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 1.13.2.7 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 */ 366
