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 (at) 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 static const 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 static const 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 static const 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 static const 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 * 1 - byte (1 - 4) Agreement Digest Format Identifier 185 * (5 - 8) Agreement Digest Format Capabilities 186 * 1 - byte (1 - 4) Agreement Digest Convention Identifier 187 * (5 - 8) Agreement Digest Convention Capabilities 188 * 2 - bytes Agreement Digest Edge Count 189 * 8 - byte Reserved Set 190 * 20 - bytes Computed Topology Digest 191 * 192 * 193 * MSTI Payload 194 * 195 * 1 - byte MSTI flag 196 * 8 - bytes MSTI Regional Root Identifier 197 * 4 - bytes MSTI Regional Path Cost 198 * 1 - byte MSTI Bridge Priority 199 * 1 - byte MSTI Port Priority 200 * 1 - byte MSTI Remaining Hops 201 * 202 */ 203 204 #define MST_BPDU_MSTI_LENGTH 16 205 #define MST_BPDU_CONFIG_INFO_LENGTH 64 206 207 /* Offsets of fields from the begginning for the packet */ 208 #define MST_BPDU_VER3_LEN_OFFSET 36 209 #define MST_BPDU_CONFIG_NAME_OFFSET 39 210 #define MST_BPDU_CONFIG_DIGEST_OFFSET 73 211 #define MST_BPDU_CIST_INT_PATH_COST_OFFSET 89 212 #define MST_BPDU_CIST_BRIDGE_ID_OFFSET 93 213 #define MST_BPDU_CIST_REMAIN_HOPS_OFFSET 101 214 #define MST_BPDU_MSTI_OFFSET 102 215 /* Offsets within an MSTI */ 216 #define MST_BPDU_MSTI_ROOT_PRIO_OFFSET 1 217 #define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9 218 #define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET 13 219 #define MST_BPDU_MSTI_PORT_PRIO_OFFSET 14 220 #define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET 15 221 222 #define SPB_BPDU_MIN_LEN 87 223 #define SPB_BPDU_CONFIG_NAME_OFFSET 3 224 #define SPB_BPDU_CONFIG_REV_OFFSET SPB_BPDU_CONFIG_NAME_OFFSET + 32 225 #define SPB_BPDU_CONFIG_DIGEST_OFFSET SPB_BPDU_CONFIG_REV_OFFSET + 2 226 #define SPB_BPDU_AGREEMENT_OFFSET SPB_BPDU_CONFIG_DIGEST_OFFSET + 16 227 #define SPB_BPDU_AGREEMENT_UNUSED_OFFSET SPB_BPDU_AGREEMENT_OFFSET + 1 228 #define SPB_BPDU_AGREEMENT_FORMAT_OFFSET SPB_BPDU_AGREEMENT_UNUSED_OFFSET + 1 229 #define SPB_BPDU_AGREEMENT_CON_OFFSET SPB_BPDU_AGREEMENT_FORMAT_OFFSET + 1 230 #define SPB_BPDU_AGREEMENT_EDGE_OFFSET SPB_BPDU_AGREEMENT_CON_OFFSET + 1 231 #define SPB_BPDU_AGREEMENT_RES1_OFFSET SPB_BPDU_AGREEMENT_EDGE_OFFSET + 2 232 #define SPB_BPDU_AGREEMENT_RES2_OFFSET SPB_BPDU_AGREEMENT_RES1_OFFSET + 4 233 #define SPB_BPDU_AGREEMENT_DIGEST_OFFSET SPB_BPDU_AGREEMENT_RES2_OFFSET + 4 234 235 236 static void 237 stp_print_mstp_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length) 238 { 239 const u_char *ptr; 240 u_int16_t v3len; 241 u_int16_t len; 242 u_int16_t msti; 243 u_int offset; 244 245 ptr = (const u_char *)stp_bpdu; 246 printf(", CIST Flags [%s], length %u", 247 bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags), length); 248 249 /* 250 * in non-verbose mode just print the flags. 251 */ 252 if (!vflag) { 253 return; 254 } 255 256 printf("\n\tport-role %s, ", 257 tok2str(rstp_obj_port_role_values, "Unknown", 258 RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags))); 259 260 printf("CIST root-id %s, CIST ext-pathcost %u ", 261 stp_print_bridge_id((const u_char *)&stp_bpdu->root_id), 262 EXTRACT_32BITS(&stp_bpdu->root_path_cost)); 263 264 printf("\n\tCIST regional-root-id %s, ", 265 stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id)); 266 267 printf("CIST port-id %04x, ", EXTRACT_16BITS(&stp_bpdu->port_id)); 268 269 printf("\n\tmessage-age %.2fs, max-age %.2fs" 270 ", hello-time %.2fs, forwarding-delay %.2fs", 271 (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE, 272 (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE, 273 (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE, 274 (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE); 275 276 printf ("\n\tv3len %d, ", EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET)); 277 printf("MCID Name %s, rev %u, " 278 "\n\t\tdigest %08x%08x%08x%08x, ", 279 ptr + MST_BPDU_CONFIG_NAME_OFFSET, 280 EXTRACT_16BITS(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32), 281 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET), 282 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4), 283 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8), 284 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12)); 285 286 printf ("CIST int-root-pathcost %u, ", 287 EXTRACT_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET)); 288 289 printf("\n\tCIST bridge-id %s, ", 290 stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET)); 291 292 printf("CIST remaining-hops %d", ptr[MST_BPDU_CIST_REMAIN_HOPS_OFFSET]); 293 294 /* Dump all MSTI's */ 295 v3len = EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET); 296 if (v3len > MST_BPDU_CONFIG_INFO_LENGTH) { 297 len = v3len - MST_BPDU_CONFIG_INFO_LENGTH; 298 offset = MST_BPDU_MSTI_OFFSET; 299 while (len >= MST_BPDU_MSTI_LENGTH) { 300 msti = EXTRACT_16BITS(ptr + offset + 301 MST_BPDU_MSTI_ROOT_PRIO_OFFSET); 302 msti = msti & 0x0FFF; 303 304 printf("\n\tMSTI %d, Flags [%s], port-role %s", 305 msti, bittok2str(stp_bpdu_flag_values, "none", ptr[offset]), 306 tok2str(rstp_obj_port_role_values, "Unknown", 307 RSTP_EXTRACT_PORT_ROLE(ptr[offset]))); 308 printf("\n\t\tMSTI regional-root-id %s, pathcost %u", 309 stp_print_bridge_id(ptr + offset + 310 MST_BPDU_MSTI_ROOT_PRIO_OFFSET), 311 EXTRACT_32BITS(ptr + offset + 312 MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET)); 313 printf("\n\t\tMSTI bridge-prio %d, port-prio %d, hops %d", 314 ptr[offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET] >> 4, 315 ptr[offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET] >> 4, 316 ptr[offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET]); 317 318 len -= MST_BPDU_MSTI_LENGTH; 319 offset += MST_BPDU_MSTI_LENGTH; 320 } 321 } 322 } 323 324 static void 325 stp_print_spb_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int offset) 326 { 327 const u_char *ptr; 328 329 /* 330 * in non-verbose mode don't print anything. 331 */ 332 if (!vflag) { 333 return; 334 } 335 336 ptr = (const u_char *)stp_bpdu; 337 printf("\n\tv4len %d AUXMCID Name %s, Rev %u, \n\t\tdigest %08x%08x%08x%08x", 338 EXTRACT_16BITS (ptr + offset), 339 ptr + offset + SPB_BPDU_CONFIG_NAME_OFFSET, 340 EXTRACT_16BITS(ptr + offset + SPB_BPDU_CONFIG_REV_OFFSET), 341 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET), 342 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 4), 343 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 8), 344 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 12)); 345 346 printf("\n\tAgreement num %d, Discarded Agreement num %d, Agreement valid-" 347 "flag %d, \n\tRestricted role-flag: %d, Format id %d cap %d, " 348 "Convention id %d cap %d, \n\tEdge count %d, " 349 "Agreement digest %08x%08x%08x%08x%08x\n", 350 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>6, 351 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>4 & 0x3, 352 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>3 & 0x1, 353 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>2 & 0x1, 354 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]>>4, 355 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]&0x00ff, 356 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]>>4, 357 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]&0x00ff, 358 EXTRACT_16BITS(ptr + offset + SPB_BPDU_AGREEMENT_EDGE_OFFSET), 359 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET), 360 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+4, 361 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+8, 362 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+12, 363 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+16); 364 } 365 366 /* 367 * Print 802.1d / 802.1w / 802.1q (mstp) / 802.1aq (spb) packets. 368 */ 369 void 370 stp_print(const u_char *p, u_int length) 371 { 372 const struct stp_bpdu_ *stp_bpdu; 373 u_int mstp_len; 374 u_int spb_len; 375 376 stp_bpdu = (struct stp_bpdu_*)p; 377 378 /* Minimum STP Frame size. */ 379 if (length < 4) 380 goto trunc; 381 382 if (EXTRACT_16BITS(&stp_bpdu->protocol_id)) { 383 printf("unknown STP version, length %u", length); 384 return; 385 } 386 387 printf("STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)", 388 stp_bpdu->protocol_version)); 389 390 switch (stp_bpdu->protocol_version) { 391 case STP_PROTO_REGULAR: 392 case STP_PROTO_RAPID: 393 case STP_PROTO_MSTP: 394 case STP_PROTO_SPB: 395 break; 396 default: 397 return; 398 } 399 400 printf(", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)", 401 stp_bpdu->bpdu_type)); 402 403 switch (stp_bpdu->bpdu_type) { 404 case STP_BPDU_TYPE_CONFIG: 405 if (length < sizeof(struct stp_bpdu_) - 1) { 406 goto trunc; 407 } 408 stp_print_config_bpdu(stp_bpdu, length); 409 break; 410 411 case STP_BPDU_TYPE_RSTP: 412 if (stp_bpdu->protocol_version == STP_PROTO_RAPID) { 413 if (length < sizeof(struct stp_bpdu_)) { 414 goto trunc; 415 } 416 stp_print_config_bpdu(stp_bpdu, length); 417 } else if (stp_bpdu->protocol_version == STP_PROTO_MSTP || 418 stp_bpdu->protocol_version == STP_PROTO_SPB) { 419 if (length < STP_BPDU_MSTP_MIN_LEN) { 420 goto trunc; 421 } 422 423 if (stp_bpdu->v1_length != 0) { 424 /* FIX ME: Emit a message here ? */ 425 goto trunc; 426 } 427 428 /* Validate v3 length */ 429 mstp_len = EXTRACT_16BITS(p + MST_BPDU_VER3_LEN_OFFSET); 430 mstp_len += 2; /* length encoding itself is 2 bytes */ 431 if (length < (sizeof(struct stp_bpdu_) + mstp_len)) { 432 goto trunc; 433 } 434 stp_print_mstp_bpdu(stp_bpdu, length); 435 436 if (stp_bpdu->protocol_version == STP_PROTO_SPB) 437 { 438 /* Validate v4 length */ 439 spb_len = EXTRACT_16BITS (p + MST_BPDU_VER3_LEN_OFFSET + mstp_len); 440 spb_len += 2; 441 if (length < (sizeof(struct stp_bpdu_) + mstp_len + spb_len) || 442 spb_len < SPB_BPDU_MIN_LEN) { 443 goto trunc; 444 } 445 stp_print_spb_bpdu(stp_bpdu, (sizeof(struct stp_bpdu_) + mstp_len)); 446 } 447 } 448 break; 449 450 case STP_BPDU_TYPE_TOPO_CHANGE: 451 /* always empty message - just break out */ 452 break; 453 454 default: 455 break; 456 } 457 458 return; 459 trunc: 460 printf("[|stp %d]", length); 461 } 462 463 /* 464 * Local Variables: 465 * c-style: whitesmith 466 * c-basic-offset: 4 467 * End: 468 */ 469
