getaddrinfo.c revision 190525
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: head/lib/libc/net/getaddrinfo.c 190525 2009-03-29 17:55:11Z ume $"); 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 const char *e_protostr; 159 int e_wild; 160#define WILD_AF(ex) ((ex)->e_wild & 0x01) 161#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 162#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 163}; 164 165static const struct explore explore[] = { 166#if 0 167 { PF_LOCAL, ANY, ANY, NULL, 0x01 }, 168#endif 169#ifdef INET6 170 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 171 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 172 { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, "sctp", 0x03 }, 173 { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, "sctp", 0x07 }, 174 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 175#endif 176 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 177 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 178 { PF_INET, SOCK_STREAM, IPPROTO_SCTP, "sctp", 0x03 }, 179 { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, "sctp", 0x07 }, 180 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 181 { -1, 0, 0, NULL, 0 }, 182}; 183 184#ifdef INET6 185#define PTON_MAX 16 186#else 187#define PTON_MAX 4 188#endif 189 190#define AIO_SRCFLAG_DEPRECATED 0x1 191 192struct ai_order { 193 union { 194 struct sockaddr_storage aiou_ss; 195 struct sockaddr aiou_sa; 196 } aio_src_un; 197#define aio_srcsa aio_src_un.aiou_sa 198 u_int32_t aio_srcflag; 199 int aio_srcscope; 200 int aio_dstscope; 201 struct policyqueue *aio_srcpolicy; 202 struct policyqueue *aio_dstpolicy; 203 struct addrinfo *aio_ai; 204 int aio_matchlen; 205}; 206 207static const ns_src default_dns_files[] = { 208 { NSSRC_FILES, NS_SUCCESS }, 209 { NSSRC_DNS, NS_SUCCESS }, 210 { 0 } 211}; 212 213struct res_target { 214 struct res_target *next; 215 const char *name; /* domain name */ 216 int qclass, qtype; /* class and type of query */ 217 u_char *answer; /* buffer to put answer */ 218 int anslen; /* size of answer buffer */ 219 int n; /* result length */ 220}; 221 222#define MAXPACKET (64*1024) 223 224typedef union { 225 HEADER hdr; 226 u_char buf[MAXPACKET]; 227} querybuf; 228 229static int str2number(const char *, int *); 230static int explore_copy(const struct addrinfo *, const struct addrinfo *, 231 struct addrinfo **); 232static int explore_null(const struct addrinfo *, 233 const char *, struct addrinfo **); 234static int explore_numeric(const struct addrinfo *, const char *, 235 const char *, struct addrinfo **, const char *); 236static int explore_numeric_scope(const struct addrinfo *, const char *, 237 const char *, struct addrinfo **); 238static int get_canonname(const struct addrinfo *, 239 struct addrinfo *, const char *); 240static struct addrinfo *get_ai(const struct addrinfo *, 241 const struct afd *, const char *); 242static struct addrinfo *copy_ai(const struct addrinfo *); 243static int get_portmatch(const struct addrinfo *, const char *); 244static int get_port(struct addrinfo *, const char *, int); 245static const struct afd *find_afd(int); 246static int addrconfig(struct addrinfo *); 247static void set_source(struct ai_order *, struct policyhead *); 248static int comp_dst(const void *, const void *); 249#ifdef INET6 250static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 251#endif 252static int gai_addr2scopetype(struct sockaddr *); 253 254static int explore_fqdn(const struct addrinfo *, const char *, 255 const char *, struct addrinfo **); 256 257static int reorder(struct addrinfo *); 258static int get_addrselectpolicy(struct policyhead *); 259static void free_addrselectpolicy(struct policyhead *); 260static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 261 struct policyhead *); 262static int matchlen(struct sockaddr *, struct sockaddr *); 263 264static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 265 const struct addrinfo *, res_state); 266#if defined(RESOLVSORT) 267static int addr4sort(struct addrinfo *, res_state); 268#endif 269static int _dns_getaddrinfo(void *, void *, va_list); 270static void _sethtent(FILE **); 271static void _endhtent(FILE **); 272static struct addrinfo *_gethtent(FILE **, const char *, 273 const struct addrinfo *); 274static int _files_getaddrinfo(void *, void *, va_list); 275#ifdef YP 276static struct addrinfo *_yphostent(char *, const struct addrinfo *); 277static int _yp_getaddrinfo(void *, void *, va_list); 278#endif 279#ifdef NS_CACHING 280static int addrinfo_id_func(char *, size_t *, va_list, void *); 281static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 282static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 283#endif 284 285static int res_queryN(const char *, struct res_target *, res_state); 286static int res_searchN(const char *, struct res_target *, res_state); 287static int res_querydomainN(const char *, const char *, 288 struct res_target *, res_state); 289 290/* XXX macros that make external reference is BAD. */ 291 292#define GET_AI(ai, afd, addr) \ 293do { \ 294 /* external reference: pai, error, and label free */ \ 295 (ai) = get_ai(pai, (afd), (addr)); \ 296 if ((ai) == NULL) { \ 297 error = EAI_MEMORY; \ 298 goto free; \ 299 } \ 300} while (/*CONSTCOND*/0) 301 302#define GET_PORT(ai, serv) \ 303do { \ 304 /* external reference: error and label free */ \ 305 error = get_port((ai), (serv), 0); \ 306 if (error != 0) \ 307 goto free; \ 308} while (/*CONSTCOND*/0) 309 310#define GET_CANONNAME(ai, str) \ 311do { \ 312 /* external reference: pai, error and label free */ \ 313 error = get_canonname(pai, (ai), (str)); \ 314 if (error != 0) \ 315 goto free; \ 316} while (/*CONSTCOND*/0) 317 318#define ERR(err) \ 319do { \ 320 /* external reference: error, and label bad */ \ 321 error = (err); \ 322 goto bad; \ 323 /*NOTREACHED*/ \ 324} while (/*CONSTCOND*/0) 325 326#define MATCH_FAMILY(x, y, w) \ 327 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 328#define MATCH(x, y, w) \ 329 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 330 331void 332freeaddrinfo(struct addrinfo *ai) 333{ 334 struct addrinfo *next; 335 336 do { 337 next = ai->ai_next; 338 if (ai->ai_canonname) 339 free(ai->ai_canonname); 340 /* no need to free(ai->ai_addr) */ 341 free(ai); 342 ai = next; 343 } while (ai); 344} 345 346static int 347str2number(const char *p, int *portp) 348{ 349 char *ep; 350 unsigned long v; 351 352 if (*p == '\0') 353 return -1; 354 ep = NULL; 355 errno = 0; 356 v = strtoul(p, &ep, 10); 357 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 358 *portp = v; 359 return 0; 360 } else 361 return -1; 362} 363 364int 365getaddrinfo(const char *hostname, const char *servname, 366 const struct addrinfo *hints, struct addrinfo **res) 367{ 368 struct addrinfo sentinel; 369 struct addrinfo *cur; 370 int error = 0; 371 struct addrinfo ai, ai0, *afai; 372 struct addrinfo *pai; 373 const struct afd *afd; 374 const struct explore *ex; 375 struct addrinfo *afailist[sizeof(afdl)/sizeof(afdl[0])]; 376 struct addrinfo *afai_unspec; 377 int found; 378 int numeric = 0; 379 380 /* ensure we return NULL on errors */ 381 *res = NULL; 382 383 memset(&ai, 0, sizeof(ai)); 384 385 memset(afailist, 0, sizeof(afailist)); 386 afai_unspec = NULL; 387 388 memset(&sentinel, 0, sizeof(sentinel)); 389 cur = &sentinel; 390 pai = &ai; 391 pai->ai_flags = 0; 392 pai->ai_family = PF_UNSPEC; 393 pai->ai_socktype = ANY; 394 pai->ai_protocol = ANY; 395 pai->ai_addrlen = 0; 396 pai->ai_canonname = NULL; 397 pai->ai_addr = NULL; 398 pai->ai_next = NULL; 399 400 if (hostname == NULL && servname == NULL) 401 return EAI_NONAME; 402 if (hints) { 403 /* error check for hints */ 404 if (hints->ai_addrlen || hints->ai_canonname || 405 hints->ai_addr || hints->ai_next) 406 ERR(EAI_BADHINTS); /* xxx */ 407 if (hints->ai_flags & ~AI_MASK) 408 ERR(EAI_BADFLAGS); 409 switch (hints->ai_family) { 410 case PF_UNSPEC: 411 case PF_INET: 412#ifdef INET6 413 case PF_INET6: 414#endif 415 break; 416 default: 417 ERR(EAI_FAMILY); 418 } 419 memcpy(pai, hints, sizeof(*pai)); 420 421 /* 422 * if both socktype/protocol are specified, check if they 423 * are meaningful combination. 424 */ 425 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 426 for (ex = explore; ex->e_af >= 0; ex++) { 427 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 428 WILD_AF(ex))) 429 continue; 430 if (!MATCH(pai->ai_socktype, ex->e_socktype, 431 WILD_SOCKTYPE(ex))) 432 continue; 433 if (!MATCH(pai->ai_protocol, ex->e_protocol, 434 WILD_PROTOCOL(ex))) 435 continue; 436 437 /* matched */ 438 break; 439 } 440 441 if (ex->e_af < 0) 442 ERR(EAI_BADHINTS); 443 } 444 } 445 446 /* 447 * check for special cases. (1) numeric servname is disallowed if 448 * socktype/protocol are left unspecified. (2) servname is disallowed 449 * for raw and other inet{,6} sockets. 450 */ 451 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 452#ifdef PF_INET6 453 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 454#endif 455 ) { 456 ai0 = *pai; /* backup *pai */ 457 458 if (pai->ai_family == PF_UNSPEC) { 459#ifdef PF_INET6 460 pai->ai_family = PF_INET6; 461#else 462 pai->ai_family = PF_INET; 463#endif 464 } 465 error = get_portmatch(pai, servname); 466 if (error) 467 ERR(error); 468 469 *pai = ai0; 470 } 471 472 ai0 = *pai; 473 474 /* 475 * NULL hostname, or numeric hostname. 476 * If numeric representation of AF1 can be interpreted as FQDN 477 * representation of AF2, we need to think again about the code below. 478 */ 479 found = 0; 480 for (afd = afdl; afd->a_af; afd++) { 481 *pai = ai0; 482 483 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 484 continue; 485 486 if (pai->ai_family == PF_UNSPEC) 487 pai->ai_family = afd->a_af; 488 489 if (hostname == NULL) { 490 error = explore_null(pai, servname, 491 &afailist[afd - afdl]); 492 493 /* 494 * Errors from explore_null should be unexpected and 495 * be caught to avoid returning an incomplete result. 496 */ 497 if (error != 0) 498 goto bad; 499 } else { 500 error = explore_numeric_scope(pai, hostname, servname, 501 &afailist[afd - afdl]); 502 503 /* 504 * explore_numeric_scope returns an error for address 505 * families that do not match that of hostname. 506 * Thus we should not catch the error at this moment. 507 */ 508 } 509 510 if (!error && afailist[afd - afdl]) 511 found++; 512 } 513 if (found) { 514 numeric = 1; 515 goto globcopy; 516 } 517 518 if (hostname == NULL) 519 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 520 if (pai->ai_flags & AI_NUMERICHOST) 521 ERR(EAI_NONAME); 522 523 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 524 ERR(EAI_FAIL); 525 526 /* 527 * hostname as alphabetical name. 528 */ 529 *pai = ai0; 530 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 531 532globcopy: 533 for (ex = explore; ex->e_af >= 0; ex++) { 534 *pai = ai0; 535 536 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 537 continue; 538 if (!MATCH(pai->ai_socktype, ex->e_socktype, 539 WILD_SOCKTYPE(ex))) 540 continue; 541 if (!MATCH(pai->ai_protocol, ex->e_protocol, 542 WILD_PROTOCOL(ex))) 543 continue; 544 545 if (pai->ai_family == PF_UNSPEC) 546 pai->ai_family = ex->e_af; 547 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 548 pai->ai_socktype = ex->e_socktype; 549 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 550 pai->ai_protocol = ex->e_protocol; 551 552 /* 553 * if the servname does not match socktype/protocol, ignore it. 554 */ 555 if (get_portmatch(pai, servname) != 0) 556 continue; 557 558 if (afai_unspec) 559 afai = afai_unspec; 560 else { 561 if ((afd = find_afd(pai->ai_family)) == NULL) 562 continue; 563 /* XXX assumes that afd points inside afdl[] */ 564 afai = afailist[afd - afdl]; 565 } 566 if (!afai) 567 continue; 568 569 error = explore_copy(pai, afai, &cur->ai_next); 570 if (error != 0) 571 goto bad; 572 573 while (cur && cur->ai_next) 574 cur = cur->ai_next; 575 } 576 577 /* 578 * ensure we return either: 579 * - error == 0, non-NULL *res 580 * - error != 0, NULL *res 581 */ 582 if (error == 0) { 583 if (sentinel.ai_next) { 584 /* 585 * If the returned entry is for an active connection, 586 * and the given name is not numeric, reorder the 587 * list, so that the application would try the list 588 * in the most efficient order. Since the head entry 589 * of the original list may contain ai_canonname and 590 * that entry may be moved elsewhere in the new list, 591 * we keep the pointer and will restore it in the new 592 * head entry. (Note that RFC3493 requires the head 593 * entry store it when requested by the caller). 594 */ 595 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 596 if (!numeric) { 597 char *canonname; 598 599 canonname = 600 sentinel.ai_next->ai_canonname; 601 sentinel.ai_next->ai_canonname = NULL; 602 (void)reorder(&sentinel); 603 if (sentinel.ai_next->ai_canonname == 604 NULL) { 605 sentinel.ai_next->ai_canonname 606 = canonname; 607 } else if (canonname != NULL) 608 free(canonname); 609 } 610 } 611 *res = sentinel.ai_next; 612 } else 613 error = EAI_FAIL; 614 } 615 616bad: 617 if (afai_unspec) 618 freeaddrinfo(afai_unspec); 619 for (afd = afdl; afd->a_af; afd++) { 620 if (afailist[afd - afdl]) 621 freeaddrinfo(afailist[afd - afdl]); 622 } 623 if (!*res) 624 if (sentinel.ai_next) 625 freeaddrinfo(sentinel.ai_next); 626 627 return (error); 628} 629 630static int 631reorder(struct addrinfo *sentinel) 632{ 633 struct addrinfo *ai, **aip; 634 struct ai_order *aio; 635 int i, n; 636 struct policyhead policyhead; 637 638 /* count the number of addrinfo elements for sorting. */ 639 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 640 ; 641 642 /* 643 * If the number is small enough, we can skip the reordering process. 644 */ 645 if (n <= 1) 646 return(n); 647 648 /* allocate a temporary array for sort and initialization of it. */ 649 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 650 return(n); /* give up reordering */ 651 memset(aio, 0, sizeof(*aio) * n); 652 653 /* retrieve address selection policy from the kernel */ 654 TAILQ_INIT(&policyhead); 655 if (!get_addrselectpolicy(&policyhead)) { 656 /* no policy is installed into kernel, we don't sort. */ 657 free(aio); 658 return (n); 659 } 660 661 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 662 aio[i].aio_ai = ai; 663 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 664 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 665 &policyhead); 666 set_source(&aio[i], &policyhead); 667 } 668 669 /* perform sorting. */ 670 qsort(aio, n, sizeof(*aio), comp_dst); 671 672 /* reorder the addrinfo chain. */ 673 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 674 *aip = aio[i].aio_ai; 675 aip = &aio[i].aio_ai->ai_next; 676 } 677 *aip = NULL; 678 679 /* cleanup and return */ 680 free(aio); 681 free_addrselectpolicy(&policyhead); 682 return(n); 683} 684 685static int 686get_addrselectpolicy(struct policyhead *head) 687{ 688#ifdef INET6 689 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 690 size_t l; 691 char *buf; 692 struct in6_addrpolicy *pol, *ep; 693 694 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 695 return (0); 696 if ((buf = malloc(l)) == NULL) 697 return (0); 698 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 699 free(buf); 700 return (0); 701 } 702 703 ep = (struct in6_addrpolicy *)(buf + l); 704 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 705 struct policyqueue *new; 706 707 if ((new = malloc(sizeof(*new))) == NULL) { 708 free_addrselectpolicy(head); /* make the list empty */ 709 break; 710 } 711 new->pc_policy = *pol; 712 TAILQ_INSERT_TAIL(head, new, pc_entry); 713 } 714 715 free(buf); 716 return (1); 717#else 718 return (0); 719#endif 720} 721 722static void 723free_addrselectpolicy(struct policyhead *head) 724{ 725 struct policyqueue *ent, *nent; 726 727 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 728 nent = TAILQ_NEXT(ent, pc_entry); 729 TAILQ_REMOVE(head, ent, pc_entry); 730 free(ent); 731 } 732} 733 734static struct policyqueue * 735match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 736{ 737#ifdef INET6 738 struct policyqueue *ent, *bestent = NULL; 739 struct in6_addrpolicy *pol; 740 int matchlen, bestmatchlen = -1; 741 u_char *mp, *ep, *k, *p, m; 742 struct sockaddr_in6 key; 743 744 switch(addr->sa_family) { 745 case AF_INET6: 746 key = *(struct sockaddr_in6 *)addr; 747 break; 748 case AF_INET: 749 /* convert the address into IPv4-mapped IPv6 address. */ 750 memset(&key, 0, sizeof(key)); 751 key.sin6_family = AF_INET6; 752 key.sin6_len = sizeof(key); 753 key.sin6_addr.s6_addr[10] = 0xff; 754 key.sin6_addr.s6_addr[11] = 0xff; 755 memcpy(&key.sin6_addr.s6_addr[12], 756 &((struct sockaddr_in *)addr)->sin_addr, 4); 757 break; 758 default: 759 return(NULL); 760 } 761 762 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 763 pol = &ent->pc_policy; 764 matchlen = 0; 765 766 mp = (u_char *)&pol->addrmask.sin6_addr; 767 ep = mp + 16; /* XXX: scope field? */ 768 k = (u_char *)&key.sin6_addr; 769 p = (u_char *)&pol->addr.sin6_addr; 770 for (; mp < ep && *mp; mp++, k++, p++) { 771 m = *mp; 772 if ((*k & m) != *p) 773 goto next; /* not match */ 774 if (m == 0xff) /* short cut for a typical case */ 775 matchlen += 8; 776 else { 777 while (m >= 0x80) { 778 matchlen++; 779 m <<= 1; 780 } 781 } 782 } 783 784 /* matched. check if this is better than the current best. */ 785 if (matchlen > bestmatchlen) { 786 bestent = ent; 787 bestmatchlen = matchlen; 788 } 789 790 next: 791 continue; 792 } 793 794 return(bestent); 795#else 796 return(NULL); 797#endif 798 799} 800 801static void 802set_source(struct ai_order *aio, struct policyhead *ph) 803{ 804 struct addrinfo ai = *aio->aio_ai; 805 struct sockaddr_storage ss; 806 socklen_t srclen; 807 int s; 808 809 /* set unspec ("no source is available"), just in case */ 810 aio->aio_srcsa.sa_family = AF_UNSPEC; 811 aio->aio_srcscope = -1; 812 813 switch(ai.ai_family) { 814 case AF_INET: 815#ifdef INET6 816 case AF_INET6: 817#endif 818 break; 819 default: /* ignore unsupported AFs explicitly */ 820 return; 821 } 822 823 /* XXX: make a dummy addrinfo to call connect() */ 824 ai.ai_socktype = SOCK_DGRAM; 825 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 826 ai.ai_next = NULL; 827 memset(&ss, 0, sizeof(ss)); 828 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 829 ai.ai_addr = (struct sockaddr *)&ss; 830 get_port(&ai, "1", 0); 831 832 /* open a socket to get the source address for the given dst */ 833 if ((s = _socket(ai.ai_family, ai.ai_socktype, ai.ai_protocol)) < 0) 834 return; /* give up */ 835 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 836 goto cleanup; 837 srclen = ai.ai_addrlen; 838 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 839 aio->aio_srcsa.sa_family = AF_UNSPEC; 840 goto cleanup; 841 } 842 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 843 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 844 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 845#ifdef INET6 846 if (ai.ai_family == AF_INET6) { 847 struct in6_ifreq ifr6; 848 u_int32_t flags6; 849 850 /* XXX: interface name should not be hardcoded */ 851 strncpy(ifr6.ifr_name, "lo0", sizeof(ifr6.ifr_name)); 852 memset(&ifr6, 0, sizeof(ifr6)); 853 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 854 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 855 flags6 = ifr6.ifr_ifru.ifru_flags6; 856 if ((flags6 & IN6_IFF_DEPRECATED)) 857 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 858 } 859 } 860#endif 861 862 cleanup: 863 _close(s); 864 return; 865} 866 867static int 868matchlen(struct sockaddr *src, struct sockaddr *dst) 869{ 870 int match = 0; 871 u_char *s, *d; 872 u_char *lim, r; 873 int addrlen; 874 875 switch (src->sa_family) { 876#ifdef INET6 877 case AF_INET6: 878 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 879 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 880 addrlen = sizeof(struct in6_addr); 881 lim = s + addrlen; 882 break; 883#endif 884 case AF_INET: 885 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 886 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 887 addrlen = sizeof(struct in_addr); 888 lim = s + addrlen; 889 break; 890 default: 891 return(0); 892 } 893 894 while (s < lim) 895 if ((r = (*d++ ^ *s++)) != 0) { 896 while (r < addrlen * 8) { 897 match++; 898 r <<= 1; 899 } 900 break; 901 } else 902 match += 8; 903 return(match); 904} 905 906static int 907comp_dst(const void *arg1, const void *arg2) 908{ 909 const struct ai_order *dst1 = arg1, *dst2 = arg2; 910 911 /* 912 * Rule 1: Avoid unusable destinations. 913 * XXX: we currently do not consider if an appropriate route exists. 914 */ 915 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 916 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 917 return(-1); 918 } 919 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 920 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 921 return(1); 922 } 923 924 /* Rule 2: Prefer matching scope. */ 925 if (dst1->aio_dstscope == dst1->aio_srcscope && 926 dst2->aio_dstscope != dst2->aio_srcscope) { 927 return(-1); 928 } 929 if (dst1->aio_dstscope != dst1->aio_srcscope && 930 dst2->aio_dstscope == dst2->aio_srcscope) { 931 return(1); 932 } 933 934 /* Rule 3: Avoid deprecated addresses. */ 935 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 936 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 937 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 938 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 939 return(-1); 940 } 941 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 942 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 943 return(1); 944 } 945 } 946 947 /* Rule 4: Prefer home addresses. */ 948 /* XXX: not implemented yet */ 949 950 /* Rule 5: Prefer matching label. */ 951#ifdef INET6 952 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 953 dst1->aio_srcpolicy->pc_policy.label == 954 dst1->aio_dstpolicy->pc_policy.label && 955 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 956 dst2->aio_srcpolicy->pc_policy.label != 957 dst2->aio_dstpolicy->pc_policy.label)) { 958 return(-1); 959 } 960 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 961 dst2->aio_srcpolicy->pc_policy.label == 962 dst2->aio_dstpolicy->pc_policy.label && 963 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 964 dst1->aio_srcpolicy->pc_policy.label != 965 dst1->aio_dstpolicy->pc_policy.label)) { 966 return(1); 967 } 968#endif 969 970 /* Rule 6: Prefer higher precedence. */ 971#ifdef INET6 972 if (dst1->aio_dstpolicy && 973 (dst2->aio_dstpolicy == NULL || 974 dst1->aio_dstpolicy->pc_policy.preced > 975 dst2->aio_dstpolicy->pc_policy.preced)) { 976 return(-1); 977 } 978 if (dst2->aio_dstpolicy && 979 (dst1->aio_dstpolicy == NULL || 980 dst2->aio_dstpolicy->pc_policy.preced > 981 dst1->aio_dstpolicy->pc_policy.preced)) { 982 return(1); 983 } 984#endif 985 986 /* Rule 7: Prefer native transport. */ 987 /* XXX: not implemented yet */ 988 989 /* Rule 8: Prefer smaller scope. */ 990 if (dst1->aio_dstscope >= 0 && 991 dst1->aio_dstscope < dst2->aio_dstscope) { 992 return(-1); 993 } 994 if (dst2->aio_dstscope >= 0 && 995 dst2->aio_dstscope < dst1->aio_dstscope) { 996 return(1); 997 } 998 999 /* 1000 * Rule 9: Use longest matching prefix. 1001 * We compare the match length in a same AF only. 1002 */ 1003 if (dst1->aio_ai->ai_addr->sa_family == 1004 dst2->aio_ai->ai_addr->sa_family) { 1005 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1006 return(-1); 1007 } 1008 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1009 return(1); 1010 } 1011 } 1012 1013 /* Rule 10: Otherwise, leave the order unchanged. */ 1014 return(-1); 1015} 1016 1017/* 1018 * Copy from scope.c. 1019 * XXX: we should standardize the functions and link them as standard 1020 * library. 1021 */ 1022static int 1023gai_addr2scopetype(struct sockaddr *sa) 1024{ 1025#ifdef INET6 1026 struct sockaddr_in6 *sa6; 1027#endif 1028 struct sockaddr_in *sa4; 1029 1030 switch(sa->sa_family) { 1031#ifdef INET6 1032 case AF_INET6: 1033 sa6 = (struct sockaddr_in6 *)sa; 1034 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1035 /* just use the scope field of the multicast address */ 1036 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1037 } 1038 /* 1039 * Unicast addresses: map scope type to corresponding scope 1040 * value defined for multcast addresses. 1041 * XXX: hardcoded scope type values are bad... 1042 */ 1043 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1044 return(1); /* node local scope */ 1045 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1046 return(2); /* link-local scope */ 1047 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1048 return(5); /* site-local scope */ 1049 return(14); /* global scope */ 1050 break; 1051#endif 1052 case AF_INET: 1053 /* 1054 * IPv4 pseudo scoping according to RFC 3484. 1055 */ 1056 sa4 = (struct sockaddr_in *)sa; 1057 /* IPv4 autoconfiguration addresses have link-local scope. */ 1058 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1059 ((u_char *)&sa4->sin_addr)[1] == 254) 1060 return(2); 1061 /* Private addresses have site-local scope. */ 1062 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1063 (((u_char *)&sa4->sin_addr)[0] == 172 && 1064 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1065 (((u_char *)&sa4->sin_addr)[0] == 192 && 1066 ((u_char *)&sa4->sin_addr)[1] == 168)) 1067 return(14); /* XXX: It should be 5 unless NAT */ 1068 /* Loopback addresses have link-local scope. */ 1069 if (((u_char *)&sa4->sin_addr)[0] == 127) 1070 return(2); 1071 return(14); 1072 break; 1073 default: 1074 errno = EAFNOSUPPORT; /* is this a good error? */ 1075 return(-1); 1076 } 1077} 1078 1079static int 1080explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1081 struct addrinfo **res) 1082{ 1083 int error; 1084 struct addrinfo sentinel, *cur; 1085 const struct addrinfo *src; 1086 1087 error = 0; 1088 sentinel.ai_next = NULL; 1089 cur = &sentinel; 1090 1091 for (src = src0; src != NULL; src = src->ai_next) { 1092 if (src->ai_family != pai->ai_family) 1093 continue; 1094 1095 cur->ai_next = copy_ai(src); 1096 if (!cur->ai_next) { 1097 error = EAI_MEMORY; 1098 goto fail; 1099 } 1100 1101 cur->ai_next->ai_socktype = pai->ai_socktype; 1102 cur->ai_next->ai_protocol = pai->ai_protocol; 1103 cur = cur->ai_next; 1104 } 1105 1106 *res = sentinel.ai_next; 1107 return 0; 1108 1109fail: 1110 freeaddrinfo(sentinel.ai_next); 1111 return error; 1112} 1113 1114/* 1115 * hostname == NULL. 1116 * passive socket -> anyaddr (0.0.0.0 or ::) 1117 * non-passive socket -> localhost (127.0.0.1 or ::1) 1118 */ 1119static int 1120explore_null(const struct addrinfo *pai, const char *servname, 1121 struct addrinfo **res) 1122{ 1123 int s; 1124 const struct afd *afd; 1125 struct addrinfo *ai; 1126 int error; 1127 1128 *res = NULL; 1129 ai = NULL; 1130 1131 /* 1132 * filter out AFs that are not supported by the kernel 1133 * XXX errno? 1134 */ 1135 s = _socket(pai->ai_family, SOCK_DGRAM, 0); 1136 if (s < 0) { 1137 if (errno != EMFILE) 1138 return 0; 1139 } else 1140 _close(s); 1141 1142 afd = find_afd(pai->ai_family); 1143 if (afd == NULL) 1144 return 0; 1145 1146 if (pai->ai_flags & AI_PASSIVE) { 1147 GET_AI(ai, afd, afd->a_addrany); 1148 GET_PORT(ai, servname); 1149 } else { 1150 GET_AI(ai, afd, afd->a_loopback); 1151 GET_PORT(ai, servname); 1152 } 1153 1154 *res = ai; 1155 return 0; 1156 1157free: 1158 if (ai != NULL) 1159 freeaddrinfo(ai); 1160 return error; 1161} 1162 1163/* 1164 * numeric hostname 1165 */ 1166static int 1167explore_numeric(const struct addrinfo *pai, const char *hostname, 1168 const char *servname, struct addrinfo **res, const char *canonname) 1169{ 1170 const struct afd *afd; 1171 struct addrinfo *ai; 1172 int error; 1173 char pton[PTON_MAX]; 1174 1175 *res = NULL; 1176 ai = NULL; 1177 1178 afd = find_afd(pai->ai_family); 1179 if (afd == NULL) 1180 return 0; 1181 1182 switch (afd->a_af) { 1183 case AF_INET: 1184 /* 1185 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1186 * that are accepted by inet_addr() and its family. The 1187 * accepted forms includes the "classful" one, which inet_pton 1188 * does not accept. So we need to separate the case for 1189 * AF_INET. 1190 */ 1191 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1192 return 0; 1193 break; 1194 default: 1195 if (inet_pton(afd->a_af, hostname, pton) != 1) 1196 return 0; 1197 break; 1198 } 1199 1200 if (pai->ai_family == afd->a_af) { 1201 GET_AI(ai, afd, pton); 1202 GET_PORT(ai, servname); 1203 if ((pai->ai_flags & AI_CANONNAME)) { 1204 /* 1205 * Set the numeric address itself as the canonical 1206 * name, based on a clarification in RFC3493. 1207 */ 1208 GET_CANONNAME(ai, canonname); 1209 } 1210 } else { 1211 /* 1212 * XXX: This should not happen since we already matched the AF 1213 * by find_afd. 1214 */ 1215 ERR(EAI_FAMILY); 1216 } 1217 1218 *res = ai; 1219 return 0; 1220 1221free: 1222bad: 1223 if (ai != NULL) 1224 freeaddrinfo(ai); 1225 return error; 1226} 1227 1228/* 1229 * numeric hostname with scope 1230 */ 1231static int 1232explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1233 const char *servname, struct addrinfo **res) 1234{ 1235#if !defined(SCOPE_DELIMITER) || !defined(INET6) 1236 return explore_numeric(pai, hostname, servname, res, hostname); 1237#else 1238 const struct afd *afd; 1239 struct addrinfo *cur; 1240 int error; 1241 char *cp, *hostname2 = NULL, *scope, *addr; 1242 struct sockaddr_in6 *sin6; 1243 1244 afd = find_afd(pai->ai_family); 1245 if (afd == NULL) 1246 return 0; 1247 1248 if (!afd->a_scoped) 1249 return explore_numeric(pai, hostname, servname, res, hostname); 1250 1251 cp = strchr(hostname, SCOPE_DELIMITER); 1252 if (cp == NULL) 1253 return explore_numeric(pai, hostname, servname, res, hostname); 1254 1255 /* 1256 * Handle special case of <scoped_address><delimiter><scope id> 1257 */ 1258 hostname2 = strdup(hostname); 1259 if (hostname2 == NULL) 1260 return EAI_MEMORY; 1261 /* terminate at the delimiter */ 1262 hostname2[cp - hostname] = '\0'; 1263 addr = hostname2; 1264 scope = cp + 1; 1265 1266 error = explore_numeric(pai, addr, servname, res, hostname); 1267 if (error == 0) { 1268 u_int32_t scopeid; 1269 1270 for (cur = *res; cur; cur = cur->ai_next) { 1271 if (cur->ai_family != AF_INET6) 1272 continue; 1273 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1274 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1275 free(hostname2); 1276 freeaddrinfo(*res); 1277 *res = NULL; 1278 return(EAI_NONAME); /* XXX: is return OK? */ 1279 } 1280 sin6->sin6_scope_id = scopeid; 1281 } 1282 } 1283 1284 free(hostname2); 1285 1286 if (error && *res) { 1287 freeaddrinfo(*res); 1288 *res = NULL; 1289 } 1290 return error; 1291#endif 1292} 1293 1294static int 1295get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1296{ 1297 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1298 ai->ai_canonname = strdup(str); 1299 if (ai->ai_canonname == NULL) 1300 return EAI_MEMORY; 1301 } 1302 return 0; 1303} 1304 1305static struct addrinfo * 1306get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1307{ 1308 char *p; 1309 struct addrinfo *ai; 1310#ifdef FAITH 1311 struct in6_addr faith_prefix; 1312 char *fp_str; 1313 int translate = 0; 1314#endif 1315 1316#ifdef FAITH 1317 /* 1318 * Transfrom an IPv4 addr into a special IPv6 addr format for 1319 * IPv6->IPv4 translation gateway. (only TCP is supported now) 1320 * 1321 * +-----------------------------------+------------+ 1322 * | faith prefix part (12 bytes) | embedded | 1323 * | | IPv4 addr part (4 bytes) 1324 * +-----------------------------------+------------+ 1325 * 1326 * faith prefix part is specified as ascii IPv6 addr format 1327 * in environmental variable GAI. 1328 * For FAITH to work correctly, routing to faith prefix must be 1329 * setup toward a machine where a FAITH daemon operates. 1330 * Also, the machine must enable some mechanizm 1331 * (e.g. faith interface hack) to divert those packet with 1332 * faith prefixed destination addr to user-land FAITH daemon. 1333 */ 1334 fp_str = getenv("GAI"); 1335 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 1336 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 1337 u_int32_t v4a; 1338 u_int8_t v4a_top; 1339 1340 memcpy(&v4a, addr, sizeof v4a); 1341 v4a_top = v4a >> IN_CLASSA_NSHIFT; 1342 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 1343 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 1344 afd = &afdl[N_INET6]; 1345 memcpy(&faith_prefix.s6_addr[12], addr, 1346 sizeof(struct in_addr)); 1347 translate = 1; 1348 } 1349 } 1350#endif 1351 1352 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1353 + (afd->a_socklen)); 1354 if (ai == NULL) 1355 return NULL; 1356 1357 memcpy(ai, pai, sizeof(struct addrinfo)); 1358 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1359 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1360 ai->ai_addr->sa_len = afd->a_socklen; 1361 ai->ai_addrlen = afd->a_socklen; 1362 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1363 p = (char *)(void *)(ai->ai_addr); 1364#ifdef FAITH 1365 if (translate == 1) 1366 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 1367 else 1368#endif 1369 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1370 return ai; 1371} 1372 1373/* XXX need to malloc() the same way we do from other functions! */ 1374static struct addrinfo * 1375copy_ai(const struct addrinfo *pai) 1376{ 1377 struct addrinfo *ai; 1378 size_t l; 1379 1380 l = sizeof(*ai) + pai->ai_addrlen; 1381 if ((ai = (struct addrinfo *)malloc(l)) == NULL) 1382 return NULL; 1383 memset(ai, 0, l); 1384 memcpy(ai, pai, sizeof(*ai)); 1385 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1386 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1387 1388 if (pai->ai_canonname) { 1389 l = strlen(pai->ai_canonname) + 1; 1390 if ((ai->ai_canonname = malloc(l)) == NULL) { 1391 free(ai); 1392 return NULL; 1393 } 1394 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1395 } else { 1396 /* just to make sure */ 1397 ai->ai_canonname = NULL; 1398 } 1399 1400 ai->ai_next = NULL; 1401 1402 return ai; 1403} 1404 1405static int 1406get_portmatch(const struct addrinfo *ai, const char *servname) 1407{ 1408 1409 /* get_port does not touch first argument when matchonly == 1. */ 1410 /* LINTED const cast */ 1411 return get_port((struct addrinfo *)ai, servname, 1); 1412} 1413 1414static int 1415get_port(struct addrinfo *ai, const char *servname, int matchonly) 1416{ 1417 const char *proto; 1418 struct servent *sp; 1419 int port, error; 1420 int allownumeric; 1421 1422 if (servname == NULL) 1423 return 0; 1424 switch (ai->ai_family) { 1425 case AF_INET: 1426#ifdef AF_INET6 1427 case AF_INET6: 1428#endif 1429 break; 1430 default: 1431 return 0; 1432 } 1433 1434 switch (ai->ai_socktype) { 1435 case SOCK_RAW: 1436 return EAI_SERVICE; 1437 case SOCK_DGRAM: 1438 case SOCK_STREAM: 1439 case SOCK_SEQPACKET: 1440 allownumeric = 1; 1441 break; 1442 case ANY: 1443 switch (ai->ai_family) { 1444 case AF_INET: 1445#ifdef AF_INET6 1446 case AF_INET6: 1447#endif 1448 allownumeric = 1; 1449 break; 1450 default: 1451 allownumeric = 0; 1452 break; 1453 } 1454 break; 1455 default: 1456 return EAI_SOCKTYPE; 1457 } 1458 1459 error = str2number(servname, &port); 1460 if (error == 0) { 1461 if (!allownumeric) 1462 return EAI_SERVICE; 1463 if (port < 0 || port > 65535) 1464 return EAI_SERVICE; 1465 port = htons(port); 1466 } else { 1467 if (ai->ai_flags & AI_NUMERICSERV) 1468 return EAI_NONAME; 1469 1470 switch (ai->ai_protocol) { 1471 case IPPROTO_UDP: 1472 proto = "udp"; 1473 break; 1474 case IPPROTO_TCP: 1475 proto = "tcp"; 1476 break; 1477 case IPPROTO_SCTP: 1478 proto = "sctp"; 1479 break; 1480 default: 1481 proto = NULL; 1482 break; 1483 } 1484 1485 if ((sp = getservbyname(servname, proto)) == NULL) 1486 return EAI_SERVICE; 1487 port = sp->s_port; 1488 } 1489 1490 if (!matchonly) { 1491 switch (ai->ai_family) { 1492 case AF_INET: 1493 ((struct sockaddr_in *)(void *) 1494 ai->ai_addr)->sin_port = port; 1495 break; 1496#ifdef INET6 1497 case AF_INET6: 1498 ((struct sockaddr_in6 *)(void *) 1499 ai->ai_addr)->sin6_port = port; 1500 break; 1501#endif 1502 } 1503 } 1504 1505 return 0; 1506} 1507 1508static const struct afd * 1509find_afd(int af) 1510{ 1511 const struct afd *afd; 1512 1513 if (af == PF_UNSPEC) 1514 return NULL; 1515 for (afd = afdl; afd->a_af; afd++) { 1516 if (afd->a_af == af) 1517 return afd; 1518 } 1519 return NULL; 1520} 1521 1522/* 1523 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1524 * will take care of it. 1525 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1526 * if the code is right or not. 1527 * 1528 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1529 * _dns_getaddrinfo. 1530 */ 1531static int 1532addrconfig(struct addrinfo *pai) 1533{ 1534 int s, af; 1535 1536 /* 1537 * TODO: 1538 * Note that implementation dependent test for address 1539 * configuration should be done everytime called 1540 * (or apropriate interval), 1541 * because addresses will be dynamically assigned or deleted. 1542 */ 1543 af = pai->ai_family; 1544 if (af == AF_UNSPEC) { 1545 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 1546 af = AF_INET; 1547 else { 1548 _close(s); 1549 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) 1550 af = AF_INET6; 1551 else 1552 _close(s); 1553 } 1554 } 1555 if (af != AF_UNSPEC) { 1556 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 1557 return 0; 1558 _close(s); 1559 } 1560 pai->ai_family = af; 1561 return 1; 1562} 1563 1564#ifdef INET6 1565/* convert a string to a scope identifier. XXX: IPv6 specific */ 1566static int 1567ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1568{ 1569 u_long lscopeid; 1570 struct in6_addr *a6; 1571 char *ep; 1572 1573 a6 = &sin6->sin6_addr; 1574 1575 /* empty scopeid portion is invalid */ 1576 if (*scope == '\0') 1577 return -1; 1578 1579 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1580 /* 1581 * We currently assume a one-to-one mapping between links 1582 * and interfaces, so we simply use interface indices for 1583 * like-local scopes. 1584 */ 1585 *scopeid = if_nametoindex(scope); 1586 if (*scopeid == 0) 1587 goto trynumeric; 1588 return 0; 1589 } 1590 1591 /* still unclear about literal, allow numeric only - placeholder */ 1592 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1593 goto trynumeric; 1594 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1595 goto trynumeric; 1596 else 1597 goto trynumeric; /* global */ 1598 1599 /* try to convert to a numeric id as a last resort */ 1600 trynumeric: 1601 errno = 0; 1602 lscopeid = strtoul(scope, &ep, 10); 1603 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1604 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1605 return 0; 1606 else 1607 return -1; 1608} 1609#endif 1610 1611 1612#ifdef NS_CACHING 1613static int 1614addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1615 void *cache_mdata) 1616{ 1617 res_state statp; 1618 u_long res_options; 1619 1620 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1621 char *hostname; 1622 struct addrinfo *hints; 1623 1624 char *p; 1625 int ai_flags, ai_family, ai_socktype, ai_protocol; 1626 size_t desired_size, size; 1627 1628 statp = __res_state(); 1629 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1630 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1631 1632 hostname = va_arg(ap, char *); 1633 hints = va_arg(ap, struct addrinfo *); 1634 1635 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1636 if (hostname != NULL) { 1637 size = strlen(hostname); 1638 desired_size += size + 1; 1639 } else 1640 size = 0; 1641 1642 if (desired_size > *buffer_size) { 1643 *buffer_size = desired_size; 1644 return (NS_RETURN); 1645 } 1646 1647 if (hints == NULL) 1648 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1649 else { 1650 ai_flags = hints->ai_flags; 1651 ai_family = hints->ai_family; 1652 ai_socktype = hints->ai_socktype; 1653 ai_protocol = hints->ai_protocol; 1654 } 1655 1656 p = buffer; 1657 memcpy(p, &res_options, sizeof(res_options)); 1658 p += sizeof(res_options); 1659 1660 memcpy(p, &op_id, sizeof(int)); 1661 p += sizeof(int); 1662 1663 memcpy(p, &ai_flags, sizeof(int)); 1664 p += sizeof(int); 1665 1666 memcpy(p, &ai_family, sizeof(int)); 1667 p += sizeof(int); 1668 1669 memcpy(p, &ai_socktype, sizeof(int)); 1670 p += sizeof(int); 1671 1672 memcpy(p, &ai_protocol, sizeof(int)); 1673 p += sizeof(int); 1674 1675 if (hostname != NULL) 1676 memcpy(p, hostname, size); 1677 1678 *buffer_size = desired_size; 1679 return (NS_SUCCESS); 1680} 1681 1682static int 1683addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1684 va_list ap, void *cache_mdata) 1685{ 1686 struct addrinfo *ai, *cai; 1687 char *p; 1688 size_t desired_size, size, ai_size; 1689 1690 ai = *((struct addrinfo **)retval); 1691 1692 desired_size = sizeof(size_t); 1693 ai_size = 0; 1694 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1695 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1696 if (cai->ai_canonname != NULL) 1697 desired_size += sizeof(size_t) + 1698 strlen(cai->ai_canonname); 1699 ++ai_size; 1700 } 1701 1702 if (desired_size > *buffer_size) { 1703 /* this assignment is here for future use */ 1704 errno = ERANGE; 1705 *buffer_size = desired_size; 1706 return (NS_RETURN); 1707 } 1708 1709 memset(buffer, 0, desired_size); 1710 p = buffer; 1711 1712 memcpy(p, &ai_size, sizeof(size_t)); 1713 p += sizeof(size_t); 1714 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1715 memcpy(p, cai, sizeof(struct addrinfo)); 1716 p += sizeof(struct addrinfo); 1717 1718 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1719 p += cai->ai_addrlen; 1720 1721 if (cai->ai_canonname != NULL) { 1722 size = strlen(cai->ai_canonname); 1723 memcpy(p, &size, sizeof(size_t)); 1724 p += sizeof(size_t); 1725 1726 memcpy(p, cai->ai_canonname, size); 1727 p += size; 1728 } 1729 } 1730 1731 return (NS_SUCCESS); 1732} 1733 1734static int 1735addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1736 va_list ap, void *cache_mdata) 1737{ 1738 struct addrinfo new_ai, *result, *sentinel, *lasts; 1739 1740 char *p; 1741 size_t ai_size, ai_i, size; 1742 1743 p = buffer; 1744 memcpy(&ai_size, p, sizeof(size_t)); 1745 p += sizeof(size_t); 1746 1747 result = NULL; 1748 lasts = NULL; 1749 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1750 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1751 p += sizeof(struct addrinfo); 1752 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1753 _ALIGNBYTES; 1754 1755 sentinel = (struct addrinfo *)malloc(size); 1756 memset(sentinel, 0, size); 1757 1758 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1759 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1760 sizeof(struct addrinfo)); 1761 1762 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1763 p += new_ai.ai_addrlen; 1764 1765 if (new_ai.ai_canonname != NULL) { 1766 memcpy(&size, p, sizeof(size_t)); 1767 p += sizeof(size_t); 1768 1769 sentinel->ai_canonname = (char *)malloc(size + 1); 1770 memset(sentinel->ai_canonname, 0, size + 1); 1771 1772 memcpy(sentinel->ai_canonname, p, size); 1773 p += size; 1774 } 1775 1776 if (result == NULL) { 1777 result = sentinel; 1778 lasts = sentinel; 1779 } else { 1780 lasts->ai_next = sentinel; 1781 lasts = sentinel; 1782 } 1783 } 1784 1785 *((struct addrinfo **)retval) = result; 1786 return (NS_SUCCESS); 1787} 1788#endif /* NS_CACHING */ 1789 1790/* 1791 * FQDN hostname, DNS lookup 1792 */ 1793static int 1794explore_fqdn(const struct addrinfo *pai, const char *hostname, 1795 const char *servname, struct addrinfo **res) 1796{ 1797 struct addrinfo *result; 1798 struct addrinfo *cur; 1799 int error = 0; 1800 1801#ifdef NS_CACHING 1802 static const nss_cache_info cache_info = 1803 NS_COMMON_CACHE_INFO_INITIALIZER( 1804 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1805 addrinfo_unmarshal_func); 1806#endif 1807 static const ns_dtab dtab[] = { 1808 NS_FILES_CB(_files_getaddrinfo, NULL) 1809 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1810 NS_NIS_CB(_yp_getaddrinfo, NULL) 1811#ifdef NS_CACHING 1812 NS_CACHE_CB(&cache_info) 1813#endif 1814 { 0 } 1815 }; 1816 1817 result = NULL; 1818 1819 /* 1820 * if the servname does not match socktype/protocol, ignore it. 1821 */ 1822 if (get_portmatch(pai, servname) != 0) 1823 return 0; 1824 1825 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1826 default_dns_files, hostname, pai)) { 1827 case NS_TRYAGAIN: 1828 error = EAI_AGAIN; 1829 goto free; 1830 case NS_UNAVAIL: 1831 error = EAI_FAIL; 1832 goto free; 1833 case NS_NOTFOUND: 1834 error = EAI_NONAME; 1835 goto free; 1836 case NS_SUCCESS: 1837 error = 0; 1838 for (cur = result; cur; cur = cur->ai_next) { 1839 GET_PORT(cur, servname); 1840 /* canonname should be filled already */ 1841 } 1842 break; 1843 } 1844 1845 *res = result; 1846 1847 return 0; 1848 1849free: 1850 if (result) 1851 freeaddrinfo(result); 1852 return error; 1853} 1854 1855#ifdef DEBUG 1856static const char AskedForGot[] = 1857 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1858#endif 1859 1860static struct addrinfo * 1861getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1862 const struct addrinfo *pai, res_state res) 1863{ 1864 struct addrinfo sentinel, *cur; 1865 struct addrinfo ai; 1866 const struct afd *afd; 1867 char *canonname; 1868 const HEADER *hp; 1869 const u_char *cp; 1870 int n; 1871 const u_char *eom; 1872 char *bp, *ep; 1873 int type, class, ancount, qdcount; 1874 int haveanswer, had_error; 1875 char tbuf[MAXDNAME]; 1876 int (*name_ok)(const char *); 1877 char hostbuf[8*1024]; 1878 1879 memset(&sentinel, 0, sizeof(sentinel)); 1880 cur = &sentinel; 1881 1882 canonname = NULL; 1883 eom = answer->buf + anslen; 1884 switch (qtype) { 1885 case T_A: 1886 case T_AAAA: 1887 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1888 name_ok = res_hnok; 1889 break; 1890 default: 1891 return (NULL); /* XXX should be abort(); */ 1892 } 1893 /* 1894 * find first satisfactory answer 1895 */ 1896 hp = &answer->hdr; 1897 ancount = ntohs(hp->ancount); 1898 qdcount = ntohs(hp->qdcount); 1899 bp = hostbuf; 1900 ep = hostbuf + sizeof hostbuf; 1901 cp = answer->buf + HFIXEDSZ; 1902 if (qdcount != 1) { 1903 RES_SET_H_ERRNO(res, NO_RECOVERY); 1904 return (NULL); 1905 } 1906 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1907 if ((n < 0) || !(*name_ok)(bp)) { 1908 RES_SET_H_ERRNO(res, NO_RECOVERY); 1909 return (NULL); 1910 } 1911 cp += n + QFIXEDSZ; 1912 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1913 /* res_send() has already verified that the query name is the 1914 * same as the one we sent; this just gets the expanded name 1915 * (i.e., with the succeeding search-domain tacked on). 1916 */ 1917 n = strlen(bp) + 1; /* for the \0 */ 1918 if (n >= MAXHOSTNAMELEN) { 1919 RES_SET_H_ERRNO(res, NO_RECOVERY); 1920 return (NULL); 1921 } 1922 canonname = bp; 1923 bp += n; 1924 /* The qname can be abbreviated, but h_name is now absolute. */ 1925 qname = canonname; 1926 } 1927 haveanswer = 0; 1928 had_error = 0; 1929 while (ancount-- > 0 && cp < eom && !had_error) { 1930 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1931 if ((n < 0) || !(*name_ok)(bp)) { 1932 had_error++; 1933 continue; 1934 } 1935 cp += n; /* name */ 1936 type = _getshort(cp); 1937 cp += INT16SZ; /* type */ 1938 class = _getshort(cp); 1939 cp += INT16SZ + INT32SZ; /* class, TTL */ 1940 n = _getshort(cp); 1941 cp += INT16SZ; /* len */ 1942 if (class != C_IN) { 1943 /* XXX - debug? syslog? */ 1944 cp += n; 1945 continue; /* XXX - had_error++ ? */ 1946 } 1947 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1948 type == T_CNAME) { 1949 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1950 if ((n < 0) || !(*name_ok)(tbuf)) { 1951 had_error++; 1952 continue; 1953 } 1954 cp += n; 1955 /* Get canonical name. */ 1956 n = strlen(tbuf) + 1; /* for the \0 */ 1957 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1958 had_error++; 1959 continue; 1960 } 1961 strlcpy(bp, tbuf, ep - bp); 1962 canonname = bp; 1963 bp += n; 1964 continue; 1965 } 1966 if (qtype == T_ANY) { 1967 if (!(type == T_A || type == T_AAAA)) { 1968 cp += n; 1969 continue; 1970 } 1971 } else if (type != qtype) { 1972#ifdef DEBUG 1973 if (type != T_KEY && type != T_SIG && 1974 type != ns_t_dname) 1975 syslog(LOG_NOTICE|LOG_AUTH, 1976 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1977 qname, p_class(C_IN), p_type(qtype), 1978 p_type(type)); 1979#endif 1980 cp += n; 1981 continue; /* XXX - had_error++ ? */ 1982 } 1983 switch (type) { 1984 case T_A: 1985 case T_AAAA: 1986 if (strcasecmp(canonname, bp) != 0) { 1987#ifdef DEBUG 1988 syslog(LOG_NOTICE|LOG_AUTH, 1989 AskedForGot, canonname, bp); 1990#endif 1991 cp += n; 1992 continue; /* XXX - had_error++ ? */ 1993 } 1994 if (type == T_A && n != INADDRSZ) { 1995 cp += n; 1996 continue; 1997 } 1998 if (type == T_AAAA && n != IN6ADDRSZ) { 1999 cp += n; 2000 continue; 2001 } 2002#ifdef FILTER_V4MAPPED 2003 if (type == T_AAAA) { 2004 struct in6_addr in6; 2005 memcpy(&in6, cp, sizeof(in6)); 2006 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2007 cp += n; 2008 continue; 2009 } 2010 } 2011#endif 2012 if (!haveanswer) { 2013 int nn; 2014 2015 canonname = bp; 2016 nn = strlen(bp) + 1; /* for the \0 */ 2017 bp += nn; 2018 } 2019 2020 /* don't overwrite pai */ 2021 ai = *pai; 2022 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2023 afd = find_afd(ai.ai_family); 2024 if (afd == NULL) { 2025 cp += n; 2026 continue; 2027 } 2028 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2029 if (cur->ai_next == NULL) 2030 had_error++; 2031 while (cur && cur->ai_next) 2032 cur = cur->ai_next; 2033 cp += n; 2034 break; 2035 default: 2036 abort(); 2037 } 2038 if (!had_error) 2039 haveanswer++; 2040 } 2041 if (haveanswer) { 2042#if defined(RESOLVSORT) 2043 /* 2044 * We support only IPv4 address for backward 2045 * compatibility against gethostbyname(3). 2046 */ 2047 if (res->nsort && qtype == T_A) { 2048 if (addr4sort(&sentinel, res) < 0) { 2049 freeaddrinfo(sentinel.ai_next); 2050 RES_SET_H_ERRNO(res, NO_RECOVERY); 2051 return NULL; 2052 } 2053 } 2054#endif /*RESOLVSORT*/ 2055 if (!canonname) 2056 (void)get_canonname(pai, sentinel.ai_next, qname); 2057 else 2058 (void)get_canonname(pai, sentinel.ai_next, canonname); 2059 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2060 return sentinel.ai_next; 2061 } 2062 2063 RES_SET_H_ERRNO(res, NO_RECOVERY); 2064 return NULL; 2065} 2066 2067#ifdef RESOLVSORT 2068struct addr_ptr { 2069 struct addrinfo *ai; 2070 int aval; 2071}; 2072 2073static int 2074addr4sort(struct addrinfo *sentinel, res_state res) 2075{ 2076 struct addrinfo *ai; 2077 struct addr_ptr *addrs, addr; 2078 struct sockaddr_in *sin; 2079 int naddrs, i, j; 2080 int needsort = 0; 2081 2082 if (!sentinel) 2083 return -1; 2084 naddrs = 0; 2085 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2086 naddrs++; 2087 if (naddrs < 2) 2088 return 0; /* We don't need sorting. */ 2089 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2090 return -1; 2091 i = 0; 2092 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2093 sin = (struct sockaddr_in *)ai->ai_addr; 2094 for (j = 0; (unsigned)j < res->nsort; j++) { 2095 if (res->sort_list[j].addr.s_addr == 2096 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2097 break; 2098 } 2099 addrs[i].ai = ai; 2100 addrs[i].aval = j; 2101 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2102 needsort = i; 2103 i++; 2104 } 2105 if (!needsort) { 2106 free(addrs); 2107 return 0; 2108 } 2109 2110 while (needsort < naddrs) { 2111 for (j = needsort - 1; j >= 0; j--) { 2112 if (addrs[j].aval > addrs[j+1].aval) { 2113 addr = addrs[j]; 2114 addrs[j] = addrs[j + 1]; 2115 addrs[j + 1] = addr; 2116 } else 2117 break; 2118 } 2119 needsort++; 2120 } 2121 2122 ai = sentinel; 2123 for (i = 0; i < naddrs; ++i) { 2124 ai->ai_next = addrs[i].ai; 2125 ai = ai->ai_next; 2126 } 2127 ai->ai_next = NULL; 2128 free(addrs); 2129 return 0; 2130} 2131#endif /*RESOLVSORT*/ 2132 2133/*ARGSUSED*/ 2134static int 2135_dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2136{ 2137 struct addrinfo *ai; 2138 querybuf *buf, *buf2; 2139 const char *hostname; 2140 const struct addrinfo *pai; 2141 struct addrinfo sentinel, *cur; 2142 struct res_target q, q2; 2143 res_state res; 2144 2145 hostname = va_arg(ap, char *); 2146 pai = va_arg(ap, const struct addrinfo *); 2147 2148 memset(&q, 0, sizeof(q)); 2149 memset(&q2, 0, sizeof(q2)); 2150 memset(&sentinel, 0, sizeof(sentinel)); 2151 cur = &sentinel; 2152 2153 buf = malloc(sizeof(*buf)); 2154 if (!buf) { 2155 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2156 return NS_NOTFOUND; 2157 } 2158 buf2 = malloc(sizeof(*buf2)); 2159 if (!buf2) { 2160 free(buf); 2161 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2162 return NS_NOTFOUND; 2163 } 2164 2165 switch (pai->ai_family) { 2166 case AF_UNSPEC: 2167 q.name = hostname; 2168 q.qclass = C_IN; 2169 q.qtype = T_A; 2170 q.answer = buf->buf; 2171 q.anslen = sizeof(buf->buf); 2172 q.next = &q2; 2173 q2.name = hostname; 2174 q2.qclass = C_IN; 2175 q2.qtype = T_AAAA; 2176 q2.answer = buf2->buf; 2177 q2.anslen = sizeof(buf2->buf); 2178 break; 2179 case AF_INET: 2180 q.name = hostname; 2181 q.qclass = C_IN; 2182 q.qtype = T_A; 2183 q.answer = buf->buf; 2184 q.anslen = sizeof(buf->buf); 2185 break; 2186 case AF_INET6: 2187 q.name = hostname; 2188 q.qclass = C_IN; 2189 q.qtype = T_AAAA; 2190 q.answer = buf->buf; 2191 q.anslen = sizeof(buf->buf); 2192 break; 2193 default: 2194 free(buf); 2195 free(buf2); 2196 return NS_UNAVAIL; 2197 } 2198 2199 res = __res_state(); 2200 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2201 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2202 free(buf); 2203 free(buf2); 2204 return NS_NOTFOUND; 2205 } 2206 2207 if (res_searchN(hostname, &q, res) < 0) { 2208 free(buf); 2209 free(buf2); 2210 return NS_NOTFOUND; 2211 } 2212 /* prefer IPv6 */ 2213 if (q.next) { 2214 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2215 if (ai) { 2216 cur->ai_next = ai; 2217 while (cur && cur->ai_next) 2218 cur = cur->ai_next; 2219 } 2220 } 2221 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2222 if (ai) 2223 cur->ai_next = ai; 2224 free(buf); 2225 free(buf2); 2226 if (sentinel.ai_next == NULL) 2227 switch (res->res_h_errno) { 2228 case HOST_NOT_FOUND: 2229 return NS_NOTFOUND; 2230 case TRY_AGAIN: 2231 return NS_TRYAGAIN; 2232 default: 2233 return NS_UNAVAIL; 2234 } 2235 *((struct addrinfo **)rv) = sentinel.ai_next; 2236 return NS_SUCCESS; 2237} 2238 2239static void 2240_sethtent(FILE **hostf) 2241{ 2242 if (!*hostf) 2243 *hostf = fopen(_PATH_HOSTS, "r"); 2244 else 2245 rewind(*hostf); 2246} 2247 2248static void 2249_endhtent(FILE **hostf) 2250{ 2251 if (*hostf) { 2252 (void) fclose(*hostf); 2253 *hostf = NULL; 2254 } 2255} 2256 2257static struct addrinfo * 2258_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2259{ 2260 char *p; 2261 char *cp, *tname, *cname; 2262 struct addrinfo hints, *res0, *res; 2263 int error; 2264 const char *addr; 2265 char hostbuf[8*1024]; 2266 2267 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r"))) 2268 return (NULL); 2269again: 2270 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2271 return (NULL); 2272 if (*p == '#') 2273 goto again; 2274 cp = strpbrk(p, "#\n"); 2275 if (cp != NULL) 2276 *cp = '\0'; 2277 if (!(cp = strpbrk(p, " \t"))) 2278 goto again; 2279 *cp++ = '\0'; 2280 addr = p; 2281 cname = NULL; 2282 /* if this is not something we're looking for, skip it. */ 2283 while (cp && *cp) { 2284 if (*cp == ' ' || *cp == '\t') { 2285 cp++; 2286 continue; 2287 } 2288 tname = cp; 2289 if (cname == NULL) 2290 cname = cp; 2291 if ((cp = strpbrk(cp, " \t")) != NULL) 2292 *cp++ = '\0'; 2293 if (strcasecmp(name, tname) == 0) 2294 goto found; 2295 } 2296 goto again; 2297 2298found: 2299 /* we should not glob socktype/protocol here */ 2300 memset(&hints, 0, sizeof(hints)); 2301 hints.ai_family = pai->ai_family; 2302 hints.ai_socktype = SOCK_DGRAM; 2303 hints.ai_protocol = 0; 2304 hints.ai_flags = AI_NUMERICHOST; 2305 error = getaddrinfo(addr, "0", &hints, &res0); 2306 if (error) 2307 goto again; 2308#ifdef FILTER_V4MAPPED 2309 /* XXX should check all items in the chain */ 2310 if (res0->ai_family == AF_INET6 && 2311 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2312 freeaddrinfo(res0); 2313 goto again; 2314 } 2315#endif 2316 for (res = res0; res; res = res->ai_next) { 2317 /* cover it up */ 2318 res->ai_flags = pai->ai_flags; 2319 res->ai_socktype = pai->ai_socktype; 2320 res->ai_protocol = pai->ai_protocol; 2321 2322 if (pai->ai_flags & AI_CANONNAME) { 2323 if (get_canonname(pai, res, cname) != 0) { 2324 freeaddrinfo(res0); 2325 goto again; 2326 } 2327 } 2328 } 2329 return res0; 2330} 2331 2332/*ARGSUSED*/ 2333static int 2334_files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2335{ 2336 const char *name; 2337 const struct addrinfo *pai; 2338 struct addrinfo sentinel, *cur; 2339 struct addrinfo *p; 2340 FILE *hostf = NULL; 2341 2342 name = va_arg(ap, char *); 2343 pai = va_arg(ap, struct addrinfo *); 2344 2345 memset(&sentinel, 0, sizeof(sentinel)); 2346 cur = &sentinel; 2347 2348 _sethtent(&hostf); 2349 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 2350 cur->ai_next = p; 2351 while (cur && cur->ai_next) 2352 cur = cur->ai_next; 2353 } 2354 _endhtent(&hostf); 2355 2356 *((struct addrinfo **)rv) = sentinel.ai_next; 2357 if (sentinel.ai_next == NULL) 2358 return NS_NOTFOUND; 2359 return NS_SUCCESS; 2360} 2361 2362#ifdef YP 2363/*ARGSUSED*/ 2364static struct addrinfo * 2365_yphostent(char *line, const struct addrinfo *pai) 2366{ 2367 struct addrinfo sentinel, *cur; 2368 struct addrinfo hints, *res, *res0; 2369 int error; 2370 char *p = line; 2371 const char *addr, *canonname; 2372 char *nextline; 2373 char *cp; 2374 2375 addr = canonname = NULL; 2376 2377 memset(&sentinel, 0, sizeof(sentinel)); 2378 cur = &sentinel; 2379 2380nextline: 2381 /* terminate line */ 2382 cp = strchr(p, '\n'); 2383 if (cp) { 2384 *cp++ = '\0'; 2385 nextline = cp; 2386 } else 2387 nextline = NULL; 2388 2389 cp = strpbrk(p, " \t"); 2390 if (cp == NULL) { 2391 if (canonname == NULL) 2392 return (NULL); 2393 else 2394 goto done; 2395 } 2396 *cp++ = '\0'; 2397 2398 addr = p; 2399 2400 while (cp && *cp) { 2401 if (*cp == ' ' || *cp == '\t') { 2402 cp++; 2403 continue; 2404 } 2405 if (!canonname) 2406 canonname = cp; 2407 if ((cp = strpbrk(cp, " \t")) != NULL) 2408 *cp++ = '\0'; 2409 } 2410 2411 hints = *pai; 2412 hints.ai_flags = AI_NUMERICHOST; 2413 error = getaddrinfo(addr, NULL, &hints, &res0); 2414 if (error == 0) { 2415 for (res = res0; res; res = res->ai_next) { 2416 /* cover it up */ 2417 res->ai_flags = pai->ai_flags; 2418 2419 if (pai->ai_flags & AI_CANONNAME) 2420 (void)get_canonname(pai, res, canonname); 2421 } 2422 } else 2423 res0 = NULL; 2424 if (res0) { 2425 cur->ai_next = res0; 2426 while (cur && cur->ai_next) 2427 cur = cur->ai_next; 2428 } 2429 2430 if (nextline) { 2431 p = nextline; 2432 goto nextline; 2433 } 2434 2435done: 2436 return sentinel.ai_next; 2437} 2438 2439/*ARGSUSED*/ 2440static int 2441_yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2442{ 2443 struct addrinfo sentinel, *cur; 2444 struct addrinfo *ai = NULL; 2445 char *ypbuf; 2446 int ypbuflen, r; 2447 const char *name; 2448 const struct addrinfo *pai; 2449 char *ypdomain; 2450 2451 if (_yp_check(&ypdomain) == 0) 2452 return NS_UNAVAIL; 2453 2454 name = va_arg(ap, char *); 2455 pai = va_arg(ap, const struct addrinfo *); 2456 2457 memset(&sentinel, 0, sizeof(sentinel)); 2458 cur = &sentinel; 2459 2460 /* hosts.byname is only for IPv4 (Solaris8) */ 2461 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 2462 r = yp_match(ypdomain, "hosts.byname", name, 2463 (int)strlen(name), &ypbuf, &ypbuflen); 2464 if (r == 0) { 2465 struct addrinfo ai4; 2466 2467 ai4 = *pai; 2468 ai4.ai_family = AF_INET; 2469 ai = _yphostent(ypbuf, &ai4); 2470 if (ai) { 2471 cur->ai_next = ai; 2472 while (cur && cur->ai_next) 2473 cur = cur->ai_next; 2474 } 2475 free(ypbuf); 2476 } 2477 } 2478 2479 /* ipnodes.byname can hold both IPv4/v6 */ 2480 r = yp_match(ypdomain, "ipnodes.byname", name, 2481 (int)strlen(name), &ypbuf, &ypbuflen); 2482 if (r == 0) { 2483 ai = _yphostent(ypbuf, pai); 2484 if (ai) 2485 cur->ai_next = ai; 2486 free(ypbuf); 2487 } 2488 2489 if (sentinel.ai_next == NULL) { 2490 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2491 return NS_NOTFOUND; 2492 } 2493 *((struct addrinfo **)rv) = sentinel.ai_next; 2494 return NS_SUCCESS; 2495} 2496#endif 2497 2498/* resolver logic */ 2499 2500/* 2501 * Formulate a normal query, send, and await answer. 2502 * Returned answer is placed in supplied buffer "answer". 2503 * Perform preliminary check of answer, returning success only 2504 * if no error is indicated and the answer count is nonzero. 2505 * Return the size of the response on success, -1 on error. 2506 * Error number is left in h_errno. 2507 * 2508 * Caller must parse answer and determine whether it answers the question. 2509 */ 2510static int 2511res_queryN(const char *name, struct res_target *target, res_state res) 2512{ 2513 u_char *buf; 2514 HEADER *hp; 2515 int n; 2516 u_int oflags; 2517 struct res_target *t; 2518 int rcode; 2519 int ancount; 2520 2521 rcode = NOERROR; 2522 ancount = 0; 2523 2524 buf = malloc(MAXPACKET); 2525 if (!buf) { 2526 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2527 return -1; 2528 } 2529 2530 for (t = target; t; t = t->next) { 2531 int class, type; 2532 u_char *answer; 2533 int anslen; 2534 2535 hp = (HEADER *)(void *)t->answer; 2536 2537 /* make it easier... */ 2538 class = t->qclass; 2539 type = t->qtype; 2540 answer = t->answer; 2541 anslen = t->anslen; 2542 2543 oflags = res->_flags; 2544 2545again: 2546 hp->rcode = NOERROR; /* default */ 2547 2548#ifdef DEBUG 2549 if (res->options & RES_DEBUG) 2550 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2551#endif 2552 2553 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2554 buf, MAXPACKET); 2555 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2556 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2557 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2558 if (n <= 0) { 2559#ifdef DEBUG 2560 if (res->options & RES_DEBUG) 2561 printf(";; res_query: mkquery failed\n"); 2562#endif 2563 free(buf); 2564 RES_SET_H_ERRNO(res, NO_RECOVERY); 2565 return (n); 2566 } 2567 n = res_nsend(res, buf, n, answer, anslen); 2568 if (n < 0) { 2569 /* 2570 * if the query choked with EDNS0, retry 2571 * without EDNS0 2572 */ 2573 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2574 != 0U && 2575 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2576 res->_flags |= RES_F_EDNS0ERR; 2577 if (res->options & RES_DEBUG) 2578 printf(";; res_nquery: retry without EDNS0\n"); 2579 goto again; 2580 } 2581 rcode = hp->rcode; /* record most recent error */ 2582#ifdef DEBUG 2583 if (res->options & RES_DEBUG) 2584 printf(";; res_query: send error\n"); 2585#endif 2586 continue; 2587 } 2588 2589 if (n > anslen) 2590 hp->rcode = FORMERR; /* XXX not very informative */ 2591 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2592 rcode = hp->rcode; /* record most recent error */ 2593#ifdef DEBUG 2594 if (res->options & RES_DEBUG) 2595 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2596 ntohs(hp->ancount)); 2597#endif 2598 continue; 2599 } 2600 2601 ancount += ntohs(hp->ancount); 2602 2603 t->n = n; 2604 } 2605 2606 free(buf); 2607 2608 if (ancount == 0) { 2609 switch (rcode) { 2610 case NXDOMAIN: 2611 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2612 break; 2613 case SERVFAIL: 2614 RES_SET_H_ERRNO(res, TRY_AGAIN); 2615 break; 2616 case NOERROR: 2617 RES_SET_H_ERRNO(res, NO_DATA); 2618 break; 2619 case FORMERR: 2620 case NOTIMP: 2621 case REFUSED: 2622 default: 2623 RES_SET_H_ERRNO(res, NO_RECOVERY); 2624 break; 2625 } 2626 return (-1); 2627 } 2628 return (ancount); 2629} 2630 2631/* 2632 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2633 * Return the size of the response on success, -1 on error. 2634 * If enabled, implement search rules until answer or unrecoverable failure 2635 * is detected. Error code, if any, is left in h_errno. 2636 */ 2637static int 2638res_searchN(const char *name, struct res_target *target, res_state res) 2639{ 2640 const char *cp, * const *domain; 2641 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2642 u_int dots; 2643 int trailing_dot, ret, saved_herrno; 2644 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2645 int tried_as_is = 0; 2646 int searched = 0; 2647 char abuf[MAXDNAME]; 2648 2649 errno = 0; 2650 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2651 dots = 0; 2652 for (cp = name; *cp; cp++) 2653 dots += (*cp == '.'); 2654 trailing_dot = 0; 2655 if (cp > name && *--cp == '.') 2656 trailing_dot++; 2657 2658 /* 2659 * if there aren't any dots, it could be a user-level alias 2660 */ 2661 if (!dots && 2662 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2663 return (res_queryN(cp, target, res)); 2664 2665 /* 2666 * If there are enough dots in the name, let's just give it a 2667 * try 'as is'. The threshold can be set with the "ndots" option. 2668 * Also, query 'as is', if there is a trailing dot in the name. 2669 */ 2670 saved_herrno = -1; 2671 if (dots >= res->ndots || trailing_dot) { 2672 ret = res_querydomainN(name, NULL, target, res); 2673 if (ret > 0 || trailing_dot) 2674 return (ret); 2675 if (errno == ECONNREFUSED) { 2676 RES_SET_H_ERRNO(res, TRY_AGAIN); 2677 return (-1); 2678 } 2679 switch (res->res_h_errno) { 2680 case NO_DATA: 2681 case HOST_NOT_FOUND: 2682 break; 2683 case TRY_AGAIN: 2684 if (hp->rcode == SERVFAIL) 2685 break; 2686 /* FALLTHROUGH */ 2687 default: 2688 return (-1); 2689 } 2690 saved_herrno = res->res_h_errno; 2691 tried_as_is++; 2692 } 2693 2694 /* 2695 * We do at least one level of search if 2696 * - there is no dot and RES_DEFNAME is set, or 2697 * - there is at least one dot, there is no trailing dot, 2698 * and RES_DNSRCH is set. 2699 */ 2700 if ((!dots && (res->options & RES_DEFNAMES)) || 2701 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2702 int done = 0; 2703 2704 for (domain = (const char * const *)res->dnsrch; 2705 *domain && !done; 2706 domain++) { 2707 searched = 1; 2708 2709 if (domain[0][0] == '\0' || 2710 (domain[0][0] == '.' && domain[0][1] == '\0')) 2711 root_on_list++; 2712 2713 if (root_on_list && tried_as_is) 2714 continue; 2715 2716 ret = res_querydomainN(name, *domain, target, res); 2717 if (ret > 0) 2718 return (ret); 2719 2720 /* 2721 * If no server present, give up. 2722 * If name isn't found in this domain, 2723 * keep trying higher domains in the search list 2724 * (if that's enabled). 2725 * On a NO_DATA error, keep trying, otherwise 2726 * a wildcard entry of another type could keep us 2727 * from finding this entry higher in the domain. 2728 * If we get some other error (negative answer or 2729 * server failure), then stop searching up, 2730 * but try the input name below in case it's 2731 * fully-qualified. 2732 */ 2733 if (errno == ECONNREFUSED) { 2734 RES_SET_H_ERRNO(res, TRY_AGAIN); 2735 return (-1); 2736 } 2737 2738 switch (res->res_h_errno) { 2739 case NO_DATA: 2740 got_nodata++; 2741 /* FALLTHROUGH */ 2742 case HOST_NOT_FOUND: 2743 /* keep trying */ 2744 break; 2745 case TRY_AGAIN: 2746 got_servfail++; 2747 if (hp->rcode == SERVFAIL) { 2748 /* try next search element, if any */ 2749 break; 2750 } 2751 /* FALLTHROUGH */ 2752 default: 2753 /* anything else implies that we're done */ 2754 done++; 2755 } 2756 /* 2757 * if we got here for some reason other than DNSRCH, 2758 * we only wanted one iteration of the loop, so stop. 2759 */ 2760 if (!(res->options & RES_DNSRCH)) 2761 done++; 2762 } 2763 } 2764 2765 switch (res->res_h_errno) { 2766 case NO_DATA: 2767 case HOST_NOT_FOUND: 2768 break; 2769 case TRY_AGAIN: 2770 if (hp->rcode == SERVFAIL) 2771 break; 2772 /* FALLTHROUGH */ 2773 default: 2774 goto giveup; 2775 } 2776 2777 /* 2778 * If the query has not already been tried as is then try it 2779 * unless RES_NOTLDQUERY is set and there were no dots. 2780 */ 2781 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2782 !(tried_as_is || root_on_list)) { 2783 ret = res_querydomainN(name, NULL, target, res); 2784 if (ret > 0) 2785 return (ret); 2786 } 2787 2788 /* 2789 * if we got here, we didn't satisfy the search. 2790 * if we did an initial full query, return that query's h_errno 2791 * (note that we wouldn't be here if that query had succeeded). 2792 * else if we ever got a nodata, send that back as the reason. 2793 * else send back meaningless h_errno, that being the one from 2794 * the last DNSRCH we did. 2795 */ 2796giveup: 2797 if (saved_herrno != -1) 2798 RES_SET_H_ERRNO(res, saved_herrno); 2799 else if (got_nodata) 2800 RES_SET_H_ERRNO(res, NO_DATA); 2801 else if (got_servfail) 2802 RES_SET_H_ERRNO(res, TRY_AGAIN); 2803 return (-1); 2804} 2805 2806/* 2807 * Perform a call on res_query on the concatenation of name and domain, 2808 * removing a trailing dot from name if domain is NULL. 2809 */ 2810static int 2811res_querydomainN(const char *name, const char *domain, 2812 struct res_target *target, res_state res) 2813{ 2814 char nbuf[MAXDNAME]; 2815 const char *longname = nbuf; 2816 size_t n, d; 2817 2818#ifdef DEBUG 2819 if (res->options & RES_DEBUG) 2820 printf(";; res_querydomain(%s, %s)\n", 2821 name, domain?domain:"<Nil>"); 2822#endif 2823 if (domain == NULL) { 2824 /* 2825 * Check for trailing '.'; 2826 * copy without '.' if present. 2827 */ 2828 n = strlen(name); 2829 if (n >= MAXDNAME) { 2830 RES_SET_H_ERRNO(res, NO_RECOVERY); 2831 return (-1); 2832 } 2833 if (n > 0 && name[--n] == '.') { 2834 strncpy(nbuf, name, n); 2835 nbuf[n] = '\0'; 2836 } else 2837 longname = name; 2838 } else { 2839 n = strlen(name); 2840 d = strlen(domain); 2841 if (n + d + 1 >= MAXDNAME) { 2842 RES_SET_H_ERRNO(res, NO_RECOVERY); 2843 return (-1); 2844 } 2845 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2846 } 2847 return (res_queryN(longname, target, res)); 2848} 2849