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 } else if (env->cfg->prefer_ip4) { 488 int got_num4 = 0; 489 int low_rtt4 = 0; 490 int i; 491 int attempt = -1; /* filter to make sure addresses have 492 less attempts on them than the first, to force round 493 robin when all the IPv4 addresses fail */ 494 int num6ok = 0; /* number ip6 at low attempt count */ 495 int num6_lowrtt = 0; 496 prev = NULL; 497 a = dp->result_list; 498 for(i = 0; i < got_num; i++) { 499 swap_to_front = 0; 500 if(a->addr.ss_family != AF_INET && attempt == -1) { 501 /* if we only have ip6 at low attempt count, 502 * then ip4 is failing, and we need to 503 * select one of the remaining IPv6 addrs */ 504 attempt = a->attempts; 505 num6ok++; 506 num6_lowrtt = a->sel_rtt; 507 } else if(a->addr.ss_family != AF_INET && attempt == a->attempts) { 508 num6ok++; 509 if(num6_lowrtt == 0 || a->sel_rtt < num6_lowrtt) { 510 num6_lowrtt = a->sel_rtt; 511 } 512 } 513 if(a->addr.ss_family == AF_INET) { 514 if(attempt == -1) { 515 attempt = a->attempts; 516 } else if(a->attempts > attempt) { 517 break; 518 } 519 got_num4++; 520 swap_to_front = 1; 521 if(low_rtt4 == 0 || a->sel_rtt < low_rtt4) { 522 low_rtt4 = a->sel_rtt; 523 } 524 } 525 /* swap to front if IPv4, or move to next result */ 526 if(swap_to_front && prev) { 527 n = a->next_result; 528 prev->next_result = n; 529 a->next_result = dp->result_list; 530 dp->result_list = a; 531 a = n; 532 } else { 533 prev = a; 534 a = a->next_result; 535 } 536 } 537 if(got_num4 > 0) { 538 got_num = got_num4; 539 *selected_rtt = low_rtt4; 540 } else if(num6ok > 0) { 541 got_num = num6ok; 542 *selected_rtt = num6_lowrtt; 543 } 544 } 545 return got_num; 546 } 547 548 struct delegpt_addr* 549 iter_server_selection(struct iter_env* iter_env, 550 struct module_env* env, struct delegpt* dp, 551 uint8_t* name, size_t namelen, uint16_t qtype, int* dnssec_lame, 552 int* chase_to_rd, int open_target, struct sock_list* blacklist, 553 time_t prefetch) 554 { 555 int sel; 556 int selrtt; 557 struct delegpt_addr* a, *prev; 558 int num = iter_filter_order(iter_env, env, name, namelen, qtype, 559 *env->now, dp, &selrtt, open_target, blacklist, prefetch); 560 561 if(num == 0) 562 return NULL; 563 verbose(VERB_ALGO, "selrtt %d", selrtt); 564 if(selrtt > BLACKLIST_PENALTY) { 565 if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*3) { 566 verbose(VERB_ALGO, "chase to " 567 "blacklisted recursion lame server"); 568 *chase_to_rd = 1; 569 } 570 if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*2) { 571 verbose(VERB_ALGO, "chase to " 572 "blacklisted dnssec lame server"); 573 *dnssec_lame = 1; 574 } 575 } else { 576 if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*3) { 577 verbose(VERB_ALGO, "chase to recursion lame server"); 578 *chase_to_rd = 1; 579 } 580 if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*2) { 581 verbose(VERB_ALGO, "chase to dnssec lame server"); 582 *dnssec_lame = 1; 583 } 584 if(selrtt == USEFUL_SERVER_TOP_TIMEOUT) { 585 verbose(VERB_ALGO, "chase to blacklisted lame server"); 586 return NULL; 587 } 588 } 589 590 if(num == 1) { 591 a = dp->result_list; 592 if(++a->attempts < OUTBOUND_MSG_RETRY) 593 return a; 594 dp->result_list = a->next_result; 595 return a; 596 } 597 598 /* randomly select a target from the list */ 599 log_assert(num > 1); 600 /* grab secure random number, to pick unexpected server. 601 * also we need it to be threadsafe. */ 602 sel = ub_random_max(env->rnd, num); 603 a = dp->result_list; 604 prev = NULL; 605 while(sel > 0 && a) { 606 prev = a; 607 a = a->next_result; 608 sel--; 609 } 610 if(!a) /* robustness */ 611 return NULL; 612 if(++a->attempts < OUTBOUND_MSG_RETRY) 613 return a; 614 /* remove it from the delegation point result list */ 615 if(prev) 616 prev->next_result = a->next_result; 617 else dp->result_list = a->next_result; 618 return a; 619 } 620 621 struct dns_msg* 622 dns_alloc_msg(sldns_buffer* pkt, struct msg_parse* msg, 623 struct regional* region) 624 { 625 struct dns_msg* m = (struct dns_msg*)regional_alloc(region, 626 sizeof(struct dns_msg)); 627 if(!m) 628 return NULL; 629 memset(m, 0, sizeof(*m)); 630 if(!parse_create_msg(pkt, msg, NULL, &m->qinfo, &m->rep, region)) { 631 log_err("malloc failure: allocating incoming dns_msg"); 632 return NULL; 633 } 634 return m; 635 } 636 637 struct dns_msg* 638 dns_copy_msg(struct dns_msg* from, struct regional* region) 639 { 640 struct dns_msg* m = (struct dns_msg*)regional_alloc(region, 641 sizeof(struct dns_msg)); 642 if(!m) 643 return NULL; 644 m->qinfo = from->qinfo; 645 if(!(m->qinfo.qname = regional_alloc_init(region, from->qinfo.qname, 646 from->qinfo.qname_len))) 647 return NULL; 648 if(!(m->rep = reply_info_copy(from->rep, NULL, region))) 649 return NULL; 650 return m; 651 } 652 653 void 654 iter_dns_store(struct module_env* env, struct query_info* msgqinf, 655 struct reply_info* msgrep, int is_referral, time_t leeway, int pside, 656 struct regional* region, uint16_t flags) 657 { 658 if(!dns_cache_store(env, msgqinf, msgrep, is_referral, leeway, 659 pside, region, flags)) 660 log_err("out of memory: cannot store data in cache"); 661 } 662 663 int 664 iter_ns_probability(struct ub_randstate* rnd, int n, int m) 665 { 666 int sel; 667 if(n == m) /* 100% chance */ 668 return 1; 669 /* we do not need secure random numbers here, but 670 * we do need it to be threadsafe, so we use this */ 671 sel = ub_random_max(rnd, m); 672 return (sel < n); 673 } 674 675 /** detect dependency cycle for query and target */ 676 static int 677 causes_cycle(struct module_qstate* qstate, uint8_t* name, size_t namelen, 678 uint16_t t, uint16_t c) 679 { 680 struct query_info qinf; 681 qinf.qname = name; 682 qinf.qname_len = namelen; 683 qinf.qtype = t; 684 qinf.qclass = c; 685 qinf.local_alias = NULL; 686 fptr_ok(fptr_whitelist_modenv_detect_cycle( 687 qstate->env->detect_cycle)); 688 return (*qstate->env->detect_cycle)(qstate, &qinf, 689 (uint16_t)(BIT_RD|BIT_CD), qstate->is_priming, 690 qstate->is_valrec); 691 } 692 693 void 694 iter_mark_cycle_targets(struct module_qstate* qstate, struct delegpt* dp) 695 { 696 struct delegpt_ns* ns; 697 for(ns = dp->nslist; ns; ns = ns->next) { 698 if(ns->resolved) 699 continue; 700 /* see if this ns as target causes dependency cycle */ 701 if(causes_cycle(qstate, ns->name, ns->namelen, 702 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass) || 703 causes_cycle(qstate, ns->name, ns->namelen, 704 LDNS_RR_TYPE_A, qstate->qinfo.qclass)) { 705 log_nametypeclass(VERB_QUERY, "skipping target due " 706 "to dependency cycle (harden-glue: no may " 707 "fix some of the cycles)", 708 ns->name, LDNS_RR_TYPE_A, 709 qstate->qinfo.qclass); 710 ns->resolved = 1; 711 } 712 } 713 } 714 715 void 716 iter_mark_pside_cycle_targets(struct module_qstate* qstate, struct delegpt* dp) 717 { 718 struct delegpt_ns* ns; 719 for(ns = dp->nslist; ns; ns = ns->next) { 720 if(ns->done_pside4 && ns->done_pside6) 721 continue; 722 /* see if this ns as target causes dependency cycle */ 723 if(causes_cycle(qstate, ns->name, ns->namelen, 724 LDNS_RR_TYPE_A, qstate->qinfo.qclass)) { 725 log_nametypeclass(VERB_QUERY, "skipping target due " 726 "to dependency cycle", ns->name, 727 LDNS_RR_TYPE_A, qstate->qinfo.qclass); 728 ns->done_pside4 = 1; 729 } 730 if(causes_cycle(qstate, ns->name, ns->namelen, 731 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass)) { 732 log_nametypeclass(VERB_QUERY, "skipping target due " 733 "to dependency cycle", ns->name, 734 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass); 735 ns->done_pside6 = 1; 736 } 737 } 738 } 739 740 int 741 iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags, 742 struct delegpt* dp) 743 { 744 struct delegpt_ns* ns; 745 /* check: 746 * o RD qflag is on. 747 * o no addresses are provided. 748 * o all NS items are required glue. 749 * OR 750 * o RD qflag is on. 751 * o no addresses are provided. 752 * o the query is for one of the nameservers in dp, 753 * and that nameserver is a glue-name for this dp. 754 */ 755 if(!(qflags&BIT_RD)) 756 return 0; 757 /* either available or unused targets */ 758 if(dp->usable_list || dp->result_list) 759 return 0; 760 761 /* see if query is for one of the nameservers, which is glue */ 762 if( (qinfo->qtype == LDNS_RR_TYPE_A || 763 qinfo->qtype == LDNS_RR_TYPE_AAAA) && 764 dname_subdomain_c(qinfo->qname, dp->name) && 765 delegpt_find_ns(dp, qinfo->qname, qinfo->qname_len)) 766 return 1; 767 768 for(ns = dp->nslist; ns; ns = ns->next) { 769 if(ns->resolved) /* skip failed targets */ 770 continue; 771 if(!dname_subdomain_c(ns->name, dp->name)) 772 return 0; /* one address is not required glue */ 773 } 774 return 1; 775 } 776 777 int 778 iter_qname_indicates_dnssec(struct module_env* env, struct query_info *qinfo) 779 { 780 struct trust_anchor* a; 781 if(!env || !env->anchors || !qinfo || !qinfo->qname) 782 return 0; 783 /* a trust anchor exists above the name? */ 784 if((a=anchors_lookup(env->anchors, qinfo->qname, qinfo->qname_len, 785 qinfo->qclass))) { 786 if(a->numDS == 0 && a->numDNSKEY == 0) { 787 /* insecure trust point */ 788 lock_basic_unlock(&a->lock); 789 return 0; 790 } 791 lock_basic_unlock(&a->lock); 792 return 1; 793 } 794 /* no trust anchor above it. */ 795 return 0; 796 } 797 798 int 799 iter_indicates_dnssec(struct module_env* env, struct delegpt* dp, 800 struct dns_msg* msg, uint16_t dclass) 801 { 802 struct trust_anchor* a; 803 /* information not available, !env->anchors can be common */ 804 if(!env || !env->anchors || !dp || !dp->name) 805 return 0; 806 /* a trust anchor exists with this name, RRSIGs expected */ 807 if((a=anchor_find(env->anchors, dp->name, dp->namelabs, dp->namelen, 808 dclass))) { 809 if(a->numDS == 0 && a->numDNSKEY == 0) { 810 /* insecure trust point */ 811 lock_basic_unlock(&a->lock); 812 return 0; 813 } 814 lock_basic_unlock(&a->lock); 815 return 1; 816 } 817 /* see if DS rrset was given, in AUTH section */ 818 if(msg && msg->rep && 819 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, 820 LDNS_RR_TYPE_DS, dclass)) 821 return 1; 822 /* look in key cache */ 823 if(env->key_cache) { 824 struct key_entry_key* kk = key_cache_obtain(env->key_cache, 825 dp->name, dp->namelen, dclass, env->scratch, *env->now); 826 if(kk) { 827 if(query_dname_compare(kk->name, dp->name) == 0) { 828 if(key_entry_isgood(kk) || key_entry_isbad(kk)) { 829 regional_free_all(env->scratch); 830 return 1; 831 } else if(key_entry_isnull(kk)) { 832 regional_free_all(env->scratch); 833 return 0; 834 } 835 } 836 regional_free_all(env->scratch); 837 } 838 } 839 return 0; 840 } 841 842 int 843 iter_msg_has_dnssec(struct dns_msg* msg) 844 { 845 size_t i; 846 if(!msg || !msg->rep) 847 return 0; 848 for(i=0; i<msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) { 849 if(((struct packed_rrset_data*)msg->rep->rrsets[i]-> 850 entry.data)->rrsig_count > 0) 851 return 1; 852 } 853 /* empty message has no DNSSEC info, with DNSSEC the reply is 854 * not empty (NSEC) */ 855 return 0; 856 } 857 858 int iter_msg_from_zone(struct dns_msg* msg, struct delegpt* dp, 859 enum response_type type, uint16_t dclass) 860 { 861 if(!msg || !dp || !msg->rep || !dp->name) 862 return 0; 863 /* SOA RRset - always from reply zone */ 864 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, 865 LDNS_RR_TYPE_SOA, dclass) || 866 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, 867 LDNS_RR_TYPE_SOA, dclass)) 868 return 1; 869 if(type == RESPONSE_TYPE_REFERRAL) { 870 size_t i; 871 /* if it adds a single label, i.e. we expect .com, 872 * and referral to example.com. NS ... , then origin zone 873 * is .com. For a referral to sub.example.com. NS ... then 874 * we do not know, since example.com. may be in between. */ 875 for(i=0; i<msg->rep->an_numrrsets+msg->rep->ns_numrrsets; 876 i++) { 877 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 878 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS && 879 ntohs(s->rk.rrset_class) == dclass) { 880 int l = dname_count_labels(s->rk.dname); 881 if(l == dp->namelabs + 1 && 882 dname_strict_subdomain(s->rk.dname, 883 l, dp->name, dp->namelabs)) 884 return 1; 885 } 886 } 887 return 0; 888 } 889 log_assert(type==RESPONSE_TYPE_ANSWER || type==RESPONSE_TYPE_CNAME); 890 /* not a referral, and not lame delegation (upwards), so, 891 * any NS rrset must be from the zone itself */ 892 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, 893 LDNS_RR_TYPE_NS, dclass) || 894 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, 895 LDNS_RR_TYPE_NS, dclass)) 896 return 1; 897 /* a DNSKEY set is expected at the zone apex as well */ 898 /* this is for 'minimal responses' for DNSKEYs */ 899 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, 900 LDNS_RR_TYPE_DNSKEY, dclass)) 901 return 1; 902 return 0; 903 } 904 905 /** 906 * check equality of two rrsets 907 * @param k1: rrset 908 * @param k2: rrset 909 * @return true if equal 910 */ 911 static int 912 rrset_equal(struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2) 913 { 914 struct packed_rrset_data* d1 = (struct packed_rrset_data*) 915 k1->entry.data; 916 struct packed_rrset_data* d2 = (struct packed_rrset_data*) 917 k2->entry.data; 918 size_t i, t; 919 if(k1->rk.dname_len != k2->rk.dname_len || 920 k1->rk.flags != k2->rk.flags || 921 k1->rk.type != k2->rk.type || 922 k1->rk.rrset_class != k2->rk.rrset_class || 923 query_dname_compare(k1->rk.dname, k2->rk.dname) != 0) 924 return 0; 925 if( /* do not check ttl: d1->ttl != d2->ttl || */ 926 d1->count != d2->count || 927 d1->rrsig_count != d2->rrsig_count || 928 d1->trust != d2->trust || 929 d1->security != d2->security) 930 return 0; 931 t = d1->count + d1->rrsig_count; 932 for(i=0; i<t; i++) { 933 if(d1->rr_len[i] != d2->rr_len[i] || 934 /* no ttl check: d1->rr_ttl[i] != d2->rr_ttl[i] ||*/ 935 memcmp(d1->rr_data[i], d2->rr_data[i], 936 d1->rr_len[i]) != 0) 937 return 0; 938 } 939 return 1; 940 } 941 942 /** compare rrsets and sort canonically. Compares rrset name, type, class. 943 * return 0 if equal, +1 if x > y, and -1 if x < y. 944 */ 945 static int 946 rrset_canonical_sort_cmp(const void* x, const void* y) 947 { 948 struct ub_packed_rrset_key* rrx = *(struct ub_packed_rrset_key**)x; 949 struct ub_packed_rrset_key* rry = *(struct ub_packed_rrset_key**)y; 950 int r = dname_canonical_compare(rrx->rk.dname, rry->rk.dname); 951 if(r != 0) 952 return r; 953 if(rrx->rk.type != rry->rk.type) { 954 if(ntohs(rrx->rk.type) > ntohs(rry->rk.type)) 955 return 1; 956 else return -1; 957 } 958 if(rrx->rk.rrset_class != rry->rk.rrset_class) { 959 if(ntohs(rrx->rk.rrset_class) > ntohs(rry->rk.rrset_class)) 960 return 1; 961 else return -1; 962 } 963 return 0; 964 } 965 966 int 967 reply_equal(struct reply_info* p, struct reply_info* q, struct regional* region) 968 { 969 size_t i; 970 struct ub_packed_rrset_key** sorted_p, **sorted_q; 971 if(p->flags != q->flags || 972 p->qdcount != q->qdcount || 973 /* do not check TTL, this may differ */ 974 /* 975 p->ttl != q->ttl || 976 p->prefetch_ttl != q->prefetch_ttl || 977 */ 978 p->security != q->security || 979 p->an_numrrsets != q->an_numrrsets || 980 p->ns_numrrsets != q->ns_numrrsets || 981 p->ar_numrrsets != q->ar_numrrsets || 982 p->rrset_count != q->rrset_count) 983 return 0; 984 /* sort the rrsets in the authority and additional sections before 985 * compare, the query and answer sections are ordered in the sequence 986 * they should have (eg. one after the other for aliases). */ 987 sorted_p = (struct ub_packed_rrset_key**)regional_alloc_init( 988 region, p->rrsets, sizeof(*sorted_p)*p->rrset_count); 989 if(!sorted_p) return 0; 990 log_assert(p->an_numrrsets + p->ns_numrrsets + p->ar_numrrsets <= 991 p->rrset_count); 992 qsort(sorted_p + p->an_numrrsets, p->ns_numrrsets, 993 sizeof(*sorted_p), rrset_canonical_sort_cmp); 994 qsort(sorted_p + p->an_numrrsets + p->ns_numrrsets, p->ar_numrrsets, 995 sizeof(*sorted_p), rrset_canonical_sort_cmp); 996 997 sorted_q = (struct ub_packed_rrset_key**)regional_alloc_init( 998 region, q->rrsets, sizeof(*sorted_q)*q->rrset_count); 999 if(!sorted_q) { 1000 regional_free_all(region); 1001 return 0; 1002 } 1003 log_assert(q->an_numrrsets + q->ns_numrrsets + q->ar_numrrsets <= 1004 q->rrset_count); 1005 qsort(sorted_q + q->an_numrrsets, q->ns_numrrsets, 1006 sizeof(*sorted_q), rrset_canonical_sort_cmp); 1007 qsort(sorted_q + q->an_numrrsets + q->ns_numrrsets, q->ar_numrrsets, 1008 sizeof(*sorted_q), rrset_canonical_sort_cmp); 1009 1010 /* compare the rrsets */ 1011 for(i=0; i<p->rrset_count; i++) { 1012 if(!rrset_equal(sorted_p[i], sorted_q[i])) { 1013 if(!rrset_canonical_equal(region, sorted_p[i], 1014 sorted_q[i])) { 1015 regional_free_all(region); 1016 return 0; 1017 } 1018 } 1019 } 1020 regional_free_all(region); 1021 return 1; 1022 } 1023 1024 void 1025 caps_strip_reply(struct reply_info* rep) 1026 { 1027 size_t i; 1028 if(!rep) return; 1029 /* see if message is a referral, in which case the additional and 1030 * NS record cannot be removed */ 1031 /* referrals have the AA flag unset (strict check, not elsewhere in 1032 * unbound, but for 0x20 this is very convenient). */ 1033 if(!(rep->flags&BIT_AA)) 1034 return; 1035 /* remove the additional section from the reply */ 1036 if(rep->ar_numrrsets != 0) { 1037 verbose(VERB_ALGO, "caps fallback: removing additional section"); 1038 rep->rrset_count -= rep->ar_numrrsets; 1039 rep->ar_numrrsets = 0; 1040 } 1041 /* is there an NS set in the authority section to remove? */ 1042 /* the failure case (Cisco firewalls) only has one rrset in authsec */ 1043 for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) { 1044 struct ub_packed_rrset_key* s = rep->rrsets[i]; 1045 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS) { 1046 /* remove NS rrset and break from loop (loop limits 1047 * have changed) */ 1048 /* move last rrset into this position (there is no 1049 * additional section any more) */ 1050 verbose(VERB_ALGO, "caps fallback: removing NS rrset"); 1051 if(i < rep->rrset_count-1) 1052 rep->rrsets[i]=rep->rrsets[rep->rrset_count-1]; 1053 rep->rrset_count --; 1054 rep->ns_numrrsets --; 1055 break; 1056 } 1057 } 1058 } 1059 1060 int caps_failed_rcode(struct reply_info* rep) 1061 { 1062 return !(FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NOERROR || 1063 FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NXDOMAIN); 1064 } 1065 1066 void 1067 iter_store_parentside_rrset(struct module_env* env, 1068 struct ub_packed_rrset_key* rrset) 1069 { 1070 struct rrset_ref ref; 1071 rrset = packed_rrset_copy_alloc(rrset, env->alloc, *env->now); 1072 if(!rrset) { 1073 log_err("malloc failure in store_parentside_rrset"); 1074 return; 1075 } 1076 rrset->rk.flags |= PACKED_RRSET_PARENT_SIDE; 1077 rrset->entry.hash = rrset_key_hash(&rrset->rk); 1078 ref.key = rrset; 1079 ref.id = rrset->id; 1080 /* ignore ret: if it was in the cache, ref updated */ 1081 (void)rrset_cache_update(env->rrset_cache, &ref, env->alloc, *env->now); 1082 } 1083 1084 /** fetch NS record from reply, if any */ 1085 static struct ub_packed_rrset_key* 1086 reply_get_NS_rrset(struct reply_info* rep) 1087 { 1088 size_t i; 1089 for(i=0; i<rep->rrset_count; i++) { 1090 if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NS)) { 1091 return rep->rrsets[i]; 1092 } 1093 } 1094 return NULL; 1095 } 1096 1097 void 1098 iter_store_parentside_NS(struct module_env* env, struct reply_info* rep) 1099 { 1100 struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep); 1101 if(rrset) { 1102 log_rrset_key(VERB_ALGO, "store parent-side NS", rrset); 1103 iter_store_parentside_rrset(env, rrset); 1104 } 1105 } 1106 1107 void iter_store_parentside_neg(struct module_env* env, 1108 struct query_info* qinfo, struct reply_info* rep) 1109 { 1110 /* TTL: NS from referral in iq->deleg_msg, 1111 * or first RR from iq->response, 1112 * or servfail5secs if !iq->response */ 1113 time_t ttl = NORR_TTL; 1114 struct ub_packed_rrset_key* neg; 1115 struct packed_rrset_data* newd; 1116 if(rep) { 1117 struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep); 1118 if(!rrset && rep->rrset_count != 0) rrset = rep->rrsets[0]; 1119 if(rrset) ttl = ub_packed_rrset_ttl(rrset); 1120 } 1121 /* create empty rrset to store */ 1122 neg = (struct ub_packed_rrset_key*)regional_alloc(env->scratch, 1123 sizeof(struct ub_packed_rrset_key)); 1124 if(!neg) { 1125 log_err("out of memory in store_parentside_neg"); 1126 return; 1127 } 1128 memset(&neg->entry, 0, sizeof(neg->entry)); 1129 neg->entry.key = neg; 1130 neg->rk.type = htons(qinfo->qtype); 1131 neg->rk.rrset_class = htons(qinfo->qclass); 1132 neg->rk.flags = 0; 1133 neg->rk.dname = regional_alloc_init(env->scratch, qinfo->qname, 1134 qinfo->qname_len); 1135 if(!neg->rk.dname) { 1136 log_err("out of memory in store_parentside_neg"); 1137 return; 1138 } 1139 neg->rk.dname_len = qinfo->qname_len; 1140 neg->entry.hash = rrset_key_hash(&neg->rk); 1141 newd = (struct packed_rrset_data*)regional_alloc_zero(env->scratch, 1142 sizeof(struct packed_rrset_data) + sizeof(size_t) + 1143 sizeof(uint8_t*) + sizeof(time_t) + sizeof(uint16_t)); 1144 if(!newd) { 1145 log_err("out of memory in store_parentside_neg"); 1146 return; 1147 } 1148 neg->entry.data = newd; 1149 newd->ttl = ttl; 1150 /* entry must have one RR, otherwise not valid in cache. 1151 * put in one RR with empty rdata: those are ignored as nameserver */ 1152 newd->count = 1; 1153 newd->rrsig_count = 0; 1154 newd->trust = rrset_trust_ans_noAA; 1155 newd->rr_len = (size_t*)((uint8_t*)newd + 1156 sizeof(struct packed_rrset_data)); 1157 newd->rr_len[0] = 0 /* zero len rdata */ + sizeof(uint16_t); 1158 packed_rrset_ptr_fixup(newd); 1159 newd->rr_ttl[0] = newd->ttl; 1160 sldns_write_uint16(newd->rr_data[0], 0 /* zero len rdata */); 1161 /* store it */ 1162 log_rrset_key(VERB_ALGO, "store parent-side negative", neg); 1163 iter_store_parentside_rrset(env, neg); 1164 } 1165 1166 int 1167 iter_lookup_parent_NS_from_cache(struct module_env* env, struct delegpt* dp, 1168 struct regional* region, struct query_info* qinfo) 1169 { 1170 struct ub_packed_rrset_key* akey; 1171 akey = rrset_cache_lookup(env->rrset_cache, dp->name, 1172 dp->namelen, LDNS_RR_TYPE_NS, qinfo->qclass, 1173 PACKED_RRSET_PARENT_SIDE, *env->now, 0); 1174 if(akey) { 1175 log_rrset_key(VERB_ALGO, "found parent-side NS in cache", akey); 1176 dp->has_parent_side_NS = 1; 1177 /* and mark the new names as lame */ 1178 if(!delegpt_rrset_add_ns(dp, region, akey, 1)) { 1179 lock_rw_unlock(&akey->entry.lock); 1180 return 0; 1181 } 1182 lock_rw_unlock(&akey->entry.lock); 1183 } 1184 return 1; 1185 } 1186 1187 int iter_lookup_parent_glue_from_cache(struct module_env* env, 1188 struct delegpt* dp, struct regional* region, struct query_info* qinfo) 1189 { 1190 struct ub_packed_rrset_key* akey; 1191 struct delegpt_ns* ns; 1192 size_t num = delegpt_count_targets(dp); 1193 for(ns = dp->nslist; ns; ns = ns->next) { 1194 /* get cached parentside A */ 1195 akey = rrset_cache_lookup(env->rrset_cache, ns->name, 1196 ns->namelen, LDNS_RR_TYPE_A, qinfo->qclass, 1197 PACKED_RRSET_PARENT_SIDE, *env->now, 0); 1198 if(akey) { 1199 log_rrset_key(VERB_ALGO, "found parent-side", akey); 1200 ns->done_pside4 = 1; 1201 /* a negative-cache-element has no addresses it adds */ 1202 if(!delegpt_add_rrset_A(dp, region, akey, 1, NULL)) 1203 log_err("malloc failure in lookup_parent_glue"); 1204 lock_rw_unlock(&akey->entry.lock); 1205 } 1206 /* get cached parentside AAAA */ 1207 akey = rrset_cache_lookup(env->rrset_cache, ns->name, 1208 ns->namelen, LDNS_RR_TYPE_AAAA, qinfo->qclass, 1209 PACKED_RRSET_PARENT_SIDE, *env->now, 0); 1210 if(akey) { 1211 log_rrset_key(VERB_ALGO, "found parent-side", akey); 1212 ns->done_pside6 = 1; 1213 /* a negative-cache-element has no addresses it adds */ 1214 if(!delegpt_add_rrset_AAAA(dp, region, akey, 1, NULL)) 1215 log_err("malloc failure in lookup_parent_glue"); 1216 lock_rw_unlock(&akey->entry.lock); 1217 } 1218 } 1219 /* see if new (but lame) addresses have become available */ 1220 return delegpt_count_targets(dp) != num; 1221 } 1222 1223 int 1224 iter_get_next_root(struct iter_hints* hints, struct iter_forwards* fwd, 1225 uint16_t* c) 1226 { 1227 uint16_t c1 = *c, c2 = *c; 1228 int r1 = hints_next_root(hints, &c1); 1229 int r2 = forwards_next_root(fwd, &c2); 1230 if(!r1 && !r2) /* got none, end of list */ 1231 return 0; 1232 else if(!r1) /* got one, return that */ 1233 *c = c2; 1234 else if(!r2) 1235 *c = c1; 1236 else if(c1 < c2) /* got both take smallest */ 1237 *c = c1; 1238 else *c = c2; 1239 return 1; 1240 } 1241 1242 void 1243 iter_scrub_ds(struct dns_msg* msg, struct ub_packed_rrset_key* ns, uint8_t* z) 1244 { 1245 /* Only the DS record for the delegation itself is expected. 1246 * We allow DS for everything between the bailiwick and the 1247 * zonecut, thus DS records must be at or above the zonecut. 1248 * And the DS records must be below the server authority zone. 1249 * The answer section is already scrubbed. */ 1250 size_t i = msg->rep->an_numrrsets; 1251 while(i < (msg->rep->an_numrrsets + msg->rep->ns_numrrsets)) { 1252 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 1253 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS && 1254 (!ns || !dname_subdomain_c(ns->rk.dname, s->rk.dname) 1255 || query_dname_compare(z, s->rk.dname) == 0)) { 1256 log_nametypeclass(VERB_ALGO, "removing irrelevant DS", 1257 s->rk.dname, ntohs(s->rk.type), 1258 ntohs(s->rk.rrset_class)); 1259 memmove(msg->rep->rrsets+i, msg->rep->rrsets+i+1, 1260 sizeof(struct ub_packed_rrset_key*) * 1261 (msg->rep->rrset_count-i-1)); 1262 msg->rep->ns_numrrsets--; 1263 msg->rep->rrset_count--; 1264 /* stay at same i, but new record */ 1265 continue; 1266 } 1267 i++; 1268 } 1269 } 1270 1271 void 1272 iter_scrub_nxdomain(struct dns_msg* msg) 1273 { 1274 if(msg->rep->an_numrrsets == 0) 1275 return; 1276 1277 memmove(msg->rep->rrsets, msg->rep->rrsets+msg->rep->an_numrrsets, 1278 sizeof(struct ub_packed_rrset_key*) * 1279 (msg->rep->rrset_count-msg->rep->an_numrrsets)); 1280 msg->rep->rrset_count -= msg->rep->an_numrrsets; 1281 msg->rep->an_numrrsets = 0; 1282 } 1283 1284 void iter_dec_attempts(struct delegpt* dp, int d) 1285 { 1286 struct delegpt_addr* a; 1287 for(a=dp->target_list; a; a = a->next_target) { 1288 if(a->attempts >= OUTBOUND_MSG_RETRY) { 1289 /* add back to result list */ 1290 a->next_result = dp->result_list; 1291 dp->result_list = a; 1292 } 1293 if(a->attempts > d) 1294 a->attempts -= d; 1295 else a->attempts = 0; 1296 } 1297 } 1298 1299 void iter_merge_retry_counts(struct delegpt* dp, struct delegpt* old) 1300 { 1301 struct delegpt_addr* a, *o, *prev; 1302 for(a=dp->target_list; a; a = a->next_target) { 1303 o = delegpt_find_addr(old, &a->addr, a->addrlen); 1304 if(o) { 1305 log_addr(VERB_ALGO, "copy attempt count previous dp", 1306 &a->addr, a->addrlen); 1307 a->attempts = o->attempts; 1308 } 1309 } 1310 prev = NULL; 1311 a = dp->usable_list; 1312 while(a) { 1313 if(a->attempts >= OUTBOUND_MSG_RETRY) { 1314 log_addr(VERB_ALGO, "remove from usable list dp", 1315 &a->addr, a->addrlen); 1316 /* remove from result list */ 1317 if(prev) 1318 prev->next_usable = a->next_usable; 1319 else dp->usable_list = a->next_usable; 1320 /* prev stays the same */ 1321 a = a->next_usable; 1322 continue; 1323 } 1324 prev = a; 1325 a = a->next_usable; 1326 } 1327 } 1328 1329 int 1330 iter_ds_toolow(struct dns_msg* msg, struct delegpt* dp) 1331 { 1332 /* if for query example.com, there is example.com SOA or a subdomain 1333 * of example.com, then we are too low and need to fetch NS. */ 1334 size_t i; 1335 /* if we have a DNAME or CNAME we are probably wrong */ 1336 /* if we have a qtype DS in the answer section, its fine */ 1337 for(i=0; i < msg->rep->an_numrrsets; i++) { 1338 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 1339 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME || 1340 ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) { 1341 /* not the right answer, maybe too low, check the 1342 * RRSIG signer name (if there is any) for a hint 1343 * that it is from the dp zone anyway */ 1344 uint8_t* sname; 1345 size_t slen; 1346 val_find_rrset_signer(s, &sname, &slen); 1347 if(sname && query_dname_compare(dp->name, sname)==0) 1348 return 0; /* it is fine, from the right dp */ 1349 return 1; 1350 } 1351 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS) 1352 return 0; /* fine, we have a DS record */ 1353 } 1354 for(i=msg->rep->an_numrrsets; 1355 i < msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) { 1356 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 1357 if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA) { 1358 if(dname_subdomain_c(s->rk.dname, msg->qinfo.qname)) 1359 return 1; /* point is too low */ 1360 if(query_dname_compare(s->rk.dname, dp->name)==0) 1361 return 0; /* right dp */ 1362 } 1363 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC || 1364 ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) { 1365 uint8_t* sname; 1366 size_t slen; 1367 val_find_rrset_signer(s, &sname, &slen); 1368 if(sname && query_dname_compare(dp->name, sname)==0) 1369 return 0; /* it is fine, from the right dp */ 1370 return 1; 1371 } 1372 } 1373 /* we do not know */ 1374 return 1; 1375 } 1376 1377 int iter_dp_cangodown(struct query_info* qinfo, struct delegpt* dp) 1378 { 1379 /* no delegation point, do not see how we can go down, 1380 * robust check, it should really exist */ 1381 if(!dp) return 0; 1382 1383 /* see if dp equals the qname, then we cannot go down further */ 1384 if(query_dname_compare(qinfo->qname, dp->name) == 0) 1385 return 0; 1386 /* if dp is one label above the name we also cannot go down further */ 1387 if(dname_count_labels(qinfo->qname) == dp->namelabs+1) 1388 return 0; 1389 return 1; 1390 } 1391 1392 int 1393 iter_stub_fwd_no_cache(struct module_qstate *qstate, struct query_info *qinf) 1394 { 1395 struct iter_hints_stub *stub; 1396 struct delegpt *dp; 1397 1398 /* Check for stub. */ 1399 stub = hints_lookup_stub(qstate->env->hints, qinf->qname, 1400 qinf->qclass, NULL); 1401 dp = forwards_lookup(qstate->env->fwds, qinf->qname, qinf->qclass); 1402 1403 /* see if forward or stub is more pertinent */ 1404 if(stub && stub->dp && dp) { 1405 if(dname_strict_subdomain(dp->name, dp->namelabs, 1406 stub->dp->name, stub->dp->namelabs)) { 1407 stub = NULL; /* ignore stub, forward is lower */ 1408 } else { 1409 dp = NULL; /* ignore forward, stub is lower */ 1410 } 1411 } 1412 1413 /* check stub */ 1414 if (stub != NULL && stub->dp != NULL) { 1415 if(stub->dp->no_cache) { 1416 char qname[255+1]; 1417 char dpname[255+1]; 1418 dname_str(qinf->qname, qname); 1419 dname_str(stub->dp->name, dpname); 1420 verbose(VERB_ALGO, "stub for %s %s has no_cache", qname, dpname); 1421 } 1422 return (stub->dp->no_cache); 1423 } 1424 1425 /* Check for forward. */ 1426 if (dp) { 1427 if(dp->no_cache) { 1428 char qname[255+1]; 1429 char dpname[255+1]; 1430 dname_str(qinf->qname, qname); 1431 dname_str(dp->name, dpname); 1432 verbose(VERB_ALGO, "forward for %s %s has no_cache", qname, dpname); 1433 } 1434 return (dp->no_cache); 1435 } 1436 return 0; 1437 } 1438