1 /* 2 * iterator/iter_hints.c - iterative resolver module stub and root hints. 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 LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE 27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /** 37 * \file 38 * 39 * This file contains functions to assist the iterator module. 40 * Keep track of stub and root hints, and read those from config. 41 */ 42 #include "config.h" 43 #include <ldns/dname.h> 44 #include <ldns/rr.h> 45 #include "iterator/iter_hints.h" 46 #include "iterator/iter_delegpt.h" 47 #include "util/log.h" 48 #include "util/config_file.h" 49 #include "util/net_help.h" 50 #include "util/data/dname.h" 51 52 struct iter_hints* 53 hints_create(void) 54 { 55 struct iter_hints* hints = (struct iter_hints*)calloc(1, 56 sizeof(struct iter_hints)); 57 if(!hints) 58 return NULL; 59 return hints; 60 } 61 62 static void hints_stub_free(struct iter_hints_stub* s) 63 { 64 if(!s) return; 65 delegpt_free_mlc(s->dp); 66 free(s); 67 } 68 69 static void delhintnode(rbnode_t* n, void* ATTR_UNUSED(arg)) 70 { 71 struct iter_hints_stub* node = (struct iter_hints_stub*)n; 72 hints_stub_free(node); 73 } 74 75 static void hints_del_tree(struct iter_hints* hints) 76 { 77 traverse_postorder(&hints->tree, &delhintnode, NULL); 78 } 79 80 void 81 hints_delete(struct iter_hints* hints) 82 { 83 if(!hints) 84 return; 85 hints_del_tree(hints); 86 free(hints); 87 } 88 89 /** add hint to delegation hints */ 90 static int 91 ah(struct delegpt* dp, const char* sv, const char* ip) 92 { 93 struct sockaddr_storage addr; 94 socklen_t addrlen; 95 ldns_rdf* rdf = ldns_dname_new_frm_str(sv); 96 if(!rdf) { 97 log_err("could not parse %s", sv); 98 return 0; 99 } 100 if(!delegpt_add_ns_mlc(dp, ldns_rdf_data(rdf), 0) || 101 !extstrtoaddr(ip, &addr, &addrlen) || 102 !delegpt_add_target_mlc(dp, ldns_rdf_data(rdf), ldns_rdf_size(rdf), 103 &addr, addrlen, 0, 0)) { 104 ldns_rdf_deep_free(rdf); 105 return 0; 106 } 107 ldns_rdf_deep_free(rdf); 108 return 1; 109 } 110 111 /** obtain compiletime provided root hints */ 112 static struct delegpt* 113 compile_time_root_prime(int do_ip4, int do_ip6) 114 { 115 /* from: 116 ; This file is made available by InterNIC 117 ; under anonymous FTP as 118 ; file /domain/named.cache 119 ; on server FTP.INTERNIC.NET 120 ; -OR- RS.INTERNIC.NET 121 ; 122 ; related version of root zone: 2010061700 123 */ 124 struct delegpt* dp = delegpt_create_mlc((uint8_t*)"\000"); 125 if(!dp) 126 return NULL; 127 dp->has_parent_side_NS = 1; 128 if(do_ip4) { 129 if(!ah(dp, "A.ROOT-SERVERS.NET.", "198.41.0.4")) goto failed; 130 if(!ah(dp, "B.ROOT-SERVERS.NET.", "192.228.79.201")) goto failed; 131 if(!ah(dp, "C.ROOT-SERVERS.NET.", "192.33.4.12")) goto failed; 132 if(!ah(dp, "D.ROOT-SERVERS.NET.", "199.7.91.13")) goto failed; 133 if(!ah(dp, "E.ROOT-SERVERS.NET.", "192.203.230.10")) goto failed; 134 if(!ah(dp, "F.ROOT-SERVERS.NET.", "192.5.5.241")) goto failed; 135 if(!ah(dp, "G.ROOT-SERVERS.NET.", "192.112.36.4")) goto failed; 136 if(!ah(dp, "H.ROOT-SERVERS.NET.", "128.63.2.53")) goto failed; 137 if(!ah(dp, "I.ROOT-SERVERS.NET.", "192.36.148.17")) goto failed; 138 if(!ah(dp, "J.ROOT-SERVERS.NET.", "192.58.128.30")) goto failed; 139 if(!ah(dp, "K.ROOT-SERVERS.NET.", "193.0.14.129")) goto failed; 140 if(!ah(dp, "L.ROOT-SERVERS.NET.", "199.7.83.42")) goto failed; 141 if(!ah(dp, "M.ROOT-SERVERS.NET.", "202.12.27.33")) goto failed; 142 } 143 if(do_ip6) { 144 if(!ah(dp, "A.ROOT-SERVERS.NET.", "2001:503:ba3e::2:30")) goto failed; 145 if(!ah(dp, "D.ROOT-SERVERS.NET.", "2001:500:2d::d")) goto failed; 146 if(!ah(dp, "F.ROOT-SERVERS.NET.", "2001:500:2f::f")) goto failed; 147 if(!ah(dp, "H.ROOT-SERVERS.NET.", "2001:500:1::803f:235")) goto failed; 148 if(!ah(dp, "I.ROOT-SERVERS.NET.", "2001:7fe::53")) goto failed; 149 if(!ah(dp, "J.ROOT-SERVERS.NET.", "2001:503:c27::2:30")) goto failed; 150 if(!ah(dp, "K.ROOT-SERVERS.NET.", "2001:7fd::1")) goto failed; 151 if(!ah(dp, "L.ROOT-SERVERS.NET.", "2001:500:3::42")) goto failed; 152 if(!ah(dp, "M.ROOT-SERVERS.NET.", "2001:dc3::35")) goto failed; 153 } 154 return dp; 155 failed: 156 delegpt_free_mlc(dp); 157 return 0; 158 } 159 160 /** insert new hint info into hint structure */ 161 static int 162 hints_insert(struct iter_hints* hints, uint16_t c, struct delegpt* dp, 163 int noprime) 164 { 165 struct iter_hints_stub* node = (struct iter_hints_stub*)malloc( 166 sizeof(struct iter_hints_stub)); 167 if(!node) { 168 delegpt_free_mlc(dp); 169 return 0; 170 } 171 node->dp = dp; 172 node->noprime = (uint8_t)noprime; 173 if(!name_tree_insert(&hints->tree, &node->node, dp->name, dp->namelen, 174 dp->namelabs, c)) { 175 log_err("second hints ignored."); 176 delegpt_free_mlc(dp); 177 free(node); 178 } 179 return 1; 180 } 181 182 /** set stub name */ 183 static struct delegpt* 184 read_stubs_name(struct config_stub* s) 185 { 186 struct delegpt* dp; 187 ldns_rdf* rdf; 188 if(!s->name) { 189 log_err("stub zone without a name"); 190 return NULL; 191 } 192 rdf = ldns_dname_new_frm_str(s->name); 193 if(!rdf) { 194 log_err("cannot parse stub zone name %s", s->name); 195 return NULL; 196 } 197 if(!(dp=delegpt_create_mlc(ldns_rdf_data(rdf)))) { 198 ldns_rdf_deep_free(rdf); 199 log_err("out of memory"); 200 return NULL; 201 } 202 ldns_rdf_deep_free(rdf); 203 return dp; 204 } 205 206 /** set stub host names */ 207 static int 208 read_stubs_host(struct config_stub* s, struct delegpt* dp) 209 { 210 struct config_strlist* p; 211 ldns_rdf* rdf; 212 for(p = s->hosts; p; p = p->next) { 213 log_assert(p->str); 214 rdf = ldns_dname_new_frm_str(p->str); 215 if(!rdf) { 216 log_err("cannot parse stub %s nameserver name: '%s'", 217 s->name, p->str); 218 return 0; 219 } 220 if(!delegpt_add_ns_mlc(dp, ldns_rdf_data(rdf), 0)) { 221 ldns_rdf_deep_free(rdf); 222 log_err("out of memory"); 223 return 0; 224 } 225 ldns_rdf_deep_free(rdf); 226 } 227 return 1; 228 } 229 230 /** set stub server addresses */ 231 static int 232 read_stubs_addr(struct config_stub* s, struct delegpt* dp) 233 { 234 struct config_strlist* p; 235 struct sockaddr_storage addr; 236 socklen_t addrlen; 237 for(p = s->addrs; p; p = p->next) { 238 log_assert(p->str); 239 if(!extstrtoaddr(p->str, &addr, &addrlen)) { 240 log_err("cannot parse stub %s ip address: '%s'", 241 s->name, p->str); 242 return 0; 243 } 244 if(!delegpt_add_addr_mlc(dp, &addr, addrlen, 0, 0)) { 245 log_err("out of memory"); 246 return 0; 247 } 248 } 249 return 1; 250 } 251 252 /** read stubs config */ 253 static int 254 read_stubs(struct iter_hints* hints, struct config_file* cfg) 255 { 256 struct config_stub* s; 257 struct delegpt* dp; 258 for(s = cfg->stubs; s; s = s->next) { 259 if(!(dp=read_stubs_name(s))) 260 return 0; 261 if(!read_stubs_host(s, dp) || !read_stubs_addr(s, dp)) { 262 delegpt_free_mlc(dp); 263 return 0; 264 } 265 /* the flag is turned off for 'stub-first' so that the 266 * last resort will ask for parent-side NS record and thus 267 * fallback to the internet name servers on a failure */ 268 dp->has_parent_side_NS = (uint8_t)!s->isfirst; 269 delegpt_log(VERB_QUERY, dp); 270 if(!hints_insert(hints, LDNS_RR_CLASS_IN, dp, !s->isprime)) 271 return 0; 272 } 273 return 1; 274 } 275 276 /** read root hints from file */ 277 static int 278 read_root_hints(struct iter_hints* hints, char* fname) 279 { 280 int lineno = 0; 281 uint32_t default_ttl = 0; 282 ldns_rdf* origin = NULL; 283 ldns_rdf* prev_rr = NULL; 284 struct delegpt* dp; 285 ldns_rr* rr = NULL; 286 ldns_status status; 287 uint16_t c = LDNS_RR_CLASS_IN; 288 FILE* f = fopen(fname, "r"); 289 if(!f) { 290 log_err("could not read root hints %s: %s", 291 fname, strerror(errno)); 292 return 0; 293 } 294 dp = delegpt_create_mlc(NULL); 295 if(!dp) { 296 log_err("out of memory reading root hints"); 297 fclose(f); 298 return 0; 299 } 300 verbose(VERB_QUERY, "Reading root hints from %s", fname); 301 dp->has_parent_side_NS = 1; 302 while(!feof(f)) { 303 status = ldns_rr_new_frm_fp_l(&rr, f, 304 &default_ttl, &origin, &prev_rr, &lineno); 305 if(status == LDNS_STATUS_SYNTAX_EMPTY || 306 status == LDNS_STATUS_SYNTAX_TTL || 307 status == LDNS_STATUS_SYNTAX_ORIGIN) 308 continue; 309 if(status != LDNS_STATUS_OK) { 310 log_err("reading root hints %s %d: %s", fname, 311 lineno, ldns_get_errorstr_by_id(status)); 312 goto stop_read; 313 } 314 if(ldns_rr_get_type(rr) == LDNS_RR_TYPE_NS) { 315 if(!delegpt_add_ns_mlc(dp, 316 ldns_rdf_data(ldns_rr_rdf(rr, 0)), 0)) { 317 log_err("out of memory reading root hints"); 318 goto stop_read; 319 } 320 c = ldns_rr_get_class(rr); 321 if(!dp->name) { 322 if(!delegpt_set_name_mlc(dp, 323 ldns_rdf_data(ldns_rr_owner(rr)))){ 324 log_err("out of memory."); 325 goto stop_read; 326 } 327 } 328 } else if(ldns_rr_get_type(rr) == LDNS_RR_TYPE_A) { 329 struct sockaddr_in sa; 330 socklen_t len = (socklen_t)sizeof(sa); 331 memset(&sa, 0, len); 332 sa.sin_family = AF_INET; 333 sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT); 334 memmove(&sa.sin_addr, 335 ldns_rdf_data(ldns_rr_rdf(rr, 0)), INET_SIZE); 336 if(!delegpt_add_target_mlc(dp, 337 ldns_rdf_data(ldns_rr_owner(rr)), 338 ldns_rdf_size(ldns_rr_owner(rr)), 339 (struct sockaddr_storage*)&sa, len, 340 0, 0)) { 341 log_err("out of memory reading root hints"); 342 goto stop_read; 343 } 344 } else if(ldns_rr_get_type(rr) == LDNS_RR_TYPE_AAAA) { 345 struct sockaddr_in6 sa; 346 socklen_t len = (socklen_t)sizeof(sa); 347 memset(&sa, 0, len); 348 sa.sin6_family = AF_INET6; 349 sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT); 350 memmove(&sa.sin6_addr, 351 ldns_rdf_data(ldns_rr_rdf(rr, 0)), INET6_SIZE); 352 if(!delegpt_add_target_mlc(dp, 353 ldns_rdf_data(ldns_rr_owner(rr)), 354 ldns_rdf_size(ldns_rr_owner(rr)), 355 (struct sockaddr_storage*)&sa, len, 356 0, 0)) { 357 log_err("out of memory reading root hints"); 358 goto stop_read; 359 } 360 } else { 361 log_warn("root hints %s:%d skipping type %d", 362 fname, lineno, ldns_rr_get_type(rr)); 363 } 364 365 ldns_rr_free(rr); 366 } 367 368 if (origin) 369 ldns_rdf_deep_free(origin); 370 if (prev_rr) 371 ldns_rdf_deep_free(prev_rr); 372 fclose(f); 373 if(!dp->name) { 374 log_warn("root hints %s: no NS content", fname); 375 delegpt_free_mlc(dp); 376 return 1; 377 } 378 if(!hints_insert(hints, c, dp, 0)) { 379 return 0; 380 } 381 delegpt_log(VERB_QUERY, dp); 382 return 1; 383 384 stop_read: 385 if (origin) 386 ldns_rdf_deep_free(origin); 387 if (prev_rr) 388 ldns_rdf_deep_free(prev_rr); 389 delegpt_free_mlc(dp); 390 fclose(f); 391 return 0; 392 } 393 394 /** read root hints list */ 395 static int 396 read_root_hints_list(struct iter_hints* hints, struct config_file* cfg) 397 { 398 struct config_strlist* p; 399 for(p = cfg->root_hints; p; p = p->next) { 400 log_assert(p->str); 401 if(p->str && p->str[0]) { 402 char* f = p->str; 403 if(cfg->chrootdir && cfg->chrootdir[0] && 404 strncmp(p->str, cfg->chrootdir, 405 strlen(cfg->chrootdir)) == 0) 406 f += strlen(cfg->chrootdir); 407 if(!read_root_hints(hints, f)) 408 return 0; 409 } 410 } 411 return 1; 412 } 413 414 int 415 hints_apply_cfg(struct iter_hints* hints, struct config_file* cfg) 416 { 417 hints_del_tree(hints); 418 name_tree_init(&hints->tree); 419 420 /* read root hints */ 421 if(!read_root_hints_list(hints, cfg)) 422 return 0; 423 424 /* read stub hints */ 425 if(!read_stubs(hints, cfg)) 426 return 0; 427 428 /* use fallback compiletime root hints */ 429 if(!hints_lookup_root(hints, LDNS_RR_CLASS_IN)) { 430 struct delegpt* dp = compile_time_root_prime(cfg->do_ip4, 431 cfg->do_ip6); 432 verbose(VERB_ALGO, "no config, using builtin root hints."); 433 if(!dp) 434 return 0; 435 if(!hints_insert(hints, LDNS_RR_CLASS_IN, dp, 0)) 436 return 0; 437 } 438 439 name_tree_init_parents(&hints->tree); 440 return 1; 441 } 442 443 struct delegpt* 444 hints_lookup_root(struct iter_hints* hints, uint16_t qclass) 445 { 446 uint8_t rootlab = 0; 447 struct iter_hints_stub *stub; 448 stub = (struct iter_hints_stub*)name_tree_find(&hints->tree, 449 &rootlab, 1, 1, qclass); 450 if(!stub) 451 return NULL; 452 return stub->dp; 453 } 454 455 struct iter_hints_stub* 456 hints_lookup_stub(struct iter_hints* hints, uint8_t* qname, 457 uint16_t qclass, struct delegpt* cache_dp) 458 { 459 size_t len; 460 int labs; 461 struct iter_hints_stub *r; 462 463 /* first lookup the stub */ 464 labs = dname_count_size_labels(qname, &len); 465 r = (struct iter_hints_stub*)name_tree_lookup(&hints->tree, qname, 466 len, labs, qclass); 467 if(!r) return NULL; 468 469 /* If there is no cache (root prime situation) */ 470 if(cache_dp == NULL) { 471 if(r->dp->namelabs != 1) 472 return r; /* no cache dp, use any non-root stub */ 473 return NULL; 474 } 475 476 /* 477 * If the stub is same as the delegation we got 478 * And has noprime set, we need to 'prime' to use this stub instead. 479 */ 480 if(r->noprime && query_dname_compare(cache_dp->name, r->dp->name)==0) 481 return r; /* use this stub instead of cached dp */ 482 483 /* 484 * If our cached delegation point is above the hint, we need to prime. 485 */ 486 if(dname_strict_subdomain(r->dp->name, r->dp->namelabs, 487 cache_dp->name, cache_dp->namelabs)) 488 return r; /* need to prime this stub */ 489 return NULL; 490 } 491 492 int hints_next_root(struct iter_hints* hints, uint16_t* qclass) 493 { 494 return name_tree_next_root(&hints->tree, qclass); 495 } 496 497 size_t 498 hints_get_mem(struct iter_hints* hints) 499 { 500 size_t s; 501 struct iter_hints_stub* p; 502 if(!hints) return 0; 503 s = sizeof(*hints); 504 RBTREE_FOR(p, struct iter_hints_stub*, &hints->tree) { 505 s += sizeof(*p) + delegpt_get_mem(p->dp); 506 } 507 return s; 508 } 509 510 int 511 hints_add_stub(struct iter_hints* hints, uint16_t c, struct delegpt* dp, 512 int noprime) 513 { 514 struct iter_hints_stub *z; 515 if((z=(struct iter_hints_stub*)name_tree_find(&hints->tree, 516 dp->name, dp->namelen, dp->namelabs, c)) != NULL) { 517 (void)rbtree_delete(&hints->tree, &z->node); 518 hints_stub_free(z); 519 } 520 if(!hints_insert(hints, c, dp, noprime)) 521 return 0; 522 name_tree_init_parents(&hints->tree); 523 return 1; 524 } 525 526 void 527 hints_delete_stub(struct iter_hints* hints, uint16_t c, uint8_t* nm) 528 { 529 struct iter_hints_stub *z; 530 size_t len; 531 int labs = dname_count_size_labels(nm, &len); 532 if(!(z=(struct iter_hints_stub*)name_tree_find(&hints->tree, 533 nm, len, labs, c))) 534 return; /* nothing to do */ 535 (void)rbtree_delete(&hints->tree, &z->node); 536 hints_stub_free(z); 537 name_tree_init_parents(&hints->tree); 538 } 539 540