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