1 /* 2 * util/data/msgparse.c - parse wireformat DNS messages. 3 * 4 * Copyright (c) 2007, NLnet Labs. All rights reserved. 5 * 6 * This software is open source. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * Redistributions of source code must retain the above copyright notice, 13 * this list of conditions and the following disclaimer. 14 * 15 * Redistributions in binary form must reproduce the above copyright notice, 16 * this list of conditions and the following disclaimer in the documentation 17 * and/or other materials provided with the distribution. 18 * 19 * Neither the name of the NLNET LABS nor the names of its contributors may 20 * be used to endorse or promote products derived from this software without 21 * specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 /** 36 * \file 37 * Routines for message parsing a packet buffer to a descriptive structure. 38 */ 39 #include "config.h" 40 #include "util/config_file.h" 41 #include "util/data/msgparse.h" 42 #include "util/data/msgreply.h" 43 #include "util/data/dname.h" 44 #include "util/data/packed_rrset.h" 45 #include "util/netevent.h" 46 #include "util/storage/lookup3.h" 47 #include "util/regional.h" 48 #include "sldns/rrdef.h" 49 #include "sldns/sbuffer.h" 50 #include "sldns/parseutil.h" 51 #include "sldns/wire2str.h" 52 53 /** smart comparison of (compressed, valid) dnames from packet */ 54 static int 55 smart_compare(sldns_buffer* pkt, uint8_t* dnow, 56 uint8_t* dprfirst, uint8_t* dprlast) 57 { 58 if(LABEL_IS_PTR(*dnow)) { 59 /* ptr points to a previous dname */ 60 uint8_t* p; 61 if((size_t)PTR_OFFSET(dnow[0], dnow[1]) 62 >= sldns_buffer_limit(pkt)) 63 return -1; 64 p = sldns_buffer_at(pkt, PTR_OFFSET(dnow[0], dnow[1])); 65 if( p == dprfirst || p == dprlast ) 66 return 0; 67 /* prev dname is also a ptr, both ptrs are the same. */ 68 if(LABEL_IS_PTR(*dprlast) && 69 dprlast[0] == dnow[0] && dprlast[1] == dnow[1]) 70 return 0; 71 } 72 return dname_pkt_compare(pkt, dnow, dprlast); 73 } 74 75 /** 76 * Allocate new rrset in region, fill with data. 77 */ 78 static struct rrset_parse* 79 new_rrset(struct msg_parse* msg, uint8_t* dname, size_t dnamelen, 80 uint16_t type, uint16_t dclass, hashvalue_type hash, 81 uint32_t rrset_flags, sldns_pkt_section section, 82 struct regional* region) 83 { 84 struct rrset_parse* p = regional_alloc(region, sizeof(*p)); 85 if(!p) return NULL; 86 p->rrset_bucket_next = msg->hashtable[hash & (PARSE_TABLE_SIZE-1)]; 87 msg->hashtable[hash & (PARSE_TABLE_SIZE-1)] = p; 88 p->rrset_all_next = 0; 89 if(msg->rrset_last) 90 msg->rrset_last->rrset_all_next = p; 91 else msg->rrset_first = p; 92 msg->rrset_last = p; 93 p->hash = hash; 94 p->section = section; 95 p->dname = dname; 96 p->dname_len = dnamelen; 97 p->type = type; 98 p->rrset_class = dclass; 99 p->flags = rrset_flags; 100 p->rr_count = 0; 101 p->size = 0; 102 p->rr_first = 0; 103 p->rr_last = 0; 104 p->rrsig_count = 0; 105 p->rrsig_first = 0; 106 p->rrsig_last = 0; 107 return p; 108 } 109 110 /** See if next rrset is nsec at zone apex */ 111 static int 112 nsec_at_apex(sldns_buffer* pkt) 113 { 114 /* we are at ttl position in packet. */ 115 size_t pos = sldns_buffer_position(pkt); 116 uint16_t rdatalen; 117 if(sldns_buffer_remaining(pkt) < 7) /* ttl+len+root */ 118 return 0; /* eek! */ 119 sldns_buffer_skip(pkt, 4); /* ttl */; 120 rdatalen = sldns_buffer_read_u16(pkt); 121 if(sldns_buffer_remaining(pkt) < rdatalen) { 122 sldns_buffer_set_position(pkt, pos); 123 return 0; /* parse error happens later */ 124 } 125 /* must validate the nsec next domain name format */ 126 if(pkt_dname_len(pkt) == 0) { 127 sldns_buffer_set_position(pkt, pos); 128 return 0; /* parse error */ 129 } 130 131 /* see if SOA bit is set. */ 132 if(sldns_buffer_position(pkt) < pos+4+rdatalen) { 133 /* nsec type bitmap contains items */ 134 uint8_t win, blen, bits; 135 /* need: windownum, bitmap len, firstbyte */ 136 if(sldns_buffer_position(pkt)+3 > pos+4+rdatalen) { 137 sldns_buffer_set_position(pkt, pos); 138 return 0; /* malformed nsec */ 139 } 140 win = sldns_buffer_read_u8(pkt); 141 blen = sldns_buffer_read_u8(pkt); 142 bits = sldns_buffer_read_u8(pkt); 143 /* 0window always first window. bitlen >=1 or parse 144 error really. bit 0x2 is SOA. */ 145 if(win == 0 && blen >= 1 && (bits & 0x02)) { 146 sldns_buffer_set_position(pkt, pos); 147 return 1; 148 } 149 } 150 151 sldns_buffer_set_position(pkt, pos); 152 return 0; 153 } 154 155 /** Calculate rrset flags */ 156 static uint32_t 157 pkt_rrset_flags(sldns_buffer* pkt, uint16_t type, sldns_pkt_section sec) 158 { 159 uint32_t f = 0; 160 if(type == LDNS_RR_TYPE_NSEC && nsec_at_apex(pkt)) { 161 f |= PACKED_RRSET_NSEC_AT_APEX; 162 } else if(type == LDNS_RR_TYPE_SOA && sec == LDNS_SECTION_AUTHORITY) { 163 f |= PACKED_RRSET_SOA_NEG; 164 } 165 return f; 166 } 167 168 hashvalue_type 169 pkt_hash_rrset(sldns_buffer* pkt, uint8_t* dname, uint16_t type, 170 uint16_t dclass, uint32_t rrset_flags) 171 { 172 /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 173 /* this routine handles compressed names */ 174 hashvalue_type h = 0xab; 175 h = dname_pkt_hash(pkt, dname, h); 176 h = hashlittle(&type, sizeof(type), h); /* host order */ 177 h = hashlittle(&dclass, sizeof(dclass), h); /* netw order */ 178 h = hashlittle(&rrset_flags, sizeof(uint32_t), h); 179 return h; 180 } 181 182 /** create partial dname hash for rrset hash */ 183 static hashvalue_type 184 pkt_hash_rrset_first(sldns_buffer* pkt, uint8_t* dname) 185 { 186 /* works together with pkt_hash_rrset_rest */ 187 /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 188 /* this routine handles compressed names */ 189 hashvalue_type h = 0xab; 190 h = dname_pkt_hash(pkt, dname, h); 191 return h; 192 } 193 194 /** create a rrset hash from a partial dname hash */ 195 static hashvalue_type 196 pkt_hash_rrset_rest(hashvalue_type dname_h, uint16_t type, uint16_t dclass, 197 uint32_t rrset_flags) 198 { 199 /* works together with pkt_hash_rrset_first */ 200 /* note this MUST be identical to rrset_key_hash in packed_rrset.c */ 201 hashvalue_type h; 202 h = hashlittle(&type, sizeof(type), dname_h); /* host order */ 203 h = hashlittle(&dclass, sizeof(dclass), h); /* netw order */ 204 h = hashlittle(&rrset_flags, sizeof(uint32_t), h); 205 return h; 206 } 207 208 /** compare rrset_parse with data */ 209 static int 210 rrset_parse_equals(struct rrset_parse* p, sldns_buffer* pkt, hashvalue_type h, 211 uint32_t rrset_flags, uint8_t* dname, size_t dnamelen, 212 uint16_t type, uint16_t dclass) 213 { 214 if(p->hash == h && p->dname_len == dnamelen && p->type == type && 215 p->rrset_class == dclass && p->flags == rrset_flags && 216 dname_pkt_compare(pkt, dname, p->dname) == 0) 217 return 1; 218 return 0; 219 } 220 221 222 struct rrset_parse* 223 msgparse_hashtable_lookup(struct msg_parse* msg, sldns_buffer* pkt, 224 hashvalue_type h, uint32_t rrset_flags, uint8_t* dname, 225 size_t dnamelen, uint16_t type, uint16_t dclass) 226 { 227 struct rrset_parse* p = msg->hashtable[h & (PARSE_TABLE_SIZE-1)]; 228 while(p) { 229 if(rrset_parse_equals(p, pkt, h, rrset_flags, dname, dnamelen, 230 type, dclass)) 231 return p; 232 p = p->rrset_bucket_next; 233 } 234 return NULL; 235 } 236 237 /** return type networkformat that rrsig in packet covers */ 238 static int 239 pkt_rrsig_covered(sldns_buffer* pkt, uint8_t* here, uint16_t* type) 240 { 241 size_t pos = sldns_buffer_position(pkt); 242 sldns_buffer_set_position(pkt, (size_t)(here-sldns_buffer_begin(pkt))); 243 /* ttl + len + size of small rrsig(rootlabel, no signature) */ 244 if(sldns_buffer_remaining(pkt) < 4+2+19) 245 return 0; 246 sldns_buffer_skip(pkt, 4); /* ttl */ 247 if(sldns_buffer_read_u16(pkt) < 19) /* too short */ { 248 sldns_buffer_set_position(pkt, pos); 249 return 0; 250 } 251 *type = sldns_buffer_read_u16(pkt); 252 sldns_buffer_set_position(pkt, pos); 253 return 1; 254 } 255 256 /** true if covered type equals prevtype */ 257 static int 258 pkt_rrsig_covered_equals(sldns_buffer* pkt, uint8_t* here, uint16_t type) 259 { 260 uint16_t t; 261 if(pkt_rrsig_covered(pkt, here, &t) && t == type) 262 return 1; 263 return 0; 264 } 265 266 void 267 msgparse_bucket_remove(struct msg_parse* msg, struct rrset_parse* rrset) 268 { 269 struct rrset_parse** p; 270 p = &msg->hashtable[ rrset->hash & (PARSE_TABLE_SIZE-1) ]; 271 while(*p) { 272 if(*p == rrset) { 273 *p = rrset->rrset_bucket_next; 274 return; 275 } 276 p = &( (*p)->rrset_bucket_next ); 277 } 278 } 279 280 /** change section of rrset from previous to current section */ 281 static void 282 change_section(struct msg_parse* msg, struct rrset_parse* rrset, 283 sldns_pkt_section section) 284 { 285 struct rrset_parse *p, *prev; 286 /* remove from list */ 287 if(section == rrset->section) 288 return; 289 p = msg->rrset_first; 290 prev = 0; 291 while(p) { 292 if(p == rrset) { 293 if(prev) prev->rrset_all_next = p->rrset_all_next; 294 else msg->rrset_first = p->rrset_all_next; 295 if(msg->rrset_last == rrset) 296 msg->rrset_last = prev; 297 break; 298 } 299 prev = p; 300 p = p->rrset_all_next; 301 } 302 /* remove from count */ 303 switch(rrset->section) { 304 case LDNS_SECTION_ANSWER: msg->an_rrsets--; break; 305 case LDNS_SECTION_AUTHORITY: msg->ns_rrsets--; break; 306 case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets--; break; 307 default: log_assert(0); 308 } 309 /* insert at end of list */ 310 rrset->rrset_all_next = 0; 311 if(msg->rrset_last) 312 msg->rrset_last->rrset_all_next = rrset; 313 else msg->rrset_first = rrset; 314 msg->rrset_last = rrset; 315 /* up count of new section */ 316 switch(section) { 317 case LDNS_SECTION_AUTHORITY: msg->ns_rrsets++; break; 318 case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets++; break; 319 default: log_assert(0); 320 } 321 rrset->section = section; 322 } 323 324 /** see if rrset of type RRSIG contains sig over given type */ 325 static int 326 rrset_has_sigover(sldns_buffer* pkt, struct rrset_parse* rrset, uint16_t type, 327 int* hasother) 328 { 329 int res = 0; 330 struct rr_parse* rr = rrset->rr_first; 331 log_assert( rrset->type == LDNS_RR_TYPE_RRSIG ); 332 while(rr) { 333 if(pkt_rrsig_covered_equals(pkt, rr->ttl_data, type)) 334 res = 1; 335 else *hasother = 1; 336 rr = rr->next; 337 } 338 return res; 339 } 340 341 /** move rrsigs from sigset to dataset */ 342 static int 343 moveover_rrsigs(sldns_buffer* pkt, struct regional* region, 344 struct rrset_parse* sigset, struct rrset_parse* dataset, int duplicate) 345 { 346 struct rr_parse* sig = sigset->rr_first; 347 struct rr_parse* prev = NULL; 348 struct rr_parse* insert; 349 struct rr_parse* nextsig; 350 while(sig) { 351 nextsig = sig->next; 352 if(pkt_rrsig_covered_equals(pkt, sig->ttl_data, 353 dataset->type)) { 354 if(duplicate) { 355 /* new */ 356 insert = (struct rr_parse*)regional_alloc( 357 region, sizeof(struct rr_parse)); 358 if(!insert) return 0; 359 insert->outside_packet = 0; 360 insert->ttl_data = sig->ttl_data; 361 insert->size = sig->size; 362 /* prev not used */ 363 } else { 364 /* remove from sigset */ 365 if(prev) prev->next = sig->next; 366 else sigset->rr_first = sig->next; 367 if(sigset->rr_last == sig) 368 sigset->rr_last = prev; 369 sigset->rr_count--; 370 sigset->size -= sig->size; 371 insert = sig; 372 /* prev not changed */ 373 } 374 /* add to dataset */ 375 dataset->rrsig_count++; 376 insert->next = 0; 377 if(dataset->rrsig_last) 378 dataset->rrsig_last->next = insert; 379 else dataset->rrsig_first = insert; 380 dataset->rrsig_last = insert; 381 dataset->size += insert->size; 382 } else { 383 prev = sig; 384 } 385 sig = nextsig; 386 } 387 return 1; 388 } 389 390 /** change an rrsig rrset for use as data rrset */ 391 static struct rrset_parse* 392 change_rrsig_rrset(struct rrset_parse* sigset, struct msg_parse* msg, 393 sldns_buffer* pkt, uint16_t datatype, uint32_t rrset_flags, 394 int hasother, sldns_pkt_section section, struct regional* region) 395 { 396 struct rrset_parse* dataset = sigset; 397 hashvalue_type hash = pkt_hash_rrset(pkt, sigset->dname, datatype, 398 sigset->rrset_class, rrset_flags); 399 log_assert( sigset->type == LDNS_RR_TYPE_RRSIG ); 400 log_assert( datatype != LDNS_RR_TYPE_RRSIG ); 401 if(hasother) { 402 /* need to make new rrset to hold data type */ 403 dataset = new_rrset(msg, sigset->dname, sigset->dname_len, 404 datatype, sigset->rrset_class, hash, rrset_flags, 405 section, region); 406 if(!dataset) 407 return NULL; 408 switch(section) { 409 case LDNS_SECTION_ANSWER: msg->an_rrsets++; break; 410 case LDNS_SECTION_AUTHORITY: msg->ns_rrsets++; break; 411 case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets++; break; 412 default: log_assert(0); 413 } 414 if(!moveover_rrsigs(pkt, region, sigset, dataset, 415 msg->qtype == LDNS_RR_TYPE_RRSIG || 416 (msg->qtype == LDNS_RR_TYPE_ANY && 417 section != LDNS_SECTION_ANSWER) )) 418 return NULL; 419 return dataset; 420 } 421 /* changeover the type of the rrset to data set */ 422 msgparse_bucket_remove(msg, dataset); 423 /* insert into new hash bucket */ 424 dataset->rrset_bucket_next = msg->hashtable[hash&(PARSE_TABLE_SIZE-1)]; 425 msg->hashtable[hash&(PARSE_TABLE_SIZE-1)] = dataset; 426 dataset->hash = hash; 427 /* use section of data item for result */ 428 change_section(msg, dataset, section); 429 dataset->type = datatype; 430 dataset->flags = rrset_flags; 431 dataset->rrsig_count += dataset->rr_count; 432 dataset->rr_count = 0; 433 /* move sigs to end of siglist */ 434 if(dataset->rrsig_last) 435 dataset->rrsig_last->next = dataset->rr_first; 436 else dataset->rrsig_first = dataset->rr_first; 437 dataset->rrsig_last = dataset->rr_last; 438 dataset->rr_first = 0; 439 dataset->rr_last = 0; 440 return dataset; 441 } 442 443 /** Find rrset. If equal to previous it is fast. hash if not so. 444 * @param msg: the message with hash table. 445 * @param pkt: the packet in wireformat (needed for compression ptrs). 446 * @param dname: pointer to start of dname (compressed) in packet. 447 * @param dnamelen: uncompressed wirefmt length of dname. 448 * @param type: type of current rr. 449 * @param dclass: class of current rr. 450 * @param hash: hash value is returned if the rrset could not be found. 451 * @param rrset_flags: is returned if the rrset could not be found. 452 * @param prev_dname_first: dname of last seen RR. First seen dname. 453 * @param prev_dname_last: dname of last seen RR. Last seen dname. 454 * @param prev_dnamelen: dname len of last seen RR. 455 * @param prev_type: type of last seen RR. 456 * @param prev_dclass: class of last seen RR. 457 * @param rrset_prev: last seen RRset. 458 * @param section: the current section in the packet. 459 * @param region: used to allocate temporary parsing data. 460 * @return 0 on out of memory. 461 */ 462 static int 463 find_rrset(struct msg_parse* msg, sldns_buffer* pkt, uint8_t* dname, 464 size_t dnamelen, uint16_t type, uint16_t dclass, hashvalue_type* hash, 465 uint32_t* rrset_flags, 466 uint8_t** prev_dname_first, uint8_t** prev_dname_last, 467 size_t* prev_dnamelen, uint16_t* prev_type, 468 uint16_t* prev_dclass, struct rrset_parse** rrset_prev, 469 sldns_pkt_section section, struct regional* region) 470 { 471 hashvalue_type dname_h = pkt_hash_rrset_first(pkt, dname); 472 uint16_t covtype; 473 if(*rrset_prev) { 474 /* check if equal to previous item */ 475 if(type == *prev_type && dclass == *prev_dclass && 476 dnamelen == *prev_dnamelen && 477 smart_compare(pkt, dname, *prev_dname_first, 478 *prev_dname_last) == 0 && 479 type != LDNS_RR_TYPE_RRSIG) { 480 /* same as previous */ 481 *prev_dname_last = dname; 482 return 1; 483 } 484 /* check if rrsig over previous item */ 485 if(type == LDNS_RR_TYPE_RRSIG && dclass == *prev_dclass && 486 pkt_rrsig_covered_equals(pkt, sldns_buffer_current(pkt), 487 *prev_type) && 488 smart_compare(pkt, dname, *prev_dname_first, 489 *prev_dname_last) == 0) { 490 /* covers previous */ 491 *prev_dname_last = dname; 492 return 1; 493 } 494 } 495 /* find by hashing and lookup in hashtable */ 496 *rrset_flags = pkt_rrset_flags(pkt, type, section); 497 498 /* if rrsig - try to lookup matching data set first */ 499 if(type == LDNS_RR_TYPE_RRSIG && pkt_rrsig_covered(pkt, 500 sldns_buffer_current(pkt), &covtype)) { 501 *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 502 *rrset_flags); 503 *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, 504 *rrset_flags, dname, dnamelen, covtype, dclass); 505 if(!*rrset_prev && covtype == LDNS_RR_TYPE_NSEC) { 506 /* if NSEC try with NSEC apex bit twiddled */ 507 *rrset_flags ^= PACKED_RRSET_NSEC_AT_APEX; 508 *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 509 *rrset_flags); 510 *rrset_prev = msgparse_hashtable_lookup(msg, pkt, 511 *hash, *rrset_flags, dname, dnamelen, covtype, 512 dclass); 513 if(!*rrset_prev) /* untwiddle if not found */ 514 *rrset_flags ^= PACKED_RRSET_NSEC_AT_APEX; 515 } 516 if(!*rrset_prev && covtype == LDNS_RR_TYPE_SOA) { 517 /* if SOA try with SOA neg flag twiddled */ 518 *rrset_flags ^= PACKED_RRSET_SOA_NEG; 519 *hash = pkt_hash_rrset_rest(dname_h, covtype, dclass, 520 *rrset_flags); 521 *rrset_prev = msgparse_hashtable_lookup(msg, pkt, 522 *hash, *rrset_flags, dname, dnamelen, covtype, 523 dclass); 524 if(!*rrset_prev) /* untwiddle if not found */ 525 *rrset_flags ^= PACKED_RRSET_SOA_NEG; 526 } 527 if(*rrset_prev) { 528 *prev_dname_first = (*rrset_prev)->dname; 529 *prev_dname_last = dname; 530 *prev_dnamelen = dnamelen; 531 *prev_type = covtype; 532 *prev_dclass = dclass; 533 return 1; 534 } 535 } 536 if(type != LDNS_RR_TYPE_RRSIG) { 537 int hasother = 0; 538 /* find matching rrsig */ 539 *hash = pkt_hash_rrset_rest(dname_h, LDNS_RR_TYPE_RRSIG, 540 dclass, 0); 541 *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, 542 0, dname, dnamelen, LDNS_RR_TYPE_RRSIG, 543 dclass); 544 if(*rrset_prev && rrset_has_sigover(pkt, *rrset_prev, type, 545 &hasother)) { 546 /* yes! */ 547 *prev_dname_first = (*rrset_prev)->dname; 548 *prev_dname_last = dname; 549 *prev_dnamelen = dnamelen; 550 *prev_type = type; 551 *prev_dclass = dclass; 552 *rrset_prev = change_rrsig_rrset(*rrset_prev, msg, 553 pkt, type, *rrset_flags, hasother, section, 554 region); 555 if(!*rrset_prev) return 0; 556 return 1; 557 } 558 } 559 560 *hash = pkt_hash_rrset_rest(dname_h, type, dclass, *rrset_flags); 561 *rrset_prev = msgparse_hashtable_lookup(msg, pkt, *hash, *rrset_flags, 562 dname, dnamelen, type, dclass); 563 if(*rrset_prev) 564 *prev_dname_first = (*rrset_prev)->dname; 565 else *prev_dname_first = dname; 566 *prev_dname_last = dname; 567 *prev_dnamelen = dnamelen; 568 *prev_type = type; 569 *prev_dclass = dclass; 570 return 1; 571 } 572 573 /** 574 * Parse query section. 575 * @param pkt: packet, position at call must be at start of query section. 576 * at end position is after query section. 577 * @param msg: store results here. 578 * @return: 0 if OK, or rcode on error. 579 */ 580 static int 581 parse_query_section(sldns_buffer* pkt, struct msg_parse* msg) 582 { 583 if(msg->qdcount == 0) 584 return 0; 585 if(msg->qdcount > 1) 586 return LDNS_RCODE_FORMERR; 587 log_assert(msg->qdcount == 1); 588 if(sldns_buffer_remaining(pkt) <= 0) 589 return LDNS_RCODE_FORMERR; 590 msg->qname = sldns_buffer_current(pkt); 591 if((msg->qname_len = pkt_dname_len(pkt)) == 0) 592 return LDNS_RCODE_FORMERR; 593 if(sldns_buffer_remaining(pkt) < sizeof(uint16_t)*2) 594 return LDNS_RCODE_FORMERR; 595 msg->qtype = sldns_buffer_read_u16(pkt); 596 msg->qclass = sldns_buffer_read_u16(pkt); 597 return 0; 598 } 599 600 size_t 601 get_rdf_size(sldns_rdf_type rdf) 602 { 603 switch(rdf) { 604 case LDNS_RDF_TYPE_CLASS: 605 case LDNS_RDF_TYPE_ALG: 606 case LDNS_RDF_TYPE_INT8: 607 return 1; 608 break; 609 case LDNS_RDF_TYPE_INT16: 610 case LDNS_RDF_TYPE_TYPE: 611 case LDNS_RDF_TYPE_CERT_ALG: 612 return 2; 613 break; 614 case LDNS_RDF_TYPE_INT32: 615 case LDNS_RDF_TYPE_TIME: 616 case LDNS_RDF_TYPE_A: 617 case LDNS_RDF_TYPE_PERIOD: 618 return 4; 619 break; 620 case LDNS_RDF_TYPE_TSIGTIME: 621 return 6; 622 break; 623 case LDNS_RDF_TYPE_AAAA: 624 return 16; 625 break; 626 default: 627 log_assert(0); /* add type above */ 628 /* only types that appear before a domain * 629 * name are needed. rest is simply copied. */ 630 } 631 return 0; 632 } 633 634 /** calculate the size of one rr */ 635 static int 636 calc_size(sldns_buffer* pkt, uint16_t type, struct rr_parse* rr) 637 { 638 const sldns_rr_descriptor* desc; 639 uint16_t pkt_len; /* length of rr inside the packet */ 640 rr->size = sizeof(uint16_t); /* the rdatalen */ 641 sldns_buffer_skip(pkt, 4); /* skip ttl */ 642 pkt_len = sldns_buffer_read_u16(pkt); 643 if(sldns_buffer_remaining(pkt) < pkt_len) 644 return 0; 645 desc = sldns_rr_descript(type); 646 if(pkt_len > 0 && desc && desc->_dname_count > 0) { 647 int count = (int)desc->_dname_count; 648 int rdf = 0; 649 size_t len; 650 size_t oldpos; 651 /* skip first part. */ 652 while(pkt_len > 0 && count) { 653 switch(desc->_wireformat[rdf]) { 654 case LDNS_RDF_TYPE_DNAME: 655 /* decompress every domain name */ 656 oldpos = sldns_buffer_position(pkt); 657 if((len = pkt_dname_len(pkt)) == 0) 658 return 0; /* malformed dname */ 659 if(sldns_buffer_position(pkt)-oldpos > pkt_len) 660 return 0; /* dname exceeds rdata */ 661 pkt_len -= sldns_buffer_position(pkt)-oldpos; 662 rr->size += len; 663 count--; 664 len = 0; 665 break; 666 case LDNS_RDF_TYPE_STR: 667 if(pkt_len < 1) { 668 /* NOTREACHED, due to 'while(>0)' */ 669 return 0; /* len byte exceeds rdata */ 670 } 671 len = sldns_buffer_current(pkt)[0] + 1; 672 break; 673 default: 674 len = get_rdf_size(desc->_wireformat[rdf]); 675 } 676 if(len) { 677 if(pkt_len < len) 678 return 0; /* exceeds rdata */ 679 pkt_len -= len; 680 sldns_buffer_skip(pkt, (ssize_t)len); 681 rr->size += len; 682 } 683 rdf++; 684 } 685 } 686 /* remaining rdata */ 687 rr->size += pkt_len; 688 sldns_buffer_skip(pkt, (ssize_t)pkt_len); 689 return 1; 690 } 691 692 /** skip rr ttl and rdata */ 693 static int 694 skip_ttl_rdata(sldns_buffer* pkt) 695 { 696 uint16_t rdatalen; 697 if(sldns_buffer_remaining(pkt) < 6) /* ttl + rdatalen */ 698 return 0; 699 sldns_buffer_skip(pkt, 4); /* ttl */ 700 rdatalen = sldns_buffer_read_u16(pkt); 701 if(sldns_buffer_remaining(pkt) < rdatalen) 702 return 0; 703 sldns_buffer_skip(pkt, (ssize_t)rdatalen); 704 return 1; 705 } 706 707 /** see if RRSIG is a duplicate of another */ 708 static int 709 sig_is_double(sldns_buffer* pkt, struct rrset_parse* rrset, uint8_t* ttldata) 710 { 711 uint16_t rlen, siglen; 712 size_t pos = sldns_buffer_position(pkt); 713 struct rr_parse* sig; 714 if(sldns_buffer_remaining(pkt) < 6) 715 return 0; 716 sldns_buffer_skip(pkt, 4); /* ttl */ 717 rlen = sldns_buffer_read_u16(pkt); 718 if(sldns_buffer_remaining(pkt) < rlen) { 719 sldns_buffer_set_position(pkt, pos); 720 return 0; 721 } 722 sldns_buffer_set_position(pkt, pos); 723 724 sig = rrset->rrsig_first; 725 while(sig) { 726 /* check if rdatalen is same */ 727 memmove(&siglen, sig->ttl_data+4, sizeof(siglen)); 728 siglen = ntohs(siglen); 729 /* checks if data in packet is exactly the same, this means 730 * also dname in rdata is the same, but rrsig is not allowed 731 * to have compressed dnames anyway. If it is compressed anyway 732 * it will lead to duplicate rrs for qtype=RRSIG. (or ANY). 733 * 734 * Cannot use sig->size because size of the other one is not 735 * calculated yet. 736 */ 737 if(siglen == rlen) { 738 if(siglen>0 && memcmp(sig->ttl_data+6, ttldata+6, 739 siglen) == 0) { 740 /* same! */ 741 return 1; 742 } 743 } 744 sig = sig->next; 745 } 746 return 0; 747 } 748 749 /** Add rr (from packet here) to rrset, skips rr */ 750 static int 751 add_rr_to_rrset(struct rrset_parse* rrset, sldns_buffer* pkt, 752 struct msg_parse* msg, struct regional* region, 753 sldns_pkt_section section, uint16_t type) 754 { 755 struct rr_parse* rr; 756 /* check section of rrset. */ 757 if(rrset->section != section && type != LDNS_RR_TYPE_RRSIG && 758 rrset->type != LDNS_RR_TYPE_RRSIG) { 759 /* silently drop it - we drop the last part, since 760 * trust in rr data depends on the section it is in. 761 * the less trustworthy part is discarded. 762 * also the last part is more likely to be incomplete. 763 * RFC 2181: must put RRset only once in response. */ 764 /* 765 verbose(VERB_QUERY, "Packet contains rrset data in " 766 "multiple sections, dropped last part."); 767 log_buf(VERB_QUERY, "packet was", pkt); 768 */ 769 /* forwards */ 770 if(!skip_ttl_rdata(pkt)) 771 return LDNS_RCODE_FORMERR; 772 return 0; 773 } 774 775 if( (msg->qtype == LDNS_RR_TYPE_RRSIG || 776 msg->qtype == LDNS_RR_TYPE_ANY) 777 && sig_is_double(pkt, rrset, sldns_buffer_current(pkt))) { 778 if(!skip_ttl_rdata(pkt)) 779 return LDNS_RCODE_FORMERR; 780 return 0; 781 } 782 783 /* create rr */ 784 if(!(rr = (struct rr_parse*)regional_alloc(region, sizeof(*rr)))) 785 return LDNS_RCODE_SERVFAIL; 786 rr->outside_packet = 0; 787 rr->ttl_data = sldns_buffer_current(pkt); 788 rr->next = 0; 789 if(type == LDNS_RR_TYPE_RRSIG && rrset->type != LDNS_RR_TYPE_RRSIG) { 790 if(rrset->rrsig_last) 791 rrset->rrsig_last->next = rr; 792 else rrset->rrsig_first = rr; 793 rrset->rrsig_last = rr; 794 rrset->rrsig_count++; 795 } else { 796 if(rrset->rr_last) 797 rrset->rr_last->next = rr; 798 else rrset->rr_first = rr; 799 rrset->rr_last = rr; 800 rrset->rr_count++; 801 } 802 803 /* calc decompressed size */ 804 if(!calc_size(pkt, type, rr)) 805 return LDNS_RCODE_FORMERR; 806 rrset->size += rr->size; 807 808 return 0; 809 } 810 811 /** 812 * Parse packet RR section, for answer, authority and additional sections. 813 * @param pkt: packet, position at call must be at start of section. 814 * at end position is after section. 815 * @param msg: store results here. 816 * @param region: how to alloc results. 817 * @param section: section enum. 818 * @param num_rrs: how many rrs are in the section. 819 * @param num_rrsets: returns number of rrsets in the section. 820 * @return: 0 if OK, or rcode on error. 821 */ 822 static int 823 parse_section(sldns_buffer* pkt, struct msg_parse* msg, 824 struct regional* region, sldns_pkt_section section, 825 uint16_t num_rrs, size_t* num_rrsets) 826 { 827 uint16_t i; 828 uint8_t* dname, *prev_dname_f = NULL, *prev_dname_l = NULL; 829 size_t dnamelen, prev_dnamelen = 0; 830 uint16_t type, prev_type = 0; 831 uint16_t dclass, prev_dclass = 0; 832 uint32_t rrset_flags = 0; 833 hashvalue_type hash = 0; 834 struct rrset_parse* rrset = NULL; 835 int r; 836 837 if(num_rrs == 0) 838 return 0; 839 if(sldns_buffer_remaining(pkt) <= 0) 840 return LDNS_RCODE_FORMERR; 841 for(i=0; i<num_rrs; i++) { 842 /* parse this RR. */ 843 dname = sldns_buffer_current(pkt); 844 if((dnamelen = pkt_dname_len(pkt)) == 0) 845 return LDNS_RCODE_FORMERR; 846 if(sldns_buffer_remaining(pkt) < 10) /* type, class, ttl, len */ 847 return LDNS_RCODE_FORMERR; 848 type = sldns_buffer_read_u16(pkt); 849 sldns_buffer_read(pkt, &dclass, sizeof(dclass)); 850 851 if(0) { /* debug show what is being parsed. */ 852 if(type == LDNS_RR_TYPE_RRSIG) { 853 uint16_t t; 854 if(pkt_rrsig_covered(pkt, 855 sldns_buffer_current(pkt), &t)) 856 fprintf(stderr, "parse of %s(%d) [%s(%d)]", 857 sldns_rr_descript(type)? 858 sldns_rr_descript(type)->_name: "??", 859 (int)type, 860 sldns_rr_descript(t)? 861 sldns_rr_descript(t)->_name: "??", 862 (int)t); 863 } else 864 fprintf(stderr, "parse of %s(%d)", 865 sldns_rr_descript(type)? 866 sldns_rr_descript(type)->_name: "??", 867 (int)type); 868 fprintf(stderr, " %s(%d) ", 869 sldns_lookup_by_id(sldns_rr_classes, 870 (int)ntohs(dclass))?sldns_lookup_by_id( 871 sldns_rr_classes, (int)ntohs(dclass))->name: 872 "??", (int)ntohs(dclass)); 873 dname_print(stderr, pkt, dname); 874 fprintf(stderr, "\n"); 875 } 876 877 /* see if it is part of an existing RR set */ 878 if(!find_rrset(msg, pkt, dname, dnamelen, type, dclass, &hash, 879 &rrset_flags, &prev_dname_f, &prev_dname_l, 880 &prev_dnamelen, &prev_type, &prev_dclass, &rrset, 881 section, region)) 882 return LDNS_RCODE_SERVFAIL; 883 if(!rrset) { 884 /* it is a new RR set. hash&flags already calculated.*/ 885 (*num_rrsets)++; 886 rrset = new_rrset(msg, dname, dnamelen, type, dclass, 887 hash, rrset_flags, section, region); 888 if(!rrset) 889 return LDNS_RCODE_SERVFAIL; 890 } 891 else if(0) { 892 fprintf(stderr, "is part of existing: "); 893 dname_print(stderr, pkt, rrset->dname); 894 fprintf(stderr, " type %s(%d)\n", 895 sldns_rr_descript(rrset->type)? 896 sldns_rr_descript(rrset->type)->_name: "??", 897 (int)rrset->type); 898 } 899 /* add to rrset. */ 900 if((r=add_rr_to_rrset(rrset, pkt, msg, region, section, 901 type)) != 0) 902 return r; 903 } 904 return 0; 905 } 906 907 int 908 parse_packet(sldns_buffer* pkt, struct msg_parse* msg, struct regional* region) 909 { 910 int ret; 911 if(sldns_buffer_remaining(pkt) < LDNS_HEADER_SIZE) 912 return LDNS_RCODE_FORMERR; 913 /* read the header */ 914 sldns_buffer_read(pkt, &msg->id, sizeof(uint16_t)); 915 msg->flags = sldns_buffer_read_u16(pkt); 916 msg->qdcount = sldns_buffer_read_u16(pkt); 917 msg->ancount = sldns_buffer_read_u16(pkt); 918 msg->nscount = sldns_buffer_read_u16(pkt); 919 msg->arcount = sldns_buffer_read_u16(pkt); 920 if(msg->qdcount > 1) 921 return LDNS_RCODE_FORMERR; 922 if((ret = parse_query_section(pkt, msg)) != 0) 923 return ret; 924 if((ret = parse_section(pkt, msg, region, LDNS_SECTION_ANSWER, 925 msg->ancount, &msg->an_rrsets)) != 0) 926 return ret; 927 if((ret = parse_section(pkt, msg, region, LDNS_SECTION_AUTHORITY, 928 msg->nscount, &msg->ns_rrsets)) != 0) 929 return ret; 930 if(sldns_buffer_remaining(pkt) == 0 && msg->arcount == 1) { 931 /* BIND accepts leniently that an EDNS record is missing. 932 * so, we do too. */ 933 } else if((ret = parse_section(pkt, msg, region, 934 LDNS_SECTION_ADDITIONAL, msg->arcount, &msg->ar_rrsets)) != 0) 935 return ret; 936 /* if(sldns_buffer_remaining(pkt) > 0) { */ 937 /* there is spurious data at end of packet. ignore */ 938 /* } */ 939 msg->rrset_count = msg->an_rrsets + msg->ns_rrsets + msg->ar_rrsets; 940 return 0; 941 } 942 943 static int 944 edns_opt_list_append_keepalive(struct edns_option** list, int msec, 945 struct regional* region) 946 { 947 uint8_t data[2]; /* For keepalive value */ 948 data[0] = (uint8_t)((msec >> 8) & 0xff); 949 data[1] = (uint8_t)(msec & 0xff); 950 return edns_opt_list_append(list, LDNS_EDNS_KEEPALIVE, sizeof(data), 951 data, region); 952 } 953 954 /** parse EDNS options from EDNS wireformat rdata */ 955 static int 956 parse_edns_options_from_query(uint8_t* rdata_ptr, size_t rdata_len, 957 struct edns_data* edns, struct config_file* cfg, struct comm_point* c, 958 struct regional* region) 959 { 960 /* To respond with a Keepalive option, the client connection must have 961 * received one message with a TCP Keepalive EDNS option, and that 962 * option must have 0 length data. Subsequent messages sent on that 963 * connection will have a TCP Keepalive option. 964 * 965 * In the if-statement below, the option is added unsolicited. This 966 * means that the client has sent an KEEPALIVE option earlier. We know 967 * here this is true, because c->tcp_keepalive is set. 968 */ 969 if (cfg && cfg->do_tcp_keepalive && c && c->type != comm_udp && c->tcp_keepalive) { 970 if(!edns_opt_list_append_keepalive(&edns->opt_list_out, 971 c->tcp_timeout_msec / 100, region)) { 972 log_err("out of memory"); 973 return LDNS_RCODE_SERVFAIL; 974 } 975 } 976 977 /* while still more options, and have code+len to read */ 978 /* ignores partial content (i.e. rdata len 3) */ 979 while(rdata_len >= 4) { 980 uint16_t opt_code = sldns_read_uint16(rdata_ptr); 981 uint16_t opt_len = sldns_read_uint16(rdata_ptr+2); 982 rdata_ptr += 4; 983 rdata_len -= 4; 984 if(opt_len > rdata_len) 985 break; /* option code partial */ 986 987 /* handle parse time edns options here */ 988 switch(opt_code) { 989 case LDNS_EDNS_NSID: 990 if (!cfg || !cfg->nsid) 991 break; 992 if(!edns_opt_list_append(&edns->opt_list_out, 993 LDNS_EDNS_NSID, cfg->nsid_len, 994 cfg->nsid, region)) { 995 log_err("out of memory"); 996 return LDNS_RCODE_SERVFAIL; 997 } 998 break; 999 1000 case LDNS_EDNS_KEEPALIVE: 1001 /* To respond with a Keepalive option, the client 1002 * connection must have received one message with a TCP 1003 * Keepalive EDNS option, and that option must have 0 1004 * length data. Subsequent messages sent on that 1005 * connection will have a TCP Keepalive option. 1006 * 1007 * This should be the first time the client sends this 1008 * option, so c->tcp_keepalive is not set. 1009 * Besides adding the reply KEEPALIVE option, 1010 * c->tcp_keepalive will be set so that the 1011 * option will be added unsolicited in subsequent 1012 * responses (see the comment above the if-statement 1013 * at the start of this function). 1014 */ 1015 if (!cfg || !cfg->do_tcp_keepalive || !c || 1016 c->type == comm_udp || c->tcp_keepalive) 1017 break; 1018 if(opt_len) { 1019 verbose(VERB_ALGO, "query with bad edns keepalive."); 1020 return LDNS_RCODE_FORMERR; 1021 } 1022 if(!edns_opt_list_append_keepalive(&edns->opt_list_out, 1023 c->tcp_timeout_msec / 100, 1024 region)) { 1025 log_err("out of memory"); 1026 return LDNS_RCODE_SERVFAIL; 1027 } 1028 c->tcp_keepalive = 1; 1029 break; 1030 1031 case LDNS_EDNS_PADDING: 1032 if(!cfg || !cfg->pad_responses || 1033 !c || c->type != comm_tcp ||!c->ssl) 1034 break; 1035 if(!edns_opt_list_append(&edns->opt_list_out, 1036 LDNS_EDNS_PADDING, 1037 0, NULL, region)) { 1038 log_err("out of memory"); 1039 return LDNS_RCODE_SERVFAIL; 1040 } 1041 edns->padding_block_size = cfg->pad_responses_block_size; 1042 break; 1043 1044 default: 1045 break; 1046 } 1047 if(!edns_opt_list_append(&edns->opt_list_in, 1048 opt_code, opt_len, rdata_ptr, region)) { 1049 log_err("out of memory"); 1050 return LDNS_RCODE_SERVFAIL; 1051 } 1052 rdata_ptr += opt_len; 1053 rdata_len -= opt_len; 1054 } 1055 return LDNS_RCODE_NOERROR; 1056 } 1057 1058 int 1059 parse_extract_edns_from_response_msg(struct msg_parse* msg, 1060 struct edns_data* edns, struct regional* region) 1061 { 1062 struct rrset_parse* rrset = msg->rrset_first; 1063 struct rrset_parse* prev = 0; 1064 struct rrset_parse* found = 0; 1065 struct rrset_parse* found_prev = 0; 1066 size_t rdata_len; 1067 uint8_t* rdata_ptr; 1068 /* since the class encodes the UDP size, we cannot use hash table to 1069 * find the EDNS OPT record. Scan the packet. */ 1070 while(rrset) { 1071 if(rrset->type == LDNS_RR_TYPE_OPT) { 1072 /* only one OPT RR allowed. */ 1073 if(found) return LDNS_RCODE_FORMERR; 1074 /* found it! */ 1075 found_prev = prev; 1076 found = rrset; 1077 } 1078 prev = rrset; 1079 rrset = rrset->rrset_all_next; 1080 } 1081 if(!found) { 1082 memset(edns, 0, sizeof(*edns)); 1083 edns->udp_size = 512; 1084 return 0; 1085 } 1086 /* check the found RRset */ 1087 /* most lenient check possible. ignore dname, use last opt */ 1088 if(found->section != LDNS_SECTION_ADDITIONAL) 1089 return LDNS_RCODE_FORMERR; 1090 if(found->rr_count == 0) 1091 return LDNS_RCODE_FORMERR; 1092 if(0) { /* strict checking of dname and RRcount */ 1093 if(found->dname_len != 1 || !found->dname 1094 || found->dname[0] != 0) return LDNS_RCODE_FORMERR; 1095 if(found->rr_count != 1) return LDNS_RCODE_FORMERR; 1096 } 1097 log_assert(found->rr_first && found->rr_last); 1098 1099 /* remove from packet */ 1100 if(found_prev) found_prev->rrset_all_next = found->rrset_all_next; 1101 else msg->rrset_first = found->rrset_all_next; 1102 if(found == msg->rrset_last) 1103 msg->rrset_last = found_prev; 1104 msg->arcount --; 1105 msg->ar_rrsets --; 1106 msg->rrset_count --; 1107 1108 /* take the data ! */ 1109 edns->edns_present = 1; 1110 edns->ext_rcode = found->rr_last->ttl_data[0]; 1111 edns->edns_version = found->rr_last->ttl_data[1]; 1112 edns->bits = sldns_read_uint16(&found->rr_last->ttl_data[2]); 1113 edns->udp_size = ntohs(found->rrset_class); 1114 edns->opt_list_in = NULL; 1115 edns->opt_list_out = NULL; 1116 edns->opt_list_inplace_cb_out = NULL; 1117 edns->padding_block_size = 0; 1118 1119 /* take the options */ 1120 rdata_len = found->rr_first->size-2; 1121 rdata_ptr = found->rr_first->ttl_data+6; 1122 1123 /* while still more options, and have code+len to read */ 1124 /* ignores partial content (i.e. rdata len 3) */ 1125 while(rdata_len >= 4) { 1126 uint16_t opt_code = sldns_read_uint16(rdata_ptr); 1127 uint16_t opt_len = sldns_read_uint16(rdata_ptr+2); 1128 rdata_ptr += 4; 1129 rdata_len -= 4; 1130 if(opt_len > rdata_len) 1131 break; /* option code partial */ 1132 1133 if(!edns_opt_list_append(&edns->opt_list_in, 1134 opt_code, opt_len, rdata_ptr, region)) { 1135 log_err("out of memory"); 1136 break; 1137 } 1138 rdata_ptr += opt_len; 1139 rdata_len -= opt_len; 1140 } 1141 /* ignore rrsigs */ 1142 return LDNS_RCODE_NOERROR; 1143 } 1144 1145 /** skip RR in packet */ 1146 static int 1147 skip_pkt_rr(sldns_buffer* pkt) 1148 { 1149 if(sldns_buffer_remaining(pkt) < 1) return 0; 1150 if(!pkt_dname_len(pkt)) 1151 return 0; 1152 if(sldns_buffer_remaining(pkt) < 4) return 0; 1153 sldns_buffer_skip(pkt, 4); /* type and class */ 1154 if(!skip_ttl_rdata(pkt)) 1155 return 0; 1156 return 1; 1157 } 1158 1159 /** skip RRs from packet */ 1160 int 1161 skip_pkt_rrs(sldns_buffer* pkt, int num) 1162 { 1163 int i; 1164 for(i=0; i<num; i++) { 1165 if(!skip_pkt_rr(pkt)) 1166 return 0; 1167 } 1168 return 1; 1169 } 1170 1171 int 1172 parse_edns_from_query_pkt(sldns_buffer* pkt, struct edns_data* edns, 1173 struct config_file* cfg, struct comm_point* c, struct regional* region) 1174 { 1175 size_t rdata_len; 1176 uint8_t* rdata_ptr; 1177 log_assert(LDNS_QDCOUNT(sldns_buffer_begin(pkt)) == 1); 1178 memset(edns, 0, sizeof(*edns)); 1179 if(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) != 0 || 1180 LDNS_NSCOUNT(sldns_buffer_begin(pkt)) != 0) { 1181 if(!skip_pkt_rrs(pkt, ((int)LDNS_ANCOUNT(sldns_buffer_begin(pkt)))+ 1182 ((int)LDNS_NSCOUNT(sldns_buffer_begin(pkt))))) 1183 return LDNS_RCODE_FORMERR; 1184 } 1185 /* check edns section is present */ 1186 if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) > 1) { 1187 return LDNS_RCODE_FORMERR; 1188 } 1189 if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) == 0) { 1190 edns->udp_size = 512; 1191 return 0; 1192 } 1193 /* domain name must be the root of length 1. */ 1194 if(pkt_dname_len(pkt) != 1) 1195 return LDNS_RCODE_FORMERR; 1196 if(sldns_buffer_remaining(pkt) < 10) /* type, class, ttl, rdatalen */ 1197 return LDNS_RCODE_FORMERR; 1198 if(sldns_buffer_read_u16(pkt) != LDNS_RR_TYPE_OPT) 1199 return LDNS_RCODE_FORMERR; 1200 edns->edns_present = 1; 1201 edns->udp_size = sldns_buffer_read_u16(pkt); /* class is udp size */ 1202 edns->ext_rcode = sldns_buffer_read_u8(pkt); /* ttl used for bits */ 1203 edns->edns_version = sldns_buffer_read_u8(pkt); 1204 edns->bits = sldns_buffer_read_u16(pkt); 1205 edns->opt_list_in = NULL; 1206 edns->opt_list_out = NULL; 1207 edns->opt_list_inplace_cb_out = NULL; 1208 edns->padding_block_size = 0; 1209 1210 /* take the options */ 1211 rdata_len = sldns_buffer_read_u16(pkt); 1212 if(sldns_buffer_remaining(pkt) < rdata_len) 1213 return LDNS_RCODE_FORMERR; 1214 rdata_ptr = sldns_buffer_current(pkt); 1215 /* ignore rrsigs */ 1216 return parse_edns_options_from_query(rdata_ptr, rdata_len, edns, cfg, 1217 c, region); 1218 } 1219 1220 void 1221 log_edns_opt_list(enum verbosity_value level, const char* info_str, 1222 struct edns_option* list) 1223 { 1224 if(verbosity >= level && list) { 1225 char str[128], *s; 1226 size_t slen; 1227 verbose(level, "%s", info_str); 1228 while(list) { 1229 s = str; 1230 slen = sizeof(str); 1231 (void)sldns_wire2str_edns_option_print(&s, &slen, list->opt_code, 1232 list->opt_data, list->opt_len); 1233 verbose(level, " %s", str); 1234 list = list->next; 1235 } 1236 } 1237 } 1238 1239