print-stp.c revision 1.7
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 * Contributed by Lennert Buytenhek <buytenh (at) gnu.org> 9 */ 10 11 /* \summary: IEEE 802.1d Spanning Tree Protocol (STP) printer */ 12 13 #include <sys/cdefs.h> 14 #ifndef lint 15 __RCSID("$NetBSD: print-stp.c,v 1.7 2017/02/05 04:05:05 spz Exp $"); 16 #endif 17 18 #ifdef HAVE_CONFIG_H 19 #include "config.h" 20 #endif 21 22 #include <netdissect-stdinc.h> 23 24 #include <stdio.h> 25 26 #include "netdissect.h" 27 #include "extract.h" 28 29 #define RSTP_EXTRACT_PORT_ROLE(x) (((x)&0x0C)>>2) 30 /* STP timers are expressed in multiples of 1/256th second */ 31 #define STP_TIME_BASE 256 32 #define STP_BPDU_MSTP_MIN_LEN 102 33 34 struct stp_bpdu_ { 35 uint8_t protocol_id[2]; 36 uint8_t protocol_version; 37 uint8_t bpdu_type; 38 uint8_t flags; 39 uint8_t root_id[8]; 40 uint8_t root_path_cost[4]; 41 uint8_t bridge_id[8]; 42 uint8_t port_id[2]; 43 uint8_t message_age[2]; 44 uint8_t max_age[2]; 45 uint8_t hello_time[2]; 46 uint8_t forward_delay[2]; 47 uint8_t v1_length; 48 }; 49 50 #define STP_PROTO_REGULAR 0x00 51 #define STP_PROTO_RAPID 0x02 52 #define STP_PROTO_MSTP 0x03 53 #define STP_PROTO_SPB 0x04 54 55 static const struct tok stp_proto_values[] = { 56 { STP_PROTO_REGULAR, "802.1d" }, 57 { STP_PROTO_RAPID, "802.1w" }, 58 { STP_PROTO_MSTP, "802.1s" }, 59 { STP_PROTO_SPB, "802.1aq" }, 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 static const 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 static const 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 static const 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 #define ND_TCHECK_BRIDGE_ID(p) ND_TCHECK2(*(p), 8) 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 int 107 stp_print_config_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu, 108 u_int length) 109 { 110 ND_TCHECK(stp_bpdu->flags); 111 ND_PRINT((ndo, ", Flags [%s]", 112 bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags))); 113 114 ND_TCHECK(stp_bpdu->port_id); 115 ND_PRINT((ndo, ", bridge-id %s.%04x, length %u", 116 stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id), 117 EXTRACT_16BITS(&stp_bpdu->port_id), length)); 118 119 /* in non-verbose mode just print the bridge-id */ 120 if (!ndo->ndo_vflag) { 121 return 1; 122 } 123 124 ND_TCHECK(stp_bpdu->forward_delay); 125 ND_PRINT((ndo, "\n\tmessage-age %.2fs, max-age %.2fs" 126 ", hello-time %.2fs, forwarding-delay %.2fs", 127 (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE, 128 (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE, 129 (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE, 130 (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE)); 131 132 ND_PRINT((ndo, "\n\troot-id %s, root-pathcost %u", 133 stp_print_bridge_id((const u_char *)&stp_bpdu->root_id), 134 EXTRACT_32BITS(&stp_bpdu->root_path_cost))); 135 136 /* Port role is only valid for 802.1w */ 137 if (stp_bpdu->protocol_version == STP_PROTO_RAPID) { 138 ND_PRINT((ndo, ", port-role %s", 139 tok2str(rstp_obj_port_role_values, "Unknown", 140 RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags)))); 141 } 142 return 1; 143 144 trunc: 145 return 0; 146 } 147 148 /* 149 * MSTP packet format 150 * Ref. IEEE 802.1Q 2003 Ed. Section 14 151 * 152 * MSTP BPDU 153 * 154 * 2 - bytes Protocol Id 155 * 1 - byte Protocol Ver. 156 * 1 - byte BPDU tye 157 * 1 - byte Flags 158 * 8 - bytes CIST Root Identifier 159 * 4 - bytes CIST External Path Cost 160 * 8 - bytes CIST Regional Root Identifier 161 * 2 - bytes CIST Port Identifier 162 * 2 - bytes Message Age 163 * 2 - bytes Max age 164 * 2 - bytes Hello Time 165 * 2 - bytes Forward delay 166 * 1 - byte Version 1 length. Must be 0 167 * 2 - bytes Version 3 length 168 * 1 - byte Config Identifier 169 * 32 - bytes Config Name 170 * 2 - bytes Revision level 171 * 16 - bytes Config Digest [MD5] 172 * 4 - bytes CIST Internal Root Path Cost 173 * 8 - bytes CIST Bridge Identifier 174 * 1 - byte CIST Remaining Hops 175 * 16 - bytes MSTI information [Max 64 MSTI, each 16 bytes] 176 * 177 * 178 * SPB BPDU 179 * Ref. IEEE 802.1aq. Section 14 180 * 181 * 2 - bytes Version 4 length 182 * 1 - byte Aux Config Identifier 183 * 32 - bytes Aux Config Name 184 * 2 - bytes Aux Revision level 185 * 16 - bytes Aux Config Digest [MD5] 186 * 1 - byte (1 - 2) Agreement Number 187 * (3 - 4) Discarded Agreement Number 188 * (5) Agreement Valid Flag 189 * (6) Restricted Role Flag 190 * (7 - 8) Unused sent zero 191 * 1 - byte Unused 192 * 1 - byte (1 - 4) Agreement Digest Format Identifier 193 * (5 - 8) Agreement Digest Format Capabilities 194 * 1 - byte (1 - 4) Agreement Digest Convention Identifier 195 * (5 - 8) Agreement Digest Convention Capabilities 196 * 2 - bytes Agreement Digest Edge Count 197 * 8 - byte Reserved Set 198 * 20 - bytes Computed Topology Digest 199 * 200 * 201 * MSTI Payload 202 * 203 * 1 - byte MSTI flag 204 * 8 - bytes MSTI Regional Root Identifier 205 * 4 - bytes MSTI Regional Path Cost 206 * 1 - byte MSTI Bridge Priority 207 * 1 - byte MSTI Port Priority 208 * 1 - byte MSTI Remaining Hops 209 * 210 */ 211 212 #define MST_BPDU_MSTI_LENGTH 16 213 #define MST_BPDU_CONFIG_INFO_LENGTH 64 214 215 /* Offsets of fields from the begginning for the packet */ 216 #define MST_BPDU_VER3_LEN_OFFSET 36 217 #define MST_BPDU_CONFIG_NAME_OFFSET 39 218 #define MST_BPDU_CONFIG_DIGEST_OFFSET 73 219 #define MST_BPDU_CIST_INT_PATH_COST_OFFSET 89 220 #define MST_BPDU_CIST_BRIDGE_ID_OFFSET 93 221 #define MST_BPDU_CIST_REMAIN_HOPS_OFFSET 101 222 #define MST_BPDU_MSTI_OFFSET 102 223 /* Offsets within an MSTI */ 224 #define MST_BPDU_MSTI_ROOT_PRIO_OFFSET 1 225 #define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9 226 #define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET 13 227 #define MST_BPDU_MSTI_PORT_PRIO_OFFSET 14 228 #define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET 15 229 230 #define SPB_BPDU_MIN_LEN 87 231 #define SPB_BPDU_CONFIG_NAME_OFFSET 3 232 #define SPB_BPDU_CONFIG_REV_OFFSET SPB_BPDU_CONFIG_NAME_OFFSET + 32 233 #define SPB_BPDU_CONFIG_DIGEST_OFFSET SPB_BPDU_CONFIG_REV_OFFSET + 2 234 #define SPB_BPDU_AGREEMENT_OFFSET SPB_BPDU_CONFIG_DIGEST_OFFSET + 16 235 #define SPB_BPDU_AGREEMENT_UNUSED_OFFSET SPB_BPDU_AGREEMENT_OFFSET + 1 236 #define SPB_BPDU_AGREEMENT_FORMAT_OFFSET SPB_BPDU_AGREEMENT_UNUSED_OFFSET + 1 237 #define SPB_BPDU_AGREEMENT_CON_OFFSET SPB_BPDU_AGREEMENT_FORMAT_OFFSET + 1 238 #define SPB_BPDU_AGREEMENT_EDGE_OFFSET SPB_BPDU_AGREEMENT_CON_OFFSET + 1 239 #define SPB_BPDU_AGREEMENT_RES1_OFFSET SPB_BPDU_AGREEMENT_EDGE_OFFSET + 2 240 #define SPB_BPDU_AGREEMENT_RES2_OFFSET SPB_BPDU_AGREEMENT_RES1_OFFSET + 4 241 #define SPB_BPDU_AGREEMENT_DIGEST_OFFSET SPB_BPDU_AGREEMENT_RES2_OFFSET + 4 242 243 static int 244 stp_print_mstp_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu, 245 u_int length) 246 { 247 const u_char *ptr; 248 uint16_t v3len; 249 uint16_t len; 250 uint16_t msti; 251 u_int offset; 252 253 ptr = (const u_char *)stp_bpdu; 254 ND_PRINT((ndo, ", CIST Flags [%s], length %u", 255 bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags), length)); 256 257 /* 258 * in non-verbose mode just print the flags. 259 */ 260 if (!ndo->ndo_vflag) { 261 return 1; 262 } 263 264 ND_PRINT((ndo, "\n\tport-role %s, ", 265 tok2str(rstp_obj_port_role_values, "Unknown", 266 RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags)))); 267 268 ND_TCHECK(stp_bpdu->root_path_cost); 269 ND_PRINT((ndo, "CIST root-id %s, CIST ext-pathcost %u", 270 stp_print_bridge_id((const u_char *)&stp_bpdu->root_id), 271 EXTRACT_32BITS(&stp_bpdu->root_path_cost))); 272 273 ND_TCHECK(stp_bpdu->bridge_id); 274 ND_PRINT((ndo, "\n\tCIST regional-root-id %s, ", 275 stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id))); 276 277 ND_TCHECK(stp_bpdu->port_id); 278 ND_PRINT((ndo, "CIST port-id %04x,", EXTRACT_16BITS(&stp_bpdu->port_id))); 279 280 ND_TCHECK(stp_bpdu->forward_delay); 281 ND_PRINT((ndo, "\n\tmessage-age %.2fs, max-age %.2fs" 282 ", hello-time %.2fs, forwarding-delay %.2fs", 283 (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE, 284 (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE, 285 (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE, 286 (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE)); 287 288 ND_TCHECK_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET); 289 ND_PRINT((ndo, "\n\tv3len %d, ", EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET))); 290 ND_TCHECK_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12); 291 ND_PRINT((ndo, "MCID Name ")); 292 if (fn_printzp(ndo, ptr + MST_BPDU_CONFIG_NAME_OFFSET, 32, ndo->ndo_snapend)) 293 goto trunc; 294 ND_PRINT((ndo, ", rev %u," 295 "\n\t\tdigest %08x%08x%08x%08x, ", 296 EXTRACT_16BITS(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32), 297 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET), 298 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4), 299 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8), 300 EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12))); 301 302 ND_TCHECK_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET); 303 ND_PRINT((ndo, "CIST int-root-pathcost %u,", 304 EXTRACT_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET))); 305 306 ND_TCHECK_BRIDGE_ID(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET); 307 ND_PRINT((ndo, "\n\tCIST bridge-id %s, ", 308 stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET))); 309 310 ND_TCHECK(ptr[MST_BPDU_CIST_REMAIN_HOPS_OFFSET]); 311 ND_PRINT((ndo, "CIST remaining-hops %d", ptr[MST_BPDU_CIST_REMAIN_HOPS_OFFSET])); 312 313 /* Dump all MSTI's */ 314 ND_TCHECK_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET); 315 v3len = EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET); 316 if (v3len > MST_BPDU_CONFIG_INFO_LENGTH) { 317 len = v3len - MST_BPDU_CONFIG_INFO_LENGTH; 318 offset = MST_BPDU_MSTI_OFFSET; 319 while (len >= MST_BPDU_MSTI_LENGTH) { 320 ND_TCHECK2(*(ptr + offset), MST_BPDU_MSTI_LENGTH); 321 322 msti = EXTRACT_16BITS(ptr + offset + 323 MST_BPDU_MSTI_ROOT_PRIO_OFFSET); 324 msti = msti & 0x0FFF; 325 326 ND_PRINT((ndo, "\n\tMSTI %d, Flags [%s], port-role %s", 327 msti, bittok2str(stp_bpdu_flag_values, "none", ptr[offset]), 328 tok2str(rstp_obj_port_role_values, "Unknown", 329 RSTP_EXTRACT_PORT_ROLE(ptr[offset])))); 330 ND_PRINT((ndo, "\n\t\tMSTI regional-root-id %s, pathcost %u", 331 stp_print_bridge_id(ptr + offset + 332 MST_BPDU_MSTI_ROOT_PRIO_OFFSET), 333 EXTRACT_32BITS(ptr + offset + 334 MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET))); 335 ND_PRINT((ndo, "\n\t\tMSTI bridge-prio %d, port-prio %d, hops %d", 336 ptr[offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET] >> 4, 337 ptr[offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET] >> 4, 338 ptr[offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET])); 339 340 len -= MST_BPDU_MSTI_LENGTH; 341 offset += MST_BPDU_MSTI_LENGTH; 342 } 343 } 344 return 1; 345 346 trunc: 347 return 0; 348 } 349 350 static int 351 stp_print_spb_bpdu(netdissect_options *ndo, const struct stp_bpdu_ *stp_bpdu, 352 u_int offset) 353 { 354 const u_char *ptr; 355 356 /* 357 * in non-verbose mode don't print anything. 358 */ 359 if (!ndo->ndo_vflag) { 360 return 1; 361 } 362 363 ptr = (const u_char *)stp_bpdu; 364 ND_TCHECK_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET + 16); 365 366 ND_PRINT((ndo, "\n\tv4len %d, ", EXTRACT_16BITS (ptr + offset))); 367 ND_PRINT((ndo, "AUXMCID Name ")); 368 if (fn_printzp(ndo, ptr + offset + SPB_BPDU_CONFIG_NAME_OFFSET, 32, 369 ndo->ndo_snapend)) 370 goto trunc; 371 ND_PRINT((ndo, ", Rev %u,\n\t\tdigest %08x%08x%08x%08x", 372 EXTRACT_16BITS(ptr + offset + SPB_BPDU_CONFIG_REV_OFFSET), 373 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET), 374 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 4), 375 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 8), 376 EXTRACT_32BITS(ptr + offset + SPB_BPDU_CONFIG_DIGEST_OFFSET + 12))); 377 378 ND_PRINT((ndo, "\n\tAgreement num %d, Discarded Agreement num %d, Agreement valid-" 379 "flag %d,\n\tRestricted role-flag: %d, Format id %d cap %d, " 380 "Convention id %d cap %d,\n\tEdge count %d, " 381 "Agreement digest %08x%08x%08x%08x%08x\n", 382 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>6, 383 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>4 & 0x3, 384 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>3 & 0x1, 385 ptr[offset + SPB_BPDU_AGREEMENT_OFFSET]>>2 & 0x1, 386 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]>>4, 387 ptr[offset + SPB_BPDU_AGREEMENT_FORMAT_OFFSET]&0x00ff, 388 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]>>4, 389 ptr[offset + SPB_BPDU_AGREEMENT_CON_OFFSET]&0x00ff, 390 EXTRACT_16BITS(ptr + offset + SPB_BPDU_AGREEMENT_EDGE_OFFSET), 391 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET), 392 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET+4), 393 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET+8), 394 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET+12), 395 EXTRACT_32BITS(ptr + offset + SPB_BPDU_AGREEMENT_DIGEST_OFFSET+16))); 396 return 1; 397 398 trunc: 399 return 0; 400 } 401 402 /* 403 * Print 802.1d / 802.1w / 802.1q (mstp) / 802.1aq (spb) packets. 404 */ 405 void 406 stp_print(netdissect_options *ndo, const u_char *p, u_int length) 407 { 408 const struct stp_bpdu_ *stp_bpdu; 409 u_int mstp_len; 410 u_int spb_len; 411 412 stp_bpdu = (const struct stp_bpdu_*)p; 413 414 /* Minimum STP Frame size. */ 415 if (length < 4) 416 goto trunc; 417 418 ND_TCHECK(stp_bpdu->protocol_id); 419 if (EXTRACT_16BITS(&stp_bpdu->protocol_id)) { 420 ND_PRINT((ndo, "unknown STP version, length %u", length)); 421 return; 422 } 423 424 ND_TCHECK(stp_bpdu->protocol_version); 425 ND_PRINT((ndo, "STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)", 426 stp_bpdu->protocol_version))); 427 428 switch (stp_bpdu->protocol_version) { 429 case STP_PROTO_REGULAR: 430 case STP_PROTO_RAPID: 431 case STP_PROTO_MSTP: 432 case STP_PROTO_SPB: 433 break; 434 default: 435 return; 436 } 437 438 ND_TCHECK(stp_bpdu->bpdu_type); 439 ND_PRINT((ndo, ", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)", 440 stp_bpdu->bpdu_type))); 441 442 switch (stp_bpdu->bpdu_type) { 443 case STP_BPDU_TYPE_CONFIG: 444 if (length < sizeof(struct stp_bpdu_) - 1) { 445 goto trunc; 446 } 447 if (!stp_print_config_bpdu(ndo, stp_bpdu, length)) 448 goto trunc; 449 break; 450 451 case STP_BPDU_TYPE_RSTP: 452 if (stp_bpdu->protocol_version == STP_PROTO_RAPID) { 453 if (length < sizeof(struct stp_bpdu_)) { 454 goto trunc; 455 } 456 if (!stp_print_config_bpdu(ndo, stp_bpdu, length)) 457 goto trunc; 458 } else if (stp_bpdu->protocol_version == STP_PROTO_MSTP || 459 stp_bpdu->protocol_version == STP_PROTO_SPB) { 460 if (length < STP_BPDU_MSTP_MIN_LEN) { 461 goto trunc; 462 } 463 464 ND_TCHECK(stp_bpdu->v1_length); 465 if (stp_bpdu->v1_length != 0) { 466 /* FIX ME: Emit a message here ? */ 467 goto trunc; 468 } 469 470 /* Validate v3 length */ 471 ND_TCHECK_16BITS(p + MST_BPDU_VER3_LEN_OFFSET); 472 mstp_len = EXTRACT_16BITS(p + MST_BPDU_VER3_LEN_OFFSET); 473 mstp_len += 2; /* length encoding itself is 2 bytes */ 474 if (length < (sizeof(struct stp_bpdu_) + mstp_len)) { 475 goto trunc; 476 } 477 if (!stp_print_mstp_bpdu(ndo, stp_bpdu, length)) 478 goto trunc; 479 480 if (stp_bpdu->protocol_version == STP_PROTO_SPB) 481 { 482 /* Validate v4 length */ 483 spb_len = EXTRACT_16BITS (p + MST_BPDU_VER3_LEN_OFFSET + mstp_len); 484 spb_len += 2; 485 if (length < (sizeof(struct stp_bpdu_) + mstp_len + spb_len) || 486 spb_len < SPB_BPDU_MIN_LEN) { 487 goto trunc; 488 } 489 if (!stp_print_spb_bpdu(ndo, stp_bpdu, (sizeof(struct stp_bpdu_) + mstp_len))) 490 goto trunc; 491 } 492 } 493 break; 494 495 case STP_BPDU_TYPE_TOPO_CHANGE: 496 /* always empty message - just break out */ 497 break; 498 499 default: 500 break; 501 } 502 503 return; 504 trunc: 505 ND_PRINT((ndo, "[|stp %d]", length)); 506 } 507 508 /* 509 * Local Variables: 510 * c-style: whitesmith 511 * c-basic-offset: 4 512 * End: 513 */ 514
Indexes created Sat Aug 15 00:25:12 UTC 2026