1 /* $NetBSD: getaddrinfo.c,v 1.85 2006/07/19 13:16:12 christos 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 * - Return values. There are nonstandard return values defined and used 36 * in the source code. This is because RFC2553 is silent about which error 37 * code must be returned for which situation. 38 * - IPv4 classful (shortened) form. RFC2553 is silent about it. XNET 5.2 39 * says to use inet_aton() to convert IPv4 numeric to binary (alows 40 * classful form as a result). 41 * current code - disallow classful form for IPv4 (due to use of inet_pton). 42 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 43 * invalid. 44 * current code - SEGV on freeaddrinfo(NULL) 45 * Note: 46 * - The code filters out AFs that are not supported by the kernel, 47 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 48 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 49 * in ai_flags? 50 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 51 * (1) what should we do against numeric hostname (2) what should we do 52 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 53 * non-loopback address configured? global address configured? 54 */ 55 56 #include <sys/cdefs.h> 57 #if defined(LIBC_SCCS) && !defined(lint) 58 __RCSID("$NetBSD: getaddrinfo.c,v 1.85 2006/07/19 13:16:12 christos Exp $"); 59 #endif /* LIBC_SCCS and not lint */ 60 61 #include "namespace.h" 62 #include <sys/types.h> 63 #include <sys/param.h> 64 #include <sys/socket.h> 65 #include <net/if.h> 66 #include <netinet/in.h> 67 #include <arpa/inet.h> 68 #include <arpa/nameser.h> 69 #include <assert.h> 70 #include <ctype.h> 71 #include <errno.h> 72 #include <netdb.h> 73 #include <resolv.h> 74 #include <stddef.h> 75 #include <stdio.h> 76 #include <stdlib.h> 77 #include <string.h> 78 #include <unistd.h> 79 80 #include <syslog.h> 81 #include <stdarg.h> 82 #include <nsswitch.h> 83 84 #ifdef YP 85 #include <rpc/rpc.h> 86 #include <rpcsvc/yp_prot.h> 87 #include <rpcsvc/ypclnt.h> 88 #endif 89 90 #include "servent.h" 91 92 #ifdef __weak_alias 93 __weak_alias(getaddrinfo,_getaddrinfo) 94 __weak_alias(freeaddrinfo,_freeaddrinfo) 95 __weak_alias(gai_strerror,_gai_strerror) 96 #endif 97 98 #define SUCCESS 0 99 #define ANY 0 100 #define YES 1 101 #define NO 0 102 103 static const char in_addrany[] = { 0, 0, 0, 0 }; 104 static const char in_loopback[] = { 127, 0, 0, 1 }; 105 #ifdef INET6 106 static const char in6_addrany[] = { 107 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 108 }; 109 static const char in6_loopback[] = { 110 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 111 }; 112 #endif 113 114 static const struct afd { 115 int a_af; 116 int a_addrlen; 117 int a_socklen; 118 int a_off; 119 const char *a_addrany; 120 const char *a_loopback; 121 int a_scoped; 122 } afdl [] = { 123 #ifdef INET6 124 {PF_INET6, sizeof(struct in6_addr), 125 sizeof(struct sockaddr_in6), 126 offsetof(struct sockaddr_in6, sin6_addr), 127 in6_addrany, in6_loopback, 1}, 128 #endif 129 {PF_INET, sizeof(struct in_addr), 130 sizeof(struct sockaddr_in), 131 offsetof(struct sockaddr_in, sin_addr), 132 in_addrany, in_loopback, 0}, 133 {0, 0, 0, 0, NULL, NULL, 0}, 134 }; 135 136 struct explore { 137 int e_af; 138 int e_socktype; 139 int e_protocol; 140 const char *e_protostr; 141 int e_wild; 142 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 143 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 144 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 145 }; 146 147 static const struct explore explore[] = { 148 #if 0 149 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 150 #endif 151 #ifdef INET6 152 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 153 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 154 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 155 #endif 156 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 157 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 158 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 159 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 160 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 161 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 162 { -1, 0, 0, NULL, 0 }, 163 }; 164 165 #ifdef INET6 166 #define PTON_MAX 16 167 #else 168 #define PTON_MAX 4 169 #endif 170 171 static const ns_src default_dns_files[] = { 172 { NSSRC_FILES, NS_SUCCESS }, 173 { NSSRC_DNS, NS_SUCCESS }, 174 { 0 } 175 }; 176 177 #define MAXPACKET (64*1024) 178 179 typedef union { 180 HEADER hdr; 181 u_char buf[MAXPACKET]; 182 } querybuf; 183 184 struct res_target { 185 struct res_target *next; 186 const char *name; /* domain name */ 187 int qclass, qtype; /* class and type of query */ 188 u_char *answer; /* buffer to put answer */ 189 int anslen; /* size of answer buffer */ 190 int n; /* result length */ 191 }; 192 193 static int str2number(const char *); 194 static int explore_fqdn(const struct addrinfo *, const char *, 195 const char *, struct addrinfo **); 196 static int explore_null(const struct addrinfo *, 197 const char *, struct addrinfo **); 198 static int explore_numeric(const struct addrinfo *, const char *, 199 const char *, struct addrinfo **, const char *); 200 static int explore_numeric_scope(const struct addrinfo *, const char *, 201 const char *, struct addrinfo **); 202 static int get_canonname(const struct addrinfo *, 203 struct addrinfo *, const char *); 204 static struct addrinfo *get_ai(const struct addrinfo *, 205 const struct afd *, const char *); 206 static int get_portmatch(const struct addrinfo *, const char *); 207 static int get_port(const struct addrinfo *, const char *, int); 208 static const struct afd *find_afd(int); 209 #ifdef INET6 210 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 211 #endif 212 213 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 214 const struct addrinfo *); 215 static void aisort(struct addrinfo *s, res_state res); 216 static int _dns_getaddrinfo(void *, void *, va_list); 217 static void _sethtent(FILE **); 218 static void _endhtent(FILE **); 219 static struct addrinfo *_gethtent(FILE **, const char *, 220 const struct addrinfo *); 221 static int _files_getaddrinfo(void *, void *, va_list); 222 #ifdef YP 223 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 224 static int _yp_getaddrinfo(void *, void *, va_list); 225 #endif 226 227 static int res_queryN(const char *, struct res_target *, res_state); 228 static int res_searchN(const char *, struct res_target *, res_state); 229 static int res_querydomainN(const char *, const char *, 230 struct res_target *, res_state); 231 232 static const char * const ai_errlist[] = { 233 "Success", 234 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 235 "Temporary failure in name resolution", /* EAI_AGAIN */ 236 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 237 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 238 "ai_family not supported", /* EAI_FAMILY */ 239 "Memory allocation failure", /* EAI_MEMORY */ 240 "No address associated with hostname", /* EAI_NODATA */ 241 "hostname nor servname provided, or not known", /* EAI_NONAME */ 242 "servname not supported for ai_socktype", /* EAI_SERVICE */ 243 "ai_socktype not supported", /* EAI_SOCKTYPE */ 244 "System error returned in errno", /* EAI_SYSTEM */ 245 "Invalid value for hints", /* EAI_BADHINTS */ 246 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 247 "Argument buffer overflow", /* EAI_OVERFLOW */ 248 "Unknown error", /* EAI_MAX */ 249 }; 250 251 /* XXX macros that make external reference is BAD. */ 252 253 #define GET_AI(ai, afd, addr) \ 254 do { \ 255 /* external reference: pai, error, and label free */ \ 256 (ai) = get_ai(pai, (afd), (addr)); \ 257 if ((ai) == NULL) { \ 258 error = EAI_MEMORY; \ 259 goto free; \ 260 } \ 261 } while (/*CONSTCOND*/0) 262 263 #define GET_PORT(ai, serv) \ 264 do { \ 265 /* external reference: error and label free */ \ 266 error = get_port((ai), (serv), 0); \ 267 if (error != 0) \ 268 goto free; \ 269 } while (/*CONSTCOND*/0) 270 271 #define GET_CANONNAME(ai, str) \ 272 do { \ 273 /* external reference: pai, error and label free */ \ 274 error = get_canonname(pai, (ai), (str)); \ 275 if (error != 0) \ 276 goto free; \ 277 } while (/*CONSTCOND*/0) 278 279 #define ERR(err) \ 280 do { \ 281 /* external reference: error, and label bad */ \ 282 error = (err); \ 283 goto bad; \ 284 /*NOTREACHED*/ \ 285 } while (/*CONSTCOND*/0) 286 287 #define MATCH_FAMILY(x, y, w) \ 288 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || \ 289 (y) == PF_UNSPEC))) 290 #define MATCH(x, y, w) \ 291 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 292 293 const char * 294 gai_strerror(int ecode) 295 { 296 if (ecode < 0 || ecode > EAI_MAX) 297 ecode = EAI_MAX; 298 return ai_errlist[ecode]; 299 } 300 301 void 302 freeaddrinfo(struct addrinfo *ai) 303 { 304 struct addrinfo *next; 305 306 _DIAGASSERT(ai != NULL); 307 308 do { 309 next = ai->ai_next; 310 if (ai->ai_canonname) 311 free(ai->ai_canonname); 312 /* no need to free(ai->ai_addr) */ 313 free(ai); 314 ai = next; 315 } while (ai); 316 } 317 318 static int 319 str2number(const char *p) 320 { 321 char *ep; 322 unsigned long v; 323 324 _DIAGASSERT(p != NULL); 325 326 if (*p == '\0') 327 return -1; 328 ep = NULL; 329 errno = 0; 330 v = strtoul(p, &ep, 10); 331 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) 332 return v; 333 else 334 return -1; 335 } 336 337 int 338 getaddrinfo(const char *hostname, const char *servname, 339 const struct addrinfo *hints, struct addrinfo **res) 340 { 341 struct addrinfo sentinel; 342 struct addrinfo *cur; 343 int error = 0; 344 struct addrinfo ai; 345 struct addrinfo ai0; 346 struct addrinfo *pai; 347 const struct explore *ex; 348 349 /* hostname is allowed to be NULL */ 350 /* servname is allowed to be NULL */ 351 /* hints is allowed to be NULL */ 352 _DIAGASSERT(res != NULL); 353 354 memset(&sentinel, 0, sizeof(sentinel)); 355 cur = &sentinel; 356 pai = &ai; 357 pai->ai_flags = 0; 358 pai->ai_family = PF_UNSPEC; 359 pai->ai_socktype = ANY; 360 pai->ai_protocol = ANY; 361 pai->ai_addrlen = 0; 362 pai->ai_canonname = NULL; 363 pai->ai_addr = NULL; 364 pai->ai_next = NULL; 365 366 if (hostname == NULL && servname == NULL) 367 return EAI_NONAME; 368 if (hints) { 369 /* error check for hints */ 370 if (hints->ai_addrlen || hints->ai_canonname || 371 hints->ai_addr || hints->ai_next) 372 ERR(EAI_BADHINTS); /* xxx */ 373 if (hints->ai_flags & ~AI_MASK) 374 ERR(EAI_BADFLAGS); 375 switch (hints->ai_family) { 376 case PF_UNSPEC: 377 case PF_INET: 378 #ifdef INET6 379 case PF_INET6: 380 #endif 381 break; 382 default: 383 ERR(EAI_FAMILY); 384 } 385 memcpy(pai, hints, sizeof(*pai)); 386 387 /* 388 * if both socktype/protocol are specified, check if they 389 * are meaningful combination. 390 */ 391 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 392 for (ex = explore; ex->e_af >= 0; ex++) { 393 if (pai->ai_family != ex->e_af) 394 continue; 395 if (ex->e_socktype == ANY) 396 continue; 397 if (ex->e_protocol == ANY) 398 continue; 399 if (pai->ai_socktype == ex->e_socktype 400 && pai->ai_protocol != ex->e_protocol) { 401 ERR(EAI_BADHINTS); 402 } 403 } 404 } 405 } 406 407 /* 408 * check for special cases. (1) numeric servname is disallowed if 409 * socktype/protocol are left unspecified. (2) servname is disallowed 410 * for raw and other inet{,6} sockets. 411 */ 412 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 413 #ifdef PF_INET6 414 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 415 #endif 416 ) { 417 ai0 = *pai; /* backup *pai */ 418 419 if (pai->ai_family == PF_UNSPEC) { 420 #ifdef PF_INET6 421 pai->ai_family = PF_INET6; 422 #else 423 pai->ai_family = PF_INET; 424 #endif 425 } 426 error = get_portmatch(pai, servname); 427 if (error) 428 ERR(error); 429 430 *pai = ai0; 431 } 432 433 ai0 = *pai; 434 435 /* NULL hostname, or numeric hostname */ 436 for (ex = explore; ex->e_af >= 0; ex++) { 437 *pai = ai0; 438 439 /* PF_UNSPEC entries are prepared for DNS queries only */ 440 if (ex->e_af == PF_UNSPEC) 441 continue; 442 443 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 444 continue; 445 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 446 continue; 447 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 448 continue; 449 450 if (pai->ai_family == PF_UNSPEC) 451 pai->ai_family = ex->e_af; 452 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 453 pai->ai_socktype = ex->e_socktype; 454 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 455 pai->ai_protocol = ex->e_protocol; 456 457 if (hostname == NULL) 458 error = explore_null(pai, servname, &cur->ai_next); 459 else 460 error = explore_numeric_scope(pai, hostname, servname, 461 &cur->ai_next); 462 463 if (error) 464 goto free; 465 466 while (cur->ai_next) 467 cur = cur->ai_next; 468 } 469 470 /* 471 * XXX 472 * If numeric representation of AF1 can be interpreted as FQDN 473 * representation of AF2, we need to think again about the code below. 474 */ 475 if (sentinel.ai_next) 476 goto good; 477 478 if (hostname == NULL) 479 ERR(EAI_NODATA); 480 if (pai->ai_flags & AI_NUMERICHOST) 481 ERR(EAI_NONAME); 482 483 /* 484 * hostname as alphabetical name. 485 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 486 * outer loop by AFs. 487 */ 488 for (ex = explore; ex->e_af >= 0; ex++) { 489 *pai = ai0; 490 491 /* require exact match for family field */ 492 if (pai->ai_family != ex->e_af) 493 continue; 494 495 if (!MATCH(pai->ai_socktype, ex->e_socktype, 496 WILD_SOCKTYPE(ex))) { 497 continue; 498 } 499 if (!MATCH(pai->ai_protocol, ex->e_protocol, 500 WILD_PROTOCOL(ex))) { 501 continue; 502 } 503 504 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 505 pai->ai_socktype = ex->e_socktype; 506 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 507 pai->ai_protocol = ex->e_protocol; 508 509 error = explore_fqdn(pai, hostname, servname, 510 &cur->ai_next); 511 512 while (cur && cur->ai_next) 513 cur = cur->ai_next; 514 } 515 516 /* XXX */ 517 if (sentinel.ai_next) 518 error = 0; 519 520 if (error) 521 goto free; 522 if (error == 0) { 523 if (sentinel.ai_next) { 524 good: 525 *res = sentinel.ai_next; 526 return SUCCESS; 527 } else 528 error = EAI_FAIL; 529 } 530 free: 531 bad: 532 if (sentinel.ai_next) 533 freeaddrinfo(sentinel.ai_next); 534 *res = NULL; 535 return error; 536 } 537 538 /* 539 * FQDN hostname, DNS lookup 540 */ 541 static int 542 explore_fqdn(const struct addrinfo *pai, const char *hostname, 543 const char *servname, struct addrinfo **res) 544 { 545 struct addrinfo *result; 546 struct addrinfo *cur; 547 int error = 0; 548 static const ns_dtab dtab[] = { 549 NS_FILES_CB(_files_getaddrinfo, NULL) 550 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 551 NS_NIS_CB(_yp_getaddrinfo, NULL) 552 { 0 } 553 }; 554 555 _DIAGASSERT(pai != NULL); 556 /* hostname may be NULL */ 557 /* servname may be NULL */ 558 _DIAGASSERT(res != NULL); 559 560 result = NULL; 561 562 /* 563 * if the servname does not match socktype/protocol, ignore it. 564 */ 565 if (get_portmatch(pai, servname) != 0) 566 return 0; 567 568 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 569 default_dns_files, hostname, pai)) { 570 case NS_TRYAGAIN: 571 error = EAI_AGAIN; 572 goto free; 573 case NS_UNAVAIL: 574 error = EAI_FAIL; 575 goto free; 576 case NS_NOTFOUND: 577 error = EAI_NODATA; 578 goto free; 579 case NS_SUCCESS: 580 error = 0; 581 for (cur = result; cur; cur = cur->ai_next) { 582 GET_PORT(cur, servname); 583 /* canonname should be filled already */ 584 } 585 break; 586 } 587 588 *res = result; 589 590 return 0; 591 592 free: 593 if (result) 594 freeaddrinfo(result); 595 return error; 596 } 597 598 /* 599 * hostname == NULL. 600 * passive socket -> anyaddr (0.0.0.0 or ::) 601 * non-passive socket -> localhost (127.0.0.1 or ::1) 602 */ 603 static int 604 explore_null(const struct addrinfo *pai, const char *servname, 605 struct addrinfo **res) 606 { 607 int s; 608 const struct afd *afd; 609 struct addrinfo *cur; 610 struct addrinfo sentinel; 611 int error; 612 613 _DIAGASSERT(pai != NULL); 614 /* servname may be NULL */ 615 _DIAGASSERT(res != NULL); 616 617 *res = NULL; 618 sentinel.ai_next = NULL; 619 cur = &sentinel; 620 621 /* 622 * filter out AFs that are not supported by the kernel 623 * XXX errno? 624 */ 625 s = socket(pai->ai_family, SOCK_DGRAM, 0); 626 if (s < 0) { 627 if (errno != EMFILE) 628 return 0; 629 } else 630 close(s); 631 632 /* 633 * if the servname does not match socktype/protocol, ignore it. 634 */ 635 if (get_portmatch(pai, servname) != 0) 636 return 0; 637 638 afd = find_afd(pai->ai_family); 639 if (afd == NULL) 640 return 0; 641 642 if (pai->ai_flags & AI_PASSIVE) { 643 GET_AI(cur->ai_next, afd, afd->a_addrany); 644 /* xxx meaningless? 645 * GET_CANONNAME(cur->ai_next, "anyaddr"); 646 */ 647 GET_PORT(cur->ai_next, servname); 648 } else { 649 GET_AI(cur->ai_next, afd, afd->a_loopback); 650 /* xxx meaningless? 651 * GET_CANONNAME(cur->ai_next, "localhost"); 652 */ 653 GET_PORT(cur->ai_next, servname); 654 } 655 cur = cur->ai_next; 656 657 *res = sentinel.ai_next; 658 return 0; 659 660 free: 661 if (sentinel.ai_next) 662 freeaddrinfo(sentinel.ai_next); 663 return error; 664 } 665 666 /* 667 * numeric hostname 668 */ 669 static int 670 explore_numeric(const struct addrinfo *pai, const char *hostname, 671 const char *servname, struct addrinfo **res, const char *canonname) 672 { 673 const struct afd *afd; 674 struct addrinfo *cur; 675 struct addrinfo sentinel; 676 int error; 677 char pton[PTON_MAX]; 678 679 _DIAGASSERT(pai != NULL); 680 /* hostname may be NULL */ 681 /* servname may be NULL */ 682 _DIAGASSERT(res != NULL); 683 684 *res = NULL; 685 sentinel.ai_next = NULL; 686 cur = &sentinel; 687 688 /* 689 * if the servname does not match socktype/protocol, ignore it. 690 */ 691 if (get_portmatch(pai, servname) != 0) 692 return 0; 693 694 afd = find_afd(pai->ai_family); 695 if (afd == NULL) 696 return 0; 697 698 switch (afd->a_af) { 699 #if 0 /*X/Open spec*/ 700 case AF_INET: 701 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 702 if (pai->ai_family == afd->a_af || 703 pai->ai_family == PF_UNSPEC /*?*/) { 704 GET_AI(cur->ai_next, afd, pton); 705 GET_PORT(cur->ai_next, servname); 706 if ((pai->ai_flags & AI_CANONNAME)) { 707 /* 708 * Set the numeric address itself as 709 * the canonical name, based on a 710 * clarification in rfc2553bis-03. 711 */ 712 GET_CANONNAME(cur->ai_next, canonname); 713 } 714 while (cur && cur->ai_next) 715 cur = cur->ai_next; 716 } else 717 ERR(EAI_FAMILY); /*xxx*/ 718 } 719 break; 720 #endif 721 default: 722 if (inet_pton(afd->a_af, hostname, 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->ai_next) 736 cur = cur->ai_next; 737 } else 738 ERR(EAI_FAMILY); /*xxx*/ 739 } 740 break; 741 } 742 743 *res = sentinel.ai_next; 744 return 0; 745 746 free: 747 bad: 748 if (sentinel.ai_next) 749 freeaddrinfo(sentinel.ai_next); 750 return error; 751 } 752 753 /* 754 * numeric hostname with scope 755 */ 756 static int 757 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 758 const char *servname, struct addrinfo **res) 759 { 760 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 761 return explore_numeric(pai, hostname, servname, res, hostname); 762 #else 763 const struct afd *afd; 764 struct addrinfo *cur; 765 int error; 766 char *cp, *hostname2 = NULL, *scope, *addr; 767 struct sockaddr_in6 *sin6; 768 769 _DIAGASSERT(pai != NULL); 770 /* hostname may be NULL */ 771 /* servname may be NULL */ 772 _DIAGASSERT(res != NULL); 773 774 /* 775 * if the servname does not match socktype/protocol, ignore it. 776 */ 777 if (get_portmatch(pai, servname) != 0) 778 return 0; 779 780 afd = find_afd(pai->ai_family); 781 if (afd == NULL) 782 return 0; 783 784 if (!afd->a_scoped) 785 return explore_numeric(pai, hostname, servname, res, hostname); 786 787 cp = strchr(hostname, SCOPE_DELIMITER); 788 if (cp == NULL) 789 return explore_numeric(pai, hostname, servname, res, hostname); 790 791 /* 792 * Handle special case of <scoped_address><delimiter><scope id> 793 */ 794 hostname2 = strdup(hostname); 795 if (hostname2 == NULL) 796 return EAI_MEMORY; 797 /* terminate at the delimiter */ 798 hostname2[cp - hostname] = '\0'; 799 addr = hostname2; 800 scope = cp + 1; 801 802 error = explore_numeric(pai, addr, servname, res, hostname); 803 if (error == 0) { 804 u_int32_t scopeid; 805 806 for (cur = *res; cur; cur = cur->ai_next) { 807 if (cur->ai_family != AF_INET6) 808 continue; 809 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 810 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 811 free(hostname2); 812 return(EAI_NODATA); /* XXX: is return OK? */ 813 } 814 sin6->sin6_scope_id = scopeid; 815 } 816 } 817 818 free(hostname2); 819 820 return error; 821 #endif 822 } 823 824 static int 825 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 826 { 827 828 _DIAGASSERT(pai != NULL); 829 _DIAGASSERT(ai != NULL); 830 _DIAGASSERT(str != NULL); 831 832 if ((pai->ai_flags & AI_CANONNAME) != 0) { 833 ai->ai_canonname = strdup(str); 834 if (ai->ai_canonname == NULL) 835 return EAI_MEMORY; 836 } 837 return 0; 838 } 839 840 static struct addrinfo * 841 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 842 { 843 char *p; 844 struct addrinfo *ai; 845 846 _DIAGASSERT(pai != NULL); 847 _DIAGASSERT(afd != NULL); 848 _DIAGASSERT(addr != NULL); 849 850 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 851 + (afd->a_socklen)); 852 if (ai == NULL) 853 return NULL; 854 855 memcpy(ai, pai, sizeof(struct addrinfo)); 856 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 857 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 858 ai->ai_addr->sa_len = afd->a_socklen; 859 ai->ai_addrlen = afd->a_socklen; 860 #if defined (__alpha__) || (defined(__i386__) && defined(_LP64)) || defined(__sparc64__) 861 ai->__ai_pad0 = 0; 862 #endif 863 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 864 p = (char *)(void *)(ai->ai_addr); 865 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 866 return ai; 867 } 868 869 static int 870 get_portmatch(const struct addrinfo *ai, const char *servname) 871 { 872 873 _DIAGASSERT(ai != NULL); 874 /* servname may be NULL */ 875 876 return get_port(ai, servname, 1); 877 } 878 879 static int 880 get_port(const struct addrinfo *ai, const char *servname, int matchonly) 881 { 882 const char *proto; 883 struct servent *sp; 884 int port; 885 int allownumeric; 886 887 _DIAGASSERT(ai != NULL); 888 /* servname may be NULL */ 889 890 if (servname == NULL) 891 return 0; 892 switch (ai->ai_family) { 893 case AF_INET: 894 #ifdef AF_INET6 895 case AF_INET6: 896 #endif 897 break; 898 default: 899 return 0; 900 } 901 902 switch (ai->ai_socktype) { 903 case SOCK_RAW: 904 return EAI_SERVICE; 905 case SOCK_DGRAM: 906 case SOCK_STREAM: 907 allownumeric = 1; 908 break; 909 case ANY: 910 allownumeric = 0; 911 break; 912 default: 913 return EAI_SOCKTYPE; 914 } 915 916 port = str2number(servname); 917 if (port >= 0) { 918 if (!allownumeric) 919 return EAI_SERVICE; 920 if (port < 0 || port > 65535) 921 return EAI_SERVICE; 922 port = htons(port); 923 } else { 924 struct servent_data svd; 925 struct servent sv; 926 if (ai->ai_flags & AI_NUMERICSERV) 927 return EAI_NONAME; 928 929 switch (ai->ai_socktype) { 930 case SOCK_DGRAM: 931 proto = "udp"; 932 break; 933 case SOCK_STREAM: 934 proto = "tcp"; 935 break; 936 default: 937 proto = NULL; 938 break; 939 } 940 941 (void)memset(&svd, 0, sizeof(svd)); 942 sp = getservbyname_r(servname, proto, &sv, &svd); 943 endservent_r(&svd); 944 if (sp == NULL) 945 return EAI_SERVICE; 946 port = sp->s_port; 947 } 948 949 if (!matchonly) { 950 switch (ai->ai_family) { 951 case AF_INET: 952 ((struct sockaddr_in *)(void *) 953 ai->ai_addr)->sin_port = port; 954 break; 955 #ifdef INET6 956 case AF_INET6: 957 ((struct sockaddr_in6 *)(void *) 958 ai->ai_addr)->sin6_port = port; 959 break; 960 #endif 961 } 962 } 963 964 return 0; 965 } 966 967 static const struct afd * 968 find_afd(int af) 969 { 970 const struct afd *afd; 971 972 if (af == PF_UNSPEC) 973 return NULL; 974 for (afd = afdl; afd->a_af; afd++) { 975 if (afd->a_af == af) 976 return afd; 977 } 978 return NULL; 979 } 980 981 #ifdef INET6 982 /* convert a string to a scope identifier. XXX: IPv6 specific */ 983 static int 984 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 985 { 986 u_long lscopeid; 987 struct in6_addr *a6; 988 char *ep; 989 990 _DIAGASSERT(scope != NULL); 991 _DIAGASSERT(sin6 != NULL); 992 _DIAGASSERT(scopeid != NULL); 993 994 a6 = &sin6->sin6_addr; 995 996 /* empty scopeid portion is invalid */ 997 if (*scope == '\0') 998 return -1; 999 1000 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1001 /* 1002 * We currently assume a one-to-one mapping between links 1003 * and interfaces, so we simply use interface indices for 1004 * like-local scopes. 1005 */ 1006 *scopeid = if_nametoindex(scope); 1007 if (*scopeid == 0) 1008 goto trynumeric; 1009 return 0; 1010 } 1011 1012 /* still unclear about literal, allow numeric only - placeholder */ 1013 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1014 goto trynumeric; 1015 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1016 goto trynumeric; 1017 else 1018 goto trynumeric; /* global */ 1019 1020 /* try to convert to a numeric id as a last resort */ 1021 trynumeric: 1022 errno = 0; 1023 lscopeid = strtoul(scope, &ep, 10); 1024 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1025 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1026 return 0; 1027 else 1028 return -1; 1029 } 1030 #endif 1031 1032 /* code duplicate with gethnamaddr.c */ 1033 1034 static const char AskedForGot[] = 1035 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1036 1037 static struct addrinfo * 1038 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1039 const struct addrinfo *pai) 1040 { 1041 struct addrinfo sentinel, *cur; 1042 struct addrinfo ai; 1043 const struct afd *afd; 1044 char *canonname; 1045 const HEADER *hp; 1046 const u_char *cp; 1047 int n; 1048 const u_char *eom; 1049 char *bp, *ep; 1050 int type, class, ancount, qdcount; 1051 int haveanswer, had_error; 1052 char tbuf[MAXDNAME]; 1053 int (*name_ok) (const char *); 1054 char hostbuf[8*1024]; 1055 1056 _DIAGASSERT(answer != NULL); 1057 _DIAGASSERT(qname != NULL); 1058 _DIAGASSERT(pai != NULL); 1059 1060 memset(&sentinel, 0, sizeof(sentinel)); 1061 cur = &sentinel; 1062 1063 canonname = NULL; 1064 eom = answer->buf + anslen; 1065 switch (qtype) { 1066 case T_A: 1067 case T_AAAA: 1068 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1069 name_ok = res_hnok; 1070 break; 1071 default: 1072 return NULL; /* XXX should be abort(); */ 1073 } 1074 /* 1075 * find first satisfactory answer 1076 */ 1077 hp = &answer->hdr; 1078 ancount = ntohs(hp->ancount); 1079 qdcount = ntohs(hp->qdcount); 1080 bp = hostbuf; 1081 ep = hostbuf + sizeof hostbuf; 1082 cp = answer->buf + HFIXEDSZ; 1083 if (qdcount != 1) { 1084 h_errno = NO_RECOVERY; 1085 return (NULL); 1086 } 1087 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1088 if ((n < 0) || !(*name_ok)(bp)) { 1089 h_errno = NO_RECOVERY; 1090 return (NULL); 1091 } 1092 cp += n + QFIXEDSZ; 1093 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1094 /* res_send() has already verified that the query name is the 1095 * same as the one we sent; this just gets the expanded name 1096 * (i.e., with the succeeding search-domain tacked on). 1097 */ 1098 n = strlen(bp) + 1; /* for the \0 */ 1099 if (n >= MAXHOSTNAMELEN) { 1100 h_errno = NO_RECOVERY; 1101 return (NULL); 1102 } 1103 canonname = bp; 1104 bp += n; 1105 /* The qname can be abbreviated, but h_name is now absolute. */ 1106 qname = canonname; 1107 } 1108 haveanswer = 0; 1109 had_error = 0; 1110 while (ancount-- > 0 && cp < eom && !had_error) { 1111 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1112 if ((n < 0) || !(*name_ok)(bp)) { 1113 had_error++; 1114 continue; 1115 } 1116 cp += n; /* name */ 1117 type = _getshort(cp); 1118 cp += INT16SZ; /* type */ 1119 class = _getshort(cp); 1120 cp += INT16SZ + INT32SZ; /* class, TTL */ 1121 n = _getshort(cp); 1122 cp += INT16SZ; /* len */ 1123 if (class != C_IN) { 1124 /* XXX - debug? syslog? */ 1125 cp += n; 1126 continue; /* XXX - had_error++ ? */ 1127 } 1128 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1129 type == T_CNAME) { 1130 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1131 if ((n < 0) || !(*name_ok)(tbuf)) { 1132 had_error++; 1133 continue; 1134 } 1135 cp += n; 1136 /* Get canonical name. */ 1137 n = strlen(tbuf) + 1; /* for the \0 */ 1138 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1139 had_error++; 1140 continue; 1141 } 1142 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1143 canonname = bp; 1144 bp += n; 1145 continue; 1146 } 1147 if (qtype == T_ANY) { 1148 if (!(type == T_A || type == T_AAAA)) { 1149 cp += n; 1150 continue; 1151 } 1152 } else if (type != qtype) { 1153 if (type != T_KEY && type != T_SIG) 1154 syslog(LOG_NOTICE|LOG_AUTH, 1155 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1156 qname, p_class(C_IN), p_type(qtype), 1157 p_type(type)); 1158 cp += n; 1159 continue; /* XXX - had_error++ ? */ 1160 } 1161 switch (type) { 1162 case T_A: 1163 case T_AAAA: 1164 if (strcasecmp(canonname, bp) != 0) { 1165 syslog(LOG_NOTICE|LOG_AUTH, 1166 AskedForGot, canonname, bp); 1167 cp += n; 1168 continue; /* XXX - had_error++ ? */ 1169 } 1170 if (type == T_A && n != INADDRSZ) { 1171 cp += n; 1172 continue; 1173 } 1174 if (type == T_AAAA && n != IN6ADDRSZ) { 1175 cp += n; 1176 continue; 1177 } 1178 if (type == T_AAAA) { 1179 struct in6_addr in6; 1180 memcpy(&in6, cp, IN6ADDRSZ); 1181 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1182 cp += n; 1183 continue; 1184 } 1185 } 1186 if (!haveanswer) { 1187 int nn; 1188 1189 canonname = bp; 1190 nn = strlen(bp) + 1; /* for the \0 */ 1191 bp += nn; 1192 } 1193 1194 /* don't overwrite pai */ 1195 ai = *pai; 1196 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1197 afd = find_afd(ai.ai_family); 1198 if (afd == NULL) { 1199 cp += n; 1200 continue; 1201 } 1202 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1203 if (cur->ai_next == NULL) 1204 had_error++; 1205 while (cur && cur->ai_next) 1206 cur = cur->ai_next; 1207 cp += n; 1208 break; 1209 default: 1210 abort(); 1211 } 1212 if (!had_error) 1213 haveanswer++; 1214 } 1215 if (haveanswer) { 1216 if (!canonname) 1217 (void)get_canonname(pai, sentinel.ai_next, qname); 1218 else 1219 (void)get_canonname(pai, sentinel.ai_next, canonname); 1220 h_errno = NETDB_SUCCESS; 1221 return sentinel.ai_next; 1222 } 1223 1224 h_errno = NO_RECOVERY; 1225 return NULL; 1226 } 1227 1228 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr) 1229 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr) 1230 1231 static void 1232 aisort(struct addrinfo *s, res_state res) 1233 { 1234 struct addrinfo head, *t, *p; 1235 int i; 1236 1237 head.ai_next = NULL; 1238 t = &head; 1239 1240 for (i = 0; i < res->nsort; i++) { 1241 p = s; 1242 while (p->ai_next) { 1243 if ((p->ai_next->ai_family != AF_INET) 1244 || SORTMATCH(p, res->sort_list[i])) { 1245 t->ai_next = p->ai_next; 1246 t = t->ai_next; 1247 p->ai_next = p->ai_next->ai_next; 1248 } else { 1249 p = p->ai_next; 1250 } 1251 } 1252 } 1253 1254 /* add rest of list and reset s to the new list*/ 1255 t->ai_next = s->ai_next; 1256 s->ai_next = head.ai_next; 1257 } 1258 1259 /*ARGSUSED*/ 1260 static int 1261 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1262 { 1263 struct addrinfo *ai; 1264 querybuf *buf, *buf2; 1265 const char *name; 1266 const struct addrinfo *pai; 1267 struct addrinfo sentinel, *cur; 1268 struct res_target q, q2; 1269 res_state res; 1270 1271 name = va_arg(ap, char *); 1272 pai = va_arg(ap, const struct addrinfo *); 1273 1274 memset(&q, 0, sizeof(q)); 1275 memset(&q2, 0, sizeof(q2)); 1276 memset(&sentinel, 0, sizeof(sentinel)); 1277 cur = &sentinel; 1278 1279 buf = malloc(sizeof(*buf)); 1280 if (buf == NULL) { 1281 h_errno = NETDB_INTERNAL; 1282 return NS_NOTFOUND; 1283 } 1284 buf2 = malloc(sizeof(*buf2)); 1285 if (buf2 == NULL) { 1286 free(buf); 1287 h_errno = NETDB_INTERNAL; 1288 return NS_NOTFOUND; 1289 } 1290 1291 switch (pai->ai_family) { 1292 case AF_UNSPEC: 1293 /* prefer IPv6 */ 1294 q.name = name; 1295 q.qclass = C_IN; 1296 q.qtype = T_AAAA; 1297 q.answer = buf->buf; 1298 q.anslen = sizeof(buf->buf); 1299 q.next = &q2; 1300 q2.name = name; 1301 q2.qclass = C_IN; 1302 q2.qtype = T_A; 1303 q2.answer = buf2->buf; 1304 q2.anslen = sizeof(buf2->buf); 1305 break; 1306 case AF_INET: 1307 q.name = name; 1308 q.qclass = C_IN; 1309 q.qtype = T_A; 1310 q.answer = buf->buf; 1311 q.anslen = sizeof(buf->buf); 1312 break; 1313 case AF_INET6: 1314 q.name = name; 1315 q.qclass = C_IN; 1316 q.qtype = T_AAAA; 1317 q.answer = buf->buf; 1318 q.anslen = sizeof(buf->buf); 1319 break; 1320 default: 1321 free(buf); 1322 free(buf2); 1323 return NS_UNAVAIL; 1324 } 1325 1326 res = __res_get_state(); 1327 if (res == NULL) { 1328 free(buf); 1329 free(buf2); 1330 return NS_NOTFOUND; 1331 } 1332 1333 if (res_searchN(name, &q, res) < 0) { 1334 __res_put_state(res); 1335 free(buf); 1336 free(buf2); 1337 return NS_NOTFOUND; 1338 } 1339 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1340 if (ai) { 1341 cur->ai_next = ai; 1342 while (cur && cur->ai_next) 1343 cur = cur->ai_next; 1344 } 1345 if (q.next) { 1346 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1347 if (ai) 1348 cur->ai_next = ai; 1349 } 1350 free(buf); 1351 free(buf2); 1352 if (sentinel.ai_next == NULL) { 1353 __res_put_state(res); 1354 switch (h_errno) { 1355 case HOST_NOT_FOUND: 1356 return NS_NOTFOUND; 1357 case TRY_AGAIN: 1358 return NS_TRYAGAIN; 1359 default: 1360 return NS_UNAVAIL; 1361 } 1362 } 1363 1364 if (res->nsort) 1365 aisort(&sentinel, res); 1366 1367 __res_put_state(res); 1368 1369 *((struct addrinfo **)rv) = sentinel.ai_next; 1370 return NS_SUCCESS; 1371 } 1372 1373 static void 1374 _sethtent(FILE **hostf) 1375 { 1376 1377 if (!*hostf) 1378 *hostf = fopen(_PATH_HOSTS, "r" ); 1379 else 1380 rewind(*hostf); 1381 } 1382 1383 static void 1384 _endhtent(FILE **hostf) 1385 { 1386 1387 if (*hostf) { 1388 (void) fclose(*hostf); 1389 *hostf = NULL; 1390 } 1391 } 1392 1393 static struct addrinfo * 1394 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1395 { 1396 char *p; 1397 char *cp, *tname, *cname; 1398 struct addrinfo hints, *res0, *res; 1399 int error; 1400 const char *addr; 1401 char hostbuf[8*1024]; 1402 1403 _DIAGASSERT(name != NULL); 1404 _DIAGASSERT(pai != NULL); 1405 1406 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r" ))) 1407 return (NULL); 1408 again: 1409 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 1410 return (NULL); 1411 if (*p == '#') 1412 goto again; 1413 if (!(cp = strpbrk(p, "#\n"))) 1414 goto again; 1415 *cp = '\0'; 1416 if (!(cp = strpbrk(p, " \t"))) 1417 goto again; 1418 *cp++ = '\0'; 1419 addr = p; 1420 /* if this is not something we're looking for, skip it. */ 1421 cname = NULL; 1422 while (cp && *cp) { 1423 if (*cp == ' ' || *cp == '\t') { 1424 cp++; 1425 continue; 1426 } 1427 if (!cname) 1428 cname = cp; 1429 tname = cp; 1430 if ((cp = strpbrk(cp, " \t")) != NULL) 1431 *cp++ = '\0'; 1432 if (strcasecmp(name, tname) == 0) 1433 goto found; 1434 } 1435 goto again; 1436 1437 found: 1438 hints = *pai; 1439 hints.ai_flags = AI_NUMERICHOST; 1440 error = getaddrinfo(addr, NULL, &hints, &res0); 1441 if (error) 1442 goto again; 1443 for (res = res0; res; res = res->ai_next) { 1444 /* cover it up */ 1445 res->ai_flags = pai->ai_flags; 1446 1447 if (pai->ai_flags & AI_CANONNAME) { 1448 if (get_canonname(pai, res, cname) != 0) { 1449 freeaddrinfo(res0); 1450 goto again; 1451 } 1452 } 1453 } 1454 return res0; 1455 } 1456 1457 /*ARGSUSED*/ 1458 static int 1459 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1460 { 1461 const char *name; 1462 const struct addrinfo *pai; 1463 struct addrinfo sentinel, *cur; 1464 struct addrinfo *p; 1465 #ifndef _REENTRANT 1466 static 1467 #endif 1468 FILE *hostf = NULL; 1469 1470 name = va_arg(ap, char *); 1471 pai = va_arg(ap, struct addrinfo *); 1472 1473 memset(&sentinel, 0, sizeof(sentinel)); 1474 cur = &sentinel; 1475 1476 _sethtent(&hostf); 1477 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1478 cur->ai_next = p; 1479 while (cur && cur->ai_next) 1480 cur = cur->ai_next; 1481 } 1482 _endhtent(&hostf); 1483 1484 *((struct addrinfo **)rv) = sentinel.ai_next; 1485 if (sentinel.ai_next == NULL) 1486 return NS_NOTFOUND; 1487 return NS_SUCCESS; 1488 } 1489 1490 #ifdef YP 1491 /*ARGSUSED*/ 1492 static struct addrinfo * 1493 _yphostent(char *line, const struct addrinfo *pai) 1494 { 1495 struct addrinfo sentinel, *cur; 1496 struct addrinfo hints, *res, *res0; 1497 int error; 1498 char *p; 1499 const char *addr, *canonname; 1500 char *nextline; 1501 char *cp; 1502 1503 _DIAGASSERT(line != NULL); 1504 _DIAGASSERT(pai != NULL); 1505 1506 p = line; 1507 addr = canonname = NULL; 1508 1509 memset(&sentinel, 0, sizeof(sentinel)); 1510 cur = &sentinel; 1511 1512 nextline: 1513 /* terminate line */ 1514 cp = strchr(p, '\n'); 1515 if (cp) { 1516 *cp++ = '\0'; 1517 nextline = cp; 1518 } else 1519 nextline = NULL; 1520 1521 cp = strpbrk(p, " \t"); 1522 if (cp == NULL) { 1523 if (canonname == NULL) 1524 return (NULL); 1525 else 1526 goto done; 1527 } 1528 *cp++ = '\0'; 1529 1530 addr = p; 1531 1532 while (cp && *cp) { 1533 if (*cp == ' ' || *cp == '\t') { 1534 cp++; 1535 continue; 1536 } 1537 if (!canonname) 1538 canonname = cp; 1539 if ((cp = strpbrk(cp, " \t")) != NULL) 1540 *cp++ = '\0'; 1541 } 1542 1543 hints = *pai; 1544 hints.ai_flags = AI_NUMERICHOST; 1545 error = getaddrinfo(addr, NULL, &hints, &res0); 1546 if (error == 0) { 1547 for (res = res0; res; res = res->ai_next) { 1548 /* cover it up */ 1549 res->ai_flags = pai->ai_flags; 1550 1551 if (pai->ai_flags & AI_CANONNAME) 1552 (void)get_canonname(pai, res, canonname); 1553 } 1554 } else 1555 res0 = NULL; 1556 if (res0) { 1557 cur->ai_next = res0; 1558 while (cur->ai_next) 1559 cur = cur->ai_next; 1560 } 1561 1562 if (nextline) { 1563 p = nextline; 1564 goto nextline; 1565 } 1566 1567 done: 1568 return sentinel.ai_next; 1569 } 1570 1571 /*ARGSUSED*/ 1572 static int 1573 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1574 { 1575 struct addrinfo sentinel, *cur; 1576 struct addrinfo *ai = NULL; 1577 char *ypbuf; 1578 int ypbuflen, r; 1579 const char *name; 1580 const struct addrinfo *pai; 1581 char *ypdomain; 1582 1583 if (_yp_check(&ypdomain) == 0) 1584 return NS_UNAVAIL; 1585 1586 name = va_arg(ap, char *); 1587 pai = va_arg(ap, const struct addrinfo *); 1588 1589 memset(&sentinel, 0, sizeof(sentinel)); 1590 cur = &sentinel; 1591 1592 /* hosts.byname is only for IPv4 (Solaris8) */ 1593 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1594 r = yp_match(ypdomain, "hosts.byname", name, 1595 (int)strlen(name), &ypbuf, &ypbuflen); 1596 if (r == 0) { 1597 struct addrinfo ai4; 1598 1599 ai4 = *pai; 1600 ai4.ai_family = AF_INET; 1601 ai = _yphostent(ypbuf, &ai4); 1602 if (ai) { 1603 cur->ai_next = ai; 1604 while (cur && cur->ai_next) 1605 cur = cur->ai_next; 1606 } 1607 } 1608 free(ypbuf); 1609 } 1610 1611 /* ipnodes.byname can hold both IPv4/v6 */ 1612 r = yp_match(ypdomain, "ipnodes.byname", name, 1613 (int)strlen(name), &ypbuf, &ypbuflen); 1614 if (r == 0) { 1615 ai = _yphostent(ypbuf, pai); 1616 if (ai) 1617 cur->ai_next = ai; 1618 free(ypbuf); 1619 } 1620 1621 if (sentinel.ai_next == NULL) { 1622 h_errno = HOST_NOT_FOUND; 1623 return NS_NOTFOUND; 1624 } 1625 *((struct addrinfo **)rv) = sentinel.ai_next; 1626 return NS_SUCCESS; 1627 } 1628 #endif 1629 1630 /* resolver logic */ 1631 1632 /* 1633 * Formulate a normal query, send, and await answer. 1634 * Returned answer is placed in supplied buffer "answer". 1635 * Perform preliminary check of answer, returning success only 1636 * if no error is indicated and the answer count is nonzero. 1637 * Return the size of the response on success, -1 on error. 1638 * Error number is left in h_errno. 1639 * 1640 * Caller must parse answer and determine whether it answers the question. 1641 */ 1642 static int 1643 res_queryN(const char *name, /* domain name */ struct res_target *target, 1644 res_state res) 1645 { 1646 u_char buf[MAXPACKET]; 1647 HEADER *hp; 1648 int n; 1649 struct res_target *t; 1650 int rcode; 1651 int ancount; 1652 1653 _DIAGASSERT(name != NULL); 1654 /* XXX: target may be NULL??? */ 1655 1656 rcode = NOERROR; 1657 ancount = 0; 1658 1659 for (t = target; t; t = t->next) { 1660 int class, type; 1661 u_char *answer; 1662 int anslen; 1663 1664 hp = (HEADER *)(void *)t->answer; 1665 hp->rcode = NOERROR; /* default */ 1666 1667 /* make it easier... */ 1668 class = t->qclass; 1669 type = t->qtype; 1670 answer = t->answer; 1671 anslen = t->anslen; 1672 #ifdef DEBUG 1673 if (res->options & RES_DEBUG) 1674 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 1675 #endif 1676 1677 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 1678 buf, sizeof(buf)); 1679 #ifdef RES_USE_EDNS0 1680 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 1681 n = res_nopt(res, n, buf, sizeof(buf), anslen); 1682 #endif 1683 if (n <= 0) { 1684 #ifdef DEBUG 1685 if (res->options & RES_DEBUG) 1686 printf(";; res_nquery: mkquery failed\n"); 1687 #endif 1688 h_errno = NO_RECOVERY; 1689 return n; 1690 } 1691 n = res_nsend(res, buf, n, answer, anslen); 1692 #if 0 1693 if (n < 0) { 1694 #ifdef DEBUG 1695 if (res->options & RES_DEBUG) 1696 printf(";; res_query: send error\n"); 1697 #endif 1698 h_errno = TRY_AGAIN; 1699 return n; 1700 } 1701 #endif 1702 1703 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1704 rcode = hp->rcode; /* record most recent error */ 1705 #ifdef DEBUG 1706 if (res->options & RES_DEBUG) 1707 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1708 ntohs(hp->ancount)); 1709 #endif 1710 continue; 1711 } 1712 1713 ancount += ntohs(hp->ancount); 1714 1715 t->n = n; 1716 } 1717 1718 if (ancount == 0) { 1719 switch (rcode) { 1720 case NXDOMAIN: 1721 h_errno = HOST_NOT_FOUND; 1722 break; 1723 case SERVFAIL: 1724 h_errno = TRY_AGAIN; 1725 break; 1726 case NOERROR: 1727 h_errno = NO_DATA; 1728 break; 1729 case FORMERR: 1730 case NOTIMP: 1731 case REFUSED: 1732 default: 1733 h_errno = NO_RECOVERY; 1734 break; 1735 } 1736 return -1; 1737 } 1738 return ancount; 1739 } 1740 1741 /* 1742 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1743 * Return the size of the response on success, -1 on error. 1744 * If enabled, implement search rules until answer or unrecoverable failure 1745 * is detected. Error code, if any, is left in h_errno. 1746 */ 1747 static int 1748 res_searchN(const char *name, struct res_target *target, res_state res) 1749 { 1750 const char *cp, * const *domain; 1751 HEADER *hp; 1752 u_int dots; 1753 int trailing_dot, ret, saved_herrno; 1754 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1755 1756 _DIAGASSERT(name != NULL); 1757 _DIAGASSERT(target != NULL); 1758 1759 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1760 1761 errno = 0; 1762 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1763 dots = 0; 1764 for (cp = name; *cp; cp++) 1765 dots += (*cp == '.'); 1766 trailing_dot = 0; 1767 if (cp > name && *--cp == '.') 1768 trailing_dot++; 1769 1770 /* 1771 * if there aren't any dots, it could be a user-level alias 1772 */ 1773 if (!dots && (cp = __hostalias(name)) != NULL) { 1774 ret = res_queryN(cp, target, res); 1775 return ret; 1776 } 1777 1778 /* 1779 * If there are dots in the name already, let's just give it a try 1780 * 'as is'. The threshold can be set with the "ndots" option. 1781 */ 1782 saved_herrno = -1; 1783 if (dots >= res->ndots) { 1784 ret = res_querydomainN(name, NULL, target, res); 1785 if (ret > 0) 1786 return (ret); 1787 saved_herrno = h_errno; 1788 tried_as_is++; 1789 } 1790 1791 /* 1792 * We do at least one level of search if 1793 * - there is no dot and RES_DEFNAME is set, or 1794 * - there is at least one dot, there is no trailing dot, 1795 * and RES_DNSRCH is set. 1796 */ 1797 if ((!dots && (res->options & RES_DEFNAMES)) || 1798 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 1799 int done = 0; 1800 1801 for (domain = (const char * const *)res->dnsrch; 1802 *domain && !done; 1803 domain++) { 1804 1805 ret = res_querydomainN(name, *domain, target, res); 1806 if (ret > 0) 1807 return ret; 1808 1809 /* 1810 * If no server present, give up. 1811 * If name isn't found in this domain, 1812 * keep trying higher domains in the search list 1813 * (if that's enabled). 1814 * On a NO_DATA error, keep trying, otherwise 1815 * a wildcard entry of another type could keep us 1816 * from finding this entry higher in the domain. 1817 * If we get some other error (negative answer or 1818 * server failure), then stop searching up, 1819 * but try the input name below in case it's 1820 * fully-qualified. 1821 */ 1822 if (errno == ECONNREFUSED) { 1823 h_errno = TRY_AGAIN; 1824 return -1; 1825 } 1826 1827 switch (h_errno) { 1828 case NO_DATA: 1829 got_nodata++; 1830 /* FALLTHROUGH */ 1831 case HOST_NOT_FOUND: 1832 /* keep trying */ 1833 break; 1834 case TRY_AGAIN: 1835 if (hp->rcode == SERVFAIL) { 1836 /* try next search element, if any */ 1837 got_servfail++; 1838 break; 1839 } 1840 /* FALLTHROUGH */ 1841 default: 1842 /* anything else implies that we're done */ 1843 done++; 1844 } 1845 /* 1846 * if we got here for some reason other than DNSRCH, 1847 * we only wanted one iteration of the loop, so stop. 1848 */ 1849 if (!(res->options & RES_DNSRCH)) 1850 done++; 1851 } 1852 } 1853 1854 /* 1855 * if we have not already tried the name "as is", do that now. 1856 * note that we do this regardless of how many dots were in the 1857 * name or whether it ends with a dot. 1858 */ 1859 if (!tried_as_is) { 1860 ret = res_querydomainN(name, NULL, target, res); 1861 if (ret > 0) 1862 return ret; 1863 } 1864 1865 /* 1866 * if we got here, we didn't satisfy the search. 1867 * if we did an initial full query, return that query's h_errno 1868 * (note that we wouldn't be here if that query had succeeded). 1869 * else if we ever got a nodata, send that back as the reason. 1870 * else send back meaningless h_errno, that being the one from 1871 * the last DNSRCH we did. 1872 */ 1873 if (saved_herrno != -1) 1874 h_errno = saved_herrno; 1875 else if (got_nodata) 1876 h_errno = NO_DATA; 1877 else if (got_servfail) 1878 h_errno = TRY_AGAIN; 1879 return -1; 1880 } 1881 1882 /* 1883 * Perform a call on res_query on the concatenation of name and domain, 1884 * removing a trailing dot from name if domain is NULL. 1885 */ 1886 static int 1887 res_querydomainN(const char *name, const char *domain, 1888 struct res_target *target, res_state res) 1889 { 1890 char nbuf[MAXDNAME]; 1891 const char *longname = nbuf; 1892 size_t n, d; 1893 1894 _DIAGASSERT(name != NULL); 1895 /* XXX: target may be NULL??? */ 1896 1897 #ifdef DEBUG 1898 if (res->options & RES_DEBUG) 1899 printf(";; res_querydomain(%s, %s)\n", 1900 name, domain?domain:"<Nil>"); 1901 #endif 1902 if (domain == NULL) { 1903 /* 1904 * Check for trailing '.'; 1905 * copy without '.' if present. 1906 */ 1907 n = strlen(name); 1908 if (n + 1 > sizeof(nbuf)) { 1909 h_errno = NO_RECOVERY; 1910 return -1; 1911 } 1912 if (n > 0 && name[--n] == '.') { 1913 strncpy(nbuf, name, n); 1914 nbuf[n] = '\0'; 1915 } else 1916 longname = name; 1917 } else { 1918 n = strlen(name); 1919 d = strlen(domain); 1920 if (n + 1 + d + 1 > sizeof(nbuf)) { 1921 h_errno = NO_RECOVERY; 1922 return -1; 1923 } 1924 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1925 } 1926 return res_queryN(longname, target, res); 1927 } 1928