1 /* $NetBSD: getaddrinfo.c,v 1.51 2001/01/04 03:57:58 lukem 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 1.51 2001/01/04 03:57:58 lukem 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 #if PACKETSZ > 1024 200 #define MAXPACKET PACKETSZ 201 #else 202 #define MAXPACKET 1024 203 #endif 204 205 typedef union { 206 HEADER hdr; 207 u_char buf[MAXPACKET]; 208 } querybuf; 209 210 struct res_target { 211 struct res_target *next; 212 const char *name; /* domain name */ 213 int qclass, qtype; /* class and type of query */ 214 u_char *answer; /* buffer to put answer */ 215 int anslen; /* size of answer buffer */ 216 int n; /* result length */ 217 }; 218 219 static int str_isnumber __P((const char *)); 220 static int explore_fqdn __P((const struct addrinfo *, const char *, 221 const char *, struct addrinfo **)); 222 static int explore_null __P((const struct addrinfo *, 223 const char *, struct addrinfo **)); 224 static int explore_numeric __P((const struct addrinfo *, const char *, 225 const char *, struct addrinfo **)); 226 static int explore_numeric_scope __P((const struct addrinfo *, const char *, 227 const char *, struct addrinfo **)); 228 static int get_canonname __P((const struct addrinfo *, 229 struct addrinfo *, const char *)); 230 static struct addrinfo *get_ai __P((const struct addrinfo *, 231 const struct afd *, const char *)); 232 static int get_portmatch __P((const struct addrinfo *, const char *)); 233 static int get_port __P((struct addrinfo *, const char *, int)); 234 static const struct afd *find_afd __P((int)); 235 #if 0 236 static int addrconfig __P((const struct addrinfo *)); 237 #endif 238 #ifdef INET6 239 static int ip6_str2scopeid __P((char *, struct sockaddr_in6 *)); 240 #endif 241 242 static struct addrinfo *getanswer __P((const querybuf *, int, const char *, int, 243 const struct addrinfo *)); 244 static int _dns_getaddrinfo __P((void *, void *, va_list)); 245 static void _sethtent __P((void)); 246 static void _endhtent __P((void)); 247 static struct addrinfo *_gethtent __P((const char *, const struct addrinfo *)); 248 static int _files_getaddrinfo __P((void *, void *, va_list)); 249 #ifdef YP 250 static struct addrinfo *_yphostent __P((char *, const struct addrinfo *)); 251 static int _yp_getaddrinfo __P((void *, void *, va_list)); 252 #endif 253 254 static int res_queryN __P((const char *, struct res_target *)); 255 static int res_searchN __P((const char *, struct res_target *)); 256 static int res_querydomainN __P((const char *, const char *, 257 struct res_target *)); 258 259 static char *ai_errlist[] = { 260 "Success", 261 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 262 "Temporary failure in name resolution", /* EAI_AGAIN */ 263 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 264 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 265 "ai_family not supported", /* EAI_FAMILY */ 266 "Memory allocation failure", /* EAI_MEMORY */ 267 "No address associated with hostname", /* EAI_NODATA */ 268 "hostname nor servname provided, or not known", /* EAI_NONAME */ 269 "servname not supported for ai_socktype", /* EAI_SERVICE */ 270 "ai_socktype not supported", /* EAI_SOCKTYPE */ 271 "System error returned in errno", /* EAI_SYSTEM */ 272 "Invalid value for hints", /* EAI_BADHINTS */ 273 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 274 "Unknown error", /* EAI_MAX */ 275 }; 276 277 /* XXX macros that make external reference is BAD. */ 278 279 #define GET_AI(ai, afd, addr) \ 280 do { \ 281 /* external reference: pai, error, and label free */ \ 282 (ai) = get_ai(pai, (afd), (addr)); \ 283 if ((ai) == NULL) { \ 284 error = EAI_MEMORY; \ 285 goto free; \ 286 } \ 287 } while (/*CONSTCOND*/0) 288 289 #define GET_PORT(ai, serv) \ 290 do { \ 291 /* external reference: error and label free */ \ 292 error = get_port((ai), (serv), 0); \ 293 if (error != 0) \ 294 goto free; \ 295 } while (/*CONSTCOND*/0) 296 297 #define GET_CANONNAME(ai, str) \ 298 do { \ 299 /* external reference: pai, error and label free */ \ 300 error = get_canonname(pai, (ai), (str)); \ 301 if (error != 0) \ 302 goto free; \ 303 } while (/*CONSTCOND*/0) 304 305 #define ERR(err) \ 306 do { \ 307 /* external reference: error, and label bad */ \ 308 error = (err); \ 309 goto bad; \ 310 /*NOTREACHED*/ \ 311 } while (/*CONSTCOND*/0) 312 313 #define MATCH_FAMILY(x, y, w) \ 314 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 315 #define MATCH(x, y, w) \ 316 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 317 318 char * 319 gai_strerror(ecode) 320 int ecode; 321 { 322 if (ecode < 0 || ecode > EAI_MAX) 323 ecode = EAI_MAX; 324 return ai_errlist[ecode]; 325 } 326 327 void 328 freeaddrinfo(ai) 329 struct addrinfo *ai; 330 { 331 struct addrinfo *next; 332 333 _DIAGASSERT(ai != NULL); 334 335 do { 336 next = ai->ai_next; 337 if (ai->ai_canonname) 338 free(ai->ai_canonname); 339 /* no need to free(ai->ai_addr) */ 340 free(ai); 341 ai = next; 342 } while (ai); 343 } 344 345 static int 346 str_isnumber(p) 347 const char *p; 348 { 349 char *ep; 350 351 _DIAGASSERT(p != NULL); 352 353 if (*p == '\0') 354 return NO; 355 ep = NULL; 356 (void)strtoul(p, &ep, 10); 357 if (ep && *ep == '\0') 358 return YES; 359 else 360 return NO; 361 } 362 363 int 364 getaddrinfo(hostname, servname, hints, res) 365 const char *hostname, *servname; 366 const struct addrinfo *hints; 367 struct addrinfo **res; 368 { 369 struct addrinfo sentinel; 370 struct addrinfo *cur; 371 int error = 0; 372 struct addrinfo ai; 373 struct addrinfo ai0; 374 struct addrinfo *pai; 375 const struct explore *ex; 376 377 /* hostname is allowed to be NULL */ 378 /* servname is allowed to be NULL */ 379 /* hints is allowed to be NULL */ 380 _DIAGASSERT(res != NULL); 381 382 memset(&sentinel, 0, sizeof(sentinel)); 383 cur = &sentinel; 384 pai = &ai; 385 pai->ai_flags = 0; 386 pai->ai_family = PF_UNSPEC; 387 pai->ai_socktype = ANY; 388 pai->ai_protocol = ANY; 389 pai->ai_addrlen = 0; 390 pai->ai_canonname = NULL; 391 pai->ai_addr = NULL; 392 pai->ai_next = NULL; 393 394 if (hostname == NULL && servname == NULL) 395 return EAI_NONAME; 396 if (hints) { 397 /* error check for hints */ 398 if (hints->ai_addrlen || hints->ai_canonname || 399 hints->ai_addr || hints->ai_next) 400 ERR(EAI_BADHINTS); /* xxx */ 401 if (hints->ai_flags & ~AI_MASK) 402 ERR(EAI_BADFLAGS); 403 switch (hints->ai_family) { 404 case PF_UNSPEC: 405 case PF_INET: 406 #ifdef INET6 407 case PF_INET6: 408 #endif 409 break; 410 default: 411 ERR(EAI_FAMILY); 412 } 413 memcpy(pai, hints, sizeof(*pai)); 414 415 /* 416 * if both socktype/protocol are specified, check if they 417 * are meaningful combination. 418 */ 419 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 420 for (ex = explore; ex->e_af >= 0; ex++) { 421 if (pai->ai_family != ex->e_af) 422 continue; 423 if (ex->e_socktype == ANY) 424 continue; 425 if (ex->e_protocol == ANY) 426 continue; 427 if (pai->ai_socktype == ex->e_socktype 428 && pai->ai_protocol != ex->e_protocol) { 429 ERR(EAI_BADHINTS); 430 } 431 } 432 } 433 } 434 435 /* 436 * check for special cases. (1) numeric servname is disallowed if 437 * socktype/protocol are left unspecified. (2) servname is disallowed 438 * for raw and other inet{,6} sockets. 439 */ 440 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 441 #ifdef PF_INET6 442 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 443 #endif 444 ) { 445 ai0 = *pai; /* backup *pai */ 446 447 if (pai->ai_family == PF_UNSPEC) { 448 #ifdef PF_INET6 449 pai->ai_family = PF_INET6; 450 #else 451 pai->ai_family = PF_INET; 452 #endif 453 } 454 error = get_portmatch(pai, servname); 455 if (error) 456 ERR(error); 457 458 *pai = ai0; 459 } 460 461 ai0 = *pai; 462 463 /* NULL hostname, or numeric hostname */ 464 for (ex = explore; ex->e_af >= 0; ex++) { 465 *pai = ai0; 466 467 /* PF_UNSPEC entries are prepared for DNS queries only */ 468 if (ex->e_af == PF_UNSPEC) 469 continue; 470 471 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 472 continue; 473 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 474 continue; 475 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 476 continue; 477 478 if (pai->ai_family == PF_UNSPEC) 479 pai->ai_family = ex->e_af; 480 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 481 pai->ai_socktype = ex->e_socktype; 482 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 483 pai->ai_protocol = ex->e_protocol; 484 485 if (hostname == NULL) 486 error = explore_null(pai, servname, &cur->ai_next); 487 else 488 error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next); 489 490 if (error) 491 goto free; 492 493 while (cur && cur->ai_next) 494 cur = cur->ai_next; 495 } 496 497 /* 498 * XXX 499 * If numreic representation of AF1 can be interpreted as FQDN 500 * representation of AF2, we need to think again about the code below. 501 */ 502 if (sentinel.ai_next) 503 goto good; 504 505 if (pai->ai_flags & AI_NUMERICHOST) 506 ERR(EAI_NODATA); 507 if (hostname == NULL) 508 ERR(EAI_NODATA); 509 510 /* 511 * hostname as alphabetical name. 512 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 513 * outer loop by AFs. 514 */ 515 for (ex = explore; ex->e_af >= 0; ex++) { 516 *pai = ai0; 517 518 /* require exact match for family field */ 519 if (pai->ai_family != ex->e_af) 520 continue; 521 522 if (!MATCH(pai->ai_socktype, ex->e_socktype, 523 WILD_SOCKTYPE(ex))) { 524 continue; 525 } 526 if (!MATCH(pai->ai_protocol, ex->e_protocol, 527 WILD_PROTOCOL(ex))) { 528 continue; 529 } 530 531 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 532 pai->ai_socktype = ex->e_socktype; 533 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 534 pai->ai_protocol = ex->e_protocol; 535 536 error = explore_fqdn(pai, hostname, servname, 537 &cur->ai_next); 538 539 while (cur && cur->ai_next) 540 cur = cur->ai_next; 541 } 542 543 /* XXX */ 544 if (sentinel.ai_next) 545 error = 0; 546 547 if (error) 548 goto free; 549 if (error == 0) { 550 if (sentinel.ai_next) { 551 good: 552 *res = sentinel.ai_next; 553 return SUCCESS; 554 } else 555 error = EAI_FAIL; 556 } 557 free: 558 bad: 559 if (sentinel.ai_next) 560 freeaddrinfo(sentinel.ai_next); 561 *res = NULL; 562 return error; 563 } 564 565 /* 566 * FQDN hostname, DNS lookup 567 */ 568 static int 569 explore_fqdn(pai, hostname, servname, res) 570 const struct addrinfo *pai; 571 const char *hostname; 572 const char *servname; 573 struct addrinfo **res; 574 { 575 struct addrinfo *result; 576 struct addrinfo *cur; 577 int error = 0; 578 static const ns_dtab dtab[] = { 579 NS_FILES_CB(_files_getaddrinfo, NULL) 580 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 581 NS_NIS_CB(_yp_getaddrinfo, NULL) 582 { 0 } 583 }; 584 585 _DIAGASSERT(pai != NULL); 586 /* hostname may be NULL */ 587 /* servname may be NULL */ 588 _DIAGASSERT(res != NULL); 589 590 result = NULL; 591 592 #if 0 593 /* 594 * If AI_ADDRCONFIG is specified, check if we are expected to 595 * return the address family or not. 596 * XXX does not handle PF_UNSPEC - should filter out result from 597 * nsdispatch() 598 */ 599 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(pai)) 600 return 0; 601 #endif 602 603 /* 604 * if the servname does not match socktype/protocol, ignore it. 605 */ 606 if (get_portmatch(pai, servname) != 0) 607 return 0; 608 609 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 610 default_dns_files, hostname, pai)) { 611 case NS_TRYAGAIN: 612 error = EAI_AGAIN; 613 goto free; 614 case NS_UNAVAIL: 615 error = EAI_FAIL; 616 goto free; 617 case NS_NOTFOUND: 618 error = EAI_NODATA; 619 goto free; 620 case NS_SUCCESS: 621 error = 0; 622 for (cur = result; cur; cur = cur->ai_next) { 623 GET_PORT(cur, servname); 624 /* canonname should be filled already */ 625 } 626 break; 627 } 628 629 *res = result; 630 631 return 0; 632 633 free: 634 if (result) 635 freeaddrinfo(result); 636 return error; 637 } 638 639 /* 640 * hostname == NULL. 641 * passive socket -> anyaddr (0.0.0.0 or ::) 642 * non-passive socket -> localhost (127.0.0.1 or ::1) 643 */ 644 static int 645 explore_null(pai, servname, res) 646 const struct addrinfo *pai; 647 const char *servname; 648 struct addrinfo **res; 649 { 650 int s; 651 const struct afd *afd; 652 struct addrinfo *cur; 653 struct addrinfo sentinel; 654 int error; 655 656 _DIAGASSERT(pai != NULL); 657 /* servname may be NULL */ 658 _DIAGASSERT(res != NULL); 659 660 *res = NULL; 661 sentinel.ai_next = NULL; 662 cur = &sentinel; 663 664 /* 665 * filter out AFs that are not supported by the kernel 666 * XXX errno? 667 */ 668 s = socket(pai->ai_family, SOCK_DGRAM, 0); 669 if (s < 0) { 670 if (errno != EMFILE) 671 return 0; 672 } else 673 close(s); 674 675 /* 676 * if the servname does not match socktype/protocol, ignore it. 677 */ 678 if (get_portmatch(pai, servname) != 0) 679 return 0; 680 681 afd = find_afd(pai->ai_family); 682 if (afd == NULL) 683 return 0; 684 685 if (pai->ai_flags & AI_PASSIVE) { 686 GET_AI(cur->ai_next, afd, afd->a_addrany); 687 /* xxx meaningless? 688 * GET_CANONNAME(cur->ai_next, "anyaddr"); 689 */ 690 GET_PORT(cur->ai_next, servname); 691 } else { 692 GET_AI(cur->ai_next, afd, afd->a_loopback); 693 /* xxx meaningless? 694 * GET_CANONNAME(cur->ai_next, "localhost"); 695 */ 696 GET_PORT(cur->ai_next, servname); 697 } 698 cur = cur->ai_next; 699 700 *res = sentinel.ai_next; 701 return 0; 702 703 free: 704 if (sentinel.ai_next) 705 freeaddrinfo(sentinel.ai_next); 706 return error; 707 } 708 709 /* 710 * numeric hostname 711 */ 712 static int 713 explore_numeric(pai, hostname, servname, res) 714 const struct addrinfo *pai; 715 const char *hostname; 716 const char *servname; 717 struct addrinfo **res; 718 { 719 const struct afd *afd; 720 struct addrinfo *cur; 721 struct addrinfo sentinel; 722 int error; 723 char pton[PTON_MAX]; 724 725 _DIAGASSERT(pai != NULL); 726 /* hostname may be NULL */ 727 /* servname may be NULL */ 728 _DIAGASSERT(res != NULL); 729 730 *res = NULL; 731 sentinel.ai_next = NULL; 732 cur = &sentinel; 733 734 /* 735 * if the servname does not match socktype/protocol, ignore it. 736 */ 737 if (get_portmatch(pai, servname) != 0) 738 return 0; 739 740 afd = find_afd(pai->ai_family); 741 if (afd == NULL) 742 return 0; 743 744 switch (afd->a_af) { 745 #if 0 /*X/Open spec*/ 746 case AF_INET: 747 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 748 if (pai->ai_family == afd->a_af || 749 pai->ai_family == PF_UNSPEC /*?*/) { 750 GET_AI(cur->ai_next, afd, pton); 751 GET_PORT(cur->ai_next, servname); 752 while (cur && cur->ai_next) 753 cur = cur->ai_next; 754 } else 755 ERR(EAI_FAMILY); /*xxx*/ 756 } 757 break; 758 #endif 759 default: 760 if (inet_pton(afd->a_af, hostname, pton) == 1) { 761 if (pai->ai_family == afd->a_af || 762 pai->ai_family == PF_UNSPEC /*?*/) { 763 GET_AI(cur->ai_next, afd, pton); 764 GET_PORT(cur->ai_next, servname); 765 while (cur && cur->ai_next) 766 cur = cur->ai_next; 767 } else 768 ERR(EAI_FAMILY); /*xxx*/ 769 } 770 break; 771 } 772 773 *res = sentinel.ai_next; 774 return 0; 775 776 free: 777 bad: 778 if (sentinel.ai_next) 779 freeaddrinfo(sentinel.ai_next); 780 return error; 781 } 782 783 /* 784 * numeric hostname with scope 785 */ 786 static int 787 explore_numeric_scope(pai, hostname, servname, res) 788 const struct addrinfo *pai; 789 const char *hostname; 790 const char *servname; 791 struct addrinfo **res; 792 { 793 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 794 return explore_numeric(pai, hostname, servname, res); 795 #else 796 const struct afd *afd; 797 struct addrinfo *cur; 798 int error; 799 char *cp, *hostname2 = NULL, *scope, *addr; 800 struct sockaddr_in6 *sin6; 801 802 _DIAGASSERT(pai != NULL); 803 /* hostname may be NULL */ 804 /* servname may be NULL */ 805 _DIAGASSERT(res != NULL); 806 807 /* 808 * if the servname does not match socktype/protocol, ignore it. 809 */ 810 if (get_portmatch(pai, servname) != 0) 811 return 0; 812 813 afd = find_afd(pai->ai_family); 814 if (afd == NULL) 815 return 0; 816 817 if (!afd->a_scoped) 818 return explore_numeric(pai, hostname, servname, res); 819 820 cp = strchr(hostname, SCOPE_DELIMITER); 821 if (cp == NULL) 822 return explore_numeric(pai, hostname, servname, res); 823 824 #if 0 825 /* 826 * Handle special case of <scope id><delimiter><scoped_address> 827 */ 828 hostname2 = strdup(hostname); 829 if (hostname2 == NULL) 830 return EAI_MEMORY; 831 /* terminate at the delimiter */ 832 hostname2[cp - hostname] = '\0'; 833 scope = hostname2; 834 addr = cp + 1; 835 #else 836 /* 837 * Handle special case of <scoped_address><delimiter><scope id> 838 */ 839 hostname2 = strdup(hostname); 840 if (hostname2 == NULL) 841 return EAI_MEMORY; 842 /* terminate at the delimiter */ 843 hostname2[cp - hostname] = '\0'; 844 addr = hostname2; 845 scope = cp + 1; 846 #endif 847 848 error = explore_numeric(pai, addr, servname, res); 849 if (error == 0) { 850 int scopeid; 851 852 for (cur = *res; cur; cur = cur->ai_next) { 853 if (cur->ai_family != AF_INET6) 854 continue; 855 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 856 if ((scopeid = ip6_str2scopeid(scope, sin6)) == -1) { 857 free(hostname2); 858 return(EAI_NODATA); /* XXX: is return OK? */ 859 } 860 sin6->sin6_scope_id = scopeid; 861 } 862 } 863 864 free(hostname2); 865 866 return error; 867 #endif 868 } 869 870 static int 871 get_canonname(pai, ai, str) 872 const struct addrinfo *pai; 873 struct addrinfo *ai; 874 const char *str; 875 { 876 877 _DIAGASSERT(pai != NULL); 878 _DIAGASSERT(ai != NULL); 879 _DIAGASSERT(str != NULL); 880 881 if ((pai->ai_flags & AI_CANONNAME) != 0) { 882 ai->ai_canonname = (char *)malloc(strlen(str) + 1); 883 if (ai->ai_canonname == NULL) 884 return EAI_MEMORY; 885 strcpy(ai->ai_canonname, str); 886 } 887 return 0; 888 } 889 890 static struct addrinfo * 891 get_ai(pai, afd, addr) 892 const struct addrinfo *pai; 893 const struct afd *afd; 894 const char *addr; 895 { 896 char *p; 897 struct addrinfo *ai; 898 899 _DIAGASSERT(pai != NULL); 900 _DIAGASSERT(afd != NULL); 901 _DIAGASSERT(addr != NULL); 902 903 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 904 + (afd->a_socklen)); 905 if (ai == NULL) 906 return NULL; 907 908 memcpy(ai, pai, sizeof(struct addrinfo)); 909 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 910 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 911 ai->ai_addr->sa_len = afd->a_socklen; 912 ai->ai_addrlen = afd->a_socklen; 913 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 914 p = (char *)(void *)(ai->ai_addr); 915 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 916 return ai; 917 } 918 919 static int 920 get_portmatch(ai, servname) 921 const struct addrinfo *ai; 922 const char *servname; 923 { 924 925 _DIAGASSERT(ai != NULL); 926 /* servname may be NULL */ 927 928 /* get_port does not touch first argument. when matchonly == 1. */ 929 /* LINTED const cast */ 930 return get_port((struct addrinfo *)ai, servname, 1); 931 } 932 933 static int 934 get_port(ai, servname, matchonly) 935 struct addrinfo *ai; 936 const char *servname; 937 int matchonly; 938 { 939 const char *proto; 940 struct servent *sp; 941 int port; 942 int allownumeric; 943 944 _DIAGASSERT(ai != NULL); 945 /* servname may be NULL */ 946 947 if (servname == NULL) 948 return 0; 949 switch (ai->ai_family) { 950 case AF_INET: 951 #ifdef AF_INET6 952 case AF_INET6: 953 #endif 954 break; 955 default: 956 return 0; 957 } 958 959 switch (ai->ai_socktype) { 960 case SOCK_RAW: 961 return EAI_SERVICE; 962 case SOCK_DGRAM: 963 case SOCK_STREAM: 964 allownumeric = 1; 965 break; 966 case ANY: 967 allownumeric = 0; 968 break; 969 default: 970 return EAI_SOCKTYPE; 971 } 972 973 if (str_isnumber(servname)) { 974 if (!allownumeric) 975 return EAI_SERVICE; 976 port = htons(atoi(servname)); 977 if (port < 0 || port > 65535) 978 return EAI_SERVICE; 979 } else { 980 switch (ai->ai_socktype) { 981 case SOCK_DGRAM: 982 proto = "udp"; 983 break; 984 case SOCK_STREAM: 985 proto = "tcp"; 986 break; 987 default: 988 proto = NULL; 989 break; 990 } 991 992 if ((sp = getservbyname(servname, proto)) == NULL) 993 return EAI_SERVICE; 994 port = sp->s_port; 995 } 996 997 if (!matchonly) { 998 switch (ai->ai_family) { 999 case AF_INET: 1000 ((struct sockaddr_in *)(void *) 1001 ai->ai_addr)->sin_port = port; 1002 break; 1003 #ifdef INET6 1004 case AF_INET6: 1005 ((struct sockaddr_in6 *)(void *) 1006 ai->ai_addr)->sin6_port = port; 1007 break; 1008 #endif 1009 } 1010 } 1011 1012 return 0; 1013 } 1014 1015 static const struct afd * 1016 find_afd(af) 1017 int af; 1018 { 1019 const struct afd *afd; 1020 1021 if (af == PF_UNSPEC) 1022 return NULL; 1023 for (afd = afdl; afd->a_af; afd++) { 1024 if (afd->a_af == af) 1025 return afd; 1026 } 1027 return NULL; 1028 } 1029 1030 #if 0 1031 /* 1032 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1033 * will take care of it. 1034 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1035 * if the code is right or not. 1036 */ 1037 static int 1038 addrconfig(pai) 1039 const struct addrinfo *pai; 1040 { 1041 int s; 1042 1043 _DIAGASSERT(pai != NULL); 1044 1045 /* XXX errno */ 1046 s = socket(pai->ai_family, SOCK_DGRAM, 0); 1047 if (s < 0) 1048 return 0; 1049 close(s); 1050 return 1; 1051 } 1052 #endif 1053 1054 #ifdef INET6 1055 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1056 static int 1057 ip6_str2scopeid(scope, sin6) 1058 char *scope; 1059 struct sockaddr_in6 *sin6; 1060 { 1061 int scopeid; 1062 struct in6_addr *a6; 1063 char *ep; 1064 1065 _DIAGASSERT(scope != NULL); 1066 _DIAGASSERT(sin6 != NULL); 1067 1068 a6 = &sin6->sin6_addr; 1069 1070 /* empty scopeid portion is invalid */ 1071 if (*scope == '\0') 1072 return -1; 1073 1074 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1075 /* 1076 * We currently assume a one-to-one mapping between links 1077 * and interfaces, so we simply use interface indices for 1078 * like-local scopes. 1079 */ 1080 scopeid = if_nametoindex(scope); 1081 if (scopeid == 0) 1082 goto trynumeric; 1083 return(scopeid); 1084 } 1085 1086 /* still unclear about literal, allow numeric only - placeholder */ 1087 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1088 goto trynumeric; 1089 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1090 goto trynumeric; 1091 else 1092 goto trynumeric; /* global */ 1093 1094 /* try to convert to a numeric id as a last resort */ 1095 trynumeric: 1096 scopeid = (int)strtoul(scope, &ep, 10); 1097 if (*ep == '\0') 1098 return scopeid; 1099 else 1100 return -1; 1101 } 1102 #endif 1103 1104 /* code duplicate with gethnamaddr.c */ 1105 1106 static const char AskedForGot[] = 1107 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1108 static FILE *hostf = NULL; 1109 1110 static struct addrinfo * 1111 getanswer(answer, anslen, qname, qtype, pai) 1112 const querybuf *answer; 1113 int anslen; 1114 const char *qname; 1115 int qtype; 1116 const struct addrinfo *pai; 1117 { 1118 struct addrinfo sentinel, *cur; 1119 struct addrinfo ai; 1120 const struct afd *afd; 1121 char *canonname; 1122 const HEADER *hp; 1123 const u_char *cp; 1124 int n; 1125 const u_char *eom; 1126 char *bp; 1127 int type, class, buflen, ancount, qdcount; 1128 int haveanswer, had_error; 1129 char tbuf[MAXDNAME]; 1130 int (*name_ok) __P((const char *)); 1131 char hostbuf[8*1024]; 1132 1133 _DIAGASSERT(answer != NULL); 1134 _DIAGASSERT(qname != NULL); 1135 _DIAGASSERT(pai != NULL); 1136 1137 memset(&sentinel, 0, sizeof(sentinel)); 1138 cur = &sentinel; 1139 1140 canonname = NULL; 1141 eom = answer->buf + anslen; 1142 switch (qtype) { 1143 case T_A: 1144 case T_AAAA: 1145 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1146 name_ok = res_hnok; 1147 break; 1148 default: 1149 return (NULL); /* XXX should be abort(); */ 1150 } 1151 /* 1152 * find first satisfactory answer 1153 */ 1154 hp = &answer->hdr; 1155 ancount = ntohs(hp->ancount); 1156 qdcount = ntohs(hp->qdcount); 1157 bp = hostbuf; 1158 buflen = sizeof hostbuf; 1159 cp = answer->buf + HFIXEDSZ; 1160 if (qdcount != 1) { 1161 h_errno = NO_RECOVERY; 1162 return (NULL); 1163 } 1164 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1165 if ((n < 0) || !(*name_ok)(bp)) { 1166 h_errno = NO_RECOVERY; 1167 return (NULL); 1168 } 1169 cp += n + QFIXEDSZ; 1170 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1171 /* res_send() has already verified that the query name is the 1172 * same as the one we sent; this just gets the expanded name 1173 * (i.e., with the succeeding search-domain tacked on). 1174 */ 1175 n = strlen(bp) + 1; /* for the \0 */ 1176 if (n >= MAXHOSTNAMELEN) { 1177 h_errno = NO_RECOVERY; 1178 return (NULL); 1179 } 1180 canonname = bp; 1181 bp += n; 1182 buflen -= n; 1183 /* The qname can be abbreviated, but h_name is now absolute. */ 1184 qname = canonname; 1185 } 1186 haveanswer = 0; 1187 had_error = 0; 1188 while (ancount-- > 0 && cp < eom && !had_error) { 1189 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1190 if ((n < 0) || !(*name_ok)(bp)) { 1191 had_error++; 1192 continue; 1193 } 1194 cp += n; /* name */ 1195 type = _getshort(cp); 1196 cp += INT16SZ; /* type */ 1197 class = _getshort(cp); 1198 cp += INT16SZ + INT32SZ; /* class, TTL */ 1199 n = _getshort(cp); 1200 cp += INT16SZ; /* len */ 1201 if (class != C_IN) { 1202 /* XXX - debug? syslog? */ 1203 cp += n; 1204 continue; /* XXX - had_error++ ? */ 1205 } 1206 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1207 type == T_CNAME) { 1208 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1209 if ((n < 0) || !(*name_ok)(tbuf)) { 1210 had_error++; 1211 continue; 1212 } 1213 cp += n; 1214 /* Get canonical name. */ 1215 n = strlen(tbuf) + 1; /* for the \0 */ 1216 if (n > buflen || n >= MAXHOSTNAMELEN) { 1217 had_error++; 1218 continue; 1219 } 1220 strcpy(bp, tbuf); 1221 canonname = bp; 1222 bp += n; 1223 buflen -= n; 1224 continue; 1225 } 1226 if (qtype == T_ANY) { 1227 if (!(type == T_A || type == T_AAAA)) { 1228 cp += n; 1229 continue; 1230 } 1231 } else if (type != qtype) { 1232 if (type != T_KEY && type != T_SIG) 1233 syslog(LOG_NOTICE|LOG_AUTH, 1234 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1235 qname, p_class(C_IN), p_type(qtype), 1236 p_type(type)); 1237 cp += n; 1238 continue; /* XXX - had_error++ ? */ 1239 } 1240 switch (type) { 1241 case T_A: 1242 case T_AAAA: 1243 if (strcasecmp(canonname, bp) != 0) { 1244 syslog(LOG_NOTICE|LOG_AUTH, 1245 AskedForGot, canonname, bp); 1246 cp += n; 1247 continue; /* XXX - had_error++ ? */ 1248 } 1249 if (type == T_A && n != INADDRSZ) { 1250 cp += n; 1251 continue; 1252 } 1253 if (type == T_AAAA && n != IN6ADDRSZ) { 1254 cp += n; 1255 continue; 1256 } 1257 if (!haveanswer) { 1258 int nn; 1259 1260 canonname = bp; 1261 nn = strlen(bp) + 1; /* for the \0 */ 1262 bp += nn; 1263 buflen -= nn; 1264 } 1265 1266 /* don't overwrite pai */ 1267 ai = *pai; 1268 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1269 afd = find_afd(ai.ai_family); 1270 if (afd == NULL) { 1271 cp += n; 1272 continue; 1273 } 1274 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1275 if (cur->ai_next == NULL) 1276 had_error++; 1277 while (cur && cur->ai_next) 1278 cur = cur->ai_next; 1279 cp += n; 1280 break; 1281 default: 1282 abort(); 1283 } 1284 if (!had_error) 1285 haveanswer++; 1286 } 1287 if (haveanswer) { 1288 if (!canonname) 1289 (void)get_canonname(pai, sentinel.ai_next, qname); 1290 else 1291 (void)get_canonname(pai, sentinel.ai_next, canonname); 1292 h_errno = NETDB_SUCCESS; 1293 return sentinel.ai_next; 1294 } 1295 1296 h_errno = NO_RECOVERY; 1297 return NULL; 1298 } 1299 1300 /*ARGSUSED*/ 1301 static int 1302 _dns_getaddrinfo(rv, cb_data, ap) 1303 void *rv; 1304 void *cb_data; 1305 va_list ap; 1306 { 1307 struct addrinfo *ai; 1308 querybuf buf, buf2; 1309 const char *name; 1310 const struct addrinfo *pai; 1311 struct addrinfo sentinel, *cur; 1312 struct res_target q, q2; 1313 1314 name = va_arg(ap, char *); 1315 pai = va_arg(ap, const struct addrinfo *); 1316 1317 memset(&q, 0, sizeof(q2)); 1318 memset(&q2, 0, sizeof(q2)); 1319 memset(&sentinel, 0, sizeof(sentinel)); 1320 cur = &sentinel; 1321 1322 switch (pai->ai_family) { 1323 case AF_UNSPEC: 1324 /* prefer IPv6 */ 1325 q.qclass = C_IN; 1326 q.qtype = T_AAAA; 1327 q.answer = buf.buf; 1328 q.anslen = sizeof(buf); 1329 q.next = &q2; 1330 q2.qclass = C_IN; 1331 q2.qtype = T_A; 1332 q2.answer = buf2.buf; 1333 q2.anslen = sizeof(buf2); 1334 break; 1335 case AF_INET: 1336 q.qclass = C_IN; 1337 q.qtype = T_A; 1338 q.answer = buf.buf; 1339 q.anslen = sizeof(buf); 1340 break; 1341 case AF_INET6: 1342 q.qclass = C_IN; 1343 q.qtype = T_AAAA; 1344 q.answer = buf.buf; 1345 q.anslen = sizeof(buf); 1346 break; 1347 default: 1348 return NS_UNAVAIL; 1349 } 1350 if (res_searchN(name, &q) < 0) 1351 return NS_NOTFOUND; 1352 ai = getanswer(&buf, q.n, q.name, q.qtype, pai); 1353 if (ai) { 1354 cur->ai_next = ai; 1355 while (cur && cur->ai_next) 1356 cur = cur->ai_next; 1357 } 1358 if (q.next) { 1359 ai = getanswer(&buf2, q2.n, q2.name, q2.qtype, pai); 1360 if (ai) 1361 cur->ai_next = ai; 1362 } 1363 if (sentinel.ai_next == NULL) 1364 switch (h_errno) { 1365 case HOST_NOT_FOUND: 1366 return NS_NOTFOUND; 1367 case TRY_AGAIN: 1368 return NS_TRYAGAIN; 1369 default: 1370 return NS_UNAVAIL; 1371 } 1372 *((struct addrinfo **)rv) = sentinel.ai_next; 1373 return NS_SUCCESS; 1374 } 1375 1376 static void 1377 _sethtent() 1378 { 1379 1380 if (!hostf) 1381 hostf = fopen(_PATH_HOSTS, "r" ); 1382 else 1383 rewind(hostf); 1384 } 1385 1386 static void 1387 _endhtent() 1388 { 1389 1390 if (hostf) { 1391 (void) fclose(hostf); 1392 hostf = NULL; 1393 } 1394 } 1395 1396 static struct addrinfo * 1397 _gethtent(name, pai) 1398 const char *name; 1399 const struct addrinfo *pai; 1400 { 1401 char *p; 1402 char *cp, *tname, *cname; 1403 struct addrinfo hints, *res0, *res; 1404 int error; 1405 const char *addr; 1406 char hostbuf[8*1024]; 1407 1408 _DIAGASSERT(name != NULL); 1409 _DIAGASSERT(pai != NULL); 1410 1411 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) 1412 return (NULL); 1413 again: 1414 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) 1415 return (NULL); 1416 if (*p == '#') 1417 goto again; 1418 if (!(cp = strpbrk(p, "#\n"))) 1419 goto again; 1420 *cp = '\0'; 1421 if (!(cp = strpbrk(p, " \t"))) 1422 goto again; 1423 *cp++ = '\0'; 1424 addr = p; 1425 /* if this is not something we're looking for, skip it. */ 1426 cname = NULL; 1427 while (cp && *cp) { 1428 if (*cp == ' ' || *cp == '\t') { 1429 cp++; 1430 continue; 1431 } 1432 if (!cname) 1433 cname = cp; 1434 tname = cp; 1435 if ((cp = strpbrk(cp, " \t")) != NULL) 1436 *cp++ = '\0'; 1437 if (strcasecmp(name, tname) == 0) 1438 goto found; 1439 } 1440 goto again; 1441 1442 found: 1443 hints = *pai; 1444 hints.ai_flags = AI_NUMERICHOST; 1445 error = getaddrinfo(addr, NULL, &hints, &res0); 1446 if (error) 1447 goto again; 1448 for (res = res0; res; res = res->ai_next) { 1449 /* cover it up */ 1450 res->ai_flags = pai->ai_flags; 1451 1452 if (pai->ai_flags & AI_CANONNAME) { 1453 if (get_canonname(pai, res, cname) != 0) { 1454 freeaddrinfo(res0); 1455 goto again; 1456 } 1457 } 1458 } 1459 return res0; 1460 } 1461 1462 /*ARGSUSED*/ 1463 static int 1464 _files_getaddrinfo(rv, cb_data, ap) 1465 void *rv; 1466 void *cb_data; 1467 va_list ap; 1468 { 1469 const char *name; 1470 const struct addrinfo *pai; 1471 struct addrinfo sentinel, *cur; 1472 struct addrinfo *p; 1473 1474 name = va_arg(ap, char *); 1475 pai = va_arg(ap, struct addrinfo *); 1476 1477 memset(&sentinel, 0, sizeof(sentinel)); 1478 cur = &sentinel; 1479 1480 _sethtent(); 1481 while ((p = _gethtent(name, pai)) != NULL) { 1482 cur->ai_next = p; 1483 while (cur && cur->ai_next) 1484 cur = cur->ai_next; 1485 } 1486 _endhtent(); 1487 1488 *((struct addrinfo **)rv) = sentinel.ai_next; 1489 if (sentinel.ai_next == NULL) 1490 return NS_NOTFOUND; 1491 return NS_SUCCESS; 1492 } 1493 1494 #ifdef YP 1495 static char *__ypdomain; 1496 1497 /*ARGSUSED*/ 1498 static struct addrinfo * 1499 _yphostent(line, pai) 1500 char *line; 1501 const struct addrinfo *pai; 1502 { 1503 struct addrinfo sentinel, *cur; 1504 struct addrinfo hints, *res, *res0; 1505 int error; 1506 char *p; 1507 const char *addr, *canonname; 1508 char *nextline; 1509 char *cp; 1510 1511 _DIAGASSERT(line != NULL); 1512 _DIAGASSERT(pai != NULL); 1513 1514 p = line; 1515 addr = canonname = NULL; 1516 1517 memset(&sentinel, 0, sizeof(sentinel)); 1518 cur = &sentinel; 1519 1520 nextline: 1521 /* terminate line */ 1522 cp = strchr(p, '\n'); 1523 if (cp) { 1524 *cp++ = '\0'; 1525 nextline = cp; 1526 } else 1527 nextline = NULL; 1528 1529 cp = strpbrk(p, " \t"); 1530 if (cp == NULL) { 1531 if (canonname == NULL) 1532 return (NULL); 1533 else 1534 goto done; 1535 } 1536 *cp++ = '\0'; 1537 1538 addr = p; 1539 1540 while (cp && *cp) { 1541 if (*cp == ' ' || *cp == '\t') { 1542 cp++; 1543 continue; 1544 } 1545 if (!canonname) 1546 canonname = cp; 1547 if ((cp = strpbrk(cp, " \t")) != NULL) 1548 *cp++ = '\0'; 1549 } 1550 1551 hints = *pai; 1552 hints.ai_flags = AI_NUMERICHOST; 1553 error = getaddrinfo(addr, NULL, &hints, &res0); 1554 if (error == 0) { 1555 for (res = res0; res; res = res->ai_next) { 1556 /* cover it up */ 1557 res->ai_flags = pai->ai_flags; 1558 1559 if (pai->ai_flags & AI_CANONNAME) 1560 (void)get_canonname(pai, res, canonname); 1561 } 1562 } else 1563 res0 = NULL; 1564 if (res0) { 1565 cur->ai_next = res0; 1566 while (cur && cur->ai_next) 1567 cur = cur->ai_next; 1568 } 1569 1570 if (nextline) { 1571 p = nextline; 1572 goto nextline; 1573 } 1574 1575 done: 1576 return sentinel.ai_next; 1577 } 1578 1579 /*ARGSUSED*/ 1580 static int 1581 _yp_getaddrinfo(rv, cb_data, ap) 1582 void *rv; 1583 void *cb_data; 1584 va_list ap; 1585 { 1586 struct addrinfo sentinel, *cur; 1587 struct addrinfo *ai = NULL; 1588 static char *__ypcurrent; 1589 int __ypcurrentlen, r; 1590 const char *name; 1591 const struct addrinfo *pai; 1592 1593 name = va_arg(ap, char *); 1594 pai = va_arg(ap, const struct addrinfo *); 1595 1596 memset(&sentinel, 0, sizeof(sentinel)); 1597 cur = &sentinel; 1598 1599 if (!__ypdomain) { 1600 if (_yp_check(&__ypdomain) == 0) 1601 return NS_UNAVAIL; 1602 } 1603 if (__ypcurrent) 1604 free(__ypcurrent); 1605 __ypcurrent = NULL; 1606 1607 /* hosts.byname is only for IPv4 (Solaris8) */ 1608 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1609 r = yp_match(__ypdomain, "hosts.byname", name, 1610 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1611 if (r == 0) { 1612 struct addrinfo ai4; 1613 1614 ai4 = *pai; 1615 ai4.ai_family = AF_INET; 1616 ai = _yphostent(__ypcurrent, &ai4); 1617 if (ai) { 1618 cur->ai_next = ai; 1619 while (cur && cur->ai_next) 1620 cur = cur->ai_next; 1621 } 1622 } 1623 } 1624 1625 /* ipnodes.byname can hold both IPv4/v6 */ 1626 r = yp_match(__ypdomain, "ipnodes.byname", name, 1627 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1628 if (r == 0) { 1629 ai = _yphostent(__ypcurrent, pai); 1630 if (ai) { 1631 cur->ai_next = ai; 1632 while (cur && cur->ai_next) 1633 cur = cur->ai_next; 1634 } 1635 } 1636 1637 if (sentinel.ai_next == NULL) { 1638 h_errno = HOST_NOT_FOUND; 1639 return NS_NOTFOUND; 1640 } 1641 *((struct addrinfo **)rv) = sentinel.ai_next; 1642 return NS_SUCCESS; 1643 } 1644 #endif 1645 1646 /* resolver logic */ 1647 1648 /* 1649 * Formulate a normal query, send, and await answer. 1650 * Returned answer is placed in supplied buffer "answer". 1651 * Perform preliminary check of answer, returning success only 1652 * if no error is indicated and the answer count is nonzero. 1653 * Return the size of the response on success, -1 on error. 1654 * Error number is left in h_errno. 1655 * 1656 * Caller must parse answer and determine whether it answers the question. 1657 */ 1658 static int 1659 res_queryN(name, target) 1660 const char *name; /* domain name */ 1661 struct res_target *target; 1662 { 1663 u_char buf[MAXPACKET]; 1664 HEADER *hp; 1665 int n; 1666 struct res_target *t; 1667 int rcode; 1668 int ancount; 1669 1670 _DIAGASSERT(name != NULL); 1671 /* XXX: target may be NULL??? */ 1672 1673 rcode = NOERROR; 1674 ancount = 0; 1675 1676 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1677 h_errno = NETDB_INTERNAL; 1678 return (-1); 1679 } 1680 1681 for (t = target; t; t = t->next) { 1682 int class, type; 1683 u_char *answer; 1684 int anslen; 1685 1686 hp = (HEADER *)(void *)t->answer; 1687 hp->rcode = NOERROR; /* default */ 1688 1689 /* make it easier... */ 1690 class = t->qclass; 1691 type = t->qtype; 1692 answer = t->answer; 1693 anslen = t->anslen; 1694 #ifdef DEBUG 1695 if (_res.options & RES_DEBUG) 1696 printf(";; res_query(%s, %d, %d)\n", name, class, type); 1697 #endif 1698 1699 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL, 1700 buf, sizeof(buf)); 1701 #ifdef RES_USE_EDNS0 1702 if (n > 0 && (_res.options & RES_USE_EDNS0) != 0) 1703 n = res_opt(n, buf, sizeof(buf), anslen); 1704 #endif 1705 if (n <= 0) { 1706 #ifdef DEBUG 1707 if (_res.options & RES_DEBUG) 1708 printf(";; res_query: mkquery failed\n"); 1709 #endif 1710 h_errno = NO_RECOVERY; 1711 return (n); 1712 } 1713 n = res_send(buf, n, answer, anslen); 1714 #if 0 1715 if (n < 0) { 1716 #ifdef DEBUG 1717 if (_res.options & RES_DEBUG) 1718 printf(";; res_query: send error\n"); 1719 #endif 1720 h_errno = TRY_AGAIN; 1721 return (n); 1722 } 1723 #endif 1724 1725 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1726 rcode = hp->rcode; /* record most recent error */ 1727 #ifdef DEBUG 1728 if (_res.options & RES_DEBUG) 1729 printf(";; rcode = %d, ancount=%d\n", hp->rcode, 1730 ntohs(hp->ancount)); 1731 #endif 1732 continue; 1733 } 1734 1735 ancount += ntohs(hp->ancount); 1736 1737 t->n = n; 1738 } 1739 1740 if (ancount == 0) { 1741 switch (rcode) { 1742 case NXDOMAIN: 1743 h_errno = HOST_NOT_FOUND; 1744 break; 1745 case SERVFAIL: 1746 h_errno = TRY_AGAIN; 1747 break; 1748 case NOERROR: 1749 h_errno = NO_DATA; 1750 break; 1751 case FORMERR: 1752 case NOTIMP: 1753 case REFUSED: 1754 default: 1755 h_errno = NO_RECOVERY; 1756 break; 1757 } 1758 return (-1); 1759 } 1760 return (ancount); 1761 } 1762 1763 /* 1764 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1765 * Return the size of the response on success, -1 on error. 1766 * If enabled, implement search rules until answer or unrecoverable failure 1767 * is detected. Error code, if any, is left in h_errno. 1768 */ 1769 static int 1770 res_searchN(name, target) 1771 const char *name; /* domain name */ 1772 struct res_target *target; 1773 { 1774 const char *cp, * const *domain; 1775 HEADER *hp; 1776 u_int dots; 1777 int trailing_dot, ret, saved_herrno; 1778 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1779 1780 _DIAGASSERT(name != NULL); 1781 _DIAGASSERT(target != NULL); 1782 1783 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1784 1785 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1786 h_errno = NETDB_INTERNAL; 1787 return (-1); 1788 } 1789 1790 errno = 0; 1791 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1792 dots = 0; 1793 for (cp = name; *cp; cp++) 1794 dots += (*cp == '.'); 1795 trailing_dot = 0; 1796 if (cp > name && *--cp == '.') 1797 trailing_dot++; 1798 1799 /* 1800 * if there aren't any dots, it could be a user-level alias 1801 */ 1802 if (!dots && (cp = __hostalias(name)) != NULL) 1803 return (res_queryN(cp, target)); 1804 1805 /* 1806 * If there are dots in the name already, let's just give it a try 1807 * 'as is'. The threshold can be set with the "ndots" option. 1808 */ 1809 saved_herrno = -1; 1810 if (dots >= _res.ndots) { 1811 ret = res_querydomainN(name, NULL, target); 1812 if (ret > 0) 1813 return (ret); 1814 saved_herrno = h_errno; 1815 tried_as_is++; 1816 } 1817 1818 /* 1819 * We do at least one level of search if 1820 * - there is no dot and RES_DEFNAME is set, or 1821 * - there is at least one dot, there is no trailing dot, 1822 * and RES_DNSRCH is set. 1823 */ 1824 if ((!dots && (_res.options & RES_DEFNAMES)) || 1825 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { 1826 int done = 0; 1827 1828 for (domain = (const char * const *)_res.dnsrch; 1829 *domain && !done; 1830 domain++) { 1831 1832 ret = res_querydomainN(name, *domain, target); 1833 if (ret > 0) 1834 return (ret); 1835 1836 /* 1837 * If no server present, give up. 1838 * If name isn't found in this domain, 1839 * keep trying higher domains in the search list 1840 * (if that's enabled). 1841 * On a NO_DATA error, keep trying, otherwise 1842 * a wildcard entry of another type could keep us 1843 * from finding this entry higher in the domain. 1844 * If we get some other error (negative answer or 1845 * server failure), then stop searching up, 1846 * but try the input name below in case it's 1847 * fully-qualified. 1848 */ 1849 if (errno == ECONNREFUSED) { 1850 h_errno = TRY_AGAIN; 1851 return (-1); 1852 } 1853 1854 switch (h_errno) { 1855 case NO_DATA: 1856 got_nodata++; 1857 /* FALLTHROUGH */ 1858 case HOST_NOT_FOUND: 1859 /* keep trying */ 1860 break; 1861 case TRY_AGAIN: 1862 if (hp->rcode == SERVFAIL) { 1863 /* try next search element, if any */ 1864 got_servfail++; 1865 break; 1866 } 1867 /* FALLTHROUGH */ 1868 default: 1869 /* anything else implies that we're done */ 1870 done++; 1871 } 1872 /* 1873 * if we got here for some reason other than DNSRCH, 1874 * we only wanted one iteration of the loop, so stop. 1875 */ 1876 if (!(_res.options & RES_DNSRCH)) 1877 done++; 1878 } 1879 } 1880 1881 /* 1882 * if we have not already tried the name "as is", do that now. 1883 * note that we do this regardless of how many dots were in the 1884 * name or whether it ends with a dot. 1885 */ 1886 if (!tried_as_is) { 1887 ret = res_querydomainN(name, NULL, target); 1888 if (ret > 0) 1889 return (ret); 1890 } 1891 1892 /* 1893 * if we got here, we didn't satisfy the search. 1894 * if we did an initial full query, return that query's h_errno 1895 * (note that we wouldn't be here if that query had succeeded). 1896 * else if we ever got a nodata, send that back as the reason. 1897 * else send back meaningless h_errno, that being the one from 1898 * the last DNSRCH we did. 1899 */ 1900 if (saved_herrno != -1) 1901 h_errno = saved_herrno; 1902 else if (got_nodata) 1903 h_errno = NO_DATA; 1904 else if (got_servfail) 1905 h_errno = TRY_AGAIN; 1906 return (-1); 1907 } 1908 1909 /* 1910 * Perform a call on res_query on the concatenation of name and domain, 1911 * removing a trailing dot from name if domain is NULL. 1912 */ 1913 static int 1914 res_querydomainN(name, domain, target) 1915 const char *name, *domain; 1916 struct res_target *target; 1917 { 1918 char nbuf[MAXDNAME]; 1919 const char *longname = nbuf; 1920 size_t n, d; 1921 1922 _DIAGASSERT(name != NULL); 1923 /* XXX: target may be NULL??? */ 1924 1925 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1926 h_errno = NETDB_INTERNAL; 1927 return (-1); 1928 } 1929 #ifdef DEBUG 1930 if (_res.options & RES_DEBUG) 1931 printf(";; res_querydomain(%s, %s)\n", 1932 name, domain?domain:"<Nil>"); 1933 #endif 1934 if (domain == NULL) { 1935 /* 1936 * Check for trailing '.'; 1937 * copy without '.' if present. 1938 */ 1939 n = strlen(name); 1940 if (n >= MAXDNAME) { 1941 h_errno = NO_RECOVERY; 1942 return (-1); 1943 } 1944 if (n > 0 && name[--n] == '.') { 1945 strncpy(nbuf, name, n); 1946 nbuf[n] = '\0'; 1947 } else 1948 longname = name; 1949 } else { 1950 n = strlen(name); 1951 d = strlen(domain); 1952 if (n + d + 1 >= MAXDNAME) { 1953 h_errno = NO_RECOVERY; 1954 return (-1); 1955 } 1956 sprintf(nbuf, "%s.%s", name, domain); 1957 } 1958 return (res_queryN(longname, target)); 1959 } 1960