getaddrinfo.c revision 265946
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 * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator. 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 - SEGV on freeaddrinfo(NULL) 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 $GAI. The code does not. 54 */ 55 56#include <sys/cdefs.h> 57__FBSDID("$FreeBSD: stable/10/lib/libc/net/getaddrinfo.c 265946 2014-05-13 06:05:53Z kevlo $"); 58 59#include "namespace.h" 60#include <sys/types.h> 61#include <sys/param.h> 62#include <sys/socket.h> 63#include <net/if.h> 64#include <netinet/in.h> 65#include <sys/queue.h> 66#ifdef INET6 67#include <net/if_var.h> 68#include <sys/sysctl.h> 69#include <sys/ioctl.h> 70#include <netinet6/in6_var.h> /* XXX */ 71#endif 72#include <arpa/inet.h> 73#include <arpa/nameser.h> 74#include <rpc/rpc.h> 75#include <rpcsvc/yp_prot.h> 76#include <rpcsvc/ypclnt.h> 77#include <netdb.h> 78#include <resolv.h> 79#include <string.h> 80#include <stdlib.h> 81#include <stddef.h> 82#include <ctype.h> 83#include <unistd.h> 84#include <stdio.h> 85#include <errno.h> 86 87#include "res_config.h" 88 89#ifdef DEBUG 90#include <syslog.h> 91#endif 92 93#include <stdarg.h> 94#include <nsswitch.h> 95#include "un-namespace.h" 96#include "libc_private.h" 97#ifdef NS_CACHING 98#include "nscache.h" 99#endif 100 101#if defined(__KAME__) && defined(INET6) 102# define FAITH 103#endif 104 105#define ANY 0 106#define YES 1 107#define NO 0 108 109static const char in_addrany[] = { 0, 0, 0, 0 }; 110static const char in_loopback[] = { 127, 0, 0, 1 }; 111#ifdef INET6 112static const char in6_addrany[] = { 113 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 114}; 115static const char in6_loopback[] = { 116 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 117}; 118#endif 119 120struct policyqueue { 121 TAILQ_ENTRY(policyqueue) pc_entry; 122#ifdef INET6 123 struct in6_addrpolicy pc_policy; 124#endif 125}; 126TAILQ_HEAD(policyhead, policyqueue); 127 128static const struct afd { 129 int a_af; 130 int a_addrlen; 131 socklen_t a_socklen; 132 int a_off; 133 const char *a_addrany; 134 const char *a_loopback; 135 int a_scoped; 136} afdl [] = { 137#ifdef INET6 138#define N_INET6 0 139 {PF_INET6, sizeof(struct in6_addr), 140 sizeof(struct sockaddr_in6), 141 offsetof(struct sockaddr_in6, sin6_addr), 142 in6_addrany, in6_loopback, 1}, 143#define N_INET 1 144#else 145#define N_INET 0 146#endif 147 {PF_INET, sizeof(struct in_addr), 148 sizeof(struct sockaddr_in), 149 offsetof(struct sockaddr_in, sin_addr), 150 in_addrany, in_loopback, 0}, 151 {0, 0, 0, 0, NULL, NULL, 0}, 152}; 153 154struct explore { 155 int e_af; 156 int e_socktype; 157 int e_protocol; 158 int e_wild; 159#define WILD_AF(ex) ((ex)->e_wild & 0x01) 160#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 161#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 162}; 163 164static const struct explore explore[] = { 165#if 0 166 { PF_LOCAL, ANY, ANY, 0x01 }, 167#endif 168#ifdef INET6 169 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 0x07 }, 170 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, 0x07 }, 171 { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 0x03 }, 172 { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 }, 173 { PF_INET6, SOCK_DGRAM, IPPROTO_UDPLITE, 0x03 }, 174 { PF_INET6, SOCK_RAW, ANY, 0x05 }, 175#endif 176 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, 0x07 }, 177 { PF_INET, SOCK_STREAM, IPPROTO_TCP, 0x07 }, 178 { PF_INET, SOCK_STREAM, IPPROTO_SCTP, 0x03 }, 179 { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 }, 180 { PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE, 0x03 }, 181 { PF_INET, SOCK_RAW, ANY, 0x05 }, 182 { -1, 0, 0, 0 }, 183}; 184 185#ifdef INET6 186#define PTON_MAX 16 187#else 188#define PTON_MAX 4 189#endif 190 191#define AIO_SRCFLAG_DEPRECATED 0x1 192 193struct ai_order { 194 union { 195 struct sockaddr_storage aiou_ss; 196 struct sockaddr aiou_sa; 197 } aio_src_un; 198#define aio_srcsa aio_src_un.aiou_sa 199 u_int32_t aio_srcflag; 200 int aio_srcscope; 201 int aio_dstscope; 202 struct policyqueue *aio_srcpolicy; 203 struct policyqueue *aio_dstpolicy; 204 struct addrinfo *aio_ai; 205 int aio_matchlen; 206}; 207 208static const ns_src default_dns_files[] = { 209 { NSSRC_FILES, NS_SUCCESS }, 210 { NSSRC_DNS, NS_SUCCESS }, 211 { 0 } 212}; 213 214struct res_target { 215 struct res_target *next; 216 const char *name; /* domain name */ 217 int qclass, qtype; /* class and type of query */ 218 u_char *answer; /* buffer to put answer */ 219 int anslen; /* size of answer buffer */ 220 int n; /* result length */ 221}; 222 223#define MAXPACKET (64*1024) 224 225typedef union { 226 HEADER hdr; 227 u_char buf[MAXPACKET]; 228} querybuf; 229 230static int str2number(const char *, int *); 231static int explore_copy(const struct addrinfo *, const struct addrinfo *, 232 struct addrinfo **); 233static int explore_null(const struct addrinfo *, 234 const char *, struct addrinfo **); 235static int explore_numeric(const struct addrinfo *, const char *, 236 const char *, struct addrinfo **, const char *); 237static int explore_numeric_scope(const struct addrinfo *, const char *, 238 const char *, struct addrinfo **); 239static int get_canonname(const struct addrinfo *, 240 struct addrinfo *, const char *); 241static struct addrinfo *get_ai(const struct addrinfo *, 242 const struct afd *, const char *); 243static struct addrinfo *copy_ai(const struct addrinfo *); 244static int get_portmatch(const struct addrinfo *, const char *); 245static int get_port(struct addrinfo *, const char *, int); 246static const struct afd *find_afd(int); 247static int addrconfig(struct addrinfo *); 248static void set_source(struct ai_order *, struct policyhead *); 249static int comp_dst(const void *, const void *); 250#ifdef INET6 251static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 252#endif 253static int gai_addr2scopetype(struct sockaddr *); 254 255static int explore_fqdn(const struct addrinfo *, const char *, 256 const char *, struct addrinfo **); 257 258static int reorder(struct addrinfo *); 259static int get_addrselectpolicy(struct policyhead *); 260static void free_addrselectpolicy(struct policyhead *); 261static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 262 struct policyhead *); 263static int matchlen(struct sockaddr *, struct sockaddr *); 264 265static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 266 const struct addrinfo *, res_state); 267#if defined(RESOLVSORT) 268static int addr4sort(struct addrinfo *, res_state); 269#endif 270static int _dns_getaddrinfo(void *, void *, va_list); 271static void _sethtent(FILE **); 272static void _endhtent(FILE **); 273static struct addrinfo *_gethtent(FILE **, const char *, 274 const struct addrinfo *); 275static int _files_getaddrinfo(void *, void *, va_list); 276#ifdef YP 277static struct addrinfo *_yphostent(char *, const struct addrinfo *); 278static int _yp_getaddrinfo(void *, void *, va_list); 279#endif 280#ifdef NS_CACHING 281static int addrinfo_id_func(char *, size_t *, va_list, void *); 282static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 283static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 284#endif 285 286static int res_queryN(const char *, struct res_target *, res_state); 287static int res_searchN(const char *, struct res_target *, res_state); 288static int res_querydomainN(const char *, const char *, 289 struct res_target *, res_state); 290 291/* XXX macros that make external reference is BAD. */ 292 293#define GET_AI(ai, afd, addr) \ 294do { \ 295 /* external reference: pai, error, and label free */ \ 296 (ai) = get_ai(pai, (afd), (addr)); \ 297 if ((ai) == NULL) { \ 298 error = EAI_MEMORY; \ 299 goto free; \ 300 } \ 301} while (/*CONSTCOND*/0) 302 303#define GET_PORT(ai, serv) \ 304do { \ 305 /* external reference: error and label free */ \ 306 error = get_port((ai), (serv), 0); \ 307 if (error != 0) \ 308 goto free; \ 309} while (/*CONSTCOND*/0) 310 311#define GET_CANONNAME(ai, str) \ 312do { \ 313 /* external reference: pai, error and label free */ \ 314 error = get_canonname(pai, (ai), (str)); \ 315 if (error != 0) \ 316 goto free; \ 317} while (/*CONSTCOND*/0) 318 319#define ERR(err) \ 320do { \ 321 /* external reference: error, and label bad */ \ 322 error = (err); \ 323 goto bad; \ 324 /*NOTREACHED*/ \ 325} while (/*CONSTCOND*/0) 326 327#define MATCH_FAMILY(x, y, w) \ 328 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 329#define MATCH(x, y, w) \ 330 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 331 332void 333freeaddrinfo(struct addrinfo *ai) 334{ 335 struct addrinfo *next; 336 337 do { 338 next = ai->ai_next; 339 if (ai->ai_canonname) 340 free(ai->ai_canonname); 341 /* no need to free(ai->ai_addr) */ 342 free(ai); 343 ai = next; 344 } while (ai); 345} 346 347static int 348str2number(const char *p, int *portp) 349{ 350 char *ep; 351 unsigned long v; 352 353 if (*p == '\0') 354 return -1; 355 ep = NULL; 356 errno = 0; 357 v = strtoul(p, &ep, 10); 358 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 359 *portp = v; 360 return 0; 361 } else 362 return -1; 363} 364 365int 366getaddrinfo(const char *hostname, const char *servname, 367 const struct addrinfo *hints, struct addrinfo **res) 368{ 369 struct addrinfo sentinel; 370 struct addrinfo *cur; 371 int error = 0; 372 struct addrinfo ai, ai0, *afai; 373 struct addrinfo *pai; 374 const struct afd *afd; 375 const struct explore *ex; 376 struct addrinfo *afailist[sizeof(afdl)/sizeof(afdl[0])]; 377 struct addrinfo *afai_unspec; 378 int found; 379 int numeric = 0; 380 381 /* ensure we return NULL on errors */ 382 *res = NULL; 383 384 memset(&ai, 0, sizeof(ai)); 385 386 memset(afailist, 0, sizeof(afailist)); 387 afai_unspec = NULL; 388 389 memset(&sentinel, 0, sizeof(sentinel)); 390 cur = &sentinel; 391 pai = &ai; 392 pai->ai_flags = 0; 393 pai->ai_family = PF_UNSPEC; 394 pai->ai_socktype = ANY; 395 pai->ai_protocol = ANY; 396 pai->ai_addrlen = 0; 397 pai->ai_canonname = NULL; 398 pai->ai_addr = NULL; 399 pai->ai_next = NULL; 400 401 if (hostname == NULL && servname == NULL) 402 return EAI_NONAME; 403 if (hints) { 404 /* error check for hints */ 405 if (hints->ai_addrlen || hints->ai_canonname || 406 hints->ai_addr || hints->ai_next) 407 ERR(EAI_BADHINTS); /* xxx */ 408 if (hints->ai_flags & ~AI_MASK) 409 ERR(EAI_BADFLAGS); 410 switch (hints->ai_family) { 411 case PF_UNSPEC: 412 case PF_INET: 413#ifdef INET6 414 case PF_INET6: 415#endif 416 break; 417 default: 418 ERR(EAI_FAMILY); 419 } 420 memcpy(pai, hints, sizeof(*pai)); 421 422 /* 423 * if both socktype/protocol are specified, check if they 424 * are meaningful combination. 425 */ 426 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 427 for (ex = explore; ex->e_af >= 0; ex++) { 428 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 429 WILD_AF(ex))) 430 continue; 431 if (!MATCH(pai->ai_socktype, ex->e_socktype, 432 WILD_SOCKTYPE(ex))) 433 continue; 434 if (!MATCH(pai->ai_protocol, ex->e_protocol, 435 WILD_PROTOCOL(ex))) 436 continue; 437 438 /* matched */ 439 break; 440 } 441 442 if (ex->e_af < 0) 443 ERR(EAI_BADHINTS); 444 } 445 } 446 447 /* 448 * check for special cases. (1) numeric servname is disallowed if 449 * socktype/protocol are left unspecified. (2) servname is disallowed 450 * for raw and other inet{,6} sockets. 451 */ 452 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 453#ifdef PF_INET6 454 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 455#endif 456 ) { 457 ai0 = *pai; /* backup *pai */ 458 459 if (pai->ai_family == PF_UNSPEC) { 460#ifdef PF_INET6 461 pai->ai_family = PF_INET6; 462#else 463 pai->ai_family = PF_INET; 464#endif 465 } 466 error = get_portmatch(pai, servname); 467 if (error) 468 goto bad; 469 470 *pai = ai0; 471 } 472 473 ai0 = *pai; 474 475 /* 476 * NULL hostname, or numeric hostname. 477 * If numeric representation of AF1 can be interpreted as FQDN 478 * representation of AF2, we need to think again about the code below. 479 */ 480 found = 0; 481 for (afd = afdl; afd->a_af; afd++) { 482 *pai = ai0; 483 484 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 485 continue; 486 487 if (pai->ai_family == PF_UNSPEC) 488 pai->ai_family = afd->a_af; 489 490 if (hostname == NULL) { 491 error = explore_null(pai, servname, 492 &afailist[afd - afdl]); 493 494 /* 495 * Errors from explore_null should be unexpected and 496 * be caught to avoid returning an incomplete result. 497 */ 498 if (error != 0) 499 goto bad; 500 } else { 501 error = explore_numeric_scope(pai, hostname, servname, 502 &afailist[afd - afdl]); 503 504 /* 505 * explore_numeric_scope returns an error for address 506 * families that do not match that of hostname. 507 * Thus we should not catch the error at this moment. 508 */ 509 } 510 511 if (!error && afailist[afd - afdl]) 512 found++; 513 } 514 if (found) { 515 numeric = 1; 516 goto globcopy; 517 } 518 519 if (hostname == NULL) 520 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 521 if (pai->ai_flags & AI_NUMERICHOST) 522 ERR(EAI_NONAME); 523 524 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 525 ERR(EAI_FAIL); 526 527 /* 528 * hostname as alphabetical name. 529 */ 530 *pai = ai0; 531 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 532 533globcopy: 534 for (ex = explore; ex->e_af >= 0; ex++) { 535 *pai = ai0; 536 537 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 538 continue; 539 if (!MATCH(pai->ai_socktype, ex->e_socktype, 540 WILD_SOCKTYPE(ex))) 541 continue; 542 if (!MATCH(pai->ai_protocol, ex->e_protocol, 543 WILD_PROTOCOL(ex))) 544 continue; 545 546 if (pai->ai_family == PF_UNSPEC) 547 pai->ai_family = ex->e_af; 548 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 549 pai->ai_socktype = ex->e_socktype; 550 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 551 pai->ai_protocol = ex->e_protocol; 552 553 /* 554 * if the servname does not match socktype/protocol, ignore it. 555 */ 556 if (get_portmatch(pai, servname) != 0) 557 continue; 558 559 if (afai_unspec) 560 afai = afai_unspec; 561 else { 562 if ((afd = find_afd(pai->ai_family)) == NULL) 563 continue; 564 /* XXX assumes that afd points inside afdl[] */ 565 afai = afailist[afd - afdl]; 566 } 567 if (!afai) 568 continue; 569 570 error = explore_copy(pai, afai, &cur->ai_next); 571 if (error != 0) 572 goto bad; 573 574 while (cur && cur->ai_next) 575 cur = cur->ai_next; 576 } 577 578 /* 579 * ensure we return either: 580 * - error == 0, non-NULL *res 581 * - error != 0, NULL *res 582 */ 583 if (error == 0) { 584 if (sentinel.ai_next) { 585 /* 586 * If the returned entry is for an active connection, 587 * and the given name is not numeric, reorder the 588 * list, so that the application would try the list 589 * in the most efficient order. Since the head entry 590 * of the original list may contain ai_canonname and 591 * that entry may be moved elsewhere in the new list, 592 * we keep the pointer and will restore it in the new 593 * head entry. (Note that RFC3493 requires the head 594 * entry store it when requested by the caller). 595 */ 596 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 597 if (!numeric) { 598 char *canonname; 599 600 canonname = 601 sentinel.ai_next->ai_canonname; 602 sentinel.ai_next->ai_canonname = NULL; 603 (void)reorder(&sentinel); 604 if (sentinel.ai_next->ai_canonname == 605 NULL) { 606 sentinel.ai_next->ai_canonname 607 = canonname; 608 } else if (canonname != NULL) 609 free(canonname); 610 } 611 } 612 *res = sentinel.ai_next; 613 } else 614 error = EAI_FAIL; 615 } 616 617bad: 618 if (afai_unspec) 619 freeaddrinfo(afai_unspec); 620 for (afd = afdl; afd->a_af; afd++) { 621 if (afailist[afd - afdl]) 622 freeaddrinfo(afailist[afd - afdl]); 623 } 624 if (!*res) 625 if (sentinel.ai_next) 626 freeaddrinfo(sentinel.ai_next); 627 628 return (error); 629} 630 631static int 632reorder(struct addrinfo *sentinel) 633{ 634 struct addrinfo *ai, **aip; 635 struct ai_order *aio; 636 int i, n; 637 struct policyhead policyhead; 638 639 /* count the number of addrinfo elements for sorting. */ 640 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 641 ; 642 643 /* 644 * If the number is small enough, we can skip the reordering process. 645 */ 646 if (n <= 1) 647 return(n); 648 649 /* allocate a temporary array for sort and initialization of it. */ 650 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 651 return(n); /* give up reordering */ 652 memset(aio, 0, sizeof(*aio) * n); 653 654 /* retrieve address selection policy from the kernel */ 655 TAILQ_INIT(&policyhead); 656 if (!get_addrselectpolicy(&policyhead)) { 657 /* no policy is installed into kernel, we don't sort. */ 658 free(aio); 659 return (n); 660 } 661 662 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 663 aio[i].aio_ai = ai; 664 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 665 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 666 &policyhead); 667 set_source(&aio[i], &policyhead); 668 } 669 670 /* perform sorting. */ 671 qsort(aio, n, sizeof(*aio), comp_dst); 672 673 /* reorder the addrinfo chain. */ 674 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 675 *aip = aio[i].aio_ai; 676 aip = &aio[i].aio_ai->ai_next; 677 } 678 *aip = NULL; 679 680 /* cleanup and return */ 681 free(aio); 682 free_addrselectpolicy(&policyhead); 683 return(n); 684} 685 686static int 687get_addrselectpolicy(struct policyhead *head) 688{ 689#ifdef INET6 690 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 691 size_t l; 692 char *buf; 693 struct in6_addrpolicy *pol, *ep; 694 695 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 696 return (0); 697 if (l == 0) 698 return (0); 699 if ((buf = malloc(l)) == NULL) 700 return (0); 701 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 702 free(buf); 703 return (0); 704 } 705 706 ep = (struct in6_addrpolicy *)(buf + l); 707 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 708 struct policyqueue *new; 709 710 if ((new = malloc(sizeof(*new))) == NULL) { 711 free_addrselectpolicy(head); /* make the list empty */ 712 break; 713 } 714 new->pc_policy = *pol; 715 TAILQ_INSERT_TAIL(head, new, pc_entry); 716 } 717 718 free(buf); 719 return (1); 720#else 721 return (0); 722#endif 723} 724 725static void 726free_addrselectpolicy(struct policyhead *head) 727{ 728 struct policyqueue *ent, *nent; 729 730 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 731 nent = TAILQ_NEXT(ent, pc_entry); 732 TAILQ_REMOVE(head, ent, pc_entry); 733 free(ent); 734 } 735} 736 737static struct policyqueue * 738match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 739{ 740#ifdef INET6 741 struct policyqueue *ent, *bestent = NULL; 742 struct in6_addrpolicy *pol; 743 int matchlen, bestmatchlen = -1; 744 u_char *mp, *ep, *k, *p, m; 745 struct sockaddr_in6 key; 746 747 switch(addr->sa_family) { 748 case AF_INET6: 749 key = *(struct sockaddr_in6 *)addr; 750 break; 751 case AF_INET: 752 /* convert the address into IPv4-mapped IPv6 address. */ 753 memset(&key, 0, sizeof(key)); 754 key.sin6_family = AF_INET6; 755 key.sin6_len = sizeof(key); 756 key.sin6_addr.s6_addr[10] = 0xff; 757 key.sin6_addr.s6_addr[11] = 0xff; 758 memcpy(&key.sin6_addr.s6_addr[12], 759 &((struct sockaddr_in *)addr)->sin_addr, 4); 760 break; 761 default: 762 return(NULL); 763 } 764 765 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 766 pol = &ent->pc_policy; 767 matchlen = 0; 768 769 mp = (u_char *)&pol->addrmask.sin6_addr; 770 ep = mp + 16; /* XXX: scope field? */ 771 k = (u_char *)&key.sin6_addr; 772 p = (u_char *)&pol->addr.sin6_addr; 773 for (; mp < ep && *mp; mp++, k++, p++) { 774 m = *mp; 775 if ((*k & m) != *p) 776 goto next; /* not match */ 777 if (m == 0xff) /* short cut for a typical case */ 778 matchlen += 8; 779 else { 780 while (m >= 0x80) { 781 matchlen++; 782 m <<= 1; 783 } 784 } 785 } 786 787 /* matched. check if this is better than the current best. */ 788 if (matchlen > bestmatchlen) { 789 bestent = ent; 790 bestmatchlen = matchlen; 791 } 792 793 next: 794 continue; 795 } 796 797 return(bestent); 798#else 799 return(NULL); 800#endif 801 802} 803 804static void 805set_source(struct ai_order *aio, struct policyhead *ph) 806{ 807 struct addrinfo ai = *aio->aio_ai; 808 struct sockaddr_storage ss; 809 socklen_t srclen; 810 int s; 811 812 /* set unspec ("no source is available"), just in case */ 813 aio->aio_srcsa.sa_family = AF_UNSPEC; 814 aio->aio_srcscope = -1; 815 816 switch(ai.ai_family) { 817 case AF_INET: 818#ifdef INET6 819 case AF_INET6: 820#endif 821 break; 822 default: /* ignore unsupported AFs explicitly */ 823 return; 824 } 825 826 /* XXX: make a dummy addrinfo to call connect() */ 827 ai.ai_socktype = SOCK_DGRAM; 828 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 829 ai.ai_next = NULL; 830 memset(&ss, 0, sizeof(ss)); 831 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 832 ai.ai_addr = (struct sockaddr *)&ss; 833 get_port(&ai, "1", 0); 834 835 /* open a socket to get the source address for the given dst */ 836 if ((s = _socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC, 837 ai.ai_protocol)) < 0) 838 return; /* give up */ 839 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 840 goto cleanup; 841 srclen = ai.ai_addrlen; 842 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 843 aio->aio_srcsa.sa_family = AF_UNSPEC; 844 goto cleanup; 845 } 846 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 847 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 848 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 849#ifdef INET6 850 if (ai.ai_family == AF_INET6) { 851 struct in6_ifreq ifr6; 852 u_int32_t flags6; 853 854 memset(&ifr6, 0, sizeof(ifr6)); 855 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 856 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 857 flags6 = ifr6.ifr_ifru.ifru_flags6; 858 if ((flags6 & IN6_IFF_DEPRECATED)) 859 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 860 } 861 } 862#endif 863 864 cleanup: 865 _close(s); 866 return; 867} 868 869static int 870matchlen(struct sockaddr *src, struct sockaddr *dst) 871{ 872 int match = 0; 873 u_char *s, *d; 874 u_char *lim, r; 875 int addrlen; 876 877 switch (src->sa_family) { 878#ifdef INET6 879 case AF_INET6: 880 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 881 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 882 addrlen = sizeof(struct in6_addr); 883 lim = s + addrlen; 884 break; 885#endif 886 case AF_INET: 887 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 888 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 889 addrlen = sizeof(struct in_addr); 890 lim = s + addrlen; 891 break; 892 default: 893 return(0); 894 } 895 896 while (s < lim) 897 if ((r = (*d++ ^ *s++)) != 0) { 898 while (r < addrlen * 8) { 899 match++; 900 r <<= 1; 901 } 902 break; 903 } else 904 match += 8; 905 return(match); 906} 907 908static int 909comp_dst(const void *arg1, const void *arg2) 910{ 911 const struct ai_order *dst1 = arg1, *dst2 = arg2; 912 913 /* 914 * Rule 1: Avoid unusable destinations. 915 * XXX: we currently do not consider if an appropriate route exists. 916 */ 917 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 918 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 919 return(-1); 920 } 921 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 922 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 923 return(1); 924 } 925 926 /* Rule 2: Prefer matching scope. */ 927 if (dst1->aio_dstscope == dst1->aio_srcscope && 928 dst2->aio_dstscope != dst2->aio_srcscope) { 929 return(-1); 930 } 931 if (dst1->aio_dstscope != dst1->aio_srcscope && 932 dst2->aio_dstscope == dst2->aio_srcscope) { 933 return(1); 934 } 935 936 /* Rule 3: Avoid deprecated addresses. */ 937 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 938 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 939 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 940 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 941 return(-1); 942 } 943 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 944 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 945 return(1); 946 } 947 } 948 949 /* Rule 4: Prefer home addresses. */ 950 /* XXX: not implemented yet */ 951 952 /* Rule 5: Prefer matching label. */ 953#ifdef INET6 954 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 955 dst1->aio_srcpolicy->pc_policy.label == 956 dst1->aio_dstpolicy->pc_policy.label && 957 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 958 dst2->aio_srcpolicy->pc_policy.label != 959 dst2->aio_dstpolicy->pc_policy.label)) { 960 return(-1); 961 } 962 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 963 dst2->aio_srcpolicy->pc_policy.label == 964 dst2->aio_dstpolicy->pc_policy.label && 965 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 966 dst1->aio_srcpolicy->pc_policy.label != 967 dst1->aio_dstpolicy->pc_policy.label)) { 968 return(1); 969 } 970#endif 971 972 /* Rule 6: Prefer higher precedence. */ 973#ifdef INET6 974 if (dst1->aio_dstpolicy && 975 (dst2->aio_dstpolicy == NULL || 976 dst1->aio_dstpolicy->pc_policy.preced > 977 dst2->aio_dstpolicy->pc_policy.preced)) { 978 return(-1); 979 } 980 if (dst2->aio_dstpolicy && 981 (dst1->aio_dstpolicy == NULL || 982 dst2->aio_dstpolicy->pc_policy.preced > 983 dst1->aio_dstpolicy->pc_policy.preced)) { 984 return(1); 985 } 986#endif 987 988 /* Rule 7: Prefer native transport. */ 989 /* XXX: not implemented yet */ 990 991 /* Rule 8: Prefer smaller scope. */ 992 if (dst1->aio_dstscope >= 0 && 993 dst1->aio_dstscope < dst2->aio_dstscope) { 994 return(-1); 995 } 996 if (dst2->aio_dstscope >= 0 && 997 dst2->aio_dstscope < dst1->aio_dstscope) { 998 return(1); 999 } 1000 1001 /* 1002 * Rule 9: Use longest matching prefix. 1003 * We compare the match length in a same AF only. 1004 */ 1005 if (dst1->aio_ai->ai_addr->sa_family == 1006 dst2->aio_ai->ai_addr->sa_family) { 1007 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1008 return(-1); 1009 } 1010 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1011 return(1); 1012 } 1013 } 1014 1015 /* Rule 10: Otherwise, leave the order unchanged. */ 1016 return(-1); 1017} 1018 1019/* 1020 * Copy from scope.c. 1021 * XXX: we should standardize the functions and link them as standard 1022 * library. 1023 */ 1024static int 1025gai_addr2scopetype(struct sockaddr *sa) 1026{ 1027#ifdef INET6 1028 struct sockaddr_in6 *sa6; 1029#endif 1030 struct sockaddr_in *sa4; 1031 1032 switch(sa->sa_family) { 1033#ifdef INET6 1034 case AF_INET6: 1035 sa6 = (struct sockaddr_in6 *)sa; 1036 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1037 /* just use the scope field of the multicast address */ 1038 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1039 } 1040 /* 1041 * Unicast addresses: map scope type to corresponding scope 1042 * value defined for multcast addresses. 1043 * XXX: hardcoded scope type values are bad... 1044 */ 1045 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1046 return(1); /* node local scope */ 1047 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1048 return(2); /* link-local scope */ 1049 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1050 return(5); /* site-local scope */ 1051 return(14); /* global scope */ 1052 break; 1053#endif 1054 case AF_INET: 1055 /* 1056 * IPv4 pseudo scoping according to RFC 3484. 1057 */ 1058 sa4 = (struct sockaddr_in *)sa; 1059 /* IPv4 autoconfiguration addresses have link-local scope. */ 1060 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1061 ((u_char *)&sa4->sin_addr)[1] == 254) 1062 return(2); 1063 /* Private addresses have site-local scope. */ 1064 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1065 (((u_char *)&sa4->sin_addr)[0] == 172 && 1066 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1067 (((u_char *)&sa4->sin_addr)[0] == 192 && 1068 ((u_char *)&sa4->sin_addr)[1] == 168)) 1069 return(14); /* XXX: It should be 5 unless NAT */ 1070 /* Loopback addresses have link-local scope. */ 1071 if (((u_char *)&sa4->sin_addr)[0] == 127) 1072 return(2); 1073 return(14); 1074 break; 1075 default: 1076 errno = EAFNOSUPPORT; /* is this a good error? */ 1077 return(-1); 1078 } 1079} 1080 1081static int 1082explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1083 struct addrinfo **res) 1084{ 1085 int error; 1086 struct addrinfo sentinel, *cur; 1087 const struct addrinfo *src; 1088 1089 error = 0; 1090 sentinel.ai_next = NULL; 1091 cur = &sentinel; 1092 1093 for (src = src0; src != NULL; src = src->ai_next) { 1094 if (src->ai_family != pai->ai_family) 1095 continue; 1096 1097 cur->ai_next = copy_ai(src); 1098 if (!cur->ai_next) { 1099 error = EAI_MEMORY; 1100 goto fail; 1101 } 1102 1103 cur->ai_next->ai_socktype = pai->ai_socktype; 1104 cur->ai_next->ai_protocol = pai->ai_protocol; 1105 cur = cur->ai_next; 1106 } 1107 1108 *res = sentinel.ai_next; 1109 return 0; 1110 1111fail: 1112 freeaddrinfo(sentinel.ai_next); 1113 return error; 1114} 1115 1116/* 1117 * hostname == NULL. 1118 * passive socket -> anyaddr (0.0.0.0 or ::) 1119 * non-passive socket -> localhost (127.0.0.1 or ::1) 1120 */ 1121static int 1122explore_null(const struct addrinfo *pai, const char *servname, 1123 struct addrinfo **res) 1124{ 1125 int s; 1126 const struct afd *afd; 1127 struct addrinfo *ai; 1128 int error; 1129 1130 *res = NULL; 1131 ai = NULL; 1132 1133 /* 1134 * filter out AFs that are not supported by the kernel 1135 * XXX errno? 1136 */ 1137 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1138 if (s < 0) { 1139 if (errno != EMFILE) 1140 return 0; 1141 } else 1142 _close(s); 1143 1144 afd = find_afd(pai->ai_family); 1145 if (afd == NULL) 1146 return 0; 1147 1148 if (pai->ai_flags & AI_PASSIVE) { 1149 GET_AI(ai, afd, afd->a_addrany); 1150 GET_PORT(ai, servname); 1151 } else { 1152 GET_AI(ai, afd, afd->a_loopback); 1153 GET_PORT(ai, servname); 1154 } 1155 1156 *res = ai; 1157 return 0; 1158 1159free: 1160 if (ai != NULL) 1161 freeaddrinfo(ai); 1162 return error; 1163} 1164 1165/* 1166 * numeric hostname 1167 */ 1168static int 1169explore_numeric(const struct addrinfo *pai, const char *hostname, 1170 const char *servname, struct addrinfo **res, const char *canonname) 1171{ 1172 const struct afd *afd; 1173 struct addrinfo *ai; 1174 int error; 1175 char pton[PTON_MAX]; 1176 1177 *res = NULL; 1178 ai = NULL; 1179 1180 afd = find_afd(pai->ai_family); 1181 if (afd == NULL) 1182 return 0; 1183 1184 switch (afd->a_af) { 1185 case AF_INET: 1186 /* 1187 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1188 * that are accepted by inet_addr() and its family. The 1189 * accepted forms includes the "classful" one, which inet_pton 1190 * does not accept. So we need to separate the case for 1191 * AF_INET. 1192 */ 1193 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1194 return 0; 1195 break; 1196 default: 1197 if (inet_pton(afd->a_af, hostname, pton) != 1) 1198 return 0; 1199 break; 1200 } 1201 1202 if (pai->ai_family == afd->a_af) { 1203 GET_AI(ai, afd, pton); 1204 GET_PORT(ai, servname); 1205 if ((pai->ai_flags & AI_CANONNAME)) { 1206 /* 1207 * Set the numeric address itself as the canonical 1208 * name, based on a clarification in RFC3493. 1209 */ 1210 GET_CANONNAME(ai, canonname); 1211 } 1212 } else { 1213 /* 1214 * XXX: This should not happen since we already matched the AF 1215 * by find_afd. 1216 */ 1217 ERR(EAI_FAMILY); 1218 } 1219 1220 *res = ai; 1221 return 0; 1222 1223free: 1224bad: 1225 if (ai != NULL) 1226 freeaddrinfo(ai); 1227 return error; 1228} 1229 1230/* 1231 * numeric hostname with scope 1232 */ 1233static int 1234explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1235 const char *servname, struct addrinfo **res) 1236{ 1237#if !defined(SCOPE_DELIMITER) || !defined(INET6) 1238 return explore_numeric(pai, hostname, servname, res, hostname); 1239#else 1240 const struct afd *afd; 1241 struct addrinfo *cur; 1242 int error; 1243 char *cp, *hostname2 = NULL, *scope, *addr; 1244 struct sockaddr_in6 *sin6; 1245 1246 afd = find_afd(pai->ai_family); 1247 if (afd == NULL) 1248 return 0; 1249 1250 if (!afd->a_scoped) 1251 return explore_numeric(pai, hostname, servname, res, hostname); 1252 1253 cp = strchr(hostname, SCOPE_DELIMITER); 1254 if (cp == NULL) 1255 return explore_numeric(pai, hostname, servname, res, hostname); 1256 1257 /* 1258 * Handle special case of <scoped_address><delimiter><scope id> 1259 */ 1260 hostname2 = strdup(hostname); 1261 if (hostname2 == NULL) 1262 return EAI_MEMORY; 1263 /* terminate at the delimiter */ 1264 hostname2[cp - hostname] = '\0'; 1265 addr = hostname2; 1266 scope = cp + 1; 1267 1268 error = explore_numeric(pai, addr, servname, res, hostname); 1269 if (error == 0) { 1270 u_int32_t scopeid; 1271 1272 for (cur = *res; cur; cur = cur->ai_next) { 1273 if (cur->ai_family != AF_INET6) 1274 continue; 1275 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1276 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1277 free(hostname2); 1278 freeaddrinfo(*res); 1279 *res = NULL; 1280 return(EAI_NONAME); /* XXX: is return OK? */ 1281 } 1282 sin6->sin6_scope_id = scopeid; 1283 } 1284 } 1285 1286 free(hostname2); 1287 1288 if (error && *res) { 1289 freeaddrinfo(*res); 1290 *res = NULL; 1291 } 1292 return error; 1293#endif 1294} 1295 1296static int 1297get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1298{ 1299 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1300 ai->ai_canonname = strdup(str); 1301 if (ai->ai_canonname == NULL) 1302 return EAI_MEMORY; 1303 } 1304 return 0; 1305} 1306 1307static struct addrinfo * 1308get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1309{ 1310 char *p; 1311 struct addrinfo *ai; 1312#ifdef FAITH 1313 struct in6_addr faith_prefix; 1314 char *fp_str; 1315 int translate = 0; 1316#endif 1317 1318#ifdef FAITH 1319 /* 1320 * Transfrom an IPv4 addr into a special IPv6 addr format for 1321 * IPv6->IPv4 translation gateway. (only TCP is supported now) 1322 * 1323 * +-----------------------------------+------------+ 1324 * | faith prefix part (12 bytes) | embedded | 1325 * | | IPv4 addr part (4 bytes) 1326 * +-----------------------------------+------------+ 1327 * 1328 * faith prefix part is specified as ascii IPv6 addr format 1329 * in environmental variable GAI. 1330 * For FAITH to work correctly, routing to faith prefix must be 1331 * setup toward a machine where a FAITH daemon operates. 1332 * Also, the machine must enable some mechanizm 1333 * (e.g. faith interface hack) to divert those packet with 1334 * faith prefixed destination addr to user-land FAITH daemon. 1335 */ 1336 fp_str = getenv("GAI"); 1337 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 1338 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 1339 u_int32_t v4a; 1340 u_int8_t v4a_top; 1341 1342 memcpy(&v4a, addr, sizeof v4a); 1343 v4a_top = v4a >> IN_CLASSA_NSHIFT; 1344 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 1345 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 1346 afd = &afdl[N_INET6]; 1347 memcpy(&faith_prefix.s6_addr[12], addr, 1348 sizeof(struct in_addr)); 1349 translate = 1; 1350 } 1351 } 1352#endif 1353 1354 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1355 + (afd->a_socklen)); 1356 if (ai == NULL) 1357 return NULL; 1358 1359 memcpy(ai, pai, sizeof(struct addrinfo)); 1360 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1361 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1362 ai->ai_addr->sa_len = afd->a_socklen; 1363 ai->ai_addrlen = afd->a_socklen; 1364 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1365 p = (char *)(void *)(ai->ai_addr); 1366#ifdef FAITH 1367 if (translate == 1) 1368 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 1369 else 1370#endif 1371 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1372 return ai; 1373} 1374 1375/* XXX need to malloc() the same way we do from other functions! */ 1376static struct addrinfo * 1377copy_ai(const struct addrinfo *pai) 1378{ 1379 struct addrinfo *ai; 1380 size_t l; 1381 1382 l = sizeof(*ai) + pai->ai_addrlen; 1383 if ((ai = (struct addrinfo *)malloc(l)) == NULL) 1384 return NULL; 1385 memset(ai, 0, l); 1386 memcpy(ai, pai, sizeof(*ai)); 1387 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1388 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1389 1390 if (pai->ai_canonname) { 1391 l = strlen(pai->ai_canonname) + 1; 1392 if ((ai->ai_canonname = malloc(l)) == NULL) { 1393 free(ai); 1394 return NULL; 1395 } 1396 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1397 } else { 1398 /* just to make sure */ 1399 ai->ai_canonname = NULL; 1400 } 1401 1402 ai->ai_next = NULL; 1403 1404 return ai; 1405} 1406 1407static int 1408get_portmatch(const struct addrinfo *ai, const char *servname) 1409{ 1410 1411 /* get_port does not touch first argument when matchonly == 1. */ 1412 /* LINTED const cast */ 1413 return get_port((struct addrinfo *)ai, servname, 1); 1414} 1415 1416static int 1417get_port(struct addrinfo *ai, const char *servname, int matchonly) 1418{ 1419 const char *proto; 1420 struct servent *sp; 1421 int port, error; 1422 int allownumeric; 1423 1424 if (servname == NULL) 1425 return 0; 1426 switch (ai->ai_family) { 1427 case AF_INET: 1428#ifdef AF_INET6 1429 case AF_INET6: 1430#endif 1431 break; 1432 default: 1433 return 0; 1434 } 1435 1436 switch (ai->ai_socktype) { 1437 case SOCK_RAW: 1438 return EAI_SERVICE; 1439 case SOCK_DGRAM: 1440 case SOCK_STREAM: 1441 case SOCK_SEQPACKET: 1442 allownumeric = 1; 1443 break; 1444 case ANY: 1445 switch (ai->ai_family) { 1446 case AF_INET: 1447#ifdef AF_INET6 1448 case AF_INET6: 1449#endif 1450 allownumeric = 1; 1451 break; 1452 default: 1453 allownumeric = 0; 1454 break; 1455 } 1456 break; 1457 default: 1458 return EAI_SOCKTYPE; 1459 } 1460 1461 error = str2number(servname, &port); 1462 if (error == 0) { 1463 if (!allownumeric) 1464 return EAI_SERVICE; 1465 if (port < 0 || port > 65535) 1466 return EAI_SERVICE; 1467 port = htons(port); 1468 } else { 1469 if (ai->ai_flags & AI_NUMERICSERV) 1470 return EAI_NONAME; 1471 1472 switch (ai->ai_protocol) { 1473 case IPPROTO_UDP: 1474 proto = "udp"; 1475 break; 1476 case IPPROTO_TCP: 1477 proto = "tcp"; 1478 break; 1479 case IPPROTO_SCTP: 1480 proto = "sctp"; 1481 break; 1482 case IPPROTO_UDPLITE: 1483 proto = "udplite"; 1484 break; 1485 default: 1486 proto = NULL; 1487 break; 1488 } 1489 1490 if ((sp = getservbyname(servname, proto)) == NULL) 1491 return EAI_SERVICE; 1492 port = sp->s_port; 1493 } 1494 1495 if (!matchonly) { 1496 switch (ai->ai_family) { 1497 case AF_INET: 1498 ((struct sockaddr_in *)(void *) 1499 ai->ai_addr)->sin_port = port; 1500 break; 1501#ifdef INET6 1502 case AF_INET6: 1503 ((struct sockaddr_in6 *)(void *) 1504 ai->ai_addr)->sin6_port = port; 1505 break; 1506#endif 1507 } 1508 } 1509 1510 return 0; 1511} 1512 1513static const struct afd * 1514find_afd(int af) 1515{ 1516 const struct afd *afd; 1517 1518 if (af == PF_UNSPEC) 1519 return NULL; 1520 for (afd = afdl; afd->a_af; afd++) { 1521 if (afd->a_af == af) 1522 return afd; 1523 } 1524 return NULL; 1525} 1526 1527/* 1528 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1529 * will take care of it. 1530 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1531 * if the code is right or not. 1532 * 1533 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1534 * _dns_getaddrinfo. 1535 */ 1536static int 1537addrconfig(struct addrinfo *pai) 1538{ 1539 int s, af; 1540 1541 /* 1542 * TODO: 1543 * Note that implementation dependent test for address 1544 * configuration should be done everytime called 1545 * (or apropriate interval), 1546 * because addresses will be dynamically assigned or deleted. 1547 */ 1548 af = pai->ai_family; 1549 if (af == AF_UNSPEC) { 1550 if ((s = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1551 af = AF_INET; 1552 else { 1553 _close(s); 1554 if ((s = _socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 1555 0)) < 0) 1556 af = AF_INET6; 1557 else 1558 _close(s); 1559 } 1560 } 1561 if (af != AF_UNSPEC) { 1562 if ((s = _socket(af, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1563 return 0; 1564 _close(s); 1565 } 1566 pai->ai_family = af; 1567 return 1; 1568} 1569 1570#ifdef INET6 1571/* convert a string to a scope identifier. XXX: IPv6 specific */ 1572static int 1573ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1574{ 1575 u_long lscopeid; 1576 struct in6_addr *a6; 1577 char *ep; 1578 1579 a6 = &sin6->sin6_addr; 1580 1581 /* empty scopeid portion is invalid */ 1582 if (*scope == '\0') 1583 return -1; 1584 1585 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1586 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1587 /* 1588 * We currently assume a one-to-one mapping between links 1589 * and interfaces, so we simply use interface indices for 1590 * like-local scopes. 1591 */ 1592 *scopeid = if_nametoindex(scope); 1593 if (*scopeid == 0) 1594 goto trynumeric; 1595 return 0; 1596 } 1597 1598 /* still unclear about literal, allow numeric only - placeholder */ 1599 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1600 goto trynumeric; 1601 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1602 goto trynumeric; 1603 else 1604 goto trynumeric; /* global */ 1605 1606 /* try to convert to a numeric id as a last resort */ 1607 trynumeric: 1608 errno = 0; 1609 lscopeid = strtoul(scope, &ep, 10); 1610 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1611 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1612 return 0; 1613 else 1614 return -1; 1615} 1616#endif 1617 1618 1619#ifdef NS_CACHING 1620static int 1621addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1622 void *cache_mdata) 1623{ 1624 res_state statp; 1625 u_long res_options; 1626 1627 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1628 char *hostname; 1629 struct addrinfo *hints; 1630 1631 char *p; 1632 int ai_flags, ai_family, ai_socktype, ai_protocol; 1633 size_t desired_size, size; 1634 1635 statp = __res_state(); 1636 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1637 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1638 1639 hostname = va_arg(ap, char *); 1640 hints = va_arg(ap, struct addrinfo *); 1641 1642 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1643 if (hostname != NULL) { 1644 size = strlen(hostname); 1645 desired_size += size + 1; 1646 } else 1647 size = 0; 1648 1649 if (desired_size > *buffer_size) { 1650 *buffer_size = desired_size; 1651 return (NS_RETURN); 1652 } 1653 1654 if (hints == NULL) 1655 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1656 else { 1657 ai_flags = hints->ai_flags; 1658 ai_family = hints->ai_family; 1659 ai_socktype = hints->ai_socktype; 1660 ai_protocol = hints->ai_protocol; 1661 } 1662 1663 p = buffer; 1664 memcpy(p, &res_options, sizeof(res_options)); 1665 p += sizeof(res_options); 1666 1667 memcpy(p, &op_id, sizeof(int)); 1668 p += sizeof(int); 1669 1670 memcpy(p, &ai_flags, sizeof(int)); 1671 p += sizeof(int); 1672 1673 memcpy(p, &ai_family, sizeof(int)); 1674 p += sizeof(int); 1675 1676 memcpy(p, &ai_socktype, sizeof(int)); 1677 p += sizeof(int); 1678 1679 memcpy(p, &ai_protocol, sizeof(int)); 1680 p += sizeof(int); 1681 1682 if (hostname != NULL) 1683 memcpy(p, hostname, size); 1684 1685 *buffer_size = desired_size; 1686 return (NS_SUCCESS); 1687} 1688 1689static int 1690addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1691 va_list ap, void *cache_mdata) 1692{ 1693 struct addrinfo *ai, *cai; 1694 char *p; 1695 size_t desired_size, size, ai_size; 1696 1697 ai = *((struct addrinfo **)retval); 1698 1699 desired_size = sizeof(size_t); 1700 ai_size = 0; 1701 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1702 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1703 if (cai->ai_canonname != NULL) 1704 desired_size += sizeof(size_t) + 1705 strlen(cai->ai_canonname); 1706 ++ai_size; 1707 } 1708 1709 if (desired_size > *buffer_size) { 1710 /* this assignment is here for future use */ 1711 errno = ERANGE; 1712 *buffer_size = desired_size; 1713 return (NS_RETURN); 1714 } 1715 1716 memset(buffer, 0, desired_size); 1717 p = buffer; 1718 1719 memcpy(p, &ai_size, sizeof(size_t)); 1720 p += sizeof(size_t); 1721 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1722 memcpy(p, cai, sizeof(struct addrinfo)); 1723 p += sizeof(struct addrinfo); 1724 1725 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1726 p += cai->ai_addrlen; 1727 1728 if (cai->ai_canonname != NULL) { 1729 size = strlen(cai->ai_canonname); 1730 memcpy(p, &size, sizeof(size_t)); 1731 p += sizeof(size_t); 1732 1733 memcpy(p, cai->ai_canonname, size); 1734 p += size; 1735 } 1736 } 1737 1738 return (NS_SUCCESS); 1739} 1740 1741static int 1742addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1743 va_list ap, void *cache_mdata) 1744{ 1745 struct addrinfo new_ai, *result, *sentinel, *lasts; 1746 1747 char *p; 1748 size_t ai_size, ai_i, size; 1749 1750 p = buffer; 1751 memcpy(&ai_size, p, sizeof(size_t)); 1752 p += sizeof(size_t); 1753 1754 result = NULL; 1755 lasts = NULL; 1756 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1757 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1758 p += sizeof(struct addrinfo); 1759 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1760 _ALIGNBYTES; 1761 1762 sentinel = (struct addrinfo *)malloc(size); 1763 memset(sentinel, 0, size); 1764 1765 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1766 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1767 sizeof(struct addrinfo)); 1768 1769 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1770 p += new_ai.ai_addrlen; 1771 1772 if (new_ai.ai_canonname != NULL) { 1773 memcpy(&size, p, sizeof(size_t)); 1774 p += sizeof(size_t); 1775 1776 sentinel->ai_canonname = (char *)malloc(size + 1); 1777 memset(sentinel->ai_canonname, 0, size + 1); 1778 1779 memcpy(sentinel->ai_canonname, p, size); 1780 p += size; 1781 } 1782 1783 if (result == NULL) { 1784 result = sentinel; 1785 lasts = sentinel; 1786 } else { 1787 lasts->ai_next = sentinel; 1788 lasts = sentinel; 1789 } 1790 } 1791 1792 *((struct addrinfo **)retval) = result; 1793 return (NS_SUCCESS); 1794} 1795#endif /* NS_CACHING */ 1796 1797/* 1798 * FQDN hostname, DNS lookup 1799 */ 1800static int 1801explore_fqdn(const struct addrinfo *pai, const char *hostname, 1802 const char *servname, struct addrinfo **res) 1803{ 1804 struct addrinfo *result; 1805 struct addrinfo *cur; 1806 int error = 0; 1807 1808#ifdef NS_CACHING 1809 static const nss_cache_info cache_info = 1810 NS_COMMON_CACHE_INFO_INITIALIZER( 1811 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1812 addrinfo_unmarshal_func); 1813#endif 1814 static const ns_dtab dtab[] = { 1815 NS_FILES_CB(_files_getaddrinfo, NULL) 1816 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1817 NS_NIS_CB(_yp_getaddrinfo, NULL) 1818#ifdef NS_CACHING 1819 NS_CACHE_CB(&cache_info) 1820#endif 1821 { 0 } 1822 }; 1823 1824 result = NULL; 1825 1826 /* 1827 * if the servname does not match socktype/protocol, ignore it. 1828 */ 1829 if (get_portmatch(pai, servname) != 0) 1830 return 0; 1831 1832 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1833 default_dns_files, hostname, pai)) { 1834 case NS_TRYAGAIN: 1835 error = EAI_AGAIN; 1836 goto free; 1837 case NS_UNAVAIL: 1838 error = EAI_FAIL; 1839 goto free; 1840 case NS_NOTFOUND: 1841 error = EAI_NONAME; 1842 goto free; 1843 case NS_SUCCESS: 1844 error = 0; 1845 for (cur = result; cur; cur = cur->ai_next) { 1846 GET_PORT(cur, servname); 1847 /* canonname should be filled already */ 1848 } 1849 break; 1850 } 1851 1852 *res = result; 1853 1854 return 0; 1855 1856free: 1857 if (result) 1858 freeaddrinfo(result); 1859 return error; 1860} 1861 1862#ifdef DEBUG 1863static const char AskedForGot[] = 1864 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1865#endif 1866 1867static struct addrinfo * 1868getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1869 const struct addrinfo *pai, res_state res) 1870{ 1871 struct addrinfo sentinel, *cur; 1872 struct addrinfo ai; 1873 const struct afd *afd; 1874 char *canonname; 1875 const HEADER *hp; 1876 const u_char *cp; 1877 int n; 1878 const u_char *eom; 1879 char *bp, *ep; 1880 int type, class, ancount, qdcount; 1881 int haveanswer, had_error; 1882 char tbuf[MAXDNAME]; 1883 int (*name_ok)(const char *); 1884 char hostbuf[8*1024]; 1885 1886 memset(&sentinel, 0, sizeof(sentinel)); 1887 cur = &sentinel; 1888 1889 canonname = NULL; 1890 eom = answer->buf + anslen; 1891 switch (qtype) { 1892 case T_A: 1893 case T_AAAA: 1894 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1895 name_ok = res_hnok; 1896 break; 1897 default: 1898 return (NULL); /* XXX should be abort(); */ 1899 } 1900 /* 1901 * find first satisfactory answer 1902 */ 1903 hp = &answer->hdr; 1904 ancount = ntohs(hp->ancount); 1905 qdcount = ntohs(hp->qdcount); 1906 bp = hostbuf; 1907 ep = hostbuf + sizeof hostbuf; 1908 cp = answer->buf + HFIXEDSZ; 1909 if (qdcount != 1) { 1910 RES_SET_H_ERRNO(res, NO_RECOVERY); 1911 return (NULL); 1912 } 1913 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1914 if ((n < 0) || !(*name_ok)(bp)) { 1915 RES_SET_H_ERRNO(res, NO_RECOVERY); 1916 return (NULL); 1917 } 1918 cp += n + QFIXEDSZ; 1919 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1920 /* res_send() has already verified that the query name is the 1921 * same as the one we sent; this just gets the expanded name 1922 * (i.e., with the succeeding search-domain tacked on). 1923 */ 1924 n = strlen(bp) + 1; /* for the \0 */ 1925 if (n >= MAXHOSTNAMELEN) { 1926 RES_SET_H_ERRNO(res, NO_RECOVERY); 1927 return (NULL); 1928 } 1929 canonname = bp; 1930 bp += n; 1931 /* The qname can be abbreviated, but h_name is now absolute. */ 1932 qname = canonname; 1933 } 1934 haveanswer = 0; 1935 had_error = 0; 1936 while (ancount-- > 0 && cp < eom && !had_error) { 1937 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1938 if ((n < 0) || !(*name_ok)(bp)) { 1939 had_error++; 1940 continue; 1941 } 1942 cp += n; /* name */ 1943 type = _getshort(cp); 1944 cp += INT16SZ; /* type */ 1945 class = _getshort(cp); 1946 cp += INT16SZ + INT32SZ; /* class, TTL */ 1947 n = _getshort(cp); 1948 cp += INT16SZ; /* len */ 1949 if (class != C_IN) { 1950 /* XXX - debug? syslog? */ 1951 cp += n; 1952 continue; /* XXX - had_error++ ? */ 1953 } 1954 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1955 type == T_CNAME) { 1956 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1957 if ((n < 0) || !(*name_ok)(tbuf)) { 1958 had_error++; 1959 continue; 1960 } 1961 cp += n; 1962 /* Get canonical name. */ 1963 n = strlen(tbuf) + 1; /* for the \0 */ 1964 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1965 had_error++; 1966 continue; 1967 } 1968 strlcpy(bp, tbuf, ep - bp); 1969 canonname = bp; 1970 bp += n; 1971 continue; 1972 } 1973 if (qtype == T_ANY) { 1974 if (!(type == T_A || type == T_AAAA)) { 1975 cp += n; 1976 continue; 1977 } 1978 } else if (type != qtype) { 1979#ifdef DEBUG 1980 if (type != T_KEY && type != T_SIG && 1981 type != ns_t_dname) 1982 syslog(LOG_NOTICE|LOG_AUTH, 1983 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1984 qname, p_class(C_IN), p_type(qtype), 1985 p_type(type)); 1986#endif 1987 cp += n; 1988 continue; /* XXX - had_error++ ? */ 1989 } 1990 switch (type) { 1991 case T_A: 1992 case T_AAAA: 1993 if (strcasecmp(canonname, bp) != 0) { 1994#ifdef DEBUG 1995 syslog(LOG_NOTICE|LOG_AUTH, 1996 AskedForGot, canonname, bp); 1997#endif 1998 cp += n; 1999 continue; /* XXX - had_error++ ? */ 2000 } 2001 if (type == T_A && n != INADDRSZ) { 2002 cp += n; 2003 continue; 2004 } 2005 if (type == T_AAAA && n != IN6ADDRSZ) { 2006 cp += n; 2007 continue; 2008 } 2009#ifdef FILTER_V4MAPPED 2010 if (type == T_AAAA) { 2011 struct in6_addr in6; 2012 memcpy(&in6, cp, sizeof(in6)); 2013 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2014 cp += n; 2015 continue; 2016 } 2017 } 2018#endif 2019 if (!haveanswer) { 2020 int nn; 2021 2022 canonname = bp; 2023 nn = strlen(bp) + 1; /* for the \0 */ 2024 bp += nn; 2025 } 2026 2027 /* don't overwrite pai */ 2028 ai = *pai; 2029 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2030 afd = find_afd(ai.ai_family); 2031 if (afd == NULL) { 2032 cp += n; 2033 continue; 2034 } 2035 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2036 if (cur->ai_next == NULL) 2037 had_error++; 2038 while (cur && cur->ai_next) 2039 cur = cur->ai_next; 2040 cp += n; 2041 break; 2042 default: 2043 abort(); 2044 } 2045 if (!had_error) 2046 haveanswer++; 2047 } 2048 if (haveanswer) { 2049#if defined(RESOLVSORT) 2050 /* 2051 * We support only IPv4 address for backward 2052 * compatibility against gethostbyname(3). 2053 */ 2054 if (res->nsort && qtype == T_A) { 2055 if (addr4sort(&sentinel, res) < 0) { 2056 freeaddrinfo(sentinel.ai_next); 2057 RES_SET_H_ERRNO(res, NO_RECOVERY); 2058 return NULL; 2059 } 2060 } 2061#endif /*RESOLVSORT*/ 2062 if (!canonname) 2063 (void)get_canonname(pai, sentinel.ai_next, qname); 2064 else 2065 (void)get_canonname(pai, sentinel.ai_next, canonname); 2066 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2067 return sentinel.ai_next; 2068 } 2069 2070 RES_SET_H_ERRNO(res, NO_RECOVERY); 2071 return NULL; 2072} 2073 2074#ifdef RESOLVSORT 2075struct addr_ptr { 2076 struct addrinfo *ai; 2077 int aval; 2078}; 2079 2080static int 2081addr4sort(struct addrinfo *sentinel, res_state res) 2082{ 2083 struct addrinfo *ai; 2084 struct addr_ptr *addrs, addr; 2085 struct sockaddr_in *sin; 2086 int naddrs, i, j; 2087 int needsort = 0; 2088 2089 if (!sentinel) 2090 return -1; 2091 naddrs = 0; 2092 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2093 naddrs++; 2094 if (naddrs < 2) 2095 return 0; /* We don't need sorting. */ 2096 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2097 return -1; 2098 i = 0; 2099 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2100 sin = (struct sockaddr_in *)ai->ai_addr; 2101 for (j = 0; (unsigned)j < res->nsort; j++) { 2102 if (res->sort_list[j].addr.s_addr == 2103 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2104 break; 2105 } 2106 addrs[i].ai = ai; 2107 addrs[i].aval = j; 2108 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2109 needsort = i; 2110 i++; 2111 } 2112 if (!needsort) { 2113 free(addrs); 2114 return 0; 2115 } 2116 2117 while (needsort < naddrs) { 2118 for (j = needsort - 1; j >= 0; j--) { 2119 if (addrs[j].aval > addrs[j+1].aval) { 2120 addr = addrs[j]; 2121 addrs[j] = addrs[j + 1]; 2122 addrs[j + 1] = addr; 2123 } else 2124 break; 2125 } 2126 needsort++; 2127 } 2128 2129 ai = sentinel; 2130 for (i = 0; i < naddrs; ++i) { 2131 ai->ai_next = addrs[i].ai; 2132 ai = ai->ai_next; 2133 } 2134 ai->ai_next = NULL; 2135 free(addrs); 2136 return 0; 2137} 2138#endif /*RESOLVSORT*/ 2139 2140/*ARGSUSED*/ 2141static int 2142_dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2143{ 2144 struct addrinfo *ai; 2145 querybuf *buf, *buf2; 2146 const char *hostname; 2147 const struct addrinfo *pai; 2148 struct addrinfo sentinel, *cur; 2149 struct res_target q, q2; 2150 res_state res; 2151 2152 hostname = va_arg(ap, char *); 2153 pai = va_arg(ap, const struct addrinfo *); 2154 2155 memset(&q, 0, sizeof(q)); 2156 memset(&q2, 0, sizeof(q2)); 2157 memset(&sentinel, 0, sizeof(sentinel)); 2158 cur = &sentinel; 2159 2160 buf = malloc(sizeof(*buf)); 2161 if (!buf) { 2162 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2163 return NS_NOTFOUND; 2164 } 2165 buf2 = malloc(sizeof(*buf2)); 2166 if (!buf2) { 2167 free(buf); 2168 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2169 return NS_NOTFOUND; 2170 } 2171 2172 switch (pai->ai_family) { 2173 case AF_UNSPEC: 2174 q.name = hostname; 2175 q.qclass = C_IN; 2176 q.qtype = T_A; 2177 q.answer = buf->buf; 2178 q.anslen = sizeof(buf->buf); 2179 q.next = &q2; 2180 q2.name = hostname; 2181 q2.qclass = C_IN; 2182 q2.qtype = T_AAAA; 2183 q2.answer = buf2->buf; 2184 q2.anslen = sizeof(buf2->buf); 2185 break; 2186 case AF_INET: 2187 q.name = hostname; 2188 q.qclass = C_IN; 2189 q.qtype = T_A; 2190 q.answer = buf->buf; 2191 q.anslen = sizeof(buf->buf); 2192 break; 2193 case AF_INET6: 2194 q.name = hostname; 2195 q.qclass = C_IN; 2196 q.qtype = T_AAAA; 2197 q.answer = buf->buf; 2198 q.anslen = sizeof(buf->buf); 2199 break; 2200 default: 2201 free(buf); 2202 free(buf2); 2203 return NS_UNAVAIL; 2204 } 2205 2206 res = __res_state(); 2207 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2208 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2209 free(buf); 2210 free(buf2); 2211 return NS_NOTFOUND; 2212 } 2213 2214 if (res_searchN(hostname, &q, res) < 0) { 2215 free(buf); 2216 free(buf2); 2217 return NS_NOTFOUND; 2218 } 2219 /* prefer IPv6 */ 2220 if (q.next) { 2221 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2222 if (ai) { 2223 cur->ai_next = ai; 2224 while (cur && cur->ai_next) 2225 cur = cur->ai_next; 2226 } 2227 } 2228 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2229 if (ai) 2230 cur->ai_next = ai; 2231 free(buf); 2232 free(buf2); 2233 if (sentinel.ai_next == NULL) 2234 switch (res->res_h_errno) { 2235 case HOST_NOT_FOUND: 2236 return NS_NOTFOUND; 2237 case TRY_AGAIN: 2238 return NS_TRYAGAIN; 2239 default: 2240 return NS_UNAVAIL; 2241 } 2242 *((struct addrinfo **)rv) = sentinel.ai_next; 2243 return NS_SUCCESS; 2244} 2245 2246static void 2247_sethtent(FILE **hostf) 2248{ 2249 if (!*hostf) 2250 *hostf = fopen(_PATH_HOSTS, "re"); 2251 else 2252 rewind(*hostf); 2253} 2254 2255static void 2256_endhtent(FILE **hostf) 2257{ 2258 if (*hostf) { 2259 (void) fclose(*hostf); 2260 *hostf = NULL; 2261 } 2262} 2263 2264static struct addrinfo * 2265_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2266{ 2267 char *p; 2268 char *cp, *tname, *cname; 2269 struct addrinfo hints, *res0, *res; 2270 int error; 2271 const char *addr; 2272 char hostbuf[8*1024]; 2273 2274 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2275 return (NULL); 2276again: 2277 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2278 return (NULL); 2279 if (*p == '#') 2280 goto again; 2281 cp = strpbrk(p, "#\n"); 2282 if (cp != NULL) 2283 *cp = '\0'; 2284 if (!(cp = strpbrk(p, " \t"))) 2285 goto again; 2286 *cp++ = '\0'; 2287 addr = p; 2288 cname = NULL; 2289 /* if this is not something we're looking for, skip it. */ 2290 while (cp && *cp) { 2291 if (*cp == ' ' || *cp == '\t') { 2292 cp++; 2293 continue; 2294 } 2295 tname = cp; 2296 if (cname == NULL) 2297 cname = cp; 2298 if ((cp = strpbrk(cp, " \t")) != NULL) 2299 *cp++ = '\0'; 2300 if (strcasecmp(name, tname) == 0) 2301 goto found; 2302 } 2303 goto again; 2304 2305found: 2306 /* we should not glob socktype/protocol here */ 2307 memset(&hints, 0, sizeof(hints)); 2308 hints.ai_family = pai->ai_family; 2309 hints.ai_socktype = SOCK_DGRAM; 2310 hints.ai_protocol = 0; 2311 hints.ai_flags = AI_NUMERICHOST; 2312 error = getaddrinfo(addr, "0", &hints, &res0); 2313 if (error) 2314 goto again; 2315#ifdef FILTER_V4MAPPED 2316 /* XXX should check all items in the chain */ 2317 if (res0->ai_family == AF_INET6 && 2318 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2319 freeaddrinfo(res0); 2320 goto again; 2321 } 2322#endif 2323 for (res = res0; res; res = res->ai_next) { 2324 /* cover it up */ 2325 res->ai_flags = pai->ai_flags; 2326 res->ai_socktype = pai->ai_socktype; 2327 res->ai_protocol = pai->ai_protocol; 2328 2329 if (pai->ai_flags & AI_CANONNAME) { 2330 if (get_canonname(pai, res, cname) != 0) { 2331 freeaddrinfo(res0); 2332 goto again; 2333 } 2334 } 2335 } 2336 return res0; 2337} 2338 2339/*ARGSUSED*/ 2340static int 2341_files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2342{ 2343 const char *name; 2344 const struct addrinfo *pai; 2345 struct addrinfo sentinel, *cur; 2346 struct addrinfo *p; 2347 FILE *hostf = NULL; 2348 2349 name = va_arg(ap, char *); 2350 pai = va_arg(ap, struct addrinfo *); 2351 2352 memset(&sentinel, 0, sizeof(sentinel)); 2353 cur = &sentinel; 2354 2355 _sethtent(&hostf); 2356 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 2357 cur->ai_next = p; 2358 while (cur && cur->ai_next) 2359 cur = cur->ai_next; 2360 } 2361 _endhtent(&hostf); 2362 2363 *((struct addrinfo **)rv) = sentinel.ai_next; 2364 if (sentinel.ai_next == NULL) 2365 return NS_NOTFOUND; 2366 return NS_SUCCESS; 2367} 2368 2369#ifdef YP 2370/*ARGSUSED*/ 2371static struct addrinfo * 2372_yphostent(char *line, const struct addrinfo *pai) 2373{ 2374 struct addrinfo sentinel, *cur; 2375 struct addrinfo hints, *res, *res0; 2376 int error; 2377 char *p = line; 2378 const char *addr, *canonname; 2379 char *nextline; 2380 char *cp; 2381 2382 addr = canonname = NULL; 2383 2384 memset(&sentinel, 0, sizeof(sentinel)); 2385 cur = &sentinel; 2386 2387nextline: 2388 /* terminate line */ 2389 cp = strchr(p, '\n'); 2390 if (cp) { 2391 *cp++ = '\0'; 2392 nextline = cp; 2393 } else 2394 nextline = NULL; 2395 2396 cp = strpbrk(p, " \t"); 2397 if (cp == NULL) { 2398 if (canonname == NULL) 2399 return (NULL); 2400 else 2401 goto done; 2402 } 2403 *cp++ = '\0'; 2404 2405 addr = p; 2406 2407 while (cp && *cp) { 2408 if (*cp == ' ' || *cp == '\t') { 2409 cp++; 2410 continue; 2411 } 2412 if (!canonname) 2413 canonname = cp; 2414 if ((cp = strpbrk(cp, " \t")) != NULL) 2415 *cp++ = '\0'; 2416 } 2417 2418 hints = *pai; 2419 hints.ai_flags = AI_NUMERICHOST; 2420 error = getaddrinfo(addr, NULL, &hints, &res0); 2421 if (error == 0) { 2422 for (res = res0; res; res = res->ai_next) { 2423 /* cover it up */ 2424 res->ai_flags = pai->ai_flags; 2425 2426 if (pai->ai_flags & AI_CANONNAME) 2427 (void)get_canonname(pai, res, canonname); 2428 } 2429 } else 2430 res0 = NULL; 2431 if (res0) { 2432 cur->ai_next = res0; 2433 while (cur && cur->ai_next) 2434 cur = cur->ai_next; 2435 } 2436 2437 if (nextline) { 2438 p = nextline; 2439 goto nextline; 2440 } 2441 2442done: 2443 return sentinel.ai_next; 2444} 2445 2446/*ARGSUSED*/ 2447static int 2448_yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2449{ 2450 struct addrinfo sentinel, *cur; 2451 struct addrinfo *ai = NULL; 2452 char *ypbuf; 2453 int ypbuflen, r; 2454 const char *name; 2455 const struct addrinfo *pai; 2456 char *ypdomain; 2457 2458 if (_yp_check(&ypdomain) == 0) 2459 return NS_UNAVAIL; 2460 2461 name = va_arg(ap, char *); 2462 pai = va_arg(ap, const struct addrinfo *); 2463 2464 memset(&sentinel, 0, sizeof(sentinel)); 2465 cur = &sentinel; 2466 2467 /* hosts.byname is only for IPv4 (Solaris8) */ 2468 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 2469 r = yp_match(ypdomain, "hosts.byname", name, 2470 (int)strlen(name), &ypbuf, &ypbuflen); 2471 if (r == 0) { 2472 struct addrinfo ai4; 2473 2474 ai4 = *pai; 2475 ai4.ai_family = AF_INET; 2476 ai = _yphostent(ypbuf, &ai4); 2477 if (ai) { 2478 cur->ai_next = ai; 2479 while (cur && cur->ai_next) 2480 cur = cur->ai_next; 2481 } 2482 free(ypbuf); 2483 } 2484 } 2485 2486 /* ipnodes.byname can hold both IPv4/v6 */ 2487 r = yp_match(ypdomain, "ipnodes.byname", name, 2488 (int)strlen(name), &ypbuf, &ypbuflen); 2489 if (r == 0) { 2490 ai = _yphostent(ypbuf, pai); 2491 if (ai) 2492 cur->ai_next = ai; 2493 free(ypbuf); 2494 } 2495 2496 if (sentinel.ai_next == NULL) { 2497 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2498 return NS_NOTFOUND; 2499 } 2500 *((struct addrinfo **)rv) = sentinel.ai_next; 2501 return NS_SUCCESS; 2502} 2503#endif 2504 2505/* resolver logic */ 2506 2507/* 2508 * Formulate a normal query, send, and await answer. 2509 * Returned answer is placed in supplied buffer "answer". 2510 * Perform preliminary check of answer, returning success only 2511 * if no error is indicated and the answer count is nonzero. 2512 * Return the size of the response on success, -1 on error. 2513 * Error number is left in h_errno. 2514 * 2515 * Caller must parse answer and determine whether it answers the question. 2516 */ 2517static int 2518res_queryN(const char *name, struct res_target *target, res_state res) 2519{ 2520 u_char *buf; 2521 HEADER *hp; 2522 int n; 2523 u_int oflags; 2524 struct res_target *t; 2525 int rcode; 2526 int ancount; 2527 2528 rcode = NOERROR; 2529 ancount = 0; 2530 2531 buf = malloc(MAXPACKET); 2532 if (!buf) { 2533 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2534 return -1; 2535 } 2536 2537 for (t = target; t; t = t->next) { 2538 int class, type; 2539 u_char *answer; 2540 int anslen; 2541 2542 hp = (HEADER *)(void *)t->answer; 2543 2544 /* make it easier... */ 2545 class = t->qclass; 2546 type = t->qtype; 2547 answer = t->answer; 2548 anslen = t->anslen; 2549 2550 oflags = res->_flags; 2551 2552again: 2553 hp->rcode = NOERROR; /* default */ 2554 2555#ifdef DEBUG 2556 if (res->options & RES_DEBUG) 2557 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2558#endif 2559 2560 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2561 buf, MAXPACKET); 2562 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2563 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2564 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2565 if (n <= 0) { 2566#ifdef DEBUG 2567 if (res->options & RES_DEBUG) 2568 printf(";; res_query: mkquery failed\n"); 2569#endif 2570 free(buf); 2571 RES_SET_H_ERRNO(res, NO_RECOVERY); 2572 return (n); 2573 } 2574 n = res_nsend(res, buf, n, answer, anslen); 2575 if (n < 0) { 2576 /* 2577 * if the query choked with EDNS0, retry 2578 * without EDNS0 2579 */ 2580 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2581 != 0U && 2582 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2583 res->_flags |= RES_F_EDNS0ERR; 2584 if (res->options & RES_DEBUG) 2585 printf(";; res_nquery: retry without EDNS0\n"); 2586 goto again; 2587 } 2588 rcode = hp->rcode; /* record most recent error */ 2589#ifdef DEBUG 2590 if (res->options & RES_DEBUG) 2591 printf(";; res_query: send error\n"); 2592#endif 2593 continue; 2594 } 2595 2596 if (n > anslen) 2597 hp->rcode = FORMERR; /* XXX not very informative */ 2598 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2599 rcode = hp->rcode; /* record most recent error */ 2600#ifdef DEBUG 2601 if (res->options & RES_DEBUG) 2602 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2603 ntohs(hp->ancount)); 2604#endif 2605 continue; 2606 } 2607 2608 ancount += ntohs(hp->ancount); 2609 2610 t->n = n; 2611 } 2612 2613 free(buf); 2614 2615 if (ancount == 0) { 2616 switch (rcode) { 2617 case NXDOMAIN: 2618 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2619 break; 2620 case SERVFAIL: 2621 RES_SET_H_ERRNO(res, TRY_AGAIN); 2622 break; 2623 case NOERROR: 2624 RES_SET_H_ERRNO(res, NO_DATA); 2625 break; 2626 case FORMERR: 2627 case NOTIMP: 2628 case REFUSED: 2629 default: 2630 RES_SET_H_ERRNO(res, NO_RECOVERY); 2631 break; 2632 } 2633 return (-1); 2634 } 2635 return (ancount); 2636} 2637 2638/* 2639 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2640 * Return the size of the response on success, -1 on error. 2641 * If enabled, implement search rules until answer or unrecoverable failure 2642 * is detected. Error code, if any, is left in h_errno. 2643 */ 2644static int 2645res_searchN(const char *name, struct res_target *target, res_state res) 2646{ 2647 const char *cp, * const *domain; 2648 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2649 u_int dots; 2650 int trailing_dot, ret, saved_herrno; 2651 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2652 int tried_as_is = 0; 2653 int searched = 0; 2654 char abuf[MAXDNAME]; 2655 2656 errno = 0; 2657 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2658 dots = 0; 2659 for (cp = name; *cp; cp++) 2660 dots += (*cp == '.'); 2661 trailing_dot = 0; 2662 if (cp > name && *--cp == '.') 2663 trailing_dot++; 2664 2665 /* 2666 * if there aren't any dots, it could be a user-level alias 2667 */ 2668 if (!dots && 2669 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2670 return (res_queryN(cp, target, res)); 2671 2672 /* 2673 * If there are enough dots in the name, let's just give it a 2674 * try 'as is'. The threshold can be set with the "ndots" option. 2675 * Also, query 'as is', if there is a trailing dot in the name. 2676 */ 2677 saved_herrno = -1; 2678 if (dots >= res->ndots || trailing_dot) { 2679 ret = res_querydomainN(name, NULL, target, res); 2680 if (ret > 0 || trailing_dot) 2681 return (ret); 2682 if (errno == ECONNREFUSED) { 2683 RES_SET_H_ERRNO(res, TRY_AGAIN); 2684 return (-1); 2685 } 2686 switch (res->res_h_errno) { 2687 case NO_DATA: 2688 case HOST_NOT_FOUND: 2689 break; 2690 case TRY_AGAIN: 2691 if (hp->rcode == SERVFAIL) 2692 break; 2693 /* FALLTHROUGH */ 2694 default: 2695 return (-1); 2696 } 2697 saved_herrno = res->res_h_errno; 2698 tried_as_is++; 2699 } 2700 2701 /* 2702 * We do at least one level of search if 2703 * - there is no dot and RES_DEFNAME is set, or 2704 * - there is at least one dot, there is no trailing dot, 2705 * and RES_DNSRCH is set. 2706 */ 2707 if ((!dots && (res->options & RES_DEFNAMES)) || 2708 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2709 int done = 0; 2710 2711 for (domain = (const char * const *)res->dnsrch; 2712 *domain && !done; 2713 domain++) { 2714 searched = 1; 2715 2716 if (domain[0][0] == '\0' || 2717 (domain[0][0] == '.' && domain[0][1] == '\0')) 2718 root_on_list++; 2719 2720 if (root_on_list && tried_as_is) 2721 continue; 2722 2723 ret = res_querydomainN(name, *domain, target, res); 2724 if (ret > 0) 2725 return (ret); 2726 2727 /* 2728 * If no server present, give up. 2729 * If name isn't found in this domain, 2730 * keep trying higher domains in the search list 2731 * (if that's enabled). 2732 * On a NO_DATA error, keep trying, otherwise 2733 * a wildcard entry of another type could keep us 2734 * from finding this entry higher in the domain. 2735 * If we get some other error (negative answer or 2736 * server failure), then stop searching up, 2737 * but try the input name below in case it's 2738 * fully-qualified. 2739 */ 2740 if (errno == ECONNREFUSED) { 2741 RES_SET_H_ERRNO(res, TRY_AGAIN); 2742 return (-1); 2743 } 2744 2745 switch (res->res_h_errno) { 2746 case NO_DATA: 2747 got_nodata++; 2748 /* FALLTHROUGH */ 2749 case HOST_NOT_FOUND: 2750 /* keep trying */ 2751 break; 2752 case TRY_AGAIN: 2753 got_servfail++; 2754 if (hp->rcode == SERVFAIL) { 2755 /* try next search element, if any */ 2756 break; 2757 } 2758 /* FALLTHROUGH */ 2759 default: 2760 /* anything else implies that we're done */ 2761 done++; 2762 } 2763 /* 2764 * if we got here for some reason other than DNSRCH, 2765 * we only wanted one iteration of the loop, so stop. 2766 */ 2767 if (!(res->options & RES_DNSRCH)) 2768 done++; 2769 } 2770 } 2771 2772 switch (res->res_h_errno) { 2773 case NO_DATA: 2774 case HOST_NOT_FOUND: 2775 break; 2776 case TRY_AGAIN: 2777 if (hp->rcode == SERVFAIL) 2778 break; 2779 /* FALLTHROUGH */ 2780 default: 2781 goto giveup; 2782 } 2783 2784 /* 2785 * If the query has not already been tried as is then try it 2786 * unless RES_NOTLDQUERY is set and there were no dots. 2787 */ 2788 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2789 !(tried_as_is || root_on_list)) { 2790 ret = res_querydomainN(name, NULL, target, res); 2791 if (ret > 0) 2792 return (ret); 2793 } 2794 2795 /* 2796 * if we got here, we didn't satisfy the search. 2797 * if we did an initial full query, return that query's h_errno 2798 * (note that we wouldn't be here if that query had succeeded). 2799 * else if we ever got a nodata, send that back as the reason. 2800 * else send back meaningless h_errno, that being the one from 2801 * the last DNSRCH we did. 2802 */ 2803giveup: 2804 if (saved_herrno != -1) 2805 RES_SET_H_ERRNO(res, saved_herrno); 2806 else if (got_nodata) 2807 RES_SET_H_ERRNO(res, NO_DATA); 2808 else if (got_servfail) 2809 RES_SET_H_ERRNO(res, TRY_AGAIN); 2810 return (-1); 2811} 2812 2813/* 2814 * Perform a call on res_query on the concatenation of name and domain, 2815 * removing a trailing dot from name if domain is NULL. 2816 */ 2817static int 2818res_querydomainN(const char *name, const char *domain, 2819 struct res_target *target, res_state res) 2820{ 2821 char nbuf[MAXDNAME]; 2822 const char *longname = nbuf; 2823 size_t n, d; 2824 2825#ifdef DEBUG 2826 if (res->options & RES_DEBUG) 2827 printf(";; res_querydomain(%s, %s)\n", 2828 name, domain?domain:"<Nil>"); 2829#endif 2830 if (domain == NULL) { 2831 /* 2832 * Check for trailing '.'; 2833 * copy without '.' if present. 2834 */ 2835 n = strlen(name); 2836 if (n >= MAXDNAME) { 2837 RES_SET_H_ERRNO(res, NO_RECOVERY); 2838 return (-1); 2839 } 2840 if (n > 0 && name[--n] == '.') { 2841 strncpy(nbuf, name, n); 2842 nbuf[n] = '\0'; 2843 } else 2844 longname = name; 2845 } else { 2846 n = strlen(name); 2847 d = strlen(domain); 2848 if (n + d + 1 >= MAXDNAME) { 2849 RES_SET_H_ERRNO(res, NO_RECOVERY); 2850 return (-1); 2851 } 2852 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2853 } 2854 return (res_queryN(longname, target, res)); 2855} 2856