1 /* $NetBSD: getaddrinfo.c,v 1.95 2009/10/02 07:41:08 wiz 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 1.95 2009/10/02 07:41:08 wiz 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 struct addrinfo * 851 allocaddrinfo(socklen_t addrlen) 852 { 853 struct addrinfo *ai; 854 855 ai = calloc(sizeof(struct addrinfo) + addrlen, 1); 856 if (ai) { 857 ai->ai_addr = (void *)(ai+1); 858 ai->ai_addrlen = ai->ai_addr->sa_len = addrlen; 859 } 860 861 return ai; 862 } 863 864 static struct addrinfo * 865 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 866 { 867 char *p; 868 struct addrinfo *ai; 869 struct sockaddr *save; 870 871 _DIAGASSERT(pai != NULL); 872 _DIAGASSERT(afd != NULL); 873 _DIAGASSERT(addr != NULL); 874 875 ai = allocaddrinfo((socklen_t)afd->a_socklen); 876 if (ai == NULL) 877 return NULL; 878 879 save = ai->ai_addr; 880 memcpy(ai, pai, sizeof(struct addrinfo)); 881 882 /* since we just overwrote all of ai, we have 883 to restore ai_addr and ai_addrlen */ 884 ai->ai_addr = save; 885 ai->ai_addrlen = (socklen_t)afd->a_socklen; 886 887 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 888 p = (char *)(void *)(ai->ai_addr); 889 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 890 return ai; 891 } 892 893 static int 894 get_portmatch(const struct addrinfo *ai, const char *servname, 895 struct servent_data *svd) 896 { 897 898 _DIAGASSERT(ai != NULL); 899 /* servname may be NULL */ 900 901 return get_port(ai, servname, 1, svd); 902 } 903 904 static int 905 get_port(const struct addrinfo *ai, const char *servname, int matchonly, 906 struct servent_data *svd) 907 { 908 const char *proto; 909 struct servent *sp; 910 int port; 911 int allownumeric; 912 913 _DIAGASSERT(ai != NULL); 914 /* servname may be NULL */ 915 916 if (servname == NULL) 917 return 0; 918 switch (ai->ai_family) { 919 case AF_INET: 920 #ifdef AF_INET6 921 case AF_INET6: 922 #endif 923 break; 924 default: 925 return 0; 926 } 927 928 switch (ai->ai_socktype) { 929 case SOCK_RAW: 930 return EAI_SERVICE; 931 case SOCK_DGRAM: 932 case SOCK_STREAM: 933 allownumeric = 1; 934 break; 935 case ANY: 936 /* 937 * This was 0. It is now 1 so that queries specifying 938 * a NULL hint, or hint without socktype (but, hopefully, 939 * with protocol) and numeric address actually work. 940 */ 941 allownumeric = 1; 942 break; 943 default: 944 return EAI_SOCKTYPE; 945 } 946 947 port = str2number(servname); 948 if (port >= 0) { 949 if (!allownumeric) 950 return EAI_SERVICE; 951 if (port < 0 || port > 65535) 952 return EAI_SERVICE; 953 port = htons(port); 954 } else { 955 struct servent sv; 956 if (ai->ai_flags & AI_NUMERICSERV) 957 return EAI_NONAME; 958 959 switch (ai->ai_socktype) { 960 case SOCK_DGRAM: 961 proto = "udp"; 962 break; 963 case SOCK_STREAM: 964 proto = "tcp"; 965 break; 966 default: 967 proto = NULL; 968 break; 969 } 970 971 sp = getservbyname_r(servname, proto, &sv, svd); 972 if (sp == NULL) 973 return EAI_SERVICE; 974 port = sp->s_port; 975 } 976 977 if (!matchonly) { 978 switch (ai->ai_family) { 979 case AF_INET: 980 ((struct sockaddr_in *)(void *) 981 ai->ai_addr)->sin_port = port; 982 break; 983 #ifdef INET6 984 case AF_INET6: 985 ((struct sockaddr_in6 *)(void *) 986 ai->ai_addr)->sin6_port = port; 987 break; 988 #endif 989 } 990 } 991 992 return 0; 993 } 994 995 static const struct afd * 996 find_afd(int af) 997 { 998 const struct afd *afd; 999 1000 if (af == PF_UNSPEC) 1001 return NULL; 1002 for (afd = afdl; afd->a_af; afd++) { 1003 if (afd->a_af == af) 1004 return afd; 1005 } 1006 return NULL; 1007 } 1008 1009 #ifdef INET6 1010 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1011 static int 1012 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1013 { 1014 u_long lscopeid; 1015 struct in6_addr *a6; 1016 char *ep; 1017 1018 _DIAGASSERT(scope != NULL); 1019 _DIAGASSERT(sin6 != NULL); 1020 _DIAGASSERT(scopeid != NULL); 1021 1022 a6 = &sin6->sin6_addr; 1023 1024 /* empty scopeid portion is invalid */ 1025 if (*scope == '\0') 1026 return -1; 1027 1028 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1029 /* 1030 * We currently assume a one-to-one mapping between links 1031 * and interfaces, so we simply use interface indices for 1032 * like-local scopes. 1033 */ 1034 *scopeid = if_nametoindex(scope); 1035 if (*scopeid == 0) 1036 goto trynumeric; 1037 return 0; 1038 } 1039 1040 /* still unclear about literal, allow numeric only - placeholder */ 1041 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1042 goto trynumeric; 1043 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1044 goto trynumeric; 1045 else 1046 goto trynumeric; /* global */ 1047 1048 /* try to convert to a numeric id as a last resort */ 1049 trynumeric: 1050 errno = 0; 1051 lscopeid = strtoul(scope, &ep, 10); 1052 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1053 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1054 return 0; 1055 else 1056 return -1; 1057 } 1058 #endif 1059 1060 /* code duplicate with gethnamaddr.c */ 1061 1062 static const char AskedForGot[] = 1063 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1064 1065 static struct addrinfo * 1066 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1067 const struct addrinfo *pai) 1068 { 1069 struct addrinfo sentinel, *cur; 1070 struct addrinfo ai; 1071 const struct afd *afd; 1072 char *canonname; 1073 const HEADER *hp; 1074 const u_char *cp; 1075 int n; 1076 const u_char *eom; 1077 char *bp, *ep; 1078 int type, class, ancount, qdcount; 1079 int haveanswer, had_error; 1080 char tbuf[MAXDNAME]; 1081 int (*name_ok) (const char *); 1082 char hostbuf[8*1024]; 1083 1084 _DIAGASSERT(answer != NULL); 1085 _DIAGASSERT(qname != NULL); 1086 _DIAGASSERT(pai != NULL); 1087 1088 memset(&sentinel, 0, sizeof(sentinel)); 1089 cur = &sentinel; 1090 1091 canonname = NULL; 1092 eom = answer->buf + anslen; 1093 switch (qtype) { 1094 case T_A: 1095 case T_AAAA: 1096 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1097 name_ok = res_hnok; 1098 break; 1099 default: 1100 return NULL; /* XXX should be abort(); */ 1101 } 1102 /* 1103 * find first satisfactory answer 1104 */ 1105 hp = &answer->hdr; 1106 ancount = ntohs(hp->ancount); 1107 qdcount = ntohs(hp->qdcount); 1108 bp = hostbuf; 1109 ep = hostbuf + sizeof hostbuf; 1110 cp = answer->buf + HFIXEDSZ; 1111 if (qdcount != 1) { 1112 h_errno = NO_RECOVERY; 1113 return (NULL); 1114 } 1115 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1116 if ((n < 0) || !(*name_ok)(bp)) { 1117 h_errno = NO_RECOVERY; 1118 return (NULL); 1119 } 1120 cp += n + QFIXEDSZ; 1121 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1122 /* res_send() has already verified that the query name is the 1123 * same as the one we sent; this just gets the expanded name 1124 * (i.e., with the succeeding search-domain tacked on). 1125 */ 1126 n = strlen(bp) + 1; /* for the \0 */ 1127 if (n >= MAXHOSTNAMELEN) { 1128 h_errno = NO_RECOVERY; 1129 return (NULL); 1130 } 1131 canonname = bp; 1132 bp += n; 1133 /* The qname can be abbreviated, but h_name is now absolute. */ 1134 qname = canonname; 1135 } 1136 haveanswer = 0; 1137 had_error = 0; 1138 while (ancount-- > 0 && cp < eom && !had_error) { 1139 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1140 if ((n < 0) || !(*name_ok)(bp)) { 1141 had_error++; 1142 continue; 1143 } 1144 cp += n; /* name */ 1145 type = _getshort(cp); 1146 cp += INT16SZ; /* type */ 1147 class = _getshort(cp); 1148 cp += INT16SZ + INT32SZ; /* class, TTL */ 1149 n = _getshort(cp); 1150 cp += INT16SZ; /* len */ 1151 if (class != C_IN) { 1152 /* XXX - debug? syslog? */ 1153 cp += n; 1154 continue; /* XXX - had_error++ ? */ 1155 } 1156 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1157 type == T_CNAME) { 1158 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1159 if ((n < 0) || !(*name_ok)(tbuf)) { 1160 had_error++; 1161 continue; 1162 } 1163 cp += n; 1164 /* Get canonical name. */ 1165 n = strlen(tbuf) + 1; /* for the \0 */ 1166 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1167 had_error++; 1168 continue; 1169 } 1170 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1171 canonname = bp; 1172 bp += n; 1173 continue; 1174 } 1175 if (qtype == T_ANY) { 1176 if (!(type == T_A || type == T_AAAA)) { 1177 cp += n; 1178 continue; 1179 } 1180 } else if (type != qtype) { 1181 if (type != T_KEY && type != T_SIG) { 1182 struct syslog_data sd = SYSLOG_DATA_INIT; 1183 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1184 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1185 qname, p_class(C_IN), p_type(qtype), 1186 p_type(type)); 1187 } 1188 cp += n; 1189 continue; /* XXX - had_error++ ? */ 1190 } 1191 switch (type) { 1192 case T_A: 1193 case T_AAAA: 1194 if (strcasecmp(canonname, bp) != 0) { 1195 struct syslog_data sd = SYSLOG_DATA_INIT; 1196 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1197 AskedForGot, canonname, bp); 1198 cp += n; 1199 continue; /* XXX - had_error++ ? */ 1200 } 1201 if (type == T_A && n != INADDRSZ) { 1202 cp += n; 1203 continue; 1204 } 1205 if (type == T_AAAA && n != IN6ADDRSZ) { 1206 cp += n; 1207 continue; 1208 } 1209 if (type == T_AAAA) { 1210 struct in6_addr in6; 1211 memcpy(&in6, cp, IN6ADDRSZ); 1212 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1213 cp += n; 1214 continue; 1215 } 1216 } 1217 if (!haveanswer) { 1218 int nn; 1219 1220 canonname = bp; 1221 nn = strlen(bp) + 1; /* for the \0 */ 1222 bp += nn; 1223 } 1224 1225 /* don't overwrite pai */ 1226 ai = *pai; 1227 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1228 afd = find_afd(ai.ai_family); 1229 if (afd == NULL) { 1230 cp += n; 1231 continue; 1232 } 1233 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1234 if (cur->ai_next == NULL) 1235 had_error++; 1236 while (cur && cur->ai_next) 1237 cur = cur->ai_next; 1238 cp += n; 1239 break; 1240 default: 1241 abort(); 1242 } 1243 if (!had_error) 1244 haveanswer++; 1245 } 1246 if (haveanswer) { 1247 if (!canonname) 1248 (void)get_canonname(pai, sentinel.ai_next, qname); 1249 else 1250 (void)get_canonname(pai, sentinel.ai_next, canonname); 1251 h_errno = NETDB_SUCCESS; 1252 return sentinel.ai_next; 1253 } 1254 1255 h_errno = NO_RECOVERY; 1256 return NULL; 1257 } 1258 1259 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr) 1260 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr) 1261 1262 static void 1263 aisort(struct addrinfo *s, res_state res) 1264 { 1265 struct addrinfo head, *t, *p; 1266 int i; 1267 1268 head.ai_next = NULL; 1269 t = &head; 1270 1271 for (i = 0; i < res->nsort; i++) { 1272 p = s; 1273 while (p->ai_next) { 1274 if ((p->ai_next->ai_family != AF_INET) 1275 || SORTMATCH(p, res->sort_list[i])) { 1276 t->ai_next = p->ai_next; 1277 t = t->ai_next; 1278 p->ai_next = p->ai_next->ai_next; 1279 } else { 1280 p = p->ai_next; 1281 } 1282 } 1283 } 1284 1285 /* add rest of list and reset s to the new list*/ 1286 t->ai_next = s->ai_next; 1287 s->ai_next = head.ai_next; 1288 } 1289 1290 /*ARGSUSED*/ 1291 static int 1292 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1293 { 1294 struct addrinfo *ai; 1295 querybuf *buf, *buf2; 1296 const char *name; 1297 const struct addrinfo *pai; 1298 struct addrinfo sentinel, *cur; 1299 struct res_target q, q2; 1300 res_state res; 1301 1302 name = va_arg(ap, char *); 1303 pai = va_arg(ap, const struct addrinfo *); 1304 1305 memset(&q, 0, sizeof(q)); 1306 memset(&q2, 0, sizeof(q2)); 1307 memset(&sentinel, 0, sizeof(sentinel)); 1308 cur = &sentinel; 1309 1310 buf = malloc(sizeof(*buf)); 1311 if (buf == NULL) { 1312 h_errno = NETDB_INTERNAL; 1313 return NS_NOTFOUND; 1314 } 1315 buf2 = malloc(sizeof(*buf2)); 1316 if (buf2 == NULL) { 1317 free(buf); 1318 h_errno = NETDB_INTERNAL; 1319 return NS_NOTFOUND; 1320 } 1321 1322 switch (pai->ai_family) { 1323 case AF_UNSPEC: 1324 /* prefer IPv6 */ 1325 q.name = name; 1326 q.qclass = C_IN; 1327 q.qtype = T_AAAA; 1328 q.answer = buf->buf; 1329 q.anslen = sizeof(buf->buf); 1330 q.next = &q2; 1331 q2.name = name; 1332 q2.qclass = C_IN; 1333 q2.qtype = T_A; 1334 q2.answer = buf2->buf; 1335 q2.anslen = sizeof(buf2->buf); 1336 break; 1337 case AF_INET: 1338 q.name = name; 1339 q.qclass = C_IN; 1340 q.qtype = T_A; 1341 q.answer = buf->buf; 1342 q.anslen = sizeof(buf->buf); 1343 break; 1344 case AF_INET6: 1345 q.name = name; 1346 q.qclass = C_IN; 1347 q.qtype = T_AAAA; 1348 q.answer = buf->buf; 1349 q.anslen = sizeof(buf->buf); 1350 break; 1351 default: 1352 free(buf); 1353 free(buf2); 1354 return NS_UNAVAIL; 1355 } 1356 1357 res = __res_get_state(); 1358 if (res == NULL) { 1359 free(buf); 1360 free(buf2); 1361 return NS_NOTFOUND; 1362 } 1363 1364 if (res_searchN(name, &q, res) < 0) { 1365 __res_put_state(res); 1366 free(buf); 1367 free(buf2); 1368 return NS_NOTFOUND; 1369 } 1370 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1371 if (ai) { 1372 cur->ai_next = ai; 1373 while (cur && cur->ai_next) 1374 cur = cur->ai_next; 1375 } 1376 if (q.next) { 1377 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1378 if (ai) 1379 cur->ai_next = ai; 1380 } 1381 free(buf); 1382 free(buf2); 1383 if (sentinel.ai_next == NULL) { 1384 __res_put_state(res); 1385 switch (h_errno) { 1386 case HOST_NOT_FOUND: 1387 return NS_NOTFOUND; 1388 case TRY_AGAIN: 1389 return NS_TRYAGAIN; 1390 default: 1391 return NS_UNAVAIL; 1392 } 1393 } 1394 1395 if (res->nsort) 1396 aisort(&sentinel, res); 1397 1398 __res_put_state(res); 1399 1400 *((struct addrinfo **)rv) = sentinel.ai_next; 1401 return NS_SUCCESS; 1402 } 1403 1404 static void 1405 _sethtent(FILE **hostf) 1406 { 1407 1408 if (!*hostf) 1409 *hostf = fopen(_PATH_HOSTS, "r" ); 1410 else 1411 rewind(*hostf); 1412 } 1413 1414 static void 1415 _endhtent(FILE **hostf) 1416 { 1417 1418 if (*hostf) { 1419 (void) fclose(*hostf); 1420 *hostf = NULL; 1421 } 1422 } 1423 1424 static struct addrinfo * 1425 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1426 { 1427 char *p; 1428 char *cp, *tname, *cname; 1429 struct addrinfo hints, *res0, *res; 1430 int error; 1431 const char *addr; 1432 char hostbuf[8*1024]; 1433 1434 _DIAGASSERT(name != NULL); 1435 _DIAGASSERT(pai != NULL); 1436 1437 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r" ))) 1438 return (NULL); 1439 again: 1440 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 1441 return (NULL); 1442 if (*p == '#') 1443 goto again; 1444 if (!(cp = strpbrk(p, "#\n"))) 1445 goto again; 1446 *cp = '\0'; 1447 if (!(cp = strpbrk(p, " \t"))) 1448 goto again; 1449 *cp++ = '\0'; 1450 addr = p; 1451 /* if this is not something we're looking for, skip it. */ 1452 cname = NULL; 1453 while (cp && *cp) { 1454 if (*cp == ' ' || *cp == '\t') { 1455 cp++; 1456 continue; 1457 } 1458 if (!cname) 1459 cname = cp; 1460 tname = cp; 1461 if ((cp = strpbrk(cp, " \t")) != NULL) 1462 *cp++ = '\0'; 1463 if (strcasecmp(name, tname) == 0) 1464 goto found; 1465 } 1466 goto again; 1467 1468 found: 1469 hints = *pai; 1470 hints.ai_flags = AI_NUMERICHOST; 1471 error = getaddrinfo(addr, NULL, &hints, &res0); 1472 if (error) 1473 goto again; 1474 for (res = res0; res; res = res->ai_next) { 1475 /* cover it up */ 1476 res->ai_flags = pai->ai_flags; 1477 1478 if (pai->ai_flags & AI_CANONNAME) { 1479 if (get_canonname(pai, res, cname) != 0) { 1480 freeaddrinfo(res0); 1481 goto again; 1482 } 1483 } 1484 } 1485 return res0; 1486 } 1487 1488 /*ARGSUSED*/ 1489 static int 1490 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1491 { 1492 const char *name; 1493 const struct addrinfo *pai; 1494 struct addrinfo sentinel, *cur; 1495 struct addrinfo *p; 1496 #ifndef _REENTRANT 1497 static 1498 #endif 1499 FILE *hostf = NULL; 1500 1501 name = va_arg(ap, char *); 1502 pai = va_arg(ap, const struct addrinfo *); 1503 1504 memset(&sentinel, 0, sizeof(sentinel)); 1505 cur = &sentinel; 1506 1507 _sethtent(&hostf); 1508 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1509 cur->ai_next = p; 1510 while (cur && cur->ai_next) 1511 cur = cur->ai_next; 1512 } 1513 _endhtent(&hostf); 1514 1515 *((struct addrinfo **)rv) = sentinel.ai_next; 1516 if (sentinel.ai_next == NULL) 1517 return NS_NOTFOUND; 1518 return NS_SUCCESS; 1519 } 1520 1521 #ifdef YP 1522 /*ARGSUSED*/ 1523 static struct addrinfo * 1524 _yphostent(char *line, const struct addrinfo *pai) 1525 { 1526 struct addrinfo sentinel, *cur; 1527 struct addrinfo hints, *res, *res0; 1528 int error; 1529 char *p; 1530 const char *addr, *canonname; 1531 char *nextline; 1532 char *cp; 1533 1534 _DIAGASSERT(line != NULL); 1535 _DIAGASSERT(pai != NULL); 1536 1537 p = line; 1538 addr = canonname = NULL; 1539 1540 memset(&sentinel, 0, sizeof(sentinel)); 1541 cur = &sentinel; 1542 1543 nextline: 1544 /* terminate line */ 1545 cp = strchr(p, '\n'); 1546 if (cp) { 1547 *cp++ = '\0'; 1548 nextline = cp; 1549 } else 1550 nextline = NULL; 1551 1552 cp = strpbrk(p, " \t"); 1553 if (cp == NULL) { 1554 if (canonname == NULL) 1555 return (NULL); 1556 else 1557 goto done; 1558 } 1559 *cp++ = '\0'; 1560 1561 addr = p; 1562 1563 while (cp && *cp) { 1564 if (*cp == ' ' || *cp == '\t') { 1565 cp++; 1566 continue; 1567 } 1568 if (!canonname) 1569 canonname = cp; 1570 if ((cp = strpbrk(cp, " \t")) != NULL) 1571 *cp++ = '\0'; 1572 } 1573 1574 hints = *pai; 1575 hints.ai_flags = AI_NUMERICHOST; 1576 error = getaddrinfo(addr, NULL, &hints, &res0); 1577 if (error == 0) { 1578 for (res = res0; res; res = res->ai_next) { 1579 /* cover it up */ 1580 res->ai_flags = pai->ai_flags; 1581 1582 if (pai->ai_flags & AI_CANONNAME) 1583 (void)get_canonname(pai, res, canonname); 1584 } 1585 } else 1586 res0 = NULL; 1587 if (res0) { 1588 cur->ai_next = res0; 1589 while (cur->ai_next) 1590 cur = cur->ai_next; 1591 } 1592 1593 if (nextline) { 1594 p = nextline; 1595 goto nextline; 1596 } 1597 1598 done: 1599 return sentinel.ai_next; 1600 } 1601 1602 /*ARGSUSED*/ 1603 static int 1604 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1605 { 1606 struct addrinfo sentinel, *cur; 1607 struct addrinfo *ai = NULL; 1608 char *ypbuf; 1609 int ypbuflen, r; 1610 const char *name; 1611 const struct addrinfo *pai; 1612 char *ypdomain; 1613 1614 if (_yp_check(&ypdomain) == 0) 1615 return NS_UNAVAIL; 1616 1617 name = va_arg(ap, char *); 1618 pai = va_arg(ap, const struct addrinfo *); 1619 1620 memset(&sentinel, 0, sizeof(sentinel)); 1621 cur = &sentinel; 1622 1623 /* hosts.byname is only for IPv4 (Solaris8) */ 1624 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1625 r = yp_match(ypdomain, "hosts.byname", name, 1626 (int)strlen(name), &ypbuf, &ypbuflen); 1627 if (r == 0) { 1628 struct addrinfo ai4; 1629 1630 ai4 = *pai; 1631 ai4.ai_family = AF_INET; 1632 ai = _yphostent(ypbuf, &ai4); 1633 if (ai) { 1634 cur->ai_next = ai; 1635 while (cur && cur->ai_next) 1636 cur = cur->ai_next; 1637 } 1638 } 1639 free(ypbuf); 1640 } 1641 1642 /* ipnodes.byname can hold both IPv4/v6 */ 1643 r = yp_match(ypdomain, "ipnodes.byname", name, 1644 (int)strlen(name), &ypbuf, &ypbuflen); 1645 if (r == 0) { 1646 ai = _yphostent(ypbuf, pai); 1647 if (ai) 1648 cur->ai_next = ai; 1649 free(ypbuf); 1650 } 1651 1652 if (sentinel.ai_next == NULL) { 1653 h_errno = HOST_NOT_FOUND; 1654 return NS_NOTFOUND; 1655 } 1656 *((struct addrinfo **)rv) = sentinel.ai_next; 1657 return NS_SUCCESS; 1658 } 1659 #endif 1660 1661 /* resolver logic */ 1662 1663 /* 1664 * Formulate a normal query, send, and await answer. 1665 * Returned answer is placed in supplied buffer "answer". 1666 * Perform preliminary check of answer, returning success only 1667 * if no error is indicated and the answer count is nonzero. 1668 * Return the size of the response on success, -1 on error. 1669 * Error number is left in h_errno. 1670 * 1671 * Caller must parse answer and determine whether it answers the question. 1672 */ 1673 static int 1674 res_queryN(const char *name, /* domain name */ struct res_target *target, 1675 res_state res) 1676 { 1677 u_char buf[MAXPACKET]; 1678 HEADER *hp; 1679 int n; 1680 struct res_target *t; 1681 int rcode; 1682 int ancount; 1683 1684 _DIAGASSERT(name != NULL); 1685 /* XXX: target may be NULL??? */ 1686 1687 rcode = NOERROR; 1688 ancount = 0; 1689 1690 for (t = target; t; t = t->next) { 1691 int class, type; 1692 u_char *answer; 1693 int anslen; 1694 1695 hp = (HEADER *)(void *)t->answer; 1696 hp->rcode = NOERROR; /* default */ 1697 1698 /* make it easier... */ 1699 class = t->qclass; 1700 type = t->qtype; 1701 answer = t->answer; 1702 anslen = t->anslen; 1703 #ifdef DEBUG 1704 if (res->options & RES_DEBUG) 1705 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 1706 #endif 1707 1708 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 1709 buf, sizeof(buf)); 1710 #ifdef RES_USE_EDNS0 1711 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 1712 n = res_nopt(res, n, buf, sizeof(buf), anslen); 1713 #endif 1714 if (n <= 0) { 1715 #ifdef DEBUG 1716 if (res->options & RES_DEBUG) 1717 printf(";; res_nquery: mkquery failed\n"); 1718 #endif 1719 h_errno = NO_RECOVERY; 1720 return n; 1721 } 1722 n = res_nsend(res, buf, n, answer, anslen); 1723 #if 0 1724 if (n < 0) { 1725 #ifdef DEBUG 1726 if (res->options & RES_DEBUG) 1727 printf(";; res_query: send error\n"); 1728 #endif 1729 h_errno = TRY_AGAIN; 1730 return n; 1731 } 1732 #endif 1733 1734 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1735 rcode = hp->rcode; /* record most recent error */ 1736 #ifdef DEBUG 1737 if (res->options & RES_DEBUG) 1738 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1739 ntohs(hp->ancount)); 1740 #endif 1741 continue; 1742 } 1743 1744 ancount += ntohs(hp->ancount); 1745 1746 t->n = n; 1747 } 1748 1749 if (ancount == 0) { 1750 switch (rcode) { 1751 case NXDOMAIN: 1752 h_errno = HOST_NOT_FOUND; 1753 break; 1754 case SERVFAIL: 1755 h_errno = TRY_AGAIN; 1756 break; 1757 case NOERROR: 1758 h_errno = NO_DATA; 1759 break; 1760 case FORMERR: 1761 case NOTIMP: 1762 case REFUSED: 1763 default: 1764 h_errno = NO_RECOVERY; 1765 break; 1766 } 1767 return -1; 1768 } 1769 return ancount; 1770 } 1771 1772 /* 1773 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1774 * Return the size of the response on success, -1 on error. 1775 * If enabled, implement search rules until answer or unrecoverable failure 1776 * is detected. Error code, if any, is left in h_errno. 1777 */ 1778 static int 1779 res_searchN(const char *name, struct res_target *target, res_state res) 1780 { 1781 const char *cp, * const *domain; 1782 HEADER *hp; 1783 u_int dots; 1784 int trailing_dot, ret, saved_herrno; 1785 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1786 1787 _DIAGASSERT(name != NULL); 1788 _DIAGASSERT(target != NULL); 1789 1790 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1791 1792 errno = 0; 1793 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1794 dots = 0; 1795 for (cp = name; *cp; cp++) 1796 dots += (*cp == '.'); 1797 trailing_dot = 0; 1798 if (cp > name && *--cp == '.') 1799 trailing_dot++; 1800 1801 /* 1802 * if there aren't any dots, it could be a user-level alias 1803 */ 1804 if (!dots && (cp = __hostalias(name)) != NULL) { 1805 ret = res_queryN(cp, target, res); 1806 return ret; 1807 } 1808 1809 /* 1810 * If there are dots in the name already, let's just give it a try 1811 * 'as is'. The threshold can be set with the "ndots" option. 1812 */ 1813 saved_herrno = -1; 1814 if (dots >= res->ndots) { 1815 ret = res_querydomainN(name, NULL, target, res); 1816 if (ret > 0) 1817 return (ret); 1818 saved_herrno = h_errno; 1819 tried_as_is++; 1820 } 1821 1822 /* 1823 * We do at least one level of search if 1824 * - there is no dot and RES_DEFNAME is set, or 1825 * - there is at least one dot, there is no trailing dot, 1826 * and RES_DNSRCH is set. 1827 */ 1828 if ((!dots && (res->options & RES_DEFNAMES)) || 1829 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 1830 int done = 0; 1831 1832 for (domain = (const char * const *)res->dnsrch; 1833 *domain && !done; 1834 domain++) { 1835 1836 ret = res_querydomainN(name, *domain, target, res); 1837 if (ret > 0) 1838 return ret; 1839 1840 /* 1841 * If no server present, give up. 1842 * If name isn't found in this domain, 1843 * keep trying higher domains in the search list 1844 * (if that's enabled). 1845 * On a NO_DATA error, keep trying, otherwise 1846 * a wildcard entry of another type could keep us 1847 * from finding this entry higher in the domain. 1848 * If we get some other error (negative answer or 1849 * server failure), then stop searching up, 1850 * but try the input name below in case it's 1851 * fully-qualified. 1852 */ 1853 if (errno == ECONNREFUSED) { 1854 h_errno = TRY_AGAIN; 1855 return -1; 1856 } 1857 1858 switch (h_errno) { 1859 case NO_DATA: 1860 got_nodata++; 1861 /* FALLTHROUGH */ 1862 case HOST_NOT_FOUND: 1863 /* keep trying */ 1864 break; 1865 case TRY_AGAIN: 1866 if (hp->rcode == SERVFAIL) { 1867 /* try next search element, if any */ 1868 got_servfail++; 1869 break; 1870 } 1871 /* FALLTHROUGH */ 1872 default: 1873 /* anything else implies that we're done */ 1874 done++; 1875 } 1876 /* 1877 * if we got here for some reason other than DNSRCH, 1878 * we only wanted one iteration of the loop, so stop. 1879 */ 1880 if (!(res->options & RES_DNSRCH)) 1881 done++; 1882 } 1883 } 1884 1885 /* 1886 * if we have not already tried the name "as is", do that now. 1887 * note that we do this regardless of how many dots were in the 1888 * name or whether it ends with a dot. 1889 */ 1890 if (!tried_as_is) { 1891 ret = res_querydomainN(name, NULL, target, res); 1892 if (ret > 0) 1893 return ret; 1894 } 1895 1896 /* 1897 * if we got here, we didn't satisfy the search. 1898 * if we did an initial full query, return that query's h_errno 1899 * (note that we wouldn't be here if that query had succeeded). 1900 * else if we ever got a nodata, send that back as the reason. 1901 * else send back meaningless h_errno, that being the one from 1902 * the last DNSRCH we did. 1903 */ 1904 if (saved_herrno != -1) 1905 h_errno = saved_herrno; 1906 else if (got_nodata) 1907 h_errno = NO_DATA; 1908 else if (got_servfail) 1909 h_errno = TRY_AGAIN; 1910 return -1; 1911 } 1912 1913 /* 1914 * Perform a call on res_query on the concatenation of name and domain, 1915 * removing a trailing dot from name if domain is NULL. 1916 */ 1917 static int 1918 res_querydomainN(const char *name, const char *domain, 1919 struct res_target *target, res_state res) 1920 { 1921 char nbuf[MAXDNAME]; 1922 const char *longname = nbuf; 1923 size_t n, d; 1924 1925 _DIAGASSERT(name != NULL); 1926 /* XXX: target may be NULL??? */ 1927 1928 #ifdef DEBUG 1929 if (res->options & RES_DEBUG) 1930 printf(";; res_querydomain(%s, %s)\n", 1931 name, domain?domain:"<Nil>"); 1932 #endif 1933 if (domain == NULL) { 1934 /* 1935 * Check for trailing '.'; 1936 * copy without '.' if present. 1937 */ 1938 n = strlen(name); 1939 if (n + 1 > sizeof(nbuf)) { 1940 h_errno = NO_RECOVERY; 1941 return -1; 1942 } 1943 if (n > 0 && name[--n] == '.') { 1944 strncpy(nbuf, name, n); 1945 nbuf[n] = '\0'; 1946 } else 1947 longname = name; 1948 } else { 1949 n = strlen(name); 1950 d = strlen(domain); 1951 if (n + 1 + d + 1 > sizeof(nbuf)) { 1952 h_errno = NO_RECOVERY; 1953 return -1; 1954 } 1955 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1956 } 1957 return res_queryN(longname, target, res); 1958 } 1959