1 /* 2 * iterator/iter_utils.c - iterative resolver module utility functions. 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 /** 37 * \file 38 * 39 * This file contains functions to assist the iterator module. 40 * Configuration options. Forward zones. 41 */ 42 #include "config.h" 43 #include "iterator/iter_utils.h" 44 #include "iterator/iterator.h" 45 #include "iterator/iter_hints.h" 46 #include "iterator/iter_fwd.h" 47 #include "iterator/iter_donotq.h" 48 #include "iterator/iter_delegpt.h" 49 #include "iterator/iter_priv.h" 50 #include "services/cache/infra.h" 51 #include "services/cache/dns.h" 52 #include "services/cache/rrset.h" 53 #include "util/net_help.h" 54 #include "util/module.h" 55 #include "util/log.h" 56 #include "util/config_file.h" 57 #include "util/regional.h" 58 #include "util/data/msgparse.h" 59 #include "util/data/dname.h" 60 #include "util/random.h" 61 #include "util/fptr_wlist.h" 62 #include "validator/val_anchor.h" 63 #include "validator/val_kcache.h" 64 #include "validator/val_kentry.h" 65 #include "validator/val_utils.h" 66 #include "validator/val_sigcrypt.h" 67 #include "sldns/sbuffer.h" 68 #include "sldns/str2wire.h" 69 70 /** time when nameserver glue is said to be 'recent' */ 71 #define SUSPICION_RECENT_EXPIRY 86400 72 /** penalty to validation failed blacklisted IPs */ 73 #define BLACKLIST_PENALTY (USEFUL_SERVER_TOP_TIMEOUT*4) 74 75 /** fillup fetch policy array */ 76 static void 77 fetch_fill(struct iter_env* ie, const char* str) 78 { 79 char* s = (char*)str, *e; 80 int i; 81 for(i=0; i<ie->max_dependency_depth+1; i++) { 82 ie->target_fetch_policy[i] = strtol(s, &e, 10); 83 if(s == e) 84 fatal_exit("cannot parse fetch policy number %s", s); 85 s = e; 86 } 87 } 88 89 /** Read config string that represents the target fetch policy */ 90 static int 91 read_fetch_policy(struct iter_env* ie, const char* str) 92 { 93 int count = cfg_count_numbers(str); 94 if(count < 1) { 95 log_err("Cannot parse target fetch policy: \"%s\"", str); 96 return 0; 97 } 98 ie->max_dependency_depth = count - 1; 99 ie->target_fetch_policy = (int*)calloc( 100 (size_t)ie->max_dependency_depth+1, sizeof(int)); 101 if(!ie->target_fetch_policy) { 102 log_err("alloc fetch policy: out of memory"); 103 return 0; 104 } 105 fetch_fill(ie, str); 106 return 1; 107 } 108 109 /** apply config caps whitelist items to name tree */ 110 static int 111 caps_white_apply_cfg(rbtree_type* ntree, struct config_file* cfg) 112 { 113 struct config_strlist* p; 114 for(p=cfg->caps_whitelist; p; p=p->next) { 115 struct name_tree_node* n; 116 size_t len; 117 uint8_t* nm = sldns_str2wire_dname(p->str, &len); 118 if(!nm) { 119 log_err("could not parse %s", p->str); 120 return 0; 121 } 122 n = (struct name_tree_node*)calloc(1, sizeof(*n)); 123 if(!n) { 124 log_err("out of memory"); 125 free(nm); 126 return 0; 127 } 128 n->node.key = n; 129 n->name = nm; 130 n->len = len; 131 n->labs = dname_count_labels(nm); 132 n->dclass = LDNS_RR_CLASS_IN; 133 if(!name_tree_insert(ntree, n, nm, len, n->labs, n->dclass)) { 134 /* duplicate element ignored, idempotent */ 135 free(n->name); 136 free(n); 137 } 138 } 139 name_tree_init_parents(ntree); 140 return 1; 141 } 142 143 int 144 iter_apply_cfg(struct iter_env* iter_env, struct config_file* cfg) 145 { 146 int i; 147 /* target fetch policy */ 148 if(!read_fetch_policy(iter_env, cfg->target_fetch_policy)) 149 return 0; 150 for(i=0; i<iter_env->max_dependency_depth+1; i++) 151 verbose(VERB_QUERY, "target fetch policy for level %d is %d", 152 i, iter_env->target_fetch_policy[i]); 153 154 if(!iter_env->donotq) 155 iter_env->donotq = donotq_create(); 156 if(!iter_env->donotq || !donotq_apply_cfg(iter_env->donotq, cfg)) { 157 log_err("Could not set donotqueryaddresses"); 158 return 0; 159 } 160 if(!iter_env->priv) 161 iter_env->priv = priv_create(); 162 if(!iter_env->priv || !priv_apply_cfg(iter_env->priv, cfg)) { 163 log_err("Could not set private addresses"); 164 return 0; 165 } 166 if(cfg->caps_whitelist) { 167 if(!iter_env->caps_white) 168 iter_env->caps_white = rbtree_create(name_tree_compare); 169 if(!iter_env->caps_white || !caps_white_apply_cfg( 170 iter_env->caps_white, cfg)) { 171 log_err("Could not set capsforid whitelist"); 172 return 0; 173 } 174 175 } 176 iter_env->supports_ipv6 = cfg->do_ip6; 177 iter_env->supports_ipv4 = cfg->do_ip4; 178 return 1; 179 } 180 181 /** filter out unsuitable targets 182 * @param iter_env: iterator environment with ipv6-support flag. 183 * @param env: module environment with infra cache. 184 * @param name: zone name 185 * @param namelen: length of name 186 * @param qtype: query type (host order). 187 * @param now: current time 188 * @param a: address in delegation point we are examining. 189 * @return an integer that signals the target suitability. 190 * as follows: 191 * -1: The address should be omitted from the list. 192 * Because: 193 * o The address is bogus (DNSSEC validation failure). 194 * o Listed as donotquery 195 * o is ipv6 but no ipv6 support (in operating system). 196 * o is ipv4 but no ipv4 support (in operating system). 197 * o is lame 198 * Otherwise, an rtt in milliseconds. 199 * 0 .. USEFUL_SERVER_TOP_TIMEOUT-1 200 * The roundtrip time timeout estimate. less than 2 minutes. 201 * Note that util/rtt.c has a MIN_TIMEOUT of 50 msec, thus 202 * values 0 .. 49 are not used, unless that is changed. 203 * USEFUL_SERVER_TOP_TIMEOUT 204 * This value exactly is given for unresponsive blacklisted. 205 * USEFUL_SERVER_TOP_TIMEOUT+1 206 * For non-blacklisted servers: huge timeout, but has traffic. 207 * USEFUL_SERVER_TOP_TIMEOUT*1 .. 208 * parent-side lame servers get this penalty. A dispreferential 209 * server. (lame in delegpt). 210 * USEFUL_SERVER_TOP_TIMEOUT*2 .. 211 * dnsseclame servers get penalty 212 * USEFUL_SERVER_TOP_TIMEOUT*3 .. 213 * recursion lame servers get penalty 214 * UNKNOWN_SERVER_NICENESS 215 * If no information is known about the server, this is 216 * returned. 376 msec or so. 217 * +BLACKLIST_PENALTY (of USEFUL_TOP_TIMEOUT*4) for dnssec failed IPs. 218 * 219 * When a final value is chosen that is dnsseclame ; dnsseclameness checking 220 * is turned off (so we do not discard the reply). 221 * When a final value is chosen that is recursionlame; RD bit is set on query. 222 * Because of the numbers this means recursionlame also have dnssec lameness 223 * checking turned off. 224 */ 225 static int 226 iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env, 227 uint8_t* name, size_t namelen, uint16_t qtype, time_t now, 228 struct delegpt_addr* a) 229 { 230 int rtt, lame, reclame, dnsseclame; 231 if(a->bogus) 232 return -1; /* address of server is bogus */ 233 if(donotq_lookup(iter_env->donotq, &a->addr, a->addrlen)) { 234 log_addr(VERB_ALGO, "skip addr on the donotquery list", 235 &a->addr, a->addrlen); 236 return -1; /* server is on the donotquery list */ 237 } 238 if(!iter_env->supports_ipv6 && addr_is_ip6(&a->addr, a->addrlen)) { 239 return -1; /* there is no ip6 available */ 240 } 241 if(!iter_env->supports_ipv4 && !addr_is_ip6(&a->addr, a->addrlen)) { 242 return -1; /* there is no ip4 available */ 243 } 244 /* check lameness - need zone , class info */ 245 if(infra_get_lame_rtt(env->infra_cache, &a->addr, a->addrlen, 246 name, namelen, qtype, &lame, &dnsseclame, &reclame, 247 &rtt, now)) { 248 log_addr(VERB_ALGO, "servselect", &a->addr, a->addrlen); 249 verbose(VERB_ALGO, " rtt=%d%s%s%s%s", rtt, 250 lame?" LAME":"", 251 dnsseclame?" DNSSEC_LAME":"", 252 reclame?" REC_LAME":"", 253 a->lame?" ADDR_LAME":""); 254 if(lame) 255 return -1; /* server is lame */ 256 else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT) 257 /* server is unresponsive, 258 * we used to return TOP_TIMEOUT, but fairly useless, 259 * because if == TOP_TIMEOUT is dropped because 260 * blacklisted later, instead, remove it here, so 261 * other choices (that are not blacklisted) can be 262 * tried */ 263 return -1; 264 /* select remainder from worst to best */ 265 else if(reclame) 266 return rtt+USEFUL_SERVER_TOP_TIMEOUT*3; /* nonpref */ 267 else if(dnsseclame || a->dnsseclame) 268 return rtt+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */ 269 else if(a->lame) 270 return rtt+USEFUL_SERVER_TOP_TIMEOUT+1; /* nonpref */ 271 else return rtt; 272 } 273 /* no server information present */ 274 if(a->dnsseclame) 275 return UNKNOWN_SERVER_NICENESS+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */ 276 else if(a->lame) 277 return USEFUL_SERVER_TOP_TIMEOUT+1+UNKNOWN_SERVER_NICENESS; /* nonpref */ 278 return UNKNOWN_SERVER_NICENESS; 279 } 280 281 /** lookup RTT information, and also store fastest rtt (if any) */ 282 static int 283 iter_fill_rtt(struct iter_env* iter_env, struct module_env* env, 284 uint8_t* name, size_t namelen, uint16_t qtype, time_t now, 285 struct delegpt* dp, int* best_rtt, struct sock_list* blacklist, 286 size_t* num_suitable_results) 287 { 288 int got_it = 0; 289 struct delegpt_addr* a; 290 *num_suitable_results = 0; 291 292 if(dp->bogus) 293 return 0; /* NS bogus, all bogus, nothing found */ 294 for(a=dp->result_list; a; a = a->next_result) { 295 a->sel_rtt = iter_filter_unsuitable(iter_env, env, 296 name, namelen, qtype, now, a); 297 if(a->sel_rtt != -1) { 298 if(sock_list_find(blacklist, &a->addr, a->addrlen)) 299 a->sel_rtt += BLACKLIST_PENALTY; 300 301 if(!got_it) { 302 *best_rtt = a->sel_rtt; 303 got_it = 1; 304 } else if(a->sel_rtt < *best_rtt) { 305 *best_rtt = a->sel_rtt; 306 } 307 (*num_suitable_results)++; 308 } 309 } 310 return got_it; 311 } 312 313 /** compare two rtts, return -1, 0 or 1 */ 314 static int 315 rtt_compare(const void* x, const void* y) 316 { 317 if(*(int*)x == *(int*)y) 318 return 0; 319 if(*(int*)x > *(int*)y) 320 return 1; 321 return -1; 322 } 323 324 /** get RTT for the Nth fastest server */ 325 static int 326 nth_rtt(struct delegpt_addr* result_list, size_t num_results, size_t n) 327 { 328 int rtt_band; 329 size_t i; 330 int* rtt_list, *rtt_index; 331 332 if(num_results < 1 || n >= num_results) { 333 return -1; 334 } 335 336 rtt_list = calloc(num_results, sizeof(int)); 337 if(!rtt_list) { 338 log_err("malloc failure: allocating rtt_list"); 339 return -1; 340 } 341 rtt_index = rtt_list; 342 343 for(i=0; i<num_results && result_list; i++) { 344 if(result_list->sel_rtt != -1) { 345 *rtt_index = result_list->sel_rtt; 346 rtt_index++; 347 } 348 result_list=result_list->next_result; 349 } 350 qsort(rtt_list, num_results, sizeof(*rtt_list), rtt_compare); 351 352 log_assert(n > 0); 353 rtt_band = rtt_list[n-1]; 354 free(rtt_list); 355 356 return rtt_band; 357 } 358 359 /** filter the address list, putting best targets at front, 360 * returns number of best targets (or 0, no suitable targets) */ 361 static int 362 iter_filter_order(struct iter_env* iter_env, struct module_env* env, 363 uint8_t* name, size_t namelen, uint16_t qtype, time_t now, 364 struct delegpt* dp, int* selected_rtt, int open_target, 365 struct sock_list* blacklist, time_t prefetch) 366 { 367 int got_num = 0, low_rtt = 0, swap_to_front, rtt_band = RTT_BAND, nth; 368 size_t num_results; 369 struct delegpt_addr* a, *n, *prev=NULL; 370 371 /* fillup sel_rtt and find best rtt in the bunch */ 372 got_num = iter_fill_rtt(iter_env, env, name, namelen, qtype, now, dp, 373 &low_rtt, blacklist, &num_results); 374 if(got_num == 0) 375 return 0; 376 if(low_rtt >= USEFUL_SERVER_TOP_TIMEOUT && 377 (delegpt_count_missing_targets(dp) > 0 || open_target > 0)) { 378 verbose(VERB_ALGO, "Bad choices, trying to get more choice"); 379 return 0; /* we want more choice. The best choice is a bad one. 380 return 0 to force the caller to fetch more */ 381 } 382 383 if(env->cfg->fast_server_permil != 0 && prefetch == 0 && 384 num_results > env->cfg->fast_server_num && 385 ub_random_max(env->rnd, 1000) < env->cfg->fast_server_permil) { 386 /* the query is not prefetch, but for a downstream client, 387 * there are more servers available then the fastest N we want 388 * to choose from. Limit our choice to the fastest servers. */ 389 nth = nth_rtt(dp->result_list, num_results, 390 env->cfg->fast_server_num); 391 if(nth > 0) { 392 rtt_band = nth - low_rtt; 393 if(rtt_band > RTT_BAND) 394 rtt_band = RTT_BAND; 395 } 396 } 397 398 got_num = 0; 399 a = dp->result_list; 400 while(a) { 401 /* skip unsuitable targets */ 402 if(a->sel_rtt == -1) { 403 prev = a; 404 a = a->next_result; 405 continue; 406 } 407 /* classify the server address and determine what to do */ 408 swap_to_front = 0; 409 if(a->sel_rtt >= low_rtt && a->sel_rtt - low_rtt <= rtt_band) { 410 got_num++; 411 swap_to_front = 1; 412 } else if(a->sel_rtt<low_rtt && low_rtt-a->sel_rtt<=rtt_band) { 413 got_num++; 414 swap_to_front = 1; 415 } 416 /* swap to front if necessary, or move to next result */ 417 if(swap_to_front && prev) { 418 n = a->next_result; 419 prev->next_result = n; 420 a->next_result = dp->result_list; 421 dp->result_list = a; 422 a = n; 423 } else { 424 prev = a; 425 a = a->next_result; 426 } 427 } 428 *selected_rtt = low_rtt; 429 430 if (env->cfg->prefer_ip6) { 431 int got_num6 = 0; 432 int low_rtt6 = 0; 433 int i; 434 int attempt = -1; /* filter to make sure addresses have 435 less attempts on them than the first, to force round 436 robin when all the IPv6 addresses fail */ 437 int num4ok = 0; /* number ip4 at low attempt count */ 438 int num4_lowrtt = 0; 439 prev = NULL; 440 a = dp->result_list; 441 for(i = 0; i < got_num; i++) { 442 swap_to_front = 0; 443 if(a->addr.ss_family != AF_INET6 && attempt == -1) { 444 /* if we only have ip4 at low attempt count, 445 * then ip6 is failing, and we need to 446 * select one of the remaining IPv4 addrs */ 447 attempt = a->attempts; 448 num4ok++; 449 num4_lowrtt = a->sel_rtt; 450 } else if(a->addr.ss_family != AF_INET6 && attempt == a->attempts) { 451 num4ok++; 452 if(num4_lowrtt == 0 || a->sel_rtt < num4_lowrtt) { 453 num4_lowrtt = a->sel_rtt; 454 } 455 } 456 if(a->addr.ss_family == AF_INET6) { 457 if(attempt == -1) { 458 attempt = a->attempts; 459 } else if(a->attempts > attempt) { 460 break; 461 } 462 got_num6++; 463 swap_to_front = 1; 464 if(low_rtt6 == 0 || a->sel_rtt < low_rtt6) { 465 low_rtt6 = a->sel_rtt; 466 } 467 } 468 /* swap to front if IPv6, or move to next result */ 469 if(swap_to_front && prev) { 470 n = a->next_result; 471 prev->next_result = n; 472 a->next_result = dp->result_list; 473 dp->result_list = a; 474 a = n; 475 } else { 476 prev = a; 477 a = a->next_result; 478 } 479 } 480 if(got_num6 > 0) { 481 got_num = got_num6; 482 *selected_rtt = low_rtt6; 483 } else if(num4ok > 0) { 484 got_num = num4ok; 485 *selected_rtt = num4_lowrtt; 486 } 487 } 488 return got_num; 489 } 490 491 struct delegpt_addr* 492 iter_server_selection(struct iter_env* iter_env, 493 struct module_env* env, struct delegpt* dp, 494 uint8_t* name, size_t namelen, uint16_t qtype, int* dnssec_lame, 495 int* chase_to_rd, int open_target, struct sock_list* blacklist, 496 time_t prefetch) 497 { 498 int sel; 499 int selrtt; 500 struct delegpt_addr* a, *prev; 501 int num = iter_filter_order(iter_env, env, name, namelen, qtype, 502 *env->now, dp, &selrtt, open_target, blacklist, prefetch); 503 504 if(num == 0) 505 return NULL; 506 verbose(VERB_ALGO, "selrtt %d", selrtt); 507 if(selrtt > BLACKLIST_PENALTY) { 508 if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*3) { 509 verbose(VERB_ALGO, "chase to " 510 "blacklisted recursion lame server"); 511 *chase_to_rd = 1; 512 } 513 if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*2) { 514 verbose(VERB_ALGO, "chase to " 515 "blacklisted dnssec lame server"); 516 *dnssec_lame = 1; 517 } 518 } else { 519 if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*3) { 520 verbose(VERB_ALGO, "chase to recursion lame server"); 521 *chase_to_rd = 1; 522 } 523 if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*2) { 524 verbose(VERB_ALGO, "chase to dnssec lame server"); 525 *dnssec_lame = 1; 526 } 527 if(selrtt == USEFUL_SERVER_TOP_TIMEOUT) { 528 verbose(VERB_ALGO, "chase to blacklisted lame server"); 529 return NULL; 530 } 531 } 532 533 if(num == 1) { 534 a = dp->result_list; 535 if(++a->attempts < OUTBOUND_MSG_RETRY) 536 return a; 537 dp->result_list = a->next_result; 538 return a; 539 } 540 541 /* randomly select a target from the list */ 542 log_assert(num > 1); 543 /* grab secure random number, to pick unexpected server. 544 * also we need it to be threadsafe. */ 545 sel = ub_random_max(env->rnd, num); 546 a = dp->result_list; 547 prev = NULL; 548 while(sel > 0 && a) { 549 prev = a; 550 a = a->next_result; 551 sel--; 552 } 553 if(!a) /* robustness */ 554 return NULL; 555 if(++a->attempts < OUTBOUND_MSG_RETRY) 556 return a; 557 /* remove it from the delegation point result list */ 558 if(prev) 559 prev->next_result = a->next_result; 560 else dp->result_list = a->next_result; 561 return a; 562 } 563 564 struct dns_msg* 565 dns_alloc_msg(sldns_buffer* pkt, struct msg_parse* msg, 566 struct regional* region) 567 { 568 struct dns_msg* m = (struct dns_msg*)regional_alloc(region, 569 sizeof(struct dns_msg)); 570 if(!m) 571 return NULL; 572 memset(m, 0, sizeof(*m)); 573 if(!parse_create_msg(pkt, msg, NULL, &m->qinfo, &m->rep, region)) { 574 log_err("malloc failure: allocating incoming dns_msg"); 575 return NULL; 576 } 577 return m; 578 } 579 580 struct dns_msg* 581 dns_copy_msg(struct dns_msg* from, struct regional* region) 582 { 583 struct dns_msg* m = (struct dns_msg*)regional_alloc(region, 584 sizeof(struct dns_msg)); 585 if(!m) 586 return NULL; 587 m->qinfo = from->qinfo; 588 if(!(m->qinfo.qname = regional_alloc_init(region, from->qinfo.qname, 589 from->qinfo.qname_len))) 590 return NULL; 591 if(!(m->rep = reply_info_copy(from->rep, NULL, region))) 592 return NULL; 593 return m; 594 } 595 596 void 597 iter_dns_store(struct module_env* env, struct query_info* msgqinf, 598 struct reply_info* msgrep, int is_referral, time_t leeway, int pside, 599 struct regional* region, uint16_t flags) 600 { 601 if(!dns_cache_store(env, msgqinf, msgrep, is_referral, leeway, 602 pside, region, flags)) 603 log_err("out of memory: cannot store data in cache"); 604 } 605 606 int 607 iter_ns_probability(struct ub_randstate* rnd, int n, int m) 608 { 609 int sel; 610 if(n == m) /* 100% chance */ 611 return 1; 612 /* we do not need secure random numbers here, but 613 * we do need it to be threadsafe, so we use this */ 614 sel = ub_random_max(rnd, m); 615 return (sel < n); 616 } 617 618 /** detect dependency cycle for query and target */ 619 static int 620 causes_cycle(struct module_qstate* qstate, uint8_t* name, size_t namelen, 621 uint16_t t, uint16_t c) 622 { 623 struct query_info qinf; 624 qinf.qname = name; 625 qinf.qname_len = namelen; 626 qinf.qtype = t; 627 qinf.qclass = c; 628 qinf.local_alias = NULL; 629 fptr_ok(fptr_whitelist_modenv_detect_cycle( 630 qstate->env->detect_cycle)); 631 return (*qstate->env->detect_cycle)(qstate, &qinf, 632 (uint16_t)(BIT_RD|BIT_CD), qstate->is_priming, 633 qstate->is_valrec); 634 } 635 636 void 637 iter_mark_cycle_targets(struct module_qstate* qstate, struct delegpt* dp) 638 { 639 struct delegpt_ns* ns; 640 for(ns = dp->nslist; ns; ns = ns->next) { 641 if(ns->resolved) 642 continue; 643 /* see if this ns as target causes dependency cycle */ 644 if(causes_cycle(qstate, ns->name, ns->namelen, 645 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass) || 646 causes_cycle(qstate, ns->name, ns->namelen, 647 LDNS_RR_TYPE_A, qstate->qinfo.qclass)) { 648 log_nametypeclass(VERB_QUERY, "skipping target due " 649 "to dependency cycle (harden-glue: no may " 650 "fix some of the cycles)", 651 ns->name, LDNS_RR_TYPE_A, 652 qstate->qinfo.qclass); 653 ns->resolved = 1; 654 } 655 } 656 } 657 658 void 659 iter_mark_pside_cycle_targets(struct module_qstate* qstate, struct delegpt* dp) 660 { 661 struct delegpt_ns* ns; 662 for(ns = dp->nslist; ns; ns = ns->next) { 663 if(ns->done_pside4 && ns->done_pside6) 664 continue; 665 /* see if this ns as target causes dependency cycle */ 666 if(causes_cycle(qstate, ns->name, ns->namelen, 667 LDNS_RR_TYPE_A, qstate->qinfo.qclass)) { 668 log_nametypeclass(VERB_QUERY, "skipping target due " 669 "to dependency cycle", ns->name, 670 LDNS_RR_TYPE_A, qstate->qinfo.qclass); 671 ns->done_pside4 = 1; 672 } 673 if(causes_cycle(qstate, ns->name, ns->namelen, 674 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass)) { 675 log_nametypeclass(VERB_QUERY, "skipping target due " 676 "to dependency cycle", ns->name, 677 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass); 678 ns->done_pside6 = 1; 679 } 680 } 681 } 682 683 int 684 iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags, 685 struct delegpt* dp) 686 { 687 struct delegpt_ns* ns; 688 /* check: 689 * o RD qflag is on. 690 * o no addresses are provided. 691 * o all NS items are required glue. 692 * OR 693 * o RD qflag is on. 694 * o no addresses are provided. 695 * o the query is for one of the nameservers in dp, 696 * and that nameserver is a glue-name for this dp. 697 */ 698 if(!(qflags&BIT_RD)) 699 return 0; 700 /* either available or unused targets */ 701 if(dp->usable_list || dp->result_list) 702 return 0; 703 704 /* see if query is for one of the nameservers, which is glue */ 705 if( (qinfo->qtype == LDNS_RR_TYPE_A || 706 qinfo->qtype == LDNS_RR_TYPE_AAAA) && 707 dname_subdomain_c(qinfo->qname, dp->name) && 708 delegpt_find_ns(dp, qinfo->qname, qinfo->qname_len)) 709 return 1; 710 711 for(ns = dp->nslist; ns; ns = ns->next) { 712 if(ns->resolved) /* skip failed targets */ 713 continue; 714 if(!dname_subdomain_c(ns->name, dp->name)) 715 return 0; /* one address is not required glue */ 716 } 717 return 1; 718 } 719 720 int 721 iter_qname_indicates_dnssec(struct module_env* env, struct query_info *qinfo) 722 { 723 struct trust_anchor* a; 724 if(!env || !env->anchors || !qinfo || !qinfo->qname) 725 return 0; 726 /* a trust anchor exists above the name? */ 727 if((a=anchors_lookup(env->anchors, qinfo->qname, qinfo->qname_len, 728 qinfo->qclass))) { 729 if(a->numDS == 0 && a->numDNSKEY == 0) { 730 /* insecure trust point */ 731 lock_basic_unlock(&a->lock); 732 return 0; 733 } 734 lock_basic_unlock(&a->lock); 735 return 1; 736 } 737 /* no trust anchor above it. */ 738 return 0; 739 } 740 741 int 742 iter_indicates_dnssec(struct module_env* env, struct delegpt* dp, 743 struct dns_msg* msg, uint16_t dclass) 744 { 745 struct trust_anchor* a; 746 /* information not available, !env->anchors can be common */ 747 if(!env || !env->anchors || !dp || !dp->name) 748 return 0; 749 /* a trust anchor exists with this name, RRSIGs expected */ 750 if((a=anchor_find(env->anchors, dp->name, dp->namelabs, dp->namelen, 751 dclass))) { 752 if(a->numDS == 0 && a->numDNSKEY == 0) { 753 /* insecure trust point */ 754 lock_basic_unlock(&a->lock); 755 return 0; 756 } 757 lock_basic_unlock(&a->lock); 758 return 1; 759 } 760 /* see if DS rrset was given, in AUTH section */ 761 if(msg && msg->rep && 762 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, 763 LDNS_RR_TYPE_DS, dclass)) 764 return 1; 765 /* look in key cache */ 766 if(env->key_cache) { 767 struct key_entry_key* kk = key_cache_obtain(env->key_cache, 768 dp->name, dp->namelen, dclass, env->scratch, *env->now); 769 if(kk) { 770 if(query_dname_compare(kk->name, dp->name) == 0) { 771 if(key_entry_isgood(kk) || key_entry_isbad(kk)) { 772 regional_free_all(env->scratch); 773 return 1; 774 } else if(key_entry_isnull(kk)) { 775 regional_free_all(env->scratch); 776 return 0; 777 } 778 } 779 regional_free_all(env->scratch); 780 } 781 } 782 return 0; 783 } 784 785 int 786 iter_msg_has_dnssec(struct dns_msg* msg) 787 { 788 size_t i; 789 if(!msg || !msg->rep) 790 return 0; 791 for(i=0; i<msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) { 792 if(((struct packed_rrset_data*)msg->rep->rrsets[i]-> 793 entry.data)->rrsig_count > 0) 794 return 1; 795 } 796 /* empty message has no DNSSEC info, with DNSSEC the reply is 797 * not empty (NSEC) */ 798 return 0; 799 } 800 801 int iter_msg_from_zone(struct dns_msg* msg, struct delegpt* dp, 802 enum response_type type, uint16_t dclass) 803 { 804 if(!msg || !dp || !msg->rep || !dp->name) 805 return 0; 806 /* SOA RRset - always from reply zone */ 807 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, 808 LDNS_RR_TYPE_SOA, dclass) || 809 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, 810 LDNS_RR_TYPE_SOA, dclass)) 811 return 1; 812 if(type == RESPONSE_TYPE_REFERRAL) { 813 size_t i; 814 /* if it adds a single label, i.e. we expect .com, 815 * and referral to example.com. NS ... , then origin zone 816 * is .com. For a referral to sub.example.com. NS ... then 817 * we do not know, since example.com. may be in between. */ 818 for(i=0; i<msg->rep->an_numrrsets+msg->rep->ns_numrrsets; 819 i++) { 820 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 821 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS && 822 ntohs(s->rk.rrset_class) == dclass) { 823 int l = dname_count_labels(s->rk.dname); 824 if(l == dp->namelabs + 1 && 825 dname_strict_subdomain(s->rk.dname, 826 l, dp->name, dp->namelabs)) 827 return 1; 828 } 829 } 830 return 0; 831 } 832 log_assert(type==RESPONSE_TYPE_ANSWER || type==RESPONSE_TYPE_CNAME); 833 /* not a referral, and not lame delegation (upwards), so, 834 * any NS rrset must be from the zone itself */ 835 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, 836 LDNS_RR_TYPE_NS, dclass) || 837 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, 838 LDNS_RR_TYPE_NS, dclass)) 839 return 1; 840 /* a DNSKEY set is expected at the zone apex as well */ 841 /* this is for 'minimal responses' for DNSKEYs */ 842 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, 843 LDNS_RR_TYPE_DNSKEY, dclass)) 844 return 1; 845 return 0; 846 } 847 848 /** 849 * check equality of two rrsets 850 * @param k1: rrset 851 * @param k2: rrset 852 * @return true if equal 853 */ 854 static int 855 rrset_equal(struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2) 856 { 857 struct packed_rrset_data* d1 = (struct packed_rrset_data*) 858 k1->entry.data; 859 struct packed_rrset_data* d2 = (struct packed_rrset_data*) 860 k2->entry.data; 861 size_t i, t; 862 if(k1->rk.dname_len != k2->rk.dname_len || 863 k1->rk.flags != k2->rk.flags || 864 k1->rk.type != k2->rk.type || 865 k1->rk.rrset_class != k2->rk.rrset_class || 866 query_dname_compare(k1->rk.dname, k2->rk.dname) != 0) 867 return 0; 868 if( /* do not check ttl: d1->ttl != d2->ttl || */ 869 d1->count != d2->count || 870 d1->rrsig_count != d2->rrsig_count || 871 d1->trust != d2->trust || 872 d1->security != d2->security) 873 return 0; 874 t = d1->count + d1->rrsig_count; 875 for(i=0; i<t; i++) { 876 if(d1->rr_len[i] != d2->rr_len[i] || 877 /* no ttl check: d1->rr_ttl[i] != d2->rr_ttl[i] ||*/ 878 memcmp(d1->rr_data[i], d2->rr_data[i], 879 d1->rr_len[i]) != 0) 880 return 0; 881 } 882 return 1; 883 } 884 885 /** compare rrsets and sort canonically. Compares rrset name, type, class. 886 * return 0 if equal, +1 if x > y, and -1 if x < y. 887 */ 888 static int 889 rrset_canonical_sort_cmp(const void* x, const void* y) 890 { 891 struct ub_packed_rrset_key* rrx = *(struct ub_packed_rrset_key**)x; 892 struct ub_packed_rrset_key* rry = *(struct ub_packed_rrset_key**)y; 893 int r = dname_canonical_compare(rrx->rk.dname, rry->rk.dname); 894 if(r != 0) 895 return r; 896 if(rrx->rk.type != rry->rk.type) { 897 if(ntohs(rrx->rk.type) > ntohs(rry->rk.type)) 898 return 1; 899 else return -1; 900 } 901 if(rrx->rk.rrset_class != rry->rk.rrset_class) { 902 if(ntohs(rrx->rk.rrset_class) > ntohs(rry->rk.rrset_class)) 903 return 1; 904 else return -1; 905 } 906 return 0; 907 } 908 909 int 910 reply_equal(struct reply_info* p, struct reply_info* q, struct regional* region) 911 { 912 size_t i; 913 struct ub_packed_rrset_key** sorted_p, **sorted_q; 914 if(p->flags != q->flags || 915 p->qdcount != q->qdcount || 916 /* do not check TTL, this may differ */ 917 /* 918 p->ttl != q->ttl || 919 p->prefetch_ttl != q->prefetch_ttl || 920 */ 921 p->security != q->security || 922 p->an_numrrsets != q->an_numrrsets || 923 p->ns_numrrsets != q->ns_numrrsets || 924 p->ar_numrrsets != q->ar_numrrsets || 925 p->rrset_count != q->rrset_count) 926 return 0; 927 /* sort the rrsets in the authority and additional sections before 928 * compare, the query and answer sections are ordered in the sequence 929 * they should have (eg. one after the other for aliases). */ 930 sorted_p = (struct ub_packed_rrset_key**)regional_alloc_init( 931 region, p->rrsets, sizeof(*sorted_p)*p->rrset_count); 932 if(!sorted_p) return 0; 933 log_assert(p->an_numrrsets + p->ns_numrrsets + p->ar_numrrsets <= 934 p->rrset_count); 935 qsort(sorted_p + p->an_numrrsets, p->ns_numrrsets, 936 sizeof(*sorted_p), rrset_canonical_sort_cmp); 937 qsort(sorted_p + p->an_numrrsets + p->ns_numrrsets, p->ar_numrrsets, 938 sizeof(*sorted_p), rrset_canonical_sort_cmp); 939 940 sorted_q = (struct ub_packed_rrset_key**)regional_alloc_init( 941 region, q->rrsets, sizeof(*sorted_q)*q->rrset_count); 942 if(!sorted_q) { 943 regional_free_all(region); 944 return 0; 945 } 946 log_assert(q->an_numrrsets + q->ns_numrrsets + q->ar_numrrsets <= 947 q->rrset_count); 948 qsort(sorted_q + q->an_numrrsets, q->ns_numrrsets, 949 sizeof(*sorted_q), rrset_canonical_sort_cmp); 950 qsort(sorted_q + q->an_numrrsets + q->ns_numrrsets, q->ar_numrrsets, 951 sizeof(*sorted_q), rrset_canonical_sort_cmp); 952 953 /* compare the rrsets */ 954 for(i=0; i<p->rrset_count; i++) { 955 if(!rrset_equal(sorted_p[i], sorted_q[i])) { 956 if(!rrset_canonical_equal(region, sorted_p[i], 957 sorted_q[i])) { 958 regional_free_all(region); 959 return 0; 960 } 961 } 962 } 963 regional_free_all(region); 964 return 1; 965 } 966 967 void 968 caps_strip_reply(struct reply_info* rep) 969 { 970 size_t i; 971 if(!rep) return; 972 /* see if message is a referral, in which case the additional and 973 * NS record cannot be removed */ 974 /* referrals have the AA flag unset (strict check, not elsewhere in 975 * unbound, but for 0x20 this is very convenient). */ 976 if(!(rep->flags&BIT_AA)) 977 return; 978 /* remove the additional section from the reply */ 979 if(rep->ar_numrrsets != 0) { 980 verbose(VERB_ALGO, "caps fallback: removing additional section"); 981 rep->rrset_count -= rep->ar_numrrsets; 982 rep->ar_numrrsets = 0; 983 } 984 /* is there an NS set in the authority section to remove? */ 985 /* the failure case (Cisco firewalls) only has one rrset in authsec */ 986 for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) { 987 struct ub_packed_rrset_key* s = rep->rrsets[i]; 988 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS) { 989 /* remove NS rrset and break from loop (loop limits 990 * have changed) */ 991 /* move last rrset into this position (there is no 992 * additional section any more) */ 993 verbose(VERB_ALGO, "caps fallback: removing NS rrset"); 994 if(i < rep->rrset_count-1) 995 rep->rrsets[i]=rep->rrsets[rep->rrset_count-1]; 996 rep->rrset_count --; 997 rep->ns_numrrsets --; 998 break; 999 } 1000 } 1001 } 1002 1003 int caps_failed_rcode(struct reply_info* rep) 1004 { 1005 return !(FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NOERROR || 1006 FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NXDOMAIN); 1007 } 1008 1009 void 1010 iter_store_parentside_rrset(struct module_env* env, 1011 struct ub_packed_rrset_key* rrset) 1012 { 1013 struct rrset_ref ref; 1014 rrset = packed_rrset_copy_alloc(rrset, env->alloc, *env->now); 1015 if(!rrset) { 1016 log_err("malloc failure in store_parentside_rrset"); 1017 return; 1018 } 1019 rrset->rk.flags |= PACKED_RRSET_PARENT_SIDE; 1020 rrset->entry.hash = rrset_key_hash(&rrset->rk); 1021 ref.key = rrset; 1022 ref.id = rrset->id; 1023 /* ignore ret: if it was in the cache, ref updated */ 1024 (void)rrset_cache_update(env->rrset_cache, &ref, env->alloc, *env->now); 1025 } 1026 1027 /** fetch NS record from reply, if any */ 1028 static struct ub_packed_rrset_key* 1029 reply_get_NS_rrset(struct reply_info* rep) 1030 { 1031 size_t i; 1032 for(i=0; i<rep->rrset_count; i++) { 1033 if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NS)) { 1034 return rep->rrsets[i]; 1035 } 1036 } 1037 return NULL; 1038 } 1039 1040 void 1041 iter_store_parentside_NS(struct module_env* env, struct reply_info* rep) 1042 { 1043 struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep); 1044 if(rrset) { 1045 log_rrset_key(VERB_ALGO, "store parent-side NS", rrset); 1046 iter_store_parentside_rrset(env, rrset); 1047 } 1048 } 1049 1050 void iter_store_parentside_neg(struct module_env* env, 1051 struct query_info* qinfo, struct reply_info* rep) 1052 { 1053 /* TTL: NS from referral in iq->deleg_msg, 1054 * or first RR from iq->response, 1055 * or servfail5secs if !iq->response */ 1056 time_t ttl = NORR_TTL; 1057 struct ub_packed_rrset_key* neg; 1058 struct packed_rrset_data* newd; 1059 if(rep) { 1060 struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep); 1061 if(!rrset && rep->rrset_count != 0) rrset = rep->rrsets[0]; 1062 if(rrset) ttl = ub_packed_rrset_ttl(rrset); 1063 } 1064 /* create empty rrset to store */ 1065 neg = (struct ub_packed_rrset_key*)regional_alloc(env->scratch, 1066 sizeof(struct ub_packed_rrset_key)); 1067 if(!neg) { 1068 log_err("out of memory in store_parentside_neg"); 1069 return; 1070 } 1071 memset(&neg->entry, 0, sizeof(neg->entry)); 1072 neg->entry.key = neg; 1073 neg->rk.type = htons(qinfo->qtype); 1074 neg->rk.rrset_class = htons(qinfo->qclass); 1075 neg->rk.flags = 0; 1076 neg->rk.dname = regional_alloc_init(env->scratch, qinfo->qname, 1077 qinfo->qname_len); 1078 if(!neg->rk.dname) { 1079 log_err("out of memory in store_parentside_neg"); 1080 return; 1081 } 1082 neg->rk.dname_len = qinfo->qname_len; 1083 neg->entry.hash = rrset_key_hash(&neg->rk); 1084 newd = (struct packed_rrset_data*)regional_alloc_zero(env->scratch, 1085 sizeof(struct packed_rrset_data) + sizeof(size_t) + 1086 sizeof(uint8_t*) + sizeof(time_t) + sizeof(uint16_t)); 1087 if(!newd) { 1088 log_err("out of memory in store_parentside_neg"); 1089 return; 1090 } 1091 neg->entry.data = newd; 1092 newd->ttl = ttl; 1093 /* entry must have one RR, otherwise not valid in cache. 1094 * put in one RR with empty rdata: those are ignored as nameserver */ 1095 newd->count = 1; 1096 newd->rrsig_count = 0; 1097 newd->trust = rrset_trust_ans_noAA; 1098 newd->rr_len = (size_t*)((uint8_t*)newd + 1099 sizeof(struct packed_rrset_data)); 1100 newd->rr_len[0] = 0 /* zero len rdata */ + sizeof(uint16_t); 1101 packed_rrset_ptr_fixup(newd); 1102 newd->rr_ttl[0] = newd->ttl; 1103 sldns_write_uint16(newd->rr_data[0], 0 /* zero len rdata */); 1104 /* store it */ 1105 log_rrset_key(VERB_ALGO, "store parent-side negative", neg); 1106 iter_store_parentside_rrset(env, neg); 1107 } 1108 1109 int 1110 iter_lookup_parent_NS_from_cache(struct module_env* env, struct delegpt* dp, 1111 struct regional* region, struct query_info* qinfo) 1112 { 1113 struct ub_packed_rrset_key* akey; 1114 akey = rrset_cache_lookup(env->rrset_cache, dp->name, 1115 dp->namelen, LDNS_RR_TYPE_NS, qinfo->qclass, 1116 PACKED_RRSET_PARENT_SIDE, *env->now, 0); 1117 if(akey) { 1118 log_rrset_key(VERB_ALGO, "found parent-side NS in cache", akey); 1119 dp->has_parent_side_NS = 1; 1120 /* and mark the new names as lame */ 1121 if(!delegpt_rrset_add_ns(dp, region, akey, 1)) { 1122 lock_rw_unlock(&akey->entry.lock); 1123 return 0; 1124 } 1125 lock_rw_unlock(&akey->entry.lock); 1126 } 1127 return 1; 1128 } 1129 1130 int iter_lookup_parent_glue_from_cache(struct module_env* env, 1131 struct delegpt* dp, struct regional* region, struct query_info* qinfo) 1132 { 1133 struct ub_packed_rrset_key* akey; 1134 struct delegpt_ns* ns; 1135 size_t num = delegpt_count_targets(dp); 1136 for(ns = dp->nslist; ns; ns = ns->next) { 1137 /* get cached parentside A */ 1138 akey = rrset_cache_lookup(env->rrset_cache, ns->name, 1139 ns->namelen, LDNS_RR_TYPE_A, qinfo->qclass, 1140 PACKED_RRSET_PARENT_SIDE, *env->now, 0); 1141 if(akey) { 1142 log_rrset_key(VERB_ALGO, "found parent-side", akey); 1143 ns->done_pside4 = 1; 1144 /* a negative-cache-element has no addresses it adds */ 1145 if(!delegpt_add_rrset_A(dp, region, akey, 1, NULL)) 1146 log_err("malloc failure in lookup_parent_glue"); 1147 lock_rw_unlock(&akey->entry.lock); 1148 } 1149 /* get cached parentside AAAA */ 1150 akey = rrset_cache_lookup(env->rrset_cache, ns->name, 1151 ns->namelen, LDNS_RR_TYPE_AAAA, qinfo->qclass, 1152 PACKED_RRSET_PARENT_SIDE, *env->now, 0); 1153 if(akey) { 1154 log_rrset_key(VERB_ALGO, "found parent-side", akey); 1155 ns->done_pside6 = 1; 1156 /* a negative-cache-element has no addresses it adds */ 1157 if(!delegpt_add_rrset_AAAA(dp, region, akey, 1, NULL)) 1158 log_err("malloc failure in lookup_parent_glue"); 1159 lock_rw_unlock(&akey->entry.lock); 1160 } 1161 } 1162 /* see if new (but lame) addresses have become available */ 1163 return delegpt_count_targets(dp) != num; 1164 } 1165 1166 int 1167 iter_get_next_root(struct iter_hints* hints, struct iter_forwards* fwd, 1168 uint16_t* c) 1169 { 1170 uint16_t c1 = *c, c2 = *c; 1171 int r1 = hints_next_root(hints, &c1); 1172 int r2 = forwards_next_root(fwd, &c2); 1173 if(!r1 && !r2) /* got none, end of list */ 1174 return 0; 1175 else if(!r1) /* got one, return that */ 1176 *c = c2; 1177 else if(!r2) 1178 *c = c1; 1179 else if(c1 < c2) /* got both take smallest */ 1180 *c = c1; 1181 else *c = c2; 1182 return 1; 1183 } 1184 1185 void 1186 iter_scrub_ds(struct dns_msg* msg, struct ub_packed_rrset_key* ns, uint8_t* z) 1187 { 1188 /* Only the DS record for the delegation itself is expected. 1189 * We allow DS for everything between the bailiwick and the 1190 * zonecut, thus DS records must be at or above the zonecut. 1191 * And the DS records must be below the server authority zone. 1192 * The answer section is already scrubbed. */ 1193 size_t i = msg->rep->an_numrrsets; 1194 while(i < (msg->rep->an_numrrsets + msg->rep->ns_numrrsets)) { 1195 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 1196 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS && 1197 (!ns || !dname_subdomain_c(ns->rk.dname, s->rk.dname) 1198 || query_dname_compare(z, s->rk.dname) == 0)) { 1199 log_nametypeclass(VERB_ALGO, "removing irrelevant DS", 1200 s->rk.dname, ntohs(s->rk.type), 1201 ntohs(s->rk.rrset_class)); 1202 memmove(msg->rep->rrsets+i, msg->rep->rrsets+i+1, 1203 sizeof(struct ub_packed_rrset_key*) * 1204 (msg->rep->rrset_count-i-1)); 1205 msg->rep->ns_numrrsets--; 1206 msg->rep->rrset_count--; 1207 /* stay at same i, but new record */ 1208 continue; 1209 } 1210 i++; 1211 } 1212 } 1213 1214 void 1215 iter_scrub_nxdomain(struct dns_msg* msg) 1216 { 1217 if(msg->rep->an_numrrsets == 0) 1218 return; 1219 1220 memmove(msg->rep->rrsets, msg->rep->rrsets+msg->rep->an_numrrsets, 1221 sizeof(struct ub_packed_rrset_key*) * 1222 (msg->rep->rrset_count-msg->rep->an_numrrsets)); 1223 msg->rep->rrset_count -= msg->rep->an_numrrsets; 1224 msg->rep->an_numrrsets = 0; 1225 } 1226 1227 void iter_dec_attempts(struct delegpt* dp, int d) 1228 { 1229 struct delegpt_addr* a; 1230 for(a=dp->target_list; a; a = a->next_target) { 1231 if(a->attempts >= OUTBOUND_MSG_RETRY) { 1232 /* add back to result list */ 1233 a->next_result = dp->result_list; 1234 dp->result_list = a; 1235 } 1236 if(a->attempts > d) 1237 a->attempts -= d; 1238 else a->attempts = 0; 1239 } 1240 } 1241 1242 void iter_merge_retry_counts(struct delegpt* dp, struct delegpt* old) 1243 { 1244 struct delegpt_addr* a, *o, *prev; 1245 for(a=dp->target_list; a; a = a->next_target) { 1246 o = delegpt_find_addr(old, &a->addr, a->addrlen); 1247 if(o) { 1248 log_addr(VERB_ALGO, "copy attempt count previous dp", 1249 &a->addr, a->addrlen); 1250 a->attempts = o->attempts; 1251 } 1252 } 1253 prev = NULL; 1254 a = dp->usable_list; 1255 while(a) { 1256 if(a->attempts >= OUTBOUND_MSG_RETRY) { 1257 log_addr(VERB_ALGO, "remove from usable list dp", 1258 &a->addr, a->addrlen); 1259 /* remove from result list */ 1260 if(prev) 1261 prev->next_usable = a->next_usable; 1262 else dp->usable_list = a->next_usable; 1263 /* prev stays the same */ 1264 a = a->next_usable; 1265 continue; 1266 } 1267 prev = a; 1268 a = a->next_usable; 1269 } 1270 } 1271 1272 int 1273 iter_ds_toolow(struct dns_msg* msg, struct delegpt* dp) 1274 { 1275 /* if for query example.com, there is example.com SOA or a subdomain 1276 * of example.com, then we are too low and need to fetch NS. */ 1277 size_t i; 1278 /* if we have a DNAME or CNAME we are probably wrong */ 1279 /* if we have a qtype DS in the answer section, its fine */ 1280 for(i=0; i < msg->rep->an_numrrsets; i++) { 1281 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 1282 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME || 1283 ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) { 1284 /* not the right answer, maybe too low, check the 1285 * RRSIG signer name (if there is any) for a hint 1286 * that it is from the dp zone anyway */ 1287 uint8_t* sname; 1288 size_t slen; 1289 val_find_rrset_signer(s, &sname, &slen); 1290 if(sname && query_dname_compare(dp->name, sname)==0) 1291 return 0; /* it is fine, from the right dp */ 1292 return 1; 1293 } 1294 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS) 1295 return 0; /* fine, we have a DS record */ 1296 } 1297 for(i=msg->rep->an_numrrsets; 1298 i < msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) { 1299 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 1300 if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA) { 1301 if(dname_subdomain_c(s->rk.dname, msg->qinfo.qname)) 1302 return 1; /* point is too low */ 1303 if(query_dname_compare(s->rk.dname, dp->name)==0) 1304 return 0; /* right dp */ 1305 } 1306 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC || 1307 ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) { 1308 uint8_t* sname; 1309 size_t slen; 1310 val_find_rrset_signer(s, &sname, &slen); 1311 if(sname && query_dname_compare(dp->name, sname)==0) 1312 return 0; /* it is fine, from the right dp */ 1313 return 1; 1314 } 1315 } 1316 /* we do not know */ 1317 return 1; 1318 } 1319 1320 int iter_dp_cangodown(struct query_info* qinfo, struct delegpt* dp) 1321 { 1322 /* no delegation point, do not see how we can go down, 1323 * robust check, it should really exist */ 1324 if(!dp) return 0; 1325 1326 /* see if dp equals the qname, then we cannot go down further */ 1327 if(query_dname_compare(qinfo->qname, dp->name) == 0) 1328 return 0; 1329 /* if dp is one label above the name we also cannot go down further */ 1330 if(dname_count_labels(qinfo->qname) == dp->namelabs+1) 1331 return 0; 1332 return 1; 1333 } 1334 1335 int 1336 iter_stub_fwd_no_cache(struct module_qstate *qstate, struct query_info *qinf) 1337 { 1338 struct iter_hints_stub *stub; 1339 struct delegpt *dp; 1340 1341 /* Check for stub. */ 1342 stub = hints_lookup_stub(qstate->env->hints, qinf->qname, 1343 qinf->qclass, NULL); 1344 dp = forwards_lookup(qstate->env->fwds, qinf->qname, qinf->qclass); 1345 1346 /* see if forward or stub is more pertinent */ 1347 if(stub && stub->dp && dp) { 1348 if(dname_strict_subdomain(dp->name, dp->namelabs, 1349 stub->dp->name, stub->dp->namelabs)) { 1350 stub = NULL; /* ignore stub, forward is lower */ 1351 } else { 1352 dp = NULL; /* ignore forward, stub is lower */ 1353 } 1354 } 1355 1356 /* check stub */ 1357 if (stub != NULL && stub->dp != NULL) { 1358 if(stub->dp->no_cache) { 1359 char qname[255+1]; 1360 char dpname[255+1]; 1361 dname_str(qinf->qname, qname); 1362 dname_str(stub->dp->name, dpname); 1363 verbose(VERB_ALGO, "stub for %s %s has no_cache", qname, dpname); 1364 } 1365 return (stub->dp->no_cache); 1366 } 1367 1368 /* Check for forward. */ 1369 if (dp) { 1370 if(dp->no_cache) { 1371 char qname[255+1]; 1372 char dpname[255+1]; 1373 dname_str(qinf->qname, qname); 1374 dname_str(dp->name, dpname); 1375 verbose(VERB_ALGO, "forward for %s %s has no_cache", qname, dpname); 1376 } 1377 return (dp->no_cache); 1378 } 1379 return 0; 1380 } 1381