1 /* $NetBSD: getaddrinfo.c,v 1.75 2005/12/02 11:22:09 yamt 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 1.75 2005/12/02 11:22:09 yamt 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(const 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 void aisort(struct addrinfo *s, res_state res); 238 static int _dns_getaddrinfo(void *, void *, va_list); 239 static void _sethtent(FILE **); 240 static void _endhtent(FILE **); 241 static struct addrinfo *_gethtent(FILE **, const char *, 242 const struct addrinfo *); 243 static int _files_getaddrinfo(void *, void *, va_list); 244 #ifdef YP 245 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 246 static int _yp_getaddrinfo(void *, void *, va_list); 247 #endif 248 249 static int res_queryN(const char *, struct res_target *, res_state); 250 static int res_searchN(const char *, struct res_target *, res_state); 251 static int res_querydomainN(const char *, const char *, 252 struct res_target *, res_state); 253 254 static const char * const ai_errlist[] = { 255 "Success", 256 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 257 "Temporary failure in name resolution", /* EAI_AGAIN */ 258 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 259 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 260 "ai_family not supported", /* EAI_FAMILY */ 261 "Memory allocation failure", /* EAI_MEMORY */ 262 "No address associated with hostname", /* EAI_NODATA */ 263 "hostname nor servname provided, or not known", /* EAI_NONAME */ 264 "servname not supported for ai_socktype", /* EAI_SERVICE */ 265 "ai_socktype not supported", /* EAI_SOCKTYPE */ 266 "System error returned in errno", /* EAI_SYSTEM */ 267 "Invalid value for hints", /* EAI_BADHINTS */ 268 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 269 "Unknown error", /* EAI_MAX */ 270 }; 271 272 /* XXX macros that make external reference is BAD. */ 273 274 #define GET_AI(ai, afd, addr) \ 275 do { \ 276 /* external reference: pai, error, and label free */ \ 277 (ai) = get_ai(pai, (afd), (addr)); \ 278 if ((ai) == NULL) { \ 279 error = EAI_MEMORY; \ 280 goto free; \ 281 } \ 282 } while (/*CONSTCOND*/0) 283 284 #define GET_PORT(ai, serv) \ 285 do { \ 286 /* external reference: error and label free */ \ 287 error = get_port((ai), (serv), 0); \ 288 if (error != 0) \ 289 goto free; \ 290 } while (/*CONSTCOND*/0) 291 292 #define GET_CANONNAME(ai, str) \ 293 do { \ 294 /* external reference: pai, error and label free */ \ 295 error = get_canonname(pai, (ai), (str)); \ 296 if (error != 0) \ 297 goto free; \ 298 } while (/*CONSTCOND*/0) 299 300 #define ERR(err) \ 301 do { \ 302 /* external reference: error, and label bad */ \ 303 error = (err); \ 304 goto bad; \ 305 /*NOTREACHED*/ \ 306 } while (/*CONSTCOND*/0) 307 308 #define MATCH_FAMILY(x, y, w) \ 309 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 310 #define MATCH(x, y, w) \ 311 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 312 313 const char * 314 gai_strerror(int ecode) 315 { 316 if (ecode < 0 || ecode > EAI_MAX) 317 ecode = EAI_MAX; 318 return ai_errlist[ecode]; 319 } 320 321 void 322 freeaddrinfo(struct addrinfo *ai) 323 { 324 struct addrinfo *next; 325 326 _DIAGASSERT(ai != NULL); 327 328 do { 329 next = ai->ai_next; 330 if (ai->ai_canonname) 331 free(ai->ai_canonname); 332 /* no need to free(ai->ai_addr) */ 333 free(ai); 334 ai = next; 335 } while (ai); 336 } 337 338 static int 339 str2number(const char *p) 340 { 341 char *ep; 342 unsigned long v; 343 344 _DIAGASSERT(p != NULL); 345 346 if (*p == '\0') 347 return -1; 348 ep = NULL; 349 errno = 0; 350 v = strtoul(p, &ep, 10); 351 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) 352 return v; 353 else 354 return -1; 355 } 356 357 int 358 getaddrinfo(const char *hostname, const char *servname, 359 const struct addrinfo *hints, struct addrinfo **res) 360 { 361 struct addrinfo sentinel; 362 struct addrinfo *cur; 363 int error = 0; 364 struct addrinfo ai; 365 struct addrinfo ai0; 366 struct addrinfo *pai; 367 const struct explore *ex; 368 369 /* hostname is allowed to be NULL */ 370 /* servname is allowed to be NULL */ 371 /* hints is allowed to be NULL */ 372 _DIAGASSERT(res != NULL); 373 374 memset(&sentinel, 0, sizeof(sentinel)); 375 cur = &sentinel; 376 pai = &ai; 377 pai->ai_flags = 0; 378 pai->ai_family = PF_UNSPEC; 379 pai->ai_socktype = ANY; 380 pai->ai_protocol = ANY; 381 pai->ai_addrlen = 0; 382 pai->ai_canonname = NULL; 383 pai->ai_addr = NULL; 384 pai->ai_next = NULL; 385 386 if (hostname == NULL && servname == NULL) 387 return EAI_NONAME; 388 if (hints) { 389 /* error check for hints */ 390 if (hints->ai_addrlen || hints->ai_canonname || 391 hints->ai_addr || hints->ai_next) 392 ERR(EAI_BADHINTS); /* xxx */ 393 if (hints->ai_flags & ~AI_MASK) 394 ERR(EAI_BADFLAGS); 395 switch (hints->ai_family) { 396 case PF_UNSPEC: 397 case PF_INET: 398 #ifdef INET6 399 case PF_INET6: 400 #endif 401 break; 402 default: 403 ERR(EAI_FAMILY); 404 } 405 memcpy(pai, hints, sizeof(*pai)); 406 407 /* 408 * if both socktype/protocol are specified, check if they 409 * are meaningful combination. 410 */ 411 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 412 for (ex = explore; ex->e_af >= 0; ex++) { 413 if (pai->ai_family != ex->e_af) 414 continue; 415 if (ex->e_socktype == ANY) 416 continue; 417 if (ex->e_protocol == ANY) 418 continue; 419 if (pai->ai_socktype == ex->e_socktype 420 && pai->ai_protocol != ex->e_protocol) { 421 ERR(EAI_BADHINTS); 422 } 423 } 424 } 425 } 426 427 /* 428 * check for special cases. (1) numeric servname is disallowed if 429 * socktype/protocol are left unspecified. (2) servname is disallowed 430 * for raw and other inet{,6} sockets. 431 */ 432 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 433 #ifdef PF_INET6 434 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 435 #endif 436 ) { 437 ai0 = *pai; /* backup *pai */ 438 439 if (pai->ai_family == PF_UNSPEC) { 440 #ifdef PF_INET6 441 pai->ai_family = PF_INET6; 442 #else 443 pai->ai_family = PF_INET; 444 #endif 445 } 446 error = get_portmatch(pai, servname); 447 if (error) 448 ERR(error); 449 450 *pai = ai0; 451 } 452 453 ai0 = *pai; 454 455 /* NULL hostname, or numeric hostname */ 456 for (ex = explore; ex->e_af >= 0; ex++) { 457 *pai = ai0; 458 459 /* PF_UNSPEC entries are prepared for DNS queries only */ 460 if (ex->e_af == PF_UNSPEC) 461 continue; 462 463 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 464 continue; 465 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 466 continue; 467 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 468 continue; 469 470 if (pai->ai_family == PF_UNSPEC) 471 pai->ai_family = ex->e_af; 472 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 473 pai->ai_socktype = ex->e_socktype; 474 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 475 pai->ai_protocol = ex->e_protocol; 476 477 if (hostname == NULL) 478 error = explore_null(pai, servname, &cur->ai_next); 479 else 480 error = explore_numeric_scope(pai, hostname, servname, 481 &cur->ai_next); 482 483 if (error) 484 goto free; 485 486 while (cur && cur->ai_next) 487 cur = cur->ai_next; 488 } 489 490 /* 491 * XXX 492 * If numreic representation of AF1 can be interpreted as FQDN 493 * representation of AF2, we need to think again about the code below. 494 */ 495 if (sentinel.ai_next) 496 goto good; 497 498 if (hostname == NULL) 499 ERR(EAI_NODATA); 500 if (pai->ai_flags & AI_NUMERICHOST) 501 ERR(EAI_NONAME); 502 503 /* 504 * hostname as alphabetical name. 505 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 506 * outer loop by AFs. 507 */ 508 for (ex = explore; ex->e_af >= 0; ex++) { 509 *pai = ai0; 510 511 /* require exact match for family field */ 512 if (pai->ai_family != ex->e_af) 513 continue; 514 515 if (!MATCH(pai->ai_socktype, ex->e_socktype, 516 WILD_SOCKTYPE(ex))) { 517 continue; 518 } 519 if (!MATCH(pai->ai_protocol, ex->e_protocol, 520 WILD_PROTOCOL(ex))) { 521 continue; 522 } 523 524 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 525 pai->ai_socktype = ex->e_socktype; 526 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 527 pai->ai_protocol = ex->e_protocol; 528 529 error = explore_fqdn(pai, hostname, servname, 530 &cur->ai_next); 531 532 while (cur && cur->ai_next) 533 cur = cur->ai_next; 534 } 535 536 /* XXX */ 537 if (sentinel.ai_next) 538 error = 0; 539 540 if (error) 541 goto free; 542 if (error == 0) { 543 if (sentinel.ai_next) { 544 good: 545 *res = sentinel.ai_next; 546 return SUCCESS; 547 } else 548 error = EAI_FAIL; 549 } 550 free: 551 bad: 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) 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 { 0 } 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) != 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); 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) 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) != 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); 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); 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 { 693 const struct afd *afd; 694 struct addrinfo *cur; 695 struct addrinfo sentinel; 696 int error; 697 char pton[PTON_MAX]; 698 699 _DIAGASSERT(pai != NULL); 700 /* hostname may be NULL */ 701 /* servname may be NULL */ 702 _DIAGASSERT(res != NULL); 703 704 *res = NULL; 705 sentinel.ai_next = NULL; 706 cur = &sentinel; 707 708 /* 709 * if the servname does not match socktype/protocol, ignore it. 710 */ 711 if (get_portmatch(pai, servname) != 0) 712 return 0; 713 714 afd = find_afd(pai->ai_family); 715 if (afd == NULL) 716 return 0; 717 718 switch (afd->a_af) { 719 #if 0 /*X/Open spec*/ 720 case AF_INET: 721 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 722 if (pai->ai_family == afd->a_af || 723 pai->ai_family == PF_UNSPEC /*?*/) { 724 GET_AI(cur->ai_next, afd, pton); 725 GET_PORT(cur->ai_next, servname); 726 if ((pai->ai_flags & AI_CANONNAME)) { 727 /* 728 * Set the numeric address itself as 729 * the canonical name, based on a 730 * clarification in rfc2553bis-03. 731 */ 732 GET_CANONNAME(cur->ai_next, canonname); 733 } 734 while (cur && cur->ai_next) 735 cur = cur->ai_next; 736 } else 737 ERR(EAI_FAMILY); /*xxx*/ 738 } 739 break; 740 #endif 741 default: 742 if (inet_pton(afd->a_af, hostname, pton) == 1) { 743 if (pai->ai_family == afd->a_af || 744 pai->ai_family == PF_UNSPEC /*?*/) { 745 GET_AI(cur->ai_next, afd, pton); 746 GET_PORT(cur->ai_next, servname); 747 if ((pai->ai_flags & AI_CANONNAME)) { 748 /* 749 * Set the numeric address itself as 750 * the canonical name, based on a 751 * clarification in rfc2553bis-03. 752 */ 753 GET_CANONNAME(cur->ai_next, canonname); 754 } 755 while (cur && cur->ai_next) 756 cur = cur->ai_next; 757 } else 758 ERR(EAI_FAMILY); /*xxx*/ 759 } 760 break; 761 } 762 763 *res = sentinel.ai_next; 764 return 0; 765 766 free: 767 bad: 768 if (sentinel.ai_next) 769 freeaddrinfo(sentinel.ai_next); 770 return error; 771 } 772 773 /* 774 * numeric hostname with scope 775 */ 776 static int 777 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 778 const char *servname, struct addrinfo **res) 779 { 780 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 781 return explore_numeric(pai, hostname, servname, res, hostname); 782 #else 783 const struct afd *afd; 784 struct addrinfo *cur; 785 int error; 786 char *cp, *hostname2 = NULL, *scope, *addr; 787 struct sockaddr_in6 *sin6; 788 789 _DIAGASSERT(pai != NULL); 790 /* hostname may be NULL */ 791 /* servname may be NULL */ 792 _DIAGASSERT(res != NULL); 793 794 /* 795 * if the servname does not match socktype/protocol, ignore it. 796 */ 797 if (get_portmatch(pai, servname) != 0) 798 return 0; 799 800 afd = find_afd(pai->ai_family); 801 if (afd == NULL) 802 return 0; 803 804 if (!afd->a_scoped) 805 return explore_numeric(pai, hostname, servname, res, hostname); 806 807 cp = strchr(hostname, SCOPE_DELIMITER); 808 if (cp == NULL) 809 return explore_numeric(pai, hostname, servname, res, hostname); 810 811 /* 812 * Handle special case of <scoped_address><delimiter><scope id> 813 */ 814 hostname2 = strdup(hostname); 815 if (hostname2 == NULL) 816 return EAI_MEMORY; 817 /* terminate at the delimiter */ 818 hostname2[cp - hostname] = '\0'; 819 addr = hostname2; 820 scope = cp + 1; 821 822 error = explore_numeric(pai, addr, servname, res, hostname); 823 if (error == 0) { 824 u_int32_t scopeid; 825 826 for (cur = *res; cur; cur = cur->ai_next) { 827 if (cur->ai_family != AF_INET6) 828 continue; 829 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 830 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 831 free(hostname2); 832 return(EAI_NODATA); /* XXX: is return OK? */ 833 } 834 sin6->sin6_scope_id = scopeid; 835 } 836 } 837 838 free(hostname2); 839 840 return error; 841 #endif 842 } 843 844 static int 845 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 846 { 847 848 _DIAGASSERT(pai != NULL); 849 _DIAGASSERT(ai != NULL); 850 _DIAGASSERT(str != NULL); 851 852 if ((pai->ai_flags & AI_CANONNAME) != 0) { 853 ai->ai_canonname = strdup(str); 854 if (ai->ai_canonname == NULL) 855 return EAI_MEMORY; 856 } 857 return 0; 858 } 859 860 static struct addrinfo * 861 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 862 { 863 char *p; 864 struct addrinfo *ai; 865 866 _DIAGASSERT(pai != NULL); 867 _DIAGASSERT(afd != NULL); 868 _DIAGASSERT(addr != NULL); 869 870 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 871 + (afd->a_socklen)); 872 if (ai == NULL) 873 return NULL; 874 875 memcpy(ai, pai, sizeof(struct addrinfo)); 876 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 877 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 878 ai->ai_addr->sa_len = afd->a_socklen; 879 ai->ai_addrlen = afd->a_socklen; 880 #if defined (__alpha__) || (defined(__i386__) && defined(_LP64)) || defined(__sparc64__) 881 ai->__ai_pad0 = 0; 882 #endif 883 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 884 p = (char *)(void *)(ai->ai_addr); 885 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 886 return ai; 887 } 888 889 static int 890 get_portmatch(const struct addrinfo *ai, const char *servname) 891 { 892 893 _DIAGASSERT(ai != NULL); 894 /* servname may be NULL */ 895 896 return get_port(ai, servname, 1); 897 } 898 899 static int 900 get_port(const struct addrinfo *ai, const char *servname, int matchonly) 901 { 902 const char *proto; 903 struct servent *sp; 904 int port; 905 int allownumeric; 906 907 _DIAGASSERT(ai != NULL); 908 /* servname may be NULL */ 909 910 if (servname == NULL) 911 return 0; 912 switch (ai->ai_family) { 913 case AF_INET: 914 #ifdef AF_INET6 915 case AF_INET6: 916 #endif 917 break; 918 default: 919 return 0; 920 } 921 922 switch (ai->ai_socktype) { 923 case SOCK_RAW: 924 return EAI_SERVICE; 925 case SOCK_DGRAM: 926 case SOCK_STREAM: 927 allownumeric = 1; 928 break; 929 case ANY: 930 allownumeric = 0; 931 break; 932 default: 933 return EAI_SOCKTYPE; 934 } 935 936 port = str2number(servname); 937 if (port >= 0) { 938 if (!allownumeric) 939 return EAI_SERVICE; 940 if (port < 0 || port > 65535) 941 return EAI_SERVICE; 942 port = htons(port); 943 } else { 944 if (ai->ai_flags & AI_NUMERICSERV) 945 return EAI_NONAME; 946 947 switch (ai->ai_socktype) { 948 case SOCK_DGRAM: 949 proto = "udp"; 950 break; 951 case SOCK_STREAM: 952 proto = "tcp"; 953 break; 954 default: 955 proto = NULL; 956 break; 957 } 958 959 if ((sp = getservbyname(servname, proto)) == NULL) 960 return EAI_SERVICE; 961 port = sp->s_port; 962 } 963 964 if (!matchonly) { 965 switch (ai->ai_family) { 966 case AF_INET: 967 ((struct sockaddr_in *)(void *) 968 ai->ai_addr)->sin_port = port; 969 break; 970 #ifdef INET6 971 case AF_INET6: 972 ((struct sockaddr_in6 *)(void *) 973 ai->ai_addr)->sin6_port = port; 974 break; 975 #endif 976 } 977 } 978 979 return 0; 980 } 981 982 static const struct afd * 983 find_afd(int af) 984 { 985 const struct afd *afd; 986 987 if (af == PF_UNSPEC) 988 return NULL; 989 for (afd = afdl; afd->a_af; afd++) { 990 if (afd->a_af == af) 991 return afd; 992 } 993 return NULL; 994 } 995 996 #ifdef INET6 997 /* convert a string to a scope identifier. XXX: IPv6 specific */ 998 static int 999 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1000 { 1001 u_long lscopeid; 1002 struct in6_addr *a6; 1003 char *ep; 1004 1005 _DIAGASSERT(scope != NULL); 1006 _DIAGASSERT(sin6 != NULL); 1007 _DIAGASSERT(scopeid != NULL); 1008 1009 a6 = &sin6->sin6_addr; 1010 1011 /* empty scopeid portion is invalid */ 1012 if (*scope == '\0') 1013 return -1; 1014 1015 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1016 /* 1017 * We currently assume a one-to-one mapping between links 1018 * and interfaces, so we simply use interface indices for 1019 * like-local scopes. 1020 */ 1021 *scopeid = if_nametoindex(scope); 1022 if (*scopeid == 0) 1023 goto trynumeric; 1024 return 0; 1025 } 1026 1027 /* still unclear about literal, allow numeric only - placeholder */ 1028 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1029 goto trynumeric; 1030 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1031 goto trynumeric; 1032 else 1033 goto trynumeric; /* global */ 1034 1035 /* try to convert to a numeric id as a last resort */ 1036 trynumeric: 1037 errno = 0; 1038 lscopeid = strtoul(scope, &ep, 10); 1039 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1040 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1041 return 0; 1042 else 1043 return -1; 1044 } 1045 #endif 1046 1047 /* code duplicate with gethnamaddr.c */ 1048 1049 static const char AskedForGot[] = 1050 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1051 1052 static struct addrinfo * 1053 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1054 const struct addrinfo *pai) 1055 { 1056 struct addrinfo sentinel, *cur; 1057 struct addrinfo ai; 1058 const struct afd *afd; 1059 char *canonname; 1060 const HEADER *hp; 1061 const u_char *cp; 1062 int n; 1063 const u_char *eom; 1064 char *bp, *ep; 1065 int type, class, ancount, qdcount; 1066 int haveanswer, had_error; 1067 char tbuf[MAXDNAME]; 1068 int (*name_ok) (const char *); 1069 char hostbuf[8*1024]; 1070 1071 _DIAGASSERT(answer != NULL); 1072 _DIAGASSERT(qname != NULL); 1073 _DIAGASSERT(pai != NULL); 1074 1075 memset(&sentinel, 0, sizeof(sentinel)); 1076 cur = &sentinel; 1077 1078 canonname = NULL; 1079 eom = answer->buf + anslen; 1080 switch (qtype) { 1081 case T_A: 1082 case T_AAAA: 1083 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1084 name_ok = res_hnok; 1085 break; 1086 default: 1087 return NULL; /* XXX should be abort(); */ 1088 } 1089 /* 1090 * find first satisfactory answer 1091 */ 1092 hp = &answer->hdr; 1093 ancount = ntohs(hp->ancount); 1094 qdcount = ntohs(hp->qdcount); 1095 bp = hostbuf; 1096 ep = hostbuf + sizeof hostbuf; 1097 cp = answer->buf + HFIXEDSZ; 1098 if (qdcount != 1) { 1099 h_errno = NO_RECOVERY; 1100 return (NULL); 1101 } 1102 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1103 if ((n < 0) || !(*name_ok)(bp)) { 1104 h_errno = NO_RECOVERY; 1105 return (NULL); 1106 } 1107 cp += n + QFIXEDSZ; 1108 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1109 /* res_send() has already verified that the query name is the 1110 * same as the one we sent; this just gets the expanded name 1111 * (i.e., with the succeeding search-domain tacked on). 1112 */ 1113 n = strlen(bp) + 1; /* for the \0 */ 1114 if (n >= MAXHOSTNAMELEN) { 1115 h_errno = NO_RECOVERY; 1116 return (NULL); 1117 } 1118 canonname = bp; 1119 bp += n; 1120 /* The qname can be abbreviated, but h_name is now absolute. */ 1121 qname = canonname; 1122 } 1123 haveanswer = 0; 1124 had_error = 0; 1125 while (ancount-- > 0 && cp < eom && !had_error) { 1126 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1127 if ((n < 0) || !(*name_ok)(bp)) { 1128 had_error++; 1129 continue; 1130 } 1131 cp += n; /* name */ 1132 type = _getshort(cp); 1133 cp += INT16SZ; /* type */ 1134 class = _getshort(cp); 1135 cp += INT16SZ + INT32SZ; /* class, TTL */ 1136 n = _getshort(cp); 1137 cp += INT16SZ; /* len */ 1138 if (class != C_IN) { 1139 /* XXX - debug? syslog? */ 1140 cp += n; 1141 continue; /* XXX - had_error++ ? */ 1142 } 1143 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1144 type == T_CNAME) { 1145 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1146 if ((n < 0) || !(*name_ok)(tbuf)) { 1147 had_error++; 1148 continue; 1149 } 1150 cp += n; 1151 /* Get canonical name. */ 1152 n = strlen(tbuf) + 1; /* for the \0 */ 1153 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1154 had_error++; 1155 continue; 1156 } 1157 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1158 canonname = bp; 1159 bp += n; 1160 continue; 1161 } 1162 if (qtype == T_ANY) { 1163 if (!(type == T_A || type == T_AAAA)) { 1164 cp += n; 1165 continue; 1166 } 1167 } else if (type != qtype) { 1168 if (type != T_KEY && type != T_SIG) 1169 syslog(LOG_NOTICE|LOG_AUTH, 1170 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1171 qname, p_class(C_IN), p_type(qtype), 1172 p_type(type)); 1173 cp += n; 1174 continue; /* XXX - had_error++ ? */ 1175 } 1176 switch (type) { 1177 case T_A: 1178 case T_AAAA: 1179 if (strcasecmp(canonname, bp) != 0) { 1180 syslog(LOG_NOTICE|LOG_AUTH, 1181 AskedForGot, canonname, bp); 1182 cp += n; 1183 continue; /* XXX - had_error++ ? */ 1184 } 1185 if (type == T_A && n != INADDRSZ) { 1186 cp += n; 1187 continue; 1188 } 1189 if (type == T_AAAA && n != IN6ADDRSZ) { 1190 cp += n; 1191 continue; 1192 } 1193 if (type == T_AAAA) { 1194 struct in6_addr in6; 1195 memcpy(&in6, cp, IN6ADDRSZ); 1196 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1197 cp += n; 1198 continue; 1199 } 1200 } 1201 if (!haveanswer) { 1202 int nn; 1203 1204 canonname = bp; 1205 nn = strlen(bp) + 1; /* for the \0 */ 1206 bp += nn; 1207 } 1208 1209 /* don't overwrite pai */ 1210 ai = *pai; 1211 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1212 afd = find_afd(ai.ai_family); 1213 if (afd == NULL) { 1214 cp += n; 1215 continue; 1216 } 1217 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1218 if (cur->ai_next == NULL) 1219 had_error++; 1220 while (cur && cur->ai_next) 1221 cur = cur->ai_next; 1222 cp += n; 1223 break; 1224 default: 1225 abort(); 1226 } 1227 if (!had_error) 1228 haveanswer++; 1229 } 1230 if (haveanswer) { 1231 if (!canonname) 1232 (void)get_canonname(pai, sentinel.ai_next, qname); 1233 else 1234 (void)get_canonname(pai, sentinel.ai_next, canonname); 1235 h_errno = NETDB_SUCCESS; 1236 return sentinel.ai_next; 1237 } 1238 1239 h_errno = NO_RECOVERY; 1240 return NULL; 1241 } 1242 1243 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr) 1244 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr) 1245 1246 static void 1247 aisort(struct addrinfo *s, res_state res) 1248 { 1249 struct addrinfo head, *t, *p; 1250 int i; 1251 1252 head.ai_next = NULL; 1253 t = &head; 1254 1255 for (i = 0; i < res->nsort; i++) { 1256 p = s; 1257 while (p->ai_next) { 1258 if ((p->ai_next->ai_family != AF_INET) 1259 || SORTMATCH(p, res->sort_list[i])) { 1260 t->ai_next = p->ai_next; 1261 t = t->ai_next; 1262 p->ai_next = p->ai_next->ai_next; 1263 } else { 1264 p = p->ai_next; 1265 } 1266 } 1267 } 1268 1269 /* add rest of list and reset s to the new list*/ 1270 t->ai_next = s->ai_next; 1271 s->ai_next = head.ai_next; 1272 } 1273 1274 /*ARGSUSED*/ 1275 static int 1276 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1277 { 1278 struct addrinfo *ai; 1279 querybuf *buf, *buf2; 1280 const char *name; 1281 const struct addrinfo *pai; 1282 struct addrinfo sentinel, *cur; 1283 struct res_target q, q2; 1284 res_state res; 1285 1286 name = va_arg(ap, char *); 1287 pai = va_arg(ap, const struct addrinfo *); 1288 1289 memset(&q, 0, sizeof(q2)); 1290 memset(&q2, 0, sizeof(q2)); 1291 memset(&sentinel, 0, sizeof(sentinel)); 1292 cur = &sentinel; 1293 1294 buf = malloc(sizeof(*buf)); 1295 if (buf == NULL) { 1296 h_errno = NETDB_INTERNAL; 1297 return NS_NOTFOUND; 1298 } 1299 buf2 = malloc(sizeof(*buf2)); 1300 if (buf2 == NULL) { 1301 free(buf); 1302 h_errno = NETDB_INTERNAL; 1303 return NS_NOTFOUND; 1304 } 1305 1306 switch (pai->ai_family) { 1307 case AF_UNSPEC: 1308 /* prefer IPv6 */ 1309 q.name = name; 1310 q.qclass = C_IN; 1311 q.qtype = T_AAAA; 1312 q.answer = buf->buf; 1313 q.anslen = sizeof(buf->buf); 1314 q.next = &q2; 1315 q2.name = name; 1316 q2.qclass = C_IN; 1317 q2.qtype = T_A; 1318 q2.answer = buf2->buf; 1319 q2.anslen = sizeof(buf2->buf); 1320 break; 1321 case AF_INET: 1322 q.name = name; 1323 q.qclass = C_IN; 1324 q.qtype = T_A; 1325 q.answer = buf->buf; 1326 q.anslen = sizeof(buf->buf); 1327 break; 1328 case AF_INET6: 1329 q.name = name; 1330 q.qclass = C_IN; 1331 q.qtype = T_AAAA; 1332 q.answer = buf->buf; 1333 q.anslen = sizeof(buf->buf); 1334 break; 1335 default: 1336 free(buf); 1337 free(buf2); 1338 return NS_UNAVAIL; 1339 } 1340 1341 res = __res_get_state(); 1342 if (res == NULL) { 1343 free(buf); 1344 free(buf2); 1345 return NS_NOTFOUND; 1346 } 1347 1348 if (res_searchN(name, &q, res) < 0) { 1349 __res_put_state(res); 1350 free(buf); 1351 free(buf2); 1352 return NS_NOTFOUND; 1353 } 1354 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1355 if (ai) { 1356 cur->ai_next = ai; 1357 while (cur && cur->ai_next) 1358 cur = cur->ai_next; 1359 } 1360 if (q.next) { 1361 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1362 if (ai) 1363 cur->ai_next = ai; 1364 } 1365 free(buf); 1366 free(buf2); 1367 if (sentinel.ai_next == NULL) { 1368 __res_put_state(res); 1369 switch (h_errno) { 1370 case HOST_NOT_FOUND: 1371 return NS_NOTFOUND; 1372 case TRY_AGAIN: 1373 return NS_TRYAGAIN; 1374 default: 1375 return NS_UNAVAIL; 1376 } 1377 } 1378 1379 if (res->nsort) 1380 aisort(&sentinel, res); 1381 1382 __res_put_state(res); 1383 1384 *((struct addrinfo **)rv) = sentinel.ai_next; 1385 return NS_SUCCESS; 1386 } 1387 1388 static void 1389 _sethtent(FILE **hostf) 1390 { 1391 1392 if (!*hostf) 1393 *hostf = fopen(_PATH_HOSTS, "r" ); 1394 else 1395 rewind(*hostf); 1396 } 1397 1398 static void 1399 _endhtent(FILE **hostf) 1400 { 1401 1402 if (*hostf) { 1403 (void) fclose(*hostf); 1404 *hostf = NULL; 1405 } 1406 } 1407 1408 static struct addrinfo * 1409 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1410 { 1411 char *p; 1412 char *cp, *tname, *cname; 1413 struct addrinfo hints, *res0, *res; 1414 int error; 1415 const char *addr; 1416 char hostbuf[8*1024]; 1417 1418 _DIAGASSERT(name != NULL); 1419 _DIAGASSERT(pai != NULL); 1420 1421 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r" ))) 1422 return (NULL); 1423 again: 1424 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 1425 return (NULL); 1426 if (*p == '#') 1427 goto again; 1428 if (!(cp = strpbrk(p, "#\n"))) 1429 goto again; 1430 *cp = '\0'; 1431 if (!(cp = strpbrk(p, " \t"))) 1432 goto again; 1433 *cp++ = '\0'; 1434 addr = p; 1435 /* if this is not something we're looking for, skip it. */ 1436 cname = NULL; 1437 while (cp && *cp) { 1438 if (*cp == ' ' || *cp == '\t') { 1439 cp++; 1440 continue; 1441 } 1442 if (!cname) 1443 cname = cp; 1444 tname = cp; 1445 if ((cp = strpbrk(cp, " \t")) != NULL) 1446 *cp++ = '\0'; 1447 if (strcasecmp(name, tname) == 0) 1448 goto found; 1449 } 1450 goto again; 1451 1452 found: 1453 hints = *pai; 1454 hints.ai_flags = AI_NUMERICHOST; 1455 error = getaddrinfo(addr, NULL, &hints, &res0); 1456 if (error) 1457 goto again; 1458 for (res = res0; res; res = res->ai_next) { 1459 /* cover it up */ 1460 res->ai_flags = pai->ai_flags; 1461 1462 if (pai->ai_flags & AI_CANONNAME) { 1463 if (get_canonname(pai, res, cname) != 0) { 1464 freeaddrinfo(res0); 1465 goto again; 1466 } 1467 } 1468 } 1469 return res0; 1470 } 1471 1472 /*ARGSUSED*/ 1473 static int 1474 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1475 { 1476 const char *name; 1477 const struct addrinfo *pai; 1478 struct addrinfo sentinel, *cur; 1479 struct addrinfo *p; 1480 #ifndef _REENTRANT 1481 static 1482 #endif 1483 FILE *hostf = NULL; 1484 1485 name = va_arg(ap, char *); 1486 pai = va_arg(ap, struct addrinfo *); 1487 1488 memset(&sentinel, 0, sizeof(sentinel)); 1489 cur = &sentinel; 1490 1491 _sethtent(&hostf); 1492 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1493 cur->ai_next = p; 1494 while (cur && cur->ai_next) 1495 cur = cur->ai_next; 1496 } 1497 _endhtent(&hostf); 1498 1499 *((struct addrinfo **)rv) = sentinel.ai_next; 1500 if (sentinel.ai_next == NULL) 1501 return NS_NOTFOUND; 1502 return NS_SUCCESS; 1503 } 1504 1505 #ifdef YP 1506 /*ARGSUSED*/ 1507 static struct addrinfo * 1508 _yphostent(char *line, const struct addrinfo *pai) 1509 { 1510 struct addrinfo sentinel, *cur; 1511 struct addrinfo hints, *res, *res0; 1512 int error; 1513 char *p; 1514 const char *addr, *canonname; 1515 char *nextline; 1516 char *cp; 1517 1518 _DIAGASSERT(line != NULL); 1519 _DIAGASSERT(pai != NULL); 1520 1521 p = line; 1522 addr = canonname = NULL; 1523 1524 memset(&sentinel, 0, sizeof(sentinel)); 1525 cur = &sentinel; 1526 1527 nextline: 1528 /* terminate line */ 1529 cp = strchr(p, '\n'); 1530 if (cp) { 1531 *cp++ = '\0'; 1532 nextline = cp; 1533 } else 1534 nextline = NULL; 1535 1536 cp = strpbrk(p, " \t"); 1537 if (cp == NULL) { 1538 if (canonname == NULL) 1539 return (NULL); 1540 else 1541 goto done; 1542 } 1543 *cp++ = '\0'; 1544 1545 addr = p; 1546 1547 while (cp && *cp) { 1548 if (*cp == ' ' || *cp == '\t') { 1549 cp++; 1550 continue; 1551 } 1552 if (!canonname) 1553 canonname = cp; 1554 if ((cp = strpbrk(cp, " \t")) != NULL) 1555 *cp++ = '\0'; 1556 } 1557 1558 hints = *pai; 1559 hints.ai_flags = AI_NUMERICHOST; 1560 error = getaddrinfo(addr, NULL, &hints, &res0); 1561 if (error == 0) { 1562 for (res = res0; res; res = res->ai_next) { 1563 /* cover it up */ 1564 res->ai_flags = pai->ai_flags; 1565 1566 if (pai->ai_flags & AI_CANONNAME) 1567 (void)get_canonname(pai, res, canonname); 1568 } 1569 } else 1570 res0 = NULL; 1571 if (res0) { 1572 cur->ai_next = res0; 1573 while (cur && cur->ai_next) 1574 cur = cur->ai_next; 1575 } 1576 1577 if (nextline) { 1578 p = nextline; 1579 goto nextline; 1580 } 1581 1582 done: 1583 return sentinel.ai_next; 1584 } 1585 1586 /*ARGSUSED*/ 1587 static int 1588 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1589 { 1590 struct addrinfo sentinel, *cur; 1591 struct addrinfo *ai = NULL; 1592 char *ypbuf; 1593 int ypbuflen, r; 1594 const char *name; 1595 const struct addrinfo *pai; 1596 char *ypdomain; 1597 1598 if (_yp_check(&ypdomain) == 0) 1599 return NS_UNAVAIL; 1600 1601 name = va_arg(ap, char *); 1602 pai = va_arg(ap, const struct addrinfo *); 1603 1604 memset(&sentinel, 0, sizeof(sentinel)); 1605 cur = &sentinel; 1606 1607 /* hosts.byname is only for IPv4 (Solaris8) */ 1608 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1609 r = yp_match(ypdomain, "hosts.byname", name, 1610 (int)strlen(name), &ypbuf, &ypbuflen); 1611 if (r == 0) { 1612 struct addrinfo ai4; 1613 1614 ai4 = *pai; 1615 ai4.ai_family = AF_INET; 1616 ai = _yphostent(ypbuf, &ai4); 1617 if (ai) { 1618 cur->ai_next = ai; 1619 while (cur && cur->ai_next) 1620 cur = cur->ai_next; 1621 } 1622 } 1623 free(ypbuf); 1624 } 1625 1626 /* ipnodes.byname can hold both IPv4/v6 */ 1627 r = yp_match(ypdomain, "ipnodes.byname", name, 1628 (int)strlen(name), &ypbuf, &ypbuflen); 1629 if (r == 0) { 1630 ai = _yphostent(ypbuf, pai); 1631 if (ai) 1632 cur->ai_next = ai; 1633 free(ypbuf); 1634 } 1635 1636 if (sentinel.ai_next == NULL) { 1637 h_errno = HOST_NOT_FOUND; 1638 return NS_NOTFOUND; 1639 } 1640 *((struct addrinfo **)rv) = sentinel.ai_next; 1641 return NS_SUCCESS; 1642 } 1643 #endif 1644 1645 /* resolver logic */ 1646 1647 /* 1648 * Formulate a normal query, send, and await answer. 1649 * Returned answer is placed in supplied buffer "answer". 1650 * Perform preliminary check of answer, returning success only 1651 * if no error is indicated and the answer count is nonzero. 1652 * Return the size of the response on success, -1 on error. 1653 * Error number is left in h_errno. 1654 * 1655 * Caller must parse answer and determine whether it answers the question. 1656 */ 1657 static int 1658 res_queryN(const char *name, /* domain name */ struct res_target *target, 1659 res_state res) 1660 { 1661 u_char buf[MAXPACKET]; 1662 HEADER *hp; 1663 int n; 1664 struct res_target *t; 1665 int rcode; 1666 int ancount; 1667 1668 _DIAGASSERT(name != NULL); 1669 /* XXX: target may be NULL??? */ 1670 1671 rcode = NOERROR; 1672 ancount = 0; 1673 1674 for (t = target; t; t = t->next) { 1675 int class, type; 1676 u_char *answer; 1677 int anslen; 1678 1679 hp = (HEADER *)(void *)t->answer; 1680 hp->rcode = NOERROR; /* default */ 1681 1682 /* make it easier... */ 1683 class = t->qclass; 1684 type = t->qtype; 1685 answer = t->answer; 1686 anslen = t->anslen; 1687 #ifdef DEBUG 1688 if (res->options & RES_DEBUG) 1689 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 1690 #endif 1691 1692 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 1693 buf, sizeof(buf)); 1694 #ifdef RES_USE_EDNS0 1695 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 1696 n = res_nopt(res, n, buf, sizeof(buf), anslen); 1697 #endif 1698 if (n <= 0) { 1699 #ifdef DEBUG 1700 if (res->options & RES_DEBUG) 1701 printf(";; res_nquery: mkquery failed\n"); 1702 #endif 1703 h_errno = NO_RECOVERY; 1704 return n; 1705 } 1706 n = res_nsend(res, buf, n, answer, anslen); 1707 #if 0 1708 if (n < 0) { 1709 #ifdef DEBUG 1710 if (res->options & RES_DEBUG) 1711 printf(";; res_query: send error\n"); 1712 #endif 1713 h_errno = TRY_AGAIN; 1714 return n; 1715 } 1716 #endif 1717 1718 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1719 rcode = hp->rcode; /* record most recent error */ 1720 #ifdef DEBUG 1721 if (res->options & RES_DEBUG) 1722 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1723 ntohs(hp->ancount)); 1724 #endif 1725 continue; 1726 } 1727 1728 ancount += ntohs(hp->ancount); 1729 1730 t->n = n; 1731 } 1732 1733 if (ancount == 0) { 1734 switch (rcode) { 1735 case NXDOMAIN: 1736 h_errno = HOST_NOT_FOUND; 1737 break; 1738 case SERVFAIL: 1739 h_errno = TRY_AGAIN; 1740 break; 1741 case NOERROR: 1742 h_errno = NO_DATA; 1743 break; 1744 case FORMERR: 1745 case NOTIMP: 1746 case REFUSED: 1747 default: 1748 h_errno = NO_RECOVERY; 1749 break; 1750 } 1751 return -1; 1752 } 1753 return ancount; 1754 } 1755 1756 /* 1757 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1758 * Return the size of the response on success, -1 on error. 1759 * If enabled, implement search rules until answer or unrecoverable failure 1760 * is detected. Error code, if any, is left in h_errno. 1761 */ 1762 static int 1763 res_searchN(const char *name, struct res_target *target, res_state res) 1764 { 1765 const char *cp, * const *domain; 1766 HEADER *hp; 1767 u_int dots; 1768 int trailing_dot, ret, saved_herrno; 1769 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1770 1771 _DIAGASSERT(name != NULL); 1772 _DIAGASSERT(target != NULL); 1773 1774 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1775 1776 errno = 0; 1777 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1778 dots = 0; 1779 for (cp = name; *cp; cp++) 1780 dots += (*cp == '.'); 1781 trailing_dot = 0; 1782 if (cp > name && *--cp == '.') 1783 trailing_dot++; 1784 1785 /* 1786 * if there aren't any dots, it could be a user-level alias 1787 */ 1788 if (!dots && (cp = __hostalias(name)) != NULL) { 1789 ret = res_queryN(cp, target, res); 1790 return ret; 1791 } 1792 1793 /* 1794 * If there are dots in the name already, let's just give it a try 1795 * 'as is'. The threshold can be set with the "ndots" option. 1796 */ 1797 saved_herrno = -1; 1798 if (dots >= res->ndots) { 1799 ret = res_querydomainN(name, NULL, target, res); 1800 if (ret > 0) 1801 return (ret); 1802 saved_herrno = h_errno; 1803 tried_as_is++; 1804 } 1805 1806 /* 1807 * We do at least one level of search if 1808 * - there is no dot and RES_DEFNAME is set, or 1809 * - there is at least one dot, there is no trailing dot, 1810 * and RES_DNSRCH is set. 1811 */ 1812 if ((!dots && (res->options & RES_DEFNAMES)) || 1813 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 1814 int done = 0; 1815 1816 for (domain = (const char * const *)res->dnsrch; 1817 *domain && !done; 1818 domain++) { 1819 1820 ret = res_querydomainN(name, *domain, target, res); 1821 if (ret > 0) 1822 return ret; 1823 1824 /* 1825 * If no server present, give up. 1826 * If name isn't found in this domain, 1827 * keep trying higher domains in the search list 1828 * (if that's enabled). 1829 * On a NO_DATA error, keep trying, otherwise 1830 * a wildcard entry of another type could keep us 1831 * from finding this entry higher in the domain. 1832 * If we get some other error (negative answer or 1833 * server failure), then stop searching up, 1834 * but try the input name below in case it's 1835 * fully-qualified. 1836 */ 1837 if (errno == ECONNREFUSED) { 1838 h_errno = TRY_AGAIN; 1839 return -1; 1840 } 1841 1842 switch (h_errno) { 1843 case NO_DATA: 1844 got_nodata++; 1845 /* FALLTHROUGH */ 1846 case HOST_NOT_FOUND: 1847 /* keep trying */ 1848 break; 1849 case TRY_AGAIN: 1850 if (hp->rcode == SERVFAIL) { 1851 /* try next search element, if any */ 1852 got_servfail++; 1853 break; 1854 } 1855 /* FALLTHROUGH */ 1856 default: 1857 /* anything else implies that we're done */ 1858 done++; 1859 } 1860 /* 1861 * if we got here for some reason other than DNSRCH, 1862 * we only wanted one iteration of the loop, so stop. 1863 */ 1864 if (!(res->options & RES_DNSRCH)) 1865 done++; 1866 } 1867 } 1868 1869 /* 1870 * if we have not already tried the name "as is", do that now. 1871 * note that we do this regardless of how many dots were in the 1872 * name or whether it ends with a dot. 1873 */ 1874 if (!tried_as_is) { 1875 ret = res_querydomainN(name, NULL, target, res); 1876 if (ret > 0) 1877 return ret; 1878 } 1879 1880 /* 1881 * if we got here, we didn't satisfy the search. 1882 * if we did an initial full query, return that query's h_errno 1883 * (note that we wouldn't be here if that query had succeeded). 1884 * else if we ever got a nodata, send that back as the reason. 1885 * else send back meaningless h_errno, that being the one from 1886 * the last DNSRCH we did. 1887 */ 1888 if (saved_herrno != -1) 1889 h_errno = saved_herrno; 1890 else if (got_nodata) 1891 h_errno = NO_DATA; 1892 else if (got_servfail) 1893 h_errno = TRY_AGAIN; 1894 return -1; 1895 } 1896 1897 /* 1898 * Perform a call on res_query on the concatenation of name and domain, 1899 * removing a trailing dot from name if domain is NULL. 1900 */ 1901 static int 1902 res_querydomainN(const char *name, const char *domain, 1903 struct res_target *target, res_state res) 1904 { 1905 char nbuf[MAXDNAME]; 1906 const char *longname = nbuf; 1907 size_t n, d; 1908 1909 _DIAGASSERT(name != NULL); 1910 /* XXX: target may be NULL??? */ 1911 1912 #ifdef DEBUG 1913 if (res->options & RES_DEBUG) 1914 printf(";; res_querydomain(%s, %s)\n", 1915 name, domain?domain:"<Nil>"); 1916 #endif 1917 if (domain == NULL) { 1918 /* 1919 * Check for trailing '.'; 1920 * copy without '.' if present. 1921 */ 1922 n = strlen(name); 1923 if (n + 1 > sizeof(nbuf)) { 1924 h_errno = NO_RECOVERY; 1925 return -1; 1926 } 1927 if (n > 0 && name[--n] == '.') { 1928 strncpy(nbuf, name, n); 1929 nbuf[n] = '\0'; 1930 } else 1931 longname = name; 1932 } else { 1933 n = strlen(name); 1934 d = strlen(domain); 1935 if (n + 1 + d + 1 > sizeof(nbuf)) { 1936 h_errno = NO_RECOVERY; 1937 return -1; 1938 } 1939 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1940 } 1941 return res_queryN(longname, target, res); 1942 } 1943