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. current code - SEGV on freeaddrinfo(NULL) 42 * 43 * Note: 44 * - The code filters out AFs that are not supported by the kernel, 45 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 46 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 47 * in ai_flags? 48 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 49 * (1) what should we do against numeric hostname (2) what should we do 50 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 51 * non-loopback address configured? global address configured? 52 * 53 * OS specific notes for netbsd/openbsd/freebsd4/bsdi4: 54 * - To avoid search order issue, we have a big amount of code duplicate 55 * from gethnamaddr.c and some other places. The issues that there's no 56 * lower layer function to lookup "IPv4 or IPv6" record. Calling 57 * gethostbyname2 from getaddrinfo will end up in wrong search order, as 58 * presented above. 59 * 60 * 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$"); 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 <resolv.h> 81 #include <string.h> 82 #include <stdlib.h> 83 #include <stddef.h> 84 #include <ctype.h> 85 #include <unistd.h> 86 #include <stdio.h> 87 #include <errno.h> 88 89 #include "res_config.h" 90 91 #ifdef DEBUG 92 #include <syslog.h> 93 #endif 94 95 #include <stdarg.h> 96 #include <nsswitch.h> 97 #include "un-namespace.h" 98 #include "libc_private.h" 99 100 #if defined(__KAME__) && defined(INET6) 101 # define FAITH 102 #endif 103 104 #define SUCCESS 0 105 #define ANY 0 106 #define YES 1 107 #define NO 0 108 109 static const char in_addrany[] = { 0, 0, 0, 0 }; 110 static const char in_loopback[] = { 127, 0, 0, 1 }; 111 #ifdef INET6 112 static const char in6_addrany[] = { 113 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 114 }; 115 static const char in6_loopback[] = { 116 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 117 }; 118 #endif 119 120 static const struct afd { 121 int a_af; 122 int a_addrlen; 123 int a_socklen; 124 int a_off; 125 const char *a_addrany; 126 const char *a_loopback; 127 int a_scoped; 128 } afdl [] = { 129 #ifdef INET6 130 #define N_INET6 0 131 {PF_INET6, sizeof(struct in6_addr), 132 sizeof(struct sockaddr_in6), 133 offsetof(struct sockaddr_in6, sin6_addr), 134 in6_addrany, in6_loopback, 1}, 135 #define N_INET 1 136 #else 137 #define N_INET 0 138 #endif 139 {PF_INET, sizeof(struct in_addr), 140 sizeof(struct sockaddr_in), 141 offsetof(struct sockaddr_in, sin_addr), 142 in_addrany, in_loopback, 0}, 143 {0, 0, 0, 0, NULL, NULL, 0}, 144 }; 145 146 struct explore { 147 int e_af; 148 int e_socktype; 149 int e_protocol; 150 const char *e_protostr; 151 int e_wild; 152 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 153 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 154 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 155 }; 156 157 static const struct explore explore[] = { 158 #if 0 159 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 160 #endif 161 #ifdef INET6 162 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 163 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 164 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 165 #endif 166 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 167 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 168 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 169 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 170 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 171 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 172 { -1, 0, 0, NULL, 0 }, 173 }; 174 175 #ifdef INET6 176 #define PTON_MAX 16 177 #else 178 #define PTON_MAX 4 179 #endif 180 181 static const ns_src default_dns_files[] = { 182 { NSSRC_FILES, NS_SUCCESS }, 183 { NSSRC_DNS, NS_SUCCESS }, 184 { 0 } 185 }; 186 187 #define MAXPACKET (64*1024) 188 189 typedef union { 190 HEADER hdr; 191 u_char buf[MAXPACKET]; 192 } querybuf; 193 194 struct res_target { 195 struct res_target *next; 196 const char *name; /* domain name */ 197 int qclass, qtype; /* class and type of query */ 198 u_char *answer; /* buffer to put answer */ 199 int anslen; /* size of answer buffer */ 200 int n; /* result length */ 201 }; 202 203 static int str_isnumber(const char *); 204 static int explore_fqdn(const struct addrinfo *, const char *, 205 const char *, struct addrinfo **); 206 static int explore_null(const struct addrinfo *, 207 const char *, struct addrinfo **); 208 static int explore_numeric(const struct addrinfo *, const char *, 209 const char *, struct addrinfo **); 210 static int explore_numeric_scope(const struct addrinfo *, const char *, 211 const char *, struct addrinfo **); 212 static int get_canonname(const struct addrinfo *, 213 struct addrinfo *, const char *); 214 static struct addrinfo *get_ai(const struct addrinfo *, 215 const struct afd *, const char *); 216 static int get_portmatch(const struct addrinfo *, const char *); 217 static int get_port(struct addrinfo *, const char *, int); 218 static const struct afd *find_afd(int); 219 static int addrconfig(struct addrinfo *); 220 #ifdef INET6 221 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 222 #endif 223 224 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 225 const struct addrinfo *); 226 static int _dns_getaddrinfo(void *, void *, va_list); 227 static void _sethtent(void); 228 static void _endhtent(void); 229 static struct addrinfo *_gethtent(const char *, const struct addrinfo *); 230 static int _files_getaddrinfo(void *, void *, va_list); 231 #ifdef YP 232 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 233 static int _yp_getaddrinfo(void *, void *, va_list); 234 #endif 235 236 static int res_queryN(const char *, struct res_target *); 237 static int res_searchN(const char *, struct res_target *); 238 static int res_querydomainN(const char *, const char *, 239 struct res_target *); 240 241 static char *ai_errlist[] = { 242 "Success", 243 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 244 "Temporary failure in name resolution", /* EAI_AGAIN */ 245 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 246 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 247 "ai_family not supported", /* EAI_FAMILY */ 248 "Memory allocation failure", /* EAI_MEMORY */ 249 "No address associated with hostname", /* EAI_NODATA */ 250 "hostname nor servname provided, or not known", /* EAI_NONAME */ 251 "servname not supported for ai_socktype", /* EAI_SERVICE */ 252 "ai_socktype not supported", /* EAI_SOCKTYPE */ 253 "System error returned in errno", /* EAI_SYSTEM */ 254 "Invalid value for hints", /* EAI_BADHINTS */ 255 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 256 "Unknown error", /* EAI_MAX */ 257 }; 258 259 /* Make getaddrinfo() thread-safe in libc for use with kernel threads. */ 260 #include "libc_private.h" 261 #include "spinlock.h" 262 /* 263 * XXX: Our res_*() is not thread-safe. So, we share lock between 264 * getaddrinfo() and getipnodeby*(). Still, we cannot use 265 * getaddrinfo() and getipnodeby*() in conjunction with other 266 * functions which call res_*(). 267 */ 268 spinlock_t __getaddrinfo_thread_lock = _SPINLOCK_INITIALIZER; 269 #define THREAD_LOCK() \ 270 if (__isthreaded) _SPINLOCK(&__getaddrinfo_thread_lock); 271 #define THREAD_UNLOCK() \ 272 if (__isthreaded) _SPINUNLOCK(&__getaddrinfo_thread_lock); 273 274 /* XXX macros that make external reference is BAD. */ 275 276 #define GET_AI(ai, afd, addr) \ 277 do { \ 278 /* external reference: pai, error, and label free */ \ 279 (ai) = get_ai(pai, (afd), (addr)); \ 280 if ((ai) == NULL) { \ 281 error = EAI_MEMORY; \ 282 goto free; \ 283 } \ 284 } while (/*CONSTCOND*/0) 285 286 #define GET_PORT(ai, serv) \ 287 do { \ 288 /* external reference: error and label free */ \ 289 error = get_port((ai), (serv), 0); \ 290 if (error != 0) \ 291 goto free; \ 292 } while (/*CONSTCOND*/0) 293 294 #define GET_CANONNAME(ai, str) \ 295 do { \ 296 /* external reference: pai, error and label free */ \ 297 error = get_canonname(pai, (ai), (str)); \ 298 if (error != 0) \ 299 goto free; \ 300 } while (/*CONSTCOND*/0) 301 302 #define ERR(err) \ 303 do { \ 304 /* external reference: error, and label bad */ \ 305 error = (err); \ 306 goto bad; \ 307 /*NOTREACHED*/ \ 308 } while (/*CONSTCOND*/0) 309 310 #define MATCH_FAMILY(x, y, w) \ 311 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 312 #define MATCH(x, y, w) \ 313 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 314 315 char * 316 gai_strerror(ecode) 317 int ecode; 318 { 319 if (ecode < 0 || ecode > EAI_MAX) 320 ecode = EAI_MAX; 321 return ai_errlist[ecode]; 322 } 323 324 void 325 freeaddrinfo(ai) 326 struct addrinfo *ai; 327 { 328 struct addrinfo *next; 329 330 do { 331 next = ai->ai_next; 332 if (ai->ai_canonname) 333 free(ai->ai_canonname); 334 /* no need to free(ai->ai_addr) */ 335 free(ai); 336 ai = next; 337 } while (ai); 338 } 339 340 static int 341 str_isnumber(p) 342 const char *p; 343 { 344 char *ep; 345 346 if (*p == '\0') 347 return NO; 348 ep = NULL; 349 errno = 0; 350 (void)strtoul(p, &ep, 10); 351 if (errno == 0 && ep && *ep == '\0') 352 return YES; 353 else 354 return NO; 355 } 356 357 int 358 getaddrinfo(hostname, servname, hints, res) 359 const char *hostname, *servname; 360 const struct addrinfo *hints; 361 struct addrinfo **res; 362 { 363 struct addrinfo sentinel; 364 struct addrinfo *cur; 365 int error = 0; 366 struct addrinfo ai; 367 struct addrinfo ai0; 368 struct addrinfo *pai; 369 const struct explore *ex; 370 371 memset(&sentinel, 0, sizeof(sentinel)); 372 cur = &sentinel; 373 pai = &ai; 374 pai->ai_flags = 0; 375 pai->ai_family = PF_UNSPEC; 376 pai->ai_socktype = ANY; 377 pai->ai_protocol = ANY; 378 pai->ai_addrlen = 0; 379 pai->ai_canonname = NULL; 380 pai->ai_addr = NULL; 381 pai->ai_next = NULL; 382 383 if (hostname == NULL && servname == NULL) 384 return EAI_NONAME; 385 if (hints) { 386 /* error check for hints */ 387 if (hints->ai_addrlen || hints->ai_canonname || 388 hints->ai_addr || hints->ai_next) 389 ERR(EAI_BADHINTS); /* xxx */ 390 if (hints->ai_flags & ~AI_MASK) 391 ERR(EAI_BADFLAGS); 392 switch (hints->ai_family) { 393 case PF_UNSPEC: 394 case PF_INET: 395 #ifdef INET6 396 case PF_INET6: 397 #endif 398 break; 399 default: 400 ERR(EAI_FAMILY); 401 } 402 memcpy(pai, hints, sizeof(*pai)); 403 404 /* 405 * if both socktype/protocol are specified, check if they 406 * are meaningful combination. 407 */ 408 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 409 for (ex = explore; ex->e_af >= 0; ex++) { 410 if (pai->ai_family != ex->e_af) 411 continue; 412 if (ex->e_socktype == ANY) 413 continue; 414 if (ex->e_protocol == ANY) 415 continue; 416 if (pai->ai_socktype == ex->e_socktype && 417 pai->ai_protocol != ex->e_protocol) { 418 ERR(EAI_BADHINTS); 419 } 420 } 421 } 422 } 423 424 /* 425 * post-2553: AI_ALL and AI_V4MAPPED are effective only against 426 * AF_INET6 query. They need to be ignored if specified in other 427 * occassions. 428 */ 429 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 430 case AI_V4MAPPED: 431 case AI_ALL | AI_V4MAPPED: 432 if (pai->ai_family != AF_INET6) 433 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 434 break; 435 case AI_ALL: 436 #if 1 437 /* illegal */ 438 ERR(EAI_BADFLAGS); 439 #else 440 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 441 #endif 442 break; 443 } 444 445 /* 446 * check for special cases. (1) numeric servname is disallowed if 447 * socktype/protocol are left unspecified. (2) servname is disallowed 448 * for raw and other inet{,6} sockets. 449 */ 450 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 451 #ifdef PF_INET6 452 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 453 #endif 454 ) { 455 ai0 = *pai; /* backup *pai */ 456 457 if (pai->ai_family == PF_UNSPEC) { 458 #ifdef PF_INET6 459 pai->ai_family = PF_INET6; 460 #else 461 pai->ai_family = PF_INET; 462 #endif 463 } 464 error = get_portmatch(pai, servname); 465 if (error) 466 ERR(error); 467 468 *pai = ai0; 469 } 470 471 ai0 = *pai; 472 473 /* NULL hostname, or numeric hostname */ 474 for (ex = explore; ex->e_af >= 0; ex++) { 475 *pai = ai0; 476 477 /* PF_UNSPEC entries are prepared for DNS queries only */ 478 if (ex->e_af == PF_UNSPEC) 479 continue; 480 481 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 482 continue; 483 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 484 continue; 485 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 486 continue; 487 488 if (pai->ai_family == PF_UNSPEC) 489 pai->ai_family = ex->e_af; 490 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 491 pai->ai_socktype = ex->e_socktype; 492 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 493 pai->ai_protocol = ex->e_protocol; 494 495 if (hostname == NULL) 496 error = explore_null(pai, servname, &cur->ai_next); 497 else 498 error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next); 499 500 if (error) 501 goto free; 502 503 while (cur && cur->ai_next) 504 cur = cur->ai_next; 505 } 506 507 /* 508 * XXX 509 * If numreic representation of AF1 can be interpreted as FQDN 510 * representation of AF2, we need to think again about the code below. 511 */ 512 if (sentinel.ai_next) 513 goto good; 514 515 if (pai->ai_flags & AI_NUMERICHOST) 516 ERR(EAI_NONAME); 517 if (hostname == NULL) 518 ERR(EAI_NODATA); 519 520 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 521 ERR(EAI_FAIL); 522 523 /* 524 * hostname as alphabetical name. 525 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 526 * outer loop by AFs. 527 */ 528 for (ex = explore; ex->e_af >= 0; ex++) { 529 *pai = ai0; 530 531 /* require exact match for family field */ 532 if (pai->ai_family != ex->e_af) 533 continue; 534 535 if (!MATCH(pai->ai_socktype, ex->e_socktype, 536 WILD_SOCKTYPE(ex))) { 537 continue; 538 } 539 if (!MATCH(pai->ai_protocol, ex->e_protocol, 540 WILD_PROTOCOL(ex))) { 541 continue; 542 } 543 544 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 545 pai->ai_socktype = ex->e_socktype; 546 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 547 pai->ai_protocol = ex->e_protocol; 548 549 error = explore_fqdn(pai, hostname, servname, 550 &cur->ai_next); 551 552 while (cur && cur->ai_next) 553 cur = cur->ai_next; 554 } 555 556 /* XXX */ 557 if (sentinel.ai_next) 558 error = 0; 559 560 if (error) 561 goto free; 562 if (error == 0) { 563 if (sentinel.ai_next) { 564 good: 565 *res = sentinel.ai_next; 566 return SUCCESS; 567 } else 568 error = EAI_FAIL; 569 } 570 free: 571 bad: 572 if (sentinel.ai_next) 573 freeaddrinfo(sentinel.ai_next); 574 *res = NULL; 575 return error; 576 } 577 578 /* 579 * FQDN hostname, DNS lookup 580 */ 581 static int 582 explore_fqdn(pai, hostname, servname, res) 583 const struct addrinfo *pai; 584 const char *hostname; 585 const char *servname; 586 struct addrinfo **res; 587 { 588 struct addrinfo *result; 589 struct addrinfo *cur; 590 int error = 0; 591 static const ns_dtab dtab[] = { 592 NS_FILES_CB(_files_getaddrinfo, NULL) 593 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 594 NS_NIS_CB(_yp_getaddrinfo, NULL) 595 { 0 } 596 }; 597 598 result = NULL; 599 600 THREAD_LOCK(); 601 602 /* 603 * if the servname does not match socktype/protocol, ignore it. 604 */ 605 if (get_portmatch(pai, servname) != 0) { 606 THREAD_UNLOCK(); 607 return 0; 608 } 609 610 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 611 default_dns_files, hostname, pai)) { 612 case NS_TRYAGAIN: 613 error = EAI_AGAIN; 614 goto free; 615 case NS_UNAVAIL: 616 error = EAI_FAIL; 617 goto free; 618 case NS_NOTFOUND: 619 error = EAI_NODATA; 620 goto free; 621 case NS_SUCCESS: 622 error = 0; 623 for (cur = result; cur; cur = cur->ai_next) { 624 GET_PORT(cur, servname); 625 /* canonname should be filled already */ 626 } 627 break; 628 } 629 THREAD_UNLOCK(); 630 631 *res = result; 632 633 return 0; 634 635 free: 636 THREAD_UNLOCK(); 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 */ 647 static int 648 explore_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; 701 702 free: 703 if (sentinel.ai_next) 704 freeaddrinfo(sentinel.ai_next); 705 return error; 706 } 707 708 /* 709 * numeric hostname 710 */ 711 static int 712 explore_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; 769 770 free: 771 bad: 772 if (sentinel.ai_next) 773 freeaddrinfo(sentinel.ai_next); 774 return error; 775 } 776 777 /* 778 * numeric hostname with scope 779 */ 780 static int 781 explore_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 u_int32_t 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 (ip6_str2scopeid(scope, sin6, &scopeid) == -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 } 845 846 static int 847 get_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 strlcpy(ai->ai_canonname, str, strlen(str) + 1); 857 } 858 return 0; 859 } 860 861 static struct addrinfo * 862 get_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 } 931 932 static int 933 get_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 } 942 943 static int 944 get_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 = atoi(servname); 984 if (port < 0 || port > 65535) 985 return EAI_SERVICE; 986 port = htons(port); 987 } else { 988 switch (ai->ai_socktype) { 989 case SOCK_DGRAM: 990 proto = "udp"; 991 break; 992 case SOCK_STREAM: 993 proto = "tcp"; 994 break; 995 default: 996 proto = NULL; 997 break; 998 } 999 1000 if ((sp = getservbyname(servname, proto)) == NULL) 1001 return EAI_SERVICE; 1002 port = sp->s_port; 1003 } 1004 1005 if (!matchonly) { 1006 switch (ai->ai_family) { 1007 case AF_INET: 1008 ((struct sockaddr_in *)(void *) 1009 ai->ai_addr)->sin_port = port; 1010 break; 1011 #ifdef INET6 1012 case AF_INET6: 1013 ((struct sockaddr_in6 *)(void *) 1014 ai->ai_addr)->sin6_port = port; 1015 break; 1016 #endif 1017 } 1018 } 1019 1020 return 0; 1021 } 1022 1023 static const struct afd * 1024 find_afd(af) 1025 int af; 1026 { 1027 const struct afd *afd; 1028 1029 if (af == PF_UNSPEC) 1030 return NULL; 1031 for (afd = afdl; afd->a_af; afd++) { 1032 if (afd->a_af == af) 1033 return afd; 1034 } 1035 return NULL; 1036 } 1037 1038 /* 1039 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1040 * will take care of it. 1041 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1042 * if the code is right or not. 1043 * 1044 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1045 * _dns_getaddrinfo. 1046 */ 1047 static int 1048 addrconfig(pai) 1049 struct addrinfo *pai; 1050 { 1051 int s, af; 1052 1053 /* 1054 * TODO: 1055 * Note that implementation dependent test for address 1056 * configuration should be done everytime called 1057 * (or apropriate interval), 1058 * because addresses will be dynamically assigned or deleted. 1059 */ 1060 af = pai->ai_family; 1061 if (af == AF_UNSPEC) { 1062 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 1063 af = AF_INET; 1064 else { 1065 _close(s); 1066 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) 1067 af = AF_INET6; 1068 else 1069 _close(s); 1070 } 1071 } 1072 if (af != AF_UNSPEC) { 1073 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 1074 return 0; 1075 _close(s); 1076 } 1077 pai->ai_family = af; 1078 return 1; 1079 } 1080 1081 #ifdef INET6 1082 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1083 static int 1084 ip6_str2scopeid(scope, sin6, scopeid) 1085 char *scope; 1086 struct sockaddr_in6 *sin6; 1087 u_int32_t *scopeid; 1088 { 1089 u_long lscopeid; 1090 struct in6_addr *a6; 1091 char *ep; 1092 1093 a6 = &sin6->sin6_addr; 1094 1095 /* empty scopeid portion is invalid */ 1096 if (*scope == '\0') 1097 return -1; 1098 1099 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1100 /* 1101 * We currently assume a one-to-one mapping between links 1102 * and interfaces, so we simply use interface indices for 1103 * like-local scopes. 1104 */ 1105 *scopeid = if_nametoindex(scope); 1106 if (*scopeid == 0) 1107 goto trynumeric; 1108 return 0; 1109 } 1110 1111 /* still unclear about literal, allow numeric only - placeholder */ 1112 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1113 goto trynumeric; 1114 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1115 goto trynumeric; 1116 else 1117 goto trynumeric; /* global */ 1118 1119 /* try to convert to a numeric id as a last resort */ 1120 trynumeric: 1121 errno = 0; 1122 lscopeid = strtoul(scope, &ep, 10); 1123 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1124 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1125 return 0; 1126 else 1127 return -1; 1128 } 1129 #endif 1130 1131 #ifdef RESOLVSORT 1132 struct addr_ptr { 1133 struct addrinfo *ai; 1134 int aval; 1135 }; 1136 1137 static int 1138 addr4sort(struct addrinfo *sentinel) 1139 { 1140 struct addrinfo *ai; 1141 struct addr_ptr *addrs, addr; 1142 struct sockaddr_in *sin; 1143 int naddrs, i, j; 1144 int needsort = 0; 1145 1146 if (!sentinel) 1147 return -1; 1148 naddrs = 0; 1149 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 1150 naddrs++; 1151 if (naddrs < 2) 1152 return 0; /* We don't need sorting. */ 1153 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 1154 return -1; 1155 i = 0; 1156 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 1157 sin = (struct sockaddr_in *)ai->ai_addr; 1158 for (j = 0; (unsigned)j < _res.nsort; j++) { 1159 if (_res.sort_list[j].addr.s_addr == 1160 (sin->sin_addr.s_addr & _res.sort_list[j].mask)) 1161 break; 1162 } 1163 addrs[i].ai = ai; 1164 addrs[i].aval = j; 1165 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 1166 needsort = i; 1167 i++; 1168 } 1169 if (!needsort) { 1170 free(addrs); 1171 return 0; 1172 } 1173 1174 while (needsort < naddrs) { 1175 for (j = needsort - 1; j >= 0; j--) { 1176 if (addrs[j].aval > addrs[j+1].aval) { 1177 addr = addrs[j]; 1178 addrs[j] = addrs[j + 1]; 1179 addrs[j + 1] = addr; 1180 } else 1181 break; 1182 } 1183 needsort++; 1184 } 1185 1186 ai = sentinel; 1187 for (i = 0; i < naddrs; ++i) { 1188 ai->ai_next = addrs[i].ai; 1189 ai = ai->ai_next; 1190 } 1191 ai->ai_next = NULL; 1192 free(addrs); 1193 return 0; 1194 } 1195 #endif /*RESOLVSORT*/ 1196 1197 #ifdef DEBUG 1198 static const char AskedForGot[] = 1199 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1200 #endif 1201 static FILE *hostf = NULL; 1202 1203 static struct addrinfo * 1204 getanswer(answer, anslen, qname, qtype, pai) 1205 const querybuf *answer; 1206 int anslen; 1207 const char *qname; 1208 int qtype; 1209 const struct addrinfo *pai; 1210 { 1211 struct addrinfo sentinel, *cur; 1212 struct addrinfo ai; 1213 const struct afd *afd; 1214 char *canonname; 1215 const HEADER *hp; 1216 const u_char *cp; 1217 int n; 1218 const u_char *eom; 1219 char *bp, *ep; 1220 int type, class, ancount, qdcount; 1221 int haveanswer, had_error; 1222 char tbuf[MAXDNAME]; 1223 int (*name_ok)(const char *); 1224 char hostbuf[8*1024]; 1225 1226 memset(&sentinel, 0, sizeof(sentinel)); 1227 cur = &sentinel; 1228 1229 canonname = NULL; 1230 eom = answer->buf + anslen; 1231 switch (qtype) { 1232 case T_A: 1233 case T_AAAA: 1234 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1235 name_ok = res_hnok; 1236 break; 1237 default: 1238 return (NULL); /* XXX should be abort(); */ 1239 } 1240 /* 1241 * find first satisfactory answer 1242 */ 1243 hp = &answer->hdr; 1244 ancount = ntohs(hp->ancount); 1245 qdcount = ntohs(hp->qdcount); 1246 bp = hostbuf; 1247 ep = hostbuf + sizeof hostbuf; 1248 cp = answer->buf + HFIXEDSZ; 1249 if (qdcount != 1) { 1250 h_errno = NO_RECOVERY; 1251 return (NULL); 1252 } 1253 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1254 if ((n < 0) || !(*name_ok)(bp)) { 1255 h_errno = NO_RECOVERY; 1256 return (NULL); 1257 } 1258 cp += n + QFIXEDSZ; 1259 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1260 /* res_send() has already verified that the query name is the 1261 * same as the one we sent; this just gets the expanded name 1262 * (i.e., with the succeeding search-domain tacked on). 1263 */ 1264 n = strlen(bp) + 1; /* for the \0 */ 1265 if (n >= MAXHOSTNAMELEN) { 1266 h_errno = NO_RECOVERY; 1267 return (NULL); 1268 } 1269 canonname = bp; 1270 bp += n; 1271 /* The qname can be abbreviated, but h_name is now absolute. */ 1272 qname = canonname; 1273 } 1274 haveanswer = 0; 1275 had_error = 0; 1276 while (ancount-- > 0 && cp < eom && !had_error) { 1277 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1278 if ((n < 0) || !(*name_ok)(bp)) { 1279 had_error++; 1280 continue; 1281 } 1282 cp += n; /* name */ 1283 type = _getshort(cp); 1284 cp += INT16SZ; /* type */ 1285 class = _getshort(cp); 1286 cp += INT16SZ + INT32SZ; /* class, TTL */ 1287 n = _getshort(cp); 1288 cp += INT16SZ; /* len */ 1289 if (class != C_IN) { 1290 /* XXX - debug? syslog? */ 1291 cp += n; 1292 continue; /* XXX - had_error++ ? */ 1293 } 1294 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1295 type == T_CNAME) { 1296 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1297 if ((n < 0) || !(*name_ok)(tbuf)) { 1298 had_error++; 1299 continue; 1300 } 1301 cp += n; 1302 /* Get canonical name. */ 1303 n = strlen(tbuf) + 1; /* for the \0 */ 1304 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1305 had_error++; 1306 continue; 1307 } 1308 strlcpy(bp, tbuf, ep - bp); 1309 canonname = bp; 1310 bp += n; 1311 continue; 1312 } 1313 if (qtype == T_ANY) { 1314 if (!(type == T_A || type == T_AAAA)) { 1315 cp += n; 1316 continue; 1317 } 1318 } else if (type != qtype) { 1319 #ifdef DEBUG 1320 if (type != T_KEY && type != T_SIG) 1321 syslog(LOG_NOTICE|LOG_AUTH, 1322 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1323 qname, p_class(C_IN), p_type(qtype), 1324 p_type(type)); 1325 #endif 1326 cp += n; 1327 continue; /* XXX - had_error++ ? */ 1328 } 1329 switch (type) { 1330 case T_A: 1331 case T_AAAA: 1332 if (strcasecmp(canonname, bp) != 0) { 1333 #ifdef DEBUG 1334 syslog(LOG_NOTICE|LOG_AUTH, 1335 AskedForGot, canonname, bp); 1336 #endif 1337 cp += n; 1338 continue; /* XXX - had_error++ ? */ 1339 } 1340 if (type == T_A && n != INADDRSZ) { 1341 cp += n; 1342 continue; 1343 } 1344 if (type == T_AAAA && n != IN6ADDRSZ) { 1345 cp += n; 1346 continue; 1347 } 1348 #ifdef FILTER_V4MAPPED 1349 if (type == T_AAAA) { 1350 struct in6_addr in6; 1351 memcpy(&in6, cp, sizeof(in6)); 1352 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1353 cp += n; 1354 continue; 1355 } 1356 } 1357 #endif 1358 if (!haveanswer) { 1359 int nn; 1360 1361 canonname = bp; 1362 nn = strlen(bp) + 1; /* for the \0 */ 1363 bp += nn; 1364 } 1365 1366 /* don't overwrite pai */ 1367 ai = *pai; 1368 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1369 afd = find_afd(ai.ai_family); 1370 if (afd == NULL) { 1371 cp += n; 1372 continue; 1373 } 1374 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1375 if (cur->ai_next == NULL) 1376 had_error++; 1377 while (cur && cur->ai_next) 1378 cur = cur->ai_next; 1379 cp += n; 1380 break; 1381 default: 1382 abort(); 1383 } 1384 if (!had_error) 1385 haveanswer++; 1386 } 1387 if (haveanswer) { 1388 #if defined(RESOLVSORT) 1389 /* 1390 * We support only IPv4 address for backward 1391 * compatibility against gethostbyname(3). 1392 */ 1393 if (_res.nsort && qtype == T_A) { 1394 if (addr4sort(&sentinel) < 0) { 1395 freeaddrinfo(sentinel.ai_next); 1396 h_errno = NO_RECOVERY; 1397 return NULL; 1398 } 1399 } 1400 #endif /*RESOLVSORT*/ 1401 if (!canonname) 1402 (void)get_canonname(pai, sentinel.ai_next, qname); 1403 else 1404 (void)get_canonname(pai, sentinel.ai_next, canonname); 1405 h_errno = NETDB_SUCCESS; 1406 return sentinel.ai_next; 1407 } 1408 1409 h_errno = NO_RECOVERY; 1410 return NULL; 1411 } 1412 1413 /*ARGSUSED*/ 1414 static int 1415 _dns_getaddrinfo(rv, cb_data, ap) 1416 void *rv; 1417 void *cb_data; 1418 va_list ap; 1419 { 1420 struct addrinfo *ai; 1421 querybuf *buf, *buf2; 1422 const char *name; 1423 const struct addrinfo *pai; 1424 struct addrinfo sentinel, *cur; 1425 struct res_target q, q2; 1426 1427 name = va_arg(ap, char *); 1428 pai = va_arg(ap, const struct addrinfo *); 1429 1430 memset(&q, 0, sizeof(q2)); 1431 memset(&q2, 0, sizeof(q2)); 1432 memset(&sentinel, 0, sizeof(sentinel)); 1433 cur = &sentinel; 1434 1435 buf = malloc(sizeof(*buf)); 1436 if (!buf) { 1437 h_errno = NETDB_INTERNAL; 1438 return NS_NOTFOUND; 1439 } 1440 buf2 = malloc(sizeof(*buf2)); 1441 if (!buf2) { 1442 free(buf); 1443 h_errno = NETDB_INTERNAL; 1444 return NS_NOTFOUND; 1445 } 1446 1447 switch (pai->ai_family) { 1448 case AF_UNSPEC: 1449 /* prefer IPv6 */ 1450 q.name = name; 1451 q.qclass = C_IN; 1452 q.qtype = T_AAAA; 1453 q.answer = buf->buf; 1454 q.anslen = sizeof(buf->buf); 1455 q.next = &q2; 1456 q2.name = name; 1457 q2.qclass = C_IN; 1458 q2.qtype = T_A; 1459 q2.answer = buf2->buf; 1460 q2.anslen = sizeof(buf2->buf); 1461 break; 1462 case AF_INET: 1463 q.name = name; 1464 q.qclass = C_IN; 1465 q.qtype = T_A; 1466 q.answer = buf->buf; 1467 q.anslen = sizeof(buf->buf); 1468 break; 1469 case AF_INET6: 1470 q.name = name; 1471 q.qclass = C_IN; 1472 q.qtype = T_AAAA; 1473 q.answer = buf->buf; 1474 q.anslen = sizeof(buf->buf); 1475 break; 1476 default: 1477 free(buf); 1478 free(buf2); 1479 return NS_UNAVAIL; 1480 } 1481 if (res_searchN(name, &q) < 0) { 1482 free(buf); 1483 free(buf2); 1484 return NS_NOTFOUND; 1485 } 1486 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1487 if (ai) { 1488 cur->ai_next = ai; 1489 while (cur && cur->ai_next) 1490 cur = cur->ai_next; 1491 } 1492 if (q.next) { 1493 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1494 if (ai) 1495 cur->ai_next = ai; 1496 } 1497 free(buf); 1498 free(buf2); 1499 if (sentinel.ai_next == NULL) 1500 switch (h_errno) { 1501 case HOST_NOT_FOUND: 1502 return NS_NOTFOUND; 1503 case TRY_AGAIN: 1504 return NS_TRYAGAIN; 1505 default: 1506 return NS_UNAVAIL; 1507 } 1508 *((struct addrinfo **)rv) = sentinel.ai_next; 1509 return NS_SUCCESS; 1510 } 1511 1512 static void 1513 _sethtent() 1514 { 1515 if (!hostf) 1516 hostf = fopen(_PATH_HOSTS, "r" ); 1517 else 1518 rewind(hostf); 1519 } 1520 1521 static void 1522 _endhtent() 1523 { 1524 if (hostf) { 1525 (void) fclose(hostf); 1526 hostf = NULL; 1527 } 1528 } 1529 1530 static struct addrinfo * 1531 _gethtent(name, pai) 1532 const char *name; 1533 const struct addrinfo *pai; 1534 { 1535 char *p; 1536 char *cp, *tname, *cname; 1537 struct addrinfo hints, *res0, *res; 1538 int error; 1539 const char *addr; 1540 char hostbuf[8*1024]; 1541 1542 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) 1543 return (NULL); 1544 again: 1545 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) 1546 return (NULL); 1547 if (*p == '#') 1548 goto again; 1549 if (!(cp = strpbrk(p, "#\n"))) 1550 goto again; 1551 *cp = '\0'; 1552 if (!(cp = strpbrk(p, " \t"))) 1553 goto again; 1554 *cp++ = '\0'; 1555 addr = p; 1556 cname = NULL; 1557 /* if this is not something we're looking for, skip it. */ 1558 while (cp && *cp) { 1559 if (*cp == ' ' || *cp == '\t') { 1560 cp++; 1561 continue; 1562 } 1563 tname = cp; 1564 if (cname == NULL) 1565 cname = cp; 1566 if ((cp = strpbrk(cp, " \t")) != NULL) 1567 *cp++ = '\0'; 1568 if (strcasecmp(name, tname) == 0) 1569 goto found; 1570 } 1571 goto again; 1572 1573 found: 1574 /* we should not glob socktype/protocol here */ 1575 memset(&hints, 0, sizeof(hints)); 1576 hints.ai_family = pai->ai_family; 1577 hints.ai_socktype = SOCK_DGRAM; 1578 hints.ai_protocol = 0; 1579 hints.ai_flags = AI_NUMERICHOST; 1580 error = getaddrinfo(addr, "0", &hints, &res0); 1581 if (error) 1582 goto again; 1583 #ifdef FILTER_V4MAPPED 1584 /* XXX should check all items in the chain */ 1585 if (res0->ai_family == AF_INET6 && 1586 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 1587 freeaddrinfo(res0); 1588 goto again; 1589 } 1590 #endif 1591 for (res = res0; res; res = res->ai_next) { 1592 /* cover it up */ 1593 res->ai_flags = pai->ai_flags; 1594 res->ai_socktype = pai->ai_socktype; 1595 res->ai_protocol = pai->ai_protocol; 1596 1597 if (pai->ai_flags & AI_CANONNAME) { 1598 if (get_canonname(pai, res, cname) != 0) { 1599 freeaddrinfo(res0); 1600 goto again; 1601 } 1602 } 1603 } 1604 return res0; 1605 } 1606 1607 /*ARGSUSED*/ 1608 static int 1609 _files_getaddrinfo(rv, cb_data, ap) 1610 void *rv; 1611 void *cb_data; 1612 va_list ap; 1613 { 1614 const char *name; 1615 const struct addrinfo *pai; 1616 struct addrinfo sentinel, *cur; 1617 struct addrinfo *p; 1618 1619 name = va_arg(ap, char *); 1620 pai = va_arg(ap, struct addrinfo *); 1621 1622 memset(&sentinel, 0, sizeof(sentinel)); 1623 cur = &sentinel; 1624 1625 _sethtent(); 1626 while ((p = _gethtent(name, pai)) != NULL) { 1627 cur->ai_next = p; 1628 while (cur && cur->ai_next) 1629 cur = cur->ai_next; 1630 } 1631 _endhtent(); 1632 1633 *((struct addrinfo **)rv) = sentinel.ai_next; 1634 if (sentinel.ai_next == NULL) 1635 return NS_NOTFOUND; 1636 return NS_SUCCESS; 1637 } 1638 1639 #ifdef YP 1640 static char *__ypdomain; 1641 1642 /*ARGSUSED*/ 1643 static struct addrinfo * 1644 _yphostent(line, pai) 1645 char *line; 1646 const struct addrinfo *pai; 1647 { 1648 struct addrinfo sentinel, *cur; 1649 struct addrinfo hints, *res, *res0; 1650 int error; 1651 char *p = line; 1652 const char *addr, *canonname; 1653 char *nextline; 1654 char *cp; 1655 1656 addr = canonname = NULL; 1657 1658 memset(&sentinel, 0, sizeof(sentinel)); 1659 cur = &sentinel; 1660 1661 nextline: 1662 /* terminate line */ 1663 cp = strchr(p, '\n'); 1664 if (cp) { 1665 *cp++ = '\0'; 1666 nextline = cp; 1667 } else 1668 nextline = NULL; 1669 1670 cp = strpbrk(p, " \t"); 1671 if (cp == NULL) { 1672 if (canonname == NULL) 1673 return (NULL); 1674 else 1675 goto done; 1676 } 1677 *cp++ = '\0'; 1678 1679 addr = p; 1680 1681 while (cp && *cp) { 1682 if (*cp == ' ' || *cp == '\t') { 1683 cp++; 1684 continue; 1685 } 1686 if (!canonname) 1687 canonname = cp; 1688 if ((cp = strpbrk(cp, " \t")) != NULL) 1689 *cp++ = '\0'; 1690 } 1691 1692 hints = *pai; 1693 hints.ai_flags = AI_NUMERICHOST; 1694 error = getaddrinfo(addr, NULL, &hints, &res0); 1695 if (error == 0) { 1696 for (res = res0; res; res = res->ai_next) { 1697 /* cover it up */ 1698 res->ai_flags = pai->ai_flags; 1699 1700 if (pai->ai_flags & AI_CANONNAME) 1701 (void)get_canonname(pai, res, canonname); 1702 } 1703 } else 1704 res0 = NULL; 1705 if (res0) { 1706 cur->ai_next = res0; 1707 while (cur && cur->ai_next) 1708 cur = cur->ai_next; 1709 } 1710 1711 if (nextline) { 1712 p = nextline; 1713 goto nextline; 1714 } 1715 1716 done: 1717 return sentinel.ai_next; 1718 } 1719 1720 /*ARGSUSED*/ 1721 static int 1722 _yp_getaddrinfo(rv, cb_data, ap) 1723 void *rv; 1724 void *cb_data; 1725 va_list ap; 1726 { 1727 struct addrinfo sentinel, *cur; 1728 struct addrinfo *ai = NULL; 1729 static char *__ypcurrent; 1730 int __ypcurrentlen, r; 1731 const char *name; 1732 const struct addrinfo *pai; 1733 1734 name = va_arg(ap, char *); 1735 pai = va_arg(ap, const struct addrinfo *); 1736 1737 memset(&sentinel, 0, sizeof(sentinel)); 1738 cur = &sentinel; 1739 1740 if (!__ypdomain) { 1741 if (_yp_check(&__ypdomain) == 0) 1742 return NS_UNAVAIL; 1743 } 1744 if (__ypcurrent) 1745 free(__ypcurrent); 1746 __ypcurrent = NULL; 1747 1748 /* hosts.byname is only for IPv4 (Solaris8) */ 1749 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1750 r = yp_match(__ypdomain, "hosts.byname", name, 1751 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1752 if (r == 0) { 1753 struct addrinfo ai4; 1754 1755 ai4 = *pai; 1756 ai4.ai_family = AF_INET; 1757 ai = _yphostent(__ypcurrent, &ai4); 1758 if (ai) { 1759 cur->ai_next = ai; 1760 while (cur && cur->ai_next) 1761 cur = cur->ai_next; 1762 } 1763 } 1764 } 1765 1766 /* ipnodes.byname can hold both IPv4/v6 */ 1767 r = yp_match(__ypdomain, "ipnodes.byname", name, 1768 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1769 if (r == 0) { 1770 ai = _yphostent(__ypcurrent, pai); 1771 if (ai) { 1772 cur->ai_next = ai; 1773 while (cur && cur->ai_next) 1774 cur = cur->ai_next; 1775 } 1776 } 1777 1778 if (sentinel.ai_next == NULL) { 1779 h_errno = HOST_NOT_FOUND; 1780 return NS_NOTFOUND; 1781 } 1782 *((struct addrinfo **)rv) = sentinel.ai_next; 1783 return NS_SUCCESS; 1784 } 1785 #endif 1786 1787 /* resolver logic */ 1788 1789 extern const char *__hostalias(const char *); 1790 extern int h_errno; 1791 1792 /* 1793 * Formulate a normal query, send, and await answer. 1794 * Returned answer is placed in supplied buffer "answer". 1795 * Perform preliminary check of answer, returning success only 1796 * if no error is indicated and the answer count is nonzero. 1797 * Return the size of the response on success, -1 on error. 1798 * Error number is left in h_errno. 1799 * 1800 * Caller must parse answer and determine whether it answers the question. 1801 */ 1802 static int 1803 res_queryN(name, target) 1804 const char *name; /* domain name */ 1805 struct res_target *target; 1806 { 1807 u_char *buf; 1808 HEADER *hp; 1809 int n; 1810 struct res_target *t; 1811 int rcode; 1812 int ancount; 1813 1814 rcode = NOERROR; 1815 ancount = 0; 1816 1817 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1818 h_errno = NETDB_INTERNAL; 1819 return (-1); 1820 } 1821 1822 buf = malloc(MAXPACKET); 1823 if (!buf) { 1824 h_errno = NETDB_INTERNAL; 1825 return -1; 1826 } 1827 1828 for (t = target; t; t = t->next) { 1829 int class, type; 1830 u_char *answer; 1831 int anslen; 1832 1833 hp = (HEADER *)(void *)t->answer; 1834 hp->rcode = NOERROR; /* default */ 1835 1836 /* make it easier... */ 1837 class = t->qclass; 1838 type = t->qtype; 1839 answer = t->answer; 1840 anslen = t->anslen; 1841 #ifdef DEBUG 1842 if (_res.options & RES_DEBUG) 1843 printf(";; res_query(%s, %d, %d)\n", name, class, type); 1844 #endif 1845 1846 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL, 1847 buf, MAXPACKET); 1848 if (n > 0 && (_res.options & RES_USE_EDNS0) != 0) 1849 n = res_opt(n, buf, MAXPACKET, anslen); 1850 if (n <= 0) { 1851 #ifdef DEBUG 1852 if (_res.options & RES_DEBUG) 1853 printf(";; res_query: mkquery failed\n"); 1854 #endif 1855 free(buf); 1856 h_errno = NO_RECOVERY; 1857 return (n); 1858 } 1859 n = res_send(buf, n, answer, anslen); 1860 #if 0 1861 if (n < 0) { 1862 #ifdef DEBUG 1863 if (_res.options & RES_DEBUG) 1864 printf(";; res_query: send error\n"); 1865 #endif 1866 free(buf); 1867 h_errno = TRY_AGAIN; 1868 return (n); 1869 } 1870 #endif 1871 1872 if (n < 0 || n > anslen) 1873 hp->rcode = FORMERR; /* XXX not very informative */ 1874 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1875 rcode = hp->rcode; /* record most recent error */ 1876 #ifdef DEBUG 1877 if (_res.options & RES_DEBUG) 1878 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1879 ntohs(hp->ancount)); 1880 #endif 1881 continue; 1882 } 1883 1884 ancount += ntohs(hp->ancount); 1885 1886 t->n = n; 1887 } 1888 1889 free(buf); 1890 1891 if (ancount == 0) { 1892 switch (rcode) { 1893 case NXDOMAIN: 1894 h_errno = HOST_NOT_FOUND; 1895 break; 1896 case SERVFAIL: 1897 h_errno = TRY_AGAIN; 1898 break; 1899 case NOERROR: 1900 h_errno = NO_DATA; 1901 break; 1902 case FORMERR: 1903 case NOTIMP: 1904 case REFUSED: 1905 default: 1906 h_errno = NO_RECOVERY; 1907 break; 1908 } 1909 return (-1); 1910 } 1911 return (ancount); 1912 } 1913 1914 /* 1915 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1916 * Return the size of the response on success, -1 on error. 1917 * If enabled, implement search rules until answer or unrecoverable failure 1918 * is detected. Error code, if any, is left in h_errno. 1919 */ 1920 static int 1921 res_searchN(name, target) 1922 const char *name; /* domain name */ 1923 struct res_target *target; 1924 { 1925 const char *cp, * const *domain; 1926 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 1927 u_int dots; 1928 int trailing_dot, ret, saved_herrno; 1929 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1930 1931 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1932 h_errno = NETDB_INTERNAL; 1933 return (-1); 1934 } 1935 1936 errno = 0; 1937 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1938 dots = 0; 1939 for (cp = name; *cp; cp++) 1940 dots += (*cp == '.'); 1941 trailing_dot = 0; 1942 if (cp > name && *--cp == '.') 1943 trailing_dot++; 1944 1945 /* 1946 * if there aren't any dots, it could be a user-level alias 1947 */ 1948 if (!dots && (cp = __hostalias(name)) != NULL) 1949 return (res_queryN(cp, target)); 1950 1951 /* 1952 * If there are dots in the name already, let's just give it a try 1953 * 'as is'. The threshold can be set with the "ndots" option. 1954 */ 1955 saved_herrno = -1; 1956 if (dots >= _res.ndots) { 1957 ret = res_querydomainN(name, NULL, target); 1958 if (ret > 0) 1959 return (ret); 1960 saved_herrno = h_errno; 1961 tried_as_is++; 1962 } 1963 1964 /* 1965 * We do at least one level of search if 1966 * - there is no dot and RES_DEFNAME is set, or 1967 * - there is at least one dot, there is no trailing dot, 1968 * and RES_DNSRCH is set. 1969 */ 1970 if ((!dots && (_res.options & RES_DEFNAMES)) || 1971 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { 1972 int done = 0; 1973 1974 for (domain = (const char * const *)_res.dnsrch; 1975 *domain && !done; 1976 domain++) { 1977 1978 ret = res_querydomainN(name, *domain, target); 1979 if (ret > 0) 1980 return (ret); 1981 1982 /* 1983 * If no server present, give up. 1984 * If name isn't found in this domain, 1985 * keep trying higher domains in the search list 1986 * (if that's enabled). 1987 * On a NO_DATA error, keep trying, otherwise 1988 * a wildcard entry of another type could keep us 1989 * from finding this entry higher in the domain. 1990 * If we get some other error (negative answer or 1991 * server failure), then stop searching up, 1992 * but try the input name below in case it's 1993 * fully-qualified. 1994 */ 1995 if (errno == ECONNREFUSED) { 1996 h_errno = TRY_AGAIN; 1997 return (-1); 1998 } 1999 2000 switch (h_errno) { 2001 case NO_DATA: 2002 got_nodata++; 2003 /* FALLTHROUGH */ 2004 case HOST_NOT_FOUND: 2005 /* keep trying */ 2006 break; 2007 case TRY_AGAIN: 2008 if (hp->rcode == SERVFAIL) { 2009 /* try next search element, if any */ 2010 got_servfail++; 2011 break; 2012 } 2013 /* FALLTHROUGH */ 2014 default: 2015 /* anything else implies that we're done */ 2016 done++; 2017 } 2018 /* 2019 * if we got here for some reason other than DNSRCH, 2020 * we only wanted one iteration of the loop, so stop. 2021 */ 2022 if (!(_res.options & RES_DNSRCH)) 2023 done++; 2024 } 2025 } 2026 2027 /* 2028 * if we have not already tried the name "as is", do that now. 2029 * note that we do this regardless of how many dots were in the 2030 * name or whether it ends with a dot. 2031 */ 2032 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) { 2033 ret = res_querydomainN(name, NULL, target); 2034 if (ret > 0) 2035 return (ret); 2036 } 2037 2038 /* 2039 * if we got here, we didn't satisfy the search. 2040 * if we did an initial full query, return that query's h_errno 2041 * (note that we wouldn't be here if that query had succeeded). 2042 * else if we ever got a nodata, send that back as the reason. 2043 * else send back meaningless h_errno, that being the one from 2044 * the last DNSRCH we did. 2045 */ 2046 if (saved_herrno != -1) 2047 h_errno = saved_herrno; 2048 else if (got_nodata) 2049 h_errno = NO_DATA; 2050 else if (got_servfail) 2051 h_errno = TRY_AGAIN; 2052 return (-1); 2053 } 2054 2055 /* 2056 * Perform a call on res_query on the concatenation of name and domain, 2057 * removing a trailing dot from name if domain is NULL. 2058 */ 2059 static int 2060 res_querydomainN(name, domain, target) 2061 const char *name, *domain; 2062 struct res_target *target; 2063 { 2064 char nbuf[MAXDNAME]; 2065 const char *longname = nbuf; 2066 size_t n, d; 2067 2068 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 2069 h_errno = NETDB_INTERNAL; 2070 return (-1); 2071 } 2072 #ifdef DEBUG 2073 if (_res.options & RES_DEBUG) 2074 printf(";; res_querydomain(%s, %s)\n", 2075 name, domain?domain:"<Nil>"); 2076 #endif 2077 if (domain == NULL) { 2078 /* 2079 * Check for trailing '.'; 2080 * copy without '.' if present. 2081 */ 2082 n = strlen(name); 2083 if (n >= MAXDNAME) { 2084 h_errno = NO_RECOVERY; 2085 return (-1); 2086 } 2087 if (n > 0 && name[--n] == '.') { 2088 strncpy(nbuf, name, n); 2089 nbuf[n] = '\0'; 2090 } else 2091 longname = name; 2092 } else { 2093 n = strlen(name); 2094 d = strlen(domain); 2095 if (n + d + 1 >= MAXDNAME) { 2096 h_errno = NO_RECOVERY; 2097 return (-1); 2098 } 2099 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2100 } 2101 return (res_queryN(longname, target)); 2102 } 2103