1 /* $NetBSD: getaddrinfo.c,v 1.87 2006/10/15 16:14:46 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 1.87 2006/10/15 16:14:46 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, 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 memset(&ai, 0, sizeof(ai)); 357 pai = &ai; 358 pai->ai_flags = 0; 359 pai->ai_family = PF_UNSPEC; 360 pai->ai_socktype = ANY; 361 pai->ai_protocol = ANY; 362 pai->ai_addrlen = 0; 363 pai->ai_canonname = NULL; 364 pai->ai_addr = NULL; 365 pai->ai_next = NULL; 366 367 if (hostname == NULL && servname == NULL) 368 return EAI_NONAME; 369 if (hints) { 370 /* error check for hints */ 371 if (hints->ai_addrlen || hints->ai_canonname || 372 hints->ai_addr || hints->ai_next) 373 ERR(EAI_BADHINTS); /* xxx */ 374 if (hints->ai_flags & ~AI_MASK) 375 ERR(EAI_BADFLAGS); 376 switch (hints->ai_family) { 377 case PF_UNSPEC: 378 case PF_INET: 379 #ifdef INET6 380 case PF_INET6: 381 #endif 382 break; 383 default: 384 ERR(EAI_FAMILY); 385 } 386 memcpy(pai, hints, sizeof(*pai)); 387 388 /* 389 * if both socktype/protocol are specified, check if they 390 * are meaningful combination. 391 */ 392 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 393 for (ex = explore; ex->e_af >= 0; ex++) { 394 if (pai->ai_family != ex->e_af) 395 continue; 396 if (ex->e_socktype == ANY) 397 continue; 398 if (ex->e_protocol == ANY) 399 continue; 400 if (pai->ai_socktype == ex->e_socktype 401 && pai->ai_protocol != ex->e_protocol) { 402 ERR(EAI_BADHINTS); 403 } 404 } 405 } 406 } 407 408 /* 409 * check for special cases. (1) numeric servname is disallowed if 410 * socktype/protocol are left unspecified. (2) servname is disallowed 411 * for raw and other inet{,6} sockets. 412 */ 413 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 414 #ifdef PF_INET6 415 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 416 #endif 417 ) { 418 ai0 = *pai; /* backup *pai */ 419 420 if (pai->ai_family == PF_UNSPEC) { 421 #ifdef PF_INET6 422 pai->ai_family = PF_INET6; 423 #else 424 pai->ai_family = PF_INET; 425 #endif 426 } 427 error = get_portmatch(pai, servname); 428 if (error) 429 ERR(error); 430 431 *pai = ai0; 432 } 433 434 ai0 = *pai; 435 436 /* NULL hostname, or numeric hostname */ 437 for (ex = explore; ex->e_af >= 0; ex++) { 438 *pai = ai0; 439 440 /* PF_UNSPEC entries are prepared for DNS queries only */ 441 if (ex->e_af == PF_UNSPEC) 442 continue; 443 444 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 445 continue; 446 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 447 continue; 448 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 449 continue; 450 451 if (pai->ai_family == PF_UNSPEC) 452 pai->ai_family = ex->e_af; 453 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 454 pai->ai_socktype = ex->e_socktype; 455 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 456 pai->ai_protocol = ex->e_protocol; 457 458 if (hostname == NULL) 459 error = explore_null(pai, servname, &cur->ai_next); 460 else 461 error = explore_numeric_scope(pai, hostname, servname, 462 &cur->ai_next); 463 464 if (error) 465 goto free; 466 467 while (cur->ai_next) 468 cur = cur->ai_next; 469 } 470 471 /* 472 * XXX 473 * If numeric representation of AF1 can be interpreted as FQDN 474 * representation of AF2, we need to think again about the code below. 475 */ 476 if (sentinel.ai_next) 477 goto good; 478 479 if (hostname == NULL) 480 ERR(EAI_NODATA); 481 if (pai->ai_flags & AI_NUMERICHOST) 482 ERR(EAI_NONAME); 483 484 /* 485 * hostname as alphabetical name. 486 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 487 * outer loop by AFs. 488 */ 489 for (ex = explore; ex->e_af >= 0; ex++) { 490 *pai = ai0; 491 492 /* require exact match for family field */ 493 if (pai->ai_family != ex->e_af) 494 continue; 495 496 if (!MATCH(pai->ai_socktype, ex->e_socktype, 497 WILD_SOCKTYPE(ex))) { 498 continue; 499 } 500 if (!MATCH(pai->ai_protocol, ex->e_protocol, 501 WILD_PROTOCOL(ex))) { 502 continue; 503 } 504 505 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 506 pai->ai_socktype = ex->e_socktype; 507 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 508 pai->ai_protocol = ex->e_protocol; 509 510 error = explore_fqdn(pai, hostname, servname, 511 &cur->ai_next); 512 513 while (cur && cur->ai_next) 514 cur = cur->ai_next; 515 } 516 517 /* XXX */ 518 if (sentinel.ai_next) 519 error = 0; 520 521 if (error) 522 goto free; 523 if (error == 0) { 524 if (sentinel.ai_next) { 525 good: 526 *res = sentinel.ai_next; 527 return SUCCESS; 528 } else 529 error = EAI_FAIL; 530 } 531 free: 532 bad: 533 if (sentinel.ai_next) 534 freeaddrinfo(sentinel.ai_next); 535 *res = NULL; 536 return error; 537 } 538 539 /* 540 * FQDN hostname, DNS lookup 541 */ 542 static int 543 explore_fqdn(const struct addrinfo *pai, const char *hostname, 544 const char *servname, struct addrinfo **res) 545 { 546 struct addrinfo *result; 547 struct addrinfo *cur; 548 int error = 0; 549 static const ns_dtab dtab[] = { 550 NS_FILES_CB(_files_getaddrinfo, NULL) 551 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 552 NS_NIS_CB(_yp_getaddrinfo, NULL) 553 NS_NULL_CB 554 }; 555 556 _DIAGASSERT(pai != NULL); 557 /* hostname may be NULL */ 558 /* servname may be NULL */ 559 _DIAGASSERT(res != NULL); 560 561 result = NULL; 562 563 /* 564 * if the servname does not match socktype/protocol, ignore it. 565 */ 566 if (get_portmatch(pai, servname) != 0) 567 return 0; 568 569 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 570 default_dns_files, hostname, pai)) { 571 case NS_TRYAGAIN: 572 error = EAI_AGAIN; 573 goto free; 574 case NS_UNAVAIL: 575 error = EAI_FAIL; 576 goto free; 577 case NS_NOTFOUND: 578 error = EAI_NODATA; 579 goto free; 580 case NS_SUCCESS: 581 error = 0; 582 for (cur = result; cur; cur = cur->ai_next) { 583 GET_PORT(cur, servname); 584 /* canonname should be filled already */ 585 } 586 break; 587 } 588 589 *res = result; 590 591 return 0; 592 593 free: 594 if (result) 595 freeaddrinfo(result); 596 return error; 597 } 598 599 /* 600 * hostname == NULL. 601 * passive socket -> anyaddr (0.0.0.0 or ::) 602 * non-passive socket -> localhost (127.0.0.1 or ::1) 603 */ 604 static int 605 explore_null(const struct addrinfo *pai, const char *servname, 606 struct addrinfo **res) 607 { 608 int s; 609 const struct afd *afd; 610 struct addrinfo *cur; 611 struct addrinfo sentinel; 612 int error; 613 614 _DIAGASSERT(pai != NULL); 615 /* servname may be NULL */ 616 _DIAGASSERT(res != NULL); 617 618 *res = NULL; 619 sentinel.ai_next = NULL; 620 cur = &sentinel; 621 622 /* 623 * filter out AFs that are not supported by the kernel 624 * XXX errno? 625 */ 626 s = socket(pai->ai_family, SOCK_DGRAM, 0); 627 if (s < 0) { 628 if (errno != EMFILE) 629 return 0; 630 } else 631 close(s); 632 633 /* 634 * if the servname does not match socktype/protocol, ignore it. 635 */ 636 if (get_portmatch(pai, servname) != 0) 637 return 0; 638 639 afd = find_afd(pai->ai_family); 640 if (afd == NULL) 641 return 0; 642 643 if (pai->ai_flags & AI_PASSIVE) { 644 GET_AI(cur->ai_next, afd, afd->a_addrany); 645 /* xxx meaningless? 646 * GET_CANONNAME(cur->ai_next, "anyaddr"); 647 */ 648 GET_PORT(cur->ai_next, servname); 649 } else { 650 GET_AI(cur->ai_next, afd, afd->a_loopback); 651 /* xxx meaningless? 652 * GET_CANONNAME(cur->ai_next, "localhost"); 653 */ 654 GET_PORT(cur->ai_next, servname); 655 } 656 cur = cur->ai_next; 657 658 *res = sentinel.ai_next; 659 return 0; 660 661 free: 662 if (sentinel.ai_next) 663 freeaddrinfo(sentinel.ai_next); 664 return error; 665 } 666 667 /* 668 * numeric hostname 669 */ 670 static int 671 explore_numeric(const struct addrinfo *pai, const char *hostname, 672 const char *servname, struct addrinfo **res, const char *canonname) 673 { 674 const struct afd *afd; 675 struct addrinfo *cur; 676 struct addrinfo sentinel; 677 int error; 678 char pton[PTON_MAX]; 679 680 _DIAGASSERT(pai != NULL); 681 /* hostname may be NULL */ 682 /* servname may be NULL */ 683 _DIAGASSERT(res != NULL); 684 685 *res = NULL; 686 sentinel.ai_next = NULL; 687 cur = &sentinel; 688 689 /* 690 * if the servname does not match socktype/protocol, ignore it. 691 */ 692 if (get_portmatch(pai, servname) != 0) 693 return 0; 694 695 afd = find_afd(pai->ai_family); 696 if (afd == NULL) 697 return 0; 698 699 switch (afd->a_af) { 700 #if 0 /*X/Open spec*/ 701 case AF_INET: 702 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 703 if (pai->ai_family == afd->a_af || 704 pai->ai_family == PF_UNSPEC /*?*/) { 705 GET_AI(cur->ai_next, afd, pton); 706 GET_PORT(cur->ai_next, servname); 707 if ((pai->ai_flags & AI_CANONNAME)) { 708 /* 709 * Set the numeric address itself as 710 * the canonical name, based on a 711 * clarification in rfc2553bis-03. 712 */ 713 GET_CANONNAME(cur->ai_next, canonname); 714 } 715 while (cur && cur->ai_next) 716 cur = cur->ai_next; 717 } else 718 ERR(EAI_FAMILY); /*xxx*/ 719 } 720 break; 721 #endif 722 default: 723 if (inet_pton(afd->a_af, hostname, pton) == 1) { 724 if (pai->ai_family == afd->a_af || 725 pai->ai_family == PF_UNSPEC /*?*/) { 726 GET_AI(cur->ai_next, afd, pton); 727 GET_PORT(cur->ai_next, servname); 728 if ((pai->ai_flags & AI_CANONNAME)) { 729 /* 730 * Set the numeric address itself as 731 * the canonical name, based on a 732 * clarification in rfc2553bis-03. 733 */ 734 GET_CANONNAME(cur->ai_next, canonname); 735 } 736 while (cur->ai_next) 737 cur = cur->ai_next; 738 } else 739 ERR(EAI_FAMILY); /*xxx*/ 740 } 741 break; 742 } 743 744 *res = sentinel.ai_next; 745 return 0; 746 747 free: 748 bad: 749 if (sentinel.ai_next) 750 freeaddrinfo(sentinel.ai_next); 751 return error; 752 } 753 754 /* 755 * numeric hostname with scope 756 */ 757 static int 758 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 759 const char *servname, struct addrinfo **res) 760 { 761 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 762 return explore_numeric(pai, hostname, servname, res, hostname); 763 #else 764 const struct afd *afd; 765 struct addrinfo *cur; 766 int error; 767 char *cp, *hostname2 = NULL, *scope, *addr; 768 struct sockaddr_in6 *sin6; 769 770 _DIAGASSERT(pai != NULL); 771 /* hostname may be NULL */ 772 /* servname may be NULL */ 773 _DIAGASSERT(res != NULL); 774 775 /* 776 * if the servname does not match socktype/protocol, ignore it. 777 */ 778 if (get_portmatch(pai, servname) != 0) 779 return 0; 780 781 afd = find_afd(pai->ai_family); 782 if (afd == NULL) 783 return 0; 784 785 if (!afd->a_scoped) 786 return explore_numeric(pai, hostname, servname, res, hostname); 787 788 cp = strchr(hostname, SCOPE_DELIMITER); 789 if (cp == NULL) 790 return explore_numeric(pai, hostname, servname, res, hostname); 791 792 /* 793 * Handle special case of <scoped_address><delimiter><scope id> 794 */ 795 hostname2 = strdup(hostname); 796 if (hostname2 == NULL) 797 return EAI_MEMORY; 798 /* terminate at the delimiter */ 799 hostname2[cp - hostname] = '\0'; 800 addr = hostname2; 801 scope = cp + 1; 802 803 error = explore_numeric(pai, addr, servname, res, hostname); 804 if (error == 0) { 805 u_int32_t scopeid; 806 807 for (cur = *res; cur; cur = cur->ai_next) { 808 if (cur->ai_family != AF_INET6) 809 continue; 810 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 811 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 812 free(hostname2); 813 return(EAI_NODATA); /* XXX: is return OK? */ 814 } 815 sin6->sin6_scope_id = scopeid; 816 } 817 } 818 819 free(hostname2); 820 821 return error; 822 #endif 823 } 824 825 static int 826 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 827 { 828 829 _DIAGASSERT(pai != NULL); 830 _DIAGASSERT(ai != NULL); 831 _DIAGASSERT(str != NULL); 832 833 if ((pai->ai_flags & AI_CANONNAME) != 0) { 834 ai->ai_canonname = strdup(str); 835 if (ai->ai_canonname == NULL) 836 return EAI_MEMORY; 837 } 838 return 0; 839 } 840 841 static struct addrinfo * 842 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 843 { 844 char *p; 845 struct addrinfo *ai; 846 847 _DIAGASSERT(pai != NULL); 848 _DIAGASSERT(afd != NULL); 849 _DIAGASSERT(addr != NULL); 850 851 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 852 + (afd->a_socklen)); 853 if (ai == NULL) 854 return NULL; 855 856 memcpy(ai, pai, sizeof(struct addrinfo)); 857 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 858 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 859 ai->ai_addr->sa_len = afd->a_socklen; 860 ai->ai_addrlen = afd->a_socklen; 861 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 862 p = (char *)(void *)(ai->ai_addr); 863 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 864 return ai; 865 } 866 867 static int 868 get_portmatch(const struct addrinfo *ai, const char *servname) 869 { 870 871 _DIAGASSERT(ai != NULL); 872 /* servname may be NULL */ 873 874 return get_port(ai, servname, 1); 875 } 876 877 static int 878 get_port(const struct addrinfo *ai, const char *servname, int matchonly) 879 { 880 const char *proto; 881 struct servent *sp; 882 int port; 883 int allownumeric; 884 885 _DIAGASSERT(ai != NULL); 886 /* servname may be NULL */ 887 888 if (servname == NULL) 889 return 0; 890 switch (ai->ai_family) { 891 case AF_INET: 892 #ifdef AF_INET6 893 case AF_INET6: 894 #endif 895 break; 896 default: 897 return 0; 898 } 899 900 switch (ai->ai_socktype) { 901 case SOCK_RAW: 902 return EAI_SERVICE; 903 case SOCK_DGRAM: 904 case SOCK_STREAM: 905 allownumeric = 1; 906 break; 907 case ANY: 908 allownumeric = 0; 909 break; 910 default: 911 return EAI_SOCKTYPE; 912 } 913 914 port = str2number(servname); 915 if (port >= 0) { 916 if (!allownumeric) 917 return EAI_SERVICE; 918 if (port < 0 || port > 65535) 919 return EAI_SERVICE; 920 port = htons(port); 921 } else { 922 struct servent_data svd; 923 struct servent sv; 924 if (ai->ai_flags & AI_NUMERICSERV) 925 return EAI_NONAME; 926 927 switch (ai->ai_socktype) { 928 case SOCK_DGRAM: 929 proto = "udp"; 930 break; 931 case SOCK_STREAM: 932 proto = "tcp"; 933 break; 934 default: 935 proto = NULL; 936 break; 937 } 938 939 (void)memset(&svd, 0, sizeof(svd)); 940 sp = getservbyname_r(servname, proto, &sv, &svd); 941 endservent_r(&svd); 942 if (sp == NULL) 943 return EAI_SERVICE; 944 port = sp->s_port; 945 } 946 947 if (!matchonly) { 948 switch (ai->ai_family) { 949 case AF_INET: 950 ((struct sockaddr_in *)(void *) 951 ai->ai_addr)->sin_port = port; 952 break; 953 #ifdef INET6 954 case AF_INET6: 955 ((struct sockaddr_in6 *)(void *) 956 ai->ai_addr)->sin6_port = port; 957 break; 958 #endif 959 } 960 } 961 962 return 0; 963 } 964 965 static const struct afd * 966 find_afd(int af) 967 { 968 const struct afd *afd; 969 970 if (af == PF_UNSPEC) 971 return NULL; 972 for (afd = afdl; afd->a_af; afd++) { 973 if (afd->a_af == af) 974 return afd; 975 } 976 return NULL; 977 } 978 979 #ifdef INET6 980 /* convert a string to a scope identifier. XXX: IPv6 specific */ 981 static int 982 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 983 { 984 u_long lscopeid; 985 struct in6_addr *a6; 986 char *ep; 987 988 _DIAGASSERT(scope != NULL); 989 _DIAGASSERT(sin6 != NULL); 990 _DIAGASSERT(scopeid != NULL); 991 992 a6 = &sin6->sin6_addr; 993 994 /* empty scopeid portion is invalid */ 995 if (*scope == '\0') 996 return -1; 997 998 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 999 /* 1000 * We currently assume a one-to-one mapping between links 1001 * and interfaces, so we simply use interface indices for 1002 * like-local scopes. 1003 */ 1004 *scopeid = if_nametoindex(scope); 1005 if (*scopeid == 0) 1006 goto trynumeric; 1007 return 0; 1008 } 1009 1010 /* still unclear about literal, allow numeric only - placeholder */ 1011 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1012 goto trynumeric; 1013 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1014 goto trynumeric; 1015 else 1016 goto trynumeric; /* global */ 1017 1018 /* try to convert to a numeric id as a last resort */ 1019 trynumeric: 1020 errno = 0; 1021 lscopeid = strtoul(scope, &ep, 10); 1022 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1023 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1024 return 0; 1025 else 1026 return -1; 1027 } 1028 #endif 1029 1030 /* code duplicate with gethnamaddr.c */ 1031 1032 static const char AskedForGot[] = 1033 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1034 1035 static struct addrinfo * 1036 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1037 const struct addrinfo *pai) 1038 { 1039 struct addrinfo sentinel, *cur; 1040 struct addrinfo ai; 1041 const struct afd *afd; 1042 char *canonname; 1043 const HEADER *hp; 1044 const u_char *cp; 1045 int n; 1046 const u_char *eom; 1047 char *bp, *ep; 1048 int type, class, ancount, qdcount; 1049 int haveanswer, had_error; 1050 char tbuf[MAXDNAME]; 1051 int (*name_ok) (const char *); 1052 char hostbuf[8*1024]; 1053 1054 _DIAGASSERT(answer != NULL); 1055 _DIAGASSERT(qname != NULL); 1056 _DIAGASSERT(pai != NULL); 1057 1058 memset(&sentinel, 0, sizeof(sentinel)); 1059 cur = &sentinel; 1060 1061 canonname = NULL; 1062 eom = answer->buf + anslen; 1063 switch (qtype) { 1064 case T_A: 1065 case T_AAAA: 1066 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1067 name_ok = res_hnok; 1068 break; 1069 default: 1070 return NULL; /* XXX should be abort(); */ 1071 } 1072 /* 1073 * find first satisfactory answer 1074 */ 1075 hp = &answer->hdr; 1076 ancount = ntohs(hp->ancount); 1077 qdcount = ntohs(hp->qdcount); 1078 bp = hostbuf; 1079 ep = hostbuf + sizeof hostbuf; 1080 cp = answer->buf + HFIXEDSZ; 1081 if (qdcount != 1) { 1082 h_errno = NO_RECOVERY; 1083 return (NULL); 1084 } 1085 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1086 if ((n < 0) || !(*name_ok)(bp)) { 1087 h_errno = NO_RECOVERY; 1088 return (NULL); 1089 } 1090 cp += n + QFIXEDSZ; 1091 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1092 /* res_send() has already verified that the query name is the 1093 * same as the one we sent; this just gets the expanded name 1094 * (i.e., with the succeeding search-domain tacked on). 1095 */ 1096 n = strlen(bp) + 1; /* for the \0 */ 1097 if (n >= MAXHOSTNAMELEN) { 1098 h_errno = NO_RECOVERY; 1099 return (NULL); 1100 } 1101 canonname = bp; 1102 bp += n; 1103 /* The qname can be abbreviated, but h_name is now absolute. */ 1104 qname = canonname; 1105 } 1106 haveanswer = 0; 1107 had_error = 0; 1108 while (ancount-- > 0 && cp < eom && !had_error) { 1109 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1110 if ((n < 0) || !(*name_ok)(bp)) { 1111 had_error++; 1112 continue; 1113 } 1114 cp += n; /* name */ 1115 type = _getshort(cp); 1116 cp += INT16SZ; /* type */ 1117 class = _getshort(cp); 1118 cp += INT16SZ + INT32SZ; /* class, TTL */ 1119 n = _getshort(cp); 1120 cp += INT16SZ; /* len */ 1121 if (class != C_IN) { 1122 /* XXX - debug? syslog? */ 1123 cp += n; 1124 continue; /* XXX - had_error++ ? */ 1125 } 1126 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1127 type == T_CNAME) { 1128 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1129 if ((n < 0) || !(*name_ok)(tbuf)) { 1130 had_error++; 1131 continue; 1132 } 1133 cp += n; 1134 /* Get canonical name. */ 1135 n = strlen(tbuf) + 1; /* for the \0 */ 1136 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1137 had_error++; 1138 continue; 1139 } 1140 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1141 canonname = bp; 1142 bp += n; 1143 continue; 1144 } 1145 if (qtype == T_ANY) { 1146 if (!(type == T_A || type == T_AAAA)) { 1147 cp += n; 1148 continue; 1149 } 1150 } else if (type != qtype) { 1151 if (type != T_KEY && type != T_SIG) 1152 syslog(LOG_NOTICE|LOG_AUTH, 1153 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1154 qname, p_class(C_IN), p_type(qtype), 1155 p_type(type)); 1156 cp += n; 1157 continue; /* XXX - had_error++ ? */ 1158 } 1159 switch (type) { 1160 case T_A: 1161 case T_AAAA: 1162 if (strcasecmp(canonname, bp) != 0) { 1163 syslog(LOG_NOTICE|LOG_AUTH, 1164 AskedForGot, canonname, bp); 1165 cp += n; 1166 continue; /* XXX - had_error++ ? */ 1167 } 1168 if (type == T_A && n != INADDRSZ) { 1169 cp += n; 1170 continue; 1171 } 1172 if (type == T_AAAA && n != IN6ADDRSZ) { 1173 cp += n; 1174 continue; 1175 } 1176 if (type == T_AAAA) { 1177 struct in6_addr in6; 1178 memcpy(&in6, cp, IN6ADDRSZ); 1179 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1180 cp += n; 1181 continue; 1182 } 1183 } 1184 if (!haveanswer) { 1185 int nn; 1186 1187 canonname = bp; 1188 nn = strlen(bp) + 1; /* for the \0 */ 1189 bp += nn; 1190 } 1191 1192 /* don't overwrite pai */ 1193 ai = *pai; 1194 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1195 afd = find_afd(ai.ai_family); 1196 if (afd == NULL) { 1197 cp += n; 1198 continue; 1199 } 1200 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1201 if (cur->ai_next == NULL) 1202 had_error++; 1203 while (cur && cur->ai_next) 1204 cur = cur->ai_next; 1205 cp += n; 1206 break; 1207 default: 1208 abort(); 1209 } 1210 if (!had_error) 1211 haveanswer++; 1212 } 1213 if (haveanswer) { 1214 if (!canonname) 1215 (void)get_canonname(pai, sentinel.ai_next, qname); 1216 else 1217 (void)get_canonname(pai, sentinel.ai_next, canonname); 1218 h_errno = NETDB_SUCCESS; 1219 return sentinel.ai_next; 1220 } 1221 1222 h_errno = NO_RECOVERY; 1223 return NULL; 1224 } 1225 1226 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr) 1227 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr) 1228 1229 static void 1230 aisort(struct addrinfo *s, res_state res) 1231 { 1232 struct addrinfo head, *t, *p; 1233 int i; 1234 1235 head.ai_next = NULL; 1236 t = &head; 1237 1238 for (i = 0; i < res->nsort; i++) { 1239 p = s; 1240 while (p->ai_next) { 1241 if ((p->ai_next->ai_family != AF_INET) 1242 || SORTMATCH(p, res->sort_list[i])) { 1243 t->ai_next = p->ai_next; 1244 t = t->ai_next; 1245 p->ai_next = p->ai_next->ai_next; 1246 } else { 1247 p = p->ai_next; 1248 } 1249 } 1250 } 1251 1252 /* add rest of list and reset s to the new list*/ 1253 t->ai_next = s->ai_next; 1254 s->ai_next = head.ai_next; 1255 } 1256 1257 /*ARGSUSED*/ 1258 static int 1259 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1260 { 1261 struct addrinfo *ai; 1262 querybuf *buf, *buf2; 1263 const char *name; 1264 const struct addrinfo *pai; 1265 struct addrinfo sentinel, *cur; 1266 struct res_target q, q2; 1267 res_state res; 1268 1269 name = va_arg(ap, char *); 1270 pai = va_arg(ap, const struct addrinfo *); 1271 1272 memset(&q, 0, sizeof(q)); 1273 memset(&q2, 0, sizeof(q2)); 1274 memset(&sentinel, 0, sizeof(sentinel)); 1275 cur = &sentinel; 1276 1277 buf = malloc(sizeof(*buf)); 1278 if (buf == NULL) { 1279 h_errno = NETDB_INTERNAL; 1280 return NS_NOTFOUND; 1281 } 1282 buf2 = malloc(sizeof(*buf2)); 1283 if (buf2 == NULL) { 1284 free(buf); 1285 h_errno = NETDB_INTERNAL; 1286 return NS_NOTFOUND; 1287 } 1288 1289 switch (pai->ai_family) { 1290 case AF_UNSPEC: 1291 /* prefer IPv6 */ 1292 q.name = name; 1293 q.qclass = C_IN; 1294 q.qtype = T_AAAA; 1295 q.answer = buf->buf; 1296 q.anslen = sizeof(buf->buf); 1297 q.next = &q2; 1298 q2.name = name; 1299 q2.qclass = C_IN; 1300 q2.qtype = T_A; 1301 q2.answer = buf2->buf; 1302 q2.anslen = sizeof(buf2->buf); 1303 break; 1304 case AF_INET: 1305 q.name = name; 1306 q.qclass = C_IN; 1307 q.qtype = T_A; 1308 q.answer = buf->buf; 1309 q.anslen = sizeof(buf->buf); 1310 break; 1311 case AF_INET6: 1312 q.name = name; 1313 q.qclass = C_IN; 1314 q.qtype = T_AAAA; 1315 q.answer = buf->buf; 1316 q.anslen = sizeof(buf->buf); 1317 break; 1318 default: 1319 free(buf); 1320 free(buf2); 1321 return NS_UNAVAIL; 1322 } 1323 1324 res = __res_get_state(); 1325 if (res == NULL) { 1326 free(buf); 1327 free(buf2); 1328 return NS_NOTFOUND; 1329 } 1330 1331 if (res_searchN(name, &q, res) < 0) { 1332 __res_put_state(res); 1333 free(buf); 1334 free(buf2); 1335 return NS_NOTFOUND; 1336 } 1337 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1338 if (ai) { 1339 cur->ai_next = ai; 1340 while (cur && cur->ai_next) 1341 cur = cur->ai_next; 1342 } 1343 if (q.next) { 1344 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1345 if (ai) 1346 cur->ai_next = ai; 1347 } 1348 free(buf); 1349 free(buf2); 1350 if (sentinel.ai_next == NULL) { 1351 __res_put_state(res); 1352 switch (h_errno) { 1353 case HOST_NOT_FOUND: 1354 return NS_NOTFOUND; 1355 case TRY_AGAIN: 1356 return NS_TRYAGAIN; 1357 default: 1358 return NS_UNAVAIL; 1359 } 1360 } 1361 1362 if (res->nsort) 1363 aisort(&sentinel, res); 1364 1365 __res_put_state(res); 1366 1367 *((struct addrinfo **)rv) = sentinel.ai_next; 1368 return NS_SUCCESS; 1369 } 1370 1371 static void 1372 _sethtent(FILE **hostf) 1373 { 1374 1375 if (!*hostf) 1376 *hostf = fopen(_PATH_HOSTS, "r" ); 1377 else 1378 rewind(*hostf); 1379 } 1380 1381 static void 1382 _endhtent(FILE **hostf) 1383 { 1384 1385 if (*hostf) { 1386 (void) fclose(*hostf); 1387 *hostf = NULL; 1388 } 1389 } 1390 1391 static struct addrinfo * 1392 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1393 { 1394 char *p; 1395 char *cp, *tname, *cname; 1396 struct addrinfo hints, *res0, *res; 1397 int error; 1398 const char *addr; 1399 char hostbuf[8*1024]; 1400 1401 _DIAGASSERT(name != NULL); 1402 _DIAGASSERT(pai != NULL); 1403 1404 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r" ))) 1405 return (NULL); 1406 again: 1407 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 1408 return (NULL); 1409 if (*p == '#') 1410 goto again; 1411 if (!(cp = strpbrk(p, "#\n"))) 1412 goto again; 1413 *cp = '\0'; 1414 if (!(cp = strpbrk(p, " \t"))) 1415 goto again; 1416 *cp++ = '\0'; 1417 addr = p; 1418 /* if this is not something we're looking for, skip it. */ 1419 cname = NULL; 1420 while (cp && *cp) { 1421 if (*cp == ' ' || *cp == '\t') { 1422 cp++; 1423 continue; 1424 } 1425 if (!cname) 1426 cname = cp; 1427 tname = cp; 1428 if ((cp = strpbrk(cp, " \t")) != NULL) 1429 *cp++ = '\0'; 1430 if (strcasecmp(name, tname) == 0) 1431 goto found; 1432 } 1433 goto again; 1434 1435 found: 1436 hints = *pai; 1437 hints.ai_flags = AI_NUMERICHOST; 1438 error = getaddrinfo(addr, NULL, &hints, &res0); 1439 if (error) 1440 goto again; 1441 for (res = res0; res; res = res->ai_next) { 1442 /* cover it up */ 1443 res->ai_flags = pai->ai_flags; 1444 1445 if (pai->ai_flags & AI_CANONNAME) { 1446 if (get_canonname(pai, res, cname) != 0) { 1447 freeaddrinfo(res0); 1448 goto again; 1449 } 1450 } 1451 } 1452 return res0; 1453 } 1454 1455 /*ARGSUSED*/ 1456 static int 1457 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1458 { 1459 const char *name; 1460 const struct addrinfo *pai; 1461 struct addrinfo sentinel, *cur; 1462 struct addrinfo *p; 1463 #ifndef _REENTRANT 1464 static 1465 #endif 1466 FILE *hostf = NULL; 1467 1468 name = va_arg(ap, char *); 1469 pai = va_arg(ap, struct addrinfo *); 1470 1471 memset(&sentinel, 0, sizeof(sentinel)); 1472 cur = &sentinel; 1473 1474 _sethtent(&hostf); 1475 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1476 cur->ai_next = p; 1477 while (cur && cur->ai_next) 1478 cur = cur->ai_next; 1479 } 1480 _endhtent(&hostf); 1481 1482 *((struct addrinfo **)rv) = sentinel.ai_next; 1483 if (sentinel.ai_next == NULL) 1484 return NS_NOTFOUND; 1485 return NS_SUCCESS; 1486 } 1487 1488 #ifdef YP 1489 /*ARGSUSED*/ 1490 static struct addrinfo * 1491 _yphostent(char *line, const struct addrinfo *pai) 1492 { 1493 struct addrinfo sentinel, *cur; 1494 struct addrinfo hints, *res, *res0; 1495 int error; 1496 char *p; 1497 const char *addr, *canonname; 1498 char *nextline; 1499 char *cp; 1500 1501 _DIAGASSERT(line != NULL); 1502 _DIAGASSERT(pai != NULL); 1503 1504 p = line; 1505 addr = canonname = NULL; 1506 1507 memset(&sentinel, 0, sizeof(sentinel)); 1508 cur = &sentinel; 1509 1510 nextline: 1511 /* terminate line */ 1512 cp = strchr(p, '\n'); 1513 if (cp) { 1514 *cp++ = '\0'; 1515 nextline = cp; 1516 } else 1517 nextline = NULL; 1518 1519 cp = strpbrk(p, " \t"); 1520 if (cp == NULL) { 1521 if (canonname == NULL) 1522 return (NULL); 1523 else 1524 goto done; 1525 } 1526 *cp++ = '\0'; 1527 1528 addr = p; 1529 1530 while (cp && *cp) { 1531 if (*cp == ' ' || *cp == '\t') { 1532 cp++; 1533 continue; 1534 } 1535 if (!canonname) 1536 canonname = cp; 1537 if ((cp = strpbrk(cp, " \t")) != NULL) 1538 *cp++ = '\0'; 1539 } 1540 1541 hints = *pai; 1542 hints.ai_flags = AI_NUMERICHOST; 1543 error = getaddrinfo(addr, NULL, &hints, &res0); 1544 if (error == 0) { 1545 for (res = res0; res; res = res->ai_next) { 1546 /* cover it up */ 1547 res->ai_flags = pai->ai_flags; 1548 1549 if (pai->ai_flags & AI_CANONNAME) 1550 (void)get_canonname(pai, res, canonname); 1551 } 1552 } else 1553 res0 = NULL; 1554 if (res0) { 1555 cur->ai_next = res0; 1556 while (cur->ai_next) 1557 cur = cur->ai_next; 1558 } 1559 1560 if (nextline) { 1561 p = nextline; 1562 goto nextline; 1563 } 1564 1565 done: 1566 return sentinel.ai_next; 1567 } 1568 1569 /*ARGSUSED*/ 1570 static int 1571 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1572 { 1573 struct addrinfo sentinel, *cur; 1574 struct addrinfo *ai = NULL; 1575 char *ypbuf; 1576 int ypbuflen, r; 1577 const char *name; 1578 const struct addrinfo *pai; 1579 char *ypdomain; 1580 1581 if (_yp_check(&ypdomain) == 0) 1582 return NS_UNAVAIL; 1583 1584 name = va_arg(ap, char *); 1585 pai = va_arg(ap, const struct addrinfo *); 1586 1587 memset(&sentinel, 0, sizeof(sentinel)); 1588 cur = &sentinel; 1589 1590 /* hosts.byname is only for IPv4 (Solaris8) */ 1591 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1592 r = yp_match(ypdomain, "hosts.byname", name, 1593 (int)strlen(name), &ypbuf, &ypbuflen); 1594 if (r == 0) { 1595 struct addrinfo ai4; 1596 1597 ai4 = *pai; 1598 ai4.ai_family = AF_INET; 1599 ai = _yphostent(ypbuf, &ai4); 1600 if (ai) { 1601 cur->ai_next = ai; 1602 while (cur && cur->ai_next) 1603 cur = cur->ai_next; 1604 } 1605 } 1606 free(ypbuf); 1607 } 1608 1609 /* ipnodes.byname can hold both IPv4/v6 */ 1610 r = yp_match(ypdomain, "ipnodes.byname", name, 1611 (int)strlen(name), &ypbuf, &ypbuflen); 1612 if (r == 0) { 1613 ai = _yphostent(ypbuf, pai); 1614 if (ai) 1615 cur->ai_next = ai; 1616 free(ypbuf); 1617 } 1618 1619 if (sentinel.ai_next == NULL) { 1620 h_errno = HOST_NOT_FOUND; 1621 return NS_NOTFOUND; 1622 } 1623 *((struct addrinfo **)rv) = sentinel.ai_next; 1624 return NS_SUCCESS; 1625 } 1626 #endif 1627 1628 /* resolver logic */ 1629 1630 /* 1631 * Formulate a normal query, send, and await answer. 1632 * Returned answer is placed in supplied buffer "answer". 1633 * Perform preliminary check of answer, returning success only 1634 * if no error is indicated and the answer count is nonzero. 1635 * Return the size of the response on success, -1 on error. 1636 * Error number is left in h_errno. 1637 * 1638 * Caller must parse answer and determine whether it answers the question. 1639 */ 1640 static int 1641 res_queryN(const char *name, /* domain name */ struct res_target *target, 1642 res_state res) 1643 { 1644 u_char buf[MAXPACKET]; 1645 HEADER *hp; 1646 int n; 1647 struct res_target *t; 1648 int rcode; 1649 int ancount; 1650 1651 _DIAGASSERT(name != NULL); 1652 /* XXX: target may be NULL??? */ 1653 1654 rcode = NOERROR; 1655 ancount = 0; 1656 1657 for (t = target; t; t = t->next) { 1658 int class, type; 1659 u_char *answer; 1660 int anslen; 1661 1662 hp = (HEADER *)(void *)t->answer; 1663 hp->rcode = NOERROR; /* default */ 1664 1665 /* make it easier... */ 1666 class = t->qclass; 1667 type = t->qtype; 1668 answer = t->answer; 1669 anslen = t->anslen; 1670 #ifdef DEBUG 1671 if (res->options & RES_DEBUG) 1672 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 1673 #endif 1674 1675 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 1676 buf, sizeof(buf)); 1677 #ifdef RES_USE_EDNS0 1678 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 1679 n = res_nopt(res, n, buf, sizeof(buf), anslen); 1680 #endif 1681 if (n <= 0) { 1682 #ifdef DEBUG 1683 if (res->options & RES_DEBUG) 1684 printf(";; res_nquery: mkquery failed\n"); 1685 #endif 1686 h_errno = NO_RECOVERY; 1687 return n; 1688 } 1689 n = res_nsend(res, buf, n, answer, anslen); 1690 #if 0 1691 if (n < 0) { 1692 #ifdef DEBUG 1693 if (res->options & RES_DEBUG) 1694 printf(";; res_query: send error\n"); 1695 #endif 1696 h_errno = TRY_AGAIN; 1697 return n; 1698 } 1699 #endif 1700 1701 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1702 rcode = hp->rcode; /* record most recent error */ 1703 #ifdef DEBUG 1704 if (res->options & RES_DEBUG) 1705 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1706 ntohs(hp->ancount)); 1707 #endif 1708 continue; 1709 } 1710 1711 ancount += ntohs(hp->ancount); 1712 1713 t->n = n; 1714 } 1715 1716 if (ancount == 0) { 1717 switch (rcode) { 1718 case NXDOMAIN: 1719 h_errno = HOST_NOT_FOUND; 1720 break; 1721 case SERVFAIL: 1722 h_errno = TRY_AGAIN; 1723 break; 1724 case NOERROR: 1725 h_errno = NO_DATA; 1726 break; 1727 case FORMERR: 1728 case NOTIMP: 1729 case REFUSED: 1730 default: 1731 h_errno = NO_RECOVERY; 1732 break; 1733 } 1734 return -1; 1735 } 1736 return ancount; 1737 } 1738 1739 /* 1740 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1741 * Return the size of the response on success, -1 on error. 1742 * If enabled, implement search rules until answer or unrecoverable failure 1743 * is detected. Error code, if any, is left in h_errno. 1744 */ 1745 static int 1746 res_searchN(const char *name, struct res_target *target, res_state res) 1747 { 1748 const char *cp, * const *domain; 1749 HEADER *hp; 1750 u_int dots; 1751 int trailing_dot, ret, saved_herrno; 1752 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1753 1754 _DIAGASSERT(name != NULL); 1755 _DIAGASSERT(target != NULL); 1756 1757 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1758 1759 errno = 0; 1760 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1761 dots = 0; 1762 for (cp = name; *cp; cp++) 1763 dots += (*cp == '.'); 1764 trailing_dot = 0; 1765 if (cp > name && *--cp == '.') 1766 trailing_dot++; 1767 1768 /* 1769 * if there aren't any dots, it could be a user-level alias 1770 */ 1771 if (!dots && (cp = __hostalias(name)) != NULL) { 1772 ret = res_queryN(cp, target, res); 1773 return ret; 1774 } 1775 1776 /* 1777 * If there are dots in the name already, let's just give it a try 1778 * 'as is'. The threshold can be set with the "ndots" option. 1779 */ 1780 saved_herrno = -1; 1781 if (dots >= res->ndots) { 1782 ret = res_querydomainN(name, NULL, target, res); 1783 if (ret > 0) 1784 return (ret); 1785 saved_herrno = h_errno; 1786 tried_as_is++; 1787 } 1788 1789 /* 1790 * We do at least one level of search if 1791 * - there is no dot and RES_DEFNAME is set, or 1792 * - there is at least one dot, there is no trailing dot, 1793 * and RES_DNSRCH is set. 1794 */ 1795 if ((!dots && (res->options & RES_DEFNAMES)) || 1796 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 1797 int done = 0; 1798 1799 for (domain = (const char * const *)res->dnsrch; 1800 *domain && !done; 1801 domain++) { 1802 1803 ret = res_querydomainN(name, *domain, target, res); 1804 if (ret > 0) 1805 return ret; 1806 1807 /* 1808 * If no server present, give up. 1809 * If name isn't found in this domain, 1810 * keep trying higher domains in the search list 1811 * (if that's enabled). 1812 * On a NO_DATA error, keep trying, otherwise 1813 * a wildcard entry of another type could keep us 1814 * from finding this entry higher in the domain. 1815 * If we get some other error (negative answer or 1816 * server failure), then stop searching up, 1817 * but try the input name below in case it's 1818 * fully-qualified. 1819 */ 1820 if (errno == ECONNREFUSED) { 1821 h_errno = TRY_AGAIN; 1822 return -1; 1823 } 1824 1825 switch (h_errno) { 1826 case NO_DATA: 1827 got_nodata++; 1828 /* FALLTHROUGH */ 1829 case HOST_NOT_FOUND: 1830 /* keep trying */ 1831 break; 1832 case TRY_AGAIN: 1833 if (hp->rcode == SERVFAIL) { 1834 /* try next search element, if any */ 1835 got_servfail++; 1836 break; 1837 } 1838 /* FALLTHROUGH */ 1839 default: 1840 /* anything else implies that we're done */ 1841 done++; 1842 } 1843 /* 1844 * if we got here for some reason other than DNSRCH, 1845 * we only wanted one iteration of the loop, so stop. 1846 */ 1847 if (!(res->options & RES_DNSRCH)) 1848 done++; 1849 } 1850 } 1851 1852 /* 1853 * if we have not already tried the name "as is", do that now. 1854 * note that we do this regardless of how many dots were in the 1855 * name or whether it ends with a dot. 1856 */ 1857 if (!tried_as_is) { 1858 ret = res_querydomainN(name, NULL, target, res); 1859 if (ret > 0) 1860 return ret; 1861 } 1862 1863 /* 1864 * if we got here, we didn't satisfy the search. 1865 * if we did an initial full query, return that query's h_errno 1866 * (note that we wouldn't be here if that query had succeeded). 1867 * else if we ever got a nodata, send that back as the reason. 1868 * else send back meaningless h_errno, that being the one from 1869 * the last DNSRCH we did. 1870 */ 1871 if (saved_herrno != -1) 1872 h_errno = saved_herrno; 1873 else if (got_nodata) 1874 h_errno = NO_DATA; 1875 else if (got_servfail) 1876 h_errno = TRY_AGAIN; 1877 return -1; 1878 } 1879 1880 /* 1881 * Perform a call on res_query on the concatenation of name and domain, 1882 * removing a trailing dot from name if domain is NULL. 1883 */ 1884 static int 1885 res_querydomainN(const char *name, const char *domain, 1886 struct res_target *target, res_state res) 1887 { 1888 char nbuf[MAXDNAME]; 1889 const char *longname = nbuf; 1890 size_t n, d; 1891 1892 _DIAGASSERT(name != NULL); 1893 /* XXX: target may be NULL??? */ 1894 1895 #ifdef DEBUG 1896 if (res->options & RES_DEBUG) 1897 printf(";; res_querydomain(%s, %s)\n", 1898 name, domain?domain:"<Nil>"); 1899 #endif 1900 if (domain == NULL) { 1901 /* 1902 * Check for trailing '.'; 1903 * copy without '.' if present. 1904 */ 1905 n = strlen(name); 1906 if (n + 1 > sizeof(nbuf)) { 1907 h_errno = NO_RECOVERY; 1908 return -1; 1909 } 1910 if (n > 0 && name[--n] == '.') { 1911 strncpy(nbuf, name, n); 1912 nbuf[n] = '\0'; 1913 } else 1914 longname = name; 1915 } else { 1916 n = strlen(name); 1917 d = strlen(domain); 1918 if (n + 1 + d + 1 > sizeof(nbuf)) { 1919 h_errno = NO_RECOVERY; 1920 return -1; 1921 } 1922 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1923 } 1924 return res_queryN(longname, target, res); 1925 } 1926