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Fix a bunch of de-constifications.
[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 <stdio.h>
19
20 #include "interface.h"
21 #include "extract.h"
22
23 #define RSTP_EXTRACT_PORT_ROLE(x) (((x)&0x0C)>>2)
24 /* STP timers are expressed in multiples of 1/256th second */
25 #define STP_TIME_BASE 256
26 #define STP_BPDU_MSTP_MIN_LEN 102
27
28 struct stp_bpdu_ {
29 uint8_t protocol_id[2];
30 uint8_t protocol_version;
31 uint8_t bpdu_type;
32 uint8_t flags;
33 uint8_t root_id[8];
34 uint8_t root_path_cost[4];
35 uint8_t bridge_id[8];
36 uint8_t port_id[2];
37 uint8_t message_age[2];
38 uint8_t max_age[2];
39 uint8_t hello_time[2];
40 uint8_t forward_delay[2];
41 uint8_t v1_length;
42 };
43
44 #define STP_PROTO_REGULAR 0x00
45 #define STP_PROTO_RAPID 0x02
46 #define STP_PROTO_MSTP 0x03
47 #define STP_PROTO_SPB 0x04
48
49 static const struct tok stp_proto_values[] = {
50 { STP_PROTO_REGULAR, "802.1d" },
51 { STP_PROTO_RAPID, "802.1w" },
52 { STP_PROTO_MSTP, "802.1s" },
53 { STP_PROTO_SPB, "802.1aq" },
54 { 0, NULL}
55 };
56
57 #define STP_BPDU_TYPE_CONFIG 0x00
58 #define STP_BPDU_TYPE_RSTP 0x02
59 #define STP_BPDU_TYPE_TOPO_CHANGE 0x80
60
61 static const struct tok stp_bpdu_flag_values[] = {
62 { 0x01, "Topology change" },
63 { 0x02, "Proposal" },
64 { 0x10, "Learn" },
65 { 0x20, "Forward" },
66 { 0x40, "Agreement" },
67 { 0x80, "Topology change ACK" },
68 { 0, NULL}
69 };
70
71 static const struct tok stp_bpdu_type_values[] = {
72 { STP_BPDU_TYPE_CONFIG, "Config" },
73 { STP_BPDU_TYPE_RSTP, "Rapid STP" },
74 { STP_BPDU_TYPE_TOPO_CHANGE, "Topology Change" },
75 { 0, NULL}
76 };
77
78 static const struct tok rstp_obj_port_role_values[] = {
79 { 0x00, "Unknown" },
80 { 0x01, "Alternate" },
81 { 0x02, "Root" },
82 { 0x03, "Designated" },
83 { 0, NULL}
84 };
85
86 static char *
87 stp_print_bridge_id(const u_char *p)
88 {
89 static char bridge_id_str[sizeof("pppp.aa:bb:cc:dd:ee:ff")];
90
91 snprintf(bridge_id_str, sizeof(bridge_id_str),
92 "%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
93 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
94
95 return bridge_id_str;
96 }
97
98 static void
99 stp_print_config_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu,
100 u_int length)
101 {
102 ND_PRINT((ndo, ", Flags [%s]",
103 bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags)));
104
105 ND_PRINT((ndo, ", bridge-id %s.%04x, length %u",
106 stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id),
107 EXTRACT_16BITS(&stp_bpdu->port_id), length));
108
109 /* in non-verbose mode just print the bridge-id */
110 if (!ndo->ndo_vflag) {
111 return;
112 }
113
114 ND_PRINT((ndo, "\n\tmessage-age %.2fs, max-age %.2fs"
115 ", hello-time %.2fs, forwarding-delay %.2fs",
116 (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE,
117 (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE,
118 (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE,
119 (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE));
120
121 ND_PRINT((ndo, "\n\troot-id %s, root-pathcost %u",
122 stp_print_bridge_id((const u_char *)&stp_bpdu->root_id),
123 EXTRACT_32BITS(&stp_bpdu->root_path_cost)));
124
125 /* Port role is only valid for 802.1w */
126 if (stp_bpdu->protocol_version == STP_PROTO_RAPID) {
127 ND_PRINT((ndo, ", port-role %s",
128 tok2str(rstp_obj_port_role_values, "Unknown",
129 RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags))));
130 }
131 }
132
133 /*
134 * MSTP packet format
135 * Ref. IEEE 802.1Q 2003 Ed. Section 14
136 *
137 * MSTP BPDU
138 *
139 * 2 - bytes Protocol Id
140 * 1 - byte Protocol Ver.
141 * 1 - byte BPDU tye
142 * 1 - byte Flags
143 * 8 - bytes CIST Root Identifier
144 * 4 - bytes CIST External Path Cost
145 * 8 - bytes CIST Regional Root Identifier
146 * 2 - bytes CIST Port Identifier
147 * 2 - bytes Message Age
148 * 2 - bytes Max age
149 * 2 - bytes Hello Time
150 * 2 - bytes Forward delay
151 * 1 - byte Version 1 length. Must be 0
152 * 2 - bytes Version 3 length
153 * 1 - byte Config Identifier
154 * 32 - bytes Config Name
155 * 2 - bytes Revision level
156 * 16 - bytes Config Digest [MD5]
157 * 4 - bytes CIST Internal Root Path Cost
158 * 8 - bytes CIST Bridge Identifier
159 * 1 - byte CIST Remaining Hops
160 * 16 - bytes MSTI information [Max 64 MSTI, each 16 bytes]
161 *
162 *
163 * SPB BPDU
164 * Ref. IEEE 802.1aq. Section 14
165 *
166 * 2 - bytes Version 4 length
167 * 1 - byte Aux Config Identifier
168 * 32 - bytes Aux Config Name
169 * 2 - bytes Aux Revision level
170 * 16 - bytes Aux Config Digest [MD5]
171 * 1 - byte (1 - 2) Agreement Number
172 * (3 - 4) Discarded Agreement Number
173 * (5) Agreement Valid Flag
174 * (6) Restricted Role Flag
175 * (7 - 8) Unused sent zero
176 * 1 - byte Unused
177 * 1 - byte (1 - 4) Agreement Digest Format Identifier
178 * (5 - 8) Agreement Digest Format Capabilities
179 * 1 - byte (1 - 4) Agreement Digest Convention Identifier
180 * (5 - 8) Agreement Digest Convention Capabilities
181 * 2 - bytes Agreement Digest Edge Count
182 * 8 - byte Reserved Set
183 * 20 - bytes Computed Topology Digest
184 *
185 *
186 * MSTI Payload
187 *
188 * 1 - byte MSTI flag
189 * 8 - bytes MSTI Regional Root Identifier
190 * 4 - bytes MSTI Regional Path Cost
191 * 1 - byte MSTI Bridge Priority
192 * 1 - byte MSTI Port Priority
193 * 1 - byte MSTI Remaining Hops
194 *
195 */
196
197 #define MST_BPDU_MSTI_LENGTH 16
198 #define MST_BPDU_CONFIG_INFO_LENGTH 64
199
200 /* Offsets of fields from the begginning for the packet */
201 #define MST_BPDU_VER3_LEN_OFFSET 36
202 #define MST_BPDU_CONFIG_NAME_OFFSET 39
203 #define MST_BPDU_CONFIG_DIGEST_OFFSET 73
204 #define MST_BPDU_CIST_INT_PATH_COST_OFFSET 89
205 #define MST_BPDU_CIST_BRIDGE_ID_OFFSET 93
206 #define MST_BPDU_CIST_REMAIN_HOPS_OFFSET 101
207 #define MST_BPDU_MSTI_OFFSET 102
208 /* Offsets within an MSTI */
209 #define MST_BPDU_MSTI_ROOT_PRIO_OFFSET 1
210 #define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9
211 #define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET 13
212 #define MST_BPDU_MSTI_PORT_PRIO_OFFSET 14
213 #define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET 15
214
215 #define SPB_BPDU_MIN_LEN 87
216 #define SPB_BPDU_CONFIG_NAME_OFFSET 3
217 #define SPB_BPDU_CONFIG_REV_OFFSET SPB_BPDU_CONFIG_NAME_OFFSET + 32
218 #define SPB_BPDU_CONFIG_DIGEST_OFFSET SPB_BPDU_CONFIG_REV_OFFSET + 2
219 #define SPB_BPDU_AGREEMENT_OFFSET SPB_BPDU_CONFIG_DIGEST_OFFSET + 16
220 #define SPB_BPDU_AGREEMENT_UNUSED_OFFSET SPB_BPDU_AGREEMENT_OFFSET + 1
221 #define SPB_BPDU_AGREEMENT_FORMAT_OFFSET SPB_BPDU_AGREEMENT_UNUSED_OFFSET + 1
222 #define SPB_BPDU_AGREEMENT_CON_OFFSET SPB_BPDU_AGREEMENT_FORMAT_OFFSET + 1
223 #define SPB_BPDU_AGREEMENT_EDGE_OFFSET SPB_BPDU_AGREEMENT_CON_OFFSET + 1
224 #define SPB_BPDU_AGREEMENT_RES1_OFFSET SPB_BPDU_AGREEMENT_EDGE_OFFSET + 2
225 #define SPB_BPDU_AGREEMENT_RES2_OFFSET SPB_BPDU_AGREEMENT_RES1_OFFSET + 4
226 #define SPB_BPDU_AGREEMENT_DIGEST_OFFSET SPB_BPDU_AGREEMENT_RES2_OFFSET + 4
227
228
229 static void
230 stp_print_mstp_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu,
231 u_int length)
232 {
233 const u_char *ptr;
234 uint16_t v3len;
235 uint16_t len;
236 uint16_t msti;
237 u_int offset;
238
239 ptr = (const u_char *)stp_bpdu;
240 ND_PRINT((ndo, ", 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 (!ndo->ndo_vflag) {
247 return;
248 }
249
250 ND_PRINT((ndo, "\n\tport-role %s, ",
251 tok2str(rstp_obj_port_role_values, "Unknown",
252 RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags))));
253
254 ND_PRINT((ndo, "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 ND_PRINT((ndo, "\n\tCIST regional-root-id %s, ",
259 stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id)));
260
261 ND_PRINT((ndo, "CIST port-id %04x, ", EXTRACT_16BITS(&stp_bpdu->port_id)));
262
263 ND_PRINT((ndo, "\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 ND_PRINT((ndo, "\n\tv3len %d, ", EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET)));
271 ND_PRINT((ndo, "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 ND_PRINT((ndo, "CIST int-root-pathcost %u, ",
281 EXTRACT_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET)));
282
283 ND_PRINT((ndo, "\n\tCIST bridge-id %s, ",
284 stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET)));
285
286 ND_PRINT((ndo, "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 ND_PRINT((ndo, "\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 ND_PRINT((ndo, "\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 ND_PRINT((ndo, "\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(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu,
320 u_int offset)
321 {
322 const u_char *ptr;
323
324 /*
325 * in non-verbose mode don't print anything.
326 */
327 if (!ndo->ndo_vflag) {
328 return;
329 }
330
331 ptr = (const u_char *)stp_bpdu;
332 ND_PRINT((ndo, "\n\tv4len %d AUXMCID Name %s, Rev %u, \n\t\tdigest %08x%08x%08x%08x",
333 EXTRACT_16BITS (ptr + offset),
334 ptr + offset + SPB_BPDU_CONFIG_NAME_OFFSET,
335 EXTRACT_16BITS(ptr + offset + SPB_BPDU_CONFIG_REV_OFFSET),
336 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET),
337 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 4),
338 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 8),
339 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 12)));
340
341 ND_PRINT((ndo, "\n\tAgreement num %d, Discarded Agreement num %d, Agreement valid-"
342 "flag %d, \n\tRestricted role-flag: %d, Format id %d cap %d, "
343 "Convention id %d cap %d, \n\tEdge count %d, "
344 "Agreement digest %08x%08x%08x%08x%08x\n",
345 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>6,
346 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>4 & 0x3,
347 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>3 & 0x1,
348 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>2 & 0x1,
349 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]>>4,
350 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]&0x00ff,
351 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]>>4,
352 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]&0x00ff,
353 EXTRACT_16BITS(ptr + offset + SPB_BPDU_AGREEMENT_EDGE_OFFSET),
354 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET),
355 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+4,
356 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+8,
357 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+12,
358 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+16));
359 }
360
361 /*
362 * Print 802.1d / 802.1w / 802.1q (mstp) / 802.1aq (spb) packets.
363 */
364 void
365 stp_print(netdissect_options *ndo, const u_char *p, u_int length)
366 {
367 const struct stp_bpdu_ *stp_bpdu;
368 u_int mstp_len;
369 u_int spb_len;
370
371 stp_bpdu = (const struct stp_bpdu_*)p;
372
373 /* Minimum STP Frame size. */
374 if (length < 4)
375 goto trunc;
376
377 if (EXTRACT_16BITS(&stp_bpdu->protocol_id)) {
378 ND_PRINT((ndo, "unknown STP version, length %u", length));
379 return;
380 }
381
382 ND_PRINT((ndo, "STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)",
383 stp_bpdu->protocol_version)));
384
385 switch (stp_bpdu->protocol_version) {
386 case STP_PROTO_REGULAR:
387 case STP_PROTO_RAPID:
388 case STP_PROTO_MSTP:
389 case STP_PROTO_SPB:
390 break;
391 default:
392 return;
393 }
394
395 ND_PRINT((ndo, ", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)",
396 stp_bpdu->bpdu_type)));
397
398 switch (stp_bpdu->bpdu_type) {
399 case STP_BPDU_TYPE_CONFIG:
400 if (length < sizeof(struct stp_bpdu_) - 1) {
401 goto trunc;
402 }
403 stp_print_config_bpdu(ndo, stp_bpdu, length);
404 break;
405
406 case STP_BPDU_TYPE_RSTP:
407 if (stp_bpdu->protocol_version == STP_PROTO_RAPID) {
408 if (length < sizeof(struct stp_bpdu_)) {
409 goto trunc;
410 }
411 stp_print_config_bpdu(ndo, stp_bpdu, length);
412 } else if (stp_bpdu->protocol_version == STP_PROTO_MSTP ||
413 stp_bpdu->protocol_version == STP_PROTO_SPB) {
414 if (length < STP_BPDU_MSTP_MIN_LEN) {
415 goto trunc;
416 }
417
418 if (stp_bpdu->v1_length != 0) {
419 /* FIX ME: Emit a message here ? */
420 goto trunc;
421 }
422
423 /* Validate v3 length */
424 mstp_len = EXTRACT_16BITS(p + MST_BPDU_VER3_LEN_OFFSET);
425 mstp_len += 2; /* length encoding itself is 2 bytes */
426 if (length < (sizeof(struct stp_bpdu_) + mstp_len)) {
427 goto trunc;
428 }
429 stp_print_mstp_bpdu(ndo, stp_bpdu, length);
430
431 if (stp_bpdu->protocol_version == STP_PROTO_SPB)
432 {
433 /* Validate v4 length */
434 spb_len = EXTRACT_16BITS (p + MST_BPDU_VER3_LEN_OFFSET + mstp_len);
435 spb_len += 2;
436 if (length < (sizeof(struct stp_bpdu_) + mstp_len + spb_len) ||
437 spb_len < SPB_BPDU_MIN_LEN) {
438 goto trunc;
439 }
440 stp_print_spb_bpdu(ndo, stp_bpdu, (sizeof(struct stp_bpdu_) + mstp_len));
441 }
442 }
443 break;
444
445 case STP_BPDU_TYPE_TOPO_CHANGE:
446 /* always empty message - just break out */
447 break;
448
449 default:
450 break;
451 }
452
453 return;
454 trunc:
455 ND_PRINT((ndo, "[|stp %d]", length));
456 }
457
458 /*
459 * Local Variables:
460 * c-style: whitesmith
461 * c-basic-offset: 4
462 * End:
463 */
[mirror] the TCPdump network dissector