live_common;
/*
* In most cases, the standard one-shot callback can
* be used for pcap_next()/pcap_next_ex().
*/
p->oneshot_callback = pcap_oneshot;
}
static pcap_t *
pcap_alloc_pcap_t(char *ebuf, size_t size)
{
char *chunk;
pcap_t *p;
/*
* Allocate a chunk of memory big enough for a pcap_t
* plus a structure following it of size "size". The
* structure following it is a private data structure
* for the routines that handle this pcap_t.
*/
chunk = malloc(sizeof (pcap_t) + size);
if (chunk == NULL) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
pcap_strerror(errno));
return (NULL);
}
memset(chunk, 0, sizeof (pcap_t) + size);
/*
* Get a pointer to the pcap_t at the beginning.
*/
p = (pcap_t *)chunk;
#ifndef WIN32
p->fd = -1; /* not opened yet */
p->selectable_fd = -1;
#endif
if (size == 0) {
/* No private data was requested. */
p->priv = NULL;
} else {
/*
* Set the pointer to the private data; that's the structure
* of size "size" following the pcap_t.
*/
p->priv = (void *)(chunk + sizeof (pcap_t));
}
return (p);
}
pcap_t *
pcap_create_common(const char *source, char *ebuf, size_t size)
{
pcap_t *p;
p = pcap_alloc_pcap_t(ebuf, size);
if (p == NULL)
return (NULL);
p->opt.source = strdup(source);
if (p->opt.source == NULL) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
pcap_strerror(errno));
free(p);
return (NULL);
}
/*
* Default to "can't set rfmon mode"; if it's supported by
* a platform, the create routine that called us can set
* the op to its routine to check whether a particular
* device supports it.
*/
p->can_set_rfmon_op = pcap_cant_set_rfmon;
initialize_ops(p);
/* put in some defaults*/
pcap_set_snaplen(p, MAXIMUM_SNAPLEN); /* max packet size */
p->opt.timeout = 0; /* no timeout specified */
p->opt.buffer_size = 0; /* use the platform's default */
p->opt.promisc = 0;
p->opt.rfmon = 0;
p->opt.immediate = 0;
p->opt.tstamp_type = -1; /* default to not setting time stamp type */
p->opt.tstamp_precision = PCAP_TSTAMP_PRECISION_MICRO;
/*
* Start out with no BPF code generation flags set.
*/
p->bpf_codegen_flags = 0;
return (p);
}
int
pcap_check_activated(pcap_t *p)
{
if (p->activated) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't perform "
" operation on activated capture");
return (-1);
}
return (0);
}
int
pcap_set_snaplen(pcap_t *p, int snaplen)
{
if (pcap_check_activated(p))
return (PCAP_ERROR_ACTIVATED);
p->snapshot = snaplen;
return (0);
}
int
pcap_set_promisc(pcap_t *p, int promisc)
{
if (pcap_check_activated(p))
return (PCAP_ERROR_ACTIVATED);
p->opt.promisc = promisc;
return (0);
}
int
pcap_set_rfmon(pcap_t *p, int rfmon)
{
if (pcap_check_activated(p))
return (PCAP_ERROR_ACTIVATED);
p->opt.rfmon = rfmon;
return (0);
}
int
pcap_set_timeout(pcap_t *p, int timeout_ms)
{
if (pcap_check_activated(p))
return (PCAP_ERROR_ACTIVATED);
p->opt.timeout = timeout_ms;
return (0);
}
int
pcap_set_tstamp_type(pcap_t *p, int tstamp_type)
{
int i;
if (pcap_check_activated(p))
return (PCAP_ERROR_ACTIVATED);
/*
* If p->tstamp_type_count is 0, we only support PCAP_TSTAMP_HOST;
* the default time stamp type is PCAP_TSTAMP_HOST.
*/
if (p->tstamp_type_count == 0) {
if (tstamp_type == PCAP_TSTAMP_HOST) {
p->opt.tstamp_type = tstamp_type;
return (0);
}
} else {
/*
* Check whether we claim to support this type of time stamp.
*/
for (i = 0; i < p->tstamp_type_count; i++) {
if (p->tstamp_type_list[i] == tstamp_type) {
/*
* Yes.
*/
p->opt.tstamp_type = tstamp_type;
return (0);
}
}
}
/*
* We don't support this type of time stamp.
*/
return (PCAP_WARNING_TSTAMP_TYPE_NOTSUP);
}
int
pcap_set_immediate_mode(pcap_t *p, int immediate)
{
if (pcap_check_activated(p))
return (PCAP_ERROR_ACTIVATED);
p->opt.immediate = immediate;
return (0);
}
int
pcap_set_buffer_size(pcap_t *p, int buffer_size)
{
if (pcap_check_activated(p))
return (PCAP_ERROR_ACTIVATED);
p->opt.buffer_size = buffer_size;
return (0);
}
int
pcap_set_tstamp_precision(pcap_t *p, int tstamp_precision)
{
int i;
if (pcap_check_activated(p))
return (PCAP_ERROR_ACTIVATED);
/*
* If p->tstamp_precision_count is 0, we only support setting
* the time stamp precision to microsecond precision; every
* pcap module *MUST* support microsecond precision, even if
* it does so by converting the native precision to
* microseconds.
*/
if (p->tstamp_precision_count == 0) {
if (tstamp_precision == PCAP_TSTAMP_PRECISION_MICRO) {
p->opt.tstamp_precision = tstamp_precision;
return (0);
}
} else {
/*
* Check whether we claim to support this precision of
* time stamp.
*/
for (i = 0; i < p->tstamp_precision_count; i++) {
if (p->tstamp_precision_list[i] == tstamp_precision) {
/*
* Yes.
*/
p->opt.tstamp_precision = tstamp_precision;
return (0);
}
}
}
/*
* We don't support this time stamp precision.
*/
return (PCAP_ERROR_TSTAMP_PRECISION_NOTSUP);
}
int
pcap_get_tstamp_precision(pcap_t *p)
{
return (p->opt.tstamp_precision);
}
int
pcap_activate(pcap_t *p)
{
int status;
/*
* Catch attempts to re-activate an already-activated
* pcap_t; this should, for example, catch code that
* calls pcap_open_live() followed by pcap_activate(),
* as some code that showed up in a Stack Exchange
* question did.
*/
if (pcap_check_activated(p))
return (PCAP_ERROR_ACTIVATED);
status = p->activate_op(p);
if (status >= 0)
p->activated = 1;
else {
if (p->errbuf[0] == '\0') {
/*
* No error message supplied by the activate routine;
* for the benefit of programs that don't specially
* handle errors other than PCAP_ERROR, return the
* error message corresponding to the status.
*/
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s",
pcap_statustostr(status));
}
/*
* Undo any operation pointer setting, etc. done by
* the activate operation.
*/
initialize_ops(p);
}
return (status);
}
pcap_t *
pcap_open_live(const char *source, int snaplen, int promisc, int to_ms, char *errbuf)
{
pcap_t *p;
int status;
p = pcap_create(source, errbuf);
if (p == NULL)
return (NULL);
status = pcap_set_snaplen(p, snaplen);
if (status < 0)
goto fail;
status = pcap_set_promisc(p, promisc);
if (status < 0)
goto fail;
status = pcap_set_timeout(p, to_ms);
if (status < 0)
goto fail;
/*
* Mark this as opened with pcap_open_live(), so that, for
* example, we show the full list of DLT_ values, rather
* than just the ones that are compatible with capturing
* when not in monitor mode. That allows existing applications
* to work the way they used to work, but allows new applications
* that know about the new open API to, for example, find out the
* DLT_ values that they can select without changing whether
* the adapter is in monitor mode or not.
*/
p->oldstyle = 1;
status = pcap_activate(p);
if (status < 0)
goto fail;
return (p);
fail:
if (status == PCAP_ERROR)
snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", source,
p->errbuf);
else if (status == PCAP_ERROR_NO_SUCH_DEVICE ||
status == PCAP_ERROR_PERM_DENIED ||
status == PCAP_ERROR_PROMISC_PERM_DENIED)
snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s (%s)", source,
pcap_statustostr(status), p->errbuf);
else
snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", source,
pcap_statustostr(status));
pcap_close(p);
return (NULL);
}
pcap_t *
pcap_open_offline_common(char *ebuf, size_t size)
{
pcap_t *p;
p = pcap_alloc_pcap_t(ebuf, size);
if (p == NULL)
return (NULL);
p->opt.tstamp_precision = PCAP_TSTAMP_PRECISION_MICRO;
p->opt.source = strdup("(savefile)");
if (p->opt.source == NULL) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
pcap_strerror(errno));
free(p);
return (NULL);
}
return (p);
}
int
pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
return (p->read_op(p, cnt, callback, user));
}
/*
* XXX - is this necessary?
*/
int
pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
return (p->read_op(p, cnt, callback, user));
}
int
pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
register int n;
for (;;) {
if (p->rfile != NULL) {
/*
* 0 means EOF, so don't loop if we get 0.
*/
n = pcap_offline_read(p, cnt, callback, user);
} else {
/*
* XXX keep reading until we get something
* (or an error occurs)
*/
do {
n = p->read_op(p, cnt, callback, user);
} while (n == 0);
}
if (n <= 0)
return (n);
if (!PACKET_COUNT_IS_UNLIMITED(cnt)) {
cnt -= n;
if (cnt <= 0)
return (0);
}
}
}
/*
* Force the loop in "pcap_read()" or "pcap_read_offline()" to terminate.
*/
void
pcap_breakloop(pcap_t *p)
{
p->break_loop = 1;
}
int
pcap_datalink(pcap_t *p)
{
if (!p->activated)
return (PCAP_ERROR_NOT_ACTIVATED);
return (p->linktype);
}
int
pcap_datalink_ext(pcap_t *p)
{
if (!p->activated)
return (PCAP_ERROR_NOT_ACTIVATED);
return (p->linktype_ext);
}
int
pcap_list_datalinks(pcap_t *p, int **dlt_buffer)
{
if (!p->activated)
return (PCAP_ERROR_NOT_ACTIVATED);
if (p->dlt_count == 0) {
/*
* We couldn't fetch the list of DLTs, which means
* this platform doesn't support changing the
* DLT for an interface. Return a list of DLTs
* containing only the DLT this device supports.
*/
*dlt_buffer = (int*)malloc(sizeof(**dlt_buffer));
if (*dlt_buffer == NULL) {
(void)snprintf(p->errbuf, sizeof(p->errbuf),
"malloc: %s", pcap_strerror(errno));
return (PCAP_ERROR);
}
**dlt_buffer = p->linktype;
return (1);
} else {
*dlt_buffer = (int*)calloc(sizeof(**dlt_buffer), p->dlt_count);
if (*dlt_buffer == NULL) {
(void)snprintf(p->errbuf, sizeof(p->errbuf),
"malloc: %s", pcap_strerror(errno));
return (PCAP_ERROR);
}
(void)memcpy(*dlt_buffer, p->dlt_list,
sizeof(**dlt_buffer) * p->dlt_count);
return (p->dlt_count);
}
}
/*
* In Windows, you might have a library built with one version of the
* C runtime library and an application built with another version of
* the C runtime library, which means that the library might use one
* version of malloc() and free() and the application might use another
* version of malloc() and free(). If so, that means something
* allocated by the library cannot be freed by the application, so we
* need to have a pcap_free_datalinks() routine to free up the list
* allocated by pcap_list_datalinks(), even though it's just a wrapper
* around free().
*/
void
pcap_free_datalinks(int *dlt_list)
{
free(dlt_list);
}
int
pcap_set_datalink(pcap_t *p, int dlt)
{
int i;
const char *dlt_name;
if (p->dlt_count == 0 || p->set_datalink_op == NULL) {
/*
* We couldn't fetch the list of DLTs, or we don't
* have a "set datalink" operation, which means
* this platform doesn't support changing the
* DLT for an interface. Check whether the new
* DLT is the one this interface supports.
*/
if (p->linktype != dlt)
goto unsupported;
/*
* It is, so there's nothing we need to do here.
*/
return (0);
}
for (i = 0; i < p->dlt_count; i++)
if (p->dlt_list[i] == dlt)
break;
if (i >= p->dlt_count)
goto unsupported;
if (p->dlt_count == 2 && p->dlt_list[0] == DLT_EN10MB &&
dlt == DLT_DOCSIS) {
/*
* This is presumably an Ethernet device, as the first
* link-layer type it offers is DLT_EN10MB, and the only
* other type it offers is DLT_DOCSIS. That means that
* we can't tell the driver to supply DOCSIS link-layer
* headers - we're just pretending that's what we're
* getting, as, presumably, we're capturing on a dedicated
* link to a Cisco Cable Modem Termination System, and
* it's putting raw DOCSIS frames on the wire inside low-level
* Ethernet framing.
*/
p->linktype = dlt;
return (0);
}
if (p->set_datalink_op(p, dlt) == -1)
return (-1);