forked from the-tcpdump-group/tcpdump
/
print-stp.c
513 lines (446 loc) · 17.5 KB
/
print-stp.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
/*
* Copyright (c) 2000 Lennert Buytenhek
*
* This software may be distributed either under the terms of the
* BSD-style license that accompanies tcpdump or the GNU General
* Public License
*
* Contributed by Lennert Buytenhek <buytenh@gnu.org>
*/
/* \summary: IEEE 802.1d Spanning Tree Protocol (STP) printer */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#include <stdio.h>
#include "netdissect.h"
#include "extract.h"
#define RSTP_EXTRACT_PORT_ROLE(x) (((x)&0x0C)>>2)
/* STP timers are expressed in multiples of 1/256th second */
#define STP_TIME_BASE 256
#define STP_BPDU_MSTP_MIN_LEN 102
struct stp_bpdu_ {
nd_uint16_t protocol_id;
nd_uint8_t protocol_version;
nd_uint8_t bpdu_type;
nd_uint8_t flags;
nd_byte root_id[8];
nd_uint32_t root_path_cost;
nd_byte bridge_id[8];
nd_uint16_t port_id;
nd_uint16_t message_age;
nd_uint16_t max_age;
nd_uint16_t hello_time;
nd_uint16_t forward_delay;
nd_uint8_t v1_length;
};
#define STP_PROTO_REGULAR 0x00
#define STP_PROTO_RAPID 0x02
#define STP_PROTO_MSTP 0x03
#define STP_PROTO_SPB 0x04
static const struct tok stp_proto_values[] = {
{ STP_PROTO_REGULAR, "802.1d" },
{ STP_PROTO_RAPID, "802.1w" },
{ STP_PROTO_MSTP, "802.1s" },
{ STP_PROTO_SPB, "802.1aq" },
{ 0, NULL}
};
#define STP_BPDU_TYPE_CONFIG 0x00
#define STP_BPDU_TYPE_RSTP 0x02
#define STP_BPDU_TYPE_TOPO_CHANGE 0x80
static const struct tok stp_bpdu_flag_values[] = {
{ 0x01, "Topology change" },
{ 0x02, "Proposal" },
{ 0x10, "Learn" },
{ 0x20, "Forward" },
{ 0x40, "Agreement" },
{ 0x80, "Topology change ACK" },
{ 0, NULL}
};
static const struct tok stp_bpdu_type_values[] = {
{ STP_BPDU_TYPE_CONFIG, "Config" },
{ STP_BPDU_TYPE_RSTP, "Rapid STP" },
{ STP_BPDU_TYPE_TOPO_CHANGE, "Topology Change" },
{ 0, NULL}
};
static const struct tok rstp_obj_port_role_values[] = {
{ 0x00, "Unknown" },
{ 0x01, "Alternate" },
{ 0x02, "Root" },
{ 0x03, "Designated" },
{ 0, NULL}
};
#define ND_TCHECK_BRIDGE_ID(p) ND_TCHECK_8(p)
static char *
stp_print_bridge_id(const u_char *p)
{
static char bridge_id_str[sizeof("pppp.aa:bb:cc:dd:ee:ff")];
nd_snprintf(bridge_id_str, sizeof(bridge_id_str),
"%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
EXTRACT_U_1(p), EXTRACT_U_1(p + 1), EXTRACT_U_1(p + 2),
EXTRACT_U_1(p + 3), EXTRACT_U_1(p + 4), EXTRACT_U_1(p + 5),
EXTRACT_U_1(p + 6), EXTRACT_U_1(p + 7));
return bridge_id_str;
}
static int
stp_print_config_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu,
u_int length)
{
uint8_t bpdu_flags;
ND_TCHECK_1(stp_bpdu->flags);
bpdu_flags = EXTRACT_U_1(stp_bpdu->flags);
ND_PRINT(", Flags [%s]",
bittok2str(stp_bpdu_flag_values, "none", bpdu_flags));
ND_TCHECK_2(stp_bpdu->port_id);
ND_PRINT(", bridge-id %s.%04x, length %u",
stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id),
EXTRACT_BE_U_2(stp_bpdu->port_id), length);
/* in non-verbose mode just print the bridge-id */
if (!ndo->ndo_vflag) {
return 1;
}
ND_TCHECK_2(stp_bpdu->forward_delay);
ND_PRINT("\n\tmessage-age %.2fs, max-age %.2fs"
", hello-time %.2fs, forwarding-delay %.2fs",
(float) EXTRACT_BE_U_2(stp_bpdu->message_age) / STP_TIME_BASE,
(float) EXTRACT_BE_U_2(stp_bpdu->max_age) / STP_TIME_BASE,
(float) EXTRACT_BE_U_2(stp_bpdu->hello_time) / STP_TIME_BASE,
(float) EXTRACT_BE_U_2(stp_bpdu->forward_delay) / STP_TIME_BASE);
ND_PRINT("\n\troot-id %s, root-pathcost %u",
stp_print_bridge_id((const u_char *)&stp_bpdu->root_id),
EXTRACT_BE_U_4(stp_bpdu->root_path_cost));
/* Port role is only valid for 802.1w */
if (EXTRACT_U_1(stp_bpdu->protocol_version) == STP_PROTO_RAPID) {
ND_PRINT(", port-role %s",
tok2str(rstp_obj_port_role_values, "Unknown",
RSTP_EXTRACT_PORT_ROLE(bpdu_flags)));
}
return 1;
trunc:
return 0;
}
/*
* MSTP packet format
* Ref. IEEE 802.1Q 2003 Ed. Section 14
*
* MSTP BPDU
*
* 2 - bytes Protocol Id
* 1 - byte Protocol Ver.
* 1 - byte BPDU tye
* 1 - byte Flags
* 8 - bytes CIST Root Identifier
* 4 - bytes CIST External Path Cost
* 8 - bytes CIST Regional Root Identifier
* 2 - bytes CIST Port Identifier
* 2 - bytes Message Age
* 2 - bytes Max age
* 2 - bytes Hello Time
* 2 - bytes Forward delay
* 1 - byte Version 1 length. Must be 0
* 2 - bytes Version 3 length
* 1 - byte Config Identifier
* 32 - bytes Config Name
* 2 - bytes Revision level
* 16 - bytes Config Digest [MD5]
* 4 - bytes CIST Internal Root Path Cost
* 8 - bytes CIST Bridge Identifier
* 1 - byte CIST Remaining Hops
* 16 - bytes MSTI information [Max 64 MSTI, each 16 bytes]
*
*
* SPB BPDU
* Ref. IEEE 802.1aq. Section 14
*
* 2 - bytes Version 4 length
* 1 - byte Aux Config Identifier
* 32 - bytes Aux Config Name
* 2 - bytes Aux Revision level
* 16 - bytes Aux Config Digest [MD5]
* 1 - byte (1 - 2) Agreement Number
* (3 - 4) Discarded Agreement Number
* (5) Agreement Valid Flag
* (6) Restricted Role Flag
* (7 - 8) Unused sent zero
* 1 - byte Unused
* 1 - byte (1 - 4) Agreement Digest Format Identifier
* (5 - 8) Agreement Digest Format Capabilities
* 1 - byte (1 - 4) Agreement Digest Convention Identifier
* (5 - 8) Agreement Digest Convention Capabilities
* 2 - bytes Agreement Digest Edge Count
* 8 - byte Reserved Set
* 20 - bytes Computed Topology Digest
*
*
* MSTI Payload
*
* 1 - byte MSTI flag
* 8 - bytes MSTI Regional Root Identifier
* 4 - bytes MSTI Regional Path Cost
* 1 - byte MSTI Bridge Priority
* 1 - byte MSTI Port Priority
* 1 - byte MSTI Remaining Hops
*
*/
#define MST_BPDU_MSTI_LENGTH 16
#define MST_BPDU_CONFIG_INFO_LENGTH 64
/* Offsets of fields from the begginning for the packet */
#define MST_BPDU_VER3_LEN_OFFSET 36
#define MST_BPDU_CONFIG_NAME_OFFSET 39
#define MST_BPDU_CONFIG_DIGEST_OFFSET 73
#define MST_BPDU_CIST_INT_PATH_COST_OFFSET 89
#define MST_BPDU_CIST_BRIDGE_ID_OFFSET 93
#define MST_BPDU_CIST_REMAIN_HOPS_OFFSET 101
#define MST_BPDU_MSTI_OFFSET 102
/* Offsets within an MSTI */
#define MST_BPDU_MSTI_ROOT_PRIO_OFFSET 1
#define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9
#define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET 13
#define MST_BPDU_MSTI_PORT_PRIO_OFFSET 14
#define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET 15
#define SPB_BPDU_MIN_LEN 87
#define SPB_BPDU_CONFIG_NAME_OFFSET 3
#define SPB_BPDU_CONFIG_REV_OFFSET SPB_BPDU_CONFIG_NAME_OFFSET + 32
#define SPB_BPDU_CONFIG_DIGEST_OFFSET SPB_BPDU_CONFIG_REV_OFFSET + 2
#define SPB_BPDU_AGREEMENT_OFFSET SPB_BPDU_CONFIG_DIGEST_OFFSET + 16
#define SPB_BPDU_AGREEMENT_UNUSED_OFFSET SPB_BPDU_AGREEMENT_OFFSET + 1
#define SPB_BPDU_AGREEMENT_FORMAT_OFFSET SPB_BPDU_AGREEMENT_UNUSED_OFFSET + 1
#define SPB_BPDU_AGREEMENT_CON_OFFSET SPB_BPDU_AGREEMENT_FORMAT_OFFSET + 1
#define SPB_BPDU_AGREEMENT_EDGE_OFFSET SPB_BPDU_AGREEMENT_CON_OFFSET + 1
#define SPB_BPDU_AGREEMENT_RES1_OFFSET SPB_BPDU_AGREEMENT_EDGE_OFFSET + 2
#define SPB_BPDU_AGREEMENT_RES2_OFFSET SPB_BPDU_AGREEMENT_RES1_OFFSET + 4
#define SPB_BPDU_AGREEMENT_DIGEST_OFFSET SPB_BPDU_AGREEMENT_RES2_OFFSET + 4
static int
stp_print_mstp_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu,
u_int length)
{
const u_char *ptr;
uint8_t bpdu_flags;
uint16_t v3len;
uint16_t len;
uint16_t msti;
u_int offset;
ptr = (const u_char *)stp_bpdu;
ND_TCHECK_1(stp_bpdu->flags);
bpdu_flags = EXTRACT_U_1(stp_bpdu->flags);
ND_PRINT(", CIST Flags [%s], length %u",
bittok2str(stp_bpdu_flag_values, "none", bpdu_flags), length);
/*
* in non-verbose mode just print the flags.
*/
if (!ndo->ndo_vflag) {
return 1;
}
ND_PRINT("\n\tport-role %s, ",
tok2str(rstp_obj_port_role_values, "Unknown",
RSTP_EXTRACT_PORT_ROLE(bpdu_flags)));
ND_TCHECK_4(stp_bpdu->root_path_cost);
ND_PRINT("CIST root-id %s, CIST ext-pathcost %u",
stp_print_bridge_id((const u_char *)&stp_bpdu->root_id),
EXTRACT_BE_U_4(stp_bpdu->root_path_cost));
ND_TCHECK_SIZE(&stp_bpdu->bridge_id);
ND_PRINT("\n\tCIST regional-root-id %s, ",
stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id));
ND_TCHECK_2(stp_bpdu->port_id);
ND_PRINT("CIST port-id %04x,", EXTRACT_BE_U_2(stp_bpdu->port_id));
ND_TCHECK_2(stp_bpdu->forward_delay);
ND_PRINT("\n\tmessage-age %.2fs, max-age %.2fs"
", hello-time %.2fs, forwarding-delay %.2fs",
(float) EXTRACT_BE_U_2(stp_bpdu->message_age) / STP_TIME_BASE,
(float) EXTRACT_BE_U_2(stp_bpdu->max_age) / STP_TIME_BASE,
(float) EXTRACT_BE_U_2(stp_bpdu->hello_time) / STP_TIME_BASE,
(float) EXTRACT_BE_U_2(stp_bpdu->forward_delay) / STP_TIME_BASE);
ND_TCHECK_2(ptr + MST_BPDU_VER3_LEN_OFFSET);
ND_PRINT("\n\tv3len %u, ", EXTRACT_BE_U_2(ptr + MST_BPDU_VER3_LEN_OFFSET));
ND_TCHECK_4(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12);
ND_PRINT("MCID Name ");
if (fn_printzp(ndo, ptr + MST_BPDU_CONFIG_NAME_OFFSET, 32, ndo->ndo_snapend))
goto trunc;
ND_PRINT(", rev %u,"
"\n\t\tdigest %08x%08x%08x%08x, ",
EXTRACT_BE_U_2(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32),
EXTRACT_BE_U_4(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET),
EXTRACT_BE_U_4(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4),
EXTRACT_BE_U_4(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8),
EXTRACT_BE_U_4(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12));
ND_TCHECK_4(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET);
ND_PRINT("CIST int-root-pathcost %u,",
EXTRACT_BE_U_4(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET));
ND_TCHECK_BRIDGE_ID(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET);
ND_PRINT("\n\tCIST bridge-id %s, ",
stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET));
ND_TCHECK_1(ptr + MST_BPDU_CIST_REMAIN_HOPS_OFFSET);
ND_PRINT("CIST remaining-hops %u", EXTRACT_U_1(ptr + MST_BPDU_CIST_REMAIN_HOPS_OFFSET));
/* Dump all MSTI's */
ND_TCHECK_2(ptr + MST_BPDU_VER3_LEN_OFFSET);
v3len = EXTRACT_BE_U_2(ptr + MST_BPDU_VER3_LEN_OFFSET);
if (v3len > MST_BPDU_CONFIG_INFO_LENGTH) {
len = v3len - MST_BPDU_CONFIG_INFO_LENGTH;
offset = MST_BPDU_MSTI_OFFSET;
while (len >= MST_BPDU_MSTI_LENGTH) {
ND_TCHECK_LEN(ptr + offset, MST_BPDU_MSTI_LENGTH);
msti = EXTRACT_BE_U_2(ptr + offset + MST_BPDU_MSTI_ROOT_PRIO_OFFSET);
msti = msti & 0x0FFF;
ND_PRINT("\n\tMSTI %u, Flags [%s], port-role %s",
msti, bittok2str(stp_bpdu_flag_values, "none", EXTRACT_U_1(ptr + offset)),
tok2str(rstp_obj_port_role_values, "Unknown",
RSTP_EXTRACT_PORT_ROLE(EXTRACT_U_1(ptr + offset))));
ND_PRINT("\n\t\tMSTI regional-root-id %s, pathcost %u",
stp_print_bridge_id(ptr + offset +
MST_BPDU_MSTI_ROOT_PRIO_OFFSET),
EXTRACT_BE_U_4(ptr + offset + MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET));
ND_PRINT("\n\t\tMSTI bridge-prio %u, port-prio %u, hops %u",
EXTRACT_U_1(ptr + offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET) >> 4,
EXTRACT_U_1(ptr + offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET) >> 4,
EXTRACT_U_1(ptr + offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET));
len -= MST_BPDU_MSTI_LENGTH;
offset += MST_BPDU_MSTI_LENGTH;
}
}
return 1;
trunc:
return 0;
}
static int
stp_print_spb_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu,
u_int offset)
{
const u_char *ptr;
/*
* in non-verbose mode don't print anything.
*/
if (!ndo->ndo_vflag) {
return 1;
}
ptr = (const u_char *)stp_bpdu;
ND_TCHECK_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET + 16);
ND_PRINT("\n\tv4len %u, ", EXTRACT_BE_U_2(ptr + offset));
ND_PRINT("AUXMCID Name ");
if (fn_printzp(ndo, ptr + offset + SPB_BPDU_CONFIG_NAME_OFFSET, 32,
ndo->ndo_snapend))
goto trunc;
ND_PRINT(", Rev %u,\n\t\tdigest %08x%08x%08x%08x",
EXTRACT_BE_U_2(ptr + offset + SPB_BPDU_CONFIG_REV_OFFSET),
EXTRACT_BE_U_4(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET),
EXTRACT_BE_U_4(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 4),
EXTRACT_BE_U_4(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 8),
EXTRACT_BE_U_4(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 12));
ND_PRINT("\n\tAgreement num %u, Discarded Agreement num %u, Agreement valid-"
"flag %u,\n\tRestricted role-flag: %u, Format id %u cap %u, "
"Convention id %u cap %u,\n\tEdge count %u, "
"Agreement digest %08x%08x%08x%08x%08x\n",
EXTRACT_U_1(ptr + offset + SPB_BPDU_AGREEMENT_OFFSET)>>6,
EXTRACT_U_1(ptr + offset + SPB_BPDU_AGREEMENT_OFFSET)>>4 & 0x3,
EXTRACT_U_1(ptr + offset + SPB_BPDU_AGREEMENT_OFFSET)>>3 & 0x1,
EXTRACT_U_1(ptr + offset + SPB_BPDU_AGREEMENT_OFFSET)>>2 & 0x1,
EXTRACT_U_1(ptr + offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET)>>4,
EXTRACT_U_1(ptr + offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET)&0x00ff,
EXTRACT_U_1(ptr + offset + SPB_BPDU_AGREEMENT_CON_OFFSET)>>4,
EXTRACT_U_1(ptr + offset + SPB_BPDU_AGREEMENT_CON_OFFSET)&0x00ff,
EXTRACT_BE_U_2(ptr + offset + SPB_BPDU_AGREEMENT_EDGE_OFFSET),
EXTRACT_BE_U_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET),
EXTRACT_BE_U_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET + 4),
EXTRACT_BE_U_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET + 8),
EXTRACT_BE_U_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET + 12),
EXTRACT_BE_U_4(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET + 16));
return 1;
trunc:
return 0;
}
/*
* Print 802.1d / 802.1w / 802.1q (mstp) / 802.1aq (spb) packets.
*/
void
stp_print(netdissect_options *ndo, const u_char *p, u_int length)
{
const struct stp_bpdu_ *stp_bpdu;
u_int protocol_version;
u_int bpdu_type;
u_int mstp_len;
u_int spb_len;
ndo->ndo_protocol = "stp";
stp_bpdu = (const struct stp_bpdu_*)p;
/* Minimum STP Frame size. */
if (length < 4)
goto trunc;
ND_TCHECK_2(stp_bpdu->protocol_id);
if (EXTRACT_BE_U_2(stp_bpdu->protocol_id)) {
ND_PRINT("unknown STP version, length %u", length);
return;
}
ND_TCHECK_1(stp_bpdu->protocol_version);
protocol_version = EXTRACT_U_1(stp_bpdu->protocol_version);
ND_PRINT("STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)",
protocol_version));
switch (protocol_version) {
case STP_PROTO_REGULAR:
case STP_PROTO_RAPID:
case STP_PROTO_MSTP:
case STP_PROTO_SPB:
break;
default:
return;
}
ND_TCHECK_1(stp_bpdu->bpdu_type);
bpdu_type = EXTRACT_U_1(stp_bpdu->bpdu_type);
ND_PRINT(", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)",
bpdu_type));
switch (bpdu_type) {
case STP_BPDU_TYPE_CONFIG:
if (length < sizeof(struct stp_bpdu_) - 1) {
goto trunc;
}
if (!stp_print_config_bpdu(ndo, stp_bpdu, length))
goto trunc;
break;
case STP_BPDU_TYPE_RSTP:
if (protocol_version == STP_PROTO_RAPID) {
if (length < sizeof(struct stp_bpdu_)) {
goto trunc;
}
if (!stp_print_config_bpdu(ndo, stp_bpdu, length))
goto trunc;
} else if (protocol_version == STP_PROTO_MSTP ||
protocol_version == STP_PROTO_SPB) {
if (length < STP_BPDU_MSTP_MIN_LEN) {
goto trunc;
}
ND_TCHECK_1(stp_bpdu->v1_length);
if (EXTRACT_U_1(stp_bpdu->v1_length) != 0) {
/* FIX ME: Emit a message here ? */
goto trunc;
}
/* Validate v3 length */
ND_TCHECK_2(p + MST_BPDU_VER3_LEN_OFFSET);
mstp_len = EXTRACT_BE_U_2(p + MST_BPDU_VER3_LEN_OFFSET);
mstp_len += 2; /* length encoding itself is 2 bytes */
if (length < (sizeof(struct stp_bpdu_) + mstp_len)) {
goto trunc;
}
if (!stp_print_mstp_bpdu(ndo, stp_bpdu, length))
goto trunc;
if (protocol_version == STP_PROTO_SPB)
{
/* Validate v4 length */
ND_TCHECK_2(p + MST_BPDU_VER3_LEN_OFFSET + mstp_len);
spb_len = EXTRACT_BE_U_2(p + MST_BPDU_VER3_LEN_OFFSET + mstp_len);
spb_len += 2;
if (length < (sizeof(struct stp_bpdu_) + mstp_len + spb_len) ||
spb_len < SPB_BPDU_MIN_LEN) {
goto trunc;
}
if (!stp_print_spb_bpdu(ndo, stp_bpdu, (sizeof(struct stp_bpdu_) + mstp_len)))
goto trunc;
}
}
break;
case STP_BPDU_TYPE_TOPO_CHANGE:
/* always empty message - just break out */
break;
default:
break;
}
return;
trunc:
ND_PRINT("[|stp %u]", length);
}