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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 #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 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 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 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 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 *
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
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 * 20 - bytes Agreement 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_int16_t 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. We dont read that much
245 * of the packet (DEFAULT_SNAPLEN) to print out cist bridge-id
246 */
247 if (!vflag) {
248 return;
249 }
250
251 printf("\n\tport-role %s, ",
252 tok2str(rstp_obj_port_role_values, "Unknown",
253 RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags)));
254
255 printf("CIST root-id %s, CIST ext-pathcost %u ",
256 stp_print_bridge_id((const u_char *)&stp_bpdu->root_id),
257 EXTRACT_32BITS(&stp_bpdu->root_path_cost));
258
259 printf("\n\tCIST regional-root-id %s, ",
260 stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id));
261
262 printf("CIST port-id %04x, ", EXTRACT_16BITS(&stp_bpdu->port_id));
263
264 printf("\n\tmessage-age %.2fs, max-age %.2fs"
265 ", hello-time %.2fs, forwarding-delay %.2fs",
266 (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE,
267 (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE,
268 (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE,
269 (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE);
270
271 printf ("\n\tv3len %d, ", EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET));
272 printf("MCID Name %s, rev %u, "
273 "\n\t\tdigest %08x%08x%08x%08x, ",
274 ptr + MST_BPDU_CONFIG_NAME_OFFSET,
275 EXTRACT_16BITS(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32),
276 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET),
277 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4),
278 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8),
279 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12));
280
281 printf ("CIST int-root-pathcost %u, ",
282 EXTRACT_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET));
283
284 printf("\n\tCIST bridge-id %s, ",
285 stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET));
286
287 printf("CIST remaining-hops %d", ptr[MST_BPDU_CIST_REMAIN_HOPS_OFFSET]);
288
289 /* Dump all MSTI's */
290 v3len = EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET);
291 if (v3len > MST_BPDU_CONFIG_INFO_LENGTH) {
292 len = v3len - MST_BPDU_CONFIG_INFO_LENGTH;
293 offset = MST_BPDU_MSTI_OFFSET;
294 while (len >= MST_BPDU_MSTI_LENGTH) {
295 msti = EXTRACT_16BITS(ptr + offset +
296 MST_BPDU_MSTI_ROOT_PRIO_OFFSET);
297 msti = msti & 0x0FFF;
298
299 printf("\n\tMSTI %d, Flags [%s], port-role %s",
300 msti, bittok2str(stp_bpdu_flag_values, "none", ptr[offset]),
301 tok2str(rstp_obj_port_role_values, "Unknown",
302 RSTP_EXTRACT_PORT_ROLE(ptr[offset])));
303 printf("\n\t\tMSTI regional-root-id %s, pathcost %u",
304 stp_print_bridge_id(ptr + offset +
305 MST_BPDU_MSTI_ROOT_PRIO_OFFSET),
306 EXTRACT_32BITS(ptr + offset +
307 MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET));
308 printf("\n\t\tMSTI bridge-prio %d, port-prio %d, hops %d",
309 ptr[offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET] >> 4,
310 ptr[offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET] >> 4,
311 ptr[offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET]);
312
313 len -= MST_BPDU_MSTI_LENGTH;
314 offset += MST_BPDU_MSTI_LENGTH;
315 }
316 }
317
318 if ((length-offset) >= SPB_BPDU_MIN_LEN)
319 {
320 printf("\n\tv4len %d AUXMCID Name %s, Rev %u, \n\t\tdigest %08x%08x%08x%08x",
321 EXTRACT_16BITS (ptr + offset),
322 ptr + offset + SPB_BPDU_CONFIG_NAME_OFFSET,
323 EXTRACT_16BITS(ptr + offset + SPB_BPDU_CONFIG_REV_OFFSET),
324 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET),
325 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 4),
326 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 8),
327 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 12));
328
329 printf("\n\tAgreement num %d, Discarded Agreement num %d, Agreement valid-"
330 "flag %d, \n\tRestricted role-flag: %d, Format id %d cap %d, "
331 "Convention id %d cap %d, \n\tEdge count %d, "
332 "Agreement digest %08x%08x%08x%08x%08x\n",
333 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>6,
334 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>4 & 0x3,
335 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>3 & 0x1,
336 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>2 & 0x1,
337 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]>>4,
338 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]&0x00ff,
339 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]>>4,
340 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]&0x00ff,
341 EXTRACT_16BITS(ptr + offset + SPB_BPDU_AGREEMENT_EDGE_OFFSET),
342 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET),
343 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+4,
344 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+8,
345 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+12,
346 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+16);
347 }
348 }
349
350 /*
351 * Print 802.1d / 802.1w / 802.1q (mstp) / 802.1aq (spb) packets.
352 */
353 void
354 stp_print(const u_char *p, u_int length)
355 {
356 const struct stp_bpdu_ *stp_bpdu;
357 u_int16_t mstp_len;
358 u_int16_t spb_len;
359
360 stp_bpdu = (struct stp_bpdu_*)p;
361
362 /* Minimum STP Frame size. */
363 if (length < 4)
364 goto trunc;
365
366 if (EXTRACT_16BITS(&stp_bpdu->protocol_id)) {
367 printf("unknown STP version, length %u", length);
368 return;
369 }
370
371 printf("STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)",
372 stp_bpdu->protocol_version));
373
374 switch (stp_bpdu->protocol_version) {
375 case STP_PROTO_REGULAR:
376 case STP_PROTO_RAPID:
377 case STP_PROTO_MSTP:
378 case STP_PROTO_SPB:
379 break;
380 default:
381 return;
382 }
383
384 printf(", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)",
385 stp_bpdu->bpdu_type));
386
387 switch (stp_bpdu->bpdu_type) {
388 case STP_BPDU_TYPE_CONFIG:
389 if (length < sizeof(struct stp_bpdu_) - 1) {
390 goto trunc;
391 }
392 stp_print_config_bpdu(stp_bpdu, length);
393 break;
394
395 case STP_BPDU_TYPE_RSTP:
396 if (stp_bpdu->protocol_version == STP_PROTO_RAPID) {
397 if (length < sizeof(struct stp_bpdu_)) {
398 goto trunc;
399 }
400 stp_print_config_bpdu(stp_bpdu, length);
401 } else if (stp_bpdu->protocol_version == STP_PROTO_MSTP ||
402 stp_bpdu->protocol_version == STP_PROTO_SPB) {
403 if (length < STP_BPDU_MSTP_MIN_LEN) {
404 goto trunc;
405 }
406 if (stp_bpdu->v1_length != 0) {
407 /* FIX ME: Emit a message here ? */
408 goto trunc;
409 }
410 /* Validate v3 length */
411 mstp_len = EXTRACT_16BITS(p + MST_BPDU_VER3_LEN_OFFSET);
412 mstp_len += 2; /* length encoding itself is 2 bytes */
413 if (length < (sizeof(struct stp_bpdu_) + mstp_len)) {
414 goto trunc;
415 }
416
417 if (stp_bpdu->protocol_version == STP_PROTO_SPB)
418 {
419 spb_len = EXTRACT_16BITS (p + MST_BPDU_VER3_LEN_OFFSET + mstp_len);
420 spb_len += 2;
421 if (length < (sizeof(struct stp_bpdu_) + mstp_len + spb_len) ||
422 spb_len < SPB_BPDU_MIN_LEN) {
423 goto trunc;
424 }
425 }
426
427 stp_print_mstp_bpdu(stp_bpdu, length);
428 }
429 break;
430
431 case STP_BPDU_TYPE_TOPO_CHANGE:
432 /* always empty message - just break out */
433 break;
434
435 default:
436 break;
437 }
438
439 return;
440 trunc:
441 printf("[|stp %d]", length);
442 }
443
444 /*
445 * Local Variables:
446 * c-style: whitesmith
447 * c-basic-offset: 4
448 * End:
449 */
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