unbound/iterator/iter_hints.c

   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