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 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 * Keep track of stub and root hints, and read those from config. 41 */ 42 #include "config.h" 43 #include "iterator/iter_hints.h" 44 #include "iterator/iter_delegpt.h" 45 #include "util/log.h" 46 #include "util/config_file.h" 47 #include "util/net_help.h" 48 #include "util/data/dname.h" 49 #include "ldns/rrdef.h" 50 #include "ldns/str2wire.h" 51 #include "ldns/wire2str.h" 52 53 struct iter_hints* 54 hints_create(void) 55 { 56 struct iter_hints* hints = (struct iter_hints*)calloc(1, 57 sizeof(struct iter_hints)); 58 if(!hints) 59 return NULL; 60 return hints; 61 } 62 63 static void hints_stub_free(struct iter_hints_stub* s) 64 { 65 if(!s) return; 66 delegpt_free_mlc(s->dp); 67 free(s); 68 } 69 70 static void delhintnode(rbnode_t* n, void* ATTR_UNUSED(arg)) 71 { 72 struct iter_hints_stub* node = (struct iter_hints_stub*)n; 73 hints_stub_free(node); 74 } 75 76 static void hints_del_tree(struct iter_hints* hints) 77 { 78 traverse_postorder(&hints->tree, &delhintnode, NULL); 79 } 80 81 void 82 hints_delete(struct iter_hints* hints) 83 { 84 if(!hints) 85 return; 86 hints_del_tree(hints); 87 free(hints); 88 } 89 90 /** add hint to delegation hints */ 91 static int 92 ah(struct delegpt* dp, const char* sv, const char* ip) 93 { 94 struct sockaddr_storage addr; 95 socklen_t addrlen; 96 size_t dname_len; 97 uint8_t* dname = sldns_str2wire_dname(sv, &dname_len); 98 if(!dname) { 99 log_err("could not parse %s", sv); 100 return 0; 101 } 102 if(!delegpt_add_ns_mlc(dp, dname, 0) || 103 !extstrtoaddr(ip, &addr, &addrlen) || 104 !delegpt_add_target_mlc(dp, dname, dname_len, 105 &addr, addrlen, 0, 0)) { 106 free(dname); 107 return 0; 108 } 109 free(dname); 110 return 1; 111 } 112 113 /** obtain compiletime provided root hints */ 114 static struct delegpt* 115 compile_time_root_prime(int do_ip4, int do_ip6) 116 { 117 /* from: 118 ; This file is made available by InterNIC 119 ; under anonymous FTP as 120 ; file /domain/named.cache 121 ; on server FTP.INTERNIC.NET 122 ; -OR- RS.INTERNIC.NET 123 ; 124 ; related version of root zone: changes-on-20120103 125 */ 126 struct delegpt* dp = delegpt_create_mlc((uint8_t*)"\000"); 127 if(!dp) 128 return NULL; 129 dp->has_parent_side_NS = 1; 130 if(do_ip4) { 131 if(!ah(dp, "A.ROOT-SERVERS.NET.", "198.41.0.4")) goto failed; 132 if(!ah(dp, "B.ROOT-SERVERS.NET.", "192.228.79.201")) goto failed; 133 if(!ah(dp, "C.ROOT-SERVERS.NET.", "192.33.4.12")) goto failed; 134 if(!ah(dp, "D.ROOT-SERVERS.NET.", "199.7.91.13")) goto failed; 135 if(!ah(dp, "E.ROOT-SERVERS.NET.", "192.203.230.10")) goto failed; 136 if(!ah(dp, "F.ROOT-SERVERS.NET.", "192.5.5.241")) goto failed; 137 if(!ah(dp, "G.ROOT-SERVERS.NET.", "192.112.36.4")) goto failed; 138 if(!ah(dp, "H.ROOT-SERVERS.NET.", "128.63.2.53")) goto failed; 139 if(!ah(dp, "I.ROOT-SERVERS.NET.", "192.36.148.17")) goto failed; 140 if(!ah(dp, "J.ROOT-SERVERS.NET.", "192.58.128.30")) goto failed; 141 if(!ah(dp, "K.ROOT-SERVERS.NET.", "193.0.14.129")) goto failed; 142 if(!ah(dp, "L.ROOT-SERVERS.NET.", "199.7.83.42")) goto failed; 143 if(!ah(dp, "M.ROOT-SERVERS.NET.", "202.12.27.33")) goto failed; 144 } 145 if(do_ip6) { 146 if(!ah(dp, "A.ROOT-SERVERS.NET.", "2001:503:ba3e::2:30")) goto failed; 147 if(!ah(dp, "B.ROOT-SERVERS.NET.", "2001:500:84::b")) goto failed; 148 if(!ah(dp, "C.ROOT-SERVERS.NET.", "2001:500:2::c")) goto failed; 149 if(!ah(dp, "D.ROOT-SERVERS.NET.", "2001:500:2d::d")) goto failed; 150 if(!ah(dp, "F.ROOT-SERVERS.NET.", "2001:500:2f::f")) goto failed; 151 if(!ah(dp, "H.ROOT-SERVERS.NET.", "2001:500:1::803f:235")) goto failed; 152 if(!ah(dp, "I.ROOT-SERVERS.NET.", "2001:7fe::53")) goto failed; 153 if(!ah(dp, "J.ROOT-SERVERS.NET.", "2001:503:c27::2:30")) goto failed; 154 if(!ah(dp, "K.ROOT-SERVERS.NET.", "2001:7fd::1")) goto failed; 155 if(!ah(dp, "L.ROOT-SERVERS.NET.", "2001:500:3::42")) goto failed; 156 if(!ah(dp, "M.ROOT-SERVERS.NET.", "2001:dc3::35")) goto failed; 157 } 158 return dp; 159 failed: 160 delegpt_free_mlc(dp); 161 return 0; 162 } 163 164 /** insert new hint info into hint structure */ 165 static int 166 hints_insert(struct iter_hints* hints, uint16_t c, struct delegpt* dp, 167 int noprime) 168 { 169 struct iter_hints_stub* node = (struct iter_hints_stub*)malloc( 170 sizeof(struct iter_hints_stub)); 171 if(!node) { 172 delegpt_free_mlc(dp); 173 return 0; 174 } 175 node->dp = dp; 176 node->noprime = (uint8_t)noprime; 177 if(!name_tree_insert(&hints->tree, &node->node, dp->name, dp->namelen, 178 dp->namelabs, c)) { 179 char buf[257]; 180 dname_str(dp->name, buf); 181 log_err("second hints for zone %s ignored.", buf); 182 delegpt_free_mlc(dp); 183 free(node); 184 } 185 return 1; 186 } 187 188 /** set stub name */ 189 static struct delegpt* 190 read_stubs_name(struct config_stub* s) 191 { 192 struct delegpt* dp; 193 size_t dname_len; 194 uint8_t* dname; 195 if(!s->name) { 196 log_err("stub zone without a name"); 197 return NULL; 198 } 199 dname = sldns_str2wire_dname(s->name, &dname_len); 200 if(!dname) { 201 log_err("cannot parse stub zone name %s", s->name); 202 return NULL; 203 } 204 if(!(dp=delegpt_create_mlc(dname))) { 205 free(dname); 206 log_err("out of memory"); 207 return NULL; 208 } 209 free(dname); 210 return dp; 211 } 212 213 /** set stub host names */ 214 static int 215 read_stubs_host(struct config_stub* s, struct delegpt* dp) 216 { 217 struct config_strlist* p; 218 size_t dname_len; 219 uint8_t* dname; 220 for(p = s->hosts; p; p = p->next) { 221 log_assert(p->str); 222 dname = sldns_str2wire_dname(p->str, &dname_len); 223 if(!dname) { 224 log_err("cannot parse stub %s nameserver name: '%s'", 225 s->name, p->str); 226 return 0; 227 } 228 if(!delegpt_add_ns_mlc(dp, dname, 0)) { 229 free(dname); 230 log_err("out of memory"); 231 return 0; 232 } 233 free(dname); 234 } 235 return 1; 236 } 237 238 /** set stub server addresses */ 239 static int 240 read_stubs_addr(struct config_stub* s, struct delegpt* dp) 241 { 242 struct config_strlist* p; 243 struct sockaddr_storage addr; 244 socklen_t addrlen; 245 for(p = s->addrs; p; p = p->next) { 246 log_assert(p->str); 247 if(!extstrtoaddr(p->str, &addr, &addrlen)) { 248 log_err("cannot parse stub %s ip address: '%s'", 249 s->name, p->str); 250 return 0; 251 } 252 if(!delegpt_add_addr_mlc(dp, &addr, addrlen, 0, 0)) { 253 log_err("out of memory"); 254 return 0; 255 } 256 } 257 return 1; 258 } 259 260 /** read stubs config */ 261 static int 262 read_stubs(struct iter_hints* hints, struct config_file* cfg) 263 { 264 struct config_stub* s; 265 struct delegpt* dp; 266 for(s = cfg->stubs; s; s = s->next) { 267 if(!(dp=read_stubs_name(s))) 268 return 0; 269 if(!read_stubs_host(s, dp) || !read_stubs_addr(s, dp)) { 270 delegpt_free_mlc(dp); 271 return 0; 272 } 273 /* the flag is turned off for 'stub-first' so that the 274 * last resort will ask for parent-side NS record and thus 275 * fallback to the internet name servers on a failure */ 276 dp->has_parent_side_NS = (uint8_t)!s->isfirst; 277 delegpt_log(VERB_QUERY, dp); 278 if(!hints_insert(hints, LDNS_RR_CLASS_IN, dp, !s->isprime)) 279 return 0; 280 } 281 return 1; 282 } 283 284 /** read root hints from file */ 285 static int 286 read_root_hints(struct iter_hints* hints, char* fname) 287 { 288 struct sldns_file_parse_state pstate; 289 struct delegpt* dp; 290 uint8_t rr[LDNS_RR_BUF_SIZE]; 291 size_t rr_len, dname_len; 292 int status; 293 uint16_t c = LDNS_RR_CLASS_IN; 294 FILE* f = fopen(fname, "r"); 295 if(!f) { 296 log_err("could not read root hints %s: %s", 297 fname, strerror(errno)); 298 return 0; 299 } 300 dp = delegpt_create_mlc(NULL); 301 if(!dp) { 302 log_err("out of memory reading root hints"); 303 fclose(f); 304 return 0; 305 } 306 verbose(VERB_QUERY, "Reading root hints from %s", fname); 307 memset(&pstate, 0, sizeof(pstate)); 308 pstate.lineno = 1; 309 dp->has_parent_side_NS = 1; 310 while(!feof(f)) { 311 rr_len = sizeof(rr); 312 dname_len = 0; 313 status = sldns_fp2wire_rr_buf(f, rr, &rr_len, &dname_len, 314 &pstate); 315 if(status != 0) { 316 log_err("reading root hints %s %d:%d: %s", fname, 317 pstate.lineno, LDNS_WIREPARSE_OFFSET(status), 318 sldns_get_errorstr_parse(status)); 319 goto stop_read; 320 } 321 if(rr_len == 0) 322 continue; /* EMPTY line, TTL or ORIGIN */ 323 if(sldns_wirerr_get_type(rr, rr_len, dname_len) 324 == LDNS_RR_TYPE_NS) { 325 if(!delegpt_add_ns_mlc(dp, sldns_wirerr_get_rdata(rr, 326 rr_len, dname_len), 0)) { 327 log_err("out of memory reading root hints"); 328 goto stop_read; 329 } 330 c = sldns_wirerr_get_class(rr, rr_len, dname_len); 331 if(!dp->name) { 332 if(!delegpt_set_name_mlc(dp, rr)) { 333 log_err("out of memory."); 334 goto stop_read; 335 } 336 } 337 } else if(sldns_wirerr_get_type(rr, rr_len, dname_len) 338 == LDNS_RR_TYPE_A && sldns_wirerr_get_rdatalen(rr, 339 rr_len, dname_len) == INET_SIZE) { 340 struct sockaddr_in sa; 341 socklen_t len = (socklen_t)sizeof(sa); 342 memset(&sa, 0, len); 343 sa.sin_family = AF_INET; 344 sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT); 345 memmove(&sa.sin_addr, 346 sldns_wirerr_get_rdata(rr, rr_len, dname_len), 347 INET_SIZE); 348 if(!delegpt_add_target_mlc(dp, rr, dname_len, 349 (struct sockaddr_storage*)&sa, len, 350 0, 0)) { 351 log_err("out of memory reading root hints"); 352 goto stop_read; 353 } 354 } else if(sldns_wirerr_get_type(rr, rr_len, dname_len) 355 == LDNS_RR_TYPE_AAAA && sldns_wirerr_get_rdatalen(rr, 356 rr_len, dname_len) == INET6_SIZE) { 357 struct sockaddr_in6 sa; 358 socklen_t len = (socklen_t)sizeof(sa); 359 memset(&sa, 0, len); 360 sa.sin6_family = AF_INET6; 361 sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT); 362 memmove(&sa.sin6_addr, 363 sldns_wirerr_get_rdata(rr, rr_len, dname_len), 364 INET6_SIZE); 365 if(!delegpt_add_target_mlc(dp, rr, dname_len, 366 (struct sockaddr_storage*)&sa, len, 367 0, 0)) { 368 log_err("out of memory reading root hints"); 369 goto stop_read; 370 } 371 } else { 372 char buf[17]; 373 sldns_wire2str_type_buf(sldns_wirerr_get_type(rr, 374 rr_len, dname_len), buf, sizeof(buf)); 375 log_warn("root hints %s:%d skipping type %s", 376 fname, pstate.lineno, buf); 377 } 378 } 379 fclose(f); 380 if(!dp->name) { 381 log_warn("root hints %s: no NS content", fname); 382 delegpt_free_mlc(dp); 383 return 1; 384 } 385 if(!hints_insert(hints, c, dp, 0)) { 386 return 0; 387 } 388 delegpt_log(VERB_QUERY, dp); 389 return 1; 390 391 stop_read: 392 delegpt_free_mlc(dp); 393 fclose(f); 394 return 0; 395 } 396 397 /** read root hints list */ 398 static int 399 read_root_hints_list(struct iter_hints* hints, struct config_file* cfg) 400 { 401 struct config_strlist* p; 402 for(p = cfg->root_hints; p; p = p->next) { 403 log_assert(p->str); 404 if(p->str && p->str[0]) { 405 char* f = p->str; 406 if(cfg->chrootdir && cfg->chrootdir[0] && 407 strncmp(p->str, cfg->chrootdir, 408 strlen(cfg->chrootdir)) == 0) 409 f += strlen(cfg->chrootdir); 410 if(!read_root_hints(hints, f)) 411 return 0; 412 } 413 } 414 return 1; 415 } 416 417 int 418 hints_apply_cfg(struct iter_hints* hints, struct config_file* cfg) 419 { 420 hints_del_tree(hints); 421 name_tree_init(&hints->tree); 422 423 /* read root hints */ 424 if(!read_root_hints_list(hints, cfg)) 425 return 0; 426 427 /* read stub hints */ 428 if(!read_stubs(hints, cfg)) 429 return 0; 430 431 /* use fallback compiletime root hints */ 432 if(!hints_lookup_root(hints, LDNS_RR_CLASS_IN)) { 433 struct delegpt* dp = compile_time_root_prime(cfg->do_ip4, 434 cfg->do_ip6); 435 verbose(VERB_ALGO, "no config, using builtin root hints."); 436 if(!dp) 437 return 0; 438 if(!hints_insert(hints, LDNS_RR_CLASS_IN, dp, 0)) 439 return 0; 440 } 441 442 name_tree_init_parents(&hints->tree); 443 return 1; 444 } 445 446 struct delegpt* 447 hints_lookup_root(struct iter_hints* hints, uint16_t qclass) 448 { 449 uint8_t rootlab = 0; 450 struct iter_hints_stub *stub; 451 stub = (struct iter_hints_stub*)name_tree_find(&hints->tree, 452 &rootlab, 1, 1, qclass); 453 if(!stub) 454 return NULL; 455 return stub->dp; 456 } 457 458 struct iter_hints_stub* 459 hints_lookup_stub(struct iter_hints* hints, uint8_t* qname, 460 uint16_t qclass, struct delegpt* cache_dp) 461 { 462 size_t len; 463 int labs; 464 struct iter_hints_stub *r; 465 466 /* first lookup the stub */ 467 labs = dname_count_size_labels(qname, &len); 468 r = (struct iter_hints_stub*)name_tree_lookup(&hints->tree, qname, 469 len, labs, qclass); 470 if(!r) return NULL; 471 472 /* If there is no cache (root prime situation) */ 473 if(cache_dp == NULL) { 474 if(r->dp->namelabs != 1) 475 return r; /* no cache dp, use any non-root stub */ 476 return NULL; 477 } 478 479 /* 480 * If the stub is same as the delegation we got 481 * And has noprime set, we need to 'prime' to use this stub instead. 482 */ 483 if(r->noprime && query_dname_compare(cache_dp->name, r->dp->name)==0) 484 return r; /* use this stub instead of cached dp */ 485 486 /* 487 * If our cached delegation point is above the hint, we need to prime. 488 */ 489 if(dname_strict_subdomain(r->dp->name, r->dp->namelabs, 490 cache_dp->name, cache_dp->namelabs)) 491 return r; /* need to prime this stub */ 492 return NULL; 493 } 494 495 int hints_next_root(struct iter_hints* hints, uint16_t* qclass) 496 { 497 return name_tree_next_root(&hints->tree, qclass); 498 } 499 500 size_t 501 hints_get_mem(struct iter_hints* hints) 502 { 503 size_t s; 504 struct iter_hints_stub* p; 505 if(!hints) return 0; 506 s = sizeof(*hints); 507 RBTREE_FOR(p, struct iter_hints_stub*, &hints->tree) { 508 s += sizeof(*p) + delegpt_get_mem(p->dp); 509 } 510 return s; 511 } 512 513 int 514 hints_add_stub(struct iter_hints* hints, uint16_t c, struct delegpt* dp, 515 int noprime) 516 { 517 struct iter_hints_stub *z; 518 if((z=(struct iter_hints_stub*)name_tree_find(&hints->tree, 519 dp->name, dp->namelen, dp->namelabs, c)) != NULL) { 520 (void)rbtree_delete(&hints->tree, &z->node); 521 hints_stub_free(z); 522 } 523 if(!hints_insert(hints, c, dp, noprime)) 524 return 0; 525 name_tree_init_parents(&hints->tree); 526 return 1; 527 } 528 529 void 530 hints_delete_stub(struct iter_hints* hints, uint16_t c, uint8_t* nm) 531 { 532 struct iter_hints_stub *z; 533 size_t len; 534 int labs = dname_count_size_labels(nm, &len); 535 if(!(z=(struct iter_hints_stub*)name_tree_find(&hints->tree, 536 nm, len, labs, c))) 537 return; /* nothing to do */ 538 (void)rbtree_delete(&hints->tree, &z->node); 539 hints_stub_free(z); 540 name_tree_init_parents(&hints->tree); 541 } 542 543