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