1 /* 2 * Redistribution and use in source and binary forms, with or without 3 * modification, are permitted provided that: (1) source code 4 * distributions retain the above copyright notice and this paragraph 5 * in its entirety, and (2) distributions including binary code include 6 * the above copyright notice and this paragraph in its entirety in 7 * the documentation or other materials provided with the distribution. 8 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND 9 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT 10 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 11 * FOR A PARTICULAR PURPOSE. 12 * 13 * Original code by Hannes Gredler (hannes (at) gredler.at) 14 */ 15 16 /* \summary: Bidirectional Forwarding Detection (BFD) printer */ 17 18 /* specification: RFC 5880 (for version 1) and RFC 5881 */ 19 20 #ifdef HAVE_CONFIG_H 21 #include "config.h" 22 #endif 23 24 #include <netdissect-stdinc.h> 25 26 #include "netdissect.h" 27 #include "extract.h" 28 29 #include "udp.h" 30 31 /* 32 * Control packet, BFDv0, draft-katz-ward-bfd-01.txt 33 * 34 * 0 1 2 3 35 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 36 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 37 * |Vers | Diag |H|D|P|F| Rsvd | Detect Mult | Length | 38 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 39 * | My Discriminator | 40 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 41 * | Your Discriminator | 42 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 43 * | Desired Min TX Interval | 44 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 45 * | Required Min RX Interval | 46 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 47 * | Required Min Echo RX Interval | 48 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 49 */ 50 51 /* 52 * Control packet, BFDv1, RFC 5880 53 * 54 * 0 1 2 3 55 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 56 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 57 * |Vers | Diag |Sta|P|F|C|A|D|M| Detect Mult | Length | 58 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 59 * | My Discriminator | 60 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 61 * | Your Discriminator | 62 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 63 * | Desired Min TX Interval | 64 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 65 * | Required Min RX Interval | 66 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 67 * | Required Min Echo RX Interval | 68 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 69 */ 70 71 struct bfd_header_t { 72 uint8_t version_diag; 73 uint8_t flags; 74 uint8_t detect_time_multiplier; 75 uint8_t length; 76 uint8_t my_discriminator[4]; 77 uint8_t your_discriminator[4]; 78 uint8_t desired_min_tx_interval[4]; 79 uint8_t required_min_rx_interval[4]; 80 uint8_t required_min_echo_interval[4]; 81 }; 82 83 /* 84 * An optional Authentication Header may be present 85 * 86 * 0 1 2 3 87 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 88 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 89 * | Auth Type | Auth Len | Authentication Data... | 90 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 91 */ 92 93 struct bfd_auth_header_t { 94 uint8_t auth_type; 95 uint8_t auth_len; 96 uint8_t auth_data; 97 uint8_t dummy; /* minimun 4 bytes */ 98 }; 99 100 enum auth_type { 101 AUTH_PASSWORD = 1, 102 AUTH_MD5 = 2, 103 AUTH_MET_MD5 = 3, 104 AUTH_SHA1 = 4, 105 AUTH_MET_SHA1 = 5 106 }; 107 108 static const struct tok bfd_v1_authentication_values[] = { 109 { AUTH_PASSWORD, "Simple Password" }, 110 { AUTH_MD5, "Keyed MD5" }, 111 { AUTH_MET_MD5, "Meticulous Keyed MD5" }, 112 { AUTH_SHA1, "Keyed SHA1" }, 113 { AUTH_MET_SHA1, "Meticulous Keyed SHA1" }, 114 { 0, NULL } 115 }; 116 117 enum auth_length { 118 AUTH_PASSWORD_FIELD_MIN_LEN = 4, /* header + password min: 3 + 1 */ 119 AUTH_PASSWORD_FIELD_MAX_LEN = 19, /* header + password max: 3 + 16 */ 120 AUTH_MD5_FIELD_LEN = 24, 121 AUTH_MD5_HASH_LEN = 16, 122 AUTH_SHA1_FIELD_LEN = 28, 123 AUTH_SHA1_HASH_LEN = 20 124 }; 125 126 #define BFD_EXTRACT_VERSION(x) (((x)&0xe0)>>5) 127 #define BFD_EXTRACT_DIAG(x) ((x)&0x1f) 128 129 static const struct tok bfd_port_values[] = { 130 { BFD_CONTROL_PORT, "Control" }, 131 { BFD_ECHO_PORT, "Echo" }, 132 { 0, NULL } 133 }; 134 135 static const struct tok bfd_diag_values[] = { 136 { 0, "No Diagnostic" }, 137 { 1, "Control Detection Time Expired" }, 138 { 2, "Echo Function Failed" }, 139 { 3, "Neighbor Signaled Session Down" }, 140 { 4, "Forwarding Plane Reset" }, 141 { 5, "Path Down" }, 142 { 6, "Concatenated Path Down" }, 143 { 7, "Administratively Down" }, 144 { 8, "Reverse Concatenated Path Down" }, 145 { 0, NULL } 146 }; 147 148 static const struct tok bfd_v0_flag_values[] = { 149 { 0x80, "I Hear You" }, 150 { 0x40, "Demand" }, 151 { 0x20, "Poll" }, 152 { 0x10, "Final" }, 153 { 0x08, "Reserved" }, 154 { 0x04, "Reserved" }, 155 { 0x02, "Reserved" }, 156 { 0x01, "Reserved" }, 157 { 0, NULL } 158 }; 159 160 #define BFD_FLAG_AUTH 0x04 161 162 static const struct tok bfd_v1_flag_values[] = { 163 { 0x20, "Poll" }, 164 { 0x10, "Final" }, 165 { 0x08, "Control Plane Independent" }, 166 { BFD_FLAG_AUTH, "Authentication Present" }, 167 { 0x02, "Demand" }, 168 { 0x01, "Multipoint" }, 169 { 0, NULL } 170 }; 171 172 static const struct tok bfd_v1_state_values[] = { 173 { 0, "AdminDown" }, 174 { 1, "Down" }, 175 { 2, "Init" }, 176 { 3, "Up" }, 177 { 0, NULL } 178 }; 179 180 static int 181 auth_print(netdissect_options *ndo, register const u_char *pptr) 182 { 183 const struct bfd_auth_header_t *bfd_auth_header; 184 int i; 185 186 pptr += sizeof (const struct bfd_header_t); 187 bfd_auth_header = (const struct bfd_auth_header_t *)pptr; 188 ND_TCHECK(*bfd_auth_header); 189 ND_PRINT((ndo, "\n\tAuthentication: %s (%u), length: %u", 190 tok2str(bfd_v1_authentication_values,"Unknown",bfd_auth_header->auth_type), 191 bfd_auth_header->auth_type, 192 bfd_auth_header->auth_len)); 193 pptr += 2; 194 ND_PRINT((ndo, "\n\t Auth Key ID: %d", *pptr)); 195 196 switch(bfd_auth_header->auth_type) { 197 case AUTH_PASSWORD: 198 /* 199 * Simple Password Authentication Section Format 200 * 201 * 0 1 2 3 202 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 203 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 204 * | Auth Type | Auth Len | Auth Key ID | Password... | 205 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 206 * | ... | 207 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 208 */ 209 if (bfd_auth_header->auth_len < AUTH_PASSWORD_FIELD_MIN_LEN || 210 bfd_auth_header->auth_len > AUTH_PASSWORD_FIELD_MAX_LEN) { 211 ND_PRINT((ndo, "[invalid length %d]", 212 bfd_auth_header->auth_len)); 213 break; 214 } 215 pptr++; 216 ND_PRINT((ndo, ", Password: ")); 217 /* the length is equal to the password length plus three */ 218 if (fn_printn(ndo, pptr, bfd_auth_header->auth_len - 3, 219 ndo->ndo_snapend)) 220 goto trunc; 221 break; 222 case AUTH_MD5: 223 case AUTH_MET_MD5: 224 /* 225 * Keyed MD5 and Meticulous Keyed MD5 Authentication Section Format 226 * 227 * 0 1 2 3 228 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 229 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 230 * | Auth Type | Auth Len | Auth Key ID | Reserved | 231 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 232 * | Sequence Number | 233 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 234 * | Auth Key/Digest... | 235 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 236 * | ... | 237 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 238 */ 239 if (bfd_auth_header->auth_len != AUTH_MD5_FIELD_LEN) { 240 ND_PRINT((ndo, "[invalid length %d]", 241 bfd_auth_header->auth_len)); 242 break; 243 } 244 pptr += 2; 245 ND_TCHECK2(*pptr, 4); 246 ND_PRINT((ndo, ", Sequence Number: 0x%08x", EXTRACT_32BITS(pptr))); 247 pptr += 4; 248 ND_TCHECK2(*pptr, AUTH_MD5_HASH_LEN); 249 ND_PRINT((ndo, "\n\t Digest: ")); 250 for(i = 0; i < AUTH_MD5_HASH_LEN; i++) 251 ND_PRINT((ndo, "%02x", pptr[i])); 252 break; 253 case AUTH_SHA1: 254 case AUTH_MET_SHA1: 255 /* 256 * Keyed SHA1 and Meticulous Keyed SHA1 Authentication Section Format 257 * 258 * 0 1 2 3 259 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 260 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 261 * | Auth Type | Auth Len | Auth Key ID | Reserved | 262 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 263 * | Sequence Number | 264 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 265 * | Auth Key/Hash... | 266 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 267 * | ... | 268 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 269 */ 270 if (bfd_auth_header->auth_len != AUTH_SHA1_FIELD_LEN) { 271 ND_PRINT((ndo, "[invalid length %d]", 272 bfd_auth_header->auth_len)); 273 break; 274 } 275 pptr += 2; 276 ND_TCHECK2(*pptr, 4); 277 ND_PRINT((ndo, ", Sequence Number: 0x%08x", EXTRACT_32BITS(pptr))); 278 pptr += 4; 279 ND_TCHECK2(*pptr, AUTH_SHA1_HASH_LEN); 280 ND_PRINT((ndo, "\n\t Hash: ")); 281 for(i = 0; i < AUTH_SHA1_HASH_LEN; i++) 282 ND_PRINT((ndo, "%02x", pptr[i])); 283 break; 284 } 285 return 0; 286 287 trunc: 288 return 1; 289 } 290 291 void 292 bfd_print(netdissect_options *ndo, register const u_char *pptr, 293 register u_int len, register u_int port) 294 { 295 const struct bfd_header_t *bfd_header; 296 uint8_t version = 0; 297 298 bfd_header = (const struct bfd_header_t *)pptr; 299 if (port == BFD_CONTROL_PORT) { 300 ND_TCHECK(*bfd_header); 301 version = BFD_EXTRACT_VERSION(bfd_header->version_diag); 302 } else if (port == BFD_ECHO_PORT) { 303 /* Echo is BFD v1 only */ 304 version = 1; 305 } 306 switch ((port << 8) | version) { 307 308 /* BFDv0 */ 309 case (BFD_CONTROL_PORT << 8): 310 if (ndo->ndo_vflag < 1) 311 { 312 ND_PRINT((ndo, "BFDv%u, %s, Flags: [%s], length: %u", 313 version, 314 tok2str(bfd_port_values, "unknown (%u)", port), 315 bittok2str(bfd_v0_flag_values, "none", bfd_header->flags), 316 len)); 317 return; 318 } 319 320 ND_PRINT((ndo, "BFDv%u, length: %u\n\t%s, Flags: [%s], Diagnostic: %s (0x%02x)", 321 version, 322 len, 323 tok2str(bfd_port_values, "unknown (%u)", port), 324 bittok2str(bfd_v0_flag_values, "none", bfd_header->flags), 325 tok2str(bfd_diag_values,"unknown",BFD_EXTRACT_DIAG(bfd_header->version_diag)), 326 BFD_EXTRACT_DIAG(bfd_header->version_diag))); 327 328 ND_PRINT((ndo, "\n\tDetection Timer Multiplier: %u (%u ms Detection time), BFD Length: %u", 329 bfd_header->detect_time_multiplier, 330 bfd_header->detect_time_multiplier * EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000, 331 bfd_header->length)); 332 333 334 ND_PRINT((ndo, "\n\tMy Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->my_discriminator))); 335 ND_PRINT((ndo, ", Your Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->your_discriminator))); 336 ND_PRINT((ndo, "\n\t Desired min Tx Interval: %4u ms", EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000)); 337 ND_PRINT((ndo, "\n\t Required min Rx Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_rx_interval)/1000)); 338 ND_PRINT((ndo, "\n\t Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000)); 339 break; 340 341 /* BFDv1 */ 342 case (BFD_CONTROL_PORT << 8 | 1): 343 if (ndo->ndo_vflag < 1) 344 { 345 ND_PRINT((ndo, "BFDv%u, %s, State %s, Flags: [%s], length: %u", 346 version, 347 tok2str(bfd_port_values, "unknown (%u)", port), 348 tok2str(bfd_v1_state_values, "unknown (%u)", (bfd_header->flags & 0xc0) >> 6), 349 bittok2str(bfd_v1_flag_values, "none", bfd_header->flags & 0x3f), 350 len)); 351 return; 352 } 353 354 ND_PRINT((ndo, "BFDv%u, length: %u\n\t%s, State %s, Flags: [%s], Diagnostic: %s (0x%02x)", 355 version, 356 len, 357 tok2str(bfd_port_values, "unknown (%u)", port), 358 tok2str(bfd_v1_state_values, "unknown (%u)", (bfd_header->flags & 0xc0) >> 6), 359 bittok2str(bfd_v1_flag_values, "none", bfd_header->flags & 0x3f), 360 tok2str(bfd_diag_values,"unknown",BFD_EXTRACT_DIAG(bfd_header->version_diag)), 361 BFD_EXTRACT_DIAG(bfd_header->version_diag))); 362 363 ND_PRINT((ndo, "\n\tDetection Timer Multiplier: %u (%u ms Detection time), BFD Length: %u", 364 bfd_header->detect_time_multiplier, 365 bfd_header->detect_time_multiplier * EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000, 366 bfd_header->length)); 367 368 369 ND_PRINT((ndo, "\n\tMy Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->my_discriminator))); 370 ND_PRINT((ndo, ", Your Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->your_discriminator))); 371 ND_PRINT((ndo, "\n\t Desired min Tx Interval: %4u ms", EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000)); 372 ND_PRINT((ndo, "\n\t Required min Rx Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_rx_interval)/1000)); 373 ND_PRINT((ndo, "\n\t Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000)); 374 375 if (bfd_header->flags & BFD_FLAG_AUTH) { 376 if (auth_print(ndo, pptr)) 377 goto trunc; 378 } 379 break; 380 381 /* BFDv0 */ 382 case (BFD_ECHO_PORT << 8): /* not yet supported - fall through */ 383 /* BFDv1 */ 384 case (BFD_ECHO_PORT << 8 | 1): 385 386 default: 387 ND_PRINT((ndo, "BFD, %s, length: %u", 388 tok2str(bfd_port_values, "unknown (%u)", port), 389 len)); 390 if (ndo->ndo_vflag >= 1) { 391 if(!print_unknown_data(ndo, pptr,"\n\t",len)) 392 return; 393 } 394 break; 395 } 396 return; 397 398 trunc: 399 ND_PRINT((ndo, "[|BFD]")); 400 } 401 /* 402 * Local Variables: 403 * c-style: whitesmith 404 * c-basic-offset: 8 405 * End: 406 */ 407
