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 "services/outside_network.h" 54#include "util/net_help.h" 55#include "util/module.h" 56#include "util/log.h" 57#include "util/config_file.h" 58#include "util/regional.h" 59#include "util/data/msgparse.h" 60#include "util/data/dname.h" 61#include "util/random.h" 62#include "util/fptr_wlist.h" 63#include "validator/val_anchor.h" 64#include "validator/val_kcache.h" 65#include "validator/val_kentry.h" 66#include "validator/val_utils.h" 67#include "validator/val_sigcrypt.h" 68#include "sldns/sbuffer.h" 69#include "sldns/str2wire.h" 70 71/** time when nameserver glue is said to be 'recent' */ 72#define SUSPICION_RECENT_EXPIRY 86400 73 74/** if NAT64 is enabled and no NAT64 prefix is configured, first fall back to 75 * DNS64 prefix. If that is not configured, fall back to this default value. 76 */ 77static const char DEFAULT_NAT64_PREFIX[] = "64:ff9b::/96"; 78 79/** fillup fetch policy array */ 80static void 81fetch_fill(struct iter_env* ie, const char* str) 82{ 83 char* s = (char*)str, *e; 84 int i; 85 for(i=0; i<ie->max_dependency_depth+1; i++) { 86 ie->target_fetch_policy[i] = strtol(s, &e, 10); 87 if(s == e) 88 fatal_exit("cannot parse fetch policy number %s", s); 89 s = e; 90 } 91} 92 93/** Read config string that represents the target fetch policy */ 94static int 95read_fetch_policy(struct iter_env* ie, const char* str) 96{ 97 int count = cfg_count_numbers(str); 98 if(count < 1) { 99 log_err("Cannot parse target fetch policy: \"%s\"", str); 100 return 0; 101 } 102 ie->max_dependency_depth = count - 1; 103 ie->target_fetch_policy = (int*)calloc( 104 (size_t)ie->max_dependency_depth+1, sizeof(int)); 105 if(!ie->target_fetch_policy) { 106 log_err("alloc fetch policy: out of memory"); 107 return 0; 108 } 109 fetch_fill(ie, str); 110 return 1; 111} 112 113/** apply config caps whitelist items to name tree */ 114static int 115caps_white_apply_cfg(rbtree_type* ntree, struct config_file* cfg) 116{ 117 struct config_strlist* p; 118 for(p=cfg->caps_whitelist; p; p=p->next) { 119 struct name_tree_node* n; 120 size_t len; 121 uint8_t* nm = sldns_str2wire_dname(p->str, &len); 122 if(!nm) { 123 log_err("could not parse %s", p->str); 124 return 0; 125 } 126 n = (struct name_tree_node*)calloc(1, sizeof(*n)); 127 if(!n) { 128 log_err("out of memory"); 129 free(nm); 130 return 0; 131 } 132 n->node.key = n; 133 n->name = nm; 134 n->len = len; 135 n->labs = dname_count_labels(nm); 136 n->dclass = LDNS_RR_CLASS_IN; 137 if(!name_tree_insert(ntree, n, nm, len, n->labs, n->dclass)) { 138 /* duplicate element ignored, idempotent */ 139 free(n->name); 140 free(n); 141 } 142 } 143 name_tree_init_parents(ntree); 144 return 1; 145} 146 147int 148iter_apply_cfg(struct iter_env* iter_env, struct config_file* cfg) 149{ 150 const char *nat64_prefix; 151 int i; 152 /* target fetch policy */ 153 if(!read_fetch_policy(iter_env, cfg->target_fetch_policy)) 154 return 0; 155 for(i=0; i<iter_env->max_dependency_depth+1; i++) 156 verbose(VERB_QUERY, "target fetch policy for level %d is %d", 157 i, iter_env->target_fetch_policy[i]); 158 159 if(!iter_env->donotq) 160 iter_env->donotq = donotq_create(); 161 if(!iter_env->donotq || !donotq_apply_cfg(iter_env->donotq, cfg)) { 162 log_err("Could not set donotqueryaddresses"); 163 return 0; 164 } 165 if(!iter_env->priv) 166 iter_env->priv = priv_create(); 167 if(!iter_env->priv || !priv_apply_cfg(iter_env->priv, cfg)) { 168 log_err("Could not set private addresses"); 169 return 0; 170 } 171 if(cfg->caps_whitelist) { 172 if(!iter_env->caps_white) 173 iter_env->caps_white = rbtree_create(name_tree_compare); 174 if(!iter_env->caps_white || !caps_white_apply_cfg( 175 iter_env->caps_white, cfg)) { 176 log_err("Could not set capsforid whitelist"); 177 return 0; 178 } 179 180 } 181 182 nat64_prefix = cfg->nat64_prefix; 183 if(!nat64_prefix) 184 nat64_prefix = cfg->dns64_prefix; 185 if(!nat64_prefix) 186 nat64_prefix = DEFAULT_NAT64_PREFIX; 187 if(!netblockstrtoaddr(nat64_prefix, 0, &iter_env->nat64_prefix_addr, 188 &iter_env->nat64_prefix_addrlen, 189 &iter_env->nat64_prefix_net)) { 190 log_err("cannot parse nat64-prefix netblock: %s", nat64_prefix); 191 return 0; 192 } 193 if(!addr_is_ip6(&iter_env->nat64_prefix_addr, 194 iter_env->nat64_prefix_addrlen)) { 195 log_err("nat64-prefix is not IPv6: %s", cfg->nat64_prefix); 196 return 0; 197 } 198 if(!prefixnet_is_nat64(iter_env->nat64_prefix_net)) { 199 log_err("nat64-prefix length it not 32, 40, 48, 56, 64 or 96: %s", 200 nat64_prefix); 201 return 0; 202 } 203 204 iter_env->supports_ipv6 = cfg->do_ip6; 205 iter_env->supports_ipv4 = cfg->do_ip4; 206 iter_env->use_nat64 = cfg->do_nat64; 207 iter_env->outbound_msg_retry = cfg->outbound_msg_retry; 208 iter_env->max_sent_count = cfg->max_sent_count; 209 iter_env->max_query_restarts = cfg->max_query_restarts; 210 return 1; 211} 212 213/** filter out unsuitable targets 214 * @param iter_env: iterator environment with ipv6-support flag. 215 * @param env: module environment with infra cache. 216 * @param name: zone name 217 * @param namelen: length of name 218 * @param qtype: query type (host order). 219 * @param now: current time 220 * @param a: address in delegation point we are examining. 221 * @return an integer that signals the target suitability. 222 * as follows: 223 * -1: The address should be omitted from the list. 224 * Because: 225 * o The address is bogus (DNSSEC validation failure). 226 * o Listed as donotquery 227 * o is ipv6 but no ipv6 support (in operating system). 228 * o is ipv4 but no ipv4 support (in operating system). 229 * o is lame 230 * Otherwise, an rtt in milliseconds. 231 * 0 .. USEFUL_SERVER_TOP_TIMEOUT-1 232 * The roundtrip time timeout estimate. less than 2 minutes. 233 * Note that util/rtt.c has a MIN_TIMEOUT of 50 msec, thus 234 * values 0 .. 49 are not used, unless that is changed. 235 * USEFUL_SERVER_TOP_TIMEOUT 236 * This value exactly is given for unresponsive blacklisted. 237 * USEFUL_SERVER_TOP_TIMEOUT+1 238 * For non-blacklisted servers: huge timeout, but has traffic. 239 * USEFUL_SERVER_TOP_TIMEOUT*1 .. 240 * parent-side lame servers get this penalty. A dispreferential 241 * server. (lame in delegpt). 242 * USEFUL_SERVER_TOP_TIMEOUT*2 .. 243 * dnsseclame servers get penalty 244 * USEFUL_SERVER_TOP_TIMEOUT*3 .. 245 * recursion lame servers get penalty 246 * UNKNOWN_SERVER_NICENESS 247 * If no information is known about the server, this is 248 * returned. 376 msec or so. 249 * +BLACKLIST_PENALTY (of USEFUL_TOP_TIMEOUT*4) for dnssec failed IPs. 250 * 251 * When a final value is chosen that is dnsseclame ; dnsseclameness checking 252 * is turned off (so we do not discard the reply). 253 * When a final value is chosen that is recursionlame; RD bit is set on query. 254 * Because of the numbers this means recursionlame also have dnssec lameness 255 * checking turned off. 256 */ 257static int 258iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env, 259 uint8_t* name, size_t namelen, uint16_t qtype, time_t now, 260 struct delegpt_addr* a) 261{ 262 int rtt, lame, reclame, dnsseclame; 263 if(a->bogus) 264 return -1; /* address of server is bogus */ 265 if(donotq_lookup(iter_env->donotq, &a->addr, a->addrlen)) { 266 log_addr(VERB_ALGO, "skip addr on the donotquery list", 267 &a->addr, a->addrlen); 268 return -1; /* server is on the donotquery list */ 269 } 270 if(!iter_env->supports_ipv6 && addr_is_ip6(&a->addr, a->addrlen)) { 271 return -1; /* there is no ip6 available */ 272 } 273 if(!iter_env->supports_ipv4 && !iter_env->use_nat64 && 274 !addr_is_ip6(&a->addr, a->addrlen)) { 275 return -1; /* there is no ip4 available */ 276 } 277 /* check lameness - need zone , class info */ 278 if(infra_get_lame_rtt(env->infra_cache, &a->addr, a->addrlen, 279 name, namelen, qtype, &lame, &dnsseclame, &reclame, 280 &rtt, now)) { 281 log_addr(VERB_ALGO, "servselect", &a->addr, a->addrlen); 282 verbose(VERB_ALGO, " rtt=%d%s%s%s%s", rtt, 283 lame?" LAME":"", 284 dnsseclame?" DNSSEC_LAME":"", 285 reclame?" REC_LAME":"", 286 a->lame?" ADDR_LAME":""); 287 if(lame) 288 return -1; /* server is lame */ 289 else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT) 290 /* server is unresponsive, 291 * we used to return TOP_TIMEOUT, but fairly useless, 292 * because if == TOP_TIMEOUT is dropped because 293 * blacklisted later, instead, remove it here, so 294 * other choices (that are not blacklisted) can be 295 * tried */ 296 return -1; 297 /* select remainder from worst to best */ 298 else if(reclame) 299 return rtt+USEFUL_SERVER_TOP_TIMEOUT*3; /* nonpref */ 300 else if(dnsseclame || a->dnsseclame) 301 return rtt+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */ 302 else if(a->lame) 303 return rtt+USEFUL_SERVER_TOP_TIMEOUT+1; /* nonpref */ 304 else return rtt; 305 } 306 /* no server information present */ 307 if(a->dnsseclame) 308 return UNKNOWN_SERVER_NICENESS+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */ 309 else if(a->lame) 310 return USEFUL_SERVER_TOP_TIMEOUT+1+UNKNOWN_SERVER_NICENESS; /* nonpref */ 311 return UNKNOWN_SERVER_NICENESS; 312} 313 314/** lookup RTT information, and also store fastest rtt (if any) */ 315static int 316iter_fill_rtt(struct iter_env* iter_env, struct module_env* env, 317 uint8_t* name, size_t namelen, uint16_t qtype, time_t now, 318 struct delegpt* dp, int* best_rtt, struct sock_list* blacklist, 319 size_t* num_suitable_results) 320{ 321 int got_it = 0; 322 struct delegpt_addr* a; 323 *num_suitable_results = 0; 324 325 if(dp->bogus) 326 return 0; /* NS bogus, all bogus, nothing found */ 327 for(a=dp->result_list; a; a = a->next_result) { 328 a->sel_rtt = iter_filter_unsuitable(iter_env, env, 329 name, namelen, qtype, now, a); 330 if(a->sel_rtt != -1) { 331 if(sock_list_find(blacklist, &a->addr, a->addrlen)) 332 a->sel_rtt += BLACKLIST_PENALTY; 333 334 if(!got_it) { 335 *best_rtt = a->sel_rtt; 336 got_it = 1; 337 } else if(a->sel_rtt < *best_rtt) { 338 *best_rtt = a->sel_rtt; 339 } 340 (*num_suitable_results)++; 341 } 342 } 343 return got_it; 344} 345 346/** compare two rtts, return -1, 0 or 1 */ 347static int 348rtt_compare(const void* x, const void* y) 349{ 350 if(*(int*)x == *(int*)y) 351 return 0; 352 if(*(int*)x > *(int*)y) 353 return 1; 354 return -1; 355} 356 357/** get RTT for the Nth fastest server */ 358static int 359nth_rtt(struct delegpt_addr* result_list, size_t num_results, size_t n) 360{ 361 int rtt_band; 362 size_t i; 363 int* rtt_list, *rtt_index; 364 365 if(num_results < 1 || n >= num_results) { 366 return -1; 367 } 368 369 rtt_list = calloc(num_results, sizeof(int)); 370 if(!rtt_list) { 371 log_err("malloc failure: allocating rtt_list"); 372 return -1; 373 } 374 rtt_index = rtt_list; 375 376 for(i=0; i<num_results && result_list; i++) { 377 if(result_list->sel_rtt != -1) { 378 *rtt_index = result_list->sel_rtt; 379 rtt_index++; 380 } 381 result_list=result_list->next_result; 382 } 383 qsort(rtt_list, num_results, sizeof(*rtt_list), rtt_compare); 384 385 log_assert(n > 0); 386 rtt_band = rtt_list[n-1]; 387 free(rtt_list); 388 389 return rtt_band; 390} 391 392/** filter the address list, putting best targets at front, 393 * returns number of best targets (or 0, no suitable targets) */ 394static int 395iter_filter_order(struct iter_env* iter_env, struct module_env* env, 396 uint8_t* name, size_t namelen, uint16_t qtype, time_t now, 397 struct delegpt* dp, int* selected_rtt, int open_target, 398 struct sock_list* blacklist, time_t prefetch) 399{ 400 int got_num = 0, low_rtt = 0, swap_to_front, rtt_band = RTT_BAND, nth; 401 int alllame = 0; 402 size_t num_results; 403 struct delegpt_addr* a, *n, *prev=NULL; 404 405 /* fillup sel_rtt and find best rtt in the bunch */ 406 got_num = iter_fill_rtt(iter_env, env, name, namelen, qtype, now, dp, 407 &low_rtt, blacklist, &num_results); 408 if(got_num == 0) 409 return 0; 410 if(low_rtt >= USEFUL_SERVER_TOP_TIMEOUT && 411 /* If all missing (or not fully resolved) targets are lame, 412 * then use the remaining lame address. */ 413 ((delegpt_count_missing_targets(dp, &alllame) > 0 && !alllame) || 414 open_target > 0)) { 415 verbose(VERB_ALGO, "Bad choices, trying to get more choice"); 416 return 0; /* we want more choice. The best choice is a bad one. 417 return 0 to force the caller to fetch more */ 418 } 419 420 if(env->cfg->fast_server_permil != 0 && prefetch == 0 && 421 num_results > env->cfg->fast_server_num && 422 ub_random_max(env->rnd, 1000) < env->cfg->fast_server_permil) { 423 /* the query is not prefetch, but for a downstream client, 424 * there are more servers available then the fastest N we want 425 * to choose from. Limit our choice to the fastest servers. */ 426 nth = nth_rtt(dp->result_list, num_results, 427 env->cfg->fast_server_num); 428 if(nth > 0) { 429 rtt_band = nth - low_rtt; 430 if(rtt_band > RTT_BAND) 431 rtt_band = RTT_BAND; 432 } 433 } 434 435 got_num = 0; 436 a = dp->result_list; 437 while(a) { 438 /* skip unsuitable targets */ 439 if(a->sel_rtt == -1) { 440 prev = a; 441 a = a->next_result; 442 continue; 443 } 444 /* classify the server address and determine what to do */ 445 swap_to_front = 0; 446 if(a->sel_rtt >= low_rtt && a->sel_rtt - low_rtt <= rtt_band) { 447 got_num++; 448 swap_to_front = 1; 449 } else if(a->sel_rtt<low_rtt && low_rtt-a->sel_rtt<=rtt_band) { 450 got_num++; 451 swap_to_front = 1; 452 } 453 /* swap to front if necessary, or move to next result */ 454 if(swap_to_front && prev) { 455 n = a->next_result; 456 prev->next_result = n; 457 a->next_result = dp->result_list; 458 dp->result_list = a; 459 a = n; 460 } else { 461 prev = a; 462 a = a->next_result; 463 } 464 } 465 *selected_rtt = low_rtt; 466 467 if (env->cfg->prefer_ip6) { 468 int got_num6 = 0; 469 int low_rtt6 = 0; 470 int i; 471 int attempt = -1; /* filter to make sure addresses have 472 less attempts on them than the first, to force round 473 robin when all the IPv6 addresses fail */ 474 int num4ok = 0; /* number ip4 at low attempt count */ 475 int num4_lowrtt = 0; 476 prev = NULL; 477 a = dp->result_list; 478 for(i = 0; i < got_num; i++) { 479 if(!a) break; /* robustness */ 480 swap_to_front = 0; 481 if(a->addr.ss_family != AF_INET6 && attempt == -1) { 482 /* if we only have ip4 at low attempt count, 483 * then ip6 is failing, and we need to 484 * select one of the remaining IPv4 addrs */ 485 attempt = a->attempts; 486 num4ok++; 487 num4_lowrtt = a->sel_rtt; 488 } else if(a->addr.ss_family != AF_INET6 && attempt == a->attempts) { 489 num4ok++; 490 if(num4_lowrtt == 0 || a->sel_rtt < num4_lowrtt) { 491 num4_lowrtt = a->sel_rtt; 492 } 493 } 494 if(a->addr.ss_family == AF_INET6) { 495 if(attempt == -1) { 496 attempt = a->attempts; 497 } else if(a->attempts > attempt) { 498 break; 499 } 500 got_num6++; 501 swap_to_front = 1; 502 if(low_rtt6 == 0 || a->sel_rtt < low_rtt6) { 503 low_rtt6 = a->sel_rtt; 504 } 505 } 506 /* swap to front if IPv6, or move to next result */ 507 if(swap_to_front && prev) { 508 n = a->next_result; 509 prev->next_result = n; 510 a->next_result = dp->result_list; 511 dp->result_list = a; 512 a = n; 513 } else { 514 prev = a; 515 a = a->next_result; 516 } 517 } 518 if(got_num6 > 0) { 519 got_num = got_num6; 520 *selected_rtt = low_rtt6; 521 } else if(num4ok > 0) { 522 got_num = num4ok; 523 *selected_rtt = num4_lowrtt; 524 } 525 } else if (env->cfg->prefer_ip4) { 526 int got_num4 = 0; 527 int low_rtt4 = 0; 528 int i; 529 int attempt = -1; /* filter to make sure addresses have 530 less attempts on them than the first, to force round 531 robin when all the IPv4 addresses fail */ 532 int num6ok = 0; /* number ip6 at low attempt count */ 533 int num6_lowrtt = 0; 534 prev = NULL; 535 a = dp->result_list; 536 for(i = 0; i < got_num; i++) { 537 if(!a) break; /* robustness */ 538 swap_to_front = 0; 539 if(a->addr.ss_family != AF_INET && attempt == -1) { 540 /* if we only have ip6 at low attempt count, 541 * then ip4 is failing, and we need to 542 * select one of the remaining IPv6 addrs */ 543 attempt = a->attempts; 544 num6ok++; 545 num6_lowrtt = a->sel_rtt; 546 } else if(a->addr.ss_family != AF_INET && attempt == a->attempts) { 547 num6ok++; 548 if(num6_lowrtt == 0 || a->sel_rtt < num6_lowrtt) { 549 num6_lowrtt = a->sel_rtt; 550 } 551 } 552 if(a->addr.ss_family == AF_INET) { 553 if(attempt == -1) { 554 attempt = a->attempts; 555 } else if(a->attempts > attempt) { 556 break; 557 } 558 got_num4++; 559 swap_to_front = 1; 560 if(low_rtt4 == 0 || a->sel_rtt < low_rtt4) { 561 low_rtt4 = a->sel_rtt; 562 } 563 } 564 /* swap to front if IPv4, or move to next result */ 565 if(swap_to_front && prev) { 566 n = a->next_result; 567 prev->next_result = n; 568 a->next_result = dp->result_list; 569 dp->result_list = a; 570 a = n; 571 } else { 572 prev = a; 573 a = a->next_result; 574 } 575 } 576 if(got_num4 > 0) { 577 got_num = got_num4; 578 *selected_rtt = low_rtt4; 579 } else if(num6ok > 0) { 580 got_num = num6ok; 581 *selected_rtt = num6_lowrtt; 582 } 583 } 584 return got_num; 585} 586 587struct delegpt_addr* 588iter_server_selection(struct iter_env* iter_env, 589 struct module_env* env, struct delegpt* dp, 590 uint8_t* name, size_t namelen, uint16_t qtype, int* dnssec_lame, 591 int* chase_to_rd, int open_target, struct sock_list* blacklist, 592 time_t prefetch) 593{ 594 int sel; 595 int selrtt; 596 struct delegpt_addr* a, *prev; 597 int num = iter_filter_order(iter_env, env, name, namelen, qtype, 598 *env->now, dp, &selrtt, open_target, blacklist, prefetch); 599 600 if(num == 0) 601 return NULL; 602 verbose(VERB_ALGO, "selrtt %d", selrtt); 603 if(selrtt > BLACKLIST_PENALTY) { 604 if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*3) { 605 verbose(VERB_ALGO, "chase to " 606 "blacklisted recursion lame server"); 607 *chase_to_rd = 1; 608 } 609 if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*2) { 610 verbose(VERB_ALGO, "chase to " 611 "blacklisted dnssec lame server"); 612 *dnssec_lame = 1; 613 } 614 } else { 615 if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*3) { 616 verbose(VERB_ALGO, "chase to recursion lame server"); 617 *chase_to_rd = 1; 618 } 619 if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*2) { 620 verbose(VERB_ALGO, "chase to dnssec lame server"); 621 *dnssec_lame = 1; 622 } 623 if(selrtt == USEFUL_SERVER_TOP_TIMEOUT) { 624 verbose(VERB_ALGO, "chase to blacklisted lame server"); 625 return NULL; 626 } 627 } 628 629 if(num == 1) { 630 a = dp->result_list; 631 if(++a->attempts < iter_env->outbound_msg_retry) 632 return a; 633 dp->result_list = a->next_result; 634 return a; 635 } 636 637 /* randomly select a target from the list */ 638 log_assert(num > 1); 639 /* grab secure random number, to pick unexpected server. 640 * also we need it to be threadsafe. */ 641 sel = ub_random_max(env->rnd, num); 642 a = dp->result_list; 643 prev = NULL; 644 while(sel > 0 && a) { 645 prev = a; 646 a = a->next_result; 647 sel--; 648 } 649 if(!a) /* robustness */ 650 return NULL; 651 if(++a->attempts < iter_env->outbound_msg_retry) 652 return a; 653 /* remove it from the delegation point result list */ 654 if(prev) 655 prev->next_result = a->next_result; 656 else dp->result_list = a->next_result; 657 return a; 658} 659 660struct dns_msg* 661dns_alloc_msg(sldns_buffer* pkt, struct msg_parse* msg, 662 struct regional* region) 663{ 664 struct dns_msg* m = (struct dns_msg*)regional_alloc(region, 665 sizeof(struct dns_msg)); 666 if(!m) 667 return NULL; 668 memset(m, 0, sizeof(*m)); 669 if(!parse_create_msg(pkt, msg, NULL, &m->qinfo, &m->rep, region)) { 670 log_err("malloc failure: allocating incoming dns_msg"); 671 return NULL; 672 } 673 return m; 674} 675 676struct dns_msg* 677dns_copy_msg(struct dns_msg* from, struct regional* region) 678{ 679 struct dns_msg* m = (struct dns_msg*)regional_alloc(region, 680 sizeof(struct dns_msg)); 681 if(!m) 682 return NULL; 683 m->qinfo = from->qinfo; 684 if(!(m->qinfo.qname = regional_alloc_init(region, from->qinfo.qname, 685 from->qinfo.qname_len))) 686 return NULL; 687 if(!(m->rep = reply_info_copy(from->rep, NULL, region))) 688 return NULL; 689 return m; 690} 691 692void 693iter_dns_store(struct module_env* env, struct query_info* msgqinf, 694 struct reply_info* msgrep, int is_referral, time_t leeway, int pside, 695 struct regional* region, uint16_t flags, time_t qstarttime) 696{ 697 if(!dns_cache_store(env, msgqinf, msgrep, is_referral, leeway, 698 pside, region, flags, qstarttime)) 699 log_err("out of memory: cannot store data in cache"); 700} 701 702int 703iter_ns_probability(struct ub_randstate* rnd, int n, int m) 704{ 705 int sel; 706 if(n == m) /* 100% chance */ 707 return 1; 708 /* we do not need secure random numbers here, but 709 * we do need it to be threadsafe, so we use this */ 710 sel = ub_random_max(rnd, m); 711 return (sel < n); 712} 713 714/** detect dependency cycle for query and target */ 715static int 716causes_cycle(struct module_qstate* qstate, uint8_t* name, size_t namelen, 717 uint16_t t, uint16_t c) 718{ 719 struct query_info qinf; 720 qinf.qname = name; 721 qinf.qname_len = namelen; 722 qinf.qtype = t; 723 qinf.qclass = c; 724 qinf.local_alias = NULL; 725 fptr_ok(fptr_whitelist_modenv_detect_cycle( 726 qstate->env->detect_cycle)); 727 return (*qstate->env->detect_cycle)(qstate, &qinf, 728 (uint16_t)(BIT_RD|BIT_CD), qstate->is_priming, 729 qstate->is_valrec); 730} 731 732void 733iter_mark_cycle_targets(struct module_qstate* qstate, struct delegpt* dp) 734{ 735 struct delegpt_ns* ns; 736 for(ns = dp->nslist; ns; ns = ns->next) { 737 if(ns->resolved) 738 continue; 739 /* see if this ns as target causes dependency cycle */ 740 if(causes_cycle(qstate, ns->name, ns->namelen, 741 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass) || 742 causes_cycle(qstate, ns->name, ns->namelen, 743 LDNS_RR_TYPE_A, qstate->qinfo.qclass)) { 744 log_nametypeclass(VERB_QUERY, "skipping target due " 745 "to dependency cycle (harden-glue: no may " 746 "fix some of the cycles)", 747 ns->name, LDNS_RR_TYPE_A, 748 qstate->qinfo.qclass); 749 ns->resolved = 1; 750 } 751 } 752} 753 754void 755iter_mark_pside_cycle_targets(struct module_qstate* qstate, struct delegpt* dp) 756{ 757 struct delegpt_ns* ns; 758 for(ns = dp->nslist; ns; ns = ns->next) { 759 if(ns->done_pside4 && ns->done_pside6) 760 continue; 761 /* see if this ns as target causes dependency cycle */ 762 if(causes_cycle(qstate, ns->name, ns->namelen, 763 LDNS_RR_TYPE_A, qstate->qinfo.qclass)) { 764 log_nametypeclass(VERB_QUERY, "skipping target due " 765 "to dependency cycle", ns->name, 766 LDNS_RR_TYPE_A, qstate->qinfo.qclass); 767 ns->done_pside4 = 1; 768 } 769 if(causes_cycle(qstate, ns->name, ns->namelen, 770 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass)) { 771 log_nametypeclass(VERB_QUERY, "skipping target due " 772 "to dependency cycle", ns->name, 773 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass); 774 ns->done_pside6 = 1; 775 } 776 } 777} 778 779int 780iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags, 781 struct delegpt* dp, int supports_ipv4, int supports_ipv6, 782 int use_nat64) 783{ 784 struct delegpt_ns* ns; 785 struct delegpt_addr* a; 786 787 if(supports_ipv6 && use_nat64) 788 supports_ipv4 = 1; 789 790 /* check: 791 * o RD qflag is on. 792 * o no addresses are provided. 793 * o all NS items are required glue. 794 * OR 795 * o RD qflag is on. 796 * o no addresses are provided. 797 * o the query is for one of the nameservers in dp, 798 * and that nameserver is a glue-name for this dp. 799 */ 800 if(!(qflags&BIT_RD)) 801 return 0; 802 /* either available or unused targets, 803 * if they exist, the dp is not useless. */ 804 for(a = dp->usable_list; a; a = a->next_usable) { 805 if(!addr_is_ip6(&a->addr, a->addrlen) && supports_ipv4) 806 return 0; 807 else if(addr_is_ip6(&a->addr, a->addrlen) && supports_ipv6) 808 return 0; 809 } 810 for(a = dp->result_list; a; a = a->next_result) { 811 if(!addr_is_ip6(&a->addr, a->addrlen) && supports_ipv4) 812 return 0; 813 else if(addr_is_ip6(&a->addr, a->addrlen) && supports_ipv6) 814 return 0; 815 } 816 817 /* see if query is for one of the nameservers, which is glue */ 818 if( ((qinfo->qtype == LDNS_RR_TYPE_A && supports_ipv4) || 819 (qinfo->qtype == LDNS_RR_TYPE_AAAA && supports_ipv6)) && 820 dname_subdomain_c(qinfo->qname, dp->name) && 821 delegpt_find_ns(dp, qinfo->qname, qinfo->qname_len)) 822 return 1; 823 824 for(ns = dp->nslist; ns; ns = ns->next) { 825 if(ns->resolved) /* skip failed targets */ 826 continue; 827 if(!dname_subdomain_c(ns->name, dp->name)) 828 return 0; /* one address is not required glue */ 829 } 830 return 1; 831} 832 833int 834iter_qname_indicates_dnssec(struct module_env* env, struct query_info *qinfo) 835{ 836 struct trust_anchor* a; 837 if(!env || !env->anchors || !qinfo || !qinfo->qname) 838 return 0; 839 /* a trust anchor exists above the name? */ 840 if((a=anchors_lookup(env->anchors, qinfo->qname, qinfo->qname_len, 841 qinfo->qclass))) { 842 if(a->numDS == 0 && a->numDNSKEY == 0) { 843 /* insecure trust point */ 844 lock_basic_unlock(&a->lock); 845 return 0; 846 } 847 lock_basic_unlock(&a->lock); 848 return 1; 849 } 850 /* no trust anchor above it. */ 851 return 0; 852} 853 854int 855iter_indicates_dnssec(struct module_env* env, struct delegpt* dp, 856 struct dns_msg* msg, uint16_t dclass) 857{ 858 struct trust_anchor* a; 859 /* information not available, !env->anchors can be common */ 860 if(!env || !env->anchors || !dp || !dp->name) 861 return 0; 862 /* a trust anchor exists with this name, RRSIGs expected */ 863 if((a=anchor_find(env->anchors, dp->name, dp->namelabs, dp->namelen, 864 dclass))) { 865 if(a->numDS == 0 && a->numDNSKEY == 0) { 866 /* insecure trust point */ 867 lock_basic_unlock(&a->lock); 868 return 0; 869 } 870 lock_basic_unlock(&a->lock); 871 return 1; 872 } 873 /* see if DS rrset was given, in AUTH section */ 874 if(msg && msg->rep && 875 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, 876 LDNS_RR_TYPE_DS, dclass)) 877 return 1; 878 /* look in key cache */ 879 if(env->key_cache) { 880 struct key_entry_key* kk = key_cache_obtain(env->key_cache, 881 dp->name, dp->namelen, dclass, env->scratch, *env->now); 882 if(kk) { 883 if(query_dname_compare(kk->name, dp->name) == 0) { 884 if(key_entry_isgood(kk) || key_entry_isbad(kk)) { 885 regional_free_all(env->scratch); 886 return 1; 887 } else if(key_entry_isnull(kk)) { 888 regional_free_all(env->scratch); 889 return 0; 890 } 891 } 892 regional_free_all(env->scratch); 893 } 894 } 895 return 0; 896} 897 898int 899iter_msg_has_dnssec(struct dns_msg* msg) 900{ 901 size_t i; 902 if(!msg || !msg->rep) 903 return 0; 904 for(i=0; i<msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) { 905 if(((struct packed_rrset_data*)msg->rep->rrsets[i]-> 906 entry.data)->rrsig_count > 0) 907 return 1; 908 } 909 /* empty message has no DNSSEC info, with DNSSEC the reply is 910 * not empty (NSEC) */ 911 return 0; 912} 913 914int iter_msg_from_zone(struct dns_msg* msg, struct delegpt* dp, 915 enum response_type type, uint16_t dclass) 916{ 917 if(!msg || !dp || !msg->rep || !dp->name) 918 return 0; 919 /* SOA RRset - always from reply zone */ 920 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, 921 LDNS_RR_TYPE_SOA, dclass) || 922 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, 923 LDNS_RR_TYPE_SOA, dclass)) 924 return 1; 925 if(type == RESPONSE_TYPE_REFERRAL) { 926 size_t i; 927 /* if it adds a single label, i.e. we expect .com, 928 * and referral to example.com. NS ... , then origin zone 929 * is .com. For a referral to sub.example.com. NS ... then 930 * we do not know, since example.com. may be in between. */ 931 for(i=0; i<msg->rep->an_numrrsets+msg->rep->ns_numrrsets; 932 i++) { 933 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 934 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS && 935 ntohs(s->rk.rrset_class) == dclass) { 936 int l = dname_count_labels(s->rk.dname); 937 if(l == dp->namelabs + 1 && 938 dname_strict_subdomain(s->rk.dname, 939 l, dp->name, dp->namelabs)) 940 return 1; 941 } 942 } 943 return 0; 944 } 945 log_assert(type==RESPONSE_TYPE_ANSWER || type==RESPONSE_TYPE_CNAME); 946 /* not a referral, and not lame delegation (upwards), so, 947 * any NS rrset must be from the zone itself */ 948 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, 949 LDNS_RR_TYPE_NS, dclass) || 950 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen, 951 LDNS_RR_TYPE_NS, dclass)) 952 return 1; 953 /* a DNSKEY set is expected at the zone apex as well */ 954 /* this is for 'minimal responses' for DNSKEYs */ 955 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen, 956 LDNS_RR_TYPE_DNSKEY, dclass)) 957 return 1; 958 return 0; 959} 960 961/** 962 * check equality of two rrsets 963 * @param k1: rrset 964 * @param k2: rrset 965 * @return true if equal 966 */ 967static int 968rrset_equal(struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2) 969{ 970 struct packed_rrset_data* d1 = (struct packed_rrset_data*) 971 k1->entry.data; 972 struct packed_rrset_data* d2 = (struct packed_rrset_data*) 973 k2->entry.data; 974 size_t i, t; 975 if(k1->rk.dname_len != k2->rk.dname_len || 976 k1->rk.flags != k2->rk.flags || 977 k1->rk.type != k2->rk.type || 978 k1->rk.rrset_class != k2->rk.rrset_class || 979 query_dname_compare(k1->rk.dname, k2->rk.dname) != 0) 980 return 0; 981 if( /* do not check ttl: d1->ttl != d2->ttl || */ 982 d1->count != d2->count || 983 d1->rrsig_count != d2->rrsig_count || 984 d1->trust != d2->trust || 985 d1->security != d2->security) 986 return 0; 987 t = d1->count + d1->rrsig_count; 988 for(i=0; i<t; i++) { 989 if(d1->rr_len[i] != d2->rr_len[i] || 990 /* no ttl check: d1->rr_ttl[i] != d2->rr_ttl[i] ||*/ 991 memcmp(d1->rr_data[i], d2->rr_data[i], 992 d1->rr_len[i]) != 0) 993 return 0; 994 } 995 return 1; 996} 997 998/** compare rrsets and sort canonically. Compares rrset name, type, class. 999 * return 0 if equal, +1 if x > y, and -1 if x < y. 1000 */ 1001static int 1002rrset_canonical_sort_cmp(const void* x, const void* y) 1003{ 1004 struct ub_packed_rrset_key* rrx = *(struct ub_packed_rrset_key**)x; 1005 struct ub_packed_rrset_key* rry = *(struct ub_packed_rrset_key**)y; 1006 int r = dname_canonical_compare(rrx->rk.dname, rry->rk.dname); 1007 if(r != 0) 1008 return r; 1009 if(rrx->rk.type != rry->rk.type) { 1010 if(ntohs(rrx->rk.type) > ntohs(rry->rk.type)) 1011 return 1; 1012 else return -1; 1013 } 1014 if(rrx->rk.rrset_class != rry->rk.rrset_class) { 1015 if(ntohs(rrx->rk.rrset_class) > ntohs(rry->rk.rrset_class)) 1016 return 1; 1017 else return -1; 1018 } 1019 return 0; 1020} 1021 1022int 1023reply_equal(struct reply_info* p, struct reply_info* q, struct regional* region) 1024{ 1025 size_t i; 1026 struct ub_packed_rrset_key** sorted_p, **sorted_q; 1027 if(p->flags != q->flags || 1028 p->qdcount != q->qdcount || 1029 /* do not check TTL, this may differ */ 1030 /* 1031 p->ttl != q->ttl || 1032 p->prefetch_ttl != q->prefetch_ttl || 1033 */ 1034 p->security != q->security || 1035 p->an_numrrsets != q->an_numrrsets || 1036 p->ns_numrrsets != q->ns_numrrsets || 1037 p->ar_numrrsets != q->ar_numrrsets || 1038 p->rrset_count != q->rrset_count) 1039 return 0; 1040 /* sort the rrsets in the authority and additional sections before 1041 * compare, the query and answer sections are ordered in the sequence 1042 * they should have (eg. one after the other for aliases). */ 1043 sorted_p = (struct ub_packed_rrset_key**)regional_alloc_init( 1044 region, p->rrsets, sizeof(*sorted_p)*p->rrset_count); 1045 if(!sorted_p) return 0; 1046 log_assert(p->an_numrrsets + p->ns_numrrsets + p->ar_numrrsets <= 1047 p->rrset_count); 1048 qsort(sorted_p + p->an_numrrsets, p->ns_numrrsets, 1049 sizeof(*sorted_p), rrset_canonical_sort_cmp); 1050 qsort(sorted_p + p->an_numrrsets + p->ns_numrrsets, p->ar_numrrsets, 1051 sizeof(*sorted_p), rrset_canonical_sort_cmp); 1052 1053 sorted_q = (struct ub_packed_rrset_key**)regional_alloc_init( 1054 region, q->rrsets, sizeof(*sorted_q)*q->rrset_count); 1055 if(!sorted_q) { 1056 regional_free_all(region); 1057 return 0; 1058 } 1059 log_assert(q->an_numrrsets + q->ns_numrrsets + q->ar_numrrsets <= 1060 q->rrset_count); 1061 qsort(sorted_q + q->an_numrrsets, q->ns_numrrsets, 1062 sizeof(*sorted_q), rrset_canonical_sort_cmp); 1063 qsort(sorted_q + q->an_numrrsets + q->ns_numrrsets, q->ar_numrrsets, 1064 sizeof(*sorted_q), rrset_canonical_sort_cmp); 1065 1066 /* compare the rrsets */ 1067 for(i=0; i<p->rrset_count; i++) { 1068 if(!rrset_equal(sorted_p[i], sorted_q[i])) { 1069 if(!rrset_canonical_equal(region, sorted_p[i], 1070 sorted_q[i])) { 1071 regional_free_all(region); 1072 return 0; 1073 } 1074 } 1075 } 1076 regional_free_all(region); 1077 return 1; 1078} 1079 1080void 1081caps_strip_reply(struct reply_info* rep) 1082{ 1083 size_t i; 1084 if(!rep) return; 1085 /* see if message is a referral, in which case the additional and 1086 * NS record cannot be removed */ 1087 /* referrals have the AA flag unset (strict check, not elsewhere in 1088 * unbound, but for 0x20 this is very convenient). */ 1089 if(!(rep->flags&BIT_AA)) 1090 return; 1091 /* remove the additional section from the reply */ 1092 if(rep->ar_numrrsets != 0) { 1093 verbose(VERB_ALGO, "caps fallback: removing additional section"); 1094 rep->rrset_count -= rep->ar_numrrsets; 1095 rep->ar_numrrsets = 0; 1096 } 1097 /* is there an NS set in the authority section to remove? */ 1098 /* the failure case (Cisco firewalls) only has one rrset in authsec */ 1099 for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) { 1100 struct ub_packed_rrset_key* s = rep->rrsets[i]; 1101 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS) { 1102 /* remove NS rrset and break from loop (loop limits 1103 * have changed) */ 1104 /* move last rrset into this position (there is no 1105 * additional section any more) */ 1106 verbose(VERB_ALGO, "caps fallback: removing NS rrset"); 1107 if(i < rep->rrset_count-1) 1108 rep->rrsets[i]=rep->rrsets[rep->rrset_count-1]; 1109 rep->rrset_count --; 1110 rep->ns_numrrsets --; 1111 break; 1112 } 1113 } 1114} 1115 1116int caps_failed_rcode(struct reply_info* rep) 1117{ 1118 return !(FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NOERROR || 1119 FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NXDOMAIN); 1120} 1121 1122void 1123iter_store_parentside_rrset(struct module_env* env, 1124 struct ub_packed_rrset_key* rrset) 1125{ 1126 struct rrset_ref ref; 1127 rrset = packed_rrset_copy_alloc(rrset, env->alloc, *env->now); 1128 if(!rrset) { 1129 log_err("malloc failure in store_parentside_rrset"); 1130 return; 1131 } 1132 rrset->rk.flags |= PACKED_RRSET_PARENT_SIDE; 1133 rrset->entry.hash = rrset_key_hash(&rrset->rk); 1134 ref.key = rrset; 1135 ref.id = rrset->id; 1136 /* ignore ret: if it was in the cache, ref updated */ 1137 (void)rrset_cache_update(env->rrset_cache, &ref, env->alloc, *env->now); 1138} 1139 1140/** fetch NS record from reply, if any */ 1141static struct ub_packed_rrset_key* 1142reply_get_NS_rrset(struct reply_info* rep) 1143{ 1144 size_t i; 1145 for(i=0; i<rep->rrset_count; i++) { 1146 if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NS)) { 1147 return rep->rrsets[i]; 1148 } 1149 } 1150 return NULL; 1151} 1152 1153void 1154iter_store_parentside_NS(struct module_env* env, struct reply_info* rep) 1155{ 1156 struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep); 1157 if(rrset) { 1158 log_rrset_key(VERB_ALGO, "store parent-side NS", rrset); 1159 iter_store_parentside_rrset(env, rrset); 1160 } 1161} 1162 1163void iter_store_parentside_neg(struct module_env* env, 1164 struct query_info* qinfo, struct reply_info* rep) 1165{ 1166 /* TTL: NS from referral in iq->deleg_msg, 1167 * or first RR from iq->response, 1168 * or servfail5secs if !iq->response */ 1169 time_t ttl = NORR_TTL; 1170 struct ub_packed_rrset_key* neg; 1171 struct packed_rrset_data* newd; 1172 if(rep) { 1173 struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep); 1174 if(!rrset && rep->rrset_count != 0) rrset = rep->rrsets[0]; 1175 if(rrset) ttl = ub_packed_rrset_ttl(rrset); 1176 } 1177 /* create empty rrset to store */ 1178 neg = (struct ub_packed_rrset_key*)regional_alloc(env->scratch, 1179 sizeof(struct ub_packed_rrset_key)); 1180 if(!neg) { 1181 log_err("out of memory in store_parentside_neg"); 1182 return; 1183 } 1184 memset(&neg->entry, 0, sizeof(neg->entry)); 1185 neg->entry.key = neg; 1186 neg->rk.type = htons(qinfo->qtype); 1187 neg->rk.rrset_class = htons(qinfo->qclass); 1188 neg->rk.flags = 0; 1189 neg->rk.dname = regional_alloc_init(env->scratch, qinfo->qname, 1190 qinfo->qname_len); 1191 if(!neg->rk.dname) { 1192 log_err("out of memory in store_parentside_neg"); 1193 return; 1194 } 1195 neg->rk.dname_len = qinfo->qname_len; 1196 neg->entry.hash = rrset_key_hash(&neg->rk); 1197 newd = (struct packed_rrset_data*)regional_alloc_zero(env->scratch, 1198 sizeof(struct packed_rrset_data) + sizeof(size_t) + 1199 sizeof(uint8_t*) + sizeof(time_t) + sizeof(uint16_t)); 1200 if(!newd) { 1201 log_err("out of memory in store_parentside_neg"); 1202 return; 1203 } 1204 neg->entry.data = newd; 1205 newd->ttl = ttl; 1206 /* entry must have one RR, otherwise not valid in cache. 1207 * put in one RR with empty rdata: those are ignored as nameserver */ 1208 newd->count = 1; 1209 newd->rrsig_count = 0; 1210 newd->trust = rrset_trust_ans_noAA; 1211 newd->rr_len = (size_t*)((uint8_t*)newd + 1212 sizeof(struct packed_rrset_data)); 1213 newd->rr_len[0] = 0 /* zero len rdata */ + sizeof(uint16_t); 1214 packed_rrset_ptr_fixup(newd); 1215 newd->rr_ttl[0] = newd->ttl; 1216 sldns_write_uint16(newd->rr_data[0], 0 /* zero len rdata */); 1217 /* store it */ 1218 log_rrset_key(VERB_ALGO, "store parent-side negative", neg); 1219 iter_store_parentside_rrset(env, neg); 1220} 1221 1222int 1223iter_lookup_parent_NS_from_cache(struct module_env* env, struct delegpt* dp, 1224 struct regional* region, struct query_info* qinfo) 1225{ 1226 struct ub_packed_rrset_key* akey; 1227 akey = rrset_cache_lookup(env->rrset_cache, dp->name, 1228 dp->namelen, LDNS_RR_TYPE_NS, qinfo->qclass, 1229 PACKED_RRSET_PARENT_SIDE, *env->now, 0); 1230 if(akey) { 1231 log_rrset_key(VERB_ALGO, "found parent-side NS in cache", akey); 1232 dp->has_parent_side_NS = 1; 1233 /* and mark the new names as lame */ 1234 if(!delegpt_rrset_add_ns(dp, region, akey, 1)) { 1235 lock_rw_unlock(&akey->entry.lock); 1236 return 0; 1237 } 1238 lock_rw_unlock(&akey->entry.lock); 1239 } 1240 return 1; 1241} 1242 1243int iter_lookup_parent_glue_from_cache(struct module_env* env, 1244 struct delegpt* dp, struct regional* region, struct query_info* qinfo) 1245{ 1246 struct ub_packed_rrset_key* akey; 1247 struct delegpt_ns* ns; 1248 size_t num = delegpt_count_targets(dp); 1249 for(ns = dp->nslist; ns; ns = ns->next) { 1250 if(ns->cache_lookup_count > ITERATOR_NAME_CACHELOOKUP_MAX_PSIDE) 1251 continue; 1252 ns->cache_lookup_count++; 1253 /* get cached parentside A */ 1254 akey = rrset_cache_lookup(env->rrset_cache, ns->name, 1255 ns->namelen, LDNS_RR_TYPE_A, qinfo->qclass, 1256 PACKED_RRSET_PARENT_SIDE, *env->now, 0); 1257 if(akey) { 1258 log_rrset_key(VERB_ALGO, "found parent-side", akey); 1259 ns->done_pside4 = 1; 1260 /* a negative-cache-element has no addresses it adds */ 1261 if(!delegpt_add_rrset_A(dp, region, akey, 1, NULL)) 1262 log_err("malloc failure in lookup_parent_glue"); 1263 lock_rw_unlock(&akey->entry.lock); 1264 } 1265 /* get cached parentside AAAA */ 1266 akey = rrset_cache_lookup(env->rrset_cache, ns->name, 1267 ns->namelen, LDNS_RR_TYPE_AAAA, qinfo->qclass, 1268 PACKED_RRSET_PARENT_SIDE, *env->now, 0); 1269 if(akey) { 1270 log_rrset_key(VERB_ALGO, "found parent-side", akey); 1271 ns->done_pside6 = 1; 1272 /* a negative-cache-element has no addresses it adds */ 1273 if(!delegpt_add_rrset_AAAA(dp, region, akey, 1, NULL)) 1274 log_err("malloc failure in lookup_parent_glue"); 1275 lock_rw_unlock(&akey->entry.lock); 1276 } 1277 } 1278 /* see if new (but lame) addresses have become available */ 1279 return delegpt_count_targets(dp) != num; 1280} 1281 1282int 1283iter_get_next_root(struct iter_hints* hints, struct iter_forwards* fwd, 1284 uint16_t* c) 1285{ 1286 uint16_t c1 = *c, c2 = *c; 1287 int r1, r2; 1288 int nolock = 1; 1289 1290 /* prelock both forwards and hints for atomic read. */ 1291 lock_rw_rdlock(&fwd->lock); 1292 lock_rw_rdlock(&hints->lock); 1293 r1 = hints_next_root(hints, &c1, nolock); 1294 r2 = forwards_next_root(fwd, &c2, nolock); 1295 lock_rw_unlock(&fwd->lock); 1296 lock_rw_unlock(&hints->lock); 1297 1298 if(!r1 && !r2) /* got none, end of list */ 1299 return 0; 1300 else if(!r1) /* got one, return that */ 1301 *c = c2; 1302 else if(!r2) 1303 *c = c1; 1304 else if(c1 < c2) /* got both take smallest */ 1305 *c = c1; 1306 else *c = c2; 1307 return 1; 1308} 1309 1310void 1311iter_scrub_ds(struct dns_msg* msg, struct ub_packed_rrset_key* ns, uint8_t* z) 1312{ 1313 /* Only the DS record for the delegation itself is expected. 1314 * We allow DS for everything between the bailiwick and the 1315 * zonecut, thus DS records must be at or above the zonecut. 1316 * And the DS records must be below the server authority zone. 1317 * The answer section is already scrubbed. */ 1318 size_t i = msg->rep->an_numrrsets; 1319 while(i < (msg->rep->an_numrrsets + msg->rep->ns_numrrsets)) { 1320 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 1321 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS && 1322 (!ns || !dname_subdomain_c(ns->rk.dname, s->rk.dname) 1323 || query_dname_compare(z, s->rk.dname) == 0)) { 1324 log_nametypeclass(VERB_ALGO, "removing irrelevant DS", 1325 s->rk.dname, ntohs(s->rk.type), 1326 ntohs(s->rk.rrset_class)); 1327 memmove(msg->rep->rrsets+i, msg->rep->rrsets+i+1, 1328 sizeof(struct ub_packed_rrset_key*) * 1329 (msg->rep->rrset_count-i-1)); 1330 msg->rep->ns_numrrsets--; 1331 msg->rep->rrset_count--; 1332 /* stay at same i, but new record */ 1333 continue; 1334 } 1335 i++; 1336 } 1337} 1338 1339void 1340iter_scrub_nxdomain(struct dns_msg* msg) 1341{ 1342 if(msg->rep->an_numrrsets == 0) 1343 return; 1344 1345 memmove(msg->rep->rrsets, msg->rep->rrsets+msg->rep->an_numrrsets, 1346 sizeof(struct ub_packed_rrset_key*) * 1347 (msg->rep->rrset_count-msg->rep->an_numrrsets)); 1348 msg->rep->rrset_count -= msg->rep->an_numrrsets; 1349 msg->rep->an_numrrsets = 0; 1350} 1351 1352void iter_dec_attempts(struct delegpt* dp, int d, int outbound_msg_retry) 1353{ 1354 struct delegpt_addr* a; 1355 for(a=dp->target_list; a; a = a->next_target) { 1356 if(a->attempts >= outbound_msg_retry) { 1357 /* add back to result list */ 1358 delegpt_add_to_result_list(dp, a); 1359 } 1360 if(a->attempts > d) 1361 a->attempts -= d; 1362 else a->attempts = 0; 1363 } 1364} 1365 1366void iter_merge_retry_counts(struct delegpt* dp, struct delegpt* old, 1367 int outbound_msg_retry) 1368{ 1369 struct delegpt_addr* a, *o, *prev; 1370 for(a=dp->target_list; a; a = a->next_target) { 1371 o = delegpt_find_addr(old, &a->addr, a->addrlen); 1372 if(o) { 1373 log_addr(VERB_ALGO, "copy attempt count previous dp", 1374 &a->addr, a->addrlen); 1375 a->attempts = o->attempts; 1376 } 1377 } 1378 prev = NULL; 1379 a = dp->usable_list; 1380 while(a) { 1381 if(a->attempts >= outbound_msg_retry) { 1382 log_addr(VERB_ALGO, "remove from usable list dp", 1383 &a->addr, a->addrlen); 1384 /* remove from result list */ 1385 if(prev) 1386 prev->next_usable = a->next_usable; 1387 else dp->usable_list = a->next_usable; 1388 /* prev stays the same */ 1389 a = a->next_usable; 1390 continue; 1391 } 1392 prev = a; 1393 a = a->next_usable; 1394 } 1395} 1396 1397int 1398iter_ds_toolow(struct dns_msg* msg, struct delegpt* dp) 1399{ 1400 /* if for query example.com, there is example.com SOA or a subdomain 1401 * of example.com, then we are too low and need to fetch NS. */ 1402 size_t i; 1403 /* if we have a DNAME or CNAME we are probably wrong */ 1404 /* if we have a qtype DS in the answer section, its fine */ 1405 for(i=0; i < msg->rep->an_numrrsets; i++) { 1406 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 1407 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME || 1408 ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) { 1409 /* not the right answer, maybe too low, check the 1410 * RRSIG signer name (if there is any) for a hint 1411 * that it is from the dp zone anyway */ 1412 uint8_t* sname; 1413 size_t slen; 1414 val_find_rrset_signer(s, &sname, &slen); 1415 if(sname && query_dname_compare(dp->name, sname)==0) 1416 return 0; /* it is fine, from the right dp */ 1417 return 1; 1418 } 1419 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS) 1420 return 0; /* fine, we have a DS record */ 1421 } 1422 for(i=msg->rep->an_numrrsets; 1423 i < msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) { 1424 struct ub_packed_rrset_key* s = msg->rep->rrsets[i]; 1425 if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA) { 1426 if(dname_subdomain_c(s->rk.dname, msg->qinfo.qname)) 1427 return 1; /* point is too low */ 1428 if(query_dname_compare(s->rk.dname, dp->name)==0) 1429 return 0; /* right dp */ 1430 } 1431 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC || 1432 ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) { 1433 uint8_t* sname; 1434 size_t slen; 1435 val_find_rrset_signer(s, &sname, &slen); 1436 if(sname && query_dname_compare(dp->name, sname)==0) 1437 return 0; /* it is fine, from the right dp */ 1438 return 1; 1439 } 1440 } 1441 /* we do not know */ 1442 return 1; 1443} 1444 1445int iter_dp_cangodown(struct query_info* qinfo, struct delegpt* dp) 1446{ 1447 /* no delegation point, do not see how we can go down, 1448 * robust check, it should really exist */ 1449 if(!dp) return 0; 1450 1451 /* see if dp equals the qname, then we cannot go down further */ 1452 if(query_dname_compare(qinfo->qname, dp->name) == 0) 1453 return 0; 1454 /* if dp is one label above the name we also cannot go down further */ 1455 if(dname_count_labels(qinfo->qname) == dp->namelabs+1) 1456 return 0; 1457 return 1; 1458} 1459 1460int 1461iter_stub_fwd_no_cache(struct module_qstate *qstate, struct query_info *qinf, 1462 uint8_t** retdpname, size_t* retdpnamelen, uint8_t* dpname_storage, 1463 size_t dpname_storage_len) 1464{ 1465 struct iter_hints_stub *stub; 1466 struct delegpt *dp; 1467 int nolock = 1; 1468 1469 /* Check for stub. */ 1470 /* Lock both forwards and hints for atomic read. */ 1471 lock_rw_rdlock(&qstate->env->fwds->lock); 1472 lock_rw_rdlock(&qstate->env->hints->lock); 1473 stub = hints_lookup_stub(qstate->env->hints, qinf->qname, 1474 qinf->qclass, NULL, nolock); 1475 dp = forwards_lookup(qstate->env->fwds, qinf->qname, qinf->qclass, 1476 nolock); 1477 1478 /* see if forward or stub is more pertinent */ 1479 if(stub && stub->dp && dp) { 1480 if(dname_strict_subdomain(dp->name, dp->namelabs, 1481 stub->dp->name, stub->dp->namelabs)) { 1482 stub = NULL; /* ignore stub, forward is lower */ 1483 } else { 1484 dp = NULL; /* ignore forward, stub is lower */ 1485 } 1486 } 1487 1488 /* check stub */ 1489 if (stub != NULL && stub->dp != NULL) { 1490 int stub_no_cache = stub->dp->no_cache; 1491 lock_rw_unlock(&qstate->env->fwds->lock); 1492 if(stub_no_cache) { 1493 char qname[255+1]; 1494 char dpname[255+1]; 1495 dname_str(qinf->qname, qname); 1496 dname_str(stub->dp->name, dpname); 1497 verbose(VERB_ALGO, "stub for %s %s has no_cache", qname, dpname); 1498 } 1499 if(retdpname) { 1500 if(stub->dp->namelen > dpname_storage_len) { 1501 verbose(VERB_ALGO, "no cache stub dpname too long"); 1502 lock_rw_unlock(&qstate->env->hints->lock); 1503 *retdpname = NULL; 1504 *retdpnamelen = 0; 1505 return stub_no_cache; 1506 } 1507 memmove(dpname_storage, stub->dp->name, 1508 stub->dp->namelen); 1509 *retdpname = dpname_storage; 1510 *retdpnamelen = stub->dp->namelen; 1511 } 1512 lock_rw_unlock(&qstate->env->hints->lock); 1513 return stub_no_cache; 1514 } 1515 1516 /* Check for forward. */ 1517 if (dp) { 1518 int dp_no_cache = dp->no_cache; 1519 lock_rw_unlock(&qstate->env->hints->lock); 1520 if(dp_no_cache) { 1521 char qname[255+1]; 1522 char dpname[255+1]; 1523 dname_str(qinf->qname, qname); 1524 dname_str(dp->name, dpname); 1525 verbose(VERB_ALGO, "forward for %s %s has no_cache", qname, dpname); 1526 } 1527 if(retdpname) { 1528 if(dp->namelen > dpname_storage_len) { 1529 verbose(VERB_ALGO, "no cache dpname too long"); 1530 lock_rw_unlock(&qstate->env->fwds->lock); 1531 *retdpname = NULL; 1532 *retdpnamelen = 0; 1533 return dp_no_cache; 1534 } 1535 memmove(dpname_storage, dp->name, dp->namelen); 1536 *retdpname = dpname_storage; 1537 *retdpnamelen = dp->namelen; 1538 } 1539 lock_rw_unlock(&qstate->env->fwds->lock); 1540 return dp_no_cache; 1541 } 1542 lock_rw_unlock(&qstate->env->fwds->lock); 1543 lock_rw_unlock(&qstate->env->hints->lock); 1544 if(retdpname) { 1545 *retdpname = NULL; 1546 *retdpnamelen = 0; 1547 } 1548 return 0; 1549} 1550 1551void iterator_set_ip46_support(struct module_stack* mods, 1552 struct module_env* env, struct outside_network* outnet) 1553{ 1554 int m = modstack_find(mods, "iterator"); 1555 struct iter_env* ie = NULL; 1556 if(m == -1) 1557 return; 1558 ie = (struct iter_env*)env->modinfo[m]; 1559 if(outnet->pending == NULL) 1560 return; /* we are in testbound, no rbtree for UDP */ 1561 if(outnet->num_ip4 == 0) 1562 ie->supports_ipv4 = 0; 1563 if(outnet->num_ip6 == 0) 1564 ie->supports_ipv6 = 0; 1565} 1566