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