1 /* $NetBSD: getaddrinfo.c,v 1.109 2015/09/10 14:05:06 christos 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 1.109 2015/09/10 14:05:06 christos Exp $"); 59 #endif /* LIBC_SCCS and not lint */ 60 61 #ifndef RUMP_ACTION 62 #include "namespace.h" 63 #endif 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 #include <ifaddrs.h> 82 83 #include <syslog.h> 84 #include <stdarg.h> 85 #include <nsswitch.h> 86 87 #ifdef YP 88 #include <rpc/rpc.h> 89 #include <rpcsvc/yp_prot.h> 90 #include <rpcsvc/ypclnt.h> 91 #endif 92 93 #include "servent.h" 94 95 #ifndef RUMP_ACTION 96 #ifdef __weak_alias 97 __weak_alias(getaddrinfo,_getaddrinfo) 98 __weak_alias(allocaddrinfo,_allocaddrinfo) 99 __weak_alias(freeaddrinfo,_freeaddrinfo) 100 __weak_alias(gai_strerror,_gai_strerror) 101 #endif 102 #endif 103 104 #define SUCCESS 0 105 #define ANY 0 106 #define YES 1 107 #define NO 0 108 109 static const char in_addrany[] = { 0, 0, 0, 0 }; 110 static const char in_loopback[] = { 127, 0, 0, 1 }; 111 #ifdef INET6 112 static const char in6_addrany[] = { 113 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 114 }; 115 static const char in6_loopback[] = { 116 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 117 }; 118 #endif 119 120 static const struct afd { 121 int a_af; 122 int a_addrlen; 123 int a_socklen; 124 int a_off; 125 const char *a_addrany; 126 const char *a_loopback; 127 int a_scoped; 128 } afdl [] = { 129 #ifdef INET6 130 {PF_INET6, sizeof(struct in6_addr), 131 sizeof(struct sockaddr_in6), 132 offsetof(struct sockaddr_in6, sin6_addr), 133 in6_addrany, in6_loopback, 1}, 134 #endif 135 {PF_INET, sizeof(struct in_addr), 136 sizeof(struct sockaddr_in), 137 offsetof(struct sockaddr_in, sin_addr), 138 in_addrany, in_loopback, 0}, 139 {0, 0, 0, 0, NULL, NULL, 0}, 140 }; 141 142 struct explore { 143 int e_af; 144 int e_socktype; 145 int e_protocol; 146 const char *e_protostr; 147 int e_wild; 148 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 149 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 150 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 151 }; 152 153 static const struct explore explore[] = { 154 #if 0 155 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 156 #endif 157 #ifdef INET6 158 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 159 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 160 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 161 #endif 162 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 163 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 164 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 165 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 166 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 167 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 168 { -1, 0, 0, NULL, 0 }, 169 }; 170 171 #ifdef INET6 172 #define PTON_MAX 16 173 #else 174 #define PTON_MAX 4 175 #endif 176 177 static const ns_src default_dns_files[] = { 178 { NSSRC_FILES, NS_SUCCESS }, 179 { NSSRC_DNS, NS_SUCCESS }, 180 { 0, 0 } 181 }; 182 183 #define MAXPACKET (64*1024) 184 185 typedef union { 186 HEADER hdr; 187 u_char buf[MAXPACKET]; 188 } querybuf; 189 190 struct res_target { 191 struct res_target *next; 192 const char *name; /* domain name */ 193 int qclass, qtype; /* class and type of query */ 194 u_char *answer; /* buffer to put answer */ 195 int anslen; /* size of answer buffer */ 196 int n; /* result length */ 197 }; 198 199 struct srvinfo { 200 struct srvinfo *next; 201 char name[MAXDNAME]; 202 int port, pri, weight; 203 }; 204 205 static int gai_srvok(const char *); 206 static int str2number(const char *); 207 static int explore_fqdn(const struct addrinfo *, const char *, 208 const char *, struct addrinfo **, struct servent_data *); 209 static int explore_null(const struct addrinfo *, 210 const char *, struct addrinfo **, struct servent_data *); 211 static int explore_numeric(const struct addrinfo *, const char *, 212 const char *, struct addrinfo **, const char *, struct servent_data *); 213 static int explore_numeric_scope(const struct addrinfo *, const char *, 214 const char *, struct addrinfo **, struct servent_data *); 215 static int get_canonname(const struct addrinfo *, 216 struct addrinfo *, const char *); 217 static struct addrinfo *get_ai(const struct addrinfo *, 218 const struct afd *, const char *); 219 static int get_portmatch(const struct addrinfo *, const char *, 220 struct servent_data *); 221 static int get_port(const struct addrinfo *, const char *, int, 222 struct servent_data *); 223 static const struct afd *find_afd(int); 224 static int addrconfig(uint64_t *); 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 struct addrinfo * _dns_query(struct res_target *, 233 const struct addrinfo *, res_state, int); 234 static struct addrinfo * _dns_srv_lookup(const char *, const char *, 235 const struct addrinfo *); 236 static struct addrinfo * _dns_host_lookup(const char *, 237 const struct addrinfo *); 238 static int _dns_getaddrinfo(void *, void *, va_list); 239 static void _sethtent(FILE **); 240 static void _endhtent(FILE **); 241 static struct addrinfo *_gethtent(FILE **, const char *, 242 const struct addrinfo *); 243 static int _files_getaddrinfo(void *, void *, va_list); 244 #ifdef YP 245 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 246 static int _yp_getaddrinfo(void *, void *, va_list); 247 #endif 248 249 static int res_queryN(const char *, struct res_target *, res_state); 250 static int res_searchN(const char *, struct res_target *, res_state); 251 static int res_querydomainN(const char *, const char *, 252 struct res_target *, res_state); 253 254 static const char * const ai_errlist[] = { 255 "Success", 256 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 257 "Temporary failure in name resolution", /* EAI_AGAIN */ 258 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 259 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 260 "ai_family not supported", /* EAI_FAMILY */ 261 "Memory allocation failure", /* EAI_MEMORY */ 262 "No address associated with hostname", /* EAI_NODATA */ 263 "hostname nor servname provided, or not known", /* EAI_NONAME */ 264 "servname not supported for ai_socktype", /* EAI_SERVICE */ 265 "ai_socktype not supported", /* EAI_SOCKTYPE */ 266 "System error returned in errno", /* EAI_SYSTEM */ 267 "Invalid value for hints", /* EAI_BADHINTS */ 268 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 269 "Argument buffer overflow", /* EAI_OVERFLOW */ 270 "Unknown error", /* EAI_MAX */ 271 }; 272 273 /* XXX macros that make external reference is BAD. */ 274 275 #define GET_AI(ai, afd, addr) \ 276 do { \ 277 /* external reference: pai, error, and label free */ \ 278 (ai) = get_ai(pai, (afd), (addr)); \ 279 if ((ai) == NULL) { \ 280 error = EAI_MEMORY; \ 281 goto free; \ 282 } \ 283 } while (/*CONSTCOND*/0) 284 285 #define GET_PORT(ai, serv, svd) \ 286 do { \ 287 /* external reference: error and label free */ \ 288 error = get_port((ai), (serv), 0, (svd)); \ 289 if (error != 0) \ 290 goto free; \ 291 } while (/*CONSTCOND*/0) 292 293 #define GET_CANONNAME(ai, str) \ 294 do { \ 295 /* external reference: pai, error and label free */ \ 296 error = get_canonname(pai, (ai), (str)); \ 297 if (error != 0) \ 298 goto free; \ 299 } while (/*CONSTCOND*/0) 300 301 #define ERR(err) \ 302 do { \ 303 /* external reference: error, and label bad */ \ 304 error = (err); \ 305 goto bad; \ 306 /*NOTREACHED*/ \ 307 } while (/*CONSTCOND*/0) 308 309 #define MATCH_FAMILY(x, y, w) \ 310 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || \ 311 (y) == PF_UNSPEC))) 312 #define MATCH(x, y, w) \ 313 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 314 315 const char * 316 gai_strerror(int ecode) 317 { 318 if (ecode < 0 || ecode > EAI_MAX) 319 ecode = EAI_MAX; 320 return ai_errlist[ecode]; 321 } 322 323 void 324 freeaddrinfo(struct addrinfo *ai) 325 { 326 struct addrinfo *next; 327 328 _DIAGASSERT(ai != NULL); 329 330 do { 331 next = ai->ai_next; 332 if (ai->ai_canonname) 333 free(ai->ai_canonname); 334 /* no need to free(ai->ai_addr) */ 335 free(ai); 336 ai = next; 337 } while (ai); 338 } 339 340 /* 341 * We don't want localization to affect us 342 */ 343 #define PERIOD '.' 344 #define hyphenchar(c) ((c) == '-') 345 #define periodchar(c) ((c) == PERIOD) 346 #define underschar(c) ((c) == '_') 347 #define alphachar(c) (((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z')) 348 #define digitchar(c) ((c) >= '0' && (c) <= '9') 349 350 #define firstchar(c) (alphachar(c) || digitchar(c) || underschar(c)) 351 #define lastchar(c) (alphachar(c) || digitchar(c)) 352 #define middlechar(c) (lastchar(c) || hyphenchar(c)) 353 354 static int 355 gai_srvok(const char *dn) 356 { 357 int nch, pch, ch; 358 359 for (pch = PERIOD, nch = ch = *dn++; ch != '\0'; pch = ch, ch = nch) { 360 if (periodchar(ch)) 361 continue; 362 if (periodchar(pch)) { 363 if (!firstchar(ch)) 364 return 0; 365 } else if (periodchar(nch) || nch == '\0') { 366 if (!lastchar(ch)) 367 return 0; 368 } else if (!middlechar(ch)) 369 return 0; 370 } 371 return 1; 372 } 373 374 static in_port_t * 375 getport(struct addrinfo *ai) { 376 static in_port_t p; 377 378 switch (ai->ai_family) { 379 case AF_INET: 380 return &((struct sockaddr_in *)(void *)ai->ai_addr)->sin_port; 381 #ifdef INET6 382 case AF_INET6: 383 return &((struct sockaddr_in6 *)(void *)ai->ai_addr)->sin6_port; 384 #endif 385 default: 386 p = 0; 387 /* XXX: abort()? */ 388 return &p; 389 } 390 } 391 392 static int 393 str2number(const char *p) 394 { 395 char *ep; 396 unsigned long v; 397 398 _DIAGASSERT(p != NULL); 399 400 if (*p == '\0') 401 return -1; 402 ep = NULL; 403 errno = 0; 404 v = strtoul(p, &ep, 10); 405 if (errno == 0 && ep && *ep == '\0' && v <= INT_MAX) 406 return (int)v; 407 else 408 return -1; 409 } 410 411 int 412 getaddrinfo(const char *hostname, const char *servname, 413 const struct addrinfo *hints, struct addrinfo **res) 414 { 415 struct addrinfo sentinel; 416 struct addrinfo *cur; 417 int error = 0; 418 struct addrinfo ai; 419 struct addrinfo ai0; 420 struct addrinfo *pai; 421 const struct explore *ex; 422 struct servent_data svd; 423 uint64_t mask = (uint64_t)~0ULL; 424 425 /* hostname is allowed to be NULL */ 426 /* servname is allowed to be NULL */ 427 /* hints is allowed to be NULL */ 428 _DIAGASSERT(res != NULL); 429 430 (void)memset(&svd, 0, sizeof(svd)); 431 memset(&sentinel, 0, sizeof(sentinel)); 432 cur = &sentinel; 433 memset(&ai, 0, sizeof(ai)); 434 pai = &ai; 435 pai->ai_flags = 0; 436 pai->ai_family = PF_UNSPEC; 437 pai->ai_socktype = ANY; 438 pai->ai_protocol = ANY; 439 pai->ai_addrlen = 0; 440 pai->ai_canonname = NULL; 441 pai->ai_addr = NULL; 442 pai->ai_next = NULL; 443 444 if (hostname == NULL && servname == NULL) 445 return EAI_NONAME; 446 if (hints) { 447 /* error check for hints */ 448 if (hints->ai_addrlen || hints->ai_canonname || 449 hints->ai_addr || hints->ai_next) 450 ERR(EAI_BADHINTS); /* xxx */ 451 if (hints->ai_flags & ~AI_MASK) 452 ERR(EAI_BADFLAGS); 453 switch (hints->ai_family) { 454 case PF_UNSPEC: 455 case PF_INET: 456 #ifdef INET6 457 case PF_INET6: 458 #endif 459 break; 460 default: 461 ERR(EAI_FAMILY); 462 } 463 memcpy(pai, hints, sizeof(*pai)); 464 465 /* 466 * if both socktype/protocol are specified, check if they 467 * are meaningful combination. 468 */ 469 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 470 for (ex = explore; ex->e_af >= 0; ex++) { 471 if (pai->ai_family != ex->e_af) 472 continue; 473 if (ex->e_socktype == ANY) 474 continue; 475 if (ex->e_protocol == ANY) 476 continue; 477 if (pai->ai_socktype == ex->e_socktype 478 && pai->ai_protocol != ex->e_protocol) { 479 ERR(EAI_BADHINTS); 480 } 481 } 482 } 483 } 484 485 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && addrconfig(&mask) == -1) 486 ERR(EAI_FAIL); 487 488 /* 489 * check for special cases. (1) numeric servname is disallowed if 490 * socktype/protocol are left unspecified. (2) servname is disallowed 491 * for raw and other inet{,6} sockets. 492 */ 493 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 494 #ifdef PF_INET6 495 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 496 #endif 497 ) { 498 ai0 = *pai; /* backup *pai */ 499 500 if (pai->ai_family == PF_UNSPEC) { 501 #ifdef PF_INET6 502 pai->ai_family = PF_INET6; 503 #else 504 pai->ai_family = PF_INET; 505 #endif 506 } 507 error = get_portmatch(pai, servname, &svd); 508 if (error) 509 goto bad; 510 511 *pai = ai0; 512 } 513 514 ai0 = *pai; 515 516 /* NULL hostname, or numeric hostname */ 517 for (ex = explore; ex->e_af >= 0; ex++) { 518 *pai = ai0; 519 520 /* ADDRCONFIG check */ 521 if ((((uint64_t)1 << ex->e_af) & mask) == 0) 522 continue; 523 524 /* PF_UNSPEC entries are prepared for DNS queries only */ 525 if (ex->e_af == PF_UNSPEC) 526 continue; 527 528 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 529 continue; 530 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 531 continue; 532 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 533 continue; 534 if (pai->ai_family == PF_UNSPEC) 535 pai->ai_family = ex->e_af; 536 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 537 pai->ai_socktype = ex->e_socktype; 538 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 539 pai->ai_protocol = ex->e_protocol; 540 541 if (hostname == NULL) 542 error = explore_null(pai, servname, &cur->ai_next, 543 &svd); 544 else 545 error = explore_numeric_scope(pai, hostname, servname, 546 &cur->ai_next, &svd); 547 548 if (error) 549 goto free; 550 551 while (cur->ai_next) 552 cur = cur->ai_next; 553 } 554 555 /* 556 * XXX 557 * If numeric representation of AF1 can be interpreted as FQDN 558 * representation of AF2, we need to think again about the code below. 559 */ 560 if (sentinel.ai_next) 561 goto good; 562 563 if (hostname == NULL) 564 ERR(EAI_NODATA); 565 if (pai->ai_flags & AI_NUMERICHOST) 566 ERR(EAI_NONAME); 567 568 /* 569 * hostname as alphabetical name. 570 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 571 * outer loop by AFs. 572 */ 573 for (ex = explore; ex->e_af >= 0; ex++) { 574 *pai = ai0; 575 576 577 /* ADDRCONFIG check */ 578 /* PF_UNSPEC entries are prepared for DNS queries only */ 579 if (ex->e_af != PF_UNSPEC && 580 (((uint64_t)1 << ex->e_af) & mask) == 0) 581 continue; 582 583 /* require exact match for family field */ 584 if (pai->ai_family != ex->e_af) 585 continue; 586 587 if (!MATCH(pai->ai_socktype, ex->e_socktype, 588 WILD_SOCKTYPE(ex))) { 589 continue; 590 } 591 if (!MATCH(pai->ai_protocol, ex->e_protocol, 592 WILD_PROTOCOL(ex))) { 593 continue; 594 } 595 596 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 597 pai->ai_socktype = ex->e_socktype; 598 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 599 pai->ai_protocol = ex->e_protocol; 600 601 error = explore_fqdn(pai, hostname, servname, &cur->ai_next, 602 &svd); 603 604 while (cur && cur->ai_next) 605 cur = cur->ai_next; 606 } 607 608 /* XXX */ 609 if (sentinel.ai_next) 610 error = 0; 611 612 if (error) 613 goto free; 614 615 if (sentinel.ai_next) { 616 good: 617 endservent_r(&svd); 618 *res = sentinel.ai_next; 619 return SUCCESS; 620 } else 621 error = EAI_FAIL; 622 free: 623 bad: 624 endservent_r(&svd); 625 if (sentinel.ai_next) 626 freeaddrinfo(sentinel.ai_next); 627 *res = NULL; 628 return error; 629 } 630 631 /* 632 * FQDN hostname, DNS lookup 633 */ 634 static int 635 explore_fqdn(const struct addrinfo *pai, const char *hostname, 636 const char *servname, struct addrinfo **res, struct servent_data *svd) 637 { 638 struct addrinfo *result; 639 struct addrinfo *cur; 640 int error = 0; 641 static const ns_dtab dtab[] = { 642 NS_FILES_CB(_files_getaddrinfo, NULL) 643 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 644 NS_NIS_CB(_yp_getaddrinfo, NULL) 645 NS_NULL_CB 646 }; 647 648 _DIAGASSERT(pai != NULL); 649 /* hostname may be NULL */ 650 /* servname may be NULL */ 651 _DIAGASSERT(res != NULL); 652 653 result = NULL; 654 655 /* 656 * if the servname does not match socktype/protocol, ignore it. 657 */ 658 if (get_portmatch(pai, servname, svd) != 0) 659 return 0; 660 661 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 662 default_dns_files, hostname, pai, servname)) { 663 case NS_TRYAGAIN: 664 error = EAI_AGAIN; 665 goto free; 666 case NS_UNAVAIL: 667 error = EAI_FAIL; 668 goto free; 669 case NS_NOTFOUND: 670 error = EAI_NODATA; 671 goto free; 672 case NS_SUCCESS: 673 error = 0; 674 for (cur = result; cur; cur = cur->ai_next) { 675 /* Check for already filled port. */ 676 if (*getport(cur)) 677 continue; 678 GET_PORT(cur, servname, svd); 679 /* canonname should be filled already */ 680 } 681 break; 682 } 683 684 *res = result; 685 686 return 0; 687 688 free: 689 if (result) 690 freeaddrinfo(result); 691 return error; 692 } 693 694 /* 695 * hostname == NULL. 696 * passive socket -> anyaddr (0.0.0.0 or ::) 697 * non-passive socket -> localhost (127.0.0.1 or ::1) 698 */ 699 static int 700 explore_null(const struct addrinfo *pai, const char *servname, 701 struct addrinfo **res, struct servent_data *svd) 702 { 703 int s; 704 const struct afd *afd; 705 struct addrinfo *cur; 706 struct addrinfo sentinel; 707 int error; 708 709 _DIAGASSERT(pai != NULL); 710 /* servname may be NULL */ 711 _DIAGASSERT(res != NULL); 712 713 *res = NULL; 714 sentinel.ai_next = NULL; 715 cur = &sentinel; 716 717 /* 718 * filter out AFs that are not supported by the kernel 719 * XXX errno? 720 */ 721 s = socket(pai->ai_family, SOCK_DGRAM, 0); 722 if (s < 0) { 723 if (errno != EMFILE) 724 return 0; 725 } else 726 close(s); 727 728 /* 729 * if the servname does not match socktype/protocol, ignore it. 730 */ 731 if (get_portmatch(pai, servname, svd) != 0) 732 return 0; 733 734 afd = find_afd(pai->ai_family); 735 if (afd == NULL) 736 return 0; 737 738 if (pai->ai_flags & AI_PASSIVE) { 739 GET_AI(cur->ai_next, afd, afd->a_addrany); 740 /* xxx meaningless? 741 * GET_CANONNAME(cur->ai_next, "anyaddr"); 742 */ 743 GET_PORT(cur->ai_next, servname, svd); 744 } else { 745 GET_AI(cur->ai_next, afd, afd->a_loopback); 746 /* xxx meaningless? 747 * GET_CANONNAME(cur->ai_next, "localhost"); 748 */ 749 GET_PORT(cur->ai_next, servname, svd); 750 } 751 cur = cur->ai_next; 752 753 *res = sentinel.ai_next; 754 return 0; 755 756 free: 757 if (sentinel.ai_next) 758 freeaddrinfo(sentinel.ai_next); 759 return error; 760 } 761 762 /* 763 * numeric hostname 764 */ 765 static int 766 explore_numeric(const struct addrinfo *pai, const char *hostname, 767 const char *servname, struct addrinfo **res, const char *canonname, 768 struct servent_data *svd) 769 { 770 const struct afd *afd; 771 struct addrinfo *cur; 772 struct addrinfo sentinel; 773 int error; 774 char pton[PTON_MAX]; 775 776 _DIAGASSERT(pai != NULL); 777 /* hostname may be NULL */ 778 /* servname may be NULL */ 779 _DIAGASSERT(res != NULL); 780 781 *res = NULL; 782 sentinel.ai_next = NULL; 783 cur = &sentinel; 784 785 /* 786 * if the servname does not match socktype/protocol, ignore it. 787 */ 788 if (get_portmatch(pai, servname, svd) != 0) 789 return 0; 790 791 afd = find_afd(pai->ai_family); 792 if (afd == NULL) 793 return 0; 794 795 switch (afd->a_af) { 796 #if 0 /*X/Open spec*/ 797 case AF_INET: 798 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 799 if (pai->ai_family == afd->a_af || 800 pai->ai_family == PF_UNSPEC /*?*/) { 801 GET_AI(cur->ai_next, afd, pton); 802 GET_PORT(cur->ai_next, servname, svd); 803 if ((pai->ai_flags & AI_CANONNAME)) { 804 /* 805 * Set the numeric address itself as 806 * the canonical name, based on a 807 * clarification in rfc2553bis-03. 808 */ 809 GET_CANONNAME(cur->ai_next, canonname); 810 } 811 while (cur && cur->ai_next) 812 cur = cur->ai_next; 813 } else 814 ERR(EAI_FAMILY); /*xxx*/ 815 } 816 break; 817 #endif 818 default: 819 if (inet_pton(afd->a_af, hostname, pton) == 1) { 820 if (pai->ai_family == afd->a_af || 821 pai->ai_family == PF_UNSPEC /*?*/) { 822 GET_AI(cur->ai_next, afd, pton); 823 GET_PORT(cur->ai_next, servname, svd); 824 if ((pai->ai_flags & AI_CANONNAME)) { 825 /* 826 * Set the numeric address itself as 827 * the canonical name, based on a 828 * clarification in rfc2553bis-03. 829 */ 830 GET_CANONNAME(cur->ai_next, canonname); 831 } 832 while (cur->ai_next) 833 cur = cur->ai_next; 834 } else 835 ERR(EAI_FAMILY); /*xxx*/ 836 } 837 break; 838 } 839 840 *res = sentinel.ai_next; 841 return 0; 842 843 free: 844 bad: 845 if (sentinel.ai_next) 846 freeaddrinfo(sentinel.ai_next); 847 return error; 848 } 849 850 /* 851 * numeric hostname with scope 852 */ 853 static int 854 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 855 const char *servname, struct addrinfo **res, struct servent_data *svd) 856 { 857 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 858 return explore_numeric(pai, hostname, servname, res, hostname, svd); 859 #else 860 const struct afd *afd; 861 struct addrinfo *cur; 862 int error; 863 char *cp, *hostname2 = NULL, *scope, *addr; 864 struct sockaddr_in6 *sin6; 865 866 _DIAGASSERT(pai != NULL); 867 /* hostname may be NULL */ 868 /* servname may be NULL */ 869 _DIAGASSERT(res != NULL); 870 871 /* 872 * if the servname does not match socktype/protocol, ignore it. 873 */ 874 if (get_portmatch(pai, servname, svd) != 0) 875 return 0; 876 877 afd = find_afd(pai->ai_family); 878 if (afd == NULL) 879 return 0; 880 881 if (!afd->a_scoped) 882 return explore_numeric(pai, hostname, servname, res, hostname, 883 svd); 884 885 cp = strchr(hostname, SCOPE_DELIMITER); 886 if (cp == NULL) 887 return explore_numeric(pai, hostname, servname, res, hostname, 888 svd); 889 890 /* 891 * Handle special case of <scoped_address><delimiter><scope id> 892 */ 893 hostname2 = strdup(hostname); 894 if (hostname2 == NULL) 895 return EAI_MEMORY; 896 /* terminate at the delimiter */ 897 hostname2[cp - hostname] = '\0'; 898 addr = hostname2; 899 scope = cp + 1; 900 901 error = explore_numeric(pai, addr, servname, res, hostname, svd); 902 if (error == 0) { 903 u_int32_t scopeid; 904 905 for (cur = *res; cur; cur = cur->ai_next) { 906 if (cur->ai_family != AF_INET6) 907 continue; 908 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 909 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 910 free(hostname2); 911 return(EAI_NODATA); /* XXX: is return OK? */ 912 } 913 sin6->sin6_scope_id = scopeid; 914 } 915 } 916 917 free(hostname2); 918 919 return error; 920 #endif 921 } 922 923 static int 924 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 925 { 926 927 _DIAGASSERT(pai != NULL); 928 _DIAGASSERT(ai != NULL); 929 _DIAGASSERT(str != NULL); 930 931 if ((pai->ai_flags & AI_CANONNAME) != 0) { 932 ai->ai_canonname = strdup(str); 933 if (ai->ai_canonname == NULL) 934 return EAI_MEMORY; 935 } 936 return 0; 937 } 938 939 struct addrinfo * 940 allocaddrinfo(socklen_t addrlen) 941 { 942 struct addrinfo *ai; 943 944 ai = calloc(sizeof(struct addrinfo) + addrlen, 1); 945 if (ai) { 946 ai->ai_addr = (void *)(ai+1); 947 ai->ai_addrlen = ai->ai_addr->sa_len = addrlen; 948 } 949 950 return ai; 951 } 952 953 static struct addrinfo * 954 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 955 { 956 char *p; 957 struct addrinfo *ai; 958 struct sockaddr *save; 959 960 _DIAGASSERT(pai != NULL); 961 _DIAGASSERT(afd != NULL); 962 _DIAGASSERT(addr != NULL); 963 964 ai = allocaddrinfo((socklen_t)afd->a_socklen); 965 if (ai == NULL) 966 return NULL; 967 968 save = ai->ai_addr; 969 memcpy(ai, pai, sizeof(struct addrinfo)); 970 971 /* since we just overwrote all of ai, we have 972 to restore ai_addr and ai_addrlen */ 973 ai->ai_addr = save; 974 ai->ai_addrlen = (socklen_t)afd->a_socklen; 975 976 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 977 p = (char *)(void *)(ai->ai_addr); 978 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 979 return ai; 980 } 981 982 static int 983 get_portmatch(const struct addrinfo *ai, const char *servname, 984 struct servent_data *svd) 985 { 986 987 _DIAGASSERT(ai != NULL); 988 /* servname may be NULL */ 989 990 return get_port(ai, servname, 1, svd); 991 } 992 993 static int 994 get_port(const struct addrinfo *ai, const char *servname, int matchonly, 995 struct servent_data *svd) 996 { 997 const char *proto; 998 struct servent *sp; 999 int port; 1000 int allownumeric; 1001 1002 _DIAGASSERT(ai != NULL); 1003 /* servname may be NULL */ 1004 1005 if (servname == NULL) 1006 return 0; 1007 switch (ai->ai_family) { 1008 case AF_INET: 1009 #ifdef AF_INET6 1010 case AF_INET6: 1011 #endif 1012 break; 1013 default: 1014 return 0; 1015 } 1016 1017 switch (ai->ai_socktype) { 1018 case SOCK_RAW: 1019 return EAI_SERVICE; 1020 case SOCK_DGRAM: 1021 case SOCK_STREAM: 1022 allownumeric = 1; 1023 break; 1024 case ANY: 1025 /* 1026 * This was 0. It is now 1 so that queries specifying 1027 * a NULL hint, or hint without socktype (but, hopefully, 1028 * with protocol) and numeric address actually work. 1029 */ 1030 allownumeric = 1; 1031 break; 1032 default: 1033 return EAI_SOCKTYPE; 1034 } 1035 1036 port = str2number(servname); 1037 if (port >= 0) { 1038 if (!allownumeric) 1039 return EAI_SERVICE; 1040 if (port < 0 || port > 65535) 1041 return EAI_SERVICE; 1042 port = htons(port); 1043 } else { 1044 struct servent sv; 1045 if (ai->ai_flags & AI_NUMERICSERV) 1046 return EAI_NONAME; 1047 1048 switch (ai->ai_socktype) { 1049 case SOCK_DGRAM: 1050 proto = "udp"; 1051 break; 1052 case SOCK_STREAM: 1053 proto = "tcp"; 1054 break; 1055 default: 1056 proto = NULL; 1057 break; 1058 } 1059 1060 sp = getservbyname_r(servname, proto, &sv, svd); 1061 if (sp == NULL) 1062 return EAI_SERVICE; 1063 port = sp->s_port; 1064 } 1065 1066 if (!matchonly) 1067 *getport(__UNCONST(ai)) = port; 1068 return 0; 1069 } 1070 1071 static const struct afd * 1072 find_afd(int af) 1073 { 1074 const struct afd *afd; 1075 1076 if (af == PF_UNSPEC) 1077 return NULL; 1078 for (afd = afdl; afd->a_af; afd++) { 1079 if (afd->a_af == af) 1080 return afd; 1081 } 1082 return NULL; 1083 } 1084 1085 /* 1086 * AI_ADDRCONFIG check: Build a mask containing a bit set for each address 1087 * family configured in the system. 1088 * 1089 */ 1090 static int 1091 addrconfig(uint64_t *mask) 1092 { 1093 struct ifaddrs *ifaddrs, *ifa; 1094 1095 if (getifaddrs(&ifaddrs) == -1) 1096 return -1; 1097 1098 *mask = 0; 1099 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) 1100 if (ifa->ifa_addr && (ifa->ifa_flags & IFF_UP)) { 1101 _DIAGASSERT(ifa->ifa_addr->sa_family < 64); 1102 *mask |= (uint64_t)1 << ifa->ifa_addr->sa_family; 1103 } 1104 1105 freeifaddrs(ifaddrs); 1106 return 0; 1107 } 1108 1109 #ifdef INET6 1110 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1111 static int 1112 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1113 { 1114 u_long lscopeid; 1115 struct in6_addr *a6; 1116 char *ep; 1117 1118 _DIAGASSERT(scope != NULL); 1119 _DIAGASSERT(sin6 != NULL); 1120 _DIAGASSERT(scopeid != NULL); 1121 1122 a6 = &sin6->sin6_addr; 1123 1124 /* empty scopeid portion is invalid */ 1125 if (*scope == '\0') 1126 return -1; 1127 1128 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1129 /* 1130 * We currently assume a one-to-one mapping between links 1131 * and interfaces, so we simply use interface indices for 1132 * like-local scopes. 1133 */ 1134 *scopeid = if_nametoindex(scope); 1135 if (*scopeid == 0) 1136 goto trynumeric; 1137 return 0; 1138 } 1139 1140 /* still unclear about literal, allow numeric only - placeholder */ 1141 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1142 goto trynumeric; 1143 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1144 goto trynumeric; 1145 else 1146 goto trynumeric; /* global */ 1147 1148 /* try to convert to a numeric id as a last resort */ 1149 trynumeric: 1150 errno = 0; 1151 lscopeid = strtoul(scope, &ep, 10); 1152 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1153 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1154 return 0; 1155 else 1156 return -1; 1157 } 1158 #endif 1159 1160 /* code duplicate with gethnamaddr.c */ 1161 1162 static const char AskedForGot[] = 1163 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1164 1165 static struct addrinfo * 1166 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1167 const struct addrinfo *pai) 1168 { 1169 struct addrinfo sentinel, *cur; 1170 struct addrinfo ai, *aip; 1171 const struct afd *afd; 1172 char *canonname; 1173 const HEADER *hp; 1174 const u_char *cp; 1175 int n; 1176 const u_char *eom; 1177 char *bp, *ep; 1178 int type, class, ancount, qdcount; 1179 int haveanswer, had_error; 1180 char tbuf[MAXDNAME]; 1181 int (*name_ok) (const char *); 1182 char hostbuf[8*1024]; 1183 int port, pri, weight; 1184 struct srvinfo *srvlist, *srv, *csrv; 1185 1186 _DIAGASSERT(answer != NULL); 1187 _DIAGASSERT(qname != NULL); 1188 _DIAGASSERT(pai != NULL); 1189 1190 memset(&sentinel, 0, sizeof(sentinel)); 1191 cur = &sentinel; 1192 1193 canonname = NULL; 1194 eom = answer->buf + anslen; 1195 switch (qtype) { 1196 case T_A: 1197 case T_AAAA: 1198 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1199 name_ok = res_hnok; 1200 break; 1201 case T_SRV: 1202 name_ok = gai_srvok; 1203 break; 1204 default: 1205 return NULL; /* XXX should be abort(); */ 1206 } 1207 /* 1208 * find first satisfactory answer 1209 */ 1210 hp = &answer->hdr; 1211 ancount = ntohs(hp->ancount); 1212 qdcount = ntohs(hp->qdcount); 1213 bp = hostbuf; 1214 ep = hostbuf + sizeof hostbuf; 1215 cp = answer->buf + HFIXEDSZ; 1216 if (qdcount != 1) { 1217 h_errno = NO_RECOVERY; 1218 return (NULL); 1219 } 1220 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp)); 1221 if ((n < 0) || !(*name_ok)(bp)) { 1222 h_errno = NO_RECOVERY; 1223 return (NULL); 1224 } 1225 cp += n + QFIXEDSZ; 1226 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1227 /* res_send() has already verified that the query name is the 1228 * same as the one we sent; this just gets the expanded name 1229 * (i.e., with the succeeding search-domain tacked on). 1230 */ 1231 n = (int)strlen(bp) + 1; /* for the \0 */ 1232 if (n >= MAXHOSTNAMELEN) { 1233 h_errno = NO_RECOVERY; 1234 return (NULL); 1235 } 1236 canonname = bp; 1237 bp += n; 1238 /* The qname can be abbreviated, but h_name is now absolute. */ 1239 qname = canonname; 1240 } 1241 haveanswer = 0; 1242 had_error = 0; 1243 srvlist = NULL; 1244 while (ancount-- > 0 && cp < eom && !had_error) { 1245 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp)); 1246 if ((n < 0) || !(*name_ok)(bp)) { 1247 had_error++; 1248 continue; 1249 } 1250 cp += n; /* name */ 1251 type = _getshort(cp); 1252 cp += INT16SZ; /* type */ 1253 class = _getshort(cp); 1254 cp += INT16SZ + INT32SZ; /* class, TTL */ 1255 n = _getshort(cp); 1256 cp += INT16SZ; /* len */ 1257 if (class != C_IN) { 1258 /* XXX - debug? syslog? */ 1259 cp += n; 1260 continue; /* XXX - had_error++ ? */ 1261 } 1262 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1263 type == T_CNAME) { 1264 n = dn_expand(answer->buf, eom, cp, tbuf, (int)sizeof tbuf); 1265 if ((n < 0) || !(*name_ok)(tbuf)) { 1266 had_error++; 1267 continue; 1268 } 1269 cp += n; 1270 /* Get canonical name. */ 1271 n = (int)strlen(tbuf) + 1; /* for the \0 */ 1272 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1273 had_error++; 1274 continue; 1275 } 1276 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1277 canonname = bp; 1278 bp += n; 1279 continue; 1280 } 1281 if (qtype == T_ANY) { 1282 if (!(type == T_A || type == T_AAAA)) { 1283 cp += n; 1284 continue; 1285 } 1286 } else if (type != qtype) { 1287 if (type != T_KEY && type != T_SIG) { 1288 struct syslog_data sd = SYSLOG_DATA_INIT; 1289 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1290 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1291 qname, p_class(C_IN), p_type(qtype), 1292 p_type(type)); 1293 } 1294 cp += n; 1295 continue; /* XXX - had_error++ ? */ 1296 } 1297 switch (type) { 1298 case T_A: 1299 case T_AAAA: 1300 if (strcasecmp(canonname, bp) != 0) { 1301 struct syslog_data sd = SYSLOG_DATA_INIT; 1302 syslog_r(LOG_NOTICE|LOG_AUTH, &sd, 1303 AskedForGot, canonname, bp); 1304 cp += n; 1305 continue; /* XXX - had_error++ ? */ 1306 } 1307 if (type == T_A && n != INADDRSZ) { 1308 cp += n; 1309 continue; 1310 } 1311 if (type == T_AAAA && n != IN6ADDRSZ) { 1312 cp += n; 1313 continue; 1314 } 1315 if (type == T_AAAA) { 1316 struct in6_addr in6; 1317 memcpy(&in6, cp, IN6ADDRSZ); 1318 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1319 cp += n; 1320 continue; 1321 } 1322 } 1323 if (!haveanswer) { 1324 int nn; 1325 1326 canonname = bp; 1327 nn = (int)strlen(bp) + 1; /* for the \0 */ 1328 bp += nn; 1329 } 1330 1331 /* don't overwrite pai */ 1332 ai = *pai; 1333 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1334 afd = find_afd(ai.ai_family); 1335 if (afd == NULL) { 1336 cp += n; 1337 continue; 1338 } 1339 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1340 if (cur->ai_next == NULL) 1341 had_error++; 1342 while (cur && cur->ai_next) 1343 cur = cur->ai_next; 1344 cp += n; 1345 break; 1346 case T_SRV: 1347 /* Add to SRV list. Insertion sort on priority. */ 1348 pri = _getshort(cp); 1349 cp += INT16SZ; 1350 weight = _getshort(cp); 1351 cp += INT16SZ; 1352 port = _getshort(cp); 1353 cp += INT16SZ; 1354 n = dn_expand(answer->buf, eom, cp, tbuf, 1355 (int)sizeof(tbuf)); 1356 if ((n < 0) || !res_hnok(tbuf)) { 1357 had_error++; 1358 continue; 1359 } 1360 cp += n; 1361 if (strlen(tbuf) + 1 >= MAXDNAME) { 1362 had_error++; 1363 continue; 1364 } 1365 srv = malloc(sizeof(*srv)); 1366 if (!srv) { 1367 had_error++; 1368 continue; 1369 } 1370 strlcpy(srv->name, tbuf, sizeof(srv->name)); 1371 srv->pri = pri; 1372 srv->weight = weight; 1373 srv->port = port; 1374 /* Weight 0 is sorted before other weights. */ 1375 if (!srvlist 1376 || srv->pri < srvlist->pri 1377 || (srv->pri == srvlist->pri && 1378 (!srv->weight || srvlist->weight))) { 1379 srv->next = srvlist; 1380 srvlist = srv; 1381 } else { 1382 for (csrv = srvlist; 1383 csrv->next && csrv->next->pri <= srv->pri; 1384 csrv = csrv->next) { 1385 if (csrv->next->pri == srv->pri 1386 && (!srv->weight || 1387 csrv->next->weight)) 1388 break; 1389 } 1390 srv->next = csrv->next; 1391 csrv->next = srv; 1392 } 1393 continue; /* Don't add to haveanswer yet. */ 1394 default: 1395 abort(); 1396 } 1397 if (!had_error) 1398 haveanswer++; 1399 } 1400 1401 if (srvlist) { 1402 res_state res; 1403 /* 1404 * Check for explicit rejection. 1405 */ 1406 if (!srvlist->next && !srvlist->name[0]) { 1407 free(srvlist); 1408 h_errno = HOST_NOT_FOUND; 1409 return NULL; 1410 } 1411 res = __res_get_state(); 1412 if (res == NULL) { 1413 while (srvlist != NULL) { 1414 srv = srvlist; 1415 srvlist = srvlist->next; 1416 free(srv); 1417 } 1418 h_errno = NETDB_INTERNAL; 1419 return NULL; 1420 } 1421 1422 while (srvlist) { 1423 struct res_target q, q2; 1424 1425 srv = srvlist; 1426 srvlist = srvlist->next; 1427 1428 /* 1429 * Since res_* doesn't give the additional 1430 * section, we always look up. 1431 */ 1432 memset(&q, 0, sizeof(q)); 1433 memset(&q2, 0, sizeof(q2)); 1434 1435 q.name = srv->name; 1436 q.qclass = C_IN; 1437 q.qtype = T_AAAA; 1438 q.next = &q2; 1439 q2.name = srv->name; 1440 q2.qclass = C_IN; 1441 q2.qtype = T_A; 1442 1443 aip = _dns_query(&q, pai, res, 0); 1444 1445 if (aip != NULL) { 1446 cur->ai_next = aip; 1447 while (cur && cur->ai_next) { 1448 cur = cur->ai_next; 1449 *getport(cur) = htons(srv->port); 1450 haveanswer++; 1451 } 1452 } 1453 free(srv); 1454 } 1455 __res_put_state(res); 1456 } 1457 if (haveanswer) { 1458 if (!sentinel.ai_next->ai_canonname) 1459 (void)get_canonname(pai, sentinel.ai_next, 1460 canonname ? canonname : qname); 1461 h_errno = NETDB_SUCCESS; 1462 return sentinel.ai_next; 1463 } 1464 1465 h_errno = NO_RECOVERY; 1466 return NULL; 1467 } 1468 1469 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr) 1470 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr) 1471 1472 static void 1473 aisort(struct addrinfo *s, res_state res) 1474 { 1475 struct addrinfo head, *t, *p; 1476 int i; 1477 1478 head.ai_next = NULL; 1479 t = &head; 1480 1481 for (i = 0; i < res->nsort; i++) { 1482 p = s; 1483 while (p->ai_next) { 1484 if ((p->ai_next->ai_family != AF_INET) 1485 || SORTMATCH(p, res->sort_list[i])) { 1486 t->ai_next = p->ai_next; 1487 t = t->ai_next; 1488 p->ai_next = p->ai_next->ai_next; 1489 } else { 1490 p = p->ai_next; 1491 } 1492 } 1493 } 1494 1495 /* add rest of list and reset s to the new list*/ 1496 t->ai_next = s->ai_next; 1497 s->ai_next = head.ai_next; 1498 } 1499 1500 static struct addrinfo * 1501 _dns_query(struct res_target *q, const struct addrinfo *pai, 1502 res_state res, int dosearch) 1503 { 1504 struct res_target *q2 = q->next; 1505 querybuf *buf, *buf2; 1506 struct addrinfo sentinel, *cur, *ai; 1507 1508 #ifdef DNS_DEBUG 1509 struct res_target *iter; 1510 for (iter = q; iter; iter = iter->next) 1511 printf("Query type %d for %s\n", iter->qtype, iter->name); 1512 #endif 1513 1514 buf = malloc(sizeof(*buf)); 1515 if (buf == NULL) { 1516 h_errno = NETDB_INTERNAL; 1517 return NULL; 1518 } 1519 buf2 = malloc(sizeof(*buf2)); 1520 if (buf2 == NULL) { 1521 free(buf); 1522 h_errno = NETDB_INTERNAL; 1523 return NULL; 1524 } 1525 1526 memset(&sentinel, 0, sizeof(sentinel)); 1527 cur = &sentinel; 1528 1529 q->answer = buf->buf; 1530 q->anslen = sizeof(buf->buf); 1531 if (q2) { 1532 q2->answer = buf2->buf; 1533 q2->anslen = sizeof(buf2->buf); 1534 } 1535 1536 if (dosearch) { 1537 if (res_searchN(q->name, q, res) < 0) 1538 goto out; 1539 } else { 1540 if (res_queryN(q->name, q, res) < 0) 1541 goto out; 1542 } 1543 1544 ai = getanswer(buf, q->n, q->name, q->qtype, pai); 1545 if (ai) { 1546 cur->ai_next = ai; 1547 while (cur && cur->ai_next) 1548 cur = cur->ai_next; 1549 } 1550 if (q2) { 1551 ai = getanswer(buf2, q2->n, q2->name, q2->qtype, pai); 1552 if (ai) 1553 cur->ai_next = ai; 1554 } 1555 free(buf); 1556 free(buf2); 1557 return sentinel.ai_next; 1558 out: 1559 free(buf); 1560 free(buf2); 1561 return NULL; 1562 } 1563 1564 /*ARGSUSED*/ 1565 static struct addrinfo * 1566 _dns_srv_lookup(const char *name, const char *servname, 1567 const struct addrinfo *pai) 1568 { 1569 static const char * const srvprotos[] = { "tcp", "udp" }; 1570 static const int srvnottype[] = { SOCK_DGRAM, SOCK_STREAM }; 1571 static const int nsrvprotos = 2; 1572 struct addrinfo sentinel, *cur, *ai; 1573 struct servent *serv, sv; 1574 struct servent_data svd; 1575 struct res_target q; 1576 res_state res; 1577 char *tname; 1578 int i; 1579 1580 res = __res_get_state(); 1581 if (res == NULL) 1582 return NULL; 1583 1584 memset(&svd, 0, sizeof(svd)); 1585 memset(&sentinel, 0, sizeof(sentinel)); 1586 cur = &sentinel; 1587 1588 /* 1589 * Iterate over supported SRV protocols. 1590 * (currently UDP and TCP only) 1591 */ 1592 for (i = 0; i < nsrvprotos; i++) { 1593 /* 1594 * Check that the caller didn't specify a hint 1595 * which precludes this protocol. 1596 */ 1597 if (pai->ai_socktype == srvnottype[i]) 1598 continue; 1599 /* 1600 * If the caller specified a port, 1601 * then lookup the database for the 1602 * official service name. 1603 */ 1604 serv = getservbyname_r(servname, srvprotos[i], &sv, &svd); 1605 if (serv == NULL) 1606 continue; 1607 1608 /* 1609 * Construct service DNS name. 1610 */ 1611 if (asprintf(&tname, "_%s._%s.%s", serv->s_name, serv->s_proto, 1612 name) < 0) 1613 continue; 1614 1615 memset(&q, 0, sizeof(q)); 1616 q.name = tname; 1617 q.qclass = C_IN; 1618 q.qtype = T_SRV; 1619 1620 /* 1621 * Do SRV query. 1622 */ 1623 ai = _dns_query(&q, pai, res, 1); 1624 if (ai) { 1625 cur->ai_next = ai; 1626 while (cur && cur->ai_next) 1627 cur = cur->ai_next; 1628 } 1629 free(tname); 1630 } 1631 1632 if (res->nsort) 1633 aisort(&sentinel, res); 1634 1635 __res_put_state(res); 1636 1637 return sentinel.ai_next; 1638 } 1639 1640 /*ARGSUSED*/ 1641 static struct addrinfo * 1642 _dns_host_lookup(const char *name, const struct addrinfo *pai) 1643 { 1644 struct res_target q, q2; 1645 struct addrinfo sentinel, *ai; 1646 res_state res; 1647 1648 res = __res_get_state(); 1649 if (res == NULL) 1650 return NULL; 1651 1652 memset(&q, 0, sizeof(q2)); 1653 memset(&q2, 0, sizeof(q2)); 1654 1655 switch (pai->ai_family) { 1656 case AF_UNSPEC: 1657 /* prefer IPv6 */ 1658 q.name = name; 1659 q.qclass = C_IN; 1660 q.qtype = T_AAAA; 1661 q.next = &q2; 1662 q2.name = name; 1663 q2.qclass = C_IN; 1664 q2.qtype = T_A; 1665 break; 1666 case AF_INET: 1667 q.name = name; 1668 q.qclass = C_IN; 1669 q.qtype = T_A; 1670 break; 1671 case AF_INET6: 1672 q.name = name; 1673 q.qclass = C_IN; 1674 q.qtype = T_AAAA; 1675 break; 1676 default: 1677 __res_put_state(res); 1678 h_errno = NETDB_INTERNAL; 1679 return NULL; 1680 } 1681 1682 ai = _dns_query(&q, pai, res, 1); 1683 1684 memset(&sentinel, 0, sizeof(sentinel)); 1685 sentinel.ai_next = ai; 1686 1687 if (ai != NULL && res->nsort) 1688 aisort(&sentinel, res); 1689 1690 __res_put_state(res); 1691 1692 return sentinel.ai_next; 1693 } 1694 1695 /*ARGSUSED*/ 1696 static int 1697 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1698 { 1699 struct addrinfo *ai = NULL; 1700 const char *name, *servname; 1701 const struct addrinfo *pai; 1702 1703 name = va_arg(ap, char *); 1704 pai = va_arg(ap, const struct addrinfo *); 1705 servname = va_arg(ap, char *); 1706 1707 /* 1708 * Try doing SRV lookup on service first. 1709 */ 1710 if (servname 1711 #ifdef AI_SRV 1712 && (pai->ai_flags & AI_SRV) 1713 #endif 1714 && !(pai->ai_flags & AI_NUMERICSERV) 1715 && str2number(servname) == -1) { 1716 1717 #ifdef DNS_DEBUG 1718 printf("%s: try SRV lookup\n", __func__); 1719 #endif 1720 ai = _dns_srv_lookup(name, servname, pai); 1721 } 1722 1723 /* 1724 * Do lookup on name. 1725 */ 1726 if (ai == NULL) { 1727 1728 #ifdef DNS_DEBUG 1729 printf("%s: try HOST lookup\n", __func__); 1730 #endif 1731 ai = _dns_host_lookup(name, pai); 1732 1733 if (ai == NULL) { 1734 switch (h_errno) { 1735 case HOST_NOT_FOUND: 1736 return NS_NOTFOUND; 1737 case TRY_AGAIN: 1738 return NS_TRYAGAIN; 1739 default: 1740 return NS_UNAVAIL; 1741 } 1742 } 1743 } 1744 1745 *((struct addrinfo **)rv) = ai; 1746 return NS_SUCCESS; 1747 } 1748 1749 static void 1750 _sethtent(FILE **hostf) 1751 { 1752 1753 if (!*hostf) 1754 *hostf = fopen(_PATH_HOSTS, "re"); 1755 else 1756 rewind(*hostf); 1757 } 1758 1759 static void 1760 _endhtent(FILE **hostf) 1761 { 1762 1763 if (*hostf) { 1764 (void) fclose(*hostf); 1765 *hostf = NULL; 1766 } 1767 } 1768 1769 static struct addrinfo * 1770 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 1771 { 1772 char *p; 1773 char *cp, *tname, *cname; 1774 struct addrinfo hints, *res0, *res; 1775 int error; 1776 const char *addr; 1777 char hostbuf[8*1024]; 1778 1779 _DIAGASSERT(name != NULL); 1780 _DIAGASSERT(pai != NULL); 1781 1782 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 1783 return (NULL); 1784 again: 1785 if (!(p = fgets(hostbuf, (int)sizeof hostbuf, *hostf))) 1786 return (NULL); 1787 if (*p == '#') 1788 goto again; 1789 if (!(cp = strpbrk(p, "#\n"))) 1790 goto again; 1791 *cp = '\0'; 1792 if (!(cp = strpbrk(p, " \t"))) 1793 goto again; 1794 *cp++ = '\0'; 1795 addr = p; 1796 /* if this is not something we're looking for, skip it. */ 1797 cname = NULL; 1798 while (cp && *cp) { 1799 if (*cp == ' ' || *cp == '\t') { 1800 cp++; 1801 continue; 1802 } 1803 if (!cname) 1804 cname = cp; 1805 tname = cp; 1806 if ((cp = strpbrk(cp, " \t")) != NULL) 1807 *cp++ = '\0'; 1808 if (strcasecmp(name, tname) == 0) 1809 goto found; 1810 } 1811 goto again; 1812 1813 found: 1814 hints = *pai; 1815 hints.ai_flags = AI_NUMERICHOST; 1816 error = getaddrinfo(addr, NULL, &hints, &res0); 1817 if (error) 1818 goto again; 1819 for (res = res0; res; res = res->ai_next) { 1820 /* cover it up */ 1821 res->ai_flags = pai->ai_flags; 1822 1823 if (pai->ai_flags & AI_CANONNAME) { 1824 if (get_canonname(pai, res, cname) != 0) { 1825 freeaddrinfo(res0); 1826 goto again; 1827 } 1828 } 1829 } 1830 return res0; 1831 } 1832 1833 /*ARGSUSED*/ 1834 static int 1835 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 1836 { 1837 const char *name; 1838 const struct addrinfo *pai; 1839 struct addrinfo sentinel, *cur; 1840 struct addrinfo *p; 1841 #ifndef _REENTRANT 1842 static 1843 #endif 1844 FILE *hostf = NULL; 1845 1846 name = va_arg(ap, char *); 1847 pai = va_arg(ap, const struct addrinfo *); 1848 1849 memset(&sentinel, 0, sizeof(sentinel)); 1850 cur = &sentinel; 1851 1852 _sethtent(&hostf); 1853 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 1854 cur->ai_next = p; 1855 while (cur && cur->ai_next) 1856 cur = cur->ai_next; 1857 } 1858 _endhtent(&hostf); 1859 1860 *((struct addrinfo **)rv) = sentinel.ai_next; 1861 if (sentinel.ai_next == NULL) 1862 return NS_NOTFOUND; 1863 return NS_SUCCESS; 1864 } 1865 1866 #ifdef YP 1867 /*ARGSUSED*/ 1868 static struct addrinfo * 1869 _yphostent(char *line, const struct addrinfo *pai) 1870 { 1871 struct addrinfo sentinel, *cur; 1872 struct addrinfo hints, *res, *res0; 1873 int error; 1874 char *p; 1875 const char *addr, *canonname; 1876 char *nextline; 1877 char *cp; 1878 1879 _DIAGASSERT(line != NULL); 1880 _DIAGASSERT(pai != NULL); 1881 1882 p = line; 1883 addr = canonname = NULL; 1884 1885 memset(&sentinel, 0, sizeof(sentinel)); 1886 cur = &sentinel; 1887 1888 nextline: 1889 /* terminate line */ 1890 cp = strchr(p, '\n'); 1891 if (cp) { 1892 *cp++ = '\0'; 1893 nextline = cp; 1894 } else 1895 nextline = NULL; 1896 1897 cp = strpbrk(p, " \t"); 1898 if (cp == NULL) { 1899 if (canonname == NULL) 1900 return (NULL); 1901 else 1902 goto done; 1903 } 1904 *cp++ = '\0'; 1905 1906 addr = p; 1907 1908 while (cp && *cp) { 1909 if (*cp == ' ' || *cp == '\t') { 1910 cp++; 1911 continue; 1912 } 1913 if (!canonname) 1914 canonname = cp; 1915 if ((cp = strpbrk(cp, " \t")) != NULL) 1916 *cp++ = '\0'; 1917 } 1918 1919 hints = *pai; 1920 hints.ai_flags = AI_NUMERICHOST; 1921 error = getaddrinfo(addr, NULL, &hints, &res0); 1922 if (error == 0) { 1923 for (res = res0; res; res = res->ai_next) { 1924 /* cover it up */ 1925 res->ai_flags = pai->ai_flags; 1926 1927 if (pai->ai_flags & AI_CANONNAME) 1928 (void)get_canonname(pai, res, canonname); 1929 } 1930 } else 1931 res0 = NULL; 1932 if (res0) { 1933 cur->ai_next = res0; 1934 while (cur->ai_next) 1935 cur = cur->ai_next; 1936 } 1937 1938 if (nextline) { 1939 p = nextline; 1940 goto nextline; 1941 } 1942 1943 done: 1944 return sentinel.ai_next; 1945 } 1946 1947 /*ARGSUSED*/ 1948 static int 1949 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 1950 { 1951 struct addrinfo sentinel, *cur; 1952 struct addrinfo *ai = NULL; 1953 char *ypbuf; 1954 int ypbuflen, r; 1955 const char *name; 1956 const struct addrinfo *pai; 1957 char *ypdomain; 1958 1959 if (_yp_check(&ypdomain) == 0) 1960 return NS_UNAVAIL; 1961 1962 name = va_arg(ap, char *); 1963 pai = va_arg(ap, const struct addrinfo *); 1964 1965 memset(&sentinel, 0, sizeof(sentinel)); 1966 cur = &sentinel; 1967 1968 /* hosts.byname is only for IPv4 (Solaris8) */ 1969 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 1970 r = yp_match(ypdomain, "hosts.byname", name, 1971 (int)strlen(name), &ypbuf, &ypbuflen); 1972 if (r == 0) { 1973 struct addrinfo ai4; 1974 1975 ai4 = *pai; 1976 ai4.ai_family = AF_INET; 1977 ai = _yphostent(ypbuf, &ai4); 1978 if (ai) { 1979 cur->ai_next = ai; 1980 while (cur && cur->ai_next) 1981 cur = cur->ai_next; 1982 } 1983 } 1984 free(ypbuf); 1985 } 1986 1987 /* ipnodes.byname can hold both IPv4/v6 */ 1988 r = yp_match(ypdomain, "ipnodes.byname", name, 1989 (int)strlen(name), &ypbuf, &ypbuflen); 1990 if (r == 0) { 1991 ai = _yphostent(ypbuf, pai); 1992 if (ai) 1993 cur->ai_next = ai; 1994 free(ypbuf); 1995 } 1996 1997 if (sentinel.ai_next == NULL) { 1998 h_errno = HOST_NOT_FOUND; 1999 return NS_NOTFOUND; 2000 } 2001 *((struct addrinfo **)rv) = sentinel.ai_next; 2002 return NS_SUCCESS; 2003 } 2004 #endif 2005 2006 /* resolver logic */ 2007 2008 /* 2009 * Formulate a normal query, send, and await answer. 2010 * Returned answer is placed in supplied buffer "answer". 2011 * Perform preliminary check of answer, returning success only 2012 * if no error is indicated and the answer count is nonzero. 2013 * Return the size of the response on success, -1 on error. 2014 * Error number is left in h_errno. 2015 * 2016 * Caller must parse answer and determine whether it answers the question. 2017 */ 2018 static int 2019 res_queryN(const char *name, /* domain name */ struct res_target *target, 2020 res_state res) 2021 { 2022 u_char buf[MAXPACKET]; 2023 HEADER *hp; 2024 int n; 2025 struct res_target *t; 2026 int rcode; 2027 int ancount; 2028 2029 _DIAGASSERT(name != NULL); 2030 /* XXX: target may be NULL??? */ 2031 2032 rcode = NOERROR; 2033 ancount = 0; 2034 2035 for (t = target; t; t = t->next) { 2036 int class, type; 2037 u_char *answer; 2038 int anslen; 2039 2040 hp = (HEADER *)(void *)t->answer; 2041 hp->rcode = NOERROR; /* default */ 2042 2043 /* make it easier... */ 2044 class = t->qclass; 2045 type = t->qtype; 2046 answer = t->answer; 2047 anslen = t->anslen; 2048 #ifdef DEBUG 2049 if (res->options & RES_DEBUG) 2050 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 2051 #endif 2052 2053 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2054 buf, (int)sizeof(buf)); 2055 #ifdef RES_USE_EDNS0 2056 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 2057 n = res_nopt(res, n, buf, (int)sizeof(buf), anslen); 2058 #endif 2059 if (n <= 0) { 2060 #ifdef DEBUG 2061 if (res->options & RES_DEBUG) 2062 printf(";; res_nquery: mkquery failed\n"); 2063 #endif 2064 h_errno = NO_RECOVERY; 2065 return n; 2066 } 2067 n = res_nsend(res, buf, n, answer, anslen); 2068 #if 0 2069 if (n < 0) { 2070 #ifdef DEBUG 2071 if (res->options & RES_DEBUG) 2072 printf(";; res_query: send error\n"); 2073 #endif 2074 h_errno = TRY_AGAIN; 2075 return n; 2076 } 2077 #endif 2078 2079 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2080 rcode = hp->rcode; /* record most recent error */ 2081 #ifdef DEBUG 2082 if (res->options & RES_DEBUG) 2083 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2084 ntohs(hp->ancount)); 2085 #endif 2086 continue; 2087 } 2088 2089 ancount += ntohs(hp->ancount); 2090 2091 t->n = n; 2092 } 2093 2094 if (ancount == 0) { 2095 switch (rcode) { 2096 case NXDOMAIN: 2097 h_errno = HOST_NOT_FOUND; 2098 break; 2099 case SERVFAIL: 2100 h_errno = TRY_AGAIN; 2101 break; 2102 case NOERROR: 2103 h_errno = NO_DATA; 2104 break; 2105 case FORMERR: 2106 case NOTIMP: 2107 case REFUSED: 2108 default: 2109 h_errno = NO_RECOVERY; 2110 break; 2111 } 2112 return -1; 2113 } 2114 return ancount; 2115 } 2116 2117 /* 2118 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2119 * Return the size of the response on success, -1 on error. 2120 * If enabled, implement search rules until answer or unrecoverable failure 2121 * is detected. Error code, if any, is left in h_errno. 2122 */ 2123 static int 2124 res_searchN(const char *name, struct res_target *target, res_state res) 2125 { 2126 const char *cp, * const *domain; 2127 HEADER *hp; 2128 u_int dots; 2129 char buf[MAXHOSTNAMELEN]; 2130 int trailing_dot, ret, saved_herrno; 2131 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 2132 2133 _DIAGASSERT(name != NULL); 2134 _DIAGASSERT(target != NULL); 2135 2136 hp = (HEADER *)(void *)target->answer; /*XXX*/ 2137 2138 errno = 0; 2139 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 2140 dots = 0; 2141 for (cp = name; *cp; cp++) 2142 dots += (*cp == '.'); 2143 trailing_dot = 0; 2144 if (cp > name && *--cp == '.') 2145 trailing_dot++; 2146 2147 /* 2148 * if there aren't any dots, it could be a user-level alias 2149 */ 2150 if (!dots && (cp = res_hostalias(res, name, buf, sizeof(buf))) != NULL) { 2151 ret = res_queryN(cp, target, res); 2152 return ret; 2153 } 2154 2155 /* 2156 * If there are dots in the name already, let's just give it a try 2157 * 'as is'. The threshold can be set with the "ndots" option. 2158 */ 2159 saved_herrno = -1; 2160 if (dots >= res->ndots) { 2161 ret = res_querydomainN(name, NULL, target, res); 2162 if (ret > 0) 2163 return (ret); 2164 saved_herrno = h_errno; 2165 tried_as_is++; 2166 } 2167 2168 /* 2169 * We do at least one level of search if 2170 * - there is no dot and RES_DEFNAME is set, or 2171 * - there is at least one dot, there is no trailing dot, 2172 * and RES_DNSRCH is set. 2173 */ 2174 if ((!dots && (res->options & RES_DEFNAMES)) || 2175 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2176 int done = 0; 2177 2178 for (domain = (const char * const *)res->dnsrch; 2179 *domain && !done; 2180 domain++) { 2181 2182 ret = res_querydomainN(name, *domain, target, res); 2183 if (ret > 0) 2184 return ret; 2185 2186 /* 2187 * If no server present, give up. 2188 * If name isn't found in this domain, 2189 * keep trying higher domains in the search list 2190 * (if that's enabled). 2191 * On a NO_DATA error, keep trying, otherwise 2192 * a wildcard entry of another type could keep us 2193 * from finding this entry higher in the domain. 2194 * If we get some other error (negative answer or 2195 * server failure), then stop searching up, 2196 * but try the input name below in case it's 2197 * fully-qualified. 2198 */ 2199 if (errno == ECONNREFUSED) { 2200 h_errno = TRY_AGAIN; 2201 return -1; 2202 } 2203 2204 switch (h_errno) { 2205 case NO_DATA: 2206 got_nodata++; 2207 /* FALLTHROUGH */ 2208 case HOST_NOT_FOUND: 2209 /* keep trying */ 2210 break; 2211 case TRY_AGAIN: 2212 if (hp->rcode == SERVFAIL) { 2213 /* try next search element, if any */ 2214 got_servfail++; 2215 break; 2216 } 2217 /* FALLTHROUGH */ 2218 default: 2219 /* anything else implies that we're done */ 2220 done++; 2221 } 2222 /* 2223 * if we got here for some reason other than DNSRCH, 2224 * we only wanted one iteration of the loop, so stop. 2225 */ 2226 if (!(res->options & RES_DNSRCH)) 2227 done++; 2228 } 2229 } 2230 2231 /* 2232 * if we have not already tried the name "as is", do that now. 2233 * note that we do this regardless of how many dots were in the 2234 * name or whether it ends with a dot. 2235 */ 2236 if (!tried_as_is) { 2237 ret = res_querydomainN(name, NULL, target, res); 2238 if (ret > 0) 2239 return ret; 2240 } 2241 2242 /* 2243 * if we got here, we didn't satisfy the search. 2244 * if we did an initial full query, return that query's h_errno 2245 * (note that we wouldn't be here if that query had succeeded). 2246 * else if we ever got a nodata, send that back as the reason. 2247 * else send back meaningless h_errno, that being the one from 2248 * the last DNSRCH we did. 2249 */ 2250 if (saved_herrno != -1) 2251 h_errno = saved_herrno; 2252 else if (got_nodata) 2253 h_errno = NO_DATA; 2254 else if (got_servfail) 2255 h_errno = TRY_AGAIN; 2256 return -1; 2257 } 2258 2259 /* 2260 * Perform a call on res_query on the concatenation of name and domain, 2261 * removing a trailing dot from name if domain is NULL. 2262 */ 2263 static int 2264 res_querydomainN(const char *name, const char *domain, 2265 struct res_target *target, res_state res) 2266 { 2267 char nbuf[MAXDNAME]; 2268 const char *longname = nbuf; 2269 size_t n, d; 2270 2271 _DIAGASSERT(name != NULL); 2272 /* XXX: target may be NULL??? */ 2273 2274 #ifdef DEBUG 2275 if (res->options & RES_DEBUG) 2276 printf(";; res_querydomain(%s, %s)\n", 2277 name, domain?domain:"<Nil>"); 2278 #endif 2279 if (domain == NULL) { 2280 /* 2281 * Check for trailing '.'; 2282 * copy without '.' if present. 2283 */ 2284 n = strlen(name); 2285 if (n + 1 > sizeof(nbuf)) { 2286 h_errno = NO_RECOVERY; 2287 return -1; 2288 } 2289 if (n > 0 && name[--n] == '.') { 2290 strncpy(nbuf, name, n); 2291 nbuf[n] = '\0'; 2292 } else 2293 longname = name; 2294 } else { 2295 n = strlen(name); 2296 d = strlen(domain); 2297 if (n + 1 + d + 1 > sizeof(nbuf)) { 2298 h_errno = NO_RECOVERY; 2299 return -1; 2300 } 2301 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2302 } 2303 return res_queryN(longname, target, res); 2304 } 2305 2306 #ifdef TEST 2307 int 2308 main(int argc, char *argv[]) { 2309 struct addrinfo *ai, *sai; 2310 int i, e; 2311 char buf[1024]; 2312 2313 for (i = 1; i < argc; i++) { 2314 if ((e = getaddrinfo(argv[i], NULL, NULL, &sai)) != 0) 2315 warnx("%s: %s", argv[i], gai_strerror(e)); 2316 for (ai = sai; ai; ai = ai->ai_next) { 2317 sockaddr_snprintf(buf, sizeof(buf), "%a", ai->ai_addr); 2318 printf("flags=0x%x family=%d socktype=%d protocol=%d " 2319 "addrlen=%zu addr=%s canonname=%s next=%p\n", 2320 ai->ai_flags, 2321 ai->ai_family, 2322 ai->ai_socktype, 2323 ai->ai_protocol, 2324 (size_t)ai->ai_addrlen, 2325 buf, 2326 ai->ai_canonname, 2327 ai->ai_next); 2328 } 2329 if (sai) 2330 freeaddrinfo(sai); 2331 } 2332 return 0; 2333 } 2334 #endif 2335