getaddrinfo.c revision 121347
1209243Sjchandra/* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 2209243Sjchandra 3209243Sjchandra/* 4209243Sjchandra * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5209243Sjchandra * All rights reserved. 6209243Sjchandra * 7209243Sjchandra * Redistribution and use in source and binary forms, with or without 8209243Sjchandra * modification, are permitted provided that the following conditions 9209243Sjchandra * are met: 10209243Sjchandra * 1. Redistributions of source code must retain the above copyright 11209243Sjchandra * notice, this list of conditions and the following disclaimer. 12209243Sjchandra * 2. Redistributions in binary form must reproduce the above copyright 13209243Sjchandra * notice, this list of conditions and the following disclaimer in the 14209243Sjchandra * documentation and/or other materials provided with the distribution. 15209243Sjchandra * 3. Neither the name of the project nor the names of its contributors 16209243Sjchandra * may be used to endorse or promote products derived from this software 17209243Sjchandra * without specific prior written permission. 18209243Sjchandra * 19209243Sjchandra * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20209243Sjchandra * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21209243Sjchandra * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22209243Sjchandra * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23209243Sjchandra * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24209243Sjchandra * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25209243Sjchandra * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26209243Sjchandra * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27209243Sjchandra * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28209243Sjchandra * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29209243Sjchandra * SUCH DAMAGE. 30209243Sjchandra */ 31209243Sjchandra 32210105Simp/* 33210105Simp * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator. 34210105Simp * 35210105Simp * Issues to be discussed: 36210105Simp * - Thread safe-ness must be checked. 37210105Simp * - Return values. There are nonstandard return values defined and used 38210105Simp * in the source code. This is because RFC2553 is silent about which error 39210105Simp * code must be returned for which situation. 40210105Simp * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 41210105Simp * invalid. current code - SEGV on freeaddrinfo(NULL) 42210105Simp * 43210105Simp * Note: 44210105Simp * - The code filters out AFs that are not supported by the kernel, 45210105Simp * when globbing NULL hostname (to loopback, or wildcard). Is it the right 46210105Simp * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 47210105Simp * in ai_flags? 48210105Simp * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 49210105Simp * (1) what should we do against numeric hostname (2) what should we do 50210105Simp * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 51210105Simp * non-loopback address configured? global address configured? 52209243Sjchandra * 53209243Sjchandra * OS specific notes for netbsd/openbsd/freebsd4/bsdi4: 54209243Sjchandra * - To avoid search order issue, we have a big amount of code duplicate 55209243Sjchandra * from gethnamaddr.c and some other places. The issues that there's no 56241123Salc * lower layer function to lookup "IPv4 or IPv6" record. Calling 57209243Sjchandra * gethostbyname2 from getaddrinfo will end up in wrong search order, as 58209243Sjchandra * presented above. 59209243Sjchandra * 60209243Sjchandra * OS specific notes for freebsd4: 61 * - FreeBSD supported $GAI. The code does not. 62 * - FreeBSD allowed classful IPv4 numeric (127.1), the code does not. 63 */ 64 65#include <sys/cdefs.h> 66__FBSDID("$FreeBSD: head/lib/libc/net/getaddrinfo.c 121347 2003-10-22 15:41:38Z ume $"); 67 68#include "namespace.h" 69#include <sys/types.h> 70#include <sys/param.h> 71#include <sys/socket.h> 72#include <net/if.h> 73#include <netinet/in.h> 74#include <arpa/inet.h> 75#include <arpa/nameser.h> 76#include <rpc/rpc.h> 77#include <rpcsvc/yp_prot.h> 78#include <rpcsvc/ypclnt.h> 79#include <netdb.h> 80#include <pthread.h> 81#include <resolv.h> 82#include <string.h> 83#include <stdlib.h> 84#include <stddef.h> 85#include <ctype.h> 86#include <unistd.h> 87#include <stdio.h> 88#include <errno.h> 89 90#include "res_config.h" 91 92#ifdef DEBUG 93#include <syslog.h> 94#endif 95 96#include <stdarg.h> 97#include <nsswitch.h> 98#include "un-namespace.h" 99#include "libc_private.h" 100 101#if defined(__KAME__) && defined(INET6) 102# define FAITH 103#endif 104 105#define SUCCESS 0 106#define ANY 0 107#define YES 1 108#define NO 0 109 110static const char in_addrany[] = { 0, 0, 0, 0 }; 111static const char in_loopback[] = { 127, 0, 0, 1 }; 112#ifdef INET6 113static const char in6_addrany[] = { 114 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 115}; 116static const char in6_loopback[] = { 117 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 118}; 119#endif 120 121static const struct afd { 122 int a_af; 123 int a_addrlen; 124 int a_socklen; 125 int a_off; 126 const char *a_addrany; 127 const char *a_loopback; 128 int a_scoped; 129} afdl [] = { 130#ifdef INET6 131#define N_INET6 0 132 {PF_INET6, sizeof(struct in6_addr), 133 sizeof(struct sockaddr_in6), 134 offsetof(struct sockaddr_in6, sin6_addr), 135 in6_addrany, in6_loopback, 1}, 136#define N_INET 1 137#else 138#define N_INET 0 139#endif 140 {PF_INET, sizeof(struct in_addr), 141 sizeof(struct sockaddr_in), 142 offsetof(struct sockaddr_in, sin_addr), 143 in_addrany, in_loopback, 0}, 144 {0, 0, 0, 0, NULL, NULL, 0}, 145}; 146 147struct explore { 148 int e_af; 149 int e_socktype; 150 int e_protocol; 151 const char *e_protostr; 152 int e_wild; 153#define WILD_AF(ex) ((ex)->e_wild & 0x01) 154#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 155#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 156}; 157 158static const struct explore explore[] = { 159#if 0 160 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 161#endif 162#ifdef INET6 163 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 164 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 165 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 166#endif 167 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 168 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 169 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 170 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 171 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 172 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 173 { -1, 0, 0, NULL, 0 }, 174}; 175 176#ifdef INET6 177#define PTON_MAX 16 178#else 179#define PTON_MAX 4 180#endif 181 182static const ns_src default_dns_files[] = { 183 { NSSRC_FILES, NS_SUCCESS }, 184 { NSSRC_DNS, NS_SUCCESS }, 185 { 0 } 186}; 187 188#define MAXPACKET (64*1024) 189 190typedef union { 191 HEADER hdr; 192 u_char buf[MAXPACKET]; 193} querybuf; 194 195struct res_target { 196 struct res_target *next; 197 const char *name; /* domain name */ 198 int qclass, qtype; /* class and type of query */ 199 u_char *answer; /* buffer to put answer */ 200 int anslen; /* size of answer buffer */ 201 int n; /* result length */ 202}; 203 204static int str_isnumber(const char *); 205static int explore_fqdn(const struct addrinfo *, const char *, 206 const char *, struct addrinfo **); 207static int explore_null(const struct addrinfo *, 208 const char *, struct addrinfo **); 209static int explore_numeric(const struct addrinfo *, const char *, 210 const char *, struct addrinfo **); 211static int explore_numeric_scope(const struct addrinfo *, const char *, 212 const char *, struct addrinfo **); 213static int get_canonname(const struct addrinfo *, 214 struct addrinfo *, const char *); 215static struct addrinfo *get_ai(const struct addrinfo *, 216 const struct afd *, const char *); 217static int get_portmatch(const struct addrinfo *, const char *); 218static int get_port(struct addrinfo *, const char *, int); 219static const struct afd *find_afd(int); 220static int addrconfig(struct addrinfo *); 221#ifdef INET6 222static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 223#endif 224 225static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 226 const struct addrinfo *); 227static int _dns_getaddrinfo(void *, void *, va_list); 228static void _sethtent(void); 229static void _endhtent(void); 230static struct addrinfo *_gethtent(const char *, const struct addrinfo *); 231static int _files_getaddrinfo(void *, void *, va_list); 232#ifdef YP 233static struct addrinfo *_yphostent(char *, const struct addrinfo *); 234static int _yp_getaddrinfo(void *, void *, va_list); 235#endif 236 237static int res_queryN(const char *, struct res_target *); 238static int res_searchN(const char *, struct res_target *); 239static int res_querydomainN(const char *, const char *, 240 struct res_target *); 241 242static struct ai_errlist { 243 const char *str; 244 int code; 245} ai_errlist[] = { 246 { "Success", 0, }, 247#ifdef EAI_ADDRFAMILY 248 { "Address family for hostname not supported", EAI_ADDRFAMILY, }, 249#endif 250 { "Temporary failure in name resolution", EAI_AGAIN, }, 251 { "Invalid value for ai_flags", EAI_BADFLAGS, }, 252 { "Non-recoverable failure in name resolution", EAI_FAIL, }, 253 { "ai_family not supported", EAI_FAMILY, }, 254 { "Memory allocation failure", EAI_MEMORY, }, 255#ifdef EAI_NODATA 256 { "No address associated with hostname", EAI_NODATA, }, 257#endif 258 { "hostname nor servname provided, or not known", EAI_NONAME, }, 259 { "servname not supported for ai_socktype", EAI_SERVICE, }, 260 { "ai_socktype not supported", EAI_SOCKTYPE, }, 261 { "System error returned in errno", EAI_SYSTEM, }, 262 { "Invalid value for hints", EAI_BADHINTS, }, 263 { "Resolved protocol is unknown", EAI_PROTOCOL, }, 264 /* backward compatibility with userland code prior to 2553bis-02 */ 265 { "Address family for hostname not supported", 1, }, 266 { "No address associated with hostname", 7, }, 267 { NULL, -1, }, 268}; 269 270/* 271 * XXX: Our res_*() is not thread-safe. So, we share lock between 272 * getaddrinfo() and getipnodeby*(). Still, we cannot use 273 * getaddrinfo() and getipnodeby*() in conjunction with other 274 * functions which call res_*(). 275 */ 276pthread_mutex_t __getaddrinfo_thread_lock = PTHREAD_MUTEX_INITIALIZER; 277#define THREAD_LOCK() \ 278 if (__isthreaded) _pthread_mutex_lock(&__getaddrinfo_thread_lock); 279#define THREAD_UNLOCK() \ 280 if (__isthreaded) _pthread_mutex_unlock(&__getaddrinfo_thread_lock); 281 282/* XXX macros that make external reference is BAD. */ 283 284#define GET_AI(ai, afd, addr) \ 285do { \ 286 /* external reference: pai, error, and label free */ \ 287 (ai) = get_ai(pai, (afd), (addr)); \ 288 if ((ai) == NULL) { \ 289 error = EAI_MEMORY; \ 290 goto free; \ 291 } \ 292} while (/*CONSTCOND*/0) 293 294#define GET_PORT(ai, serv) \ 295do { \ 296 /* external reference: error and label free */ \ 297 error = get_port((ai), (serv), 0); \ 298 if (error != 0) \ 299 goto free; \ 300} while (/*CONSTCOND*/0) 301 302#define GET_CANONNAME(ai, str) \ 303do { \ 304 /* external reference: pai, error and label free */ \ 305 error = get_canonname(pai, (ai), (str)); \ 306 if (error != 0) \ 307 goto free; \ 308} while (/*CONSTCOND*/0) 309 310#define ERR(err) \ 311do { \ 312 /* external reference: error, and label bad */ \ 313 error = (err); \ 314 goto bad; \ 315 /*NOTREACHED*/ \ 316} while (/*CONSTCOND*/0) 317 318#define MATCH_FAMILY(x, y, w) \ 319 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 320#define MATCH(x, y, w) \ 321 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 322 323char * 324gai_strerror(ecode) 325 int ecode; 326{ 327 struct ai_errlist *p; 328 329 for (p = ai_errlist; p->str; p++) { 330 if (p->code == ecode) 331 return (char *)p->str; 332 } 333} 334 335void 336freeaddrinfo(ai) 337 struct addrinfo *ai; 338{ 339 struct addrinfo *next; 340 341 do { 342 next = ai->ai_next; 343 if (ai->ai_canonname) 344 free(ai->ai_canonname); 345 /* no need to free(ai->ai_addr) */ 346 free(ai); 347 ai = next; 348 } while (ai); 349} 350 351static int 352str_isnumber(p) 353 const char *p; 354{ 355 char *ep; 356 357 if (*p == '\0') 358 return NO; 359 ep = NULL; 360 errno = 0; 361 (void)strtoul(p, &ep, 10); 362 if (errno == 0 && ep && *ep == '\0') 363 return YES; 364 else 365 return NO; 366} 367 368int 369getaddrinfo(hostname, servname, hints, res) 370 const char *hostname, *servname; 371 const struct addrinfo *hints; 372 struct addrinfo **res; 373{ 374 struct addrinfo sentinel; 375 struct addrinfo *cur; 376 int error = 0; 377 struct addrinfo ai; 378 struct addrinfo ai0; 379 struct addrinfo *pai; 380 const struct explore *ex; 381 382 memset(&sentinel, 0, sizeof(sentinel)); 383 cur = &sentinel; 384 pai = &ai; 385 pai->ai_flags = 0; 386 pai->ai_family = PF_UNSPEC; 387 pai->ai_socktype = ANY; 388 pai->ai_protocol = ANY; 389 pai->ai_addrlen = 0; 390 pai->ai_canonname = NULL; 391 pai->ai_addr = NULL; 392 pai->ai_next = NULL; 393 394 if (hostname == NULL && servname == NULL) 395 return EAI_NONAME; 396 if (hints) { 397 /* error check for hints */ 398 if (hints->ai_addrlen || hints->ai_canonname || 399 hints->ai_addr || hints->ai_next) 400 ERR(EAI_BADHINTS); /* xxx */ 401 if (hints->ai_flags & ~AI_MASK) 402 ERR(EAI_BADFLAGS); 403 switch (hints->ai_family) { 404 case PF_UNSPEC: 405 case PF_INET: 406#ifdef INET6 407 case PF_INET6: 408#endif 409 break; 410 default: 411 ERR(EAI_FAMILY); 412 } 413 memcpy(pai, hints, sizeof(*pai)); 414 415 /* 416 * if both socktype/protocol are specified, check if they 417 * are meaningful combination. 418 */ 419 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 420 for (ex = explore; ex->e_af >= 0; ex++) { 421 if (pai->ai_family != ex->e_af) 422 continue; 423 if (ex->e_socktype == ANY) 424 continue; 425 if (ex->e_protocol == ANY) 426 continue; 427 if (pai->ai_socktype == ex->e_socktype && 428 pai->ai_protocol != ex->e_protocol) { 429 ERR(EAI_BADHINTS); 430 } 431 } 432 } 433 } 434 435 /* 436 * post-2553: AI_ALL and AI_V4MAPPED are effective only against 437 * AF_INET6 query. They need to be ignored if specified in other 438 * occassions. 439 */ 440 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 441 case AI_V4MAPPED: 442 case AI_ALL | AI_V4MAPPED: 443 if (pai->ai_family != AF_INET6) 444 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 445 break; 446 case AI_ALL: 447#if 1 448 /* illegal */ 449 ERR(EAI_BADFLAGS); 450#else 451 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 452#endif 453 break; 454 } 455 456 /* 457 * check for special cases. (1) numeric servname is disallowed if 458 * socktype/protocol are left unspecified. (2) servname is disallowed 459 * for raw and other inet{,6} sockets. 460 */ 461 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 462#ifdef PF_INET6 463 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 464#endif 465 ) { 466 ai0 = *pai; /* backup *pai */ 467 468 if (pai->ai_family == PF_UNSPEC) { 469#ifdef PF_INET6 470 pai->ai_family = PF_INET6; 471#else 472 pai->ai_family = PF_INET; 473#endif 474 } 475 error = get_portmatch(pai, servname); 476 if (error) 477 ERR(error); 478 479 *pai = ai0; 480 } 481 482 ai0 = *pai; 483 484 /* NULL hostname, or numeric hostname */ 485 for (ex = explore; ex->e_af >= 0; ex++) { 486 *pai = ai0; 487 488 /* PF_UNSPEC entries are prepared for DNS queries only */ 489 if (ex->e_af == PF_UNSPEC) 490 continue; 491 492 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 493 continue; 494 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 495 continue; 496 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 497 continue; 498 499 if (pai->ai_family == PF_UNSPEC) 500 pai->ai_family = ex->e_af; 501 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 502 pai->ai_socktype = ex->e_socktype; 503 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 504 pai->ai_protocol = ex->e_protocol; 505 506 if (hostname == NULL) 507 error = explore_null(pai, servname, &cur->ai_next); 508 else 509 error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next); 510 511 if (error) 512 goto free; 513 514 while (cur && cur->ai_next) 515 cur = cur->ai_next; 516 } 517 518 /* 519 * XXX 520 * If numreic representation of AF1 can be interpreted as FQDN 521 * representation of AF2, we need to think again about the code below. 522 */ 523 if (sentinel.ai_next) 524 goto good; 525 526 if (pai->ai_flags & AI_NUMERICHOST) 527 ERR(EAI_NONAME); 528 if (hostname == NULL) 529 ERR(EAI_NODATA); 530 531 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 532 ERR(EAI_FAIL); 533 534 /* 535 * hostname as alphabetical name. 536 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 537 * outer loop by AFs. 538 */ 539 for (ex = explore; ex->e_af >= 0; ex++) { 540 *pai = ai0; 541 542 /* require exact match for family field */ 543 if (pai->ai_family != ex->e_af) 544 continue; 545 546 if (!MATCH(pai->ai_socktype, ex->e_socktype, 547 WILD_SOCKTYPE(ex))) { 548 continue; 549 } 550 if (!MATCH(pai->ai_protocol, ex->e_protocol, 551 WILD_PROTOCOL(ex))) { 552 continue; 553 } 554 555 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 556 pai->ai_socktype = ex->e_socktype; 557 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 558 pai->ai_protocol = ex->e_protocol; 559 560 error = explore_fqdn(pai, hostname, servname, 561 &cur->ai_next); 562 563 while (cur && cur->ai_next) 564 cur = cur->ai_next; 565 } 566 567 /* XXX */ 568 if (sentinel.ai_next) 569 error = 0; 570 571 if (error) 572 goto free; 573 if (error == 0) { 574 if (sentinel.ai_next) { 575 good: 576 *res = sentinel.ai_next; 577 return SUCCESS; 578 } else 579 error = EAI_FAIL; 580 } 581 free: 582 bad: 583 if (sentinel.ai_next) 584 freeaddrinfo(sentinel.ai_next); 585 *res = NULL; 586 return error; 587} 588 589/* 590 * FQDN hostname, DNS lookup 591 */ 592static int 593explore_fqdn(pai, hostname, servname, res) 594 const struct addrinfo *pai; 595 const char *hostname; 596 const char *servname; 597 struct addrinfo **res; 598{ 599 struct addrinfo *result; 600 struct addrinfo *cur; 601 int error = 0; 602 static const ns_dtab dtab[] = { 603 NS_FILES_CB(_files_getaddrinfo, NULL) 604 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 605 NS_NIS_CB(_yp_getaddrinfo, NULL) 606 { 0 } 607 }; 608 609 result = NULL; 610 611 THREAD_LOCK(); 612 613 /* 614 * if the servname does not match socktype/protocol, ignore it. 615 */ 616 if (get_portmatch(pai, servname) != 0) { 617 THREAD_UNLOCK(); 618 return 0; 619 } 620 621 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 622 default_dns_files, hostname, pai)) { 623 case NS_TRYAGAIN: 624 error = EAI_AGAIN; 625 goto free; 626 case NS_UNAVAIL: 627 error = EAI_FAIL; 628 goto free; 629 case NS_NOTFOUND: 630 error = EAI_NODATA; 631 goto free; 632 case NS_SUCCESS: 633 error = 0; 634 for (cur = result; cur; cur = cur->ai_next) { 635 GET_PORT(cur, servname); 636 /* canonname should be filled already */ 637 } 638 break; 639 } 640 THREAD_UNLOCK(); 641 642 *res = result; 643 644 return 0; 645 646free: 647 THREAD_UNLOCK(); 648 if (result) 649 freeaddrinfo(result); 650 return error; 651} 652 653/* 654 * hostname == NULL. 655 * passive socket -> anyaddr (0.0.0.0 or ::) 656 * non-passive socket -> localhost (127.0.0.1 or ::1) 657 */ 658static int 659explore_null(pai, servname, res) 660 const struct addrinfo *pai; 661 const char *servname; 662 struct addrinfo **res; 663{ 664 int s; 665 const struct afd *afd; 666 struct addrinfo *cur; 667 struct addrinfo sentinel; 668 int error; 669 670 *res = NULL; 671 sentinel.ai_next = NULL; 672 cur = &sentinel; 673 674 /* 675 * filter out AFs that are not supported by the kernel 676 * XXX errno? 677 */ 678 s = _socket(pai->ai_family, SOCK_DGRAM, 0); 679 if (s < 0) { 680 if (errno != EMFILE) 681 return 0; 682 } else 683 _close(s); 684 685 /* 686 * if the servname does not match socktype/protocol, ignore it. 687 */ 688 if (get_portmatch(pai, servname) != 0) 689 return 0; 690 691 afd = find_afd(pai->ai_family); 692 if (afd == NULL) 693 return 0; 694 695 if (pai->ai_flags & AI_PASSIVE) { 696 GET_AI(cur->ai_next, afd, afd->a_addrany); 697 /* xxx meaningless? 698 * GET_CANONNAME(cur->ai_next, "anyaddr"); 699 */ 700 GET_PORT(cur->ai_next, servname); 701 } else { 702 GET_AI(cur->ai_next, afd, afd->a_loopback); 703 /* xxx meaningless? 704 * GET_CANONNAME(cur->ai_next, "localhost"); 705 */ 706 GET_PORT(cur->ai_next, servname); 707 } 708 cur = cur->ai_next; 709 710 *res = sentinel.ai_next; 711 return 0; 712 713free: 714 if (sentinel.ai_next) 715 freeaddrinfo(sentinel.ai_next); 716 return error; 717} 718 719/* 720 * numeric hostname 721 */ 722static int 723explore_numeric(pai, hostname, servname, res) 724 const struct addrinfo *pai; 725 const char *hostname; 726 const char *servname; 727 struct addrinfo **res; 728{ 729 const struct afd *afd; 730 struct addrinfo *cur; 731 struct addrinfo sentinel; 732 int error; 733 char pton[PTON_MAX]; 734 735 *res = NULL; 736 sentinel.ai_next = NULL; 737 cur = &sentinel; 738 739 /* 740 * if the servname does not match socktype/protocol, ignore it. 741 */ 742 if (get_portmatch(pai, servname) != 0) 743 return 0; 744 745 afd = find_afd(pai->ai_family); 746 if (afd == NULL) 747 return 0; 748 749 switch (afd->a_af) { 750#if 1 /*X/Open spec*/ 751 case AF_INET: 752 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 753 if (pai->ai_family == afd->a_af || 754 pai->ai_family == PF_UNSPEC /*?*/) { 755 GET_AI(cur->ai_next, afd, pton); 756 GET_PORT(cur->ai_next, servname); 757 while (cur && cur->ai_next) 758 cur = cur->ai_next; 759 } else 760 ERR(EAI_FAMILY); /*xxx*/ 761 } 762 break; 763#endif 764 default: 765 if (inet_pton(afd->a_af, hostname, pton) == 1) { 766 if (pai->ai_family == afd->a_af || 767 pai->ai_family == PF_UNSPEC /*?*/) { 768 GET_AI(cur->ai_next, afd, pton); 769 GET_PORT(cur->ai_next, servname); 770 while (cur && cur->ai_next) 771 cur = cur->ai_next; 772 } else 773 ERR(EAI_FAMILY); /* XXX */ 774 } 775 break; 776 } 777 778 *res = sentinel.ai_next; 779 return 0; 780 781free: 782bad: 783 if (sentinel.ai_next) 784 freeaddrinfo(sentinel.ai_next); 785 return error; 786} 787 788/* 789 * numeric hostname with scope 790 */ 791static int 792explore_numeric_scope(pai, hostname, servname, res) 793 const struct addrinfo *pai; 794 const char *hostname; 795 const char *servname; 796 struct addrinfo **res; 797{ 798#if !defined(SCOPE_DELIMITER) || !defined(INET6) 799 return explore_numeric(pai, hostname, servname, res); 800#else 801 const struct afd *afd; 802 struct addrinfo *cur; 803 int error; 804 char *cp, *hostname2 = NULL, *scope, *addr; 805 struct sockaddr_in6 *sin6; 806 807 /* 808 * if the servname does not match socktype/protocol, ignore it. 809 */ 810 if (get_portmatch(pai, servname) != 0) 811 return 0; 812 813 afd = find_afd(pai->ai_family); 814 if (afd == NULL) 815 return 0; 816 817 if (!afd->a_scoped) 818 return explore_numeric(pai, hostname, servname, res); 819 820 cp = strchr(hostname, SCOPE_DELIMITER); 821 if (cp == NULL) 822 return explore_numeric(pai, hostname, servname, res); 823 824 /* 825 * Handle special case of <scoped_address><delimiter><scope id> 826 */ 827 hostname2 = strdup(hostname); 828 if (hostname2 == NULL) 829 return EAI_MEMORY; 830 /* terminate at the delimiter */ 831 hostname2[cp - hostname] = '\0'; 832 addr = hostname2; 833 scope = cp + 1; 834 835 error = explore_numeric(pai, addr, servname, res); 836 if (error == 0) { 837 u_int32_t scopeid; 838 839 for (cur = *res; cur; cur = cur->ai_next) { 840 if (cur->ai_family != AF_INET6) 841 continue; 842 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 843 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 844 free(hostname2); 845 return(EAI_NODATA); /* XXX: is return OK? */ 846 } 847 sin6->sin6_scope_id = scopeid; 848 } 849 } 850 851 free(hostname2); 852 853 return error; 854#endif 855} 856 857static int 858get_canonname(pai, ai, str) 859 const struct addrinfo *pai; 860 struct addrinfo *ai; 861 const char *str; 862{ 863 if ((pai->ai_flags & AI_CANONNAME) != 0) { 864 ai->ai_canonname = (char *)malloc(strlen(str) + 1); 865 if (ai->ai_canonname == NULL) 866 return EAI_MEMORY; 867 strlcpy(ai->ai_canonname, str, strlen(str) + 1); 868 } 869 return 0; 870} 871 872static struct addrinfo * 873get_ai(pai, afd, addr) 874 const struct addrinfo *pai; 875 const struct afd *afd; 876 const char *addr; 877{ 878 char *p; 879 struct addrinfo *ai; 880#ifdef FAITH 881 struct in6_addr faith_prefix; 882 char *fp_str; 883 int translate = 0; 884#endif 885 886#ifdef FAITH 887 /* 888 * Transfrom an IPv4 addr into a special IPv6 addr format for 889 * IPv6->IPv4 translation gateway. (only TCP is supported now) 890 * 891 * +-----------------------------------+------------+ 892 * | faith prefix part (12 bytes) | embedded | 893 * | | IPv4 addr part (4 bytes) 894 * +-----------------------------------+------------+ 895 * 896 * faith prefix part is specified as ascii IPv6 addr format 897 * in environmental variable GAI. 898 * For FAITH to work correctly, routing to faith prefix must be 899 * setup toward a machine where a FAITH daemon operates. 900 * Also, the machine must enable some mechanizm 901 * (e.g. faith interface hack) to divert those packet with 902 * faith prefixed destination addr to user-land FAITH daemon. 903 */ 904 fp_str = getenv("GAI"); 905 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 906 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 907 u_int32_t v4a; 908 u_int8_t v4a_top; 909 910 memcpy(&v4a, addr, sizeof v4a); 911 v4a_top = v4a >> IN_CLASSA_NSHIFT; 912 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 913 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 914 afd = &afdl[N_INET6]; 915 memcpy(&faith_prefix.s6_addr[12], addr, 916 sizeof(struct in_addr)); 917 translate = 1; 918 } 919 } 920#endif 921 922 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 923 + (afd->a_socklen)); 924 if (ai == NULL) 925 return NULL; 926 927 memcpy(ai, pai, sizeof(struct addrinfo)); 928 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 929 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 930 ai->ai_addr->sa_len = afd->a_socklen; 931 ai->ai_addrlen = afd->a_socklen; 932 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 933 p = (char *)(void *)(ai->ai_addr); 934#ifdef FAITH 935 if (translate == 1) 936 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 937 else 938#endif 939 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 940 return ai; 941} 942 943static int 944get_portmatch(ai, servname) 945 const struct addrinfo *ai; 946 const char *servname; 947{ 948 949 /* get_port does not touch first argument. when matchonly == 1. */ 950 /* LINTED const cast */ 951 return get_port((struct addrinfo *)ai, servname, 1); 952} 953 954static int 955get_port(ai, servname, matchonly) 956 struct addrinfo *ai; 957 const char *servname; 958 int matchonly; 959{ 960 const char *proto; 961 struct servent *sp; 962 int port; 963 int allownumeric; 964 965 if (servname == NULL) 966 return 0; 967 switch (ai->ai_family) { 968 case AF_INET: 969#ifdef AF_INET6 970 case AF_INET6: 971#endif 972 break; 973 default: 974 return 0; 975 } 976 977 switch (ai->ai_socktype) { 978 case SOCK_RAW: 979 return EAI_SERVICE; 980 case SOCK_DGRAM: 981 case SOCK_STREAM: 982 allownumeric = 1; 983 break; 984 case ANY: 985 allownumeric = 0; 986 break; 987 default: 988 return EAI_SOCKTYPE; 989 } 990 991 if (str_isnumber(servname)) { 992 if (!allownumeric) 993 return EAI_SERVICE; 994 port = atoi(servname); 995 if (port < 0 || port > 65535) 996 return EAI_SERVICE; 997 port = htons(port); 998 } else { 999 switch (ai->ai_socktype) { 1000 case SOCK_DGRAM: 1001 proto = "udp"; 1002 break; 1003 case SOCK_STREAM: 1004 proto = "tcp"; 1005 break; 1006 default: 1007 proto = NULL; 1008 break; 1009 } 1010 1011 if ((sp = getservbyname(servname, proto)) == NULL) 1012 return EAI_SERVICE; 1013 port = sp->s_port; 1014 } 1015 1016 if (!matchonly) { 1017 switch (ai->ai_family) { 1018 case AF_INET: 1019 ((struct sockaddr_in *)(void *) 1020 ai->ai_addr)->sin_port = port; 1021 break; 1022#ifdef INET6 1023 case AF_INET6: 1024 ((struct sockaddr_in6 *)(void *) 1025 ai->ai_addr)->sin6_port = port; 1026 break; 1027#endif 1028 } 1029 } 1030 1031 return 0; 1032} 1033 1034static const struct afd * 1035find_afd(af) 1036 int af; 1037{ 1038 const struct afd *afd; 1039 1040 if (af == PF_UNSPEC) 1041 return NULL; 1042 for (afd = afdl; afd->a_af; afd++) { 1043 if (afd->a_af == af) 1044 return afd; 1045 } 1046 return NULL; 1047} 1048 1049/* 1050 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1051 * will take care of it. 1052 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1053 * if the code is right or not. 1054 * 1055 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1056 * _dns_getaddrinfo. 1057 */ 1058static int 1059addrconfig(pai) 1060 struct addrinfo *pai; 1061{ 1062 int s, af; 1063 1064 /* 1065 * TODO: 1066 * Note that implementation dependent test for address 1067 * configuration should be done everytime called 1068 * (or apropriate interval), 1069 * because addresses will be dynamically assigned or deleted. 1070 */ 1071 af = pai->ai_family; 1072 if (af == AF_UNSPEC) { 1073 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 1074 af = AF_INET; 1075 else { 1076 _close(s); 1077 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) 1078 af = AF_INET6; 1079 else 1080 _close(s); 1081 } 1082 } 1083 if (af != AF_UNSPEC) { 1084 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 1085 return 0; 1086 _close(s); 1087 } 1088 pai->ai_family = af; 1089 return 1; 1090} 1091 1092#ifdef INET6 1093/* convert a string to a scope identifier. XXX: IPv6 specific */ 1094static int 1095ip6_str2scopeid(scope, sin6, scopeid) 1096 char *scope; 1097 struct sockaddr_in6 *sin6; 1098 u_int32_t *scopeid; 1099{ 1100 u_long lscopeid; 1101 struct in6_addr *a6; 1102 char *ep; 1103 1104 a6 = &sin6->sin6_addr; 1105 1106 /* empty scopeid portion is invalid */ 1107 if (*scope == '\0') 1108 return -1; 1109 1110 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1111 /* 1112 * We currently assume a one-to-one mapping between links 1113 * and interfaces, so we simply use interface indices for 1114 * like-local scopes. 1115 */ 1116 *scopeid = if_nametoindex(scope); 1117 if (*scopeid == 0) 1118 goto trynumeric; 1119 return 0; 1120 } 1121 1122 /* still unclear about literal, allow numeric only - placeholder */ 1123 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1124 goto trynumeric; 1125 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1126 goto trynumeric; 1127 else 1128 goto trynumeric; /* global */ 1129 1130 /* try to convert to a numeric id as a last resort */ 1131 trynumeric: 1132 errno = 0; 1133 lscopeid = strtoul(scope, &ep, 10); 1134 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1135 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1136 return 0; 1137 else 1138 return -1; 1139} 1140#endif 1141 1142#ifdef RESOLVSORT 1143struct addr_ptr { 1144 struct addrinfo *ai; 1145 int aval; 1146}; 1147 1148static int 1149addr4sort(struct addrinfo *sentinel) 1150{ 1151 struct addrinfo *ai; 1152 struct addr_ptr *addrs, addr; 1153 struct sockaddr_in *sin; 1154 int naddrs, i, j; 1155 int needsort = 0; 1156 1157 if (!sentinel) 1158 return -1; 1159 naddrs = 0; 1160 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 1161 naddrs++; 1162 if (naddrs < 2) 1163 return 0; /* We don't need sorting. */ 1164 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 1165 return -1; 1166 i = 0; 1167 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 1168 sin = (struct sockaddr_in *)ai->ai_addr; 1169 for (j = 0; (unsigned)j < _res.nsort; j++) { 1170 if (_res.sort_list[j].addr.s_addr == 1171 (sin->sin_addr.s_addr & _res.sort_list[j].mask)) 1172 break; 1173 } 1174 addrs[i].ai = ai; 1175 addrs[i].aval = j; 1176 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 1177 needsort = i; 1178 i++; 1179 } 1180 if (!needsort) { 1181 free(addrs); 1182 return 0; 1183 } 1184 1185 while (needsort < naddrs) { 1186 for (j = needsort - 1; j >= 0; j--) { 1187 if (addrs[j].aval > addrs[j+1].aval) { 1188 addr = addrs[j]; 1189 addrs[j] = addrs[j + 1]; 1190 addrs[j + 1] = addr; 1191 } else 1192 break; 1193 } 1194 needsort++; 1195 } 1196 1197 ai = sentinel; 1198 for (i = 0; i < naddrs; ++i) { 1199 ai->ai_next = addrs[i].ai; 1200 ai = ai->ai_next; 1201 } 1202 ai->ai_next = NULL; 1203 free(addrs); 1204 return 0; 1205} 1206#endif /*RESOLVSORT*/ 1207 1208#ifdef DEBUG 1209static const char AskedForGot[] = 1210 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1211#endif 1212static FILE *hostf = NULL; 1213 1214static struct addrinfo * 1215getanswer(answer, anslen, qname, qtype, pai) 1216 const querybuf *answer; 1217 int anslen; 1218 const char *qname; 1219 int qtype; 1220 const struct addrinfo *pai; 1221{ 1222 struct addrinfo sentinel, *cur; 1223 struct addrinfo ai; 1224 const struct afd *afd; 1225 char *canonname; 1226 const HEADER *hp; 1227 const u_char *cp; 1228 int n; 1229 const u_char *eom; 1230 char *bp, *ep; 1231 int type, class, ancount, qdcount; 1232 int haveanswer, had_error; 1233 char tbuf[MAXDNAME]; 1234 int (*name_ok)(const char *); 1235 char hostbuf[8*1024]; 1236 1237 memset(&sentinel, 0, sizeof(sentinel)); 1238 cur = &sentinel; 1239 1240 canonname = NULL; 1241 eom = answer->buf + anslen; 1242 switch (qtype) { 1243 case T_A: 1244 case T_AAAA: 1245 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1246 name_ok = res_hnok; 1247 break; 1248 default: 1249 return (NULL); /* XXX should be abort(); */ 1250 } 1251 /* 1252 * find first satisfactory answer 1253 */ 1254 hp = &answer->hdr; 1255 ancount = ntohs(hp->ancount); 1256 qdcount = ntohs(hp->qdcount); 1257 bp = hostbuf; 1258 ep = hostbuf + sizeof hostbuf; 1259 cp = answer->buf + HFIXEDSZ; 1260 if (qdcount != 1) { 1261 h_errno = NO_RECOVERY; 1262 return (NULL); 1263 } 1264 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1265 if ((n < 0) || !(*name_ok)(bp)) { 1266 h_errno = NO_RECOVERY; 1267 return (NULL); 1268 } 1269 cp += n + QFIXEDSZ; 1270 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1271 /* res_send() has already verified that the query name is the 1272 * same as the one we sent; this just gets the expanded name 1273 * (i.e., with the succeeding search-domain tacked on). 1274 */ 1275 n = strlen(bp) + 1; /* for the \0 */ 1276 if (n >= MAXHOSTNAMELEN) { 1277 h_errno = NO_RECOVERY; 1278 return (NULL); 1279 } 1280 canonname = bp; 1281 bp += n; 1282 /* The qname can be abbreviated, but h_name is now absolute. */ 1283 qname = canonname; 1284 } 1285 haveanswer = 0; 1286 had_error = 0; 1287 while (ancount-- > 0 && cp < eom && !had_error) { 1288 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1289 if ((n < 0) || !(*name_ok)(bp)) { 1290 had_error++; 1291 continue; 1292 } 1293 cp += n; /* name */ 1294 type = _getshort(cp); 1295 cp += INT16SZ; /* type */ 1296 class = _getshort(cp); 1297 cp += INT16SZ + INT32SZ; /* class, TTL */ 1298 n = _getshort(cp); 1299 cp += INT16SZ; /* len */ 1300 if (class != C_IN) { 1301 /* XXX - debug? syslog? */ 1302 cp += n; 1303 continue; /* XXX - had_error++ ? */ 1304 } 1305 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1306 type == T_CNAME) { 1307 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1308 if ((n < 0) || !(*name_ok)(tbuf)) { 1309 had_error++; 1310 continue; 1311 } 1312 cp += n; 1313 /* Get canonical name. */ 1314 n = strlen(tbuf) + 1; /* for the \0 */ 1315 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1316 had_error++; 1317 continue; 1318 } 1319 strlcpy(bp, tbuf, ep - bp); 1320 canonname = bp; 1321 bp += n; 1322 continue; 1323 } 1324 if (qtype == T_ANY) { 1325 if (!(type == T_A || type == T_AAAA)) { 1326 cp += n; 1327 continue; 1328 } 1329 } else if (type != qtype) { 1330#ifdef DEBUG 1331 if (type != T_KEY && type != T_SIG) 1332 syslog(LOG_NOTICE|LOG_AUTH, 1333 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1334 qname, p_class(C_IN), p_type(qtype), 1335 p_type(type)); 1336#endif 1337 cp += n; 1338 continue; /* XXX - had_error++ ? */ 1339 } 1340 switch (type) { 1341 case T_A: 1342 case T_AAAA: 1343 if (strcasecmp(canonname, bp) != 0) { 1344#ifdef DEBUG 1345 syslog(LOG_NOTICE|LOG_AUTH, 1346 AskedForGot, canonname, bp); 1347#endif 1348 cp += n; 1349 continue; /* XXX - had_error++ ? */ 1350 } 1351 if (type == T_A && n != INADDRSZ) { 1352 cp += n; 1353 continue; 1354 } 1355 if (type == T_AAAA && n != IN6ADDRSZ) { 1356 cp += n; 1357 continue; 1358 } 1359#ifdef FILTER_V4MAPPED 1360 if (type == T_AAAA) { 1361 struct in6_addr in6; 1362 memcpy(&in6, cp, sizeof(in6)); 1363 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1364 cp += n; 1365 continue; 1366 } 1367 } 1368#endif 1369 if (!haveanswer) { 1370 int nn; 1371 1372 canonname = bp; 1373 nn = strlen(bp) + 1; /* for the \0 */ 1374 bp += nn; 1375 } 1376 1377 /* don't overwrite pai */ 1378 ai = *pai; 1379 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1380 afd = find_afd(ai.ai_family); 1381 if (afd == NULL) { 1382 cp += n; 1383 continue; 1384 } 1385 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1386 if (cur->ai_next == NULL) 1387 had_error++; 1388 while (cur && cur->ai_next) 1389 cur = cur->ai_next; 1390 cp += n; 1391 break; 1392 default: 1393 abort(); 1394 } 1395 if (!had_error) 1396 haveanswer++; 1397 } 1398 if (haveanswer) { 1399#if defined(RESOLVSORT) 1400 /* 1401 * We support only IPv4 address for backward 1402 * compatibility against gethostbyname(3). 1403 */ 1404 if (_res.nsort && qtype == T_A) { 1405 if (addr4sort(&sentinel) < 0) { 1406 freeaddrinfo(sentinel.ai_next); 1407 h_errno = NO_RECOVERY; 1408 return NULL; 1409 } 1410 } 1411#endif /*RESOLVSORT*/ 1412 if (!canonname) 1413 (void)get_canonname(pai, sentinel.ai_next, qname); 1414 else 1415 (void)get_canonname(pai, sentinel.ai_next, canonname); 1416 h_errno = NETDB_SUCCESS; 1417 return sentinel.ai_next; 1418 } 1419 1420 h_errno = NO_RECOVERY; 1421 return NULL; 1422} 1423 1424/*ARGSUSED*/ 1425static int 1426_dns_getaddrinfo(rv, cb_data, ap) 1427 void *rv; 1428 void *cb_data; 1429 va_list ap; 1430{ 1431 struct addrinfo *ai; 1432 querybuf *buf, *buf2; 1433 const char *name; 1434 const struct addrinfo *pai; 1435 struct addrinfo sentinel, *cur; 1436 struct res_target q, q2; 1437 1438 name = va_arg(ap, char *); 1439 pai = va_arg(ap, const struct addrinfo *); 1440 1441 memset(&q, 0, sizeof(q2)); 1442 memset(&q2, 0, sizeof(q2)); 1443 memset(&sentinel, 0, sizeof(sentinel)); 1444 cur = &sentinel; 1445 1446 buf = malloc(sizeof(*buf)); 1447 if (!buf) { 1448 h_errno = NETDB_INTERNAL; 1449 return NS_NOTFOUND; 1450 } 1451 buf2 = malloc(sizeof(*buf2)); 1452 if (!buf2) { 1453 free(buf); 1454 h_errno = NETDB_INTERNAL; 1455 return NS_NOTFOUND; 1456 } 1457 1458 switch (pai->ai_family) { 1459 case AF_UNSPEC: 1460 /* prefer IPv6 */ 1461 q.name = name; 1462 q.qclass = C_IN; 1463 q.qtype = T_AAAA; 1464 q.answer = buf->buf; 1465 q.anslen = sizeof(buf->buf); 1466 q.next = &q2; 1467 q2.name = name; 1468 q2.qclass = C_IN; 1469 q2.qtype = T_A; 1470 q2.answer = buf2->buf; 1471 q2.anslen = sizeof(buf2->buf); 1472 break; 1473 case AF_INET: 1474 q.name = name; 1475 q.qclass = C_IN; 1476 q.qtype = T_A; 1477 q.answer = buf->buf; 1478 q.anslen = sizeof(buf->buf); 1479 break; 1480 case AF_INET6: 1481 q.name = name; 1482 q.qclass = C_IN; 1483 q.qtype = T_AAAA; 1484 q.answer = buf->buf; 1485 q.anslen = sizeof(buf->buf); 1486 break; 1487 default: 1488 free(buf); 1489 free(buf2); 1490 return NS_UNAVAIL; 1491 } 1492 if (res_searchN(name, &q) < 0) { 1493 free(buf); 1494 free(buf2); 1495 return NS_NOTFOUND; 1496 } 1497 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1498 if (ai) { 1499 cur->ai_next = ai; 1500 while (cur && cur->ai_next) 1501 cur = cur->ai_next; 1502 } 1503 if (q.next) { 1504 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1505 if (ai) 1506 cur->ai_next = ai; 1507 } 1508 free(buf); 1509 free(buf2); 1510 if (sentinel.ai_next == NULL) 1511 switch (h_errno) { 1512 case HOST_NOT_FOUND: 1513 return NS_NOTFOUND; 1514 case TRY_AGAIN: 1515 return NS_TRYAGAIN; 1516 default: 1517 return NS_UNAVAIL; 1518 } 1519 *((struct addrinfo **)rv) = sentinel.ai_next; 1520 return NS_SUCCESS; 1521} 1522 1523static void 1524_sethtent() 1525{ 1526 if (!hostf) 1527 hostf = fopen(_PATH_HOSTS, "r" ); 1528 else 1529 rewind(hostf); 1530} 1531 1532static void 1533_endhtent() 1534{ 1535 if (hostf) { 1536 (void) fclose(hostf); 1537 hostf = NULL; 1538 } 1539} 1540 1541static struct addrinfo * 1542_gethtent(name, pai) 1543 const char *name; 1544 const struct addrinfo *pai; 1545{ 1546 char *p; 1547 char *cp, *tname, *cname; 1548 struct addrinfo hints, *res0, *res; 1549 int error; 1550 const char *addr; 1551 char hostbuf[8*1024]; 1552 1553 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) 1554 return (NULL); 1555again: 1556 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) 1557 return (NULL); 1558 if (*p == '#') 1559 goto again; 1560 if (!(cp = strpbrk(p, "#\n"))) 1561 goto again; 1562 *cp = '\0'; 1563 if (!(cp = strpbrk(p, " \t"))) 1564 goto again; 1565 *cp++ = '\0'; 1566 addr = p; 1567 cname = NULL; 1568 /* if this is not something we're looking for, skip it. */ 1569 while (cp && *cp) { 1570 if (*cp == ' ' || *cp == '\t') { 1571 cp++; 1572 continue; 1573 } 1574 tname = cp; 1575 if (cname == NULL) 1576 cname = cp; 1577 if ((cp = strpbrk(cp, " \t")) != NULL) 1578 *cp++ = '\0'; 1579 if (strcasecmp(name, tname) == 0) 1580 goto found; 1581 } 1582 goto again; 1583 1584found: 1585 /* we should not glob socktype/protocol here */ 1586 memset(&hints, 0, sizeof(hints)); 1587 hints.ai_family = pai->ai_family; 1588 hints.ai_socktype = SOCK_DGRAM; 1589 hints.ai_protocol = 0; 1590 hints.ai_flags = AI_NUMERICHOST; 1591 error = getaddrinfo(addr, "0", &hints, &res0); 1592 if (error) 1593 goto again; 1594#ifdef FILTER_V4MAPPED 1595 /* XXX should check all items in the chain */ 1596 if (res0->ai_family == AF_INET6 && 1597 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 1598 freeaddrinfo(res0); 1599 goto again; 1600 } 1601#endif 1602 for (res = res0; res; res = res->ai_next) { 1603 /* cover it up */ 1604 res->ai_flags = pai->ai_flags; 1605 res->ai_socktype = pai->ai_socktype; 1606 res->ai_protocol = pai->ai_protocol; 1607 1608 if (pai->ai_flags & AI_CANONNAME) { 1609 if (get_canonname(pai, res, cname) != 0) { 1610 freeaddrinfo(res0); 1611 goto again; 1612 } 1613 } 1614 } 1615 return res0; 1616} 1617 1618/*ARGSUSED*/ 1619static int 1620_files_getaddrinfo(rv, cb_data, ap) 1621 void *rv; 1622 void *cb_data; 1623 va_list ap; 1624{ 1625 const char *name; 1626 const struct addrinfo *pai; 1627 struct addrinfo sentinel, *cur; 1628 struct addrinfo *p; 1629 1630 name = va_arg(ap, char *); 1631 pai = va_arg(ap, struct addrinfo *); 1632 1633 memset(&sentinel, 0, sizeof(sentinel)); 1634 cur = &sentinel; 1635 1636 _sethtent(); 1637 while ((p = _gethtent(name, pai)) != NULL) { 1638 cur->ai_next = p; 1639 while (cur && cur->ai_next) 1640 cur = cur->ai_next; 1641 } 1642 _endhtent(); 1643 1644 *((struct addrinfo **)rv) = sentinel.ai_next; 1645 if (sentinel.ai_next == NULL) 1646 return NS_NOTFOUND; 1647 return NS_SUCCESS; 1648} 1649 1650#ifdef YP 1651static char *__ypdomain; 1652 1653/*ARGSUSED*/ 1654static struct addrinfo * 1655_yphostent(line, pai) 1656 char *line; 1657 const struct addrinfo *pai; 1658{ 1659 struct addrinfo sentinel, *cur; 1660 struct addrinfo hints, *res, *res0; 1661 int error; 1662 char *p = line; 1663 const char *addr, *canonname; 1664 char *nextline; 1665 char *cp; 1666 1667 addr = canonname = NULL; 1668 1669 memset(&sentinel, 0, sizeof(sentinel)); 1670 cur = &sentinel; 1671 1672nextline: 1673 /* terminate line */ 1674 cp = strchr(p, '\n'); 1675 if (cp) { 1676 *cp++ = '\0'; 1677 nextline = cp; 1678 } else 1679 nextline = NULL; 1680 1681 cp = strpbrk(p, " \t"); 1682 if (cp == NULL) { 1683 if (canonname == NULL) 1684 return (NULL); 1685 else 1686 goto done; 1687 } 1688 *cp++ = '\0'; 1689 1690 addr = p; 1691 1692 while (cp && *cp) { 1693 if (*cp == ' ' || *cp == '\t') { 1694 cp++; 1695 continue; 1696 } 1697 if (!canonname) 1698 canonname = cp; 1699 if ((cp = strpbrk(cp, " \t")) != NULL) 1700 *cp++ = '\0'; 1701 } 1702 1703 hints = *pai; 1704 hints.ai_flags = AI_NUMERICHOST; 1705 error = getaddrinfo(addr, NULL, &hints, &res0); 1706 if (error == 0) { 1707 for (res = res0; res; res = res->ai_next) { 1708 /* cover it up */ 1709 res->ai_flags = pai->ai_flags; 1710 1711 if (pai->ai_flags & AI_CANONNAME) 1712 (void)get_canonname(pai, res, canonname); 1713 } 1714 } else 1715 res0 = NULL; 1716 if (res0) { 1717 cur->ai_next = res0; 1718 while (cur && cur->ai_next) 1719 cur = cur->ai_next; 1720 } 1721 1722 if (nextline) { 1723 p = nextline; 1724 goto nextline; 1725 } 1726 1727done: 1728 return sentinel.ai_next; 1729} 1730 1731/*ARGSUSED*/ 1732static int 1733_yp_getaddrinfo(rv, cb_data, ap) 1734 void *rv; 1735 void *cb_data; 1736 va_list ap; 1737{ 1738 struct addrinfo sentinel, *cur; 1739 struct addrinfo *ai = NULL; 1740 static char *__ypcurrent; 1741 int __ypcurrentlen, r; 1742 const char *name; 1743 const struct addrinfo *pai; 1744 1745 name = va_arg(ap, char *); 1746 pai = va_arg(ap, const struct addrinfo *); 1747 1748 memset(&sentinel, 0, sizeof(sentinel)); 1749 cur = &sentinel; 1750 1751 if (!__ypdomain) { 1752 if (_yp_check(&__ypdomain) == 0) 1753 return NS_UNAVAIL; 1754 } 1755 if (__ypcurrent) 1756 free(__ypcurrent); 1757 __ypcurrent = NULL; 1758 1759 /* hosts.byname is only for IPv4 (Solaris8) */ 1760 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1761 r = yp_match(__ypdomain, "hosts.byname", name, 1762 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1763 if (r == 0) { 1764 struct addrinfo ai4; 1765 1766 ai4 = *pai; 1767 ai4.ai_family = AF_INET; 1768 ai = _yphostent(__ypcurrent, &ai4); 1769 if (ai) { 1770 cur->ai_next = ai; 1771 while (cur && cur->ai_next) 1772 cur = cur->ai_next; 1773 } 1774 } 1775 } 1776 1777 /* ipnodes.byname can hold both IPv4/v6 */ 1778 r = yp_match(__ypdomain, "ipnodes.byname", name, 1779 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1780 if (r == 0) { 1781 ai = _yphostent(__ypcurrent, pai); 1782 if (ai) { 1783 cur->ai_next = ai; 1784 while (cur && cur->ai_next) 1785 cur = cur->ai_next; 1786 } 1787 } 1788 1789 if (sentinel.ai_next == NULL) { 1790 h_errno = HOST_NOT_FOUND; 1791 return NS_NOTFOUND; 1792 } 1793 *((struct addrinfo **)rv) = sentinel.ai_next; 1794 return NS_SUCCESS; 1795} 1796#endif 1797 1798/* resolver logic */ 1799 1800extern const char *__hostalias(const char *); 1801extern int h_errno; 1802 1803/* 1804 * Formulate a normal query, send, and await answer. 1805 * Returned answer is placed in supplied buffer "answer". 1806 * Perform preliminary check of answer, returning success only 1807 * if no error is indicated and the answer count is nonzero. 1808 * Return the size of the response on success, -1 on error. 1809 * Error number is left in h_errno. 1810 * 1811 * Caller must parse answer and determine whether it answers the question. 1812 */ 1813static int 1814res_queryN(name, target) 1815 const char *name; /* domain name */ 1816 struct res_target *target; 1817{ 1818 u_char *buf; 1819 HEADER *hp; 1820 int n; 1821 struct res_target *t; 1822 int rcode; 1823 int ancount; 1824 1825 rcode = NOERROR; 1826 ancount = 0; 1827 1828 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1829 h_errno = NETDB_INTERNAL; 1830 return (-1); 1831 } 1832 1833 buf = malloc(MAXPACKET); 1834 if (!buf) { 1835 h_errno = NETDB_INTERNAL; 1836 return -1; 1837 } 1838 1839 for (t = target; t; t = t->next) { 1840 int class, type; 1841 u_char *answer; 1842 int anslen; 1843 1844 hp = (HEADER *)(void *)t->answer; 1845 hp->rcode = NOERROR; /* default */ 1846 1847 /* make it easier... */ 1848 class = t->qclass; 1849 type = t->qtype; 1850 answer = t->answer; 1851 anslen = t->anslen; 1852#ifdef DEBUG 1853 if (_res.options & RES_DEBUG) 1854 printf(";; res_query(%s, %d, %d)\n", name, class, type); 1855#endif 1856 1857 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL, 1858 buf, MAXPACKET); 1859 if (n > 0 && (_res.options & RES_USE_EDNS0) != 0) 1860 n = res_opt(n, buf, MAXPACKET, anslen); 1861 if (n <= 0) { 1862#ifdef DEBUG 1863 if (_res.options & RES_DEBUG) 1864 printf(";; res_query: mkquery failed\n"); 1865#endif 1866 free(buf); 1867 h_errno = NO_RECOVERY; 1868 return (n); 1869 } 1870 n = res_send(buf, n, answer, anslen); 1871#if 0 1872 if (n < 0) { 1873#ifdef DEBUG 1874 if (_res.options & RES_DEBUG) 1875 printf(";; res_query: send error\n"); 1876#endif 1877 free(buf); 1878 h_errno = TRY_AGAIN; 1879 return (n); 1880 } 1881#endif 1882 1883 if (n < 0 || n > anslen) 1884 hp->rcode = FORMERR; /* XXX not very informative */ 1885 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1886 rcode = hp->rcode; /* record most recent error */ 1887#ifdef DEBUG 1888 if (_res.options & RES_DEBUG) 1889 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1890 ntohs(hp->ancount)); 1891#endif 1892 continue; 1893 } 1894 1895 ancount += ntohs(hp->ancount); 1896 1897 t->n = n; 1898 } 1899 1900 free(buf); 1901 1902 if (ancount == 0) { 1903 switch (rcode) { 1904 case NXDOMAIN: 1905 h_errno = HOST_NOT_FOUND; 1906 break; 1907 case SERVFAIL: 1908 h_errno = TRY_AGAIN; 1909 break; 1910 case NOERROR: 1911 h_errno = NO_DATA; 1912 break; 1913 case FORMERR: 1914 case NOTIMP: 1915 case REFUSED: 1916 default: 1917 h_errno = NO_RECOVERY; 1918 break; 1919 } 1920 return (-1); 1921 } 1922 return (ancount); 1923} 1924 1925/* 1926 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1927 * Return the size of the response on success, -1 on error. 1928 * If enabled, implement search rules until answer or unrecoverable failure 1929 * is detected. Error code, if any, is left in h_errno. 1930 */ 1931static int 1932res_searchN(name, target) 1933 const char *name; /* domain name */ 1934 struct res_target *target; 1935{ 1936 const char *cp, * const *domain; 1937 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 1938 u_int dots; 1939 int trailing_dot, ret, saved_herrno; 1940 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1941 1942 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1943 h_errno = NETDB_INTERNAL; 1944 return (-1); 1945 } 1946 1947 errno = 0; 1948 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1949 dots = 0; 1950 for (cp = name; *cp; cp++) 1951 dots += (*cp == '.'); 1952 trailing_dot = 0; 1953 if (cp > name && *--cp == '.') 1954 trailing_dot++; 1955 1956 /* 1957 * if there aren't any dots, it could be a user-level alias 1958 */ 1959 if (!dots && (cp = __hostalias(name)) != NULL) 1960 return (res_queryN(cp, target)); 1961 1962 /* 1963 * If there are dots in the name already, let's just give it a try 1964 * 'as is'. The threshold can be set with the "ndots" option. 1965 */ 1966 saved_herrno = -1; 1967 if (dots >= _res.ndots) { 1968 ret = res_querydomainN(name, NULL, target); 1969 if (ret > 0) 1970 return (ret); 1971 saved_herrno = h_errno; 1972 tried_as_is++; 1973 } 1974 1975 /* 1976 * We do at least one level of search if 1977 * - there is no dot and RES_DEFNAME is set, or 1978 * - there is at least one dot, there is no trailing dot, 1979 * and RES_DNSRCH is set. 1980 */ 1981 if ((!dots && (_res.options & RES_DEFNAMES)) || 1982 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { 1983 int done = 0; 1984 1985 for (domain = (const char * const *)_res.dnsrch; 1986 *domain && !done; 1987 domain++) { 1988 1989 ret = res_querydomainN(name, *domain, target); 1990 if (ret > 0) 1991 return (ret); 1992 1993 /* 1994 * If no server present, give up. 1995 * If name isn't found in this domain, 1996 * keep trying higher domains in the search list 1997 * (if that's enabled). 1998 * On a NO_DATA error, keep trying, otherwise 1999 * a wildcard entry of another type could keep us 2000 * from finding this entry higher in the domain. 2001 * If we get some other error (negative answer or 2002 * server failure), then stop searching up, 2003 * but try the input name below in case it's 2004 * fully-qualified. 2005 */ 2006 if (errno == ECONNREFUSED) { 2007 h_errno = TRY_AGAIN; 2008 return (-1); 2009 } 2010 2011 switch (h_errno) { 2012 case NO_DATA: 2013 got_nodata++; 2014 /* FALLTHROUGH */ 2015 case HOST_NOT_FOUND: 2016 /* keep trying */ 2017 break; 2018 case TRY_AGAIN: 2019 if (hp->rcode == SERVFAIL) { 2020 /* try next search element, if any */ 2021 got_servfail++; 2022 break; 2023 } 2024 /* FALLTHROUGH */ 2025 default: 2026 /* anything else implies that we're done */ 2027 done++; 2028 } 2029 /* 2030 * if we got here for some reason other than DNSRCH, 2031 * we only wanted one iteration of the loop, so stop. 2032 */ 2033 if (!(_res.options & RES_DNSRCH)) 2034 done++; 2035 } 2036 } 2037 2038 /* 2039 * if we have not already tried the name "as is", do that now. 2040 * note that we do this regardless of how many dots were in the 2041 * name or whether it ends with a dot. 2042 */ 2043 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) { 2044 ret = res_querydomainN(name, NULL, target); 2045 if (ret > 0) 2046 return (ret); 2047 } 2048 2049 /* 2050 * if we got here, we didn't satisfy the search. 2051 * if we did an initial full query, return that query's h_errno 2052 * (note that we wouldn't be here if that query had succeeded). 2053 * else if we ever got a nodata, send that back as the reason. 2054 * else send back meaningless h_errno, that being the one from 2055 * the last DNSRCH we did. 2056 */ 2057 if (saved_herrno != -1) 2058 h_errno = saved_herrno; 2059 else if (got_nodata) 2060 h_errno = NO_DATA; 2061 else if (got_servfail) 2062 h_errno = TRY_AGAIN; 2063 return (-1); 2064} 2065 2066/* 2067 * Perform a call on res_query on the concatenation of name and domain, 2068 * removing a trailing dot from name if domain is NULL. 2069 */ 2070static int 2071res_querydomainN(name, domain, target) 2072 const char *name, *domain; 2073 struct res_target *target; 2074{ 2075 char nbuf[MAXDNAME]; 2076 const char *longname = nbuf; 2077 size_t n, d; 2078 2079 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 2080 h_errno = NETDB_INTERNAL; 2081 return (-1); 2082 } 2083#ifdef DEBUG 2084 if (_res.options & RES_DEBUG) 2085 printf(";; res_querydomain(%s, %s)\n", 2086 name, domain?domain:"<Nil>"); 2087#endif 2088 if (domain == NULL) { 2089 /* 2090 * Check for trailing '.'; 2091 * copy without '.' if present. 2092 */ 2093 n = strlen(name); 2094 if (n >= MAXDNAME) { 2095 h_errno = NO_RECOVERY; 2096 return (-1); 2097 } 2098 if (n > 0 && name[--n] == '.') { 2099 strncpy(nbuf, name, n); 2100 nbuf[n] = '\0'; 2101 } else 2102 longname = name; 2103 } else { 2104 n = strlen(name); 2105 d = strlen(domain); 2106 if (n + d + 1 >= MAXDNAME) { 2107 h_errno = NO_RECOVERY; 2108 return (-1); 2109 } 2110 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2111 } 2112 return (res_queryN(longname, target)); 2113} 2114