1 /* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator. 34 * 35 * Issues to be discussed: 36 * - Thread safe-ness must be checked. 37 * - Return values. There are nonstandard return values defined and used 38 * in the source code. This is because RFC2553 is silent about which error 39 * code must be returned for which situation. 40 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 41 * invalid. 42 * current code - SEGV on freeaddrinfo(NULL) 43 * Note: 44 * - We use getipnodebyname() just for thread-safeness. There's no intent 45 * to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to 46 * getipnodebyname(). 47 * - The code filters out AFs that are not supported by the kernel, 48 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 49 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 50 * in ai_flags? 51 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 52 * (1) what should we do against numeric hostname (2) what should we do 53 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 54 * non-loopback address configured? global address configured? 55 * - To avoid search order issue, we have a big amount of code duplicate 56 * from gethnamaddr.c and some other places. The issues that there's no 57 * lower layer function to lookup "IPv4 or IPv6" record. Calling 58 * gethostbyname2 from getaddrinfo will end up in wrong search order, as 59 * follows: 60 * - The code makes use of following calls when asked to resolver with 61 * ai_family = PF_UNSPEC: 62 * getipnodebyname(host, AF_INET6); 63 * getipnodebyname(host, AF_INET); 64 * This will result in the following queries if the node is configure to 65 * prefer /etc/hosts than DNS: 66 * lookup /etc/hosts for IPv6 address 67 * lookup DNS for IPv6 address 68 * lookup /etc/hosts for IPv4 address 69 * lookup DNS for IPv4 address 70 * which may not meet people's requirement. 71 * The right thing to happen is to have underlying layer which does 72 * PF_UNSPEC lookup (lookup both) and return chain of addrinfos. 73 * This would result in a bit of code duplicate with _dns_ghbyname() and 74 * friends. 75 */ 76 /* 77 * diffs with other KAME platforms: 78 * - other KAME platforms already nuked FAITH ($GAI), but as FreeBSD 79 * 4.0-RELEASE supplies it, we still have the code here. 80 * - AI_ADDRCONFIG support is supplied 81 * - some of FreeBSD style (#define tabify and others) 82 * - classful IPv4 numeric (127.1) is allowed. 83 */ 84 85 #include <sys/cdefs.h> 86 __FBSDID("$FreeBSD$"); 87 88 #include "namespace.h" 89 #include <sys/types.h> 90 #include <sys/param.h> 91 #include <sys/socket.h> 92 #include <net/if.h> 93 #include <netinet/in.h> 94 #include <arpa/inet.h> 95 #include <arpa/nameser.h> 96 #include <rpc/rpc.h> 97 #include <rpcsvc/yp_prot.h> 98 #include <rpcsvc/ypclnt.h> 99 #include <netdb.h> 100 #include <resolv.h> 101 #include <string.h> 102 #include <stdlib.h> 103 #include <stddef.h> 104 #include <ctype.h> 105 #include <unistd.h> 106 #include <stdio.h> 107 #include <errno.h> 108 109 #include "res_config.h" 110 111 #ifdef DEBUG 112 #include <syslog.h> 113 #endif 114 115 #include <stdarg.h> 116 #include <nsswitch.h> 117 #include "un-namespace.h" 118 119 #if defined(__KAME__) && defined(INET6) 120 # define FAITH 121 #endif 122 123 #define SUCCESS 0 124 #define ANY 0 125 #define YES 1 126 #define NO 0 127 128 static const char in_addrany[] = { 0, 0, 0, 0 }; 129 static const char in6_addrany[] = { 130 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 131 }; 132 static const char in_loopback[] = { 127, 0, 0, 1 }; 133 static const char in6_loopback[] = { 134 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 135 }; 136 137 static const struct afd { 138 int a_af; 139 int a_addrlen; 140 int a_socklen; 141 int a_off; 142 const char *a_addrany; 143 const char *a_loopback; 144 int a_scoped; 145 } afdl [] = { 146 #ifdef INET6 147 #define N_INET6 0 148 {PF_INET6, sizeof(struct in6_addr), 149 sizeof(struct sockaddr_in6), 150 offsetof(struct sockaddr_in6, sin6_addr), 151 in6_addrany, in6_loopback, 1}, 152 #define N_INET 1 153 #else 154 #define N_INET 0 155 #endif 156 {PF_INET, sizeof(struct in_addr), 157 sizeof(struct sockaddr_in), 158 offsetof(struct sockaddr_in, sin_addr), 159 in_addrany, in_loopback, 0}, 160 {0, 0, 0, 0, NULL, NULL, 0}, 161 }; 162 163 struct explore { 164 int e_af; 165 int e_socktype; 166 int e_protocol; 167 const char *e_protostr; 168 int e_wild; 169 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 170 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 171 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 172 }; 173 174 static const struct explore explore[] = { 175 #if 0 176 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 177 #endif 178 #ifdef INET6 179 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 180 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 181 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 182 #endif 183 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 184 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 185 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 186 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 187 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 188 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 189 { -1, 0, 0, NULL, 0 }, 190 }; 191 192 #ifdef INET6 193 #define PTON_MAX 16 194 #else 195 #define PTON_MAX 4 196 #endif 197 198 static const ns_src default_dns_files[] = { 199 { NSSRC_FILES, NS_SUCCESS }, 200 { NSSRC_DNS, NS_SUCCESS }, 201 { 0 } 202 }; 203 204 #define MAXPACKET (64*1024) 205 206 typedef union { 207 HEADER hdr; 208 u_char buf[MAXPACKET]; 209 } querybuf; 210 211 struct res_target { 212 struct res_target *next; 213 const char *name; /* domain name */ 214 int qclass, qtype; /* class and type of query */ 215 u_char *answer; /* buffer to put answer */ 216 int anslen; /* size of answer buffer */ 217 int n; /* result length */ 218 }; 219 220 static int str_isnumber(const char *); 221 static int explore_fqdn(const struct addrinfo *, const char *, 222 const char *, struct addrinfo **); 223 static int explore_null(const struct addrinfo *, 224 const char *, struct addrinfo **); 225 static int explore_numeric(const struct addrinfo *, const char *, 226 const char *, struct addrinfo **); 227 static int explore_numeric_scope(const struct addrinfo *, const char *, 228 const char *, struct addrinfo **); 229 static int get_canonname(const struct addrinfo *, 230 struct addrinfo *, const char *); 231 static struct addrinfo *get_ai(const struct addrinfo *, 232 const struct afd *, const char *); 233 static int get_portmatch(const struct addrinfo *, const char *); 234 static int get_port(struct addrinfo *, const char *, int); 235 static const struct afd *find_afd(int); 236 static int addrconfig(struct addrinfo *); 237 #ifdef INET6 238 static int ip6_str2scopeid(char *, struct sockaddr_in6 *); 239 #endif 240 241 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 242 const struct addrinfo *); 243 static int _dns_getaddrinfo(void *, void *, va_list); 244 static void _sethtent(void); 245 static void _endhtent(void); 246 static struct addrinfo *_gethtent(const char *, const struct addrinfo *); 247 static int _files_getaddrinfo(void *, void *, va_list); 248 #ifdef YP 249 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 250 static int _yp_getaddrinfo(void *, void *, va_list); 251 extern int _yp_check(char **); 252 #endif 253 254 static int res_queryN(const char *, struct res_target *); 255 static int res_searchN(const char *, struct res_target *); 256 static int res_querydomainN(const char *, const char *, 257 struct res_target *); 258 259 static char *ai_errlist[] = { 260 "Success", 261 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 262 "Temporary failure in name resolution", /* EAI_AGAIN */ 263 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 264 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 265 "ai_family not supported", /* EAI_FAMILY */ 266 "Memory allocation failure", /* EAI_MEMORY */ 267 "No address associated with hostname", /* EAI_NODATA */ 268 "hostname nor servname provided, or not known", /* EAI_NONAME */ 269 "servname not supported for ai_socktype", /* EAI_SERVICE */ 270 "ai_socktype not supported", /* EAI_SOCKTYPE */ 271 "System error returned in errno", /* EAI_SYSTEM */ 272 "Invalid value for hints", /* EAI_BADHINTS */ 273 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 274 "Unknown error", /* EAI_MAX */ 275 }; 276 277 /* Make getaddrinfo() thread-safe in libc for use with kernel threads. */ 278 #include "libc_private.h" 279 #include "spinlock.h" 280 /* 281 * XXX: Our res_*() is not thread-safe. So, we share lock between 282 * getaddrinfo() and getipnodeby*(). Still, we cannot use 283 * getaddrinfo() and getipnodeby*() in conjunction with other 284 * functions which call res_*(). 285 */ 286 spinlock_t __getaddrinfo_thread_lock = _SPINLOCK_INITIALIZER; 287 #define THREAD_LOCK() \ 288 if (__isthreaded) _SPINLOCK(&__getaddrinfo_thread_lock); 289 #define THREAD_UNLOCK() \ 290 if (__isthreaded) _SPINUNLOCK(&__getaddrinfo_thread_lock); 291 292 /* XXX macros that make external reference is BAD. */ 293 294 #define GET_AI(ai, afd, addr) \ 295 do { \ 296 /* external reference: pai, error, and label free */ \ 297 (ai) = get_ai(pai, (afd), (addr)); \ 298 if ((ai) == NULL) { \ 299 error = EAI_MEMORY; \ 300 goto free; \ 301 } \ 302 } while (/*CONSTCOND*/0) 303 304 #define GET_PORT(ai, serv) \ 305 do { \ 306 /* external reference: error and label free */ \ 307 error = get_port((ai), (serv), 0); \ 308 if (error != 0) \ 309 goto free; \ 310 } while (/*CONSTCOND*/0) 311 312 #define GET_CANONNAME(ai, str) \ 313 do { \ 314 /* external reference: pai, error and label free */ \ 315 error = get_canonname(pai, (ai), (str)); \ 316 if (error != 0) \ 317 goto free; \ 318 } while (/*CONSTCOND*/0) 319 320 #define ERR(err) \ 321 do { \ 322 /* external reference: error, and label bad */ \ 323 error = (err); \ 324 goto bad; \ 325 /*NOTREACHED*/ \ 326 } while (/*CONSTCOND*/0) 327 328 #define MATCH_FAMILY(x, y, w) \ 329 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 330 #define MATCH(x, y, w) \ 331 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 332 333 char * 334 gai_strerror(ecode) 335 int ecode; 336 { 337 if (ecode < 0 || ecode > EAI_MAX) 338 ecode = EAI_MAX; 339 return ai_errlist[ecode]; 340 } 341 342 void 343 freeaddrinfo(ai) 344 struct addrinfo *ai; 345 { 346 struct addrinfo *next; 347 348 do { 349 next = ai->ai_next; 350 if (ai->ai_canonname) 351 free(ai->ai_canonname); 352 /* no need to free(ai->ai_addr) */ 353 free(ai); 354 ai = next; 355 } while (ai); 356 } 357 358 static int 359 str_isnumber(p) 360 const char *p; 361 { 362 char *ep; 363 364 if (*p == '\0') 365 return NO; 366 ep = NULL; 367 (void)strtoul(p, &ep, 10); 368 if (ep && *ep == '\0') 369 return YES; 370 else 371 return NO; 372 } 373 374 int 375 getaddrinfo(hostname, servname, hints, res) 376 const char *hostname, *servname; 377 const struct addrinfo *hints; 378 struct addrinfo **res; 379 { 380 struct addrinfo sentinel; 381 struct addrinfo *cur; 382 int error = 0; 383 struct addrinfo ai; 384 struct addrinfo ai0; 385 struct addrinfo *pai; 386 const struct explore *ex; 387 388 memset(&sentinel, 0, sizeof(sentinel)); 389 cur = &sentinel; 390 pai = &ai; 391 pai->ai_flags = 0; 392 pai->ai_family = PF_UNSPEC; 393 pai->ai_socktype = ANY; 394 pai->ai_protocol = ANY; 395 pai->ai_addrlen = 0; 396 pai->ai_canonname = NULL; 397 pai->ai_addr = NULL; 398 pai->ai_next = NULL; 399 400 if (hostname == NULL && servname == NULL) 401 return EAI_NONAME; 402 if (hints) { 403 /* error check for hints */ 404 if (hints->ai_addrlen || hints->ai_canonname || 405 hints->ai_addr || hints->ai_next) 406 ERR(EAI_BADHINTS); /* xxx */ 407 if (hints->ai_flags & ~AI_MASK) 408 ERR(EAI_BADFLAGS); 409 switch (hints->ai_family) { 410 case PF_UNSPEC: 411 case PF_INET: 412 #ifdef INET6 413 case PF_INET6: 414 #endif 415 break; 416 default: 417 ERR(EAI_FAMILY); 418 } 419 memcpy(pai, hints, sizeof(*pai)); 420 421 /* 422 * if both socktype/protocol are specified, check if they 423 * are meaningful combination. 424 */ 425 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 426 for (ex = explore; ex->e_af >= 0; ex++) { 427 if (pai->ai_family != ex->e_af) 428 continue; 429 if (ex->e_socktype == ANY) 430 continue; 431 if (ex->e_protocol == ANY) 432 continue; 433 if (pai->ai_socktype == ex->e_socktype 434 && pai->ai_protocol != ex->e_protocol) { 435 ERR(EAI_BADHINTS); 436 } 437 } 438 } 439 } 440 441 /* 442 * post-2553: AI_ALL and AI_V4MAPPED are effective only against 443 * AF_INET6 query. They needs to be ignored if specified in other 444 * occassions. 445 */ 446 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 447 case AI_V4MAPPED: 448 case AI_ALL | AI_V4MAPPED: 449 if (pai->ai_family != AF_INET6) 450 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 451 break; 452 case AI_ALL: 453 #if 1 454 /* illegal */ 455 ERR(EAI_BADFLAGS); 456 #else 457 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 458 #endif 459 break; 460 } 461 462 /* 463 * check for special cases. (1) numeric servname is disallowed if 464 * socktype/protocol are left unspecified. (2) servname is disallowed 465 * for raw and other inet{,6} sockets. 466 */ 467 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 468 #ifdef PF_INET6 469 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 470 #endif 471 ) { 472 ai0 = *pai; /* backup *pai */ 473 474 if (pai->ai_family == PF_UNSPEC) { 475 #ifdef PF_INET6 476 pai->ai_family = PF_INET6; 477 #else 478 pai->ai_family = PF_INET; 479 #endif 480 } 481 error = get_portmatch(pai, servname); 482 if (error) 483 ERR(error); 484 485 *pai = ai0; 486 } 487 488 ai0 = *pai; 489 490 /* NULL hostname, or numeric hostname */ 491 for (ex = explore; ex->e_af >= 0; ex++) { 492 *pai = ai0; 493 494 /* PF_UNSPEC entries are prepared for DNS queries only */ 495 if (ex->e_af == PF_UNSPEC) 496 continue; 497 498 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 499 continue; 500 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 501 continue; 502 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 503 continue; 504 505 if (pai->ai_family == PF_UNSPEC) 506 pai->ai_family = ex->e_af; 507 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 508 pai->ai_socktype = ex->e_socktype; 509 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 510 pai->ai_protocol = ex->e_protocol; 511 512 if (hostname == NULL) 513 error = explore_null(pai, servname, &cur->ai_next); 514 else 515 error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next); 516 517 if (error) 518 goto free; 519 520 while (cur && cur->ai_next) 521 cur = cur->ai_next; 522 } 523 524 /* 525 * XXX 526 * If numreic representation of AF1 can be interpreted as FQDN 527 * representation of AF2, we need to think again about the code below. 528 */ 529 if (sentinel.ai_next) 530 goto good; 531 532 if (pai->ai_flags & AI_NUMERICHOST) 533 ERR(EAI_NONAME); 534 if (hostname == NULL) 535 ERR(EAI_NODATA); 536 537 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 538 ERR(EAI_FAIL); 539 540 /* 541 * hostname as alphabetical name. 542 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 543 * outer loop by AFs. 544 */ 545 for (ex = explore; ex->e_af >= 0; ex++) { 546 *pai = ai0; 547 548 /* require exact match for family field */ 549 if (pai->ai_family != ex->e_af) 550 continue; 551 552 if (!MATCH(pai->ai_socktype, ex->e_socktype, 553 WILD_SOCKTYPE(ex))) { 554 continue; 555 } 556 if (!MATCH(pai->ai_protocol, ex->e_protocol, 557 WILD_PROTOCOL(ex))) { 558 continue; 559 } 560 561 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 562 pai->ai_socktype = ex->e_socktype; 563 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 564 pai->ai_protocol = ex->e_protocol; 565 566 error = explore_fqdn(pai, hostname, servname, 567 &cur->ai_next); 568 569 while (cur && cur->ai_next) 570 cur = cur->ai_next; 571 } 572 573 /* XXX */ 574 if (sentinel.ai_next) 575 error = 0; 576 577 if (error) 578 goto free; 579 if (error == 0) { 580 if (sentinel.ai_next) { 581 good: 582 *res = sentinel.ai_next; 583 return SUCCESS; 584 } else 585 error = EAI_FAIL; 586 } 587 free: 588 bad: 589 if (sentinel.ai_next) 590 freeaddrinfo(sentinel.ai_next); 591 *res = NULL; 592 return error; 593 } 594 595 /* 596 * FQDN hostname, DNS lookup 597 */ 598 static int 599 explore_fqdn(pai, hostname, servname, res) 600 const struct addrinfo *pai; 601 const char *hostname; 602 const char *servname; 603 struct addrinfo **res; 604 { 605 struct addrinfo *result; 606 struct addrinfo *cur; 607 int error = 0; 608 static const ns_dtab dtab[] = { 609 NS_FILES_CB(_files_getaddrinfo, NULL) 610 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 611 NS_NIS_CB(_yp_getaddrinfo, NULL) 612 { 0 } 613 }; 614 615 result = NULL; 616 617 THREAD_LOCK(); 618 619 /* 620 * if the servname does not match socktype/protocol, ignore it. 621 */ 622 if (get_portmatch(pai, servname) != 0) { 623 THREAD_UNLOCK(); 624 return 0; 625 } 626 627 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 628 default_dns_files, hostname, pai)) { 629 case NS_TRYAGAIN: 630 error = EAI_AGAIN; 631 goto free; 632 case NS_UNAVAIL: 633 error = EAI_FAIL; 634 goto free; 635 case NS_NOTFOUND: 636 error = EAI_NODATA; 637 goto free; 638 case NS_SUCCESS: 639 error = 0; 640 for (cur = result; cur; cur = cur->ai_next) { 641 GET_PORT(cur, servname); 642 /* canonname should be filled already */ 643 } 644 break; 645 } 646 THREAD_UNLOCK(); 647 648 *res = result; 649 650 return 0; 651 652 free: 653 THREAD_UNLOCK(); 654 if (result) 655 freeaddrinfo(result); 656 return error; 657 } 658 659 /* 660 * hostname == NULL. 661 * passive socket -> anyaddr (0.0.0.0 or ::) 662 * non-passive socket -> localhost (127.0.0.1 or ::1) 663 */ 664 static int 665 explore_null(pai, servname, res) 666 const struct addrinfo *pai; 667 const char *servname; 668 struct addrinfo **res; 669 { 670 int s; 671 const struct afd *afd; 672 struct addrinfo *cur; 673 struct addrinfo sentinel; 674 int error; 675 676 *res = NULL; 677 sentinel.ai_next = NULL; 678 cur = &sentinel; 679 680 /* 681 * filter out AFs that are not supported by the kernel 682 * XXX errno? 683 */ 684 s = _socket(pai->ai_family, SOCK_DGRAM, 0); 685 if (s < 0) { 686 if (errno != EMFILE) 687 return 0; 688 } else 689 _close(s); 690 691 /* 692 * if the servname does not match socktype/protocol, ignore it. 693 */ 694 if (get_portmatch(pai, servname) != 0) 695 return 0; 696 697 afd = find_afd(pai->ai_family); 698 if (afd == NULL) 699 return 0; 700 701 if (pai->ai_flags & AI_PASSIVE) { 702 GET_AI(cur->ai_next, afd, afd->a_addrany); 703 /* xxx meaningless? 704 * GET_CANONNAME(cur->ai_next, "anyaddr"); 705 */ 706 GET_PORT(cur->ai_next, servname); 707 } else { 708 GET_AI(cur->ai_next, afd, afd->a_loopback); 709 /* xxx meaningless? 710 * GET_CANONNAME(cur->ai_next, "localhost"); 711 */ 712 GET_PORT(cur->ai_next, servname); 713 } 714 cur = cur->ai_next; 715 716 *res = sentinel.ai_next; 717 return 0; 718 719 free: 720 if (sentinel.ai_next) 721 freeaddrinfo(sentinel.ai_next); 722 return error; 723 } 724 725 /* 726 * numeric hostname 727 */ 728 static int 729 explore_numeric(pai, hostname, servname, res) 730 const struct addrinfo *pai; 731 const char *hostname; 732 const char *servname; 733 struct addrinfo **res; 734 { 735 const struct afd *afd; 736 struct addrinfo *cur; 737 struct addrinfo sentinel; 738 int error; 739 char pton[PTON_MAX]; 740 741 *res = NULL; 742 sentinel.ai_next = NULL; 743 cur = &sentinel; 744 745 /* 746 * if the servname does not match socktype/protocol, ignore it. 747 */ 748 if (get_portmatch(pai, servname) != 0) 749 return 0; 750 751 afd = find_afd(pai->ai_family); 752 if (afd == NULL) 753 return 0; 754 755 switch (afd->a_af) { 756 #if 1 /*X/Open spec*/ 757 case AF_INET: 758 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 759 if (pai->ai_family == afd->a_af || 760 pai->ai_family == PF_UNSPEC /*?*/) { 761 GET_AI(cur->ai_next, afd, pton); 762 GET_PORT(cur->ai_next, servname); 763 while (cur && cur->ai_next) 764 cur = cur->ai_next; 765 } else 766 ERR(EAI_FAMILY); /*xxx*/ 767 } 768 break; 769 #endif 770 default: 771 if (inet_pton(afd->a_af, hostname, pton) == 1) { 772 if (pai->ai_family == afd->a_af || 773 pai->ai_family == PF_UNSPEC /*?*/) { 774 GET_AI(cur->ai_next, afd, pton); 775 GET_PORT(cur->ai_next, servname); 776 while (cur && cur->ai_next) 777 cur = cur->ai_next; 778 } else 779 ERR(EAI_FAMILY); /*xxx*/ 780 } 781 break; 782 } 783 784 *res = sentinel.ai_next; 785 return 0; 786 787 free: 788 bad: 789 if (sentinel.ai_next) 790 freeaddrinfo(sentinel.ai_next); 791 return error; 792 } 793 794 /* 795 * numeric hostname with scope 796 */ 797 static int 798 explore_numeric_scope(pai, hostname, servname, res) 799 const struct addrinfo *pai; 800 const char *hostname; 801 const char *servname; 802 struct addrinfo **res; 803 { 804 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 805 return explore_numeric(pai, hostname, servname, res); 806 #else 807 const struct afd *afd; 808 struct addrinfo *cur; 809 int error; 810 char *cp, *hostname2 = NULL, *scope, *addr; 811 struct sockaddr_in6 *sin6; 812 813 /* 814 * if the servname does not match socktype/protocol, ignore it. 815 */ 816 if (get_portmatch(pai, servname) != 0) 817 return 0; 818 819 afd = find_afd(pai->ai_family); 820 if (afd == NULL) 821 return 0; 822 823 if (!afd->a_scoped) 824 return explore_numeric(pai, hostname, servname, res); 825 826 cp = strchr(hostname, SCOPE_DELIMITER); 827 if (cp == NULL) 828 return explore_numeric(pai, hostname, servname, res); 829 830 /* 831 * Handle special case of <scoped_address><delimiter><scope id> 832 */ 833 hostname2 = strdup(hostname); 834 if (hostname2 == NULL) 835 return EAI_MEMORY; 836 /* terminate at the delimiter */ 837 hostname2[cp - hostname] = '\0'; 838 addr = hostname2; 839 scope = cp + 1; 840 841 error = explore_numeric(pai, addr, servname, res); 842 if (error == 0) { 843 int scopeid; 844 845 for (cur = *res; cur; cur = cur->ai_next) { 846 if (cur->ai_family != AF_INET6) 847 continue; 848 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 849 if ((scopeid = ip6_str2scopeid(scope, sin6)) == -1) { 850 free(hostname2); 851 return(EAI_NODATA); /* XXX: is return OK? */ 852 } 853 sin6->sin6_scope_id = scopeid; 854 } 855 } 856 857 free(hostname2); 858 859 return error; 860 #endif 861 } 862 863 static int 864 get_canonname(pai, ai, str) 865 const struct addrinfo *pai; 866 struct addrinfo *ai; 867 const char *str; 868 { 869 if ((pai->ai_flags & AI_CANONNAME) != 0) { 870 ai->ai_canonname = (char *)malloc(strlen(str) + 1); 871 if (ai->ai_canonname == NULL) 872 return EAI_MEMORY; 873 strcpy(ai->ai_canonname, str); 874 } 875 return 0; 876 } 877 878 static struct addrinfo * 879 get_ai(pai, afd, addr) 880 const struct addrinfo *pai; 881 const struct afd *afd; 882 const char *addr; 883 { 884 char *p; 885 struct addrinfo *ai; 886 #ifdef FAITH 887 struct in6_addr faith_prefix; 888 char *fp_str; 889 int translate = 0; 890 #endif 891 892 #ifdef FAITH 893 /* 894 * Transfrom an IPv4 addr into a special IPv6 addr format for 895 * IPv6->IPv4 translation gateway. (only TCP is supported now) 896 * 897 * +-----------------------------------+------------+ 898 * | faith prefix part (12 bytes) | embedded | 899 * | | IPv4 addr part (4 bytes) 900 * +-----------------------------------+------------+ 901 * 902 * faith prefix part is specified as ascii IPv6 addr format 903 * in environmental variable GAI. 904 * For FAITH to work correctly, routing to faith prefix must be 905 * setup toward a machine where a FAITH daemon operates. 906 * Also, the machine must enable some mechanizm 907 * (e.g. faith interface hack) to divert those packet with 908 * faith prefixed destination addr to user-land FAITH daemon. 909 */ 910 fp_str = getenv("GAI"); 911 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 912 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 913 u_int32_t v4a; 914 u_int8_t v4a_top; 915 916 memcpy(&v4a, addr, sizeof v4a); 917 v4a_top = v4a >> IN_CLASSA_NSHIFT; 918 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 919 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 920 afd = &afdl[N_INET6]; 921 memcpy(&faith_prefix.s6_addr[12], addr, 922 sizeof(struct in_addr)); 923 translate = 1; 924 } 925 } 926 #endif 927 928 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 929 + (afd->a_socklen)); 930 if (ai == NULL) 931 return NULL; 932 933 memcpy(ai, pai, sizeof(struct addrinfo)); 934 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 935 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 936 ai->ai_addr->sa_len = afd->a_socklen; 937 ai->ai_addrlen = afd->a_socklen; 938 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 939 p = (char *)(void *)(ai->ai_addr); 940 #ifdef FAITH 941 if (translate == 1) 942 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 943 else 944 #endif 945 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 946 return ai; 947 } 948 949 static int 950 get_portmatch(ai, servname) 951 const struct addrinfo *ai; 952 const char *servname; 953 { 954 955 /* get_port does not touch first argument. when matchonly == 1. */ 956 /* LINTED const cast */ 957 return get_port((struct addrinfo *)ai, servname, 1); 958 } 959 960 static int 961 get_port(ai, servname, matchonly) 962 struct addrinfo *ai; 963 const char *servname; 964 int matchonly; 965 { 966 const char *proto; 967 struct servent *sp; 968 int port; 969 int allownumeric; 970 971 if (servname == NULL) 972 return 0; 973 switch (ai->ai_family) { 974 case AF_INET: 975 #ifdef AF_INET6 976 case AF_INET6: 977 #endif 978 break; 979 default: 980 return 0; 981 } 982 983 switch (ai->ai_socktype) { 984 case SOCK_RAW: 985 return EAI_SERVICE; 986 case SOCK_DGRAM: 987 case SOCK_STREAM: 988 allownumeric = 1; 989 break; 990 case ANY: 991 allownumeric = 0; 992 break; 993 default: 994 return EAI_SOCKTYPE; 995 } 996 997 if (str_isnumber(servname)) { 998 if (!allownumeric) 999 return EAI_SERVICE; 1000 port = htons(atoi(servname)); 1001 if (port < 0 || port > 65535) 1002 return EAI_SERVICE; 1003 } else { 1004 switch (ai->ai_socktype) { 1005 case SOCK_DGRAM: 1006 proto = "udp"; 1007 break; 1008 case SOCK_STREAM: 1009 proto = "tcp"; 1010 break; 1011 default: 1012 proto = NULL; 1013 break; 1014 } 1015 1016 if ((sp = getservbyname(servname, proto)) == NULL) 1017 return EAI_SERVICE; 1018 port = sp->s_port; 1019 } 1020 1021 if (!matchonly) { 1022 switch (ai->ai_family) { 1023 case AF_INET: 1024 ((struct sockaddr_in *)(void *) 1025 ai->ai_addr)->sin_port = port; 1026 break; 1027 #ifdef INET6 1028 case AF_INET6: 1029 ((struct sockaddr_in6 *)(void *) 1030 ai->ai_addr)->sin6_port = port; 1031 break; 1032 #endif 1033 } 1034 } 1035 1036 return 0; 1037 } 1038 1039 static const struct afd * 1040 find_afd(af) 1041 int af; 1042 { 1043 const struct afd *afd; 1044 1045 if (af == PF_UNSPEC) 1046 return NULL; 1047 for (afd = afdl; afd->a_af; afd++) { 1048 if (afd->a_af == af) 1049 return afd; 1050 } 1051 return NULL; 1052 } 1053 1054 /* 1055 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1056 * will take care of it. 1057 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1058 * if the code is right or not. 1059 * 1060 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1061 * _dns_getaddrinfo. 1062 */ 1063 static int 1064 addrconfig(pai) 1065 struct addrinfo *pai; 1066 { 1067 int s, af; 1068 1069 /* 1070 * TODO: 1071 * Note that implementation dependent test for address 1072 * configuration should be done everytime called 1073 * (or apropriate interval), 1074 * because addresses will be dynamically assigned or deleted. 1075 */ 1076 af = pai->ai_family; 1077 if (af == AF_UNSPEC) { 1078 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 1079 af = AF_INET; 1080 else { 1081 _close(s); 1082 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) 1083 af = AF_INET6; 1084 else 1085 _close(s); 1086 } 1087 } 1088 if (af != AF_UNSPEC) { 1089 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 1090 return 0; 1091 _close(s); 1092 } 1093 pai->ai_family = af; 1094 return 1; 1095 } 1096 1097 #ifdef INET6 1098 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1099 static int 1100 ip6_str2scopeid(scope, sin6) 1101 char *scope; 1102 struct sockaddr_in6 *sin6; 1103 { 1104 int scopeid; 1105 struct in6_addr *a6 = &sin6->sin6_addr; 1106 char *ep; 1107 1108 /* empty scopeid portion is invalid */ 1109 if (*scope == '\0') 1110 return -1; 1111 1112 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1113 /* 1114 * We currently assume a one-to-one mapping between links 1115 * and interfaces, so we simply use interface indices for 1116 * like-local scopes. 1117 */ 1118 scopeid = if_nametoindex(scope); 1119 if (scopeid == 0) 1120 goto trynumeric; 1121 return(scopeid); 1122 } 1123 1124 /* still unclear about literal, allow numeric only - placeholder */ 1125 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1126 goto trynumeric; 1127 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1128 goto trynumeric; 1129 else 1130 goto trynumeric; /* global */ 1131 1132 /* try to convert to a numeric id as a last resort */ 1133 trynumeric: 1134 scopeid = (int)strtoul(scope, &ep, 10); 1135 if (*ep == '\0') 1136 return scopeid; 1137 else 1138 return -1; 1139 } 1140 #endif 1141 1142 #ifdef RESOLVSORT 1143 struct addr_ptr { 1144 struct addrinfo *ai; 1145 int aval; 1146 }; 1147 1148 static int 1149 addr4sort(struct addrinfo *sentinel) 1150 { 1151 struct addrinfo *ai; 1152 struct addr_ptr *addrs, addr; 1153 struct sockaddr_in *sin; 1154 int naddrs, i, j; 1155 int needsort = 0; 1156 1157 if (!sentinel) 1158 return -1; 1159 naddrs = 0; 1160 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 1161 naddrs++; 1162 if (naddrs < 2) 1163 return 0; /* We don't need sorting. */ 1164 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 1165 return -1; 1166 i = 0; 1167 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 1168 sin = (struct sockaddr_in *)ai->ai_addr; 1169 for (j = 0; (unsigned)j < _res.nsort; j++) { 1170 if (_res.sort_list[j].addr.s_addr == 1171 (sin->sin_addr.s_addr & _res.sort_list[j].mask)) 1172 break; 1173 } 1174 addrs[i].ai = ai; 1175 addrs[i].aval = j; 1176 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 1177 needsort = i; 1178 i++; 1179 } 1180 if (!needsort) { 1181 free(addrs); 1182 return 0; 1183 } 1184 1185 while (needsort < naddrs) { 1186 for (j = needsort - 1; j >= 0; j--) { 1187 if (addrs[j].aval > addrs[j+1].aval) { 1188 addr = addrs[j]; 1189 addrs[j] = addrs[j + 1]; 1190 addrs[j + 1] = addr; 1191 } else 1192 break; 1193 } 1194 needsort++; 1195 } 1196 1197 ai = sentinel; 1198 for (i = 0; i < naddrs; ++i) { 1199 ai->ai_next = addrs[i].ai; 1200 ai = ai->ai_next; 1201 } 1202 ai->ai_next = NULL; 1203 free(addrs); 1204 return 0; 1205 } 1206 #endif /*RESOLVSORT*/ 1207 1208 #ifdef DEBUG 1209 static const char AskedForGot[] = 1210 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1211 #endif 1212 static FILE *hostf = NULL; 1213 1214 static struct addrinfo * 1215 getanswer(answer, anslen, qname, qtype, pai) 1216 const querybuf *answer; 1217 int anslen; 1218 const char *qname; 1219 int qtype; 1220 const struct addrinfo *pai; 1221 { 1222 struct addrinfo sentinel, *cur; 1223 struct addrinfo ai; 1224 const struct afd *afd; 1225 char *canonname; 1226 const HEADER *hp; 1227 const u_char *cp; 1228 int n; 1229 const u_char *eom; 1230 char *bp; 1231 int type, class, buflen, ancount, qdcount; 1232 int haveanswer, had_error; 1233 char tbuf[MAXDNAME]; 1234 int (*name_ok)(const char *); 1235 char hostbuf[8*1024]; 1236 1237 memset(&sentinel, 0, sizeof(sentinel)); 1238 cur = &sentinel; 1239 1240 canonname = NULL; 1241 eom = answer->buf + anslen; 1242 switch (qtype) { 1243 case T_A: 1244 case T_AAAA: 1245 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1246 name_ok = res_hnok; 1247 break; 1248 default: 1249 return (NULL); /* XXX should be abort(); */ 1250 } 1251 /* 1252 * find first satisfactory answer 1253 */ 1254 hp = &answer->hdr; 1255 ancount = ntohs(hp->ancount); 1256 qdcount = ntohs(hp->qdcount); 1257 bp = hostbuf; 1258 buflen = sizeof hostbuf; 1259 cp = answer->buf + HFIXEDSZ; 1260 if (qdcount != 1) { 1261 h_errno = NO_RECOVERY; 1262 return (NULL); 1263 } 1264 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1265 if ((n < 0) || !(*name_ok)(bp)) { 1266 h_errno = NO_RECOVERY; 1267 return (NULL); 1268 } 1269 cp += n + QFIXEDSZ; 1270 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1271 /* res_send() has already verified that the query name is the 1272 * same as the one we sent; this just gets the expanded name 1273 * (i.e., with the succeeding search-domain tacked on). 1274 */ 1275 n = strlen(bp) + 1; /* for the \0 */ 1276 if (n >= MAXHOSTNAMELEN) { 1277 h_errno = NO_RECOVERY; 1278 return (NULL); 1279 } 1280 canonname = bp; 1281 bp += n; 1282 buflen -= n; 1283 /* The qname can be abbreviated, but h_name is now absolute. */ 1284 qname = canonname; 1285 } 1286 haveanswer = 0; 1287 had_error = 0; 1288 while (ancount-- > 0 && cp < eom && !had_error) { 1289 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1290 if ((n < 0) || !(*name_ok)(bp)) { 1291 had_error++; 1292 continue; 1293 } 1294 cp += n; /* name */ 1295 type = _getshort(cp); 1296 cp += INT16SZ; /* type */ 1297 class = _getshort(cp); 1298 cp += INT16SZ + INT32SZ; /* class, TTL */ 1299 n = _getshort(cp); 1300 cp += INT16SZ; /* len */ 1301 if (class != C_IN) { 1302 /* XXX - debug? syslog? */ 1303 cp += n; 1304 continue; /* XXX - had_error++ ? */ 1305 } 1306 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1307 type == T_CNAME) { 1308 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1309 if ((n < 0) || !(*name_ok)(tbuf)) { 1310 had_error++; 1311 continue; 1312 } 1313 cp += n; 1314 /* Get canonical name. */ 1315 n = strlen(tbuf) + 1; /* for the \0 */ 1316 if (n > buflen || n >= MAXHOSTNAMELEN) { 1317 had_error++; 1318 continue; 1319 } 1320 strcpy(bp, tbuf); 1321 canonname = bp; 1322 bp += n; 1323 buflen -= n; 1324 continue; 1325 } 1326 if (qtype == T_ANY) { 1327 if (!(type == T_A || type == T_AAAA)) { 1328 cp += n; 1329 continue; 1330 } 1331 } else if (type != qtype) { 1332 #ifdef DEBUG 1333 if (type != T_KEY && type != T_SIG) 1334 syslog(LOG_NOTICE|LOG_AUTH, 1335 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1336 qname, p_class(C_IN), p_type(qtype), 1337 p_type(type)); 1338 #endif 1339 cp += n; 1340 continue; /* XXX - had_error++ ? */ 1341 } 1342 switch (type) { 1343 case T_A: 1344 case T_AAAA: 1345 if (strcasecmp(canonname, bp) != 0) { 1346 #ifdef DEBUG 1347 syslog(LOG_NOTICE|LOG_AUTH, 1348 AskedForGot, canonname, bp); 1349 #endif 1350 cp += n; 1351 continue; /* XXX - had_error++ ? */ 1352 } 1353 if (type == T_A && n != INADDRSZ) { 1354 cp += n; 1355 continue; 1356 } 1357 if (type == T_AAAA && n != IN6ADDRSZ) { 1358 cp += n; 1359 continue; 1360 } 1361 #ifdef FILTER_V4MAPPED 1362 if (type == T_AAAA) { 1363 struct in6_addr in6; 1364 memcpy(&in6, cp, sizeof(in6)); 1365 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1366 cp += n; 1367 continue; 1368 } 1369 } 1370 #endif 1371 if (!haveanswer) { 1372 int nn; 1373 1374 canonname = bp; 1375 nn = strlen(bp) + 1; /* for the \0 */ 1376 bp += nn; 1377 buflen -= nn; 1378 } 1379 1380 /* don't overwrite pai */ 1381 ai = *pai; 1382 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1383 afd = find_afd(ai.ai_family); 1384 if (afd == NULL) { 1385 cp += n; 1386 continue; 1387 } 1388 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1389 if (cur->ai_next == NULL) 1390 had_error++; 1391 while (cur && cur->ai_next) 1392 cur = cur->ai_next; 1393 cp += n; 1394 break; 1395 default: 1396 abort(); 1397 } 1398 if (!had_error) 1399 haveanswer++; 1400 } 1401 if (haveanswer) { 1402 #if defined(RESOLVSORT) 1403 /* 1404 * We support only IPv4 address for backward 1405 * compatibility against gethostbyname(3). 1406 */ 1407 if (_res.nsort && qtype == T_A) { 1408 if (addr4sort(&sentinel) < 0) { 1409 freeaddrinfo(sentinel.ai_next); 1410 h_errno = NO_RECOVERY; 1411 return NULL; 1412 } 1413 } 1414 #endif /*RESOLVSORT*/ 1415 if (!canonname) 1416 (void)get_canonname(pai, sentinel.ai_next, qname); 1417 else 1418 (void)get_canonname(pai, sentinel.ai_next, canonname); 1419 h_errno = NETDB_SUCCESS; 1420 return sentinel.ai_next; 1421 } 1422 1423 h_errno = NO_RECOVERY; 1424 return NULL; 1425 } 1426 1427 /*ARGSUSED*/ 1428 static int 1429 _dns_getaddrinfo(rv, cb_data, ap) 1430 void *rv; 1431 void *cb_data; 1432 va_list ap; 1433 { 1434 struct addrinfo *ai; 1435 querybuf *buf, *buf2; 1436 const char *name; 1437 const struct addrinfo *pai; 1438 struct addrinfo sentinel, *cur; 1439 struct res_target q, q2; 1440 1441 name = va_arg(ap, char *); 1442 pai = va_arg(ap, const struct addrinfo *); 1443 1444 memset(&q, 0, sizeof(q2)); 1445 memset(&q2, 0, sizeof(q2)); 1446 memset(&sentinel, 0, sizeof(sentinel)); 1447 cur = &sentinel; 1448 1449 buf = malloc(sizeof(*buf)); 1450 if (!buf) { 1451 h_errno = NETDB_INTERNAL; 1452 return NS_NOTFOUND; 1453 } 1454 buf2 = malloc(sizeof(*buf2)); 1455 if (!buf2) { 1456 free(buf); 1457 h_errno = NETDB_INTERNAL; 1458 return NS_NOTFOUND; 1459 } 1460 1461 switch (pai->ai_family) { 1462 case AF_UNSPEC: 1463 /* prefer IPv6 */ 1464 q.qclass = C_IN; 1465 q.qtype = T_AAAA; 1466 q.answer = buf->buf; 1467 q.anslen = sizeof(buf->buf); 1468 q.next = &q2; 1469 q2.qclass = C_IN; 1470 q2.qtype = T_A; 1471 q2.answer = buf2->buf; 1472 q2.anslen = sizeof(buf2->buf); 1473 break; 1474 case AF_INET: 1475 q.qclass = C_IN; 1476 q.qtype = T_A; 1477 q.answer = buf->buf; 1478 q.anslen = sizeof(buf->buf); 1479 break; 1480 case AF_INET6: 1481 q.qclass = C_IN; 1482 q.qtype = T_AAAA; 1483 q.answer = buf->buf; 1484 q.anslen = sizeof(buf->buf); 1485 break; 1486 default: 1487 free(buf); 1488 free(buf2); 1489 return NS_UNAVAIL; 1490 } 1491 if (res_searchN(name, &q) < 0) { 1492 free(buf); 1493 free(buf2); 1494 return NS_NOTFOUND; 1495 } 1496 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1497 if (ai) { 1498 cur->ai_next = ai; 1499 while (cur && cur->ai_next) 1500 cur = cur->ai_next; 1501 } 1502 if (q.next) { 1503 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1504 if (ai) 1505 cur->ai_next = ai; 1506 } 1507 free(buf); 1508 free(buf2); 1509 if (sentinel.ai_next == NULL) 1510 switch (h_errno) { 1511 case HOST_NOT_FOUND: 1512 return NS_NOTFOUND; 1513 case TRY_AGAIN: 1514 return NS_TRYAGAIN; 1515 default: 1516 return NS_UNAVAIL; 1517 } 1518 *((struct addrinfo **)rv) = sentinel.ai_next; 1519 return NS_SUCCESS; 1520 } 1521 1522 static void 1523 _sethtent() 1524 { 1525 if (!hostf) 1526 hostf = fopen(_PATH_HOSTS, "r" ); 1527 else 1528 rewind(hostf); 1529 } 1530 1531 static void 1532 _endhtent() 1533 { 1534 if (hostf) { 1535 (void) fclose(hostf); 1536 hostf = NULL; 1537 } 1538 } 1539 1540 static struct addrinfo * 1541 _gethtent(name, pai) 1542 const char *name; 1543 const struct addrinfo *pai; 1544 { 1545 char *p; 1546 char *cp, *tname, *cname; 1547 struct addrinfo hints, *res0, *res; 1548 int error; 1549 const char *addr; 1550 char hostbuf[8*1024]; 1551 1552 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) 1553 return (NULL); 1554 again: 1555 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) 1556 return (NULL); 1557 if (*p == '#') 1558 goto again; 1559 if (!(cp = strpbrk(p, "#\n"))) 1560 goto again; 1561 *cp = '\0'; 1562 if (!(cp = strpbrk(p, " \t"))) 1563 goto again; 1564 *cp++ = '\0'; 1565 addr = p; 1566 cname = NULL; 1567 /* if this is not something we're looking for, skip it. */ 1568 while (cp && *cp) { 1569 if (*cp == ' ' || *cp == '\t') { 1570 cp++; 1571 continue; 1572 } 1573 tname = cp; 1574 if (cname == NULL) 1575 cname = cp; 1576 if ((cp = strpbrk(cp, " \t")) != NULL) 1577 *cp++ = '\0'; 1578 if (strcasecmp(name, tname) == 0) 1579 goto found; 1580 } 1581 goto again; 1582 1583 found: 1584 hints = *pai; 1585 hints.ai_flags = AI_NUMERICHOST; 1586 error = getaddrinfo(addr, NULL, &hints, &res0); 1587 if (error) 1588 goto again; 1589 #ifdef FILTER_V4MAPPED 1590 /* XXX should check all items in the chain */ 1591 if (res0->ai_family == AF_INET6 && 1592 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 1593 freeaddrinfo(res0); 1594 goto again; 1595 } 1596 #endif 1597 for (res = res0; res; res = res->ai_next) { 1598 /* cover it up */ 1599 res->ai_flags = pai->ai_flags; 1600 1601 if (pai->ai_flags & AI_CANONNAME) { 1602 if (get_canonname(pai, res, cname) != 0) { 1603 freeaddrinfo(res0); 1604 goto again; 1605 } 1606 } 1607 } 1608 return res0; 1609 } 1610 1611 /*ARGSUSED*/ 1612 static int 1613 _files_getaddrinfo(rv, cb_data, ap) 1614 void *rv; 1615 void *cb_data; 1616 va_list ap; 1617 { 1618 const char *name; 1619 const struct addrinfo *pai; 1620 struct addrinfo sentinel, *cur; 1621 struct addrinfo *p; 1622 1623 name = va_arg(ap, char *); 1624 pai = va_arg(ap, struct addrinfo *); 1625 1626 memset(&sentinel, 0, sizeof(sentinel)); 1627 cur = &sentinel; 1628 1629 _sethtent(); 1630 while ((p = _gethtent(name, pai)) != NULL) { 1631 cur->ai_next = p; 1632 while (cur && cur->ai_next) 1633 cur = cur->ai_next; 1634 } 1635 _endhtent(); 1636 1637 *((struct addrinfo **)rv) = sentinel.ai_next; 1638 if (sentinel.ai_next == NULL) 1639 return NS_NOTFOUND; 1640 return NS_SUCCESS; 1641 } 1642 1643 #ifdef YP 1644 static char *__ypdomain; 1645 1646 /*ARGSUSED*/ 1647 static struct addrinfo * 1648 _yphostent(line, pai) 1649 char *line; 1650 const struct addrinfo *pai; 1651 { 1652 struct addrinfo sentinel, *cur; 1653 struct addrinfo hints, *res, *res0; 1654 int error; 1655 char *p = line; 1656 const char *addr, *canonname; 1657 char *nextline; 1658 char *cp; 1659 1660 addr = canonname = NULL; 1661 1662 memset(&sentinel, 0, sizeof(sentinel)); 1663 cur = &sentinel; 1664 1665 nextline: 1666 /* terminate line */ 1667 cp = strchr(p, '\n'); 1668 if (cp) { 1669 *cp++ = '\0'; 1670 nextline = cp; 1671 } else 1672 nextline = NULL; 1673 1674 cp = strpbrk(p, " \t"); 1675 if (cp == NULL) { 1676 if (canonname == NULL) 1677 return (NULL); 1678 else 1679 goto done; 1680 } 1681 *cp++ = '\0'; 1682 1683 addr = p; 1684 1685 while (cp && *cp) { 1686 if (*cp == ' ' || *cp == '\t') { 1687 cp++; 1688 continue; 1689 } 1690 if (!canonname) 1691 canonname = cp; 1692 if ((cp = strpbrk(cp, " \t")) != NULL) 1693 *cp++ = '\0'; 1694 } 1695 1696 hints = *pai; 1697 hints.ai_flags = AI_NUMERICHOST; 1698 error = getaddrinfo(addr, NULL, &hints, &res0); 1699 if (error == 0) { 1700 for (res = res0; res; res = res->ai_next) { 1701 /* cover it up */ 1702 res->ai_flags = pai->ai_flags; 1703 1704 if (pai->ai_flags & AI_CANONNAME) 1705 (void)get_canonname(pai, res, canonname); 1706 } 1707 } else 1708 res0 = NULL; 1709 if (res0) { 1710 cur->ai_next = res0; 1711 while (cur && cur->ai_next) 1712 cur = cur->ai_next; 1713 } 1714 1715 if (nextline) { 1716 p = nextline; 1717 goto nextline; 1718 } 1719 1720 done: 1721 return sentinel.ai_next; 1722 } 1723 1724 /*ARGSUSED*/ 1725 static int 1726 _yp_getaddrinfo(rv, cb_data, ap) 1727 void *rv; 1728 void *cb_data; 1729 va_list ap; 1730 { 1731 struct addrinfo sentinel, *cur; 1732 struct addrinfo *ai = NULL; 1733 static char *__ypcurrent; 1734 int __ypcurrentlen, r; 1735 const char *name; 1736 const struct addrinfo *pai; 1737 1738 name = va_arg(ap, char *); 1739 pai = va_arg(ap, const struct addrinfo *); 1740 1741 memset(&sentinel, 0, sizeof(sentinel)); 1742 cur = &sentinel; 1743 1744 if (!__ypdomain) { 1745 if (_yp_check(&__ypdomain) == 0) 1746 return NS_UNAVAIL; 1747 } 1748 if (__ypcurrent) 1749 free(__ypcurrent); 1750 __ypcurrent = NULL; 1751 1752 /* hosts.byname is only for IPv4 (Solaris8) */ 1753 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1754 r = yp_match(__ypdomain, "hosts.byname", name, 1755 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1756 if (r == 0) { 1757 struct addrinfo ai4; 1758 1759 ai4 = *pai; 1760 ai4.ai_family = AF_INET; 1761 ai = _yphostent(__ypcurrent, &ai4); 1762 if (ai) { 1763 cur->ai_next = ai; 1764 while (cur && cur->ai_next) 1765 cur = cur->ai_next; 1766 } 1767 } 1768 } 1769 1770 /* ipnodes.byname can hold both IPv4/v6 */ 1771 r = yp_match(__ypdomain, "ipnodes.byname", name, 1772 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1773 if (r == 0) { 1774 ai = _yphostent(__ypcurrent, pai); 1775 if (ai) { 1776 cur->ai_next = ai; 1777 while (cur && cur->ai_next) 1778 cur = cur->ai_next; 1779 } 1780 } 1781 1782 if (sentinel.ai_next == NULL) { 1783 h_errno = HOST_NOT_FOUND; 1784 return NS_NOTFOUND; 1785 } 1786 *((struct addrinfo **)rv) = sentinel.ai_next; 1787 return NS_SUCCESS; 1788 } 1789 #endif 1790 1791 /* resolver logic */ 1792 1793 extern const char *__hostalias(const char *); 1794 extern int h_errno; 1795 1796 /* 1797 * Formulate a normal query, send, and await answer. 1798 * Returned answer is placed in supplied buffer "answer". 1799 * Perform preliminary check of answer, returning success only 1800 * if no error is indicated and the answer count is nonzero. 1801 * Return the size of the response on success, -1 on error. 1802 * Error number is left in h_errno. 1803 * 1804 * Caller must parse answer and determine whether it answers the question. 1805 */ 1806 static int 1807 res_queryN(name, target) 1808 const char *name; /* domain name */ 1809 struct res_target *target; 1810 { 1811 u_char *buf; 1812 HEADER *hp; 1813 int n; 1814 struct res_target *t; 1815 int rcode; 1816 int ancount; 1817 1818 rcode = NOERROR; 1819 ancount = 0; 1820 1821 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1822 h_errno = NETDB_INTERNAL; 1823 return (-1); 1824 } 1825 1826 buf = malloc(MAXPACKET); 1827 if (!buf) { 1828 h_errno = NETDB_INTERNAL; 1829 return -1; 1830 } 1831 1832 for (t = target; t; t = t->next) { 1833 int class, type; 1834 u_char *answer; 1835 int anslen; 1836 1837 hp = (HEADER *)(void *)t->answer; 1838 hp->rcode = NOERROR; /* default */ 1839 1840 /* make it easier... */ 1841 class = t->qclass; 1842 type = t->qtype; 1843 answer = t->answer; 1844 anslen = t->anslen; 1845 #ifdef DEBUG 1846 if (_res.options & RES_DEBUG) 1847 printf(";; res_query(%s, %d, %d)\n", name, class, type); 1848 #endif 1849 1850 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL, 1851 buf, MAXPACKET); 1852 if (n > 0 && (_res.options & RES_USE_EDNS0) != 0) 1853 n = res_opt(n, buf, MAXPACKET, anslen); 1854 if (n <= 0) { 1855 #ifdef DEBUG 1856 if (_res.options & RES_DEBUG) 1857 printf(";; res_query: mkquery failed\n"); 1858 #endif 1859 free(buf); 1860 h_errno = NO_RECOVERY; 1861 return (n); 1862 } 1863 n = res_send(buf, n, answer, anslen); 1864 #if 0 1865 if (n < 0) { 1866 #ifdef DEBUG 1867 if (_res.options & RES_DEBUG) 1868 printf(";; res_query: send error\n"); 1869 #endif 1870 free(buf); 1871 h_errno = TRY_AGAIN; 1872 return (n); 1873 } 1874 #endif 1875 1876 if (n < 0 || n > anslen) 1877 hp->rcode = FORMERR; /* XXX not very informative */ 1878 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1879 rcode = hp->rcode; /* record most recent error */ 1880 #ifdef DEBUG 1881 if (_res.options & RES_DEBUG) 1882 printf(";; rcode = %d, ancount=%d\n", hp->rcode, 1883 ntohs(hp->ancount)); 1884 #endif 1885 continue; 1886 } 1887 1888 ancount += ntohs(hp->ancount); 1889 1890 t->n = n; 1891 } 1892 1893 free(buf); 1894 1895 if (ancount == 0) { 1896 switch (rcode) { 1897 case NXDOMAIN: 1898 h_errno = HOST_NOT_FOUND; 1899 break; 1900 case SERVFAIL: 1901 h_errno = TRY_AGAIN; 1902 break; 1903 case NOERROR: 1904 h_errno = NO_DATA; 1905 break; 1906 case FORMERR: 1907 case NOTIMP: 1908 case REFUSED: 1909 default: 1910 h_errno = NO_RECOVERY; 1911 break; 1912 } 1913 return (-1); 1914 } 1915 return (ancount); 1916 } 1917 1918 /* 1919 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1920 * Return the size of the response on success, -1 on error. 1921 * If enabled, implement search rules until answer or unrecoverable failure 1922 * is detected. Error code, if any, is left in h_errno. 1923 */ 1924 static int 1925 res_searchN(name, target) 1926 const char *name; /* domain name */ 1927 struct res_target *target; 1928 { 1929 const char *cp, * const *domain; 1930 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 1931 u_int dots; 1932 int trailing_dot, ret, saved_herrno; 1933 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1934 1935 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1936 h_errno = NETDB_INTERNAL; 1937 return (-1); 1938 } 1939 1940 errno = 0; 1941 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1942 dots = 0; 1943 for (cp = name; *cp; cp++) 1944 dots += (*cp == '.'); 1945 trailing_dot = 0; 1946 if (cp > name && *--cp == '.') 1947 trailing_dot++; 1948 1949 /* 1950 * if there aren't any dots, it could be a user-level alias 1951 */ 1952 if (!dots && (cp = __hostalias(name)) != NULL) 1953 return (res_queryN(cp, target)); 1954 1955 /* 1956 * If there are dots in the name already, let's just give it a try 1957 * 'as is'. The threshold can be set with the "ndots" option. 1958 */ 1959 saved_herrno = -1; 1960 if (dots >= _res.ndots) { 1961 ret = res_querydomainN(name, NULL, target); 1962 if (ret > 0) 1963 return (ret); 1964 saved_herrno = h_errno; 1965 tried_as_is++; 1966 } 1967 1968 /* 1969 * We do at least one level of search if 1970 * - there is no dot and RES_DEFNAME is set, or 1971 * - there is at least one dot, there is no trailing dot, 1972 * and RES_DNSRCH is set. 1973 */ 1974 if ((!dots && (_res.options & RES_DEFNAMES)) || 1975 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { 1976 int done = 0; 1977 1978 for (domain = (const char * const *)_res.dnsrch; 1979 *domain && !done; 1980 domain++) { 1981 1982 ret = res_querydomainN(name, *domain, target); 1983 if (ret > 0) 1984 return (ret); 1985 1986 /* 1987 * If no server present, give up. 1988 * If name isn't found in this domain, 1989 * keep trying higher domains in the search list 1990 * (if that's enabled). 1991 * On a NO_DATA error, keep trying, otherwise 1992 * a wildcard entry of another type could keep us 1993 * from finding this entry higher in the domain. 1994 * If we get some other error (negative answer or 1995 * server failure), then stop searching up, 1996 * but try the input name below in case it's 1997 * fully-qualified. 1998 */ 1999 if (errno == ECONNREFUSED) { 2000 h_errno = TRY_AGAIN; 2001 return (-1); 2002 } 2003 2004 switch (h_errno) { 2005 case NO_DATA: 2006 got_nodata++; 2007 /* FALLTHROUGH */ 2008 case HOST_NOT_FOUND: 2009 /* keep trying */ 2010 break; 2011 case TRY_AGAIN: 2012 if (hp->rcode == SERVFAIL) { 2013 /* try next search element, if any */ 2014 got_servfail++; 2015 break; 2016 } 2017 /* FALLTHROUGH */ 2018 default: 2019 /* anything else implies that we're done */ 2020 done++; 2021 } 2022 /* 2023 * if we got here for some reason other than DNSRCH, 2024 * we only wanted one iteration of the loop, so stop. 2025 */ 2026 if (!(_res.options & RES_DNSRCH)) 2027 done++; 2028 } 2029 } 2030 2031 /* 2032 * if we have not already tried the name "as is", do that now. 2033 * note that we do this regardless of how many dots were in the 2034 * name or whether it ends with a dot. 2035 */ 2036 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) { 2037 ret = res_querydomainN(name, NULL, target); 2038 if (ret > 0) 2039 return (ret); 2040 } 2041 2042 /* 2043 * if we got here, we didn't satisfy the search. 2044 * if we did an initial full query, return that query's h_errno 2045 * (note that we wouldn't be here if that query had succeeded). 2046 * else if we ever got a nodata, send that back as the reason. 2047 * else send back meaningless h_errno, that being the one from 2048 * the last DNSRCH we did. 2049 */ 2050 if (saved_herrno != -1) 2051 h_errno = saved_herrno; 2052 else if (got_nodata) 2053 h_errno = NO_DATA; 2054 else if (got_servfail) 2055 h_errno = TRY_AGAIN; 2056 return (-1); 2057 } 2058 2059 /* 2060 * Perform a call on res_query on the concatenation of name and domain, 2061 * removing a trailing dot from name if domain is NULL. 2062 */ 2063 static int 2064 res_querydomainN(name, domain, target) 2065 const char *name, *domain; 2066 struct res_target *target; 2067 { 2068 char nbuf[MAXDNAME]; 2069 const char *longname = nbuf; 2070 size_t n, d; 2071 2072 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 2073 h_errno = NETDB_INTERNAL; 2074 return (-1); 2075 } 2076 #ifdef DEBUG 2077 if (_res.options & RES_DEBUG) 2078 printf(";; res_querydomain(%s, %s)\n", 2079 name, domain?domain:"<Nil>"); 2080 #endif 2081 if (domain == NULL) { 2082 /* 2083 * Check for trailing '.'; 2084 * copy without '.' if present. 2085 */ 2086 n = strlen(name); 2087 if (n >= MAXDNAME) { 2088 h_errno = NO_RECOVERY; 2089 return (-1); 2090 } 2091 if (n > 0 && name[--n] == '.') { 2092 strncpy(nbuf, name, n); 2093 nbuf[n] = '\0'; 2094 } else 2095 longname = name; 2096 } else { 2097 n = strlen(name); 2098 d = strlen(domain); 2099 if (n + d + 1 >= MAXDNAME) { 2100 h_errno = NO_RECOVERY; 2101 return (-1); 2102 } 2103 sprintf(nbuf, "%s.%s", name, domain); 2104 } 2105 return (res_queryN(longname, target)); 2106 } 2107