1 /* $NetBSD: getaddrinfo.c,v 1.91.6.1 2009/01/26 00:27:34 snj 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 * - Return values. There are nonstandard return values defined and used 36 * in the source code. This is because RFC2553 is silent about which error 37 * code must be returned for which situation. 38 * - IPv4 classful (shortened) form. RFC2553 is silent about it. XNET 5.2 39 * says to use inet_aton() to convert IPv4 numeric to binary (alows 40 * classful form as a result). 41 * current code - disallow classful form for IPv4 (due to use of inet_pton). 42 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 43 * invalid. 44 * current code - SEGV on freeaddrinfo(NULL) 45 * Note: 46 * - The code filters out AFs that are not supported by the kernel, 47 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 48 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 49 * in ai_flags? 50 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 51 * (1) what should we do against numeric hostname (2) what should we do 52 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 53 * non-loopback address configured? global address configured? 54 */ 55 56 #include <sys/cdefs.h> 57 #if defined(LIBC_SCCS) && !defined(lint) 58 __RCSID("$NetBSD: getaddrinfo.c,v 1.91.6.1 2009/01/26 00:27:34 snj Exp $"); 59 #endif /* LIBC_SCCS and not lint */ 60 61 #define INET6 1 62 63 #include "namespace.h" 64 #include <sys/types.h> 65 #include <sys/param.h> 66 #include <sys/socket.h> 67 #include <net/if.h> 68 #include <netinet/in.h> 69 #include <arpa/inet.h> 70 #include <arpa/nameser.h> 71 #include <assert.h> 72 #include <ctype.h> 73 #include <errno.h> 74 #include <netdb.h> 75 #include <resolv.h> 76 #include <stddef.h> 77 #include <stdio.h> 78 #include <stdlib.h> 79 #include <string.h> 80 #include <unistd.h> 81 82 #include <stdarg.h> 83 #include <nsswitch.h> 84 #include <resolv.h> 85 86 //#ifdef YP 87 //#include <rpc/rpc.h> 88 //#include <rpcsvc/yp_prot.h> 89 //#include <rpcsvc/ypclnt.h> 90 //#endif 91 92 #include <net/servent.h> 93 94 #define endservent_r(svd) endservent() 95 #define nsdispatch(pResult,dtab,database,routine,files,hostname,pai) NS_NOTFOUND 96 #define res_nmkquery(state,op,dname,class,type,data,datalen,newrr_in,buf,buflen) res_mkquery( op, dname, class, type, data, datalen, newrr_in, buf, buflen ) 97 #define res_nsend(state,buf,buflen,ans,anssiz) res_send ( buf, buflen, ans, anssiz ) 98 99 /* Things involving an internal (static) resolver context. */ 100 __BEGIN_DECLS 101 #define __res_get_state() (( 0 != _res.nscount ) ? &_res : NULL ) 102 #define __res_put_state(state) 103 #define __res_state() _res 104 __END_DECLS 105 106 #ifdef __weak_alias 107 __weak_alias(getaddrinfo,_getaddrinfo) 108 __weak_alias(freeaddrinfo,_freeaddrinfo) 109 __weak_alias(gai_strerror,_gai_strerror) 110 #endif 111 112 #define SUCCESS 0 113 #define ANY 0 114 #define YES 1 115 #define NO 0 116 117 static const char in_addrany[] = { 0, 0, 0, 0 }; 118 static const char in_loopback[] = { 127, 0, 0, 1 }; 119 #ifdef INET6 120 static const char in6_addrany[] = { 121 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 122 }; 123 static const char in6_loopback[] = { 124 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 125 }; 126 #endif 127 128 static const struct afd { 129 int a_af; 130 int a_addrlen; 131 int a_socklen; 132 int a_off; 133 const char *a_addrany; 134 const char *a_loopback; 135 int a_scoped; 136 } afdl [] = { 137 #ifdef INET6 138 {PF_INET6, sizeof(struct in6_addr), 139 sizeof(struct sockaddr_in6), 140 offsetof(struct sockaddr_in6, sin6_addr), 141 in6_addrany, in6_loopback, 1}, 142 #endif 143 {PF_INET, sizeof(struct in_addr), 144 sizeof(struct sockaddr_in), 145 offsetof(struct sockaddr_in, sin_addr), 146 in_addrany, in_loopback, 0}, 147 {0, 0, 0, 0, NULL, NULL, 0}, 148 }; 149 150 struct explore { 151 int e_af; 152 int e_socktype; 153 int e_protocol; 154 const char *e_protostr; 155 int e_wild; 156 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 157 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 158 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 159 }; 160 161 static const struct explore explore[] = { 162 #if 0 163 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 164 #endif 165 #ifdef INET6 166 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 167 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 168 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 169 #endif 170 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 171 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 172 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 173 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 174 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 175 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 176 { -1, 0, 0, NULL, 0 }, 177 }; 178 179 #ifdef INET6 180 #define PTON_MAX 16 181 #else 182 #define PTON_MAX 4 183 #endif 184 185 static const ns_src default_dns_files[] = { 186 { NSSRC_FILES, NS_SUCCESS }, 187 { NSSRC_DNS, NS_SUCCESS }, 188 { 0, 0 } 189 }; 190 191 #define MAXPACKET (64*1024) 192 193 typedef union { 194 HEADER hdr; 195 u_char buf[MAXPACKET]; 196 } querybuf; 197 198 struct res_target { 199 struct res_target *next; 200 const char *name; /* domain name */ 201 int qclass, qtype; /* class and type of query */ 202 u_char *answer; /* buffer to put answer */ 203 int anslen; /* size of answer buffer */ 204 int n; /* result length */ 205 }; 206 207 static int str2number(const char *); 208 static int explore_fqdn(const struct addrinfo *, const char *, 209 const char *, struct addrinfo **, struct servent_data *); 210 static int explore_null(const struct addrinfo *, 211 const char *, struct addrinfo **, struct servent_data *); 212 static int explore_numeric(const struct addrinfo *, const char *, 213 const char *, struct addrinfo **, const char *, struct servent_data *); 214 static int explore_numeric_scope(const struct addrinfo *, const char *, 215 const char *, struct addrinfo **, struct servent_data *); 216 static int get_canonname(const struct addrinfo *, 217 struct addrinfo *, const char *); 218 static struct addrinfo *get_ai(const struct addrinfo *, 219 const struct afd *, const char *); 220 static int get_portmatch(const struct addrinfo *, const char *, 221 struct servent_data *); 222 static int get_port(const struct addrinfo *, const char *, int, 223 struct servent_data *); 224 static const struct afd *find_afd(int); 225 #ifdef INET6 226 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 227 #endif 228 229 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 230 const struct addrinfo *); 231 static void aisort(struct addrinfo *s, res_state res); 232 static int _dns_getaddrinfo(void *, void *, va_list); 233 static void _sethtent(FILE **); 234 static void _endhtent(FILE **); 235 static struct addrinfo *_gethtent(FILE **, const char *, 236 const struct addrinfo *); 237 static int _files_getaddrinfo(void *, void *, va_list); 238 #ifdef YP 239 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 240 static int _yp_getaddrinfo(void *, void *, va_list); 241 #endif 242 243 static int res_queryN(const char *, struct res_target *, res_state); 244 static int res_searchN(const char *, struct res_target *, res_state); 245 static int res_querydomainN(const char *, const char *, 246 struct res_target *, res_state); 247 248 static const char * const ai_errlist[] = { 249 "Success", 250 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 251 "Temporary failure in name resolution", /* EAI_AGAIN */ 252 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 253 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 254 "ai_family not supported", /* EAI_FAMILY */ 255 "Memory allocation failure", /* EAI_MEMORY */ 256 "No address associated with hostname", /* EAI_NODATA */ 257 "hostname nor servname provided, or not known", /* EAI_NONAME */ 258 "servname not supported for ai_socktype", /* EAI_SERVICE */ 259 "ai_socktype not supported", /* EAI_SOCKTYPE */ 260 "System error returned in errno", /* EAI_SYSTEM */ 261 "Invalid value for hints", /* EAI_BADHINTS */ 262 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 263 "Argument buffer overflow", /* EAI_OVERFLOW */ 264 "Unknown error", /* EAI_MAX */ 265 }; 266 267 /* XXX macros that make external reference is BAD. */ 268 269 #define GET_AI(ai, afd, addr) \ 270 do { \ 271 /* external reference: pai, error, and label free */ \ 272 (ai) = get_ai(pai, (afd), (addr)); \ 273 if ((ai) == NULL) { \ 274 error = EAI_MEMORY; \ 275 goto free; \ 276 } \ 277 } while (/*CONSTCOND*/0) 278 279 #define GET_PORT(ai, serv, svd) \ 280 do { \ 281 /* external reference: error and label free */ \ 282 error = get_port((ai), (serv), 0, (svd)); \ 283 if (error != 0) \ 284 goto free; \ 285 } while (/*CONSTCOND*/0) 286 287 #define GET_CANONNAME(ai, str) \ 288 do { \ 289 /* external reference: pai, error and label free */ \ 290 error = get_canonname(pai, (ai), (str)); \ 291 if (error != 0) \ 292 goto free; \ 293 } while (/*CONSTCOND*/0) 294 295 #define ERR(err) \ 296 do { \ 297 /* external reference: error, and label bad */ \ 298 error = (err); \ 299 goto bad; \ 300 /*NOTREACHED*/ \ 301 } while (/*CONSTCOND*/0) 302 303 #define MATCH_FAMILY(x, y, w) \ 304 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || \ 305 (y) == PF_UNSPEC))) 306 #define MATCH(x, y, w) \ 307 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 308 309 const char * 310 gai_strerror(int ecode) 311 { 312 if (ecode < 0 || ecode > EAI_MAX) 313 ecode = EAI_MAX; 314 return ai_errlist[ecode]; 315 } 316 317 void 318 freeaddrinfo(struct addrinfo *ai) 319 { 320 struct addrinfo *next; 321 322 _DIAGASSERT(ai != NULL); 323 324 do { 325 next = ai->ai_next; 326 if (ai->ai_canonname) 327 free(ai->ai_canonname); 328 /* no need to free(ai->ai_addr) */ 329 free(ai); 330 ai = next; 331 } while (ai); 332 } 333 334 static int 335 str2number(const char *p) 336 { 337 char *ep; 338 unsigned long v; 339 340 _DIAGASSERT(p != NULL); 341 342 if (*p == '\0') 343 return -1; 344 ep = NULL; 345 errno = 0; 346 v = strtoul(p, &ep, 10); 347 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) 348 return v; 349 else 350 return -1; 351 } 352 353 int 354 getaddrinfo(const char *hostname, const char *servname, 355 const struct addrinfo *hints, struct addrinfo **res) 356 { 357 struct addrinfo sentinel; 358 struct addrinfo *cur; 359 int error = 0; 360 struct addrinfo ai; 361 struct addrinfo ai0; 362 struct addrinfo *pai; 363 const struct explore *ex; 364 struct servent_data svd; 365 366 /* hostname is allowed to be NULL */ 367 /* servname is allowed to be NULL */ 368 /* hints is allowed to be NULL */ 369 _DIAGASSERT(res != NULL); 370 371 (void)memset(&svd, 0, sizeof(svd)); 372 memset(&sentinel, 0, sizeof(sentinel)); 373 cur = &sentinel; 374 memset(&ai, 0, sizeof(ai)); 375 pai = &ai; 376 pai->ai_flags = 0; 377 pai->ai_family = PF_UNSPEC; 378 pai->ai_socktype = ANY; 379 pai->ai_protocol = ANY; 380 pai->ai_addrlen = 0; 381 pai->ai_canonname = NULL; 382 pai->ai_addr = NULL; 383 pai->ai_next = NULL; 384 385 if (hostname == NULL && servname == NULL) 386 return EAI_NONAME; 387 if (hints) { 388 /* error check for hints */ 389 if (hints->ai_addrlen || hints->ai_canonname || 390 hints->ai_addr || hints->ai_next) 391 ERR(EAI_BADHINTS); /* xxx */ 392 if (hints->ai_flags & ~AI_MASK) 393 ERR(EAI_BADFLAGS); 394 switch (hints->ai_family) { 395 case PF_UNSPEC: 396 case PF_INET: 397 #ifdef INET6 398 case PF_INET6: 399 #endif 400 break; 401 default: 402 ERR(EAI_FAMILY); 403 } 404 memcpy(pai, hints, sizeof(*pai)); 405 406 /* 407 * if both socktype/protocol are specified, check if they 408 * are meaningful combination. 409 */ 410 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 411 for (ex = explore; ex->e_af >= 0; ex++) { 412 if (pai->ai_family != ex->e_af) 413 continue; 414 if (ex->e_socktype == ANY) 415 continue; 416 if (ex->e_protocol == ANY) 417 continue; 418 if (pai->ai_socktype == ex->e_socktype 419 && pai->ai_protocol != ex->e_protocol) { 420 ERR(EAI_BADHINTS); 421 } 422 } 423 } 424 } 425 426 /* 427 * check for special cases. (1) numeric servname is disallowed if 428 * socktype/protocol are left unspecified. (2) servname is disallowed 429 * for raw and other inet{,6} sockets. 430 */ 431 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 432 #ifdef PF_INET6 433 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 434 #endif 435 ) { 436 ai0 = *pai; /* backup *pai */ 437 438 if (pai->ai_family == PF_UNSPEC) { 439 #ifdef PF_INET6 440 pai->ai_family = PF_INET6; 441 #else 442 pai->ai_family = PF_INET; 443 #endif 444 } 445 error = get_portmatch(pai, servname, &svd); 446 if (error) 447 ERR(error); 448 449 *pai = ai0; 450 } 451 452 ai0 = *pai; 453 454 /* NULL hostname, or numeric hostname */ 455 for (ex = explore; ex->e_af >= 0; ex++) { 456 *pai = ai0; 457 458 /* PF_UNSPEC entries are prepared for DNS queries only */ 459 if (ex->e_af == PF_UNSPEC) 460 continue; 461 462 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 463 continue; 464 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 465 continue; 466 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 467 continue; 468 469 if (pai->ai_family == PF_UNSPEC) 470 pai->ai_family = ex->e_af; 471 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 472 pai->ai_socktype = ex->e_socktype; 473 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 474 pai->ai_protocol = ex->e_protocol; 475 476 if (hostname == NULL) 477 error = explore_null(pai, servname, &cur->ai_next, 478 &svd); 479 else 480 error = explore_numeric_scope(pai, hostname, servname, 481 &cur->ai_next, &svd); 482 483 if (error) 484 goto free; 485 486 while (cur->ai_next) 487 cur = cur->ai_next; 488 } 489 490 /* 491 * XXX 492 * If numeric representation of AF1 can be interpreted as FQDN 493 * representation of AF2, we need to think again about the code below. 494 */ 495 if (sentinel.ai_next) 496 goto good; 497 498 if (hostname == NULL) 499 ERR(EAI_NODATA); 500 if (pai->ai_flags & AI_NUMERICHOST) 501 ERR(EAI_NONAME); 502 503 /* 504 * hostname as alphabetical name. 505 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 506 * outer loop by AFs. 507 */ 508 for (ex = explore; ex->e_af >= 0; ex++) { 509 *pai = ai0; 510 511 /* require exact match for family field */ 512 if (pai->ai_family != ex->e_af) 513 continue; 514 515 if (!MATCH(pai->ai_socktype, ex->e_socktype, 516 WILD_SOCKTYPE(ex))) { 517 continue; 518 } 519 if (!MATCH(pai->ai_protocol, ex->e_protocol, 520 WILD_PROTOCOL(ex))) { 521 continue; 522 } 523 524 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 525 pai->ai_socktype = ex->e_socktype; 526 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 527 pai->ai_protocol = ex->e_protocol; 528 529 error = explore_fqdn(pai, hostname, servname, &cur->ai_next, 530 &svd); 531 532 while (cur && cur->ai_next) 533 cur = cur->ai_next; 534 } 535 536 /* XXX */ 537 if (sentinel.ai_next) 538 error = 0; 539 540 if (error) 541 goto free; 542 543 if (sentinel.ai_next) { 544 good: 545 endservent_r(&svd); 546 *res = sentinel.ai_next; 547 return SUCCESS; 548 } else 549 error = EAI_FAIL; 550 free: 551 bad: 552 endservent_r(&svd); 553 if (sentinel.ai_next) 554 freeaddrinfo(sentinel.ai_next); 555 *res = NULL; 556 return error; 557 } 558 559 static const ns_dtab dtab[] = { 560 NS_FILES_CB(((nss_method)_files_getaddrinfo), NULL) 561 { NSSRC_DNS, ((nss_method)_dns_getaddrinfo), NULL }, /* force -DHESIOD */ 562 NS_NIS_CB(_yp_getaddrinfo, NULL) 563 NS_NULL_CB 564 }; 565 566 /* 567 * FQDN hostname, DNS lookup 568 */ 569 static int 570 explore_fqdn(const struct addrinfo *pai, const char *hostname, 571 const char *servname, struct addrinfo **res, struct servent_data *svd) 572 { 573 struct addrinfo *result; 574 struct addrinfo *cur; 575 int error = 0; 576 577 _DIAGASSERT(pai != NULL); 578 /* hostname may be NULL */ 579 /* servname may be NULL */ 580 _DIAGASSERT(res != NULL); 581 582 result = NULL; 583 584 /* 585 * if the servname does not match socktype/protocol, ignore it. 586 */ 587 if (get_portmatch(pai, servname, svd) != 0) 588 return 0; 589 590 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 591 default_dns_files, hostname, pai)) { 592 case NS_TRYAGAIN: 593 error = EAI_AGAIN; 594 goto free; 595 case NS_UNAVAIL: 596 error = EAI_FAIL; 597 goto free; 598 case NS_NOTFOUND: 599 error = EAI_NODATA; 600 goto free; 601 case NS_SUCCESS: 602 error = 0; 603 for (cur = result; cur; cur = cur->ai_next) { 604 GET_PORT(cur, servname, svd); 605 /* canonname should be filled already */ 606 } 607 break; 608 } 609 610 *res = result; 611 612 return 0; 613 614 free: 615 if (result) 616 freeaddrinfo(result); 617 return error; 618 } 619 620 /* 621 * hostname == NULL. 622 * passive socket -> anyaddr (0.0.0.0 or ::) 623 * non-passive socket -> localhost (127.0.0.1 or ::1) 624 */ 625 static int 626 explore_null(const struct addrinfo *pai, const char *servname, 627 struct addrinfo **res, struct servent_data *svd) 628 { 629 int s; 630 const struct afd *afd; 631 struct addrinfo *cur; 632 struct addrinfo sentinel; 633 int error; 634 635 _DIAGASSERT(pai != NULL); 636 /* servname may be NULL */ 637 _DIAGASSERT(res != NULL); 638 639 *res = NULL; 640 sentinel.ai_next = NULL; 641 cur = &sentinel; 642 643 /* 644 * filter out AFs that are not supported by the kernel 645 * XXX errno? 646 */ 647 s = socket(pai->ai_family, SOCK_DGRAM, 0); 648 if (s < 0) { 649 if (errno != EMFILE) 650 return 0; 651 } else 652 close(s); 653 654 /* 655 * if the servname does not match socktype/protocol, ignore it. 656 */ 657 if (get_portmatch(pai, servname, svd) != 0) 658 return 0; 659 660 afd = find_afd(pai->ai_family); 661 if (afd == NULL) 662 return 0; 663 664 if (pai->ai_flags & AI_PASSIVE) { 665 GET_AI(cur->ai_next, afd, afd->a_addrany); 666 /* xxx meaningless? 667 * GET_CANONNAME(cur->ai_next, "anyaddr"); 668 */ 669 GET_PORT(cur->ai_next, servname, svd); 670 } else { 671 GET_AI(cur->ai_next, afd, afd->a_loopback); 672 /* xxx meaningless? 673 * GET_CANONNAME(cur->ai_next, "localhost"); 674 */ 675 GET_PORT(cur->ai_next, servname, svd); 676 } 677 cur = cur->ai_next; 678 679 *res = sentinel.ai_next; 680 return 0; 681 682 free: 683 if (sentinel.ai_next) 684 freeaddrinfo(sentinel.ai_next); 685 return error; 686 } 687 688 /* 689 * numeric hostname 690 */ 691 static int 692 explore_numeric(const struct addrinfo *pai, const char *hostname, 693 const char *servname, struct addrinfo **res, const char *canonname, 694 struct servent_data *svd) 695 { 696 const struct afd *afd; 697 struct addrinfo *cur; 698 struct addrinfo sentinel; 699 int error; 700 char pton[PTON_MAX]; 701 702 _DIAGASSERT(pai != NULL); 703 /* hostname may be NULL */ 704 /* servname may be NULL */ 705 _DIAGASSERT(res != NULL); 706 707 *res = NULL; 708 sentinel.ai_next = NULL; 709 cur = &sentinel; 710 711 /* 712 * if the servname does not match socktype/protocol, ignore it. 713 */ 714 if (get_portmatch(pai, servname, svd) != 0) 715 return 0; 716 717 afd = find_afd(pai->ai_family); 718 if (afd == NULL) 719 return 0; 720 721 switch (afd->a_af) { 722 #if 0 /*X/Open spec*/ 723 case AF_INET: 724 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 725 if (pai->ai_family == afd->a_af || 726 pai->ai_family == PF_UNSPEC /*?*/) { 727 GET_AI(cur->ai_next, afd, pton); 728 GET_PORT(cur->ai_next, servname, svd); 729 if ((pai->ai_flags & AI_CANONNAME)) { 730 /* 731 * Set the numeric address itself as 732 * the canonical name, based on a 733 * clarification in rfc2553bis-03. 734 */ 735 GET_CANONNAME(cur->ai_next, canonname); 736 } 737 while (cur && cur->ai_next) 738 cur = cur->ai_next; 739 } else 740 ERR(EAI_FAMILY); /*xxx*/ 741 } 742 break; 743 #endif 744 default: 745 if (inet_pton(afd->a_af, hostname, 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, svd); 750 if ((pai->ai_flags & AI_CANONNAME)) { 751 /* 752 * Set the numeric address itself as 753 * the canonical name, based on a 754 * clarification in rfc2553bis-03. 755 */ 756 GET_CANONNAME(cur->ai_next, canonname); 757 } 758 while (cur->ai_next) 759 cur = cur->ai_next; 760 } else 761 ERR(EAI_FAMILY); /*xxx*/ 762 } 763 break; 764 } 765 766 *res = sentinel.ai_next; 767 return 0; 768 769 free: 770 bad: 771 if (sentinel.ai_next) 772 freeaddrinfo(sentinel.ai_next); 773 return error; 774 } 775 776 /* 777 * numeric hostname with scope 778 */ 779 static int 780 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 781 const char *servname, struct addrinfo **res, struct servent_data *svd) 782 { 783 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 784 return explore_numeric(pai, hostname, servname, res, hostname, svd); 785 #else 786 const struct afd *afd; 787 struct addrinfo *cur; 788 int error; 789 char *cp, *hostname2 = NULL, *scope, *addr; 790 struct sockaddr_in6 *sin6; 791 792 _DIAGASSERT(pai != NULL); 793 /* hostname may be NULL */ 794 /* servname may be NULL */ 795 _DIAGASSERT(res != NULL); 796 797 /* 798 * if the servname does not match socktype/protocol, ignore it. 799 */ 800 if (get_portmatch(pai, servname, svd) != 0) 801 return 0; 802 803 afd = find_afd(pai->ai_family); 804 if (afd == NULL) 805 return 0; 806 807 if (!afd->a_scoped) 808 return explore_numeric(pai, hostname, servname, res, hostname, 809 svd); 810 811 cp = strchr(hostname, SCOPE_DELIMITER); 812 if (cp == NULL) 813 return explore_numeric(pai, hostname, servname, res, hostname, 814 svd); 815 816 /* 817 * Handle special case of <scoped_address><delimiter><scope id> 818 */ 819 hostname2 = strdup(hostname); 820 if (hostname2 == NULL) 821 return EAI_MEMORY; 822 /* terminate at the delimiter */ 823 hostname2[cp - hostname] = '\0'; 824 addr = hostname2; 825 scope = cp + 1; 826 827 error = explore_numeric(pai, addr, servname, res, hostname, svd); 828 if (error == 0) { 829 u_int32_t scopeid; 830 831 for (cur = *res; cur; cur = cur->ai_next) { 832 if (cur->ai_family != AF_INET6) 833 continue; 834 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 835 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 836 free(hostname2); 837 return(EAI_NODATA); /* XXX: is return OK? */ 838 } 839 sin6->sin6_scope_id = scopeid; 840 } 841 } 842 843 free(hostname2); 844 845 return error; 846 #endif 847 } 848 849 static int 850 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 851 { 852 853 _DIAGASSERT(pai != NULL); 854 _DIAGASSERT(ai != NULL); 855 _DIAGASSERT(str != NULL); 856 857 if ((pai->ai_flags & AI_CANONNAME) != 0) { 858 ai->ai_canonname = strdup(str); 859 if (ai->ai_canonname == NULL) 860 return EAI_MEMORY; 861 } 862 return 0; 863 } 864 865 static struct addrinfo * 866 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 867 { 868 char *p; 869 struct addrinfo *ai; 870 871 _DIAGASSERT(pai != NULL); 872 _DIAGASSERT(afd != NULL); 873 _DIAGASSERT(addr != NULL); 874 875 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 876 + (afd->a_socklen)); 877 if (ai == NULL) 878 return NULL; 879 880 memcpy(ai, pai, sizeof(struct addrinfo)); 881 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 882 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 883 ai->ai_addr->sa_len = (uint8_t)afd->a_socklen; 884 ai->ai_addrlen = afd->a_socklen; 885 ai->ai_family = afd->a_af; 886 ai->ai_addr->sa_family = (sa_family_t)ai->ai_family; 887 p = (char *)(void *)(ai->ai_addr); 888 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 889 return ai; 890 } 891 892 static int 893 get_portmatch(const struct addrinfo *ai, const char *servname, 894 struct servent_data *svd) 895 { 896 897 _DIAGASSERT(ai != NULL); 898 /* servname may be NULL */ 899 900 return get_port(ai, servname, 1, svd); 901 } 902 903 static int 904 get_port(const struct addrinfo *ai, const char *servname, int matchonly, 905 struct servent_data *svd) 906 { 907 const char *proto; 908 struct servent *sp; 909 int port; 910 int allownumeric; 911 912 _DIAGASSERT(ai != NULL); 913 /* servname may be NULL */ 914 915 if (servname == NULL) 916 return 0; 917 switch (ai->ai_family) { 918 case AF_INET: 919 #ifdef AF_INET6 920 case AF_INET6: 921 #endif 922 break; 923 default: 924 return 0; 925 } 926 927 switch (ai->ai_socktype) { 928 case SOCK_RAW: 929 return EAI_SERVICE; 930 case SOCK_DGRAM: 931 case SOCK_STREAM: 932 allownumeric = 1; 933 break; 934 case ANY: 935 /* 936 * This was 0. It is now 1 so that queries specifying 937 * a NULL hint, or hint without socktype (but, hopefully, 938 * with protocol) and numeric address actually work. 939 */ 940 allownumeric = 1; 941 break; 942 default: 943 return EAI_SOCKTYPE; 944 } 945 946 port = str2number(servname); 947 if (port >= 0) { 948 if (!allownumeric) 949 return EAI_SERVICE; 950 if (port < 0 || port > 65535) 951 return EAI_SERVICE; 952 port = htons(port); 953 } else { 954 // struct servent sv; 955 if (ai->ai_flags & AI_NUMERICSERV) 956 return EAI_NONAME; 957 958 switch (ai->ai_socktype) { 959 case SOCK_DGRAM: 960 proto = "udp"; 961 break; 962 case SOCK_STREAM: 963 proto = "tcp"; 964 break; 965 default: 966 proto = NULL; 967 break; 968 } 969 970 // sp = getservbyname_r(servname, proto, &sv, svd); 971 sp = getservbyname ( servname, proto ); 972 if (sp == NULL) 973 return EAI_SERVICE; 974 port = sp->s_port; 975 } 976 977 if (!matchonly) { 978 switch (ai->ai_family) { 979 case AF_INET: 980 ((struct sockaddr_in *)(void *) 981 ai->ai_addr)->sin_port = (in_port_t)port; 982 break; 983 #ifdef INET6 984 case AF_INET6: 985 ((struct sockaddr_in6 *)(void *) 986 ai->ai_addr)->sin6_port = (in_port_t)port; 987 break; 988 #endif 989 } 990 } 991 992 return 0; 993 } 994 995 static const struct afd * 996 find_afd(int af) 997 { 998 const struct afd *afd; 999 1000 if (af == PF_UNSPEC) 1001 return NULL; 1002 for (afd = afdl; afd->a_af; afd++) { 1003 if (afd->a_af == af) 1004 return afd; 1005 } 1006 return NULL; 1007 } 1008 1009 #ifdef INET6 1010 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1011 static int 1012 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1013 { 1014 u_long lscopeid; 1015 struct in6_addr *a6; 1016 char *ep; 1017 1018 _DIAGASSERT(scope != NULL); 1019 _DIAGASSERT(sin6 != NULL); 1020 _DIAGASSERT(scopeid != NULL); 1021 1022 a6 = &sin6->sin6_addr; 1023 1024 /* empty scopeid portion is invalid */ 1025 if (*scope == '\0') 1026 return -1; 1027 1028 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1029 /* 1030 * We currently assume a one-to-one mapping between links 1031 * and interfaces, so we simply use interface indices for 1032 * like-local scopes. 1033 */ 1034 /* 1035 *scopeid = if_nametoindex(scope); 1036 if (*scopeid == 0) 1037 goto trynumeric; 1038 return 0; 1039 */ 1040 return -1; 1041 } 1042 1043 /* still unclear about literal, allow numeric only - placeholder */ 1044 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1045 goto trynumeric; 1046 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1047 goto trynumeric; 1048 else 1049 goto trynumeric; /* global */ 1050 1051 /* try to convert to a numeric id as a last resort */ 1052 trynumeric: 1053 errno = 0; 1054 lscopeid = strtoul(scope, &ep, 10); 1055 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1056 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1057 return 0; 1058 else 1059 return -1; 1060 } 1061 #endif 1062 1063 /* code duplicate with gethnamaddr.c */ 1064 1065 static const char AskedForGot[] = 1066 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1067 1068 static struct addrinfo * 1069 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1070 const struct addrinfo *pai) 1071 { 1072 struct addrinfo sentinel, *cur; 1073 struct addrinfo ai; 1074 const struct afd *afd; 1075 char *canonname; 1076 const HEADER *hp; 1077 const u_char *cp; 1078 int n; 1079 const u_char *eom; 1080 char *bp, *ep; 1081 int type, class, ancount, qdcount; 1082 int haveanswer, had_error; 1083 char tbuf[MAXDNAME]; 1084 int (*name_ok) (const char *); 1085 static char hostbuf[8*1024]; 1086 1087 _DIAGASSERT(answer != NULL); 1088 _DIAGASSERT(qname != NULL); 1089 _DIAGASSERT(pai != NULL); 1090 1091 memset(&sentinel, 0, sizeof(sentinel)); 1092 cur = &sentinel; 1093 1094 canonname = NULL; 1095 eom = answer->buf + anslen; 1096 switch (qtype) { 1097 case T_A: 1098 case T_AAAA: 1099 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1100 name_ok = res_hnok; 1101 break; 1102 default: 1103 return NULL; /* XXX should be abort(); */ 1104 } 1105 /* 1106 * find first satisfactory answer 1107 */ 1108 hp = &answer->hdr; 1109 ancount = ntohs(hp->ancount); 1110 qdcount = ntohs(hp->qdcount); 1111 bp = hostbuf; 1112 ep = hostbuf + sizeof hostbuf; 1113 cp = answer->buf + HFIXEDSZ; 1114 if (qdcount != 1) { 1115 h_errno = NO_RECOVERY; 1116 return (NULL); 1117 } 1118 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp)); 1119 if ((n < 0) || !(*name_ok)(bp)) { 1120 h_errno = NO_RECOVERY; 1121 return (NULL); 1122 } 1123 cp += n + QFIXEDSZ; 1124 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1125 /* res_send() has already verified that the query name is the 1126 * same as the one we sent; this just gets the expanded name 1127 * (i.e., with the succeeding search-domain tacked on). 1128 */ 1129 n = (int)strlen(bp) + 1; /* for the \0 */ 1130 if (n >= MAXHOSTNAMELEN) { 1131 h_errno = NO_RECOVERY; 1132 return (NULL); 1133 } 1134 canonname = bp; 1135 bp += n; 1136 /* The qname can be abbreviated, but h_name is now absolute. */ 1137 qname = canonname; 1138 } 1139 haveanswer = 0; 1140 had_error = 0; 1141 while (ancount-- > 0 && cp < eom && !had_error) { 1142 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp)); 1143 if ((n < 0) || !(*name_ok)(bp)) { 1144 had_error++; 1145 continue; 1146 } 1147 cp += n; /* name */ 1148 type = _getshort(cp); 1149 cp += INT16SZ; /* type */ 1150 class = _getshort(cp); 1151 cp += INT16SZ + INT32SZ; /* class, TTL */ 1152 n = _getshort(cp); 1153 cp += INT16SZ; /* len */ 1154 if (class != C_IN) { 1155 /* XXX - debug? syslog? */ 1156 cp += n; 1157 continue; /* XXX - had_error++ ? */ 1158 } 1159 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1160 type == T_CNAME) { 1161 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1162 if ((n < 0) || !(*name_ok)(tbuf)) { 1163 had_error++; 1164 continue; 1165 } 1166 cp += n; 1167 /* Get canonical name. */ 1168 n = (int)strlen(tbuf) + 1; /* for the \0 */ 1169 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1170 had_error++; 1171 continue; 1172 } 1173 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1174 canonname = bp; 1175 bp += n; 1176 continue; 1177 } 1178 if (qtype == T_ANY) { 1179 if (!(type == T_A || type == T_AAAA)) { 1180 cp += n; 1181 continue; 1182 } 1183 } else if (type != qtype) { 1184 if (type != T_KEY && type != T_SIG) { 1185 #ifdef _ORG_FREEBSD_ 1186 struct syslog_data sd = SYSLOG_DATA_INIT; 1187 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1188 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1189 qname, p_class(C_IN), p_type(qtype), 1190 p_type(type)); 1191 #endif 1192 } 1193 cp += n; 1194 continue; /* XXX - had_error++ ? */ 1195 } 1196 switch (type) { 1197 case T_A: 1198 case T_AAAA: 1199 if (strcasecmp(canonname, bp) != 0) { 1200 #ifdef _ORG_FREEBSD_ 1201 struct syslog_data sd = SYSLOG_DATA_INIT; 1202 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1203 AskedForGot, canonname, bp); 1204 #endif 1205 cp += n; 1206 continue; /* XXX - had_error++ ? */ 1207 } 1208 if (type == T_A && n != INADDRSZ) { 1209 cp += n; 1210 continue; 1211 } 1212 if (type == T_AAAA && n != IN6ADDRSZ) { 1213 cp += n; 1214 continue; 1215 } 1216 if (type == T_AAAA) { 1217 struct in6_addr in6; 1218 memcpy(&in6, cp, IN6ADDRSZ); 1219 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1220 cp += n; 1221 continue; 1222 } 1223 } 1224 if (!haveanswer) { 1225 int nn; 1226 1227 canonname = bp; 1228 nn = (int)strlen(bp) + 1; /* for the \0 */ 1229 bp += nn; 1230 } 1231 1232 /* don't overwrite pai */ 1233 ai = *pai; 1234 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1235 afd = find_afd(ai.ai_family); 1236 if (afd == NULL) { 1237 cp += n; 1238 continue; 1239 } 1240 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1241 if (cur->ai_next == NULL) 1242 had_error++; 1243 while (cur && cur->ai_next) 1244 cur = cur->ai_next; 1245 cp += n; 1246 break; 1247 default: 1248 abort(); 1249 } 1250 if (!had_error) 1251 haveanswer++; 1252 } 1253 if (haveanswer) { 1254 if (!canonname) 1255 (void)get_canonname(pai, sentinel.ai_next, qname); 1256 else 1257 (void)get_canonname(pai, sentinel.ai_next, canonname); 1258 h_errno = NETDB_SUCCESS; 1259 return sentinel.ai_next; 1260 } 1261 1262 h_errno = NO_RECOVERY; 1263 return NULL; 1264 } 1265 1266 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr) 1267 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr) 1268 1269 static void 1270 aisort(struct addrinfo *s, res_state res) 1271 { 1272 struct addrinfo head, *t, *p; 1273 int i; 1274 1275 head.ai_next = NULL; 1276 t = &head; 1277 1278 for (i = 0; i < (int)res->nsort; i++) { 1279 p = s; 1280 while (p->ai_next) { 1281 if ((p->ai_next->ai_family != AF_INET) 1282 || SORTMATCH(p, res->sort_list[i])) { 1283 t->ai_next = p->ai_next; 1284 t = t->ai_next; 1285 p->ai_next = p->ai_next->ai_next; 1286 } else { 1287 p = p->ai_next; 1288 } 1289 } 1290 } 1291 1292 /* add rest of list and reset s to the new list*/ 1293 t->ai_next = s->ai_next; 1294 s->ai_next = head.ai_next; 1295 } 1296 1297 /*ARGSUSED*/ 1298 static int 1299 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1300 { 1301 struct addrinfo *ai; 1302 querybuf *buf, *buf2; 1303 const char *name; 1304 const struct addrinfo *pai; 1305 struct addrinfo sentinel, *cur; 1306 struct res_target q, q2; 1307 res_state res; 1308 1309 name = va_arg(ap, char *); 1310 pai = va_arg(ap, const struct addrinfo *); 1311 1312 memset(&q, 0, sizeof(q)); 1313 memset(&q2, 0, sizeof(q2)); 1314 memset(&sentinel, 0, sizeof(sentinel)); 1315 cur = &sentinel; 1316 1317 buf = malloc(sizeof(*buf)); 1318 if (buf == NULL) { 1319 h_errno = NETDB_INTERNAL; 1320 return NS_NOTFOUND; 1321 } 1322 buf2 = malloc(sizeof(*buf2)); 1323 if (buf2 == NULL) { 1324 free(buf); 1325 h_errno = NETDB_INTERNAL; 1326 return NS_NOTFOUND; 1327 } 1328 1329 switch (pai->ai_family) { 1330 case AF_UNSPEC: 1331 /* prefer IPv6 */ 1332 q.name = name; 1333 q.qclass = C_IN; 1334 q.qtype = T_AAAA; 1335 q.answer = buf->buf; 1336 q.anslen = sizeof(buf->buf); 1337 q.next = &q2; 1338 q2.name = name; 1339 q2.qclass = C_IN; 1340 q2.qtype = T_A; 1341 q2.answer = buf2->buf; 1342 q2.anslen = sizeof(buf2->buf); 1343 break; 1344 case AF_INET: 1345 q.name = name; 1346 q.qclass = C_IN; 1347 q.qtype = T_A; 1348 q.answer = buf->buf; 1349 q.anslen = sizeof(buf->buf); 1350 break; 1351 case AF_INET6: 1352 q.name = name; 1353 q.qclass = C_IN; 1354 q.qtype = T_AAAA; 1355 q.answer = buf->buf; 1356 q.anslen = sizeof(buf->buf); 1357 break; 1358 default: 1359 free(buf); 1360 free(buf2); 1361 return NS_UNAVAIL; 1362 } 1363 1364 res = __res_get_state(); 1365 if (res == NULL) { 1366 free(buf); 1367 free(buf2); 1368 return NS_NOTFOUND; 1369 } 1370 1371 if (res_searchN(name, &q, res) < 0) { 1372 __res_put_state(res); 1373 free(buf); 1374 free(buf2); 1375 return NS_NOTFOUND; 1376 } 1377 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1378 if (ai) { 1379 cur->ai_next = ai; 1380 while (cur && cur->ai_next) 1381 cur = cur->ai_next; 1382 } 1383 if (q.next) { 1384 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1385 if (ai) 1386 cur->ai_next = ai; 1387 } 1388 free(buf); 1389 free(buf2); 1390 if (sentinel.ai_next == NULL) { 1391 __res_put_state(res); 1392 switch (h_errno) { 1393 case HOST_NOT_FOUND: 1394 return NS_NOTFOUND; 1395 case TRY_AGAIN: 1396 return NS_TRYAGAIN; 1397 default: 1398 return NS_UNAVAIL; 1399 } 1400 } 1401 1402 if (res->nsort) 1403 aisort(&sentinel, res); 1404 1405 __res_put_state(res); 1406 1407 *((struct addrinfo **)rv) = sentinel.ai_next; 1408 return NS_SUCCESS; 1409 } 1410 1411 static void 1412 _sethtent(FILE **hostf) 1413 { 1414 1415 if (!*hostf) 1416 *hostf = fopen(_PATH_HOSTS, "r" ); 1417 else 1418 rewind(*hostf); 1419 } 1420 1421 static void 1422 _endhtent(FILE **hostf) 1423 { 1424 1425 if (*hostf) { 1426 (void) fclose(*hostf); 1427 *hostf = NULL; 1428 } 1429 } 1430 1431 static struct addrinfo * 1432 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1433 { 1434 char *p; 1435 char *cp, *tname, *cname; 1436 struct addrinfo hints, *res0, *res; 1437 int error; 1438 const char *addr; 1439 static char hostbuf[8*1024]; 1440 1441 _DIAGASSERT(name != NULL); 1442 _DIAGASSERT(pai != NULL); 1443 1444 if (!*hostf && ( NULL == (*hostf = fopen(_PATH_HOSTS, "r" )))) 1445 return (NULL); 1446 again: 1447 if ( NULL == (p = fgets(hostbuf, sizeof hostbuf, *hostf))) 1448 return (NULL); 1449 if (*p == '#') 1450 goto again; 1451 if ( NULL == (cp = strpbrk(p, "#\n"))) 1452 goto again; 1453 *cp = '\0'; 1454 if ( NULL == (cp = strpbrk(p, " \t"))) 1455 goto again; 1456 *cp++ = '\0'; 1457 addr = p; 1458 /* if this is not something we're looking for, skip it. */ 1459 cname = NULL; 1460 while (cp && *cp) { 1461 if (*cp == ' ' || *cp == '\t') { 1462 cp++; 1463 continue; 1464 } 1465 if (!cname) 1466 cname = cp; 1467 tname = cp; 1468 if ((cp = strpbrk(cp, " \t")) != NULL) 1469 *cp++ = '\0'; 1470 if (strcasecmp(name, tname) == 0) 1471 goto found; 1472 } 1473 goto again; 1474 1475 found: 1476 hints = *pai; 1477 hints.ai_flags = AI_NUMERICHOST; 1478 error = getaddrinfo(addr, NULL, &hints, &res0); 1479 if (error) 1480 goto again; 1481 for (res = res0; res; res = res->ai_next) { 1482 /* cover it up */ 1483 res->ai_flags = pai->ai_flags; 1484 1485 if (pai->ai_flags & AI_CANONNAME) { 1486 if (get_canonname(pai, res, cname) != 0) { 1487 freeaddrinfo(res0); 1488 goto again; 1489 } 1490 } 1491 } 1492 return res0; 1493 } 1494 1495 /*ARGSUSED*/ 1496 static int 1497 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1498 { 1499 const char *name; 1500 const struct addrinfo *pai; 1501 struct addrinfo sentinel, *cur; 1502 struct addrinfo *p; 1503 #ifndef _REENTRANT 1504 static 1505 #endif 1506 FILE *hostf = NULL; 1507 1508 name = va_arg(ap, char *); 1509 pai = va_arg(ap, const struct addrinfo *); 1510 1511 memset(&sentinel, 0, sizeof(sentinel)); 1512 cur = &sentinel; 1513 1514 _sethtent(&hostf); 1515 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1516 cur->ai_next = p; 1517 while (cur && cur->ai_next) 1518 cur = cur->ai_next; 1519 } 1520 _endhtent(&hostf); 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 /*ARGSUSED*/ 1530 static struct addrinfo * 1531 _yphostent(char *line, const struct addrinfo *pai) 1532 { 1533 struct addrinfo sentinel, *cur; 1534 struct addrinfo hints, *res, *res0; 1535 int error; 1536 char *p; 1537 const char *addr, *canonname; 1538 char *nextline; 1539 char *cp; 1540 1541 _DIAGASSERT(line != NULL); 1542 _DIAGASSERT(pai != NULL); 1543 1544 p = line; 1545 addr = canonname = NULL; 1546 1547 memset(&sentinel, 0, sizeof(sentinel)); 1548 cur = &sentinel; 1549 1550 nextline: 1551 /* terminate line */ 1552 cp = strchr(p, '\n'); 1553 if (cp) { 1554 *cp++ = '\0'; 1555 nextline = cp; 1556 } else 1557 nextline = NULL; 1558 1559 cp = strpbrk(p, " \t"); 1560 if (cp == NULL) { 1561 if (canonname == NULL) 1562 return (NULL); 1563 else 1564 goto done; 1565 } 1566 *cp++ = '\0'; 1567 1568 addr = p; 1569 1570 while (cp && *cp) { 1571 if (*cp == ' ' || *cp == '\t') { 1572 cp++; 1573 continue; 1574 } 1575 if (!canonname) 1576 canonname = cp; 1577 if ((cp = strpbrk(cp, " \t")) != NULL) 1578 *cp++ = '\0'; 1579 } 1580 1581 hints = *pai; 1582 hints.ai_flags = AI_NUMERICHOST; 1583 error = getaddrinfo(addr, NULL, &hints, &res0); 1584 if (error == 0) { 1585 for (res = res0; res; res = res->ai_next) { 1586 /* cover it up */ 1587 res->ai_flags = pai->ai_flags; 1588 1589 if (pai->ai_flags & AI_CANONNAME) 1590 (void)get_canonname(pai, res, canonname); 1591 } 1592 } else 1593 res0 = NULL; 1594 if (res0) { 1595 cur->ai_next = res0; 1596 while (cur->ai_next) 1597 cur = cur->ai_next; 1598 } 1599 1600 if (nextline) { 1601 p = nextline; 1602 goto nextline; 1603 } 1604 1605 done: 1606 return sentinel.ai_next; 1607 } 1608 1609 /*ARGSUSED*/ 1610 static int 1611 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1612 { 1613 struct addrinfo sentinel, *cur; 1614 struct addrinfo *ai = NULL; 1615 char *ypbuf; 1616 int ypbuflen, r; 1617 const char *name; 1618 const struct addrinfo *pai; 1619 char *ypdomain; 1620 1621 if (_yp_check(&ypdomain) == 0) 1622 return NS_UNAVAIL; 1623 1624 name = va_arg(ap, char *); 1625 pai = va_arg(ap, const struct addrinfo *); 1626 1627 memset(&sentinel, 0, sizeof(sentinel)); 1628 cur = &sentinel; 1629 1630 /* hosts.byname is only for IPv4 (Solaris8) */ 1631 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1632 r = yp_match(ypdomain, "hosts.byname", name, 1633 (int)strlen(name), &ypbuf, &ypbuflen); 1634 if (r == 0) { 1635 struct addrinfo ai4; 1636 1637 ai4 = *pai; 1638 ai4.ai_family = AF_INET; 1639 ai = _yphostent(ypbuf, &ai4); 1640 if (ai) { 1641 cur->ai_next = ai; 1642 while (cur && cur->ai_next) 1643 cur = cur->ai_next; 1644 } 1645 } 1646 free(ypbuf); 1647 } 1648 1649 /* ipnodes.byname can hold both IPv4/v6 */ 1650 r = yp_match(ypdomain, "ipnodes.byname", name, 1651 (int)strlen(name), &ypbuf, &ypbuflen); 1652 if (r == 0) { 1653 ai = _yphostent(ypbuf, pai); 1654 if (ai) 1655 cur->ai_next = ai; 1656 free(ypbuf); 1657 } 1658 1659 if (sentinel.ai_next == NULL) { 1660 h_errno = HOST_NOT_FOUND; 1661 return NS_NOTFOUND; 1662 } 1663 *((struct addrinfo **)rv) = sentinel.ai_next; 1664 return NS_SUCCESS; 1665 } 1666 #endif 1667 1668 /* resolver logic */ 1669 1670 /* 1671 * Formulate a normal query, send, and await answer. 1672 * Returned answer is placed in supplied buffer "answer". 1673 * Perform preliminary check of answer, returning success only 1674 * if no error is indicated and the answer count is nonzero. 1675 * Return the size of the response on success, -1 on error. 1676 * Error number is left in h_errno. 1677 * 1678 * Caller must parse answer and determine whether it answers the question. 1679 */ 1680 static int 1681 res_queryN(const char *name, /* domain name */ struct res_target *target, 1682 res_state res) 1683 { 1684 static u_char buf[MAXPACKET]; 1685 HEADER *hp; 1686 int n; 1687 struct res_target *t; 1688 int rcode; 1689 int ancount; 1690 1691 _DIAGASSERT(name != NULL); 1692 /* XXX: target may be NULL??? */ 1693 1694 rcode = NOERROR; 1695 ancount = 0; 1696 1697 for (t = target; t; t = t->next) { 1698 int class, type; 1699 u_char *answer; 1700 int anslen; 1701 1702 hp = (HEADER *)(void *)t->answer; 1703 hp->rcode = NOERROR; /* default */ 1704 1705 /* make it easier... */ 1706 class = t->qclass; 1707 type = t->qtype; 1708 answer = t->answer; 1709 anslen = t->anslen; 1710 #ifdef DEBUG 1711 if (res->options & RES_DEBUG) 1712 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 1713 #endif 1714 1715 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 1716 buf, sizeof(buf)); 1717 #ifdef RES_USE_EDNS0 1718 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 1719 n = res_nopt(res, n, buf, sizeof(buf), anslen); 1720 #endif 1721 if (n <= 0) { 1722 #ifdef DEBUG 1723 if (res->options & RES_DEBUG) 1724 printf(";; res_nquery: mkquery failed\n"); 1725 #endif 1726 h_errno = NO_RECOVERY; 1727 return n; 1728 } 1729 n = res_nsend(res, buf, n, answer, anslen); 1730 #if 0 1731 if (n < 0) { 1732 #ifdef DEBUG 1733 if (res->options & RES_DEBUG) 1734 printf(";; res_query: send error\n"); 1735 #endif 1736 h_errno = TRY_AGAIN; 1737 return n; 1738 } 1739 #endif 1740 1741 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 1742 rcode = hp->rcode; /* record most recent error */ 1743 #ifdef DEBUG 1744 if (res->options & RES_DEBUG) 1745 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 1746 ntohs(hp->ancount)); 1747 #endif 1748 continue; 1749 } 1750 1751 ancount += ntohs(hp->ancount); 1752 1753 t->n = n; 1754 } 1755 1756 if (ancount == 0) { 1757 switch (rcode) { 1758 case NXDOMAIN: 1759 h_errno = HOST_NOT_FOUND; 1760 break; 1761 case SERVFAIL: 1762 h_errno = TRY_AGAIN; 1763 break; 1764 case NOERROR: 1765 h_errno = NO_DATA; 1766 break; 1767 case FORMERR: 1768 case NOTIMP: 1769 case REFUSED: 1770 default: 1771 h_errno = NO_RECOVERY; 1772 break; 1773 } 1774 return -1; 1775 } 1776 return ancount; 1777 } 1778 1779 /* 1780 * Formulate a normal query, send, and retrieve answer in supplied buffer. 1781 * Return the size of the response on success, -1 on error. 1782 * If enabled, implement search rules until answer or unrecoverable failure 1783 * is detected. Error code, if any, is left in h_errno. 1784 */ 1785 static int 1786 res_searchN(const char *name, struct res_target *target, res_state res) 1787 { 1788 const char *cp, * const *domain; 1789 HEADER *hp; 1790 u_int dots; 1791 int trailing_dot, ret, saved_herrno; 1792 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1793 1794 _DIAGASSERT(name != NULL); 1795 _DIAGASSERT(target != NULL); 1796 1797 hp = (HEADER *)(void *)target->answer; /*XXX*/ 1798 1799 errno = 0; 1800 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 1801 dots = 0; 1802 for (cp = name; *cp; cp++) 1803 dots += (*cp == '.'); 1804 trailing_dot = 0; 1805 if (cp > name && *--cp == '.') 1806 trailing_dot++; 1807 1808 /* 1809 * if there aren't any dots, it could be a user-level alias 1810 */ 1811 if (!dots && (cp = __hostalias(name)) != NULL) { 1812 ret = res_queryN(cp, target, res); 1813 return ret; 1814 } 1815 1816 /* 1817 * If there are dots in the name already, let's just give it a try 1818 * 'as is'. The threshold can be set with the "ndots" option. 1819 */ 1820 saved_herrno = -1; 1821 if (dots >= res->ndots) { 1822 ret = res_querydomainN(name, NULL, target, res); 1823 if (ret > 0) 1824 return (ret); 1825 saved_herrno = h_errno; 1826 tried_as_is++; 1827 } 1828 1829 /* 1830 * We do at least one level of search if 1831 * - there is no dot and RES_DEFNAME is set, or 1832 * - there is at least one dot, there is no trailing dot, 1833 * and RES_DNSRCH is set. 1834 */ 1835 if ((!dots && (res->options & RES_DEFNAMES)) || 1836 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 1837 int done = 0; 1838 1839 for (domain = (const char * const *)res->dnsrch; 1840 *domain && !done; 1841 domain++) { 1842 1843 ret = res_querydomainN(name, *domain, target, res); 1844 if (ret > 0) 1845 return ret; 1846 1847 /* 1848 * If no server present, give up. 1849 * If name isn't found in this domain, 1850 * keep trying higher domains in the search list 1851 * (if that's enabled). 1852 * On a NO_DATA error, keep trying, otherwise 1853 * a wildcard entry of another type could keep us 1854 * from finding this entry higher in the domain. 1855 * If we get some other error (negative answer or 1856 * server failure), then stop searching up, 1857 * but try the input name below in case it's 1858 * fully-qualified. 1859 */ 1860 if (errno == ECONNREFUSED) { 1861 h_errno = TRY_AGAIN; 1862 return -1; 1863 } 1864 1865 switch (h_errno) { 1866 case NO_DATA: 1867 got_nodata++; 1868 /* FALLTHROUGH */ 1869 case HOST_NOT_FOUND: 1870 /* keep trying */ 1871 break; 1872 case TRY_AGAIN: 1873 if (hp->rcode == SERVFAIL) { 1874 /* try next search element, if any */ 1875 got_servfail++; 1876 break; 1877 } 1878 /* FALLTHROUGH */ 1879 default: 1880 /* anything else implies that we're done */ 1881 done++; 1882 } 1883 /* 1884 * if we got here for some reason other than DNSRCH, 1885 * we only wanted one iteration of the loop, so stop. 1886 */ 1887 if (!(res->options & RES_DNSRCH)) 1888 done++; 1889 } 1890 } 1891 1892 /* 1893 * if we have not already tried the name "as is", do that now. 1894 * note that we do this regardless of how many dots were in the 1895 * name or whether it ends with a dot. 1896 */ 1897 if (!tried_as_is) { 1898 ret = res_querydomainN(name, NULL, target, res); 1899 if (ret > 0) 1900 return ret; 1901 } 1902 1903 /* 1904 * if we got here, we didn't satisfy the search. 1905 * if we did an initial full query, return that query's h_errno 1906 * (note that we wouldn't be here if that query had succeeded). 1907 * else if we ever got a nodata, send that back as the reason. 1908 * else send back meaningless h_errno, that being the one from 1909 * the last DNSRCH we did. 1910 */ 1911 if (saved_herrno != -1) 1912 h_errno = saved_herrno; 1913 else if (got_nodata) 1914 h_errno = NO_DATA; 1915 else if (got_servfail) 1916 h_errno = TRY_AGAIN; 1917 return -1; 1918 } 1919 1920 /* 1921 * Perform a call on res_query on the concatenation of name and domain, 1922 * removing a trailing dot from name if domain is NULL. 1923 */ 1924 static int 1925 res_querydomainN(const char *name, const char *domain, 1926 struct res_target *target, res_state res) 1927 { 1928 char nbuf[MAXDNAME]; 1929 const char *longname = nbuf; 1930 size_t n, d; 1931 1932 _DIAGASSERT(name != NULL); 1933 /* XXX: target may be NULL??? */ 1934 1935 #ifdef DEBUG 1936 if (res->options & RES_DEBUG) 1937 printf(";; res_querydomain(%s, %s)\n", 1938 name, domain?domain:"<Nil>"); 1939 #endif 1940 if (domain == NULL) { 1941 /* 1942 * Check for trailing '.'; 1943 * copy without '.' if present. 1944 */ 1945 n = strlen(name); 1946 if (n + 1 > sizeof(nbuf)) { 1947 h_errno = NO_RECOVERY; 1948 return -1; 1949 } 1950 if (n > 0 && name[--n] == '.') { 1951 strncpy(nbuf, name, n); 1952 nbuf[n] = '\0'; 1953 } else 1954 longname = name; 1955 } else { 1956 n = strlen(name); 1957 d = strlen(domain); 1958 if (n + 1 + d + 1 > sizeof(nbuf)) { 1959 h_errno = NO_RECOVERY; 1960 return -1; 1961 } 1962 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 1963 } 1964 return res_queryN(longname, target, res); 1965 } 1966
