| 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 1.13.2.7 2007/03/18 17:12:36 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 | |
| 56 | struct tok stp_proto_values[] = { |
| 57 | { STP_PROTO_REGULAR, "802.1d" }, |
| 58 | { STP_PROTO_RAPID, "802.1w" }, |
| 59 | { STP_PROTO_MSTP, "802.1s" }, |
| 60 | { 0, NULL} |
| 61 | }; |
| 62 | |
| 63 | #define STP_BPDU_TYPE_CONFIG 0x00 |
| 64 | #define STP_BPDU_TYPE_RSTP 0x02 |
| 65 | #define STP_BPDU_TYPE_TOPO_CHANGE 0x80 |
| 66 | |
| 67 | struct tok stp_bpdu_flag_values[] = { |
| 68 | { 0x01, "Topology change" }, |
| 69 | { 0x02, "Proposal" }, |
| 70 | { 0x10, "Learn" }, |
| 71 | { 0x20, "Forward" }, |
| 72 | { 0x40, "Agreement" }, |
| 73 | { 0x80, "Topology change ACK" }, |
| 74 | { 0, NULL} |
| 75 | }; |
| 76 | |
| 77 | struct tok stp_bpdu_type_values[] = { |
| 78 | { STP_BPDU_TYPE_CONFIG, "Config" }, |
| 79 | { STP_BPDU_TYPE_RSTP, "Rapid STP" }, |
| 80 | { STP_BPDU_TYPE_TOPO_CHANGE, "Topology Change" }, |
| 81 | { 0, NULL} |
| 82 | }; |
| 83 | |
| 84 | struct tok rstp_obj_port_role_values[] = { |
| 85 | { 0x00, "Unknown" }, |
| 86 | { 0x01, "Alternate" }, |
| 87 | { 0x02, "Root" }, |
| 88 | { 0x03, "Designated" }, |
| 89 | { 0, NULL} |
| 90 | }; |
| 91 | |
| 92 | static char * |
| 93 | stp_print_bridge_id(const u_char *p) |
| 94 | { |
| 95 | static char bridge_id_str[sizeof("pppp.aa:bb:cc:dd:ee:ff")]; |
| 96 | |
| 97 | snprintf(bridge_id_str, sizeof(bridge_id_str), |
| 98 | "%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x", |
| 99 | p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]); |
| 100 | |
| 101 | return bridge_id_str; |
| 102 | } |
| 103 | |
| 104 | static void |
| 105 | stp_print_config_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length) |
| 106 | { |
| 107 | printf(", Flags [%s]", |
| 108 | bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags)); |
| 109 | |
| 110 | printf(", bridge-id %s.%04x, length %u", |
| 111 | stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id), |
| 112 | EXTRACT_16BITS(&stp_bpdu->port_id), length); |
| 113 | |
| 114 | /* in non-verbose mode just print the bridge-id */ |
| 115 | if (!vflag) { |
| 116 | return; |
| 117 | } |
| 118 | |
| 119 | printf("\n\tmessage-age %.2fs, max-age %.2fs" |
| 120 | ", hello-time %.2fs, forwarding-delay %.2fs", |
| 121 | (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE, |
| 122 | (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE, |
| 123 | (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE, |
| 124 | (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE); |
| 125 | |
| 126 | printf("\n\troot-id %s, root-pathcost %u", |
| 127 | stp_print_bridge_id((const u_char *)&stp_bpdu->root_id), |
| 128 | EXTRACT_32BITS(&stp_bpdu->root_path_cost)); |
| 129 | |
| 130 | /* Port role is only valid for 802.1w */ |
| 131 | if (stp_bpdu->protocol_version == STP_PROTO_RAPID) { |
| 132 | printf(", port-role %s", |
| 133 | tok2str(rstp_obj_port_role_values, "Unknown", |
| 134 | RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags))); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | /* |
| 139 | * MSTP packet format |
| 140 | * Ref. IEEE 802.1Q 2003 Ed. Section 14 |
| 141 | * |
| 142 | * MSTP BPDU |
| 143 | * |
| 144 | * 2 - bytes Protocol Id |
| 145 | * 1 - byte Protocol Ver. |
| 146 | * 1 - byte BPDU tye |
| 147 | * 1 - byte Flags |
| 148 | * 8 - bytes CIST Root Identifier |
| 149 | * 4 - bytes CIST External Path Cost |
| 150 | * 8 - bytes CIST Regional Root Identifier |
| 151 | * 2 - bytes CIST Port Identifier |
| 152 | * 2 - bytes Message Age |
| 153 | * 2 - bytes Max age |
| 154 | * 2 - bytes Hello Time |
| 155 | * 2 - bytes Forward delay |
| 156 | * 1 - byte Version 1 length. Must be 0 |
| 157 | * 2 - bytes Version 3 length |
| 158 | * 1 - byte Config Identifier |
| 159 | * 32 - bytes Config Name |
| 160 | * 2 - bytes Revision level |
| 161 | * 16 - bytes Config Digest [MD5] |
| 162 | * 4 - bytes CIST Internal Root Path Cost |
| 163 | * 8 - bytes CIST Bridge Identifier |
| 164 | * 1 - byte CIST Remaining Hops |
| 165 | * 16 - bytes MSTI information [Max 64 MSTI, each 16 bytes] |
| 166 | * |
| 167 | * MSTI Payload |
| 168 | * |
| 169 | * 1 - byte MSTI flag |
| 170 | * 8 - bytes MSTI Regional Root Identifier |
| 171 | * 4 - bytes MSTI Regional Path Cost |
| 172 | * 1 - byte MSTI Bridge Priority |
| 173 | * 1 - byte MSTI Port Priority |
| 174 | * 1 - byte MSTI Remaining Hops |
| 175 | */ |
| 176 | |
| 177 | #define MST_BPDU_MSTI_LENGTH 16 |
| 178 | #define MST_BPDU_CONFIG_INFO_LENGTH 64 |
| 179 | |
| 180 | /* Offsets of fields from the begginning for the packet */ |
| 181 | #define MST_BPDU_VER3_LEN_OFFSET 36 |
| 182 | #define MST_BPDU_CONFIG_NAME_OFFSET 39 |
| 183 | #define MST_BPDU_CONFIG_DIGEST_OFFSET 73 |
| 184 | #define MST_BPDU_CIST_INT_PATH_COST_OFFSET 89 |
| 185 | #define MST_BPDU_CIST_BRIDGE_ID_OFFSET 93 |
| 186 | #define MST_BPDU_CIST_REMAIN_HOPS_OFFSET 101 |
| 187 | #define MST_BPDU_MSTI_OFFSET 102 |
| 188 | /* Offsets within an MSTI */ |
| 189 | #define MST_BPDU_MSTI_ROOT_PRIO_OFFSET 1 |
| 190 | #define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9 |
| 191 | #define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET 13 |
| 192 | #define MST_BPDU_MSTI_PORT_PRIO_OFFSET 14 |
| 193 | #define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET 15 |
| 194 | |
| 195 | static void |
| 196 | stp_print_mstp_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length) |
| 197 | { |
| 198 | const u_char *ptr; |
| 199 | u_int16_t v3len; |
| 200 | u_int16_t len; |
| 201 | u_int16_t msti; |
| 202 | u_int16_t offset; |
| 203 | |
| 204 | ptr = (const u_char *)stp_bpdu; |
| 205 | printf(", CIST Flags [%s]", |
| 206 | bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags)); |
| 207 | |
| 208 | /* |
| 209 | * in non-verbose mode just print the flags. We dont read that much |
| 210 | * of the packet (DEFAULT_SNAPLEN) to print out cist bridge-id |
| 211 | */ |
| 212 | if (!vflag) { |
| 213 | return; |
| 214 | } |
| 215 | |
| 216 | printf(", CIST bridge-id %s.%04x, length %u", |
| 217 | stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET), |
| 218 | EXTRACT_16BITS(&stp_bpdu->port_id), length); |
| 219 | |
| 220 | |
| 221 | printf("\n\tmessage-age %.2fs, max-age %.2fs" |
| 222 | ", hello-time %.2fs, forwarding-delay %.2fs", |
| 223 | (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE, |
| 224 | (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE, |
| 225 | (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE, |
| 226 | (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE); |
| 227 | |
| 228 | printf("\n\tCIST root-id %s, ext-pathcost %u int-pathcost %u", |
| 229 | stp_print_bridge_id((const u_char *)&stp_bpdu->root_id), |
| 230 | EXTRACT_32BITS(&stp_bpdu->root_path_cost), |
| 231 | EXTRACT_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET)); |
| 232 | |
| 233 | printf(", port-role %s", |
| 234 | tok2str(rstp_obj_port_role_values, "Unknown", |
| 235 | RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags))); |
| 236 | |
| 237 | printf("\n\tCIST regional-root-id %s", |
| 238 | stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id)); |
| 239 | |
| 240 | printf("\n\tMSTP Configuration Name %s, revision %u, digest %08x%08x%08x%08x", |
| 241 | ptr + MST_BPDU_CONFIG_NAME_OFFSET, |
| 242 | EXTRACT_16BITS(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32), |
| 243 | EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET), |
| 244 | EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4), |
| 245 | EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8), |
| 246 | EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12)); |
| 247 | |
| 248 | printf("\n\tCIST remaining-hops %d", ptr[MST_BPDU_CIST_REMAIN_HOPS_OFFSET]); |
| 249 | |
| 250 | /* Dump all MSTI's */ |
| 251 | v3len = EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET); |
| 252 | if (v3len > MST_BPDU_CONFIG_INFO_LENGTH) { |
| 253 | len = v3len - MST_BPDU_CONFIG_INFO_LENGTH; |
| 254 | offset = MST_BPDU_MSTI_OFFSET; |
| 255 | while (len >= MST_BPDU_MSTI_LENGTH) { |
| 256 | msti = EXTRACT_16BITS(ptr + offset + |
| 257 | MST_BPDU_MSTI_ROOT_PRIO_OFFSET); |
| 258 | msti = msti & 0x0FFF; |
| 259 | |
| 260 | printf("\n\tMSTI %d, Flags [%s], port-role %s", |
| 261 | msti, bittok2str(stp_bpdu_flag_values, "none", ptr[offset]), |
| 262 | tok2str(rstp_obj_port_role_values, "Unknown", |
| 263 | RSTP_EXTRACT_PORT_ROLE(ptr[offset]))); |
| 264 | printf("\n\t\tMSTI regional-root-id %s, pathcost %u", |
| 265 | stp_print_bridge_id(ptr + offset + |
| 266 | MST_BPDU_MSTI_ROOT_PRIO_OFFSET), |
| 267 | EXTRACT_32BITS(ptr + offset + |
| 268 | MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET)); |
| 269 | printf("\n\t\tMSTI bridge-prio %d, port-prio %d, hops %d", |
| 270 | ptr[offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET] >> 4, |
| 271 | ptr[offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET] >> 4, |
| 272 | ptr[offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET]); |
| 273 | |
| 274 | len -= MST_BPDU_MSTI_LENGTH; |
| 275 | offset += MST_BPDU_MSTI_LENGTH; |
| 276 | } |
| 277 | } |
| 278 | } |
| 279 | |
| 280 | /* |
| 281 | * Print 802.1d / 802.1w / 802.1q (mstp) packets. |
| 282 | */ |
| 283 | void |
| 284 | stp_print(const u_char *p, u_int length) |
| 285 | { |
| 286 | const struct stp_bpdu_ *stp_bpdu; |
| 287 | u_int16_t mstp_len; |
| 288 | |
| 289 | stp_bpdu = (struct stp_bpdu_*)p; |
| 290 | |
| 291 | /* Minimum STP Frame size. */ |
| 292 | if (length < 4) |
| 293 | goto trunc; |
| 294 | |
| 295 | if (EXTRACT_16BITS(&stp_bpdu->protocol_id)) { |
| 296 | printf("unknown STP version, length %u", length); |
| 297 | return; |
| 298 | } |
| 299 | |
| 300 | printf("STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)", |
| 301 | stp_bpdu->protocol_version)); |
| 302 | |
| 303 | switch (stp_bpdu->protocol_version) { |
| 304 | case STP_PROTO_REGULAR: |
| 305 | case STP_PROTO_RAPID: |
| 306 | case STP_PROTO_MSTP: |
| 307 | break; |
| 308 | default: |
| 309 | return; |
| 310 | } |
| 311 | |
| 312 | printf(", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)", |
| 313 | stp_bpdu->bpdu_type)); |
| 314 | |
| 315 | switch (stp_bpdu->bpdu_type) { |
| 316 | case STP_BPDU_TYPE_CONFIG: |
| 317 | if (length < sizeof(struct stp_bpdu_) - 1) { |
| 318 | goto trunc; |
| 319 | } |
| 320 | stp_print_config_bpdu(stp_bpdu, length); |
| 321 | break; |
| 322 | |
| 323 | case STP_BPDU_TYPE_RSTP: |
| 324 | if (stp_bpdu->protocol_version == STP_PROTO_RAPID) { |
| 325 | if (length < sizeof(struct stp_bpdu_)) { |
| 326 | goto trunc; |
| 327 | } |
| 328 | stp_print_config_bpdu(stp_bpdu, length); |
| 329 | } else if (stp_bpdu->protocol_version == STP_PROTO_MSTP) { |
| 330 | if (length < STP_BPDU_MSTP_MIN_LEN) { |
| 331 | goto trunc; |
| 332 | } |
| 333 | if (stp_bpdu->v1_length != 0) { |
| 334 | /* FIX ME: Emit a message here ? */ |
| 335 | goto trunc; |
| 336 | } |
| 337 | /* Validate v3 length */ |
| 338 | mstp_len = EXTRACT_16BITS(p + MST_BPDU_VER3_LEN_OFFSET); |
| 339 | mstp_len += 2; /* length encoding itself is 2 bytes */ |
| 340 | if (length < (sizeof(struct stp_bpdu_) + mstp_len)) { |
| 341 | goto trunc; |
| 342 | } |
| 343 | stp_print_mstp_bpdu(stp_bpdu, length); |
| 344 | } |
| 345 | break; |
| 346 | |
| 347 | case STP_BPDU_TYPE_TOPO_CHANGE: |
| 348 | /* always empty message - just break out */ |
| 349 | break; |
| 350 | |
| 351 | default: |
| 352 | break; |
| 353 | } |
| 354 | |
| 355 | return; |
| 356 | trunc: |
| 357 | printf("[|stp %d]", length); |
| 358 | } |
| 359 | |
| 360 | /* |
| 361 | * Local Variables: |
| 362 | * c-style: whitesmith |
| 363 | * c-basic-offset: 4 |
| 364 | * End: |
| 365 | */ |