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 #include <sys/cdefs.h> 13 #ifndef lint 14 #if 0 15 static const char rcsid[] _U_ = 16 "@(#) Header: /tcpdump/master/tcpdump/print-stp.c,v 1.20 2007-03-18 17:11:46 hannes Exp "; 17 #else 18 __RCSID("$NetBSD: print-stp.c,v 1.4 2013/12/31 17:33:31 christos Exp $"); 19 #endif 20 #endif 21 22 #ifdef HAVE_CONFIG_H 23 #include "config.h" 24 #endif 25 26 #include <tcpdump-stdinc.h> 27 28 #include <stdlib.h> 29 #include <stdio.h> 30 #include <string.h> 31 32 #include "interface.h" 33 #include "addrtoname.h" 34 #include "extract.h" 35 36 #define RSTP_EXTRACT_PORT_ROLE(x) (((x)&0x0C)>>2) 37 /* STP timers are expressed in multiples of 1/256th second */ 38 #define STP_TIME_BASE 256 39 #define STP_BPDU_MSTP_MIN_LEN 102 40 41 struct stp_bpdu_ { 42 u_int8_t protocol_id[2]; 43 u_int8_t protocol_version; 44 u_int8_t bpdu_type; 45 u_int8_t flags; 46 u_int8_t root_id[8]; 47 u_int8_t root_path_cost[4]; 48 u_int8_t bridge_id[8]; 49 u_int8_t port_id[2]; 50 u_int8_t message_age[2]; 51 u_int8_t max_age[2]; 52 u_int8_t hello_time[2]; 53 u_int8_t forward_delay[2]; 54 u_int8_t v1_length; 55 }; 56 57 #define STP_PROTO_REGULAR 0x00 58 #define STP_PROTO_RAPID 0x02 59 #define STP_PROTO_MSTP 0x03 60 #define STP_PROTO_SPB 0x04 61 62 static const struct tok stp_proto_values[] = { 63 { STP_PROTO_REGULAR, "802.1d" }, 64 { STP_PROTO_RAPID, "802.1w" }, 65 { STP_PROTO_MSTP, "802.1s" }, 66 { STP_PROTO_SPB, "802.1aq" }, 67 { 0, NULL} 68 }; 69 70 #define STP_BPDU_TYPE_CONFIG 0x00 71 #define STP_BPDU_TYPE_RSTP 0x02 72 #define STP_BPDU_TYPE_TOPO_CHANGE 0x80 73 74 static const struct tok stp_bpdu_flag_values[] = { 75 { 0x01, "Topology change" }, 76 { 0x02, "Proposal" }, 77 { 0x10, "Learn" }, 78 { 0x20, "Forward" }, 79 { 0x40, "Agreement" }, 80 { 0x80, "Topology change ACK" }, 81 { 0, NULL} 82 }; 83 84 static const struct tok stp_bpdu_type_values[] = { 85 { STP_BPDU_TYPE_CONFIG, "Config" }, 86 { STP_BPDU_TYPE_RSTP, "Rapid STP" }, 87 { STP_BPDU_TYPE_TOPO_CHANGE, "Topology Change" }, 88 { 0, NULL} 89 }; 90 91 static const struct tok rstp_obj_port_role_values[] = { 92 { 0x00, "Unknown" }, 93 { 0x01, "Alternate" }, 94 { 0x02, "Root" }, 95 { 0x03, "Designated" }, 96 { 0, NULL} 97 }; 98 99 static char * 100 stp_print_bridge_id(const u_char *p) 101 { 102 static char bridge_id_str[sizeof("pppp.aa:bb:cc:dd:ee:ff")]; 103 104 snprintf(bridge_id_str, sizeof(bridge_id_str), 105 "%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x", 106 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]); 107 108 return bridge_id_str; 109 } 110 111 static void 112 stp_print_config_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length) 113 { 114 printf(", Flags [%s]", 115 bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags)); 116 117 printf(", bridge-id %s.%04x, length %u", 118 stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id), 119 EXTRACT_16BITS(&stp_bpdu->port_id), length); 120 121 /* in non-verbose mode just print the bridge-id */ 122 if (!vflag) { 123 return; 124 } 125 126 printf("\n\tmessage-age %.2fs, max-age %.2fs" 127 ", hello-time %.2fs, forwarding-delay %.2fs", 128 (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE, 129 (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE, 130 (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE, 131 (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE); 132 133 printf("\n\troot-id %s, root-pathcost %u", 134 stp_print_bridge_id((const u_char *)&stp_bpdu->root_id), 135 EXTRACT_32BITS(&stp_bpdu->root_path_cost)); 136 137 /* Port role is only valid for 802.1w */ 138 if (stp_bpdu->protocol_version == STP_PROTO_RAPID) { 139 printf(", port-role %s", 140 tok2str(rstp_obj_port_role_values, "Unknown", 141 RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags))); 142 } 143 } 144 145 /* 146 * MSTP packet format 147 * Ref. IEEE 802.1Q 2003 Ed. Section 14 148 * 149 * MSTP BPDU 150 * 151 * 2 - bytes Protocol Id 152 * 1 - byte Protocol Ver. 153 * 1 - byte BPDU tye 154 * 1 - byte Flags 155 * 8 - bytes CIST Root Identifier 156 * 4 - bytes CIST External Path Cost 157 * 8 - bytes CIST Regional Root Identifier 158 * 2 - bytes CIST Port Identifier 159 * 2 - bytes Message Age 160 * 2 - bytes Max age 161 * 2 - bytes Hello Time 162 * 2 - bytes Forward delay 163 * 1 - byte Version 1 length. Must be 0 164 * 2 - bytes Version 3 length 165 * 1 - byte Config Identifier 166 * 32 - bytes Config Name 167 * 2 - bytes Revision level 168 * 16 - bytes Config Digest [MD5] 169 * 4 - bytes CIST Internal Root Path Cost 170 * 8 - bytes CIST Bridge Identifier 171 * 1 - byte CIST Remaining Hops 172 * 16 - bytes MSTI information [Max 64 MSTI, each 16 bytes] 173 * 174 * 175 * SPB BPDU 176 * Ref. IEEE 802.1aq. Section 14 177 * 178 * 2 - bytes Version 4 length 179 * 1 - byte Aux Config Identifier 180 * 32 - bytes Aux Config Name 181 * 2 - bytes Aux Revision level 182 * 16 - bytes Aux Config Digest [MD5] 183 * 1 - byte (1 - 2) Agreement Number 184 * (3 - 4) Discarded Agreement Number 185 * (5) Agreement Valid Flag 186 * (6) Restricted Role Flag 187 * (7 - 8) Unused sent zero 188 * 1 - byte Unused 189 * 1 - byte (1 - 4) Agreement Digest Format Identifier 190 * (5 - 8) Agreement Digest Format Capabilities 191 * 1 - byte (1 - 4) Agreement Digest Convention Identifier 192 * (5 - 8) Agreement Digest Convention Capabilities 193 * 2 - bytes Agreement Digest Edge Count 194 * 8 - byte Reserved Set 195 * 20 - bytes Computed Topology Digest 196 * 197 * 198 * MSTI Payload 199 * 200 * 1 - byte MSTI flag 201 * 8 - bytes MSTI Regional Root Identifier 202 * 4 - bytes MSTI Regional Path Cost 203 * 1 - byte MSTI Bridge Priority 204 * 1 - byte MSTI Port Priority 205 * 1 - byte MSTI Remaining Hops 206 * 207 */ 208 209 #define MST_BPDU_MSTI_LENGTH 16 210 #define MST_BPDU_CONFIG_INFO_LENGTH 64 211 212 /* Offsets of fields from the begginning for the packet */ 213 #define MST_BPDU_VER3_LEN_OFFSET 36 214 #define MST_BPDU_CONFIG_NAME_OFFSET 39 215 #define MST_BPDU_CONFIG_DIGEST_OFFSET 73 216 #define MST_BPDU_CIST_INT_PATH_COST_OFFSET 89 217 #define MST_BPDU_CIST_BRIDGE_ID_OFFSET 93 218 #define MST_BPDU_CIST_REMAIN_HOPS_OFFSET 101 219 #define MST_BPDU_MSTI_OFFSET 102 220 /* Offsets within an MSTI */ 221 #define MST_BPDU_MSTI_ROOT_PRIO_OFFSET 1 222 #define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9 223 #define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET 13 224 #define MST_BPDU_MSTI_PORT_PRIO_OFFSET 14 225 #define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET 15 226 227 #define SPB_BPDU_MIN_LEN 87 228 #define SPB_BPDU_CONFIG_NAME_OFFSET 3 229 #define SPB_BPDU_CONFIG_REV_OFFSET SPB_BPDU_CONFIG_NAME_OFFSET + 32 230 #define SPB_BPDU_CONFIG_DIGEST_OFFSET SPB_BPDU_CONFIG_REV_OFFSET + 2 231 #define SPB_BPDU_AGREEMENT_OFFSET SPB_BPDU_CONFIG_DIGEST_OFFSET + 16 232 #define SPB_BPDU_AGREEMENT_UNUSED_OFFSET SPB_BPDU_AGREEMENT_OFFSET + 1 233 #define SPB_BPDU_AGREEMENT_FORMAT_OFFSET SPB_BPDU_AGREEMENT_UNUSED_OFFSET + 1 234 #define SPB_BPDU_AGREEMENT_CON_OFFSET SPB_BPDU_AGREEMENT_FORMAT_OFFSET + 1 235 #define SPB_BPDU_AGREEMENT_EDGE_OFFSET SPB_BPDU_AGREEMENT_CON_OFFSET + 1 236 #define SPB_BPDU_AGREEMENT_RES1_OFFSET SPB_BPDU_AGREEMENT_EDGE_OFFSET + 2 237 #define SPB_BPDU_AGREEMENT_RES2_OFFSET SPB_BPDU_AGREEMENT_RES1_OFFSET + 4 238 #define SPB_BPDU_AGREEMENT_DIGEST_OFFSET SPB_BPDU_AGREEMENT_RES2_OFFSET + 4 239 240 241 static void 242 stp_print_mstp_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length) 243 { 244 const u_char *ptr; 245 u_int16_t v3len; 246 u_int16_t len; 247 u_int16_t msti; 248 u_int offset; 249 250 ptr = (const u_char *)stp_bpdu; 251 printf(", CIST Flags [%s], length %u", 252 bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags), length); 253 254 /* 255 * in non-verbose mode just print the flags. 256 */ 257 if (!vflag) { 258 return; 259 } 260 261 printf("\n\tport-role %s, ", 262 tok2str(rstp_obj_port_role_values, "Unknown", 263 RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags))); 264 265 printf("CIST root-id %s, CIST ext-pathcost %u ", 266 stp_print_bridge_id((const u_char *)&stp_bpdu->root_id), 267 EXTRACT_32BITS(&stp_bpdu->root_path_cost)); 268 269 printf("\n\tCIST regional-root-id %s, ", 270 stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id)); 271 272 printf("CIST port-id %04x, ", EXTRACT_16BITS(&stp_bpdu->port_id)); 273 274 printf("\n\tmessage-age %.2fs, max-age %.2fs" 275 ", hello-time %.2fs, forwarding-delay %.2fs", 276 (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE, 277 (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE, 278 (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE, 279 (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE); 280 281 printf ("\n\tv3len %d, ", EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET)); 282 printf("MCID Name %s, rev %u, " 283 "\n\t\tdigest %08x%08x%08x%08x, ", 284 ptr + MST_BPDU_CONFIG_NAME_OFFSET, 285 EXTRACT_16BITS(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32), 286 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET), 287 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4), 288 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8), 289 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12)); 290 291 printf ("CIST int-root-pathcost %u, ", 292 EXTRACT_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET)); 293 294 printf("\n\tCIST bridge-id %s, ", 295 stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET)); 296 297 printf("CIST remaining-hops %d", ptr[MST_BPDU_CIST_REMAIN_HOPS_OFFSET]); 298 299 /* Dump all MSTI's */ 300 v3len = EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET); 301 if (v3len > MST_BPDU_CONFIG_INFO_LENGTH) { 302 len = v3len - MST_BPDU_CONFIG_INFO_LENGTH; 303 offset = MST_BPDU_MSTI_OFFSET; 304 while (len >= MST_BPDU_MSTI_LENGTH) { 305 msti = EXTRACT_16BITS(ptr + offset + 306 MST_BPDU_MSTI_ROOT_PRIO_OFFSET); 307 msti = msti & 0x0FFF; 308 309 printf("\n\tMSTI %d, Flags [%s], port-role %s", 310 msti, bittok2str(stp_bpdu_flag_values, "none", ptr[offset]), 311 tok2str(rstp_obj_port_role_values, "Unknown", 312 RSTP_EXTRACT_PORT_ROLE(ptr[offset]))); 313 printf("\n\t\tMSTI regional-root-id %s, pathcost %u", 314 stp_print_bridge_id(ptr + offset + 315 MST_BPDU_MSTI_ROOT_PRIO_OFFSET), 316 EXTRACT_32BITS(ptr + offset + 317 MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET)); 318 printf("\n\t\tMSTI bridge-prio %d, port-prio %d, hops %d", 319 ptr[offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET] >> 4, 320 ptr[offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET] >> 4, 321 ptr[offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET]); 322 323 len -= MST_BPDU_MSTI_LENGTH; 324 offset += MST_BPDU_MSTI_LENGTH; 325 } 326 } 327 } 328 329 static void 330 stp_print_spb_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int offset) 331 { 332 const u_char *ptr; 333 334 /* 335 * in non-verbose mode don't print anything. 336 */ 337 if (!vflag) { 338 return; 339 } 340 341 ptr = (const u_char *)stp_bpdu; 342 printf("\n\tv4len %d AUXMCID Name %s, Rev %u, \n\t\tdigest %08x%08x%08x%08x", 343 EXTRACT_16BITS (ptr + offset), 344 ptr + offset + SPB_BPDU_CONFIG_NAME_OFFSET, 345 EXTRACT_16BITS(ptr + offset + SPB_BPDU_CONFIG_REV_OFFSET), 346 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET), 347 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 4), 348 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 8), 349 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 12)); 350 351 printf("\n\tAgreement num %d, Discarded Agreement num %d, Agreement valid-" 352 "flag %d, \n\tRestricted role-flag: %d, Format id %d cap %d, " 353 "Convention id %d cap %d, \n\tEdge count %d, " 354 "Agreement digest %08x%08x%08x%08x%08x\n", 355 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>6, 356 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>4 & 0x3, 357 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>3 & 0x1, 358 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>2 & 0x1, 359 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]>>4, 360 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]&0x00ff, 361 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]>>4, 362 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]&0x00ff, 363 EXTRACT_16BITS(ptr + offset + SPB_BPDU_AGREEMENT_EDGE_OFFSET), 364 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET), 365 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+4, 366 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+8, 367 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+12, 368 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET)+16); 369 } 370 371 /* 372 * Print 802.1d / 802.1w / 802.1q (mstp) / 802.1aq (spb) packets. 373 */ 374 void 375 stp_print(const u_char *p, u_int length) 376 { 377 const struct stp_bpdu_ *stp_bpdu; 378 u_int mstp_len; 379 u_int spb_len; 380 381 stp_bpdu = (struct stp_bpdu_*)p; 382 383 /* Minimum STP Frame size. */ 384 if (length < 4) 385 goto trunc; 386 387 if (EXTRACT_16BITS(&stp_bpdu->protocol_id)) { 388 printf("unknown STP version, length %u", length); 389 return; 390 } 391 392 printf("STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)", 393 stp_bpdu->protocol_version)); 394 395 switch (stp_bpdu->protocol_version) { 396 case STP_PROTO_REGULAR: 397 case STP_PROTO_RAPID: 398 case STP_PROTO_MSTP: 399 case STP_PROTO_SPB: 400 break; 401 default: 402 return; 403 } 404 405 printf(", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)", 406 stp_bpdu->bpdu_type)); 407 408 switch (stp_bpdu->bpdu_type) { 409 case STP_BPDU_TYPE_CONFIG: 410 if (length < sizeof(struct stp_bpdu_) - 1) { 411 goto trunc; 412 } 413 stp_print_config_bpdu(stp_bpdu, length); 414 break; 415 416 case STP_BPDU_TYPE_RSTP: 417 if (stp_bpdu->protocol_version == STP_PROTO_RAPID) { 418 if (length < sizeof(struct stp_bpdu_)) { 419 goto trunc; 420 } 421 stp_print_config_bpdu(stp_bpdu, length); 422 } else if (stp_bpdu->protocol_version == STP_PROTO_MSTP || 423 stp_bpdu->protocol_version == STP_PROTO_SPB) { 424 if (length < STP_BPDU_MSTP_MIN_LEN) { 425 goto trunc; 426 } 427 428 if (stp_bpdu->v1_length != 0) { 429 /* FIX ME: Emit a message here ? */ 430 goto trunc; 431 } 432 433 /* Validate v3 length */ 434 mstp_len = EXTRACT_16BITS(p + MST_BPDU_VER3_LEN_OFFSET); 435 mstp_len += 2; /* length encoding itself is 2 bytes */ 436 if (length < (sizeof(struct stp_bpdu_) + mstp_len)) { 437 goto trunc; 438 } 439 stp_print_mstp_bpdu(stp_bpdu, length); 440 441 if (stp_bpdu->protocol_version == STP_PROTO_SPB) 442 { 443 /* Validate v4 length */ 444 spb_len = EXTRACT_16BITS (p + MST_BPDU_VER3_LEN_OFFSET + mstp_len); 445 spb_len += 2; 446 if (length < (sizeof(struct stp_bpdu_) + mstp_len + spb_len) || 447 spb_len < SPB_BPDU_MIN_LEN) { 448 goto trunc; 449 } 450 stp_print_spb_bpdu(stp_bpdu, (sizeof(struct stp_bpdu_) + mstp_len)); 451 } 452 } 453 break; 454 455 case STP_BPDU_TYPE_TOPO_CHANGE: 456 /* always empty message - just break out */ 457 break; 458 459 default: 460 break; 461 } 462 463 return; 464 trunc: 465 printf("[|stp %d]", length); 466 } 467 468 /* 469 * Local Variables: 470 * c-style: whitesmith 471 * c-basic-offset: 4 472 * End: 473 */ 474