1 /*
2 * Copyright (c) 2000 Lennert Buytenhek
3 *
4 * This software may be distributed either under the terms of the
5 * BSD-style license that accompanies tcpdump or the GNU General
6 * Public License
7 *
8 * Format and print IEEE 802.1d spanning tree protocol packets.
9 * Contributed by Lennert Buytenhek <buytenh@gnu.org>
10 */
11
12 #ifndef lint
13 static const char rcsid[] _U_ =
14 "@(#) $Header: /tcpdump/master/tcpdump/print-stp.c,v 1.20 2007-03-18 17:11:46 hannes Exp $";
15 #endif
16
17 #ifdef HAVE_CONFIG_H
18 #include "config.h"
19 #endif
20
21 #include <tcpdump-stdinc.h>
22
23 #include <stdlib.h>
24 #include <stdio.h>
25 #include <string.h>
26
27 #include "interface.h"
28 #include "addrtoname.h"
29 #include "extract.h"
30
31 #define RSTP_EXTRACT_PORT_ROLE(x) (((x)&0x0C)>>2)
32 /* STP timers are expressed in multiples of 1/256th second */
33 #define STP_TIME_BASE 256
34 #define STP_BPDU_MSTP_MIN_LEN 102
35
36 struct stp_bpdu_ {
37 u_int8_t protocol_id[2];
38 u_int8_t protocol_version;
39 u_int8_t bpdu_type;
40 u_int8_t flags;
41 u_int8_t root_id[8];
42 u_int8_t root_path_cost[4];
43 u_int8_t bridge_id[8];
44 u_int8_t port_id[2];
45 u_int8_t message_age[2];
46 u_int8_t max_age[2];
47 u_int8_t hello_time[2];
48 u_int8_t forward_delay[2];
49 u_int8_t v1_length;
50 };
51
52 #define STP_PROTO_REGULAR 0x00
53 #define STP_PROTO_RAPID 0x02
54 #define STP_PROTO_MSTP 0x03
55 #define STP_PROTO_SPB 0x04
56
57 static const struct tok stp_proto_values[] = {
58 { STP_PROTO_REGULAR, "802.1d" },
59 { STP_PROTO_RAPID, "802.1w" },
60 { STP_PROTO_MSTP, "802.1s" },
61 { STP_PROTO_SPB, "802.1aq" },
62 { 0, NULL}
63 };
64
65 #define STP_BPDU_TYPE_CONFIG 0x00
66 #define STP_BPDU_TYPE_RSTP 0x02
67 #define STP_BPDU_TYPE_TOPO_CHANGE 0x80
68
69 static const struct tok stp_bpdu_flag_values[] = {
70 { 0x01, "Topology change" },
71 { 0x02, "Proposal" },
72 { 0x10, "Learn" },
73 { 0x20, "Forward" },
74 { 0x40, "Agreement" },
75 { 0x80, "Topology change ACK" },
76 { 0, NULL}
77 };
78
79 static const struct tok stp_bpdu_type_values[] = {
80 { STP_BPDU_TYPE_CONFIG, "Config" },
81 { STP_BPDU_TYPE_RSTP, "Rapid STP" },
82 { STP_BPDU_TYPE_TOPO_CHANGE, "Topology Change" },
83 { 0, NULL}
84 };
85
86 static const struct tok rstp_obj_port_role_values[] = {
87 { 0x00, "Unknown" },
88 { 0x01, "Alternate" },
89 { 0x02, "Root" },
90 { 0x03, "Designated" },
91 { 0, NULL}
92 };
93
94 static char *
stp_print_bridge_id(const u_char * p)95 stp_print_bridge_id(const u_char *p)
96 {
97 static char bridge_id_str[sizeof("pppp.aa:bb:cc:dd:ee:ff")];
98
99 snprintf(bridge_id_str, sizeof(bridge_id_str),
100 "%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
101 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
102
103 return bridge_id_str;
104 }
105
106 static void
stp_print_config_bpdu(const struct stp_bpdu_ * stp_bpdu,u_int length)107 stp_print_config_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length)
108 {
109 printf(", Flags [%s]",
110 bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags));
111
112 printf(", bridge-id %s.%04x, length %u",
113 stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id),
114 EXTRACT_16BITS(&stp_bpdu->port_id), length);
115
116 /* in non-verbose mode just print the bridge-id */
117 if (!vflag) {
118 return;
119 }
120
121 printf("\n\tmessage-age %.2fs, max-age %.2fs"
122 ", hello-time %.2fs, forwarding-delay %.2fs",
123 (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE,
124 (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE,
125 (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE,
126 (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE);
127
128 printf("\n\troot-id %s, root-pathcost %u",
129 stp_print_bridge_id((const u_char *)&stp_bpdu->root_id),
130 EXTRACT_32BITS(&stp_bpdu->root_path_cost));
131
132 /* Port role is only valid for 802.1w */
133 if (stp_bpdu->protocol_version == STP_PROTO_RAPID) {
134 printf(", port-role %s",
135 tok2str(rstp_obj_port_role_values, "Unknown",
136 RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags)));
137 }
138 }
139
140 /*
141 * MSTP packet format
142 * Ref. IEEE 802.1Q 2003 Ed. Section 14
143 *
144 * MSTP BPDU
145 *
146 * 2 - bytes Protocol Id
147 * 1 - byte Protocol Ver.
148 * 1 - byte BPDU tye
149 * 1 - byte Flags
150 * 8 - bytes CIST Root Identifier
151 * 4 - bytes CIST External Path Cost
152 * 8 - bytes CIST Regional Root Identifier
153 * 2 - bytes CIST Port Identifier
154 * 2 - bytes Message Age
155 * 2 - bytes Max age
156 * 2 - bytes Hello Time
157 * 2 - bytes Forward delay
158 * 1 - byte Version 1 length. Must be 0
159 * 2 - bytes Version 3 length
160 * 1 - byte Config Identifier
161 * 32 - bytes Config Name
162 * 2 - bytes Revision level
163 * 16 - bytes Config Digest [MD5]
164 * 4 - bytes CIST Internal Root Path Cost
165 * 8 - bytes CIST Bridge Identifier
166 * 1 - byte CIST Remaining Hops
167 * 16 - bytes MSTI information [Max 64 MSTI, each 16 bytes]
168 *
169 *
170 * SPB BPDU
171 * Ref. IEEE 802.1aq. Section 14
172 *
173 * 2 - bytes Version 4 length
174 * 1 - byte Aux Config Identifier
175 * 32 - bytes Aux Config Name
176 * 2 - bytes Aux Revision level
177 * 16 - bytes Aux Config Digest [MD5]
178 * 1 - byte (1 - 2) Agreement Number
179 * (3 - 4) Discarded Agreement Number
180 * (5) Agreement Valid Flag
181 * (6) Restricted Role Flag
182 * (7 - 8) Unused sent zero
183 * 1 - byte Unused
184 * 1 - byte (1 - 4) Agreement Digest Format Identifier
185 * (5 - 8) Agreement Digest Format Capabilities
186 * 1 - byte (1 - 4) Agreement Digest Convention Identifier
187 * (5 - 8) Agreement Digest Convention Capabilities
188 * 2 - bytes Agreement Digest Edge Count
189 * 8 - byte Reserved Set
190 * 20 - bytes Computed Topology Digest
191 *
192 *
193 * MSTI Payload
194 *
195 * 1 - byte MSTI flag
196 * 8 - bytes MSTI Regional Root Identifier
197 * 4 - bytes MSTI Regional Path Cost
198 * 1 - byte MSTI Bridge Priority
199 * 1 - byte MSTI Port Priority
200 * 1 - byte MSTI Remaining Hops
201 *
202 */
203
204 #define MST_BPDU_MSTI_LENGTH 16
205 #define MST_BPDU_CONFIG_INFO_LENGTH 64
206
207 /* Offsets of fields from the begginning for the packet */
208 #define MST_BPDU_VER3_LEN_OFFSET 36
209 #define MST_BPDU_CONFIG_NAME_OFFSET 39
210 #define MST_BPDU_CONFIG_DIGEST_OFFSET 73
211 #define MST_BPDU_CIST_INT_PATH_COST_OFFSET 89
212 #define MST_BPDU_CIST_BRIDGE_ID_OFFSET 93
213 #define MST_BPDU_CIST_REMAIN_HOPS_OFFSET 101
214 #define MST_BPDU_MSTI_OFFSET 102
215 /* Offsets within an MSTI */
216 #define MST_BPDU_MSTI_ROOT_PRIO_OFFSET 1
217 #define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9
218 #define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET 13
219 #define MST_BPDU_MSTI_PORT_PRIO_OFFSET 14
220 #define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET 15
221
222 #define SPB_BPDU_MIN_LEN 87
223 #define SPB_BPDU_CONFIG_NAME_OFFSET 3
224 #define SPB_BPDU_CONFIG_REV_OFFSET SPB_BPDU_CONFIG_NAME_OFFSET + 32
225 #define SPB_BPDU_CONFIG_DIGEST_OFFSET SPB_BPDU_CONFIG_REV_OFFSET + 2
226 #define SPB_BPDU_AGREEMENT_OFFSET SPB_BPDU_CONFIG_DIGEST_OFFSET + 16
227 #define SPB_BPDU_AGREEMENT_UNUSED_OFFSET SPB_BPDU_AGREEMENT_OFFSET + 1
228 #define SPB_BPDU_AGREEMENT_FORMAT_OFFSET SPB_BPDU_AGREEMENT_UNUSED_OFFSET + 1
229 #define SPB_BPDU_AGREEMENT_CON_OFFSET SPB_BPDU_AGREEMENT_FORMAT_OFFSET + 1
230 #define SPB_BPDU_AGREEMENT_EDGE_OFFSET SPB_BPDU_AGREEMENT_CON_OFFSET + 1
231 #define SPB_BPDU_AGREEMENT_RES1_OFFSET SPB_BPDU_AGREEMENT_EDGE_OFFSET + 2
232 #define SPB_BPDU_AGREEMENT_RES2_OFFSET SPB_BPDU_AGREEMENT_RES1_OFFSET + 4
233 #define SPB_BPDU_AGREEMENT_DIGEST_OFFSET SPB_BPDU_AGREEMENT_RES2_OFFSET + 4
234
235
236 static void
stp_print_mstp_bpdu(const struct stp_bpdu_ * stp_bpdu,u_int length)237 stp_print_mstp_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length)
238 {
239 const u_char *ptr;
240 u_int16_t v3len;
241 u_int16_t len;
242 u_int16_t msti;
243 u_int offset;
244
245 ptr = (const u_char *)stp_bpdu;
246 printf(", CIST Flags [%s], length %u",
247 bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags), length);
248
249 /*
250 * in non-verbose mode just print the flags.
251 */
252 if (!vflag) {
253 return;
254 }
255
256 printf("\n\tport-role %s, ",
257 tok2str(rstp_obj_port_role_values, "Unknown",
258 RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags)));
259
260 printf("CIST root-id %s, CIST ext-pathcost %u ",
261 stp_print_bridge_id((const u_char *)&stp_bpdu->root_id),
262 EXTRACT_32BITS(&stp_bpdu->root_path_cost));
263
264 printf("\n\tCIST regional-root-id %s, ",
265 stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id));
266
267 printf("CIST port-id %04x, ", EXTRACT_16BITS(&stp_bpdu->port_id));
268
269 printf("\n\tmessage-age %.2fs, max-age %.2fs"
270 ", hello-time %.2fs, forwarding-delay %.2fs",
271 (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE,
272 (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE,
273 (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE,
274 (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE);
275
276 printf ("\n\tv3len %d, ", EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET));
277 printf("MCID Name %s, rev %u, "
278 "\n\t\tdigest %08x%08x%08x%08x, ",
279 ptr + MST_BPDU_CONFIG_NAME_OFFSET,
280 EXTRACT_16BITS(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32),
281 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET),
282 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4),
283 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8),
284 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12));
285
286 printf ("CIST int-root-pathcost %u, ",
287 EXTRACT_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET));
288
289 printf("\n\tCIST bridge-id %s, ",
290 stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET));
291
292 printf("CIST remaining-hops %d", ptr[MST_BPDU_CIST_REMAIN_HOPS_OFFSET]);
293
294 /* Dump all MSTI's */
295 v3len = EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET);
296 if (v3len > MST_BPDU_CONFIG_INFO_LENGTH) {
297 len = v3len - MST_BPDU_CONFIG_INFO_LENGTH;
298 offset = MST_BPDU_MSTI_OFFSET;
299 while (len >= MST_BPDU_MSTI_LENGTH) {
300 msti = EXTRACT_16BITS(ptr + offset +
301 MST_BPDU_MSTI_ROOT_PRIO_OFFSET);
302 msti = msti & 0x0FFF;
303
304 printf("\n\tMSTI %d, Flags [%s], port-role %s",
305 msti, bittok2str(stp_bpdu_flag_values, "none", ptr[offset]),
306 tok2str(rstp_obj_port_role_values, "Unknown",
307 RSTP_EXTRACT_PORT_ROLE(ptr[offset])));
308 printf("\n\t\tMSTI regional-root-id %s, pathcost %u",
309 stp_print_bridge_id(ptr + offset +
310 MST_BPDU_MSTI_ROOT_PRIO_OFFSET),
311 EXTRACT_32BITS(ptr + offset +
312 MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET));
313 printf("\n\t\tMSTI bridge-prio %d, port-prio %d, hops %d",
314 ptr[offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET] >> 4,
315 ptr[offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET] >> 4,
316 ptr[offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET]);
317
318 len -= MST_BPDU_MSTI_LENGTH;
319 offset += MST_BPDU_MSTI_LENGTH;
320 }
321 }
322 }
323
324 static void
stp_print_spb_bpdu(const struct stp_bpdu_ * stp_bpdu,u_int offset)325 stp_print_spb_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int offset)
326 {
327 const u_char *ptr;
328
329 /*
330 * in non-verbose mode don't print anything.
331 */
332 if (!vflag) {
333 return;
334 }
335
336 ptr = (const u_char *)stp_bpdu;
337 printf("\n\tv4len %d AUXMCID Name %s, Rev %u, \n\t\tdigest %08x%08x%08x%08x",
338 EXTRACT_16BITS (ptr + offset),
339 ptr + offset + SPB_BPDU_CONFIG_NAME_OFFSET,
340 EXTRACT_16BITS(ptr + offset + SPB_BPDU_CONFIG_REV_OFFSET),
341 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET),
342 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 4),
343 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 8),
344 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 12));
345
346 printf("\n\tAgreement num %d, Discarded Agreement num %d, Agreement valid-"
347 "flag %d, \n\tRestricted role-flag: %d, Format id %d cap %d, "
348 "Convention id %d cap %d, \n\tEdge count %d, "
349 "Agreement digest %08x%08x%08x%08x%08x\n",
350 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>6,
351 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>4 & 0x3,
352 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>3 & 0x1,
353 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>2 & 0x1,
354 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]>>4,
355 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]&0x00ff,
356 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]>>4,
357 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]&0x00ff,
358 EXTRACT_16BITS(ptr + offset + SPB_BPDU_AGREEMENT_EDGE_OFFSET),
359 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET),
360 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+4,
361 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+8,
362 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+12,
363 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+16);
364 }
365
366 /*
367 * Print 802.1d / 802.1w / 802.1q (mstp) / 802.1aq (spb) packets.
368 */
369 void
stp_print(const u_char * p,u_int length)370 stp_print(const u_char *p, u_int length)
371 {
372 const struct stp_bpdu_ *stp_bpdu;
373 u_int mstp_len;
374 u_int spb_len;
375
376 stp_bpdu = (struct stp_bpdu_*)p;
377
378 /* Minimum STP Frame size. */
379 if (length < 4)
380 goto trunc;
381
382 if (EXTRACT_16BITS(&stp_bpdu->protocol_id)) {
383 printf("unknown STP version, length %u", length);
384 return;
385 }
386
387 printf("STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)",
388 stp_bpdu->protocol_version));
389
390 switch (stp_bpdu->protocol_version) {
391 case STP_PROTO_REGULAR:
392 case STP_PROTO_RAPID:
393 case STP_PROTO_MSTP:
394 case STP_PROTO_SPB:
395 break;
396 default:
397 return;
398 }
399
400 printf(", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)",
401 stp_bpdu->bpdu_type));
402
403 switch (stp_bpdu->bpdu_type) {
404 case STP_BPDU_TYPE_CONFIG:
405 if (length < sizeof(struct stp_bpdu_) - 1) {
406 goto trunc;
407 }
408 stp_print_config_bpdu(stp_bpdu, length);
409 break;
410
411 case STP_BPDU_TYPE_RSTP:
412 if (stp_bpdu->protocol_version == STP_PROTO_RAPID) {
413 if (length < sizeof(struct stp_bpdu_)) {
414 goto trunc;
415 }
416 stp_print_config_bpdu(stp_bpdu, length);
417 } else if (stp_bpdu->protocol_version == STP_PROTO_MSTP ||
418 stp_bpdu->protocol_version == STP_PROTO_SPB) {
419 if (length < STP_BPDU_MSTP_MIN_LEN) {
420 goto trunc;
421 }
422
423 if (stp_bpdu->v1_length != 0) {
424 /* FIX ME: Emit a message here ? */
425 goto trunc;
426 }
427
428 /* Validate v3 length */
429 mstp_len = EXTRACT_16BITS(p + MST_BPDU_VER3_LEN_OFFSET);
430 mstp_len += 2; /* length encoding itself is 2 bytes */
431 if (length < (sizeof(struct stp_bpdu_) + mstp_len)) {
432 goto trunc;
433 }
434 stp_print_mstp_bpdu(stp_bpdu, length);
435
436 if (stp_bpdu->protocol_version == STP_PROTO_SPB)
437 {
438 /* Validate v4 length */
439 spb_len = EXTRACT_16BITS (p + MST_BPDU_VER3_LEN_OFFSET + mstp_len);
440 spb_len += 2;
441 if (length < (sizeof(struct stp_bpdu_) + mstp_len + spb_len) ||
442 spb_len < SPB_BPDU_MIN_LEN) {
443 goto trunc;
444 }
445 stp_print_spb_bpdu(stp_bpdu, (sizeof(struct stp_bpdu_) + mstp_len));
446 }
447 }
448 break;
449
450 case STP_BPDU_TYPE_TOPO_CHANGE:
451 /* always empty message - just break out */
452 break;
453
454 default:
455 break;
456 }
457
458 return;
459 trunc:
460 printf("[|stp %d]", length);
461 }
462
463 /*
464 * Local Variables:
465 * c-style: whitesmith
466 * c-basic-offset: 4
467 * End:
468 */
469