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