1 /* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * Issues to be discussed: 34 * - Return values. There are nonstandard return values defined and used 35 * in the source code. This is because RFC2553 is silent about which error 36 * code must be returned for which situation. 37 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 38 * invalid. current code - SEGV on freeaddrinfo(NULL) 39 * 40 * Note: 41 * - The code filters out AFs that are not supported by the kernel, 42 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 43 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 44 * in ai_flags? 45 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 46 * (1) what should we do against numeric hostname (2) what should we do 47 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 48 * non-loopback address configured? global address configured? 49 * 50 * OS specific notes for freebsd4: 51 * - FreeBSD supported $GAI. The code does not. 52 */ 53 54 #include <sys/cdefs.h> 55 __FBSDID("$FreeBSD$"); 56 57 #include "namespace.h" 58 #include <sys/types.h> 59 #include <sys/param.h> 60 #include <sys/socket.h> 61 #include <net/if.h> 62 #include <netinet/in.h> 63 #include <net/if_types.h> 64 #include <ifaddrs.h> 65 #include <sys/queue.h> 66 #ifdef INET6 67 #include <sys/sysctl.h> 68 #include <sys/ioctl.h> 69 #include <netinet6/in6_var.h> 70 #include <netinet6/nd6.h> 71 #endif 72 #include <arpa/inet.h> 73 #include <arpa/nameser.h> 74 #include <rpc/rpc.h> 75 #include <rpcsvc/yp_prot.h> 76 #include <rpcsvc/ypclnt.h> 77 #include <netdb.h> 78 #include <resolv.h> 79 #include <string.h> 80 #include <stdlib.h> 81 #include <stddef.h> 82 #include <ctype.h> 83 #include <unistd.h> 84 #include <stdio.h> 85 #include <errno.h> 86 87 #include "res_config.h" 88 89 #ifdef DEBUG 90 #include <syslog.h> 91 #endif 92 93 #include <stdarg.h> 94 #include <nsswitch.h> 95 #include "un-namespace.h" 96 #include "libc_private.h" 97 #ifdef NS_CACHING 98 #include "nscache.h" 99 #endif 100 101 #define ANY 0 102 #define YES 1 103 #define NO 0 104 105 static const char in_addrany[] = { 0, 0, 0, 0 }; 106 static const char in_loopback[] = { 127, 0, 0, 1 }; 107 #ifdef INET6 108 static const char in6_addrany[] = { 109 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 110 }; 111 static const char in6_loopback[] = { 112 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 113 }; 114 #endif 115 116 struct policyqueue { 117 TAILQ_ENTRY(policyqueue) pc_entry; 118 #ifdef INET6 119 struct in6_addrpolicy pc_policy; 120 #endif 121 }; 122 TAILQ_HEAD(policyhead, policyqueue); 123 124 static const struct afd { 125 int a_af; 126 int a_addrlen; 127 socklen_t a_socklen; 128 int a_off; 129 const char *a_addrany; 130 const char *a_loopback; 131 int a_scoped; 132 } afdl [] = { 133 #ifdef INET6 134 #define N_INET6 0 135 {PF_INET6, sizeof(struct in6_addr), 136 sizeof(struct sockaddr_in6), 137 offsetof(struct sockaddr_in6, sin6_addr), 138 in6_addrany, in6_loopback, 1}, 139 #define N_INET 1 140 #define N_LOCAL 2 141 #else 142 #define N_INET 0 143 #define N_LOCAL 1 144 #endif 145 {PF_INET, sizeof(struct in_addr), 146 sizeof(struct sockaddr_in), 147 offsetof(struct sockaddr_in, sin_addr), 148 in_addrany, in_loopback, 0}, 149 #define sizeofmember(type, member) (sizeof(((type *)0)->member)) 150 {PF_LOCAL, sizeofmember(struct sockaddr_un, sun_path), 151 sizeof(struct sockaddr_un), 152 offsetof(struct sockaddr_un, sun_path), 153 NULL, NULL, 0}, 154 {0, 0, 0, 0, NULL, NULL, 0}, 155 }; 156 157 struct explore { 158 int e_af; 159 int e_socktype; 160 int e_protocol; 161 int e_wild; 162 #define AF_ANY 0x01 163 #define SOCKTYPE_ANY 0x02 164 #define PROTOCOL_ANY 0x04 165 #define WILD_AF(ex) ((ex)->e_wild & AF_ANY) 166 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & SOCKTYPE_ANY) 167 #define WILD_PROTOCOL(ex) ((ex)->e_wild & PROTOCOL_ANY) 168 }; 169 170 static const struct explore explore[] = { 171 #ifdef INET6 172 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 173 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 174 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, 175 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 176 { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 177 AF_ANY | SOCKTYPE_ANY }, 178 { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 179 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 180 { PF_INET6, SOCK_DGRAM, IPPROTO_UDPLITE, 181 AF_ANY | SOCKTYPE_ANY }, 182 { PF_INET6, SOCK_RAW, ANY, 183 AF_ANY | PROTOCOL_ANY }, 184 #endif 185 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, 186 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 187 { PF_INET, SOCK_STREAM, IPPROTO_TCP, 188 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 189 { PF_INET, SOCK_STREAM, IPPROTO_SCTP, 190 AF_ANY | SOCKTYPE_ANY }, 191 { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 192 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 193 { PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE, 194 AF_ANY | SOCKTYPE_ANY }, 195 { PF_INET, SOCK_RAW, ANY, 196 AF_ANY | PROTOCOL_ANY }, 197 { PF_LOCAL, SOCK_DGRAM, ANY, 198 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 199 { PF_LOCAL, SOCK_STREAM, ANY, 200 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 201 { PF_LOCAL, SOCK_SEQPACKET, ANY, 202 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 203 { -1, 0, 0, 0 }, 204 }; 205 206 #ifdef INET6 207 #define PTON_MAX 16 208 #else 209 #define PTON_MAX 4 210 #endif 211 212 #define AIO_SRCFLAG_DEPRECATED 0x1 213 214 struct ai_order { 215 union { 216 struct sockaddr_storage aiou_ss; 217 struct sockaddr aiou_sa; 218 } aio_src_un; 219 #define aio_srcsa aio_src_un.aiou_sa 220 u_int32_t aio_srcflag; 221 int aio_srcscope; 222 int aio_dstscope; 223 struct policyqueue *aio_srcpolicy; 224 struct policyqueue *aio_dstpolicy; 225 struct addrinfo *aio_ai; 226 int aio_matchlen; 227 }; 228 229 static const ns_src default_dns_files[] = { 230 { NSSRC_FILES, NS_SUCCESS }, 231 { NSSRC_DNS, NS_SUCCESS }, 232 { 0 } 233 }; 234 235 struct res_target { 236 struct res_target *next; 237 const char *name; /* domain name */ 238 int qclass, qtype; /* class and type of query */ 239 u_char *answer; /* buffer to put answer */ 240 int anslen; /* size of answer buffer */ 241 int n; /* result length */ 242 }; 243 244 #define MAXPACKET (64*1024) 245 246 typedef union { 247 HEADER hdr; 248 u_char buf[MAXPACKET]; 249 } querybuf; 250 251 static int str2number(const char *, int *); 252 static int explore_copy(const struct addrinfo *, const struct addrinfo *, 253 struct addrinfo **); 254 static int explore_null(const struct addrinfo *, 255 const char *, struct addrinfo **); 256 static int explore_numeric(const struct addrinfo *, const char *, 257 const char *, struct addrinfo **, const char *); 258 static int explore_numeric_scope(const struct addrinfo *, const char *, 259 const char *, struct addrinfo **); 260 static int get_canonname(const struct addrinfo *, 261 struct addrinfo *, const char *); 262 static struct addrinfo *get_ai(const struct addrinfo *, 263 const struct afd *, const char *); 264 static struct addrinfo *copy_ai(const struct addrinfo *); 265 static int get_portmatch(const struct addrinfo *, const char *); 266 static int get_port(struct addrinfo *, const char *, int); 267 static const struct afd *find_afd(int); 268 static int addrconfig(struct addrinfo *); 269 #ifdef INET6 270 static int is_ifdisabled(char *); 271 #endif 272 static void set_source(struct ai_order *, struct policyhead *); 273 static int comp_dst(const void *, const void *); 274 #ifdef INET6 275 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 276 #endif 277 static int gai_addr2scopetype(struct sockaddr *); 278 279 static int explore_fqdn(const struct addrinfo *, const char *, 280 const char *, struct addrinfo **); 281 282 static int reorder(struct addrinfo *); 283 static int get_addrselectpolicy(struct policyhead *); 284 static void free_addrselectpolicy(struct policyhead *); 285 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 286 struct policyhead *); 287 static int matchlen(struct sockaddr *, struct sockaddr *); 288 289 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 290 const struct addrinfo *, res_state); 291 #if defined(RESOLVSORT) 292 static int addr4sort(struct addrinfo *, res_state); 293 #endif 294 static int _dns_getaddrinfo(void *, void *, va_list); 295 static void _sethtent(FILE **); 296 static void _endhtent(FILE **); 297 static struct addrinfo *_gethtent(FILE **, const char *, 298 const struct addrinfo *); 299 static int _files_getaddrinfo(void *, void *, va_list); 300 #ifdef YP 301 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 302 static int _yp_getaddrinfo(void *, void *, va_list); 303 #endif 304 #ifdef NS_CACHING 305 static int addrinfo_id_func(char *, size_t *, va_list, void *); 306 static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 307 static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 308 #endif 309 310 static int res_queryN(const char *, struct res_target *, res_state); 311 static int res_searchN(const char *, struct res_target *, res_state); 312 static int res_querydomainN(const char *, const char *, 313 struct res_target *, res_state); 314 315 /* XXX macros that make external reference is BAD. */ 316 317 #define GET_AI(ai, afd, addr) \ 318 do { \ 319 /* external reference: pai, error, and label free */ \ 320 (ai) = get_ai(pai, (afd), (addr)); \ 321 if ((ai) == NULL) { \ 322 error = EAI_MEMORY; \ 323 goto free; \ 324 } \ 325 } while (/*CONSTCOND*/0) 326 327 #define GET_PORT(ai, serv) \ 328 do { \ 329 /* external reference: error and label free */ \ 330 error = get_port((ai), (serv), 0); \ 331 if (error != 0) \ 332 goto free; \ 333 } while (/*CONSTCOND*/0) 334 335 #define GET_CANONNAME(ai, str) \ 336 do { \ 337 /* external reference: pai, error and label free */ \ 338 error = get_canonname(pai, (ai), (str)); \ 339 if (error != 0) \ 340 goto free; \ 341 } while (/*CONSTCOND*/0) 342 343 #define ERR(err) \ 344 do { \ 345 /* external reference: error, and label bad */ \ 346 error = (err); \ 347 goto bad; \ 348 /*NOTREACHED*/ \ 349 } while (/*CONSTCOND*/0) 350 351 #define MATCH_FAMILY(x, y, w) \ 352 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 353 #define MATCH(x, y, w) \ 354 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 355 356 void 357 freeaddrinfo(struct addrinfo *ai) 358 { 359 struct addrinfo *next; 360 361 do { 362 next = ai->ai_next; 363 if (ai->ai_canonname) 364 free(ai->ai_canonname); 365 /* no need to free(ai->ai_addr) */ 366 free(ai); 367 ai = next; 368 } while (ai); 369 } 370 371 static int 372 str2number(const char *p, int *portp) 373 { 374 char *ep; 375 unsigned long v; 376 377 if (*p == '\0') 378 return -1; 379 ep = NULL; 380 errno = 0; 381 v = strtoul(p, &ep, 10); 382 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 383 *portp = v; 384 return 0; 385 } else 386 return -1; 387 } 388 389 int 390 getaddrinfo(const char *hostname, const char *servname, 391 const struct addrinfo *hints, struct addrinfo **res) 392 { 393 struct addrinfo sentinel; 394 struct addrinfo *cur; 395 int error = 0; 396 struct addrinfo ai, ai0, *afai; 397 struct addrinfo *pai; 398 const struct afd *afd; 399 const struct explore *ex; 400 struct addrinfo *afailist[sizeof(afdl)/sizeof(afdl[0])]; 401 struct addrinfo *afai_unspec; 402 int found; 403 int numeric = 0; 404 405 /* ensure we return NULL on errors */ 406 *res = NULL; 407 408 memset(&ai, 0, sizeof(ai)); 409 410 memset(afailist, 0, sizeof(afailist)); 411 afai_unspec = NULL; 412 413 memset(&sentinel, 0, sizeof(sentinel)); 414 cur = &sentinel; 415 pai = &ai; 416 pai->ai_flags = 0; 417 pai->ai_family = PF_UNSPEC; 418 pai->ai_socktype = ANY; 419 pai->ai_protocol = ANY; 420 pai->ai_addrlen = 0; 421 pai->ai_canonname = NULL; 422 pai->ai_addr = NULL; 423 pai->ai_next = NULL; 424 425 if (hostname == NULL && servname == NULL) 426 return EAI_NONAME; 427 if (hints) { 428 /* error check for hints */ 429 if (hints->ai_addrlen || hints->ai_canonname || 430 hints->ai_addr || hints->ai_next) 431 ERR(EAI_BADHINTS); /* xxx */ 432 if (hints->ai_flags & ~AI_MASK) 433 ERR(EAI_BADFLAGS); 434 switch (hints->ai_family) { 435 case PF_UNSPEC: 436 case PF_LOCAL: 437 case PF_INET: 438 #ifdef INET6 439 case PF_INET6: 440 #endif 441 break; 442 default: 443 ERR(EAI_FAMILY); 444 } 445 memcpy(pai, hints, sizeof(*pai)); 446 447 /* 448 * if both socktype/protocol are specified, check if they 449 * are meaningful combination. 450 */ 451 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 452 for (ex = explore; ex->e_af >= 0; ex++) { 453 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 454 WILD_AF(ex))) 455 continue; 456 if (!MATCH(pai->ai_socktype, ex->e_socktype, 457 WILD_SOCKTYPE(ex))) 458 continue; 459 if (!MATCH(pai->ai_protocol, ex->e_protocol, 460 WILD_PROTOCOL(ex))) 461 continue; 462 463 /* matched */ 464 break; 465 } 466 467 if (ex->e_af < 0) 468 ERR(EAI_BADHINTS); 469 } 470 } 471 472 /* 473 * check for special cases. (1) numeric servname is disallowed if 474 * socktype/protocol are left unspecified. (2) servname is disallowed 475 * for raw and other inet{,6} sockets. 476 */ 477 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 478 #ifdef PF_INET6 479 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 480 #endif 481 ) { 482 ai0 = *pai; /* backup *pai */ 483 484 if (pai->ai_family == PF_UNSPEC) { 485 #ifdef PF_INET6 486 pai->ai_family = PF_INET6; 487 #else 488 pai->ai_family = PF_INET; 489 #endif 490 } 491 error = get_portmatch(pai, servname); 492 if (error) 493 goto bad; 494 495 *pai = ai0; 496 } 497 498 ai0 = *pai; 499 500 /* 501 * NULL hostname, or numeric hostname. 502 * If numeric representation of AF1 can be interpreted as FQDN 503 * representation of AF2, we need to think again about the code below. 504 */ 505 found = 0; 506 for (afd = afdl; afd->a_af; afd++) { 507 *pai = ai0; 508 509 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 510 continue; 511 512 if (pai->ai_family == PF_UNSPEC) 513 pai->ai_family = afd->a_af; 514 515 if (hostname == NULL) { 516 error = explore_null(pai, servname, 517 &afailist[afd - afdl]); 518 519 /* 520 * Errors from explore_null should be unexpected and 521 * be caught to avoid returning an incomplete result. 522 */ 523 if (error != 0) 524 goto bad; 525 } else { 526 error = explore_numeric_scope(pai, hostname, servname, 527 &afailist[afd - afdl]); 528 529 /* 530 * explore_numeric_scope returns an error for address 531 * families that do not match that of hostname. 532 * Thus we should not catch the error at this moment. 533 */ 534 } 535 536 if (!error && afailist[afd - afdl]) 537 found++; 538 } 539 if (found) { 540 numeric = 1; 541 goto globcopy; 542 } 543 544 if (hostname == NULL) 545 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 546 if (pai->ai_flags & AI_NUMERICHOST) 547 ERR(EAI_NONAME); 548 549 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 550 ERR(EAI_FAIL); 551 552 /* 553 * hostname as alphabetical name. 554 */ 555 *pai = ai0; 556 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 557 558 globcopy: 559 for (ex = explore; ex->e_af >= 0; ex++) { 560 *pai = ai0; 561 562 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 563 continue; 564 if (!MATCH(pai->ai_socktype, ex->e_socktype, 565 WILD_SOCKTYPE(ex))) 566 continue; 567 if (!MATCH(pai->ai_protocol, ex->e_protocol, 568 WILD_PROTOCOL(ex))) 569 continue; 570 571 if (pai->ai_family == PF_UNSPEC) 572 pai->ai_family = ex->e_af; 573 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 574 pai->ai_socktype = ex->e_socktype; 575 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 576 pai->ai_protocol = ex->e_protocol; 577 578 /* 579 * if the servname does not match socktype/protocol, ignore it. 580 */ 581 if (get_portmatch(pai, servname) != 0) 582 continue; 583 584 if (afai_unspec) 585 afai = afai_unspec; 586 else { 587 if ((afd = find_afd(pai->ai_family)) == NULL) 588 continue; 589 /* XXX assumes that afd points inside afdl[] */ 590 afai = afailist[afd - afdl]; 591 } 592 if (!afai) 593 continue; 594 595 error = explore_copy(pai, afai, &cur->ai_next); 596 if (error != 0) 597 goto bad; 598 599 while (cur && cur->ai_next) 600 cur = cur->ai_next; 601 } 602 603 /* 604 * ensure we return either: 605 * - error == 0, non-NULL *res 606 * - error != 0, NULL *res 607 */ 608 if (error == 0) { 609 if (sentinel.ai_next) { 610 /* 611 * If the returned entry is for an active connection, 612 * and the given name is not numeric, reorder the 613 * list, so that the application would try the list 614 * in the most efficient order. Since the head entry 615 * of the original list may contain ai_canonname and 616 * that entry may be moved elsewhere in the new list, 617 * we keep the pointer and will restore it in the new 618 * head entry. (Note that RFC3493 requires the head 619 * entry store it when requested by the caller). 620 */ 621 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 622 if (!numeric) { 623 char *canonname; 624 625 canonname = 626 sentinel.ai_next->ai_canonname; 627 sentinel.ai_next->ai_canonname = NULL; 628 (void)reorder(&sentinel); 629 if (sentinel.ai_next->ai_canonname == 630 NULL) { 631 sentinel.ai_next->ai_canonname 632 = canonname; 633 } else if (canonname != NULL) 634 free(canonname); 635 } 636 } 637 *res = sentinel.ai_next; 638 } else 639 error = EAI_FAIL; 640 } 641 642 bad: 643 if (afai_unspec) 644 freeaddrinfo(afai_unspec); 645 for (afd = afdl; afd->a_af; afd++) { 646 if (afailist[afd - afdl]) 647 freeaddrinfo(afailist[afd - afdl]); 648 } 649 if (!*res) 650 if (sentinel.ai_next) 651 freeaddrinfo(sentinel.ai_next); 652 653 return (error); 654 } 655 656 static int 657 reorder(struct addrinfo *sentinel) 658 { 659 struct addrinfo *ai, **aip; 660 struct ai_order *aio; 661 int i, n; 662 struct policyhead policyhead; 663 664 /* count the number of addrinfo elements for sorting. */ 665 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 666 ; 667 668 /* 669 * If the number is small enough, we can skip the reordering process. 670 */ 671 if (n <= 1) 672 return(n); 673 674 /* allocate a temporary array for sort and initialization of it. */ 675 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 676 return(n); /* give up reordering */ 677 memset(aio, 0, sizeof(*aio) * n); 678 679 /* retrieve address selection policy from the kernel */ 680 TAILQ_INIT(&policyhead); 681 if (!get_addrselectpolicy(&policyhead)) { 682 /* no policy is installed into kernel, we don't sort. */ 683 free(aio); 684 return (n); 685 } 686 687 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 688 aio[i].aio_ai = ai; 689 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 690 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 691 &policyhead); 692 set_source(&aio[i], &policyhead); 693 } 694 695 /* perform sorting. */ 696 qsort(aio, n, sizeof(*aio), comp_dst); 697 698 /* reorder the addrinfo chain. */ 699 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 700 *aip = aio[i].aio_ai; 701 aip = &aio[i].aio_ai->ai_next; 702 } 703 *aip = NULL; 704 705 /* cleanup and return */ 706 free(aio); 707 free_addrselectpolicy(&policyhead); 708 return(n); 709 } 710 711 static int 712 get_addrselectpolicy(struct policyhead *head) 713 { 714 #ifdef INET6 715 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 716 size_t l; 717 char *buf; 718 struct in6_addrpolicy *pol, *ep; 719 720 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 721 return (0); 722 if (l == 0) 723 return (0); 724 if ((buf = malloc(l)) == NULL) 725 return (0); 726 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 727 free(buf); 728 return (0); 729 } 730 731 ep = (struct in6_addrpolicy *)(buf + l); 732 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 733 struct policyqueue *new; 734 735 if ((new = malloc(sizeof(*new))) == NULL) { 736 free_addrselectpolicy(head); /* make the list empty */ 737 break; 738 } 739 new->pc_policy = *pol; 740 TAILQ_INSERT_TAIL(head, new, pc_entry); 741 } 742 743 free(buf); 744 return (1); 745 #else 746 return (0); 747 #endif 748 } 749 750 static void 751 free_addrselectpolicy(struct policyhead *head) 752 { 753 struct policyqueue *ent, *nent; 754 755 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 756 nent = TAILQ_NEXT(ent, pc_entry); 757 TAILQ_REMOVE(head, ent, pc_entry); 758 free(ent); 759 } 760 } 761 762 static struct policyqueue * 763 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 764 { 765 #ifdef INET6 766 struct policyqueue *ent, *bestent = NULL; 767 struct in6_addrpolicy *pol; 768 int matchlen, bestmatchlen = -1; 769 u_char *mp, *ep, *k, *p, m; 770 struct sockaddr_in6 key; 771 772 switch(addr->sa_family) { 773 case AF_INET6: 774 key = *(struct sockaddr_in6 *)addr; 775 break; 776 case AF_INET: 777 /* convert the address into IPv4-mapped IPv6 address. */ 778 memset(&key, 0, sizeof(key)); 779 key.sin6_family = AF_INET6; 780 key.sin6_len = sizeof(key); 781 key.sin6_addr.s6_addr[10] = 0xff; 782 key.sin6_addr.s6_addr[11] = 0xff; 783 memcpy(&key.sin6_addr.s6_addr[12], 784 &((struct sockaddr_in *)addr)->sin_addr, 4); 785 break; 786 default: 787 return(NULL); 788 } 789 790 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 791 pol = &ent->pc_policy; 792 matchlen = 0; 793 794 mp = (u_char *)&pol->addrmask.sin6_addr; 795 ep = mp + 16; /* XXX: scope field? */ 796 k = (u_char *)&key.sin6_addr; 797 p = (u_char *)&pol->addr.sin6_addr; 798 for (; mp < ep && *mp; mp++, k++, p++) { 799 m = *mp; 800 if ((*k & m) != *p) 801 goto next; /* not match */ 802 if (m == 0xff) /* short cut for a typical case */ 803 matchlen += 8; 804 else { 805 while (m >= 0x80) { 806 matchlen++; 807 m <<= 1; 808 } 809 } 810 } 811 812 /* matched. check if this is better than the current best. */ 813 if (matchlen > bestmatchlen) { 814 bestent = ent; 815 bestmatchlen = matchlen; 816 } 817 818 next: 819 continue; 820 } 821 822 return(bestent); 823 #else 824 return(NULL); 825 #endif 826 827 } 828 829 static void 830 set_source(struct ai_order *aio, struct policyhead *ph) 831 { 832 struct addrinfo ai = *aio->aio_ai; 833 struct sockaddr_storage ss; 834 socklen_t srclen; 835 int s; 836 837 /* set unspec ("no source is available"), just in case */ 838 aio->aio_srcsa.sa_family = AF_UNSPEC; 839 aio->aio_srcscope = -1; 840 841 switch(ai.ai_family) { 842 case AF_INET: 843 #ifdef INET6 844 case AF_INET6: 845 #endif 846 break; 847 default: /* ignore unsupported AFs explicitly */ 848 return; 849 } 850 851 /* XXX: make a dummy addrinfo to call connect() */ 852 ai.ai_socktype = SOCK_DGRAM; 853 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 854 ai.ai_next = NULL; 855 memset(&ss, 0, sizeof(ss)); 856 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 857 ai.ai_addr = (struct sockaddr *)&ss; 858 get_port(&ai, "1", 0); 859 860 /* open a socket to get the source address for the given dst */ 861 if ((s = _socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC, 862 ai.ai_protocol)) < 0) 863 return; /* give up */ 864 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 865 goto cleanup; 866 srclen = ai.ai_addrlen; 867 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 868 aio->aio_srcsa.sa_family = AF_UNSPEC; 869 goto cleanup; 870 } 871 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 872 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 873 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 874 #ifdef INET6 875 if (ai.ai_family == AF_INET6) { 876 struct in6_ifreq ifr6; 877 u_int32_t flags6; 878 879 memset(&ifr6, 0, sizeof(ifr6)); 880 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 881 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 882 flags6 = ifr6.ifr_ifru.ifru_flags6; 883 if ((flags6 & IN6_IFF_DEPRECATED)) 884 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 885 } 886 } 887 #endif 888 889 cleanup: 890 _close(s); 891 return; 892 } 893 894 static int 895 matchlen(struct sockaddr *src, struct sockaddr *dst) 896 { 897 int match = 0; 898 u_char *s, *d; 899 u_char *lim, r; 900 int addrlen; 901 902 switch (src->sa_family) { 903 #ifdef INET6 904 case AF_INET6: 905 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 906 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 907 addrlen = sizeof(struct in6_addr); 908 lim = s + addrlen; 909 break; 910 #endif 911 case AF_INET: 912 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 913 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 914 addrlen = sizeof(struct in_addr); 915 lim = s + addrlen; 916 break; 917 default: 918 return(0); 919 } 920 921 while (s < lim) 922 if ((r = (*d++ ^ *s++)) != 0) { 923 while (r < addrlen * 8) { 924 match++; 925 r <<= 1; 926 } 927 break; 928 } else 929 match += 8; 930 return(match); 931 } 932 933 static int 934 comp_dst(const void *arg1, const void *arg2) 935 { 936 const struct ai_order *dst1 = arg1, *dst2 = arg2; 937 938 /* 939 * Rule 1: Avoid unusable destinations. 940 * XXX: we currently do not consider if an appropriate route exists. 941 */ 942 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 943 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 944 return(-1); 945 } 946 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 947 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 948 return(1); 949 } 950 951 /* Rule 2: Prefer matching scope. */ 952 if (dst1->aio_dstscope == dst1->aio_srcscope && 953 dst2->aio_dstscope != dst2->aio_srcscope) { 954 return(-1); 955 } 956 if (dst1->aio_dstscope != dst1->aio_srcscope && 957 dst2->aio_dstscope == dst2->aio_srcscope) { 958 return(1); 959 } 960 961 /* Rule 3: Avoid deprecated addresses. */ 962 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 963 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 964 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 965 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 966 return(-1); 967 } 968 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 969 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 970 return(1); 971 } 972 } 973 974 /* Rule 4: Prefer home addresses. */ 975 /* XXX: not implemented yet */ 976 977 /* Rule 5: Prefer matching label. */ 978 #ifdef INET6 979 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 980 dst1->aio_srcpolicy->pc_policy.label == 981 dst1->aio_dstpolicy->pc_policy.label && 982 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 983 dst2->aio_srcpolicy->pc_policy.label != 984 dst2->aio_dstpolicy->pc_policy.label)) { 985 return(-1); 986 } 987 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 988 dst2->aio_srcpolicy->pc_policy.label == 989 dst2->aio_dstpolicy->pc_policy.label && 990 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 991 dst1->aio_srcpolicy->pc_policy.label != 992 dst1->aio_dstpolicy->pc_policy.label)) { 993 return(1); 994 } 995 #endif 996 997 /* Rule 6: Prefer higher precedence. */ 998 #ifdef INET6 999 if (dst1->aio_dstpolicy && 1000 (dst2->aio_dstpolicy == NULL || 1001 dst1->aio_dstpolicy->pc_policy.preced > 1002 dst2->aio_dstpolicy->pc_policy.preced)) { 1003 return(-1); 1004 } 1005 if (dst2->aio_dstpolicy && 1006 (dst1->aio_dstpolicy == NULL || 1007 dst2->aio_dstpolicy->pc_policy.preced > 1008 dst1->aio_dstpolicy->pc_policy.preced)) { 1009 return(1); 1010 } 1011 #endif 1012 1013 /* Rule 7: Prefer native transport. */ 1014 /* XXX: not implemented yet */ 1015 1016 /* Rule 8: Prefer smaller scope. */ 1017 if (dst1->aio_dstscope >= 0 && 1018 dst1->aio_dstscope < dst2->aio_dstscope) { 1019 return(-1); 1020 } 1021 if (dst2->aio_dstscope >= 0 && 1022 dst2->aio_dstscope < dst1->aio_dstscope) { 1023 return(1); 1024 } 1025 1026 /* 1027 * Rule 9: Use longest matching prefix. 1028 * We compare the match length in a same AF only. 1029 */ 1030 if (dst1->aio_ai->ai_addr->sa_family == 1031 dst2->aio_ai->ai_addr->sa_family && 1032 dst1->aio_ai->ai_addr->sa_family != AF_INET) { 1033 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1034 return(-1); 1035 } 1036 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1037 return(1); 1038 } 1039 } 1040 1041 /* Rule 10: Otherwise, leave the order unchanged. */ 1042 return(-1); 1043 } 1044 1045 /* 1046 * Copy from scope.c. 1047 * XXX: we should standardize the functions and link them as standard 1048 * library. 1049 */ 1050 static int 1051 gai_addr2scopetype(struct sockaddr *sa) 1052 { 1053 #ifdef INET6 1054 struct sockaddr_in6 *sa6; 1055 #endif 1056 struct sockaddr_in *sa4; 1057 1058 switch(sa->sa_family) { 1059 #ifdef INET6 1060 case AF_INET6: 1061 sa6 = (struct sockaddr_in6 *)sa; 1062 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1063 /* just use the scope field of the multicast address */ 1064 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1065 } 1066 /* 1067 * Unicast addresses: map scope type to corresponding scope 1068 * value defined for multcast addresses. 1069 * XXX: hardcoded scope type values are bad... 1070 */ 1071 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1072 return(1); /* node local scope */ 1073 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1074 return(2); /* link-local scope */ 1075 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1076 return(5); /* site-local scope */ 1077 return(14); /* global scope */ 1078 break; 1079 #endif 1080 case AF_INET: 1081 /* 1082 * IPv4 pseudo scoping according to RFC 3484. 1083 */ 1084 sa4 = (struct sockaddr_in *)sa; 1085 /* IPv4 autoconfiguration addresses have link-local scope. */ 1086 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1087 ((u_char *)&sa4->sin_addr)[1] == 254) 1088 return(2); 1089 /* Private addresses have site-local scope. */ 1090 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1091 (((u_char *)&sa4->sin_addr)[0] == 172 && 1092 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1093 (((u_char *)&sa4->sin_addr)[0] == 192 && 1094 ((u_char *)&sa4->sin_addr)[1] == 168)) 1095 return(14); /* XXX: It should be 5 unless NAT */ 1096 /* Loopback addresses have link-local scope. */ 1097 if (((u_char *)&sa4->sin_addr)[0] == 127) 1098 return(2); 1099 return(14); 1100 break; 1101 default: 1102 errno = EAFNOSUPPORT; /* is this a good error? */ 1103 return(-1); 1104 } 1105 } 1106 1107 static int 1108 explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1109 struct addrinfo **res) 1110 { 1111 int error; 1112 struct addrinfo sentinel, *cur; 1113 const struct addrinfo *src; 1114 1115 error = 0; 1116 sentinel.ai_next = NULL; 1117 cur = &sentinel; 1118 1119 for (src = src0; src != NULL; src = src->ai_next) { 1120 if (src->ai_family != pai->ai_family) 1121 continue; 1122 1123 cur->ai_next = copy_ai(src); 1124 if (!cur->ai_next) { 1125 error = EAI_MEMORY; 1126 goto fail; 1127 } 1128 1129 cur->ai_next->ai_socktype = pai->ai_socktype; 1130 cur->ai_next->ai_protocol = pai->ai_protocol; 1131 cur = cur->ai_next; 1132 } 1133 1134 *res = sentinel.ai_next; 1135 return 0; 1136 1137 fail: 1138 freeaddrinfo(sentinel.ai_next); 1139 return error; 1140 } 1141 1142 /* 1143 * hostname == NULL. 1144 * passive socket -> anyaddr (0.0.0.0 or ::) 1145 * non-passive socket -> localhost (127.0.0.1 or ::1) 1146 */ 1147 static int 1148 explore_null(const struct addrinfo *pai, const char *servname, 1149 struct addrinfo **res) 1150 { 1151 int s; 1152 const struct afd *afd; 1153 struct addrinfo *ai; 1154 int error; 1155 1156 *res = NULL; 1157 ai = NULL; 1158 1159 if (pai->ai_family == PF_LOCAL) 1160 return (0); 1161 1162 /* 1163 * filter out AFs that are not supported by the kernel 1164 * XXX errno? 1165 */ 1166 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1167 if (s < 0) { 1168 if (errno != EMFILE) 1169 return 0; 1170 } else 1171 _close(s); 1172 1173 afd = find_afd(pai->ai_family); 1174 if (afd == NULL) 1175 return 0; 1176 1177 if (pai->ai_flags & AI_PASSIVE) { 1178 GET_AI(ai, afd, afd->a_addrany); 1179 GET_PORT(ai, servname); 1180 } else { 1181 GET_AI(ai, afd, afd->a_loopback); 1182 GET_PORT(ai, servname); 1183 } 1184 1185 *res = ai; 1186 return 0; 1187 1188 free: 1189 if (ai != NULL) 1190 freeaddrinfo(ai); 1191 return error; 1192 } 1193 1194 /* 1195 * numeric hostname 1196 */ 1197 static int 1198 explore_numeric(const struct addrinfo *pai, const char *hostname, 1199 const char *servname, struct addrinfo **res, const char *canonname) 1200 { 1201 const struct afd *afd; 1202 struct addrinfo *ai; 1203 int error; 1204 char pton[PTON_MAX], path[PATH_MAX], *p; 1205 1206 #ifdef CTASSERT 1207 CTASSERT(sizeofmember(struct sockaddr_un, sun_path) <= PATH_MAX); 1208 #endif 1209 *res = NULL; 1210 ai = NULL; 1211 1212 afd = find_afd(pai->ai_family); 1213 if (afd == NULL) 1214 return 0; 1215 1216 switch (afd->a_af) { 1217 case AF_LOCAL: 1218 if (hostname[0] != '/') 1219 ERR(EAI_NONAME); 1220 if (strlen(hostname) > afd->a_addrlen) 1221 ERR(EAI_MEMORY); 1222 /* NUL-termination does not need to be guaranteed. */ 1223 strncpy(path, hostname, afd->a_addrlen); 1224 p = &path[0]; 1225 break; 1226 case AF_INET: 1227 /* 1228 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1229 * that are accepted by inet_addr() and its family. The 1230 * accepted forms includes the "classful" one, which inet_pton 1231 * does not accept. So we need to separate the case for 1232 * AF_INET. 1233 */ 1234 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1235 return 0; 1236 p = pton; 1237 break; 1238 default: 1239 if (inet_pton(afd->a_af, hostname, pton) != 1) 1240 return 0; 1241 p = pton; 1242 break; 1243 } 1244 1245 if (pai->ai_family == afd->a_af) { 1246 GET_AI(ai, afd, p); 1247 GET_PORT(ai, servname); 1248 if ((pai->ai_family == AF_INET || 1249 pai->ai_family == AF_INET6) && 1250 (pai->ai_flags & AI_CANONNAME)) { 1251 /* 1252 * Set the numeric address itself as the canonical 1253 * name, based on a clarification in RFC3493. 1254 */ 1255 GET_CANONNAME(ai, canonname); 1256 } 1257 } else { 1258 /* 1259 * XXX: This should not happen since we already matched the AF 1260 * by find_afd. 1261 */ 1262 ERR(EAI_FAMILY); 1263 } 1264 1265 *res = ai; 1266 return 0; 1267 1268 free: 1269 bad: 1270 if (ai != NULL) 1271 freeaddrinfo(ai); 1272 return error; 1273 } 1274 1275 /* 1276 * numeric hostname with scope 1277 */ 1278 static int 1279 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1280 const char *servname, struct addrinfo **res) 1281 { 1282 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 1283 return explore_numeric(pai, hostname, servname, res, hostname); 1284 #else 1285 const struct afd *afd; 1286 struct addrinfo *cur; 1287 int error; 1288 char *cp, *hostname2 = NULL, *scope, *addr; 1289 struct sockaddr_in6 *sin6; 1290 1291 afd = find_afd(pai->ai_family); 1292 if (afd == NULL) 1293 return 0; 1294 1295 if (!afd->a_scoped) 1296 return explore_numeric(pai, hostname, servname, res, hostname); 1297 1298 cp = strchr(hostname, SCOPE_DELIMITER); 1299 if (cp == NULL) 1300 return explore_numeric(pai, hostname, servname, res, hostname); 1301 1302 /* 1303 * Handle special case of <scoped_address><delimiter><scope id> 1304 */ 1305 hostname2 = strdup(hostname); 1306 if (hostname2 == NULL) 1307 return EAI_MEMORY; 1308 /* terminate at the delimiter */ 1309 hostname2[cp - hostname] = '\0'; 1310 addr = hostname2; 1311 scope = cp + 1; 1312 1313 error = explore_numeric(pai, addr, servname, res, hostname); 1314 if (error == 0) { 1315 u_int32_t scopeid; 1316 1317 for (cur = *res; cur; cur = cur->ai_next) { 1318 if (cur->ai_family != AF_INET6) 1319 continue; 1320 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1321 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1322 free(hostname2); 1323 freeaddrinfo(*res); 1324 *res = NULL; 1325 return(EAI_NONAME); /* XXX: is return OK? */ 1326 } 1327 sin6->sin6_scope_id = scopeid; 1328 } 1329 } 1330 1331 free(hostname2); 1332 1333 if (error && *res) { 1334 freeaddrinfo(*res); 1335 *res = NULL; 1336 } 1337 return error; 1338 #endif 1339 } 1340 1341 static int 1342 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1343 { 1344 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1345 ai->ai_canonname = strdup(str); 1346 if (ai->ai_canonname == NULL) 1347 return EAI_MEMORY; 1348 } 1349 return 0; 1350 } 1351 1352 static struct addrinfo * 1353 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1354 { 1355 char *p; 1356 struct addrinfo *ai; 1357 1358 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1359 + (afd->a_socklen)); 1360 if (ai == NULL) 1361 return NULL; 1362 1363 memcpy(ai, pai, sizeof(struct addrinfo)); 1364 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1365 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1366 ai->ai_addr->sa_len = afd->a_socklen; 1367 ai->ai_addrlen = afd->a_socklen; 1368 if (ai->ai_family == PF_LOCAL) { 1369 size_t n = strnlen(addr, afd->a_addrlen); 1370 1371 ai->ai_addrlen -= afd->a_addrlen - n; 1372 ai->ai_addr->sa_len -= afd->a_addrlen - n; 1373 } 1374 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1375 p = (char *)(void *)(ai->ai_addr); 1376 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1377 return ai; 1378 } 1379 1380 /* XXX need to malloc() the same way we do from other functions! */ 1381 static struct addrinfo * 1382 copy_ai(const struct addrinfo *pai) 1383 { 1384 struct addrinfo *ai; 1385 size_t l; 1386 1387 l = sizeof(*ai) + pai->ai_addrlen; 1388 if ((ai = (struct addrinfo *)malloc(l)) == NULL) 1389 return NULL; 1390 memset(ai, 0, l); 1391 memcpy(ai, pai, sizeof(*ai)); 1392 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1393 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1394 1395 if (pai->ai_canonname) { 1396 l = strlen(pai->ai_canonname) + 1; 1397 if ((ai->ai_canonname = malloc(l)) == NULL) { 1398 free(ai); 1399 return NULL; 1400 } 1401 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1402 } else { 1403 /* just to make sure */ 1404 ai->ai_canonname = NULL; 1405 } 1406 1407 ai->ai_next = NULL; 1408 1409 return ai; 1410 } 1411 1412 static int 1413 get_portmatch(const struct addrinfo *ai, const char *servname) 1414 { 1415 1416 /* get_port does not touch first argument when matchonly == 1. */ 1417 /* LINTED const cast */ 1418 return get_port((struct addrinfo *)ai, servname, 1); 1419 } 1420 1421 static int 1422 get_port(struct addrinfo *ai, const char *servname, int matchonly) 1423 { 1424 const char *proto; 1425 struct servent *sp; 1426 int port, error; 1427 int allownumeric; 1428 1429 if (servname == NULL) 1430 return 0; 1431 switch (ai->ai_family) { 1432 case AF_LOCAL: 1433 /* AF_LOCAL ignores servname silently. */ 1434 return (0); 1435 case AF_INET: 1436 #ifdef AF_INET6 1437 case AF_INET6: 1438 #endif 1439 break; 1440 default: 1441 return 0; 1442 } 1443 1444 switch (ai->ai_socktype) { 1445 case SOCK_RAW: 1446 return EAI_SERVICE; 1447 case SOCK_DGRAM: 1448 case SOCK_STREAM: 1449 case SOCK_SEQPACKET: 1450 allownumeric = 1; 1451 break; 1452 case ANY: 1453 switch (ai->ai_family) { 1454 case AF_INET: 1455 #ifdef AF_INET6 1456 case AF_INET6: 1457 #endif 1458 allownumeric = 1; 1459 break; 1460 default: 1461 allownumeric = 0; 1462 break; 1463 } 1464 break; 1465 default: 1466 return EAI_SOCKTYPE; 1467 } 1468 1469 error = str2number(servname, &port); 1470 if (error == 0) { 1471 if (!allownumeric) 1472 return EAI_SERVICE; 1473 if (port < 0 || port > 65535) 1474 return EAI_SERVICE; 1475 port = htons(port); 1476 } else { 1477 if (ai->ai_flags & AI_NUMERICSERV) 1478 return EAI_NONAME; 1479 1480 switch (ai->ai_protocol) { 1481 case IPPROTO_UDP: 1482 proto = "udp"; 1483 break; 1484 case IPPROTO_TCP: 1485 proto = "tcp"; 1486 break; 1487 case IPPROTO_SCTP: 1488 proto = "sctp"; 1489 break; 1490 case IPPROTO_UDPLITE: 1491 proto = "udplite"; 1492 break; 1493 default: 1494 proto = NULL; 1495 break; 1496 } 1497 1498 if ((sp = getservbyname(servname, proto)) == NULL) 1499 return EAI_SERVICE; 1500 port = sp->s_port; 1501 } 1502 1503 if (!matchonly) { 1504 switch (ai->ai_family) { 1505 case AF_INET: 1506 ((struct sockaddr_in *)(void *) 1507 ai->ai_addr)->sin_port = port; 1508 break; 1509 #ifdef INET6 1510 case AF_INET6: 1511 ((struct sockaddr_in6 *)(void *) 1512 ai->ai_addr)->sin6_port = port; 1513 break; 1514 #endif 1515 } 1516 } 1517 1518 return 0; 1519 } 1520 1521 static const struct afd * 1522 find_afd(int af) 1523 { 1524 const struct afd *afd; 1525 1526 if (af == PF_UNSPEC) 1527 return NULL; 1528 for (afd = afdl; afd->a_af; afd++) { 1529 if (afd->a_af == af) 1530 return afd; 1531 } 1532 return NULL; 1533 } 1534 1535 /* 1536 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are 1537 * configured on the local system and correlates with pai->ai_family value. 1538 * If an address family is not configured on the system, it will not be 1539 * queried for. For this purpose, loopback addresses are not considered 1540 * configured addresses. 1541 * 1542 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1543 * _dns_getaddrinfo. 1544 */ 1545 static int 1546 addrconfig(struct addrinfo *pai) 1547 { 1548 struct ifaddrs *ifaddrs, *ifa; 1549 struct sockaddr_in *sin; 1550 #ifdef INET6 1551 struct sockaddr_in6 *sin6; 1552 #endif 1553 int seen_inet = 0, seen_inet6 = 0; 1554 1555 if (getifaddrs(&ifaddrs) != 0) 1556 return (0); 1557 1558 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1559 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1560 continue; 1561 switch (ifa->ifa_addr->sa_family) { 1562 case AF_INET: 1563 if (seen_inet) 1564 continue; 1565 sin = (struct sockaddr_in *)(ifa->ifa_addr); 1566 if (IN_LOOPBACK(htonl(sin->sin_addr.s_addr))) 1567 continue; 1568 seen_inet = 1; 1569 break; 1570 #ifdef INET6 1571 case AF_INET6: 1572 if (seen_inet6) 1573 continue; 1574 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); 1575 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 1576 continue; 1577 if ((ifa->ifa_flags & IFT_LOOP) != 0 && 1578 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 1579 continue; 1580 if (is_ifdisabled(ifa->ifa_name)) 1581 continue; 1582 seen_inet6 = 1; 1583 break; 1584 #endif 1585 } 1586 } 1587 freeifaddrs(ifaddrs); 1588 1589 switch(pai->ai_family) { 1590 case AF_INET6: 1591 return (seen_inet6); 1592 case AF_INET: 1593 return (seen_inet); 1594 case AF_UNSPEC: 1595 if (seen_inet == seen_inet6) 1596 return (seen_inet); 1597 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1598 return (1); 1599 } 1600 return (1); 1601 } 1602 1603 #ifdef INET6 1604 static int 1605 is_ifdisabled(char *name) 1606 { 1607 struct in6_ndireq nd; 1608 int fd; 1609 1610 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1611 return (-1); 1612 memset(&nd, 0, sizeof(nd)); 1613 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1614 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1615 _close(fd); 1616 return (-1); 1617 } 1618 _close(fd); 1619 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1620 } 1621 1622 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1623 static int 1624 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1625 { 1626 u_long lscopeid; 1627 struct in6_addr *a6; 1628 char *ep; 1629 1630 a6 = &sin6->sin6_addr; 1631 1632 /* empty scopeid portion is invalid */ 1633 if (*scope == '\0') 1634 return -1; 1635 1636 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1637 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1638 /* 1639 * We currently assume a one-to-one mapping between links 1640 * and interfaces, so we simply use interface indices for 1641 * like-local scopes. 1642 */ 1643 *scopeid = if_nametoindex(scope); 1644 if (*scopeid == 0) 1645 goto trynumeric; 1646 return 0; 1647 } 1648 1649 /* still unclear about literal, allow numeric only - placeholder */ 1650 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1651 goto trynumeric; 1652 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1653 goto trynumeric; 1654 else 1655 goto trynumeric; /* global */ 1656 1657 /* try to convert to a numeric id as a last resort */ 1658 trynumeric: 1659 errno = 0; 1660 lscopeid = strtoul(scope, &ep, 10); 1661 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1662 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1663 return 0; 1664 else 1665 return -1; 1666 } 1667 #endif 1668 1669 1670 #ifdef NS_CACHING 1671 static int 1672 addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1673 void *cache_mdata) 1674 { 1675 res_state statp; 1676 u_long res_options; 1677 1678 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1679 char *hostname; 1680 struct addrinfo *hints; 1681 1682 char *p; 1683 int ai_flags, ai_family, ai_socktype, ai_protocol; 1684 size_t desired_size, size; 1685 1686 statp = __res_state(); 1687 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1688 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1689 1690 hostname = va_arg(ap, char *); 1691 hints = va_arg(ap, struct addrinfo *); 1692 1693 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1694 if (hostname != NULL) { 1695 size = strlen(hostname); 1696 desired_size += size + 1; 1697 } else 1698 size = 0; 1699 1700 if (desired_size > *buffer_size) { 1701 *buffer_size = desired_size; 1702 return (NS_RETURN); 1703 } 1704 1705 if (hints == NULL) 1706 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1707 else { 1708 ai_flags = hints->ai_flags; 1709 ai_family = hints->ai_family; 1710 ai_socktype = hints->ai_socktype; 1711 ai_protocol = hints->ai_protocol; 1712 } 1713 1714 p = buffer; 1715 memcpy(p, &res_options, sizeof(res_options)); 1716 p += sizeof(res_options); 1717 1718 memcpy(p, &op_id, sizeof(int)); 1719 p += sizeof(int); 1720 1721 memcpy(p, &ai_flags, sizeof(int)); 1722 p += sizeof(int); 1723 1724 memcpy(p, &ai_family, sizeof(int)); 1725 p += sizeof(int); 1726 1727 memcpy(p, &ai_socktype, sizeof(int)); 1728 p += sizeof(int); 1729 1730 memcpy(p, &ai_protocol, sizeof(int)); 1731 p += sizeof(int); 1732 1733 if (hostname != NULL) 1734 memcpy(p, hostname, size); 1735 1736 *buffer_size = desired_size; 1737 return (NS_SUCCESS); 1738 } 1739 1740 static int 1741 addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1742 va_list ap, void *cache_mdata) 1743 { 1744 struct addrinfo *ai, *cai; 1745 char *p; 1746 size_t desired_size, size, ai_size; 1747 1748 ai = *((struct addrinfo **)retval); 1749 1750 desired_size = sizeof(size_t); 1751 ai_size = 0; 1752 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1753 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1754 if (cai->ai_canonname != NULL) 1755 desired_size += sizeof(size_t) + 1756 strlen(cai->ai_canonname); 1757 ++ai_size; 1758 } 1759 1760 if (desired_size > *buffer_size) { 1761 /* this assignment is here for future use */ 1762 errno = ERANGE; 1763 *buffer_size = desired_size; 1764 return (NS_RETURN); 1765 } 1766 1767 memset(buffer, 0, desired_size); 1768 p = buffer; 1769 1770 memcpy(p, &ai_size, sizeof(size_t)); 1771 p += sizeof(size_t); 1772 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1773 memcpy(p, cai, sizeof(struct addrinfo)); 1774 p += sizeof(struct addrinfo); 1775 1776 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1777 p += cai->ai_addrlen; 1778 1779 if (cai->ai_canonname != NULL) { 1780 size = strlen(cai->ai_canonname); 1781 memcpy(p, &size, sizeof(size_t)); 1782 p += sizeof(size_t); 1783 1784 memcpy(p, cai->ai_canonname, size); 1785 p += size; 1786 } 1787 } 1788 1789 return (NS_SUCCESS); 1790 } 1791 1792 static int 1793 addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1794 va_list ap, void *cache_mdata) 1795 { 1796 struct addrinfo new_ai, *result, *sentinel, *lasts; 1797 1798 char *p; 1799 size_t ai_size, ai_i, size; 1800 1801 p = buffer; 1802 memcpy(&ai_size, p, sizeof(size_t)); 1803 p += sizeof(size_t); 1804 1805 result = NULL; 1806 lasts = NULL; 1807 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1808 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1809 p += sizeof(struct addrinfo); 1810 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1811 _ALIGNBYTES; 1812 1813 sentinel = (struct addrinfo *)malloc(size); 1814 memset(sentinel, 0, size); 1815 1816 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1817 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1818 sizeof(struct addrinfo)); 1819 1820 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1821 p += new_ai.ai_addrlen; 1822 1823 if (new_ai.ai_canonname != NULL) { 1824 memcpy(&size, p, sizeof(size_t)); 1825 p += sizeof(size_t); 1826 1827 sentinel->ai_canonname = (char *)malloc(size + 1); 1828 memset(sentinel->ai_canonname, 0, size + 1); 1829 1830 memcpy(sentinel->ai_canonname, p, size); 1831 p += size; 1832 } 1833 1834 if (result == NULL) { 1835 result = sentinel; 1836 lasts = sentinel; 1837 } else { 1838 lasts->ai_next = sentinel; 1839 lasts = sentinel; 1840 } 1841 } 1842 1843 *((struct addrinfo **)retval) = result; 1844 return (NS_SUCCESS); 1845 } 1846 #endif /* NS_CACHING */ 1847 1848 /* 1849 * FQDN hostname, DNS lookup 1850 */ 1851 static int 1852 explore_fqdn(const struct addrinfo *pai, const char *hostname, 1853 const char *servname, struct addrinfo **res) 1854 { 1855 struct addrinfo *result; 1856 struct addrinfo *cur; 1857 int error = 0; 1858 1859 #ifdef NS_CACHING 1860 static const nss_cache_info cache_info = 1861 NS_COMMON_CACHE_INFO_INITIALIZER( 1862 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1863 addrinfo_unmarshal_func); 1864 #endif 1865 static const ns_dtab dtab[] = { 1866 NS_FILES_CB(_files_getaddrinfo, NULL) 1867 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1868 NS_NIS_CB(_yp_getaddrinfo, NULL) 1869 #ifdef NS_CACHING 1870 NS_CACHE_CB(&cache_info) 1871 #endif 1872 { 0 } 1873 }; 1874 1875 result = NULL; 1876 1877 /* 1878 * if the servname does not match socktype/protocol, ignore it. 1879 */ 1880 if (get_portmatch(pai, servname) != 0) 1881 return 0; 1882 1883 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1884 default_dns_files, hostname, pai)) { 1885 case NS_TRYAGAIN: 1886 error = EAI_AGAIN; 1887 goto free; 1888 case NS_UNAVAIL: 1889 error = EAI_FAIL; 1890 goto free; 1891 case NS_NOTFOUND: 1892 error = EAI_NONAME; 1893 goto free; 1894 case NS_SUCCESS: 1895 error = 0; 1896 for (cur = result; cur; cur = cur->ai_next) { 1897 GET_PORT(cur, servname); 1898 /* canonname should be filled already */ 1899 } 1900 break; 1901 } 1902 1903 *res = result; 1904 1905 return 0; 1906 1907 free: 1908 if (result) 1909 freeaddrinfo(result); 1910 return error; 1911 } 1912 1913 #ifdef DEBUG 1914 static const char AskedForGot[] = 1915 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1916 #endif 1917 1918 static struct addrinfo * 1919 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1920 const struct addrinfo *pai, res_state res) 1921 { 1922 struct addrinfo sentinel, *cur; 1923 struct addrinfo ai; 1924 const struct afd *afd; 1925 char *canonname; 1926 const HEADER *hp; 1927 const u_char *cp; 1928 int n; 1929 const u_char *eom; 1930 char *bp, *ep; 1931 int type, class, ancount, qdcount; 1932 int haveanswer, had_error; 1933 char tbuf[MAXDNAME]; 1934 int (*name_ok)(const char *); 1935 char hostbuf[8*1024]; 1936 1937 memset(&sentinel, 0, sizeof(sentinel)); 1938 cur = &sentinel; 1939 1940 canonname = NULL; 1941 eom = answer->buf + anslen; 1942 switch (qtype) { 1943 case T_A: 1944 case T_AAAA: 1945 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1946 name_ok = res_hnok; 1947 break; 1948 default: 1949 return (NULL); /* XXX should be abort(); */ 1950 } 1951 /* 1952 * find first satisfactory answer 1953 */ 1954 hp = &answer->hdr; 1955 ancount = ntohs(hp->ancount); 1956 qdcount = ntohs(hp->qdcount); 1957 bp = hostbuf; 1958 ep = hostbuf + sizeof hostbuf; 1959 cp = answer->buf + HFIXEDSZ; 1960 if (qdcount != 1) { 1961 RES_SET_H_ERRNO(res, NO_RECOVERY); 1962 return (NULL); 1963 } 1964 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1965 if ((n < 0) || !(*name_ok)(bp)) { 1966 RES_SET_H_ERRNO(res, NO_RECOVERY); 1967 return (NULL); 1968 } 1969 cp += n + QFIXEDSZ; 1970 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1971 /* res_send() has already verified that the query name is the 1972 * same as the one we sent; this just gets the expanded name 1973 * (i.e., with the succeeding search-domain tacked on). 1974 */ 1975 n = strlen(bp) + 1; /* for the \0 */ 1976 if (n >= MAXHOSTNAMELEN) { 1977 RES_SET_H_ERRNO(res, NO_RECOVERY); 1978 return (NULL); 1979 } 1980 canonname = bp; 1981 bp += n; 1982 /* The qname can be abbreviated, but h_name is now absolute. */ 1983 qname = canonname; 1984 } 1985 haveanswer = 0; 1986 had_error = 0; 1987 while (ancount-- > 0 && cp < eom && !had_error) { 1988 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1989 if ((n < 0) || !(*name_ok)(bp)) { 1990 had_error++; 1991 continue; 1992 } 1993 cp += n; /* name */ 1994 type = _getshort(cp); 1995 cp += INT16SZ; /* type */ 1996 class = _getshort(cp); 1997 cp += INT16SZ + INT32SZ; /* class, TTL */ 1998 n = _getshort(cp); 1999 cp += INT16SZ; /* len */ 2000 if (class != C_IN) { 2001 /* XXX - debug? syslog? */ 2002 cp += n; 2003 continue; /* XXX - had_error++ ? */ 2004 } 2005 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 2006 type == T_CNAME) { 2007 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 2008 if ((n < 0) || !(*name_ok)(tbuf)) { 2009 had_error++; 2010 continue; 2011 } 2012 cp += n; 2013 /* Get canonical name. */ 2014 n = strlen(tbuf) + 1; /* for the \0 */ 2015 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 2016 had_error++; 2017 continue; 2018 } 2019 strlcpy(bp, tbuf, ep - bp); 2020 canonname = bp; 2021 bp += n; 2022 continue; 2023 } 2024 if (qtype == T_ANY) { 2025 if (!(type == T_A || type == T_AAAA)) { 2026 cp += n; 2027 continue; 2028 } 2029 } else if (type != qtype) { 2030 #ifdef DEBUG 2031 if (type != T_KEY && type != T_SIG && 2032 type != ns_t_dname) 2033 syslog(LOG_NOTICE|LOG_AUTH, 2034 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2035 qname, p_class(C_IN), p_type(qtype), 2036 p_type(type)); 2037 #endif 2038 cp += n; 2039 continue; /* XXX - had_error++ ? */ 2040 } 2041 switch (type) { 2042 case T_A: 2043 case T_AAAA: 2044 if (strcasecmp(canonname, bp) != 0) { 2045 #ifdef DEBUG 2046 syslog(LOG_NOTICE|LOG_AUTH, 2047 AskedForGot, canonname, bp); 2048 #endif 2049 cp += n; 2050 continue; /* XXX - had_error++ ? */ 2051 } 2052 if (type == T_A && n != INADDRSZ) { 2053 cp += n; 2054 continue; 2055 } 2056 if (type == T_AAAA && n != IN6ADDRSZ) { 2057 cp += n; 2058 continue; 2059 } 2060 #ifdef FILTER_V4MAPPED 2061 if (type == T_AAAA) { 2062 struct in6_addr in6; 2063 memcpy(&in6, cp, sizeof(in6)); 2064 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2065 cp += n; 2066 continue; 2067 } 2068 } 2069 #endif 2070 if (!haveanswer) { 2071 int nn; 2072 2073 canonname = bp; 2074 nn = strlen(bp) + 1; /* for the \0 */ 2075 bp += nn; 2076 } 2077 2078 /* don't overwrite pai */ 2079 ai = *pai; 2080 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2081 afd = find_afd(ai.ai_family); 2082 if (afd == NULL) { 2083 cp += n; 2084 continue; 2085 } 2086 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2087 if (cur->ai_next == NULL) 2088 had_error++; 2089 while (cur && cur->ai_next) 2090 cur = cur->ai_next; 2091 cp += n; 2092 break; 2093 default: 2094 abort(); 2095 } 2096 if (!had_error) 2097 haveanswer++; 2098 } 2099 if (haveanswer) { 2100 #if defined(RESOLVSORT) 2101 /* 2102 * We support only IPv4 address for backward 2103 * compatibility against gethostbyname(3). 2104 */ 2105 if (res->nsort && qtype == T_A) { 2106 if (addr4sort(&sentinel, res) < 0) { 2107 freeaddrinfo(sentinel.ai_next); 2108 RES_SET_H_ERRNO(res, NO_RECOVERY); 2109 return NULL; 2110 } 2111 } 2112 #endif /*RESOLVSORT*/ 2113 if (!canonname) 2114 (void)get_canonname(pai, sentinel.ai_next, qname); 2115 else 2116 (void)get_canonname(pai, sentinel.ai_next, canonname); 2117 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2118 return sentinel.ai_next; 2119 } 2120 2121 RES_SET_H_ERRNO(res, NO_RECOVERY); 2122 return NULL; 2123 } 2124 2125 #ifdef RESOLVSORT 2126 struct addr_ptr { 2127 struct addrinfo *ai; 2128 int aval; 2129 }; 2130 2131 static int 2132 addr4sort(struct addrinfo *sentinel, res_state res) 2133 { 2134 struct addrinfo *ai; 2135 struct addr_ptr *addrs, addr; 2136 struct sockaddr_in *sin; 2137 int naddrs, i, j; 2138 int needsort = 0; 2139 2140 if (!sentinel) 2141 return -1; 2142 naddrs = 0; 2143 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2144 naddrs++; 2145 if (naddrs < 2) 2146 return 0; /* We don't need sorting. */ 2147 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2148 return -1; 2149 i = 0; 2150 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2151 sin = (struct sockaddr_in *)ai->ai_addr; 2152 for (j = 0; (unsigned)j < res->nsort; j++) { 2153 if (res->sort_list[j].addr.s_addr == 2154 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2155 break; 2156 } 2157 addrs[i].ai = ai; 2158 addrs[i].aval = j; 2159 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2160 needsort = i; 2161 i++; 2162 } 2163 if (!needsort) { 2164 free(addrs); 2165 return 0; 2166 } 2167 2168 while (needsort < naddrs) { 2169 for (j = needsort - 1; j >= 0; j--) { 2170 if (addrs[j].aval > addrs[j+1].aval) { 2171 addr = addrs[j]; 2172 addrs[j] = addrs[j + 1]; 2173 addrs[j + 1] = addr; 2174 } else 2175 break; 2176 } 2177 needsort++; 2178 } 2179 2180 ai = sentinel; 2181 for (i = 0; i < naddrs; ++i) { 2182 ai->ai_next = addrs[i].ai; 2183 ai = ai->ai_next; 2184 } 2185 ai->ai_next = NULL; 2186 free(addrs); 2187 return 0; 2188 } 2189 #endif /*RESOLVSORT*/ 2190 2191 /*ARGSUSED*/ 2192 static int 2193 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2194 { 2195 struct addrinfo *ai; 2196 querybuf *buf, *buf2; 2197 const char *hostname; 2198 const struct addrinfo *pai; 2199 struct addrinfo sentinel, *cur; 2200 struct res_target q, q2; 2201 res_state res; 2202 2203 hostname = va_arg(ap, char *); 2204 pai = va_arg(ap, const struct addrinfo *); 2205 2206 memset(&q, 0, sizeof(q)); 2207 memset(&q2, 0, sizeof(q2)); 2208 memset(&sentinel, 0, sizeof(sentinel)); 2209 cur = &sentinel; 2210 2211 buf = malloc(sizeof(*buf)); 2212 if (!buf) { 2213 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2214 return NS_NOTFOUND; 2215 } 2216 buf2 = malloc(sizeof(*buf2)); 2217 if (!buf2) { 2218 free(buf); 2219 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2220 return NS_NOTFOUND; 2221 } 2222 2223 switch (pai->ai_family) { 2224 case AF_UNSPEC: 2225 q.name = hostname; 2226 q.qclass = C_IN; 2227 q.qtype = T_A; 2228 q.answer = buf->buf; 2229 q.anslen = sizeof(buf->buf); 2230 q.next = &q2; 2231 q2.name = hostname; 2232 q2.qclass = C_IN; 2233 q2.qtype = T_AAAA; 2234 q2.answer = buf2->buf; 2235 q2.anslen = sizeof(buf2->buf); 2236 break; 2237 case AF_INET: 2238 q.name = hostname; 2239 q.qclass = C_IN; 2240 q.qtype = T_A; 2241 q.answer = buf->buf; 2242 q.anslen = sizeof(buf->buf); 2243 break; 2244 case AF_INET6: 2245 q.name = hostname; 2246 q.qclass = C_IN; 2247 q.qtype = T_AAAA; 2248 q.answer = buf->buf; 2249 q.anslen = sizeof(buf->buf); 2250 break; 2251 default: 2252 free(buf); 2253 free(buf2); 2254 return NS_UNAVAIL; 2255 } 2256 2257 res = __res_state(); 2258 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2259 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2260 free(buf); 2261 free(buf2); 2262 return NS_NOTFOUND; 2263 } 2264 2265 if (res_searchN(hostname, &q, res) < 0) { 2266 free(buf); 2267 free(buf2); 2268 return NS_NOTFOUND; 2269 } 2270 /* prefer IPv6 */ 2271 if (q.next) { 2272 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2273 if (ai) { 2274 cur->ai_next = ai; 2275 while (cur && cur->ai_next) 2276 cur = cur->ai_next; 2277 } 2278 } 2279 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2280 if (ai) 2281 cur->ai_next = ai; 2282 free(buf); 2283 free(buf2); 2284 if (sentinel.ai_next == NULL) 2285 switch (res->res_h_errno) { 2286 case HOST_NOT_FOUND: 2287 return NS_NOTFOUND; 2288 case TRY_AGAIN: 2289 return NS_TRYAGAIN; 2290 default: 2291 return NS_UNAVAIL; 2292 } 2293 *((struct addrinfo **)rv) = sentinel.ai_next; 2294 return NS_SUCCESS; 2295 } 2296 2297 static void 2298 _sethtent(FILE **hostf) 2299 { 2300 if (!*hostf) 2301 *hostf = fopen(_PATH_HOSTS, "re"); 2302 else 2303 rewind(*hostf); 2304 } 2305 2306 static void 2307 _endhtent(FILE **hostf) 2308 { 2309 if (*hostf) { 2310 (void) fclose(*hostf); 2311 *hostf = NULL; 2312 } 2313 } 2314 2315 static struct addrinfo * 2316 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2317 { 2318 char *p; 2319 char *cp, *tname, *cname; 2320 struct addrinfo hints, *res0, *res; 2321 int error; 2322 const char *addr; 2323 char hostbuf[8*1024]; 2324 2325 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2326 return (NULL); 2327 again: 2328 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2329 return (NULL); 2330 if (*p == '#') 2331 goto again; 2332 cp = strpbrk(p, "#\n"); 2333 if (cp != NULL) 2334 *cp = '\0'; 2335 if (!(cp = strpbrk(p, " \t"))) 2336 goto again; 2337 *cp++ = '\0'; 2338 addr = p; 2339 cname = NULL; 2340 /* if this is not something we're looking for, skip it. */ 2341 while (cp && *cp) { 2342 if (*cp == ' ' || *cp == '\t') { 2343 cp++; 2344 continue; 2345 } 2346 tname = cp; 2347 if (cname == NULL) 2348 cname = cp; 2349 if ((cp = strpbrk(cp, " \t")) != NULL) 2350 *cp++ = '\0'; 2351 if (strcasecmp(name, tname) == 0) 2352 goto found; 2353 } 2354 goto again; 2355 2356 found: 2357 /* we should not glob socktype/protocol here */ 2358 memset(&hints, 0, sizeof(hints)); 2359 hints.ai_family = pai->ai_family; 2360 hints.ai_socktype = SOCK_DGRAM; 2361 hints.ai_protocol = 0; 2362 hints.ai_flags = AI_NUMERICHOST; 2363 error = getaddrinfo(addr, "0", &hints, &res0); 2364 if (error) 2365 goto again; 2366 #ifdef FILTER_V4MAPPED 2367 /* XXX should check all items in the chain */ 2368 if (res0->ai_family == AF_INET6 && 2369 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2370 freeaddrinfo(res0); 2371 goto again; 2372 } 2373 #endif 2374 for (res = res0; res; res = res->ai_next) { 2375 /* cover it up */ 2376 res->ai_flags = pai->ai_flags; 2377 res->ai_socktype = pai->ai_socktype; 2378 res->ai_protocol = pai->ai_protocol; 2379 2380 if (pai->ai_flags & AI_CANONNAME) { 2381 if (get_canonname(pai, res, cname) != 0) { 2382 freeaddrinfo(res0); 2383 goto again; 2384 } 2385 } 2386 } 2387 return res0; 2388 } 2389 2390 /*ARGSUSED*/ 2391 static int 2392 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2393 { 2394 const char *name; 2395 const struct addrinfo *pai; 2396 struct addrinfo sentinel, *cur; 2397 struct addrinfo *p; 2398 FILE *hostf = NULL; 2399 2400 name = va_arg(ap, char *); 2401 pai = va_arg(ap, struct addrinfo *); 2402 2403 memset(&sentinel, 0, sizeof(sentinel)); 2404 cur = &sentinel; 2405 2406 _sethtent(&hostf); 2407 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 2408 cur->ai_next = p; 2409 while (cur && cur->ai_next) 2410 cur = cur->ai_next; 2411 } 2412 _endhtent(&hostf); 2413 2414 *((struct addrinfo **)rv) = sentinel.ai_next; 2415 if (sentinel.ai_next == NULL) 2416 return NS_NOTFOUND; 2417 return NS_SUCCESS; 2418 } 2419 2420 #ifdef YP 2421 /*ARGSUSED*/ 2422 static struct addrinfo * 2423 _yphostent(char *line, const struct addrinfo *pai) 2424 { 2425 struct addrinfo sentinel, *cur; 2426 struct addrinfo hints, *res, *res0; 2427 int error; 2428 char *p = line; 2429 const char *addr, *canonname; 2430 char *nextline; 2431 char *cp; 2432 2433 addr = canonname = NULL; 2434 2435 memset(&sentinel, 0, sizeof(sentinel)); 2436 cur = &sentinel; 2437 2438 nextline: 2439 /* terminate line */ 2440 cp = strchr(p, '\n'); 2441 if (cp) { 2442 *cp++ = '\0'; 2443 nextline = cp; 2444 } else 2445 nextline = NULL; 2446 2447 cp = strpbrk(p, " \t"); 2448 if (cp == NULL) { 2449 if (canonname == NULL) 2450 return (NULL); 2451 else 2452 goto done; 2453 } 2454 *cp++ = '\0'; 2455 2456 addr = p; 2457 2458 while (cp && *cp) { 2459 if (*cp == ' ' || *cp == '\t') { 2460 cp++; 2461 continue; 2462 } 2463 if (!canonname) 2464 canonname = cp; 2465 if ((cp = strpbrk(cp, " \t")) != NULL) 2466 *cp++ = '\0'; 2467 } 2468 2469 hints = *pai; 2470 hints.ai_flags = AI_NUMERICHOST; 2471 error = getaddrinfo(addr, NULL, &hints, &res0); 2472 if (error == 0) { 2473 for (res = res0; res; res = res->ai_next) { 2474 /* cover it up */ 2475 res->ai_flags = pai->ai_flags; 2476 2477 if (pai->ai_flags & AI_CANONNAME) 2478 (void)get_canonname(pai, res, canonname); 2479 } 2480 } else 2481 res0 = NULL; 2482 if (res0) { 2483 cur->ai_next = res0; 2484 while (cur && cur->ai_next) 2485 cur = cur->ai_next; 2486 } 2487 2488 if (nextline) { 2489 p = nextline; 2490 goto nextline; 2491 } 2492 2493 done: 2494 return sentinel.ai_next; 2495 } 2496 2497 /*ARGSUSED*/ 2498 static int 2499 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2500 { 2501 struct addrinfo sentinel, *cur; 2502 struct addrinfo *ai = NULL; 2503 char *ypbuf; 2504 int ypbuflen, r; 2505 const char *name; 2506 const struct addrinfo *pai; 2507 char *ypdomain; 2508 2509 if (_yp_check(&ypdomain) == 0) 2510 return NS_UNAVAIL; 2511 2512 name = va_arg(ap, char *); 2513 pai = va_arg(ap, const struct addrinfo *); 2514 2515 memset(&sentinel, 0, sizeof(sentinel)); 2516 cur = &sentinel; 2517 2518 /* hosts.byname is only for IPv4 (Solaris8) */ 2519 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 2520 r = yp_match(ypdomain, "hosts.byname", name, 2521 (int)strlen(name), &ypbuf, &ypbuflen); 2522 if (r == 0) { 2523 struct addrinfo ai4; 2524 2525 ai4 = *pai; 2526 ai4.ai_family = AF_INET; 2527 ai = _yphostent(ypbuf, &ai4); 2528 if (ai) { 2529 cur->ai_next = ai; 2530 while (cur && cur->ai_next) 2531 cur = cur->ai_next; 2532 } 2533 free(ypbuf); 2534 } 2535 } 2536 2537 /* ipnodes.byname can hold both IPv4/v6 */ 2538 r = yp_match(ypdomain, "ipnodes.byname", name, 2539 (int)strlen(name), &ypbuf, &ypbuflen); 2540 if (r == 0) { 2541 ai = _yphostent(ypbuf, pai); 2542 if (ai) 2543 cur->ai_next = ai; 2544 free(ypbuf); 2545 } 2546 2547 if (sentinel.ai_next == NULL) { 2548 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2549 return NS_NOTFOUND; 2550 } 2551 *((struct addrinfo **)rv) = sentinel.ai_next; 2552 return NS_SUCCESS; 2553 } 2554 #endif 2555 2556 /* resolver logic */ 2557 2558 /* 2559 * Formulate a normal query, send, and await answer. 2560 * Returned answer is placed in supplied buffer "answer". 2561 * Perform preliminary check of answer, returning success only 2562 * if no error is indicated and the answer count is nonzero. 2563 * Return the size of the response on success, -1 on error. 2564 * Error number is left in h_errno. 2565 * 2566 * Caller must parse answer and determine whether it answers the question. 2567 */ 2568 static int 2569 res_queryN(const char *name, struct res_target *target, res_state res) 2570 { 2571 u_char *buf; 2572 HEADER *hp; 2573 int n; 2574 u_int oflags; 2575 struct res_target *t; 2576 int rcode; 2577 int ancount; 2578 2579 rcode = NOERROR; 2580 ancount = 0; 2581 2582 buf = malloc(MAXPACKET); 2583 if (!buf) { 2584 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2585 return -1; 2586 } 2587 2588 for (t = target; t; t = t->next) { 2589 int class, type; 2590 u_char *answer; 2591 int anslen; 2592 2593 hp = (HEADER *)(void *)t->answer; 2594 2595 /* make it easier... */ 2596 class = t->qclass; 2597 type = t->qtype; 2598 answer = t->answer; 2599 anslen = t->anslen; 2600 2601 oflags = res->_flags; 2602 2603 again: 2604 hp->rcode = NOERROR; /* default */ 2605 2606 #ifdef DEBUG 2607 if (res->options & RES_DEBUG) 2608 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2609 #endif 2610 2611 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2612 buf, MAXPACKET); 2613 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2614 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2615 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2616 if (n <= 0) { 2617 #ifdef DEBUG 2618 if (res->options & RES_DEBUG) 2619 printf(";; res_query: mkquery failed\n"); 2620 #endif 2621 free(buf); 2622 RES_SET_H_ERRNO(res, NO_RECOVERY); 2623 return (n); 2624 } 2625 n = res_nsend(res, buf, n, answer, anslen); 2626 if (n < 0) { 2627 /* 2628 * if the query choked with EDNS0, retry 2629 * without EDNS0 2630 */ 2631 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2632 != 0U && 2633 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2634 res->_flags |= RES_F_EDNS0ERR; 2635 if (res->options & RES_DEBUG) 2636 printf(";; res_nquery: retry without EDNS0\n"); 2637 goto again; 2638 } 2639 rcode = hp->rcode; /* record most recent error */ 2640 #ifdef DEBUG 2641 if (res->options & RES_DEBUG) 2642 printf(";; res_query: send error\n"); 2643 #endif 2644 continue; 2645 } 2646 2647 if (n > anslen) 2648 hp->rcode = FORMERR; /* XXX not very informative */ 2649 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2650 rcode = hp->rcode; /* record most recent error */ 2651 #ifdef DEBUG 2652 if (res->options & RES_DEBUG) 2653 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2654 ntohs(hp->ancount)); 2655 #endif 2656 continue; 2657 } 2658 2659 ancount += ntohs(hp->ancount); 2660 2661 t->n = n; 2662 } 2663 2664 free(buf); 2665 2666 if (ancount == 0) { 2667 switch (rcode) { 2668 case NXDOMAIN: 2669 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2670 break; 2671 case SERVFAIL: 2672 RES_SET_H_ERRNO(res, TRY_AGAIN); 2673 break; 2674 case NOERROR: 2675 RES_SET_H_ERRNO(res, NO_DATA); 2676 break; 2677 case FORMERR: 2678 case NOTIMP: 2679 case REFUSED: 2680 default: 2681 RES_SET_H_ERRNO(res, NO_RECOVERY); 2682 break; 2683 } 2684 return (-1); 2685 } 2686 return (ancount); 2687 } 2688 2689 /* 2690 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2691 * Return the size of the response on success, -1 on error. 2692 * If enabled, implement search rules until answer or unrecoverable failure 2693 * is detected. Error code, if any, is left in h_errno. 2694 */ 2695 static int 2696 res_searchN(const char *name, struct res_target *target, res_state res) 2697 { 2698 const char *cp, * const *domain; 2699 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2700 u_int dots; 2701 int trailing_dot, ret, saved_herrno; 2702 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2703 int tried_as_is = 0; 2704 int searched = 0; 2705 char abuf[MAXDNAME]; 2706 2707 errno = 0; 2708 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2709 dots = 0; 2710 for (cp = name; *cp; cp++) 2711 dots += (*cp == '.'); 2712 trailing_dot = 0; 2713 if (cp > name && *--cp == '.') 2714 trailing_dot++; 2715 2716 /* 2717 * if there aren't any dots, it could be a user-level alias 2718 */ 2719 if (!dots && 2720 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2721 return (res_queryN(cp, target, res)); 2722 2723 /* 2724 * If there are enough dots in the name, let's just give it a 2725 * try 'as is'. The threshold can be set with the "ndots" option. 2726 * Also, query 'as is', if there is a trailing dot in the name. 2727 */ 2728 saved_herrno = -1; 2729 if (dots >= res->ndots || trailing_dot) { 2730 ret = res_querydomainN(name, NULL, target, res); 2731 if (ret > 0 || trailing_dot) 2732 return (ret); 2733 if (errno == ECONNREFUSED) { 2734 RES_SET_H_ERRNO(res, TRY_AGAIN); 2735 return (-1); 2736 } 2737 switch (res->res_h_errno) { 2738 case NO_DATA: 2739 case HOST_NOT_FOUND: 2740 break; 2741 case TRY_AGAIN: 2742 if (hp->rcode == SERVFAIL) 2743 break; 2744 /* FALLTHROUGH */ 2745 default: 2746 return (-1); 2747 } 2748 saved_herrno = res->res_h_errno; 2749 tried_as_is++; 2750 } 2751 2752 /* 2753 * We do at least one level of search if 2754 * - there is no dot and RES_DEFNAME is set, or 2755 * - there is at least one dot, there is no trailing dot, 2756 * and RES_DNSRCH is set. 2757 */ 2758 if ((!dots && (res->options & RES_DEFNAMES)) || 2759 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2760 int done = 0; 2761 2762 for (domain = (const char * const *)res->dnsrch; 2763 *domain && !done; 2764 domain++) { 2765 searched = 1; 2766 2767 if (domain[0][0] == '\0' || 2768 (domain[0][0] == '.' && domain[0][1] == '\0')) 2769 root_on_list++; 2770 2771 if (root_on_list && tried_as_is) 2772 continue; 2773 2774 ret = res_querydomainN(name, *domain, target, res); 2775 if (ret > 0) 2776 return (ret); 2777 2778 /* 2779 * If no server present, give up. 2780 * If name isn't found in this domain, 2781 * keep trying higher domains in the search list 2782 * (if that's enabled). 2783 * On a NO_DATA error, keep trying, otherwise 2784 * a wildcard entry of another type could keep us 2785 * from finding this entry higher in the domain. 2786 * If we get some other error (negative answer or 2787 * server failure), then stop searching up, 2788 * but try the input name below in case it's 2789 * fully-qualified. 2790 */ 2791 if (errno == ECONNREFUSED) { 2792 RES_SET_H_ERRNO(res, TRY_AGAIN); 2793 return (-1); 2794 } 2795 2796 switch (res->res_h_errno) { 2797 case NO_DATA: 2798 got_nodata++; 2799 /* FALLTHROUGH */ 2800 case HOST_NOT_FOUND: 2801 /* keep trying */ 2802 break; 2803 case TRY_AGAIN: 2804 got_servfail++; 2805 if (hp->rcode == SERVFAIL) { 2806 /* try next search element, if any */ 2807 break; 2808 } 2809 /* FALLTHROUGH */ 2810 default: 2811 /* anything else implies that we're done */ 2812 done++; 2813 } 2814 /* 2815 * if we got here for some reason other than DNSRCH, 2816 * we only wanted one iteration of the loop, so stop. 2817 */ 2818 if (!(res->options & RES_DNSRCH)) 2819 done++; 2820 } 2821 } 2822 2823 switch (res->res_h_errno) { 2824 case NO_DATA: 2825 case HOST_NOT_FOUND: 2826 break; 2827 case TRY_AGAIN: 2828 if (hp->rcode == SERVFAIL) 2829 break; 2830 /* FALLTHROUGH */ 2831 default: 2832 goto giveup; 2833 } 2834 2835 /* 2836 * If the query has not already been tried as is then try it 2837 * unless RES_NOTLDQUERY is set and there were no dots. 2838 */ 2839 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2840 !(tried_as_is || root_on_list)) { 2841 ret = res_querydomainN(name, NULL, target, res); 2842 if (ret > 0) 2843 return (ret); 2844 } 2845 2846 /* 2847 * if we got here, we didn't satisfy the search. 2848 * if we did an initial full query, return that query's h_errno 2849 * (note that we wouldn't be here if that query had succeeded). 2850 * else if we ever got a nodata, send that back as the reason. 2851 * else send back meaningless h_errno, that being the one from 2852 * the last DNSRCH we did. 2853 */ 2854 giveup: 2855 if (saved_herrno != -1) 2856 RES_SET_H_ERRNO(res, saved_herrno); 2857 else if (got_nodata) 2858 RES_SET_H_ERRNO(res, NO_DATA); 2859 else if (got_servfail) 2860 RES_SET_H_ERRNO(res, TRY_AGAIN); 2861 return (-1); 2862 } 2863 2864 /* 2865 * Perform a call on res_query on the concatenation of name and domain, 2866 * removing a trailing dot from name if domain is NULL. 2867 */ 2868 static int 2869 res_querydomainN(const char *name, const char *domain, 2870 struct res_target *target, res_state res) 2871 { 2872 char nbuf[MAXDNAME]; 2873 const char *longname = nbuf; 2874 size_t n, d; 2875 2876 #ifdef DEBUG 2877 if (res->options & RES_DEBUG) 2878 printf(";; res_querydomain(%s, %s)\n", 2879 name, domain?domain:"<Nil>"); 2880 #endif 2881 if (domain == NULL) { 2882 /* 2883 * Check for trailing '.'; 2884 * copy without '.' if present. 2885 */ 2886 n = strlen(name); 2887 if (n >= MAXDNAME) { 2888 RES_SET_H_ERRNO(res, NO_RECOVERY); 2889 return (-1); 2890 } 2891 if (n > 0 && name[--n] == '.') { 2892 strncpy(nbuf, name, n); 2893 nbuf[n] = '\0'; 2894 } else 2895 longname = name; 2896 } else { 2897 n = strlen(name); 2898 d = strlen(domain); 2899 if (n + d + 1 >= MAXDNAME) { 2900 RES_SET_H_ERRNO(res, NO_RECOVERY); 2901 return (-1); 2902 } 2903 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2904 } 2905 return (res_queryN(longname, target, res)); 2906 } 2907