1 /* 2 * Copyright (c) 2007-2011 Grgoire 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 #define NETDISSECT_REWORKED 30 #ifdef HAVE_CONFIG_H 31 #include "config.h" 32 #endif 33 34 #include <tcpdump-stdinc.h> 35 36 #include <stdio.h> 37 #include <string.h> 38 39 #include "interface.h" 40 #include "addrtoname.h" 41 #include "extract.h" 42 43 static const char tstr[] = "[|babel]"; 44 45 static void babel_print_v2(netdissect_options *, const u_char *cp, u_int length); 46 47 void 48 babel_print(netdissect_options *ndo, 49 const u_char *cp, u_int length) 50 { 51 ND_PRINT((ndo, "babel")); 52 53 ND_TCHECK2(*cp, 4); 54 55 if(cp[0] != 42) { 56 ND_PRINT((ndo, " malformed header")); 57 return; 58 } else { 59 ND_PRINT((ndo, " %d", cp[1])); 60 } 61 62 switch(cp[1]) { 63 case 2: 64 babel_print_v2(ndo, cp, length); 65 break; 66 default: 67 ND_PRINT((ndo, " unknown version")); 68 break; 69 } 70 71 return; 72 73 trunc: 74 ND_PRINT((ndo, " %s", tstr)); 75 return; 76 } 77 78 /* TLVs */ 79 #define MESSAGE_PAD1 0 80 #define MESSAGE_PADN 1 81 #define MESSAGE_ACK_REQ 2 82 #define MESSAGE_ACK 3 83 #define MESSAGE_HELLO 4 84 #define MESSAGE_IHU 5 85 #define MESSAGE_ROUTER_ID 6 86 #define MESSAGE_NH 7 87 #define MESSAGE_UPDATE 8 88 #define MESSAGE_REQUEST 9 89 #define MESSAGE_MH_REQUEST 10 90 #define MESSAGE_TSPC 11 91 #define MESSAGE_HMAC 12 92 93 /* sub-TLVs */ 94 #define MESSAGE_SUB_PAD1 0 95 #define MESSAGE_SUB_PADN 1 96 #define MESSAGE_SUB_DIVERSITY 2 97 #define MESSAGE_SUB_TIMESTAMP 3 98 99 /* Diversity sub-TLV channel codes */ 100 static const struct tok diversity_str[] = { 101 { 0, "reserved" }, 102 { 255, "all" }, 103 { 0, NULL } 104 }; 105 106 static const char * 107 format_id(const u_char *id) 108 { 109 static char buf[25]; 110 snprintf(buf, 25, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x", 111 id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7]); 112 buf[24] = '\0'; 113 return buf; 114 } 115 116 static const unsigned char v4prefix[16] = 117 {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 }; 118 119 static const char * 120 format_prefix(netdissect_options *ndo, const u_char *prefix, unsigned char plen) 121 { 122 static char buf[50]; 123 if(plen >= 96 && memcmp(prefix, v4prefix, 12) == 0) 124 snprintf(buf, 50, "%s/%u", ipaddr_string(ndo, prefix + 12), plen - 96); 125 else 126 #ifdef INET6 127 snprintf(buf, 50, "%s/%u", ip6addr_string(ndo, prefix), plen); 128 #else 129 snprintf(buf, 50, "IPv6 addresses not supported"); 130 #endif 131 buf[49] = '\0'; 132 return buf; 133 } 134 135 static const char * 136 format_address(netdissect_options *ndo, const u_char *prefix) 137 { 138 if(memcmp(prefix, v4prefix, 12) == 0) 139 return ipaddr_string(ndo, prefix + 12); 140 else 141 #ifdef INET6 142 return ip6addr_string(ndo, prefix); 143 #else 144 return "IPv6 addresses not supported"; 145 #endif 146 } 147 148 static const char * 149 format_interval(const uint16_t i) 150 { 151 static char buf[sizeof("000.00s")]; 152 153 if (i == 0) 154 return "0.0s (bogus)"; 155 snprintf(buf, sizeof(buf), "%u.%02us", i / 100, i % 100); 156 return buf; 157 } 158 159 static const char * 160 format_interval_update(const uint16_t i) 161 { 162 return i == 0xFFFF ? "infinity" : format_interval(i); 163 } 164 165 static const char * 166 format_timestamp(const uint32_t i) 167 { 168 static char buf[sizeof("0000.000000s")]; 169 snprintf(buf, sizeof(buf), "%u.%06us", i / 1000000, i % 1000000); 170 return buf; 171 } 172 173 /* Return number of octets consumed from the input buffer (not the prefix length 174 * in bytes), or -1 for encoding error. */ 175 static int 176 network_prefix(int ae, int plen, unsigned int omitted, 177 const unsigned char *p, const unsigned char *dp, 178 unsigned int len, unsigned char *p_r) 179 { 180 unsigned pb; 181 unsigned char prefix[16]; 182 int consumed = 0; 183 184 if(plen >= 0) 185 pb = (plen + 7) / 8; 186 else if(ae == 1) 187 pb = 4; 188 else 189 pb = 16; 190 191 if(pb > 16) 192 return -1; 193 194 memset(prefix, 0, 16); 195 196 switch(ae) { 197 case 0: break; 198 case 1: 199 if(omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted)) 200 return -1; 201 memcpy(prefix, v4prefix, 12); 202 if(omitted) { 203 if (dp == NULL) return -1; 204 memcpy(prefix, dp, 12 + omitted); 205 } 206 if(pb > omitted) { 207 memcpy(prefix + 12 + omitted, p, pb - omitted); 208 consumed = pb - omitted; 209 } 210 break; 211 case 2: 212 if(omitted > 16 || (pb > omitted && len < pb - omitted)) 213 return -1; 214 if(omitted) { 215 if (dp == NULL) return -1; 216 memcpy(prefix, dp, omitted); 217 } 218 if(pb > omitted) { 219 memcpy(prefix + omitted, p, pb - omitted); 220 consumed = pb - omitted; 221 } 222 break; 223 case 3: 224 if(pb > 8 && len < pb - 8) return -1; 225 prefix[0] = 0xfe; 226 prefix[1] = 0x80; 227 if(pb > 8) { 228 memcpy(prefix + 8, p, pb - 8); 229 consumed = pb - 8; 230 } 231 break; 232 default: 233 return -1; 234 } 235 236 memcpy(p_r, prefix, 16); 237 return consumed; 238 } 239 240 static int 241 network_address(int ae, const unsigned char *a, unsigned int len, 242 unsigned char *a_r) 243 { 244 return network_prefix(ae, -1, 0, a, NULL, len, a_r); 245 } 246 247 /* 248 * Sub-TLVs consume the "extra data" of Babel TLVs (see Section 4.3 of RFC6126), 249 * their encoding is similar to the encoding of TLVs, but the type namespace is 250 * different: 251 * 252 * o Type 0 stands for Pad1 sub-TLV with the same encoding as the Pad1 TLV. 253 * o Type 1 stands for PadN sub-TLV with the same encoding as the PadN TLV. 254 * o Type 2 stands for Diversity sub-TLV, which propagates diversity routing 255 * data. Its body is a variable-length sequence of 8-bit unsigned integers, 256 * each representing per-hop number of interferring radio channel for the 257 * prefix. Channel 0 is invalid and must not be used in the sub-TLV, channel 258 * 255 interferes with any other channel. 259 * o Type 3 stands for Timestamp sub-TLV, used to compute RTT between 260 * neighbours. In the case of a Hello TLV, the body stores a 32-bits 261 * timestamp, while in the case of a IHU TLV, two 32-bits timestamps are 262 * stored. 263 * 264 * Sub-TLV types 0 and 1 are valid for any TLV type, whether sub-TLV type 2 is 265 * only valid for TLV type 8 (Update). Note that within an Update TLV a missing 266 * Diversity sub-TLV is not the same as a Diversity sub-TLV with an empty body. 267 * The former would mean a lack of any claims about the interference, and the 268 * latter would state that interference is definitely absent. 269 * A type 3 sub-TLV is valid both for Hello and IHU TLVs, though the exact 270 * semantic of the sub-TLV is different in each case. 271 */ 272 static void 273 subtlvs_print(netdissect_options *ndo, 274 const u_char *cp, const u_char *ep, const uint8_t tlv_type) 275 { 276 uint8_t subtype, sublen; 277 const char *sep; 278 uint32_t t1, t2; 279 280 while (cp < ep) { 281 subtype = *cp++; 282 if(subtype == MESSAGE_SUB_PAD1) { 283 ND_PRINT((ndo, " sub-pad1")); 284 continue; 285 } 286 if(cp == ep) 287 goto corrupt; 288 sublen = *cp++; 289 if(cp + sublen > ep) 290 goto corrupt; 291 292 switch(subtype) { 293 case MESSAGE_SUB_PADN: 294 ND_PRINT((ndo, " sub-padn")); 295 cp += sublen; 296 break; 297 case MESSAGE_SUB_DIVERSITY: 298 ND_PRINT((ndo, " sub-diversity")); 299 if (sublen == 0) { 300 ND_PRINT((ndo, " empty")); 301 break; 302 } 303 sep = " "; 304 while(sublen--) { 305 ND_PRINT((ndo, "%s%s", sep, tok2str(diversity_str, "%u", *cp++))); 306 sep = "-"; 307 } 308 if(tlv_type != MESSAGE_UPDATE) 309 ND_PRINT((ndo, " (bogus)")); 310 break; 311 case MESSAGE_SUB_TIMESTAMP: 312 ND_PRINT((ndo, " sub-timestamp")); 313 if(tlv_type == MESSAGE_HELLO) { 314 if(sublen < 4) 315 goto corrupt; 316 t1 = EXTRACT_32BITS(cp); 317 ND_PRINT((ndo, " %s", format_timestamp(t1))); 318 } else if(tlv_type == MESSAGE_IHU) { 319 if(sublen < 8) 320 goto corrupt; 321 t1 = EXTRACT_32BITS(cp); 322 ND_PRINT((ndo, " %s", format_timestamp(t1))); 323 t2 = EXTRACT_32BITS(cp + 4); 324 ND_PRINT((ndo, "|%s", format_timestamp(t2))); 325 } else 326 ND_PRINT((ndo, " (bogus)")); 327 cp += sublen; 328 break; 329 default: 330 ND_PRINT((ndo, " sub-unknown-0x%02x", subtype)); 331 cp += sublen; 332 } /* switch */ 333 } /* while */ 334 return; 335 336 corrupt: 337 ND_PRINT((ndo, " (corrupt)")); 338 } 339 340 #define ICHECK(i, l) \ 341 if ((i) + (l) > bodylen || (i) + (l) > length) goto corrupt; 342 343 static void 344 babel_print_v2(netdissect_options *ndo, 345 const u_char *cp, u_int length) 346 { 347 u_int i; 348 u_short bodylen; 349 u_char v4_prefix[16] = 350 {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 }; 351 u_char v6_prefix[16] = {0}; 352 353 ND_TCHECK2(*cp, 4); 354 if (length < 4) 355 goto corrupt; 356 bodylen = EXTRACT_16BITS(cp + 2); 357 ND_PRINT((ndo, " (%u)", bodylen)); 358 359 /* Process the TLVs in the body */ 360 i = 0; 361 while(i < bodylen) { 362 const u_char *message; 363 u_int type, len; 364 365 message = cp + 4 + i; 366 367 ND_TCHECK2(*message, 1); 368 if((type = message[0]) == MESSAGE_PAD1) { 369 ND_PRINT((ndo, ndo->ndo_vflag ? "\n\tPad 1" : " pad1")); 370 i += 1; 371 continue; 372 } 373 374 ND_TCHECK2(*message, 2); 375 ICHECK(i, 2); 376 len = message[1]; 377 378 ND_TCHECK2(*message, 2 + len); 379 ICHECK(i, 2 + len); 380 381 switch(type) { 382 case MESSAGE_PADN: { 383 if (!ndo->ndo_vflag) 384 ND_PRINT((ndo, " padN")); 385 else 386 ND_PRINT((ndo, "\n\tPad %d", len + 2)); 387 } 388 break; 389 390 case MESSAGE_ACK_REQ: { 391 u_short nonce, interval; 392 if (!ndo->ndo_vflag) 393 ND_PRINT((ndo, " ack-req")); 394 else { 395 ND_PRINT((ndo, "\n\tAcknowledgment Request ")); 396 if(len < 6) goto corrupt; 397 nonce = EXTRACT_16BITS(message + 4); 398 interval = EXTRACT_16BITS(message + 6); 399 ND_PRINT((ndo, "%04x %s", nonce, format_interval(interval))); 400 } 401 } 402 break; 403 404 case MESSAGE_ACK: { 405 u_short nonce; 406 if (!ndo->ndo_vflag) 407 ND_PRINT((ndo, " ack")); 408 else { 409 ND_PRINT((ndo, "\n\tAcknowledgment ")); 410 if(len < 2) goto corrupt; 411 nonce = EXTRACT_16BITS(message + 2); 412 ND_PRINT((ndo, "%04x", nonce)); 413 } 414 } 415 break; 416 417 case MESSAGE_HELLO: { 418 u_short seqno, interval; 419 if (!ndo->ndo_vflag) 420 ND_PRINT((ndo, " hello")); 421 else { 422 ND_PRINT((ndo, "\n\tHello ")); 423 if(len < 6) goto corrupt; 424 seqno = EXTRACT_16BITS(message + 4); 425 interval = EXTRACT_16BITS(message + 6); 426 ND_PRINT((ndo, "seqno %u interval %s", seqno, format_interval(interval))); 427 /* Extra data. */ 428 if(len > 6) 429 subtlvs_print(ndo, message + 8, message + 2 + len, type); 430 } 431 } 432 break; 433 434 case MESSAGE_IHU: { 435 unsigned short txcost, interval; 436 if (!ndo->ndo_vflag) 437 ND_PRINT((ndo, " ihu")); 438 else { 439 u_char address[16]; 440 int rc; 441 ND_PRINT((ndo, "\n\tIHU ")); 442 if(len < 6) goto corrupt; 443 txcost = EXTRACT_16BITS(message + 4); 444 interval = EXTRACT_16BITS(message + 6); 445 rc = network_address(message[2], message + 8, len - 6, address); 446 if(rc < 0) { ND_PRINT((ndo, "%s", tstr)); break; } 447 ND_PRINT((ndo, "%s txcost %u interval %s", 448 format_address(ndo, address), txcost, format_interval(interval))); 449 /* Extra data. */ 450 if((u_int)rc < len - 6) 451 subtlvs_print(ndo, message + 8 + rc, message + 2 + len, 452 type); 453 } 454 } 455 break; 456 457 case MESSAGE_ROUTER_ID: { 458 if (!ndo->ndo_vflag) 459 ND_PRINT((ndo, " router-id")); 460 else { 461 ND_PRINT((ndo, "\n\tRouter Id")); 462 if(len < 10) goto corrupt; 463 ND_PRINT((ndo, " %s", format_id(message + 4))); 464 } 465 } 466 break; 467 468 case MESSAGE_NH: { 469 if (!ndo->ndo_vflag) 470 ND_PRINT((ndo, " nh")); 471 else { 472 int rc; 473 u_char nh[16]; 474 ND_PRINT((ndo, "\n\tNext Hop")); 475 if(len < 2) goto corrupt; 476 rc = network_address(message[2], message + 4, len - 2, nh); 477 if(rc < 0) goto corrupt; 478 ND_PRINT((ndo, " %s", format_address(ndo, nh))); 479 } 480 } 481 break; 482 483 case MESSAGE_UPDATE: { 484 if (!ndo->ndo_vflag) { 485 ND_PRINT((ndo, " update")); 486 if(len < 1) 487 ND_PRINT((ndo, "/truncated")); 488 else 489 ND_PRINT((ndo, "%s%s%s", 490 (message[3] & 0x80) ? "/prefix": "", 491 (message[3] & 0x40) ? "/id" : "", 492 (message[3] & 0x3f) ? "/unknown" : "")); 493 } else { 494 u_short interval, seqno, metric; 495 u_char plen; 496 int rc; 497 u_char prefix[16]; 498 ND_PRINT((ndo, "\n\tUpdate")); 499 if(len < 10) goto corrupt; 500 plen = message[4] + (message[2] == 1 ? 96 : 0); 501 rc = network_prefix(message[2], message[4], message[5], 502 message + 12, 503 message[2] == 1 ? v4_prefix : v6_prefix, 504 len - 10, prefix); 505 if(rc < 0) goto corrupt; 506 interval = EXTRACT_16BITS(message + 6); 507 seqno = EXTRACT_16BITS(message + 8); 508 metric = EXTRACT_16BITS(message + 10); 509 ND_PRINT((ndo, "%s%s%s %s metric %u seqno %u interval %s", 510 (message[3] & 0x80) ? "/prefix": "", 511 (message[3] & 0x40) ? "/id" : "", 512 (message[3] & 0x3f) ? "/unknown" : "", 513 format_prefix(ndo, prefix, plen), 514 metric, seqno, format_interval_update(interval))); 515 if(message[3] & 0x80) { 516 if(message[2] == 1) 517 memcpy(v4_prefix, prefix, 16); 518 else 519 memcpy(v6_prefix, prefix, 16); 520 } 521 /* extra data? */ 522 if((u_int)rc < len - 10) 523 subtlvs_print(ndo, message + 12 + rc, message + 2 + len, type); 524 } 525 } 526 break; 527 528 case MESSAGE_REQUEST: { 529 if (!ndo->ndo_vflag) 530 ND_PRINT((ndo, " request")); 531 else { 532 int rc; 533 u_char prefix[16], plen; 534 ND_PRINT((ndo, "\n\tRequest ")); 535 if(len < 2) goto corrupt; 536 plen = message[3] + (message[2] == 1 ? 96 : 0); 537 rc = network_prefix(message[2], message[3], 0, 538 message + 4, NULL, len - 2, prefix); 539 if(rc < 0) goto corrupt; 540 ND_PRINT((ndo, "for %s", 541 message[2] == 0 ? "any" : format_prefix(ndo, prefix, plen))); 542 } 543 } 544 break; 545 546 case MESSAGE_MH_REQUEST : { 547 if (!ndo->ndo_vflag) 548 ND_PRINT((ndo, " mh-request")); 549 else { 550 int rc; 551 u_short seqno; 552 u_char prefix[16], plen; 553 ND_PRINT((ndo, "\n\tMH-Request ")); 554 if(len < 14) goto corrupt; 555 seqno = EXTRACT_16BITS(message + 4); 556 rc = network_prefix(message[2], message[3], 0, 557 message + 16, NULL, len - 14, prefix); 558 if(rc < 0) goto corrupt; 559 plen = message[3] + (message[2] == 1 ? 96 : 0); 560 ND_PRINT((ndo, "(%u hops) for %s seqno %u id %s", 561 message[6], format_prefix(ndo, prefix, plen), 562 seqno, format_id(message + 8))); 563 } 564 } 565 break; 566 case MESSAGE_TSPC : 567 if (!ndo->ndo_vflag) 568 ND_PRINT((ndo, " tspc")); 569 else { 570 ND_PRINT((ndo, "\n\tTS/PC ")); 571 if(len < 6) goto corrupt; 572 ND_PRINT((ndo, "timestamp %u packetcounter %u", EXTRACT_32BITS (message + 4), 573 EXTRACT_16BITS(message + 2))); 574 } 575 break; 576 case MESSAGE_HMAC : { 577 if (!ndo->ndo_vflag) 578 ND_PRINT((ndo, " hmac")); 579 else { 580 unsigned j; 581 ND_PRINT((ndo, "\n\tHMAC ")); 582 if(len < 18) goto corrupt; 583 ND_PRINT((ndo, "key-id %u digest-%u ", EXTRACT_16BITS(message + 2), len - 2)); 584 for (j = 0; j < len - 2; j++) 585 ND_PRINT((ndo, "%02X", message[4 + j])); 586 } 587 } 588 break; 589 default: 590 if (!ndo->ndo_vflag) 591 ND_PRINT((ndo, " unknown")); 592 else 593 ND_PRINT((ndo, "\n\tUnknown message type %d", type)); 594 } 595 i += len + 2; 596 } 597 return; 598 599 trunc: 600 ND_PRINT((ndo, " %s", tstr)); 601 return; 602 603 corrupt: 604 ND_PRINT((ndo, " (corrupt)")); 605 return; 606 } 607
