2 * Copyright (c) 2000 Lennert Buytenhek
4 * This software may be distributed either under the terms of the
5 * BSD-style license that accompanies tcpdump or the GNU General
8 * Contributed by Lennert Buytenhek <buytenh@gnu.org>
11 /* \summary: IEEE 802.1d Spanning Tree Protocol (STP) printer */
15 #include "netdissect-stdinc.h"
19 #include "netdissect.h"
22 #define RSTP_EXTRACT_PORT_ROLE(x) (((x)&0x0C)>>2)
23 /* STP timers are expressed in multiples of 1/256th second */
24 #define STP_TIME_BASE 256
25 #define STP_BPDU_MSTP_MIN_LEN 102
28 nd_uint16_t protocol_id
;
29 nd_uint8_t protocol_version
;
33 nd_uint32_t root_path_cost
;
36 nd_uint16_t message_age
;
38 nd_uint16_t hello_time
;
39 nd_uint16_t forward_delay
;
43 #define STP_PROTO_REGULAR 0x00
44 #define STP_PROTO_RAPID 0x02
45 #define STP_PROTO_MSTP 0x03
46 #define STP_PROTO_SPB 0x04
48 static const struct tok stp_proto_values
[] = {
49 { STP_PROTO_REGULAR
, "802.1d" },
50 { STP_PROTO_RAPID
, "802.1w" },
51 { STP_PROTO_MSTP
, "802.1s" },
52 { STP_PROTO_SPB
, "802.1aq" },
56 #define STP_BPDU_TYPE_CONFIG 0x00
57 #define STP_BPDU_TYPE_RSTP 0x02
58 #define STP_BPDU_TYPE_TOPO_CHANGE 0x80
60 static const struct tok stp_bpdu_flag_values
[] = {
61 { 0x01, "Topology change" },
65 { 0x40, "Agreement" },
66 { 0x80, "Topology change ACK" },
70 static const struct tok stp_bpdu_type_values
[] = {
71 { STP_BPDU_TYPE_CONFIG
, "Config" },
72 { STP_BPDU_TYPE_RSTP
, "Rapid STP" },
73 { STP_BPDU_TYPE_TOPO_CHANGE
, "Topology Change" },
77 static const struct tok rstp_obj_port_role_values
[] = {
79 { 0x01, "Alternate" },
81 { 0x03, "Designated" },
86 stp_print_bridge_id(netdissect_options
*ndo
, const u_char
*p
)
88 static char bridge_id_str
[sizeof("pppp.aa:bb:cc:dd:ee:ff")];
90 snprintf(bridge_id_str
, sizeof(bridge_id_str
),
91 "%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
92 GET_U_1(p
), GET_U_1(p
+ 1), GET_U_1(p
+ 2),
93 GET_U_1(p
+ 3), GET_U_1(p
+ 4), GET_U_1(p
+ 5),
94 GET_U_1(p
+ 6), GET_U_1(p
+ 7));
100 stp_print_config_bpdu(netdissect_options
*ndo
, const struct stp_bpdu_
*stp_bpdu
,
105 bpdu_flags
= GET_U_1(stp_bpdu
->flags
);
106 ND_PRINT(", Flags [%s]",
107 bittok2str(stp_bpdu_flag_values
, "none", bpdu_flags
));
109 ND_PRINT(", bridge-id %s.%04x, length %u",
110 stp_print_bridge_id(ndo
, stp_bpdu
->bridge_id
),
111 GET_BE_U_2(stp_bpdu
->port_id
), length
);
113 /* in non-verbose mode just print the bridge-id */
114 if (!ndo
->ndo_vflag
) {
118 ND_PRINT("\n\tmessage-age %.2fs, max-age %.2fs"
119 ", hello-time %.2fs, forwarding-delay %.2fs",
120 (float) GET_BE_U_2(stp_bpdu
->message_age
) / STP_TIME_BASE
,
121 (float) GET_BE_U_2(stp_bpdu
->max_age
) / STP_TIME_BASE
,
122 (float) GET_BE_U_2(stp_bpdu
->hello_time
) / STP_TIME_BASE
,
123 (float) GET_BE_U_2(stp_bpdu
->forward_delay
) / STP_TIME_BASE
);
125 ND_PRINT("\n\troot-id %s, root-pathcost %u",
126 stp_print_bridge_id(ndo
, stp_bpdu
->root_id
),
127 GET_BE_U_4(stp_bpdu
->root_path_cost
));
129 /* Port role is only valid for 802.1w */
130 if (GET_U_1(stp_bpdu
->protocol_version
) == STP_PROTO_RAPID
) {
131 ND_PRINT(", port-role %s",
132 tok2str(rstp_obj_port_role_values
, "Unknown",
133 RSTP_EXTRACT_PORT_ROLE(bpdu_flags
)));
139 * Ref. IEEE 802.1Q 2003 Ed. Section 14
143 * 2 - bytes Protocol Id
144 * 1 - byte Protocol Ver.
147 * 8 - bytes CIST Root Identifier
148 * 4 - bytes CIST External Path Cost
149 * 8 - bytes CIST Regional Root Identifier
150 * 2 - bytes CIST Port Identifier
151 * 2 - bytes Message Age
153 * 2 - bytes Hello Time
154 * 2 - bytes Forward delay
155 * 1 - byte Version 1 length. Must be 0
156 * 2 - bytes Version 3 length
157 * 1 - byte Config Identifier
158 * 32 - bytes Config Name
159 * 2 - bytes Revision level
160 * 16 - bytes Config Digest [MD5]
161 * 4 - bytes CIST Internal Root Path Cost
162 * 8 - bytes CIST Bridge Identifier
163 * 1 - byte CIST Remaining Hops
164 * 16 - bytes MSTI information [Max 64 MSTI, each 16 bytes]
168 * Ref. IEEE 802.1aq. Section 14
170 * 2 - bytes Version 4 length
171 * 1 - byte Aux Config Identifier
172 * 32 - bytes Aux Config Name
173 * 2 - bytes Aux Revision level
174 * 16 - bytes Aux Config Digest [MD5]
175 * 1 - byte (1 - 2) Agreement Number
176 * (3 - 4) Discarded Agreement Number
177 * (5) Agreement Valid Flag
178 * (6) Restricted Role Flag
179 * (7 - 8) Unused sent zero
181 * 1 - byte (1 - 4) Agreement Digest Format Identifier
182 * (5 - 8) Agreement Digest Format Capabilities
183 * 1 - byte (1 - 4) Agreement Digest Convention Identifier
184 * (5 - 8) Agreement Digest Convention Capabilities
185 * 2 - bytes Agreement Digest Edge Count
186 * 8 - byte Reserved Set
187 * 20 - bytes Computed Topology Digest
193 * 8 - bytes MSTI Regional Root Identifier
194 * 4 - bytes MSTI Regional Path Cost
195 * 1 - byte MSTI Bridge Priority
196 * 1 - byte MSTI Port Priority
197 * 1 - byte MSTI Remaining Hops
201 #define MST_BPDU_MSTI_LENGTH 16
202 #define MST_BPDU_CONFIG_INFO_LENGTH 64
204 /* Offsets of fields from the beginning for the packet */
205 #define MST_BPDU_VER3_LEN_OFFSET 36
206 #define MST_BPDU_CONFIG_NAME_OFFSET 39
207 #define MST_BPDU_CONFIG_DIGEST_OFFSET 73
208 #define MST_BPDU_CIST_INT_PATH_COST_OFFSET 89
209 #define MST_BPDU_CIST_BRIDGE_ID_OFFSET 93
210 #define MST_BPDU_CIST_REMAIN_HOPS_OFFSET 101
211 #define MST_BPDU_MSTI_OFFSET 102
212 /* Offsets within an MSTI */
213 #define MST_BPDU_MSTI_ROOT_PRIO_OFFSET 1
214 #define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9
215 #define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET 13
216 #define MST_BPDU_MSTI_PORT_PRIO_OFFSET 14
217 #define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET 15
219 #define SPB_BPDU_MIN_LEN 87
220 #define SPB_BPDU_CONFIG_NAME_OFFSET 3
221 #define SPB_BPDU_CONFIG_REV_OFFSET SPB_BPDU_CONFIG_NAME_OFFSET + 32
222 #define SPB_BPDU_CONFIG_DIGEST_OFFSET SPB_BPDU_CONFIG_REV_OFFSET + 2
223 #define SPB_BPDU_AGREEMENT_OFFSET SPB_BPDU_CONFIG_DIGEST_OFFSET + 16
224 #define SPB_BPDU_AGREEMENT_UNUSED_OFFSET SPB_BPDU_AGREEMENT_OFFSET + 1
225 #define SPB_BPDU_AGREEMENT_FORMAT_OFFSET SPB_BPDU_AGREEMENT_UNUSED_OFFSET + 1
226 #define SPB_BPDU_AGREEMENT_CON_OFFSET SPB_BPDU_AGREEMENT_FORMAT_OFFSET + 1
227 #define SPB_BPDU_AGREEMENT_EDGE_OFFSET SPB_BPDU_AGREEMENT_CON_OFFSET + 1
228 #define SPB_BPDU_AGREEMENT_RES1_OFFSET SPB_BPDU_AGREEMENT_EDGE_OFFSET + 2
229 #define SPB_BPDU_AGREEMENT_RES2_OFFSET SPB_BPDU_AGREEMENT_RES1_OFFSET + 4
230 #define SPB_BPDU_AGREEMENT_DIGEST_OFFSET SPB_BPDU_AGREEMENT_RES2_OFFSET + 4
233 stp_print_mstp_bpdu(netdissect_options
*ndo
, const struct stp_bpdu_
*stp_bpdu
,
243 ptr
= (const u_char
*)stp_bpdu
;
244 bpdu_flags
= GET_U_1(stp_bpdu
->flags
);
245 ND_PRINT(", CIST Flags [%s], length %u",
246 bittok2str(stp_bpdu_flag_values
, "none", bpdu_flags
), length
);
249 * in non-verbose mode just print the flags.
251 if (!ndo
->ndo_vflag
) {
255 ND_PRINT("\n\tport-role %s, ",
256 tok2str(rstp_obj_port_role_values
, "Unknown",
257 RSTP_EXTRACT_PORT_ROLE(bpdu_flags
)));
259 ND_PRINT("CIST root-id %s, CIST ext-pathcost %u",
260 stp_print_bridge_id(ndo
, stp_bpdu
->root_id
),
261 GET_BE_U_4(stp_bpdu
->root_path_cost
));
263 ND_PRINT("\n\tCIST regional-root-id %s, ",
264 stp_print_bridge_id(ndo
, stp_bpdu
->bridge_id
));
266 ND_PRINT("CIST port-id %04x,", GET_BE_U_2(stp_bpdu
->port_id
));
268 ND_PRINT("\n\tmessage-age %.2fs, max-age %.2fs"
269 ", hello-time %.2fs, forwarding-delay %.2fs",
270 (float) GET_BE_U_2(stp_bpdu
->message_age
) / STP_TIME_BASE
,
271 (float) GET_BE_U_2(stp_bpdu
->max_age
) / STP_TIME_BASE
,
272 (float) GET_BE_U_2(stp_bpdu
->hello_time
) / STP_TIME_BASE
,
273 (float) GET_BE_U_2(stp_bpdu
->forward_delay
) / STP_TIME_BASE
);
275 ND_PRINT("\n\tv3len %u, ", GET_BE_U_2(ptr
+ MST_BPDU_VER3_LEN_OFFSET
));
276 ND_PRINT("MCID Name ");
277 nd_printjnp(ndo
, ptr
+ MST_BPDU_CONFIG_NAME_OFFSET
, 32);
279 "\n\t\tdigest %08x%08x%08x%08x, ",
280 GET_BE_U_2(ptr
+ MST_BPDU_CONFIG_NAME_OFFSET
+ 32),
281 GET_BE_U_4(ptr
+ MST_BPDU_CONFIG_DIGEST_OFFSET
),
282 GET_BE_U_4(ptr
+ MST_BPDU_CONFIG_DIGEST_OFFSET
+ 4),
283 GET_BE_U_4(ptr
+ MST_BPDU_CONFIG_DIGEST_OFFSET
+ 8),
284 GET_BE_U_4(ptr
+ MST_BPDU_CONFIG_DIGEST_OFFSET
+ 12));
286 ND_PRINT("CIST int-root-pathcost %u,",
287 GET_BE_U_4(ptr
+ MST_BPDU_CIST_INT_PATH_COST_OFFSET
));
289 ND_PRINT("\n\tCIST bridge-id %s, ",
290 stp_print_bridge_id(ndo
, ptr
+ MST_BPDU_CIST_BRIDGE_ID_OFFSET
));
292 ND_PRINT("CIST remaining-hops %u",
293 GET_U_1(ptr
+ MST_BPDU_CIST_REMAIN_HOPS_OFFSET
));
295 /* Dump all MSTI's */
296 v3len
= GET_BE_U_2(ptr
+ MST_BPDU_VER3_LEN_OFFSET
);
297 if (v3len
> MST_BPDU_CONFIG_INFO_LENGTH
) {
298 len
= v3len
- MST_BPDU_CONFIG_INFO_LENGTH
;
299 offset
= MST_BPDU_MSTI_OFFSET
;
300 while (len
>= MST_BPDU_MSTI_LENGTH
) {
301 msti
= GET_BE_U_2(ptr
+ offset
+ MST_BPDU_MSTI_ROOT_PRIO_OFFSET
);
302 msti
= msti
& 0x0FFF;
304 ND_PRINT("\n\tMSTI %u, Flags [%s], port-role %s",
306 bittok2str(stp_bpdu_flag_values
, "none", GET_U_1(ptr
+ offset
)),
307 tok2str(rstp_obj_port_role_values
, "Unknown",
308 RSTP_EXTRACT_PORT_ROLE(GET_U_1(ptr
+ offset
))));
309 ND_PRINT("\n\t\tMSTI regional-root-id %s, pathcost %u",
310 stp_print_bridge_id(ndo
, ptr
+ offset
+
311 MST_BPDU_MSTI_ROOT_PRIO_OFFSET
),
312 GET_BE_U_4(ptr
+ offset
+ MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET
));
313 ND_PRINT("\n\t\tMSTI bridge-prio %u, port-prio %u, hops %u",
314 GET_U_1(ptr
+ offset
+ MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET
) >> 4,
315 GET_U_1(ptr
+ offset
+ MST_BPDU_MSTI_PORT_PRIO_OFFSET
) >> 4,
316 GET_U_1(ptr
+ offset
+ MST_BPDU_MSTI_REMAIN_HOPS_OFFSET
));
318 len
-= MST_BPDU_MSTI_LENGTH
;
319 offset
+= MST_BPDU_MSTI_LENGTH
;
325 stp_print_spb_bpdu(netdissect_options
*ndo
, const struct stp_bpdu_
*stp_bpdu
,
331 * in non-verbose mode don't print anything.
333 if (!ndo
->ndo_vflag
) {
337 ptr
= (const u_char
*)stp_bpdu
;
339 ND_PRINT("\n\tv4len %u, ", GET_BE_U_2(ptr
+ offset
));
340 ND_PRINT("AUXMCID Name ");
341 nd_printjnp(ndo
, ptr
+ offset
+ SPB_BPDU_CONFIG_NAME_OFFSET
, 32);
342 ND_PRINT(", Rev %u,\n\t\tdigest %08x%08x%08x%08x",
343 GET_BE_U_2(ptr
+ offset
+ SPB_BPDU_CONFIG_REV_OFFSET
),
344 GET_BE_U_4(ptr
+ offset
+ SPB_BPDU_CONFIG_DIGEST_OFFSET
),
345 GET_BE_U_4(ptr
+ offset
+ SPB_BPDU_CONFIG_DIGEST_OFFSET
+ 4),
346 GET_BE_U_4(ptr
+ offset
+ SPB_BPDU_CONFIG_DIGEST_OFFSET
+ 8),
347 GET_BE_U_4(ptr
+ offset
+ SPB_BPDU_CONFIG_DIGEST_OFFSET
+ 12));
349 ND_PRINT("\n\tAgreement num %u, Discarded Agreement num %u, Agreement valid-"
350 "flag %u,\n\tRestricted role-flag: %u, Format id %u cap %u, "
351 "Convention id %u cap %u,\n\tEdge count %u, "
352 "Agreement digest %08x%08x%08x%08x%08x",
353 GET_U_1(ptr
+ offset
+ SPB_BPDU_AGREEMENT_OFFSET
)>>6,
354 GET_U_1(ptr
+ offset
+ SPB_BPDU_AGREEMENT_OFFSET
)>>4 & 0x3,
355 GET_U_1(ptr
+ offset
+ SPB_BPDU_AGREEMENT_OFFSET
)>>3 & 0x1,
356 GET_U_1(ptr
+ offset
+ SPB_BPDU_AGREEMENT_OFFSET
)>>2 & 0x1,
357 GET_U_1(ptr
+ offset
+ SPB_BPDU_AGREEMENT_FORMAT_OFFSET
)>>4,
358 GET_U_1(ptr
+ offset
+ SPB_BPDU_AGREEMENT_FORMAT_OFFSET
)&0x00ff,
359 GET_U_1(ptr
+ offset
+ SPB_BPDU_AGREEMENT_CON_OFFSET
)>>4,
360 GET_U_1(ptr
+ offset
+ SPB_BPDU_AGREEMENT_CON_OFFSET
)&0x00ff,
361 GET_BE_U_2(ptr
+ offset
+ SPB_BPDU_AGREEMENT_EDGE_OFFSET
),
362 GET_BE_U_4(ptr
+ offset
+ SPB_BPDU_AGREEMENT_DIGEST_OFFSET
),
363 GET_BE_U_4(ptr
+ offset
+ SPB_BPDU_AGREEMENT_DIGEST_OFFSET
+ 4),
364 GET_BE_U_4(ptr
+ offset
+ SPB_BPDU_AGREEMENT_DIGEST_OFFSET
+ 8),
365 GET_BE_U_4(ptr
+ offset
+ SPB_BPDU_AGREEMENT_DIGEST_OFFSET
+ 12),
366 GET_BE_U_4(ptr
+ offset
+ SPB_BPDU_AGREEMENT_DIGEST_OFFSET
+ 16));
370 * Print 802.1d / 802.1w / 802.1q (mstp) / 802.1aq (spb) packets.
373 stp_print(netdissect_options
*ndo
, const u_char
*p
, u_int length
)
375 const struct stp_bpdu_
*stp_bpdu
;
376 u_int protocol_version
;
381 ndo
->ndo_protocol
= "stp";
382 stp_bpdu
= (const struct stp_bpdu_
*)p
;
384 /* Minimum STP Frame size. */
388 if (GET_BE_U_2(stp_bpdu
->protocol_id
)) {
389 ND_PRINT("unknown STP version, length %u", length
);
393 protocol_version
= GET_U_1(stp_bpdu
->protocol_version
);
394 ND_PRINT("STP %s", tok2str(stp_proto_values
, "Unknown STP protocol (0x%02x)",
397 switch (protocol_version
) {
398 case STP_PROTO_REGULAR
:
399 case STP_PROTO_RAPID
:
407 bpdu_type
= GET_U_1(stp_bpdu
->bpdu_type
);
408 ND_PRINT(", %s", tok2str(stp_bpdu_type_values
, "Unknown BPDU Type (0x%02x)",
412 case STP_BPDU_TYPE_CONFIG
:
413 if (length
< sizeof(struct stp_bpdu_
) - 1) {
416 stp_print_config_bpdu(ndo
, stp_bpdu
, length
);
419 case STP_BPDU_TYPE_RSTP
:
420 if (protocol_version
== STP_PROTO_RAPID
) {
421 if (length
< sizeof(struct stp_bpdu_
)) {
424 stp_print_config_bpdu(ndo
, stp_bpdu
, length
);
425 } else if (protocol_version
== STP_PROTO_MSTP
||
426 protocol_version
== STP_PROTO_SPB
) {
427 if (length
< STP_BPDU_MSTP_MIN_LEN
) {
431 if (GET_U_1(stp_bpdu
->v1_length
) != 0) {
432 /* FIX ME: Emit a message here ? */
436 /* Validate v3 length */
437 mstp_len
= GET_BE_U_2(p
+ MST_BPDU_VER3_LEN_OFFSET
);
438 mstp_len
+= 2; /* length encoding itself is 2 bytes */
439 if (length
< (sizeof(struct stp_bpdu_
) + mstp_len
)) {
442 stp_print_mstp_bpdu(ndo
, stp_bpdu
, length
);
444 if (protocol_version
== STP_PROTO_SPB
) {
445 /* Validate v4 length */
446 spb_len
= GET_BE_U_2(p
+ MST_BPDU_VER3_LEN_OFFSET
+ mstp_len
);
448 if (length
< (sizeof(struct stp_bpdu_
) + mstp_len
+ spb_len
) ||
449 spb_len
< SPB_BPDU_MIN_LEN
) {
452 stp_print_spb_bpdu(ndo
, stp_bpdu
, (sizeof(struct stp_bpdu_
) + mstp_len
));
457 case STP_BPDU_TYPE_TOPO_CHANGE
:
458 /* always empty message - just break out */
467 nd_print_invalid(ndo
);