1/* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 2 3/*- 4 * SPDX-License-Identifier: BSD-3-Clause 5 * 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34/* 35 * Issues to be discussed: 36 * - Return values. There are nonstandard return values defined and used 37 * in the source code. This is because RFC2553 is silent about which error 38 * code must be returned for which situation. 39 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 40 * invalid. Current code accepts NULL to be compatible with other OSes. 41 * 42 * Note: 43 * - The code filters out AFs that are not supported by the kernel, 44 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 45 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 46 * in ai_flags? 47 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 48 * (1) what should we do against numeric hostname (2) what should we do 49 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 50 * non-loopback address configured? global address configured? 51 * 52 * OS specific notes for freebsd4: 53 * - FreeBSD supported $GAI. The code does not. 54 */ 55 56#include "namespace.h" 57#include <sys/param.h> 58#include <sys/socket.h> 59#include <net/if.h> 60#include <netinet/in.h> 61#include <net/if_types.h> 62#include <ifaddrs.h> 63#include <sys/queue.h> 64#ifdef INET6 65#include <sys/sysctl.h> 66#include <sys/ioctl.h> 67#include <netinet6/in6_var.h> 68#include <netinet6/nd6.h> 69#endif 70#include <arpa/inet.h> 71#include <arpa/nameser.h> 72#include <rpc/rpc.h> 73#include <rpcsvc/yp_prot.h> 74#include <rpcsvc/ypclnt.h> 75#include <netdb.h> 76#include <resolv.h> 77#include <string.h> 78#include <stdlib.h> 79#include <stddef.h> 80#include <ctype.h> 81#include <unistd.h> 82#include <stdio.h> 83#include <errno.h> 84 85#include "res_config.h" 86 87#ifdef DEBUG 88#include <syslog.h> 89#endif 90 91#include <stdarg.h> 92#include <nsswitch.h> 93#include "un-namespace.h" 94#include "netdb_private.h" 95#include "libc_private.h" 96#ifdef NS_CACHING 97#include "nscache.h" 98#endif 99 100#define ANY 0 101#define YES 1 102#define NO 0 103 104static const char in_addrany[] = { 0, 0, 0, 0 }; 105static const char in_loopback[] = { 127, 0, 0, 1 }; 106#ifdef INET6 107static const char in6_addrany[] = { 108 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 109}; 110static const char in6_loopback[] = { 111 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 112}; 113#endif 114 115struct policyqueue { 116 TAILQ_ENTRY(policyqueue) pc_entry; 117#ifdef INET6 118 struct in6_addrpolicy pc_policy; 119#endif 120}; 121TAILQ_HEAD(policyhead, policyqueue); 122 123static const struct afd { 124 int a_af; 125 int a_addrlen; 126 socklen_t a_socklen; 127 int a_off; 128 const char *a_addrany; 129 const char *a_loopback; 130 int a_scoped; 131} afdl [] = { 132#ifdef INET6 133#define N_INET6 0 134 {PF_INET6, sizeof(struct in6_addr), 135 sizeof(struct sockaddr_in6), 136 offsetof(struct sockaddr_in6, sin6_addr), 137 in6_addrany, in6_loopback, 1}, 138#define N_INET 1 139#define N_LOCAL 2 140#else 141#define N_INET 0 142#define N_LOCAL 1 143#endif 144 {PF_INET, sizeof(struct in_addr), 145 sizeof(struct sockaddr_in), 146 offsetof(struct sockaddr_in, sin_addr), 147 in_addrany, in_loopback, 0}, 148#define sizeofmember(type, member) (sizeof(((type *)0)->member)) 149 {PF_LOCAL, sizeofmember(struct sockaddr_un, sun_path), 150 sizeof(struct sockaddr_un), 151 offsetof(struct sockaddr_un, sun_path), 152 NULL, NULL, 0}, 153 {0, 0, 0, 0, NULL, NULL, 0}, 154}; 155 156struct explore { 157 int e_af; 158 int e_socktype; 159 int e_protocol; 160 int e_wild; 161#define AF_ANY 0x01 162#define SOCKTYPE_ANY 0x02 163#define PROTOCOL_ANY 0x04 164#define WILD_AF(ex) ((ex)->e_wild & AF_ANY) 165#define WILD_SOCKTYPE(ex) ((ex)->e_wild & SOCKTYPE_ANY) 166#define WILD_PROTOCOL(ex) ((ex)->e_wild & PROTOCOL_ANY) 167}; 168 169static const struct explore explore[] = { 170#ifdef INET6 171 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 172 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 173 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, 174 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 175 { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 176 AF_ANY | SOCKTYPE_ANY }, 177 { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 178 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 179 { PF_INET6, SOCK_DGRAM, IPPROTO_UDPLITE, 180 AF_ANY | SOCKTYPE_ANY }, 181 { PF_INET6, SOCK_RAW, ANY, 182 AF_ANY | PROTOCOL_ANY }, 183#endif 184 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, 185 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 186 { PF_INET, SOCK_STREAM, IPPROTO_TCP, 187 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 188 { PF_INET, SOCK_STREAM, IPPROTO_SCTP, 189 AF_ANY | SOCKTYPE_ANY }, 190 { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 191 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 192 { PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE, 193 AF_ANY | SOCKTYPE_ANY }, 194 { PF_INET, SOCK_RAW, ANY, 195 AF_ANY | PROTOCOL_ANY }, 196 { PF_LOCAL, SOCK_DGRAM, ANY, 197 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 198 { PF_LOCAL, SOCK_STREAM, ANY, 199 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 200 { PF_LOCAL, SOCK_SEQPACKET, ANY, 201 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 202 { -1, 0, 0, 0 }, 203}; 204 205#ifdef INET6 206#define PTON_MAX 16 207#else 208#define PTON_MAX 4 209#endif 210 211#define AIO_SRCFLAG_DEPRECATED 0x1 212 213struct ai_order { 214 union { 215 struct sockaddr_storage aiou_ss; 216 struct sockaddr aiou_sa; 217 } aio_src_un; 218#define aio_srcsa aio_src_un.aiou_sa 219 u_int32_t aio_srcflag; 220 int aio_srcscope; 221 int aio_dstscope; 222 struct policyqueue *aio_srcpolicy; 223 struct policyqueue *aio_dstpolicy; 224 struct addrinfo *aio_ai; 225 int aio_matchlen; 226 int aio_initial_sequence; 227}; 228 229static const ns_src default_dns_files[] = { 230 { NSSRC_FILES, NS_SUCCESS }, 231 { NSSRC_DNS, NS_SUCCESS }, 232 { 0 } 233}; 234 235struct 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 246typedef union { 247 HEADER hdr; 248 u_char buf[MAXPACKET]; 249} querybuf; 250 251static int str2number(const char *, int *); 252static int explore_copy(const struct addrinfo *, const struct addrinfo *, 253 struct addrinfo **); 254static int explore_null(const struct addrinfo *, 255 const char *, struct addrinfo **); 256static int explore_numeric(const struct addrinfo *, const char *, 257 const char *, struct addrinfo **, const char *); 258static int explore_numeric_scope(const struct addrinfo *, const char *, 259 const char *, struct addrinfo **); 260static int get_canonname(const struct addrinfo *, 261 struct addrinfo *, const char *); 262static struct addrinfo *get_ai(const struct addrinfo *, 263 const struct afd *, const char *); 264static struct addrinfo *copy_ai(const struct addrinfo *); 265static int get_portmatch(const struct addrinfo *, const char *); 266static int get_port(struct addrinfo *, const char *, int); 267static const struct afd *find_afd(int); 268static int addrconfig(struct addrinfo *); 269#ifdef INET6 270static int is_ifdisabled(char *); 271#endif 272static void set_source(struct ai_order *, struct policyhead *); 273static int comp_dst(const void *, const void *); 274#ifdef INET6 275static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 276#endif 277static int gai_addr2scopetype(struct sockaddr *); 278 279static int explore_fqdn(const struct addrinfo *, const char *, 280 const char *, struct addrinfo **); 281 282static int reorder(struct addrinfo *); 283static int get_addrselectpolicy(struct policyhead *); 284static void free_addrselectpolicy(struct policyhead *); 285static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 286 struct policyhead *); 287static int matchlen(struct sockaddr *, struct sockaddr *); 288 289static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 290 const struct addrinfo *, res_state); 291#if defined(RESOLVSORT) 292static int addr4sort(struct addrinfo *, res_state); 293#endif 294static int _dns_getaddrinfo(void *, void *, va_list); 295static void _sethtent(FILE **); 296static void _endhtent(FILE **); 297static struct addrinfo *_gethtent(FILE **, const char *, 298 const struct addrinfo *); 299static int _files_getaddrinfo(void *, void *, va_list); 300#ifdef YP 301static struct addrinfo *_yphostent(char *, const struct addrinfo *); 302static int _yp_getaddrinfo(void *, void *, va_list); 303#endif 304#ifdef NS_CACHING 305static int addrinfo_id_func(char *, size_t *, va_list, void *); 306static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 307static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 308#endif 309 310static int res_queryN(const char *, struct res_target *, res_state); 311static int res_searchN(const char *, struct res_target *, res_state); 312static 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) \ 318do { \ 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) \ 328do { \ 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) \ 336do { \ 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) \ 344do { \ 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 356void 357freeaddrinfo(struct addrinfo *ai) 358{ 359 struct addrinfo *next; 360 361 while (ai != NULL) { 362 next = ai->ai_next; 363 free(ai->ai_canonname); 364 /* no need to free(ai->ai_addr) */ 365 free(ai); 366 ai = next; 367 } 368} 369 370static int 371str2number(const char *p, int *portp) 372{ 373 char *ep; 374 unsigned long v; 375 376 if (*p == '\0') 377 return -1; 378 ep = NULL; 379 errno = 0; 380 v = strtoul(p, &ep, 10); 381 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 382 *portp = v; 383 return 0; 384 } else 385 return -1; 386} 387 388int 389getaddrinfo(const char *hostname, const char *servname, 390 const struct addrinfo *hints, struct addrinfo **res) 391{ 392 struct addrinfo sentinel; 393 struct addrinfo *cur; 394 int error = 0; 395 struct addrinfo ai, ai0, *afai; 396 struct addrinfo *pai; 397 const struct afd *afd; 398 const struct explore *ex; 399 struct addrinfo *afailist[nitems(afdl)]; 400 struct addrinfo *afai_unspec; 401 int found; 402 int numeric = 0; 403 404 /* ensure we return NULL on errors */ 405 *res = NULL; 406 407 memset(&ai, 0, sizeof(ai)); 408 409 memset(afailist, 0, sizeof(afailist)); 410 afai_unspec = NULL; 411 412 memset(&sentinel, 0, sizeof(sentinel)); 413 cur = &sentinel; 414 pai = &ai; 415 pai->ai_flags = 0; 416 pai->ai_family = PF_UNSPEC; 417 pai->ai_socktype = ANY; 418 pai->ai_protocol = ANY; 419 pai->ai_addrlen = 0; 420 pai->ai_canonname = NULL; 421 pai->ai_addr = NULL; 422 pai->ai_next = NULL; 423 424 if (hostname == NULL && servname == NULL) 425 return EAI_NONAME; 426 if (hints) { 427 /* error check for hints */ 428 if (hints->ai_addrlen || hints->ai_canonname || 429 hints->ai_addr || hints->ai_next) 430 ERR(EAI_BADHINTS); /* xxx */ 431 if (hints->ai_flags & ~AI_MASK) 432 ERR(EAI_BADFLAGS); 433 switch (hints->ai_family) { 434 case PF_UNSPEC: 435 case PF_LOCAL: 436 case PF_INET: 437#ifdef INET6 438 case PF_INET6: 439#endif 440 break; 441 default: 442 ERR(EAI_FAMILY); 443 } 444 memcpy(pai, hints, sizeof(*pai)); 445 446 /* 447 * if both socktype/protocol are specified, check if they 448 * are meaningful combination. 449 */ 450 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 451 for (ex = explore; ex->e_af >= 0; ex++) { 452 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 453 WILD_AF(ex))) 454 continue; 455 if (!MATCH(pai->ai_socktype, ex->e_socktype, 456 WILD_SOCKTYPE(ex))) 457 continue; 458 if (!MATCH(pai->ai_protocol, ex->e_protocol, 459 WILD_PROTOCOL(ex))) 460 continue; 461 462 /* matched */ 463 break; 464 } 465 466 if (ex->e_af < 0) 467 ERR(EAI_BADHINTS); 468 } 469 } 470 471 /* 472 * RFC 3493: AI_ALL and AI_V4MAPPED are effective only against 473 * AF_INET6 query. They need to be ignored if specified in other 474 * occasions. 475 */ 476 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 477 case AI_V4MAPPED: 478 case AI_ALL | AI_V4MAPPED: 479#ifdef INET6 480 if (pai->ai_family != AF_INET6) 481 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 482 break; 483#endif 484 case AI_ALL: 485 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 486 break; 487 } 488 489 /* 490 * check for special cases. (1) numeric servname is disallowed if 491 * socktype/protocol are left unspecified. (2) servname is disallowed 492 * for raw and other inet{,6} sockets. 493 */ 494 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 495#ifdef PF_INET6 496 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 497#endif 498 ) { 499 ai0 = *pai; /* backup *pai */ 500 501 if (pai->ai_family == PF_UNSPEC) { 502#ifdef PF_INET6 503 pai->ai_family = PF_INET6; 504#else 505 pai->ai_family = PF_INET; 506#endif 507 } 508 error = get_portmatch(pai, servname); 509 if (error) 510 goto bad; 511 512 *pai = ai0; 513 } 514 515 ai0 = *pai; 516 517 /* 518 * NULL hostname, or numeric hostname. 519 * If numeric representation of AF1 can be interpreted as FQDN 520 * representation of AF2, we need to think again about the code below. 521 */ 522 found = 0; 523 for (afd = afdl; afd->a_af; afd++) { 524 *pai = ai0; 525 526 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 527 continue; 528 529 if (pai->ai_family == PF_UNSPEC) 530 pai->ai_family = afd->a_af; 531 532 if (hostname == NULL) { 533 error = explore_null(pai, servname, 534 &afailist[afd - afdl]); 535 536 /* 537 * Errors from explore_null should be unexpected and 538 * be caught to avoid returning an incomplete result. 539 */ 540 if (error != 0) 541 goto bad; 542 } else { 543 error = explore_numeric_scope(pai, hostname, servname, 544 &afailist[afd - afdl]); 545 546 /* 547 * explore_numeric_scope returns an error for address 548 * families that do not match that of hostname. 549 * Thus we should not catch the error at this moment. 550 */ 551 } 552 553 if (!error && afailist[afd - afdl]) 554 found++; 555 } 556 if (found) { 557 numeric = 1; 558 goto globcopy; 559 } 560 561 if (hostname == NULL) 562 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 563 if (pai->ai_flags & AI_NUMERICHOST) 564 ERR(EAI_NONAME); 565 566 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 567 ERR(EAI_FAIL); 568 569 /* 570 * hostname as alphabetical name. 571 */ 572 *pai = ai0; 573 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 574 575globcopy: 576 for (ex = explore; ex->e_af >= 0; ex++) { 577 *pai = ai0; 578 579 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 580 continue; 581 if (!MATCH(pai->ai_socktype, ex->e_socktype, 582 WILD_SOCKTYPE(ex))) 583 continue; 584 if (!MATCH(pai->ai_protocol, ex->e_protocol, 585 WILD_PROTOCOL(ex))) 586 continue; 587 588 if (pai->ai_family == PF_UNSPEC) 589 pai->ai_family = ex->e_af; 590 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 591 pai->ai_socktype = ex->e_socktype; 592 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 593 pai->ai_protocol = ex->e_protocol; 594 595 /* 596 * if the servname does not match socktype/protocol, ignore it. 597 */ 598 if (get_portmatch(pai, servname) != 0) 599 continue; 600 601 if (afai_unspec) 602 afai = afai_unspec; 603 else { 604 if ((afd = find_afd(pai->ai_family)) == NULL) 605 continue; 606 /* XXX assumes that afd points inside afdl[] */ 607 afai = afailist[afd - afdl]; 608 } 609 if (!afai) 610 continue; 611 612 error = explore_copy(pai, afai, &cur->ai_next); 613 if (error != 0) 614 goto bad; 615 616 while (cur && cur->ai_next) 617 cur = cur->ai_next; 618 } 619 620 /* 621 * ensure we return either: 622 * - error == 0, non-NULL *res 623 * - error != 0, NULL *res 624 */ 625 if (error == 0) { 626 if (sentinel.ai_next) { 627 /* 628 * If the returned entry is for an active connection, 629 * and the given name is not numeric, reorder the 630 * list, so that the application would try the list 631 * in the most efficient order. Since the head entry 632 * of the original list may contain ai_canonname and 633 * that entry may be moved elsewhere in the new list, 634 * we keep the pointer and will restore it in the new 635 * head entry. (Note that RFC3493 requires the head 636 * entry store it when requested by the caller). 637 */ 638 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 639 if (!numeric) { 640 char *canonname; 641 642 canonname = 643 sentinel.ai_next->ai_canonname; 644 sentinel.ai_next->ai_canonname = NULL; 645 (void)reorder(&sentinel); 646 if (sentinel.ai_next->ai_canonname == 647 NULL) { 648 sentinel.ai_next->ai_canonname 649 = canonname; 650 } else if (canonname != NULL) 651 free(canonname); 652 } 653 } 654 *res = sentinel.ai_next; 655 } else 656 error = EAI_FAIL; 657 } 658 659bad: 660 if (afai_unspec) 661 freeaddrinfo(afai_unspec); 662 for (afd = afdl; afd->a_af; afd++) { 663 if (afailist[afd - afdl]) 664 freeaddrinfo(afailist[afd - afdl]); 665 } 666 if (!*res) 667 if (sentinel.ai_next) 668 freeaddrinfo(sentinel.ai_next); 669 670 return (error); 671} 672 673static int 674reorder(struct addrinfo *sentinel) 675{ 676 struct addrinfo *ai, **aip; 677 struct ai_order *aio; 678 int i, n; 679 struct policyhead policyhead; 680 681 /* count the number of addrinfo elements for sorting. */ 682 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 683 ; 684 685 /* 686 * If the number is small enough, we can skip the reordering process. 687 */ 688 if (n <= 1) 689 return(n); 690 691 /* allocate a temporary array for sort and initialization of it. */ 692 if ((aio = calloc(n, sizeof(*aio))) == NULL) 693 return(n); /* give up reordering */ 694 695 /* retrieve address selection policy from the kernel */ 696 TAILQ_INIT(&policyhead); 697 if (!get_addrselectpolicy(&policyhead)) { 698 /* no policy is installed into kernel, we don't sort. */ 699 free(aio); 700 return (n); 701 } 702 703 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 704 aio[i].aio_ai = ai; 705 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 706 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 707 &policyhead); 708 set_source(&aio[i], &policyhead); 709 aio[i].aio_initial_sequence = i; 710 } 711 712 /* perform sorting. */ 713 qsort(aio, n, sizeof(*aio), comp_dst); 714 715 /* reorder the addrinfo chain. */ 716 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 717 *aip = aio[i].aio_ai; 718 aip = &aio[i].aio_ai->ai_next; 719 } 720 *aip = NULL; 721 722 /* cleanup and return */ 723 free(aio); 724 free_addrselectpolicy(&policyhead); 725 return(n); 726} 727 728static int 729get_addrselectpolicy(struct policyhead *head) 730{ 731#ifdef INET6 732 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 733 size_t l; 734 char *buf; 735 struct in6_addrpolicy *pol, *ep; 736 737 if (sysctl(mib, nitems(mib), NULL, &l, NULL, 0) < 0) 738 return (0); 739 if (l == 0) 740 return (0); 741 if ((buf = malloc(l)) == NULL) 742 return (0); 743 if (sysctl(mib, nitems(mib), buf, &l, NULL, 0) < 0) { 744 free(buf); 745 return (0); 746 } 747 748 ep = (struct in6_addrpolicy *)(buf + l); 749 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 750 struct policyqueue *new; 751 752 if ((new = malloc(sizeof(*new))) == NULL) { 753 free_addrselectpolicy(head); /* make the list empty */ 754 break; 755 } 756 new->pc_policy = *pol; 757 TAILQ_INSERT_TAIL(head, new, pc_entry); 758 } 759 760 free(buf); 761 return (1); 762#else 763 return (0); 764#endif 765} 766 767static void 768free_addrselectpolicy(struct policyhead *head) 769{ 770 struct policyqueue *ent, *nent; 771 772 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 773 nent = TAILQ_NEXT(ent, pc_entry); 774 TAILQ_REMOVE(head, ent, pc_entry); 775 free(ent); 776 } 777} 778 779static struct policyqueue * 780match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 781{ 782#ifdef INET6 783 struct policyqueue *ent, *bestent = NULL; 784 struct in6_addrpolicy *pol; 785 int matchlen, bestmatchlen = -1; 786 u_char *mp, *ep, *k, *p, m; 787 struct sockaddr_in6 key; 788 789 switch(addr->sa_family) { 790 case AF_INET6: 791 key = *(struct sockaddr_in6 *)addr; 792 break; 793 case AF_INET: 794 /* convert the address into IPv4-mapped IPv6 address. */ 795 memset(&key, 0, sizeof(key)); 796 key.sin6_family = AF_INET6; 797 key.sin6_len = sizeof(key); 798 _map_v4v6_address( 799 (char *)&((struct sockaddr_in *)addr)->sin_addr, 800 (char *)&key.sin6_addr); 801 break; 802 default: 803 return(NULL); 804 } 805 806 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 807 pol = &ent->pc_policy; 808 matchlen = 0; 809 810 mp = (u_char *)&pol->addrmask.sin6_addr; 811 ep = mp + 16; /* XXX: scope field? */ 812 k = (u_char *)&key.sin6_addr; 813 p = (u_char *)&pol->addr.sin6_addr; 814 for (; mp < ep && *mp; mp++, k++, p++) { 815 m = *mp; 816 if ((*k & m) != *p) 817 goto next; /* not match */ 818 if (m == 0xff) /* short cut for a typical case */ 819 matchlen += 8; 820 else { 821 while (m >= 0x80) { 822 matchlen++; 823 m <<= 1; 824 } 825 } 826 } 827 828 /* matched. check if this is better than the current best. */ 829 if (matchlen > bestmatchlen) { 830 bestent = ent; 831 bestmatchlen = matchlen; 832 } 833 834 next: 835 continue; 836 } 837 838 return(bestent); 839#else 840 return(NULL); 841#endif 842 843} 844 845static void 846set_source(struct ai_order *aio, struct policyhead *ph) 847{ 848 struct addrinfo ai = *aio->aio_ai; 849 struct sockaddr_storage ss; 850 socklen_t srclen; 851 int s; 852 853 /* set unspec ("no source is available"), just in case */ 854 aio->aio_srcsa.sa_family = AF_UNSPEC; 855 aio->aio_srcscope = -1; 856 857 switch(ai.ai_family) { 858 case AF_INET: 859#ifdef INET6 860 case AF_INET6: 861#endif 862 break; 863 default: /* ignore unsupported AFs explicitly */ 864 return; 865 } 866 867 /* XXX: make a dummy addrinfo to call connect() */ 868 ai.ai_socktype = SOCK_DGRAM; 869 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 870 ai.ai_next = NULL; 871 memset(&ss, 0, sizeof(ss)); 872 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 873 ai.ai_addr = (struct sockaddr *)&ss; 874 get_port(&ai, "1", 0); 875 876 /* open a socket to get the source address for the given dst */ 877 if ((s = _socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC, 878 ai.ai_protocol)) < 0) 879 return; /* give up */ 880#ifdef INET6 881 if (ai.ai_family == AF_INET6) { 882 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ai.ai_addr; 883 int off = 0; 884 885 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 886 (void)_setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, 887 (char *)&off, sizeof(off)); 888 } 889#endif 890 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 891 goto cleanup; 892 srclen = ai.ai_addrlen; 893 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 894 aio->aio_srcsa.sa_family = AF_UNSPEC; 895 goto cleanup; 896 } 897 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 898 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 899 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 900#ifdef INET6 901 if (ai.ai_family == AF_INET6) { 902 struct in6_ifreq ifr6; 903 u_int32_t flags6; 904 905 memset(&ifr6, 0, sizeof(ifr6)); 906 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 907 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 908 flags6 = ifr6.ifr_ifru.ifru_flags6; 909 if ((flags6 & IN6_IFF_DEPRECATED)) 910 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 911 } 912 } 913#endif 914 915 cleanup: 916 _close(s); 917 return; 918} 919 920static int 921matchlen(struct sockaddr *src, struct sockaddr *dst) 922{ 923 int match = 0; 924 u_char *s, *d; 925 u_char *lim, r; 926 int addrlen; 927 928 switch (src->sa_family) { 929#ifdef INET6 930 case AF_INET6: 931 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 932 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 933 addrlen = sizeof(struct in6_addr); 934 lim = s + addrlen; 935 break; 936#endif 937 case AF_INET: 938 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 939 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 940 addrlen = sizeof(struct in_addr); 941 lim = s + addrlen; 942 break; 943 default: 944 return(0); 945 } 946 947 while (s < lim) 948 if ((r = (*d++ ^ *s++)) != 0) { 949 while ((r & 0x80) == 0) { 950 match++; 951 r <<= 1; 952 } 953 break; 954 } else 955 match += 8; 956 return(match); 957} 958 959static int 960comp_dst(const void *arg1, const void *arg2) 961{ 962 const struct ai_order *dst1 = arg1, *dst2 = arg2; 963 964 /* 965 * Rule 1: Avoid unusable destinations. 966 * XXX: we currently do not consider if an appropriate route exists. 967 */ 968 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 969 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 970 return(-1); 971 } 972 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 973 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 974 return(1); 975 } 976 977 /* Rule 2: Prefer matching scope. */ 978 if (dst1->aio_dstscope == dst1->aio_srcscope && 979 dst2->aio_dstscope != dst2->aio_srcscope) { 980 return(-1); 981 } 982 if (dst1->aio_dstscope != dst1->aio_srcscope && 983 dst2->aio_dstscope == dst2->aio_srcscope) { 984 return(1); 985 } 986 987 /* Rule 3: Avoid deprecated addresses. */ 988 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 989 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 990 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 991 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 992 return(-1); 993 } 994 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 995 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 996 return(1); 997 } 998 } 999 1000 /* Rule 4: Prefer home addresses. */ 1001 /* XXX: not implemented yet */ 1002 1003 /* Rule 5: Prefer matching label. */ 1004#ifdef INET6 1005 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 1006 dst1->aio_srcpolicy->pc_policy.label == 1007 dst1->aio_dstpolicy->pc_policy.label && 1008 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 1009 dst2->aio_srcpolicy->pc_policy.label != 1010 dst2->aio_dstpolicy->pc_policy.label)) { 1011 return(-1); 1012 } 1013 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 1014 dst2->aio_srcpolicy->pc_policy.label == 1015 dst2->aio_dstpolicy->pc_policy.label && 1016 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 1017 dst1->aio_srcpolicy->pc_policy.label != 1018 dst1->aio_dstpolicy->pc_policy.label)) { 1019 return(1); 1020 } 1021#endif 1022 1023 /* Rule 6: Prefer higher precedence. */ 1024#ifdef INET6 1025 if (dst1->aio_dstpolicy && 1026 (dst2->aio_dstpolicy == NULL || 1027 dst1->aio_dstpolicy->pc_policy.preced > 1028 dst2->aio_dstpolicy->pc_policy.preced)) { 1029 return(-1); 1030 } 1031 if (dst2->aio_dstpolicy && 1032 (dst1->aio_dstpolicy == NULL || 1033 dst2->aio_dstpolicy->pc_policy.preced > 1034 dst1->aio_dstpolicy->pc_policy.preced)) { 1035 return(1); 1036 } 1037#endif 1038 1039 /* Rule 7: Prefer native transport. */ 1040 /* XXX: not implemented yet */ 1041 1042 /* Rule 8: Prefer smaller scope. */ 1043 if (dst1->aio_dstscope >= 0 && 1044 dst1->aio_dstscope < dst2->aio_dstscope) { 1045 return(-1); 1046 } 1047 if (dst2->aio_dstscope >= 0 && 1048 dst2->aio_dstscope < dst1->aio_dstscope) { 1049 return(1); 1050 } 1051 1052 /* 1053 * Rule 9: Use longest matching prefix. 1054 * We compare the match length in a same AF only. 1055 */ 1056 if (dst1->aio_ai->ai_addr->sa_family == 1057 dst2->aio_ai->ai_addr->sa_family && 1058 dst1->aio_ai->ai_addr->sa_family != AF_INET) { 1059 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1060 return(-1); 1061 } 1062 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1063 return(1); 1064 } 1065 } 1066 1067 /* Rule 10: Otherwise, leave the order unchanged. */ 1068 1069 /* 1070 * Note that qsort is unstable; so, we can't return zero and 1071 * expect the order to be unchanged. 1072 * That also means we can't depend on the current position of 1073 * dst2 being after dst1. We must enforce the initial order 1074 * with an explicit compare on the original position. 1075 * The qsort specification requires that "When the same objects 1076 * (consisting of width bytes, irrespective of their current 1077 * positions in the array) are passed more than once to the 1078 * comparison function, the results shall be consistent with one 1079 * another." 1080 * In other words, If A < B, then we must also return B > A. 1081 */ 1082 if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) 1083 return(1); 1084 1085 return(-1); 1086} 1087 1088/* 1089 * Copy from scope.c. 1090 * XXX: we should standardize the functions and link them as standard 1091 * library. 1092 */ 1093static int 1094gai_addr2scopetype(struct sockaddr *sa) 1095{ 1096#ifdef INET6 1097 struct sockaddr_in6 *sa6; 1098#endif 1099 struct sockaddr_in *sa4; 1100 1101 switch(sa->sa_family) { 1102#ifdef INET6 1103 case AF_INET6: 1104 sa6 = (struct sockaddr_in6 *)sa; 1105 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1106 /* just use the scope field of the multicast address */ 1107 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1108 } 1109 /* 1110 * Unicast addresses: map scope type to corresponding scope 1111 * value defined for multcast addresses. 1112 * XXX: hardcoded scope type values are bad... 1113 */ 1114 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1115 return(1); /* node local scope */ 1116 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1117 return(2); /* link-local scope */ 1118 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1119 return(5); /* site-local scope */ 1120 return(14); /* global scope */ 1121 break; 1122#endif 1123 case AF_INET: 1124 /* 1125 * IPv4 pseudo scoping according to RFC 3484. 1126 */ 1127 sa4 = (struct sockaddr_in *)sa; 1128 /* IPv4 autoconfiguration addresses have link-local scope. */ 1129 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1130 ((u_char *)&sa4->sin_addr)[1] == 254) 1131 return(2); 1132 /* Private addresses have site-local scope. */ 1133 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1134 (((u_char *)&sa4->sin_addr)[0] == 172 && 1135 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1136 (((u_char *)&sa4->sin_addr)[0] == 192 && 1137 ((u_char *)&sa4->sin_addr)[1] == 168)) 1138 return(14); /* XXX: It should be 5 unless NAT */ 1139 /* Loopback addresses have link-local scope. */ 1140 if (((u_char *)&sa4->sin_addr)[0] == 127) 1141 return(2); 1142 return(14); 1143 break; 1144 default: 1145 errno = EAFNOSUPPORT; /* is this a good error? */ 1146 return(-1); 1147 } 1148} 1149 1150static int 1151explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1152 struct addrinfo **res) 1153{ 1154 int error; 1155 struct addrinfo sentinel, *cur; 1156 const struct addrinfo *src; 1157 1158 error = 0; 1159 sentinel.ai_next = NULL; 1160 cur = &sentinel; 1161 1162 for (src = src0; src != NULL; src = src->ai_next) { 1163 if (src->ai_family != pai->ai_family) 1164 continue; 1165 1166 cur->ai_next = copy_ai(src); 1167 if (!cur->ai_next) { 1168 error = EAI_MEMORY; 1169 goto fail; 1170 } 1171 1172 cur->ai_next->ai_socktype = pai->ai_socktype; 1173 cur->ai_next->ai_protocol = pai->ai_protocol; 1174 cur = cur->ai_next; 1175 } 1176 1177 *res = sentinel.ai_next; 1178 return 0; 1179 1180fail: 1181 freeaddrinfo(sentinel.ai_next); 1182 return error; 1183} 1184 1185/* 1186 * hostname == NULL. 1187 * passive socket -> anyaddr (0.0.0.0 or ::) 1188 * non-passive socket -> localhost (127.0.0.1 or ::1) 1189 */ 1190static int 1191explore_null(const struct addrinfo *pai, const char *servname, 1192 struct addrinfo **res) 1193{ 1194 int s; 1195 const struct afd *afd; 1196 struct addrinfo *ai; 1197 int error; 1198 1199 *res = NULL; 1200 ai = NULL; 1201 1202 if (pai->ai_family == PF_LOCAL) 1203 return (0); 1204 1205 /* 1206 * filter out AFs that are not supported by the kernel 1207 * XXX errno? 1208 */ 1209 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1210 if (s < 0) { 1211 if (errno != EMFILE) 1212 return 0; 1213 } else 1214 _close(s); 1215 1216 afd = find_afd(pai->ai_family); 1217 if (afd == NULL) 1218 return 0; 1219 1220 if (pai->ai_flags & AI_PASSIVE) { 1221 GET_AI(ai, afd, afd->a_addrany); 1222 GET_PORT(ai, servname); 1223 } else { 1224 GET_AI(ai, afd, afd->a_loopback); 1225 GET_PORT(ai, servname); 1226 } 1227 1228 *res = ai; 1229 return 0; 1230 1231free: 1232 if (ai != NULL) 1233 freeaddrinfo(ai); 1234 return error; 1235} 1236 1237/* 1238 * numeric hostname 1239 */ 1240static int 1241explore_numeric(const struct addrinfo *pai, const char *hostname, 1242 const char *servname, struct addrinfo **res, const char *canonname) 1243{ 1244 const struct afd *afd; 1245 struct addrinfo *ai, ai0; 1246 int error; 1247 char pton[PTON_MAX], path[PATH_MAX], *p; 1248 1249#ifdef CTASSERT 1250 CTASSERT(sizeofmember(struct sockaddr_un, sun_path) <= PATH_MAX); 1251#endif 1252 *res = NULL; 1253 ai = NULL; 1254 1255 afd = find_afd(pai->ai_family); 1256 if (afd == NULL) 1257 return 0; 1258 1259 switch (afd->a_af) { 1260 case AF_LOCAL: 1261 if (hostname[0] != '/') 1262 ERR(EAI_NONAME); 1263 if (strlen(hostname) > afd->a_addrlen) 1264 ERR(EAI_MEMORY); 1265 /* NUL-termination does not need to be guaranteed. */ 1266 strncpy(path, hostname, afd->a_addrlen); 1267 p = &path[0]; 1268 break; 1269 case AF_INET: 1270 /* 1271 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1272 * that are accepted by inet_addr() and its family. The 1273 * accepted forms includes the "classful" one, which inet_pton 1274 * does not accept. So we need to separate the case for 1275 * AF_INET. 1276 */ 1277 if (inet_aton(hostname, (struct in_addr *)pton) != 1 || 1278 hostname[strspn(hostname, "0123456789.xabcdefXABCDEF")] != '\0') 1279 return 0; 1280 p = pton; 1281 break; 1282 default: 1283 if (inet_pton(afd->a_af, hostname, pton) != 1) { 1284 if (pai->ai_family != AF_INET6 || 1285 (pai->ai_flags & AI_V4MAPPED) != AI_V4MAPPED) 1286 return 0; 1287 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1288 return 0; 1289 afd = &afdl[N_INET]; 1290 ai0 = *pai; 1291 ai0.ai_family = AF_INET; 1292 pai = &ai0; 1293 } 1294 p = pton; 1295 break; 1296 } 1297 1298 if (pai->ai_family == afd->a_af) { 1299 GET_AI(ai, afd, p); 1300 GET_PORT(ai, servname); 1301 if ((pai->ai_family == AF_INET || 1302 pai->ai_family == AF_INET6) && 1303 (pai->ai_flags & AI_CANONNAME)) { 1304 /* 1305 * Set the numeric address itself as the canonical 1306 * name, based on a clarification in RFC3493. 1307 */ 1308 GET_CANONNAME(ai, canonname); 1309 } 1310 } else { 1311 /* 1312 * XXX: This should not happen since we already matched the AF 1313 * by find_afd. 1314 */ 1315 ERR(EAI_FAMILY); 1316 } 1317 1318 *res = ai; 1319 return 0; 1320 1321free: 1322bad: 1323 if (ai != NULL) 1324 freeaddrinfo(ai); 1325 return error; 1326} 1327 1328/* 1329 * numeric hostname with scope 1330 */ 1331static int 1332explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1333 const char *servname, struct addrinfo **res) 1334{ 1335#if !defined(SCOPE_DELIMITER) || !defined(INET6) 1336 return explore_numeric(pai, hostname, servname, res, hostname); 1337#else 1338 const struct afd *afd; 1339 struct addrinfo *cur; 1340 int error; 1341 char *cp, *hostname2 = NULL, *scope, *addr; 1342 struct sockaddr_in6 *sin6; 1343 1344 afd = find_afd(pai->ai_family); 1345 if (afd == NULL) 1346 return 0; 1347 1348 if (!afd->a_scoped) 1349 return explore_numeric(pai, hostname, servname, res, hostname); 1350 1351 cp = strchr(hostname, SCOPE_DELIMITER); 1352 if (cp == NULL) 1353 return explore_numeric(pai, hostname, servname, res, hostname); 1354 1355 /* 1356 * Handle special case of <scoped_address><delimiter><scope id> 1357 */ 1358 hostname2 = strdup(hostname); 1359 if (hostname2 == NULL) 1360 return EAI_MEMORY; 1361 /* terminate at the delimiter */ 1362 hostname2[cp - hostname] = '\0'; 1363 addr = hostname2; 1364 scope = cp + 1; 1365 1366 error = explore_numeric(pai, addr, servname, res, hostname); 1367 if (error == 0) { 1368 u_int32_t scopeid; 1369 1370 for (cur = *res; cur; cur = cur->ai_next) { 1371 if (cur->ai_family != AF_INET6) 1372 continue; 1373 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1374 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1375 free(hostname2); 1376 freeaddrinfo(*res); 1377 *res = NULL; 1378 return(EAI_NONAME); /* XXX: is return OK? */ 1379 } 1380 sin6->sin6_scope_id = scopeid; 1381 } 1382 } 1383 1384 free(hostname2); 1385 1386 if (error && *res) { 1387 freeaddrinfo(*res); 1388 *res = NULL; 1389 } 1390 return error; 1391#endif 1392} 1393 1394static int 1395get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1396{ 1397 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1398 ai->ai_canonname = strdup(str); 1399 if (ai->ai_canonname == NULL) 1400 return EAI_MEMORY; 1401 } 1402 return 0; 1403} 1404 1405static struct addrinfo * 1406get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1407{ 1408 char *p; 1409 struct addrinfo *ai; 1410#ifdef INET6 1411 struct in6_addr mapaddr; 1412 1413 if (afd->a_af == AF_INET && (pai->ai_flags & AI_V4MAPPED) != 0) { 1414 afd = &afdl[N_INET6]; 1415 _map_v4v6_address(addr, (char *)&mapaddr); 1416 addr = (char *)&mapaddr; 1417 } 1418#endif 1419 1420 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1421 + (afd->a_socklen)); 1422 if (ai == NULL) 1423 return NULL; 1424 1425 memcpy(ai, pai, sizeof(struct addrinfo)); 1426 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1427 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1428 ai->ai_addr->sa_len = afd->a_socklen; 1429 ai->ai_addrlen = afd->a_socklen; 1430 if (ai->ai_family == PF_LOCAL) { 1431 size_t n = strnlen(addr, afd->a_addrlen); 1432 1433 ai->ai_addrlen -= afd->a_addrlen - n; 1434 ai->ai_addr->sa_len -= afd->a_addrlen - n; 1435 } 1436 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1437 p = (char *)(void *)(ai->ai_addr); 1438 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1439 return ai; 1440} 1441 1442/* XXX need to malloc() the same way we do from other functions! */ 1443static struct addrinfo * 1444copy_ai(const struct addrinfo *pai) 1445{ 1446 struct addrinfo *ai; 1447 size_t l; 1448 1449 l = sizeof(*ai) + pai->ai_addrlen; 1450 if ((ai = calloc(1, l)) == NULL) 1451 return NULL; 1452 memcpy(ai, pai, sizeof(*ai)); 1453 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1454 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1455 1456 if (pai->ai_canonname) { 1457 l = strlen(pai->ai_canonname) + 1; 1458 if ((ai->ai_canonname = malloc(l)) == NULL) { 1459 free(ai); 1460 return NULL; 1461 } 1462 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1463 } else { 1464 /* just to make sure */ 1465 ai->ai_canonname = NULL; 1466 } 1467 1468 ai->ai_next = NULL; 1469 1470 return ai; 1471} 1472 1473static int 1474get_portmatch(const struct addrinfo *ai, const char *servname) 1475{ 1476 1477 /* get_port does not touch first argument when matchonly == 1. */ 1478 /* LINTED const cast */ 1479 return get_port((struct addrinfo *)ai, servname, 1); 1480} 1481 1482static int 1483get_port(struct addrinfo *ai, const char *servname, int matchonly) 1484{ 1485 const char *proto; 1486 struct servent *sp; 1487 int port, error; 1488 int allownumeric; 1489 1490 if (servname == NULL) 1491 return 0; 1492 switch (ai->ai_family) { 1493 case AF_LOCAL: 1494 /* AF_LOCAL ignores servname silently. */ 1495 return (0); 1496 case AF_INET: 1497#ifdef AF_INET6 1498 case AF_INET6: 1499#endif 1500 break; 1501 default: 1502 return 0; 1503 } 1504 1505 switch (ai->ai_socktype) { 1506 case SOCK_RAW: 1507 return EAI_SERVICE; 1508 case SOCK_DGRAM: 1509 case SOCK_STREAM: 1510 case SOCK_SEQPACKET: 1511 allownumeric = 1; 1512 break; 1513 case ANY: 1514 switch (ai->ai_family) { 1515 case AF_INET: 1516#ifdef AF_INET6 1517 case AF_INET6: 1518#endif 1519 allownumeric = 1; 1520 break; 1521 default: 1522 allownumeric = 0; 1523 break; 1524 } 1525 break; 1526 default: 1527 return EAI_SOCKTYPE; 1528 } 1529 1530 error = str2number(servname, &port); 1531 if (error == 0) { 1532 if (!allownumeric) 1533 return EAI_SERVICE; 1534 if (port < 0 || port > 65535) 1535 return EAI_SERVICE; 1536 port = htons(port); 1537 } else { 1538 if (ai->ai_flags & AI_NUMERICSERV) 1539 return EAI_NONAME; 1540 1541 switch (ai->ai_protocol) { 1542 case IPPROTO_UDP: 1543 proto = "udp"; 1544 break; 1545 case IPPROTO_TCP: 1546 proto = "tcp"; 1547 break; 1548 case IPPROTO_SCTP: 1549 proto = "sctp"; 1550 break; 1551 case IPPROTO_UDPLITE: 1552 proto = "udplite"; 1553 break; 1554 default: 1555 proto = NULL; 1556 break; 1557 } 1558 1559 if ((sp = getservbyname(servname, proto)) == NULL) 1560 return EAI_SERVICE; 1561 port = sp->s_port; 1562 } 1563 1564 if (!matchonly) { 1565 switch (ai->ai_family) { 1566 case AF_INET: 1567 ((struct sockaddr_in *)(void *) 1568 ai->ai_addr)->sin_port = port; 1569 break; 1570#ifdef INET6 1571 case AF_INET6: 1572 ((struct sockaddr_in6 *)(void *) 1573 ai->ai_addr)->sin6_port = port; 1574 break; 1575#endif 1576 } 1577 } 1578 1579 return 0; 1580} 1581 1582static const struct afd * 1583find_afd(int af) 1584{ 1585 const struct afd *afd; 1586 1587 if (af == PF_UNSPEC) 1588 return NULL; 1589 for (afd = afdl; afd->a_af; afd++) { 1590 if (afd->a_af == af) 1591 return afd; 1592 } 1593 return NULL; 1594} 1595 1596/* 1597 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are 1598 * configured on the local system and correlates with pai->ai_family value. 1599 * If an address family is not configured on the system, it will not be 1600 * queried for. For this purpose, loopback addresses are not considered 1601 * configured addresses. 1602 * 1603 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1604 * _dns_getaddrinfo. 1605 */ 1606static int 1607addrconfig(struct addrinfo *pai) 1608{ 1609 struct ifaddrs *ifaddrs, *ifa; 1610 struct sockaddr_in *sin; 1611#ifdef INET6 1612 struct sockaddr_in6 *sin6; 1613#endif 1614 int seen_inet = 0, seen_inet6 = 0; 1615 1616 if (getifaddrs(&ifaddrs) != 0) 1617 return (0); 1618 1619 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1620 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1621 continue; 1622 switch (ifa->ifa_addr->sa_family) { 1623 case AF_INET: 1624 if (seen_inet) 1625 continue; 1626 sin = (struct sockaddr_in *)(ifa->ifa_addr); 1627 if (htonl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) 1628 continue; 1629 seen_inet = 1; 1630 break; 1631#ifdef INET6 1632 case AF_INET6: 1633 if (seen_inet6) 1634 continue; 1635 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); 1636 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 1637 continue; 1638 if ((ifa->ifa_flags & IFT_LOOP) != 0 && 1639 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 1640 continue; 1641 if (is_ifdisabled(ifa->ifa_name)) 1642 continue; 1643 seen_inet6 = 1; 1644 break; 1645#endif 1646 } 1647 } 1648 freeifaddrs(ifaddrs); 1649 1650 switch(pai->ai_family) { 1651 case AF_INET6: 1652 return (seen_inet6); 1653 case AF_INET: 1654 return (seen_inet); 1655 case AF_UNSPEC: 1656 if (seen_inet == seen_inet6) 1657 return (seen_inet); 1658 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1659 return (1); 1660 } 1661 return (1); 1662} 1663 1664#ifdef INET6 1665static int 1666is_ifdisabled(char *name) 1667{ 1668 struct in6_ndireq nd; 1669 int fd; 1670 1671 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1672 return (-1); 1673 memset(&nd, 0, sizeof(nd)); 1674 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1675 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1676 _close(fd); 1677 return (-1); 1678 } 1679 _close(fd); 1680 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1681} 1682 1683/* convert a string to a scope identifier. XXX: IPv6 specific */ 1684static int 1685ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1686{ 1687 u_long lscopeid; 1688 struct in6_addr *a6; 1689 char *ep; 1690 1691 a6 = &sin6->sin6_addr; 1692 1693 /* empty scopeid portion is invalid */ 1694 if (*scope == '\0') 1695 return -1; 1696 1697 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1698 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1699 /* 1700 * We currently assume a one-to-one mapping between links 1701 * and interfaces, so we simply use interface indices for 1702 * like-local scopes. 1703 */ 1704 *scopeid = if_nametoindex(scope); 1705 if (*scopeid == 0) 1706 goto trynumeric; 1707 return 0; 1708 } 1709 1710 /* still unclear about literal, allow numeric only - placeholder */ 1711 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1712 goto trynumeric; 1713 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1714 goto trynumeric; 1715 else 1716 goto trynumeric; /* global */ 1717 1718 /* try to convert to a numeric id as a last resort */ 1719 trynumeric: 1720 errno = 0; 1721 lscopeid = strtoul(scope, &ep, 10); 1722 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1723 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1724 return 0; 1725 else 1726 return -1; 1727} 1728#endif 1729 1730 1731#ifdef NS_CACHING 1732static int 1733addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1734 void *cache_mdata) 1735{ 1736 res_state statp; 1737 u_long res_options; 1738 1739 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1740 char *hostname; 1741 struct addrinfo *hints; 1742 1743 char *p; 1744 int ai_flags, ai_family, ai_socktype, ai_protocol; 1745 size_t desired_size, size; 1746 1747 statp = __res_state(); 1748 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1749 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1750 1751 hostname = va_arg(ap, char *); 1752 hints = va_arg(ap, struct addrinfo *); 1753 1754 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1755 if (hostname != NULL) { 1756 size = strlen(hostname); 1757 desired_size += size + 1; 1758 } else 1759 size = 0; 1760 1761 if (desired_size > *buffer_size) { 1762 *buffer_size = desired_size; 1763 return (NS_RETURN); 1764 } 1765 1766 if (hints == NULL) 1767 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1768 else { 1769 ai_flags = hints->ai_flags; 1770 ai_family = hints->ai_family; 1771 ai_socktype = hints->ai_socktype; 1772 ai_protocol = hints->ai_protocol; 1773 } 1774 1775 p = buffer; 1776 memcpy(p, &res_options, sizeof(res_options)); 1777 p += sizeof(res_options); 1778 1779 memcpy(p, &op_id, sizeof(int)); 1780 p += sizeof(int); 1781 1782 memcpy(p, &ai_flags, sizeof(int)); 1783 p += sizeof(int); 1784 1785 memcpy(p, &ai_family, sizeof(int)); 1786 p += sizeof(int); 1787 1788 memcpy(p, &ai_socktype, sizeof(int)); 1789 p += sizeof(int); 1790 1791 memcpy(p, &ai_protocol, sizeof(int)); 1792 p += sizeof(int); 1793 1794 if (hostname != NULL) 1795 memcpy(p, hostname, size); 1796 1797 *buffer_size = desired_size; 1798 return (NS_SUCCESS); 1799} 1800 1801static int 1802addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1803 va_list ap, void *cache_mdata) 1804{ 1805 struct addrinfo *ai, *cai; 1806 char *p; 1807 size_t desired_size, size, ai_size; 1808 1809 ai = *((struct addrinfo **)retval); 1810 1811 desired_size = sizeof(size_t); 1812 ai_size = 0; 1813 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1814 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1815 if (cai->ai_canonname != NULL) 1816 desired_size += sizeof(size_t) + 1817 strlen(cai->ai_canonname); 1818 ++ai_size; 1819 } 1820 1821 if (desired_size > *buffer_size) { 1822 /* this assignment is here for future use */ 1823 errno = ERANGE; 1824 *buffer_size = desired_size; 1825 return (NS_RETURN); 1826 } 1827 1828 memset(buffer, 0, desired_size); 1829 p = buffer; 1830 1831 memcpy(p, &ai_size, sizeof(size_t)); 1832 p += sizeof(size_t); 1833 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1834 memcpy(p, cai, sizeof(struct addrinfo)); 1835 p += sizeof(struct addrinfo); 1836 1837 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1838 p += cai->ai_addrlen; 1839 1840 if (cai->ai_canonname != NULL) { 1841 size = strlen(cai->ai_canonname); 1842 memcpy(p, &size, sizeof(size_t)); 1843 p += sizeof(size_t); 1844 1845 memcpy(p, cai->ai_canonname, size); 1846 p += size; 1847 } 1848 } 1849 1850 return (NS_SUCCESS); 1851} 1852 1853static int 1854addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1855 va_list ap, void *cache_mdata) 1856{ 1857 struct addrinfo new_ai, *result, *sentinel, *lasts; 1858 1859 char *p; 1860 size_t ai_size, ai_i, size; 1861 1862 p = buffer; 1863 memcpy(&ai_size, p, sizeof(size_t)); 1864 p += sizeof(size_t); 1865 1866 result = NULL; 1867 lasts = NULL; 1868 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1869 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1870 p += sizeof(struct addrinfo); 1871 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1872 _ALIGNBYTES; 1873 1874 sentinel = calloc(1, size); 1875 1876 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1877 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1878 sizeof(struct addrinfo)); 1879 1880 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1881 p += new_ai.ai_addrlen; 1882 1883 if (new_ai.ai_canonname != NULL) { 1884 memcpy(&size, p, sizeof(size_t)); 1885 p += sizeof(size_t); 1886 1887 sentinel->ai_canonname = calloc(1, size + 1); 1888 1889 memcpy(sentinel->ai_canonname, p, size); 1890 p += size; 1891 } 1892 1893 if (result == NULL) { 1894 result = sentinel; 1895 lasts = sentinel; 1896 } else { 1897 lasts->ai_next = sentinel; 1898 lasts = sentinel; 1899 } 1900 } 1901 1902 *((struct addrinfo **)retval) = result; 1903 return (NS_SUCCESS); 1904} 1905#endif /* NS_CACHING */ 1906 1907/* 1908 * FQDN hostname, DNS lookup 1909 */ 1910static int 1911explore_fqdn(const struct addrinfo *pai, const char *hostname, 1912 const char *servname, struct addrinfo **res) 1913{ 1914 struct addrinfo *result; 1915 struct addrinfo *cur; 1916 int error = 0; 1917 1918#ifdef NS_CACHING 1919 static const nss_cache_info cache_info = 1920 NS_COMMON_CACHE_INFO_INITIALIZER( 1921 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1922 addrinfo_unmarshal_func); 1923#endif 1924 static const ns_dtab dtab[] = { 1925 NS_FILES_CB(_files_getaddrinfo, NULL) 1926 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1927 NS_NIS_CB(_yp_getaddrinfo, NULL) 1928#ifdef NS_CACHING 1929 NS_CACHE_CB(&cache_info) 1930#endif 1931 { 0 } 1932 }; 1933 1934 result = NULL; 1935 1936 /* 1937 * if the servname does not match socktype/protocol, ignore it. 1938 */ 1939 if (get_portmatch(pai, servname) != 0) 1940 return 0; 1941 1942 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1943 default_dns_files, hostname, pai)) { 1944 case NS_TRYAGAIN: 1945 error = EAI_AGAIN; 1946 goto free; 1947 case NS_UNAVAIL: 1948 error = EAI_FAIL; 1949 goto free; 1950 case NS_NOTFOUND: 1951 error = EAI_NONAME; 1952 goto free; 1953 case NS_ADDRFAMILY: 1954 error = EAI_ADDRFAMILY; 1955 goto free; 1956 case NS_SUCCESS: 1957 error = 0; 1958 for (cur = result; cur; cur = cur->ai_next) { 1959 GET_PORT(cur, servname); 1960 /* canonname should be filled already */ 1961 } 1962 break; 1963 } 1964 1965 *res = result; 1966 1967 return 0; 1968 1969free: 1970 if (result) 1971 freeaddrinfo(result); 1972 return error; 1973} 1974 1975#ifdef DEBUG 1976static const char AskedForGot[] = 1977 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1978#endif 1979 1980static struct addrinfo * 1981getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1982 const struct addrinfo *pai, res_state res) 1983{ 1984 struct addrinfo sentinel, *cur; 1985 struct addrinfo ai; 1986 const struct afd *afd; 1987 char *canonname; 1988 const HEADER *hp; 1989 const u_char *cp; 1990 int n; 1991 const u_char *eom; 1992 char *bp, *ep; 1993 int type, class, ancount, qdcount; 1994 int haveanswer, had_error; 1995 char tbuf[MAXDNAME]; 1996 int (*name_ok)(const char *); 1997 char hostbuf[8*1024]; 1998 1999 memset(&sentinel, 0, sizeof(sentinel)); 2000 cur = &sentinel; 2001 2002 canonname = NULL; 2003 eom = answer->buf + anslen; 2004 switch (qtype) { 2005 case T_A: 2006 case T_AAAA: 2007 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 2008 name_ok = res_hnok; 2009 break; 2010 default: 2011 return (NULL); /* XXX should be abort(); */ 2012 } 2013 /* 2014 * find first satisfactory answer 2015 */ 2016 hp = &answer->hdr; 2017 ancount = ntohs(hp->ancount); 2018 qdcount = ntohs(hp->qdcount); 2019 bp = hostbuf; 2020 ep = hostbuf + sizeof hostbuf; 2021 cp = answer->buf + HFIXEDSZ; 2022 if (qdcount != 1) { 2023 RES_SET_H_ERRNO(res, NO_RECOVERY); 2024 return (NULL); 2025 } 2026 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2027 if ((n < 0) || !(*name_ok)(bp)) { 2028 RES_SET_H_ERRNO(res, NO_RECOVERY); 2029 return (NULL); 2030 } 2031 cp += n + QFIXEDSZ; 2032 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 2033 /* res_send() has already verified that the query name is the 2034 * same as the one we sent; this just gets the expanded name 2035 * (i.e., with the succeeding search-domain tacked on). 2036 */ 2037 n = strlen(bp) + 1; /* for the \0 */ 2038 if (n >= MAXHOSTNAMELEN) { 2039 RES_SET_H_ERRNO(res, NO_RECOVERY); 2040 return (NULL); 2041 } 2042 canonname = bp; 2043 bp += n; 2044 /* The qname can be abbreviated, but h_name is now absolute. */ 2045 qname = canonname; 2046 } 2047 haveanswer = 0; 2048 had_error = 0; 2049 while (ancount-- > 0 && cp < eom && !had_error) { 2050 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2051 if ((n < 0) || !(*name_ok)(bp)) { 2052 had_error++; 2053 continue; 2054 } 2055 cp += n; /* name */ 2056 type = _getshort(cp); 2057 cp += INT16SZ; /* type */ 2058 class = _getshort(cp); 2059 cp += INT16SZ + INT32SZ; /* class, TTL */ 2060 n = _getshort(cp); 2061 cp += INT16SZ; /* len */ 2062 if (class != C_IN) { 2063 /* XXX - debug? syslog? */ 2064 cp += n; 2065 continue; /* XXX - had_error++ ? */ 2066 } 2067 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 2068 type == T_CNAME) { 2069 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 2070 if ((n < 0) || !(*name_ok)(tbuf)) { 2071 had_error++; 2072 continue; 2073 } 2074 cp += n; 2075 /* Get canonical name. */ 2076 n = strlen(tbuf) + 1; /* for the \0 */ 2077 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 2078 had_error++; 2079 continue; 2080 } 2081 strlcpy(bp, tbuf, ep - bp); 2082 canonname = bp; 2083 bp += n; 2084 continue; 2085 } 2086 if (qtype == T_ANY) { 2087 if (!(type == T_A || type == T_AAAA)) { 2088 cp += n; 2089 continue; 2090 } 2091 } else if (type != qtype) { 2092#ifdef DEBUG 2093 if (type != T_KEY && type != T_SIG && 2094 type != T_DNAME && type != T_RRSIG) 2095 syslog(LOG_NOTICE|LOG_AUTH, 2096 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2097 qname, p_class(C_IN), p_type(qtype), 2098 p_type(type)); 2099#endif 2100 cp += n; 2101 continue; /* XXX - had_error++ ? */ 2102 } 2103 switch (type) { 2104 case T_A: 2105 case T_AAAA: 2106 if (strcasecmp(canonname, bp) != 0) { 2107#ifdef DEBUG 2108 syslog(LOG_NOTICE|LOG_AUTH, 2109 AskedForGot, canonname, bp); 2110#endif 2111 cp += n; 2112 continue; /* XXX - had_error++ ? */ 2113 } 2114 if (type == T_A && n != INADDRSZ) { 2115 cp += n; 2116 continue; 2117 } 2118 if (type == T_AAAA && n != IN6ADDRSZ) { 2119 cp += n; 2120 continue; 2121 } 2122#ifdef FILTER_V4MAPPED 2123 if (type == T_AAAA) { 2124 struct in6_addr in6; 2125 memcpy(&in6, cp, sizeof(in6)); 2126 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2127 cp += n; 2128 continue; 2129 } 2130 } 2131#endif 2132 if (!haveanswer) { 2133 int nn; 2134 2135 canonname = bp; 2136 nn = strlen(bp) + 1; /* for the \0 */ 2137 bp += nn; 2138 } 2139 2140 /* don't overwrite pai */ 2141 ai = *pai; 2142 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2143 afd = find_afd(ai.ai_family); 2144 if (afd == NULL) { 2145 cp += n; 2146 continue; 2147 } 2148 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2149 if (cur->ai_next == NULL) 2150 had_error++; 2151 while (cur && cur->ai_next) 2152 cur = cur->ai_next; 2153 cp += n; 2154 break; 2155 default: 2156 abort(); 2157 } 2158 if (!had_error) 2159 haveanswer++; 2160 } 2161 if (haveanswer) { 2162#if defined(RESOLVSORT) 2163 /* 2164 * We support only IPv4 address for backward 2165 * compatibility against gethostbyname(3). 2166 */ 2167 if (res->nsort && qtype == T_A) { 2168 if (addr4sort(&sentinel, res) < 0) { 2169 freeaddrinfo(sentinel.ai_next); 2170 RES_SET_H_ERRNO(res, NO_RECOVERY); 2171 return NULL; 2172 } 2173 } 2174#endif /*RESOLVSORT*/ 2175 if (!canonname) 2176 (void)get_canonname(pai, sentinel.ai_next, qname); 2177 else 2178 (void)get_canonname(pai, sentinel.ai_next, canonname); 2179 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2180 return sentinel.ai_next; 2181 } 2182 2183 /* 2184 * We could have walked a CNAME chain, but the ultimate target 2185 * may not have what we looked for. 2186 */ 2187 RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : NO_RECOVERY); 2188 return NULL; 2189} 2190 2191#ifdef RESOLVSORT 2192struct addr_ptr { 2193 struct addrinfo *ai; 2194 int aval; 2195}; 2196 2197static int 2198addr4sort(struct addrinfo *sentinel, res_state res) 2199{ 2200 struct addrinfo *ai; 2201 struct addr_ptr *addrs, addr; 2202 struct sockaddr_in *sin; 2203 int naddrs, i, j; 2204 int needsort = 0; 2205 2206 if (!sentinel) 2207 return -1; 2208 naddrs = 0; 2209 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2210 naddrs++; 2211 if (naddrs < 2) 2212 return 0; /* We don't need sorting. */ 2213 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2214 return -1; 2215 i = 0; 2216 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2217 sin = (struct sockaddr_in *)ai->ai_addr; 2218 for (j = 0; (unsigned)j < res->nsort; j++) { 2219 if (res->sort_list[j].addr.s_addr == 2220 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2221 break; 2222 } 2223 addrs[i].ai = ai; 2224 addrs[i].aval = j; 2225 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2226 needsort = i; 2227 i++; 2228 } 2229 if (!needsort) { 2230 free(addrs); 2231 return 0; 2232 } 2233 2234 while (needsort < naddrs) { 2235 for (j = needsort - 1; j >= 0; j--) { 2236 if (addrs[j].aval > addrs[j+1].aval) { 2237 addr = addrs[j]; 2238 addrs[j] = addrs[j + 1]; 2239 addrs[j + 1] = addr; 2240 } else 2241 break; 2242 } 2243 needsort++; 2244 } 2245 2246 ai = sentinel; 2247 for (i = 0; i < naddrs; ++i) { 2248 ai->ai_next = addrs[i].ai; 2249 ai = ai->ai_next; 2250 } 2251 ai->ai_next = NULL; 2252 free(addrs); 2253 return 0; 2254} 2255#endif /*RESOLVSORT*/ 2256 2257/*ARGSUSED*/ 2258static int 2259_dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2260{ 2261 struct addrinfo *ai, ai0; 2262 querybuf *buf, *buf2; 2263 const char *hostname; 2264 const struct addrinfo *pai; 2265 struct addrinfo sentinel, *cur; 2266 struct res_target q, q2; 2267 res_state res; 2268 2269 ai = NULL; 2270 2271 hostname = va_arg(ap, char *); 2272 pai = va_arg(ap, const struct addrinfo *); 2273 2274 memset(&q, 0, sizeof(q)); 2275 memset(&q2, 0, sizeof(q2)); 2276 memset(&sentinel, 0, sizeof(sentinel)); 2277 cur = &sentinel; 2278 2279 res = __res_state(); 2280 2281 buf = malloc(sizeof(*buf)); 2282 if (!buf) { 2283 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2284 return NS_NOTFOUND; 2285 } 2286 buf2 = malloc(sizeof(*buf2)); 2287 if (!buf2) { 2288 free(buf); 2289 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2290 return NS_NOTFOUND; 2291 } 2292 2293 if (pai->ai_family == AF_INET6 && 2294 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) { 2295 ai0 = *pai; 2296 ai0.ai_family = AF_UNSPEC; 2297 pai = &ai0; 2298 } 2299 2300 switch (pai->ai_family) { 2301 case AF_UNSPEC: 2302 q.name = hostname; 2303 q.qclass = C_IN; 2304 q.qtype = T_A; 2305 q.answer = buf->buf; 2306 q.anslen = sizeof(buf->buf); 2307 q.next = &q2; 2308 q2.name = hostname; 2309 q2.qclass = C_IN; 2310 q2.qtype = T_AAAA; 2311 q2.answer = buf2->buf; 2312 q2.anslen = sizeof(buf2->buf); 2313 break; 2314 case AF_INET: 2315 q.name = hostname; 2316 q.qclass = C_IN; 2317 q.qtype = T_A; 2318 q.answer = buf->buf; 2319 q.anslen = sizeof(buf->buf); 2320 break; 2321 case AF_INET6: 2322 q.name = hostname; 2323 q.qclass = C_IN; 2324 q.qtype = T_AAAA; 2325 q.answer = buf->buf; 2326 q.anslen = sizeof(buf->buf); 2327 break; 2328 default: 2329 free(buf); 2330 free(buf2); 2331 return NS_UNAVAIL; 2332 } 2333 2334 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2335 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2336 free(buf); 2337 free(buf2); 2338 return NS_NOTFOUND; 2339 } 2340 2341 if (res_searchN(hostname, &q, res) < 0) { 2342 free(buf); 2343 free(buf2); 2344 if (res->res_h_errno == NO_DATA) 2345 return (NS_ADDRFAMILY); 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 return (NS_NOTFOUND); 2369 case NO_DATA: 2370 return (NS_ADDRFAMILY); 2371 case TRY_AGAIN: 2372 return (NS_TRYAGAIN); 2373 default: 2374 return (NS_UNAVAIL); 2375 } 2376 *((struct addrinfo **)rv) = sentinel.ai_next; 2377 return (NS_SUCCESS); 2378} 2379 2380static void 2381_sethtent(FILE **hostf) 2382{ 2383 if (!*hostf) 2384 *hostf = fopen(_PATH_HOSTS, "re"); 2385 else 2386 rewind(*hostf); 2387} 2388 2389static void 2390_endhtent(FILE **hostf) 2391{ 2392 if (*hostf) { 2393 (void) fclose(*hostf); 2394 *hostf = NULL; 2395 } 2396} 2397 2398static struct addrinfo * 2399_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2400{ 2401 char *p; 2402 char *cp, *tname, *cname; 2403 struct addrinfo hints, *res0, *res; 2404 int error; 2405 const char *addr; 2406 char hostbuf[8*1024]; 2407 2408 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2409 return (NULL); 2410again: 2411 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2412 return (NULL); 2413 if (*p == '#') 2414 goto again; 2415 cp = strpbrk(p, "#\n"); 2416 if (cp != NULL) 2417 *cp = '\0'; 2418 if (!(cp = strpbrk(p, " \t"))) 2419 goto again; 2420 *cp++ = '\0'; 2421 addr = p; 2422 cname = NULL; 2423 /* if this is not something we're looking for, skip it. */ 2424 while (cp && *cp) { 2425 if (*cp == ' ' || *cp == '\t') { 2426 cp++; 2427 continue; 2428 } 2429 tname = cp; 2430 if (cname == NULL) 2431 cname = cp; 2432 if ((cp = strpbrk(cp, " \t")) != NULL) 2433 *cp++ = '\0'; 2434 if (strcasecmp(name, tname) == 0) 2435 goto found; 2436 } 2437 goto again; 2438 2439found: 2440 /* we should not glob socktype/protocol here */ 2441 memset(&hints, 0, sizeof(hints)); 2442 hints.ai_family = pai->ai_family; 2443 hints.ai_socktype = SOCK_DGRAM; 2444 hints.ai_protocol = 0; 2445 hints.ai_flags = AI_NUMERICHOST; 2446 if (pai->ai_family == AF_INET6 && 2447 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2448 hints.ai_flags |= AI_V4MAPPED; 2449 error = getaddrinfo(addr, "0", &hints, &res0); 2450 if (error) 2451 goto again; 2452#ifdef FILTER_V4MAPPED 2453 /* XXX should check all items in the chain */ 2454 if (res0->ai_family == AF_INET6 && 2455 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2456 freeaddrinfo(res0); 2457 goto again; 2458 } 2459#endif 2460 for (res = res0; res; res = res->ai_next) { 2461 /* cover it up */ 2462 res->ai_flags = pai->ai_flags; 2463 res->ai_socktype = pai->ai_socktype; 2464 res->ai_protocol = pai->ai_protocol; 2465 2466 if (pai->ai_flags & AI_CANONNAME) { 2467 if (get_canonname(pai, res, cname) != 0) { 2468 freeaddrinfo(res0); 2469 goto again; 2470 } 2471 } 2472 } 2473 return res0; 2474} 2475 2476static struct addrinfo * 2477_getht(FILE **hostf, const char *name, const struct addrinfo *pai, 2478 struct addrinfo *cur) 2479{ 2480 struct addrinfo *p; 2481 2482 while ((p = _gethtent(hostf, name, pai)) != NULL) { 2483 cur->ai_next = p; 2484 while (cur && cur->ai_next) 2485 cur = cur->ai_next; 2486 } 2487 return (cur); 2488} 2489 2490/*ARGSUSED*/ 2491static int 2492_files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2493{ 2494 const char *name; 2495 const struct addrinfo *pai; 2496 struct addrinfo sentinel, *cur; 2497 FILE *hostf = NULL; 2498 2499 name = va_arg(ap, char *); 2500 pai = va_arg(ap, struct addrinfo *); 2501 2502 memset(&sentinel, 0, sizeof(sentinel)); 2503 cur = &sentinel; 2504 2505 _sethtent(&hostf); 2506 if (pai->ai_family == AF_INET6 && 2507 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) == AI_V4MAPPED) { 2508 struct addrinfo ai0 = *pai; 2509 2510 ai0.ai_flags &= ~AI_V4MAPPED; 2511 cur = _getht(&hostf, name, &ai0, cur); 2512 if (sentinel.ai_next == NULL) { 2513 _sethtent(&hostf); 2514 ai0.ai_flags |= AI_V4MAPPED; 2515 cur = _getht(&hostf, name, &ai0, cur); 2516 } 2517 } else 2518 cur = _getht(&hostf, name, pai, cur); 2519 _endhtent(&hostf); 2520 2521 *((struct addrinfo **)rv) = sentinel.ai_next; 2522 if (sentinel.ai_next == NULL) 2523 return NS_NOTFOUND; 2524 return NS_SUCCESS; 2525} 2526 2527#ifdef YP 2528/*ARGSUSED*/ 2529static struct addrinfo * 2530_yphostent(char *line, const struct addrinfo *pai) 2531{ 2532 struct addrinfo sentinel, *cur; 2533 struct addrinfo hints, *res, *res0; 2534 int error; 2535 char *p = line; 2536 const char *addr, *canonname; 2537 char *nextline; 2538 char *cp; 2539 2540 addr = canonname = NULL; 2541 2542 memset(&sentinel, 0, sizeof(sentinel)); 2543 cur = &sentinel; 2544 2545nextline: 2546 /* terminate line */ 2547 cp = strchr(p, '\n'); 2548 if (cp) { 2549 *cp++ = '\0'; 2550 nextline = cp; 2551 } else 2552 nextline = NULL; 2553 2554 cp = strpbrk(p, " \t"); 2555 if (cp == NULL) { 2556 if (canonname == NULL) 2557 return (NULL); 2558 else 2559 goto done; 2560 } 2561 *cp++ = '\0'; 2562 2563 addr = p; 2564 2565 while (cp && *cp) { 2566 if (*cp == ' ' || *cp == '\t') { 2567 cp++; 2568 continue; 2569 } 2570 if (!canonname) 2571 canonname = cp; 2572 if ((cp = strpbrk(cp, " \t")) != NULL) 2573 *cp++ = '\0'; 2574 } 2575 2576 hints = *pai; 2577 hints.ai_flags = AI_NUMERICHOST; 2578 if (pai->ai_family == AF_INET6 && 2579 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2580 hints.ai_flags |= AI_V4MAPPED; 2581 error = getaddrinfo(addr, NULL, &hints, &res0); 2582 if (error == 0) { 2583 for (res = res0; res; res = res->ai_next) { 2584 /* cover it up */ 2585 res->ai_flags = pai->ai_flags; 2586 2587 if (pai->ai_flags & AI_CANONNAME) 2588 (void)get_canonname(pai, res, canonname); 2589 } 2590 } else 2591 res0 = NULL; 2592 if (res0) { 2593 cur->ai_next = res0; 2594 while (cur && cur->ai_next) 2595 cur = cur->ai_next; 2596 } 2597 2598 if (nextline) { 2599 p = nextline; 2600 goto nextline; 2601 } 2602 2603done: 2604 return sentinel.ai_next; 2605} 2606 2607/*ARGSUSED*/ 2608static int 2609_yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2610{ 2611 struct addrinfo sentinel, *cur; 2612 struct addrinfo *ai = NULL; 2613 char *ypbuf; 2614 int ypbuflen, r; 2615 const char *name; 2616 const struct addrinfo *pai; 2617 char *ypdomain; 2618 2619 if (_yp_check(&ypdomain) == 0) 2620 return NS_UNAVAIL; 2621 2622 name = va_arg(ap, char *); 2623 pai = va_arg(ap, const struct addrinfo *); 2624 2625 memset(&sentinel, 0, sizeof(sentinel)); 2626 cur = &sentinel; 2627 2628 /* ipnodes.byname can hold both IPv4/v6 */ 2629 r = yp_match(ypdomain, "ipnodes.byname", name, 2630 (int)strlen(name), &ypbuf, &ypbuflen); 2631 if (r == 0) { 2632 ai = _yphostent(ypbuf, pai); 2633 if (ai) { 2634 cur->ai_next = ai; 2635 while (cur && cur->ai_next) 2636 cur = cur->ai_next; 2637 } 2638 free(ypbuf); 2639 } 2640 2641 if (ai != NULL) { 2642 struct sockaddr_in6 *sin6; 2643 2644 switch (ai->ai_family) { 2645 case AF_INET: 2646 goto done; 2647 case AF_INET6: 2648 sin6 = (struct sockaddr_in6 *)ai->ai_addr; 2649 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 2650 goto done; 2651 break; 2652 } 2653 } 2654 2655 /* hosts.byname is only for IPv4 (Solaris8) */ 2656 if (pai->ai_family == AF_UNSPEC || pai->ai_family == AF_INET || 2657 ((pai->ai_family == AF_INET6 && 2658 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) && 2659 (ai == NULL || (pai->ai_flags & AI_ALL) == AI_ALL))) { 2660 r = yp_match(ypdomain, "hosts.byname", name, 2661 (int)strlen(name), &ypbuf, &ypbuflen); 2662 if (r == 0) { 2663 struct addrinfo ai4; 2664 2665 ai4 = *pai; 2666 if (pai->ai_family == AF_UNSPEC) 2667 ai4.ai_family = AF_INET; 2668 ai = _yphostent(ypbuf, &ai4); 2669 if (ai) { 2670 cur->ai_next = ai; 2671 while (cur && cur->ai_next) 2672 cur = cur->ai_next; 2673 } 2674 free(ypbuf); 2675 } 2676 } 2677 2678done: 2679 if (sentinel.ai_next == NULL) { 2680 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2681 return NS_NOTFOUND; 2682 } 2683 *((struct addrinfo **)rv) = sentinel.ai_next; 2684 return NS_SUCCESS; 2685} 2686#endif 2687 2688/* resolver logic */ 2689 2690/* 2691 * Formulate a normal query, send, and await answer. 2692 * Returned answer is placed in supplied buffer "answer". 2693 * Perform preliminary check of answer, returning success only 2694 * if no error is indicated and the answer count is nonzero. 2695 * Return the size of the response on success, -1 on error. 2696 * Error number is left in h_errno. 2697 * 2698 * Caller must parse answer and determine whether it answers the question. 2699 */ 2700static int 2701res_queryN(const char *name, struct res_target *target, res_state res) 2702{ 2703 u_char *buf; 2704 HEADER *hp; 2705 int n; 2706 u_int oflags; 2707 struct res_target *t; 2708 int rcode; 2709 int ancount; 2710 2711 rcode = NOERROR; 2712 ancount = 0; 2713 2714 buf = malloc(MAXPACKET); 2715 if (!buf) { 2716 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2717 return -1; 2718 } 2719 2720 for (t = target; t; t = t->next) { 2721 int class, type; 2722 u_char *answer; 2723 int anslen; 2724 2725 hp = (HEADER *)(void *)t->answer; 2726 2727 /* make it easier... */ 2728 class = t->qclass; 2729 type = t->qtype; 2730 answer = t->answer; 2731 anslen = t->anslen; 2732 2733 oflags = res->_flags; 2734 2735again: 2736 hp->rcode = NOERROR; /* default */ 2737 2738#ifdef DEBUG 2739 if (res->options & RES_DEBUG) 2740 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2741#endif 2742 2743 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2744 buf, MAXPACKET); 2745 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2746 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2747 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2748 if (n <= 0) { 2749#ifdef DEBUG 2750 if (res->options & RES_DEBUG) 2751 printf(";; res_query: mkquery failed\n"); 2752#endif 2753 free(buf); 2754 RES_SET_H_ERRNO(res, NO_RECOVERY); 2755 return (n); 2756 } 2757 n = res_nsend(res, buf, n, answer, anslen); 2758 if (n < 0) { 2759 /* 2760 * if the query choked with EDNS0, retry 2761 * without EDNS0 2762 */ 2763 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2764 != 0U && 2765 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2766 res->_flags |= RES_F_EDNS0ERR; 2767 if (res->options & RES_DEBUG) 2768 printf(";; res_nquery: retry without EDNS0\n"); 2769 goto again; 2770 } 2771 rcode = hp->rcode; /* record most recent error */ 2772#ifdef DEBUG 2773 if (res->options & RES_DEBUG) 2774 printf(";; res_query: send error\n"); 2775#endif 2776 continue; 2777 } 2778 2779 if (n > anslen) 2780 hp->rcode = FORMERR; /* XXX not very informative */ 2781 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2782 rcode = hp->rcode; /* record most recent error */ 2783#ifdef DEBUG 2784 if (res->options & RES_DEBUG) 2785 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2786 ntohs(hp->ancount)); 2787#endif 2788 continue; 2789 } 2790 2791 ancount += ntohs(hp->ancount); 2792 2793 t->n = n; 2794 } 2795 2796 free(buf); 2797 2798 if (ancount == 0) { 2799 switch (rcode) { 2800 case NXDOMAIN: 2801 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2802 break; 2803 case SERVFAIL: 2804 RES_SET_H_ERRNO(res, TRY_AGAIN); 2805 break; 2806 case NOERROR: 2807 RES_SET_H_ERRNO(res, NO_DATA); 2808 break; 2809 case FORMERR: 2810 case NOTIMP: 2811 case REFUSED: 2812 default: 2813 RES_SET_H_ERRNO(res, NO_RECOVERY); 2814 break; 2815 } 2816 return (-1); 2817 } 2818 return (ancount); 2819} 2820 2821/* 2822 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2823 * Return the size of the response on success, -1 on error. 2824 * If enabled, implement search rules until answer or unrecoverable failure 2825 * is detected. Error code, if any, is left in h_errno. 2826 */ 2827static int 2828res_searchN(const char *name, struct res_target *target, res_state res) 2829{ 2830 const char *cp, * const *domain; 2831 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2832 u_int dots; 2833 int trailing_dot, ret, saved_herrno; 2834 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2835 int tried_as_is = 0; 2836 int searched = 0; 2837 char abuf[MAXDNAME]; 2838 2839 errno = 0; 2840 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2841 dots = 0; 2842 for (cp = name; *cp; cp++) 2843 dots += (*cp == '.'); 2844 trailing_dot = 0; 2845 if (cp > name && *--cp == '.') 2846 trailing_dot++; 2847 2848 /* 2849 * if there aren't any dots, it could be a user-level alias 2850 */ 2851 if (!dots && 2852 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2853 return (res_queryN(cp, target, res)); 2854 2855 /* 2856 * If there are enough dots in the name, let's just give it a 2857 * try 'as is'. The threshold can be set with the "ndots" option. 2858 * Also, query 'as is', if there is a trailing dot in the name. 2859 */ 2860 saved_herrno = -1; 2861 if (dots >= res->ndots || trailing_dot) { 2862 ret = res_querydomainN(name, NULL, target, res); 2863 if (ret > 0 || trailing_dot) 2864 return (ret); 2865 if (errno == ECONNREFUSED) { 2866 RES_SET_H_ERRNO(res, TRY_AGAIN); 2867 return (-1); 2868 } 2869 switch (res->res_h_errno) { 2870 case NO_DATA: 2871 case HOST_NOT_FOUND: 2872 break; 2873 case TRY_AGAIN: 2874 if (hp->rcode == SERVFAIL) 2875 break; 2876 /* FALLTHROUGH */ 2877 default: 2878 return (-1); 2879 } 2880 saved_herrno = res->res_h_errno; 2881 tried_as_is++; 2882 } 2883 2884 /* 2885 * We do at least one level of search if 2886 * - there is no dot and RES_DEFNAME is set, or 2887 * - there is at least one dot, there is no trailing dot, 2888 * and RES_DNSRCH is set. 2889 */ 2890 if ((!dots && (res->options & RES_DEFNAMES)) || 2891 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2892 int done = 0; 2893 2894 for (domain = (const char * const *)res->dnsrch; 2895 *domain && !done; 2896 domain++) { 2897 searched = 1; 2898 2899 if (domain[0][0] == '\0' || 2900 (domain[0][0] == '.' && domain[0][1] == '\0')) 2901 root_on_list++; 2902 2903 if (root_on_list && tried_as_is) 2904 continue; 2905 2906 ret = res_querydomainN(name, *domain, target, res); 2907 if (ret > 0) 2908 return (ret); 2909 2910 /* 2911 * If no server present, give up. 2912 * If name isn't found in this domain, 2913 * keep trying higher domains in the search list 2914 * (if that's enabled). 2915 * On a NO_DATA error, keep trying, otherwise 2916 * a wildcard entry of another type could keep us 2917 * from finding this entry higher in the domain. 2918 * If we get some other error (negative answer or 2919 * server failure), then stop searching up, 2920 * but try the input name below in case it's 2921 * fully-qualified. 2922 */ 2923 if (errno == ECONNREFUSED) { 2924 RES_SET_H_ERRNO(res, TRY_AGAIN); 2925 return (-1); 2926 } 2927 2928 switch (res->res_h_errno) { 2929 case NO_DATA: 2930 got_nodata++; 2931 /* FALLTHROUGH */ 2932 case HOST_NOT_FOUND: 2933 /* keep trying */ 2934 break; 2935 case TRY_AGAIN: 2936 got_servfail++; 2937 if (hp->rcode == SERVFAIL) { 2938 /* try next search element, if any */ 2939 break; 2940 } 2941 /* FALLTHROUGH */ 2942 default: 2943 /* anything else implies that we're done */ 2944 done++; 2945 } 2946 /* 2947 * if we got here for some reason other than DNSRCH, 2948 * we only wanted one iteration of the loop, so stop. 2949 */ 2950 if (!(res->options & RES_DNSRCH)) 2951 done++; 2952 } 2953 } 2954 2955 switch (res->res_h_errno) { 2956 case NO_DATA: 2957 case HOST_NOT_FOUND: 2958 break; 2959 case TRY_AGAIN: 2960 if (hp->rcode == SERVFAIL) 2961 break; 2962 /* FALLTHROUGH */ 2963 default: 2964 goto giveup; 2965 } 2966 2967 /* 2968 * If the query has not already been tried as is then try it 2969 * unless RES_NOTLDQUERY is set and there were no dots. 2970 */ 2971 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2972 !(tried_as_is || root_on_list)) { 2973 ret = res_querydomainN(name, NULL, target, res); 2974 if (ret > 0) 2975 return (ret); 2976 } 2977 2978 /* 2979 * if we got here, we didn't satisfy the search. 2980 * if we did an initial full query, return that query's h_errno 2981 * (note that we wouldn't be here if that query had succeeded). 2982 * else if we ever got a nodata, send that back as the reason. 2983 * else send back meaningless h_errno, that being the one from 2984 * the last DNSRCH we did. 2985 */ 2986giveup: 2987 if (saved_herrno != -1) 2988 RES_SET_H_ERRNO(res, saved_herrno); 2989 else if (got_nodata) 2990 RES_SET_H_ERRNO(res, NO_DATA); 2991 else if (got_servfail) 2992 RES_SET_H_ERRNO(res, TRY_AGAIN); 2993 return (-1); 2994} 2995 2996/* 2997 * Perform a call on res_query on the concatenation of name and domain, 2998 * removing a trailing dot from name if domain is NULL. 2999 */ 3000static int 3001res_querydomainN(const char *name, const char *domain, 3002 struct res_target *target, res_state res) 3003{ 3004 char nbuf[MAXDNAME]; 3005 const char *longname = nbuf; 3006 size_t n, d; 3007 3008#ifdef DEBUG 3009 if (res->options & RES_DEBUG) 3010 printf(";; res_querydomain(%s, %s)\n", 3011 name, domain?domain:"<Nil>"); 3012#endif 3013 if (domain == NULL) { 3014 /* 3015 * Check for trailing '.'; 3016 * copy without '.' if present. 3017 */ 3018 n = strlen(name); 3019 if (n >= MAXDNAME) { 3020 RES_SET_H_ERRNO(res, NO_RECOVERY); 3021 return (-1); 3022 } 3023 if (n > 0 && name[--n] == '.') { 3024 strncpy(nbuf, name, n); 3025 nbuf[n] = '\0'; 3026 } else 3027 longname = name; 3028 } else { 3029 n = strlen(name); 3030 d = strlen(domain); 3031 if (n + d + 1 >= MAXDNAME) { 3032 RES_SET_H_ERRNO(res, NO_RECOVERY); 3033 return (-1); 3034 } 3035 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 3036 } 3037 return (res_queryN(longname, target, res)); 3038} 3039