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/param.h> 59#include <sys/socket.h> 60#include <net/if.h> 61#include <netinet/in.h> 62#include <net/if_types.h> 63#include <ifaddrs.h> 64#include <sys/queue.h> 65#ifdef INET6 66#include <sys/sysctl.h> 67#include <sys/ioctl.h> 68#include <netinet6/in6_var.h> 69#include <netinet6/nd6.h> 70#endif 71#include <arpa/inet.h> 72#include <arpa/nameser.h> 73#include <rpc/rpc.h> 74#include <rpcsvc/yp_prot.h> 75#include <rpcsvc/ypclnt.h> 76#include <netdb.h> 77#include <resolv.h> 78#include <string.h> 79#include <stdlib.h> 80#include <stddef.h> 81#include <ctype.h> 82#include <unistd.h> 83#include <stdio.h> 84#include <errno.h> 85 86#include "res_config.h" 87 88#ifdef DEBUG 89#include <syslog.h> 90#endif 91 92#include <stdarg.h> 93#include <nsswitch.h> 94#include "un-namespace.h" 95#include "netdb_private.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 105static const char in_addrany[] = { 0, 0, 0, 0 }; 106static const char in_loopback[] = { 127, 0, 0, 1 }; 107#ifdef INET6 108static const char in6_addrany[] = { 109 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 110}; 111static 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 116struct policyqueue { 117 TAILQ_ENTRY(policyqueue) pc_entry; 118#ifdef INET6 119 struct in6_addrpolicy pc_policy; 120#endif 121}; 122TAILQ_HEAD(policyhead, policyqueue); 123 124static 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 157struct 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 170static 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 214struct 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 int aio_initial_sequence; 228}; 229 230static const ns_src default_dns_files[] = { 231 { NSSRC_FILES, NS_SUCCESS }, 232 { NSSRC_DNS, NS_SUCCESS }, 233 { 0 } 234}; 235 236struct res_target { 237 struct res_target *next; 238 const char *name; /* domain name */ 239 int qclass, qtype; /* class and type of query */ 240 u_char *answer; /* buffer to put answer */ 241 int anslen; /* size of answer buffer */ 242 int n; /* result length */ 243}; 244 245#define MAXPACKET (64*1024) 246 247typedef union { 248 HEADER hdr; 249 u_char buf[MAXPACKET]; 250} querybuf; 251 252static int str2number(const char *, int *); 253static int explore_copy(const struct addrinfo *, const struct addrinfo *, 254 struct addrinfo **); 255static int explore_null(const struct addrinfo *, 256 const char *, struct addrinfo **); 257static int explore_numeric(const struct addrinfo *, const char *, 258 const char *, struct addrinfo **, const char *); 259static int explore_numeric_scope(const struct addrinfo *, const char *, 260 const char *, struct addrinfo **); 261static int get_canonname(const struct addrinfo *, 262 struct addrinfo *, const char *); 263static struct addrinfo *get_ai(const struct addrinfo *, 264 const struct afd *, const char *); 265static struct addrinfo *copy_ai(const struct addrinfo *); 266static int get_portmatch(const struct addrinfo *, const char *); 267static int get_port(struct addrinfo *, const char *, int); 268static const struct afd *find_afd(int); 269static int addrconfig(struct addrinfo *); 270#ifdef INET6 271static int is_ifdisabled(char *); 272#endif 273static void set_source(struct ai_order *, struct policyhead *); 274static int comp_dst(const void *, const void *); 275#ifdef INET6 276static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 277#endif 278static int gai_addr2scopetype(struct sockaddr *); 279 280static int explore_fqdn(const struct addrinfo *, const char *, 281 const char *, struct addrinfo **); 282 283static int reorder(struct addrinfo *); 284static int get_addrselectpolicy(struct policyhead *); 285static void free_addrselectpolicy(struct policyhead *); 286static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 287 struct policyhead *); 288static int matchlen(struct sockaddr *, struct sockaddr *); 289 290static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 291 const struct addrinfo *, res_state); 292#if defined(RESOLVSORT) 293static int addr4sort(struct addrinfo *, res_state); 294#endif 295static int _dns_getaddrinfo(void *, void *, va_list); 296static void _sethtent(FILE **); 297static void _endhtent(FILE **); 298static struct addrinfo *_gethtent(FILE **, const char *, 299 const struct addrinfo *); 300static int _files_getaddrinfo(void *, void *, va_list); 301#ifdef YP 302static struct addrinfo *_yphostent(char *, const struct addrinfo *); 303static int _yp_getaddrinfo(void *, void *, va_list); 304#endif 305#ifdef NS_CACHING 306static int addrinfo_id_func(char *, size_t *, va_list, void *); 307static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 308static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 309#endif 310 311static int res_queryN(const char *, struct res_target *, res_state); 312static int res_searchN(const char *, struct res_target *, res_state); 313static int res_querydomainN(const char *, const char *, 314 struct res_target *, res_state); 315 316/* XXX macros that make external reference is BAD. */ 317 318#define GET_AI(ai, afd, addr) \ 319do { \ 320 /* external reference: pai, error, and label free */ \ 321 (ai) = get_ai(pai, (afd), (addr)); \ 322 if ((ai) == NULL) { \ 323 error = EAI_MEMORY; \ 324 goto free; \ 325 } \ 326} while (/*CONSTCOND*/0) 327 328#define GET_PORT(ai, serv) \ 329do { \ 330 /* external reference: error and label free */ \ 331 error = get_port((ai), (serv), 0); \ 332 if (error != 0) \ 333 goto free; \ 334} while (/*CONSTCOND*/0) 335 336#define GET_CANONNAME(ai, str) \ 337do { \ 338 /* external reference: pai, error and label free */ \ 339 error = get_canonname(pai, (ai), (str)); \ 340 if (error != 0) \ 341 goto free; \ 342} while (/*CONSTCOND*/0) 343 344#define ERR(err) \ 345do { \ 346 /* external reference: error, and label bad */ \ 347 error = (err); \ 348 goto bad; \ 349 /*NOTREACHED*/ \ 350} while (/*CONSTCOND*/0) 351 352#define MATCH_FAMILY(x, y, w) \ 353 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 354#define MATCH(x, y, w) \ 355 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 356 357void 358freeaddrinfo(struct addrinfo *ai) 359{ 360 struct addrinfo *next; 361 362 do { 363 next = ai->ai_next; 364 if (ai->ai_canonname) 365 free(ai->ai_canonname); 366 /* no need to free(ai->ai_addr) */ 367 free(ai); 368 ai = next; 369 } while (ai); 370} 371 372static int 373str2number(const char *p, int *portp) 374{ 375 char *ep; 376 unsigned long v; 377 378 if (*p == '\0') 379 return -1; 380 ep = NULL; 381 errno = 0; 382 v = strtoul(p, &ep, 10); 383 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 384 *portp = v; 385 return 0; 386 } else 387 return -1; 388} 389 390int 391getaddrinfo(const char *hostname, const char *servname, 392 const struct addrinfo *hints, struct addrinfo **res) 393{ 394 struct addrinfo sentinel; 395 struct addrinfo *cur; 396 int error = 0; 397 struct addrinfo ai, ai0, *afai; 398 struct addrinfo *pai; 399 const struct afd *afd; 400 const struct explore *ex; 401 struct addrinfo *afailist[nitems(afdl)]; 402 struct addrinfo *afai_unspec; 403 int found; 404 int numeric = 0; 405 406 /* ensure we return NULL on errors */ 407 *res = NULL; 408 409 memset(&ai, 0, sizeof(ai)); 410 411 memset(afailist, 0, sizeof(afailist)); 412 afai_unspec = NULL; 413 414 memset(&sentinel, 0, sizeof(sentinel)); 415 cur = &sentinel; 416 pai = &ai; 417 pai->ai_flags = 0; 418 pai->ai_family = PF_UNSPEC; 419 pai->ai_socktype = ANY; 420 pai->ai_protocol = ANY; 421 pai->ai_addrlen = 0; 422 pai->ai_canonname = NULL; 423 pai->ai_addr = NULL; 424 pai->ai_next = NULL; 425 426 if (hostname == NULL && servname == NULL) 427 return EAI_NONAME; 428 if (hints) { 429 /* error check for hints */ 430 if (hints->ai_addrlen || hints->ai_canonname || 431 hints->ai_addr || hints->ai_next) 432 ERR(EAI_BADHINTS); /* xxx */ 433 if (hints->ai_flags & ~AI_MASK) 434 ERR(EAI_BADFLAGS); 435 switch (hints->ai_family) { 436 case PF_UNSPEC: 437 case PF_LOCAL: 438 case PF_INET: 439#ifdef INET6 440 case PF_INET6: 441#endif 442 break; 443 default: 444 ERR(EAI_FAMILY); 445 } 446 memcpy(pai, hints, sizeof(*pai)); 447 448 /* 449 * if both socktype/protocol are specified, check if they 450 * are meaningful combination. 451 */ 452 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 453 for (ex = explore; ex->e_af >= 0; ex++) { 454 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 455 WILD_AF(ex))) 456 continue; 457 if (!MATCH(pai->ai_socktype, ex->e_socktype, 458 WILD_SOCKTYPE(ex))) 459 continue; 460 if (!MATCH(pai->ai_protocol, ex->e_protocol, 461 WILD_PROTOCOL(ex))) 462 continue; 463 464 /* matched */ 465 break; 466 } 467 468 if (ex->e_af < 0) 469 ERR(EAI_BADHINTS); 470 } 471 } 472 473 /* 474 * RFC 3493: AI_ALL and AI_V4MAPPED are effective only against 475 * AF_INET6 query. They need to be ignored if specified in other 476 * occasions. 477 */ 478 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 479 case AI_V4MAPPED: 480 case AI_ALL | AI_V4MAPPED: 481#ifdef INET6 482 if (pai->ai_family != AF_INET6) 483 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 484 break; 485#endif 486 case AI_ALL: 487 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 488 break; 489 } 490 491 /* 492 * check for special cases. (1) numeric servname is disallowed if 493 * socktype/protocol are left unspecified. (2) servname is disallowed 494 * for raw and other inet{,6} sockets. 495 */ 496 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 497#ifdef PF_INET6 498 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 499#endif 500 ) { 501 ai0 = *pai; /* backup *pai */ 502 503 if (pai->ai_family == PF_UNSPEC) { 504#ifdef PF_INET6 505 pai->ai_family = PF_INET6; 506#else 507 pai->ai_family = PF_INET; 508#endif 509 } 510 error = get_portmatch(pai, servname); 511 if (error) 512 goto bad; 513 514 *pai = ai0; 515 } 516 517 ai0 = *pai; 518 519 /* 520 * NULL hostname, or numeric hostname. 521 * If numeric representation of AF1 can be interpreted as FQDN 522 * representation of AF2, we need to think again about the code below. 523 */ 524 found = 0; 525 for (afd = afdl; afd->a_af; afd++) { 526 *pai = ai0; 527 528 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 529 continue; 530 531 if (pai->ai_family == PF_UNSPEC) 532 pai->ai_family = afd->a_af; 533 534 if (hostname == NULL) { 535 error = explore_null(pai, servname, 536 &afailist[afd - afdl]); 537 538 /* 539 * Errors from explore_null should be unexpected and 540 * be caught to avoid returning an incomplete result. 541 */ 542 if (error != 0) 543 goto bad; 544 } else { 545 error = explore_numeric_scope(pai, hostname, servname, 546 &afailist[afd - afdl]); 547 548 /* 549 * explore_numeric_scope returns an error for address 550 * families that do not match that of hostname. 551 * Thus we should not catch the error at this moment. 552 */ 553 } 554 555 if (!error && afailist[afd - afdl]) 556 found++; 557 } 558 if (found) { 559 numeric = 1; 560 goto globcopy; 561 } 562 563 if (hostname == NULL) 564 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 565 if (pai->ai_flags & AI_NUMERICHOST) 566 ERR(EAI_NONAME); 567 568 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 569 ERR(EAI_FAIL); 570 571 /* 572 * hostname as alphabetical name. 573 */ 574 *pai = ai0; 575 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 576 577globcopy: 578 for (ex = explore; ex->e_af >= 0; ex++) { 579 *pai = ai0; 580 581 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 582 continue; 583 if (!MATCH(pai->ai_socktype, ex->e_socktype, 584 WILD_SOCKTYPE(ex))) 585 continue; 586 if (!MATCH(pai->ai_protocol, ex->e_protocol, 587 WILD_PROTOCOL(ex))) 588 continue; 589 590 if (pai->ai_family == PF_UNSPEC) 591 pai->ai_family = ex->e_af; 592 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 593 pai->ai_socktype = ex->e_socktype; 594 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 595 pai->ai_protocol = ex->e_protocol; 596 597 /* 598 * if the servname does not match socktype/protocol, ignore it. 599 */ 600 if (get_portmatch(pai, servname) != 0) 601 continue; 602 603 if (afai_unspec) 604 afai = afai_unspec; 605 else { 606 if ((afd = find_afd(pai->ai_family)) == NULL) 607 continue; 608 /* XXX assumes that afd points inside afdl[] */ 609 afai = afailist[afd - afdl]; 610 } 611 if (!afai) 612 continue; 613 614 error = explore_copy(pai, afai, &cur->ai_next); 615 if (error != 0) 616 goto bad; 617 618 while (cur && cur->ai_next) 619 cur = cur->ai_next; 620 } 621 622 /* 623 * ensure we return either: 624 * - error == 0, non-NULL *res 625 * - error != 0, NULL *res 626 */ 627 if (error == 0) { 628 if (sentinel.ai_next) { 629 /* 630 * If the returned entry is for an active connection, 631 * and the given name is not numeric, reorder the 632 * list, so that the application would try the list 633 * in the most efficient order. Since the head entry 634 * of the original list may contain ai_canonname and 635 * that entry may be moved elsewhere in the new list, 636 * we keep the pointer and will restore it in the new 637 * head entry. (Note that RFC3493 requires the head 638 * entry store it when requested by the caller). 639 */ 640 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 641 if (!numeric) { 642 char *canonname; 643 644 canonname = 645 sentinel.ai_next->ai_canonname; 646 sentinel.ai_next->ai_canonname = NULL; 647 (void)reorder(&sentinel); 648 if (sentinel.ai_next->ai_canonname == 649 NULL) { 650 sentinel.ai_next->ai_canonname 651 = canonname; 652 } else if (canonname != NULL) 653 free(canonname); 654 } 655 } 656 *res = sentinel.ai_next; 657 } else 658 error = EAI_FAIL; 659 } 660 661bad: 662 if (afai_unspec) 663 freeaddrinfo(afai_unspec); 664 for (afd = afdl; afd->a_af; afd++) { 665 if (afailist[afd - afdl]) 666 freeaddrinfo(afailist[afd - afdl]); 667 } 668 if (!*res) 669 if (sentinel.ai_next) 670 freeaddrinfo(sentinel.ai_next); 671 672 return (error); 673} 674 675static int 676reorder(struct addrinfo *sentinel) 677{ 678 struct addrinfo *ai, **aip; 679 struct ai_order *aio; 680 int i, n; 681 struct policyhead policyhead; 682 683 /* count the number of addrinfo elements for sorting. */ 684 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 685 ; 686 687 /* 688 * If the number is small enough, we can skip the reordering process. 689 */ 690 if (n <= 1) 691 return(n); 692 693 /* allocate a temporary array for sort and initialization of it. */ 694 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 695 return(n); /* give up reordering */ 696 memset(aio, 0, sizeof(*aio) * n); 697 698 /* retrieve address selection policy from the kernel */ 699 TAILQ_INIT(&policyhead); 700 if (!get_addrselectpolicy(&policyhead)) { 701 /* no policy is installed into kernel, we don't sort. */ 702 free(aio); 703 return (n); 704 } 705 706 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 707 aio[i].aio_ai = ai; 708 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 709 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 710 &policyhead); 711 set_source(&aio[i], &policyhead); 712 aio[i].aio_initial_sequence = i; 713 } 714 715 /* perform sorting. */ 716 qsort(aio, n, sizeof(*aio), comp_dst); 717 718 /* reorder the addrinfo chain. */ 719 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 720 *aip = aio[i].aio_ai; 721 aip = &aio[i].aio_ai->ai_next; 722 } 723 *aip = NULL; 724 725 /* cleanup and return */ 726 free(aio); 727 free_addrselectpolicy(&policyhead); 728 return(n); 729} 730 731static int 732get_addrselectpolicy(struct policyhead *head) 733{ 734#ifdef INET6 735 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 736 size_t l; 737 char *buf; 738 struct in6_addrpolicy *pol, *ep; 739 740 if (sysctl(mib, nitems(mib), NULL, &l, NULL, 0) < 0) 741 return (0); 742 if (l == 0) 743 return (0); 744 if ((buf = malloc(l)) == NULL) 745 return (0); 746 if (sysctl(mib, nitems(mib), buf, &l, NULL, 0) < 0) { 747 free(buf); 748 return (0); 749 } 750 751 ep = (struct in6_addrpolicy *)(buf + l); 752 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 753 struct policyqueue *new; 754 755 if ((new = malloc(sizeof(*new))) == NULL) { 756 free_addrselectpolicy(head); /* make the list empty */ 757 break; 758 } 759 new->pc_policy = *pol; 760 TAILQ_INSERT_TAIL(head, new, pc_entry); 761 } 762 763 free(buf); 764 return (1); 765#else 766 return (0); 767#endif 768} 769 770static void 771free_addrselectpolicy(struct policyhead *head) 772{ 773 struct policyqueue *ent, *nent; 774 775 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 776 nent = TAILQ_NEXT(ent, pc_entry); 777 TAILQ_REMOVE(head, ent, pc_entry); 778 free(ent); 779 } 780} 781 782static struct policyqueue * 783match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 784{ 785#ifdef INET6 786 struct policyqueue *ent, *bestent = NULL; 787 struct in6_addrpolicy *pol; 788 int matchlen, bestmatchlen = -1; 789 u_char *mp, *ep, *k, *p, m; 790 struct sockaddr_in6 key; 791 792 switch(addr->sa_family) { 793 case AF_INET6: 794 key = *(struct sockaddr_in6 *)addr; 795 break; 796 case AF_INET: 797 /* convert the address into IPv4-mapped IPv6 address. */ 798 memset(&key, 0, sizeof(key)); 799 key.sin6_family = AF_INET6; 800 key.sin6_len = sizeof(key); 801 _map_v4v6_address( 802 (char *)&((struct sockaddr_in *)addr)->sin_addr, 803 (char *)&key.sin6_addr); 804 break; 805 default: 806 return(NULL); 807 } 808 809 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 810 pol = &ent->pc_policy; 811 matchlen = 0; 812 813 mp = (u_char *)&pol->addrmask.sin6_addr; 814 ep = mp + 16; /* XXX: scope field? */ 815 k = (u_char *)&key.sin6_addr; 816 p = (u_char *)&pol->addr.sin6_addr; 817 for (; mp < ep && *mp; mp++, k++, p++) { 818 m = *mp; 819 if ((*k & m) != *p) 820 goto next; /* not match */ 821 if (m == 0xff) /* short cut for a typical case */ 822 matchlen += 8; 823 else { 824 while (m >= 0x80) { 825 matchlen++; 826 m <<= 1; 827 } 828 } 829 } 830 831 /* matched. check if this is better than the current best. */ 832 if (matchlen > bestmatchlen) { 833 bestent = ent; 834 bestmatchlen = matchlen; 835 } 836 837 next: 838 continue; 839 } 840 841 return(bestent); 842#else 843 return(NULL); 844#endif 845 846} 847 848static void 849set_source(struct ai_order *aio, struct policyhead *ph) 850{ 851 struct addrinfo ai = *aio->aio_ai; 852 struct sockaddr_storage ss; 853 socklen_t srclen; 854 int s; 855 856 /* set unspec ("no source is available"), just in case */ 857 aio->aio_srcsa.sa_family = AF_UNSPEC; 858 aio->aio_srcscope = -1; 859 860 switch(ai.ai_family) { 861 case AF_INET: 862#ifdef INET6 863 case AF_INET6: 864#endif 865 break; 866 default: /* ignore unsupported AFs explicitly */ 867 return; 868 } 869 870 /* XXX: make a dummy addrinfo to call connect() */ 871 ai.ai_socktype = SOCK_DGRAM; 872 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 873 ai.ai_next = NULL; 874 memset(&ss, 0, sizeof(ss)); 875 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 876 ai.ai_addr = (struct sockaddr *)&ss; 877 get_port(&ai, "1", 0); 878 879 /* open a socket to get the source address for the given dst */ 880 if ((s = _socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC, 881 ai.ai_protocol)) < 0) 882 return; /* give up */ 883#ifdef INET6 884 if (ai.ai_family == AF_INET6) { 885 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ai.ai_addr; 886 int off = 0; 887 888 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 889 (void)_setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, 890 (char *)&off, sizeof(off)); 891 } 892#endif 893 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 894 goto cleanup; 895 srclen = ai.ai_addrlen; 896 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 897 aio->aio_srcsa.sa_family = AF_UNSPEC; 898 goto cleanup; 899 } 900 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 901 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 902 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 903#ifdef INET6 904 if (ai.ai_family == AF_INET6) { 905 struct in6_ifreq ifr6; 906 u_int32_t flags6; 907 908 memset(&ifr6, 0, sizeof(ifr6)); 909 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 910 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 911 flags6 = ifr6.ifr_ifru.ifru_flags6; 912 if ((flags6 & IN6_IFF_DEPRECATED)) 913 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 914 } 915 } 916#endif 917 918 cleanup: 919 _close(s); 920 return; 921} 922 923static int 924matchlen(struct sockaddr *src, struct sockaddr *dst) 925{ 926 int match = 0; 927 u_char *s, *d; 928 u_char *lim, r; 929 int addrlen; 930 931 switch (src->sa_family) { 932#ifdef INET6 933 case AF_INET6: 934 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 935 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 936 addrlen = sizeof(struct in6_addr); 937 lim = s + addrlen; 938 break; 939#endif 940 case AF_INET: 941 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 942 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 943 addrlen = sizeof(struct in_addr); 944 lim = s + addrlen; 945 break; 946 default: 947 return(0); 948 } 949 950 while (s < lim) 951 if ((r = (*d++ ^ *s++)) != 0) { 952 while ((r & 0x80) == 0) { 953 match++; 954 r <<= 1; 955 } 956 break; 957 } else 958 match += 8; 959 return(match); 960} 961 962static int 963comp_dst(const void *arg1, const void *arg2) 964{ 965 const struct ai_order *dst1 = arg1, *dst2 = arg2; 966 967 /* 968 * Rule 1: Avoid unusable destinations. 969 * XXX: we currently do not consider if an appropriate route exists. 970 */ 971 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 972 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 973 return(-1); 974 } 975 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 976 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 977 return(1); 978 } 979 980 /* Rule 2: Prefer matching scope. */ 981 if (dst1->aio_dstscope == dst1->aio_srcscope && 982 dst2->aio_dstscope != dst2->aio_srcscope) { 983 return(-1); 984 } 985 if (dst1->aio_dstscope != dst1->aio_srcscope && 986 dst2->aio_dstscope == dst2->aio_srcscope) { 987 return(1); 988 } 989 990 /* Rule 3: Avoid deprecated addresses. */ 991 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 992 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 993 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 994 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 995 return(-1); 996 } 997 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 998 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 999 return(1); 1000 } 1001 } 1002 1003 /* Rule 4: Prefer home addresses. */ 1004 /* XXX: not implemented yet */ 1005 1006 /* Rule 5: Prefer matching label. */ 1007#ifdef INET6 1008 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 1009 dst1->aio_srcpolicy->pc_policy.label == 1010 dst1->aio_dstpolicy->pc_policy.label && 1011 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 1012 dst2->aio_srcpolicy->pc_policy.label != 1013 dst2->aio_dstpolicy->pc_policy.label)) { 1014 return(-1); 1015 } 1016 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 1017 dst2->aio_srcpolicy->pc_policy.label == 1018 dst2->aio_dstpolicy->pc_policy.label && 1019 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 1020 dst1->aio_srcpolicy->pc_policy.label != 1021 dst1->aio_dstpolicy->pc_policy.label)) { 1022 return(1); 1023 } 1024#endif 1025 1026 /* Rule 6: Prefer higher precedence. */ 1027#ifdef INET6 1028 if (dst1->aio_dstpolicy && 1029 (dst2->aio_dstpolicy == NULL || 1030 dst1->aio_dstpolicy->pc_policy.preced > 1031 dst2->aio_dstpolicy->pc_policy.preced)) { 1032 return(-1); 1033 } 1034 if (dst2->aio_dstpolicy && 1035 (dst1->aio_dstpolicy == NULL || 1036 dst2->aio_dstpolicy->pc_policy.preced > 1037 dst1->aio_dstpolicy->pc_policy.preced)) { 1038 return(1); 1039 } 1040#endif 1041 1042 /* Rule 7: Prefer native transport. */ 1043 /* XXX: not implemented yet */ 1044 1045 /* Rule 8: Prefer smaller scope. */ 1046 if (dst1->aio_dstscope >= 0 && 1047 dst1->aio_dstscope < dst2->aio_dstscope) { 1048 return(-1); 1049 } 1050 if (dst2->aio_dstscope >= 0 && 1051 dst2->aio_dstscope < dst1->aio_dstscope) { 1052 return(1); 1053 } 1054 1055 /* 1056 * Rule 9: Use longest matching prefix. 1057 * We compare the match length in a same AF only. 1058 */ 1059 if (dst1->aio_ai->ai_addr->sa_family == 1060 dst2->aio_ai->ai_addr->sa_family && 1061 dst1->aio_ai->ai_addr->sa_family != AF_INET) { 1062 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1063 return(-1); 1064 } 1065 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1066 return(1); 1067 } 1068 } 1069 1070 /* Rule 10: Otherwise, leave the order unchanged. */ 1071 1072 /* 1073 * Note that qsort is unstable; so, we can't return zero and 1074 * expect the order to be unchanged. 1075 * That also means we can't depend on the current position of 1076 * dst2 being after dst1. We must enforce the initial order 1077 * with an explicit compare on the original position. 1078 * The qsort specification requires that "When the same objects 1079 * (consisting of width bytes, irrespective of their current 1080 * positions in the array) are passed more than once to the 1081 * comparison function, the results shall be consistent with one 1082 * another." 1083 * In other words, If A < B, then we must also return B > A. 1084 */ 1085 if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) 1086 return(1); 1087 1088 return(-1); 1089} 1090 1091/* 1092 * Copy from scope.c. 1093 * XXX: we should standardize the functions and link them as standard 1094 * library. 1095 */ 1096static int 1097gai_addr2scopetype(struct sockaddr *sa) 1098{ 1099#ifdef INET6 1100 struct sockaddr_in6 *sa6; 1101#endif 1102 struct sockaddr_in *sa4; 1103 1104 switch(sa->sa_family) { 1105#ifdef INET6 1106 case AF_INET6: 1107 sa6 = (struct sockaddr_in6 *)sa; 1108 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1109 /* just use the scope field of the multicast address */ 1110 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1111 } 1112 /* 1113 * Unicast addresses: map scope type to corresponding scope 1114 * value defined for multcast addresses. 1115 * XXX: hardcoded scope type values are bad... 1116 */ 1117 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1118 return(1); /* node local scope */ 1119 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1120 return(2); /* link-local scope */ 1121 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1122 return(5); /* site-local scope */ 1123 return(14); /* global scope */ 1124 break; 1125#endif 1126 case AF_INET: 1127 /* 1128 * IPv4 pseudo scoping according to RFC 3484. 1129 */ 1130 sa4 = (struct sockaddr_in *)sa; 1131 /* IPv4 autoconfiguration addresses have link-local scope. */ 1132 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1133 ((u_char *)&sa4->sin_addr)[1] == 254) 1134 return(2); 1135 /* Private addresses have site-local scope. */ 1136 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1137 (((u_char *)&sa4->sin_addr)[0] == 172 && 1138 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1139 (((u_char *)&sa4->sin_addr)[0] == 192 && 1140 ((u_char *)&sa4->sin_addr)[1] == 168)) 1141 return(14); /* XXX: It should be 5 unless NAT */ 1142 /* Loopback addresses have link-local scope. */ 1143 if (((u_char *)&sa4->sin_addr)[0] == 127) 1144 return(2); 1145 return(14); 1146 break; 1147 default: 1148 errno = EAFNOSUPPORT; /* is this a good error? */ 1149 return(-1); 1150 } 1151} 1152 1153static int 1154explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1155 struct addrinfo **res) 1156{ 1157 int error; 1158 struct addrinfo sentinel, *cur; 1159 const struct addrinfo *src; 1160 1161 error = 0; 1162 sentinel.ai_next = NULL; 1163 cur = &sentinel; 1164 1165 for (src = src0; src != NULL; src = src->ai_next) { 1166 if (src->ai_family != pai->ai_family) 1167 continue; 1168 1169 cur->ai_next = copy_ai(src); 1170 if (!cur->ai_next) { 1171 error = EAI_MEMORY; 1172 goto fail; 1173 } 1174 1175 cur->ai_next->ai_socktype = pai->ai_socktype; 1176 cur->ai_next->ai_protocol = pai->ai_protocol; 1177 cur = cur->ai_next; 1178 } 1179 1180 *res = sentinel.ai_next; 1181 return 0; 1182 1183fail: 1184 freeaddrinfo(sentinel.ai_next); 1185 return error; 1186} 1187 1188/* 1189 * hostname == NULL. 1190 * passive socket -> anyaddr (0.0.0.0 or ::) 1191 * non-passive socket -> localhost (127.0.0.1 or ::1) 1192 */ 1193static int 1194explore_null(const struct addrinfo *pai, const char *servname, 1195 struct addrinfo **res) 1196{ 1197 int s; 1198 const struct afd *afd; 1199 struct addrinfo *ai; 1200 int error; 1201 1202 *res = NULL; 1203 ai = NULL; 1204 1205 if (pai->ai_family == PF_LOCAL) 1206 return (0); 1207 1208 /* 1209 * filter out AFs that are not supported by the kernel 1210 * XXX errno? 1211 */ 1212 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1213 if (s < 0) { 1214 if (errno != EMFILE) 1215 return 0; 1216 } else 1217 _close(s); 1218 1219 afd = find_afd(pai->ai_family); 1220 if (afd == NULL) 1221 return 0; 1222 1223 if (pai->ai_flags & AI_PASSIVE) { 1224 GET_AI(ai, afd, afd->a_addrany); 1225 GET_PORT(ai, servname); 1226 } else { 1227 GET_AI(ai, afd, afd->a_loopback); 1228 GET_PORT(ai, servname); 1229 } 1230 1231 *res = ai; 1232 return 0; 1233 1234free: 1235 if (ai != NULL) 1236 freeaddrinfo(ai); 1237 return error; 1238} 1239 1240/* 1241 * numeric hostname 1242 */ 1243static int 1244explore_numeric(const struct addrinfo *pai, const char *hostname, 1245 const char *servname, struct addrinfo **res, const char *canonname) 1246{ 1247 const struct afd *afd; 1248 struct addrinfo *ai, ai0; 1249 int error; 1250 char pton[PTON_MAX], path[PATH_MAX], *p; 1251 1252#ifdef CTASSERT 1253 CTASSERT(sizeofmember(struct sockaddr_un, sun_path) <= PATH_MAX); 1254#endif 1255 *res = NULL; 1256 ai = NULL; 1257 1258 afd = find_afd(pai->ai_family); 1259 if (afd == NULL) 1260 return 0; 1261 1262 switch (afd->a_af) { 1263 case AF_LOCAL: 1264 if (hostname[0] != '/') 1265 ERR(EAI_NONAME); 1266 if (strlen(hostname) > afd->a_addrlen) 1267 ERR(EAI_MEMORY); 1268 /* NUL-termination does not need to be guaranteed. */ 1269 strncpy(path, hostname, afd->a_addrlen); 1270 p = &path[0]; 1271 break; 1272 case AF_INET: 1273 /* 1274 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1275 * that are accepted by inet_addr() and its family. The 1276 * accepted forms includes the "classful" one, which inet_pton 1277 * does not accept. So we need to separate the case for 1278 * AF_INET. 1279 */ 1280 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1281 return 0; 1282 p = pton; 1283 break; 1284 default: 1285 if (inet_pton(afd->a_af, hostname, pton) != 1) { 1286 if (pai->ai_family != AF_INET6 || 1287 (pai->ai_flags & AI_V4MAPPED) != AI_V4MAPPED) 1288 return 0; 1289 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1290 return 0; 1291 afd = &afdl[N_INET]; 1292 ai0 = *pai; 1293 ai0.ai_family = AF_INET; 1294 pai = &ai0; 1295 } 1296 p = pton; 1297 break; 1298 } 1299 1300 if (pai->ai_family == afd->a_af) { 1301 GET_AI(ai, afd, p); 1302 GET_PORT(ai, servname); 1303 if ((pai->ai_family == AF_INET || 1304 pai->ai_family == AF_INET6) && 1305 (pai->ai_flags & AI_CANONNAME)) { 1306 /* 1307 * Set the numeric address itself as the canonical 1308 * name, based on a clarification in RFC3493. 1309 */ 1310 GET_CANONNAME(ai, canonname); 1311 } 1312 } else { 1313 /* 1314 * XXX: This should not happen since we already matched the AF 1315 * by find_afd. 1316 */ 1317 ERR(EAI_FAMILY); 1318 } 1319 1320 *res = ai; 1321 return 0; 1322 1323free: 1324bad: 1325 if (ai != NULL) 1326 freeaddrinfo(ai); 1327 return error; 1328} 1329 1330/* 1331 * numeric hostname with scope 1332 */ 1333static int 1334explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1335 const char *servname, struct addrinfo **res) 1336{ 1337#if !defined(SCOPE_DELIMITER) || !defined(INET6) 1338 return explore_numeric(pai, hostname, servname, res, hostname); 1339#else 1340 const struct afd *afd; 1341 struct addrinfo *cur; 1342 int error; 1343 char *cp, *hostname2 = NULL, *scope, *addr; 1344 struct sockaddr_in6 *sin6; 1345 1346 afd = find_afd(pai->ai_family); 1347 if (afd == NULL) 1348 return 0; 1349 1350 if (!afd->a_scoped) 1351 return explore_numeric(pai, hostname, servname, res, hostname); 1352 1353 cp = strchr(hostname, SCOPE_DELIMITER); 1354 if (cp == NULL) 1355 return explore_numeric(pai, hostname, servname, res, hostname); 1356 1357 /* 1358 * Handle special case of <scoped_address><delimiter><scope id> 1359 */ 1360 hostname2 = strdup(hostname); 1361 if (hostname2 == NULL) 1362 return EAI_MEMORY; 1363 /* terminate at the delimiter */ 1364 hostname2[cp - hostname] = '\0'; 1365 addr = hostname2; 1366 scope = cp + 1; 1367 1368 error = explore_numeric(pai, addr, servname, res, hostname); 1369 if (error == 0) { 1370 u_int32_t scopeid; 1371 1372 for (cur = *res; cur; cur = cur->ai_next) { 1373 if (cur->ai_family != AF_INET6) 1374 continue; 1375 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1376 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1377 free(hostname2); 1378 freeaddrinfo(*res); 1379 *res = NULL; 1380 return(EAI_NONAME); /* XXX: is return OK? */ 1381 } 1382 sin6->sin6_scope_id = scopeid; 1383 } 1384 } 1385 1386 free(hostname2); 1387 1388 if (error && *res) { 1389 freeaddrinfo(*res); 1390 *res = NULL; 1391 } 1392 return error; 1393#endif 1394} 1395 1396static int 1397get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1398{ 1399 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1400 ai->ai_canonname = strdup(str); 1401 if (ai->ai_canonname == NULL) 1402 return EAI_MEMORY; 1403 } 1404 return 0; 1405} 1406 1407static struct addrinfo * 1408get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1409{ 1410 char *p; 1411 struct addrinfo *ai; 1412#ifdef INET6 1413 struct in6_addr mapaddr; 1414 1415 if (afd->a_af == AF_INET && (pai->ai_flags & AI_V4MAPPED) != 0) { 1416 afd = &afdl[N_INET6]; 1417 _map_v4v6_address(addr, (char *)&mapaddr); 1418 addr = (char *)&mapaddr; 1419 } 1420#endif 1421 1422 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1423 + (afd->a_socklen)); 1424 if (ai == NULL) 1425 return NULL; 1426 1427 memcpy(ai, pai, sizeof(struct addrinfo)); 1428 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1429 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1430 ai->ai_addr->sa_len = afd->a_socklen; 1431 ai->ai_addrlen = afd->a_socklen; 1432 if (ai->ai_family == PF_LOCAL) { 1433 size_t n = strnlen(addr, afd->a_addrlen); 1434 1435 ai->ai_addrlen -= afd->a_addrlen - n; 1436 ai->ai_addr->sa_len -= afd->a_addrlen - n; 1437 } 1438 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1439 p = (char *)(void *)(ai->ai_addr); 1440 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1441 return ai; 1442} 1443 1444/* XXX need to malloc() the same way we do from other functions! */ 1445static struct addrinfo * 1446copy_ai(const struct addrinfo *pai) 1447{ 1448 struct addrinfo *ai; 1449 size_t l; 1450 1451 l = sizeof(*ai) + pai->ai_addrlen; 1452 if ((ai = (struct addrinfo *)malloc(l)) == NULL) 1453 return NULL; 1454 memset(ai, 0, l); 1455 memcpy(ai, pai, sizeof(*ai)); 1456 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1457 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1458 1459 if (pai->ai_canonname) { 1460 l = strlen(pai->ai_canonname) + 1; 1461 if ((ai->ai_canonname = malloc(l)) == NULL) { 1462 free(ai); 1463 return NULL; 1464 } 1465 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1466 } else { 1467 /* just to make sure */ 1468 ai->ai_canonname = NULL; 1469 } 1470 1471 ai->ai_next = NULL; 1472 1473 return ai; 1474} 1475 1476static int 1477get_portmatch(const struct addrinfo *ai, const char *servname) 1478{ 1479 1480 /* get_port does not touch first argument when matchonly == 1. */ 1481 /* LINTED const cast */ 1482 return get_port((struct addrinfo *)ai, servname, 1); 1483} 1484 1485static int 1486get_port(struct addrinfo *ai, const char *servname, int matchonly) 1487{ 1488 const char *proto; 1489 struct servent *sp; 1490 int port, error; 1491 int allownumeric; 1492 1493 if (servname == NULL) 1494 return 0; 1495 switch (ai->ai_family) { 1496 case AF_LOCAL: 1497 /* AF_LOCAL ignores servname silently. */ 1498 return (0); 1499 case AF_INET: 1500#ifdef AF_INET6 1501 case AF_INET6: 1502#endif 1503 break; 1504 default: 1505 return 0; 1506 } 1507 1508 switch (ai->ai_socktype) { 1509 case SOCK_RAW: 1510 return EAI_SERVICE; 1511 case SOCK_DGRAM: 1512 case SOCK_STREAM: 1513 case SOCK_SEQPACKET: 1514 allownumeric = 1; 1515 break; 1516 case ANY: 1517 switch (ai->ai_family) { 1518 case AF_INET: 1519#ifdef AF_INET6 1520 case AF_INET6: 1521#endif 1522 allownumeric = 1; 1523 break; 1524 default: 1525 allownumeric = 0; 1526 break; 1527 } 1528 break; 1529 default: 1530 return EAI_SOCKTYPE; 1531 } 1532 1533 error = str2number(servname, &port); 1534 if (error == 0) { 1535 if (!allownumeric) 1536 return EAI_SERVICE; 1537 if (port < 0 || port > 65535) 1538 return EAI_SERVICE; 1539 port = htons(port); 1540 } else { 1541 if (ai->ai_flags & AI_NUMERICSERV) 1542 return EAI_NONAME; 1543 1544 switch (ai->ai_protocol) { 1545 case IPPROTO_UDP: 1546 proto = "udp"; 1547 break; 1548 case IPPROTO_TCP: 1549 proto = "tcp"; 1550 break; 1551 case IPPROTO_SCTP: 1552 proto = "sctp"; 1553 break; 1554 case IPPROTO_UDPLITE: 1555 proto = "udplite"; 1556 break; 1557 default: 1558 proto = NULL; 1559 break; 1560 } 1561 1562 if ((sp = getservbyname(servname, proto)) == NULL) 1563 return EAI_SERVICE; 1564 port = sp->s_port; 1565 } 1566 1567 if (!matchonly) { 1568 switch (ai->ai_family) { 1569 case AF_INET: 1570 ((struct sockaddr_in *)(void *) 1571 ai->ai_addr)->sin_port = port; 1572 break; 1573#ifdef INET6 1574 case AF_INET6: 1575 ((struct sockaddr_in6 *)(void *) 1576 ai->ai_addr)->sin6_port = port; 1577 break; 1578#endif 1579 } 1580 } 1581 1582 return 0; 1583} 1584 1585static const struct afd * 1586find_afd(int af) 1587{ 1588 const struct afd *afd; 1589 1590 if (af == PF_UNSPEC) 1591 return NULL; 1592 for (afd = afdl; afd->a_af; afd++) { 1593 if (afd->a_af == af) 1594 return afd; 1595 } 1596 return NULL; 1597} 1598 1599/* 1600 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are 1601 * configured on the local system and correlates with pai->ai_family value. 1602 * If an address family is not configured on the system, it will not be 1603 * queried for. For this purpose, loopback addresses are not considered 1604 * configured addresses. 1605 * 1606 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1607 * _dns_getaddrinfo. 1608 */ 1609static int 1610addrconfig(struct addrinfo *pai) 1611{ 1612 struct ifaddrs *ifaddrs, *ifa; 1613 struct sockaddr_in *sin; 1614#ifdef INET6 1615 struct sockaddr_in6 *sin6; 1616#endif 1617 int seen_inet = 0, seen_inet6 = 0; 1618 1619 if (getifaddrs(&ifaddrs) != 0) 1620 return (0); 1621 1622 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1623 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1624 continue; 1625 switch (ifa->ifa_addr->sa_family) { 1626 case AF_INET: 1627 if (seen_inet) 1628 continue; 1629 sin = (struct sockaddr_in *)(ifa->ifa_addr); 1630 if (htonl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) 1631 continue; 1632 seen_inet = 1; 1633 break; 1634#ifdef INET6 1635 case AF_INET6: 1636 if (seen_inet6) 1637 continue; 1638 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); 1639 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 1640 continue; 1641 if ((ifa->ifa_flags & IFT_LOOP) != 0 && 1642 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 1643 continue; 1644 if (is_ifdisabled(ifa->ifa_name)) 1645 continue; 1646 seen_inet6 = 1; 1647 break; 1648#endif 1649 } 1650 } 1651 freeifaddrs(ifaddrs); 1652 1653 switch(pai->ai_family) { 1654 case AF_INET6: 1655 return (seen_inet6); 1656 case AF_INET: 1657 return (seen_inet); 1658 case AF_UNSPEC: 1659 if (seen_inet == seen_inet6) 1660 return (seen_inet); 1661 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1662 return (1); 1663 } 1664 return (1); 1665} 1666 1667#ifdef INET6 1668static int 1669is_ifdisabled(char *name) 1670{ 1671 struct in6_ndireq nd; 1672 int fd; 1673 1674 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1675 return (-1); 1676 memset(&nd, 0, sizeof(nd)); 1677 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1678 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1679 _close(fd); 1680 return (-1); 1681 } 1682 _close(fd); 1683 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1684} 1685 1686/* convert a string to a scope identifier. XXX: IPv6 specific */ 1687static int 1688ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1689{ 1690 u_long lscopeid; 1691 struct in6_addr *a6; 1692 char *ep; 1693 1694 a6 = &sin6->sin6_addr; 1695 1696 /* empty scopeid portion is invalid */ 1697 if (*scope == '\0') 1698 return -1; 1699 1700 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1701 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1702 /* 1703 * We currently assume a one-to-one mapping between links 1704 * and interfaces, so we simply use interface indices for 1705 * like-local scopes. 1706 */ 1707 *scopeid = if_nametoindex(scope); 1708 if (*scopeid == 0) 1709 goto trynumeric; 1710 return 0; 1711 } 1712 1713 /* still unclear about literal, allow numeric only - placeholder */ 1714 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1715 goto trynumeric; 1716 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1717 goto trynumeric; 1718 else 1719 goto trynumeric; /* global */ 1720 1721 /* try to convert to a numeric id as a last resort */ 1722 trynumeric: 1723 errno = 0; 1724 lscopeid = strtoul(scope, &ep, 10); 1725 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1726 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1727 return 0; 1728 else 1729 return -1; 1730} 1731#endif 1732 1733 1734#ifdef NS_CACHING 1735static int 1736addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1737 void *cache_mdata) 1738{ 1739 res_state statp; 1740 u_long res_options; 1741 1742 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1743 char *hostname; 1744 struct addrinfo *hints; 1745 1746 char *p; 1747 int ai_flags, ai_family, ai_socktype, ai_protocol; 1748 size_t desired_size, size; 1749 1750 statp = __res_state(); 1751 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1752 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1753 1754 hostname = va_arg(ap, char *); 1755 hints = va_arg(ap, struct addrinfo *); 1756 1757 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1758 if (hostname != NULL) { 1759 size = strlen(hostname); 1760 desired_size += size + 1; 1761 } else 1762 size = 0; 1763 1764 if (desired_size > *buffer_size) { 1765 *buffer_size = desired_size; 1766 return (NS_RETURN); 1767 } 1768 1769 if (hints == NULL) 1770 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1771 else { 1772 ai_flags = hints->ai_flags; 1773 ai_family = hints->ai_family; 1774 ai_socktype = hints->ai_socktype; 1775 ai_protocol = hints->ai_protocol; 1776 } 1777 1778 p = buffer; 1779 memcpy(p, &res_options, sizeof(res_options)); 1780 p += sizeof(res_options); 1781 1782 memcpy(p, &op_id, sizeof(int)); 1783 p += sizeof(int); 1784 1785 memcpy(p, &ai_flags, sizeof(int)); 1786 p += sizeof(int); 1787 1788 memcpy(p, &ai_family, sizeof(int)); 1789 p += sizeof(int); 1790 1791 memcpy(p, &ai_socktype, sizeof(int)); 1792 p += sizeof(int); 1793 1794 memcpy(p, &ai_protocol, sizeof(int)); 1795 p += sizeof(int); 1796 1797 if (hostname != NULL) 1798 memcpy(p, hostname, size); 1799 1800 *buffer_size = desired_size; 1801 return (NS_SUCCESS); 1802} 1803 1804static int 1805addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1806 va_list ap, void *cache_mdata) 1807{ 1808 struct addrinfo *ai, *cai; 1809 char *p; 1810 size_t desired_size, size, ai_size; 1811 1812 ai = *((struct addrinfo **)retval); 1813 1814 desired_size = sizeof(size_t); 1815 ai_size = 0; 1816 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1817 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1818 if (cai->ai_canonname != NULL) 1819 desired_size += sizeof(size_t) + 1820 strlen(cai->ai_canonname); 1821 ++ai_size; 1822 } 1823 1824 if (desired_size > *buffer_size) { 1825 /* this assignment is here for future use */ 1826 errno = ERANGE; 1827 *buffer_size = desired_size; 1828 return (NS_RETURN); 1829 } 1830 1831 memset(buffer, 0, desired_size); 1832 p = buffer; 1833 1834 memcpy(p, &ai_size, sizeof(size_t)); 1835 p += sizeof(size_t); 1836 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1837 memcpy(p, cai, sizeof(struct addrinfo)); 1838 p += sizeof(struct addrinfo); 1839 1840 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1841 p += cai->ai_addrlen; 1842 1843 if (cai->ai_canonname != NULL) { 1844 size = strlen(cai->ai_canonname); 1845 memcpy(p, &size, sizeof(size_t)); 1846 p += sizeof(size_t); 1847 1848 memcpy(p, cai->ai_canonname, size); 1849 p += size; 1850 } 1851 } 1852 1853 return (NS_SUCCESS); 1854} 1855 1856static int 1857addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1858 va_list ap, void *cache_mdata) 1859{ 1860 struct addrinfo new_ai, *result, *sentinel, *lasts; 1861 1862 char *p; 1863 size_t ai_size, ai_i, size; 1864 1865 p = buffer; 1866 memcpy(&ai_size, p, sizeof(size_t)); 1867 p += sizeof(size_t); 1868 1869 result = NULL; 1870 lasts = NULL; 1871 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1872 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1873 p += sizeof(struct addrinfo); 1874 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1875 _ALIGNBYTES; 1876 1877 sentinel = (struct addrinfo *)malloc(size); 1878 memset(sentinel, 0, size); 1879 1880 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1881 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1882 sizeof(struct addrinfo)); 1883 1884 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1885 p += new_ai.ai_addrlen; 1886 1887 if (new_ai.ai_canonname != NULL) { 1888 memcpy(&size, p, sizeof(size_t)); 1889 p += sizeof(size_t); 1890 1891 sentinel->ai_canonname = (char *)malloc(size + 1); 1892 memset(sentinel->ai_canonname, 0, size + 1); 1893 1894 memcpy(sentinel->ai_canonname, p, size); 1895 p += size; 1896 } 1897 1898 if (result == NULL) { 1899 result = sentinel; 1900 lasts = sentinel; 1901 } else { 1902 lasts->ai_next = sentinel; 1903 lasts = sentinel; 1904 } 1905 } 1906 1907 *((struct addrinfo **)retval) = result; 1908 return (NS_SUCCESS); 1909} 1910#endif /* NS_CACHING */ 1911 1912/* 1913 * FQDN hostname, DNS lookup 1914 */ 1915static int 1916explore_fqdn(const struct addrinfo *pai, const char *hostname, 1917 const char *servname, struct addrinfo **res) 1918{ 1919 struct addrinfo *result; 1920 struct addrinfo *cur; 1921 int error = 0; 1922 1923#ifdef NS_CACHING 1924 static const nss_cache_info cache_info = 1925 NS_COMMON_CACHE_INFO_INITIALIZER( 1926 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1927 addrinfo_unmarshal_func); 1928#endif 1929 static const ns_dtab dtab[] = { 1930 NS_FILES_CB(_files_getaddrinfo, NULL) 1931 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1932 NS_NIS_CB(_yp_getaddrinfo, NULL) 1933#ifdef NS_CACHING 1934 NS_CACHE_CB(&cache_info) 1935#endif 1936 { 0 } 1937 }; 1938 1939 result = NULL; 1940 1941 /* 1942 * if the servname does not match socktype/protocol, ignore it. 1943 */ 1944 if (get_portmatch(pai, servname) != 0) 1945 return 0; 1946 1947 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1948 default_dns_files, hostname, pai)) { 1949 case NS_TRYAGAIN: 1950 error = EAI_AGAIN; 1951 goto free; 1952 case NS_UNAVAIL: 1953 error = EAI_FAIL; 1954 goto free; 1955 case NS_NOTFOUND: 1956 error = EAI_NONAME; 1957 goto free; 1958 case NS_SUCCESS: 1959 error = 0; 1960 for (cur = result; cur; cur = cur->ai_next) { 1961 GET_PORT(cur, servname); 1962 /* canonname should be filled already */ 1963 } 1964 break; 1965 } 1966 1967 *res = result; 1968 1969 return 0; 1970 1971free: 1972 if (result) 1973 freeaddrinfo(result); 1974 return error; 1975} 1976 1977#ifdef DEBUG 1978static const char AskedForGot[] = 1979 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1980#endif 1981 1982static struct addrinfo * 1983getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1984 const struct addrinfo *pai, res_state res) 1985{ 1986 struct addrinfo sentinel, *cur; 1987 struct addrinfo ai; 1988 const struct afd *afd; 1989 char *canonname; 1990 const HEADER *hp; 1991 const u_char *cp; 1992 int n; 1993 const u_char *eom; 1994 char *bp, *ep; 1995 int type, class, ancount, qdcount; 1996 int haveanswer, had_error; 1997 char tbuf[MAXDNAME]; 1998 int (*name_ok)(const char *); 1999 char hostbuf[8*1024]; 2000 2001 memset(&sentinel, 0, sizeof(sentinel)); 2002 cur = &sentinel; 2003 2004 canonname = NULL; 2005 eom = answer->buf + anslen; 2006 switch (qtype) { 2007 case T_A: 2008 case T_AAAA: 2009 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 2010 name_ok = res_hnok; 2011 break; 2012 default: 2013 return (NULL); /* XXX should be abort(); */ 2014 } 2015 /* 2016 * find first satisfactory answer 2017 */ 2018 hp = &answer->hdr; 2019 ancount = ntohs(hp->ancount); 2020 qdcount = ntohs(hp->qdcount); 2021 bp = hostbuf; 2022 ep = hostbuf + sizeof hostbuf; 2023 cp = answer->buf + HFIXEDSZ; 2024 if (qdcount != 1) { 2025 RES_SET_H_ERRNO(res, NO_RECOVERY); 2026 return (NULL); 2027 } 2028 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2029 if ((n < 0) || !(*name_ok)(bp)) { 2030 RES_SET_H_ERRNO(res, NO_RECOVERY); 2031 return (NULL); 2032 } 2033 cp += n + QFIXEDSZ; 2034 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 2035 /* res_send() has already verified that the query name is the 2036 * same as the one we sent; this just gets the expanded name 2037 * (i.e., with the succeeding search-domain tacked on). 2038 */ 2039 n = strlen(bp) + 1; /* for the \0 */ 2040 if (n >= MAXHOSTNAMELEN) { 2041 RES_SET_H_ERRNO(res, NO_RECOVERY); 2042 return (NULL); 2043 } 2044 canonname = bp; 2045 bp += n; 2046 /* The qname can be abbreviated, but h_name is now absolute. */ 2047 qname = canonname; 2048 } 2049 haveanswer = 0; 2050 had_error = 0; 2051 while (ancount-- > 0 && cp < eom && !had_error) { 2052 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2053 if ((n < 0) || !(*name_ok)(bp)) { 2054 had_error++; 2055 continue; 2056 } 2057 cp += n; /* name */ 2058 type = _getshort(cp); 2059 cp += INT16SZ; /* type */ 2060 class = _getshort(cp); 2061 cp += INT16SZ + INT32SZ; /* class, TTL */ 2062 n = _getshort(cp); 2063 cp += INT16SZ; /* len */ 2064 if (class != C_IN) { 2065 /* XXX - debug? syslog? */ 2066 cp += n; 2067 continue; /* XXX - had_error++ ? */ 2068 } 2069 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 2070 type == T_CNAME) { 2071 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 2072 if ((n < 0) || !(*name_ok)(tbuf)) { 2073 had_error++; 2074 continue; 2075 } 2076 cp += n; 2077 /* Get canonical name. */ 2078 n = strlen(tbuf) + 1; /* for the \0 */ 2079 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 2080 had_error++; 2081 continue; 2082 } 2083 strlcpy(bp, tbuf, ep - bp); 2084 canonname = bp; 2085 bp += n; 2086 continue; 2087 } 2088 if (qtype == T_ANY) { 2089 if (!(type == T_A || type == T_AAAA)) { 2090 cp += n; 2091 continue; 2092 } 2093 } else if (type != qtype) { 2094#ifdef DEBUG 2095 if (type != T_KEY && type != T_SIG && 2096 type != ns_t_dname) 2097 syslog(LOG_NOTICE|LOG_AUTH, 2098 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2099 qname, p_class(C_IN), p_type(qtype), 2100 p_type(type)); 2101#endif 2102 cp += n; 2103 continue; /* XXX - had_error++ ? */ 2104 } 2105 switch (type) { 2106 case T_A: 2107 case T_AAAA: 2108 if (strcasecmp(canonname, bp) != 0) { 2109#ifdef DEBUG 2110 syslog(LOG_NOTICE|LOG_AUTH, 2111 AskedForGot, canonname, bp); 2112#endif 2113 cp += n; 2114 continue; /* XXX - had_error++ ? */ 2115 } 2116 if (type == T_A && n != INADDRSZ) { 2117 cp += n; 2118 continue; 2119 } 2120 if (type == T_AAAA && n != IN6ADDRSZ) { 2121 cp += n; 2122 continue; 2123 } 2124#ifdef FILTER_V4MAPPED 2125 if (type == T_AAAA) { 2126 struct in6_addr in6; 2127 memcpy(&in6, cp, sizeof(in6)); 2128 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2129 cp += n; 2130 continue; 2131 } 2132 } 2133#endif 2134 if (!haveanswer) { 2135 int nn; 2136 2137 canonname = bp; 2138 nn = strlen(bp) + 1; /* for the \0 */ 2139 bp += nn; 2140 } 2141 2142 /* don't overwrite pai */ 2143 ai = *pai; 2144 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2145 afd = find_afd(ai.ai_family); 2146 if (afd == NULL) { 2147 cp += n; 2148 continue; 2149 } 2150 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2151 if (cur->ai_next == NULL) 2152 had_error++; 2153 while (cur && cur->ai_next) 2154 cur = cur->ai_next; 2155 cp += n; 2156 break; 2157 default: 2158 abort(); 2159 } 2160 if (!had_error) 2161 haveanswer++; 2162 } 2163 if (haveanswer) { 2164#if defined(RESOLVSORT) 2165 /* 2166 * We support only IPv4 address for backward 2167 * compatibility against gethostbyname(3). 2168 */ 2169 if (res->nsort && qtype == T_A) { 2170 if (addr4sort(&sentinel, res) < 0) { 2171 freeaddrinfo(sentinel.ai_next); 2172 RES_SET_H_ERRNO(res, NO_RECOVERY); 2173 return NULL; 2174 } 2175 } 2176#endif /*RESOLVSORT*/ 2177 if (!canonname) 2178 (void)get_canonname(pai, sentinel.ai_next, qname); 2179 else 2180 (void)get_canonname(pai, sentinel.ai_next, canonname); 2181 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2182 return sentinel.ai_next; 2183 } 2184 2185 /* 2186 * We could have walked a CNAME chain, but the ultimate target 2187 * may not have what we looked for. 2188 */ 2189 RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : NO_RECOVERY); 2190 return NULL; 2191} 2192 2193#ifdef RESOLVSORT 2194struct addr_ptr { 2195 struct addrinfo *ai; 2196 int aval; 2197}; 2198 2199static int 2200addr4sort(struct addrinfo *sentinel, res_state res) 2201{ 2202 struct addrinfo *ai; 2203 struct addr_ptr *addrs, addr; 2204 struct sockaddr_in *sin; 2205 int naddrs, i, j; 2206 int needsort = 0; 2207 2208 if (!sentinel) 2209 return -1; 2210 naddrs = 0; 2211 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2212 naddrs++; 2213 if (naddrs < 2) 2214 return 0; /* We don't need sorting. */ 2215 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2216 return -1; 2217 i = 0; 2218 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2219 sin = (struct sockaddr_in *)ai->ai_addr; 2220 for (j = 0; (unsigned)j < res->nsort; j++) { 2221 if (res->sort_list[j].addr.s_addr == 2222 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2223 break; 2224 } 2225 addrs[i].ai = ai; 2226 addrs[i].aval = j; 2227 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2228 needsort = i; 2229 i++; 2230 } 2231 if (!needsort) { 2232 free(addrs); 2233 return 0; 2234 } 2235 2236 while (needsort < naddrs) { 2237 for (j = needsort - 1; j >= 0; j--) { 2238 if (addrs[j].aval > addrs[j+1].aval) { 2239 addr = addrs[j]; 2240 addrs[j] = addrs[j + 1]; 2241 addrs[j + 1] = addr; 2242 } else 2243 break; 2244 } 2245 needsort++; 2246 } 2247 2248 ai = sentinel; 2249 for (i = 0; i < naddrs; ++i) { 2250 ai->ai_next = addrs[i].ai; 2251 ai = ai->ai_next; 2252 } 2253 ai->ai_next = NULL; 2254 free(addrs); 2255 return 0; 2256} 2257#endif /*RESOLVSORT*/ 2258 2259/*ARGSUSED*/ 2260static int 2261_dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2262{ 2263 struct addrinfo *ai, ai0; 2264 querybuf *buf, *buf2; 2265 const char *hostname; 2266 const struct addrinfo *pai; 2267 struct addrinfo sentinel, *cur; 2268 struct res_target q, q2; 2269 res_state res; 2270 2271 ai = NULL; 2272 2273 hostname = va_arg(ap, char *); 2274 pai = va_arg(ap, const struct addrinfo *); 2275 2276 memset(&q, 0, sizeof(q)); 2277 memset(&q2, 0, sizeof(q2)); 2278 memset(&sentinel, 0, sizeof(sentinel)); 2279 cur = &sentinel; 2280 2281 res = __res_state(); 2282 2283 buf = malloc(sizeof(*buf)); 2284 if (!buf) { 2285 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2286 return NS_NOTFOUND; 2287 } 2288 buf2 = malloc(sizeof(*buf2)); 2289 if (!buf2) { 2290 free(buf); 2291 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2292 return NS_NOTFOUND; 2293 } 2294 2295 if (pai->ai_family == AF_INET6 && 2296 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) { 2297 ai0 = *pai; 2298 ai0.ai_family = AF_UNSPEC; 2299 pai = &ai0; 2300 } 2301 2302 switch (pai->ai_family) { 2303 case AF_UNSPEC: 2304 q.name = hostname; 2305 q.qclass = C_IN; 2306 q.qtype = T_A; 2307 q.answer = buf->buf; 2308 q.anslen = sizeof(buf->buf); 2309 q.next = &q2; 2310 q2.name = hostname; 2311 q2.qclass = C_IN; 2312 q2.qtype = T_AAAA; 2313 q2.answer = buf2->buf; 2314 q2.anslen = sizeof(buf2->buf); 2315 break; 2316 case AF_INET: 2317 q.name = hostname; 2318 q.qclass = C_IN; 2319 q.qtype = T_A; 2320 q.answer = buf->buf; 2321 q.anslen = sizeof(buf->buf); 2322 break; 2323 case AF_INET6: 2324 q.name = hostname; 2325 q.qclass = C_IN; 2326 q.qtype = T_AAAA; 2327 q.answer = buf->buf; 2328 q.anslen = sizeof(buf->buf); 2329 break; 2330 default: 2331 free(buf); 2332 free(buf2); 2333 return NS_UNAVAIL; 2334 } 2335 2336 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2337 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2338 free(buf); 2339 free(buf2); 2340 return NS_NOTFOUND; 2341 } 2342 2343 if (res_searchN(hostname, &q, res) < 0) { 2344 free(buf); 2345 free(buf2); 2346 return NS_NOTFOUND; 2347 } 2348 /* prefer IPv6 */ 2349 if (q.next) { 2350 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2351 if (ai != NULL) { 2352 cur->ai_next = ai; 2353 while (cur && cur->ai_next) 2354 cur = cur->ai_next; 2355 } 2356 } 2357 if (ai == NULL || pai->ai_family != AF_UNSPEC || 2358 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) != AI_V4MAPPED) { 2359 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2360 if (ai != NULL) 2361 cur->ai_next = ai; 2362 } 2363 free(buf); 2364 free(buf2); 2365 if (sentinel.ai_next == NULL) 2366 switch (res->res_h_errno) { 2367 case HOST_NOT_FOUND: 2368 case NO_DATA: 2369 return NS_NOTFOUND; 2370 case TRY_AGAIN: 2371 return NS_TRYAGAIN; 2372 default: 2373 return NS_UNAVAIL; 2374 } 2375 *((struct addrinfo **)rv) = sentinel.ai_next; 2376 return NS_SUCCESS; 2377} 2378 2379static void 2380_sethtent(FILE **hostf) 2381{ 2382 if (!*hostf) 2383 *hostf = fopen(_PATH_HOSTS, "re"); 2384 else 2385 rewind(*hostf); 2386} 2387 2388static void 2389_endhtent(FILE **hostf) 2390{ 2391 if (*hostf) { 2392 (void) fclose(*hostf); 2393 *hostf = NULL; 2394 } 2395} 2396 2397static struct addrinfo * 2398_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2399{ 2400 char *p; 2401 char *cp, *tname, *cname; 2402 struct addrinfo hints, *res0, *res; 2403 int error; 2404 const char *addr; 2405 char hostbuf[8*1024]; 2406 2407 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2408 return (NULL); 2409again: 2410 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2411 return (NULL); 2412 if (*p == '#') 2413 goto again; 2414 cp = strpbrk(p, "#\n"); 2415 if (cp != NULL) 2416 *cp = '\0'; 2417 if (!(cp = strpbrk(p, " \t"))) 2418 goto again; 2419 *cp++ = '\0'; 2420 addr = p; 2421 cname = NULL; 2422 /* if this is not something we're looking for, skip it. */ 2423 while (cp && *cp) { 2424 if (*cp == ' ' || *cp == '\t') { 2425 cp++; 2426 continue; 2427 } 2428 tname = cp; 2429 if (cname == NULL) 2430 cname = cp; 2431 if ((cp = strpbrk(cp, " \t")) != NULL) 2432 *cp++ = '\0'; 2433 if (strcasecmp(name, tname) == 0) 2434 goto found; 2435 } 2436 goto again; 2437 2438found: 2439 /* we should not glob socktype/protocol here */ 2440 memset(&hints, 0, sizeof(hints)); 2441 hints.ai_family = pai->ai_family; 2442 hints.ai_socktype = SOCK_DGRAM; 2443 hints.ai_protocol = 0; 2444 hints.ai_flags = AI_NUMERICHOST; 2445 if (pai->ai_family == AF_INET6 && 2446 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2447 hints.ai_flags |= AI_V4MAPPED; 2448 error = getaddrinfo(addr, "0", &hints, &res0); 2449 if (error) 2450 goto again; 2451#ifdef FILTER_V4MAPPED 2452 /* XXX should check all items in the chain */ 2453 if (res0->ai_family == AF_INET6 && 2454 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2455 freeaddrinfo(res0); 2456 goto again; 2457 } 2458#endif 2459 for (res = res0; res; res = res->ai_next) { 2460 /* cover it up */ 2461 res->ai_flags = pai->ai_flags; 2462 res->ai_socktype = pai->ai_socktype; 2463 res->ai_protocol = pai->ai_protocol; 2464 2465 if (pai->ai_flags & AI_CANONNAME) { 2466 if (get_canonname(pai, res, cname) != 0) { 2467 freeaddrinfo(res0); 2468 goto again; 2469 } 2470 } 2471 } 2472 return res0; 2473} 2474 2475static struct addrinfo * 2476_getht(FILE **hostf, const char *name, const struct addrinfo *pai, 2477 struct addrinfo *cur) 2478{ 2479 struct addrinfo *p; 2480 2481 while ((p = _gethtent(hostf, name, pai)) != NULL) { 2482 cur->ai_next = p; 2483 while (cur && cur->ai_next) 2484 cur = cur->ai_next; 2485 } 2486 return (cur); 2487} 2488 2489/*ARGSUSED*/ 2490static int 2491_files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2492{ 2493 const char *name; 2494 const struct addrinfo *pai; 2495 struct addrinfo sentinel, *cur; 2496 FILE *hostf = NULL; 2497 2498 name = va_arg(ap, char *); 2499 pai = va_arg(ap, struct addrinfo *); 2500 2501 memset(&sentinel, 0, sizeof(sentinel)); 2502 cur = &sentinel; 2503 2504 _sethtent(&hostf); 2505 if (pai->ai_family == AF_INET6 && 2506 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) == AI_V4MAPPED) { 2507 struct addrinfo ai0 = *pai; 2508 2509 ai0.ai_flags &= ~AI_V4MAPPED; 2510 cur = _getht(&hostf, name, &ai0, cur); 2511 if (sentinel.ai_next == NULL) { 2512 _sethtent(&hostf); 2513 ai0.ai_flags |= AI_V4MAPPED; 2514 cur = _getht(&hostf, name, &ai0, cur); 2515 } 2516 } else 2517 cur = _getht(&hostf, name, pai, cur); 2518 _endhtent(&hostf); 2519 2520 *((struct addrinfo **)rv) = sentinel.ai_next; 2521 if (sentinel.ai_next == NULL) 2522 return NS_NOTFOUND; 2523 return NS_SUCCESS; 2524} 2525 2526#ifdef YP 2527/*ARGSUSED*/ 2528static struct addrinfo * 2529_yphostent(char *line, const struct addrinfo *pai) 2530{ 2531 struct addrinfo sentinel, *cur; 2532 struct addrinfo hints, *res, *res0; 2533 int error; 2534 char *p = line; 2535 const char *addr, *canonname; 2536 char *nextline; 2537 char *cp; 2538 2539 addr = canonname = NULL; 2540 2541 memset(&sentinel, 0, sizeof(sentinel)); 2542 cur = &sentinel; 2543 2544nextline: 2545 /* terminate line */ 2546 cp = strchr(p, '\n'); 2547 if (cp) { 2548 *cp++ = '\0'; 2549 nextline = cp; 2550 } else 2551 nextline = NULL; 2552 2553 cp = strpbrk(p, " \t"); 2554 if (cp == NULL) { 2555 if (canonname == NULL) 2556 return (NULL); 2557 else 2558 goto done; 2559 } 2560 *cp++ = '\0'; 2561 2562 addr = p; 2563 2564 while (cp && *cp) { 2565 if (*cp == ' ' || *cp == '\t') { 2566 cp++; 2567 continue; 2568 } 2569 if (!canonname) 2570 canonname = cp; 2571 if ((cp = strpbrk(cp, " \t")) != NULL) 2572 *cp++ = '\0'; 2573 } 2574 2575 hints = *pai; 2576 hints.ai_flags = AI_NUMERICHOST; 2577 if (pai->ai_family == AF_INET6 && 2578 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2579 hints.ai_flags |= AI_V4MAPPED; 2580 error = getaddrinfo(addr, NULL, &hints, &res0); 2581 if (error == 0) { 2582 for (res = res0; res; res = res->ai_next) { 2583 /* cover it up */ 2584 res->ai_flags = pai->ai_flags; 2585 2586 if (pai->ai_flags & AI_CANONNAME) 2587 (void)get_canonname(pai, res, canonname); 2588 } 2589 } else 2590 res0 = NULL; 2591 if (res0) { 2592 cur->ai_next = res0; 2593 while (cur && cur->ai_next) 2594 cur = cur->ai_next; 2595 } 2596 2597 if (nextline) { 2598 p = nextline; 2599 goto nextline; 2600 } 2601 2602done: 2603 return sentinel.ai_next; 2604} 2605 2606/*ARGSUSED*/ 2607static int 2608_yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2609{ 2610 struct addrinfo sentinel, *cur; 2611 struct addrinfo *ai = NULL; 2612 char *ypbuf; 2613 int ypbuflen, r; 2614 const char *name; 2615 const struct addrinfo *pai; 2616 char *ypdomain; 2617 2618 if (_yp_check(&ypdomain) == 0) 2619 return NS_UNAVAIL; 2620 2621 name = va_arg(ap, char *); 2622 pai = va_arg(ap, const struct addrinfo *); 2623 2624 memset(&sentinel, 0, sizeof(sentinel)); 2625 cur = &sentinel; 2626 2627 /* ipnodes.byname can hold both IPv4/v6 */ 2628 r = yp_match(ypdomain, "ipnodes.byname", name, 2629 (int)strlen(name), &ypbuf, &ypbuflen); 2630 if (r == 0) { 2631 ai = _yphostent(ypbuf, pai); 2632 if (ai) { 2633 cur->ai_next = ai; 2634 while (cur && cur->ai_next) 2635 cur = cur->ai_next; 2636 } 2637 free(ypbuf); 2638 } 2639 2640 if (ai != NULL) { 2641 struct sockaddr_in6 *sin6; 2642 2643 switch (ai->ai_family) { 2644 case AF_INET: 2645 goto done; 2646 case AF_INET6: 2647 sin6 = (struct sockaddr_in6 *)ai->ai_addr; 2648 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 2649 goto done; 2650 break; 2651 } 2652 } 2653 2654 /* hosts.byname is only for IPv4 (Solaris8) */ 2655 if (pai->ai_family == AF_UNSPEC || pai->ai_family == AF_INET || 2656 ((pai->ai_family == AF_INET6 && 2657 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) && 2658 (ai == NULL || (pai->ai_flags & AI_ALL) == AI_ALL))) { 2659 r = yp_match(ypdomain, "hosts.byname", name, 2660 (int)strlen(name), &ypbuf, &ypbuflen); 2661 if (r == 0) { 2662 struct addrinfo ai4; 2663 2664 ai4 = *pai; 2665 if (pai->ai_family == AF_UNSPEC) 2666 ai4.ai_family = AF_INET; 2667 ai = _yphostent(ypbuf, &ai4); 2668 if (ai) { 2669 cur->ai_next = ai; 2670 while (cur && cur->ai_next) 2671 cur = cur->ai_next; 2672 } 2673 free(ypbuf); 2674 } 2675 } 2676 2677done: 2678 if (sentinel.ai_next == NULL) { 2679 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2680 return NS_NOTFOUND; 2681 } 2682 *((struct addrinfo **)rv) = sentinel.ai_next; 2683 return NS_SUCCESS; 2684} 2685#endif 2686 2687/* resolver logic */ 2688 2689/* 2690 * Formulate a normal query, send, and await answer. 2691 * Returned answer is placed in supplied buffer "answer". 2692 * Perform preliminary check of answer, returning success only 2693 * if no error is indicated and the answer count is nonzero. 2694 * Return the size of the response on success, -1 on error. 2695 * Error number is left in h_errno. 2696 * 2697 * Caller must parse answer and determine whether it answers the question. 2698 */ 2699static int 2700res_queryN(const char *name, struct res_target *target, res_state res) 2701{ 2702 u_char *buf; 2703 HEADER *hp; 2704 int n; 2705 u_int oflags; 2706 struct res_target *t; 2707 int rcode; 2708 int ancount; 2709 2710 rcode = NOERROR; 2711 ancount = 0; 2712 2713 buf = malloc(MAXPACKET); 2714 if (!buf) { 2715 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2716 return -1; 2717 } 2718 2719 for (t = target; t; t = t->next) { 2720 int class, type; 2721 u_char *answer; 2722 int anslen; 2723 2724 hp = (HEADER *)(void *)t->answer; 2725 2726 /* make it easier... */ 2727 class = t->qclass; 2728 type = t->qtype; 2729 answer = t->answer; 2730 anslen = t->anslen; 2731 2732 oflags = res->_flags; 2733 2734again: 2735 hp->rcode = NOERROR; /* default */ 2736 2737#ifdef DEBUG 2738 if (res->options & RES_DEBUG) 2739 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2740#endif 2741 2742 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2743 buf, MAXPACKET); 2744 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2745 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2746 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2747 if (n <= 0) { 2748#ifdef DEBUG 2749 if (res->options & RES_DEBUG) 2750 printf(";; res_query: mkquery failed\n"); 2751#endif 2752 free(buf); 2753 RES_SET_H_ERRNO(res, NO_RECOVERY); 2754 return (n); 2755 } 2756 n = res_nsend(res, buf, n, answer, anslen); 2757 if (n < 0) { 2758 /* 2759 * if the query choked with EDNS0, retry 2760 * without EDNS0 2761 */ 2762 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2763 != 0U && 2764 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2765 res->_flags |= RES_F_EDNS0ERR; 2766 if (res->options & RES_DEBUG) 2767 printf(";; res_nquery: retry without EDNS0\n"); 2768 goto again; 2769 } 2770 rcode = hp->rcode; /* record most recent error */ 2771#ifdef DEBUG 2772 if (res->options & RES_DEBUG) 2773 printf(";; res_query: send error\n"); 2774#endif 2775 continue; 2776 } 2777 2778 if (n > anslen) 2779 hp->rcode = FORMERR; /* XXX not very informative */ 2780 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2781 rcode = hp->rcode; /* record most recent error */ 2782#ifdef DEBUG 2783 if (res->options & RES_DEBUG) 2784 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2785 ntohs(hp->ancount)); 2786#endif 2787 continue; 2788 } 2789 2790 ancount += ntohs(hp->ancount); 2791 2792 t->n = n; 2793 } 2794 2795 free(buf); 2796 2797 if (ancount == 0) { 2798 switch (rcode) { 2799 case NXDOMAIN: 2800 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2801 break; 2802 case SERVFAIL: 2803 RES_SET_H_ERRNO(res, TRY_AGAIN); 2804 break; 2805 case NOERROR: 2806 RES_SET_H_ERRNO(res, NO_DATA); 2807 break; 2808 case FORMERR: 2809 case NOTIMP: 2810 case REFUSED: 2811 default: 2812 RES_SET_H_ERRNO(res, NO_RECOVERY); 2813 break; 2814 } 2815 return (-1); 2816 } 2817 return (ancount); 2818} 2819 2820/* 2821 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2822 * Return the size of the response on success, -1 on error. 2823 * If enabled, implement search rules until answer or unrecoverable failure 2824 * is detected. Error code, if any, is left in h_errno. 2825 */ 2826static int 2827res_searchN(const char *name, struct res_target *target, res_state res) 2828{ 2829 const char *cp, * const *domain; 2830 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2831 u_int dots; 2832 int trailing_dot, ret, saved_herrno; 2833 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2834 int tried_as_is = 0; 2835 int searched = 0; 2836 char abuf[MAXDNAME]; 2837 2838 errno = 0; 2839 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2840 dots = 0; 2841 for (cp = name; *cp; cp++) 2842 dots += (*cp == '.'); 2843 trailing_dot = 0; 2844 if (cp > name && *--cp == '.') 2845 trailing_dot++; 2846 2847 /* 2848 * if there aren't any dots, it could be a user-level alias 2849 */ 2850 if (!dots && 2851 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2852 return (res_queryN(cp, target, res)); 2853 2854 /* 2855 * If there are enough dots in the name, let's just give it a 2856 * try 'as is'. The threshold can be set with the "ndots" option. 2857 * Also, query 'as is', if there is a trailing dot in the name. 2858 */ 2859 saved_herrno = -1; 2860 if (dots >= res->ndots || trailing_dot) { 2861 ret = res_querydomainN(name, NULL, target, res); 2862 if (ret > 0 || trailing_dot) 2863 return (ret); 2864 if (errno == ECONNREFUSED) { 2865 RES_SET_H_ERRNO(res, TRY_AGAIN); 2866 return (-1); 2867 } 2868 switch (res->res_h_errno) { 2869 case NO_DATA: 2870 case HOST_NOT_FOUND: 2871 break; 2872 case TRY_AGAIN: 2873 if (hp->rcode == SERVFAIL) 2874 break; 2875 /* FALLTHROUGH */ 2876 default: 2877 return (-1); 2878 } 2879 saved_herrno = res->res_h_errno; 2880 tried_as_is++; 2881 } 2882 2883 /* 2884 * We do at least one level of search if 2885 * - there is no dot and RES_DEFNAME is set, or 2886 * - there is at least one dot, there is no trailing dot, 2887 * and RES_DNSRCH is set. 2888 */ 2889 if ((!dots && (res->options & RES_DEFNAMES)) || 2890 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2891 int done = 0; 2892 2893 for (domain = (const char * const *)res->dnsrch; 2894 *domain && !done; 2895 domain++) { 2896 searched = 1; 2897 2898 if (domain[0][0] == '\0' || 2899 (domain[0][0] == '.' && domain[0][1] == '\0')) 2900 root_on_list++; 2901 2902 if (root_on_list && tried_as_is) 2903 continue; 2904 2905 ret = res_querydomainN(name, *domain, target, res); 2906 if (ret > 0) 2907 return (ret); 2908 2909 /* 2910 * If no server present, give up. 2911 * If name isn't found in this domain, 2912 * keep trying higher domains in the search list 2913 * (if that's enabled). 2914 * On a NO_DATA error, keep trying, otherwise 2915 * a wildcard entry of another type could keep us 2916 * from finding this entry higher in the domain. 2917 * If we get some other error (negative answer or 2918 * server failure), then stop searching up, 2919 * but try the input name below in case it's 2920 * fully-qualified. 2921 */ 2922 if (errno == ECONNREFUSED) { 2923 RES_SET_H_ERRNO(res, TRY_AGAIN); 2924 return (-1); 2925 } 2926 2927 switch (res->res_h_errno) { 2928 case NO_DATA: 2929 got_nodata++; 2930 /* FALLTHROUGH */ 2931 case HOST_NOT_FOUND: 2932 /* keep trying */ 2933 break; 2934 case TRY_AGAIN: 2935 got_servfail++; 2936 if (hp->rcode == SERVFAIL) { 2937 /* try next search element, if any */ 2938 break; 2939 } 2940 /* FALLTHROUGH */ 2941 default: 2942 /* anything else implies that we're done */ 2943 done++; 2944 } 2945 /* 2946 * if we got here for some reason other than DNSRCH, 2947 * we only wanted one iteration of the loop, so stop. 2948 */ 2949 if (!(res->options & RES_DNSRCH)) 2950 done++; 2951 } 2952 } 2953 2954 switch (res->res_h_errno) { 2955 case NO_DATA: 2956 case HOST_NOT_FOUND: 2957 break; 2958 case TRY_AGAIN: 2959 if (hp->rcode == SERVFAIL) 2960 break; 2961 /* FALLTHROUGH */ 2962 default: 2963 goto giveup; 2964 } 2965 2966 /* 2967 * If the query has not already been tried as is then try it 2968 * unless RES_NOTLDQUERY is set and there were no dots. 2969 */ 2970 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2971 !(tried_as_is || root_on_list)) { 2972 ret = res_querydomainN(name, NULL, target, res); 2973 if (ret > 0) 2974 return (ret); 2975 } 2976 2977 /* 2978 * if we got here, we didn't satisfy the search. 2979 * if we did an initial full query, return that query's h_errno 2980 * (note that we wouldn't be here if that query had succeeded). 2981 * else if we ever got a nodata, send that back as the reason. 2982 * else send back meaningless h_errno, that being the one from 2983 * the last DNSRCH we did. 2984 */ 2985giveup: 2986 if (saved_herrno != -1) 2987 RES_SET_H_ERRNO(res, saved_herrno); 2988 else if (got_nodata) 2989 RES_SET_H_ERRNO(res, NO_DATA); 2990 else if (got_servfail) 2991 RES_SET_H_ERRNO(res, TRY_AGAIN); 2992 return (-1); 2993} 2994 2995/* 2996 * Perform a call on res_query on the concatenation of name and domain, 2997 * removing a trailing dot from name if domain is NULL. 2998 */ 2999static int 3000res_querydomainN(const char *name, const char *domain, 3001 struct res_target *target, res_state res) 3002{ 3003 char nbuf[MAXDNAME]; 3004 const char *longname = nbuf; 3005 size_t n, d; 3006 3007#ifdef DEBUG 3008 if (res->options & RES_DEBUG) 3009 printf(";; res_querydomain(%s, %s)\n", 3010 name, domain?domain:"<Nil>"); 3011#endif 3012 if (domain == NULL) { 3013 /* 3014 * Check for trailing '.'; 3015 * copy without '.' if present. 3016 */ 3017 n = strlen(name); 3018 if (n >= MAXDNAME) { 3019 RES_SET_H_ERRNO(res, NO_RECOVERY); 3020 return (-1); 3021 } 3022 if (n > 0 && name[--n] == '.') { 3023 strncpy(nbuf, name, n); 3024 nbuf[n] = '\0'; 3025 } else 3026 longname = name; 3027 } else { 3028 n = strlen(name); 3029 d = strlen(domain); 3030 if (n + d + 1 >= MAXDNAME) { 3031 RES_SET_H_ERRNO(res, NO_RECOVERY); 3032 return (-1); 3033 } 3034 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 3035 } 3036 return (res_queryN(longname, target, res)); 3037} 3038