1 /* $NetBSD: getaddrinfo.c,v 1.77 2006/02/17 15:55:01 ginsbach Exp $ */ 2 /* $KAME: getaddrinfo.c,v 1.29 2000/08/31 17:26:57 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 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 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Issues to be discussed: 35 * - Thread safe-ness must be checked. 36 * - Return values. There are nonstandard return values defined and used 37 * in the source code. This is because RFC2553 is silent about which error 38 * code must be returned for which situation. 39 * - IPv4 classful (shortened) form. RFC2553 is silent about it. XNET 5.2 40 * says to use inet_aton() to convert IPv4 numeric to binary (alows 41 * classful form as a result). 42 * current code - disallow classful form for IPv4 (due to use of inet_pton). 43 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 44 * invalid. 45 * current code - SEGV on freeaddrinfo(NULL) 46 * Note: 47 * - We use getipnodebyname() just for thread-safeness. There's no intent 48 * to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to 49 * getipnodebyname(). 50 * - The code filters out AFs that are not supported by the kernel, 51 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 52 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 53 * in ai_flags? 54 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 55 * (1) what should we do against numeric hostname (2) what should we do 56 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 57 * non-loopback address configured? global address configured? 58 * - To avoid search order issue, we have a big amount of code duplicate 59 * from gethnamaddr.c and some other places. The issues that there's no 60 * lower layer function to lookup "IPv4 or IPv6" record. Calling 61 * gethostbyname2 from getaddrinfo will end up in wrong search order, as 62 * follows: 63 * - The code makes use of following calls when asked to resolver with 64 * ai_family = PF_UNSPEC: 65 * getipnodebyname(host, AF_INET6); 66 * getipnodebyname(host, AF_INET); 67 * This will result in the following queries if the node is configure to 68 * prefer /etc/hosts than DNS: 69 * lookup /etc/hosts for IPv6 address 70 * lookup DNS for IPv6 address 71 * lookup /etc/hosts for IPv4 address 72 * lookup DNS for IPv4 address 73 * which may not meet people's requirement. 74 * The right thing to happen is to have underlying layer which does 75 * PF_UNSPEC lookup (lookup both) and return chain of addrinfos. 76 * This would result in a bit of code duplicate with _dns_ghbyname() and 77 * friends. 78 */ 79 80 #include <sys/cdefs.h> 81 #if defined(LIBC_SCCS) && !defined(lint) 82 __RCSID("$NetBSD: getaddrinfo.c,v 1.77 2006/02/17 15:55:01 ginsbach Exp $"); 83 #endif /* LIBC_SCCS and not lint */ 84 85 #include "namespace.h" 86 #include <sys/types.h> 87 #include <sys/param.h> 88 #include <sys/socket.h> 89 #include <net/if.h> 90 #include <netinet/in.h> 91 #include <arpa/inet.h> 92 #include <arpa/nameser.h> 93 #include <assert.h> 94 #include <ctype.h> 95 #include <errno.h> 96 #include <netdb.h> 97 #include <resolv.h> 98 #include <stddef.h> 99 #include <stdio.h> 100 #include <stdlib.h> 101 #include <string.h> 102 #include <unistd.h> 103 104 #include <syslog.h> 105 #include <stdarg.h> 106 #include <nsswitch.h> 107 108 #ifdef YP 109 #include <rpc/rpc.h> 110 #include <rpcsvc/yp_prot.h> 111 #include <rpcsvc/ypclnt.h> 112 #endif 113 114 #ifdef __weak_alias 115 __weak_alias(getaddrinfo,_getaddrinfo) 116 __weak_alias(freeaddrinfo,_freeaddrinfo) 117 __weak_alias(gai_strerror,_gai_strerror) 118 #endif 119 120 #define SUCCESS 0 121 #define ANY 0 122 #define YES 1 123 #define NO 0 124 125 static const char in_addrany[] = { 0, 0, 0, 0 }; 126 static const char in_loopback[] = { 127, 0, 0, 1 }; 127 #ifdef INET6 128 static const char in6_addrany[] = { 129 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 130 }; 131 static const char in6_loopback[] = { 132 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 133 }; 134 #endif 135 136 static const struct afd { 137 int a_af; 138 int a_addrlen; 139 int a_socklen; 140 int a_off; 141 const char *a_addrany; 142 const char *a_loopback; 143 int a_scoped; 144 } afdl [] = { 145 #ifdef INET6 146 {PF_INET6, sizeof(struct in6_addr), 147 sizeof(struct sockaddr_in6), 148 offsetof(struct sockaddr_in6, sin6_addr), 149 in6_addrany, in6_loopback, 1}, 150 #endif 151 {PF_INET, sizeof(struct in_addr), 152 sizeof(struct sockaddr_in), 153 offsetof(struct sockaddr_in, sin_addr), 154 in_addrany, in_loopback, 0}, 155 {0, 0, 0, 0, NULL, NULL, 0}, 156 }; 157 158 struct explore { 159 int e_af; 160 int e_socktype; 161 int e_protocol; 162 const char *e_protostr; 163 int e_wild; 164 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 165 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 166 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 167 }; 168 169 static const struct explore explore[] = { 170 #if 0 171 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 172 #endif 173 #ifdef INET6 174 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 175 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 176 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 177 #endif 178 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 179 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 180 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 181 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 182 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 183 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 184 { -1, 0, 0, NULL, 0 }, 185 }; 186 187 #ifdef INET6 188 #define PTON_MAX 16 189 #else 190 #define PTON_MAX 4 191 #endif 192 193 static const ns_src default_dns_files[] = { 194 { NSSRC_FILES, NS_SUCCESS }, 195 { NSSRC_DNS, NS_SUCCESS }, 196 { 0 } 197 }; 198 199 #define MAXPACKET (64*1024) 200 201 typedef union { 202 HEADER hdr; 203 u_char buf[MAXPACKET]; 204 } querybuf; 205 206 struct res_target { 207 struct res_target *next; 208 const char *name; /* domain name */ 209 int qclass, qtype; /* class and type of query */ 210 u_char *answer; /* buffer to put answer */ 211 int anslen; /* size of answer buffer */ 212 int n; /* result length */ 213 }; 214 215 static int str2number(const char *); 216 static int explore_fqdn(const struct addrinfo *, const char *, 217 const char *, struct addrinfo **); 218 static int explore_null(const struct addrinfo *, 219 const char *, struct addrinfo **); 220 static int explore_numeric(const struct addrinfo *, const char *, 221 const char *, struct addrinfo **, const char *); 222 static int explore_numeric_scope(const struct addrinfo *, const char *, 223 const char *, struct addrinfo **); 224 static int get_canonname(const struct addrinfo *, 225 struct addrinfo *, const char *); 226 static struct addrinfo *get_ai(const struct addrinfo *, 227 const struct afd *, const char *); 228 static int get_portmatch(const struct addrinfo *, const char *); 229 static int get_port(const struct addrinfo *, const char *, int); 230 static const struct afd *find_afd(int); 231 #ifdef INET6 232 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 233 #endif 234 235 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 236 const struct addrinfo *); 237 static void aisort(struct addrinfo *s, res_state res); 238 static int _dns_getaddrinfo(void *, void *, va_list); 239 static void _sethtent(FILE **); 240 static void _endhtent(FILE **); 241 static struct addrinfo *_gethtent(FILE **, const char *, 242 const struct addrinfo *); 243 static int _files_getaddrinfo(void *, void *, va_list); 244 #ifdef YP 245 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 246 static int _yp_getaddrinfo(void *, void *, va_list); 247 #endif 248 249 static int res_queryN(const char *, struct res_target *, res_state); 250 static int res_searchN(const char *, struct res_target *, res_state); 251 static int res_querydomainN(const char *, const char *, 252 struct res_target *, res_state); 253 254 static const char * const ai_errlist[] = { 255 "Success", 256 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 257 "Temporary failure in name resolution", /* EAI_AGAIN */ 258 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 259 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 260 "ai_family not supported", /* EAI_FAMILY */ 261 "Memory allocation failure", /* EAI_MEMORY */ 262 "No address associated with hostname", /* EAI_NODATA */ 263 "hostname nor servname provided, or not known", /* EAI_NONAME */ 264 "servname not supported for ai_socktype", /* EAI_SERVICE */ 265 "ai_socktype not supported", /* EAI_SOCKTYPE */ 266 "System error returned in errno", /* EAI_SYSTEM */ 267 "Invalid value for hints", /* EAI_BADHINTS */ 268 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 269 "Argument buffer overflow", /* EAI_OVERFLOW */ 270 "Unknown error", /* EAI_MAX */ 271 }; 272 273 /* XXX macros that make external reference is BAD. */ 274 275 #define GET_AI(ai, afd, addr) \ 276 do { \ 277 /* external reference: pai, error, and label free */ \ 278 (ai) = get_ai(pai, (afd), (addr)); \ 279 if ((ai) == NULL) { \ 280 error = EAI_MEMORY; \ 281 goto free; \ 282 } \ 283 } while (/*CONSTCOND*/0) 284 285 #define GET_PORT(ai, serv) \ 286 do { \ 287 /* external reference: error and label free */ \ 288 error = get_port((ai), (serv), 0); \ 289 if (error != 0) \ 290 goto free; \ 291 } while (/*CONSTCOND*/0) 292 293 #define GET_CANONNAME(ai, str) \ 294 do { \ 295 /* external reference: pai, error and label free */ \ 296 error = get_canonname(pai, (ai), (str)); \ 297 if (error != 0) \ 298 goto free; \ 299 } while (/*CONSTCOND*/0) 300 301 #define ERR(err) \ 302 do { \ 303 /* external reference: error, and label bad */ \ 304 error = (err); \ 305 goto bad; \ 306 /*NOTREACHED*/ \ 307 } while (/*CONSTCOND*/0) 308 309 #define MATCH_FAMILY(x, y, w) \ 310 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 311 #define MATCH(x, y, w) \ 312 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 313 314 const char * 315 gai_strerror(int ecode) 316 { 317 if (ecode < 0 || ecode > EAI_MAX) 318 ecode = EAI_MAX; 319 return ai_errlist[ecode]; 320 } 321 322 void 323 freeaddrinfo(struct addrinfo *ai) 324 { 325 struct addrinfo *next; 326 327 _DIAGASSERT(ai != NULL); 328 329 do { 330 next = ai->ai_next; 331 if (ai->ai_canonname) 332 free(ai->ai_canonname); 333 /* no need to free(ai->ai_addr) */ 334 free(ai); 335 ai = next; 336 } while (ai); 337 } 338 339 static int 340 str2number(const char *p) 341 { 342 char *ep; 343 unsigned long v; 344 345 _DIAGASSERT(p != NULL); 346 347 if (*p == '\0') 348 return -1; 349 ep = NULL; 350 errno = 0; 351 v = strtoul(p, &ep, 10); 352 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) 353 return v; 354 else 355 return -1; 356 } 357 358 int 359 getaddrinfo(const char *hostname, const char *servname, 360 const struct addrinfo *hints, struct addrinfo **res) 361 { 362 struct addrinfo sentinel; 363 struct addrinfo *cur; 364 int error = 0; 365 struct addrinfo ai; 366 struct addrinfo ai0; 367 struct addrinfo *pai; 368 const struct explore *ex; 369 370 /* hostname is allowed to be NULL */ 371 /* servname is allowed to be NULL */ 372 /* hints is allowed to be NULL */ 373 _DIAGASSERT(res != NULL); 374 375 memset(&sentinel, 0, sizeof(sentinel)); 376 cur = &sentinel; 377 pai = &ai; 378 pai->ai_flags = 0; 379 pai->ai_family = PF_UNSPEC; 380 pai->ai_socktype = ANY; 381 pai->ai_protocol = ANY; 382 pai->ai_addrlen = 0; 383 pai->ai_canonname = NULL; 384 pai->ai_addr = NULL; 385 pai->ai_next = NULL; 386 387 if (hostname == NULL && servname == NULL) 388 return EAI_NONAME; 389 if (hints) { 390 /* error check for hints */ 391 if (hints->ai_addrlen || hints->ai_canonname || 392 hints->ai_addr || hints->ai_next) 393 ERR(EAI_BADHINTS); /* xxx */ 394 if (hints->ai_flags & ~AI_MASK) 395 ERR(EAI_BADFLAGS); 396 switch (hints->ai_family) { 397 case PF_UNSPEC: 398 case PF_INET: 399 #ifdef INET6 400 case PF_INET6: 401 #endif 402 break; 403 default: 404 ERR(EAI_FAMILY); 405 } 406 memcpy(pai, hints, sizeof(*pai)); 407 408 /* 409 * if both socktype/protocol are specified, check if they 410 * are meaningful combination. 411 */ 412 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 413 for (ex = explore; ex->e_af >= 0; ex++) { 414 if (pai->ai_family != ex->e_af) 415 continue; 416 if (ex->e_socktype == ANY) 417 continue; 418 if (ex->e_protocol == ANY) 419 continue; 420 if (pai->ai_socktype == ex->e_socktype 421 && pai->ai_protocol != ex->e_protocol) { 422 ERR(EAI_BADHINTS); 423 } 424 } 425 } 426 } 427 428 /* 429 * check for special cases. (1) numeric servname is disallowed if 430 * socktype/protocol are left unspecified. (2) servname is disallowed 431 * for raw and other inet{,6} sockets. 432 */ 433 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 434 #ifdef PF_INET6 435 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 436 #endif 437 ) { 438 ai0 = *pai; /* backup *pai */ 439 440 if (pai->ai_family == PF_UNSPEC) { 441 #ifdef PF_INET6 442 pai->ai_family = PF_INET6; 443 #else 444 pai->ai_family = PF_INET; 445 #endif 446 } 447 error = get_portmatch(pai, servname); 448 if (error) 449 ERR(error); 450 451 *pai = ai0; 452 } 453 454 ai0 = *pai; 455 456 /* NULL hostname, or numeric hostname */ 457 for (ex = explore; ex->e_af >= 0; ex++) { 458 *pai = ai0; 459 460 /* PF_UNSPEC entries are prepared for DNS queries only */ 461 if (ex->e_af == PF_UNSPEC) 462 continue; 463 464 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 465 continue; 466 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 467 continue; 468 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 469 continue; 470 471 if (pai->ai_family == PF_UNSPEC) 472 pai->ai_family = ex->e_af; 473 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 474 pai->ai_socktype = ex->e_socktype; 475 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 476 pai->ai_protocol = ex->e_protocol; 477 478 if (hostname == NULL) 479 error = explore_null(pai, servname, &cur->ai_next); 480 else 481 error = explore_numeric_scope(pai, hostname, servname, 482 &cur->ai_next); 483 484 if (error) 485 goto free; 486 487 while (cur && cur->ai_next) 488 cur = cur->ai_next; 489 } 490 491 /* 492 * XXX 493 * If numeric representation of AF1 can be interpreted as FQDN 494 * representation of AF2, we need to think again about the code below. 495 */ 496 if (sentinel.ai_next) 497 goto good; 498 499 if (hostname == NULL) 500 ERR(EAI_NODATA); 501 if (pai->ai_flags & AI_NUMERICHOST) 502 ERR(EAI_NONAME); 503 504 /* 505 * hostname as alphabetical name. 506 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 507 * outer loop by AFs. 508 */ 509 for (ex = explore; ex->e_af >= 0; ex++) { 510 *pai = ai0; 511 512 /* require exact match for family field */ 513 if (pai->ai_family != ex->e_af) 514 continue; 515 516 if (!MATCH(pai->ai_socktype, ex->e_socktype, 517 WILD_SOCKTYPE(ex))) { 518 continue; 519 } 520 if (!MATCH(pai->ai_protocol, ex->e_protocol, 521 WILD_PROTOCOL(ex))) { 522 continue; 523 } 524 525 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 526 pai->ai_socktype = ex->e_socktype; 527 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 528 pai->ai_protocol = ex->e_protocol; 529 530 error = explore_fqdn(pai, hostname, servname, 531 &cur->ai_next); 532 533 while (cur && cur->ai_next) 534 cur = cur->ai_next; 535 } 536 537 /* XXX */ 538 if (sentinel.ai_next) 539 error = 0; 540 541 if (error) 542 goto free; 543 if (error == 0) { 544 if (sentinel.ai_next) { 545 good: 546 *res = sentinel.ai_next; 547 return SUCCESS; 548 } else 549 error = EAI_FAIL; 550 } 551 free: 552 bad: 553 if (sentinel.ai_next) 554 freeaddrinfo(sentinel.ai_next); 555 *res = NULL; 556 return error; 557 } 558 559 /* 560 * FQDN hostname, DNS lookup 561 */ 562 static int 563 explore_fqdn(const struct addrinfo *pai, const char *hostname, 564 const char *servname, struct addrinfo **res) 565 { 566 struct addrinfo *result; 567 struct addrinfo *cur; 568 int error = 0; 569 static const ns_dtab dtab[] = { 570 NS_FILES_CB(_files_getaddrinfo, NULL) 571 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 572 NS_NIS_CB(_yp_getaddrinfo, NULL) 573 { 0 } 574 }; 575 576 _DIAGASSERT(pai != NULL); 577 /* hostname may be NULL */ 578 /* servname may be NULL */ 579 _DIAGASSERT(res != NULL); 580 581 result = NULL; 582 583 /* 584 * if the servname does not match socktype/protocol, ignore it. 585 */ 586 if (get_portmatch(pai, servname) != 0) 587 return 0; 588 589 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 590 default_dns_files, hostname, pai)) { 591 case NS_TRYAGAIN: 592 error = EAI_AGAIN; 593 goto free; 594 case NS_UNAVAIL: 595 error = EAI_FAIL; 596 goto free; 597 case NS_NOTFOUND: 598 error = EAI_NODATA; 599 goto free; 600 case NS_SUCCESS: 601 error = 0; 602 for (cur = result; cur; cur = cur->ai_next) { 603 GET_PORT(cur, servname); 604 /* canonname should be filled already */ 605 } 606 break; 607 } 608 609 *res = result; 610 611 return 0; 612 613 free: 614 if (result) 615 freeaddrinfo(result); 616 return error; 617 } 618 619 /* 620 * hostname == NULL. 621 * passive socket -> anyaddr (0.0.0.0 or ::) 622 * non-passive socket -> localhost (127.0.0.1 or ::1) 623 */ 624 static int 625 explore_null(const struct addrinfo *pai, const char *servname, 626 struct addrinfo **res) 627 { 628 int s; 629 const struct afd *afd; 630 struct addrinfo *cur; 631 struct addrinfo sentinel; 632 int error; 633 634 _DIAGASSERT(pai != NULL); 635 /* servname may be NULL */ 636 _DIAGASSERT(res != NULL); 637 638 *res = NULL; 639 sentinel.ai_next = NULL; 640 cur = &sentinel; 641 642 /* 643 * filter out AFs that are not supported by the kernel 644 * XXX errno? 645 */ 646 s = socket(pai->ai_family, SOCK_DGRAM, 0); 647 if (s < 0) { 648 if (errno != EMFILE) 649 return 0; 650 } else 651 close(s); 652 653 /* 654 * if the servname does not match socktype/protocol, ignore it. 655 */ 656 if (get_portmatch(pai, servname) != 0) 657 return 0; 658 659 afd = find_afd(pai->ai_family); 660 if (afd == NULL) 661 return 0; 662 663 if (pai->ai_flags & AI_PASSIVE) { 664 GET_AI(cur->ai_next, afd, afd->a_addrany); 665 /* xxx meaningless? 666 * GET_CANONNAME(cur->ai_next, "anyaddr"); 667 */ 668 GET_PORT(cur->ai_next, servname); 669 } else { 670 GET_AI(cur->ai_next, afd, afd->a_loopback); 671 /* xxx meaningless? 672 * GET_CANONNAME(cur->ai_next, "localhost"); 673 */ 674 GET_PORT(cur->ai_next, servname); 675 } 676 cur = cur->ai_next; 677 678 *res = sentinel.ai_next; 679 return 0; 680 681 free: 682 if (sentinel.ai_next) 683 freeaddrinfo(sentinel.ai_next); 684 return error; 685 } 686 687 /* 688 * numeric hostname 689 */ 690 static int 691 explore_numeric(const struct addrinfo *pai, const char *hostname, 692 const char *servname, struct addrinfo **res, const char *canonname) 693 { 694 const struct afd *afd; 695 struct addrinfo *cur; 696 struct addrinfo sentinel; 697 int error; 698 char pton[PTON_MAX]; 699 700 _DIAGASSERT(pai != NULL); 701 /* hostname may be NULL */ 702 /* servname may be NULL */ 703 _DIAGASSERT(res != NULL); 704 705 *res = NULL; 706 sentinel.ai_next = NULL; 707 cur = &sentinel; 708 709 /* 710 * if the servname does not match socktype/protocol, ignore it. 711 */ 712 if (get_portmatch(pai, servname) != 0) 713 return 0; 714 715 afd = find_afd(pai->ai_family); 716 if (afd == NULL) 717 return 0; 718 719 switch (afd->a_af) { 720 #if 0 /*X/Open spec*/ 721 case AF_INET: 722 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 723 if (pai->ai_family == afd->a_af || 724 pai->ai_family == PF_UNSPEC /*?*/) { 725 GET_AI(cur->ai_next, afd, pton); 726 GET_PORT(cur->ai_next, servname); 727 if ((pai->ai_flags & AI_CANONNAME)) { 728 /* 729 * Set the numeric address itself as 730 * the canonical name, based on a 731 * clarification in rfc2553bis-03. 732 */ 733 GET_CANONNAME(cur->ai_next, canonname); 734 } 735 while (cur && cur->ai_next) 736 cur = cur->ai_next; 737 } else 738 ERR(EAI_FAMILY); /*xxx*/ 739 } 740 break; 741 #endif 742 default: 743 if (inet_pton(afd->a_af, hostname, pton) == 1) { 744 if (pai->ai_family == afd->a_af || 745 pai->ai_family == PF_UNSPEC /*?*/) { 746 GET_AI(cur->ai_next, afd, pton); 747 GET_PORT(cur->ai_next, servname); 748 if ((pai->ai_flags & AI_CANONNAME)) { 749 /* 750 * Set the numeric address itself as 751 * the canonical name, based on a 752 * clarification in rfc2553bis-03. 753 */ 754 GET_CANONNAME(cur->ai_next, canonname); 755 } 756 while (cur && cur->ai_next) 757 cur = cur->ai_next; 758 } else 759 ERR(EAI_FAMILY); /*xxx*/ 760 } 761 break; 762 } 763 764 *res = sentinel.ai_next; 765 return 0; 766 767 free: 768 bad: 769 if (sentinel.ai_next) 770 freeaddrinfo(sentinel.ai_next); 771 return error; 772 } 773 774 /* 775 * numeric hostname with scope 776 */ 777 static int 778 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 779 const char *servname, struct addrinfo **res) 780 { 781 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 782 return explore_numeric(pai, hostname, servname, res, hostname); 783 #else 784 const struct afd *afd; 785 struct addrinfo *cur; 786 int error; 787 char *cp, *hostname2 = NULL, *scope, *addr; 788 struct sockaddr_in6 *sin6; 789 790 _DIAGASSERT(pai != NULL); 791 /* hostname may be NULL */ 792 /* servname may be NULL */ 793 _DIAGASSERT(res != NULL); 794 795 /* 796 * if the servname does not match socktype/protocol, ignore it. 797 */ 798 if (get_portmatch(pai, servname) != 0) 799 return 0; 800 801 afd = find_afd(pai->ai_family); 802 if (afd == NULL) 803 return 0; 804 805 if (!afd->a_scoped) 806 return explore_numeric(pai, hostname, servname, res, hostname); 807 808 cp = strchr(hostname, SCOPE_DELIMITER); 809 if (cp == NULL) 810 return explore_numeric(pai, hostname, servname, res, hostname); 811 812 /* 813 * Handle special case of <scoped_address><delimiter><scope id> 814 */ 815 hostname2 = strdup(hostname); 816 if (hostname2 == NULL) 817 return EAI_MEMORY; 818 /* terminate at the delimiter */ 819 hostname2[cp - hostname] = '\0'; 820 addr = hostname2; 821 scope = cp + 1; 822 823 error = explore_numeric(pai, addr, servname, res, hostname); 824 if (error == 0) { 825 u_int32_t scopeid; 826 827 for (cur = *res; cur; cur = cur->ai_next) { 828 if (cur->ai_family != AF_INET6) 829 continue; 830 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 831 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 832 free(hostname2); 833 return(EAI_NODATA); /* XXX: is return OK? */ 834 } 835 sin6->sin6_scope_id = scopeid; 836 } 837 } 838 839 free(hostname2); 840 841 return error; 842 #endif 843 } 844 845 static int 846 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 847 { 848 849 _DIAGASSERT(pai != NULL); 850 _DIAGASSERT(ai != NULL); 851 _DIAGASSERT(str != NULL); 852 853 if ((pai->ai_flags & AI_CANONNAME) != 0) { 854 ai->ai_canonname = strdup(str); 855 if (ai->ai_canonname == NULL) 856 return EAI_MEMORY; 857 } 858 return 0; 859 } 860 861 static struct addrinfo * 862 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 863 { 864 char *p; 865 struct addrinfo *ai; 866 867 _DIAGASSERT(pai != NULL); 868 _DIAGASSERT(afd != NULL); 869 _DIAGASSERT(addr != NULL); 870 871 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 872 + (afd->a_socklen)); 873 if (ai == NULL) 874 return NULL; 875 876 memcpy(ai, pai, sizeof(struct addrinfo)); 877 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 878 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 879 ai->ai_addr->sa_len = afd->a_socklen; 880 ai->ai_addrlen = afd->a_socklen; 881 #if defined (__alpha__) || (defined(__i386__) && defined(_LP64)) || defined(__sparc64__) 882 ai->__ai_pad0 = 0; 883 #endif 884 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 885 p = (char *)(void *)(ai->ai_addr); 886 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 887 return ai; 888 } 889 890 static int 891 get_portmatch(const struct addrinfo *ai, const char *servname) 892 { 893 894 _DIAGASSERT(ai != NULL); 895 /* servname may be NULL */ 896 897 return get_port(ai, servname, 1); 898 } 899 900 static int 901 get_port(const struct addrinfo *ai, const char *servname, int matchonly) 902 { 903 const char *proto; 904 struct servent *sp; 905 int port; 906 int allownumeric; 907 908 _DIAGASSERT(ai != NULL); 909 /* servname may be NULL */ 910 911 if (servname == NULL) 912 return 0; 913 switch (ai->ai_family) { 914 case AF_INET: 915 #ifdef AF_INET6 916 case AF_INET6: 917 #endif 918 break; 919 default: 920 return 0; 921 } 922 923 switch (ai->ai_socktype) { 924 case SOCK_RAW: 925 return EAI_SERVICE; 926 case SOCK_DGRAM: 927 case SOCK_STREAM: 928 allownumeric = 1; 929 break; 930 case ANY: 931 allownumeric = 0; 932 break; 933 default: 934 return EAI_SOCKTYPE; 935 } 936 937 port = str2number(servname); 938 if (port >= 0) { 939 if (!allownumeric) 940 return EAI_SERVICE; 941 if (port < 0 || port > 65535) 942 return EAI_SERVICE; 943 port = htons(port); 944 } else { 945 if (ai->ai_flags & AI_NUMERICSERV) 946 return EAI_NONAME; 947 948 switch (ai->ai_socktype) { 949 case SOCK_DGRAM: 950 proto = "udp"; 951 break; 952 case SOCK_STREAM: 953 proto = "tcp"; 954 break; 955 default: 956 proto = NULL; 957 break; 958 } 959 960 if ((sp = getservbyname(servname, proto)) == NULL) 961 return EAI_SERVICE; 962 port = sp->s_port; 963 } 964 965 if (!matchonly) { 966 switch (ai->ai_family) { 967 case AF_INET: 968 ((struct sockaddr_in *)(void *) 969 ai->ai_addr)->sin_port = port; 970 break; 971 #ifdef INET6 972 case AF_INET6: 973 ((struct sockaddr_in6 *)(void *) 974 ai->ai_addr)->sin6_port = port; 975 break; 976 #endif 977 } 978 } 979 980 return 0; 981 } 982 983 static const struct afd * 984 find_afd(int af) 985 { 986 const struct afd *afd; 987 988 if (af == PF_UNSPEC) 989 return NULL; 990 for (afd = afdl; afd->a_af; afd++) { 991 if (afd->a_af == af) 992 return afd; 993 } 994 return NULL; 995 } 996 997 #ifdef INET6 998 /* convert a string to a scope identifier. XXX: IPv6 specific */ 999 static int 1000 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1001 { 1002 u_long lscopeid; 1003 struct in6_addr *a6; 1004 char *ep; 1005 1006 _DIAGASSERT(scope != NULL); 1007 _DIAGASSERT(sin6 != NULL); 1008 _DIAGASSERT(scopeid != NULL); 1009 1010 a6 = &sin6->sin6_addr; 1011 1012 /* empty scopeid portion is invalid */ 1013 if (*scope == '\0') 1014 return -1; 1015 1016 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1017 /* 1018 * We currently assume a one-to-one mapping between links 1019 * and interfaces, so we simply use interface indices for 1020 * like-local scopes. 1021 */ 1022 *scopeid = if_nametoindex(scope); 1023 if (*scopeid == 0) 1024 goto trynumeric; 1025 return 0; 1026 } 1027 1028 /* still unclear about literal, allow numeric only - placeholder */ 1029 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1030 goto trynumeric; 1031 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1032 goto trynumeric; 1033 else 1034 goto trynumeric; /* global */ 1035 1036 /* try to convert to a numeric id as a last resort */ 1037 trynumeric: 1038 errno = 0; 1039 lscopeid = strtoul(scope, &ep, 10); 1040 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1041 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1042 return 0; 1043 else 1044 return -1; 1045 } 1046 #endif 1047 1048 /* code duplicate with gethnamaddr.c */ 1049 1050 static const char AskedForGot[] = 1051 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1052 1053 static struct addrinfo * 1054 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1055 const struct addrinfo *pai) 1056 { 1057 struct addrinfo sentinel, *cur; 1058 struct addrinfo ai; 1059 const struct afd *afd; 1060 char *canonname; 1061 const HEADER *hp; 1062 const u_char *cp; 1063 int n; 1064 const u_char *eom; 1065 char *bp, *ep; 1066 int type, class, ancount, qdcount; 1067 int haveanswer, had_error; 1068 char tbuf[MAXDNAME]; 1069 int (*name_ok) (const char *); 1070 char hostbuf[8*1024]; 1071 1072 _DIAGASSERT(answer != NULL); 1073 _DIAGASSERT(qname != NULL); 1074 _DIAGASSERT(pai != NULL); 1075 1076 memset(&sentinel, 0, sizeof(sentinel)); 1077 cur = &sentinel; 1078 1079 canonname = NULL; 1080 eom = answer->buf + anslen; 1081 switch (qtype) { 1082 case T_A: 1083 case T_AAAA: 1084 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1085 name_ok = res_hnok; 1086 break; 1087 default: 1088 return NULL; /* XXX should be abort(); */ 1089 } 1090 /* 1091 * find first satisfactory answer 1092 */ 1093 hp = &answer->hdr; 1094 ancount = ntohs(hp->ancount); 1095 qdcount = ntohs(hp->qdcount); 1096 bp = hostbuf; 1097 ep = hostbuf + sizeof hostbuf; 1098 cp = answer->buf + HFIXEDSZ; 1099 if (qdcount != 1) { 1100 h_errno = NO_RECOVERY; 1101 return (NULL); 1102 } 1103 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1104 if ((n < 0) || !(*name_ok)(bp)) { 1105 h_errno = NO_RECOVERY; 1106 return (NULL); 1107 } 1108 cp += n + QFIXEDSZ; 1109 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1110 /* res_send() has already verified that the query name is the 1111 * same as the one we sent; this just gets the expanded name 1112 * (i.e., with the succeeding search-domain tacked on). 1113 */ 1114 n = strlen(bp) + 1; /* for the \0 */ 1115 if (n >= MAXHOSTNAMELEN) { 1116 h_errno = NO_RECOVERY; 1117 return (NULL); 1118 } 1119 canonname = bp; 1120 bp += n; 1121 /* The qname can be abbreviated, but h_name is now absolute. */ 1122 qname = canonname; 1123 } 1124 haveanswer = 0; 1125 had_error = 0; 1126 while (ancount-- > 0 && cp < eom && !had_error) { 1127 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1128 if ((n < 0) || !(*name_ok)(bp)) { 1129 had_error++; 1130 continue; 1131 } 1132 cp += n; /* name */ 1133 type = _getshort(cp); 1134 cp += INT16SZ; /* type */ 1135 class = _getshort(cp); 1136 cp += INT16SZ + INT32SZ; /* class, TTL */ 1137 n = _getshort(cp); 1138 cp += INT16SZ; /* len */ 1139 if (class != C_IN) { 1140 /* XXX - debug? syslog? */ 1141 cp += n; 1142 continue; /* XXX - had_error++ ? */ 1143 } 1144 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1145 type == T_CNAME) { 1146 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1147 if ((n < 0) || !(*name_ok)(tbuf)) { 1148 had_error++; 1149 continue; 1150 } 1151 cp += n; 1152 /* Get canonical name. */ 1153 n = strlen(tbuf) + 1; /* for the \0 */ 1154 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1155 had_error++; 1156 continue; 1157 } 1158 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1159 canonname = bp; 1160 bp += n; 1161 continue; 1162 } 1163 if (qtype == T_ANY) { 1164 if (!(type == T_A || type == T_AAAA)) { 1165 cp += n; 1166 continue; 1167 } 1168 } else if (type != qtype) { 1169 if (type != T_KEY && type != T_SIG) 1170 syslog(LOG_NOTICE|LOG_AUTH, 1171 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1172 qname, p_class(C_IN), p_type(qtype), 1173 p_type(type)); 1174 cp += n; 1175 continue; /* XXX - had_error++ ? */ 1176 } 1177 switch (type) { 1178 case T_A: 1179 case T_AAAA: 1180 if (strcasecmp(canonname, bp) != 0) { 1181 syslog(LOG_NOTICE|LOG_AUTH, 1182 AskedForGot, canonname, bp); 1183 cp += n; 1184 continue; /* XXX - had_error++ ? */ 1185 } 1186 if (type == T_A && n != INADDRSZ) { 1187 cp += n; 1188 continue; 1189 } 1190 if (type == T_AAAA && n != IN6ADDRSZ) { 1191 cp += n; 1192 continue; 1193 } 1194 if (type == T_AAAA) { 1195 struct in6_addr in6; 1196 memcpy(&in6, cp, IN6ADDRSZ); 1197 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1198 cp += n; 1199 continue; 1200 } 1201 } 1202 if (!haveanswer) { 1203 int nn; 1204 1205 canonname = bp; 1206 nn = strlen(bp) + 1; /* for the \0 */ 1207 bp += nn; 1208 } 1209 1210 /* don't overwrite pai */ 1211 ai = *pai; 1212 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1213 afd = find_afd(ai.ai_family); 1214 if (afd == NULL) { 1215 cp += n; 1216 continue; 1217 } 1218 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1219 if (cur->ai_next == NULL) 1220 had_error++; 1221 while (cur && cur->ai_next) 1222 cur = cur->ai_next; 1223 cp += n; 1224 break; 1225 default: 1226 abort(); 1227 } 1228 if (!had_error) 1229 haveanswer++; 1230 } 1231 if (haveanswer) { 1232 if (!canonname) 1233 (void)get_canonname(pai, sentinel.ai_next, qname); 1234 else 1235 (void)get_canonname(pai, sentinel.ai_next, canonname); 1236 h_errno = NETDB_SUCCESS; 1237 return sentinel.ai_next; 1238 } 1239 1240 h_errno = NO_RECOVERY; 1241 return NULL; 1242 } 1243 1244 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr) 1245 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr) 1246 1247 static void 1248 aisort(struct addrinfo *s, res_state res) 1249 { 1250 struct addrinfo head, *t, *p; 1251 int i; 1252 1253 head.ai_next = NULL; 1254 t = &head; 1255 1256 for (i = 0; i < res->nsort; i++) { 1257 p = s; 1258 while (p->ai_next) { 1259 if ((p->ai_next->ai_family != AF_INET) 1260 || SORTMATCH(p, res->sort_list[i])) { 1261 t->ai_next = p->ai_next; 1262 t = t->ai_next; 1263 p->ai_next = p->ai_next->ai_next; 1264 } else { 1265 p = p->ai_next; 1266 } 1267 } 1268 } 1269 1270 /* add rest of list and reset s to the new list*/ 1271 t->ai_next = s->ai_next; 1272 s->ai_next = head.ai_next; 1273 } 1274 1275 /*ARGSUSED*/ 1276 static int 1277 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1278 { 1279 struct addrinfo *ai; 1280 querybuf *buf, *buf2; 1281 const char *name; 1282 const struct addrinfo *pai; 1283 struct addrinfo sentinel, *cur; 1284 struct res_target q, q2; 1285 res_state res; 1286 1287 name = va_arg(ap, char *); 1288 pai = va_arg(ap, const struct addrinfo *); 1289 1290 memset(&q, 0, sizeof(q2)); 1291 memset(&q2, 0, sizeof(q2)); 1292 memset(&sentinel, 0, sizeof(sentinel)); 1293 cur = &sentinel; 1294 1295 buf = malloc(sizeof(*buf)); 1296 if (buf == NULL) { 1297 h_errno = NETDB_INTERNAL; 1298 return NS_NOTFOUND; 1299 } 1300 buf2 = malloc(sizeof(*buf2)); 1301 if (buf2 == NULL) { 1302 free(buf); 1303 h_errno = NETDB_INTERNAL; 1304 return NS_NOTFOUND; 1305 } 1306 1307 switch (pai->ai_family) { 1308 case AF_UNSPEC: 1309 /* prefer IPv6 */ 1310 q.name = name; 1311 q.qclass = C_IN; 1312 q.qtype = T_AAAA; 1313 q.answer = buf->buf; 1314 q.anslen = sizeof(buf->buf); 1315 q.next = &q2; 1316 q2.name = name; 1317 q2.qclass = C_IN; 1318 q2.qtype = T_A; 1319 q2.answer = buf2->buf; 1320 q2.anslen = sizeof(buf2->buf); 1321 break; 1322 case AF_INET: 1323 q.name = name; 1324 q.qclass = C_IN; 1325 q.qtype = T_A; 1326 q.answer = buf->buf; 1327 q.anslen = sizeof(buf->buf); 1328 break; 1329 case AF_INET6: 1330 q.name = name; 1331 q.qclass = C_IN; 1332 q.qtype = T_AAAA; 1333 q.answer = buf->buf; 1334 q.anslen = sizeof(buf->buf); 1335 break; 1336 default: 1337 free(buf); 1338 free(buf2); 1339 return NS_UNAVAIL; 1340 } 1341 1342 res = __res_get_state(); 1343 if (res == NULL) { 1344 free(buf); 1345 free(buf2); 1346 return NS_NOTFOUND; 1347 } 1348 1349 if (res_searchN(name, &q, res) < 0) { 1350 __res_put_state(res); 1351 free(buf); 1352 free(buf2); 1353 return NS_NOTFOUND; 1354 } 1355 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1356 if (ai) { 1357 cur->ai_next = ai; 1358 while (cur && cur->ai_next) 1359 cur = cur->ai_next; 1360 } 1361 if (q.next) { 1362 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1363 if (ai) 1364 cur->ai_next = ai; 1365 } 1366 free(buf); 1367 free(buf2); 1368 if (sentinel.ai_next == NULL) { 1369 __res_put_state(res); 1370 switch (h_errno) { 1371 case HOST_NOT_FOUND: 1372 return NS_NOTFOUND; 1373 case TRY_AGAIN: 1374 return NS_TRYAGAIN; 1375 default: 1376 return NS_UNAVAIL; 1377 } 1378 } 1379 1380 if (res->nsort) 1381 aisort(&sentinel, res); 1382 1383 __res_put_state(res); 1384 1385 *((struct addrinfo **)rv) = sentinel.ai_next; 1386 return NS_SUCCESS; 1387 } 1388 1389 static void 1390 _sethtent(FILE **hostf) 1391 { 1392 1393 if (!*hostf) 1394 *hostf = fopen(_PATH_HOSTS, "r" ); 1395 else 1396 rewind(*hostf); 1397 } 1398 1399 static void 1400 _endhtent(FILE **hostf) 1401 { 1402 1403 if (*hostf) { 1404 (void) fclose(*hostf); 1405 *hostf = NULL; 1406 } 1407 } 1408 1409 static struct addrinfo * 1410 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1411 { 1412 char *p; 1413 char *cp, *tname, *cname; 1414 struct addrinfo hints, *res0, *res; 1415 int error; 1416 const char *addr; 1417 char hostbuf[8*1024]; 1418 1419 _DIAGASSERT(name != NULL); 1420 _DIAGASSERT(pai != NULL); 1421 1422 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r" ))) 1423 return (NULL); 1424 again: 1425 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 1426 return (NULL); 1427 if (*p == '#') 1428 goto again; 1429 if (!(cp = strpbrk(p, "#\n"))) 1430 goto again; 1431 *cp = '\0'; 1432 if (!(cp = strpbrk(p, " \t"))) 1433 goto again; 1434 *cp++ = '\0'; 1435 addr = p; 1436 /* if this is not something we're looking for, skip it. */ 1437 cname = NULL; 1438 while (cp && *cp) { 1439 if (*cp == ' ' || *cp == '\t') { 1440 cp++; 1441 continue; 1442 } 1443 if (!cname) 1444 cname = cp; 1445 tname = cp; 1446 if ((cp = strpbrk(cp, " \t")) != NULL) 1447 *cp++ = '\0'; 1448 if (strcasecmp(name, tname) == 0) 1449 goto found; 1450 } 1451 goto again; 1452 1453 found: 1454 hints = *pai; 1455 hints.ai_flags = AI_NUMERICHOST; 1456 error = getaddrinfo(addr, NULL, &hints, &res0); 1457 if (error) 1458 goto again; 1459 for (res = res0; res; res = res->ai_next) { 1460 /* cover it up */ 1461 res->ai_flags = pai->ai_flags; 1462 1463 if (pai->ai_flags & AI_CANONNAME) { 1464 if (get_canonname(pai, res, cname) != 0) { 1465 freeaddrinfo(res0); 1466 goto again; 1467 } 1468 } 1469 } 1470 return res0; 1471 } 1472 1473 /*ARGSUSED*/ 1474 static int 1475 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1476 { 1477 const char *name; 1478 const struct addrinfo *pai; 1479 struct addrinfo sentinel, *cur; 1480 struct addrinfo *p; 1481 #ifndef _REENTRANT 1482 static 1483 #endif 1484 FILE *hostf = NULL; 1485 1486 name = va_arg(ap, char *); 1487 pai = va_arg(ap, struct addrinfo *); 1488 1489 memset(&sentinel, 0, sizeof(sentinel)); 1490 cur = &sentinel; 1491 1492 _sethtent(&hostf); 1493 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1494 cur->ai_next = p; 1495 while (cur && cur->ai_next) 1496 cur = cur->ai_next; 1497 } 1498 _endhtent(&hostf); 1499 1500 *((struct addrinfo **)rv) = sentinel.ai_next; 1501 if (sentinel.ai_next == NULL) 1502 return NS_NOTFOUND; 1503 return NS_SUCCESS; 1504 } 1505 1506 #ifdef YP 1507 /*ARGSUSED*/ 1508 static struct addrinfo * 1509 _yphostent(char *line, const struct addrinfo *pai) 1510 { 1511 struct addrinfo sentinel, *cur; 1512 struct addrinfo hints, *res, *res0; 1513 int error; 1514 char *p; 1515 const char *addr, *canonname; 1516 char *nextline; 1517 char *cp; 1518 1519 _DIAGASSERT(line != NULL); 1520 _DIAGASSERT(pai != NULL); 1521 1522 p = line; 1523 addr = canonname = NULL; 1524 1525 memset(&sentinel, 0, sizeof(sentinel)); 1526 cur = &sentinel; 1527 1528 nextline: 1529 /* terminate line */ 1530 cp = strchr(p, '\n'); 1531 if (cp) { 1532 *cp++ = '\0'; 1533 nextline = cp; 1534 } else 1535 nextline = NULL; 1536 1537 cp = strpbrk(p, " \t"); 1538 if (cp == NULL) { 1539 if (canonname == NULL) 1540 return (NULL); 1541 else 1542 goto done; 1543 } 1544 *cp++ = '\0'; 1545 1546 addr = p; 1547 1548 while (cp && *cp) { 1549 if (*cp == ' ' || *cp == '\t') { 1550 cp++; 1551 continue; 1552 } 1553 if (!canonname) 1554 canonname = cp; 1555 if ((cp = strpbrk(cp, " \t")) != NULL) 1556 *cp++ = '\0'; 1557 } 1558 1559 hints = *pai; 1560 hints.ai_flags = AI_NUMERICHOST; 1561 error = getaddrinfo(addr, NULL, &hints, &res0); 1562 if (error == 0) { 1563 for (res = res0; res; res = res->ai_next) { 1564 /* cover it up */ 1565 res->ai_flags = pai->ai_flags; 1566 1567 if (pai->ai_flags & AI_CANONNAME) 1568 (void)get_canonname(pai, res, canonname); 1569 } 1570 } else 1571 res0 = NULL; 1572 if (res0) { 1573 cur->ai_next = res0; 1574 while (cur && cur->ai_next) 1575 cur = cur->ai_next; 1576 } 1577 1578 if (nextline) { 1579 p = nextline; 1580 goto nextline; 1581 } 1582 1583 done: 1584 return sentinel.ai_next; 1585 } 1586 1587 /*ARGSUSED*/ 1588 static int 1589 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1590 { 1591 struct addrinfo sentinel, *cur; 1592 struct addrinfo *ai = NULL; 1593 char *ypbuf; 1594 int ypbuflen, r; 1595 const char *name; 1596 const struct addrinfo *pai; 1597 char *ypdomain; 1598 1599 if (_yp_check(&ypdomain) == 0) 1600 return NS_UNAVAIL; 1601 1602 name = va_arg(ap, char *); 1603 pai = va_arg(ap, const struct addrinfo *); 1604 1605 memset(&sentinel, 0, sizeof(sentinel)); 1606 cur = &sentinel; 1607 1608 /* hosts.byname is only for IPv4 (Solaris8) */ 1609 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1610 r = yp_match(ypdomain, "hosts.byname", name, 1611 (int)strlen(name), &ypbuf, &ypbuflen); 1612 if (r == 0) { 1613 struct addrinfo ai4; 1614 1615 ai4 = *pai; 1616 ai4.ai_family = AF_INET; 1617 ai = _yphostent(ypbuf, &ai4); 1618 if (ai) { 1619 cur->ai_next = ai; 1620 while (cur && cur->ai_next) 1621 cur = cur->ai_next; 1622 } 1623 } 1624 free(ypbuf); 1625 } 1626 1627 /* ipnodes.byname can hold both IPv4/v6 */ 1628 r = yp_match(ypdomain, "ipnodes.byname", name, 1629 (int)strlen(name), &ypbuf, &ypbuflen); 1630 if (r == 0) { 1631 ai = _yphostent(ypbuf, pai); 1632 if (ai) 1633 cur->ai_next = ai; 1634 free(ypbuf); 1635 } 1636 1637 if (sentinel.ai_next == NULL) { 1638 h_errno = HOST_NOT_FOUND; 1639 return NS_NOTFOUND; 1640 } 1641 *((struct addrinfo **)rv) = sentinel.ai_next; 1642 return NS_SUCCESS; 1643 } 1644 #endif 1645 1646 /* resolver logic */ 1647 1648 /* 1649 * Formulate a normal query, send, and await answer. 1650 * Returned answer is placed in supplied buffer "answer". 1651 * Perform preliminary check of answer, returning success only 1652 * if no error is indicated and the answer count is nonzero. 1653 * Return the size of the response on success, -1 on error. 1654 * Error number is left in h_errno. 1655 * 1656 * Caller must parse answer and determine whether it answers the question. 1657 */ 1658 static int 1659 res_queryN(const char *name, /* domain name */ struct res_target *target, 1660 res_state res) 1661 { 1662 u_char buf[MAXPACKET]; 1663 HEADER *hp; 1664 int n; 1665 struct res_target *t; 1666 int rcode; 1667 int ancount; 1668 1669 _DIAGASSERT(name != NULL); 1670 /* XXX: target may be NULL??? */ 1671 1672 rcode = NOERROR; 1673 ancount = 0; 1674 1675 for (t = target; t; t = t->next) { 1676 int class, type; 1677 u_char *answer; 1678 int anslen; 1679 1680 hp = (HEADER *)(void *)t->answer; 1681 hp->rcode = NOERROR; /* default */ 1682 1683 /* make it easier... */ 1684 class = t->qclass; 1685 type = t->qtype; 1686 answer = t->answer; 1687 anslen = t->anslen; 1688 #ifdef DEBUG 1689 if (res->options & RES_DEBUG) 1690 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 1691 #endif 1692 1693 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 1694 buf, sizeof(buf)); 1695 #ifdef RES_USE_EDNS0 1696 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 1697 n = res_nopt(res, n, buf, sizeof(buf), anslen); 1698 #endif 1699 if (n <= 0) { 1700 #ifdef DEBUG 1701 if (res->options & RES_DEBUG) 1702 printf(";; res_nquery: mkquery failed\n"); 1703 #endif 1704 h_errno = NO_RECOVERY; 1705 return n; 1706 } 1707 n = res_nsend(res, buf, n, answer, anslen); 1708 #if 0 1709 if (n < 0) { 1710 #ifdef DEBUG 1711 if (res->options & RES_DEBUG) 1712 printf(";; res_query: send error\n"); 1713 #endif 1714 h_errno = TRY_AGAIN; 1715 return n; 1716 } 1717 #endif 1718 1719 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1720 rcode = hp->rcode; /* record most recent error */ 1721 #ifdef DEBUG 1722 if (res->options & RES_DEBUG) 1723 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1724 ntohs(hp->ancount)); 1725 #endif 1726 continue; 1727 } 1728 1729 ancount += ntohs(hp->ancount); 1730 1731 t->n = n; 1732 } 1733 1734 if (ancount == 0) { 1735 switch (rcode) { 1736 case NXDOMAIN: 1737 h_errno = HOST_NOT_FOUND; 1738 break; 1739 case SERVFAIL: 1740 h_errno = TRY_AGAIN; 1741 break; 1742 case NOERROR: 1743 h_errno = NO_DATA; 1744 break; 1745 case FORMERR: 1746 case NOTIMP: 1747 case REFUSED: 1748 default: 1749 h_errno = NO_RECOVERY; 1750 break; 1751 } 1752 return -1; 1753 } 1754 return ancount; 1755 } 1756 1757 /* 1758 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1759 * Return the size of the response on success, -1 on error. 1760 * If enabled, implement search rules until answer or unrecoverable failure 1761 * is detected. Error code, if any, is left in h_errno. 1762 */ 1763 static int 1764 res_searchN(const char *name, struct res_target *target, res_state res) 1765 { 1766 const char *cp, * const *domain; 1767 HEADER *hp; 1768 u_int dots; 1769 int trailing_dot, ret, saved_herrno; 1770 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1771 1772 _DIAGASSERT(name != NULL); 1773 _DIAGASSERT(target != NULL); 1774 1775 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1776 1777 errno = 0; 1778 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1779 dots = 0; 1780 for (cp = name; *cp; cp++) 1781 dots += (*cp == '.'); 1782 trailing_dot = 0; 1783 if (cp > name && *--cp == '.') 1784 trailing_dot++; 1785 1786 /* 1787 * if there aren't any dots, it could be a user-level alias 1788 */ 1789 if (!dots && (cp = __hostalias(name)) != NULL) { 1790 ret = res_queryN(cp, target, res); 1791 return ret; 1792 } 1793 1794 /* 1795 * If there are dots in the name already, let's just give it a try 1796 * 'as is'. The threshold can be set with the "ndots" option. 1797 */ 1798 saved_herrno = -1; 1799 if (dots >= res->ndots) { 1800 ret = res_querydomainN(name, NULL, target, res); 1801 if (ret > 0) 1802 return (ret); 1803 saved_herrno = h_errno; 1804 tried_as_is++; 1805 } 1806 1807 /* 1808 * We do at least one level of search if 1809 * - there is no dot and RES_DEFNAME is set, or 1810 * - there is at least one dot, there is no trailing dot, 1811 * and RES_DNSRCH is set. 1812 */ 1813 if ((!dots && (res->options & RES_DEFNAMES)) || 1814 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 1815 int done = 0; 1816 1817 for (domain = (const char * const *)res->dnsrch; 1818 *domain && !done; 1819 domain++) { 1820 1821 ret = res_querydomainN(name, *domain, target, res); 1822 if (ret > 0) 1823 return ret; 1824 1825 /* 1826 * If no server present, give up. 1827 * If name isn't found in this domain, 1828 * keep trying higher domains in the search list 1829 * (if that's enabled). 1830 * On a NO_DATA error, keep trying, otherwise 1831 * a wildcard entry of another type could keep us 1832 * from finding this entry higher in the domain. 1833 * If we get some other error (negative answer or 1834 * server failure), then stop searching up, 1835 * but try the input name below in case it's 1836 * fully-qualified. 1837 */ 1838 if (errno == ECONNREFUSED) { 1839 h_errno = TRY_AGAIN; 1840 return -1; 1841 } 1842 1843 switch (h_errno) { 1844 case NO_DATA: 1845 got_nodata++; 1846 /* FALLTHROUGH */ 1847 case HOST_NOT_FOUND: 1848 /* keep trying */ 1849 break; 1850 case TRY_AGAIN: 1851 if (hp->rcode == SERVFAIL) { 1852 /* try next search element, if any */ 1853 got_servfail++; 1854 break; 1855 } 1856 /* FALLTHROUGH */ 1857 default: 1858 /* anything else implies that we're done */ 1859 done++; 1860 } 1861 /* 1862 * if we got here for some reason other than DNSRCH, 1863 * we only wanted one iteration of the loop, so stop. 1864 */ 1865 if (!(res->options & RES_DNSRCH)) 1866 done++; 1867 } 1868 } 1869 1870 /* 1871 * if we have not already tried the name "as is", do that now. 1872 * note that we do this regardless of how many dots were in the 1873 * name or whether it ends with a dot. 1874 */ 1875 if (!tried_as_is) { 1876 ret = res_querydomainN(name, NULL, target, res); 1877 if (ret > 0) 1878 return ret; 1879 } 1880 1881 /* 1882 * if we got here, we didn't satisfy the search. 1883 * if we did an initial full query, return that query's h_errno 1884 * (note that we wouldn't be here if that query had succeeded). 1885 * else if we ever got a nodata, send that back as the reason. 1886 * else send back meaningless h_errno, that being the one from 1887 * the last DNSRCH we did. 1888 */ 1889 if (saved_herrno != -1) 1890 h_errno = saved_herrno; 1891 else if (got_nodata) 1892 h_errno = NO_DATA; 1893 else if (got_servfail) 1894 h_errno = TRY_AGAIN; 1895 return -1; 1896 } 1897 1898 /* 1899 * Perform a call on res_query on the concatenation of name and domain, 1900 * removing a trailing dot from name if domain is NULL. 1901 */ 1902 static int 1903 res_querydomainN(const char *name, const char *domain, 1904 struct res_target *target, res_state res) 1905 { 1906 char nbuf[MAXDNAME]; 1907 const char *longname = nbuf; 1908 size_t n, d; 1909 1910 _DIAGASSERT(name != NULL); 1911 /* XXX: target may be NULL??? */ 1912 1913 #ifdef DEBUG 1914 if (res->options & RES_DEBUG) 1915 printf(";; res_querydomain(%s, %s)\n", 1916 name, domain?domain:"<Nil>"); 1917 #endif 1918 if (domain == NULL) { 1919 /* 1920 * Check for trailing '.'; 1921 * copy without '.' if present. 1922 */ 1923 n = strlen(name); 1924 if (n + 1 > sizeof(nbuf)) { 1925 h_errno = NO_RECOVERY; 1926 return -1; 1927 } 1928 if (n > 0 && name[--n] == '.') { 1929 strncpy(nbuf, name, n); 1930 nbuf[n] = '\0'; 1931 } else 1932 longname = name; 1933 } else { 1934 n = strlen(name); 1935 d = strlen(domain); 1936 if (n + 1 + d + 1 > sizeof(nbuf)) { 1937 h_errno = NO_RECOVERY; 1938 return -1; 1939 } 1940 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1941 } 1942 return res_queryN(longname, target, res); 1943 } 1944