1 /* 2 * query.c -- nsd(8) the resolver. 3 * 4 * Copyright (c) 2001-2011, NLnet Labs. All rights reserved. 5 * 6 * See LICENSE for the license. 7 * 8 */ 9 10 #include <config.h> 11 12 #include <sys/types.h> 13 #include <sys/socket.h> 14 #include <netinet/in.h> 15 #include <arpa/inet.h> 16 #include <assert.h> 17 #include <ctype.h> 18 #include <errno.h> 19 #include <limits.h> 20 #include <netdb.h> 21 #include <stddef.h> 22 #include <stdio.h> 23 #include <stdlib.h> 24 #include <string.h> 25 #include <time.h> 26 #include <unistd.h> 27 #include <netdb.h> 28 29 #include "answer.h" 30 #include "axfr.h" 31 #include "dns.h" 32 #include "dname.h" 33 #include "nsd.h" 34 #include "namedb.h" 35 #include "query.h" 36 #include "util.h" 37 #include "options.h" 38 #include "nsec3.h" 39 #include "tsig.h" 40 41 /* [Bug #253] Adding unnecessary NS RRset may lead to undesired truncation. 42 * This function determines if the final response packet needs the NS RRset 43 * included. Currently, it will only return negative if QTYPE == DNSKEY|DS. 44 * This way, resolvers won't fallback to TCP unnecessarily when priming 45 * trust anchors. 46 */ 47 static int answer_needs_ns(struct query *query); 48 49 static int add_rrset(struct query *query, 50 answer_type *answer, 51 rr_section_type section, 52 domain_type *owner, 53 rrset_type *rrset); 54 55 static void answer_authoritative(struct nsd *nsd, 56 struct query *q, 57 answer_type *answer, 58 uint32_t domain_number, 59 int exact, 60 domain_type *closest_match, 61 domain_type *closest_encloser, 62 const dname_type *qname); 63 64 static void answer_lookup_zone(struct nsd *nsd, struct query *q, 65 answer_type *answer, uint32_t domain_number, 66 int exact, domain_type *closest_match, 67 domain_type *closest_encloser, 68 const dname_type *qname); 69 70 void 71 query_put_dname_offset(struct query *q, domain_type *domain, uint16_t offset) 72 { 73 assert(q); 74 assert(domain); 75 assert(domain->number > 0); 76 77 if (offset > MAX_COMPRESSION_OFFSET) 78 return; 79 if (q->compressed_dname_count >= MAX_COMPRESSED_DNAMES) 80 return; 81 82 q->compressed_dname_offsets[domain->number] = offset; 83 q->compressed_dnames[q->compressed_dname_count] = domain; 84 ++q->compressed_dname_count; 85 } 86 87 void 88 query_clear_dname_offsets(struct query *q, size_t max_offset) 89 { 90 while (q->compressed_dname_count > 0 91 && (q->compressed_dname_offsets[q->compressed_dnames[q->compressed_dname_count - 1]->number] 92 >= max_offset)) 93 { 94 q->compressed_dname_offsets[q->compressed_dnames[q->compressed_dname_count - 1]->number] = 0; 95 --q->compressed_dname_count; 96 } 97 } 98 99 void 100 query_clear_compression_tables(struct query *q) 101 { 102 uint16_t i; 103 104 for (i = 0; i < q->compressed_dname_count; ++i) { 105 assert(q->compressed_dnames); 106 q->compressed_dname_offsets[q->compressed_dnames[i]->number] = 0; 107 } 108 q->compressed_dname_count = 0; 109 } 110 111 void 112 query_add_compression_domain(struct query *q, domain_type *domain, uint16_t offset) 113 { 114 while (domain->parent) { 115 DEBUG(DEBUG_NAME_COMPRESSION, 2, 116 (LOG_INFO, "query dname: %s, number: %lu, offset: %u\n", 117 dname_to_string(domain_dname(domain), NULL), 118 (unsigned long) domain->number, 119 offset)); 120 query_put_dname_offset(q, domain, offset); 121 offset += label_length(dname_name(domain_dname(domain))) + 1; 122 domain = domain->parent; 123 } 124 } 125 126 /* 127 * Generate an error response with the specified RCODE. 128 */ 129 query_state_type 130 query_error (struct query *q, nsd_rc_type rcode) 131 { 132 if (rcode == NSD_RC_DISCARD) { 133 return QUERY_DISCARDED; 134 } 135 136 buffer_clear(q->packet); 137 138 QR_SET(q->packet); /* This is an answer. */ 139 RCODE_SET(q->packet, (int) rcode); /* Error code. */ 140 141 /* Truncate the question as well... */ 142 QDCOUNT_SET(q->packet, 0); 143 ANCOUNT_SET(q->packet, 0); 144 NSCOUNT_SET(q->packet, 0); 145 ARCOUNT_SET(q->packet, 0); 146 buffer_set_position(q->packet, QHEADERSZ); 147 return QUERY_PROCESSED; 148 } 149 150 static query_state_type 151 query_formerr (struct query *query) 152 { 153 int opcode = OPCODE(query->packet); 154 FLAGS_SET(query->packet, FLAGS(query->packet) & 0x0100U); 155 /* Preserve the RD flag. Clear the rest. */ 156 OPCODE_SET(query->packet, opcode); 157 return query_error(query, NSD_RC_FORMAT); 158 } 159 160 static void 161 query_cleanup(void *data) 162 { 163 query_type *query = (query_type *) data; 164 region_destroy(query->region); 165 } 166 167 query_type * 168 query_create(region_type *region, uint16_t *compressed_dname_offsets, 169 uint32_t compressed_dname_size) 170 { 171 query_type *query 172 = (query_type *) region_alloc_zero(region, sizeof(query_type)); 173 /* create region with large block size, because the initial chunk 174 saves many mallocs in the server */ 175 query->region = region_create_custom(xalloc, free, 16384, 16384/8, 32, 0); 176 query->compressed_dname_offsets = compressed_dname_offsets; 177 query->packet = buffer_create(region, QIOBUFSZ); 178 region_add_cleanup(region, query_cleanup, query); 179 query->compressed_dname_offsets_size = compressed_dname_size; 180 tsig_create_record(&query->tsig, region); 181 query->tsig_prepare_it = 1; 182 query->tsig_update_it = 1; 183 query->tsig_sign_it = 1; 184 return query; 185 } 186 187 void 188 query_reset(query_type *q, size_t maxlen, int is_tcp) 189 { 190 /* 191 * As long as less than 4Kb (region block size) has been used, 192 * this call to free_all is free, the block is saved for re-use, 193 * so no malloc() or free() calls are done. 194 * at present use of the region is for: 195 * o query qname dname_type (255 max). 196 * o wildcard expansion domain_type (7*ptr+u32+2bytes)+(5*ptr nsec3) 197 * o wildcard expansion for additional section domain_type. 198 * o nsec3 hashed name(s) (3 dnames for a nonexist_proof, 199 * one proof per wildcard and for nx domain). 200 */ 201 region_free_all(q->region); 202 q->addrlen = sizeof(q->addr); 203 q->maxlen = maxlen; 204 q->reserved_space = 0; 205 buffer_clear(q->packet); 206 edns_init_record(&q->edns); 207 tsig_init_record(&q->tsig, NULL, NULL); 208 q->tsig_prepare_it = 1; 209 q->tsig_update_it = 1; 210 q->tsig_sign_it = 1; 211 q->tcp = is_tcp; 212 q->qname = NULL; 213 q->qtype = 0; 214 q->qclass = 0; 215 q->zone = NULL; 216 q->domain = NULL; 217 q->opcode = 0; 218 q->cname_count = 0; 219 q->delegation_domain = NULL; 220 q->delegation_rrset = NULL; 221 q->compressed_dname_count = 0; 222 q->number_temporary_domains = 0; 223 224 q->axfr_is_done = 0; 225 q->axfr_zone = NULL; 226 q->axfr_current_domain = NULL; 227 q->axfr_current_rrset = NULL; 228 q->axfr_current_rr = 0; 229 } 230 231 /* get a temporary domain number (or 0=failure) */ 232 static domain_type* 233 query_get_tempdomain(struct query *q) 234 { 235 static domain_type d[EXTRA_DOMAIN_NUMBERS]; 236 if(q->number_temporary_domains >= EXTRA_DOMAIN_NUMBERS) 237 return 0; 238 q->number_temporary_domains ++; 239 memset(&d[q->number_temporary_domains-1], 0, sizeof(domain_type)); 240 d[q->number_temporary_domains-1].number = q->compressed_dname_offsets_size + 241 q->number_temporary_domains - 1; 242 return &d[q->number_temporary_domains-1]; 243 } 244 245 static void 246 query_addtxt(struct query *q, 247 const uint8_t *dname, 248 uint16_t klass, 249 uint32_t ttl, 250 const char *txt) 251 { 252 size_t txt_length = strlen(txt); 253 uint8_t len = (uint8_t) txt_length; 254 255 assert(txt_length <= UCHAR_MAX); 256 257 /* Add the dname */ 258 if (dname >= buffer_begin(q->packet) 259 && dname <= buffer_current(q->packet)) 260 { 261 buffer_write_u16(q->packet, 262 0xc000 | (dname - buffer_begin(q->packet))); 263 } else { 264 buffer_write(q->packet, dname + 1, *dname); 265 } 266 267 buffer_write_u16(q->packet, TYPE_TXT); 268 buffer_write_u16(q->packet, klass); 269 buffer_write_u32(q->packet, ttl); 270 buffer_write_u16(q->packet, len + 1); 271 buffer_write_u8(q->packet, len); 272 buffer_write(q->packet, txt, len); 273 } 274 275 /* 276 * Parse the question section of a query. The normalized query name 277 * is stored in QUERY->name, the class in QUERY->klass, and the type 278 * in QUERY->type. 279 */ 280 static int 281 process_query_section(query_type *query) 282 { 283 uint8_t qnamebuf[MAXDOMAINLEN]; 284 285 buffer_set_position(query->packet, QHEADERSZ); 286 /* Lets parse the query name and convert it to lower case. */ 287 if(!packet_read_query_section(query->packet, qnamebuf, 288 &query->qtype, &query->qclass)) 289 return 0; 290 query->qname = dname_make(query->region, qnamebuf, 1); 291 query->opcode = OPCODE(query->packet); 292 return 1; 293 } 294 295 296 /* 297 * Process an optional EDNS OPT record. Sets QUERY->EDNS to 0 if 298 * there was no EDNS record, to -1 if there was an invalid or 299 * unsupported EDNS record, and to 1 otherwise. Updates QUERY->MAXLEN 300 * if the EDNS record specifies a maximum supported response length. 301 * 302 * Return NSD_RC_FORMAT on failure, NSD_RC_OK on success. 303 */ 304 static nsd_rc_type 305 process_edns(nsd_type* nsd, struct query *q) 306 { 307 if (q->edns.status == EDNS_ERROR) { 308 return NSD_RC_FORMAT; 309 } 310 311 if (q->edns.status == EDNS_OK) { 312 /* Only care about UDP size larger than normal... */ 313 if (!q->tcp && q->edns.maxlen > UDP_MAX_MESSAGE_LEN) { 314 size_t edns_size; 315 #if defined(INET6) 316 if (q->addr.ss_family == AF_INET6) { 317 edns_size = nsd->ipv6_edns_size; 318 } else 319 #endif 320 edns_size = nsd->ipv4_edns_size; 321 322 if (q->edns.maxlen < edns_size) { 323 q->maxlen = q->edns.maxlen; 324 } else { 325 q->maxlen = edns_size; 326 } 327 328 #if defined(INET6) && !defined(IPV6_USE_MIN_MTU) && !defined(IPV6_MTU) 329 /* 330 * Use IPv6 minimum MTU to avoid sending 331 * packets that are too large for some links. 332 * IPv6 will not automatically fragment in 333 * this case (unlike IPv4). 334 */ 335 if (q->addr.ss_family == AF_INET6 336 && q->maxlen > IPV6_MIN_MTU) 337 { 338 q->maxlen = IPV6_MIN_MTU; 339 } 340 #endif 341 } 342 343 /* Strip the OPT resource record off... */ 344 buffer_set_position(q->packet, q->edns.position); 345 buffer_set_limit(q->packet, q->edns.position); 346 ARCOUNT_SET(q->packet, ARCOUNT(q->packet) - 1); 347 } 348 return NSD_RC_OK; 349 } 350 351 /* 352 * Processes TSIG. 353 * Sets error when tsig does not verify on the query. 354 */ 355 static nsd_rc_type 356 process_tsig(struct query* q) 357 { 358 if(q->tsig.status == TSIG_ERROR) 359 return NSD_RC_FORMAT; 360 if(q->tsig.status == TSIG_OK) { 361 if(!tsig_from_query(&q->tsig)) { 362 log_msg(LOG_ERR, "query tsig unknown key/algorithm"); 363 return NSD_RC_REFUSE; 364 } 365 buffer_set_limit(q->packet, q->tsig.position); 366 ARCOUNT_SET(q->packet, ARCOUNT(q->packet) - 1); 367 tsig_prepare(&q->tsig); 368 tsig_update(&q->tsig, q->packet, buffer_limit(q->packet)); 369 if(!tsig_verify(&q->tsig)) { 370 log_msg(LOG_ERR, "query: bad tsig signature for key %s", 371 dname_to_string(q->tsig.key->name, NULL)); 372 return NSD_RC_REFUSE; 373 } 374 DEBUG(DEBUG_XFRD,1, (LOG_INFO, "query good tsig signature for %s", 375 dname_to_string(q->tsig.key->name, NULL))); 376 } 377 return NSD_RC_OK; 378 } 379 380 /* 381 * Check notify acl and forward to xfrd (or return an error). 382 */ 383 static query_state_type 384 answer_notify(struct nsd* nsd, struct query *query) 385 { 386 int acl_num; 387 acl_options_t *why; 388 nsd_rc_type rc; 389 390 zone_options_t* zone_opt; 391 DEBUG(DEBUG_XFRD,1, (LOG_INFO, "got notify %s processing acl", 392 dname_to_string(query->qname, NULL))); 393 394 zone_opt = zone_options_find(nsd->options, query->qname); 395 if(!zone_opt) 396 return query_error(query, NSD_RC_NXDOMAIN); 397 398 if(!nsd->this_child) /* we are in debug mode or something */ 399 return query_error(query, NSD_RC_SERVFAIL); 400 401 if(!tsig_find_rr(&query->tsig, query->packet)) { 402 DEBUG(DEBUG_XFRD,2, (LOG_ERR, "bad tsig RR format")); 403 return query_error(query, NSD_RC_FORMAT); 404 } 405 rc = process_tsig(query); 406 if(rc != NSD_RC_OK) 407 return query_error(query, rc); 408 409 /* check if it passes acl */ 410 if((acl_num = acl_check_incoming(zone_opt->allow_notify, query, 411 &why)) != -1) 412 { 413 sig_atomic_t mode = NSD_PASS_TO_XFRD; 414 int s = nsd->this_child->parent_fd; 415 uint16_t sz; 416 uint32_t acl_send = htonl(acl_num); 417 size_t pos; 418 assert(why); 419 DEBUG(DEBUG_XFRD,1, (LOG_INFO, "got notify %s passed acl %s %s", 420 dname_to_string(query->qname, NULL), 421 why->ip_address_spec, 422 why->nokey?"NOKEY": 423 (why->blocked?"BLOCKED":why->key_name))); 424 sz = buffer_limit(query->packet); 425 if(buffer_limit(query->packet) > MAX_PACKET_SIZE) 426 return query_error(query, NSD_RC_SERVFAIL); 427 /* forward to xfrd for processing 428 Note. Blocking IPC I/O, but acl is OK. */ 429 sz = htons(sz); 430 if(!write_socket(s, &mode, sizeof(mode)) || 431 !write_socket(s, &sz, sizeof(sz)) || 432 !write_socket(s, buffer_begin(query->packet), 433 buffer_limit(query->packet)) || 434 !write_socket(s, &acl_send, sizeof(acl_send))) { 435 log_msg(LOG_ERR, "error in IPC notify server2main, %s", 436 strerror(errno)); 437 return query_error(query, NSD_RC_SERVFAIL); 438 } 439 440 /* create notify reply - keep same query contents */ 441 QR_SET(query->packet); /* This is an answer. */ 442 AA_SET(query->packet); /* we are authoritative. */ 443 ANCOUNT_SET(query->packet, 0); 444 NSCOUNT_SET(query->packet, 0); 445 ARCOUNT_SET(query->packet, 0); 446 RCODE_SET(query->packet, RCODE_OK); /* Error code. */ 447 /* position is right after the query */ 448 pos = buffer_position(query->packet); 449 buffer_clear(query->packet); 450 buffer_set_position(query->packet, pos); 451 VERBOSITY(2, (LOG_INFO, "Notify received and accepted, forward to xfrd")); 452 /* tsig is added in add_additional later (if needed) */ 453 return QUERY_PROCESSED; 454 } 455 456 if (verbosity > 1) { 457 char address[128]; 458 if (addr2ip(query->addr, address, sizeof(address))) { 459 DEBUG(DEBUG_XFRD,1, (LOG_INFO, "addr2ip failed")); 460 strlcpy(address, "[unknown]", sizeof(address)); 461 } 462 463 VERBOSITY(1, (LOG_INFO, "notify for zone %s from client %s refused, %s%s", 464 dname_to_string(query->qname, NULL), 465 address, 466 why?why->key_name:"no acl matches", 467 why?why->ip_address_spec:".")); 468 } 469 470 return query_error(query, NSD_RC_REFUSE); 471 } 472 473 474 /* 475 * Answer a query in the CHAOS class. 476 */ 477 static query_state_type 478 answer_chaos(struct nsd *nsd, query_type *q) 479 { 480 AA_CLR(q->packet); 481 switch (q->qtype) { 482 case TYPE_ANY: 483 case TYPE_TXT: 484 if ((q->qname->name_size == 11 485 && memcmp(dname_name(q->qname), "\002id\006server", 11) == 0) || 486 (q->qname->name_size == 15 487 && memcmp(dname_name(q->qname), "\010hostname\004bind", 15) == 0)) 488 { 489 /* Add ID */ 490 query_addtxt(q, 491 buffer_begin(q->packet) + QHEADERSZ, 492 CLASS_CH, 493 0, 494 nsd->identity); 495 ANCOUNT_SET(q->packet, ANCOUNT(q->packet) + 1); 496 } else if ((q->qname->name_size == 16 497 && memcmp(dname_name(q->qname), "\007version\006server", 16) == 0) || 498 (q->qname->name_size == 14 499 && memcmp(dname_name(q->qname), "\007version\004bind", 14) == 0)) 500 { 501 if(!nsd->options->hide_version) { 502 /* Add version */ 503 query_addtxt(q, 504 buffer_begin(q->packet) + QHEADERSZ, 505 CLASS_CH, 506 0, 507 nsd->version); 508 ANCOUNT_SET(q->packet, ANCOUNT(q->packet) + 1); 509 } else { 510 RCODE_SET(q->packet, RCODE_REFUSE); 511 } 512 } 513 break; 514 default: 515 RCODE_SET(q->packet, RCODE_REFUSE); 516 break; 517 } 518 519 return QUERY_PROCESSED; 520 } 521 522 523 /* 524 * Find the covering NSEC for a non-existent domain name. Normally 525 * the NSEC will be located at CLOSEST_MATCH, except when it is an 526 * empty non-terminal. In this case the NSEC may be located at the 527 * previous domain name (in canonical ordering). 528 */ 529 static domain_type * 530 find_covering_nsec(domain_type *closest_match, 531 zone_type *zone, 532 rrset_type **nsec_rrset) 533 { 534 assert(closest_match); 535 assert(nsec_rrset); 536 537 /* loop away temporary created domains. For real ones it is &RBTREE_NULL */ 538 while (closest_match->node.parent == NULL) 539 closest_match = closest_match->parent; 540 while (closest_match) { 541 *nsec_rrset = domain_find_rrset(closest_match, zone, TYPE_NSEC); 542 if (*nsec_rrset) { 543 return closest_match; 544 } 545 if (closest_match == zone->apex) { 546 /* Don't look outside the current zone. */ 547 return NULL; 548 } 549 closest_match = domain_previous(closest_match); 550 } 551 return NULL; 552 } 553 554 555 struct additional_rr_types 556 { 557 uint16_t rr_type; 558 rr_section_type rr_section; 559 }; 560 561 struct additional_rr_types default_additional_rr_types[] = { 562 { TYPE_A, ADDITIONAL_A_SECTION }, 563 { TYPE_AAAA, ADDITIONAL_AAAA_SECTION }, 564 { 0, (rr_section_type) 0 } 565 }; 566 567 struct additional_rr_types rt_additional_rr_types[] = { 568 { TYPE_A, ADDITIONAL_A_SECTION }, 569 { TYPE_AAAA, ADDITIONAL_AAAA_SECTION }, 570 { TYPE_X25, ADDITIONAL_OTHER_SECTION }, 571 { TYPE_ISDN, ADDITIONAL_OTHER_SECTION }, 572 { 0, (rr_section_type) 0 } 573 }; 574 575 static void 576 add_additional_rrsets(struct query *query, answer_type *answer, 577 rrset_type *master_rrset, size_t rdata_index, 578 int allow_glue, struct additional_rr_types types[]) 579 { 580 size_t i; 581 582 assert(query); 583 assert(answer); 584 assert(master_rrset); 585 assert(rdata_atom_is_domain(rrset_rrtype(master_rrset), rdata_index)); 586 587 for (i = 0; i < master_rrset->rr_count; ++i) { 588 int j; 589 domain_type *additional = rdata_atom_domain(master_rrset->rrs[i].rdatas[rdata_index]); 590 domain_type *match = additional; 591 592 assert(additional); 593 594 if (!allow_glue && domain_is_glue(match, query->zone)) 595 continue; 596 597 /* 598 * Check to see if we need to generate the dependent 599 * based on a wildcard domain. 600 */ 601 while (!match->is_existing) { 602 match = match->parent; 603 } 604 if (additional != match && domain_wildcard_child(match)) { 605 domain_type *wildcard_child = domain_wildcard_child(match); 606 domain_type *temp = (domain_type *) region_alloc( 607 query->region, sizeof(domain_type)); 608 memcpy(&temp->node, &additional->node, sizeof(rbnode_t)); 609 temp->number = additional->number; 610 temp->parent = match; 611 temp->wildcard_child_closest_match = temp; 612 temp->rrsets = wildcard_child->rrsets; 613 temp->is_existing = wildcard_child->is_existing; 614 additional = temp; 615 } 616 617 for (j = 0; types[j].rr_type != 0; ++j) { 618 rrset_type *rrset = domain_find_rrset( 619 additional, query->zone, types[j].rr_type); 620 if (rrset) { 621 answer_add_rrset(answer, types[j].rr_section, 622 additional, rrset); 623 } 624 } 625 } 626 } 627 628 static int 629 answer_needs_ns(struct query* query) 630 { 631 assert(query); 632 /* Currently, only troublesome for DNSKEY and DS, 633 * cuz their RRSETs are quite large. */ 634 return (query->qtype != TYPE_DNSKEY && query->qtype != TYPE_DS); 635 } 636 637 static int 638 add_rrset(struct query *query, 639 answer_type *answer, 640 rr_section_type section, 641 domain_type *owner, 642 rrset_type *rrset) 643 { 644 int result; 645 646 assert(query); 647 assert(answer); 648 assert(owner); 649 assert(rrset); 650 assert(rrset_rrclass(rrset) == CLASS_IN); 651 652 result = answer_add_rrset(answer, section, owner, rrset); 653 switch (rrset_rrtype(rrset)) { 654 case TYPE_NS: 655 add_additional_rrsets(query, answer, rrset, 0, 1, 656 default_additional_rr_types); 657 break; 658 case TYPE_MB: 659 add_additional_rrsets(query, answer, rrset, 0, 0, 660 default_additional_rr_types); 661 break; 662 case TYPE_MX: 663 case TYPE_KX: 664 add_additional_rrsets(query, answer, rrset, 1, 0, 665 default_additional_rr_types); 666 break; 667 case TYPE_RT: 668 add_additional_rrsets(query, answer, rrset, 1, 0, 669 rt_additional_rr_types); 670 break; 671 default: 672 break; 673 } 674 675 return result; 676 } 677 678 679 /* returns 0 on error, or the domain number for to_name. 680 from_name is changes to to_name by the DNAME rr. 681 DNAME rr is from src to dest. 682 closest encloser encloses the to_name. */ 683 static uint32_t 684 query_synthesize_cname(struct query* q, struct answer* answer, const dname_type* from_name, 685 const dname_type* to_name, domain_type* src, domain_type* to_closest_encloser, 686 domain_type** to_closest_match) 687 { 688 /* add temporary domains for from_name and to_name and all 689 their (not allocated yet) parents */ 690 /* any domains below src are not_existing (because of DNAME at src) */ 691 int i; 692 domain_type* cname_domain; 693 domain_type* cname_dest; 694 rrset_type* rrset; 695 696 /* allocate source part */ 697 domain_type* lastparent = src; 698 assert(q && answer && from_name && to_name && src && to_closest_encloser); 699 assert(to_closest_match); 700 for(i=0; i < from_name->label_count - domain_dname(src)->label_count; i++) 701 { 702 domain_type* newdom = query_get_tempdomain(q); 703 if(!newdom) 704 return 0; 705 newdom->is_existing = 1; 706 newdom->parent = lastparent; 707 newdom->node.key = dname_partial_copy(q->region, 708 from_name, domain_dname(src)->label_count + i + 1); 709 if(dname_compare(domain_dname(newdom), q->qname) == 0) { 710 /* 0 good for query name, otherwise new number */ 711 newdom->number = 0; 712 } 713 DEBUG(DEBUG_QUERY,2, (LOG_INFO, "created temp domain src %d. %s nr %d", i, 714 dname_to_string(domain_dname(newdom), NULL), 715 newdom->number)); 716 lastparent = newdom; 717 } 718 cname_domain = lastparent; 719 720 /* allocate dest part */ 721 lastparent = to_closest_encloser; 722 for(i=0; i < to_name->label_count - domain_dname(to_closest_encloser)->label_count; 723 i++) 724 { 725 domain_type* newdom = query_get_tempdomain(q); 726 if(!newdom) 727 return 0; 728 newdom->is_existing = 0; 729 newdom->parent = lastparent; 730 newdom->node.key = dname_partial_copy(q->region, 731 to_name, domain_dname(to_closest_encloser)->label_count + i + 1); 732 DEBUG(DEBUG_QUERY,2, (LOG_INFO, "created temp domain dest %d. %s nr %d", i, 733 dname_to_string(domain_dname(newdom), NULL), 734 newdom->number)); 735 lastparent = newdom; 736 } 737 cname_dest = lastparent; 738 *to_closest_match = cname_dest; 739 740 /* allocate the CNAME RR */ 741 rrset = (rrset_type*) region_alloc(q->region, sizeof(rrset_type)); 742 memset(rrset, 0, sizeof(rrset_type)); 743 rrset->zone = q->zone; 744 rrset->rr_count = 1; 745 rrset->rrs = (rr_type*) region_alloc(q->region, sizeof(rr_type)); 746 memset(rrset->rrs, 0, sizeof(rr_type)); 747 rrset->rrs->owner = cname_domain; 748 rrset->rrs->ttl = 0; 749 rrset->rrs->type = TYPE_CNAME; 750 rrset->rrs->klass = CLASS_IN; 751 rrset->rrs->rdata_count = 1; 752 rrset->rrs->rdatas = (rdata_atom_type*)region_alloc(q->region, 753 sizeof(rdata_atom_type)); 754 rrset->rrs->rdatas->domain = cname_dest; 755 756 if(!add_rrset(q, answer, ANSWER_SECTION, cname_domain, rrset)) { 757 log_msg(LOG_ERR, "could not add synthesized CNAME rrset to packet"); 758 } 759 760 return cname_dest->number; 761 } 762 763 /* 764 * Answer delegation information. 765 * 766 * DNSSEC: Include the DS RRset if present. Otherwise include an NSEC 767 * record proving the DS RRset does not exist. 768 */ 769 static void 770 answer_delegation(query_type *query, answer_type *answer) 771 { 772 assert(answer); 773 assert(query->delegation_domain); 774 assert(query->delegation_rrset); 775 776 AA_CLR(query->packet); 777 add_rrset(query, 778 answer, 779 AUTHORITY_SECTION, 780 query->delegation_domain, 781 query->delegation_rrset); 782 if (query->edns.dnssec_ok && zone_is_secure(query->zone)) { 783 rrset_type *rrset; 784 if ((rrset = domain_find_rrset(query->delegation_domain, query->zone, TYPE_DS))) { 785 add_rrset(query, answer, AUTHORITY_SECTION, 786 query->delegation_domain, rrset); 787 #ifdef NSEC3 788 } else if (query->zone->nsec3_soa_rr) { 789 nsec3_answer_delegation(query, answer); 790 #endif 791 } else if ((rrset = domain_find_rrset(query->delegation_domain, query->zone, TYPE_NSEC))) { 792 add_rrset(query, answer, AUTHORITY_SECTION, 793 query->delegation_domain, rrset); 794 } 795 } 796 query->domain = query->delegation_domain; 797 } 798 799 800 /* 801 * Answer SOA information. 802 */ 803 static void 804 answer_soa(struct query *query, answer_type *answer) 805 { 806 query->domain = query->zone->apex; 807 808 if (query->qclass != CLASS_ANY) { 809 add_rrset(query, answer, 810 AUTHORITY_SECTION, 811 query->zone->apex, 812 query->zone->soa_nx_rrset); 813 } 814 } 815 816 817 /* 818 * Answer that the domain name exists but there is no RRset with the 819 * requested type. 820 * 821 * DNSSEC: Include the correct NSEC record proving that the type does 822 * not exist. In the wildcard no data (3.1.3.4) case the wildcard IS 823 * NOT expanded, so the ORIGINAL parameter must point to the original 824 * wildcard entry, not to the generated entry. 825 */ 826 static void 827 answer_nodata(struct query *query, answer_type *answer, domain_type *original) 828 { 829 if (query->cname_count == 0) { 830 answer_soa(query, answer); 831 } 832 833 #ifdef NSEC3 834 if (query->edns.dnssec_ok && query->zone->nsec3_soa_rr) { 835 nsec3_answer_nodata(query, answer, original); 836 } else 837 #endif 838 if (query->edns.dnssec_ok && zone_is_secure(query->zone)) { 839 domain_type *nsec_domain; 840 rrset_type *nsec_rrset; 841 842 nsec_domain = find_covering_nsec(original, query->zone, &nsec_rrset); 843 if (nsec_domain) { 844 add_rrset(query, answer, AUTHORITY_SECTION, nsec_domain, nsec_rrset); 845 } 846 } 847 } 848 849 static void 850 answer_nxdomain(query_type *query, answer_type *answer) 851 { 852 if (query->cname_count == 0) { 853 RCODE_SET(query->packet, RCODE_NXDOMAIN); 854 answer_soa(query, answer); 855 } 856 } 857 858 859 /* 860 * Answer domain information (or SOA if we do not have an RRset for 861 * the type specified by the query). 862 */ 863 static void 864 answer_domain(struct nsd* nsd, struct query *q, answer_type *answer, 865 domain_type *domain, domain_type *original) 866 { 867 rrset_type *rrset; 868 869 if (q->qtype == TYPE_ANY) { 870 int added = 0; 871 for (rrset = domain_find_any_rrset(domain, q->zone); rrset; rrset = rrset->next) { 872 if (rrset->zone == q->zone 873 #ifdef NSEC3 874 && rrset_rrtype(rrset) != TYPE_NSEC3 875 #endif 876 /* 877 * Don't include the RRSIG RRset when 878 * DNSSEC is used, because it is added 879 * automatically on an per-RRset basis. 880 */ 881 && !(q->edns.dnssec_ok 882 && zone_is_secure(q->zone) 883 && rrset_rrtype(rrset) == TYPE_RRSIG)) 884 { 885 add_rrset(q, answer, ANSWER_SECTION, domain, rrset); 886 ++added; 887 } 888 } 889 if (added == 0) { 890 answer_nodata(q, answer, original); 891 return; 892 } 893 #ifdef NSEC3 894 } else if (q->qtype == TYPE_NSEC3) { 895 answer_nodata(q, answer, original); 896 return; 897 #endif 898 } else if ((rrset = domain_find_rrset(domain, q->zone, q->qtype))) { 899 add_rrset(q, answer, ANSWER_SECTION, domain, rrset); 900 } else if ((rrset = domain_find_rrset(domain, q->zone, TYPE_CNAME))) { 901 int added; 902 903 /* 904 * If the CNAME is not added it is already in the 905 * answer, so we have a CNAME loop. Don't follow the 906 * CNAME target in this case. 907 */ 908 added = add_rrset(q, answer, ANSWER_SECTION, domain, rrset); 909 assert(rrset->rr_count > 0); 910 if (added) { 911 /* only process first CNAME record */ 912 domain_type *closest_match = rdata_atom_domain(rrset->rrs[0].rdatas[0]); 913 domain_type *closest_encloser = closest_match; 914 zone_type* origzone = q->zone; 915 ++q->cname_count; 916 917 while (!closest_encloser->is_existing) 918 closest_encloser = closest_encloser->parent; 919 920 answer_lookup_zone(nsd, q, answer, closest_match->number, 921 closest_match == closest_encloser, 922 closest_match, closest_encloser, 923 domain_dname(closest_match)); 924 q->zone = origzone; 925 } 926 } else { 927 answer_nodata(q, answer, original); 928 return; 929 } 930 931 q->domain = domain; 932 933 if (q->qclass != CLASS_ANY && q->zone->ns_rrset && answer_needs_ns(q)) { 934 add_rrset(q, answer, AUTHORITY_SECTION, q->zone->apex, 935 q->zone->ns_rrset); 936 } 937 } 938 939 940 /* 941 * Answer with authoritative data. If a wildcard is matched the owner 942 * name will be expanded to the domain name specified by 943 * DOMAIN_NUMBER. DOMAIN_NUMBER 0 (zero) is reserved for the original 944 * query name. 945 * 946 * DNSSEC: Include the necessary NSEC records in case the request 947 * domain name does not exist and/or a wildcard match does not exist. 948 */ 949 static void 950 answer_authoritative(struct nsd *nsd, 951 struct query *q, 952 answer_type *answer, 953 uint32_t domain_number, 954 int exact, 955 domain_type *closest_match, 956 domain_type *closest_encloser, 957 const dname_type *qname) 958 { 959 domain_type *match; 960 domain_type *original = closest_match; 961 rrset_type *rrset; 962 963 #ifdef NSEC3 964 if(exact && domain_has_only_NSEC3(closest_match, q->zone)) { 965 exact = 0; /* pretend it does not exist */ 966 if(closest_encloser->parent) 967 closest_encloser = closest_encloser->parent; 968 } 969 #endif /* NSEC3 */ 970 971 if (exact) { 972 match = closest_match; 973 } else if ((rrset=domain_find_rrset(closest_encloser, q->zone, TYPE_DNAME))) { 974 /* process DNAME */ 975 const dname_type* name = qname; 976 domain_type *dest = rdata_atom_domain(rrset->rrs[0].rdatas[0]); 977 int added; 978 assert(rrset->rr_count > 0); 979 if(domain_number != 0) /* we followed CNAMEs or DNAMEs */ 980 name = domain_dname(closest_match); 981 DEBUG(DEBUG_QUERY,2, (LOG_INFO, "expanding DNAME for q=%s", dname_to_string(name, NULL))); 982 DEBUG(DEBUG_QUERY,2, (LOG_INFO, "->src is %s", 983 dname_to_string(domain_dname(closest_encloser), NULL))); 984 DEBUG(DEBUG_QUERY,2, (LOG_INFO, "->dest is %s", 985 dname_to_string(domain_dname(dest), NULL))); 986 /* if the DNAME set is not added we have a loop, do not follow */ 987 added = add_rrset(q, answer, ANSWER_SECTION, closest_encloser, rrset); 988 if(added) { 989 domain_type* src = closest_encloser; 990 const dname_type* newname = dname_replace(q->region, name, 991 domain_dname(src), domain_dname(dest)); 992 uint32_t newnum = 0; 993 zone_type* origzone = q->zone; 994 ++q->cname_count; 995 if(!newname) { /* newname too long */ 996 RCODE_SET(q->packet, RCODE_YXDOMAIN); 997 return; 998 } 999 DEBUG(DEBUG_QUERY,2, (LOG_INFO, "->result is %s", dname_to_string(newname, NULL))); 1000 /* follow the DNAME */ 1001 exact = namedb_lookup(nsd->db, newname, &closest_match, &closest_encloser); 1002 /* synthesize CNAME record */ 1003 newnum = query_synthesize_cname(q, answer, name, newname, 1004 src, closest_encloser, &closest_match); 1005 if(!newnum) { 1006 /* could not synthesize the CNAME. */ 1007 /* return previous CNAMEs to make resolver recurse for us */ 1008 return; 1009 } 1010 1011 while (closest_encloser && !closest_encloser->is_existing) 1012 closest_encloser = closest_encloser->parent; 1013 answer_lookup_zone(nsd, q, answer, newnum, 1014 closest_match == closest_encloser, 1015 closest_match, closest_encloser, newname); 1016 q->zone = origzone; 1017 } 1018 if(!added) /* log the error so operator can find looping recursors */ 1019 log_msg(LOG_INFO, "DNAME processing stopped due to loop, qname %s", 1020 dname_to_string(q->qname, NULL)); 1021 return; 1022 } else if (domain_wildcard_child(closest_encloser)) { 1023 /* Generate the domain from the wildcard. */ 1024 domain_type *wildcard_child = domain_wildcard_child(closest_encloser); 1025 1026 match = (domain_type *) region_alloc(q->region, 1027 sizeof(domain_type)); 1028 memcpy(&match->node, &wildcard_child->node, sizeof(rbnode_t)); 1029 match->parent = closest_encloser; 1030 match->wildcard_child_closest_match = match; 1031 match->number = domain_number; 1032 match->rrsets = wildcard_child->rrsets; 1033 match->is_existing = wildcard_child->is_existing; 1034 #ifdef NSEC3 1035 match->nsec3_is_exact = wildcard_child->nsec3_is_exact; 1036 match->nsec3_cover = wildcard_child->nsec3_cover; 1037 match->nsec3_wcard_child_cover = wildcard_child->nsec3_wcard_child_cover; 1038 match->nsec3_ds_parent_is_exact = wildcard_child->nsec3_ds_parent_is_exact; 1039 match->nsec3_ds_parent_cover = wildcard_child->nsec3_ds_parent_cover; 1040 1041 if (q->edns.dnssec_ok && q->zone->nsec3_soa_rr) { 1042 /* Only add nsec3 wildcard data when do bit is set */ 1043 nsec3_answer_wildcard(q, answer, wildcard_child, nsd->db, qname); 1044 } 1045 #endif 1046 1047 /* 1048 * Remember the original domain in case a Wildcard No 1049 * Data (3.1.3.4) response needs to be generated. In 1050 * this particular case the wildcard IS NOT 1051 * expanded. 1052 */ 1053 original = wildcard_child; 1054 } else { 1055 match = NULL; 1056 } 1057 1058 /* Authorative zone. */ 1059 #ifdef NSEC3 1060 if (q->edns.dnssec_ok && q->zone->nsec3_soa_rr) { 1061 nsec3_answer_authoritative(&match, q, answer, 1062 closest_encloser, nsd->db, qname); 1063 } else 1064 #endif 1065 if (q->edns.dnssec_ok && zone_is_secure(q->zone)) { 1066 if (match != closest_encloser) { 1067 domain_type *nsec_domain; 1068 rrset_type *nsec_rrset; 1069 1070 /* 1071 * No match found or generated from wildcard, 1072 * include NSEC record. 1073 */ 1074 nsec_domain = find_covering_nsec(closest_match, q->zone, &nsec_rrset); 1075 if (nsec_domain) { 1076 add_rrset(q, answer, AUTHORITY_SECTION, nsec_domain, nsec_rrset); 1077 } 1078 } 1079 if (!match) { 1080 domain_type *nsec_domain; 1081 rrset_type *nsec_rrset; 1082 1083 /* 1084 * No match and no wildcard. Include NSEC 1085 * proving there is no wildcard. 1086 */ 1087 nsec_domain = find_covering_nsec(closest_encloser->wildcard_child_closest_match, q->zone, &nsec_rrset); 1088 if (nsec_domain) { 1089 add_rrset(q, answer, AUTHORITY_SECTION, nsec_domain, nsec_rrset); 1090 } 1091 } 1092 } 1093 1094 #ifdef NSEC3 1095 if (RCODE(q->packet)!=RCODE_OK) { 1096 return; /* nsec3 collision failure */ 1097 } 1098 #endif 1099 if (match) { 1100 answer_domain(nsd, q, answer, match, original); 1101 } else { 1102 answer_nxdomain(q, answer); 1103 } 1104 } 1105 1106 /* 1107 * qname may be different after CNAMEs have been followed from query->qname. 1108 */ 1109 static void 1110 answer_lookup_zone(struct nsd *nsd, struct query *q, answer_type *answer, 1111 uint32_t domain_number, int exact, domain_type *closest_match, 1112 domain_type *closest_encloser, const dname_type *qname) 1113 { 1114 q->zone = domain_find_zone(closest_encloser); 1115 if (!q->zone) { 1116 if(q->cname_count == 0) 1117 RCODE_SET(q->packet, RCODE_SERVFAIL); 1118 return; 1119 } 1120 1121 /* 1122 * See RFC 4035 (DNSSEC protocol) section 3.1.4.1 Responding 1123 * to Queries for DS RRs. 1124 */ 1125 if (exact && q->qtype == TYPE_DS && closest_encloser == q->zone->apex) { 1126 /* 1127 * Type DS query at a zone cut, use the responsible 1128 * parent zone to generate the answer if we are 1129 * authoritative for the parent zone. 1130 */ 1131 zone_type *zone = domain_find_parent_zone(q->zone); 1132 if (zone) 1133 q->zone = zone; 1134 } 1135 1136 /* see if the zone has expired (for secondary zones) */ 1137 if(q->zone && q->zone->opts && zone_is_slave(q->zone->opts) 1138 && !q->zone->is_ok) { 1139 if(q->cname_count == 0) 1140 RCODE_SET(q->packet, RCODE_SERVFAIL); 1141 return; 1142 } 1143 1144 if (exact && q->qtype == TYPE_DS && closest_encloser == q->zone->apex) { 1145 /* 1146 * Type DS query at the zone apex (and the server is 1147 * not authoratitive for the parent zone). 1148 */ 1149 if (q->qclass == CLASS_ANY) { 1150 AA_CLR(q->packet); 1151 } else { 1152 AA_SET(q->packet); 1153 } 1154 answer_nodata(q, answer, closest_encloser); 1155 } else { 1156 q->delegation_domain = domain_find_ns_rrsets( 1157 closest_encloser, q->zone, &q->delegation_rrset); 1158 1159 if (!q->delegation_domain 1160 || (exact && q->qtype == TYPE_DS && closest_encloser == q->delegation_domain)) 1161 { 1162 if (q->qclass == CLASS_ANY) { 1163 AA_CLR(q->packet); 1164 } else { 1165 AA_SET(q->packet); 1166 } 1167 answer_authoritative(nsd, q, answer, domain_number, exact, 1168 closest_match, closest_encloser, qname); 1169 } 1170 else { 1171 answer_delegation(q, answer); 1172 } 1173 } 1174 } 1175 1176 static void 1177 answer_query(struct nsd *nsd, struct query *q) 1178 { 1179 domain_type *closest_match; 1180 domain_type *closest_encloser; 1181 int exact; 1182 uint16_t offset; 1183 answer_type answer; 1184 1185 answer_init(&answer); 1186 1187 exact = namedb_lookup(nsd->db, q->qname, &closest_match, &closest_encloser); 1188 if (!closest_encloser->is_existing) { 1189 exact = 0; 1190 while (closest_encloser != NULL && !closest_encloser->is_existing) 1191 closest_encloser = closest_encloser->parent; 1192 } 1193 if(!closest_encloser) { 1194 RCODE_SET(q->packet, RCODE_SERVFAIL); 1195 return; 1196 } 1197 1198 q->domain = closest_encloser; 1199 answer_lookup_zone(nsd, q, &answer, 0, exact, closest_match, 1200 closest_encloser, q->qname); 1201 1202 offset = dname_label_offsets(q->qname)[domain_dname(closest_encloser)->label_count - 1] + QHEADERSZ; 1203 query_add_compression_domain(q, closest_encloser, offset); 1204 encode_answer(q, &answer); 1205 query_clear_compression_tables(q); 1206 } 1207 1208 void 1209 query_prepare_response(query_type *q) 1210 { 1211 uint16_t flags; 1212 1213 /* 1214 * Preserve the data up-to the current packet's limit. 1215 */ 1216 buffer_set_position(q->packet, buffer_limit(q->packet)); 1217 buffer_set_limit(q->packet, buffer_capacity(q->packet)); 1218 1219 /* 1220 * Reserve space for the EDNS records if required. 1221 */ 1222 q->reserved_space = edns_reserved_space(&q->edns); 1223 q->reserved_space += tsig_reserved_space(&q->tsig); 1224 1225 /* Update the flags. */ 1226 flags = FLAGS(q->packet); 1227 flags &= 0x0100U; /* Preserve the RD flag. */ 1228 /* CD flag must be cleared for auth answers */ 1229 flags |= 0x8000U; /* Set the QR flag. */ 1230 FLAGS_SET(q->packet, flags); 1231 } 1232 1233 /* 1234 * Processes the query. 1235 * 1236 */ 1237 query_state_type 1238 query_process(query_type *q, nsd_type *nsd) 1239 { 1240 /* The query... */ 1241 nsd_rc_type rc; 1242 query_state_type query_state; 1243 uint16_t arcount; 1244 1245 /* Sanity checks */ 1246 if (buffer_limit(q->packet) < QHEADERSZ) { 1247 /* packet too small to contain DNS header. 1248 Now packet investigation macros will work without problems. */ 1249 return QUERY_DISCARDED; 1250 } 1251 if (QR(q->packet)) { 1252 /* Not a query? Drop it on the floor. */ 1253 return QUERY_DISCARDED; 1254 } 1255 1256 if(!process_query_section(q)) { 1257 return query_formerr(q); 1258 } 1259 1260 /* Update statistics. */ 1261 STATUP2(nsd, opcode, q->opcode); 1262 STATUP2(nsd, qtype, q->qtype); 1263 STATUP2(nsd, qclass, q->qclass); 1264 1265 if (q->opcode != OPCODE_QUERY) { 1266 if (q->opcode == OPCODE_NOTIFY) { 1267 return answer_notify(nsd, q); 1268 } else { 1269 return query_error(q, NSD_RC_IMPL); 1270 } 1271 } 1272 1273 /* Dont bother to answer more than one question at once... */ 1274 if (QDCOUNT(q->packet) != 1 || TC(q->packet)) { 1275 FLAGS_SET(q->packet, 0); 1276 return query_formerr(q); 1277 } 1278 1279 /* Dont allow any records in the answer or authority section... 1280 except for IXFR queries. */ 1281 if (ANCOUNT(q->packet) != 0 || 1282 (q->qtype!=TYPE_IXFR && NSCOUNT(q->packet) != 0)) { 1283 return query_formerr(q); 1284 } 1285 if(q->qtype==TYPE_IXFR && NSCOUNT(q->packet) > 0) { 1286 int i; /* skip ixfr soa information data here */ 1287 for(i=0; i< NSCOUNT(q->packet); i++) 1288 if(!packet_skip_rr(q->packet, 0)) 1289 return query_formerr(q); 1290 } 1291 1292 arcount = ARCOUNT(q->packet); 1293 if (arcount > 0) { 1294 /* see if tsig is before edns record */ 1295 if (!tsig_parse_rr(&q->tsig, q->packet)) 1296 return query_formerr(q); 1297 if(q->tsig.status != TSIG_NOT_PRESENT) 1298 --arcount; 1299 } 1300 if (arcount > 0) { 1301 if (edns_parse_record(&q->edns, q->packet)) 1302 --arcount; 1303 } 1304 if (arcount > 0 && q->tsig.status == TSIG_NOT_PRESENT) { 1305 /* see if tsig is after the edns record */ 1306 if (!tsig_parse_rr(&q->tsig, q->packet)) 1307 return query_formerr(q); 1308 if(q->tsig.status != TSIG_NOT_PRESENT) 1309 --arcount; 1310 } 1311 if (arcount > 0) { 1312 return query_formerr(q); 1313 } 1314 1315 /* Do we have any trailing garbage? */ 1316 #ifdef STRICT_MESSAGE_PARSE 1317 if (buffer_remaining(q->packet) > 0) { 1318 /* If we're strict.... */ 1319 return query_formerr(q); 1320 } 1321 #endif 1322 /* Remove trailing garbage. */ 1323 buffer_set_limit(q->packet, buffer_position(q->packet)); 1324 1325 rc = process_tsig(q); 1326 if (rc != NSD_RC_OK) { 1327 return query_error(q, rc); 1328 } 1329 rc = process_edns(nsd, q); 1330 if (rc != NSD_RC_OK) { 1331 /* We should not return FORMERR, but BADVERS (=16). 1332 * BADVERS is created with Ext. RCODE, followed by RCODE. 1333 * Ext. RCODE is set to 1, RCODE must be 0 (getting 0x10 = 16). 1334 * Thus RCODE = NOERROR = NSD_RC_OK. */ 1335 return query_error(q, NSD_RC_OK); 1336 } 1337 1338 query_prepare_response(q); 1339 1340 if (q->qclass != CLASS_IN && q->qclass != CLASS_ANY) { 1341 if (q->qclass == CLASS_CH) { 1342 return answer_chaos(nsd, q); 1343 } else { 1344 return query_error(q, NSD_RC_REFUSE); 1345 } 1346 } 1347 1348 query_state = answer_axfr_ixfr(nsd, q); 1349 if (query_state == QUERY_PROCESSED || query_state == QUERY_IN_AXFR) { 1350 return query_state; 1351 } 1352 1353 answer_query(nsd, q); 1354 1355 return QUERY_PROCESSED; 1356 } 1357 1358 void 1359 query_add_optional(query_type *q, nsd_type *nsd) 1360 { 1361 struct edns_data *edns = &nsd->edns_ipv4; 1362 #if defined(INET6) 1363 if (q->addr.ss_family == AF_INET6) { 1364 edns = &nsd->edns_ipv6; 1365 } 1366 #endif 1367 switch (q->edns.status) { 1368 case EDNS_NOT_PRESENT: 1369 break; 1370 case EDNS_OK: 1371 buffer_write(q->packet, edns->ok, OPT_LEN); 1372 if (nsd->nsid_len > 0 && q->edns.nsid == 1 && 1373 !query_overflow_nsid(q, nsd->nsid_len)) { 1374 /* rdata length */ 1375 buffer_write(q->packet, edns->rdata_nsid, OPT_RDATA); 1376 /* nsid opt header */ 1377 buffer_write(q->packet, edns->nsid, OPT_HDR); 1378 /* nsid payload */ 1379 buffer_write(q->packet, nsd->nsid, nsd->nsid_len); 1380 } else { 1381 /* fill with NULLs */ 1382 buffer_write(q->packet, edns->rdata_none, OPT_RDATA); 1383 } 1384 ARCOUNT_SET(q->packet, ARCOUNT(q->packet) + 1); 1385 STATUP(nsd, edns); 1386 break; 1387 case EDNS_ERROR: 1388 buffer_write(q->packet, edns->error, OPT_LEN); 1389 buffer_write(q->packet, edns->rdata_none, OPT_RDATA); 1390 ARCOUNT_SET(q->packet, ARCOUNT(q->packet) + 1); 1391 STATUP(nsd, ednserr); 1392 break; 1393 } 1394 1395 if (q->tsig.status != TSIG_NOT_PRESENT) { 1396 if (q->tsig.status == TSIG_ERROR || 1397 q->tsig.error_code != TSIG_ERROR_NOERROR) { 1398 tsig_error_reply(&q->tsig); 1399 tsig_append_rr(&q->tsig, q->packet); 1400 ARCOUNT_SET(q->packet, ARCOUNT(q->packet) + 1); 1401 } else if(q->tsig.status == TSIG_OK && 1402 q->tsig.error_code == TSIG_ERROR_NOERROR) 1403 { 1404 if(q->tsig_prepare_it) 1405 tsig_prepare(&q->tsig); 1406 if(q->tsig_update_it) 1407 tsig_update(&q->tsig, q->packet, buffer_position(q->packet)); 1408 if(q->tsig_sign_it) { 1409 tsig_sign(&q->tsig); 1410 tsig_append_rr(&q->tsig, q->packet); 1411 ARCOUNT_SET(q->packet, ARCOUNT(q->packet) + 1); 1412 } 1413 } 1414 } 1415 } 1416