forked from regit/suricata
-
Notifications
You must be signed in to change notification settings - Fork 0
/
detect-parse.c
3231 lines (2756 loc) · 95.6 KB
/
detect-parse.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) 2007-2010 Open Information Security Foundation
*
* You can copy, redistribute or modify this Program under the terms of
* the GNU General Public License version 2 as published by the Free
* Software Foundation.
*
* 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
* version 2 along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
/**
* \file
*
* \author Victor Julien <victor@inliniac.net>
*
* signature parser
*/
#include "suricata-common.h"
#include "debug.h"
#include "detect.h"
#include "detect-engine.h"
#include "detect-engine-address.h"
#include "detect-engine-port.h"
#include "detect-engine-mpm.h"
#include "detect-content.h"
#include "detect-uricontent.h"
#include "detect-reference.h"
#include "detect-ipproto.h"
#include "detect-flow.h"
#include "flow.h"
#include "util-rule-vars.h"
#include "conf.h"
#include "conf-yaml-loader.h"
#include "app-layer-protos.h"
#include "app-layer-parser.h"
#include "util-classification-config.h"
#include "util-unittest.h"
#include "util-unittest-helper.h"
#include "util-debug.h"
#include "string.h"
#include "detect-parse.h"
#include "detect-engine-iponly.h"
#include "app-layer-detect-proto.h"
extern int sc_set_caps;
static pcre *config_pcre = NULL;
static pcre *option_pcre = NULL;
static pcre_extra *config_pcre_extra = NULL;
static pcre_extra *option_pcre_extra = NULL;
static uint32_t dbg_srcportany_cnt = 0;
static uint32_t dbg_dstportany_cnt = 0;
/* Context of the app layer proto detection */
extern AlpProtoDetectCtx alp_proto_ctx;
/**
* \brief We use this as data to the hash table DetectEngineCtx->dup_sig_hash_table.
*/
typedef struct SigDuplWrapper_ {
/* the signature we want to wrap */
Signature *s;
/* the signature right before the above signatue in the det_ctx->sig_list */
Signature *s_prev;
} SigDuplWrapper;
#define CONFIG_PARTS 8
#define CONFIG_ACTION 0
#define CONFIG_PROTO 1
#define CONFIG_SRC 2
#define CONFIG_SP 3
#define CONFIG_DIREC 4
#define CONFIG_DST 5
#define CONFIG_DP 6
#define CONFIG_OPTS 7
// action protocol src sp dir dst dp options
#define CONFIG_PCRE "^([A-z]+)\\s+([A-z0-9\\-]+)\\s+([\\[\\]A-z0-9\\.\\:_\\$\\!\\-,\\/]+)\\s+([\\:A-z0-9_\\$\\!,]+)\\s+(-\\>|\\<\\>|\\<\\-)\\s+([\\[\\]A-z0-9\\.\\:_\\$\\!\\-,/]+)\\s+([\\:A-z0-9_\\$\\!,]+)(?:\\s+\\((.*)?(?:\\s*)\\))?(?:(?:\\s*)\\n)?\\s*$"
#define OPTION_PARTS 3
#define OPTION_PCRE "^\\s*([A-z_0-9-\\.]+)(?:\\s*\\:\\s*(.*)(?<!\\\\))?\\s*;\\s*(?:\\s*(.*))?\\s*$"
uint32_t DbgGetSrcPortAnyCnt(void) {
return dbg_srcportany_cnt;
}
uint32_t DbgGetDstPortAnyCnt(void) {
return dbg_dstportany_cnt;
}
SigMatch *SigMatchAlloc(void) {
SigMatch *sm = SCMalloc(sizeof(SigMatch));
if (unlikely(sm == NULL))
return NULL;
memset(sm, 0, sizeof(SigMatch));
sm->prev = NULL;
sm->next = NULL;
return sm;
}
/** \brief free a SigMatch
* \param sm SigMatch to free.
*/
void SigMatchFree(SigMatch *sm) {
if (sm == NULL)
return;
/** free the ctx, for that we call the Free func */
if (sm->ctx != NULL) {
if (sigmatch_table[sm->type].Free != NULL) {
sigmatch_table[sm->type].Free(sm->ctx);
}
}
SCFree(sm);
}
/* Get the detection module by name */
SigTableElmt *SigTableGet(char *name) {
SigTableElmt *st = NULL;
int i = 0;
for (i = 0; i < DETECT_TBLSIZE; i++) {
st = &sigmatch_table[i];
if (st->name != NULL) {
if (strcasecmp(name,st->name) == 0)
return st;
}
}
return NULL;
}
/**
* \brief Append a SigMatch to the list type.
*
* \param s Signature.
* \param new The sig match to append.
* \param list The list to append to.
*/
void SigMatchAppendSMToList(Signature *s, SigMatch *new, int list)
{
if (s->sm_lists[list] == NULL) {
s->sm_lists[list] = new;
s->sm_lists_tail[list] = new;
new->next = NULL;
new->prev = NULL;
} else {
SigMatch *cur = s->sm_lists_tail[list];
cur->next = new;
new->prev = cur;
new->next = NULL;
s->sm_lists_tail[list] = new;
}
new->idx = s->sm_cnt;
s->sm_cnt++;
}
void SigMatchRemoveSMFromList(Signature *s, SigMatch *sm, int sm_list)
{
if (sm == s->sm_lists[sm_list]) {
s->sm_lists[sm_list] = sm->next;
}
if (sm == s->sm_lists_tail[sm_list]) {
s->sm_lists_tail[sm_list] = sm->prev;
}
if (sm->prev != NULL)
sm->prev->next = sm->next;
if (sm->next != NULL)
sm->next->prev = sm->prev;
return;
}
/**
* \brief Returns a pointer to the last SigMatch instance of a particular type
* in a Signature of the payload list.
*
* \param s Pointer to the tail of the sigmatch list
* \param type SigMatch type which has to be searched for in the Signature.
*
* \retval match Pointer to the last SigMatch instance of type 'type'.
*/
static inline SigMatch *SigMatchGetLastSM(SigMatch *sm, uint8_t type)
{
while (sm != NULL) {
if (sm->type == type) {
return sm;
}
sm = sm->prev;
}
return NULL;
}
SigMatch *SigMatchGetLastSMFromLists(Signature *s, int args, ...)
{
if (args == 0 || args % 2 != 0) {
SCLogError(SC_ERR_INVALID_ARGUMENTS, "You need to send an even no of args "
"(non zero as well) to this function, since we need a "
"SigMatch list for every SigMatch type(send a map of sm_type "
"and sm_list) sent");
/* as this is a bug we should abort to ease debugging */
BUG_ON(1);
}
SigMatch *sm_list[args / 2];
int sm_type[args / 2];
int list_index = 0;
va_list ap;
int i = 0, j = 0;
va_start(ap, args);
for (i = 0; i < args; i += 2) {
sm_type[list_index] = va_arg(ap, int);
sm_list[list_index] = va_arg(ap, SigMatch *);
if (sm_list[list_index] != NULL)
list_index++;
}
va_end(ap);
if (list_index == 0)
return NULL;
SigMatch *sm[list_index];
int sm_entries = 0;
for (i = 0; i < list_index; i++) {
sm[sm_entries] = SigMatchGetLastSM(sm_list[i], sm_type[i]);
if (sm[sm_entries] != NULL)
sm_entries++;
}
if (sm_entries == 0)
return NULL;
SigMatch *temp_sm = NULL;
for (i = 1; i < sm_entries; i++) {
for (j = i - 1; j >= 0; j--) {
if (sm[j + 1]->idx > sm[j]->idx) {
temp_sm = sm[j + 1];
sm[j + 1] = sm[j];
sm[j] = temp_sm;
continue;
}
break;
}
}
return sm[0];
}
void SigMatchTransferSigMatchAcrossLists(SigMatch *sm,
SigMatch **src_sm_list, SigMatch **src_sm_list_tail,
SigMatch **dst_sm_list, SigMatch **dst_sm_list_tail)
{
/* we won't do any checks for args */
if (sm->prev != NULL)
sm->prev->next = sm->next;
if (sm->next != NULL)
sm->next->prev = sm->prev;
if (sm == *src_sm_list)
*src_sm_list = sm->next;
if (sm == *src_sm_list_tail)
*src_sm_list_tail = sm->prev;
if (*dst_sm_list == NULL) {
*dst_sm_list = sm;
*dst_sm_list_tail = sm;
sm->next = NULL;
sm->prev = NULL;
} else {
SigMatch *cur = *dst_sm_list_tail;
cur->next = sm;
sm->prev = cur;
sm->next = NULL;
*dst_sm_list_tail = sm;
}
return;
}
int SigMatchListSMBelongsTo(Signature *s, SigMatch *key_sm)
{
int list = 0;
for (list = 0; list < DETECT_SM_LIST_MAX; list++) {
SigMatch *sm = s->sm_lists[list];
while (sm != NULL) {
if (sm == key_sm)
return list;
sm = sm->next;
}
}
SCLogError(SC_ERR_INVALID_SIGNATURE, "Unable to find the sm in any of the "
"sm lists");
return -1;
}
void SigParsePrepare(void) {
char *regexstr = CONFIG_PCRE;
const char *eb;
int eo;
int opts = 0;
opts |= PCRE_UNGREEDY;
config_pcre = pcre_compile(regexstr, opts, &eb, &eo, NULL);
if(config_pcre == NULL)
{
SCLogError(SC_ERR_PCRE_COMPILE, "pcre compile of \"%s\" failed at offset %" PRId32 ": %s", regexstr, eo, eb);
exit(1);
}
config_pcre_extra = pcre_study(config_pcre, 0, &eb);
if(eb != NULL)
{
SCLogError(SC_ERR_PCRE_STUDY, "pcre study failed: %s", eb);
exit(1);
}
regexstr = OPTION_PCRE;
opts |= PCRE_UNGREEDY;
option_pcre = pcre_compile(regexstr, opts, &eb, &eo, NULL);
if(option_pcre == NULL)
{
SCLogError(SC_ERR_PCRE_COMPILE, "pcre compile of \"%s\" failed at offset %" PRId32 ": %s", regexstr, eo, eb);
exit(1);
}
option_pcre_extra = pcre_study(option_pcre, 0, &eb);
if(eb != NULL)
{
SCLogError(SC_ERR_PCRE_STUDY, "pcre study failed: %s", eb);
exit(1);
}
}
static int SigParseOptions(DetectEngineCtx *de_ctx, Signature *s, char *optstr) {
#define MAX_SUBSTRINGS 30
int ov[MAX_SUBSTRINGS];
int ret = 0, i = 0;
SigTableElmt *st = NULL;
char *optname = NULL, *optvalue = NULL, *optmore = NULL;
const char **arr = SCCalloc(OPTION_PARTS+1, sizeof(char *));
if (unlikely(arr == NULL))
return -1;
ret = pcre_exec(option_pcre, option_pcre_extra, optstr, strlen(optstr), 0, 0, ov, MAX_SUBSTRINGS);
/* if successful, we either have:
* 2: keyword w/o value
* 3: keyword w value, final opt OR keyword w/o value, more options coming
* 4: keyword w value, more options coming
*/
if (ret != 2 && ret != 3 && ret != 4) {
SCLogError(SC_ERR_PCRE_MATCH, "pcre_exec failed: ret %" PRId32 ", optstr \"%s\"", ret, optstr);
goto error;
}
/* extract the substrings */
for (i = 1; i <= ret-1; i++) {
if (pcre_get_substring(optstr, ov, MAX_SUBSTRINGS, i, &arr[i-1]) < 0) {
goto error;
}
//printf("SigParseOptions: arr[%" PRId32 "] = \"%s\"\n", i-1, arr[i-1]);
}
arr[i-1]=NULL;
/* Call option parsing */
st = SigTableGet((char *)arr[0]);
if (st == NULL) {
SCLogError(SC_ERR_RULE_KEYWORD_UNKNOWN, "unknown rule keyword '%s'.", (char *)arr[0]);
goto error;
}
if (st->flags & SIGMATCH_NOOPT) {
optname = (char *)arr[0];
optvalue = NULL;
if (ret == 3) optmore = (char *)arr[1];
else if (ret == 4) optmore = (char *)arr[2];
else optmore = NULL;
} else {
optname = (char *)arr[0];
optvalue = (char *)arr[1];
if (ret == 4) optmore = (char *)arr[2];
else optmore = NULL;
}
/* setup may or may not add a new SigMatch to the list */
if (st->Setup(de_ctx, s, optvalue) < 0) {
SCLogDebug("\"%s\" failed to setup", st->name);
goto error;
}
if (ret == 4 && optmore != NULL) {
//printf("SigParseOptions: recursive call for more options... (s:%p,m:%p)\n", s, m);
if (optname) pcre_free_substring(optname);
if (optvalue) pcre_free_substring(optvalue);
if (optstr) SCFree(optstr);
//if (optmore) pcre_free_substring(optmore);
if (arr != NULL) pcre_free_substring_list(arr);
return SigParseOptions(de_ctx, s, optmore);
}
if (optname) pcre_free_substring(optname);
if (optvalue) pcre_free_substring(optvalue);
if (optmore) pcre_free_substring(optmore);
if (optstr) SCFree(optstr);
if (arr != NULL) pcre_free_substring_list(arr);
return 0;
error:
if (optname) pcre_free_substring(optname);
if (optvalue) pcre_free_substring(optvalue);
if (optmore) pcre_free_substring(optmore);
if (optstr) SCFree(optstr);
if (arr != NULL) pcre_free_substring_list(arr);
return -1;
}
/* XXX implement this for real
*
*/
int SigParseAddress(Signature *s, const char *addrstr, char flag)
{
SCLogDebug("Address Group \"%s\" to be parsed now", addrstr);
/* pass on to the address(list) parser */
if (flag == 0) {
if (strcasecmp(addrstr, "any") == 0)
s->flags |= SIG_FLAG_SRC_ANY;
if (DetectAddressParse(&s->src, (char *)addrstr) < 0)
goto error;
} else {
if (strcasecmp(addrstr, "any") == 0)
s->flags |= SIG_FLAG_DST_ANY;
if (DetectAddressParse(&s->dst, (char *)addrstr) < 0)
goto error;
}
return 0;
error:
return -1;
}
/**
* \brief Parses the protocol supplied by the Signature.
*
* http://www.iana.org/assignments/protocol-numbers
*
* \param s Pointer to the Signature instance to which the parsed
* protocol has to be added.
* \param protostr Pointer to the character string containing the protocol name.
*
* \retval 0 On successfully parsing the protocl sent as the argument.
* \retval -1 On failure
*/
int SigParseProto(Signature *s, const char *protostr) {
SCEnter();
int r = DetectProtoParse(&s->proto, (char *)protostr);
if (r < 0) {
s->alproto = AppLayerGetProtoByName(protostr);
if (s->alproto != ALPROTO_UNKNOWN) {
/* indicate that the signature is app-layer */
s->flags |= SIG_FLAG_APPLAYER;
/* We are going to set ip proto from the
* registered applayer signatures for proto detection */
AlpProtoSignature *als = alp_proto_ctx.head;
while (als != NULL) {
if (als->proto == s->alproto) {
/* Set the ipproto that this AL proto detection sig needs
* Note that an AL proto can be present in more than one
* IP proto (over TCP, UDP..) */
s->proto.proto[als->ip_proto / 8] |= 1 << (als->ip_proto % 8);
}
als = als->next;
}
SCReturnInt(0);
}
AppLayerProbingParserInfo *ppi =
AppLayerGetProbingParserInfo(alp_proto_ctx.probing_parsers_info,
protostr);
if (ppi != NULL) {
/* indicate that the signature is app-layer */
s->flags |= SIG_FLAG_APPLAYER;
s->alproto = ppi->al_proto;
s->proto.proto[ppi->ip_proto / 8] |= 1 << (ppi->ip_proto % 8);
SCReturnInt(0);
}
SCLogError(SC_ERR_UNKNOWN_PROTOCOL, "protocol \"%s\" cannot be used "
"in a signature", protostr);
SCReturnInt(-1);
}
/* if any of these flags are set they are set in a mutually exclusive
* manner */
if (s->proto.flags & DETECT_PROTO_ONLY_PKT) {
s->flags |= SIG_FLAG_REQUIRE_PACKET;
} else if (s->proto.flags & DETECT_PROTO_ONLY_STREAM) {
s->flags |= SIG_FLAG_REQUIRE_STREAM;
}
SCReturnInt(0);
}
/**
* \brief Parses the port(source or destination) field, from a Signature.
*
* \param s Pointer to the signature which has to be updated with the
* port information.
* \param portstr Pointer to the character string containing the port info.
* \param Flag which indicates if the portstr received is src or dst
* port. For src port: flag = 0, dst port: flag = 1.
*
* \retval 0 On success.
* \retval -1 On failure.
*/
int SigParsePort(Signature *s, const char *portstr, char flag)
{
int r = 0;
/* XXX VJ exclude handling this for none UDP/TCP proto's */
SCLogDebug("Port group \"%s\" to be parsed", portstr);
if (flag == 0) {
if (strcasecmp(portstr, "any") == 0)
s->flags |= SIG_FLAG_SP_ANY;
r = DetectPortParse(&s->sp, (char *)portstr);
} else if (flag == 1) {
if (strcasecmp(portstr, "any") == 0)
s->flags |= SIG_FLAG_DP_ANY;
r = DetectPortParse(&s->dp, (char *)portstr);
}
if (r < 0)
return -1;
return 0;
}
/** \retval 1 valid
* \retval 0 invalid
*/
static int SigParseActionRejectValidate(const char *action) {
#ifdef HAVE_LIBNET11
#ifdef HAVE_LIBCAP_NG
if (sc_set_caps == TRUE) {
SCLogError(SC_ERR_LIBNET11_INCOMPATIBLE_WITH_LIBCAP_NG, "Libnet 1.1 is "
"incompatible with POSIX based capabilities with privs dropping. "
"For rejects to work, run as root/super user.");
return 0;
}
#endif
#else /* no libnet 1.1 */
SCLogError(SC_ERR_LIBNET_REQUIRED_FOR_ACTION, "Libnet 1.1.x is "
"required for action \"%s\" but is not compiled into Suricata",
action);
return 0;
#endif
return 1;
}
/**
* \brief Parses the action that has been used by the Signature and allots it
* to its Signature instance.
*
* \param s Pointer to the Signature instance to which the action belongs.
* \param action Pointer to the action string used by the Signature.
*
* \retval 0 On successfully parsing the action string and adding it to the
* Signature.
* \retval -1 On failure.
*/
int SigParseAction(Signature *s, const char *action) {
if (strcasecmp(action, "alert") == 0) {
s->action = ACTION_ALERT;
return 0;
} else if (strcasecmp(action, "drop") == 0) {
s->action = ACTION_DROP;
return 0;
} else if (strcasecmp(action, "pass") == 0) {
s->action = ACTION_PASS;
return 0;
} else if (strcasecmp(action, "reject") == 0) {
if (!(SigParseActionRejectValidate(action)))
return -1;
s->action = ACTION_REJECT|ACTION_DROP;
return 0;
} else if (strcasecmp(action, "rejectsrc") == 0) {
if (!(SigParseActionRejectValidate(action)))
return -1;
s->action = ACTION_REJECT|ACTION_DROP;
return 0;
} else if (strcasecmp(action, "rejectdst") == 0) {
if (!(SigParseActionRejectValidate(action)))
return -1;
s->action = ACTION_REJECT_DST|ACTION_DROP;
return 0;
} else if (strcasecmp(action, "rejectboth") == 0) {
if (!(SigParseActionRejectValidate(action)))
return -1;
s->action = ACTION_REJECT_BOTH|ACTION_DROP;
return 0;
} else {
SCLogError(SC_ERR_INVALID_ACTION,"An invalid action \"%s\" was given",action);
return -1;
}
}
/**
* \internal
* \brief split a signature string into a few blocks for further parsing
*/
static int SigParseBasics(Signature *s, char *sigstr, char ***result, uint8_t addrs_direction) {
#define MAX_SUBSTRINGS 30
int ov[MAX_SUBSTRINGS];
int ret = 0, i = 0;
const char **arr = SCCalloc(CONFIG_PARTS + 1, sizeof(char *));
if (unlikely(arr == NULL))
return -1;
ret = pcre_exec(config_pcre, config_pcre_extra, sigstr, strlen(sigstr), 0, 0, ov, MAX_SUBSTRINGS);
if (ret != 8 && ret != 9) {
SCLogDebug("pcre_exec failed: ret %" PRId32 ", sigstr \"%s\"", ret, sigstr);
goto error;
}
for (i = 1; i <= ret - 1; i++) {
pcre_get_substring(sigstr, ov, MAX_SUBSTRINGS, i, &arr[i - 1]);
//printf("SigParseBasics: arr[%" PRId32 "] = \"%s\"\n", i-1, arr[i-1]);
}
arr[i - 1] = NULL;
/* Parse Action */
if (SigParseAction(s, arr[CONFIG_ACTION]) < 0)
goto error;
/* Parse Proto */
if (SigParseProto(s, arr[CONFIG_PROTO]) < 0)
goto error;
if (strcmp(arr[CONFIG_DIREC], "<-") == 0) {
SCLogError(SC_ERR_INVALID_DIRECTION, "\"<-\" is not a valid direction modifier, \"->\" and \"<>\" are supported.");
goto error;
}
/* Check if it is bidirectional */
if (strcmp(arr[CONFIG_DIREC], "<>") == 0)
s->init_flags |= SIG_FLAG_INIT_BIDIREC;
/* Parse Address & Ports */
if (SigParseAddress(s, arr[CONFIG_SRC], SIG_DIREC_SRC ^ addrs_direction) < 0)
goto error;
if (SigParseAddress(s, arr[CONFIG_DST], SIG_DIREC_DST ^ addrs_direction) < 0)
goto error;
/* For IPOnly */
if (IPOnlySigParseAddress(s, arr[CONFIG_SRC], SIG_DIREC_SRC ^ addrs_direction) < 0)
goto error;
if (IPOnlySigParseAddress(s, arr[CONFIG_DST], SIG_DIREC_DST ^ addrs_direction) < 0)
goto error;
/* For "ip" we parse the ports as well, even though they will be just "any".
* We do this for later sgh building for the tcp and udp protocols. */
if (DetectProtoContainsProto(&s->proto, IPPROTO_TCP) ||
DetectProtoContainsProto(&s->proto, IPPROTO_UDP) ||
DetectProtoContainsProto(&s->proto, IPPROTO_SCTP))
{
if (SigParsePort(s, arr[CONFIG_SP], SIG_DIREC_SRC ^ addrs_direction) < 0)
goto error;
if (SigParsePort(s, arr[CONFIG_DP], SIG_DIREC_DST ^ addrs_direction) < 0)
goto error;
}
*result = (char **)arr;
return 0;
error:
if (arr != NULL) {
for (i = 1; i <= ret - 1; i++) {
if (arr[i - 1] == NULL)
continue;
pcre_free_substring(arr[i - 1]);
}
SCFree(arr);
}
*result = NULL;
return -1;
}
/**
* \brief parse a signature
*
* \param de_ctx detection engine ctx to add it to
* \param s memory structure to store the signature in
* \param sigstr the raw signature as a null terminated string
* \param addrs_direction direction (for bi-directional sigs)
*
* \param -1 parse error
* \param 0 ok
*/
int SigParse(DetectEngineCtx *de_ctx, Signature *s, char *sigstr, uint8_t addrs_direction) {
SCEnter();
char **basics;
s->sig_str = sigstr;
int ret = SigParseBasics(s, sigstr, &basics, addrs_direction);
if (ret < 0 || basics == NULL) {
SCLogDebug("SigParseBasics failed");
SCReturnInt(-1);
}
#ifdef DEBUG
if (SCLogDebugEnabled()) {
int i;
for (i = 0; basics[i] != NULL; i++) {
SCLogDebug("basics[%" PRId32 "]: %p, %s", i, basics[i], basics[i]);
}
}
#endif /* DEBUG */
/* we can have no options, so make sure we have them */
if (basics[CONFIG_OPTS] != NULL) {
ret = SigParseOptions(de_ctx, s, SCStrdup(basics[CONFIG_OPTS]));
SCLogDebug("ret from SigParseOptions %d", ret);
}
/* cleanup */
int i = 0;
while (basics[i] != NULL) {
SCFree(basics[i]);
i++;
}
SCFree(basics);
s->sig_str = NULL;
DetectIPProtoRemoveAllSMs(s);
SCReturnInt(ret);
}
Signature *SigAlloc (void) {
Signature *sig = SCMalloc(sizeof(Signature));
if (unlikely(sig == NULL))
return NULL;
memset(sig, 0, sizeof(Signature));
/* assign it to -1, so that we can later check if the value has been
* overwritten after the Signature has been parsed, and if it hasn't been
* overwritten, we can then assign the default value of 3 */
sig->prio = -1;
return sig;
}
/**
* \internal
* \brief Free Reference list
*
* \param s Pointer to the signature
*/
static void SigRefFree (Signature *s) {
SCEnter();
DetectReference *ref = NULL;
DetectReference *next_ref = NULL;
if (s == NULL) {
SCReturn;
}
SCLogDebug("s %p, s->references %p", s, s->references);
for (ref = s->references; ref != NULL;) {
next_ref = ref->next;
DetectReferenceFree(ref);
ref = next_ref;
}
s->references = NULL;
SCReturn;
}
void SigFree(Signature *s) {
if (s == NULL)
return;
if (s->CidrDst != NULL)
IPOnlyCIDRListFree(s->CidrDst);
if (s->CidrSrc != NULL)
IPOnlyCIDRListFree(s->CidrSrc);
int i;
for (i = 0; i < DETECT_SM_LIST_MAX; i++) {
SigMatch *sm = s->sm_lists[i], *nsm;
while (sm != NULL) {
nsm = sm->next;
SigMatchFree(sm);
sm = nsm;
}
}
DetectAddressHeadCleanup(&s->src);
DetectAddressHeadCleanup(&s->dst);
if (s->sp != NULL) {
DetectPortCleanupList(s->sp);
}
if (s->dp != NULL) {
DetectPortCleanupList(s->dp);
}
if (s->msg != NULL)
SCFree(s->msg);
if (s->addr_src_match4 != NULL) {
SCFree(s->addr_src_match4);
}
if (s->addr_dst_match4 != NULL) {
SCFree(s->addr_dst_match4);
}
if (s->addr_src_match6 != NULL) {
SCFree(s->addr_src_match6);
}
if (s->addr_dst_match6 != NULL) {
SCFree(s->addr_dst_match6);
}
SigRefFree(s);
SCFree(s);
}
/**
* \internal
* \brief build address match array for cache efficient matching
*
* \param s the signature
*/
static void SigBuildAddressMatchArray(Signature *s) {
/* source addresses */
uint16_t cnt = 0;
uint16_t idx = 0;
DetectAddress *da = s->src.ipv4_head;
for ( ; da != NULL; da = da->next) {
cnt++;
}
if (cnt > 0) {
s->addr_src_match4 = SCMalloc(cnt * sizeof(DetectMatchAddressIPv4));
if (s->addr_src_match4 == NULL) {
exit(EXIT_FAILURE);
}
for (da = s->src.ipv4_head; da != NULL; da = da->next) {
s->addr_src_match4[idx].ip = ntohl(da->ip.addr_data32[0]);
s->addr_src_match4[idx].ip2 = ntohl(da->ip2.addr_data32[0]);
idx++;
}
s->addr_src_match4_cnt = cnt;
}
/* destination addresses */
cnt = 0;
idx = 0;
da = s->dst.ipv4_head;
for ( ; da != NULL; da = da->next) {
cnt++;
}
if (cnt > 0) {
s->addr_dst_match4 = SCMalloc(cnt * sizeof(DetectMatchAddressIPv4));
if (s->addr_dst_match4 == NULL) {
exit(EXIT_FAILURE);
}
for (da = s->dst.ipv4_head; da != NULL; da = da->next) {
s->addr_dst_match4[idx].ip = ntohl(da->ip.addr_data32[0]);
s->addr_dst_match4[idx].ip2 = ntohl(da->ip2.addr_data32[0]);
idx++;
}
s->addr_dst_match4_cnt = cnt;
}
/* source addresses IPv6 */
cnt = 0;
idx = 0;
da = s->src.ipv6_head;
for ( ; da != NULL; da = da->next) {
cnt++;
}
if (cnt > 0) {
s->addr_src_match6 = SCMalloc(cnt * sizeof(DetectMatchAddressIPv6));
if (s->addr_src_match6 == NULL) {
exit(EXIT_FAILURE);
}
for (da = s->src.ipv6_head; da != NULL; da = da->next) {
s->addr_src_match6[idx].ip[0] = ntohl(da->ip.addr_data32[0]);
s->addr_src_match6[idx].ip[1] = ntohl(da->ip.addr_data32[1]);
s->addr_src_match6[idx].ip[2] = ntohl(da->ip.addr_data32[2]);
s->addr_src_match6[idx].ip[3] = ntohl(da->ip.addr_data32[3]);
s->addr_src_match6[idx].ip2[0] = ntohl(da->ip2.addr_data32[0]);
s->addr_src_match6[idx].ip2[1] = ntohl(da->ip2.addr_data32[1]);
s->addr_src_match6[idx].ip2[2] = ntohl(da->ip2.addr_data32[2]);
s->addr_src_match6[idx].ip2[3] = ntohl(da->ip2.addr_data32[3]);
idx++;
}
s->addr_src_match6_cnt = cnt;
}
/* destination addresses IPv6 */
cnt = 0;
idx = 0;
da = s->dst.ipv6_head;
for ( ; da != NULL; da = da->next) {
cnt++;
}
if (cnt > 0) {
s->addr_dst_match6 = SCMalloc(cnt * sizeof(DetectMatchAddressIPv6));
if (s->addr_dst_match6 == NULL) {
exit(EXIT_FAILURE);
}
for (da = s->dst.ipv6_head; da != NULL; da = da->next) {
s->addr_dst_match6[idx].ip[0] = ntohl(da->ip.addr_data32[0]);
s->addr_dst_match6[idx].ip[1] = ntohl(da->ip.addr_data32[1]);
s->addr_dst_match6[idx].ip[2] = ntohl(da->ip.addr_data32[2]);
s->addr_dst_match6[idx].ip[3] = ntohl(da->ip.addr_data32[3]);
s->addr_dst_match6[idx].ip2[0] = ntohl(da->ip2.addr_data32[0]);
s->addr_dst_match6[idx].ip2[1] = ntohl(da->ip2.addr_data32[1]);
s->addr_dst_match6[idx].ip2[2] = ntohl(da->ip2.addr_data32[2]);
s->addr_dst_match6[idx].ip2[3] = ntohl(da->ip2.addr_data32[3]);
idx++;
}
s->addr_dst_match6_cnt = cnt;
}
}
/**
* \internal
* \brief validate a just parsed signature for internal inconsistencies
*
* \param s just parsed signature
*
* \retval 0 invalid
* \retval 1 valid
*/
static int SigValidate(Signature *s) {
SCEnter();
if ((s->flags & SIG_FLAG_REQUIRE_PACKET) &&
(s->flags & SIG_FLAG_REQUIRE_STREAM)) {
SCLogError(SC_ERR_INVALID_SIGNATURE, "can't mix packet keywords with "
"tcp-stream or flow:only_stream. Invalidating signature.");
SCReturnInt(0);
}