1 /* $NetBSD: getaddrinfo.c,v 1.91 2008/04/19 07:56:34 lukem 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 1.91 2008/04/19 07:56:34 lukem 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 **, struct servent_data *); 196 static int explore_null(const struct addrinfo *, 197 const char *, struct addrinfo **, struct servent_data *); 198 static int explore_numeric(const struct addrinfo *, const char *, 199 const char *, struct addrinfo **, const char *, struct servent_data *); 200 static int explore_numeric_scope(const struct addrinfo *, const char *, 201 const char *, struct addrinfo **, struct servent_data *); 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 struct servent_data *); 208 static int get_port(const struct addrinfo *, const char *, int, 209 struct servent_data *); 210 static const struct afd *find_afd(int); 211 #ifdef INET6 212 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 213 #endif 214 215 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 216 const struct addrinfo *); 217 static void aisort(struct addrinfo *s, res_state res); 218 static int _dns_getaddrinfo(void *, void *, va_list); 219 static void _sethtent(FILE **); 220 static void _endhtent(FILE **); 221 static struct addrinfo *_gethtent(FILE **, const char *, 222 const struct addrinfo *); 223 static int _files_getaddrinfo(void *, void *, va_list); 224 #ifdef YP 225 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 226 static int _yp_getaddrinfo(void *, void *, va_list); 227 #endif 228 229 static int res_queryN(const char *, struct res_target *, res_state); 230 static int res_searchN(const char *, struct res_target *, res_state); 231 static int res_querydomainN(const char *, const char *, 232 struct res_target *, res_state); 233 234 static const char * const ai_errlist[] = { 235 "Success", 236 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 237 "Temporary failure in name resolution", /* EAI_AGAIN */ 238 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 239 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 240 "ai_family not supported", /* EAI_FAMILY */ 241 "Memory allocation failure", /* EAI_MEMORY */ 242 "No address associated with hostname", /* EAI_NODATA */ 243 "hostname nor servname provided, or not known", /* EAI_NONAME */ 244 "servname not supported for ai_socktype", /* EAI_SERVICE */ 245 "ai_socktype not supported", /* EAI_SOCKTYPE */ 246 "System error returned in errno", /* EAI_SYSTEM */ 247 "Invalid value for hints", /* EAI_BADHINTS */ 248 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 249 "Argument buffer overflow", /* EAI_OVERFLOW */ 250 "Unknown error", /* EAI_MAX */ 251 }; 252 253 /* XXX macros that make external reference is BAD. */ 254 255 #define GET_AI(ai, afd, addr) \ 256 do { \ 257 /* external reference: pai, error, and label free */ \ 258 (ai) = get_ai(pai, (afd), (addr)); \ 259 if ((ai) == NULL) { \ 260 error = EAI_MEMORY; \ 261 goto free; \ 262 } \ 263 } while (/*CONSTCOND*/0) 264 265 #define GET_PORT(ai, serv, svd) \ 266 do { \ 267 /* external reference: error and label free */ \ 268 error = get_port((ai), (serv), 0, (svd)); \ 269 if (error != 0) \ 270 goto free; \ 271 } while (/*CONSTCOND*/0) 272 273 #define GET_CANONNAME(ai, str) \ 274 do { \ 275 /* external reference: pai, error and label free */ \ 276 error = get_canonname(pai, (ai), (str)); \ 277 if (error != 0) \ 278 goto free; \ 279 } while (/*CONSTCOND*/0) 280 281 #define ERR(err) \ 282 do { \ 283 /* external reference: error, and label bad */ \ 284 error = (err); \ 285 goto bad; \ 286 /*NOTREACHED*/ \ 287 } while (/*CONSTCOND*/0) 288 289 #define MATCH_FAMILY(x, y, w) \ 290 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || \ 291 (y) == PF_UNSPEC))) 292 #define MATCH(x, y, w) \ 293 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 294 295 const char * 296 gai_strerror(int ecode) 297 { 298 if (ecode < 0 || ecode > EAI_MAX) 299 ecode = EAI_MAX; 300 return ai_errlist[ecode]; 301 } 302 303 void 304 freeaddrinfo(struct addrinfo *ai) 305 { 306 struct addrinfo *next; 307 308 _DIAGASSERT(ai != NULL); 309 310 do { 311 next = ai->ai_next; 312 if (ai->ai_canonname) 313 free(ai->ai_canonname); 314 /* no need to free(ai->ai_addr) */ 315 free(ai); 316 ai = next; 317 } while (ai); 318 } 319 320 static int 321 str2number(const char *p) 322 { 323 char *ep; 324 unsigned long v; 325 326 _DIAGASSERT(p != NULL); 327 328 if (*p == '\0') 329 return -1; 330 ep = NULL; 331 errno = 0; 332 v = strtoul(p, &ep, 10); 333 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) 334 return v; 335 else 336 return -1; 337 } 338 339 int 340 getaddrinfo(const char *hostname, const char *servname, 341 const struct addrinfo *hints, struct addrinfo **res) 342 { 343 struct addrinfo sentinel; 344 struct addrinfo *cur; 345 int error = 0; 346 struct addrinfo ai; 347 struct addrinfo ai0; 348 struct addrinfo *pai; 349 const struct explore *ex; 350 struct servent_data svd; 351 352 /* hostname is allowed to be NULL */ 353 /* servname is allowed to be NULL */ 354 /* hints is allowed to be NULL */ 355 _DIAGASSERT(res != NULL); 356 357 (void)memset(&svd, 0, sizeof(svd)); 358 memset(&sentinel, 0, sizeof(sentinel)); 359 cur = &sentinel; 360 memset(&ai, 0, sizeof(ai)); 361 pai = &ai; 362 pai->ai_flags = 0; 363 pai->ai_family = PF_UNSPEC; 364 pai->ai_socktype = ANY; 365 pai->ai_protocol = ANY; 366 pai->ai_addrlen = 0; 367 pai->ai_canonname = NULL; 368 pai->ai_addr = NULL; 369 pai->ai_next = NULL; 370 371 if (hostname == NULL && servname == NULL) 372 return EAI_NONAME; 373 if (hints) { 374 /* error check for hints */ 375 if (hints->ai_addrlen || hints->ai_canonname || 376 hints->ai_addr || hints->ai_next) 377 ERR(EAI_BADHINTS); /* xxx */ 378 if (hints->ai_flags & ~AI_MASK) 379 ERR(EAI_BADFLAGS); 380 switch (hints->ai_family) { 381 case PF_UNSPEC: 382 case PF_INET: 383 #ifdef INET6 384 case PF_INET6: 385 #endif 386 break; 387 default: 388 ERR(EAI_FAMILY); 389 } 390 memcpy(pai, hints, sizeof(*pai)); 391 392 /* 393 * if both socktype/protocol are specified, check if they 394 * are meaningful combination. 395 */ 396 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 397 for (ex = explore; ex->e_af >= 0; ex++) { 398 if (pai->ai_family != ex->e_af) 399 continue; 400 if (ex->e_socktype == ANY) 401 continue; 402 if (ex->e_protocol == ANY) 403 continue; 404 if (pai->ai_socktype == ex->e_socktype 405 && pai->ai_protocol != ex->e_protocol) { 406 ERR(EAI_BADHINTS); 407 } 408 } 409 } 410 } 411 412 /* 413 * check for special cases. (1) numeric servname is disallowed if 414 * socktype/protocol are left unspecified. (2) servname is disallowed 415 * for raw and other inet{,6} sockets. 416 */ 417 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 418 #ifdef PF_INET6 419 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 420 #endif 421 ) { 422 ai0 = *pai; /* backup *pai */ 423 424 if (pai->ai_family == PF_UNSPEC) { 425 #ifdef PF_INET6 426 pai->ai_family = PF_INET6; 427 #else 428 pai->ai_family = PF_INET; 429 #endif 430 } 431 error = get_portmatch(pai, servname, &svd); 432 if (error) 433 ERR(error); 434 435 *pai = ai0; 436 } 437 438 ai0 = *pai; 439 440 /* NULL hostname, or numeric hostname */ 441 for (ex = explore; ex->e_af >= 0; ex++) { 442 *pai = ai0; 443 444 /* PF_UNSPEC entries are prepared for DNS queries only */ 445 if (ex->e_af == PF_UNSPEC) 446 continue; 447 448 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 449 continue; 450 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 451 continue; 452 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 453 continue; 454 455 if (pai->ai_family == PF_UNSPEC) 456 pai->ai_family = ex->e_af; 457 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 458 pai->ai_socktype = ex->e_socktype; 459 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 460 pai->ai_protocol = ex->e_protocol; 461 462 if (hostname == NULL) 463 error = explore_null(pai, servname, &cur->ai_next, 464 &svd); 465 else 466 error = explore_numeric_scope(pai, hostname, servname, 467 &cur->ai_next, &svd); 468 469 if (error) 470 goto free; 471 472 while (cur->ai_next) 473 cur = cur->ai_next; 474 } 475 476 /* 477 * XXX 478 * If numeric representation of AF1 can be interpreted as FQDN 479 * representation of AF2, we need to think again about the code below. 480 */ 481 if (sentinel.ai_next) 482 goto good; 483 484 if (hostname == NULL) 485 ERR(EAI_NODATA); 486 if (pai->ai_flags & AI_NUMERICHOST) 487 ERR(EAI_NONAME); 488 489 /* 490 * hostname as alphabetical name. 491 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 492 * outer loop by AFs. 493 */ 494 for (ex = explore; ex->e_af >= 0; ex++) { 495 *pai = ai0; 496 497 /* require exact match for family field */ 498 if (pai->ai_family != ex->e_af) 499 continue; 500 501 if (!MATCH(pai->ai_socktype, ex->e_socktype, 502 WILD_SOCKTYPE(ex))) { 503 continue; 504 } 505 if (!MATCH(pai->ai_protocol, ex->e_protocol, 506 WILD_PROTOCOL(ex))) { 507 continue; 508 } 509 510 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 511 pai->ai_socktype = ex->e_socktype; 512 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 513 pai->ai_protocol = ex->e_protocol; 514 515 error = explore_fqdn(pai, hostname, servname, &cur->ai_next, 516 &svd); 517 518 while (cur && cur->ai_next) 519 cur = cur->ai_next; 520 } 521 522 /* XXX */ 523 if (sentinel.ai_next) 524 error = 0; 525 526 if (error) 527 goto free; 528 529 if (sentinel.ai_next) { 530 good: 531 endservent_r(&svd); 532 *res = sentinel.ai_next; 533 return SUCCESS; 534 } else 535 error = EAI_FAIL; 536 free: 537 bad: 538 endservent_r(&svd); 539 if (sentinel.ai_next) 540 freeaddrinfo(sentinel.ai_next); 541 *res = NULL; 542 return error; 543 } 544 545 /* 546 * FQDN hostname, DNS lookup 547 */ 548 static int 549 explore_fqdn(const struct addrinfo *pai, const char *hostname, 550 const char *servname, struct addrinfo **res, struct servent_data *svd) 551 { 552 struct addrinfo *result; 553 struct addrinfo *cur; 554 int error = 0; 555 static const ns_dtab dtab[] = { 556 NS_FILES_CB(_files_getaddrinfo, NULL) 557 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 558 NS_NIS_CB(_yp_getaddrinfo, NULL) 559 NS_NULL_CB 560 }; 561 562 _DIAGASSERT(pai != NULL); 563 /* hostname may be NULL */ 564 /* servname may be NULL */ 565 _DIAGASSERT(res != NULL); 566 567 result = NULL; 568 569 /* 570 * if the servname does not match socktype/protocol, ignore it. 571 */ 572 if (get_portmatch(pai, servname, svd) != 0) 573 return 0; 574 575 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 576 default_dns_files, hostname, pai)) { 577 case NS_TRYAGAIN: 578 error = EAI_AGAIN; 579 goto free; 580 case NS_UNAVAIL: 581 error = EAI_FAIL; 582 goto free; 583 case NS_NOTFOUND: 584 error = EAI_NODATA; 585 goto free; 586 case NS_SUCCESS: 587 error = 0; 588 for (cur = result; cur; cur = cur->ai_next) { 589 GET_PORT(cur, servname, svd); 590 /* canonname should be filled already */ 591 } 592 break; 593 } 594 595 *res = result; 596 597 return 0; 598 599 free: 600 if (result) 601 freeaddrinfo(result); 602 return error; 603 } 604 605 /* 606 * hostname == NULL. 607 * passive socket -> anyaddr (0.0.0.0 or ::) 608 * non-passive socket -> localhost (127.0.0.1 or ::1) 609 */ 610 static int 611 explore_null(const struct addrinfo *pai, const char *servname, 612 struct addrinfo **res, struct servent_data *svd) 613 { 614 int s; 615 const struct afd *afd; 616 struct addrinfo *cur; 617 struct addrinfo sentinel; 618 int error; 619 620 _DIAGASSERT(pai != NULL); 621 /* servname may be NULL */ 622 _DIAGASSERT(res != NULL); 623 624 *res = NULL; 625 sentinel.ai_next = NULL; 626 cur = &sentinel; 627 628 /* 629 * filter out AFs that are not supported by the kernel 630 * XXX errno? 631 */ 632 s = socket(pai->ai_family, SOCK_DGRAM, 0); 633 if (s < 0) { 634 if (errno != EMFILE) 635 return 0; 636 } else 637 close(s); 638 639 /* 640 * if the servname does not match socktype/protocol, ignore it. 641 */ 642 if (get_portmatch(pai, servname, svd) != 0) 643 return 0; 644 645 afd = find_afd(pai->ai_family); 646 if (afd == NULL) 647 return 0; 648 649 if (pai->ai_flags & AI_PASSIVE) { 650 GET_AI(cur->ai_next, afd, afd->a_addrany); 651 /* xxx meaningless? 652 * GET_CANONNAME(cur->ai_next, "anyaddr"); 653 */ 654 GET_PORT(cur->ai_next, servname, svd); 655 } else { 656 GET_AI(cur->ai_next, afd, afd->a_loopback); 657 /* xxx meaningless? 658 * GET_CANONNAME(cur->ai_next, "localhost"); 659 */ 660 GET_PORT(cur->ai_next, servname, svd); 661 } 662 cur = cur->ai_next; 663 664 *res = sentinel.ai_next; 665 return 0; 666 667 free: 668 if (sentinel.ai_next) 669 freeaddrinfo(sentinel.ai_next); 670 return error; 671 } 672 673 /* 674 * numeric hostname 675 */ 676 static int 677 explore_numeric(const struct addrinfo *pai, const char *hostname, 678 const char *servname, struct addrinfo **res, const char *canonname, 679 struct servent_data *svd) 680 { 681 const struct afd *afd; 682 struct addrinfo *cur; 683 struct addrinfo sentinel; 684 int error; 685 char pton[PTON_MAX]; 686 687 _DIAGASSERT(pai != NULL); 688 /* hostname may be NULL */ 689 /* servname may be NULL */ 690 _DIAGASSERT(res != NULL); 691 692 *res = NULL; 693 sentinel.ai_next = NULL; 694 cur = &sentinel; 695 696 /* 697 * if the servname does not match socktype/protocol, ignore it. 698 */ 699 if (get_portmatch(pai, servname, svd) != 0) 700 return 0; 701 702 afd = find_afd(pai->ai_family); 703 if (afd == NULL) 704 return 0; 705 706 switch (afd->a_af) { 707 #if 0 /*X/Open spec*/ 708 case AF_INET: 709 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 710 if (pai->ai_family == afd->a_af || 711 pai->ai_family == PF_UNSPEC /*?*/) { 712 GET_AI(cur->ai_next, afd, pton); 713 GET_PORT(cur->ai_next, servname, svd); 714 if ((pai->ai_flags & AI_CANONNAME)) { 715 /* 716 * Set the numeric address itself as 717 * the canonical name, based on a 718 * clarification in rfc2553bis-03. 719 */ 720 GET_CANONNAME(cur->ai_next, canonname); 721 } 722 while (cur && cur->ai_next) 723 cur = cur->ai_next; 724 } else 725 ERR(EAI_FAMILY); /*xxx*/ 726 } 727 break; 728 #endif 729 default: 730 if (inet_pton(afd->a_af, hostname, pton) == 1) { 731 if (pai->ai_family == afd->a_af || 732 pai->ai_family == PF_UNSPEC /*?*/) { 733 GET_AI(cur->ai_next, afd, pton); 734 GET_PORT(cur->ai_next, servname, svd); 735 if ((pai->ai_flags & AI_CANONNAME)) { 736 /* 737 * Set the numeric address itself as 738 * the canonical name, based on a 739 * clarification in rfc2553bis-03. 740 */ 741 GET_CANONNAME(cur->ai_next, canonname); 742 } 743 while (cur->ai_next) 744 cur = cur->ai_next; 745 } else 746 ERR(EAI_FAMILY); /*xxx*/ 747 } 748 break; 749 } 750 751 *res = sentinel.ai_next; 752 return 0; 753 754 free: 755 bad: 756 if (sentinel.ai_next) 757 freeaddrinfo(sentinel.ai_next); 758 return error; 759 } 760 761 /* 762 * numeric hostname with scope 763 */ 764 static int 765 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 766 const char *servname, struct addrinfo **res, struct servent_data *svd) 767 { 768 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 769 return explore_numeric(pai, hostname, servname, res, hostname, svd); 770 #else 771 const struct afd *afd; 772 struct addrinfo *cur; 773 int error; 774 char *cp, *hostname2 = NULL, *scope, *addr; 775 struct sockaddr_in6 *sin6; 776 777 _DIAGASSERT(pai != NULL); 778 /* hostname may be NULL */ 779 /* servname may be NULL */ 780 _DIAGASSERT(res != NULL); 781 782 /* 783 * if the servname does not match socktype/protocol, ignore it. 784 */ 785 if (get_portmatch(pai, servname, svd) != 0) 786 return 0; 787 788 afd = find_afd(pai->ai_family); 789 if (afd == NULL) 790 return 0; 791 792 if (!afd->a_scoped) 793 return explore_numeric(pai, hostname, servname, res, hostname, 794 svd); 795 796 cp = strchr(hostname, SCOPE_DELIMITER); 797 if (cp == NULL) 798 return explore_numeric(pai, hostname, servname, res, hostname, 799 svd); 800 801 /* 802 * Handle special case of <scoped_address><delimiter><scope id> 803 */ 804 hostname2 = strdup(hostname); 805 if (hostname2 == NULL) 806 return EAI_MEMORY; 807 /* terminate at the delimiter */ 808 hostname2[cp - hostname] = '\0'; 809 addr = hostname2; 810 scope = cp + 1; 811 812 error = explore_numeric(pai, addr, servname, res, hostname, svd); 813 if (error == 0) { 814 u_int32_t scopeid; 815 816 for (cur = *res; cur; cur = cur->ai_next) { 817 if (cur->ai_family != AF_INET6) 818 continue; 819 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 820 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 821 free(hostname2); 822 return(EAI_NODATA); /* XXX: is return OK? */ 823 } 824 sin6->sin6_scope_id = scopeid; 825 } 826 } 827 828 free(hostname2); 829 830 return error; 831 #endif 832 } 833 834 static int 835 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 836 { 837 838 _DIAGASSERT(pai != NULL); 839 _DIAGASSERT(ai != NULL); 840 _DIAGASSERT(str != NULL); 841 842 if ((pai->ai_flags & AI_CANONNAME) != 0) { 843 ai->ai_canonname = strdup(str); 844 if (ai->ai_canonname == NULL) 845 return EAI_MEMORY; 846 } 847 return 0; 848 } 849 850 static struct addrinfo * 851 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 852 { 853 char *p; 854 struct addrinfo *ai; 855 856 _DIAGASSERT(pai != NULL); 857 _DIAGASSERT(afd != NULL); 858 _DIAGASSERT(addr != NULL); 859 860 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 861 + (afd->a_socklen)); 862 if (ai == NULL) 863 return NULL; 864 865 memcpy(ai, pai, sizeof(struct addrinfo)); 866 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 867 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 868 ai->ai_addr->sa_len = afd->a_socklen; 869 ai->ai_addrlen = afd->a_socklen; 870 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 871 p = (char *)(void *)(ai->ai_addr); 872 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 873 return ai; 874 } 875 876 static int 877 get_portmatch(const struct addrinfo *ai, const char *servname, 878 struct servent_data *svd) 879 { 880 881 _DIAGASSERT(ai != NULL); 882 /* servname may be NULL */ 883 884 return get_port(ai, servname, 1, svd); 885 } 886 887 static int 888 get_port(const struct addrinfo *ai, const char *servname, int matchonly, 889 struct servent_data *svd) 890 { 891 const char *proto; 892 struct servent *sp; 893 int port; 894 int allownumeric; 895 896 _DIAGASSERT(ai != NULL); 897 /* servname may be NULL */ 898 899 if (servname == NULL) 900 return 0; 901 switch (ai->ai_family) { 902 case AF_INET: 903 #ifdef AF_INET6 904 case AF_INET6: 905 #endif 906 break; 907 default: 908 return 0; 909 } 910 911 switch (ai->ai_socktype) { 912 case SOCK_RAW: 913 return EAI_SERVICE; 914 case SOCK_DGRAM: 915 case SOCK_STREAM: 916 allownumeric = 1; 917 break; 918 case ANY: 919 allownumeric = 0; 920 break; 921 default: 922 return EAI_SOCKTYPE; 923 } 924 925 port = str2number(servname); 926 if (port >= 0) { 927 if (!allownumeric) 928 return EAI_SERVICE; 929 if (port < 0 || port > 65535) 930 return EAI_SERVICE; 931 port = htons(port); 932 } else { 933 struct servent sv; 934 if (ai->ai_flags & AI_NUMERICSERV) 935 return EAI_NONAME; 936 937 switch (ai->ai_socktype) { 938 case SOCK_DGRAM: 939 proto = "udp"; 940 break; 941 case SOCK_STREAM: 942 proto = "tcp"; 943 break; 944 default: 945 proto = NULL; 946 break; 947 } 948 949 sp = getservbyname_r(servname, proto, &sv, svd); 950 if (sp == NULL) 951 return EAI_SERVICE; 952 port = sp->s_port; 953 } 954 955 if (!matchonly) { 956 switch (ai->ai_family) { 957 case AF_INET: 958 ((struct sockaddr_in *)(void *) 959 ai->ai_addr)->sin_port = port; 960 break; 961 #ifdef INET6 962 case AF_INET6: 963 ((struct sockaddr_in6 *)(void *) 964 ai->ai_addr)->sin6_port = port; 965 break; 966 #endif 967 } 968 } 969 970 return 0; 971 } 972 973 static const struct afd * 974 find_afd(int af) 975 { 976 const struct afd *afd; 977 978 if (af == PF_UNSPEC) 979 return NULL; 980 for (afd = afdl; afd->a_af; afd++) { 981 if (afd->a_af == af) 982 return afd; 983 } 984 return NULL; 985 } 986 987 #ifdef INET6 988 /* convert a string to a scope identifier. XXX: IPv6 specific */ 989 static int 990 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 991 { 992 u_long lscopeid; 993 struct in6_addr *a6; 994 char *ep; 995 996 _DIAGASSERT(scope != NULL); 997 _DIAGASSERT(sin6 != NULL); 998 _DIAGASSERT(scopeid != NULL); 999 1000 a6 = &sin6->sin6_addr; 1001 1002 /* empty scopeid portion is invalid */ 1003 if (*scope == '\0') 1004 return -1; 1005 1006 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1007 /* 1008 * We currently assume a one-to-one mapping between links 1009 * and interfaces, so we simply use interface indices for 1010 * like-local scopes. 1011 */ 1012 *scopeid = if_nametoindex(scope); 1013 if (*scopeid == 0) 1014 goto trynumeric; 1015 return 0; 1016 } 1017 1018 /* still unclear about literal, allow numeric only - placeholder */ 1019 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1020 goto trynumeric; 1021 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1022 goto trynumeric; 1023 else 1024 goto trynumeric; /* global */ 1025 1026 /* try to convert to a numeric id as a last resort */ 1027 trynumeric: 1028 errno = 0; 1029 lscopeid = strtoul(scope, &ep, 10); 1030 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1031 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1032 return 0; 1033 else 1034 return -1; 1035 } 1036 #endif 1037 1038 /* code duplicate with gethnamaddr.c */ 1039 1040 static const char AskedForGot[] = 1041 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1042 1043 static struct addrinfo * 1044 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1045 const struct addrinfo *pai) 1046 { 1047 struct addrinfo sentinel, *cur; 1048 struct addrinfo ai; 1049 const struct afd *afd; 1050 char *canonname; 1051 const HEADER *hp; 1052 const u_char *cp; 1053 int n; 1054 const u_char *eom; 1055 char *bp, *ep; 1056 int type, class, ancount, qdcount; 1057 int haveanswer, had_error; 1058 char tbuf[MAXDNAME]; 1059 int (*name_ok) (const char *); 1060 char hostbuf[8*1024]; 1061 1062 _DIAGASSERT(answer != NULL); 1063 _DIAGASSERT(qname != NULL); 1064 _DIAGASSERT(pai != NULL); 1065 1066 memset(&sentinel, 0, sizeof(sentinel)); 1067 cur = &sentinel; 1068 1069 canonname = NULL; 1070 eom = answer->buf + anslen; 1071 switch (qtype) { 1072 case T_A: 1073 case T_AAAA: 1074 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1075 name_ok = res_hnok; 1076 break; 1077 default: 1078 return NULL; /* XXX should be abort(); */ 1079 } 1080 /* 1081 * find first satisfactory answer 1082 */ 1083 hp = &answer->hdr; 1084 ancount = ntohs(hp->ancount); 1085 qdcount = ntohs(hp->qdcount); 1086 bp = hostbuf; 1087 ep = hostbuf + sizeof hostbuf; 1088 cp = answer->buf + HFIXEDSZ; 1089 if (qdcount != 1) { 1090 h_errno = NO_RECOVERY; 1091 return (NULL); 1092 } 1093 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1094 if ((n < 0) || !(*name_ok)(bp)) { 1095 h_errno = NO_RECOVERY; 1096 return (NULL); 1097 } 1098 cp += n + QFIXEDSZ; 1099 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1100 /* res_send() has already verified that the query name is the 1101 * same as the one we sent; this just gets the expanded name 1102 * (i.e., with the succeeding search-domain tacked on). 1103 */ 1104 n = strlen(bp) + 1; /* for the \0 */ 1105 if (n >= MAXHOSTNAMELEN) { 1106 h_errno = NO_RECOVERY; 1107 return (NULL); 1108 } 1109 canonname = bp; 1110 bp += n; 1111 /* The qname can be abbreviated, but h_name is now absolute. */ 1112 qname = canonname; 1113 } 1114 haveanswer = 0; 1115 had_error = 0; 1116 while (ancount-- > 0 && cp < eom && !had_error) { 1117 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1118 if ((n < 0) || !(*name_ok)(bp)) { 1119 had_error++; 1120 continue; 1121 } 1122 cp += n; /* name */ 1123 type = _getshort(cp); 1124 cp += INT16SZ; /* type */ 1125 class = _getshort(cp); 1126 cp += INT16SZ + INT32SZ; /* class, TTL */ 1127 n = _getshort(cp); 1128 cp += INT16SZ; /* len */ 1129 if (class != C_IN) { 1130 /* XXX - debug? syslog? */ 1131 cp += n; 1132 continue; /* XXX - had_error++ ? */ 1133 } 1134 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1135 type == T_CNAME) { 1136 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1137 if ((n < 0) || !(*name_ok)(tbuf)) { 1138 had_error++; 1139 continue; 1140 } 1141 cp += n; 1142 /* Get canonical name. */ 1143 n = strlen(tbuf) + 1; /* for the \0 */ 1144 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1145 had_error++; 1146 continue; 1147 } 1148 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1149 canonname = bp; 1150 bp += n; 1151 continue; 1152 } 1153 if (qtype == T_ANY) { 1154 if (!(type == T_A || type == T_AAAA)) { 1155 cp += n; 1156 continue; 1157 } 1158 } else if (type != qtype) { 1159 if (type != T_KEY && type != T_SIG) { 1160 struct syslog_data sd = SYSLOG_DATA_INIT; 1161 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1162 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1163 qname, p_class(C_IN), p_type(qtype), 1164 p_type(type)); 1165 } 1166 cp += n; 1167 continue; /* XXX - had_error++ ? */ 1168 } 1169 switch (type) { 1170 case T_A: 1171 case T_AAAA: 1172 if (strcasecmp(canonname, bp) != 0) { 1173 struct syslog_data sd = SYSLOG_DATA_INIT; 1174 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1175 AskedForGot, canonname, bp); 1176 cp += n; 1177 continue; /* XXX - had_error++ ? */ 1178 } 1179 if (type == T_A && n != INADDRSZ) { 1180 cp += n; 1181 continue; 1182 } 1183 if (type == T_AAAA && n != IN6ADDRSZ) { 1184 cp += n; 1185 continue; 1186 } 1187 if (type == T_AAAA) { 1188 struct in6_addr in6; 1189 memcpy(&in6, cp, IN6ADDRSZ); 1190 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1191 cp += n; 1192 continue; 1193 } 1194 } 1195 if (!haveanswer) { 1196 int nn; 1197 1198 canonname = bp; 1199 nn = strlen(bp) + 1; /* for the \0 */ 1200 bp += nn; 1201 } 1202 1203 /* don't overwrite pai */ 1204 ai = *pai; 1205 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1206 afd = find_afd(ai.ai_family); 1207 if (afd == NULL) { 1208 cp += n; 1209 continue; 1210 } 1211 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1212 if (cur->ai_next == NULL) 1213 had_error++; 1214 while (cur && cur->ai_next) 1215 cur = cur->ai_next; 1216 cp += n; 1217 break; 1218 default: 1219 abort(); 1220 } 1221 if (!had_error) 1222 haveanswer++; 1223 } 1224 if (haveanswer) { 1225 if (!canonname) 1226 (void)get_canonname(pai, sentinel.ai_next, qname); 1227 else 1228 (void)get_canonname(pai, sentinel.ai_next, canonname); 1229 h_errno = NETDB_SUCCESS; 1230 return sentinel.ai_next; 1231 } 1232 1233 h_errno = NO_RECOVERY; 1234 return NULL; 1235 } 1236 1237 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr) 1238 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr) 1239 1240 static void 1241 aisort(struct addrinfo *s, res_state res) 1242 { 1243 struct addrinfo head, *t, *p; 1244 int i; 1245 1246 head.ai_next = NULL; 1247 t = &head; 1248 1249 for (i = 0; i < res->nsort; i++) { 1250 p = s; 1251 while (p->ai_next) { 1252 if ((p->ai_next->ai_family != AF_INET) 1253 || SORTMATCH(p, res->sort_list[i])) { 1254 t->ai_next = p->ai_next; 1255 t = t->ai_next; 1256 p->ai_next = p->ai_next->ai_next; 1257 } else { 1258 p = p->ai_next; 1259 } 1260 } 1261 } 1262 1263 /* add rest of list and reset s to the new list*/ 1264 t->ai_next = s->ai_next; 1265 s->ai_next = head.ai_next; 1266 } 1267 1268 /*ARGSUSED*/ 1269 static int 1270 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1271 { 1272 struct addrinfo *ai; 1273 querybuf *buf, *buf2; 1274 const char *name; 1275 const struct addrinfo *pai; 1276 struct addrinfo sentinel, *cur; 1277 struct res_target q, q2; 1278 res_state res; 1279 1280 name = va_arg(ap, char *); 1281 pai = va_arg(ap, const struct addrinfo *); 1282 1283 memset(&q, 0, sizeof(q)); 1284 memset(&q2, 0, sizeof(q2)); 1285 memset(&sentinel, 0, sizeof(sentinel)); 1286 cur = &sentinel; 1287 1288 buf = malloc(sizeof(*buf)); 1289 if (buf == NULL) { 1290 h_errno = NETDB_INTERNAL; 1291 return NS_NOTFOUND; 1292 } 1293 buf2 = malloc(sizeof(*buf2)); 1294 if (buf2 == NULL) { 1295 free(buf); 1296 h_errno = NETDB_INTERNAL; 1297 return NS_NOTFOUND; 1298 } 1299 1300 switch (pai->ai_family) { 1301 case AF_UNSPEC: 1302 /* prefer IPv6 */ 1303 q.name = name; 1304 q.qclass = C_IN; 1305 q.qtype = T_AAAA; 1306 q.answer = buf->buf; 1307 q.anslen = sizeof(buf->buf); 1308 q.next = &q2; 1309 q2.name = name; 1310 q2.qclass = C_IN; 1311 q2.qtype = T_A; 1312 q2.answer = buf2->buf; 1313 q2.anslen = sizeof(buf2->buf); 1314 break; 1315 case AF_INET: 1316 q.name = name; 1317 q.qclass = C_IN; 1318 q.qtype = T_A; 1319 q.answer = buf->buf; 1320 q.anslen = sizeof(buf->buf); 1321 break; 1322 case AF_INET6: 1323 q.name = name; 1324 q.qclass = C_IN; 1325 q.qtype = T_AAAA; 1326 q.answer = buf->buf; 1327 q.anslen = sizeof(buf->buf); 1328 break; 1329 default: 1330 free(buf); 1331 free(buf2); 1332 return NS_UNAVAIL; 1333 } 1334 1335 res = __res_get_state(); 1336 if (res == NULL) { 1337 free(buf); 1338 free(buf2); 1339 return NS_NOTFOUND; 1340 } 1341 1342 if (res_searchN(name, &q, res) < 0) { 1343 __res_put_state(res); 1344 free(buf); 1345 free(buf2); 1346 return NS_NOTFOUND; 1347 } 1348 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1349 if (ai) { 1350 cur->ai_next = ai; 1351 while (cur && cur->ai_next) 1352 cur = cur->ai_next; 1353 } 1354 if (q.next) { 1355 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1356 if (ai) 1357 cur->ai_next = ai; 1358 } 1359 free(buf); 1360 free(buf2); 1361 if (sentinel.ai_next == NULL) { 1362 __res_put_state(res); 1363 switch (h_errno) { 1364 case HOST_NOT_FOUND: 1365 return NS_NOTFOUND; 1366 case TRY_AGAIN: 1367 return NS_TRYAGAIN; 1368 default: 1369 return NS_UNAVAIL; 1370 } 1371 } 1372 1373 if (res->nsort) 1374 aisort(&sentinel, res); 1375 1376 __res_put_state(res); 1377 1378 *((struct addrinfo **)rv) = sentinel.ai_next; 1379 return NS_SUCCESS; 1380 } 1381 1382 static void 1383 _sethtent(FILE **hostf) 1384 { 1385 1386 if (!*hostf) 1387 *hostf = fopen(_PATH_HOSTS, "r" ); 1388 else 1389 rewind(*hostf); 1390 } 1391 1392 static void 1393 _endhtent(FILE **hostf) 1394 { 1395 1396 if (*hostf) { 1397 (void) fclose(*hostf); 1398 *hostf = NULL; 1399 } 1400 } 1401 1402 static struct addrinfo * 1403 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1404 { 1405 char *p; 1406 char *cp, *tname, *cname; 1407 struct addrinfo hints, *res0, *res; 1408 int error; 1409 const char *addr; 1410 char hostbuf[8*1024]; 1411 1412 _DIAGASSERT(name != NULL); 1413 _DIAGASSERT(pai != NULL); 1414 1415 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r" ))) 1416 return (NULL); 1417 again: 1418 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 1419 return (NULL); 1420 if (*p == '#') 1421 goto again; 1422 if (!(cp = strpbrk(p, "#\n"))) 1423 goto again; 1424 *cp = '\0'; 1425 if (!(cp = strpbrk(p, " \t"))) 1426 goto again; 1427 *cp++ = '\0'; 1428 addr = p; 1429 /* if this is not something we're looking for, skip it. */ 1430 cname = NULL; 1431 while (cp && *cp) { 1432 if (*cp == ' ' || *cp == '\t') { 1433 cp++; 1434 continue; 1435 } 1436 if (!cname) 1437 cname = cp; 1438 tname = cp; 1439 if ((cp = strpbrk(cp, " \t")) != NULL) 1440 *cp++ = '\0'; 1441 if (strcasecmp(name, tname) == 0) 1442 goto found; 1443 } 1444 goto again; 1445 1446 found: 1447 hints = *pai; 1448 hints.ai_flags = AI_NUMERICHOST; 1449 error = getaddrinfo(addr, NULL, &hints, &res0); 1450 if (error) 1451 goto again; 1452 for (res = res0; res; res = res->ai_next) { 1453 /* cover it up */ 1454 res->ai_flags = pai->ai_flags; 1455 1456 if (pai->ai_flags & AI_CANONNAME) { 1457 if (get_canonname(pai, res, cname) != 0) { 1458 freeaddrinfo(res0); 1459 goto again; 1460 } 1461 } 1462 } 1463 return res0; 1464 } 1465 1466 /*ARGSUSED*/ 1467 static int 1468 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1469 { 1470 const char *name; 1471 const struct addrinfo *pai; 1472 struct addrinfo sentinel, *cur; 1473 struct addrinfo *p; 1474 #ifndef _REENTRANT 1475 static 1476 #endif 1477 FILE *hostf = NULL; 1478 1479 name = va_arg(ap, char *); 1480 pai = va_arg(ap, const struct addrinfo *); 1481 1482 memset(&sentinel, 0, sizeof(sentinel)); 1483 cur = &sentinel; 1484 1485 _sethtent(&hostf); 1486 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1487 cur->ai_next = p; 1488 while (cur && cur->ai_next) 1489 cur = cur->ai_next; 1490 } 1491 _endhtent(&hostf); 1492 1493 *((struct addrinfo **)rv) = sentinel.ai_next; 1494 if (sentinel.ai_next == NULL) 1495 return NS_NOTFOUND; 1496 return NS_SUCCESS; 1497 } 1498 1499 #ifdef YP 1500 /*ARGSUSED*/ 1501 static struct addrinfo * 1502 _yphostent(char *line, const struct addrinfo *pai) 1503 { 1504 struct addrinfo sentinel, *cur; 1505 struct addrinfo hints, *res, *res0; 1506 int error; 1507 char *p; 1508 const char *addr, *canonname; 1509 char *nextline; 1510 char *cp; 1511 1512 _DIAGASSERT(line != NULL); 1513 _DIAGASSERT(pai != NULL); 1514 1515 p = line; 1516 addr = canonname = NULL; 1517 1518 memset(&sentinel, 0, sizeof(sentinel)); 1519 cur = &sentinel; 1520 1521 nextline: 1522 /* terminate line */ 1523 cp = strchr(p, '\n'); 1524 if (cp) { 1525 *cp++ = '\0'; 1526 nextline = cp; 1527 } else 1528 nextline = NULL; 1529 1530 cp = strpbrk(p, " \t"); 1531 if (cp == NULL) { 1532 if (canonname == NULL) 1533 return (NULL); 1534 else 1535 goto done; 1536 } 1537 *cp++ = '\0'; 1538 1539 addr = p; 1540 1541 while (cp && *cp) { 1542 if (*cp == ' ' || *cp == '\t') { 1543 cp++; 1544 continue; 1545 } 1546 if (!canonname) 1547 canonname = cp; 1548 if ((cp = strpbrk(cp, " \t")) != NULL) 1549 *cp++ = '\0'; 1550 } 1551 1552 hints = *pai; 1553 hints.ai_flags = AI_NUMERICHOST; 1554 error = getaddrinfo(addr, NULL, &hints, &res0); 1555 if (error == 0) { 1556 for (res = res0; res; res = res->ai_next) { 1557 /* cover it up */ 1558 res->ai_flags = pai->ai_flags; 1559 1560 if (pai->ai_flags & AI_CANONNAME) 1561 (void)get_canonname(pai, res, canonname); 1562 } 1563 } else 1564 res0 = NULL; 1565 if (res0) { 1566 cur->ai_next = res0; 1567 while (cur->ai_next) 1568 cur = cur->ai_next; 1569 } 1570 1571 if (nextline) { 1572 p = nextline; 1573 goto nextline; 1574 } 1575 1576 done: 1577 return sentinel.ai_next; 1578 } 1579 1580 /*ARGSUSED*/ 1581 static int 1582 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1583 { 1584 struct addrinfo sentinel, *cur; 1585 struct addrinfo *ai = NULL; 1586 char *ypbuf; 1587 int ypbuflen, r; 1588 const char *name; 1589 const struct addrinfo *pai; 1590 char *ypdomain; 1591 1592 if (_yp_check(&ypdomain) == 0) 1593 return NS_UNAVAIL; 1594 1595 name = va_arg(ap, char *); 1596 pai = va_arg(ap, const struct addrinfo *); 1597 1598 memset(&sentinel, 0, sizeof(sentinel)); 1599 cur = &sentinel; 1600 1601 /* hosts.byname is only for IPv4 (Solaris8) */ 1602 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1603 r = yp_match(ypdomain, "hosts.byname", name, 1604 (int)strlen(name), &ypbuf, &ypbuflen); 1605 if (r == 0) { 1606 struct addrinfo ai4; 1607 1608 ai4 = *pai; 1609 ai4.ai_family = AF_INET; 1610 ai = _yphostent(ypbuf, &ai4); 1611 if (ai) { 1612 cur->ai_next = ai; 1613 while (cur && cur->ai_next) 1614 cur = cur->ai_next; 1615 } 1616 } 1617 free(ypbuf); 1618 } 1619 1620 /* ipnodes.byname can hold both IPv4/v6 */ 1621 r = yp_match(ypdomain, "ipnodes.byname", name, 1622 (int)strlen(name), &ypbuf, &ypbuflen); 1623 if (r == 0) { 1624 ai = _yphostent(ypbuf, pai); 1625 if (ai) 1626 cur->ai_next = ai; 1627 free(ypbuf); 1628 } 1629 1630 if (sentinel.ai_next == NULL) { 1631 h_errno = HOST_NOT_FOUND; 1632 return NS_NOTFOUND; 1633 } 1634 *((struct addrinfo **)rv) = sentinel.ai_next; 1635 return NS_SUCCESS; 1636 } 1637 #endif 1638 1639 /* resolver logic */ 1640 1641 /* 1642 * Formulate a normal query, send, and await answer. 1643 * Returned answer is placed in supplied buffer "answer". 1644 * Perform preliminary check of answer, returning success only 1645 * if no error is indicated and the answer count is nonzero. 1646 * Return the size of the response on success, -1 on error. 1647 * Error number is left in h_errno. 1648 * 1649 * Caller must parse answer and determine whether it answers the question. 1650 */ 1651 static int 1652 res_queryN(const char *name, /* domain name */ struct res_target *target, 1653 res_state res) 1654 { 1655 u_char buf[MAXPACKET]; 1656 HEADER *hp; 1657 int n; 1658 struct res_target *t; 1659 int rcode; 1660 int ancount; 1661 1662 _DIAGASSERT(name != NULL); 1663 /* XXX: target may be NULL??? */ 1664 1665 rcode = NOERROR; 1666 ancount = 0; 1667 1668 for (t = target; t; t = t->next) { 1669 int class, type; 1670 u_char *answer; 1671 int anslen; 1672 1673 hp = (HEADER *)(void *)t->answer; 1674 hp->rcode = NOERROR; /* default */ 1675 1676 /* make it easier... */ 1677 class = t->qclass; 1678 type = t->qtype; 1679 answer = t->answer; 1680 anslen = t->anslen; 1681 #ifdef DEBUG 1682 if (res->options & RES_DEBUG) 1683 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 1684 #endif 1685 1686 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 1687 buf, sizeof(buf)); 1688 #ifdef RES_USE_EDNS0 1689 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 1690 n = res_nopt(res, n, buf, sizeof(buf), anslen); 1691 #endif 1692 if (n <= 0) { 1693 #ifdef DEBUG 1694 if (res->options & RES_DEBUG) 1695 printf(";; res_nquery: mkquery failed\n"); 1696 #endif 1697 h_errno = NO_RECOVERY; 1698 return n; 1699 } 1700 n = res_nsend(res, buf, n, answer, anslen); 1701 #if 0 1702 if (n < 0) { 1703 #ifdef DEBUG 1704 if (res->options & RES_DEBUG) 1705 printf(";; res_query: send error\n"); 1706 #endif 1707 h_errno = TRY_AGAIN; 1708 return n; 1709 } 1710 #endif 1711 1712 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1713 rcode = hp->rcode; /* record most recent error */ 1714 #ifdef DEBUG 1715 if (res->options & RES_DEBUG) 1716 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1717 ntohs(hp->ancount)); 1718 #endif 1719 continue; 1720 } 1721 1722 ancount += ntohs(hp->ancount); 1723 1724 t->n = n; 1725 } 1726 1727 if (ancount == 0) { 1728 switch (rcode) { 1729 case NXDOMAIN: 1730 h_errno = HOST_NOT_FOUND; 1731 break; 1732 case SERVFAIL: 1733 h_errno = TRY_AGAIN; 1734 break; 1735 case NOERROR: 1736 h_errno = NO_DATA; 1737 break; 1738 case FORMERR: 1739 case NOTIMP: 1740 case REFUSED: 1741 default: 1742 h_errno = NO_RECOVERY; 1743 break; 1744 } 1745 return -1; 1746 } 1747 return ancount; 1748 } 1749 1750 /* 1751 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1752 * Return the size of the response on success, -1 on error. 1753 * If enabled, implement search rules until answer or unrecoverable failure 1754 * is detected. Error code, if any, is left in h_errno. 1755 */ 1756 static int 1757 res_searchN(const char *name, struct res_target *target, res_state res) 1758 { 1759 const char *cp, * const *domain; 1760 HEADER *hp; 1761 u_int dots; 1762 int trailing_dot, ret, saved_herrno; 1763 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1764 1765 _DIAGASSERT(name != NULL); 1766 _DIAGASSERT(target != NULL); 1767 1768 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1769 1770 errno = 0; 1771 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1772 dots = 0; 1773 for (cp = name; *cp; cp++) 1774 dots += (*cp == '.'); 1775 trailing_dot = 0; 1776 if (cp > name && *--cp == '.') 1777 trailing_dot++; 1778 1779 /* 1780 * if there aren't any dots, it could be a user-level alias 1781 */ 1782 if (!dots && (cp = __hostalias(name)) != NULL) { 1783 ret = res_queryN(cp, target, res); 1784 return ret; 1785 } 1786 1787 /* 1788 * If there are dots in the name already, let's just give it a try 1789 * 'as is'. The threshold can be set with the "ndots" option. 1790 */ 1791 saved_herrno = -1; 1792 if (dots >= res->ndots) { 1793 ret = res_querydomainN(name, NULL, target, res); 1794 if (ret > 0) 1795 return (ret); 1796 saved_herrno = h_errno; 1797 tried_as_is++; 1798 } 1799 1800 /* 1801 * We do at least one level of search if 1802 * - there is no dot and RES_DEFNAME is set, or 1803 * - there is at least one dot, there is no trailing dot, 1804 * and RES_DNSRCH is set. 1805 */ 1806 if ((!dots && (res->options & RES_DEFNAMES)) || 1807 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 1808 int done = 0; 1809 1810 for (domain = (const char * const *)res->dnsrch; 1811 *domain && !done; 1812 domain++) { 1813 1814 ret = res_querydomainN(name, *domain, target, res); 1815 if (ret > 0) 1816 return ret; 1817 1818 /* 1819 * If no server present, give up. 1820 * If name isn't found in this domain, 1821 * keep trying higher domains in the search list 1822 * (if that's enabled). 1823 * On a NO_DATA error, keep trying, otherwise 1824 * a wildcard entry of another type could keep us 1825 * from finding this entry higher in the domain. 1826 * If we get some other error (negative answer or 1827 * server failure), then stop searching up, 1828 * but try the input name below in case it's 1829 * fully-qualified. 1830 */ 1831 if (errno == ECONNREFUSED) { 1832 h_errno = TRY_AGAIN; 1833 return -1; 1834 } 1835 1836 switch (h_errno) { 1837 case NO_DATA: 1838 got_nodata++; 1839 /* FALLTHROUGH */ 1840 case HOST_NOT_FOUND: 1841 /* keep trying */ 1842 break; 1843 case TRY_AGAIN: 1844 if (hp->rcode == SERVFAIL) { 1845 /* try next search element, if any */ 1846 got_servfail++; 1847 break; 1848 } 1849 /* FALLTHROUGH */ 1850 default: 1851 /* anything else implies that we're done */ 1852 done++; 1853 } 1854 /* 1855 * if we got here for some reason other than DNSRCH, 1856 * we only wanted one iteration of the loop, so stop. 1857 */ 1858 if (!(res->options & RES_DNSRCH)) 1859 done++; 1860 } 1861 } 1862 1863 /* 1864 * if we have not already tried the name "as is", do that now. 1865 * note that we do this regardless of how many dots were in the 1866 * name or whether it ends with a dot. 1867 */ 1868 if (!tried_as_is) { 1869 ret = res_querydomainN(name, NULL, target, res); 1870 if (ret > 0) 1871 return ret; 1872 } 1873 1874 /* 1875 * if we got here, we didn't satisfy the search. 1876 * if we did an initial full query, return that query's h_errno 1877 * (note that we wouldn't be here if that query had succeeded). 1878 * else if we ever got a nodata, send that back as the reason. 1879 * else send back meaningless h_errno, that being the one from 1880 * the last DNSRCH we did. 1881 */ 1882 if (saved_herrno != -1) 1883 h_errno = saved_herrno; 1884 else if (got_nodata) 1885 h_errno = NO_DATA; 1886 else if (got_servfail) 1887 h_errno = TRY_AGAIN; 1888 return -1; 1889 } 1890 1891 /* 1892 * Perform a call on res_query on the concatenation of name and domain, 1893 * removing a trailing dot from name if domain is NULL. 1894 */ 1895 static int 1896 res_querydomainN(const char *name, const char *domain, 1897 struct res_target *target, res_state res) 1898 { 1899 char nbuf[MAXDNAME]; 1900 const char *longname = nbuf; 1901 size_t n, d; 1902 1903 _DIAGASSERT(name != NULL); 1904 /* XXX: target may be NULL??? */ 1905 1906 #ifdef DEBUG 1907 if (res->options & RES_DEBUG) 1908 printf(";; res_querydomain(%s, %s)\n", 1909 name, domain?domain:"<Nil>"); 1910 #endif 1911 if (domain == NULL) { 1912 /* 1913 * Check for trailing '.'; 1914 * copy without '.' if present. 1915 */ 1916 n = strlen(name); 1917 if (n + 1 > sizeof(nbuf)) { 1918 h_errno = NO_RECOVERY; 1919 return -1; 1920 } 1921 if (n > 0 && name[--n] == '.') { 1922 strncpy(nbuf, name, n); 1923 nbuf[n] = '\0'; 1924 } else 1925 longname = name; 1926 } else { 1927 n = strlen(name); 1928 d = strlen(domain); 1929 if (n + 1 + d + 1 > sizeof(nbuf)) { 1930 h_errno = NO_RECOVERY; 1931 return -1; 1932 } 1933 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1934 } 1935 return res_queryN(longname, target, res); 1936 } 1937