1 /* $NetBSD: getaddrinfo.c,v 1.72 2004/05/27 18:40:07 christos Exp $ */ 2 /* $KAME: getaddrinfo.c,v 1.29 2000/08/31 17:26:57 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Issues to be discussed: 35 * - Thread safe-ness must be checked. 36 * - Return values. There are nonstandard return values defined and used 37 * in the source code. This is because RFC2553 is silent about which error 38 * code must be returned for which situation. 39 * - IPv4 classful (shortened) form. RFC2553 is silent about it. XNET 5.2 40 * says to use inet_aton() to convert IPv4 numeric to binary (alows 41 * classful form as a result). 42 * current code - disallow classful form for IPv4 (due to use of inet_pton). 43 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 44 * invalid. 45 * current code - SEGV on freeaddrinfo(NULL) 46 * Note: 47 * - We use getipnodebyname() just for thread-safeness. There's no intent 48 * to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to 49 * getipnodebyname(). 50 * - The code filters out AFs that are not supported by the kernel, 51 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 52 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 53 * in ai_flags? 54 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 55 * (1) what should we do against numeric hostname (2) what should we do 56 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 57 * non-loopback address configured? global address configured? 58 * - To avoid search order issue, we have a big amount of code duplicate 59 * from gethnamaddr.c and some other places. The issues that there's no 60 * lower layer function to lookup "IPv4 or IPv6" record. Calling 61 * gethostbyname2 from getaddrinfo will end up in wrong search order, as 62 * follows: 63 * - The code makes use of following calls when asked to resolver with 64 * ai_family = PF_UNSPEC: 65 * getipnodebyname(host, AF_INET6); 66 * getipnodebyname(host, AF_INET); 67 * This will result in the following queries if the node is configure to 68 * prefer /etc/hosts than DNS: 69 * lookup /etc/hosts for IPv6 address 70 * lookup DNS for IPv6 address 71 * lookup /etc/hosts for IPv4 address 72 * lookup DNS for IPv4 address 73 * which may not meet people's requirement. 74 * The right thing to happen is to have underlying layer which does 75 * PF_UNSPEC lookup (lookup both) and return chain of addrinfos. 76 * This would result in a bit of code duplicate with _dns_ghbyname() and 77 * friends. 78 */ 79 80 #include <sys/cdefs.h> 81 #if defined(LIBC_SCCS) && !defined(lint) 82 __RCSID("$NetBSD: getaddrinfo.c,v 1.72 2004/05/27 18:40:07 christos Exp $"); 83 #endif /* LIBC_SCCS and not lint */ 84 85 #include "namespace.h" 86 #include <sys/types.h> 87 #include <sys/param.h> 88 #include <sys/socket.h> 89 #include <net/if.h> 90 #include <netinet/in.h> 91 #include <arpa/inet.h> 92 #include <arpa/nameser.h> 93 #include <assert.h> 94 #include <ctype.h> 95 #include <errno.h> 96 #include <netdb.h> 97 #include <resolv.h> 98 #include <stddef.h> 99 #include <stdio.h> 100 #include <stdlib.h> 101 #include <string.h> 102 #include <unistd.h> 103 104 #include <syslog.h> 105 #include <stdarg.h> 106 #include <nsswitch.h> 107 108 #ifdef YP 109 #include <rpc/rpc.h> 110 #include <rpcsvc/yp_prot.h> 111 #include <rpcsvc/ypclnt.h> 112 #endif 113 114 #ifdef __weak_alias 115 __weak_alias(getaddrinfo,_getaddrinfo) 116 __weak_alias(freeaddrinfo,_freeaddrinfo) 117 __weak_alias(gai_strerror,_gai_strerror) 118 #endif 119 120 #define SUCCESS 0 121 #define ANY 0 122 #define YES 1 123 #define NO 0 124 125 static const char in_addrany[] = { 0, 0, 0, 0 }; 126 static const char in_loopback[] = { 127, 0, 0, 1 }; 127 #ifdef INET6 128 static const char in6_addrany[] = { 129 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 130 }; 131 static const char in6_loopback[] = { 132 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 133 }; 134 #endif 135 136 static const struct afd { 137 int a_af; 138 int a_addrlen; 139 int a_socklen; 140 int a_off; 141 const char *a_addrany; 142 const char *a_loopback; 143 int a_scoped; 144 } afdl [] = { 145 #ifdef INET6 146 {PF_INET6, sizeof(struct in6_addr), 147 sizeof(struct sockaddr_in6), 148 offsetof(struct sockaddr_in6, sin6_addr), 149 in6_addrany, in6_loopback, 1}, 150 #endif 151 {PF_INET, sizeof(struct in_addr), 152 sizeof(struct sockaddr_in), 153 offsetof(struct sockaddr_in, sin_addr), 154 in_addrany, in_loopback, 0}, 155 {0, 0, 0, 0, NULL, NULL, 0}, 156 }; 157 158 struct explore { 159 int e_af; 160 int e_socktype; 161 int e_protocol; 162 const char *e_protostr; 163 int e_wild; 164 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 165 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 166 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 167 }; 168 169 static const struct explore explore[] = { 170 #if 0 171 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 172 #endif 173 #ifdef INET6 174 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 175 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 176 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 177 #endif 178 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 179 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 180 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 181 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 182 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 183 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 184 { -1, 0, 0, NULL, 0 }, 185 }; 186 187 #ifdef INET6 188 #define PTON_MAX 16 189 #else 190 #define PTON_MAX 4 191 #endif 192 193 static const ns_src default_dns_files[] = { 194 { NSSRC_FILES, NS_SUCCESS }, 195 { NSSRC_DNS, NS_SUCCESS }, 196 { 0 } 197 }; 198 199 #define MAXPACKET (64*1024) 200 201 typedef union { 202 HEADER hdr; 203 u_char buf[MAXPACKET]; 204 } querybuf; 205 206 struct res_target { 207 struct res_target *next; 208 const char *name; /* domain name */ 209 int qclass, qtype; /* class and type of query */ 210 u_char *answer; /* buffer to put answer */ 211 int anslen; /* size of answer buffer */ 212 int n; /* result length */ 213 }; 214 215 static int str2number(const char *); 216 static int explore_fqdn(const struct addrinfo *, const char *, 217 const char *, struct addrinfo **); 218 static int explore_null(const struct addrinfo *, 219 const char *, struct addrinfo **); 220 static int explore_numeric(const struct addrinfo *, const char *, 221 const char *, struct addrinfo **, const char *); 222 static int explore_numeric_scope(const struct addrinfo *, const char *, 223 const char *, struct addrinfo **); 224 static int get_canonname(const struct addrinfo *, 225 struct addrinfo *, const char *); 226 static struct addrinfo *get_ai(const struct addrinfo *, 227 const struct afd *, const char *); 228 static int get_portmatch(const struct addrinfo *, const char *); 229 static int get_port(struct addrinfo *, const char *, int); 230 static const struct afd *find_afd(int); 231 #ifdef INET6 232 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 233 #endif 234 235 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 236 const struct addrinfo *); 237 static int _dns_getaddrinfo(void *, void *, va_list); 238 static void _sethtent(FILE **); 239 static void _endhtent(FILE **); 240 static struct addrinfo *_gethtent(FILE **, const char *, 241 const struct addrinfo *); 242 static int _files_getaddrinfo(void *, void *, va_list); 243 #ifdef YP 244 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 245 static int _yp_getaddrinfo(void *, void *, va_list); 246 #endif 247 248 static int res_queryN(const char *, struct res_target *, res_state); 249 static int res_searchN(const char *, struct res_target *); 250 static int res_querydomainN(const char *, const char *, 251 struct res_target *, res_state); 252 253 static const char * const ai_errlist[] = { 254 "Success", 255 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 256 "Temporary failure in name resolution", /* EAI_AGAIN */ 257 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 258 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 259 "ai_family not supported", /* EAI_FAMILY */ 260 "Memory allocation failure", /* EAI_MEMORY */ 261 "No address associated with hostname", /* EAI_NODATA */ 262 "hostname nor servname provided, or not known", /* EAI_NONAME */ 263 "servname not supported for ai_socktype", /* EAI_SERVICE */ 264 "ai_socktype not supported", /* EAI_SOCKTYPE */ 265 "System error returned in errno", /* EAI_SYSTEM */ 266 "Invalid value for hints", /* EAI_BADHINTS */ 267 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 268 "Unknown error", /* EAI_MAX */ 269 }; 270 271 /* XXX macros that make external reference is BAD. */ 272 273 #define GET_AI(ai, afd, addr) \ 274 do { \ 275 /* external reference: pai, error, and label free */ \ 276 (ai) = get_ai(pai, (afd), (addr)); \ 277 if ((ai) == NULL) { \ 278 error = EAI_MEMORY; \ 279 goto free; \ 280 } \ 281 } while (/*CONSTCOND*/0) 282 283 #define GET_PORT(ai, serv) \ 284 do { \ 285 /* external reference: error and label free */ \ 286 error = get_port((ai), (serv), 0); \ 287 if (error != 0) \ 288 goto free; \ 289 } while (/*CONSTCOND*/0) 290 291 #define GET_CANONNAME(ai, str) \ 292 do { \ 293 /* external reference: pai, error and label free */ \ 294 error = get_canonname(pai, (ai), (str)); \ 295 if (error != 0) \ 296 goto free; \ 297 } while (/*CONSTCOND*/0) 298 299 #define ERR(err) \ 300 do { \ 301 /* external reference: error, and label bad */ \ 302 error = (err); \ 303 goto bad; \ 304 /*NOTREACHED*/ \ 305 } while (/*CONSTCOND*/0) 306 307 #define MATCH_FAMILY(x, y, w) \ 308 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 309 #define MATCH(x, y, w) \ 310 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 311 312 const char * 313 gai_strerror(int ecode) 314 { 315 if (ecode < 0 || ecode > EAI_MAX) 316 ecode = EAI_MAX; 317 return ai_errlist[ecode]; 318 } 319 320 void 321 freeaddrinfo(struct addrinfo *ai) 322 { 323 struct addrinfo *next; 324 325 _DIAGASSERT(ai != NULL); 326 327 do { 328 next = ai->ai_next; 329 if (ai->ai_canonname) 330 free(ai->ai_canonname); 331 /* no need to free(ai->ai_addr) */ 332 free(ai); 333 ai = next; 334 } while (ai); 335 } 336 337 static int 338 str2number(const char *p) 339 { 340 char *ep; 341 unsigned long v; 342 343 _DIAGASSERT(p != NULL); 344 345 if (*p == '\0') 346 return -1; 347 ep = NULL; 348 errno = 0; 349 v = strtoul(p, &ep, 10); 350 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) 351 return v; 352 else 353 return -1; 354 } 355 356 int 357 getaddrinfo(const char *hostname, const char *servname, 358 const struct addrinfo *hints, struct addrinfo **res) 359 { 360 struct addrinfo sentinel; 361 struct addrinfo *cur; 362 int error = 0; 363 struct addrinfo ai; 364 struct addrinfo ai0; 365 struct addrinfo *pai; 366 const struct explore *ex; 367 368 /* hostname is allowed to be NULL */ 369 /* servname is allowed to be NULL */ 370 /* hints is allowed to be NULL */ 371 _DIAGASSERT(res != NULL); 372 373 memset(&sentinel, 0, sizeof(sentinel)); 374 cur = &sentinel; 375 pai = &ai; 376 pai->ai_flags = 0; 377 pai->ai_family = PF_UNSPEC; 378 pai->ai_socktype = ANY; 379 pai->ai_protocol = ANY; 380 pai->ai_addrlen = 0; 381 pai->ai_canonname = NULL; 382 pai->ai_addr = NULL; 383 pai->ai_next = NULL; 384 385 if (hostname == NULL && servname == NULL) 386 return EAI_NONAME; 387 if (hints) { 388 /* error check for hints */ 389 if (hints->ai_addrlen || hints->ai_canonname || 390 hints->ai_addr || hints->ai_next) 391 ERR(EAI_BADHINTS); /* xxx */ 392 if (hints->ai_flags & ~AI_MASK) 393 ERR(EAI_BADFLAGS); 394 switch (hints->ai_family) { 395 case PF_UNSPEC: 396 case PF_INET: 397 #ifdef INET6 398 case PF_INET6: 399 #endif 400 break; 401 default: 402 ERR(EAI_FAMILY); 403 } 404 memcpy(pai, hints, sizeof(*pai)); 405 406 /* 407 * if both socktype/protocol are specified, check if they 408 * are meaningful combination. 409 */ 410 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 411 for (ex = explore; ex->e_af >= 0; ex++) { 412 if (pai->ai_family != ex->e_af) 413 continue; 414 if (ex->e_socktype == ANY) 415 continue; 416 if (ex->e_protocol == ANY) 417 continue; 418 if (pai->ai_socktype == ex->e_socktype 419 && pai->ai_protocol != ex->e_protocol) { 420 ERR(EAI_BADHINTS); 421 } 422 } 423 } 424 } 425 426 /* 427 * check for special cases. (1) numeric servname is disallowed if 428 * socktype/protocol are left unspecified. (2) servname is disallowed 429 * for raw and other inet{,6} sockets. 430 */ 431 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 432 #ifdef PF_INET6 433 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 434 #endif 435 ) { 436 ai0 = *pai; /* backup *pai */ 437 438 if (pai->ai_family == PF_UNSPEC) { 439 #ifdef PF_INET6 440 pai->ai_family = PF_INET6; 441 #else 442 pai->ai_family = PF_INET; 443 #endif 444 } 445 error = get_portmatch(pai, servname); 446 if (error) 447 ERR(error); 448 449 *pai = ai0; 450 } 451 452 ai0 = *pai; 453 454 /* NULL hostname, or numeric hostname */ 455 for (ex = explore; ex->e_af >= 0; ex++) { 456 *pai = ai0; 457 458 /* PF_UNSPEC entries are prepared for DNS queries only */ 459 if (ex->e_af == PF_UNSPEC) 460 continue; 461 462 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 463 continue; 464 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 465 continue; 466 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 467 continue; 468 469 if (pai->ai_family == PF_UNSPEC) 470 pai->ai_family = ex->e_af; 471 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 472 pai->ai_socktype = ex->e_socktype; 473 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 474 pai->ai_protocol = ex->e_protocol; 475 476 if (hostname == NULL) 477 error = explore_null(pai, servname, &cur->ai_next); 478 else 479 error = explore_numeric_scope(pai, hostname, servname, 480 &cur->ai_next); 481 482 if (error) 483 goto free; 484 485 while (cur && cur->ai_next) 486 cur = cur->ai_next; 487 } 488 489 /* 490 * XXX 491 * If numreic representation of AF1 can be interpreted as FQDN 492 * representation of AF2, we need to think again about the code below. 493 */ 494 if (sentinel.ai_next) 495 goto good; 496 497 if (hostname == NULL) 498 ERR(EAI_NODATA); 499 if (pai->ai_flags & AI_NUMERICHOST) 500 ERR(EAI_NONAME); 501 502 /* 503 * hostname as alphabetical name. 504 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 505 * outer loop by AFs. 506 */ 507 for (ex = explore; ex->e_af >= 0; ex++) { 508 *pai = ai0; 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, 529 &cur->ai_next); 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 if (error == 0) { 542 if (sentinel.ai_next) { 543 good: 544 *res = sentinel.ai_next; 545 return SUCCESS; 546 } else 547 error = EAI_FAIL; 548 } 549 free: 550 bad: 551 if (sentinel.ai_next) 552 freeaddrinfo(sentinel.ai_next); 553 *res = NULL; 554 return error; 555 } 556 557 /* 558 * FQDN hostname, DNS lookup 559 */ 560 static int 561 explore_fqdn(const struct addrinfo *pai, const char *hostname, 562 const char *servname, struct addrinfo **res) 563 { 564 struct addrinfo *result; 565 struct addrinfo *cur; 566 int error = 0; 567 static const ns_dtab dtab[] = { 568 NS_FILES_CB(_files_getaddrinfo, NULL) 569 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 570 NS_NIS_CB(_yp_getaddrinfo, NULL) 571 { 0 } 572 }; 573 574 _DIAGASSERT(pai != NULL); 575 /* hostname may be NULL */ 576 /* servname may be NULL */ 577 _DIAGASSERT(res != NULL); 578 579 result = NULL; 580 581 /* 582 * if the servname does not match socktype/protocol, ignore it. 583 */ 584 if (get_portmatch(pai, servname) != 0) 585 return 0; 586 587 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 588 default_dns_files, hostname, pai)) { 589 case NS_TRYAGAIN: 590 error = EAI_AGAIN; 591 goto free; 592 case NS_UNAVAIL: 593 error = EAI_FAIL; 594 goto free; 595 case NS_NOTFOUND: 596 error = EAI_NODATA; 597 goto free; 598 case NS_SUCCESS: 599 error = 0; 600 for (cur = result; cur; cur = cur->ai_next) { 601 GET_PORT(cur, servname); 602 /* canonname should be filled already */ 603 } 604 break; 605 } 606 607 *res = result; 608 609 return 0; 610 611 free: 612 if (result) 613 freeaddrinfo(result); 614 return error; 615 } 616 617 /* 618 * hostname == NULL. 619 * passive socket -> anyaddr (0.0.0.0 or ::) 620 * non-passive socket -> localhost (127.0.0.1 or ::1) 621 */ 622 static int 623 explore_null(const struct addrinfo *pai, const char *servname, 624 struct addrinfo **res) 625 { 626 int s; 627 const struct afd *afd; 628 struct addrinfo *cur; 629 struct addrinfo sentinel; 630 int error; 631 632 _DIAGASSERT(pai != NULL); 633 /* servname may be NULL */ 634 _DIAGASSERT(res != NULL); 635 636 *res = NULL; 637 sentinel.ai_next = NULL; 638 cur = &sentinel; 639 640 /* 641 * filter out AFs that are not supported by the kernel 642 * XXX errno? 643 */ 644 s = socket(pai->ai_family, SOCK_DGRAM, 0); 645 if (s < 0) { 646 if (errno != EMFILE) 647 return 0; 648 } else 649 close(s); 650 651 /* 652 * if the servname does not match socktype/protocol, ignore it. 653 */ 654 if (get_portmatch(pai, servname) != 0) 655 return 0; 656 657 afd = find_afd(pai->ai_family); 658 if (afd == NULL) 659 return 0; 660 661 if (pai->ai_flags & AI_PASSIVE) { 662 GET_AI(cur->ai_next, afd, afd->a_addrany); 663 /* xxx meaningless? 664 * GET_CANONNAME(cur->ai_next, "anyaddr"); 665 */ 666 GET_PORT(cur->ai_next, servname); 667 } else { 668 GET_AI(cur->ai_next, afd, afd->a_loopback); 669 /* xxx meaningless? 670 * GET_CANONNAME(cur->ai_next, "localhost"); 671 */ 672 GET_PORT(cur->ai_next, servname); 673 } 674 cur = cur->ai_next; 675 676 *res = sentinel.ai_next; 677 return 0; 678 679 free: 680 if (sentinel.ai_next) 681 freeaddrinfo(sentinel.ai_next); 682 return error; 683 } 684 685 /* 686 * numeric hostname 687 */ 688 static int 689 explore_numeric(const struct addrinfo *pai, const char *hostname, 690 const char *servname, struct addrinfo **res, const char *canonname) 691 { 692 const struct afd *afd; 693 struct addrinfo *cur; 694 struct addrinfo sentinel; 695 int error; 696 char pton[PTON_MAX]; 697 698 _DIAGASSERT(pai != NULL); 699 /* hostname may be NULL */ 700 /* servname may be NULL */ 701 _DIAGASSERT(res != NULL); 702 703 *res = NULL; 704 sentinel.ai_next = NULL; 705 cur = &sentinel; 706 707 /* 708 * if the servname does not match socktype/protocol, ignore it. 709 */ 710 if (get_portmatch(pai, servname) != 0) 711 return 0; 712 713 afd = find_afd(pai->ai_family); 714 if (afd == NULL) 715 return 0; 716 717 switch (afd->a_af) { 718 #if 0 /*X/Open spec*/ 719 case AF_INET: 720 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 721 if (pai->ai_family == afd->a_af || 722 pai->ai_family == PF_UNSPEC /*?*/) { 723 GET_AI(cur->ai_next, afd, pton); 724 GET_PORT(cur->ai_next, servname); 725 if ((pai->ai_flags & AI_CANONNAME)) { 726 /* 727 * Set the numeric address itself as 728 * the canonical name, based on a 729 * clarification in rfc2553bis-03. 730 */ 731 GET_CANONNAME(cur->ai_next, canonname); 732 } 733 while (cur && cur->ai_next) 734 cur = cur->ai_next; 735 } else 736 ERR(EAI_FAMILY); /*xxx*/ 737 } 738 break; 739 #endif 740 default: 741 if (inet_pton(afd->a_af, hostname, pton) == 1) { 742 if (pai->ai_family == afd->a_af || 743 pai->ai_family == PF_UNSPEC /*?*/) { 744 GET_AI(cur->ai_next, afd, pton); 745 GET_PORT(cur->ai_next, servname); 746 if ((pai->ai_flags & AI_CANONNAME)) { 747 /* 748 * Set the numeric address itself as 749 * the canonical name, based on a 750 * clarification in rfc2553bis-03. 751 */ 752 GET_CANONNAME(cur->ai_next, canonname); 753 } 754 while (cur && cur->ai_next) 755 cur = cur->ai_next; 756 } else 757 ERR(EAI_FAMILY); /*xxx*/ 758 } 759 break; 760 } 761 762 *res = sentinel.ai_next; 763 return 0; 764 765 free: 766 bad: 767 if (sentinel.ai_next) 768 freeaddrinfo(sentinel.ai_next); 769 return error; 770 } 771 772 /* 773 * numeric hostname with scope 774 */ 775 static int 776 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 777 const char *servname, struct addrinfo **res) 778 { 779 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 780 return explore_numeric(pai, hostname, servname, res, hostname); 781 #else 782 const struct afd *afd; 783 struct addrinfo *cur; 784 int error; 785 char *cp, *hostname2 = NULL, *scope, *addr; 786 struct sockaddr_in6 *sin6; 787 788 _DIAGASSERT(pai != NULL); 789 /* hostname may be NULL */ 790 /* servname may be NULL */ 791 _DIAGASSERT(res != NULL); 792 793 /* 794 * if the servname does not match socktype/protocol, ignore it. 795 */ 796 if (get_portmatch(pai, servname) != 0) 797 return 0; 798 799 afd = find_afd(pai->ai_family); 800 if (afd == NULL) 801 return 0; 802 803 if (!afd->a_scoped) 804 return explore_numeric(pai, hostname, servname, res, hostname); 805 806 cp = strchr(hostname, SCOPE_DELIMITER); 807 if (cp == NULL) 808 return explore_numeric(pai, hostname, servname, res, hostname); 809 810 /* 811 * Handle special case of <scoped_address><delimiter><scope id> 812 */ 813 hostname2 = strdup(hostname); 814 if (hostname2 == NULL) 815 return EAI_MEMORY; 816 /* terminate at the delimiter */ 817 hostname2[cp - hostname] = '\0'; 818 addr = hostname2; 819 scope = cp + 1; 820 821 error = explore_numeric(pai, addr, servname, res, hostname); 822 if (error == 0) { 823 u_int32_t scopeid; 824 825 for (cur = *res; cur; cur = cur->ai_next) { 826 if (cur->ai_family != AF_INET6) 827 continue; 828 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 829 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 830 free(hostname2); 831 return(EAI_NODATA); /* XXX: is return OK? */ 832 } 833 sin6->sin6_scope_id = scopeid; 834 } 835 } 836 837 free(hostname2); 838 839 return error; 840 #endif 841 } 842 843 static int 844 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 845 { 846 847 _DIAGASSERT(pai != NULL); 848 _DIAGASSERT(ai != NULL); 849 _DIAGASSERT(str != NULL); 850 851 if ((pai->ai_flags & AI_CANONNAME) != 0) { 852 ai->ai_canonname = strdup(str); 853 if (ai->ai_canonname == NULL) 854 return EAI_MEMORY; 855 } 856 return 0; 857 } 858 859 static struct addrinfo * 860 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 861 { 862 char *p; 863 struct addrinfo *ai; 864 865 _DIAGASSERT(pai != NULL); 866 _DIAGASSERT(afd != NULL); 867 _DIAGASSERT(addr != NULL); 868 869 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 870 + (afd->a_socklen)); 871 if (ai == NULL) 872 return NULL; 873 874 memcpy(ai, pai, sizeof(struct addrinfo)); 875 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 876 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 877 ai->ai_addr->sa_len = afd->a_socklen; 878 ai->ai_addrlen = afd->a_socklen; 879 #if defined (__alpha__) || (defined(__i386__) && defined(_LP64)) || defined(__sparc64__) 880 ai->__ai_pad0 = 0; 881 #endif 882 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 883 p = (char *)(void *)(ai->ai_addr); 884 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 885 return ai; 886 } 887 888 static int 889 get_portmatch(const struct addrinfo *ai, const char *servname) 890 { 891 892 _DIAGASSERT(ai != NULL); 893 /* servname may be NULL */ 894 895 /* get_port does not touch first argument when matchonly == 1. */ 896 /* LINTED const cast */ 897 return get_port((struct addrinfo *)ai, servname, 1); 898 } 899 900 static int 901 get_port(struct addrinfo *ai, const char *servname, int matchonly) 902 { 903 const char *proto; 904 struct servent *sp; 905 int port; 906 int allownumeric; 907 908 _DIAGASSERT(ai != NULL); 909 /* servname may be NULL */ 910 911 if (servname == NULL) 912 return 0; 913 switch (ai->ai_family) { 914 case AF_INET: 915 #ifdef AF_INET6 916 case AF_INET6: 917 #endif 918 break; 919 default: 920 return 0; 921 } 922 923 switch (ai->ai_socktype) { 924 case SOCK_RAW: 925 return EAI_SERVICE; 926 case SOCK_DGRAM: 927 case SOCK_STREAM: 928 allownumeric = 1; 929 break; 930 case ANY: 931 allownumeric = 0; 932 break; 933 default: 934 return EAI_SOCKTYPE; 935 } 936 937 port = str2number(servname); 938 if (port >= 0) { 939 if (!allownumeric) 940 return EAI_SERVICE; 941 if (port < 0 || port > 65535) 942 return EAI_SERVICE; 943 port = htons(port); 944 } else { 945 if (ai->ai_flags & AI_NUMERICSERV) 946 return EAI_NONAME; 947 948 switch (ai->ai_socktype) { 949 case SOCK_DGRAM: 950 proto = "udp"; 951 break; 952 case SOCK_STREAM: 953 proto = "tcp"; 954 break; 955 default: 956 proto = NULL; 957 break; 958 } 959 960 if ((sp = getservbyname(servname, proto)) == NULL) 961 return EAI_SERVICE; 962 port = sp->s_port; 963 } 964 965 if (!matchonly) { 966 switch (ai->ai_family) { 967 case AF_INET: 968 ((struct sockaddr_in *)(void *) 969 ai->ai_addr)->sin_port = port; 970 break; 971 #ifdef INET6 972 case AF_INET6: 973 ((struct sockaddr_in6 *)(void *) 974 ai->ai_addr)->sin6_port = port; 975 break; 976 #endif 977 } 978 } 979 980 return 0; 981 } 982 983 static const struct afd * 984 find_afd(int af) 985 { 986 const struct afd *afd; 987 988 if (af == PF_UNSPEC) 989 return NULL; 990 for (afd = afdl; afd->a_af; afd++) { 991 if (afd->a_af == af) 992 return afd; 993 } 994 return NULL; 995 } 996 997 #ifdef INET6 998 /* convert a string to a scope identifier. XXX: IPv6 specific */ 999 static int 1000 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1001 { 1002 u_long lscopeid; 1003 struct in6_addr *a6; 1004 char *ep; 1005 1006 _DIAGASSERT(scope != NULL); 1007 _DIAGASSERT(sin6 != NULL); 1008 _DIAGASSERT(scopeid != NULL); 1009 1010 a6 = &sin6->sin6_addr; 1011 1012 /* empty scopeid portion is invalid */ 1013 if (*scope == '\0') 1014 return -1; 1015 1016 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1017 /* 1018 * We currently assume a one-to-one mapping between links 1019 * and interfaces, so we simply use interface indices for 1020 * like-local scopes. 1021 */ 1022 *scopeid = if_nametoindex(scope); 1023 if (*scopeid == 0) 1024 goto trynumeric; 1025 return 0; 1026 } 1027 1028 /* still unclear about literal, allow numeric only - placeholder */ 1029 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1030 goto trynumeric; 1031 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1032 goto trynumeric; 1033 else 1034 goto trynumeric; /* global */ 1035 1036 /* try to convert to a numeric id as a last resort */ 1037 trynumeric: 1038 errno = 0; 1039 lscopeid = strtoul(scope, &ep, 10); 1040 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1041 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1042 return 0; 1043 else 1044 return -1; 1045 } 1046 #endif 1047 1048 /* code duplicate with gethnamaddr.c */ 1049 1050 static const char AskedForGot[] = 1051 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1052 1053 static struct addrinfo * 1054 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1055 const struct addrinfo *pai) 1056 { 1057 struct addrinfo sentinel, *cur; 1058 struct addrinfo ai; 1059 const struct afd *afd; 1060 char *canonname; 1061 const HEADER *hp; 1062 const u_char *cp; 1063 int n; 1064 const u_char *eom; 1065 char *bp, *ep; 1066 int type, class, ancount, qdcount; 1067 int haveanswer, had_error; 1068 char tbuf[MAXDNAME]; 1069 int (*name_ok) (const char *); 1070 char hostbuf[8*1024]; 1071 1072 _DIAGASSERT(answer != NULL); 1073 _DIAGASSERT(qname != NULL); 1074 _DIAGASSERT(pai != NULL); 1075 1076 memset(&sentinel, 0, sizeof(sentinel)); 1077 cur = &sentinel; 1078 1079 canonname = NULL; 1080 eom = answer->buf + anslen; 1081 switch (qtype) { 1082 case T_A: 1083 case T_AAAA: 1084 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1085 name_ok = res_hnok; 1086 break; 1087 default: 1088 return NULL; /* XXX should be abort(); */ 1089 } 1090 /* 1091 * find first satisfactory answer 1092 */ 1093 hp = &answer->hdr; 1094 ancount = ntohs(hp->ancount); 1095 qdcount = ntohs(hp->qdcount); 1096 bp = hostbuf; 1097 ep = hostbuf + sizeof hostbuf; 1098 cp = answer->buf + HFIXEDSZ; 1099 if (qdcount != 1) { 1100 h_errno = NO_RECOVERY; 1101 return (NULL); 1102 } 1103 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1104 if ((n < 0) || !(*name_ok)(bp)) { 1105 h_errno = NO_RECOVERY; 1106 return (NULL); 1107 } 1108 cp += n + QFIXEDSZ; 1109 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1110 /* res_send() has already verified that the query name is the 1111 * same as the one we sent; this just gets the expanded name 1112 * (i.e., with the succeeding search-domain tacked on). 1113 */ 1114 n = strlen(bp) + 1; /* for the \0 */ 1115 if (n >= MAXHOSTNAMELEN) { 1116 h_errno = NO_RECOVERY; 1117 return (NULL); 1118 } 1119 canonname = bp; 1120 bp += n; 1121 /* The qname can be abbreviated, but h_name is now absolute. */ 1122 qname = canonname; 1123 } 1124 haveanswer = 0; 1125 had_error = 0; 1126 while (ancount-- > 0 && cp < eom && !had_error) { 1127 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1128 if ((n < 0) || !(*name_ok)(bp)) { 1129 had_error++; 1130 continue; 1131 } 1132 cp += n; /* name */ 1133 type = _getshort(cp); 1134 cp += INT16SZ; /* type */ 1135 class = _getshort(cp); 1136 cp += INT16SZ + INT32SZ; /* class, TTL */ 1137 n = _getshort(cp); 1138 cp += INT16SZ; /* len */ 1139 if (class != C_IN) { 1140 /* XXX - debug? syslog? */ 1141 cp += n; 1142 continue; /* XXX - had_error++ ? */ 1143 } 1144 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1145 type == T_CNAME) { 1146 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1147 if ((n < 0) || !(*name_ok)(tbuf)) { 1148 had_error++; 1149 continue; 1150 } 1151 cp += n; 1152 /* Get canonical name. */ 1153 n = strlen(tbuf) + 1; /* for the \0 */ 1154 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1155 had_error++; 1156 continue; 1157 } 1158 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1159 canonname = bp; 1160 bp += n; 1161 continue; 1162 } 1163 if (qtype == T_ANY) { 1164 if (!(type == T_A || type == T_AAAA)) { 1165 cp += n; 1166 continue; 1167 } 1168 } else if (type != qtype) { 1169 if (type != T_KEY && type != T_SIG) 1170 syslog(LOG_NOTICE|LOG_AUTH, 1171 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1172 qname, p_class(C_IN), p_type(qtype), 1173 p_type(type)); 1174 cp += n; 1175 continue; /* XXX - had_error++ ? */ 1176 } 1177 switch (type) { 1178 case T_A: 1179 case T_AAAA: 1180 if (strcasecmp(canonname, bp) != 0) { 1181 syslog(LOG_NOTICE|LOG_AUTH, 1182 AskedForGot, canonname, bp); 1183 cp += n; 1184 continue; /* XXX - had_error++ ? */ 1185 } 1186 if (type == T_A && n != INADDRSZ) { 1187 cp += n; 1188 continue; 1189 } 1190 if (type == T_AAAA && n != IN6ADDRSZ) { 1191 cp += n; 1192 continue; 1193 } 1194 if (type == T_AAAA) { 1195 struct in6_addr in6; 1196 memcpy(&in6, cp, IN6ADDRSZ); 1197 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1198 cp += n; 1199 continue; 1200 } 1201 } 1202 if (!haveanswer) { 1203 int nn; 1204 1205 canonname = bp; 1206 nn = strlen(bp) + 1; /* for the \0 */ 1207 bp += nn; 1208 } 1209 1210 /* don't overwrite pai */ 1211 ai = *pai; 1212 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1213 afd = find_afd(ai.ai_family); 1214 if (afd == NULL) { 1215 cp += n; 1216 continue; 1217 } 1218 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1219 if (cur->ai_next == NULL) 1220 had_error++; 1221 while (cur && cur->ai_next) 1222 cur = cur->ai_next; 1223 cp += n; 1224 break; 1225 default: 1226 abort(); 1227 } 1228 if (!had_error) 1229 haveanswer++; 1230 } 1231 if (haveanswer) { 1232 if (!canonname) 1233 (void)get_canonname(pai, sentinel.ai_next, qname); 1234 else 1235 (void)get_canonname(pai, sentinel.ai_next, canonname); 1236 h_errno = NETDB_SUCCESS; 1237 return sentinel.ai_next; 1238 } 1239 1240 h_errno = NO_RECOVERY; 1241 return NULL; 1242 } 1243 1244 /*ARGSUSED*/ 1245 static int 1246 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1247 { 1248 struct addrinfo *ai; 1249 querybuf *buf, *buf2; 1250 const char *name; 1251 const struct addrinfo *pai; 1252 struct addrinfo sentinel, *cur; 1253 struct res_target q, q2; 1254 1255 name = va_arg(ap, char *); 1256 pai = va_arg(ap, const struct addrinfo *); 1257 1258 memset(&q, 0, sizeof(q2)); 1259 memset(&q2, 0, sizeof(q2)); 1260 memset(&sentinel, 0, sizeof(sentinel)); 1261 cur = &sentinel; 1262 1263 buf = malloc(sizeof(*buf)); 1264 if (buf == NULL) { 1265 h_errno = NETDB_INTERNAL; 1266 return NS_NOTFOUND; 1267 } 1268 buf2 = malloc(sizeof(*buf2)); 1269 if (buf2 == NULL) { 1270 free(buf); 1271 h_errno = NETDB_INTERNAL; 1272 return NS_NOTFOUND; 1273 } 1274 1275 switch (pai->ai_family) { 1276 case AF_UNSPEC: 1277 /* prefer IPv6 */ 1278 q.name = name; 1279 q.qclass = C_IN; 1280 q.qtype = T_AAAA; 1281 q.answer = buf->buf; 1282 q.anslen = sizeof(buf->buf); 1283 q.next = &q2; 1284 q2.name = name; 1285 q2.qclass = C_IN; 1286 q2.qtype = T_A; 1287 q2.answer = buf2->buf; 1288 q2.anslen = sizeof(buf2->buf); 1289 break; 1290 case AF_INET: 1291 q.name = name; 1292 q.qclass = C_IN; 1293 q.qtype = T_A; 1294 q.answer = buf->buf; 1295 q.anslen = sizeof(buf->buf); 1296 break; 1297 case AF_INET6: 1298 q.name = name; 1299 q.qclass = C_IN; 1300 q.qtype = T_AAAA; 1301 q.answer = buf->buf; 1302 q.anslen = sizeof(buf->buf); 1303 break; 1304 default: 1305 free(buf); 1306 free(buf2); 1307 return NS_UNAVAIL; 1308 } 1309 if (res_searchN(name, &q) < 0) { 1310 free(buf); 1311 free(buf2); 1312 return NS_NOTFOUND; 1313 } 1314 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1315 if (ai) { 1316 cur->ai_next = ai; 1317 while (cur && cur->ai_next) 1318 cur = cur->ai_next; 1319 } 1320 if (q.next) { 1321 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1322 if (ai) 1323 cur->ai_next = ai; 1324 } 1325 free(buf); 1326 free(buf2); 1327 if (sentinel.ai_next == NULL) 1328 switch (h_errno) { 1329 case HOST_NOT_FOUND: 1330 return NS_NOTFOUND; 1331 case TRY_AGAIN: 1332 return NS_TRYAGAIN; 1333 default: 1334 return NS_UNAVAIL; 1335 } 1336 *((struct addrinfo **)rv) = sentinel.ai_next; 1337 return NS_SUCCESS; 1338 } 1339 1340 static void 1341 _sethtent(FILE **hostf) 1342 { 1343 1344 if (!*hostf) 1345 *hostf = fopen(_PATH_HOSTS, "r" ); 1346 else 1347 rewind(*hostf); 1348 } 1349 1350 static void 1351 _endhtent(FILE **hostf) 1352 { 1353 1354 if (*hostf) { 1355 (void) fclose(*hostf); 1356 *hostf = NULL; 1357 } 1358 } 1359 1360 static struct addrinfo * 1361 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1362 { 1363 char *p; 1364 char *cp, *tname, *cname; 1365 struct addrinfo hints, *res0, *res; 1366 int error; 1367 const char *addr; 1368 char hostbuf[8*1024]; 1369 1370 _DIAGASSERT(name != NULL); 1371 _DIAGASSERT(pai != NULL); 1372 1373 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r" ))) 1374 return (NULL); 1375 again: 1376 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 1377 return (NULL); 1378 if (*p == '#') 1379 goto again; 1380 if (!(cp = strpbrk(p, "#\n"))) 1381 goto again; 1382 *cp = '\0'; 1383 if (!(cp = strpbrk(p, " \t"))) 1384 goto again; 1385 *cp++ = '\0'; 1386 addr = p; 1387 /* if this is not something we're looking for, skip it. */ 1388 cname = NULL; 1389 while (cp && *cp) { 1390 if (*cp == ' ' || *cp == '\t') { 1391 cp++; 1392 continue; 1393 } 1394 if (!cname) 1395 cname = cp; 1396 tname = cp; 1397 if ((cp = strpbrk(cp, " \t")) != NULL) 1398 *cp++ = '\0'; 1399 if (strcasecmp(name, tname) == 0) 1400 goto found; 1401 } 1402 goto again; 1403 1404 found: 1405 hints = *pai; 1406 hints.ai_flags = AI_NUMERICHOST; 1407 error = getaddrinfo(addr, NULL, &hints, &res0); 1408 if (error) 1409 goto again; 1410 for (res = res0; res; res = res->ai_next) { 1411 /* cover it up */ 1412 res->ai_flags = pai->ai_flags; 1413 1414 if (pai->ai_flags & AI_CANONNAME) { 1415 if (get_canonname(pai, res, cname) != 0) { 1416 freeaddrinfo(res0); 1417 goto again; 1418 } 1419 } 1420 } 1421 return res0; 1422 } 1423 1424 /*ARGSUSED*/ 1425 static int 1426 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1427 { 1428 const char *name; 1429 const struct addrinfo *pai; 1430 struct addrinfo sentinel, *cur; 1431 struct addrinfo *p; 1432 #ifndef _REENTRANT 1433 static 1434 #endif 1435 FILE *hostf = NULL; 1436 1437 name = va_arg(ap, char *); 1438 pai = va_arg(ap, struct addrinfo *); 1439 1440 memset(&sentinel, 0, sizeof(sentinel)); 1441 cur = &sentinel; 1442 1443 _sethtent(&hostf); 1444 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1445 cur->ai_next = p; 1446 while (cur && cur->ai_next) 1447 cur = cur->ai_next; 1448 } 1449 _endhtent(&hostf); 1450 1451 *((struct addrinfo **)rv) = sentinel.ai_next; 1452 if (sentinel.ai_next == NULL) 1453 return NS_NOTFOUND; 1454 return NS_SUCCESS; 1455 } 1456 1457 #ifdef YP 1458 /*ARGSUSED*/ 1459 static struct addrinfo * 1460 _yphostent(char *line, const struct addrinfo *pai) 1461 { 1462 struct addrinfo sentinel, *cur; 1463 struct addrinfo hints, *res, *res0; 1464 int error; 1465 char *p; 1466 const char *addr, *canonname; 1467 char *nextline; 1468 char *cp; 1469 1470 _DIAGASSERT(line != NULL); 1471 _DIAGASSERT(pai != NULL); 1472 1473 p = line; 1474 addr = canonname = NULL; 1475 1476 memset(&sentinel, 0, sizeof(sentinel)); 1477 cur = &sentinel; 1478 1479 nextline: 1480 /* terminate line */ 1481 cp = strchr(p, '\n'); 1482 if (cp) { 1483 *cp++ = '\0'; 1484 nextline = cp; 1485 } else 1486 nextline = NULL; 1487 1488 cp = strpbrk(p, " \t"); 1489 if (cp == NULL) { 1490 if (canonname == NULL) 1491 return (NULL); 1492 else 1493 goto done; 1494 } 1495 *cp++ = '\0'; 1496 1497 addr = p; 1498 1499 while (cp && *cp) { 1500 if (*cp == ' ' || *cp == '\t') { 1501 cp++; 1502 continue; 1503 } 1504 if (!canonname) 1505 canonname = cp; 1506 if ((cp = strpbrk(cp, " \t")) != NULL) 1507 *cp++ = '\0'; 1508 } 1509 1510 hints = *pai; 1511 hints.ai_flags = AI_NUMERICHOST; 1512 error = getaddrinfo(addr, NULL, &hints, &res0); 1513 if (error == 0) { 1514 for (res = res0; res; res = res->ai_next) { 1515 /* cover it up */ 1516 res->ai_flags = pai->ai_flags; 1517 1518 if (pai->ai_flags & AI_CANONNAME) 1519 (void)get_canonname(pai, res, canonname); 1520 } 1521 } else 1522 res0 = NULL; 1523 if (res0) { 1524 cur->ai_next = res0; 1525 while (cur && cur->ai_next) 1526 cur = cur->ai_next; 1527 } 1528 1529 if (nextline) { 1530 p = nextline; 1531 goto nextline; 1532 } 1533 1534 done: 1535 return sentinel.ai_next; 1536 } 1537 1538 /*ARGSUSED*/ 1539 static int 1540 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1541 { 1542 struct addrinfo sentinel, *cur; 1543 struct addrinfo *ai = NULL; 1544 char *ypbuf; 1545 int ypbuflen, r; 1546 const char *name; 1547 const struct addrinfo *pai; 1548 char *ypdomain; 1549 1550 if (_yp_check(&ypdomain) == 0) 1551 return NS_UNAVAIL; 1552 1553 name = va_arg(ap, char *); 1554 pai = va_arg(ap, const struct addrinfo *); 1555 1556 memset(&sentinel, 0, sizeof(sentinel)); 1557 cur = &sentinel; 1558 1559 /* hosts.byname is only for IPv4 (Solaris8) */ 1560 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1561 r = yp_match(ypdomain, "hosts.byname", name, 1562 (int)strlen(name), &ypbuf, &ypbuflen); 1563 if (r == 0) { 1564 struct addrinfo ai4; 1565 1566 ai4 = *pai; 1567 ai4.ai_family = AF_INET; 1568 ai = _yphostent(ypbuf, &ai4); 1569 if (ai) { 1570 cur->ai_next = ai; 1571 while (cur && cur->ai_next) 1572 cur = cur->ai_next; 1573 } 1574 } 1575 free(ypbuf); 1576 } 1577 1578 /* ipnodes.byname can hold both IPv4/v6 */ 1579 r = yp_match(ypdomain, "ipnodes.byname", name, 1580 (int)strlen(name), &ypbuf, &ypbuflen); 1581 if (r == 0) { 1582 ai = _yphostent(ypbuf, pai); 1583 if (ai) 1584 cur->ai_next = ai; 1585 free(ypbuf); 1586 } 1587 1588 if (sentinel.ai_next == NULL) { 1589 h_errno = HOST_NOT_FOUND; 1590 return NS_NOTFOUND; 1591 } 1592 *((struct addrinfo **)rv) = sentinel.ai_next; 1593 return NS_SUCCESS; 1594 } 1595 #endif 1596 1597 /* resolver logic */ 1598 1599 /* 1600 * Formulate a normal query, send, and await answer. 1601 * Returned answer is placed in supplied buffer "answer". 1602 * Perform preliminary check of answer, returning success only 1603 * if no error is indicated and the answer count is nonzero. 1604 * Return the size of the response on success, -1 on error. 1605 * Error number is left in h_errno. 1606 * 1607 * Caller must parse answer and determine whether it answers the question. 1608 */ 1609 static int 1610 res_queryN(const char *name, /* domain name */ struct res_target *target, 1611 res_state res) 1612 { 1613 u_char buf[MAXPACKET]; 1614 HEADER *hp; 1615 int n; 1616 struct res_target *t; 1617 int rcode; 1618 int ancount; 1619 1620 _DIAGASSERT(name != NULL); 1621 /* XXX: target may be NULL??? */ 1622 1623 rcode = NOERROR; 1624 ancount = 0; 1625 1626 for (t = target; t; t = t->next) { 1627 int class, type; 1628 u_char *answer; 1629 int anslen; 1630 1631 hp = (HEADER *)(void *)t->answer; 1632 hp->rcode = NOERROR; /* default */ 1633 1634 /* make it easier... */ 1635 class = t->qclass; 1636 type = t->qtype; 1637 answer = t->answer; 1638 anslen = t->anslen; 1639 #ifdef DEBUG 1640 if (res->options & RES_DEBUG) 1641 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 1642 #endif 1643 1644 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 1645 buf, sizeof(buf)); 1646 #ifdef RES_USE_EDNS0 1647 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 1648 n = res_nopt(res, n, buf, sizeof(buf), anslen); 1649 #endif 1650 if (n <= 0) { 1651 #ifdef DEBUG 1652 if (res->options & RES_DEBUG) 1653 printf(";; res_nquery: mkquery failed\n"); 1654 #endif 1655 h_errno = NO_RECOVERY; 1656 return n; 1657 } 1658 n = res_nsend(res, buf, n, answer, anslen); 1659 #if 0 1660 if (n < 0) { 1661 #ifdef DEBUG 1662 if (res->options & RES_DEBUG) 1663 printf(";; res_query: send error\n"); 1664 #endif 1665 h_errno = TRY_AGAIN; 1666 return n; 1667 } 1668 #endif 1669 1670 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1671 rcode = hp->rcode; /* record most recent error */ 1672 #ifdef DEBUG 1673 if (res->options & RES_DEBUG) 1674 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1675 ntohs(hp->ancount)); 1676 #endif 1677 continue; 1678 } 1679 1680 ancount += ntohs(hp->ancount); 1681 1682 t->n = n; 1683 } 1684 1685 if (ancount == 0) { 1686 switch (rcode) { 1687 case NXDOMAIN: 1688 h_errno = HOST_NOT_FOUND; 1689 break; 1690 case SERVFAIL: 1691 h_errno = TRY_AGAIN; 1692 break; 1693 case NOERROR: 1694 h_errno = NO_DATA; 1695 break; 1696 case FORMERR: 1697 case NOTIMP: 1698 case REFUSED: 1699 default: 1700 h_errno = NO_RECOVERY; 1701 break; 1702 } 1703 return -1; 1704 } 1705 return ancount; 1706 } 1707 1708 /* 1709 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1710 * Return the size of the response on success, -1 on error. 1711 * If enabled, implement search rules until answer or unrecoverable failure 1712 * is detected. Error code, if any, is left in h_errno. 1713 */ 1714 static int 1715 res_searchN(const char *name, /* domain name */ struct res_target *target) 1716 { 1717 const char *cp, * const *domain; 1718 HEADER *hp; 1719 u_int dots; 1720 int trailing_dot, ret, saved_herrno; 1721 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1722 res_state res = __res_get_state(); 1723 1724 if (res == NULL) 1725 return -1; 1726 1727 _DIAGASSERT(name != NULL); 1728 _DIAGASSERT(target != NULL); 1729 1730 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1731 1732 errno = 0; 1733 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1734 dots = 0; 1735 for (cp = name; *cp; cp++) 1736 dots += (*cp == '.'); 1737 trailing_dot = 0; 1738 if (cp > name && *--cp == '.') 1739 trailing_dot++; 1740 1741 /* 1742 * if there aren't any dots, it could be a user-level alias 1743 */ 1744 if (!dots && (cp = __hostalias(name)) != NULL) { 1745 ret = res_queryN(cp, target, res); 1746 __res_put_state(res); 1747 return ret; 1748 } 1749 1750 /* 1751 * If there are dots in the name already, let's just give it a try 1752 * 'as is'. The threshold can be set with the "ndots" option. 1753 */ 1754 saved_herrno = -1; 1755 if (dots >= res->ndots) { 1756 ret = res_querydomainN(name, NULL, target, res); 1757 if (ret > 0) { 1758 __res_put_state(res); 1759 return (ret); 1760 } 1761 saved_herrno = h_errno; 1762 tried_as_is++; 1763 } 1764 1765 /* 1766 * We do at least one level of search if 1767 * - there is no dot and RES_DEFNAME is set, or 1768 * - there is at least one dot, there is no trailing dot, 1769 * and RES_DNSRCH is set. 1770 */ 1771 if ((!dots && (res->options & RES_DEFNAMES)) || 1772 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 1773 int done = 0; 1774 1775 for (domain = (const char * const *)res->dnsrch; 1776 *domain && !done; 1777 domain++) { 1778 1779 ret = res_querydomainN(name, *domain, target, res); 1780 if (ret > 0) { 1781 __res_put_state(res); 1782 return ret; 1783 } 1784 1785 /* 1786 * If no server present, give up. 1787 * If name isn't found in this domain, 1788 * keep trying higher domains in the search list 1789 * (if that's enabled). 1790 * On a NO_DATA error, keep trying, otherwise 1791 * a wildcard entry of another type could keep us 1792 * from finding this entry higher in the domain. 1793 * If we get some other error (negative answer or 1794 * server failure), then stop searching up, 1795 * but try the input name below in case it's 1796 * fully-qualified. 1797 */ 1798 if (errno == ECONNREFUSED) { 1799 h_errno = TRY_AGAIN; 1800 __res_put_state(res); 1801 return -1; 1802 } 1803 1804 switch (h_errno) { 1805 case NO_DATA: 1806 got_nodata++; 1807 /* FALLTHROUGH */ 1808 case HOST_NOT_FOUND: 1809 /* keep trying */ 1810 break; 1811 case TRY_AGAIN: 1812 if (hp->rcode == SERVFAIL) { 1813 /* try next search element, if any */ 1814 got_servfail++; 1815 break; 1816 } 1817 /* FALLTHROUGH */ 1818 default: 1819 /* anything else implies that we're done */ 1820 done++; 1821 } 1822 /* 1823 * if we got here for some reason other than DNSRCH, 1824 * we only wanted one iteration of the loop, so stop. 1825 */ 1826 if (!(res->options & RES_DNSRCH)) 1827 done++; 1828 } 1829 } 1830 1831 /* 1832 * if we have not already tried the name "as is", do that now. 1833 * note that we do this regardless of how many dots were in the 1834 * name or whether it ends with a dot. 1835 */ 1836 if (!tried_as_is) { 1837 ret = res_querydomainN(name, NULL, target, res); 1838 if (ret > 0) { 1839 __res_put_state(res); 1840 return ret; 1841 } 1842 } 1843 1844 __res_put_state(res); 1845 /* 1846 * if we got here, we didn't satisfy the search. 1847 * if we did an initial full query, return that query's h_errno 1848 * (note that we wouldn't be here if that query had succeeded). 1849 * else if we ever got a nodata, send that back as the reason. 1850 * else send back meaningless h_errno, that being the one from 1851 * the last DNSRCH we did. 1852 */ 1853 if (saved_herrno != -1) 1854 h_errno = saved_herrno; 1855 else if (got_nodata) 1856 h_errno = NO_DATA; 1857 else if (got_servfail) 1858 h_errno = TRY_AGAIN; 1859 return -1; 1860 } 1861 1862 /* 1863 * Perform a call on res_query on the concatenation of name and domain, 1864 * removing a trailing dot from name if domain is NULL. 1865 */ 1866 static int 1867 res_querydomainN(const char *name, const char *domain, 1868 struct res_target *target, res_state res) 1869 { 1870 char nbuf[MAXDNAME]; 1871 const char *longname = nbuf; 1872 size_t n, d; 1873 1874 _DIAGASSERT(name != NULL); 1875 /* XXX: target may be NULL??? */ 1876 1877 #ifdef DEBUG 1878 if (res->options & RES_DEBUG) 1879 printf(";; res_querydomain(%s, %s)\n", 1880 name, domain?domain:"<Nil>"); 1881 #endif 1882 if (domain == NULL) { 1883 /* 1884 * Check for trailing '.'; 1885 * copy without '.' if present. 1886 */ 1887 n = strlen(name); 1888 if (n + 1 > sizeof(nbuf)) { 1889 h_errno = NO_RECOVERY; 1890 return -1; 1891 } 1892 if (n > 0 && name[--n] == '.') { 1893 strncpy(nbuf, name, n); 1894 nbuf[n] = '\0'; 1895 } else 1896 longname = name; 1897 } else { 1898 n = strlen(name); 1899 d = strlen(domain); 1900 if (n + 1 + d + 1 > sizeof(nbuf)) { 1901 h_errno = NO_RECOVERY; 1902 return -1; 1903 } 1904 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1905 } 1906 return res_queryN(longname, target, res); 1907 } 1908