getaddrinfo.c revision 102237
1/* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 2 3/* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32/* 33 * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator. 34 * 35 * Issues to be discussed: 36 * - Thread safe-ness must be checked. 37 * - Return values. There are nonstandard return values defined and used 38 * in the source code. This is because RFC2553 is silent about which error 39 * code must be returned for which situation. 40 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 41 * invalid. 42 * current code - SEGV on freeaddrinfo(NULL) 43 * Note: 44 * - We use getipnodebyname() just for thread-safeness. There's no intent 45 * to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to 46 * getipnodebyname(). 47 * - The code filters out AFs that are not supported by the kernel, 48 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 49 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 50 * in ai_flags? 51 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 52 * (1) what should we do against numeric hostname (2) what should we do 53 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 54 * non-loopback address configured? global address configured? 55 * - To avoid search order issue, we have a big amount of code duplicate 56 * from gethnamaddr.c and some other places. The issues that there's no 57 * lower layer function to lookup "IPv4 or IPv6" record. Calling 58 * gethostbyname2 from getaddrinfo will end up in wrong search order, as 59 * follows: 60 * - The code makes use of following calls when asked to resolver with 61 * ai_family = PF_UNSPEC: 62 * getipnodebyname(host, AF_INET6); 63 * getipnodebyname(host, AF_INET); 64 * This will result in the following queries if the node is configure to 65 * prefer /etc/hosts than DNS: 66 * lookup /etc/hosts for IPv6 address 67 * lookup DNS for IPv6 address 68 * lookup /etc/hosts for IPv4 address 69 * lookup DNS for IPv4 address 70 * which may not meet people's requirement. 71 * The right thing to happen is to have underlying layer which does 72 * PF_UNSPEC lookup (lookup both) and return chain of addrinfos. 73 * This would result in a bit of code duplicate with _dns_ghbyname() and 74 * friends. 75 */ 76/* 77 * diffs with other KAME platforms: 78 * - other KAME platforms already nuked FAITH ($GAI), but as FreeBSD 79 * 4.0-RELEASE supplies it, we still have the code here. 80 * - AI_ADDRCONFIG support is supplied 81 * - some of FreeBSD style (#define tabify and others) 82 * - classful IPv4 numeric (127.1) is allowed. 83 */ 84 85#include <sys/cdefs.h> 86__FBSDID("$FreeBSD: head/lib/libc/net/getaddrinfo.c 102237 2002-08-21 19:57:53Z pirzyk $"); 87 88#include "namespace.h" 89#include <sys/types.h> 90#include <sys/param.h> 91#include <sys/socket.h> 92#include <net/if.h> 93#include <netinet/in.h> 94#include <arpa/inet.h> 95#include <arpa/nameser.h> 96#include <rpc/rpc.h> 97#include <rpcsvc/yp_prot.h> 98#include <rpcsvc/ypclnt.h> 99#include <netdb.h> 100#include <resolv.h> 101#include <string.h> 102#include <stdlib.h> 103#include <stddef.h> 104#include <ctype.h> 105#include <unistd.h> 106#include <stdio.h> 107#include <errno.h> 108 109#include "res_config.h" 110 111#ifdef DEBUG 112#include <syslog.h> 113#endif 114 115#include <stdarg.h> 116#include <nsswitch.h> 117#include "un-namespace.h" 118 119#if defined(__KAME__) && defined(INET6) 120# define FAITH 121#endif 122 123#define SUCCESS 0 124#define ANY 0 125#define YES 1 126#define NO 0 127 128static const char in_addrany[] = { 0, 0, 0, 0 }; 129static const char in6_addrany[] = { 130 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 131}; 132static const char in_loopback[] = { 127, 0, 0, 1 }; 133static const char in6_loopback[] = { 134 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 135}; 136 137static const struct afd { 138 int a_af; 139 int a_addrlen; 140 int a_socklen; 141 int a_off; 142 const char *a_addrany; 143 const char *a_loopback; 144 int a_scoped; 145} afdl [] = { 146#ifdef INET6 147#define N_INET6 0 148 {PF_INET6, sizeof(struct in6_addr), 149 sizeof(struct sockaddr_in6), 150 offsetof(struct sockaddr_in6, sin6_addr), 151 in6_addrany, in6_loopback, 1}, 152#define N_INET 1 153#else 154#define N_INET 0 155#endif 156 {PF_INET, sizeof(struct in_addr), 157 sizeof(struct sockaddr_in), 158 offsetof(struct sockaddr_in, sin_addr), 159 in_addrany, in_loopback, 0}, 160 {0, 0, 0, 0, NULL, NULL, 0}, 161}; 162 163struct explore { 164 int e_af; 165 int e_socktype; 166 int e_protocol; 167 const char *e_protostr; 168 int e_wild; 169#define WILD_AF(ex) ((ex)->e_wild & 0x01) 170#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 171#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 172}; 173 174static const struct explore explore[] = { 175#if 0 176 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 177#endif 178#ifdef INET6 179 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 180 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 181 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 182#endif 183 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 184 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 185 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 186 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 187 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 188 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 189 { -1, 0, 0, NULL, 0 }, 190}; 191 192#ifdef INET6 193#define PTON_MAX 16 194#else 195#define PTON_MAX 4 196#endif 197 198static const ns_src default_dns_files[] = { 199 { NSSRC_FILES, NS_SUCCESS }, 200 { NSSRC_DNS, NS_SUCCESS }, 201 { 0 } 202}; 203 204#if PACKETSZ > 1024 205#define MAXPACKET PACKETSZ 206#else 207#define MAXPACKET 1024 208#endif 209 210typedef union { 211 HEADER hdr; 212 u_char buf[MAXPACKET]; 213} querybuf; 214 215struct res_target { 216 struct res_target *next; 217 const char *name; /* domain name */ 218 int qclass, qtype; /* class and type of query */ 219 u_char *answer; /* buffer to put answer */ 220 int anslen; /* size of answer buffer */ 221 int n; /* result length */ 222}; 223 224static int str_isnumber(const char *); 225static int explore_fqdn(const struct addrinfo *, const char *, 226 const char *, struct addrinfo **); 227static int explore_null(const struct addrinfo *, 228 const char *, struct addrinfo **); 229static int explore_numeric(const struct addrinfo *, const char *, 230 const char *, struct addrinfo **); 231static int explore_numeric_scope(const struct addrinfo *, const char *, 232 const char *, struct addrinfo **); 233static int get_canonname(const struct addrinfo *, 234 struct addrinfo *, const char *); 235static struct addrinfo *get_ai(const struct addrinfo *, 236 const struct afd *, const char *); 237static int get_portmatch(const struct addrinfo *, const char *); 238static int get_port(struct addrinfo *, const char *, int); 239static const struct afd *find_afd(int); 240static int addrconfig(struct addrinfo *); 241#ifdef INET6 242static int ip6_str2scopeid(char *, struct sockaddr_in6 *); 243#endif 244 245static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 246 const struct addrinfo *); 247static int _dns_getaddrinfo(void *, void *, va_list); 248static void _sethtent(void); 249static void _endhtent(void); 250static struct addrinfo *_gethtent(const char *, const struct addrinfo *); 251static int _files_getaddrinfo(void *, void *, va_list); 252#ifdef YP 253static struct addrinfo *_yphostent(char *, const struct addrinfo *); 254static int _yp_getaddrinfo(void *, void *, va_list); 255extern int _yp_check(char **); 256#endif 257 258static int res_queryN(const char *, struct res_target *); 259static int res_searchN(const char *, struct res_target *); 260static int res_querydomainN(const char *, const char *, 261 struct res_target *); 262 263static char *ai_errlist[] = { 264 "Success", 265 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 266 "Temporary failure in name resolution", /* EAI_AGAIN */ 267 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 268 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 269 "ai_family not supported", /* EAI_FAMILY */ 270 "Memory allocation failure", /* EAI_MEMORY */ 271 "No address associated with hostname", /* EAI_NODATA */ 272 "hostname nor servname provided, or not known", /* EAI_NONAME */ 273 "servname not supported for ai_socktype", /* EAI_SERVICE */ 274 "ai_socktype not supported", /* EAI_SOCKTYPE */ 275 "System error returned in errno", /* EAI_SYSTEM */ 276 "Invalid value for hints", /* EAI_BADHINTS */ 277 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 278 "Unknown error", /* EAI_MAX */ 279}; 280 281/* XXX macros that make external reference is BAD. */ 282 283#define GET_AI(ai, afd, addr) \ 284do { \ 285 /* external reference: pai, error, and label free */ \ 286 (ai) = get_ai(pai, (afd), (addr)); \ 287 if ((ai) == NULL) { \ 288 error = EAI_MEMORY; \ 289 goto free; \ 290 } \ 291} while (/*CONSTCOND*/0) 292 293#define GET_PORT(ai, serv) \ 294do { \ 295 /* external reference: error and label free */ \ 296 error = get_port((ai), (serv), 0); \ 297 if (error != 0) \ 298 goto free; \ 299} while (/*CONSTCOND*/0) 300 301#define GET_CANONNAME(ai, str) \ 302do { \ 303 /* external reference: pai, error and label free */ \ 304 error = get_canonname(pai, (ai), (str)); \ 305 if (error != 0) \ 306 goto free; \ 307} while (/*CONSTCOND*/0) 308 309#define ERR(err) \ 310do { \ 311 /* external reference: error, and label bad */ \ 312 error = (err); \ 313 goto bad; \ 314 /*NOTREACHED*/ \ 315} while (/*CONSTCOND*/0) 316 317#define MATCH_FAMILY(x, y, w) \ 318 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 319#define MATCH(x, y, w) \ 320 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 321 322char * 323gai_strerror(ecode) 324 int ecode; 325{ 326 if (ecode < 0 || ecode > EAI_MAX) 327 ecode = EAI_MAX; 328 return ai_errlist[ecode]; 329} 330 331void 332freeaddrinfo(ai) 333 struct addrinfo *ai; 334{ 335 struct addrinfo *next; 336 337 do { 338 next = ai->ai_next; 339 if (ai->ai_canonname) 340 free(ai->ai_canonname); 341 /* no need to free(ai->ai_addr) */ 342 free(ai); 343 ai = next; 344 } while (ai); 345} 346 347static int 348str_isnumber(p) 349 const char *p; 350{ 351 char *ep; 352 353 if (*p == '\0') 354 return NO; 355 ep = NULL; 356 (void)strtoul(p, &ep, 10); 357 if (ep && *ep == '\0') 358 return YES; 359 else 360 return NO; 361} 362 363int 364getaddrinfo(hostname, servname, hints, res) 365 const char *hostname, *servname; 366 const struct addrinfo *hints; 367 struct addrinfo **res; 368{ 369 struct addrinfo sentinel; 370 struct addrinfo *cur; 371 int error = 0; 372 struct addrinfo ai; 373 struct addrinfo ai0; 374 struct addrinfo *pai; 375 const struct explore *ex; 376 377 memset(&sentinel, 0, sizeof(sentinel)); 378 cur = &sentinel; 379 pai = &ai; 380 pai->ai_flags = 0; 381 pai->ai_family = PF_UNSPEC; 382 pai->ai_socktype = ANY; 383 pai->ai_protocol = ANY; 384 pai->ai_addrlen = 0; 385 pai->ai_canonname = NULL; 386 pai->ai_addr = NULL; 387 pai->ai_next = NULL; 388 389 if (hostname == NULL && servname == NULL) 390 return EAI_NONAME; 391 if (hints) { 392 /* error check for hints */ 393 if (hints->ai_addrlen || hints->ai_canonname || 394 hints->ai_addr || hints->ai_next) 395 ERR(EAI_BADHINTS); /* xxx */ 396 if (hints->ai_flags & ~AI_MASK) 397 ERR(EAI_BADFLAGS); 398 switch (hints->ai_family) { 399 case PF_UNSPEC: 400 case PF_INET: 401#ifdef INET6 402 case PF_INET6: 403#endif 404 break; 405 default: 406 ERR(EAI_FAMILY); 407 } 408 memcpy(pai, hints, sizeof(*pai)); 409 410 /* 411 * if both socktype/protocol are specified, check if they 412 * are meaningful combination. 413 */ 414 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 415 for (ex = explore; ex->e_af >= 0; ex++) { 416 if (pai->ai_family != ex->e_af) 417 continue; 418 if (ex->e_socktype == ANY) 419 continue; 420 if (ex->e_protocol == ANY) 421 continue; 422 if (pai->ai_socktype == ex->e_socktype 423 && pai->ai_protocol != ex->e_protocol) { 424 ERR(EAI_BADHINTS); 425 } 426 } 427 } 428 } 429 430 /* 431 * post-2553: AI_ALL and AI_V4MAPPED are effective only against 432 * AF_INET6 query. They needs to be ignored if specified in other 433 * occassions. 434 */ 435 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 436 case AI_V4MAPPED: 437 case AI_ALL | AI_V4MAPPED: 438 if (pai->ai_family != AF_INET6) 439 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 440 break; 441 case AI_ALL: 442#if 1 443 /* illegal */ 444 ERR(EAI_BADFLAGS); 445#else 446 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 447#endif 448 break; 449 } 450 451 /* 452 * check for special cases. (1) numeric servname is disallowed if 453 * socktype/protocol are left unspecified. (2) servname is disallowed 454 * for raw and other inet{,6} sockets. 455 */ 456 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 457#ifdef PF_INET6 458 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 459#endif 460 ) { 461 ai0 = *pai; /* backup *pai */ 462 463 if (pai->ai_family == PF_UNSPEC) { 464#ifdef PF_INET6 465 pai->ai_family = PF_INET6; 466#else 467 pai->ai_family = PF_INET; 468#endif 469 } 470 error = get_portmatch(pai, servname); 471 if (error) 472 ERR(error); 473 474 *pai = ai0; 475 } 476 477 ai0 = *pai; 478 479 /* NULL hostname, or numeric hostname */ 480 for (ex = explore; ex->e_af >= 0; ex++) { 481 *pai = ai0; 482 483 /* PF_UNSPEC entries are prepared for DNS queries only */ 484 if (ex->e_af == PF_UNSPEC) 485 continue; 486 487 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 488 continue; 489 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 490 continue; 491 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 492 continue; 493 494 if (pai->ai_family == PF_UNSPEC) 495 pai->ai_family = ex->e_af; 496 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 497 pai->ai_socktype = ex->e_socktype; 498 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 499 pai->ai_protocol = ex->e_protocol; 500 501 if (hostname == NULL) 502 error = explore_null(pai, servname, &cur->ai_next); 503 else 504 error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next); 505 506 if (error) 507 goto free; 508 509 while (cur && cur->ai_next) 510 cur = cur->ai_next; 511 } 512 513 /* 514 * XXX 515 * If numreic representation of AF1 can be interpreted as FQDN 516 * representation of AF2, we need to think again about the code below. 517 */ 518 if (sentinel.ai_next) 519 goto good; 520 521 if (pai->ai_flags & AI_NUMERICHOST) 522 ERR(EAI_NONAME); 523 if (hostname == NULL) 524 ERR(EAI_NODATA); 525 526 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 527 ERR(EAI_FAIL); 528 529 /* 530 * hostname as alphabetical name. 531 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 532 * outer loop by AFs. 533 */ 534 for (ex = explore; ex->e_af >= 0; ex++) { 535 *pai = ai0; 536 537 /* require exact match for family field */ 538 if (pai->ai_family != ex->e_af) 539 continue; 540 541 if (!MATCH(pai->ai_socktype, ex->e_socktype, 542 WILD_SOCKTYPE(ex))) { 543 continue; 544 } 545 if (!MATCH(pai->ai_protocol, ex->e_protocol, 546 WILD_PROTOCOL(ex))) { 547 continue; 548 } 549 550 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 551 pai->ai_socktype = ex->e_socktype; 552 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 553 pai->ai_protocol = ex->e_protocol; 554 555 error = explore_fqdn(pai, hostname, servname, 556 &cur->ai_next); 557 558 while (cur && cur->ai_next) 559 cur = cur->ai_next; 560 } 561 562 /* XXX */ 563 if (sentinel.ai_next) 564 error = 0; 565 566 if (error) 567 goto free; 568 if (error == 0) { 569 if (sentinel.ai_next) { 570 good: 571 *res = sentinel.ai_next; 572 return SUCCESS; 573 } else 574 error = EAI_FAIL; 575 } 576 free: 577 bad: 578 if (sentinel.ai_next) 579 freeaddrinfo(sentinel.ai_next); 580 *res = NULL; 581 return error; 582} 583 584/* 585 * FQDN hostname, DNS lookup 586 */ 587static int 588explore_fqdn(pai, hostname, servname, res) 589 const struct addrinfo *pai; 590 const char *hostname; 591 const char *servname; 592 struct addrinfo **res; 593{ 594 struct addrinfo *result; 595 struct addrinfo *cur; 596 int error = 0; 597 static const ns_dtab dtab[] = { 598 NS_FILES_CB(_files_getaddrinfo, NULL) 599 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 600 NS_NIS_CB(_yp_getaddrinfo, NULL) 601 { 0 } 602 }; 603 604 result = NULL; 605 606 /* 607 * if the servname does not match socktype/protocol, ignore it. 608 */ 609 if (get_portmatch(pai, servname) != 0) 610 return 0; 611 612 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 613 default_dns_files, hostname, pai)) { 614 case NS_TRYAGAIN: 615 error = EAI_AGAIN; 616 goto free; 617 case NS_UNAVAIL: 618 error = EAI_FAIL; 619 goto free; 620 case NS_NOTFOUND: 621 error = EAI_NODATA; 622 goto free; 623 case NS_SUCCESS: 624 error = 0; 625 for (cur = result; cur; cur = cur->ai_next) { 626 GET_PORT(cur, servname); 627 /* canonname should be filled already */ 628 } 629 break; 630 } 631 632 *res = result; 633 634 return 0; 635 636free: 637 if (result) 638 freeaddrinfo(result); 639 return error; 640} 641 642/* 643 * hostname == NULL. 644 * passive socket -> anyaddr (0.0.0.0 or ::) 645 * non-passive socket -> localhost (127.0.0.1 or ::1) 646 */ 647static int 648explore_null(pai, servname, res) 649 const struct addrinfo *pai; 650 const char *servname; 651 struct addrinfo **res; 652{ 653 int s; 654 const struct afd *afd; 655 struct addrinfo *cur; 656 struct addrinfo sentinel; 657 int error; 658 659 *res = NULL; 660 sentinel.ai_next = NULL; 661 cur = &sentinel; 662 663 /* 664 * filter out AFs that are not supported by the kernel 665 * XXX errno? 666 */ 667 s = _socket(pai->ai_family, SOCK_DGRAM, 0); 668 if (s < 0) { 669 if (errno != EMFILE) 670 return 0; 671 } else 672 _close(s); 673 674 /* 675 * if the servname does not match socktype/protocol, ignore it. 676 */ 677 if (get_portmatch(pai, servname) != 0) 678 return 0; 679 680 afd = find_afd(pai->ai_family); 681 if (afd == NULL) 682 return 0; 683 684 if (pai->ai_flags & AI_PASSIVE) { 685 GET_AI(cur->ai_next, afd, afd->a_addrany); 686 /* xxx meaningless? 687 * GET_CANONNAME(cur->ai_next, "anyaddr"); 688 */ 689 GET_PORT(cur->ai_next, servname); 690 } else { 691 GET_AI(cur->ai_next, afd, afd->a_loopback); 692 /* xxx meaningless? 693 * GET_CANONNAME(cur->ai_next, "localhost"); 694 */ 695 GET_PORT(cur->ai_next, servname); 696 } 697 cur = cur->ai_next; 698 699 *res = sentinel.ai_next; 700 return 0; 701 702free: 703 if (sentinel.ai_next) 704 freeaddrinfo(sentinel.ai_next); 705 return error; 706} 707 708/* 709 * numeric hostname 710 */ 711static int 712explore_numeric(pai, hostname, servname, res) 713 const struct addrinfo *pai; 714 const char *hostname; 715 const char *servname; 716 struct addrinfo **res; 717{ 718 const struct afd *afd; 719 struct addrinfo *cur; 720 struct addrinfo sentinel; 721 int error; 722 char pton[PTON_MAX]; 723 724 *res = NULL; 725 sentinel.ai_next = NULL; 726 cur = &sentinel; 727 728 /* 729 * if the servname does not match socktype/protocol, ignore it. 730 */ 731 if (get_portmatch(pai, servname) != 0) 732 return 0; 733 734 afd = find_afd(pai->ai_family); 735 if (afd == NULL) 736 return 0; 737 738 switch (afd->a_af) { 739#if 1 /*X/Open spec*/ 740 case AF_INET: 741 if (inet_aton(hostname, (struct in_addr *)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 while (cur && cur->ai_next) 747 cur = cur->ai_next; 748 } else 749 ERR(EAI_FAMILY); /*xxx*/ 750 } 751 break; 752#endif 753 default: 754 if (inet_pton(afd->a_af, hostname, pton) == 1) { 755 if (pai->ai_family == afd->a_af || 756 pai->ai_family == PF_UNSPEC /*?*/) { 757 GET_AI(cur->ai_next, afd, pton); 758 GET_PORT(cur->ai_next, servname); 759 while (cur && cur->ai_next) 760 cur = cur->ai_next; 761 } else 762 ERR(EAI_FAMILY); /*xxx*/ 763 } 764 break; 765 } 766 767 *res = sentinel.ai_next; 768 return 0; 769 770free: 771bad: 772 if (sentinel.ai_next) 773 freeaddrinfo(sentinel.ai_next); 774 return error; 775} 776 777/* 778 * numeric hostname with scope 779 */ 780static int 781explore_numeric_scope(pai, hostname, servname, res) 782 const struct addrinfo *pai; 783 const char *hostname; 784 const char *servname; 785 struct addrinfo **res; 786{ 787#if !defined(SCOPE_DELIMITER) || !defined(INET6) 788 return explore_numeric(pai, hostname, servname, res); 789#else 790 const struct afd *afd; 791 struct addrinfo *cur; 792 int error; 793 char *cp, *hostname2 = NULL, *scope, *addr; 794 struct sockaddr_in6 *sin6; 795 796 /* 797 * if the servname does not match socktype/protocol, ignore it. 798 */ 799 if (get_portmatch(pai, servname) != 0) 800 return 0; 801 802 afd = find_afd(pai->ai_family); 803 if (afd == NULL) 804 return 0; 805 806 if (!afd->a_scoped) 807 return explore_numeric(pai, hostname, servname, res); 808 809 cp = strchr(hostname, SCOPE_DELIMITER); 810 if (cp == NULL) 811 return explore_numeric(pai, hostname, servname, res); 812 813 /* 814 * Handle special case of <scoped_address><delimiter><scope id> 815 */ 816 hostname2 = strdup(hostname); 817 if (hostname2 == NULL) 818 return EAI_MEMORY; 819 /* terminate at the delimiter */ 820 hostname2[cp - hostname] = '\0'; 821 addr = hostname2; 822 scope = cp + 1; 823 824 error = explore_numeric(pai, addr, servname, res); 825 if (error == 0) { 826 int scopeid; 827 828 for (cur = *res; cur; cur = cur->ai_next) { 829 if (cur->ai_family != AF_INET6) 830 continue; 831 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 832 if ((scopeid = ip6_str2scopeid(scope, sin6)) == -1) { 833 free(hostname2); 834 return(EAI_NODATA); /* XXX: is return OK? */ 835 } 836 sin6->sin6_scope_id = scopeid; 837 } 838 } 839 840 free(hostname2); 841 842 return error; 843#endif 844} 845 846static int 847get_canonname(pai, ai, str) 848 const struct addrinfo *pai; 849 struct addrinfo *ai; 850 const char *str; 851{ 852 if ((pai->ai_flags & AI_CANONNAME) != 0) { 853 ai->ai_canonname = (char *)malloc(strlen(str) + 1); 854 if (ai->ai_canonname == NULL) 855 return EAI_MEMORY; 856 strcpy(ai->ai_canonname, str); 857 } 858 return 0; 859} 860 861static struct addrinfo * 862get_ai(pai, afd, addr) 863 const struct addrinfo *pai; 864 const struct afd *afd; 865 const char *addr; 866{ 867 char *p; 868 struct addrinfo *ai; 869#ifdef FAITH 870 struct in6_addr faith_prefix; 871 char *fp_str; 872 int translate = 0; 873#endif 874 875#ifdef FAITH 876 /* 877 * Transfrom an IPv4 addr into a special IPv6 addr format for 878 * IPv6->IPv4 translation gateway. (only TCP is supported now) 879 * 880 * +-----------------------------------+------------+ 881 * | faith prefix part (12 bytes) | embedded | 882 * | | IPv4 addr part (4 bytes) 883 * +-----------------------------------+------------+ 884 * 885 * faith prefix part is specified as ascii IPv6 addr format 886 * in environmental variable GAI. 887 * For FAITH to work correctly, routing to faith prefix must be 888 * setup toward a machine where a FAITH daemon operates. 889 * Also, the machine must enable some mechanizm 890 * (e.g. faith interface hack) to divert those packet with 891 * faith prefixed destination addr to user-land FAITH daemon. 892 */ 893 fp_str = getenv("GAI"); 894 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 895 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 896 u_int32_t v4a; 897 u_int8_t v4a_top; 898 899 memcpy(&v4a, addr, sizeof v4a); 900 v4a_top = v4a >> IN_CLASSA_NSHIFT; 901 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 902 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 903 afd = &afdl[N_INET6]; 904 memcpy(&faith_prefix.s6_addr[12], addr, 905 sizeof(struct in_addr)); 906 translate = 1; 907 } 908 } 909#endif 910 911 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 912 + (afd->a_socklen)); 913 if (ai == NULL) 914 return NULL; 915 916 memcpy(ai, pai, sizeof(struct addrinfo)); 917 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 918 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 919 ai->ai_addr->sa_len = afd->a_socklen; 920 ai->ai_addrlen = afd->a_socklen; 921 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 922 p = (char *)(void *)(ai->ai_addr); 923#ifdef FAITH 924 if (translate == 1) 925 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 926 else 927#endif 928 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 929 return ai; 930} 931 932static int 933get_portmatch(ai, servname) 934 const struct addrinfo *ai; 935 const char *servname; 936{ 937 938 /* get_port does not touch first argument. when matchonly == 1. */ 939 /* LINTED const cast */ 940 return get_port((struct addrinfo *)ai, servname, 1); 941} 942 943static int 944get_port(ai, servname, matchonly) 945 struct addrinfo *ai; 946 const char *servname; 947 int matchonly; 948{ 949 const char *proto; 950 struct servent *sp; 951 int port; 952 int allownumeric; 953 954 if (servname == NULL) 955 return 0; 956 switch (ai->ai_family) { 957 case AF_INET: 958#ifdef AF_INET6 959 case AF_INET6: 960#endif 961 break; 962 default: 963 return 0; 964 } 965 966 switch (ai->ai_socktype) { 967 case SOCK_RAW: 968 return EAI_SERVICE; 969 case SOCK_DGRAM: 970 case SOCK_STREAM: 971 allownumeric = 1; 972 break; 973 case ANY: 974 allownumeric = 0; 975 break; 976 default: 977 return EAI_SOCKTYPE; 978 } 979 980 if (str_isnumber(servname)) { 981 if (!allownumeric) 982 return EAI_SERVICE; 983 port = htons(atoi(servname)); 984 if (port < 0 || port > 65535) 985 return EAI_SERVICE; 986 } else { 987 switch (ai->ai_socktype) { 988 case SOCK_DGRAM: 989 proto = "udp"; 990 break; 991 case SOCK_STREAM: 992 proto = "tcp"; 993 break; 994 default: 995 proto = NULL; 996 break; 997 } 998 999 if ((sp = getservbyname(servname, proto)) == NULL) 1000 return EAI_SERVICE; 1001 port = sp->s_port; 1002 } 1003 1004 if (!matchonly) { 1005 switch (ai->ai_family) { 1006 case AF_INET: 1007 ((struct sockaddr_in *)(void *) 1008 ai->ai_addr)->sin_port = port; 1009 break; 1010#ifdef INET6 1011 case AF_INET6: 1012 ((struct sockaddr_in6 *)(void *) 1013 ai->ai_addr)->sin6_port = port; 1014 break; 1015#endif 1016 } 1017 } 1018 1019 return 0; 1020} 1021 1022static const struct afd * 1023find_afd(af) 1024 int af; 1025{ 1026 const struct afd *afd; 1027 1028 if (af == PF_UNSPEC) 1029 return NULL; 1030 for (afd = afdl; afd->a_af; afd++) { 1031 if (afd->a_af == af) 1032 return afd; 1033 } 1034 return NULL; 1035} 1036 1037/* 1038 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1039 * will take care of it. 1040 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1041 * if the code is right or not. 1042 * 1043 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1044 * _dns_getaddrinfo. 1045 */ 1046static int 1047addrconfig(pai) 1048 struct addrinfo *pai; 1049{ 1050 int s, af; 1051 1052 /* 1053 * TODO: 1054 * Note that implementation dependent test for address 1055 * configuration should be done everytime called 1056 * (or apropriate interval), 1057 * because addresses will be dynamically assigned or deleted. 1058 */ 1059 af = pai->ai_family; 1060 if (af == AF_UNSPEC) { 1061 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 1062 af = AF_INET; 1063 else { 1064 _close(s); 1065 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) 1066 af = AF_INET6; 1067 else 1068 _close(s); 1069 } 1070 } 1071 if (af != AF_UNSPEC) { 1072 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 1073 return 0; 1074 _close(s); 1075 } 1076 pai->ai_family = af; 1077 return 1; 1078} 1079 1080#ifdef INET6 1081/* convert a string to a scope identifier. XXX: IPv6 specific */ 1082static int 1083ip6_str2scopeid(scope, sin6) 1084 char *scope; 1085 struct sockaddr_in6 *sin6; 1086{ 1087 int scopeid; 1088 struct in6_addr *a6 = &sin6->sin6_addr; 1089 char *ep; 1090 1091 /* empty scopeid portion is invalid */ 1092 if (*scope == '\0') 1093 return -1; 1094 1095 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1096 /* 1097 * We currently assume a one-to-one mapping between links 1098 * and interfaces, so we simply use interface indices for 1099 * like-local scopes. 1100 */ 1101 scopeid = if_nametoindex(scope); 1102 if (scopeid == 0) 1103 goto trynumeric; 1104 return(scopeid); 1105 } 1106 1107 /* still unclear about literal, allow numeric only - placeholder */ 1108 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1109 goto trynumeric; 1110 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1111 goto trynumeric; 1112 else 1113 goto trynumeric; /* global */ 1114 1115 /* try to convert to a numeric id as a last resort */ 1116 trynumeric: 1117 scopeid = (int)strtoul(scope, &ep, 10); 1118 if (*ep == '\0') 1119 return scopeid; 1120 else 1121 return -1; 1122} 1123#endif 1124 1125#ifdef RESOLVSORT 1126struct addr_ptr { 1127 struct addrinfo *ai; 1128 int aval; 1129}; 1130 1131static int 1132addr4sort(struct addrinfo *sentinel) 1133{ 1134 struct addrinfo *ai; 1135 struct addr_ptr *addrs, addr; 1136 struct sockaddr_in *sin; 1137 int naddrs, i, j; 1138 int needsort = 0; 1139 1140 if (!sentinel) 1141 return -1; 1142 naddrs = 0; 1143 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 1144 naddrs++; 1145 if (naddrs < 2) 1146 return 0; /* We don't need sorting. */ 1147 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 1148 return -1; 1149 i = 0; 1150 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 1151 sin = (struct sockaddr_in *)ai->ai_addr; 1152 for (j = 0; (unsigned)j < _res.nsort; j++) { 1153 if (_res.sort_list[j].addr.s_addr == 1154 (sin->sin_addr.s_addr & _res.sort_list[j].mask)) 1155 break; 1156 } 1157 addrs[i].ai = ai; 1158 addrs[i].aval = j; 1159 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 1160 needsort = i; 1161 i++; 1162 } 1163 if (!needsort) { 1164 free(addrs); 1165 return 0; 1166 } 1167 1168 while (needsort < naddrs) { 1169 for (j = needsort - 1; j >= 0; j--) { 1170 if (addrs[j].aval > addrs[j+1].aval) { 1171 addr = addrs[j]; 1172 addrs[j] = addrs[j + 1]; 1173 addrs[j + 1] = addr; 1174 } else 1175 break; 1176 } 1177 needsort++; 1178 } 1179 1180 ai = sentinel; 1181 for (i = 0; i < naddrs; ++i) { 1182 ai->ai_next = addrs[i].ai; 1183 ai = ai->ai_next; 1184 } 1185 ai->ai_next = NULL; 1186 free(addrs); 1187 return 0; 1188} 1189#endif /*RESOLVSORT*/ 1190 1191#ifdef DEBUG 1192static const char AskedForGot[] = 1193 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1194#endif 1195static FILE *hostf = NULL; 1196 1197static struct addrinfo * 1198getanswer(answer, anslen, qname, qtype, pai) 1199 const querybuf *answer; 1200 int anslen; 1201 const char *qname; 1202 int qtype; 1203 const struct addrinfo *pai; 1204{ 1205 struct addrinfo sentinel, *cur; 1206 struct addrinfo ai; 1207 const struct afd *afd; 1208 char *canonname; 1209 const HEADER *hp; 1210 const u_char *cp; 1211 int n; 1212 const u_char *eom; 1213 char *bp; 1214 int type, class, buflen, ancount, qdcount; 1215 int haveanswer, had_error; 1216 char tbuf[MAXDNAME]; 1217 int (*name_ok)(const char *); 1218 char hostbuf[8*1024]; 1219 1220 memset(&sentinel, 0, sizeof(sentinel)); 1221 cur = &sentinel; 1222 1223 canonname = NULL; 1224 eom = answer->buf + anslen; 1225 switch (qtype) { 1226 case T_A: 1227 case T_AAAA: 1228 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1229 name_ok = res_hnok; 1230 break; 1231 default: 1232 return (NULL); /* XXX should be abort(); */ 1233 } 1234 /* 1235 * find first satisfactory answer 1236 */ 1237 hp = &answer->hdr; 1238 ancount = ntohs(hp->ancount); 1239 qdcount = ntohs(hp->qdcount); 1240 bp = hostbuf; 1241 buflen = sizeof hostbuf; 1242 cp = answer->buf + HFIXEDSZ; 1243 if (qdcount != 1) { 1244 h_errno = NO_RECOVERY; 1245 return (NULL); 1246 } 1247 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1248 if ((n < 0) || !(*name_ok)(bp)) { 1249 h_errno = NO_RECOVERY; 1250 return (NULL); 1251 } 1252 cp += n + QFIXEDSZ; 1253 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1254 /* res_send() has already verified that the query name is the 1255 * same as the one we sent; this just gets the expanded name 1256 * (i.e., with the succeeding search-domain tacked on). 1257 */ 1258 n = strlen(bp) + 1; /* for the \0 */ 1259 if (n >= MAXHOSTNAMELEN) { 1260 h_errno = NO_RECOVERY; 1261 return (NULL); 1262 } 1263 canonname = bp; 1264 bp += n; 1265 buflen -= n; 1266 /* The qname can be abbreviated, but h_name is now absolute. */ 1267 qname = canonname; 1268 } 1269 haveanswer = 0; 1270 had_error = 0; 1271 while (ancount-- > 0 && cp < eom && !had_error) { 1272 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1273 if ((n < 0) || !(*name_ok)(bp)) { 1274 had_error++; 1275 continue; 1276 } 1277 cp += n; /* name */ 1278 type = _getshort(cp); 1279 cp += INT16SZ; /* type */ 1280 class = _getshort(cp); 1281 cp += INT16SZ + INT32SZ; /* class, TTL */ 1282 n = _getshort(cp); 1283 cp += INT16SZ; /* len */ 1284 if (class != C_IN) { 1285 /* XXX - debug? syslog? */ 1286 cp += n; 1287 continue; /* XXX - had_error++ ? */ 1288 } 1289 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1290 type == T_CNAME) { 1291 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1292 if ((n < 0) || !(*name_ok)(tbuf)) { 1293 had_error++; 1294 continue; 1295 } 1296 cp += n; 1297 /* Get canonical name. */ 1298 n = strlen(tbuf) + 1; /* for the \0 */ 1299 if (n > buflen || n >= MAXHOSTNAMELEN) { 1300 had_error++; 1301 continue; 1302 } 1303 strcpy(bp, tbuf); 1304 canonname = bp; 1305 bp += n; 1306 buflen -= n; 1307 continue; 1308 } 1309 if (qtype == T_ANY) { 1310 if (!(type == T_A || type == T_AAAA)) { 1311 cp += n; 1312 continue; 1313 } 1314 } else if (type != qtype) { 1315#ifdef DEBUG 1316 if (type != T_KEY && type != T_SIG) 1317 syslog(LOG_NOTICE|LOG_AUTH, 1318 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1319 qname, p_class(C_IN), p_type(qtype), 1320 p_type(type)); 1321#endif 1322 cp += n; 1323 continue; /* XXX - had_error++ ? */ 1324 } 1325 switch (type) { 1326 case T_A: 1327 case T_AAAA: 1328 if (strcasecmp(canonname, bp) != 0) { 1329#ifdef DEBUG 1330 syslog(LOG_NOTICE|LOG_AUTH, 1331 AskedForGot, canonname, bp); 1332#endif 1333 cp += n; 1334 continue; /* XXX - had_error++ ? */ 1335 } 1336 if (type == T_A && n != INADDRSZ) { 1337 cp += n; 1338 continue; 1339 } 1340 if (type == T_AAAA && n != IN6ADDRSZ) { 1341 cp += n; 1342 continue; 1343 } 1344#ifdef FILTER_V4MAPPED 1345 if (type == T_AAAA) { 1346 struct in6_addr in6; 1347 memcpy(&in6, cp, sizeof(in6)); 1348 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1349 cp += n; 1350 continue; 1351 } 1352 } 1353#endif 1354 if (!haveanswer) { 1355 int nn; 1356 1357 canonname = bp; 1358 nn = strlen(bp) + 1; /* for the \0 */ 1359 bp += nn; 1360 buflen -= nn; 1361 } 1362 1363 /* don't overwrite pai */ 1364 ai = *pai; 1365 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1366 afd = find_afd(ai.ai_family); 1367 if (afd == NULL) { 1368 cp += n; 1369 continue; 1370 } 1371 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1372 if (cur->ai_next == NULL) 1373 had_error++; 1374 while (cur && cur->ai_next) 1375 cur = cur->ai_next; 1376 cp += n; 1377 break; 1378 default: 1379 abort(); 1380 } 1381 if (!had_error) 1382 haveanswer++; 1383 } 1384 if (haveanswer) { 1385#if defined(RESOLVSORT) 1386 /* 1387 * We support only IPv4 address for backward 1388 * compatibility against gethostbyname(3). 1389 */ 1390 if (_res.nsort && qtype == T_A) { 1391 if (addr4sort(&sentinel) < 0) { 1392 freeaddrinfo(sentinel.ai_next); 1393 h_errno = NO_RECOVERY; 1394 return NULL; 1395 } 1396 } 1397#endif /*RESOLVSORT*/ 1398 if (!canonname) 1399 (void)get_canonname(pai, sentinel.ai_next, qname); 1400 else 1401 (void)get_canonname(pai, sentinel.ai_next, canonname); 1402 h_errno = NETDB_SUCCESS; 1403 return sentinel.ai_next; 1404 } 1405 1406 h_errno = NO_RECOVERY; 1407 return NULL; 1408} 1409 1410/*ARGSUSED*/ 1411static int 1412_dns_getaddrinfo(rv, cb_data, ap) 1413 void *rv; 1414 void *cb_data; 1415 va_list ap; 1416{ 1417 struct addrinfo *ai; 1418 querybuf buf, buf2; 1419 const char *name; 1420 const struct addrinfo *pai; 1421 struct addrinfo sentinel, *cur; 1422 struct res_target q, q2; 1423 1424 name = va_arg(ap, char *); 1425 pai = va_arg(ap, const struct addrinfo *); 1426 1427 memset(&q, 0, sizeof(q2)); 1428 memset(&q2, 0, sizeof(q2)); 1429 memset(&sentinel, 0, sizeof(sentinel)); 1430 cur = &sentinel; 1431 1432 switch (pai->ai_family) { 1433 case AF_UNSPEC: 1434 /* prefer IPv6 */ 1435 q.qclass = C_IN; 1436 q.qtype = T_AAAA; 1437 q.answer = buf.buf; 1438 q.anslen = sizeof(buf); 1439 q.next = &q2; 1440 q2.qclass = C_IN; 1441 q2.qtype = T_A; 1442 q2.answer = buf2.buf; 1443 q2.anslen = sizeof(buf2); 1444 break; 1445 case AF_INET: 1446 q.qclass = C_IN; 1447 q.qtype = T_A; 1448 q.answer = buf.buf; 1449 q.anslen = sizeof(buf); 1450 break; 1451 case AF_INET6: 1452 q.qclass = C_IN; 1453 q.qtype = T_AAAA; 1454 q.answer = buf.buf; 1455 q.anslen = sizeof(buf); 1456 break; 1457 default: 1458 return NS_UNAVAIL; 1459 } 1460 if (res_searchN(name, &q) < 0) 1461 return NS_NOTFOUND; 1462 ai = getanswer(&buf, q.n, q.name, q.qtype, pai); 1463 if (ai) { 1464 cur->ai_next = ai; 1465 while (cur && cur->ai_next) 1466 cur = cur->ai_next; 1467 } 1468 if (q.next) { 1469 ai = getanswer(&buf2, q2.n, q2.name, q2.qtype, pai); 1470 if (ai) 1471 cur->ai_next = ai; 1472 } 1473 if (sentinel.ai_next == NULL) 1474 switch (h_errno) { 1475 case HOST_NOT_FOUND: 1476 return NS_NOTFOUND; 1477 case TRY_AGAIN: 1478 return NS_TRYAGAIN; 1479 default: 1480 return NS_UNAVAIL; 1481 } 1482 *((struct addrinfo **)rv) = sentinel.ai_next; 1483 return NS_SUCCESS; 1484} 1485 1486static void 1487_sethtent() 1488{ 1489 if (!hostf) 1490 hostf = fopen(_PATH_HOSTS, "r" ); 1491 else 1492 rewind(hostf); 1493} 1494 1495static void 1496_endhtent() 1497{ 1498 if (hostf) { 1499 (void) fclose(hostf); 1500 hostf = NULL; 1501 } 1502} 1503 1504static struct addrinfo * 1505_gethtent(name, pai) 1506 const char *name; 1507 const struct addrinfo *pai; 1508{ 1509 char *p; 1510 char *cp, *tname, *cname; 1511 struct addrinfo hints, *res0, *res; 1512 int error; 1513 const char *addr; 1514 char hostbuf[8*1024]; 1515 1516 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) 1517 return (NULL); 1518 again: 1519 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) 1520 return (NULL); 1521 if (*p == '#') 1522 goto again; 1523 if (!(cp = strpbrk(p, "#\n"))) 1524 goto again; 1525 *cp = '\0'; 1526 if (!(cp = strpbrk(p, " \t"))) 1527 goto again; 1528 *cp++ = '\0'; 1529 addr = p; 1530 cname = NULL; 1531 /* if this is not something we're looking for, skip it. */ 1532 while (cp && *cp) { 1533 if (*cp == ' ' || *cp == '\t') { 1534 cp++; 1535 continue; 1536 } 1537 tname = cp; 1538 if (cname == NULL) 1539 cname = cp; 1540 if ((cp = strpbrk(cp, " \t")) != NULL) 1541 *cp++ = '\0'; 1542 if (strcasecmp(name, tname) == 0) 1543 goto found; 1544 } 1545 goto again; 1546 1547found: 1548 hints = *pai; 1549 hints.ai_flags = AI_NUMERICHOST; 1550 error = getaddrinfo(addr, NULL, &hints, &res0); 1551 if (error) 1552 goto again; 1553#ifdef FILTER_V4MAPPED 1554 /* XXX should check all items in the chain */ 1555 if (res0->ai_family == AF_INET6 && 1556 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 1557 freeaddrinfo(res0); 1558 goto again; 1559 } 1560#endif 1561 for (res = res0; res; res = res->ai_next) { 1562 /* cover it up */ 1563 res->ai_flags = pai->ai_flags; 1564 1565 if (pai->ai_flags & AI_CANONNAME) { 1566 if (get_canonname(pai, res, cname) != 0) { 1567 freeaddrinfo(res0); 1568 goto again; 1569 } 1570 } 1571 } 1572 return res0; 1573} 1574 1575/*ARGSUSED*/ 1576static int 1577_files_getaddrinfo(rv, cb_data, ap) 1578 void *rv; 1579 void *cb_data; 1580 va_list ap; 1581{ 1582 const char *name; 1583 const struct addrinfo *pai; 1584 struct addrinfo sentinel, *cur; 1585 struct addrinfo *p; 1586 1587 name = va_arg(ap, char *); 1588 pai = va_arg(ap, struct addrinfo *); 1589 1590 memset(&sentinel, 0, sizeof(sentinel)); 1591 cur = &sentinel; 1592 1593 _sethtent(); 1594 while ((p = _gethtent(name, pai)) != NULL) { 1595 cur->ai_next = p; 1596 while (cur && cur->ai_next) 1597 cur = cur->ai_next; 1598 } 1599 _endhtent(); 1600 1601 *((struct addrinfo **)rv) = sentinel.ai_next; 1602 if (sentinel.ai_next == NULL) 1603 return NS_NOTFOUND; 1604 return NS_SUCCESS; 1605} 1606 1607#ifdef YP 1608static char *__ypdomain; 1609 1610/*ARGSUSED*/ 1611static struct addrinfo * 1612_yphostent(line, pai) 1613 char *line; 1614 const struct addrinfo *pai; 1615{ 1616 struct addrinfo sentinel, *cur; 1617 struct addrinfo hints, *res, *res0; 1618 int error; 1619 char *p = line; 1620 const char *addr, *canonname; 1621 char *nextline; 1622 char *cp; 1623 1624 addr = canonname = NULL; 1625 1626 memset(&sentinel, 0, sizeof(sentinel)); 1627 cur = &sentinel; 1628 1629nextline: 1630 /* terminate line */ 1631 cp = strchr(p, '\n'); 1632 if (cp) { 1633 *cp++ = '\0'; 1634 nextline = cp; 1635 } else 1636 nextline = NULL; 1637 1638 cp = strpbrk(p, " \t"); 1639 if (cp == NULL) { 1640 if (canonname == NULL) 1641 return (NULL); 1642 else 1643 goto done; 1644 } 1645 *cp++ = '\0'; 1646 1647 addr = p; 1648 1649 while (cp && *cp) { 1650 if (*cp == ' ' || *cp == '\t') { 1651 cp++; 1652 continue; 1653 } 1654 if (!canonname) 1655 canonname = cp; 1656 if ((cp = strpbrk(cp, " \t")) != NULL) 1657 *cp++ = '\0'; 1658 } 1659 1660 hints = *pai; 1661 hints.ai_flags = AI_NUMERICHOST; 1662 error = getaddrinfo(addr, NULL, &hints, &res0); 1663 if (error == 0) { 1664 for (res = res0; res; res = res->ai_next) { 1665 /* cover it up */ 1666 res->ai_flags = pai->ai_flags; 1667 1668 if (pai->ai_flags & AI_CANONNAME) 1669 (void)get_canonname(pai, res, canonname); 1670 } 1671 } else 1672 res0 = NULL; 1673 if (res0) { 1674 cur->ai_next = res0; 1675 while (cur && cur->ai_next) 1676 cur = cur->ai_next; 1677 } 1678 1679 if (nextline) { 1680 p = nextline; 1681 goto nextline; 1682 } 1683 1684done: 1685 return sentinel.ai_next; 1686} 1687 1688/*ARGSUSED*/ 1689static int 1690_yp_getaddrinfo(rv, cb_data, ap) 1691 void *rv; 1692 void *cb_data; 1693 va_list ap; 1694{ 1695 struct addrinfo sentinel, *cur; 1696 struct addrinfo *ai = NULL; 1697 static char *__ypcurrent; 1698 int __ypcurrentlen, r; 1699 const char *name; 1700 const struct addrinfo *pai; 1701 1702 name = va_arg(ap, char *); 1703 pai = va_arg(ap, const struct addrinfo *); 1704 1705 memset(&sentinel, 0, sizeof(sentinel)); 1706 cur = &sentinel; 1707 1708 if (!__ypdomain) { 1709 if (_yp_check(&__ypdomain) == 0) 1710 return NS_UNAVAIL; 1711 } 1712 if (__ypcurrent) 1713 free(__ypcurrent); 1714 __ypcurrent = NULL; 1715 1716 /* hosts.byname is only for IPv4 (Solaris8) */ 1717 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1718 r = yp_match(__ypdomain, "hosts.byname", name, 1719 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1720 if (r == 0) { 1721 struct addrinfo ai4; 1722 1723 ai4 = *pai; 1724 ai4.ai_family = AF_INET; 1725 ai = _yphostent(__ypcurrent, &ai4); 1726 if (ai) { 1727 cur->ai_next = ai; 1728 while (cur && cur->ai_next) 1729 cur = cur->ai_next; 1730 } 1731 } 1732 } 1733 1734 /* ipnodes.byname can hold both IPv4/v6 */ 1735 r = yp_match(__ypdomain, "ipnodes.byname", name, 1736 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1737 if (r == 0) { 1738 ai = _yphostent(__ypcurrent, pai); 1739 if (ai) { 1740 cur->ai_next = ai; 1741 while (cur && cur->ai_next) 1742 cur = cur->ai_next; 1743 } 1744 } 1745 1746 if (sentinel.ai_next == NULL) { 1747 h_errno = HOST_NOT_FOUND; 1748 return NS_NOTFOUND; 1749 } 1750 *((struct addrinfo **)rv) = sentinel.ai_next; 1751 return NS_SUCCESS; 1752} 1753#endif 1754 1755/* resolver logic */ 1756 1757extern const char *__hostalias(const char *); 1758extern int h_errno; 1759 1760/* 1761 * Formulate a normal query, send, and await answer. 1762 * Returned answer is placed in supplied buffer "answer". 1763 * Perform preliminary check of answer, returning success only 1764 * if no error is indicated and the answer count is nonzero. 1765 * Return the size of the response on success, -1 on error. 1766 * Error number is left in h_errno. 1767 * 1768 * Caller must parse answer and determine whether it answers the question. 1769 */ 1770static int 1771res_queryN(name, target) 1772 const char *name; /* domain name */ 1773 struct res_target *target; 1774{ 1775 u_char buf[MAXPACKET]; 1776 HEADER *hp; 1777 int n; 1778 struct res_target *t; 1779 int rcode; 1780 int ancount; 1781 1782 rcode = NOERROR; 1783 ancount = 0; 1784 1785 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1786 h_errno = NETDB_INTERNAL; 1787 return (-1); 1788 } 1789 1790 for (t = target; t; t = t->next) { 1791 int class, type; 1792 u_char *answer; 1793 int anslen; 1794 1795 hp = (HEADER *)(void *)t->answer; 1796 hp->rcode = NOERROR; /* default */ 1797 1798 /* make it easier... */ 1799 class = t->qclass; 1800 type = t->qtype; 1801 answer = t->answer; 1802 anslen = t->anslen; 1803#ifdef DEBUG 1804 if (_res.options & RES_DEBUG) 1805 printf(";; res_query(%s, %d, %d)\n", name, class, type); 1806#endif 1807 1808 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL, 1809 buf, sizeof(buf)); 1810 if (n > 0 && (_res.options & RES_USE_EDNS0) != 0) 1811 n = res_opt(n, buf, sizeof(buf), anslen); 1812 if (n <= 0) { 1813#ifdef DEBUG 1814 if (_res.options & RES_DEBUG) 1815 printf(";; res_query: mkquery failed\n"); 1816#endif 1817 h_errno = NO_RECOVERY; 1818 return (n); 1819 } 1820 n = res_send(buf, n, answer, anslen); 1821#if 0 1822 if (n < 0) { 1823#ifdef DEBUG 1824 if (_res.options & RES_DEBUG) 1825 printf(";; res_query: send error\n"); 1826#endif 1827 h_errno = TRY_AGAIN; 1828 return (n); 1829 } 1830#endif 1831 1832 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1833 rcode = hp->rcode; /* record most recent error */ 1834#ifdef DEBUG 1835 if (_res.options & RES_DEBUG) 1836 printf(";; rcode = %d, ancount=%d\n", hp->rcode, 1837 ntohs(hp->ancount)); 1838#endif 1839 continue; 1840 } 1841 1842 ancount += ntohs(hp->ancount); 1843 1844 t->n = n; 1845 } 1846 1847 if (ancount == 0) { 1848 switch (rcode) { 1849 case NXDOMAIN: 1850 h_errno = HOST_NOT_FOUND; 1851 break; 1852 case SERVFAIL: 1853 h_errno = TRY_AGAIN; 1854 break; 1855 case NOERROR: 1856 h_errno = NO_DATA; 1857 break; 1858 case FORMERR: 1859 case NOTIMP: 1860 case REFUSED: 1861 default: 1862 h_errno = NO_RECOVERY; 1863 break; 1864 } 1865 return (-1); 1866 } 1867 return (ancount); 1868} 1869 1870/* 1871 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1872 * Return the size of the response on success, -1 on error. 1873 * If enabled, implement search rules until answer or unrecoverable failure 1874 * is detected. Error code, if any, is left in h_errno. 1875 */ 1876static int 1877res_searchN(name, target) 1878 const char *name; /* domain name */ 1879 struct res_target *target; 1880{ 1881 const char *cp, * const *domain; 1882 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 1883 u_int dots; 1884 int trailing_dot, ret, saved_herrno; 1885 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1886 1887 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1888 h_errno = NETDB_INTERNAL; 1889 return (-1); 1890 } 1891 1892 errno = 0; 1893 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1894 dots = 0; 1895 for (cp = name; *cp; cp++) 1896 dots += (*cp == '.'); 1897 trailing_dot = 0; 1898 if (cp > name && *--cp == '.') 1899 trailing_dot++; 1900 1901 /* 1902 * if there aren't any dots, it could be a user-level alias 1903 */ 1904 if (!dots && (cp = __hostalias(name)) != NULL) 1905 return (res_queryN(cp, target)); 1906 1907 /* 1908 * If there are dots in the name already, let's just give it a try 1909 * 'as is'. The threshold can be set with the "ndots" option. 1910 */ 1911 saved_herrno = -1; 1912 if (dots >= _res.ndots) { 1913 ret = res_querydomainN(name, NULL, target); 1914 if (ret > 0) 1915 return (ret); 1916 saved_herrno = h_errno; 1917 tried_as_is++; 1918 } 1919 1920 /* 1921 * We do at least one level of search if 1922 * - there is no dot and RES_DEFNAME is set, or 1923 * - there is at least one dot, there is no trailing dot, 1924 * and RES_DNSRCH is set. 1925 */ 1926 if ((!dots && (_res.options & RES_DEFNAMES)) || 1927 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { 1928 int done = 0; 1929 1930 for (domain = (const char * const *)_res.dnsrch; 1931 *domain && !done; 1932 domain++) { 1933 1934 ret = res_querydomainN(name, *domain, target); 1935 if (ret > 0) 1936 return (ret); 1937 1938 /* 1939 * If no server present, give up. 1940 * If name isn't found in this domain, 1941 * keep trying higher domains in the search list 1942 * (if that's enabled). 1943 * On a NO_DATA error, keep trying, otherwise 1944 * a wildcard entry of another type could keep us 1945 * from finding this entry higher in the domain. 1946 * If we get some other error (negative answer or 1947 * server failure), then stop searching up, 1948 * but try the input name below in case it's 1949 * fully-qualified. 1950 */ 1951 if (errno == ECONNREFUSED) { 1952 h_errno = TRY_AGAIN; 1953 return (-1); 1954 } 1955 1956 switch (h_errno) { 1957 case NO_DATA: 1958 got_nodata++; 1959 /* FALLTHROUGH */ 1960 case HOST_NOT_FOUND: 1961 /* keep trying */ 1962 break; 1963 case TRY_AGAIN: 1964 if (hp->rcode == SERVFAIL) { 1965 /* try next search element, if any */ 1966 got_servfail++; 1967 break; 1968 } 1969 /* FALLTHROUGH */ 1970 default: 1971 /* anything else implies that we're done */ 1972 done++; 1973 } 1974 /* 1975 * if we got here for some reason other than DNSRCH, 1976 * we only wanted one iteration of the loop, so stop. 1977 */ 1978 if (!(_res.options & RES_DNSRCH)) 1979 done++; 1980 } 1981 } 1982 1983 /* 1984 * if we have not already tried the name "as is", do that now. 1985 * note that we do this regardless of how many dots were in the 1986 * name or whether it ends with a dot. 1987 */ 1988 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) { 1989 ret = res_querydomainN(name, NULL, target); 1990 if (ret > 0) 1991 return (ret); 1992 } 1993 1994 /* 1995 * if we got here, we didn't satisfy the search. 1996 * if we did an initial full query, return that query's h_errno 1997 * (note that we wouldn't be here if that query had succeeded). 1998 * else if we ever got a nodata, send that back as the reason. 1999 * else send back meaningless h_errno, that being the one from 2000 * the last DNSRCH we did. 2001 */ 2002 if (saved_herrno != -1) 2003 h_errno = saved_herrno; 2004 else if (got_nodata) 2005 h_errno = NO_DATA; 2006 else if (got_servfail) 2007 h_errno = TRY_AGAIN; 2008 return (-1); 2009} 2010 2011/* 2012 * Perform a call on res_query on the concatenation of name and domain, 2013 * removing a trailing dot from name if domain is NULL. 2014 */ 2015static int 2016res_querydomainN(name, domain, target) 2017 const char *name, *domain; 2018 struct res_target *target; 2019{ 2020 char nbuf[MAXDNAME]; 2021 const char *longname = nbuf; 2022 size_t n, d; 2023 2024 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 2025 h_errno = NETDB_INTERNAL; 2026 return (-1); 2027 } 2028#ifdef DEBUG 2029 if (_res.options & RES_DEBUG) 2030 printf(";; res_querydomain(%s, %s)\n", 2031 name, domain?domain:"<Nil>"); 2032#endif 2033 if (domain == NULL) { 2034 /* 2035 * Check for trailing '.'; 2036 * copy without '.' if present. 2037 */ 2038 n = strlen(name); 2039 if (n >= MAXDNAME) { 2040 h_errno = NO_RECOVERY; 2041 return (-1); 2042 } 2043 if (n > 0 && name[--n] == '.') { 2044 strncpy(nbuf, name, n); 2045 nbuf[n] = '\0'; 2046 } else 2047 longname = name; 2048 } else { 2049 n = strlen(name); 2050 d = strlen(domain); 2051 if (n + d + 1 >= MAXDNAME) { 2052 h_errno = NO_RECOVERY; 2053 return (-1); 2054 } 2055 sprintf(nbuf, "%s.%s", name, domain); 2056 } 2057 return (res_queryN(longname, target)); 2058} 2059