1 /* $NetBSD: getaddrinfo.c,v 1.92 2009/01/23 00:48:57 tls 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 1.92 2009/01/23 00:48:57 tls 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 /* 920 * This was 0. It is now 1 so that queries specifying 921 * a NULL hint, or hint without socktype (but, hopefully, 922 * with protocol) and numeric address actually work. 923 */ 924 allownumeric = 1; 925 break; 926 default: 927 return EAI_SOCKTYPE; 928 } 929 930 port = str2number(servname); 931 if (port >= 0) { 932 if (!allownumeric) 933 return EAI_SERVICE; 934 if (port < 0 || port > 65535) 935 return EAI_SERVICE; 936 port = htons(port); 937 } else { 938 struct servent sv; 939 if (ai->ai_flags & AI_NUMERICSERV) 940 return EAI_NONAME; 941 942 switch (ai->ai_socktype) { 943 case SOCK_DGRAM: 944 proto = "udp"; 945 break; 946 case SOCK_STREAM: 947 proto = "tcp"; 948 break; 949 default: 950 proto = NULL; 951 break; 952 } 953 954 sp = getservbyname_r(servname, proto, &sv, svd); 955 if (sp == NULL) 956 return EAI_SERVICE; 957 port = sp->s_port; 958 } 959 960 if (!matchonly) { 961 switch (ai->ai_family) { 962 case AF_INET: 963 ((struct sockaddr_in *)(void *) 964 ai->ai_addr)->sin_port = port; 965 break; 966 #ifdef INET6 967 case AF_INET6: 968 ((struct sockaddr_in6 *)(void *) 969 ai->ai_addr)->sin6_port = port; 970 break; 971 #endif 972 } 973 } 974 975 return 0; 976 } 977 978 static const struct afd * 979 find_afd(int af) 980 { 981 const struct afd *afd; 982 983 if (af == PF_UNSPEC) 984 return NULL; 985 for (afd = afdl; afd->a_af; afd++) { 986 if (afd->a_af == af) 987 return afd; 988 } 989 return NULL; 990 } 991 992 #ifdef INET6 993 /* convert a string to a scope identifier. XXX: IPv6 specific */ 994 static int 995 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 996 { 997 u_long lscopeid; 998 struct in6_addr *a6; 999 char *ep; 1000 1001 _DIAGASSERT(scope != NULL); 1002 _DIAGASSERT(sin6 != NULL); 1003 _DIAGASSERT(scopeid != NULL); 1004 1005 a6 = &sin6->sin6_addr; 1006 1007 /* empty scopeid portion is invalid */ 1008 if (*scope == '\0') 1009 return -1; 1010 1011 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1012 /* 1013 * We currently assume a one-to-one mapping between links 1014 * and interfaces, so we simply use interface indices for 1015 * like-local scopes. 1016 */ 1017 *scopeid = if_nametoindex(scope); 1018 if (*scopeid == 0) 1019 goto trynumeric; 1020 return 0; 1021 } 1022 1023 /* still unclear about literal, allow numeric only - placeholder */ 1024 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1025 goto trynumeric; 1026 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1027 goto trynumeric; 1028 else 1029 goto trynumeric; /* global */ 1030 1031 /* try to convert to a numeric id as a last resort */ 1032 trynumeric: 1033 errno = 0; 1034 lscopeid = strtoul(scope, &ep, 10); 1035 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1036 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1037 return 0; 1038 else 1039 return -1; 1040 } 1041 #endif 1042 1043 /* code duplicate with gethnamaddr.c */ 1044 1045 static const char AskedForGot[] = 1046 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1047 1048 static struct addrinfo * 1049 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1050 const struct addrinfo *pai) 1051 { 1052 struct addrinfo sentinel, *cur; 1053 struct addrinfo ai; 1054 const struct afd *afd; 1055 char *canonname; 1056 const HEADER *hp; 1057 const u_char *cp; 1058 int n; 1059 const u_char *eom; 1060 char *bp, *ep; 1061 int type, class, ancount, qdcount; 1062 int haveanswer, had_error; 1063 char tbuf[MAXDNAME]; 1064 int (*name_ok) (const char *); 1065 char hostbuf[8*1024]; 1066 1067 _DIAGASSERT(answer != NULL); 1068 _DIAGASSERT(qname != NULL); 1069 _DIAGASSERT(pai != NULL); 1070 1071 memset(&sentinel, 0, sizeof(sentinel)); 1072 cur = &sentinel; 1073 1074 canonname = NULL; 1075 eom = answer->buf + anslen; 1076 switch (qtype) { 1077 case T_A: 1078 case T_AAAA: 1079 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1080 name_ok = res_hnok; 1081 break; 1082 default: 1083 return NULL; /* XXX should be abort(); */ 1084 } 1085 /* 1086 * find first satisfactory answer 1087 */ 1088 hp = &answer->hdr; 1089 ancount = ntohs(hp->ancount); 1090 qdcount = ntohs(hp->qdcount); 1091 bp = hostbuf; 1092 ep = hostbuf + sizeof hostbuf; 1093 cp = answer->buf + HFIXEDSZ; 1094 if (qdcount != 1) { 1095 h_errno = NO_RECOVERY; 1096 return (NULL); 1097 } 1098 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1099 if ((n < 0) || !(*name_ok)(bp)) { 1100 h_errno = NO_RECOVERY; 1101 return (NULL); 1102 } 1103 cp += n + QFIXEDSZ; 1104 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1105 /* res_send() has already verified that the query name is the 1106 * same as the one we sent; this just gets the expanded name 1107 * (i.e., with the succeeding search-domain tacked on). 1108 */ 1109 n = strlen(bp) + 1; /* for the \0 */ 1110 if (n >= MAXHOSTNAMELEN) { 1111 h_errno = NO_RECOVERY; 1112 return (NULL); 1113 } 1114 canonname = bp; 1115 bp += n; 1116 /* The qname can be abbreviated, but h_name is now absolute. */ 1117 qname = canonname; 1118 } 1119 haveanswer = 0; 1120 had_error = 0; 1121 while (ancount-- > 0 && cp < eom && !had_error) { 1122 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1123 if ((n < 0) || !(*name_ok)(bp)) { 1124 had_error++; 1125 continue; 1126 } 1127 cp += n; /* name */ 1128 type = _getshort(cp); 1129 cp += INT16SZ; /* type */ 1130 class = _getshort(cp); 1131 cp += INT16SZ + INT32SZ; /* class, TTL */ 1132 n = _getshort(cp); 1133 cp += INT16SZ; /* len */ 1134 if (class != C_IN) { 1135 /* XXX - debug? syslog? */ 1136 cp += n; 1137 continue; /* XXX - had_error++ ? */ 1138 } 1139 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1140 type == T_CNAME) { 1141 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1142 if ((n < 0) || !(*name_ok)(tbuf)) { 1143 had_error++; 1144 continue; 1145 } 1146 cp += n; 1147 /* Get canonical name. */ 1148 n = strlen(tbuf) + 1; /* for the \0 */ 1149 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1150 had_error++; 1151 continue; 1152 } 1153 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1154 canonname = bp; 1155 bp += n; 1156 continue; 1157 } 1158 if (qtype == T_ANY) { 1159 if (!(type == T_A || type == T_AAAA)) { 1160 cp += n; 1161 continue; 1162 } 1163 } else if (type != qtype) { 1164 if (type != T_KEY && type != T_SIG) { 1165 struct syslog_data sd = SYSLOG_DATA_INIT; 1166 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1167 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1168 qname, p_class(C_IN), p_type(qtype), 1169 p_type(type)); 1170 } 1171 cp += n; 1172 continue; /* XXX - had_error++ ? */ 1173 } 1174 switch (type) { 1175 case T_A: 1176 case T_AAAA: 1177 if (strcasecmp(canonname, bp) != 0) { 1178 struct syslog_data sd = SYSLOG_DATA_INIT; 1179 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1180 AskedForGot, canonname, bp); 1181 cp += n; 1182 continue; /* XXX - had_error++ ? */ 1183 } 1184 if (type == T_A && n != INADDRSZ) { 1185 cp += n; 1186 continue; 1187 } 1188 if (type == T_AAAA && n != IN6ADDRSZ) { 1189 cp += n; 1190 continue; 1191 } 1192 if (type == T_AAAA) { 1193 struct in6_addr in6; 1194 memcpy(&in6, cp, IN6ADDRSZ); 1195 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1196 cp += n; 1197 continue; 1198 } 1199 } 1200 if (!haveanswer) { 1201 int nn; 1202 1203 canonname = bp; 1204 nn = strlen(bp) + 1; /* for the \0 */ 1205 bp += nn; 1206 } 1207 1208 /* don't overwrite pai */ 1209 ai = *pai; 1210 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1211 afd = find_afd(ai.ai_family); 1212 if (afd == NULL) { 1213 cp += n; 1214 continue; 1215 } 1216 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1217 if (cur->ai_next == NULL) 1218 had_error++; 1219 while (cur && cur->ai_next) 1220 cur = cur->ai_next; 1221 cp += n; 1222 break; 1223 default: 1224 abort(); 1225 } 1226 if (!had_error) 1227 haveanswer++; 1228 } 1229 if (haveanswer) { 1230 if (!canonname) 1231 (void)get_canonname(pai, sentinel.ai_next, qname); 1232 else 1233 (void)get_canonname(pai, sentinel.ai_next, canonname); 1234 h_errno = NETDB_SUCCESS; 1235 return sentinel.ai_next; 1236 } 1237 1238 h_errno = NO_RECOVERY; 1239 return NULL; 1240 } 1241 1242 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr) 1243 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr) 1244 1245 static void 1246 aisort(struct addrinfo *s, res_state res) 1247 { 1248 struct addrinfo head, *t, *p; 1249 int i; 1250 1251 head.ai_next = NULL; 1252 t = &head; 1253 1254 for (i = 0; i < res->nsort; i++) { 1255 p = s; 1256 while (p->ai_next) { 1257 if ((p->ai_next->ai_family != AF_INET) 1258 || SORTMATCH(p, res->sort_list[i])) { 1259 t->ai_next = p->ai_next; 1260 t = t->ai_next; 1261 p->ai_next = p->ai_next->ai_next; 1262 } else { 1263 p = p->ai_next; 1264 } 1265 } 1266 } 1267 1268 /* add rest of list and reset s to the new list*/ 1269 t->ai_next = s->ai_next; 1270 s->ai_next = head.ai_next; 1271 } 1272 1273 /*ARGSUSED*/ 1274 static int 1275 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1276 { 1277 struct addrinfo *ai; 1278 querybuf *buf, *buf2; 1279 const char *name; 1280 const struct addrinfo *pai; 1281 struct addrinfo sentinel, *cur; 1282 struct res_target q, q2; 1283 res_state res; 1284 1285 name = va_arg(ap, char *); 1286 pai = va_arg(ap, const struct addrinfo *); 1287 1288 memset(&q, 0, sizeof(q)); 1289 memset(&q2, 0, sizeof(q2)); 1290 memset(&sentinel, 0, sizeof(sentinel)); 1291 cur = &sentinel; 1292 1293 buf = malloc(sizeof(*buf)); 1294 if (buf == NULL) { 1295 h_errno = NETDB_INTERNAL; 1296 return NS_NOTFOUND; 1297 } 1298 buf2 = malloc(sizeof(*buf2)); 1299 if (buf2 == NULL) { 1300 free(buf); 1301 h_errno = NETDB_INTERNAL; 1302 return NS_NOTFOUND; 1303 } 1304 1305 switch (pai->ai_family) { 1306 case AF_UNSPEC: 1307 /* prefer IPv6 */ 1308 q.name = name; 1309 q.qclass = C_IN; 1310 q.qtype = T_AAAA; 1311 q.answer = buf->buf; 1312 q.anslen = sizeof(buf->buf); 1313 q.next = &q2; 1314 q2.name = name; 1315 q2.qclass = C_IN; 1316 q2.qtype = T_A; 1317 q2.answer = buf2->buf; 1318 q2.anslen = sizeof(buf2->buf); 1319 break; 1320 case AF_INET: 1321 q.name = name; 1322 q.qclass = C_IN; 1323 q.qtype = T_A; 1324 q.answer = buf->buf; 1325 q.anslen = sizeof(buf->buf); 1326 break; 1327 case AF_INET6: 1328 q.name = name; 1329 q.qclass = C_IN; 1330 q.qtype = T_AAAA; 1331 q.answer = buf->buf; 1332 q.anslen = sizeof(buf->buf); 1333 break; 1334 default: 1335 free(buf); 1336 free(buf2); 1337 return NS_UNAVAIL; 1338 } 1339 1340 res = __res_get_state(); 1341 if (res == NULL) { 1342 free(buf); 1343 free(buf2); 1344 return NS_NOTFOUND; 1345 } 1346 1347 if (res_searchN(name, &q, res) < 0) { 1348 __res_put_state(res); 1349 free(buf); 1350 free(buf2); 1351 return NS_NOTFOUND; 1352 } 1353 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1354 if (ai) { 1355 cur->ai_next = ai; 1356 while (cur && cur->ai_next) 1357 cur = cur->ai_next; 1358 } 1359 if (q.next) { 1360 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1361 if (ai) 1362 cur->ai_next = ai; 1363 } 1364 free(buf); 1365 free(buf2); 1366 if (sentinel.ai_next == NULL) { 1367 __res_put_state(res); 1368 switch (h_errno) { 1369 case HOST_NOT_FOUND: 1370 return NS_NOTFOUND; 1371 case TRY_AGAIN: 1372 return NS_TRYAGAIN; 1373 default: 1374 return NS_UNAVAIL; 1375 } 1376 } 1377 1378 if (res->nsort) 1379 aisort(&sentinel, res); 1380 1381 __res_put_state(res); 1382 1383 *((struct addrinfo **)rv) = sentinel.ai_next; 1384 return NS_SUCCESS; 1385 } 1386 1387 static void 1388 _sethtent(FILE **hostf) 1389 { 1390 1391 if (!*hostf) 1392 *hostf = fopen(_PATH_HOSTS, "r" ); 1393 else 1394 rewind(*hostf); 1395 } 1396 1397 static void 1398 _endhtent(FILE **hostf) 1399 { 1400 1401 if (*hostf) { 1402 (void) fclose(*hostf); 1403 *hostf = NULL; 1404 } 1405 } 1406 1407 static struct addrinfo * 1408 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1409 { 1410 char *p; 1411 char *cp, *tname, *cname; 1412 struct addrinfo hints, *res0, *res; 1413 int error; 1414 const char *addr; 1415 char hostbuf[8*1024]; 1416 1417 _DIAGASSERT(name != NULL); 1418 _DIAGASSERT(pai != NULL); 1419 1420 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r" ))) 1421 return (NULL); 1422 again: 1423 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 1424 return (NULL); 1425 if (*p == '#') 1426 goto again; 1427 if (!(cp = strpbrk(p, "#\n"))) 1428 goto again; 1429 *cp = '\0'; 1430 if (!(cp = strpbrk(p, " \t"))) 1431 goto again; 1432 *cp++ = '\0'; 1433 addr = p; 1434 /* if this is not something we're looking for, skip it. */ 1435 cname = NULL; 1436 while (cp && *cp) { 1437 if (*cp == ' ' || *cp == '\t') { 1438 cp++; 1439 continue; 1440 } 1441 if (!cname) 1442 cname = cp; 1443 tname = cp; 1444 if ((cp = strpbrk(cp, " \t")) != NULL) 1445 *cp++ = '\0'; 1446 if (strcasecmp(name, tname) == 0) 1447 goto found; 1448 } 1449 goto again; 1450 1451 found: 1452 hints = *pai; 1453 hints.ai_flags = AI_NUMERICHOST; 1454 error = getaddrinfo(addr, NULL, &hints, &res0); 1455 if (error) 1456 goto again; 1457 for (res = res0; res; res = res->ai_next) { 1458 /* cover it up */ 1459 res->ai_flags = pai->ai_flags; 1460 1461 if (pai->ai_flags & AI_CANONNAME) { 1462 if (get_canonname(pai, res, cname) != 0) { 1463 freeaddrinfo(res0); 1464 goto again; 1465 } 1466 } 1467 } 1468 return res0; 1469 } 1470 1471 /*ARGSUSED*/ 1472 static int 1473 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1474 { 1475 const char *name; 1476 const struct addrinfo *pai; 1477 struct addrinfo sentinel, *cur; 1478 struct addrinfo *p; 1479 #ifndef _REENTRANT 1480 static 1481 #endif 1482 FILE *hostf = NULL; 1483 1484 name = va_arg(ap, char *); 1485 pai = va_arg(ap, const struct addrinfo *); 1486 1487 memset(&sentinel, 0, sizeof(sentinel)); 1488 cur = &sentinel; 1489 1490 _sethtent(&hostf); 1491 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1492 cur->ai_next = p; 1493 while (cur && cur->ai_next) 1494 cur = cur->ai_next; 1495 } 1496 _endhtent(&hostf); 1497 1498 *((struct addrinfo **)rv) = sentinel.ai_next; 1499 if (sentinel.ai_next == NULL) 1500 return NS_NOTFOUND; 1501 return NS_SUCCESS; 1502 } 1503 1504 #ifdef YP 1505 /*ARGSUSED*/ 1506 static struct addrinfo * 1507 _yphostent(char *line, const struct addrinfo *pai) 1508 { 1509 struct addrinfo sentinel, *cur; 1510 struct addrinfo hints, *res, *res0; 1511 int error; 1512 char *p; 1513 const char *addr, *canonname; 1514 char *nextline; 1515 char *cp; 1516 1517 _DIAGASSERT(line != NULL); 1518 _DIAGASSERT(pai != NULL); 1519 1520 p = line; 1521 addr = canonname = NULL; 1522 1523 memset(&sentinel, 0, sizeof(sentinel)); 1524 cur = &sentinel; 1525 1526 nextline: 1527 /* terminate line */ 1528 cp = strchr(p, '\n'); 1529 if (cp) { 1530 *cp++ = '\0'; 1531 nextline = cp; 1532 } else 1533 nextline = NULL; 1534 1535 cp = strpbrk(p, " \t"); 1536 if (cp == NULL) { 1537 if (canonname == NULL) 1538 return (NULL); 1539 else 1540 goto done; 1541 } 1542 *cp++ = '\0'; 1543 1544 addr = p; 1545 1546 while (cp && *cp) { 1547 if (*cp == ' ' || *cp == '\t') { 1548 cp++; 1549 continue; 1550 } 1551 if (!canonname) 1552 canonname = cp; 1553 if ((cp = strpbrk(cp, " \t")) != NULL) 1554 *cp++ = '\0'; 1555 } 1556 1557 hints = *pai; 1558 hints.ai_flags = AI_NUMERICHOST; 1559 error = getaddrinfo(addr, NULL, &hints, &res0); 1560 if (error == 0) { 1561 for (res = res0; res; res = res->ai_next) { 1562 /* cover it up */ 1563 res->ai_flags = pai->ai_flags; 1564 1565 if (pai->ai_flags & AI_CANONNAME) 1566 (void)get_canonname(pai, res, canonname); 1567 } 1568 } else 1569 res0 = NULL; 1570 if (res0) { 1571 cur->ai_next = res0; 1572 while (cur->ai_next) 1573 cur = cur->ai_next; 1574 } 1575 1576 if (nextline) { 1577 p = nextline; 1578 goto nextline; 1579 } 1580 1581 done: 1582 return sentinel.ai_next; 1583 } 1584 1585 /*ARGSUSED*/ 1586 static int 1587 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1588 { 1589 struct addrinfo sentinel, *cur; 1590 struct addrinfo *ai = NULL; 1591 char *ypbuf; 1592 int ypbuflen, r; 1593 const char *name; 1594 const struct addrinfo *pai; 1595 char *ypdomain; 1596 1597 if (_yp_check(&ypdomain) == 0) 1598 return NS_UNAVAIL; 1599 1600 name = va_arg(ap, char *); 1601 pai = va_arg(ap, const struct addrinfo *); 1602 1603 memset(&sentinel, 0, sizeof(sentinel)); 1604 cur = &sentinel; 1605 1606 /* hosts.byname is only for IPv4 (Solaris8) */ 1607 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1608 r = yp_match(ypdomain, "hosts.byname", name, 1609 (int)strlen(name), &ypbuf, &ypbuflen); 1610 if (r == 0) { 1611 struct addrinfo ai4; 1612 1613 ai4 = *pai; 1614 ai4.ai_family = AF_INET; 1615 ai = _yphostent(ypbuf, &ai4); 1616 if (ai) { 1617 cur->ai_next = ai; 1618 while (cur && cur->ai_next) 1619 cur = cur->ai_next; 1620 } 1621 } 1622 free(ypbuf); 1623 } 1624 1625 /* ipnodes.byname can hold both IPv4/v6 */ 1626 r = yp_match(ypdomain, "ipnodes.byname", name, 1627 (int)strlen(name), &ypbuf, &ypbuflen); 1628 if (r == 0) { 1629 ai = _yphostent(ypbuf, pai); 1630 if (ai) 1631 cur->ai_next = ai; 1632 free(ypbuf); 1633 } 1634 1635 if (sentinel.ai_next == NULL) { 1636 h_errno = HOST_NOT_FOUND; 1637 return NS_NOTFOUND; 1638 } 1639 *((struct addrinfo **)rv) = sentinel.ai_next; 1640 return NS_SUCCESS; 1641 } 1642 #endif 1643 1644 /* resolver logic */ 1645 1646 /* 1647 * Formulate a normal query, send, and await answer. 1648 * Returned answer is placed in supplied buffer "answer". 1649 * Perform preliminary check of answer, returning success only 1650 * if no error is indicated and the answer count is nonzero. 1651 * Return the size of the response on success, -1 on error. 1652 * Error number is left in h_errno. 1653 * 1654 * Caller must parse answer and determine whether it answers the question. 1655 */ 1656 static int 1657 res_queryN(const char *name, /* domain name */ struct res_target *target, 1658 res_state res) 1659 { 1660 u_char buf[MAXPACKET]; 1661 HEADER *hp; 1662 int n; 1663 struct res_target *t; 1664 int rcode; 1665 int ancount; 1666 1667 _DIAGASSERT(name != NULL); 1668 /* XXX: target may be NULL??? */ 1669 1670 rcode = NOERROR; 1671 ancount = 0; 1672 1673 for (t = target; t; t = t->next) { 1674 int class, type; 1675 u_char *answer; 1676 int anslen; 1677 1678 hp = (HEADER *)(void *)t->answer; 1679 hp->rcode = NOERROR; /* default */ 1680 1681 /* make it easier... */ 1682 class = t->qclass; 1683 type = t->qtype; 1684 answer = t->answer; 1685 anslen = t->anslen; 1686 #ifdef DEBUG 1687 if (res->options & RES_DEBUG) 1688 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 1689 #endif 1690 1691 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 1692 buf, sizeof(buf)); 1693 #ifdef RES_USE_EDNS0 1694 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 1695 n = res_nopt(res, n, buf, sizeof(buf), anslen); 1696 #endif 1697 if (n <= 0) { 1698 #ifdef DEBUG 1699 if (res->options & RES_DEBUG) 1700 printf(";; res_nquery: mkquery failed\n"); 1701 #endif 1702 h_errno = NO_RECOVERY; 1703 return n; 1704 } 1705 n = res_nsend(res, buf, n, answer, anslen); 1706 #if 0 1707 if (n < 0) { 1708 #ifdef DEBUG 1709 if (res->options & RES_DEBUG) 1710 printf(";; res_query: send error\n"); 1711 #endif 1712 h_errno = TRY_AGAIN; 1713 return n; 1714 } 1715 #endif 1716 1717 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1718 rcode = hp->rcode; /* record most recent error */ 1719 #ifdef DEBUG 1720 if (res->options & RES_DEBUG) 1721 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1722 ntohs(hp->ancount)); 1723 #endif 1724 continue; 1725 } 1726 1727 ancount += ntohs(hp->ancount); 1728 1729 t->n = n; 1730 } 1731 1732 if (ancount == 0) { 1733 switch (rcode) { 1734 case NXDOMAIN: 1735 h_errno = HOST_NOT_FOUND; 1736 break; 1737 case SERVFAIL: 1738 h_errno = TRY_AGAIN; 1739 break; 1740 case NOERROR: 1741 h_errno = NO_DATA; 1742 break; 1743 case FORMERR: 1744 case NOTIMP: 1745 case REFUSED: 1746 default: 1747 h_errno = NO_RECOVERY; 1748 break; 1749 } 1750 return -1; 1751 } 1752 return ancount; 1753 } 1754 1755 /* 1756 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1757 * Return the size of the response on success, -1 on error. 1758 * If enabled, implement search rules until answer or unrecoverable failure 1759 * is detected. Error code, if any, is left in h_errno. 1760 */ 1761 static int 1762 res_searchN(const char *name, struct res_target *target, res_state res) 1763 { 1764 const char *cp, * const *domain; 1765 HEADER *hp; 1766 u_int dots; 1767 int trailing_dot, ret, saved_herrno; 1768 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1769 1770 _DIAGASSERT(name != NULL); 1771 _DIAGASSERT(target != NULL); 1772 1773 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1774 1775 errno = 0; 1776 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1777 dots = 0; 1778 for (cp = name; *cp; cp++) 1779 dots += (*cp == '.'); 1780 trailing_dot = 0; 1781 if (cp > name && *--cp == '.') 1782 trailing_dot++; 1783 1784 /* 1785 * if there aren't any dots, it could be a user-level alias 1786 */ 1787 if (!dots && (cp = __hostalias(name)) != NULL) { 1788 ret = res_queryN(cp, target, res); 1789 return ret; 1790 } 1791 1792 /* 1793 * If there are dots in the name already, let's just give it a try 1794 * 'as is'. The threshold can be set with the "ndots" option. 1795 */ 1796 saved_herrno = -1; 1797 if (dots >= res->ndots) { 1798 ret = res_querydomainN(name, NULL, target, res); 1799 if (ret > 0) 1800 return (ret); 1801 saved_herrno = h_errno; 1802 tried_as_is++; 1803 } 1804 1805 /* 1806 * We do at least one level of search if 1807 * - there is no dot and RES_DEFNAME is set, or 1808 * - there is at least one dot, there is no trailing dot, 1809 * and RES_DNSRCH is set. 1810 */ 1811 if ((!dots && (res->options & RES_DEFNAMES)) || 1812 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 1813 int done = 0; 1814 1815 for (domain = (const char * const *)res->dnsrch; 1816 *domain && !done; 1817 domain++) { 1818 1819 ret = res_querydomainN(name, *domain, target, res); 1820 if (ret > 0) 1821 return ret; 1822 1823 /* 1824 * If no server present, give up. 1825 * If name isn't found in this domain, 1826 * keep trying higher domains in the search list 1827 * (if that's enabled). 1828 * On a NO_DATA error, keep trying, otherwise 1829 * a wildcard entry of another type could keep us 1830 * from finding this entry higher in the domain. 1831 * If we get some other error (negative answer or 1832 * server failure), then stop searching up, 1833 * but try the input name below in case it's 1834 * fully-qualified. 1835 */ 1836 if (errno == ECONNREFUSED) { 1837 h_errno = TRY_AGAIN; 1838 return -1; 1839 } 1840 1841 switch (h_errno) { 1842 case NO_DATA: 1843 got_nodata++; 1844 /* FALLTHROUGH */ 1845 case HOST_NOT_FOUND: 1846 /* keep trying */ 1847 break; 1848 case TRY_AGAIN: 1849 if (hp->rcode == SERVFAIL) { 1850 /* try next search element, if any */ 1851 got_servfail++; 1852 break; 1853 } 1854 /* FALLTHROUGH */ 1855 default: 1856 /* anything else implies that we're done */ 1857 done++; 1858 } 1859 /* 1860 * if we got here for some reason other than DNSRCH, 1861 * we only wanted one iteration of the loop, so stop. 1862 */ 1863 if (!(res->options & RES_DNSRCH)) 1864 done++; 1865 } 1866 } 1867 1868 /* 1869 * if we have not already tried the name "as is", do that now. 1870 * note that we do this regardless of how many dots were in the 1871 * name or whether it ends with a dot. 1872 */ 1873 if (!tried_as_is) { 1874 ret = res_querydomainN(name, NULL, target, res); 1875 if (ret > 0) 1876 return ret; 1877 } 1878 1879 /* 1880 * if we got here, we didn't satisfy the search. 1881 * if we did an initial full query, return that query's h_errno 1882 * (note that we wouldn't be here if that query had succeeded). 1883 * else if we ever got a nodata, send that back as the reason. 1884 * else send back meaningless h_errno, that being the one from 1885 * the last DNSRCH we did. 1886 */ 1887 if (saved_herrno != -1) 1888 h_errno = saved_herrno; 1889 else if (got_nodata) 1890 h_errno = NO_DATA; 1891 else if (got_servfail) 1892 h_errno = TRY_AGAIN; 1893 return -1; 1894 } 1895 1896 /* 1897 * Perform a call on res_query on the concatenation of name and domain, 1898 * removing a trailing dot from name if domain is NULL. 1899 */ 1900 static int 1901 res_querydomainN(const char *name, const char *domain, 1902 struct res_target *target, res_state res) 1903 { 1904 char nbuf[MAXDNAME]; 1905 const char *longname = nbuf; 1906 size_t n, d; 1907 1908 _DIAGASSERT(name != NULL); 1909 /* XXX: target may be NULL??? */ 1910 1911 #ifdef DEBUG 1912 if (res->options & RES_DEBUG) 1913 printf(";; res_querydomain(%s, %s)\n", 1914 name, domain?domain:"<Nil>"); 1915 #endif 1916 if (domain == NULL) { 1917 /* 1918 * Check for trailing '.'; 1919 * copy without '.' if present. 1920 */ 1921 n = strlen(name); 1922 if (n + 1 > sizeof(nbuf)) { 1923 h_errno = NO_RECOVERY; 1924 return -1; 1925 } 1926 if (n > 0 && name[--n] == '.') { 1927 strncpy(nbuf, name, n); 1928 nbuf[n] = '\0'; 1929 } else 1930 longname = name; 1931 } else { 1932 n = strlen(name); 1933 d = strlen(domain); 1934 if (n + 1 + d + 1 > sizeof(nbuf)) { 1935 h_errno = NO_RECOVERY; 1936 return -1; 1937 } 1938 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1939 } 1940 return res_queryN(longname, target, res); 1941 } 1942