getaddrinfo.c revision 1.53.2.4
1 /* $NetBSD: getaddrinfo.c,v 1.53.2.4 2002/08/27 23:49:33 nathanw Exp $ */ 2 /* $KAME: getaddrinfo.c,v 1.29 2000/08/31 17:26:57 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Issues to be discussed: 35 * - Thread safe-ness must be checked. 36 * - Return values. There are nonstandard return values defined and used 37 * in the source code. This is because RFC2553 is silent about which error 38 * code must be returned for which situation. 39 * - IPv4 classful (shortened) form. RFC2553 is silent about it. XNET 5.2 40 * says to use inet_aton() to convert IPv4 numeric to binary (alows 41 * classful form as a result). 42 * current code - disallow classful form for IPv4 (due to use of inet_pton). 43 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 44 * invalid. 45 * current code - SEGV on freeaddrinfo(NULL) 46 * Note: 47 * - We use getipnodebyname() just for thread-safeness. There's no intent 48 * to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to 49 * getipnodebyname(). 50 * - The code filters out AFs that are not supported by the kernel, 51 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 52 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 53 * in ai_flags? 54 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 55 * (1) what should we do against numeric hostname (2) what should we do 56 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 57 * non-loopback address configured? global address configured? 58 * - To avoid search order issue, we have a big amount of code duplicate 59 * from gethnamaddr.c and some other places. The issues that there's no 60 * lower layer function to lookup "IPv4 or IPv6" record. Calling 61 * gethostbyname2 from getaddrinfo will end up in wrong search order, as 62 * follows: 63 * - The code makes use of following calls when asked to resolver with 64 * ai_family = PF_UNSPEC: 65 * getipnodebyname(host, AF_INET6); 66 * getipnodebyname(host, AF_INET); 67 * This will result in the following queries if the node is configure to 68 * prefer /etc/hosts than DNS: 69 * lookup /etc/hosts for IPv6 address 70 * lookup DNS for IPv6 address 71 * lookup /etc/hosts for IPv4 address 72 * lookup DNS for IPv4 address 73 * which may not meet people's requirement. 74 * The right thing to happen is to have underlying layer which does 75 * PF_UNSPEC lookup (lookup both) and return chain of addrinfos. 76 * This would result in a bit of code duplicate with _dns_ghbyname() and 77 * friends. 78 */ 79 80 #include <sys/cdefs.h> 81 #if defined(LIBC_SCCS) && !defined(lint) 82 __RCSID("$NetBSD: getaddrinfo.c,v 1.53.2.4 2002/08/27 23:49:33 nathanw Exp $"); 83 #endif /* LIBC_SCCS and not lint */ 84 85 #include "namespace.h" 86 #include <sys/types.h> 87 #include <sys/param.h> 88 #include <sys/socket.h> 89 #include <net/if.h> 90 #include <netinet/in.h> 91 #include <arpa/inet.h> 92 #include <arpa/nameser.h> 93 #include <assert.h> 94 #include <ctype.h> 95 #include <errno.h> 96 #include <netdb.h> 97 #include <resolv.h> 98 #include <stddef.h> 99 #include <stdio.h> 100 #include <stdlib.h> 101 #include <string.h> 102 #include <unistd.h> 103 104 #include <syslog.h> 105 #include <stdarg.h> 106 #include <nsswitch.h> 107 108 #ifdef YP 109 #include <rpc/rpc.h> 110 #include <rpcsvc/yp_prot.h> 111 #include <rpcsvc/ypclnt.h> 112 #endif 113 114 #ifdef __weak_alias 115 __weak_alias(getaddrinfo,_getaddrinfo) 116 __weak_alias(freeaddrinfo,_freeaddrinfo) 117 __weak_alias(gai_strerror,_gai_strerror) 118 #endif 119 120 #define SUCCESS 0 121 #define ANY 0 122 #define YES 1 123 #define NO 0 124 125 static const char in_addrany[] = { 0, 0, 0, 0 }; 126 static const char in_loopback[] = { 127, 0, 0, 1 }; 127 #ifdef INET6 128 static const char in6_addrany[] = { 129 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 130 }; 131 static const char in6_loopback[] = { 132 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 133 }; 134 #endif 135 136 static const struct afd { 137 int a_af; 138 int a_addrlen; 139 int a_socklen; 140 int a_off; 141 const char *a_addrany; 142 const char *a_loopback; 143 int a_scoped; 144 } afdl [] = { 145 #ifdef INET6 146 {PF_INET6, sizeof(struct in6_addr), 147 sizeof(struct sockaddr_in6), 148 offsetof(struct sockaddr_in6, sin6_addr), 149 in6_addrany, in6_loopback, 1}, 150 #endif 151 {PF_INET, sizeof(struct in_addr), 152 sizeof(struct sockaddr_in), 153 offsetof(struct sockaddr_in, sin_addr), 154 in_addrany, in_loopback, 0}, 155 {0, 0, 0, 0, NULL, NULL, 0}, 156 }; 157 158 struct explore { 159 int e_af; 160 int e_socktype; 161 int e_protocol; 162 const char *e_protostr; 163 int e_wild; 164 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 165 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 166 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 167 }; 168 169 static const struct explore explore[] = { 170 #if 0 171 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 172 #endif 173 #ifdef INET6 174 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 175 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 176 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 177 #endif 178 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 179 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 180 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 181 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 182 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 183 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 184 { -1, 0, 0, NULL, 0 }, 185 }; 186 187 #ifdef INET6 188 #define PTON_MAX 16 189 #else 190 #define PTON_MAX 4 191 #endif 192 193 static const ns_src default_dns_files[] = { 194 { NSSRC_FILES, NS_SUCCESS }, 195 { NSSRC_DNS, NS_SUCCESS }, 196 { 0 } 197 }; 198 199 #define MAXPACKET (64*1024) 200 201 typedef union { 202 HEADER hdr; 203 u_char buf[MAXPACKET]; 204 } querybuf; 205 206 struct res_target { 207 struct res_target *next; 208 const char *name; /* domain name */ 209 int qclass, qtype; /* class and type of query */ 210 u_char *answer; /* buffer to put answer */ 211 int anslen; /* size of answer buffer */ 212 int n; /* result length */ 213 }; 214 215 static int str_isnumber __P((const char *)); 216 static int explore_fqdn __P((const struct addrinfo *, const char *, 217 const char *, struct addrinfo **)); 218 static int explore_null __P((const struct addrinfo *, 219 const char *, struct addrinfo **)); 220 static int explore_numeric __P((const struct addrinfo *, const char *, 221 const char *, struct addrinfo **)); 222 static int explore_numeric_scope __P((const struct addrinfo *, const char *, 223 const char *, struct addrinfo **)); 224 static int get_canonname __P((const struct addrinfo *, 225 struct addrinfo *, const char *)); 226 static struct addrinfo *get_ai __P((const struct addrinfo *, 227 const struct afd *, const char *)); 228 static int get_portmatch __P((const struct addrinfo *, const char *)); 229 static int get_port __P((struct addrinfo *, const char *, int)); 230 static const struct afd *find_afd __P((int)); 231 #if 0 232 static int addrconfig __P((const struct addrinfo *)); 233 #endif 234 #ifdef INET6 235 static int ip6_str2scopeid __P((char *, struct sockaddr_in6 *, u_int32_t *)); 236 #endif 237 238 static struct addrinfo *getanswer __P((const querybuf *, int, const char *, int, 239 const struct addrinfo *)); 240 static int _dns_getaddrinfo __P((void *, void *, va_list)); 241 static void _sethtent __P((void)); 242 static void _endhtent __P((void)); 243 static struct addrinfo *_gethtent __P((const char *, const struct addrinfo *)); 244 static int _files_getaddrinfo __P((void *, void *, va_list)); 245 #ifdef YP 246 static struct addrinfo *_yphostent __P((char *, const struct addrinfo *)); 247 static int _yp_getaddrinfo __P((void *, void *, va_list)); 248 #endif 249 250 static int res_queryN __P((const char *, struct res_target *)); 251 static int res_searchN __P((const char *, struct res_target *)); 252 static int res_querydomainN __P((const char *, const char *, 253 struct res_target *)); 254 255 static const char * const ai_errlist[] = { 256 "Success", 257 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 258 "Temporary failure in name resolution", /* EAI_AGAIN */ 259 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 260 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 261 "ai_family not supported", /* EAI_FAMILY */ 262 "Memory allocation failure", /* EAI_MEMORY */ 263 "No address associated with hostname", /* EAI_NODATA */ 264 "hostname nor servname provided, or not known", /* EAI_NONAME */ 265 "servname not supported for ai_socktype", /* EAI_SERVICE */ 266 "ai_socktype not supported", /* EAI_SOCKTYPE */ 267 "System error returned in errno", /* EAI_SYSTEM */ 268 "Invalid value for hints", /* EAI_BADHINTS */ 269 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 270 "Unknown error", /* EAI_MAX */ 271 }; 272 273 /* XXX macros that make external reference is BAD. */ 274 275 #define GET_AI(ai, afd, addr) \ 276 do { \ 277 /* external reference: pai, error, and label free */ \ 278 (ai) = get_ai(pai, (afd), (addr)); \ 279 if ((ai) == NULL) { \ 280 error = EAI_MEMORY; \ 281 goto free; \ 282 } \ 283 } while (/*CONSTCOND*/0) 284 285 #define GET_PORT(ai, serv) \ 286 do { \ 287 /* external reference: error and label free */ \ 288 error = get_port((ai), (serv), 0); \ 289 if (error != 0) \ 290 goto free; \ 291 } while (/*CONSTCOND*/0) 292 293 #define GET_CANONNAME(ai, str) \ 294 do { \ 295 /* external reference: pai, error and label free */ \ 296 error = get_canonname(pai, (ai), (str)); \ 297 if (error != 0) \ 298 goto free; \ 299 } while (/*CONSTCOND*/0) 300 301 #define ERR(err) \ 302 do { \ 303 /* external reference: error, and label bad */ \ 304 error = (err); \ 305 goto bad; \ 306 /*NOTREACHED*/ \ 307 } while (/*CONSTCOND*/0) 308 309 #define MATCH_FAMILY(x, y, w) \ 310 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 311 #define MATCH(x, y, w) \ 312 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 313 314 char * 315 gai_strerror(ecode) 316 int ecode; 317 { 318 if (ecode < 0 || ecode > EAI_MAX) 319 ecode = EAI_MAX; 320 /* LINTED const castaway */ 321 return (char *) ai_errlist[ecode]; 322 } 323 324 void 325 freeaddrinfo(ai) 326 struct addrinfo *ai; 327 { 328 struct addrinfo *next; 329 330 _DIAGASSERT(ai != NULL); 331 332 do { 333 next = ai->ai_next; 334 if (ai->ai_canonname) 335 free(ai->ai_canonname); 336 /* no need to free(ai->ai_addr) */ 337 free(ai); 338 ai = next; 339 } while (ai); 340 } 341 342 static int 343 str_isnumber(p) 344 const char *p; 345 { 346 char *ep; 347 348 _DIAGASSERT(p != NULL); 349 350 if (*p == '\0') 351 return NO; 352 ep = NULL; 353 errno = 0; 354 (void)strtoul(p, &ep, 10); 355 if (errno == 0 && ep && *ep == '\0') 356 return YES; 357 else 358 return NO; 359 } 360 361 int 362 getaddrinfo(hostname, servname, hints, res) 363 const char *hostname, *servname; 364 const struct addrinfo *hints; 365 struct addrinfo **res; 366 { 367 struct addrinfo sentinel; 368 struct addrinfo *cur; 369 int error = 0; 370 struct addrinfo ai; 371 struct addrinfo ai0; 372 struct addrinfo *pai; 373 const struct explore *ex; 374 375 /* hostname is allowed to be NULL */ 376 /* servname is allowed to be NULL */ 377 /* hints is allowed to be NULL */ 378 _DIAGASSERT(res != NULL); 379 380 memset(&sentinel, 0, sizeof(sentinel)); 381 cur = &sentinel; 382 pai = &ai; 383 pai->ai_flags = 0; 384 pai->ai_family = PF_UNSPEC; 385 pai->ai_socktype = ANY; 386 pai->ai_protocol = ANY; 387 pai->ai_addrlen = 0; 388 pai->ai_canonname = NULL; 389 pai->ai_addr = NULL; 390 pai->ai_next = NULL; 391 392 if (hostname == NULL && servname == NULL) 393 return EAI_NONAME; 394 if (hints) { 395 /* error check for hints */ 396 if (hints->ai_addrlen || hints->ai_canonname || 397 hints->ai_addr || hints->ai_next) 398 ERR(EAI_BADHINTS); /* xxx */ 399 if (hints->ai_flags & ~AI_MASK) 400 ERR(EAI_BADFLAGS); 401 switch (hints->ai_family) { 402 case PF_UNSPEC: 403 case PF_INET: 404 #ifdef INET6 405 case PF_INET6: 406 #endif 407 break; 408 default: 409 ERR(EAI_FAMILY); 410 } 411 memcpy(pai, hints, sizeof(*pai)); 412 413 /* 414 * if both socktype/protocol are specified, check if they 415 * are meaningful combination. 416 */ 417 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 418 for (ex = explore; ex->e_af >= 0; ex++) { 419 if (pai->ai_family != ex->e_af) 420 continue; 421 if (ex->e_socktype == ANY) 422 continue; 423 if (ex->e_protocol == ANY) 424 continue; 425 if (pai->ai_socktype == ex->e_socktype 426 && pai->ai_protocol != ex->e_protocol) { 427 ERR(EAI_BADHINTS); 428 } 429 } 430 } 431 } 432 433 /* 434 * check for special cases. (1) numeric servname is disallowed if 435 * socktype/protocol are left unspecified. (2) servname is disallowed 436 * for raw and other inet{,6} sockets. 437 */ 438 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 439 #ifdef PF_INET6 440 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 441 #endif 442 ) { 443 ai0 = *pai; /* backup *pai */ 444 445 if (pai->ai_family == PF_UNSPEC) { 446 #ifdef PF_INET6 447 pai->ai_family = PF_INET6; 448 #else 449 pai->ai_family = PF_INET; 450 #endif 451 } 452 error = get_portmatch(pai, servname); 453 if (error) 454 ERR(error); 455 456 *pai = ai0; 457 } 458 459 ai0 = *pai; 460 461 /* NULL hostname, or numeric hostname */ 462 for (ex = explore; ex->e_af >= 0; ex++) { 463 *pai = ai0; 464 465 /* PF_UNSPEC entries are prepared for DNS queries only */ 466 if (ex->e_af == PF_UNSPEC) 467 continue; 468 469 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 470 continue; 471 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 472 continue; 473 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 474 continue; 475 476 if (pai->ai_family == PF_UNSPEC) 477 pai->ai_family = ex->e_af; 478 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 479 pai->ai_socktype = ex->e_socktype; 480 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 481 pai->ai_protocol = ex->e_protocol; 482 483 if (hostname == NULL) 484 error = explore_null(pai, servname, &cur->ai_next); 485 else 486 error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next); 487 488 if (error) 489 goto free; 490 491 while (cur && cur->ai_next) 492 cur = cur->ai_next; 493 } 494 495 /* 496 * XXX 497 * If numreic representation of AF1 can be interpreted as FQDN 498 * representation of AF2, we need to think again about the code below. 499 */ 500 if (sentinel.ai_next) 501 goto good; 502 503 if (pai->ai_flags & AI_NUMERICHOST) 504 ERR(EAI_NODATA); 505 if (hostname == NULL) 506 ERR(EAI_NODATA); 507 508 /* 509 * hostname as alphabetical name. 510 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 511 * outer loop by AFs. 512 */ 513 for (ex = explore; ex->e_af >= 0; ex++) { 514 *pai = ai0; 515 516 /* require exact match for family field */ 517 if (pai->ai_family != ex->e_af) 518 continue; 519 520 if (!MATCH(pai->ai_socktype, ex->e_socktype, 521 WILD_SOCKTYPE(ex))) { 522 continue; 523 } 524 if (!MATCH(pai->ai_protocol, ex->e_protocol, 525 WILD_PROTOCOL(ex))) { 526 continue; 527 } 528 529 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 530 pai->ai_socktype = ex->e_socktype; 531 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 532 pai->ai_protocol = ex->e_protocol; 533 534 error = explore_fqdn(pai, hostname, servname, 535 &cur->ai_next); 536 537 while (cur && cur->ai_next) 538 cur = cur->ai_next; 539 } 540 541 /* XXX */ 542 if (sentinel.ai_next) 543 error = 0; 544 545 if (error) 546 goto free; 547 if (error == 0) { 548 if (sentinel.ai_next) { 549 good: 550 *res = sentinel.ai_next; 551 return SUCCESS; 552 } else 553 error = EAI_FAIL; 554 } 555 free: 556 bad: 557 if (sentinel.ai_next) 558 freeaddrinfo(sentinel.ai_next); 559 *res = NULL; 560 return error; 561 } 562 563 /* 564 * FQDN hostname, DNS lookup 565 */ 566 static int 567 explore_fqdn(pai, hostname, servname, res) 568 const struct addrinfo *pai; 569 const char *hostname; 570 const char *servname; 571 struct addrinfo **res; 572 { 573 struct addrinfo *result; 574 struct addrinfo *cur; 575 int error = 0; 576 static const ns_dtab dtab[] = { 577 NS_FILES_CB(_files_getaddrinfo, NULL) 578 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 579 NS_NIS_CB(_yp_getaddrinfo, NULL) 580 { 0 } 581 }; 582 583 _DIAGASSERT(pai != NULL); 584 /* hostname may be NULL */ 585 /* servname may be NULL */ 586 _DIAGASSERT(res != NULL); 587 588 result = NULL; 589 590 #if 0 591 /* 592 * If AI_ADDRCONFIG is specified, check if we are expected to 593 * return the address family or not. 594 * XXX does not handle PF_UNSPEC - should filter out result from 595 * nsdispatch() 596 */ 597 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(pai)) 598 return 0; 599 #endif 600 601 /* 602 * if the servname does not match socktype/protocol, ignore it. 603 */ 604 if (get_portmatch(pai, servname) != 0) 605 return 0; 606 607 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 608 default_dns_files, hostname, pai)) { 609 case NS_TRYAGAIN: 610 error = EAI_AGAIN; 611 goto free; 612 case NS_UNAVAIL: 613 error = EAI_FAIL; 614 goto free; 615 case NS_NOTFOUND: 616 error = EAI_NODATA; 617 goto free; 618 case NS_SUCCESS: 619 error = 0; 620 for (cur = result; cur; cur = cur->ai_next) { 621 GET_PORT(cur, servname); 622 /* canonname should be filled already */ 623 } 624 break; 625 } 626 627 *res = result; 628 629 return 0; 630 631 free: 632 if (result) 633 freeaddrinfo(result); 634 return error; 635 } 636 637 /* 638 * hostname == NULL. 639 * passive socket -> anyaddr (0.0.0.0 or ::) 640 * non-passive socket -> localhost (127.0.0.1 or ::1) 641 */ 642 static int 643 explore_null(pai, servname, res) 644 const struct addrinfo *pai; 645 const char *servname; 646 struct addrinfo **res; 647 { 648 int s; 649 const struct afd *afd; 650 struct addrinfo *cur; 651 struct addrinfo sentinel; 652 int error; 653 654 _DIAGASSERT(pai != NULL); 655 /* servname may be NULL */ 656 _DIAGASSERT(res != NULL); 657 658 *res = NULL; 659 sentinel.ai_next = NULL; 660 cur = &sentinel; 661 662 /* 663 * filter out AFs that are not supported by the kernel 664 * XXX errno? 665 */ 666 s = socket(pai->ai_family, SOCK_DGRAM, 0); 667 if (s < 0) { 668 if (errno != EMFILE) 669 return 0; 670 } else 671 close(s); 672 673 /* 674 * if the servname does not match socktype/protocol, ignore it. 675 */ 676 if (get_portmatch(pai, servname) != 0) 677 return 0; 678 679 afd = find_afd(pai->ai_family); 680 if (afd == NULL) 681 return 0; 682 683 if (pai->ai_flags & AI_PASSIVE) { 684 GET_AI(cur->ai_next, afd, afd->a_addrany); 685 /* xxx meaningless? 686 * GET_CANONNAME(cur->ai_next, "anyaddr"); 687 */ 688 GET_PORT(cur->ai_next, servname); 689 } else { 690 GET_AI(cur->ai_next, afd, afd->a_loopback); 691 /* xxx meaningless? 692 * GET_CANONNAME(cur->ai_next, "localhost"); 693 */ 694 GET_PORT(cur->ai_next, servname); 695 } 696 cur = cur->ai_next; 697 698 *res = sentinel.ai_next; 699 return 0; 700 701 free: 702 if (sentinel.ai_next) 703 freeaddrinfo(sentinel.ai_next); 704 return error; 705 } 706 707 /* 708 * numeric hostname 709 */ 710 static int 711 explore_numeric(pai, hostname, servname, res) 712 const struct addrinfo *pai; 713 const char *hostname; 714 const char *servname; 715 struct addrinfo **res; 716 { 717 const struct afd *afd; 718 struct addrinfo *cur; 719 struct addrinfo sentinel; 720 int error; 721 char pton[PTON_MAX]; 722 723 _DIAGASSERT(pai != NULL); 724 /* hostname may be NULL */ 725 /* servname may be NULL */ 726 _DIAGASSERT(res != NULL); 727 728 *res = NULL; 729 sentinel.ai_next = NULL; 730 cur = &sentinel; 731 732 /* 733 * if the servname does not match socktype/protocol, ignore it. 734 */ 735 if (get_portmatch(pai, servname) != 0) 736 return 0; 737 738 afd = find_afd(pai->ai_family); 739 if (afd == NULL) 740 return 0; 741 742 switch (afd->a_af) { 743 #if 0 /*X/Open spec*/ 744 case AF_INET: 745 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 746 if (pai->ai_family == afd->a_af || 747 pai->ai_family == PF_UNSPEC /*?*/) { 748 GET_AI(cur->ai_next, afd, pton); 749 GET_PORT(cur->ai_next, servname); 750 while (cur && cur->ai_next) 751 cur = cur->ai_next; 752 } else 753 ERR(EAI_FAMILY); /*xxx*/ 754 } 755 break; 756 #endif 757 default: 758 if (inet_pton(afd->a_af, hostname, pton) == 1) { 759 if (pai->ai_family == afd->a_af || 760 pai->ai_family == PF_UNSPEC /*?*/) { 761 GET_AI(cur->ai_next, afd, pton); 762 GET_PORT(cur->ai_next, servname); 763 while (cur && cur->ai_next) 764 cur = cur->ai_next; 765 } else 766 ERR(EAI_FAMILY); /*xxx*/ 767 } 768 break; 769 } 770 771 *res = sentinel.ai_next; 772 return 0; 773 774 free: 775 bad: 776 if (sentinel.ai_next) 777 freeaddrinfo(sentinel.ai_next); 778 return error; 779 } 780 781 /* 782 * numeric hostname with scope 783 */ 784 static int 785 explore_numeric_scope(pai, hostname, servname, res) 786 const struct addrinfo *pai; 787 const char *hostname; 788 const char *servname; 789 struct addrinfo **res; 790 { 791 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 792 return explore_numeric(pai, hostname, servname, res); 793 #else 794 const struct afd *afd; 795 struct addrinfo *cur; 796 int error; 797 char *cp, *hostname2 = NULL, *scope, *addr; 798 struct sockaddr_in6 *sin6; 799 800 _DIAGASSERT(pai != NULL); 801 /* hostname may be NULL */ 802 /* servname may be NULL */ 803 _DIAGASSERT(res != NULL); 804 805 /* 806 * if the servname does not match socktype/protocol, ignore it. 807 */ 808 if (get_portmatch(pai, servname) != 0) 809 return 0; 810 811 afd = find_afd(pai->ai_family); 812 if (afd == NULL) 813 return 0; 814 815 if (!afd->a_scoped) 816 return explore_numeric(pai, hostname, servname, res); 817 818 cp = strchr(hostname, SCOPE_DELIMITER); 819 if (cp == NULL) 820 return explore_numeric(pai, hostname, servname, res); 821 822 #if 0 823 /* 824 * Handle special case of <scope id><delimiter><scoped_address> 825 */ 826 hostname2 = strdup(hostname); 827 if (hostname2 == NULL) 828 return EAI_MEMORY; 829 /* terminate at the delimiter */ 830 hostname2[cp - hostname] = '\0'; 831 scope = hostname2; 832 addr = cp + 1; 833 #else 834 /* 835 * Handle special case of <scoped_address><delimiter><scope id> 836 */ 837 hostname2 = strdup(hostname); 838 if (hostname2 == NULL) 839 return EAI_MEMORY; 840 /* terminate at the delimiter */ 841 hostname2[cp - hostname] = '\0'; 842 addr = hostname2; 843 scope = cp + 1; 844 #endif 845 846 error = explore_numeric(pai, addr, servname, res); 847 if (error == 0) { 848 u_int32_t scopeid; 849 850 for (cur = *res; cur; cur = cur->ai_next) { 851 if (cur->ai_family != AF_INET6) 852 continue; 853 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 854 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 855 free(hostname2); 856 return(EAI_NODATA); /* XXX: is return OK? */ 857 } 858 sin6->sin6_scope_id = scopeid; 859 } 860 } 861 862 free(hostname2); 863 864 return error; 865 #endif 866 } 867 868 static int 869 get_canonname(pai, ai, str) 870 const struct addrinfo *pai; 871 struct addrinfo *ai; 872 const char *str; 873 { 874 875 _DIAGASSERT(pai != NULL); 876 _DIAGASSERT(ai != NULL); 877 _DIAGASSERT(str != NULL); 878 879 if ((pai->ai_flags & AI_CANONNAME) != 0) { 880 ai->ai_canonname = (char *)malloc(strlen(str) + 1); 881 if (ai->ai_canonname == NULL) 882 return EAI_MEMORY; 883 strcpy(ai->ai_canonname, str); 884 } 885 return 0; 886 } 887 888 static struct addrinfo * 889 get_ai(pai, afd, addr) 890 const struct addrinfo *pai; 891 const struct afd *afd; 892 const char *addr; 893 { 894 char *p; 895 struct addrinfo *ai; 896 897 _DIAGASSERT(pai != NULL); 898 _DIAGASSERT(afd != NULL); 899 _DIAGASSERT(addr != NULL); 900 901 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 902 + (afd->a_socklen)); 903 if (ai == NULL) 904 return NULL; 905 906 memcpy(ai, pai, sizeof(struct addrinfo)); 907 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 908 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 909 ai->ai_addr->sa_len = afd->a_socklen; 910 ai->ai_addrlen = afd->a_socklen; 911 #if defined (__alpha__) || (defined(__i386__) && defined(_LP64)) || defined(__sparc64__) 912 ai->__ai_pad0 = 0; 913 #endif 914 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 915 p = (char *)(void *)(ai->ai_addr); 916 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 917 return ai; 918 } 919 920 static int 921 get_portmatch(ai, servname) 922 const struct addrinfo *ai; 923 const char *servname; 924 { 925 926 _DIAGASSERT(ai != NULL); 927 /* servname may be NULL */ 928 929 /* get_port does not touch first argument. when matchonly == 1. */ 930 /* LINTED const cast */ 931 return get_port((struct addrinfo *)ai, servname, 1); 932 } 933 934 static int 935 get_port(ai, servname, matchonly) 936 struct addrinfo *ai; 937 const char *servname; 938 int matchonly; 939 { 940 const char *proto; 941 struct servent *sp; 942 int port; 943 int allownumeric; 944 945 _DIAGASSERT(ai != NULL); 946 /* servname may be NULL */ 947 948 if (servname == NULL) 949 return 0; 950 switch (ai->ai_family) { 951 case AF_INET: 952 #ifdef AF_INET6 953 case AF_INET6: 954 #endif 955 break; 956 default: 957 return 0; 958 } 959 960 switch (ai->ai_socktype) { 961 case SOCK_RAW: 962 return EAI_SERVICE; 963 case SOCK_DGRAM: 964 case SOCK_STREAM: 965 allownumeric = 1; 966 break; 967 case ANY: 968 allownumeric = 0; 969 break; 970 default: 971 return EAI_SOCKTYPE; 972 } 973 974 if (str_isnumber(servname)) { 975 if (!allownumeric) 976 return EAI_SERVICE; 977 port = atoi(servname); 978 if (port < 0 || port > 65535) 979 return EAI_SERVICE; 980 port = htons(port); 981 } else { 982 switch (ai->ai_socktype) { 983 case SOCK_DGRAM: 984 proto = "udp"; 985 break; 986 case SOCK_STREAM: 987 proto = "tcp"; 988 break; 989 default: 990 proto = NULL; 991 break; 992 } 993 994 if ((sp = getservbyname(servname, proto)) == NULL) 995 return EAI_SERVICE; 996 port = sp->s_port; 997 } 998 999 if (!matchonly) { 1000 switch (ai->ai_family) { 1001 case AF_INET: 1002 ((struct sockaddr_in *)(void *) 1003 ai->ai_addr)->sin_port = port; 1004 break; 1005 #ifdef INET6 1006 case AF_INET6: 1007 ((struct sockaddr_in6 *)(void *) 1008 ai->ai_addr)->sin6_port = port; 1009 break; 1010 #endif 1011 } 1012 } 1013 1014 return 0; 1015 } 1016 1017 static const struct afd * 1018 find_afd(af) 1019 int af; 1020 { 1021 const struct afd *afd; 1022 1023 if (af == PF_UNSPEC) 1024 return NULL; 1025 for (afd = afdl; afd->a_af; afd++) { 1026 if (afd->a_af == af) 1027 return afd; 1028 } 1029 return NULL; 1030 } 1031 1032 #if 0 1033 /* 1034 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1035 * will take care of it. 1036 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1037 * if the code is right or not. 1038 */ 1039 static int 1040 addrconfig(pai) 1041 const struct addrinfo *pai; 1042 { 1043 int s; 1044 1045 _DIAGASSERT(pai != NULL); 1046 1047 /* XXX errno */ 1048 s = socket(pai->ai_family, SOCK_DGRAM, 0); 1049 if (s < 0) 1050 return 0; 1051 close(s); 1052 return 1; 1053 } 1054 #endif 1055 1056 #ifdef INET6 1057 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1058 static int 1059 ip6_str2scopeid(scope, sin6, scopeid) 1060 char *scope; 1061 struct sockaddr_in6 *sin6; 1062 u_int32_t *scopeid; 1063 { 1064 u_long lscopeid; 1065 struct in6_addr *a6; 1066 char *ep; 1067 1068 _DIAGASSERT(scope != NULL); 1069 _DIAGASSERT(sin6 != NULL); 1070 _DIAGASSERT(scopeid != NULL); 1071 1072 a6 = &sin6->sin6_addr; 1073 1074 /* empty scopeid portion is invalid */ 1075 if (*scope == '\0') 1076 return -1; 1077 1078 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1079 /* 1080 * We currently assume a one-to-one mapping between links 1081 * and interfaces, so we simply use interface indices for 1082 * like-local scopes. 1083 */ 1084 *scopeid = if_nametoindex(scope); 1085 if (*scopeid == 0) 1086 goto trynumeric; 1087 return 0; 1088 } 1089 1090 /* still unclear about literal, allow numeric only - placeholder */ 1091 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1092 goto trynumeric; 1093 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1094 goto trynumeric; 1095 else 1096 goto trynumeric; /* global */ 1097 1098 /* try to convert to a numeric id as a last resort */ 1099 trynumeric: 1100 errno = 0; 1101 lscopeid = strtoul(scope, &ep, 10); 1102 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1103 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1104 return 0; 1105 else 1106 return -1; 1107 } 1108 #endif 1109 1110 /* code duplicate with gethnamaddr.c */ 1111 1112 static const char AskedForGot[] = 1113 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1114 static FILE *hostf = NULL; 1115 1116 static struct addrinfo * 1117 getanswer(answer, anslen, qname, qtype, pai) 1118 const querybuf *answer; 1119 int anslen; 1120 const char *qname; 1121 int qtype; 1122 const struct addrinfo *pai; 1123 { 1124 struct addrinfo sentinel, *cur; 1125 struct addrinfo ai; 1126 const struct afd *afd; 1127 char *canonname; 1128 const HEADER *hp; 1129 const u_char *cp; 1130 int n; 1131 const u_char *eom; 1132 char *bp, *ep; 1133 int type, class, ancount, qdcount; 1134 int haveanswer, had_error; 1135 char tbuf[MAXDNAME]; 1136 int (*name_ok) __P((const char *)); 1137 char hostbuf[8*1024]; 1138 1139 _DIAGASSERT(answer != NULL); 1140 _DIAGASSERT(qname != NULL); 1141 _DIAGASSERT(pai != NULL); 1142 1143 memset(&sentinel, 0, sizeof(sentinel)); 1144 cur = &sentinel; 1145 1146 canonname = NULL; 1147 eom = answer->buf + anslen; 1148 switch (qtype) { 1149 case T_A: 1150 case T_AAAA: 1151 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1152 name_ok = res_hnok; 1153 break; 1154 default: 1155 return (NULL); /* XXX should be abort(); */ 1156 } 1157 /* 1158 * find first satisfactory answer 1159 */ 1160 hp = &answer->hdr; 1161 ancount = ntohs(hp->ancount); 1162 qdcount = ntohs(hp->qdcount); 1163 bp = hostbuf; 1164 ep = hostbuf + sizeof hostbuf; 1165 cp = answer->buf + HFIXEDSZ; 1166 if (qdcount != 1) { 1167 h_errno = NO_RECOVERY; 1168 return (NULL); 1169 } 1170 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1171 if ((n < 0) || !(*name_ok)(bp)) { 1172 h_errno = NO_RECOVERY; 1173 return (NULL); 1174 } 1175 cp += n + QFIXEDSZ; 1176 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1177 /* res_send() has already verified that the query name is the 1178 * same as the one we sent; this just gets the expanded name 1179 * (i.e., with the succeeding search-domain tacked on). 1180 */ 1181 n = strlen(bp) + 1; /* for the \0 */ 1182 if (n >= MAXHOSTNAMELEN) { 1183 h_errno = NO_RECOVERY; 1184 return (NULL); 1185 } 1186 canonname = bp; 1187 bp += n; 1188 /* The qname can be abbreviated, but h_name is now absolute. */ 1189 qname = canonname; 1190 } 1191 haveanswer = 0; 1192 had_error = 0; 1193 while (ancount-- > 0 && cp < eom && !had_error) { 1194 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1195 if ((n < 0) || !(*name_ok)(bp)) { 1196 had_error++; 1197 continue; 1198 } 1199 cp += n; /* name */ 1200 type = _getshort(cp); 1201 cp += INT16SZ; /* type */ 1202 class = _getshort(cp); 1203 cp += INT16SZ + INT32SZ; /* class, TTL */ 1204 n = _getshort(cp); 1205 cp += INT16SZ; /* len */ 1206 if (class != C_IN) { 1207 /* XXX - debug? syslog? */ 1208 cp += n; 1209 continue; /* XXX - had_error++ ? */ 1210 } 1211 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1212 type == T_CNAME) { 1213 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1214 if ((n < 0) || !(*name_ok)(tbuf)) { 1215 had_error++; 1216 continue; 1217 } 1218 cp += n; 1219 /* Get canonical name. */ 1220 n = strlen(tbuf) + 1; /* for the \0 */ 1221 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1222 had_error++; 1223 continue; 1224 } 1225 strcpy(bp, tbuf); 1226 canonname = bp; 1227 bp += n; 1228 continue; 1229 } 1230 if (qtype == T_ANY) { 1231 if (!(type == T_A || type == T_AAAA)) { 1232 cp += n; 1233 continue; 1234 } 1235 } else if (type != qtype) { 1236 if (type != T_KEY && type != T_SIG) 1237 syslog(LOG_NOTICE|LOG_AUTH, 1238 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1239 qname, p_class(C_IN), p_type(qtype), 1240 p_type(type)); 1241 cp += n; 1242 continue; /* XXX - had_error++ ? */ 1243 } 1244 switch (type) { 1245 case T_A: 1246 case T_AAAA: 1247 if (strcasecmp(canonname, bp) != 0) { 1248 syslog(LOG_NOTICE|LOG_AUTH, 1249 AskedForGot, canonname, bp); 1250 cp += n; 1251 continue; /* XXX - had_error++ ? */ 1252 } 1253 if (type == T_A && n != INADDRSZ) { 1254 cp += n; 1255 continue; 1256 } 1257 if (type == T_AAAA && n != IN6ADDRSZ) { 1258 cp += n; 1259 continue; 1260 } 1261 if (type == T_AAAA) { 1262 struct in6_addr in6; 1263 memcpy(&in6, cp, IN6ADDRSZ); 1264 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1265 cp += n; 1266 continue; 1267 } 1268 } 1269 if (!haveanswer) { 1270 int nn; 1271 1272 canonname = bp; 1273 nn = strlen(bp) + 1; /* for the \0 */ 1274 bp += nn; 1275 } 1276 1277 /* don't overwrite pai */ 1278 ai = *pai; 1279 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1280 afd = find_afd(ai.ai_family); 1281 if (afd == NULL) { 1282 cp += n; 1283 continue; 1284 } 1285 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1286 if (cur->ai_next == NULL) 1287 had_error++; 1288 while (cur && cur->ai_next) 1289 cur = cur->ai_next; 1290 cp += n; 1291 break; 1292 default: 1293 abort(); 1294 } 1295 if (!had_error) 1296 haveanswer++; 1297 } 1298 if (haveanswer) { 1299 if (!canonname) 1300 (void)get_canonname(pai, sentinel.ai_next, qname); 1301 else 1302 (void)get_canonname(pai, sentinel.ai_next, canonname); 1303 h_errno = NETDB_SUCCESS; 1304 return sentinel.ai_next; 1305 } 1306 1307 h_errno = NO_RECOVERY; 1308 return NULL; 1309 } 1310 1311 /*ARGSUSED*/ 1312 static int 1313 _dns_getaddrinfo(rv, cb_data, ap) 1314 void *rv; 1315 void *cb_data; 1316 va_list ap; 1317 { 1318 struct addrinfo *ai; 1319 querybuf *buf, *buf2; 1320 const char *name; 1321 const struct addrinfo *pai; 1322 struct addrinfo sentinel, *cur; 1323 struct res_target q, q2; 1324 1325 name = va_arg(ap, char *); 1326 pai = va_arg(ap, const struct addrinfo *); 1327 1328 memset(&q, 0, sizeof(q2)); 1329 memset(&q2, 0, sizeof(q2)); 1330 memset(&sentinel, 0, sizeof(sentinel)); 1331 cur = &sentinel; 1332 1333 buf = malloc(sizeof(*buf)); 1334 if (buf == NULL) { 1335 h_errno = NETDB_INTERNAL; 1336 return NS_NOTFOUND; 1337 } 1338 buf2 = malloc(sizeof(*buf2)); 1339 if (buf2 == NULL) { 1340 free(buf); 1341 h_errno = NETDB_INTERNAL; 1342 return NS_NOTFOUND; 1343 } 1344 1345 switch (pai->ai_family) { 1346 case AF_UNSPEC: 1347 /* prefer IPv6 */ 1348 q.name = name; 1349 q.qclass = C_IN; 1350 q.qtype = T_AAAA; 1351 q.answer = buf->buf; 1352 q.anslen = sizeof(buf->buf); 1353 q.next = &q2; 1354 q2.name = name; 1355 q2.qclass = C_IN; 1356 q2.qtype = T_A; 1357 q2.answer = buf2->buf; 1358 q2.anslen = sizeof(buf2->buf); 1359 break; 1360 case AF_INET: 1361 q.name = name; 1362 q.qclass = C_IN; 1363 q.qtype = T_A; 1364 q.answer = buf->buf; 1365 q.anslen = sizeof(buf->buf); 1366 break; 1367 case AF_INET6: 1368 q.name = name; 1369 q.qclass = C_IN; 1370 q.qtype = T_AAAA; 1371 q.answer = buf->buf; 1372 q.anslen = sizeof(buf->buf); 1373 break; 1374 default: 1375 free(buf); 1376 free(buf2); 1377 return NS_UNAVAIL; 1378 } 1379 if (res_searchN(name, &q) < 0) { 1380 free(buf); 1381 free(buf2); 1382 return NS_NOTFOUND; 1383 } 1384 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1385 if (ai) { 1386 cur->ai_next = ai; 1387 while (cur && cur->ai_next) 1388 cur = cur->ai_next; 1389 } 1390 if (q.next) { 1391 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1392 if (ai) 1393 cur->ai_next = ai; 1394 } 1395 free(buf); 1396 free(buf2); 1397 if (sentinel.ai_next == NULL) 1398 switch (h_errno) { 1399 case HOST_NOT_FOUND: 1400 return NS_NOTFOUND; 1401 case TRY_AGAIN: 1402 return NS_TRYAGAIN; 1403 default: 1404 return NS_UNAVAIL; 1405 } 1406 *((struct addrinfo **)rv) = sentinel.ai_next; 1407 return NS_SUCCESS; 1408 } 1409 1410 static void 1411 _sethtent() 1412 { 1413 1414 if (!hostf) 1415 hostf = fopen(_PATH_HOSTS, "r" ); 1416 else 1417 rewind(hostf); 1418 } 1419 1420 static void 1421 _endhtent() 1422 { 1423 1424 if (hostf) { 1425 (void) fclose(hostf); 1426 hostf = NULL; 1427 } 1428 } 1429 1430 static struct addrinfo * 1431 _gethtent(name, pai) 1432 const char *name; 1433 const struct addrinfo *pai; 1434 { 1435 char *p; 1436 char *cp, *tname, *cname; 1437 struct addrinfo hints, *res0, *res; 1438 int error; 1439 const char *addr; 1440 char hostbuf[8*1024]; 1441 1442 _DIAGASSERT(name != NULL); 1443 _DIAGASSERT(pai != NULL); 1444 1445 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) 1446 return (NULL); 1447 again: 1448 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) 1449 return (NULL); 1450 if (*p == '#') 1451 goto again; 1452 if (!(cp = strpbrk(p, "#\n"))) 1453 goto again; 1454 *cp = '\0'; 1455 if (!(cp = strpbrk(p, " \t"))) 1456 goto again; 1457 *cp++ = '\0'; 1458 addr = p; 1459 /* if this is not something we're looking for, skip it. */ 1460 cname = NULL; 1461 while (cp && *cp) { 1462 if (*cp == ' ' || *cp == '\t') { 1463 cp++; 1464 continue; 1465 } 1466 if (!cname) 1467 cname = cp; 1468 tname = cp; 1469 if ((cp = strpbrk(cp, " \t")) != NULL) 1470 *cp++ = '\0'; 1471 if (strcasecmp(name, tname) == 0) 1472 goto found; 1473 } 1474 goto again; 1475 1476 found: 1477 hints = *pai; 1478 hints.ai_flags = AI_NUMERICHOST; 1479 error = getaddrinfo(addr, NULL, &hints, &res0); 1480 if (error) 1481 goto again; 1482 for (res = res0; res; res = res->ai_next) { 1483 /* cover it up */ 1484 res->ai_flags = pai->ai_flags; 1485 1486 if (pai->ai_flags & AI_CANONNAME) { 1487 if (get_canonname(pai, res, cname) != 0) { 1488 freeaddrinfo(res0); 1489 goto again; 1490 } 1491 } 1492 } 1493 return res0; 1494 } 1495 1496 /*ARGSUSED*/ 1497 static int 1498 _files_getaddrinfo(rv, cb_data, ap) 1499 void *rv; 1500 void *cb_data; 1501 va_list ap; 1502 { 1503 const char *name; 1504 const struct addrinfo *pai; 1505 struct addrinfo sentinel, *cur; 1506 struct addrinfo *p; 1507 1508 name = va_arg(ap, char *); 1509 pai = va_arg(ap, struct addrinfo *); 1510 1511 memset(&sentinel, 0, sizeof(sentinel)); 1512 cur = &sentinel; 1513 1514 _sethtent(); 1515 while ((p = _gethtent(name, pai)) != NULL) { 1516 cur->ai_next = p; 1517 while (cur && cur->ai_next) 1518 cur = cur->ai_next; 1519 } 1520 _endhtent(); 1521 1522 *((struct addrinfo **)rv) = sentinel.ai_next; 1523 if (sentinel.ai_next == NULL) 1524 return NS_NOTFOUND; 1525 return NS_SUCCESS; 1526 } 1527 1528 #ifdef YP 1529 static char *__ypdomain; 1530 1531 /*ARGSUSED*/ 1532 static struct addrinfo * 1533 _yphostent(line, pai) 1534 char *line; 1535 const struct addrinfo *pai; 1536 { 1537 struct addrinfo sentinel, *cur; 1538 struct addrinfo hints, *res, *res0; 1539 int error; 1540 char *p; 1541 const char *addr, *canonname; 1542 char *nextline; 1543 char *cp; 1544 1545 _DIAGASSERT(line != NULL); 1546 _DIAGASSERT(pai != NULL); 1547 1548 p = line; 1549 addr = canonname = NULL; 1550 1551 memset(&sentinel, 0, sizeof(sentinel)); 1552 cur = &sentinel; 1553 1554 nextline: 1555 /* terminate line */ 1556 cp = strchr(p, '\n'); 1557 if (cp) { 1558 *cp++ = '\0'; 1559 nextline = cp; 1560 } else 1561 nextline = NULL; 1562 1563 cp = strpbrk(p, " \t"); 1564 if (cp == NULL) { 1565 if (canonname == NULL) 1566 return (NULL); 1567 else 1568 goto done; 1569 } 1570 *cp++ = '\0'; 1571 1572 addr = p; 1573 1574 while (cp && *cp) { 1575 if (*cp == ' ' || *cp == '\t') { 1576 cp++; 1577 continue; 1578 } 1579 if (!canonname) 1580 canonname = cp; 1581 if ((cp = strpbrk(cp, " \t")) != NULL) 1582 *cp++ = '\0'; 1583 } 1584 1585 hints = *pai; 1586 hints.ai_flags = AI_NUMERICHOST; 1587 error = getaddrinfo(addr, NULL, &hints, &res0); 1588 if (error == 0) { 1589 for (res = res0; res; res = res->ai_next) { 1590 /* cover it up */ 1591 res->ai_flags = pai->ai_flags; 1592 1593 if (pai->ai_flags & AI_CANONNAME) 1594 (void)get_canonname(pai, res, canonname); 1595 } 1596 } else 1597 res0 = NULL; 1598 if (res0) { 1599 cur->ai_next = res0; 1600 while (cur && cur->ai_next) 1601 cur = cur->ai_next; 1602 } 1603 1604 if (nextline) { 1605 p = nextline; 1606 goto nextline; 1607 } 1608 1609 done: 1610 return sentinel.ai_next; 1611 } 1612 1613 /*ARGSUSED*/ 1614 static int 1615 _yp_getaddrinfo(rv, cb_data, ap) 1616 void *rv; 1617 void *cb_data; 1618 va_list ap; 1619 { 1620 struct addrinfo sentinel, *cur; 1621 struct addrinfo *ai = NULL; 1622 static char *__ypcurrent; 1623 int __ypcurrentlen, r; 1624 const char *name; 1625 const struct addrinfo *pai; 1626 1627 name = va_arg(ap, char *); 1628 pai = va_arg(ap, const struct addrinfo *); 1629 1630 memset(&sentinel, 0, sizeof(sentinel)); 1631 cur = &sentinel; 1632 1633 if (!__ypdomain) { 1634 if (_yp_check(&__ypdomain) == 0) 1635 return NS_UNAVAIL; 1636 } 1637 if (__ypcurrent) 1638 free(__ypcurrent); 1639 __ypcurrent = NULL; 1640 1641 /* hosts.byname is only for IPv4 (Solaris8) */ 1642 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1643 r = yp_match(__ypdomain, "hosts.byname", name, 1644 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1645 if (r == 0) { 1646 struct addrinfo ai4; 1647 1648 ai4 = *pai; 1649 ai4.ai_family = AF_INET; 1650 ai = _yphostent(__ypcurrent, &ai4); 1651 if (ai) { 1652 cur->ai_next = ai; 1653 while (cur && cur->ai_next) 1654 cur = cur->ai_next; 1655 } 1656 } 1657 } 1658 1659 /* ipnodes.byname can hold both IPv4/v6 */ 1660 r = yp_match(__ypdomain, "ipnodes.byname", name, 1661 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1662 if (r == 0) { 1663 ai = _yphostent(__ypcurrent, pai); 1664 if (ai) { 1665 cur->ai_next = ai; 1666 while (cur && cur->ai_next) 1667 cur = cur->ai_next; 1668 } 1669 } 1670 1671 if (sentinel.ai_next == NULL) { 1672 h_errno = HOST_NOT_FOUND; 1673 return NS_NOTFOUND; 1674 } 1675 *((struct addrinfo **)rv) = sentinel.ai_next; 1676 return NS_SUCCESS; 1677 } 1678 #endif 1679 1680 /* resolver logic */ 1681 1682 /* 1683 * Formulate a normal query, send, and await answer. 1684 * Returned answer is placed in supplied buffer "answer". 1685 * Perform preliminary check of answer, returning success only 1686 * if no error is indicated and the answer count is nonzero. 1687 * Return the size of the response on success, -1 on error. 1688 * Error number is left in h_errno. 1689 * 1690 * Caller must parse answer and determine whether it answers the question. 1691 */ 1692 static int 1693 res_queryN(name, target) 1694 const char *name; /* domain name */ 1695 struct res_target *target; 1696 { 1697 u_char buf[MAXPACKET]; 1698 HEADER *hp; 1699 int n; 1700 struct res_target *t; 1701 int rcode; 1702 int ancount; 1703 1704 _DIAGASSERT(name != NULL); 1705 /* XXX: target may be NULL??? */ 1706 1707 rcode = NOERROR; 1708 ancount = 0; 1709 1710 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1711 h_errno = NETDB_INTERNAL; 1712 return (-1); 1713 } 1714 1715 for (t = target; t; t = t->next) { 1716 int class, type; 1717 u_char *answer; 1718 int anslen; 1719 1720 hp = (HEADER *)(void *)t->answer; 1721 hp->rcode = NOERROR; /* default */ 1722 1723 /* make it easier... */ 1724 class = t->qclass; 1725 type = t->qtype; 1726 answer = t->answer; 1727 anslen = t->anslen; 1728 #ifdef DEBUG 1729 if (_res.options & RES_DEBUG) 1730 printf(";; res_query(%s, %d, %d)\n", name, class, type); 1731 #endif 1732 1733 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL, 1734 buf, sizeof(buf)); 1735 #ifdef RES_USE_EDNS0 1736 if (n > 0 && (_res.options & RES_USE_EDNS0) != 0) 1737 n = res_opt(n, buf, sizeof(buf), anslen); 1738 #endif 1739 if (n <= 0) { 1740 #ifdef DEBUG 1741 if (_res.options & RES_DEBUG) 1742 printf(";; res_query: mkquery failed\n"); 1743 #endif 1744 h_errno = NO_RECOVERY; 1745 return (n); 1746 } 1747 n = res_send(buf, n, answer, anslen); 1748 #if 0 1749 if (n < 0) { 1750 #ifdef DEBUG 1751 if (_res.options & RES_DEBUG) 1752 printf(";; res_query: send error\n"); 1753 #endif 1754 h_errno = TRY_AGAIN; 1755 return (n); 1756 } 1757 #endif 1758 1759 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1760 rcode = hp->rcode; /* record most recent error */ 1761 #ifdef DEBUG 1762 if (_res.options & RES_DEBUG) 1763 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1764 ntohs(hp->ancount)); 1765 #endif 1766 continue; 1767 } 1768 1769 ancount += ntohs(hp->ancount); 1770 1771 t->n = n; 1772 } 1773 1774 if (ancount == 0) { 1775 switch (rcode) { 1776 case NXDOMAIN: 1777 h_errno = HOST_NOT_FOUND; 1778 break; 1779 case SERVFAIL: 1780 h_errno = TRY_AGAIN; 1781 break; 1782 case NOERROR: 1783 h_errno = NO_DATA; 1784 break; 1785 case FORMERR: 1786 case NOTIMP: 1787 case REFUSED: 1788 default: 1789 h_errno = NO_RECOVERY; 1790 break; 1791 } 1792 return (-1); 1793 } 1794 return (ancount); 1795 } 1796 1797 /* 1798 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1799 * Return the size of the response on success, -1 on error. 1800 * If enabled, implement search rules until answer or unrecoverable failure 1801 * is detected. Error code, if any, is left in h_errno. 1802 */ 1803 static int 1804 res_searchN(name, target) 1805 const char *name; /* domain name */ 1806 struct res_target *target; 1807 { 1808 const char *cp, * const *domain; 1809 HEADER *hp; 1810 u_int dots; 1811 int trailing_dot, ret, saved_herrno; 1812 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1813 1814 _DIAGASSERT(name != NULL); 1815 _DIAGASSERT(target != NULL); 1816 1817 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1818 1819 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1820 h_errno = NETDB_INTERNAL; 1821 return (-1); 1822 } 1823 1824 errno = 0; 1825 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1826 dots = 0; 1827 for (cp = name; *cp; cp++) 1828 dots += (*cp == '.'); 1829 trailing_dot = 0; 1830 if (cp > name && *--cp == '.') 1831 trailing_dot++; 1832 1833 /* 1834 * if there aren't any dots, it could be a user-level alias 1835 */ 1836 if (!dots && (cp = __hostalias(name)) != NULL) 1837 return (res_queryN(cp, target)); 1838 1839 /* 1840 * If there are dots in the name already, let's just give it a try 1841 * 'as is'. The threshold can be set with the "ndots" option. 1842 */ 1843 saved_herrno = -1; 1844 if (dots >= _res.ndots) { 1845 ret = res_querydomainN(name, NULL, target); 1846 if (ret > 0) 1847 return (ret); 1848 saved_herrno = h_errno; 1849 tried_as_is++; 1850 } 1851 1852 /* 1853 * We do at least one level of search if 1854 * - there is no dot and RES_DEFNAME is set, or 1855 * - there is at least one dot, there is no trailing dot, 1856 * and RES_DNSRCH is set. 1857 */ 1858 if ((!dots && (_res.options & RES_DEFNAMES)) || 1859 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { 1860 int done = 0; 1861 1862 for (domain = (const char * const *)_res.dnsrch; 1863 *domain && !done; 1864 domain++) { 1865 1866 ret = res_querydomainN(name, *domain, target); 1867 if (ret > 0) 1868 return (ret); 1869 1870 /* 1871 * If no server present, give up. 1872 * If name isn't found in this domain, 1873 * keep trying higher domains in the search list 1874 * (if that's enabled). 1875 * On a NO_DATA error, keep trying, otherwise 1876 * a wildcard entry of another type could keep us 1877 * from finding this entry higher in the domain. 1878 * If we get some other error (negative answer or 1879 * server failure), then stop searching up, 1880 * but try the input name below in case it's 1881 * fully-qualified. 1882 */ 1883 if (errno == ECONNREFUSED) { 1884 h_errno = TRY_AGAIN; 1885 return (-1); 1886 } 1887 1888 switch (h_errno) { 1889 case NO_DATA: 1890 got_nodata++; 1891 /* FALLTHROUGH */ 1892 case HOST_NOT_FOUND: 1893 /* keep trying */ 1894 break; 1895 case TRY_AGAIN: 1896 if (hp->rcode == SERVFAIL) { 1897 /* try next search element, if any */ 1898 got_servfail++; 1899 break; 1900 } 1901 /* FALLTHROUGH */ 1902 default: 1903 /* anything else implies that we're done */ 1904 done++; 1905 } 1906 /* 1907 * if we got here for some reason other than DNSRCH, 1908 * we only wanted one iteration of the loop, so stop. 1909 */ 1910 if (!(_res.options & RES_DNSRCH)) 1911 done++; 1912 } 1913 } 1914 1915 /* 1916 * if we have not already tried the name "as is", do that now. 1917 * note that we do this regardless of how many dots were in the 1918 * name or whether it ends with a dot. 1919 */ 1920 if (!tried_as_is) { 1921 ret = res_querydomainN(name, NULL, target); 1922 if (ret > 0) 1923 return (ret); 1924 } 1925 1926 /* 1927 * if we got here, we didn't satisfy the search. 1928 * if we did an initial full query, return that query's h_errno 1929 * (note that we wouldn't be here if that query had succeeded). 1930 * else if we ever got a nodata, send that back as the reason. 1931 * else send back meaningless h_errno, that being the one from 1932 * the last DNSRCH we did. 1933 */ 1934 if (saved_herrno != -1) 1935 h_errno = saved_herrno; 1936 else if (got_nodata) 1937 h_errno = NO_DATA; 1938 else if (got_servfail) 1939 h_errno = TRY_AGAIN; 1940 return (-1); 1941 } 1942 1943 /* 1944 * Perform a call on res_query on the concatenation of name and domain, 1945 * removing a trailing dot from name if domain is NULL. 1946 */ 1947 static int 1948 res_querydomainN(name, domain, target) 1949 const char *name, *domain; 1950 struct res_target *target; 1951 { 1952 char nbuf[MAXDNAME]; 1953 const char *longname = nbuf; 1954 size_t n, d; 1955 1956 _DIAGASSERT(name != NULL); 1957 /* XXX: target may be NULL??? */ 1958 1959 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1960 h_errno = NETDB_INTERNAL; 1961 return (-1); 1962 } 1963 #ifdef DEBUG 1964 if (_res.options & RES_DEBUG) 1965 printf(";; res_querydomain(%s, %s)\n", 1966 name, domain?domain:"<Nil>"); 1967 #endif 1968 if (domain == NULL) { 1969 /* 1970 * Check for trailing '.'; 1971 * copy without '.' if present. 1972 */ 1973 n = strlen(name); 1974 if (n + 1 > sizeof(nbuf)) { 1975 h_errno = NO_RECOVERY; 1976 return (-1); 1977 } 1978 if (n > 0 && name[--n] == '.') { 1979 strncpy(nbuf, name, n); 1980 nbuf[n] = '\0'; 1981 } else 1982 longname = name; 1983 } else { 1984 n = strlen(name); 1985 d = strlen(domain); 1986 if (n + 1 + d + 1 > sizeof(nbuf)) { 1987 h_errno = NO_RECOVERY; 1988 return (-1); 1989 } 1990 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1991 } 1992 return (res_queryN(longname, target)); 1993 } 1994
Indexes created Tue Sep 30 06:09:59 GMT 2025