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
|
/* packet-hsrp.c
* Routines for the Cisco Hot Standby Router Protocol (HSRP)
*
* Heikki Vatiainen <hessu@cs.tut.fi>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* Copied from packet-vrrp.c
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
* RFC 2281 describes opcodes 0 - 2
*
* Op Code 3: **** HSRP Interface State Advertisements ****
* http://www.cisco.com/en/US/products/sw/iosswrel/ps1834/products_feature_guide09186a00800e9763.html
*
* An HSRP interface-state advertisement is sent:
*
* * when HSRP on the interface enters or leaves the passive state
* * when a group on the interface learns a new Active router
* * periodically while the interface is in the passive state
*
* 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Version | Op Code = 3 | TLV Type |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | TLV Length | State | Reserved |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Active Group Count | Passive Group Count |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Reserved |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Passive Group Count: 2 octet
*
* A count of the number of passive groups on the interface. The range
* of values are 0-256.
*
* Active Group Count: 2 octet
*
* A count of the number of active groups on the interface. The range
* of values are 0-256.
*
*
* HSRP Version 2
* Ref. http://www.smartnetworks.jp/2006/02/hsrp_8_hsrp_version_2.html (Japanese Only)
*
* Group State TLV
*
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type=1 | Length=40 | HSRP Version | Opcode |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | State | IP Version | Group Number |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Identifier(6octets) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Identifier | Priority(4octets) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Priority cont. | Hello Time(4octets) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Hello Time cont. | Hold Time(4octets) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Hold Time cont. | Virtual IP Address(16octets) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Virtual IP Address cont. |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Virtual IP Address cont. |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Virtual IP Address cont. |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Virtual IP Address cont. |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Interface State TLV
*
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type=2 | Length=4 | Active Groups |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Passive Groups |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Text Authentication TLV
*
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type=3 | Length=8 | Authentication Data(8octets) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Authentication Data cont. |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Authentication Data cont. |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* MD5 Authentication TLV
*
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type=4 | Length | Algorithm | Padding |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Flags | IP Address(4octets) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | IP Address cont. | Key ID(4octets) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Key ID cont. | Authentication Data(16octets) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Authentication Data cont. |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Authentication Data cont. |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Authentication Data cont. |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Authentication Data cont. |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/to_str.h>
#include <epan/expert.h>
void proto_register_hsrp(void);
void proto_reg_handoff_hsrp(void);
static dissector_handle_t hsrp_handle;
static int proto_hsrp;
static int hf_hsrp_version;
static int hf_hsrp_opcode;
/* Opcode 0-2 */
static int hf_hsrp_state;
static int hf_hsrp_hellotime;
static int hf_hsrp_holdtime;
static int hf_hsrp_priority;
static int hf_hsrp_group;
static int hf_hsrp_reserved;
static int hf_hsrp_auth_data;
static int hf_hsrp_virt_ip_addr;
/* Advertise (3) */
static int hf_hsrp_adv_type;
static int hf_hsrp_adv_length;
static int hf_hsrp_adv_state;
static int hf_hsrp_adv_reserved1;
static int hf_hsrp_adv_activegrp;
static int hf_hsrp_adv_passivegrp;
static int hf_hsrp_adv_reserved2;
static int ett_hsrp;
/* HSRPv2 */
static int hf_hsrp2_version;
static int hf_hsrp2_opcode;
static int hf_hsrp2_state;
static int hf_hsrp2_group_state_tlv;
static int hf_hsrp2_interface_state_tlv;
static int hf_hsrp2_text_auth_tlv;
static int hf_hsrp2_md5_auth_tlv;
static int hf_hsrp2_ipversion;
static int hf_hsrp2_hellotime;
static int hf_hsrp2_holdtime;
static int hf_hsrp2_priority;
static int hf_hsrp2_identifier;
static int hf_hsrp2_group;
static int hf_hsrp2_virt_ip_addr;
static int hf_hsrp2_virt_ip_addr_v6;
static int hf_hsrp2_auth_data;
static int hf_hsrp2_active_group;
static int hf_hsrp2_passive_group;
static int hf_hsrp2_md5_algorithm;
static int hf_hsrp2_md5_padding;
static int hf_hsrp2_md5_flags;
static int hf_hsrp2_md5_ip_address;
static int hf_hsrp2_md5_key_id;
static int hf_hsrp2_md5_auth_data;
static int ett_hsrp2_group_state_tlv;
static int ett_hsrp2_interface_state_tlv;
static int ett_hsrp2_text_auth_tlv;
static int ett_hsrp2_md5_auth_tlv;
static expert_field ei_hsrp_unknown_tlv;
#define UDP_PORT_HSRP 1985
#define UDP_PORT_HSRP2_V6 2029
#define UDP_PORT_HSRP_RANGE "1985,2029"
#define HSRP_DST_IP_ADDR 0xE0000002
#define HSRP2_DST_IP_ADDR 0xE0000066
struct hsrp_packet { /* Multicast to 224.0.0.2, TTL 1, UDP, port 1985 */
uint8_t version; /* RFC2281 describes version 0 */
uint8_t opcode;
uint8_t state;
#define HSRP_DEFAULT_HELLOTIME 3
uint8_t hellotime; /* In seconds */
#define HSRP_DEFAULT_HOLDTIME 10
uint8_t holdtime; /* In seconds */
uint8_t priority; /* Higher is stronger, highest IP address tie-breaker */
uint8_t group; /* Identifies the standby group */
uint8_t reserved;
uint8_t auth_data[8]; /* Clear-text password, recommended default is `cisco' */
uint32_t virt_ip_addr; /* The virtual IP address used by this group */
};
struct hsrpv2_packet { /* Multicast to 224.0.0.102, TTL 1, UDP, port 1985 */
uint8_t version;
uint8_t opcode;
uint8_t state;
#define HSRP2_DEFAULT_HELLOTIME 3000
uint32_t hellotime; /* In msecs */
#define HSRP2_DEFAULT_HOLDTIME 10000
uint32_t holdtime; /* In msecs */
uint32_t priority; /* Higher is stronger, highest IP address tie-breaker */
uint16_t group; /* Identifies the standby group */
uint8_t identifier[6]; /* Identifier of sender's MAC address */
uint8_t auth_data[8]; /* Clear-text password, recommended default is `cisco' */
char virt_ip_addr[16]; /* The virtual IPv4/IPv6 address used by this group */
uint8_t md5_algorithm; /* MD5 Hash algorithm */
uint8_t md5_flags; /* Undefined */
uint8_t md5_ip_address; /* IP address of sender interface */
uint8_t md5_key_id; /* Name of key chain */
uint8_t md5_auth_data[16]; /* MD5 digest data */
};
#define HSRP_OPCODE_HELLO 0
#define HSRP_OPCODE_COUP 1
#define HSRP_OPCODE_RESIGN 2
#define HSRP_OPCODE_ADVERTISE 3
static const value_string hsrp_opcode_vals[] = {
{HSRP_OPCODE_HELLO, "Hello"},
{HSRP_OPCODE_COUP, "Coup"},
{HSRP_OPCODE_RESIGN, "Resign"},
{HSRP_OPCODE_ADVERTISE, "Advertise"},
{0, NULL}
};
#define HSRP_STATE_INITIAL 0
#define HSRP_STATE_LEARN 1
#define HSRP_STATE_LISTEN 2
#define HSRP_STATE_SPEAK 4
#define HSRP_STATE_STANDBY 8
#define HSRP_STATE_ACTIVE 16
static const value_string hsrp_state_vals[] = {
{HSRP_STATE_INITIAL, "Initial"},
{HSRP_STATE_LEARN, "Learn"},
{HSRP_STATE_LISTEN, "Listen"},
{HSRP_STATE_SPEAK, "Speak"},
{HSRP_STATE_STANDBY, "Standby"},
{HSRP_STATE_ACTIVE, "Active"},
{0, NULL}
};
#define HSRP_ADV_TYPE_INTSTATE 1
#define HSRP_ADV_TYPE_IPREDUN 2
static const value_string hsrp_adv_type_vals[] = {
{HSRP_ADV_TYPE_INTSTATE, "HSRP interface state"},
{HSRP_ADV_TYPE_IPREDUN, "IP redundancy"},
{0, NULL}
};
#define HSRP_ADV_STATE_DORMANT 1
#define HSRP_ADV_STATE_PASSIVE 2
#define HSRP_ADV_STATE_ACTIVE 3
static const value_string hsrp_adv_state_vals[] = {
{HSRP_ADV_STATE_DORMANT, "Dormant"},
{HSRP_ADV_STATE_PASSIVE, "Passive"},
{HSRP_ADV_STATE_ACTIVE, "Active"},
{0, NULL}
};
#define HSRP2_OPCODE_HELLO 0
#define HSRP2_OPCODE_COUP 1
#define HSRP2_OPCODE_RESIGN 2
static const value_string hsrp2_opcode_vals[] = {
{HSRP2_OPCODE_HELLO, "Hello"},
{HSRP2_OPCODE_COUP, "Coup"},
{HSRP2_OPCODE_RESIGN, "Resign"},
{0, NULL}
};
#define HSRP2_STATE_DISABLED 0
#define HSRP2_STATE_INIT 1
#define HSRP2_STATE_LEARN 2
#define HSRP2_STATE_LISTEN 3
#define HSRP2_STATE_SPEAK 4
#define HSRP2_STATE_STANDBY 5
#define HSRP2_STATE_ACTIVE 6
static const value_string hsrp2_state_vals[] = {
{HSRP2_STATE_INIT, "Init"},
{HSRP2_STATE_LEARN, "Learn"},
{HSRP2_STATE_LISTEN, "Listen"},
{HSRP2_STATE_SPEAK, "Speak"},
{HSRP2_STATE_STANDBY, "Standby"},
{HSRP2_STATE_ACTIVE, "Active"},
{0, NULL}
};
#define HSRP2_IPVERSION_IPV4 4
#define HSRP2_IPVERSION_IPV6 6
static const value_string hsrp2_ipversion_vals[] = {
{HSRP2_IPVERSION_IPV4, "IPv4"},
{HSRP2_IPVERSION_IPV6, "IPv6"},
{0, NULL}
};
#define HSRP2_MD5_ALGORITHM 1
static const value_string hsrp2_md5_algorithm_vals[] = {
{HSRP2_MD5_ALGORITHM, "MD5"},
{0, NULL}
};
static void
process_hsrp_md5_tlv_sequence(tvbuff_t *tvb, proto_tree *hsrp_tree, unsigned offset)
{
uint8_t type = tvb_get_uint8(tvb, offset);
uint8_t len = tvb_get_uint8(tvb, offset+1);
proto_item *ti;
proto_tree *md5_auth_tlv;
ti = proto_tree_add_uint_format_value(hsrp_tree, hf_hsrp2_md5_auth_tlv, tvb, offset, 1, type, "Type=%d Len=%d", type, len);
offset+=2;
/* Making MD5 Authentication TLV subtree */
md5_auth_tlv = proto_item_add_subtree(ti, ett_hsrp2_md5_auth_tlv);
proto_tree_add_item(md5_auth_tlv, hf_hsrp2_md5_algorithm, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
/* padding field */
proto_tree_add_item(md5_auth_tlv, hf_hsrp2_md5_padding, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
proto_tree_add_item(md5_auth_tlv, hf_hsrp2_md5_flags, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
proto_tree_add_item(md5_auth_tlv, hf_hsrp2_md5_ip_address, tvb, offset, 4, ENC_BIG_ENDIAN);
offset+=4;
proto_tree_add_item(md5_auth_tlv, hf_hsrp2_md5_key_id, tvb, offset, 4, ENC_BIG_ENDIAN);
offset+=4; /* this now points to the start of the MD5 hash */
proto_tree_add_item(md5_auth_tlv, hf_hsrp2_md5_auth_data, tvb, offset, 16, ENC_NA);
}
static int
dissect_hsrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
tvbuff_t *next_tvb;
uint32_t hsrpv1 = g_htonl(HSRP_DST_IP_ADDR),
hsrpv2 = g_htonl(HSRP2_DST_IP_ADDR);
/* Return if this isn't really HSRP traffic
* (source and destination port must be UDP_PORT_HSRP on HSRPv1 or HSRPv2(IPv4))
* (source and destination port must be UDP_PORT_HSRP2_V6 on HSRPv2(IPv6))
*/
if(pinfo->destport != UDP_PORT_HSRP && pinfo->destport != UDP_PORT_HSRP2_V6)
return 0;
/*
* To check whether this is an HSRPv1 packet or HSRPv2 on dest IPv4 addr.
*/
if (pinfo->dst.type == AT_IPv4 && memcmp(pinfo->dst.data, &hsrpv1, 4) == 0) {
/* HSRPv1 */
uint8_t opcode, state = 0;
proto_item *ti;
proto_tree *hsrp_tree;
int offset;
uint8_t hellotime, holdtime;
char *auth;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "HSRP");
opcode = tvb_get_uint8(tvb, 1);
col_set_str(pinfo->cinfo, COL_INFO,
val_to_str_const(opcode, hsrp_opcode_vals, "Unknown"));
if (opcode < 3) {
state = tvb_get_uint8(tvb, 2);
col_append_fstr(pinfo->cinfo, COL_INFO, " (state %s)",
val_to_str_const(state, hsrp_state_vals, "Unknown"));
} else if (opcode == 3) {
state = tvb_get_uint8(tvb, 6);
col_append_fstr(pinfo->cinfo, COL_INFO, " (state %s)",
val_to_str_const(state, hsrp_adv_state_vals, "Unknown"));
}
offset = 0;
ti = proto_tree_add_item(tree, proto_hsrp, tvb, offset, -1, ENC_NA);
hsrp_tree = proto_item_add_subtree(ti, ett_hsrp);
proto_tree_add_item(hsrp_tree, hf_hsrp_version, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
proto_tree_add_uint(hsrp_tree, hf_hsrp_opcode, tvb, offset, 1, opcode);
offset++;
if (opcode < 3) {
proto_tree_add_uint(hsrp_tree, hf_hsrp_state, tvb, offset, 1, state);
offset++;
hellotime = tvb_get_uint8(tvb, offset);
proto_tree_add_uint_format_value(hsrp_tree, hf_hsrp_hellotime, tvb, offset, 1, hellotime,
"%sDefault (%u)",
(hellotime == HSRP_DEFAULT_HELLOTIME) ? "" : "Non-",
hellotime);
offset++;
holdtime = tvb_get_uint8(tvb, offset);
proto_tree_add_uint_format_value(hsrp_tree, hf_hsrp_holdtime, tvb, offset, 1, holdtime,
"%sDefault (%u)",
(holdtime == HSRP_DEFAULT_HOLDTIME) ? "" : "Non-",
holdtime);
offset++;
proto_tree_add_item(hsrp_tree, hf_hsrp_priority, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
proto_tree_add_item(hsrp_tree, hf_hsrp_group, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
proto_tree_add_item(hsrp_tree, hf_hsrp_reserved, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
auth = (char *) tvb_get_string_enc(pinfo->pool, tvb, offset, 8, ENC_ASCII|ENC_NA);
proto_tree_add_string_format_value(hsrp_tree, hf_hsrp_auth_data, tvb, offset, 8, auth,
"%sDefault (%s)",
(strcmp(auth, "cisco") == 0) ? "" : "Non-",
auth);
offset += 8;
proto_tree_add_item(hsrp_tree, hf_hsrp_virt_ip_addr, tvb, offset, 4, ENC_BIG_ENDIAN);
/* offset += 4; */
} else if (opcode == 3) {
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_type, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_length, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_state, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_reserved1, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_activegrp, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_passivegrp, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_reserved2, tvb, offset, 4, ENC_BIG_ENDIAN);
/* offset += 4; */
} else {
next_tvb = tvb_new_subset_remaining(tvb, offset);
call_data_dissector(next_tvb, pinfo, hsrp_tree);
}
/* is MD5 authentication being used with HSRPv1? */
if (tvb_captured_length(tvb) == 50) { /* 20 bytes of regular HSRP data + 30 bytes of authentication payload */
unsigned offset2 = offset + 4; /* this now points to the start of a possible TLV sequence */
uint8_t type = tvb_get_uint8(tvb, offset2);
uint8_t len = tvb_get_uint8(tvb, offset2+1);
if (type == 4 && len == 28) {
/* MD5 Authentication TLV */
if (tree) {
process_hsrp_md5_tlv_sequence(tvb, hsrp_tree, offset2);
}
} else {
expert_add_info_format(pinfo, ti, &ei_hsrp_unknown_tlv,
"Unknown TLV sequence in HSRPv1 dissection, Type=(%d) Len=(%d)", type, len);
}
}
} else if ((pinfo->dst.type == AT_IPv4 && memcmp(pinfo->dst.data, &hsrpv2, 4) == 0) ||
(pinfo->dst.type == AT_IPv6 && pinfo->destport == UDP_PORT_HSRP2_V6)) {
/* HSRPv2 */
unsigned offset = 0, offset2;
proto_item *ti = NULL;
proto_tree *hsrp_tree = NULL;
uint8_t type,len;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "HSRPv2");
if (tree) {
ti = proto_tree_add_item(tree, proto_hsrp, tvb, offset, -1, ENC_NA);
hsrp_tree = proto_item_add_subtree(ti, ett_hsrp);
}
while (tvb_reported_length_remaining(tvb, offset) > 0) {
type = tvb_get_uint8(tvb, offset);
len = tvb_get_uint8(tvb, offset+1);
offset2 = offset;
if (type == 1 && len == 40) {
/* Group State TLV */
uint8_t opcode, state = 0, ipver;
uint32_t hellotime, holdtime;
proto_tree *group_state_tlv;
if (tree) {
ti = proto_tree_add_uint_format_value(hsrp_tree, hf_hsrp2_group_state_tlv, tvb, offset, 2+len, type,
"Type=%d Len=%d", type, len);
}
offset+=2;
opcode = tvb_get_uint8(tvb, offset+1);
col_set_str(pinfo->cinfo, COL_INFO,
val_to_str_const(opcode, hsrp2_opcode_vals, "Unknown"));
state = tvb_get_uint8(tvb, offset+2);
col_append_fstr(pinfo->cinfo, COL_INFO, " (state %s)",
val_to_str_const(state, hsrp2_state_vals, "Unknown"));
if (tree) {
/* Making Group State TLV subtree. */
group_state_tlv = proto_item_add_subtree(ti, ett_hsrp2_group_state_tlv);
proto_tree_add_item(group_state_tlv, hf_hsrp2_version, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
proto_tree_add_uint(group_state_tlv, hf_hsrp2_opcode, tvb, offset, 1, opcode);
offset++;
proto_tree_add_uint(group_state_tlv, hf_hsrp2_state, tvb, offset, 1, state);
offset++;
ipver = tvb_get_uint8(tvb, offset);
proto_tree_add_uint(group_state_tlv, hf_hsrp2_ipversion, tvb, offset, 1, ipver);
offset++;
proto_tree_add_item(group_state_tlv, hf_hsrp2_group, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
proto_tree_add_item(group_state_tlv, hf_hsrp2_identifier, tvb, offset, 6, ENC_NA);
offset+=6;
proto_tree_add_item(group_state_tlv, hf_hsrp2_priority, tvb, offset, 4, ENC_BIG_ENDIAN);
offset+=4;
hellotime = tvb_get_ntohl(tvb, offset);
proto_tree_add_uint_format_value(group_state_tlv, hf_hsrp2_hellotime, tvb, offset, 4, hellotime,
"%sDefault (%u)",
(hellotime == HSRP2_DEFAULT_HELLOTIME) ? "" : "Non-",
hellotime);
offset+=4;
holdtime = tvb_get_ntohl(tvb, offset);
proto_tree_add_uint_format_value(group_state_tlv, hf_hsrp2_holdtime, tvb, offset, 4, holdtime,
"%sDefault (%u)",
(holdtime == HSRP2_DEFAULT_HOLDTIME) ? "" : "Non-",
holdtime);
offset+=4;
if (ipver == 4) {
/* Fetch Virtual IP as IPv4 */
proto_tree_add_item(group_state_tlv, hf_hsrp2_virt_ip_addr, tvb, offset, 4, ENC_BIG_ENDIAN);
} else if (ipver == 6) {
/* Fetch Virtual IP as IPv6 */
proto_tree_add_item(group_state_tlv, hf_hsrp2_virt_ip_addr_v6, tvb, offset, 16, ENC_NA);
} else {
/* Unknown protocol */
next_tvb = tvb_new_subset_remaining(tvb, offset);
call_data_dissector(next_tvb, pinfo, hsrp_tree);
break;
}
/* offset+=16; */
}
} else if (type == 2 && len == 4) {
/* Interface State TLV */
uint16_t active,passive;
active = tvb_get_ntohs(tvb, offset+2);
passive = tvb_get_ntohs(tvb, offset+4);
col_add_fstr(pinfo->cinfo, COL_INFO, "Interface State TLV (Act=%d Pass=%d)",active,passive);
if (tree) {
proto_tree *interface_state_tlv;
ti = proto_tree_add_uint_format_value(hsrp_tree, hf_hsrp2_interface_state_tlv, tvb, offset, 1, type,
"Type=%d Len=%d", type, 2+len);
offset+=2;
/* Making Interface State TLV subtree */
interface_state_tlv = proto_item_add_subtree(ti, ett_hsrp2_interface_state_tlv);
proto_tree_add_item(interface_state_tlv, hf_hsrp2_active_group, tvb, offset, 2, ENC_BIG_ENDIAN);
offset+=2;
proto_tree_add_item(interface_state_tlv, hf_hsrp2_passive_group, tvb, offset, 2, ENC_BIG_ENDIAN);
/* offset+=2; */
}
} else if (type == 3 && len == 8) {
/* Text Authentication TLV */
/* FIXME: Is the length of the authentication string really restricted to 8 bytes
* or is it maybe padded to multiples of 4 or 8 bytes?
*/
if (tree) {
proto_tree *text_auth_tlv;
char *auth;
ti = proto_tree_add_uint_format_value(hsrp_tree, hf_hsrp2_text_auth_tlv, tvb, offset, 2+len, type,
"Type=%d Len=%d", type, len);
offset+=2;
/* Making Text Authentication TLV subtree */
text_auth_tlv = proto_item_add_subtree(ti, ett_hsrp2_text_auth_tlv);
auth = (char *) tvb_get_string_enc(pinfo->pool, tvb, offset, 8, ENC_ASCII|ENC_NA);
proto_tree_add_string_format_value(text_auth_tlv, hf_hsrp2_auth_data, tvb, offset, 8, auth,
"%sDefault (%s)",
(strcmp(auth, "cisco") == 0) ? "" : "Non-",
auth);
/* offset += 8; */
}
} else if (type == 4 && len == 28) {
/* MD5 Authentication TLV */
if (tree) {
process_hsrp_md5_tlv_sequence(tvb, hsrp_tree, offset);
/* offset += 16; */
}
} else {
/* Undefined TLV */
next_tvb = tvb_new_subset_remaining(tvb, offset);
call_data_dissector(next_tvb, pinfo, hsrp_tree);
break;
}
offset = offset2+len+2;
}
}
return tvb_captured_length(tvb);
}
void proto_register_hsrp(void)
{
expert_module_t* expert_hsrp;
static hf_register_info hf[] = {
{ &hf_hsrp_version,
{ "Version", "hsrp.version",
FT_UINT8, BASE_DEC, NULL, 0x0,
"The version of the HSRP messages", HFILL }},
{ &hf_hsrp_opcode,
{ "Op Code", "hsrp.opcode",
FT_UINT8, BASE_DEC, VALS(hsrp_opcode_vals), 0x0,
"The type of message contained in this packet", HFILL }},
{ &hf_hsrp_state,
{ "State", "hsrp.state",
FT_UINT8, BASE_DEC, VALS(hsrp_state_vals), 0x0,
"The current state of the router sending the message", HFILL }},
{ &hf_hsrp_hellotime,
{ "Hellotime", "hsrp.hellotime",
FT_UINT8, BASE_DEC, NULL, 0x0,
"The approximate period between the Hello messages that the router sends", HFILL }},
{ &hf_hsrp_holdtime,
{ "Holdtime", "hsrp.holdtime",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Time that the current Hello message should be considered valid", HFILL }},
{ &hf_hsrp_priority,
{ "Priority", "hsrp.priority",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Used to elect the active and standby routers. Numerically higher priority wins vote", HFILL }},
{ &hf_hsrp_group,
{ "Group", "hsrp.group",
FT_UINT8, BASE_DEC, NULL, 0x0,
"This field identifies the standby group", HFILL }},
{ &hf_hsrp_reserved,
{ "Reserved", "hsrp.reserved",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_hsrp_auth_data,
{ "Authentication Data", "hsrp.auth_data",
FT_STRING, BASE_NONE, NULL, 0x0,
"Contains a clear-text 8 character reused password", HFILL }},
{ &hf_hsrp_virt_ip_addr,
{ "Virtual IP Address", "hsrp.virt_ip",
FT_IPv4, BASE_NONE, NULL, 0x0,
"The virtual IP address used by this group", HFILL }},
{ &hf_hsrp_adv_type,
{ "Adv type", "hsrp.adv.tlvtype",
FT_UINT16, BASE_DEC, VALS(hsrp_adv_type_vals), 0x0,
"Advertisement tlv type", HFILL }},
{ &hf_hsrp_adv_length,
{ "Adv length", "hsrp.adv.tlvlength",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Advertisement tlv length", HFILL }},
{ &hf_hsrp_adv_state,
{ "Adv state", "hsrp.adv.state",
FT_UINT8, BASE_DEC, VALS(hsrp_adv_state_vals), 0x0,
"Advertisement tlv length", HFILL }},
{ &hf_hsrp_adv_reserved1,
{ "Adv reserved1", "hsrp.adv.reserved1",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Advertisement tlv length", HFILL }},
{ &hf_hsrp_adv_activegrp,
{ "Adv active groups", "hsrp.adv.activegrp",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Advertisement active group count", HFILL }},
{ &hf_hsrp_adv_passivegrp,
{ "Adv passive groups", "hsrp.adv.passivegrp",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Advertisement passive group count", HFILL }},
{ &hf_hsrp_adv_reserved2,
{ "Adv reserved2", "hsrp.adv.reserved2",
FT_UINT32, BASE_DEC, NULL, 0x0,
"Advertisement tlv length", HFILL }},
{ &hf_hsrp2_version,
{ "Version", "hsrp2.version",
FT_UINT8, BASE_DEC, NULL, 0x0,
"The version of the HSRP messages", HFILL }},
{ &hf_hsrp2_opcode,
{ "Op Code", "hsrp2.opcode",
FT_UINT8, BASE_DEC, VALS(hsrp2_opcode_vals), 0x0,
"The type of message contained in this packet", HFILL }},
{ &hf_hsrp2_state,
{ "State", "hsrp2.state",
FT_UINT8, BASE_DEC, VALS(hsrp2_state_vals), 0x0,
"The current state of the router sending the message", HFILL }},
{ &hf_hsrp2_group_state_tlv,
{ "Group State TLV", "hsrp2.group_state_tlv",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_hsrp2_interface_state_tlv,
{ "Interface State TLV", "hsrp2.interface_state_tlv",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_hsrp2_text_auth_tlv,
{ "Text Authentication TLV", "hsrp2.text_auth_tlv",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_hsrp2_md5_auth_tlv,
{ "MD5 Authentication TLV", "hsrp2.md5_auth_tlv",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_hsrp2_ipversion,
{ "IP Ver.", "hsrp2.ipversion",
FT_UINT8, BASE_DEC, VALS(hsrp2_ipversion_vals), 0x0,
"The IP protocol version used in this hsrp message", HFILL }},
{ &hf_hsrp2_group,
{ "Group", "hsrp2.group",
FT_UINT16, BASE_DEC, NULL, 0x0,
"This field identifies the standby group", HFILL }},
{ &hf_hsrp2_identifier,
{ "Identifier", "hsrp2.identifier",
FT_ETHER, BASE_NONE, NULL, 0x0,
"BIA value of a sender interface", HFILL }},
{ &hf_hsrp2_hellotime,
{ "Hellotime", "hsrp2.hellotime",
FT_UINT32, BASE_DEC, NULL, 0x0,
"The approximate period between the Hello messages that the router sends", HFILL }},
{ &hf_hsrp2_holdtime,
{ "Holdtime", "hsrp2.holdtime",
FT_UINT32, BASE_DEC, NULL, 0x0,
"Time that the current Hello message should be considered valid", HFILL }},
{ &hf_hsrp2_priority,
{ "Priority", "hsrp2.priority",
FT_UINT32, BASE_DEC, NULL, 0x0,
"Used to elect the active and standby routers. Numerically higher priority wins vote", HFILL }},
{ &hf_hsrp2_auth_data,
{ "Authentication Data", "hsrp2.auth_data",
FT_STRING, BASE_NONE, NULL, 0x0,
"Contains a clear-text 8 character reused password", HFILL }},
{ &hf_hsrp2_virt_ip_addr,
{ "Virtual IP Address", "hsrp2.virt_ip",
FT_IPv4, BASE_NONE, NULL, 0x0,
"The virtual IP address used by this group", HFILL }},
{ &hf_hsrp2_virt_ip_addr_v6,
{ "Virtual IPv6 Address", "hsrp2.virt_ip_v6",
FT_IPv6, BASE_NONE, NULL, 0x0,
"The virtual IPv6 address used by this group", HFILL }},
{ &hf_hsrp2_active_group,
{ "Active Groups", "hsrp2.active_groups",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Active group number which becomes the active router myself", HFILL }},
{ &hf_hsrp2_passive_group,
{ "Passive Groups", "hsrp2.passive_groups",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Standby group number which doesn't become the active router myself", HFILL }},
{ &hf_hsrp2_md5_algorithm,
{ "MD5 Algorithm", "hsrp2.md5_algorithm",
FT_UINT8, BASE_DEC, VALS(hsrp2_md5_algorithm_vals), 0x0,
"Hash Algorithm used by this group", HFILL }},
{ &hf_hsrp2_md5_padding,
{ "Padding", "hsrp2.md5_padding",
FT_UINT8, BASE_HEX, NULL, 0x0,
"Must be zero", HFILL }},
{ &hf_hsrp2_md5_flags,
{ "MD5 Flags", "hsrp2.md5_flags",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Undefined", HFILL }},
{ &hf_hsrp2_md5_ip_address,
{ "Sender's IP Address", "hsrp.md5_ip_address",
FT_IPv4, BASE_NONE, NULL, 0x0,
"IP Address of the sender interface", HFILL }},
{ &hf_hsrp2_md5_key_id,
{ "MD5 Key ID", "hsrp2.md5_key_id",
FT_UINT32, BASE_DEC, NULL, 0x0,
"This field contains Key chain ID", HFILL }},
{ &hf_hsrp2_md5_auth_data,
{ "MD5 Authentication Data", "hsrp2.md5_auth_data",
FT_BYTES, BASE_NONE, NULL, 0x0,
"MD5 digest string is contained.", HFILL }}
};
static int *ett[] = {
&ett_hsrp,
&ett_hsrp2_group_state_tlv,
&ett_hsrp2_interface_state_tlv,
&ett_hsrp2_text_auth_tlv,
&ett_hsrp2_md5_auth_tlv
};
static ei_register_info ei[] = {
{ &ei_hsrp_unknown_tlv, { "hsrp.unknown_tlv", PI_UNDECODED, PI_WARN, "Unknown TLV sequence (HSRPv1)", EXPFILL }},
};
proto_hsrp = proto_register_protocol("Cisco Hot Standby Router Protocol", "HSRP", "hsrp");
proto_register_field_array(proto_hsrp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_hsrp = expert_register_protocol(proto_hsrp);
expert_register_field_array(expert_hsrp, ei, array_length(ei));
hsrp_handle = register_dissector("hsrp", dissect_hsrp, proto_hsrp);
}
void
proto_reg_handoff_hsrp(void)
{
dissector_add_uint_range_with_preference("udp.port", UDP_PORT_HSRP_RANGE, hsrp_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=8 tabstop=8 expandtab:
* :indentSize=8:tabSize=8:noTabs=true:
*/
|
