JP Abgrall | 53f17a9 | 2014-02-12 14:02:41 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2007-2011 Grégoire Henry, Juliusz Chroboczek |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * 1. Redistributions of source code must retain the above copyright |
| 8 | * notice, this list of conditions and the following disclaimer. |
| 9 | * 2. Redistributions in binary form must reproduce the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer in the |
| 11 | * documentation and/or other materials provided with the distribution. |
| 12 | * 3. Neither the name of the project nor the names of its contributors |
| 13 | * may be used to endorse or promote products derived from this software |
| 14 | * without specific prior written permission. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND |
| 17 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE |
| 20 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 21 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 22 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 23 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 24 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 25 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 26 | * SUCH DAMAGE. |
| 27 | */ |
| 28 | |
| 29 | #ifdef HAVE_CONFIG_H |
| 30 | #include "config.h" |
| 31 | #endif |
| 32 | |
| 33 | #include <tcpdump-stdinc.h> |
| 34 | |
| 35 | #include <stdio.h> |
| 36 | #include <string.h> |
| 37 | |
| 38 | #include "addrtoname.h" |
| 39 | #include "interface.h" |
| 40 | #include "extract.h" |
| 41 | |
| 42 | static void babel_print_v2(const u_char *cp, u_int length); |
| 43 | |
| 44 | void |
| 45 | babel_print(const u_char *cp, u_int length) { |
| 46 | printf("babel"); |
| 47 | |
| 48 | TCHECK2(*cp, 4); |
| 49 | |
| 50 | if(cp[0] != 42) { |
| 51 | printf(" malformed header"); |
| 52 | return; |
| 53 | } else { |
| 54 | printf(" %d", cp[1]); |
| 55 | } |
| 56 | |
| 57 | switch(cp[1]) { |
| 58 | case 2: |
| 59 | babel_print_v2(cp,length); |
| 60 | break; |
| 61 | default: |
| 62 | printf(" unknown version"); |
| 63 | break; |
| 64 | } |
| 65 | |
| 66 | return; |
| 67 | |
| 68 | trunc: |
| 69 | printf(" [|babel]"); |
| 70 | return; |
| 71 | } |
| 72 | |
| 73 | /* TLVs */ |
| 74 | #define MESSAGE_PAD1 0 |
| 75 | #define MESSAGE_PADN 1 |
| 76 | #define MESSAGE_ACK_REQ 2 |
| 77 | #define MESSAGE_ACK 3 |
| 78 | #define MESSAGE_HELLO 4 |
| 79 | #define MESSAGE_IHU 5 |
| 80 | #define MESSAGE_ROUTER_ID 6 |
| 81 | #define MESSAGE_NH 7 |
| 82 | #define MESSAGE_UPDATE 8 |
| 83 | #define MESSAGE_REQUEST 9 |
| 84 | #define MESSAGE_MH_REQUEST 10 |
| 85 | #define MESSAGE_TSPC 11 |
| 86 | #define MESSAGE_HMAC 12 |
| 87 | |
| 88 | /* sub-TLVs */ |
| 89 | #define MESSAGE_SUB_PAD1 0 |
| 90 | #define MESSAGE_SUB_PADN 1 |
| 91 | #define MESSAGE_SUB_DIVERSITY 2 |
| 92 | |
| 93 | /* Diversity sub-TLV channel codes */ |
| 94 | static const struct tok diversity_str[] = { |
| 95 | { 0, "reserved" }, |
| 96 | { 255, "all" }, |
| 97 | { 0, NULL } |
| 98 | }; |
| 99 | |
| 100 | static const char * |
| 101 | format_id(const u_char *id) |
| 102 | { |
| 103 | static char buf[25]; |
| 104 | snprintf(buf, 25, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x", |
| 105 | id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7]); |
| 106 | buf[24] = '\0'; |
| 107 | return buf; |
| 108 | } |
| 109 | |
| 110 | static const unsigned char v4prefix[16] = |
| 111 | {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 }; |
| 112 | |
| 113 | static const char * |
| 114 | format_prefix(const u_char *prefix, unsigned char plen) |
| 115 | { |
| 116 | static char buf[50]; |
| 117 | if(plen >= 96 && memcmp(prefix, v4prefix, 12) == 0) |
| 118 | snprintf(buf, 50, "%s/%u", ipaddr_string(prefix + 12), plen - 96); |
| 119 | else |
| 120 | #ifdef INET6 |
| 121 | snprintf(buf, 50, "%s/%u", ip6addr_string(prefix), plen); |
| 122 | #else |
| 123 | snprintf(buf, 50, "IPv6 addresses not supported"); |
| 124 | #endif |
| 125 | buf[49] = '\0'; |
| 126 | return buf; |
| 127 | } |
| 128 | |
| 129 | static const char * |
| 130 | format_address(const u_char *prefix) |
| 131 | { |
| 132 | if(memcmp(prefix, v4prefix, 12) == 0) |
| 133 | return ipaddr_string(prefix + 12); |
| 134 | else |
| 135 | #ifdef INET6 |
| 136 | return ip6addr_string(prefix); |
| 137 | #else |
| 138 | return "IPv6 addresses not supported"; |
| 139 | #endif |
| 140 | } |
| 141 | |
| 142 | static const char * |
| 143 | format_interval(const u_int16_t i) |
| 144 | { |
| 145 | static char buf[sizeof("0000.0s")]; |
| 146 | |
| 147 | if (i == 0) |
| 148 | return "0.0s (bogus)"; |
| 149 | snprintf(buf, sizeof(buf), "%u.%us", i / 10, i % 10); |
| 150 | return buf; |
| 151 | } |
| 152 | |
| 153 | static const char * |
| 154 | format_interval_update(const u_int16_t i) |
| 155 | { |
| 156 | return i == 0xFFFF ? "infinity" : format_interval(i); |
| 157 | } |
| 158 | |
| 159 | /* Return number of octets consumed from the input buffer (not the prefix length |
| 160 | * in bytes), or -1 for encoding error. */ |
| 161 | static int |
| 162 | network_prefix(int ae, int plen, unsigned int omitted, |
| 163 | const unsigned char *p, const unsigned char *dp, |
| 164 | unsigned int len, unsigned char *p_r) |
| 165 | { |
| 166 | unsigned pb; |
| 167 | unsigned char prefix[16]; |
| 168 | int consumed = 0; |
| 169 | |
| 170 | if(plen >= 0) |
| 171 | pb = (plen + 7) / 8; |
| 172 | else if(ae == 1) |
| 173 | pb = 4; |
| 174 | else |
| 175 | pb = 16; |
| 176 | |
| 177 | if(pb > 16) |
| 178 | return -1; |
| 179 | |
| 180 | memset(prefix, 0, 16); |
| 181 | |
| 182 | switch(ae) { |
| 183 | case 0: break; |
| 184 | case 1: |
| 185 | if(omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted)) |
| 186 | return -1; |
| 187 | memcpy(prefix, v4prefix, 12); |
| 188 | if(omitted) { |
| 189 | if (dp == NULL) return -1; |
| 190 | memcpy(prefix, dp, 12 + omitted); |
| 191 | } |
| 192 | if(pb > omitted) { |
| 193 | memcpy(prefix + 12 + omitted, p, pb - omitted); |
| 194 | consumed = pb - omitted; |
| 195 | } |
| 196 | break; |
| 197 | case 2: |
| 198 | if(omitted > 16 || (pb > omitted && len < pb - omitted)) |
| 199 | return -1; |
| 200 | if(omitted) { |
| 201 | if (dp == NULL) return -1; |
| 202 | memcpy(prefix, dp, omitted); |
| 203 | } |
| 204 | if(pb > omitted) { |
| 205 | memcpy(prefix + omitted, p, pb - omitted); |
| 206 | consumed = pb - omitted; |
| 207 | } |
| 208 | break; |
| 209 | case 3: |
| 210 | if(pb > 8 && len < pb - 8) return -1; |
| 211 | prefix[0] = 0xfe; |
| 212 | prefix[1] = 0x80; |
| 213 | if(pb > 8) { |
| 214 | memcpy(prefix + 8, p, pb - 8); |
| 215 | consumed = pb - 8; |
| 216 | } |
| 217 | break; |
| 218 | default: |
| 219 | return -1; |
| 220 | } |
| 221 | |
| 222 | memcpy(p_r, prefix, 16); |
| 223 | return consumed; |
| 224 | } |
| 225 | |
| 226 | static int |
| 227 | network_address(int ae, const unsigned char *a, unsigned int len, |
| 228 | unsigned char *a_r) |
| 229 | { |
| 230 | return network_prefix(ae, -1, 0, a, NULL, len, a_r); |
| 231 | } |
| 232 | |
| 233 | /* |
| 234 | * Sub-TLVs consume the "extra data" of Babel TLVs (see Section 4.3 of RFC6126), |
| 235 | * their encoding is similar to the encoding of TLVs, but the type namespace is |
| 236 | * different: |
| 237 | * |
| 238 | * o Type 0 stands for Pad1 sub-TLV with the same encoding as the Pad1 TLV. |
| 239 | * o Type 1 stands for PadN sub-TLV with the same encoding as the PadN TLV. |
| 240 | * o Type 2 stands for Diversity sub-TLV, which propagates diversity routing |
| 241 | * data. Its body is a variable-length sequence of 8-bit unsigned integers, |
| 242 | * each representing per-hop number of interferring radio channel for the |
| 243 | * prefix. Channel 0 is invalid and must not be used in the sub-TLV, channel |
| 244 | * 255 interferes with any other channel. |
| 245 | * |
| 246 | * Sub-TLV types 0 and 1 are valid for any TLV type, whether sub-TLV type 2 is |
| 247 | * only valid for TLV type 8 (Update). Note that within an Update TLV a missing |
| 248 | * Diversity sub-TLV is not the same as a Diversity sub-TLV with an empty body. |
| 249 | * The former would mean a lack of any claims about the interference, and the |
| 250 | * latter would state that interference is definitely absent. */ |
| 251 | static void |
| 252 | subtlvs_print(const u_char *cp, const u_char *ep, const uint8_t tlv_type) { |
| 253 | uint8_t subtype, sublen; |
| 254 | const char *sep; |
| 255 | |
| 256 | while (cp < ep) { |
| 257 | subtype = *cp++; |
| 258 | if(subtype == MESSAGE_SUB_PAD1) { |
| 259 | printf(" sub-pad1"); |
| 260 | continue; |
| 261 | } |
| 262 | if(cp == ep) |
| 263 | goto corrupt; |
| 264 | sublen = *cp++; |
| 265 | if(cp + sublen > ep) |
| 266 | goto corrupt; |
| 267 | |
| 268 | switch(subtype) { |
| 269 | case MESSAGE_SUB_PADN: |
| 270 | printf(" sub-padn"); |
| 271 | cp += sublen; |
| 272 | break; |
| 273 | case MESSAGE_SUB_DIVERSITY: |
| 274 | printf(" sub-diversity"); |
| 275 | if (sublen == 0) { |
| 276 | printf(" empty"); |
| 277 | break; |
| 278 | } |
| 279 | sep = " "; |
| 280 | while(sublen--) { |
| 281 | printf("%s%s", sep, tok2str(diversity_str, "%u", *cp++)); |
| 282 | sep = "-"; |
| 283 | } |
| 284 | if(tlv_type != MESSAGE_UPDATE) |
| 285 | printf(" (bogus)"); |
| 286 | break; |
| 287 | default: |
| 288 | printf(" sub-unknown-0x%02x", subtype); |
| 289 | cp += sublen; |
| 290 | } /* switch */ |
| 291 | } /* while */ |
| 292 | return; |
| 293 | |
| 294 | corrupt: |
| 295 | printf(" (corrupt)"); |
| 296 | } |
| 297 | |
| 298 | #define ICHECK(i, l) \ |
| 299 | if ((i) + (l) > bodylen || (i) + (l) > length) goto corrupt; |
| 300 | |
| 301 | static void |
| 302 | babel_print_v2(const u_char *cp, u_int length) { |
| 303 | u_int i; |
| 304 | u_short bodylen; |
| 305 | u_char v4_prefix[16] = |
| 306 | {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 }; |
| 307 | u_char v6_prefix[16] = {0}; |
| 308 | |
| 309 | TCHECK2(*cp, 4); |
| 310 | if (length < 4) |
| 311 | goto corrupt; |
| 312 | bodylen = EXTRACT_16BITS(cp + 2); |
| 313 | printf(" (%u)", bodylen); |
| 314 | |
| 315 | /* Process the TLVs in the body */ |
| 316 | i = 0; |
| 317 | while(i < bodylen) { |
| 318 | const u_char *message; |
| 319 | u_int type, len; |
| 320 | |
| 321 | message = cp + 4 + i; |
| 322 | |
| 323 | TCHECK2(*message, 1); |
| 324 | if((type = message[0]) == MESSAGE_PAD1) { |
| 325 | printf(vflag ? "\n\tPad 1" : " pad1"); |
| 326 | i += 1; |
| 327 | continue; |
| 328 | } |
| 329 | |
| 330 | TCHECK2(*message, 2); |
| 331 | ICHECK(i, 2); |
| 332 | len = message[1]; |
| 333 | |
| 334 | TCHECK2(*message, 2 + len); |
| 335 | ICHECK(i, 2 + len); |
| 336 | |
| 337 | switch(type) { |
| 338 | case MESSAGE_PADN: { |
| 339 | if(!vflag) |
| 340 | printf(" padN"); |
| 341 | else |
| 342 | printf("\n\tPad %d", len + 2); |
| 343 | } |
| 344 | break; |
| 345 | |
| 346 | case MESSAGE_ACK_REQ: { |
| 347 | u_short nonce, interval; |
| 348 | if(!vflag) |
| 349 | printf(" ack-req"); |
| 350 | else { |
| 351 | printf("\n\tAcknowledgment Request "); |
| 352 | if(len < 6) goto corrupt; |
| 353 | nonce = EXTRACT_16BITS(message + 4); |
| 354 | interval = EXTRACT_16BITS(message + 6); |
| 355 | printf("%04x %s", nonce, format_interval(interval)); |
| 356 | } |
| 357 | } |
| 358 | break; |
| 359 | |
| 360 | case MESSAGE_ACK: { |
| 361 | u_short nonce; |
| 362 | if(!vflag) |
| 363 | printf(" ack"); |
| 364 | else { |
| 365 | printf("\n\tAcknowledgment "); |
| 366 | if(len < 2) goto corrupt; |
| 367 | nonce = EXTRACT_16BITS(message + 2); |
| 368 | printf("%04x", nonce); |
| 369 | } |
| 370 | } |
| 371 | break; |
| 372 | |
| 373 | case MESSAGE_HELLO: { |
| 374 | u_short seqno, interval; |
| 375 | if(!vflag) |
| 376 | printf(" hello"); |
| 377 | else { |
| 378 | printf("\n\tHello "); |
| 379 | if(len < 6) goto corrupt; |
| 380 | seqno = EXTRACT_16BITS(message + 4); |
| 381 | interval = EXTRACT_16BITS(message + 6); |
| 382 | printf("seqno %u interval %s", seqno, format_interval(interval)); |
| 383 | } |
| 384 | } |
| 385 | break; |
| 386 | |
| 387 | case MESSAGE_IHU: { |
| 388 | unsigned short txcost, interval; |
| 389 | if(!vflag) |
| 390 | printf(" ihu"); |
| 391 | else { |
| 392 | u_char address[16]; |
| 393 | int rc; |
| 394 | printf("\n\tIHU "); |
| 395 | if(len < 6) goto corrupt; |
| 396 | txcost = EXTRACT_16BITS(message + 4); |
| 397 | interval = EXTRACT_16BITS(message + 6); |
| 398 | rc = network_address(message[2], message + 8, len - 6, address); |
| 399 | if(rc < 0) { printf("[|babel]"); break; } |
| 400 | printf("%s txcost %u interval %s", |
| 401 | format_address(address), txcost, format_interval(interval)); |
| 402 | } |
| 403 | } |
| 404 | break; |
| 405 | |
| 406 | case MESSAGE_ROUTER_ID: { |
| 407 | if(!vflag) |
| 408 | printf(" router-id"); |
| 409 | else { |
| 410 | printf("\n\tRouter Id"); |
| 411 | if(len < 10) goto corrupt; |
| 412 | printf(" %s", format_id(message + 4)); |
| 413 | } |
| 414 | } |
| 415 | break; |
| 416 | |
| 417 | case MESSAGE_NH: { |
| 418 | if(!vflag) |
| 419 | printf(" nh"); |
| 420 | else { |
| 421 | int rc; |
| 422 | u_char nh[16]; |
| 423 | printf("\n\tNext Hop"); |
| 424 | if(len < 2) goto corrupt; |
| 425 | rc = network_address(message[2], message + 4, len - 2, nh); |
| 426 | if(rc < 0) goto corrupt; |
| 427 | printf(" %s", format_address(nh)); |
| 428 | } |
| 429 | } |
| 430 | break; |
| 431 | |
| 432 | case MESSAGE_UPDATE: { |
| 433 | if(!vflag) { |
| 434 | printf(" update"); |
| 435 | if(len < 1) |
| 436 | printf("/truncated"); |
| 437 | else |
| 438 | printf("%s%s%s", |
| 439 | (message[3] & 0x80) ? "/prefix": "", |
| 440 | (message[3] & 0x40) ? "/id" : "", |
| 441 | (message[3] & 0x3f) ? "/unknown" : ""); |
| 442 | } else { |
| 443 | u_short interval, seqno, metric; |
| 444 | u_char plen; |
| 445 | int rc; |
| 446 | u_char prefix[16]; |
| 447 | printf("\n\tUpdate"); |
| 448 | if(len < 10) goto corrupt; |
| 449 | plen = message[4] + (message[2] == 1 ? 96 : 0); |
| 450 | rc = network_prefix(message[2], message[4], message[5], |
| 451 | message + 12, |
| 452 | message[2] == 1 ? v4_prefix : v6_prefix, |
| 453 | len - 10, prefix); |
| 454 | if(rc < 0) goto corrupt; |
| 455 | interval = EXTRACT_16BITS(message + 6); |
| 456 | seqno = EXTRACT_16BITS(message + 8); |
| 457 | metric = EXTRACT_16BITS(message + 10); |
| 458 | printf("%s%s%s %s metric %u seqno %u interval %s", |
| 459 | (message[3] & 0x80) ? "/prefix": "", |
| 460 | (message[3] & 0x40) ? "/id" : "", |
| 461 | (message[3] & 0x3f) ? "/unknown" : "", |
| 462 | format_prefix(prefix, plen), |
| 463 | metric, seqno, format_interval_update(interval)); |
| 464 | if(message[3] & 0x80) { |
| 465 | if(message[2] == 1) |
| 466 | memcpy(v4_prefix, prefix, 16); |
| 467 | else |
| 468 | memcpy(v6_prefix, prefix, 16); |
| 469 | } |
| 470 | /* extra data? */ |
| 471 | if((u_int)rc < len - 10) |
| 472 | subtlvs_print(message + 12 + rc, message + 2 + len, type); |
| 473 | } |
| 474 | } |
| 475 | break; |
| 476 | |
| 477 | case MESSAGE_REQUEST: { |
| 478 | if(!vflag) |
| 479 | printf(" request"); |
| 480 | else { |
| 481 | int rc; |
| 482 | u_char prefix[16], plen; |
| 483 | printf("\n\tRequest "); |
| 484 | if(len < 2) goto corrupt; |
| 485 | plen = message[3] + (message[2] == 1 ? 96 : 0); |
| 486 | rc = network_prefix(message[2], message[3], 0, |
| 487 | message + 4, NULL, len - 2, prefix); |
| 488 | if(rc < 0) goto corrupt; |
| 489 | plen = message[3] + (message[2] == 1 ? 96 : 0); |
| 490 | printf("for %s", |
| 491 | message[2] == 0 ? "any" : format_prefix(prefix, plen)); |
| 492 | } |
| 493 | } |
| 494 | break; |
| 495 | |
| 496 | case MESSAGE_MH_REQUEST : { |
| 497 | if(!vflag) |
| 498 | printf(" mh-request"); |
| 499 | else { |
| 500 | int rc; |
| 501 | u_short seqno; |
| 502 | u_char prefix[16], plen; |
| 503 | printf("\n\tMH-Request "); |
| 504 | if(len < 14) goto corrupt; |
| 505 | seqno = EXTRACT_16BITS(message + 4); |
| 506 | rc = network_prefix(message[2], message[3], 0, |
| 507 | message + 16, NULL, len - 14, prefix); |
| 508 | if(rc < 0) goto corrupt; |
| 509 | plen = message[3] + (message[2] == 1 ? 96 : 0); |
| 510 | printf("(%u hops) for %s seqno %u id %s", |
| 511 | message[6], format_prefix(prefix, plen), |
| 512 | seqno, format_id(message + 8)); |
| 513 | } |
| 514 | } |
| 515 | break; |
| 516 | case MESSAGE_TSPC : |
| 517 | if(!vflag) |
| 518 | printf(" tspc"); |
| 519 | else { |
| 520 | printf("\n\tTS/PC "); |
| 521 | if(len < 6) goto corrupt; |
| 522 | printf("timestamp %u packetcounter %u", EXTRACT_32BITS (message + 4), |
| 523 | EXTRACT_16BITS(message + 2)); |
| 524 | } |
| 525 | break; |
| 526 | case MESSAGE_HMAC : { |
| 527 | if(!vflag) |
| 528 | printf(" hmac"); |
| 529 | else { |
| 530 | unsigned j; |
| 531 | printf("\n\tHMAC "); |
| 532 | if(len < 18) goto corrupt; |
| 533 | printf("key-id %u digest-%u ", EXTRACT_16BITS(message + 2), len - 2); |
| 534 | for (j = 0; j < len - 2; j++) |
| 535 | printf ("%02X", message[4 + j]); |
| 536 | } |
| 537 | } |
| 538 | break; |
| 539 | default: |
| 540 | if(!vflag) |
| 541 | printf(" unknown"); |
| 542 | else |
| 543 | printf("\n\tUnknown message type %d", type); |
| 544 | } |
| 545 | i += len + 2; |
| 546 | } |
| 547 | return; |
| 548 | |
| 549 | trunc: |
| 550 | printf(" [|babel]"); |
| 551 | return; |
| 552 | |
| 553 | corrupt: |
| 554 | printf(" (corrupt)"); |
| 555 | return; |
| 556 | } |