getaddrinfo.c revision 1.99
1 /* $NetBSD: getaddrinfo.c,v 1.99 2012/03/20 10:34:33 kardel 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 1.99 2012/03/20 10:34:33 kardel 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 #include <ifaddrs.h> 80 81 #include <syslog.h> 82 #include <stdarg.h> 83 #include <nsswitch.h> 84 85 #ifdef YP 86 #include <rpc/rpc.h> 87 #include <rpcsvc/yp_prot.h> 88 #include <rpcsvc/ypclnt.h> 89 #endif 90 91 #include "servent.h" 92 93 #ifdef __weak_alias 94 __weak_alias(getaddrinfo,_getaddrinfo) 95 __weak_alias(freeaddrinfo,_freeaddrinfo) 96 __weak_alias(gai_strerror,_gai_strerror) 97 #endif 98 99 #define SUCCESS 0 100 #define ANY 0 101 #define YES 1 102 #define NO 0 103 104 static const char in_addrany[] = { 0, 0, 0, 0 }; 105 static const char in_loopback[] = { 127, 0, 0, 1 }; 106 #ifdef INET6 107 static const char in6_addrany[] = { 108 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 109 }; 110 static const char in6_loopback[] = { 111 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 112 }; 113 #endif 114 115 static const struct afd { 116 int a_af; 117 int a_addrlen; 118 int a_socklen; 119 int a_off; 120 const char *a_addrany; 121 const char *a_loopback; 122 int a_scoped; 123 } afdl [] = { 124 #ifdef INET6 125 {PF_INET6, sizeof(struct in6_addr), 126 sizeof(struct sockaddr_in6), 127 offsetof(struct sockaddr_in6, sin6_addr), 128 in6_addrany, in6_loopback, 1}, 129 #endif 130 {PF_INET, sizeof(struct in_addr), 131 sizeof(struct sockaddr_in), 132 offsetof(struct sockaddr_in, sin_addr), 133 in_addrany, in_loopback, 0}, 134 {0, 0, 0, 0, NULL, NULL, 0}, 135 }; 136 137 struct explore { 138 int e_af; 139 int e_socktype; 140 int e_protocol; 141 const char *e_protostr; 142 int e_wild; 143 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 144 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 145 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 146 }; 147 148 static const struct explore explore[] = { 149 #if 0 150 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 151 #endif 152 #ifdef INET6 153 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 154 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 155 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 156 #endif 157 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 158 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 159 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 160 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 161 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 162 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 163 { -1, 0, 0, NULL, 0 }, 164 }; 165 166 #ifdef INET6 167 #define PTON_MAX 16 168 #else 169 #define PTON_MAX 4 170 #endif 171 172 static const ns_src default_dns_files[] = { 173 { NSSRC_FILES, NS_SUCCESS }, 174 { NSSRC_DNS, NS_SUCCESS }, 175 { 0, 0 } 176 }; 177 178 #define MAXPACKET (64*1024) 179 180 typedef union { 181 HEADER hdr; 182 u_char buf[MAXPACKET]; 183 } querybuf; 184 185 struct res_target { 186 struct res_target *next; 187 const char *name; /* domain name */ 188 int qclass, qtype; /* class and type of query */ 189 u_char *answer; /* buffer to put answer */ 190 int anslen; /* size of answer buffer */ 191 int n; /* result length */ 192 }; 193 194 static int str2number(const char *); 195 static int explore_fqdn(const struct addrinfo *, const char *, 196 const char *, struct addrinfo **, struct servent_data *); 197 static int explore_null(const struct addrinfo *, 198 const char *, struct addrinfo **, struct servent_data *); 199 static int explore_numeric(const struct addrinfo *, const char *, 200 const char *, struct addrinfo **, const char *, struct servent_data *); 201 static int explore_numeric_scope(const struct addrinfo *, const char *, 202 const char *, struct addrinfo **, struct servent_data *); 203 static int get_canonname(const struct addrinfo *, 204 struct addrinfo *, const char *); 205 static struct addrinfo *get_ai(const struct addrinfo *, 206 const struct afd *, const char *); 207 static int get_portmatch(const struct addrinfo *, const char *, 208 struct servent_data *); 209 static int get_port(const struct addrinfo *, const char *, int, 210 struct servent_data *); 211 static const struct afd *find_afd(int); 212 static int addrconfig(uint64_t *); 213 #ifdef INET6 214 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 215 #endif 216 217 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 218 const struct addrinfo *); 219 static void aisort(struct addrinfo *s, res_state res); 220 static int _dns_getaddrinfo(void *, void *, va_list); 221 static void _sethtent(FILE **); 222 static void _endhtent(FILE **); 223 static struct addrinfo *_gethtent(FILE **, const char *, 224 const struct addrinfo *); 225 static int _files_getaddrinfo(void *, void *, va_list); 226 #ifdef YP 227 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 228 static int _yp_getaddrinfo(void *, void *, va_list); 229 #endif 230 231 static int res_queryN(const char *, struct res_target *, res_state); 232 static int res_searchN(const char *, struct res_target *, res_state); 233 static int res_querydomainN(const char *, const char *, 234 struct res_target *, res_state); 235 236 static const char * const ai_errlist[] = { 237 "Success", 238 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 239 "Temporary failure in name resolution", /* EAI_AGAIN */ 240 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 241 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 242 "ai_family not supported", /* EAI_FAMILY */ 243 "Memory allocation failure", /* EAI_MEMORY */ 244 "No address associated with hostname", /* EAI_NODATA */ 245 "hostname nor servname provided, or not known", /* EAI_NONAME */ 246 "servname not supported for ai_socktype", /* EAI_SERVICE */ 247 "ai_socktype not supported", /* EAI_SOCKTYPE */ 248 "System error returned in errno", /* EAI_SYSTEM */ 249 "Invalid value for hints", /* EAI_BADHINTS */ 250 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 251 "Argument buffer overflow", /* EAI_OVERFLOW */ 252 "Unknown error", /* EAI_MAX */ 253 }; 254 255 /* XXX macros that make external reference is BAD. */ 256 257 #define GET_AI(ai, afd, addr) \ 258 do { \ 259 /* external reference: pai, error, and label free */ \ 260 (ai) = get_ai(pai, (afd), (addr)); \ 261 if ((ai) == NULL) { \ 262 error = EAI_MEMORY; \ 263 goto free; \ 264 } \ 265 } while (/*CONSTCOND*/0) 266 267 #define GET_PORT(ai, serv, svd) \ 268 do { \ 269 /* external reference: error and label free */ \ 270 error = get_port((ai), (serv), 0, (svd)); \ 271 if (error != 0) \ 272 goto free; \ 273 } while (/*CONSTCOND*/0) 274 275 #define GET_CANONNAME(ai, str) \ 276 do { \ 277 /* external reference: pai, error and label free */ \ 278 error = get_canonname(pai, (ai), (str)); \ 279 if (error != 0) \ 280 goto free; \ 281 } while (/*CONSTCOND*/0) 282 283 #define ERR(err) \ 284 do { \ 285 /* external reference: error, and label bad */ \ 286 error = (err); \ 287 goto bad; \ 288 /*NOTREACHED*/ \ 289 } while (/*CONSTCOND*/0) 290 291 #define MATCH_FAMILY(x, y, w) \ 292 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || \ 293 (y) == PF_UNSPEC))) 294 #define MATCH(x, y, w) \ 295 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 296 297 const char * 298 gai_strerror(int ecode) 299 { 300 if (ecode < 0 || ecode > EAI_MAX) 301 ecode = EAI_MAX; 302 return ai_errlist[ecode]; 303 } 304 305 void 306 freeaddrinfo(struct addrinfo *ai) 307 { 308 struct addrinfo *next; 309 310 _DIAGASSERT(ai != NULL); 311 312 do { 313 next = ai->ai_next; 314 if (ai->ai_canonname) 315 free(ai->ai_canonname); 316 /* no need to free(ai->ai_addr) */ 317 free(ai); 318 ai = next; 319 } while (ai); 320 } 321 322 static int 323 str2number(const char *p) 324 { 325 char *ep; 326 unsigned long v; 327 328 _DIAGASSERT(p != NULL); 329 330 if (*p == '\0') 331 return -1; 332 ep = NULL; 333 errno = 0; 334 v = strtoul(p, &ep, 10); 335 if (errno == 0 && ep && *ep == '\0' && v <= INT_MAX) 336 return (int)v; 337 else 338 return -1; 339 } 340 341 int 342 getaddrinfo(const char *hostname, const char *servname, 343 const struct addrinfo *hints, struct addrinfo **res) 344 { 345 struct addrinfo sentinel; 346 struct addrinfo *cur; 347 int error = 0; 348 struct addrinfo ai; 349 struct addrinfo ai0; 350 struct addrinfo *pai; 351 const struct explore *ex; 352 struct servent_data svd; 353 uint64_t mask = (uint64_t)~0ULL; 354 355 /* hostname is allowed to be NULL */ 356 /* servname is allowed to be NULL */ 357 /* hints is allowed to be NULL */ 358 _DIAGASSERT(res != NULL); 359 360 (void)memset(&svd, 0, sizeof(svd)); 361 memset(&sentinel, 0, sizeof(sentinel)); 362 cur = &sentinel; 363 memset(&ai, 0, sizeof(ai)); 364 pai = &ai; 365 pai->ai_flags = 0; 366 pai->ai_family = PF_UNSPEC; 367 pai->ai_socktype = ANY; 368 pai->ai_protocol = ANY; 369 pai->ai_addrlen = 0; 370 pai->ai_canonname = NULL; 371 pai->ai_addr = NULL; 372 pai->ai_next = NULL; 373 374 if (hostname == NULL && servname == NULL) 375 return EAI_NONAME; 376 if (hints) { 377 /* error check for hints */ 378 if (hints->ai_addrlen || hints->ai_canonname || 379 hints->ai_addr || hints->ai_next) 380 ERR(EAI_BADHINTS); /* xxx */ 381 if (hints->ai_flags & ~AI_MASK) 382 ERR(EAI_BADFLAGS); 383 switch (hints->ai_family) { 384 case PF_UNSPEC: 385 case PF_INET: 386 #ifdef INET6 387 case PF_INET6: 388 #endif 389 break; 390 default: 391 ERR(EAI_FAMILY); 392 } 393 memcpy(pai, hints, sizeof(*pai)); 394 395 /* 396 * if both socktype/protocol are specified, check if they 397 * are meaningful combination. 398 */ 399 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 400 for (ex = explore; ex->e_af >= 0; ex++) { 401 if (pai->ai_family != ex->e_af) 402 continue; 403 if (ex->e_socktype == ANY) 404 continue; 405 if (ex->e_protocol == ANY) 406 continue; 407 if (pai->ai_socktype == ex->e_socktype 408 && pai->ai_protocol != ex->e_protocol) { 409 ERR(EAI_BADHINTS); 410 } 411 } 412 } 413 } 414 415 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && addrconfig(&mask) == -1) 416 ERR(EAI_FAIL); 417 418 /* 419 * check for special cases. (1) numeric servname is disallowed if 420 * socktype/protocol are left unspecified. (2) servname is disallowed 421 * for raw and other inet{,6} sockets. 422 */ 423 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 424 #ifdef PF_INET6 425 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 426 #endif 427 ) { 428 ai0 = *pai; /* backup *pai */ 429 430 if (pai->ai_family == PF_UNSPEC) { 431 #ifdef PF_INET6 432 pai->ai_family = PF_INET6; 433 #else 434 pai->ai_family = PF_INET; 435 #endif 436 } 437 error = get_portmatch(pai, servname, &svd); 438 if (error) 439 ERR(error); 440 441 *pai = ai0; 442 } 443 444 ai0 = *pai; 445 446 /* NULL hostname, or numeric hostname */ 447 for (ex = explore; ex->e_af >= 0; ex++) { 448 *pai = ai0; 449 450 /* ADDRCONFIG check */ 451 if ((((uint64_t)1 << ex->e_af) & mask) == 0) 452 continue; 453 454 /* PF_UNSPEC entries are prepared for DNS queries only */ 455 if (ex->e_af == PF_UNSPEC) 456 continue; 457 458 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 459 continue; 460 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 461 continue; 462 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 463 continue; 464 if (pai->ai_family == PF_UNSPEC) 465 pai->ai_family = ex->e_af; 466 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 467 pai->ai_socktype = ex->e_socktype; 468 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 469 pai->ai_protocol = ex->e_protocol; 470 471 if (hostname == NULL) 472 error = explore_null(pai, servname, &cur->ai_next, 473 &svd); 474 else 475 error = explore_numeric_scope(pai, hostname, servname, 476 &cur->ai_next, &svd); 477 478 if (error) 479 goto free; 480 481 while (cur->ai_next) 482 cur = cur->ai_next; 483 } 484 485 /* 486 * XXX 487 * If numeric representation of AF1 can be interpreted as FQDN 488 * representation of AF2, we need to think again about the code below. 489 */ 490 if (sentinel.ai_next) 491 goto good; 492 493 if (hostname == NULL) 494 ERR(EAI_NODATA); 495 if (pai->ai_flags & AI_NUMERICHOST) 496 ERR(EAI_NONAME); 497 498 /* 499 * hostname as alphabetical name. 500 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 501 * outer loop by AFs. 502 */ 503 for (ex = explore; ex->e_af >= 0; ex++) { 504 *pai = ai0; 505 506 /* ADDRCONFIG check */ 507 if ((((uint64_t)1 << ex->e_af) & mask) == 0) 508 continue; 509 510 /* require exact match for family field */ 511 if (pai->ai_family != ex->e_af) 512 continue; 513 514 if (!MATCH(pai->ai_socktype, ex->e_socktype, 515 WILD_SOCKTYPE(ex))) { 516 continue; 517 } 518 if (!MATCH(pai->ai_protocol, ex->e_protocol, 519 WILD_PROTOCOL(ex))) { 520 continue; 521 } 522 523 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 524 pai->ai_socktype = ex->e_socktype; 525 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 526 pai->ai_protocol = ex->e_protocol; 527 528 error = explore_fqdn(pai, hostname, servname, &cur->ai_next, 529 &svd); 530 531 while (cur && cur->ai_next) 532 cur = cur->ai_next; 533 } 534 535 /* XXX */ 536 if (sentinel.ai_next) 537 error = 0; 538 539 if (error) 540 goto free; 541 542 if (sentinel.ai_next) { 543 good: 544 endservent_r(&svd); 545 *res = sentinel.ai_next; 546 return SUCCESS; 547 } else 548 error = EAI_FAIL; 549 free: 550 bad: 551 endservent_r(&svd); 552 if (sentinel.ai_next) 553 freeaddrinfo(sentinel.ai_next); 554 *res = NULL; 555 return error; 556 } 557 558 /* 559 * FQDN hostname, DNS lookup 560 */ 561 static int 562 explore_fqdn(const struct addrinfo *pai, const char *hostname, 563 const char *servname, struct addrinfo **res, struct servent_data *svd) 564 { 565 struct addrinfo *result; 566 struct addrinfo *cur; 567 int error = 0; 568 static const ns_dtab dtab[] = { 569 NS_FILES_CB(_files_getaddrinfo, NULL) 570 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 571 NS_NIS_CB(_yp_getaddrinfo, NULL) 572 NS_NULL_CB 573 }; 574 575 _DIAGASSERT(pai != NULL); 576 /* hostname may be NULL */ 577 /* servname may be NULL */ 578 _DIAGASSERT(res != NULL); 579 580 result = NULL; 581 582 /* 583 * if the servname does not match socktype/protocol, ignore it. 584 */ 585 if (get_portmatch(pai, servname, svd) != 0) 586 return 0; 587 588 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 589 default_dns_files, hostname, pai)) { 590 case NS_TRYAGAIN: 591 error = EAI_AGAIN; 592 goto free; 593 case NS_UNAVAIL: 594 error = EAI_FAIL; 595 goto free; 596 case NS_NOTFOUND: 597 error = EAI_NODATA; 598 goto free; 599 case NS_SUCCESS: 600 error = 0; 601 for (cur = result; cur; cur = cur->ai_next) { 602 GET_PORT(cur, servname, svd); 603 /* canonname should be filled already */ 604 } 605 break; 606 } 607 608 *res = result; 609 610 return 0; 611 612 free: 613 if (result) 614 freeaddrinfo(result); 615 return error; 616 } 617 618 /* 619 * hostname == NULL. 620 * passive socket -> anyaddr (0.0.0.0 or ::) 621 * non-passive socket -> localhost (127.0.0.1 or ::1) 622 */ 623 static int 624 explore_null(const struct addrinfo *pai, const char *servname, 625 struct addrinfo **res, struct servent_data *svd) 626 { 627 int s; 628 const struct afd *afd; 629 struct addrinfo *cur; 630 struct addrinfo sentinel; 631 int error; 632 633 _DIAGASSERT(pai != NULL); 634 /* servname may be NULL */ 635 _DIAGASSERT(res != NULL); 636 637 *res = NULL; 638 sentinel.ai_next = NULL; 639 cur = &sentinel; 640 641 /* 642 * filter out AFs that are not supported by the kernel 643 * XXX errno? 644 */ 645 s = socket(pai->ai_family, SOCK_DGRAM, 0); 646 if (s < 0) { 647 if (errno != EMFILE) 648 return 0; 649 } else 650 close(s); 651 652 /* 653 * if the servname does not match socktype/protocol, ignore it. 654 */ 655 if (get_portmatch(pai, servname, svd) != 0) 656 return 0; 657 658 afd = find_afd(pai->ai_family); 659 if (afd == NULL) 660 return 0; 661 662 if (pai->ai_flags & AI_PASSIVE) { 663 GET_AI(cur->ai_next, afd, afd->a_addrany); 664 /* xxx meaningless? 665 * GET_CANONNAME(cur->ai_next, "anyaddr"); 666 */ 667 GET_PORT(cur->ai_next, servname, svd); 668 } else { 669 GET_AI(cur->ai_next, afd, afd->a_loopback); 670 /* xxx meaningless? 671 * GET_CANONNAME(cur->ai_next, "localhost"); 672 */ 673 GET_PORT(cur->ai_next, servname, svd); 674 } 675 cur = cur->ai_next; 676 677 *res = sentinel.ai_next; 678 return 0; 679 680 free: 681 if (sentinel.ai_next) 682 freeaddrinfo(sentinel.ai_next); 683 return error; 684 } 685 686 /* 687 * numeric hostname 688 */ 689 static int 690 explore_numeric(const struct addrinfo *pai, const char *hostname, 691 const char *servname, struct addrinfo **res, const char *canonname, 692 struct servent_data *svd) 693 { 694 const struct afd *afd; 695 struct addrinfo *cur; 696 struct addrinfo sentinel; 697 int error; 698 char pton[PTON_MAX]; 699 700 _DIAGASSERT(pai != NULL); 701 /* hostname may be NULL */ 702 /* servname may be NULL */ 703 _DIAGASSERT(res != NULL); 704 705 *res = NULL; 706 sentinel.ai_next = NULL; 707 cur = &sentinel; 708 709 /* 710 * if the servname does not match socktype/protocol, ignore it. 711 */ 712 if (get_portmatch(pai, servname, svd) != 0) 713 return 0; 714 715 afd = find_afd(pai->ai_family); 716 if (afd == NULL) 717 return 0; 718 719 switch (afd->a_af) { 720 #if 0 /*X/Open spec*/ 721 case AF_INET: 722 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 723 if (pai->ai_family == afd->a_af || 724 pai->ai_family == PF_UNSPEC /*?*/) { 725 GET_AI(cur->ai_next, afd, pton); 726 GET_PORT(cur->ai_next, servname, svd); 727 if ((pai->ai_flags & AI_CANONNAME)) { 728 /* 729 * Set the numeric address itself as 730 * the canonical name, based on a 731 * clarification in rfc2553bis-03. 732 */ 733 GET_CANONNAME(cur->ai_next, canonname); 734 } 735 while (cur && cur->ai_next) 736 cur = cur->ai_next; 737 } else 738 ERR(EAI_FAMILY); /*xxx*/ 739 } 740 break; 741 #endif 742 default: 743 if (inet_pton(afd->a_af, hostname, pton) == 1) { 744 if (pai->ai_family == afd->a_af || 745 pai->ai_family == PF_UNSPEC /*?*/) { 746 GET_AI(cur->ai_next, afd, pton); 747 GET_PORT(cur->ai_next, servname, svd); 748 if ((pai->ai_flags & AI_CANONNAME)) { 749 /* 750 * Set the numeric address itself as 751 * the canonical name, based on a 752 * clarification in rfc2553bis-03. 753 */ 754 GET_CANONNAME(cur->ai_next, canonname); 755 } 756 while (cur->ai_next) 757 cur = cur->ai_next; 758 } else 759 ERR(EAI_FAMILY); /*xxx*/ 760 } 761 break; 762 } 763 764 *res = sentinel.ai_next; 765 return 0; 766 767 free: 768 bad: 769 if (sentinel.ai_next) 770 freeaddrinfo(sentinel.ai_next); 771 return error; 772 } 773 774 /* 775 * numeric hostname with scope 776 */ 777 static int 778 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 779 const char *servname, struct addrinfo **res, struct servent_data *svd) 780 { 781 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 782 return explore_numeric(pai, hostname, servname, res, hostname, svd); 783 #else 784 const struct afd *afd; 785 struct addrinfo *cur; 786 int error; 787 char *cp, *hostname2 = NULL, *scope, *addr; 788 struct sockaddr_in6 *sin6; 789 790 _DIAGASSERT(pai != NULL); 791 /* hostname may be NULL */ 792 /* servname may be NULL */ 793 _DIAGASSERT(res != NULL); 794 795 /* 796 * if the servname does not match socktype/protocol, ignore it. 797 */ 798 if (get_portmatch(pai, servname, svd) != 0) 799 return 0; 800 801 afd = find_afd(pai->ai_family); 802 if (afd == NULL) 803 return 0; 804 805 if (!afd->a_scoped) 806 return explore_numeric(pai, hostname, servname, res, hostname, 807 svd); 808 809 cp = strchr(hostname, SCOPE_DELIMITER); 810 if (cp == NULL) 811 return explore_numeric(pai, hostname, servname, res, hostname, 812 svd); 813 814 /* 815 * Handle special case of <scoped_address><delimiter><scope id> 816 */ 817 hostname2 = strdup(hostname); 818 if (hostname2 == NULL) 819 return EAI_MEMORY; 820 /* terminate at the delimiter */ 821 hostname2[cp - hostname] = '\0'; 822 addr = hostname2; 823 scope = cp + 1; 824 825 error = explore_numeric(pai, addr, servname, res, hostname, svd); 826 if (error == 0) { 827 u_int32_t scopeid; 828 829 for (cur = *res; cur; cur = cur->ai_next) { 830 if (cur->ai_family != AF_INET6) 831 continue; 832 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 833 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 834 free(hostname2); 835 return(EAI_NODATA); /* XXX: is return OK? */ 836 } 837 sin6->sin6_scope_id = scopeid; 838 } 839 } 840 841 free(hostname2); 842 843 return error; 844 #endif 845 } 846 847 static int 848 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 849 { 850 851 _DIAGASSERT(pai != NULL); 852 _DIAGASSERT(ai != NULL); 853 _DIAGASSERT(str != NULL); 854 855 if ((pai->ai_flags & AI_CANONNAME) != 0) { 856 ai->ai_canonname = strdup(str); 857 if (ai->ai_canonname == NULL) 858 return EAI_MEMORY; 859 } 860 return 0; 861 } 862 863 struct addrinfo * 864 allocaddrinfo(socklen_t addrlen) 865 { 866 struct addrinfo *ai; 867 868 ai = calloc(sizeof(struct addrinfo) + addrlen, 1); 869 if (ai) { 870 ai->ai_addr = (void *)(ai+1); 871 ai->ai_addrlen = ai->ai_addr->sa_len = addrlen; 872 } 873 874 return ai; 875 } 876 877 static struct addrinfo * 878 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 879 { 880 char *p; 881 struct addrinfo *ai; 882 struct sockaddr *save; 883 884 _DIAGASSERT(pai != NULL); 885 _DIAGASSERT(afd != NULL); 886 _DIAGASSERT(addr != NULL); 887 888 ai = allocaddrinfo((socklen_t)afd->a_socklen); 889 if (ai == NULL) 890 return NULL; 891 892 save = ai->ai_addr; 893 memcpy(ai, pai, sizeof(struct addrinfo)); 894 895 /* since we just overwrote all of ai, we have 896 to restore ai_addr and ai_addrlen */ 897 ai->ai_addr = save; 898 ai->ai_addrlen = (socklen_t)afd->a_socklen; 899 900 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 901 p = (char *)(void *)(ai->ai_addr); 902 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 903 return ai; 904 } 905 906 static int 907 get_portmatch(const struct addrinfo *ai, const char *servname, 908 struct servent_data *svd) 909 { 910 911 _DIAGASSERT(ai != NULL); 912 /* servname may be NULL */ 913 914 return get_port(ai, servname, 1, svd); 915 } 916 917 static int 918 get_port(const struct addrinfo *ai, const char *servname, int matchonly, 919 struct servent_data *svd) 920 { 921 const char *proto; 922 struct servent *sp; 923 int port; 924 int allownumeric; 925 926 _DIAGASSERT(ai != NULL); 927 /* servname may be NULL */ 928 929 if (servname == NULL) 930 return 0; 931 switch (ai->ai_family) { 932 case AF_INET: 933 #ifdef AF_INET6 934 case AF_INET6: 935 #endif 936 break; 937 default: 938 return 0; 939 } 940 941 switch (ai->ai_socktype) { 942 case SOCK_RAW: 943 return EAI_SERVICE; 944 case SOCK_DGRAM: 945 case SOCK_STREAM: 946 allownumeric = 1; 947 break; 948 case ANY: 949 /* 950 * This was 0. It is now 1 so that queries specifying 951 * a NULL hint, or hint without socktype (but, hopefully, 952 * with protocol) and numeric address actually work. 953 */ 954 allownumeric = 1; 955 break; 956 default: 957 return EAI_SOCKTYPE; 958 } 959 960 port = str2number(servname); 961 if (port >= 0) { 962 if (!allownumeric) 963 return EAI_SERVICE; 964 if (port < 0 || port > 65535) 965 return EAI_SERVICE; 966 port = htons(port); 967 } else { 968 struct servent sv; 969 if (ai->ai_flags & AI_NUMERICSERV) 970 return EAI_NONAME; 971 972 switch (ai->ai_socktype) { 973 case SOCK_DGRAM: 974 proto = "udp"; 975 break; 976 case SOCK_STREAM: 977 proto = "tcp"; 978 break; 979 default: 980 proto = NULL; 981 break; 982 } 983 984 sp = getservbyname_r(servname, proto, &sv, svd); 985 if (sp == NULL) 986 return EAI_SERVICE; 987 port = sp->s_port; 988 } 989 990 if (!matchonly) { 991 switch (ai->ai_family) { 992 case AF_INET: 993 ((struct sockaddr_in *)(void *) 994 ai->ai_addr)->sin_port = port; 995 break; 996 #ifdef INET6 997 case AF_INET6: 998 ((struct sockaddr_in6 *)(void *) 999 ai->ai_addr)->sin6_port = port; 1000 break; 1001 #endif 1002 } 1003 } 1004 1005 return 0; 1006 } 1007 1008 static const struct afd * 1009 find_afd(int af) 1010 { 1011 const struct afd *afd; 1012 1013 if (af == PF_UNSPEC) 1014 return NULL; 1015 for (afd = afdl; afd->a_af; afd++) { 1016 if (afd->a_af == af) 1017 return afd; 1018 } 1019 return NULL; 1020 } 1021 1022 /* 1023 * AI_ADDRCONFIG check: Build a mask containing a bit set for each address 1024 * family configured in the system. 1025 * 1026 */ 1027 static int 1028 addrconfig(uint64_t *mask) 1029 { 1030 struct ifaddrs *ifaddrs, *ifa; 1031 1032 if (getifaddrs(&ifaddrs) == -1) 1033 return -1; 1034 1035 *mask = 0; 1036 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) 1037 if (ifa->ifa_addr && (ifa->ifa_flags & IFF_UP)) { 1038 _DIAGASSERT(ifa->ifa_addr->sa_family < 64); 1039 *mask |= (uint64_t)1 << ifa->ifa_addr->sa_family; 1040 } 1041 1042 freeifaddrs(ifaddrs); 1043 return 0; 1044 } 1045 1046 #ifdef INET6 1047 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1048 static int 1049 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1050 { 1051 u_long lscopeid; 1052 struct in6_addr *a6; 1053 char *ep; 1054 1055 _DIAGASSERT(scope != NULL); 1056 _DIAGASSERT(sin6 != NULL); 1057 _DIAGASSERT(scopeid != NULL); 1058 1059 a6 = &sin6->sin6_addr; 1060 1061 /* empty scopeid portion is invalid */ 1062 if (*scope == '\0') 1063 return -1; 1064 1065 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1066 /* 1067 * We currently assume a one-to-one mapping between links 1068 * and interfaces, so we simply use interface indices for 1069 * like-local scopes. 1070 */ 1071 *scopeid = if_nametoindex(scope); 1072 if (*scopeid == 0) 1073 goto trynumeric; 1074 return 0; 1075 } 1076 1077 /* still unclear about literal, allow numeric only - placeholder */ 1078 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1079 goto trynumeric; 1080 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1081 goto trynumeric; 1082 else 1083 goto trynumeric; /* global */ 1084 1085 /* try to convert to a numeric id as a last resort */ 1086 trynumeric: 1087 errno = 0; 1088 lscopeid = strtoul(scope, &ep, 10); 1089 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1090 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1091 return 0; 1092 else 1093 return -1; 1094 } 1095 #endif 1096 1097 /* code duplicate with gethnamaddr.c */ 1098 1099 static const char AskedForGot[] = 1100 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1101 1102 static struct addrinfo * 1103 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1104 const struct addrinfo *pai) 1105 { 1106 struct addrinfo sentinel, *cur; 1107 struct addrinfo ai; 1108 const struct afd *afd; 1109 char *canonname; 1110 const HEADER *hp; 1111 const u_char *cp; 1112 int n; 1113 const u_char *eom; 1114 char *bp, *ep; 1115 int type, class, ancount, qdcount; 1116 int haveanswer, had_error; 1117 char tbuf[MAXDNAME]; 1118 int (*name_ok) (const char *); 1119 char hostbuf[8*1024]; 1120 1121 _DIAGASSERT(answer != NULL); 1122 _DIAGASSERT(qname != NULL); 1123 _DIAGASSERT(pai != NULL); 1124 1125 memset(&sentinel, 0, sizeof(sentinel)); 1126 cur = &sentinel; 1127 1128 canonname = NULL; 1129 eom = answer->buf + anslen; 1130 switch (qtype) { 1131 case T_A: 1132 case T_AAAA: 1133 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1134 name_ok = res_hnok; 1135 break; 1136 default: 1137 return NULL; /* XXX should be abort(); */ 1138 } 1139 /* 1140 * find first satisfactory answer 1141 */ 1142 hp = &answer->hdr; 1143 ancount = ntohs(hp->ancount); 1144 qdcount = ntohs(hp->qdcount); 1145 bp = hostbuf; 1146 ep = hostbuf + sizeof hostbuf; 1147 cp = answer->buf + HFIXEDSZ; 1148 if (qdcount != 1) { 1149 h_errno = NO_RECOVERY; 1150 return (NULL); 1151 } 1152 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp)); 1153 if ((n < 0) || !(*name_ok)(bp)) { 1154 h_errno = NO_RECOVERY; 1155 return (NULL); 1156 } 1157 cp += n + QFIXEDSZ; 1158 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1159 /* res_send() has already verified that the query name is the 1160 * same as the one we sent; this just gets the expanded name 1161 * (i.e., with the succeeding search-domain tacked on). 1162 */ 1163 n = (int)strlen(bp) + 1; /* for the \0 */ 1164 if (n >= MAXHOSTNAMELEN) { 1165 h_errno = NO_RECOVERY; 1166 return (NULL); 1167 } 1168 canonname = bp; 1169 bp += n; 1170 /* The qname can be abbreviated, but h_name is now absolute. */ 1171 qname = canonname; 1172 } 1173 haveanswer = 0; 1174 had_error = 0; 1175 while (ancount-- > 0 && cp < eom && !had_error) { 1176 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp)); 1177 if ((n < 0) || !(*name_ok)(bp)) { 1178 had_error++; 1179 continue; 1180 } 1181 cp += n; /* name */ 1182 type = _getshort(cp); 1183 cp += INT16SZ; /* type */ 1184 class = _getshort(cp); 1185 cp += INT16SZ + INT32SZ; /* class, TTL */ 1186 n = _getshort(cp); 1187 cp += INT16SZ; /* len */ 1188 if (class != C_IN) { 1189 /* XXX - debug? syslog? */ 1190 cp += n; 1191 continue; /* XXX - had_error++ ? */ 1192 } 1193 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1194 type == T_CNAME) { 1195 n = dn_expand(answer->buf, eom, cp, tbuf, (int)sizeof tbuf); 1196 if ((n < 0) || !(*name_ok)(tbuf)) { 1197 had_error++; 1198 continue; 1199 } 1200 cp += n; 1201 /* Get canonical name. */ 1202 n = (int)strlen(tbuf) + 1; /* for the \0 */ 1203 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1204 had_error++; 1205 continue; 1206 } 1207 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1208 canonname = bp; 1209 bp += n; 1210 continue; 1211 } 1212 if (qtype == T_ANY) { 1213 if (!(type == T_A || type == T_AAAA)) { 1214 cp += n; 1215 continue; 1216 } 1217 } else if (type != qtype) { 1218 if (type != T_KEY && type != T_SIG) { 1219 struct syslog_data sd = SYSLOG_DATA_INIT; 1220 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1221 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1222 qname, p_class(C_IN), p_type(qtype), 1223 p_type(type)); 1224 } 1225 cp += n; 1226 continue; /* XXX - had_error++ ? */ 1227 } 1228 switch (type) { 1229 case T_A: 1230 case T_AAAA: 1231 if (strcasecmp(canonname, bp) != 0) { 1232 struct syslog_data sd = SYSLOG_DATA_INIT; 1233 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1234 AskedForGot, canonname, bp); 1235 cp += n; 1236 continue; /* XXX - had_error++ ? */ 1237 } 1238 if (type == T_A && n != INADDRSZ) { 1239 cp += n; 1240 continue; 1241 } 1242 if (type == T_AAAA && n != IN6ADDRSZ) { 1243 cp += n; 1244 continue; 1245 } 1246 if (type == T_AAAA) { 1247 struct in6_addr in6; 1248 memcpy(&in6, cp, IN6ADDRSZ); 1249 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1250 cp += n; 1251 continue; 1252 } 1253 } 1254 if (!haveanswer) { 1255 int nn; 1256 1257 canonname = bp; 1258 nn = (int)strlen(bp) + 1; /* for the \0 */ 1259 bp += nn; 1260 } 1261 1262 /* don't overwrite pai */ 1263 ai = *pai; 1264 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1265 afd = find_afd(ai.ai_family); 1266 if (afd == NULL) { 1267 cp += n; 1268 continue; 1269 } 1270 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1271 if (cur->ai_next == NULL) 1272 had_error++; 1273 while (cur && cur->ai_next) 1274 cur = cur->ai_next; 1275 cp += n; 1276 break; 1277 default: 1278 abort(); 1279 } 1280 if (!had_error) 1281 haveanswer++; 1282 } 1283 if (haveanswer) { 1284 if (!canonname) 1285 (void)get_canonname(pai, sentinel.ai_next, qname); 1286 else 1287 (void)get_canonname(pai, sentinel.ai_next, canonname); 1288 h_errno = NETDB_SUCCESS; 1289 return sentinel.ai_next; 1290 } 1291 1292 h_errno = NO_RECOVERY; 1293 return NULL; 1294 } 1295 1296 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr) 1297 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr) 1298 1299 static void 1300 aisort(struct addrinfo *s, res_state res) 1301 { 1302 struct addrinfo head, *t, *p; 1303 int i; 1304 1305 head.ai_next = NULL; 1306 t = &head; 1307 1308 for (i = 0; i < res->nsort; i++) { 1309 p = s; 1310 while (p->ai_next) { 1311 if ((p->ai_next->ai_family != AF_INET) 1312 || SORTMATCH(p, res->sort_list[i])) { 1313 t->ai_next = p->ai_next; 1314 t = t->ai_next; 1315 p->ai_next = p->ai_next->ai_next; 1316 } else { 1317 p = p->ai_next; 1318 } 1319 } 1320 } 1321 1322 /* add rest of list and reset s to the new list*/ 1323 t->ai_next = s->ai_next; 1324 s->ai_next = head.ai_next; 1325 } 1326 1327 /*ARGSUSED*/ 1328 static int 1329 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1330 { 1331 struct addrinfo *ai; 1332 querybuf *buf, *buf2; 1333 const char *name; 1334 const struct addrinfo *pai; 1335 struct addrinfo sentinel, *cur; 1336 struct res_target q, q2; 1337 res_state res; 1338 1339 name = va_arg(ap, char *); 1340 pai = va_arg(ap, const struct addrinfo *); 1341 1342 memset(&q, 0, sizeof(q)); 1343 memset(&q2, 0, sizeof(q2)); 1344 memset(&sentinel, 0, sizeof(sentinel)); 1345 cur = &sentinel; 1346 1347 buf = malloc(sizeof(*buf)); 1348 if (buf == NULL) { 1349 h_errno = NETDB_INTERNAL; 1350 return NS_NOTFOUND; 1351 } 1352 buf2 = malloc(sizeof(*buf2)); 1353 if (buf2 == NULL) { 1354 free(buf); 1355 h_errno = NETDB_INTERNAL; 1356 return NS_NOTFOUND; 1357 } 1358 1359 switch (pai->ai_family) { 1360 case AF_UNSPEC: 1361 /* prefer IPv6 */ 1362 q.name = name; 1363 q.qclass = C_IN; 1364 q.qtype = T_AAAA; 1365 q.answer = buf->buf; 1366 q.anslen = sizeof(buf->buf); 1367 q.next = &q2; 1368 q2.name = name; 1369 q2.qclass = C_IN; 1370 q2.qtype = T_A; 1371 q2.answer = buf2->buf; 1372 q2.anslen = sizeof(buf2->buf); 1373 break; 1374 case AF_INET: 1375 q.name = name; 1376 q.qclass = C_IN; 1377 q.qtype = T_A; 1378 q.answer = buf->buf; 1379 q.anslen = sizeof(buf->buf); 1380 break; 1381 case AF_INET6: 1382 q.name = name; 1383 q.qclass = C_IN; 1384 q.qtype = T_AAAA; 1385 q.answer = buf->buf; 1386 q.anslen = sizeof(buf->buf); 1387 break; 1388 default: 1389 free(buf); 1390 free(buf2); 1391 return NS_UNAVAIL; 1392 } 1393 1394 res = __res_get_state(); 1395 if (res == NULL) { 1396 free(buf); 1397 free(buf2); 1398 return NS_NOTFOUND; 1399 } 1400 1401 if (res_searchN(name, &q, res) < 0) { 1402 __res_put_state(res); 1403 free(buf); 1404 free(buf2); 1405 return NS_NOTFOUND; 1406 } 1407 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1408 if (ai) { 1409 cur->ai_next = ai; 1410 while (cur && cur->ai_next) 1411 cur = cur->ai_next; 1412 } 1413 if (q.next) { 1414 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1415 if (ai) 1416 cur->ai_next = ai; 1417 } 1418 free(buf); 1419 free(buf2); 1420 if (sentinel.ai_next == NULL) { 1421 __res_put_state(res); 1422 switch (h_errno) { 1423 case HOST_NOT_FOUND: 1424 return NS_NOTFOUND; 1425 case TRY_AGAIN: 1426 return NS_TRYAGAIN; 1427 default: 1428 return NS_UNAVAIL; 1429 } 1430 } 1431 1432 if (res->nsort) 1433 aisort(&sentinel, res); 1434 1435 __res_put_state(res); 1436 1437 *((struct addrinfo **)rv) = sentinel.ai_next; 1438 return NS_SUCCESS; 1439 } 1440 1441 static void 1442 _sethtent(FILE **hostf) 1443 { 1444 1445 if (!*hostf) 1446 *hostf = fopen(_PATH_HOSTS, "re"); 1447 else 1448 rewind(*hostf); 1449 } 1450 1451 static void 1452 _endhtent(FILE **hostf) 1453 { 1454 1455 if (*hostf) { 1456 (void) fclose(*hostf); 1457 *hostf = NULL; 1458 } 1459 } 1460 1461 static struct addrinfo * 1462 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1463 { 1464 char *p; 1465 char *cp, *tname, *cname; 1466 struct addrinfo hints, *res0, *res; 1467 int error; 1468 const char *addr; 1469 char hostbuf[8*1024]; 1470 1471 _DIAGASSERT(name != NULL); 1472 _DIAGASSERT(pai != NULL); 1473 1474 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 1475 return (NULL); 1476 again: 1477 if (!(p = fgets(hostbuf, (int)sizeof hostbuf, *hostf))) 1478 return (NULL); 1479 if (*p == '#') 1480 goto again; 1481 if (!(cp = strpbrk(p, "#\n"))) 1482 goto again; 1483 *cp = '\0'; 1484 if (!(cp = strpbrk(p, " \t"))) 1485 goto again; 1486 *cp++ = '\0'; 1487 addr = p; 1488 /* if this is not something we're looking for, skip it. */ 1489 cname = NULL; 1490 while (cp && *cp) { 1491 if (*cp == ' ' || *cp == '\t') { 1492 cp++; 1493 continue; 1494 } 1495 if (!cname) 1496 cname = cp; 1497 tname = cp; 1498 if ((cp = strpbrk(cp, " \t")) != NULL) 1499 *cp++ = '\0'; 1500 if (strcasecmp(name, tname) == 0) 1501 goto found; 1502 } 1503 goto again; 1504 1505 found: 1506 hints = *pai; 1507 hints.ai_flags = AI_NUMERICHOST; 1508 error = getaddrinfo(addr, NULL, &hints, &res0); 1509 if (error) 1510 goto again; 1511 for (res = res0; res; res = res->ai_next) { 1512 /* cover it up */ 1513 res->ai_flags = pai->ai_flags; 1514 1515 if (pai->ai_flags & AI_CANONNAME) { 1516 if (get_canonname(pai, res, cname) != 0) { 1517 freeaddrinfo(res0); 1518 goto again; 1519 } 1520 } 1521 } 1522 return res0; 1523 } 1524 1525 /*ARGSUSED*/ 1526 static int 1527 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1528 { 1529 const char *name; 1530 const struct addrinfo *pai; 1531 struct addrinfo sentinel, *cur; 1532 struct addrinfo *p; 1533 #ifndef _REENTRANT 1534 static 1535 #endif 1536 FILE *hostf = NULL; 1537 1538 name = va_arg(ap, char *); 1539 pai = va_arg(ap, const struct addrinfo *); 1540 1541 memset(&sentinel, 0, sizeof(sentinel)); 1542 cur = &sentinel; 1543 1544 _sethtent(&hostf); 1545 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1546 cur->ai_next = p; 1547 while (cur && cur->ai_next) 1548 cur = cur->ai_next; 1549 } 1550 _endhtent(&hostf); 1551 1552 *((struct addrinfo **)rv) = sentinel.ai_next; 1553 if (sentinel.ai_next == NULL) 1554 return NS_NOTFOUND; 1555 return NS_SUCCESS; 1556 } 1557 1558 #ifdef YP 1559 /*ARGSUSED*/ 1560 static struct addrinfo * 1561 _yphostent(char *line, const struct addrinfo *pai) 1562 { 1563 struct addrinfo sentinel, *cur; 1564 struct addrinfo hints, *res, *res0; 1565 int error; 1566 char *p; 1567 const char *addr, *canonname; 1568 char *nextline; 1569 char *cp; 1570 1571 _DIAGASSERT(line != NULL); 1572 _DIAGASSERT(pai != NULL); 1573 1574 p = line; 1575 addr = canonname = NULL; 1576 1577 memset(&sentinel, 0, sizeof(sentinel)); 1578 cur = &sentinel; 1579 1580 nextline: 1581 /* terminate line */ 1582 cp = strchr(p, '\n'); 1583 if (cp) { 1584 *cp++ = '\0'; 1585 nextline = cp; 1586 } else 1587 nextline = NULL; 1588 1589 cp = strpbrk(p, " \t"); 1590 if (cp == NULL) { 1591 if (canonname == NULL) 1592 return (NULL); 1593 else 1594 goto done; 1595 } 1596 *cp++ = '\0'; 1597 1598 addr = p; 1599 1600 while (cp && *cp) { 1601 if (*cp == ' ' || *cp == '\t') { 1602 cp++; 1603 continue; 1604 } 1605 if (!canonname) 1606 canonname = cp; 1607 if ((cp = strpbrk(cp, " \t")) != NULL) 1608 *cp++ = '\0'; 1609 } 1610 1611 hints = *pai; 1612 hints.ai_flags = AI_NUMERICHOST; 1613 error = getaddrinfo(addr, NULL, &hints, &res0); 1614 if (error == 0) { 1615 for (res = res0; res; res = res->ai_next) { 1616 /* cover it up */ 1617 res->ai_flags = pai->ai_flags; 1618 1619 if (pai->ai_flags & AI_CANONNAME) 1620 (void)get_canonname(pai, res, canonname); 1621 } 1622 } else 1623 res0 = NULL; 1624 if (res0) { 1625 cur->ai_next = res0; 1626 while (cur->ai_next) 1627 cur = cur->ai_next; 1628 } 1629 1630 if (nextline) { 1631 p = nextline; 1632 goto nextline; 1633 } 1634 1635 done: 1636 return sentinel.ai_next; 1637 } 1638 1639 /*ARGSUSED*/ 1640 static int 1641 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1642 { 1643 struct addrinfo sentinel, *cur; 1644 struct addrinfo *ai = NULL; 1645 char *ypbuf; 1646 int ypbuflen, r; 1647 const char *name; 1648 const struct addrinfo *pai; 1649 char *ypdomain; 1650 1651 if (_yp_check(&ypdomain) == 0) 1652 return NS_UNAVAIL; 1653 1654 name = va_arg(ap, char *); 1655 pai = va_arg(ap, const struct addrinfo *); 1656 1657 memset(&sentinel, 0, sizeof(sentinel)); 1658 cur = &sentinel; 1659 1660 /* hosts.byname is only for IPv4 (Solaris8) */ 1661 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1662 r = yp_match(ypdomain, "hosts.byname", name, 1663 (int)strlen(name), &ypbuf, &ypbuflen); 1664 if (r == 0) { 1665 struct addrinfo ai4; 1666 1667 ai4 = *pai; 1668 ai4.ai_family = AF_INET; 1669 ai = _yphostent(ypbuf, &ai4); 1670 if (ai) { 1671 cur->ai_next = ai; 1672 while (cur && cur->ai_next) 1673 cur = cur->ai_next; 1674 } 1675 } 1676 free(ypbuf); 1677 } 1678 1679 /* ipnodes.byname can hold both IPv4/v6 */ 1680 r = yp_match(ypdomain, "ipnodes.byname", name, 1681 (int)strlen(name), &ypbuf, &ypbuflen); 1682 if (r == 0) { 1683 ai = _yphostent(ypbuf, pai); 1684 if (ai) 1685 cur->ai_next = ai; 1686 free(ypbuf); 1687 } 1688 1689 if (sentinel.ai_next == NULL) { 1690 h_errno = HOST_NOT_FOUND; 1691 return NS_NOTFOUND; 1692 } 1693 *((struct addrinfo **)rv) = sentinel.ai_next; 1694 return NS_SUCCESS; 1695 } 1696 #endif 1697 1698 /* resolver logic */ 1699 1700 /* 1701 * Formulate a normal query, send, and await answer. 1702 * Returned answer is placed in supplied buffer "answer". 1703 * Perform preliminary check of answer, returning success only 1704 * if no error is indicated and the answer count is nonzero. 1705 * Return the size of the response on success, -1 on error. 1706 * Error number is left in h_errno. 1707 * 1708 * Caller must parse answer and determine whether it answers the question. 1709 */ 1710 static int 1711 res_queryN(const char *name, /* domain name */ struct res_target *target, 1712 res_state res) 1713 { 1714 u_char buf[MAXPACKET]; 1715 HEADER *hp; 1716 int n; 1717 struct res_target *t; 1718 int rcode; 1719 int ancount; 1720 1721 _DIAGASSERT(name != NULL); 1722 /* XXX: target may be NULL??? */ 1723 1724 rcode = NOERROR; 1725 ancount = 0; 1726 1727 for (t = target; t; t = t->next) { 1728 int class, type; 1729 u_char *answer; 1730 int anslen; 1731 1732 hp = (HEADER *)(void *)t->answer; 1733 hp->rcode = NOERROR; /* default */ 1734 1735 /* make it easier... */ 1736 class = t->qclass; 1737 type = t->qtype; 1738 answer = t->answer; 1739 anslen = t->anslen; 1740 #ifdef DEBUG 1741 if (res->options & RES_DEBUG) 1742 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 1743 #endif 1744 1745 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 1746 buf, (int)sizeof(buf)); 1747 #ifdef RES_USE_EDNS0 1748 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 1749 n = res_nopt(res, n, buf, (int)sizeof(buf), anslen); 1750 #endif 1751 if (n <= 0) { 1752 #ifdef DEBUG 1753 if (res->options & RES_DEBUG) 1754 printf(";; res_nquery: mkquery failed\n"); 1755 #endif 1756 h_errno = NO_RECOVERY; 1757 return n; 1758 } 1759 n = res_nsend(res, buf, n, answer, anslen); 1760 #if 0 1761 if (n < 0) { 1762 #ifdef DEBUG 1763 if (res->options & RES_DEBUG) 1764 printf(";; res_query: send error\n"); 1765 #endif 1766 h_errno = TRY_AGAIN; 1767 return n; 1768 } 1769 #endif 1770 1771 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1772 rcode = hp->rcode; /* record most recent error */ 1773 #ifdef DEBUG 1774 if (res->options & RES_DEBUG) 1775 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1776 ntohs(hp->ancount)); 1777 #endif 1778 continue; 1779 } 1780 1781 ancount += ntohs(hp->ancount); 1782 1783 t->n = n; 1784 } 1785 1786 if (ancount == 0) { 1787 switch (rcode) { 1788 case NXDOMAIN: 1789 h_errno = HOST_NOT_FOUND; 1790 break; 1791 case SERVFAIL: 1792 h_errno = TRY_AGAIN; 1793 break; 1794 case NOERROR: 1795 h_errno = NO_DATA; 1796 break; 1797 case FORMERR: 1798 case NOTIMP: 1799 case REFUSED: 1800 default: 1801 h_errno = NO_RECOVERY; 1802 break; 1803 } 1804 return -1; 1805 } 1806 return ancount; 1807 } 1808 1809 /* 1810 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1811 * Return the size of the response on success, -1 on error. 1812 * If enabled, implement search rules until answer or unrecoverable failure 1813 * is detected. Error code, if any, is left in h_errno. 1814 */ 1815 static int 1816 res_searchN(const char *name, struct res_target *target, res_state res) 1817 { 1818 const char *cp, * const *domain; 1819 HEADER *hp; 1820 u_int dots; 1821 int trailing_dot, ret, saved_herrno; 1822 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1823 1824 _DIAGASSERT(name != NULL); 1825 _DIAGASSERT(target != NULL); 1826 1827 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1828 1829 errno = 0; 1830 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1831 dots = 0; 1832 for (cp = name; *cp; cp++) 1833 dots += (*cp == '.'); 1834 trailing_dot = 0; 1835 if (cp > name && *--cp == '.') 1836 trailing_dot++; 1837 1838 /* 1839 * if there aren't any dots, it could be a user-level alias 1840 */ 1841 if (!dots && (cp = __hostalias(name)) != NULL) { 1842 ret = res_queryN(cp, target, res); 1843 return ret; 1844 } 1845 1846 /* 1847 * If there are dots in the name already, let's just give it a try 1848 * 'as is'. The threshold can be set with the "ndots" option. 1849 */ 1850 saved_herrno = -1; 1851 if (dots >= res->ndots) { 1852 ret = res_querydomainN(name, NULL, target, res); 1853 if (ret > 0) 1854 return (ret); 1855 saved_herrno = h_errno; 1856 tried_as_is++; 1857 } 1858 1859 /* 1860 * We do at least one level of search if 1861 * - there is no dot and RES_DEFNAME is set, or 1862 * - there is at least one dot, there is no trailing dot, 1863 * and RES_DNSRCH is set. 1864 */ 1865 if ((!dots && (res->options & RES_DEFNAMES)) || 1866 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 1867 int done = 0; 1868 1869 for (domain = (const char * const *)res->dnsrch; 1870 *domain && !done; 1871 domain++) { 1872 1873 ret = res_querydomainN(name, *domain, target, res); 1874 if (ret > 0) 1875 return ret; 1876 1877 /* 1878 * If no server present, give up. 1879 * If name isn't found in this domain, 1880 * keep trying higher domains in the search list 1881 * (if that's enabled). 1882 * On a NO_DATA error, keep trying, otherwise 1883 * a wildcard entry of another type could keep us 1884 * from finding this entry higher in the domain. 1885 * If we get some other error (negative answer or 1886 * server failure), then stop searching up, 1887 * but try the input name below in case it's 1888 * fully-qualified. 1889 */ 1890 if (errno == ECONNREFUSED) { 1891 h_errno = TRY_AGAIN; 1892 return -1; 1893 } 1894 1895 switch (h_errno) { 1896 case NO_DATA: 1897 got_nodata++; 1898 /* FALLTHROUGH */ 1899 case HOST_NOT_FOUND: 1900 /* keep trying */ 1901 break; 1902 case TRY_AGAIN: 1903 if (hp->rcode == SERVFAIL) { 1904 /* try next search element, if any */ 1905 got_servfail++; 1906 break; 1907 } 1908 /* FALLTHROUGH */ 1909 default: 1910 /* anything else implies that we're done */ 1911 done++; 1912 } 1913 /* 1914 * if we got here for some reason other than DNSRCH, 1915 * we only wanted one iteration of the loop, so stop. 1916 */ 1917 if (!(res->options & RES_DNSRCH)) 1918 done++; 1919 } 1920 } 1921 1922 /* 1923 * if we have not already tried the name "as is", do that now. 1924 * note that we do this regardless of how many dots were in the 1925 * name or whether it ends with a dot. 1926 */ 1927 if (!tried_as_is) { 1928 ret = res_querydomainN(name, NULL, target, res); 1929 if (ret > 0) 1930 return ret; 1931 } 1932 1933 /* 1934 * if we got here, we didn't satisfy the search. 1935 * if we did an initial full query, return that query's h_errno 1936 * (note that we wouldn't be here if that query had succeeded). 1937 * else if we ever got a nodata, send that back as the reason. 1938 * else send back meaningless h_errno, that being the one from 1939 * the last DNSRCH we did. 1940 */ 1941 if (saved_herrno != -1) 1942 h_errno = saved_herrno; 1943 else if (got_nodata) 1944 h_errno = NO_DATA; 1945 else if (got_servfail) 1946 h_errno = TRY_AGAIN; 1947 return -1; 1948 } 1949 1950 /* 1951 * Perform a call on res_query on the concatenation of name and domain, 1952 * removing a trailing dot from name if domain is NULL. 1953 */ 1954 static int 1955 res_querydomainN(const char *name, const char *domain, 1956 struct res_target *target, res_state res) 1957 { 1958 char nbuf[MAXDNAME]; 1959 const char *longname = nbuf; 1960 size_t n, d; 1961 1962 _DIAGASSERT(name != NULL); 1963 /* XXX: target may be NULL??? */ 1964 1965 #ifdef DEBUG 1966 if (res->options & RES_DEBUG) 1967 printf(";; res_querydomain(%s, %s)\n", 1968 name, domain?domain:"<Nil>"); 1969 #endif 1970 if (domain == NULL) { 1971 /* 1972 * Check for trailing '.'; 1973 * copy without '.' if present. 1974 */ 1975 n = strlen(name); 1976 if (n + 1 > sizeof(nbuf)) { 1977 h_errno = NO_RECOVERY; 1978 return -1; 1979 } 1980 if (n > 0 && name[--n] == '.') { 1981 strncpy(nbuf, name, n); 1982 nbuf[n] = '\0'; 1983 } else 1984 longname = name; 1985 } else { 1986 n = strlen(name); 1987 d = strlen(domain); 1988 if (n + 1 + d + 1 > sizeof(nbuf)) { 1989 h_errno = NO_RECOVERY; 1990 return -1; 1991 } 1992 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1993 } 1994 return res_queryN(longname, target, res); 1995 } 1996
Indexes created Tue Sep 30 11:09:46 GMT 2025