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 327238 2017-12-27 14:50:07Z 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 <net/if_types.h> 66#include <ifaddrs.h> 67#include <sys/queue.h> 68#ifdef INET6 69#include <net/if_var.h> 70#include <sys/sysctl.h> 71#include <sys/ioctl.h> 72#include <netinet6/in6_var.h> 73#include <netinet6/nd6.h> 74#endif 75#include <arpa/inet.h> 76#include <arpa/nameser.h> 77#include <rpc/rpc.h> 78#include <rpcsvc/yp_prot.h> 79#include <rpcsvc/ypclnt.h> 80#include <netdb.h> 81#include <resolv.h> 82#include <string.h> 83#include <stdlib.h> 84#include <stddef.h> 85#include <ctype.h> 86#include <unistd.h> 87#include <stdio.h> 88#include <errno.h> 89 90#include "res_config.h" 91 92#ifdef DEBUG 93#include <syslog.h> 94#endif 95 96#include <stdarg.h> 97#include <nsswitch.h> 98#include "un-namespace.h" 99#include "netdb_private.h" 100#include "libc_private.h" 101#ifdef NS_CACHING 102#include "nscache.h" 103#endif 104 105#if defined(__KAME__) && defined(INET6) 106# define FAITH 107#endif 108 109#define ANY 0 110#define YES 1 111#define NO 0 112 113static const char in_addrany[] = { 0, 0, 0, 0 }; 114static const char in_loopback[] = { 127, 0, 0, 1 }; 115#ifdef INET6 116static const char in6_addrany[] = { 117 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 118}; 119static const char in6_loopback[] = { 120 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 121}; 122#endif 123 124struct policyqueue { 125 TAILQ_ENTRY(policyqueue) pc_entry; 126#ifdef INET6 127 struct in6_addrpolicy pc_policy; 128#endif 129}; 130TAILQ_HEAD(policyhead, policyqueue); 131 132static const struct afd { 133 int a_af; 134 int a_addrlen; 135 socklen_t a_socklen; 136 int a_off; 137 const char *a_addrany; 138 const char *a_loopback; 139 int a_scoped; 140} afdl [] = { 141#ifdef INET6 142#define N_INET6 0 143 {PF_INET6, sizeof(struct in6_addr), 144 sizeof(struct sockaddr_in6), 145 offsetof(struct sockaddr_in6, sin6_addr), 146 in6_addrany, in6_loopback, 1}, 147#define N_INET 1 148#else 149#define N_INET 0 150#endif 151 {PF_INET, sizeof(struct in_addr), 152 sizeof(struct sockaddr_in), 153 offsetof(struct sockaddr_in, sin_addr), 154 in_addrany, in_loopback, 0}, 155 {0, 0, 0, 0, NULL, NULL, 0}, 156}; 157 158struct explore { 159 int e_af; 160 int e_socktype; 161 int e_protocol; 162 int e_wild; 163#define WILD_AF(ex) ((ex)->e_wild & 0x01) 164#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 165#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 166}; 167 168static const struct explore explore[] = { 169#if 0 170 { PF_LOCAL, ANY, ANY, 0x01 }, 171#endif 172#ifdef INET6 173 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 0x07 }, 174 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, 0x07 }, 175 { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 0x03 }, 176 { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 }, 177 { PF_INET6, SOCK_DGRAM, IPPROTO_UDPLITE, 0x03 }, 178 { PF_INET6, SOCK_RAW, ANY, 0x05 }, 179#endif 180 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, 0x07 }, 181 { PF_INET, SOCK_STREAM, IPPROTO_TCP, 0x07 }, 182 { PF_INET, SOCK_STREAM, IPPROTO_SCTP, 0x03 }, 183 { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 }, 184 { PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE, 0x03 }, 185 { PF_INET, SOCK_RAW, ANY, 0x05 }, 186 { -1, 0, 0, 0 }, 187}; 188 189#ifdef INET6 190#define PTON_MAX 16 191#else 192#define PTON_MAX 4 193#endif 194 195#define AIO_SRCFLAG_DEPRECATED 0x1 196 197struct ai_order { 198 union { 199 struct sockaddr_storage aiou_ss; 200 struct sockaddr aiou_sa; 201 } aio_src_un; 202#define aio_srcsa aio_src_un.aiou_sa 203 u_int32_t aio_srcflag; 204 int aio_srcscope; 205 int aio_dstscope; 206 struct policyqueue *aio_srcpolicy; 207 struct policyqueue *aio_dstpolicy; 208 struct addrinfo *aio_ai; 209 int aio_matchlen; 210 int aio_initial_sequence; 211}; 212 213static const ns_src default_dns_files[] = { 214 { NSSRC_FILES, NS_SUCCESS }, 215 { NSSRC_DNS, NS_SUCCESS }, 216 { 0 } 217}; 218 219struct res_target { 220 struct res_target *next; 221 const char *name; /* domain name */ 222 int qclass, qtype; /* class and type of query */ 223 u_char *answer; /* buffer to put answer */ 224 int anslen; /* size of answer buffer */ 225 int n; /* result length */ 226}; 227 228#define MAXPACKET (64*1024) 229 230typedef union { 231 HEADER hdr; 232 u_char buf[MAXPACKET]; 233} querybuf; 234 235static int str2number(const char *, int *); 236static int explore_copy(const struct addrinfo *, const struct addrinfo *, 237 struct addrinfo **); 238static int explore_null(const struct addrinfo *, 239 const char *, struct addrinfo **); 240static int explore_numeric(const struct addrinfo *, const char *, 241 const char *, struct addrinfo **, const char *); 242static int explore_numeric_scope(const struct addrinfo *, const char *, 243 const char *, struct addrinfo **); 244static int get_canonname(const struct addrinfo *, 245 struct addrinfo *, const char *); 246static struct addrinfo *get_ai(const struct addrinfo *, 247 const struct afd *, const char *); 248static struct addrinfo *copy_ai(const struct addrinfo *); 249static int get_portmatch(const struct addrinfo *, const char *); 250static int get_port(struct addrinfo *, const char *, int); 251static const struct afd *find_afd(int); 252static int addrconfig(struct addrinfo *); 253#ifdef INET6 254static int is_ifdisabled(char *); 255#endif 256static void set_source(struct ai_order *, struct policyhead *); 257static int comp_dst(const void *, const void *); 258#ifdef INET6 259static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 260#endif 261static int gai_addr2scopetype(struct sockaddr *); 262 263static int explore_fqdn(const struct addrinfo *, const char *, 264 const char *, struct addrinfo **); 265 266static int reorder(struct addrinfo *); 267static int get_addrselectpolicy(struct policyhead *); 268static void free_addrselectpolicy(struct policyhead *); 269static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 270 struct policyhead *); 271static int matchlen(struct sockaddr *, struct sockaddr *); 272 273static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 274 const struct addrinfo *, res_state); 275#if defined(RESOLVSORT) 276static int addr4sort(struct addrinfo *, res_state); 277#endif 278static int _dns_getaddrinfo(void *, void *, va_list); 279static void _sethtent(FILE **); 280static void _endhtent(FILE **); 281static struct addrinfo *_gethtent(FILE **, const char *, 282 const struct addrinfo *); 283static int _files_getaddrinfo(void *, void *, va_list); 284#ifdef YP 285static struct addrinfo *_yphostent(char *, const struct addrinfo *); 286static int _yp_getaddrinfo(void *, void *, va_list); 287#endif 288#ifdef NS_CACHING 289static int addrinfo_id_func(char *, size_t *, va_list, void *); 290static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 291static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 292#endif 293 294static int res_queryN(const char *, struct res_target *, res_state); 295static int res_searchN(const char *, struct res_target *, res_state); 296static int res_querydomainN(const char *, const char *, 297 struct res_target *, res_state); 298 299/* XXX macros that make external reference is BAD. */ 300 301#define GET_AI(ai, afd, addr) \ 302do { \ 303 /* external reference: pai, error, and label free */ \ 304 (ai) = get_ai(pai, (afd), (addr)); \ 305 if ((ai) == NULL) { \ 306 error = EAI_MEMORY; \ 307 goto free; \ 308 } \ 309} while (/*CONSTCOND*/0) 310 311#define GET_PORT(ai, serv) \ 312do { \ 313 /* external reference: error and label free */ \ 314 error = get_port((ai), (serv), 0); \ 315 if (error != 0) \ 316 goto free; \ 317} while (/*CONSTCOND*/0) 318 319#define GET_CANONNAME(ai, str) \ 320do { \ 321 /* external reference: pai, error and label free */ \ 322 error = get_canonname(pai, (ai), (str)); \ 323 if (error != 0) \ 324 goto free; \ 325} while (/*CONSTCOND*/0) 326 327#define ERR(err) \ 328do { \ 329 /* external reference: error, and label bad */ \ 330 error = (err); \ 331 goto bad; \ 332 /*NOTREACHED*/ \ 333} while (/*CONSTCOND*/0) 334 335#define MATCH_FAMILY(x, y, w) \ 336 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 337#define MATCH(x, y, w) \ 338 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 339 340void 341freeaddrinfo(struct addrinfo *ai) 342{ 343 struct addrinfo *next; 344 345 do { 346 next = ai->ai_next; 347 if (ai->ai_canonname) 348 free(ai->ai_canonname); 349 /* no need to free(ai->ai_addr) */ 350 free(ai); 351 ai = next; 352 } while (ai); 353} 354 355static int 356str2number(const char *p, int *portp) 357{ 358 char *ep; 359 unsigned long v; 360 361 if (*p == '\0') 362 return -1; 363 ep = NULL; 364 errno = 0; 365 v = strtoul(p, &ep, 10); 366 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 367 *portp = v; 368 return 0; 369 } else 370 return -1; 371} 372 373int 374getaddrinfo(const char *hostname, const char *servname, 375 const struct addrinfo *hints, struct addrinfo **res) 376{ 377 struct addrinfo sentinel; 378 struct addrinfo *cur; 379 int error = 0; 380 struct addrinfo ai, ai0, *afai; 381 struct addrinfo *pai; 382 const struct afd *afd; 383 const struct explore *ex; 384 struct addrinfo *afailist[sizeof(afdl)/sizeof(afdl[0])]; 385 struct addrinfo *afai_unspec; 386 int found; 387 int numeric = 0; 388 389 /* ensure we return NULL on errors */ 390 *res = NULL; 391 392 memset(&ai, 0, sizeof(ai)); 393 394 memset(afailist, 0, sizeof(afailist)); 395 afai_unspec = NULL; 396 397 memset(&sentinel, 0, sizeof(sentinel)); 398 cur = &sentinel; 399 pai = &ai; 400 pai->ai_flags = 0; 401 pai->ai_family = PF_UNSPEC; 402 pai->ai_socktype = ANY; 403 pai->ai_protocol = ANY; 404 pai->ai_addrlen = 0; 405 pai->ai_canonname = NULL; 406 pai->ai_addr = NULL; 407 pai->ai_next = NULL; 408 409 if (hostname == NULL && servname == NULL) 410 return EAI_NONAME; 411 if (hints) { 412 /* error check for hints */ 413 if (hints->ai_addrlen || hints->ai_canonname || 414 hints->ai_addr || hints->ai_next) 415 ERR(EAI_BADHINTS); /* xxx */ 416 if (hints->ai_flags & ~AI_MASK) 417 ERR(EAI_BADFLAGS); 418 switch (hints->ai_family) { 419 case PF_UNSPEC: 420 case PF_INET: 421#ifdef INET6 422 case PF_INET6: 423#endif 424 break; 425 default: 426 ERR(EAI_FAMILY); 427 } 428 memcpy(pai, hints, sizeof(*pai)); 429 430 /* 431 * if both socktype/protocol are specified, check if they 432 * are meaningful combination. 433 */ 434 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 435 for (ex = explore; ex->e_af >= 0; ex++) { 436 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 437 WILD_AF(ex))) 438 continue; 439 if (!MATCH(pai->ai_socktype, ex->e_socktype, 440 WILD_SOCKTYPE(ex))) 441 continue; 442 if (!MATCH(pai->ai_protocol, ex->e_protocol, 443 WILD_PROTOCOL(ex))) 444 continue; 445 446 /* matched */ 447 break; 448 } 449 450 if (ex->e_af < 0) 451 ERR(EAI_BADHINTS); 452 } 453 } 454 455 /* 456 * RFC 3493: AI_ALL and AI_V4MAPPED are effective only against 457 * AF_INET6 query. They need to be ignored if specified in other 458 * occassions. 459 */ 460 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 461 case AI_V4MAPPED: 462 case AI_ALL | AI_V4MAPPED: 463#ifdef INET6 464 if (pai->ai_family != AF_INET6) 465 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 466 break; 467#endif 468 case AI_ALL: 469 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 470 break; 471 } 472 473 /* 474 * check for special cases. (1) numeric servname is disallowed if 475 * socktype/protocol are left unspecified. (2) servname is disallowed 476 * for raw and other inet{,6} sockets. 477 */ 478 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 479#ifdef PF_INET6 480 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 481#endif 482 ) { 483 ai0 = *pai; /* backup *pai */ 484 485 if (pai->ai_family == PF_UNSPEC) { 486#ifdef PF_INET6 487 pai->ai_family = PF_INET6; 488#else 489 pai->ai_family = PF_INET; 490#endif 491 } 492 error = get_portmatch(pai, servname); 493 if (error) 494 goto bad; 495 496 *pai = ai0; 497 } 498 499 ai0 = *pai; 500 501 /* 502 * NULL hostname, or numeric hostname. 503 * If numeric representation of AF1 can be interpreted as FQDN 504 * representation of AF2, we need to think again about the code below. 505 */ 506 found = 0; 507 for (afd = afdl; afd->a_af; afd++) { 508 *pai = ai0; 509 510 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 511 continue; 512 513 if (pai->ai_family == PF_UNSPEC) 514 pai->ai_family = afd->a_af; 515 516 if (hostname == NULL) { 517 error = explore_null(pai, servname, 518 &afailist[afd - afdl]); 519 520 /* 521 * Errors from explore_null should be unexpected and 522 * be caught to avoid returning an incomplete result. 523 */ 524 if (error != 0) 525 goto bad; 526 } else { 527 error = explore_numeric_scope(pai, hostname, servname, 528 &afailist[afd - afdl]); 529 530 /* 531 * explore_numeric_scope returns an error for address 532 * families that do not match that of hostname. 533 * Thus we should not catch the error at this moment. 534 */ 535 } 536 537 if (!error && afailist[afd - afdl]) 538 found++; 539 } 540 if (found) { 541 numeric = 1; 542 goto globcopy; 543 } 544 545 if (hostname == NULL) 546 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 547 if (pai->ai_flags & AI_NUMERICHOST) 548 ERR(EAI_NONAME); 549 550 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 551 ERR(EAI_FAIL); 552 553 /* 554 * hostname as alphabetical name. 555 */ 556 *pai = ai0; 557 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 558 559globcopy: 560 for (ex = explore; ex->e_af >= 0; ex++) { 561 *pai = ai0; 562 563 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 564 continue; 565 if (!MATCH(pai->ai_socktype, ex->e_socktype, 566 WILD_SOCKTYPE(ex))) 567 continue; 568 if (!MATCH(pai->ai_protocol, ex->e_protocol, 569 WILD_PROTOCOL(ex))) 570 continue; 571 572 if (pai->ai_family == PF_UNSPEC) 573 pai->ai_family = ex->e_af; 574 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 575 pai->ai_socktype = ex->e_socktype; 576 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 577 pai->ai_protocol = ex->e_protocol; 578 579 /* 580 * if the servname does not match socktype/protocol, ignore it. 581 */ 582 if (get_portmatch(pai, servname) != 0) 583 continue; 584 585 if (afai_unspec) 586 afai = afai_unspec; 587 else { 588 if ((afd = find_afd(pai->ai_family)) == NULL) 589 continue; 590 /* XXX assumes that afd points inside afdl[] */ 591 afai = afailist[afd - afdl]; 592 } 593 if (!afai) 594 continue; 595 596 error = explore_copy(pai, afai, &cur->ai_next); 597 if (error != 0) 598 goto bad; 599 600 while (cur && cur->ai_next) 601 cur = cur->ai_next; 602 } 603 604 /* 605 * ensure we return either: 606 * - error == 0, non-NULL *res 607 * - error != 0, NULL *res 608 */ 609 if (error == 0) { 610 if (sentinel.ai_next) { 611 /* 612 * If the returned entry is for an active connection, 613 * and the given name is not numeric, reorder the 614 * list, so that the application would try the list 615 * in the most efficient order. Since the head entry 616 * of the original list may contain ai_canonname and 617 * that entry may be moved elsewhere in the new list, 618 * we keep the pointer and will restore it in the new 619 * head entry. (Note that RFC3493 requires the head 620 * entry store it when requested by the caller). 621 */ 622 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 623 if (!numeric) { 624 char *canonname; 625 626 canonname = 627 sentinel.ai_next->ai_canonname; 628 sentinel.ai_next->ai_canonname = NULL; 629 (void)reorder(&sentinel); 630 if (sentinel.ai_next->ai_canonname == 631 NULL) { 632 sentinel.ai_next->ai_canonname 633 = canonname; 634 } else if (canonname != NULL) 635 free(canonname); 636 } 637 } 638 *res = sentinel.ai_next; 639 } else 640 error = EAI_FAIL; 641 } 642 643bad: 644 if (afai_unspec) 645 freeaddrinfo(afai_unspec); 646 for (afd = afdl; afd->a_af; afd++) { 647 if (afailist[afd - afdl]) 648 freeaddrinfo(afailist[afd - afdl]); 649 } 650 if (!*res) 651 if (sentinel.ai_next) 652 freeaddrinfo(sentinel.ai_next); 653 654 return (error); 655} 656 657static int 658reorder(struct addrinfo *sentinel) 659{ 660 struct addrinfo *ai, **aip; 661 struct ai_order *aio; 662 int i, n; 663 struct policyhead policyhead; 664 665 /* count the number of addrinfo elements for sorting. */ 666 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 667 ; 668 669 /* 670 * If the number is small enough, we can skip the reordering process. 671 */ 672 if (n <= 1) 673 return(n); 674 675 /* allocate a temporary array for sort and initialization of it. */ 676 if ((aio = calloc(n, sizeof(*aio))) == NULL) 677 return(n); /* give up reordering */ 678 679 /* retrieve address selection policy from the kernel */ 680 TAILQ_INIT(&policyhead); 681 if (!get_addrselectpolicy(&policyhead)) { 682 /* no policy is installed into kernel, we don't sort. */ 683 free(aio); 684 return (n); 685 } 686 687 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 688 aio[i].aio_ai = ai; 689 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 690 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 691 &policyhead); 692 set_source(&aio[i], &policyhead); 693 aio[i].aio_initial_sequence = i; 694 } 695 696 /* perform sorting. */ 697 qsort(aio, n, sizeof(*aio), comp_dst); 698 699 /* reorder the addrinfo chain. */ 700 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 701 *aip = aio[i].aio_ai; 702 aip = &aio[i].aio_ai->ai_next; 703 } 704 *aip = NULL; 705 706 /* cleanup and return */ 707 free(aio); 708 free_addrselectpolicy(&policyhead); 709 return(n); 710} 711 712static int 713get_addrselectpolicy(struct policyhead *head) 714{ 715#ifdef INET6 716 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 717 size_t l; 718 char *buf; 719 struct in6_addrpolicy *pol, *ep; 720 721 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 722 return (0); 723 if (l == 0) 724 return (0); 725 if ((buf = malloc(l)) == NULL) 726 return (0); 727 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 728 free(buf); 729 return (0); 730 } 731 732 ep = (struct in6_addrpolicy *)(buf + l); 733 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 734 struct policyqueue *new; 735 736 if ((new = malloc(sizeof(*new))) == NULL) { 737 free_addrselectpolicy(head); /* make the list empty */ 738 break; 739 } 740 new->pc_policy = *pol; 741 TAILQ_INSERT_TAIL(head, new, pc_entry); 742 } 743 744 free(buf); 745 return (1); 746#else 747 return (0); 748#endif 749} 750 751static void 752free_addrselectpolicy(struct policyhead *head) 753{ 754 struct policyqueue *ent, *nent; 755 756 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 757 nent = TAILQ_NEXT(ent, pc_entry); 758 TAILQ_REMOVE(head, ent, pc_entry); 759 free(ent); 760 } 761} 762 763static struct policyqueue * 764match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 765{ 766#ifdef INET6 767 struct policyqueue *ent, *bestent = NULL; 768 struct in6_addrpolicy *pol; 769 int matchlen, bestmatchlen = -1; 770 u_char *mp, *ep, *k, *p, m; 771 struct sockaddr_in6 key; 772 773 switch(addr->sa_family) { 774 case AF_INET6: 775 key = *(struct sockaddr_in6 *)addr; 776 break; 777 case AF_INET: 778 /* convert the address into IPv4-mapped IPv6 address. */ 779 memset(&key, 0, sizeof(key)); 780 key.sin6_family = AF_INET6; 781 key.sin6_len = sizeof(key); 782 _map_v4v6_address( 783 (char *)&((struct sockaddr_in *)addr)->sin_addr, 784 (char *)&key.sin6_addr); 785 break; 786 default: 787 return(NULL); 788 } 789 790 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 791 pol = &ent->pc_policy; 792 matchlen = 0; 793 794 mp = (u_char *)&pol->addrmask.sin6_addr; 795 ep = mp + 16; /* XXX: scope field? */ 796 k = (u_char *)&key.sin6_addr; 797 p = (u_char *)&pol->addr.sin6_addr; 798 for (; mp < ep && *mp; mp++, k++, p++) { 799 m = *mp; 800 if ((*k & m) != *p) 801 goto next; /* not match */ 802 if (m == 0xff) /* short cut for a typical case */ 803 matchlen += 8; 804 else { 805 while (m >= 0x80) { 806 matchlen++; 807 m <<= 1; 808 } 809 } 810 } 811 812 /* matched. check if this is better than the current best. */ 813 if (matchlen > bestmatchlen) { 814 bestent = ent; 815 bestmatchlen = matchlen; 816 } 817 818 next: 819 continue; 820 } 821 822 return(bestent); 823#else 824 return(NULL); 825#endif 826 827} 828 829static void 830set_source(struct ai_order *aio, struct policyhead *ph) 831{ 832 struct addrinfo ai = *aio->aio_ai; 833 struct sockaddr_storage ss; 834 socklen_t srclen; 835 int s; 836 837 /* set unspec ("no source is available"), just in case */ 838 aio->aio_srcsa.sa_family = AF_UNSPEC; 839 aio->aio_srcscope = -1; 840 841 switch(ai.ai_family) { 842 case AF_INET: 843#ifdef INET6 844 case AF_INET6: 845#endif 846 break; 847 default: /* ignore unsupported AFs explicitly */ 848 return; 849 } 850 851 /* XXX: make a dummy addrinfo to call connect() */ 852 ai.ai_socktype = SOCK_DGRAM; 853 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 854 ai.ai_next = NULL; 855 memset(&ss, 0, sizeof(ss)); 856 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 857 ai.ai_addr = (struct sockaddr *)&ss; 858 get_port(&ai, "1", 0); 859 860 /* open a socket to get the source address for the given dst */ 861 if ((s = _socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC, 862 ai.ai_protocol)) < 0) 863 return; /* give up */ 864#ifdef INET6 865 if (ai.ai_family == AF_INET6) { 866 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ai.ai_addr; 867 int off = 0; 868 869 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 870 (void)_setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, 871 (char *)&off, sizeof(off)); 872 } 873#endif 874 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 875 goto cleanup; 876 srclen = ai.ai_addrlen; 877 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 878 aio->aio_srcsa.sa_family = AF_UNSPEC; 879 goto cleanup; 880 } 881 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 882 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 883 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 884#ifdef INET6 885 if (ai.ai_family == AF_INET6) { 886 struct in6_ifreq ifr6; 887 u_int32_t flags6; 888 889 memset(&ifr6, 0, sizeof(ifr6)); 890 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 891 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 892 flags6 = ifr6.ifr_ifru.ifru_flags6; 893 if ((flags6 & IN6_IFF_DEPRECATED)) 894 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 895 } 896 } 897#endif 898 899 cleanup: 900 _close(s); 901 return; 902} 903 904static int 905matchlen(struct sockaddr *src, struct sockaddr *dst) 906{ 907 int match = 0; 908 u_char *s, *d; 909 u_char *lim, r; 910 int addrlen; 911 912 switch (src->sa_family) { 913#ifdef INET6 914 case AF_INET6: 915 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 916 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 917 addrlen = sizeof(struct in6_addr); 918 lim = s + addrlen; 919 break; 920#endif 921 case AF_INET: 922 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 923 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 924 addrlen = sizeof(struct in_addr); 925 lim = s + addrlen; 926 break; 927 default: 928 return(0); 929 } 930 931 while (s < lim) 932 if ((r = (*d++ ^ *s++)) != 0) { 933 while ((r & 0x80) == 0) { 934 match++; 935 r <<= 1; 936 } 937 break; 938 } else 939 match += 8; 940 return(match); 941} 942 943static int 944comp_dst(const void *arg1, const void *arg2) 945{ 946 const struct ai_order *dst1 = arg1, *dst2 = arg2; 947 948 /* 949 * Rule 1: Avoid unusable destinations. 950 * XXX: we currently do not consider if an appropriate route exists. 951 */ 952 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 953 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 954 return(-1); 955 } 956 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 957 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 958 return(1); 959 } 960 961 /* Rule 2: Prefer matching scope. */ 962 if (dst1->aio_dstscope == dst1->aio_srcscope && 963 dst2->aio_dstscope != dst2->aio_srcscope) { 964 return(-1); 965 } 966 if (dst1->aio_dstscope != dst1->aio_srcscope && 967 dst2->aio_dstscope == dst2->aio_srcscope) { 968 return(1); 969 } 970 971 /* Rule 3: Avoid deprecated addresses. */ 972 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 973 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 974 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 975 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 976 return(-1); 977 } 978 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 979 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 980 return(1); 981 } 982 } 983 984 /* Rule 4: Prefer home addresses. */ 985 /* XXX: not implemented yet */ 986 987 /* Rule 5: Prefer matching label. */ 988#ifdef INET6 989 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 990 dst1->aio_srcpolicy->pc_policy.label == 991 dst1->aio_dstpolicy->pc_policy.label && 992 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 993 dst2->aio_srcpolicy->pc_policy.label != 994 dst2->aio_dstpolicy->pc_policy.label)) { 995 return(-1); 996 } 997 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 998 dst2->aio_srcpolicy->pc_policy.label == 999 dst2->aio_dstpolicy->pc_policy.label && 1000 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 1001 dst1->aio_srcpolicy->pc_policy.label != 1002 dst1->aio_dstpolicy->pc_policy.label)) { 1003 return(1); 1004 } 1005#endif 1006 1007 /* Rule 6: Prefer higher precedence. */ 1008#ifdef INET6 1009 if (dst1->aio_dstpolicy && 1010 (dst2->aio_dstpolicy == NULL || 1011 dst1->aio_dstpolicy->pc_policy.preced > 1012 dst2->aio_dstpolicy->pc_policy.preced)) { 1013 return(-1); 1014 } 1015 if (dst2->aio_dstpolicy && 1016 (dst1->aio_dstpolicy == NULL || 1017 dst2->aio_dstpolicy->pc_policy.preced > 1018 dst1->aio_dstpolicy->pc_policy.preced)) { 1019 return(1); 1020 } 1021#endif 1022 1023 /* Rule 7: Prefer native transport. */ 1024 /* XXX: not implemented yet */ 1025 1026 /* Rule 8: Prefer smaller scope. */ 1027 if (dst1->aio_dstscope >= 0 && 1028 dst1->aio_dstscope < dst2->aio_dstscope) { 1029 return(-1); 1030 } 1031 if (dst2->aio_dstscope >= 0 && 1032 dst2->aio_dstscope < dst1->aio_dstscope) { 1033 return(1); 1034 } 1035 1036 /* 1037 * Rule 9: Use longest matching prefix. 1038 * We compare the match length in a same AF only. 1039 */ 1040 if (dst1->aio_ai->ai_addr->sa_family == 1041 dst2->aio_ai->ai_addr->sa_family && 1042 dst1->aio_ai->ai_addr->sa_family != AF_INET) { 1043 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1044 return(-1); 1045 } 1046 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1047 return(1); 1048 } 1049 } 1050 1051 /* Rule 10: Otherwise, leave the order unchanged. */ 1052 1053 /* 1054 * Note that qsort is unstable; so, we can't return zero and 1055 * expect the order to be unchanged. 1056 * That also means we can't depend on the current position of 1057 * dst2 being after dst1. We must enforce the initial order 1058 * with an explicit compare on the original position. 1059 * The qsort specification requires that "When the same objects 1060 * (consisting of width bytes, irrespective of their current 1061 * positions in the array) are passed more than once to the 1062 * comparison function, the results shall be consistent with one 1063 * another." 1064 * In other words, If A < B, then we must also return B > A. 1065 */ 1066 if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) 1067 return(1); 1068 1069 return(-1); 1070} 1071 1072/* 1073 * Copy from scope.c. 1074 * XXX: we should standardize the functions and link them as standard 1075 * library. 1076 */ 1077static int 1078gai_addr2scopetype(struct sockaddr *sa) 1079{ 1080#ifdef INET6 1081 struct sockaddr_in6 *sa6; 1082#endif 1083 struct sockaddr_in *sa4; 1084 1085 switch(sa->sa_family) { 1086#ifdef INET6 1087 case AF_INET6: 1088 sa6 = (struct sockaddr_in6 *)sa; 1089 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1090 /* just use the scope field of the multicast address */ 1091 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1092 } 1093 /* 1094 * Unicast addresses: map scope type to corresponding scope 1095 * value defined for multcast addresses. 1096 * XXX: hardcoded scope type values are bad... 1097 */ 1098 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1099 return(1); /* node local scope */ 1100 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1101 return(2); /* link-local scope */ 1102 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1103 return(5); /* site-local scope */ 1104 return(14); /* global scope */ 1105 break; 1106#endif 1107 case AF_INET: 1108 /* 1109 * IPv4 pseudo scoping according to RFC 3484. 1110 */ 1111 sa4 = (struct sockaddr_in *)sa; 1112 /* IPv4 autoconfiguration addresses have link-local scope. */ 1113 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1114 ((u_char *)&sa4->sin_addr)[1] == 254) 1115 return(2); 1116 /* Private addresses have site-local scope. */ 1117 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1118 (((u_char *)&sa4->sin_addr)[0] == 172 && 1119 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1120 (((u_char *)&sa4->sin_addr)[0] == 192 && 1121 ((u_char *)&sa4->sin_addr)[1] == 168)) 1122 return(14); /* XXX: It should be 5 unless NAT */ 1123 /* Loopback addresses have link-local scope. */ 1124 if (((u_char *)&sa4->sin_addr)[0] == 127) 1125 return(2); 1126 return(14); 1127 break; 1128 default: 1129 errno = EAFNOSUPPORT; /* is this a good error? */ 1130 return(-1); 1131 } 1132} 1133 1134static int 1135explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1136 struct addrinfo **res) 1137{ 1138 int error; 1139 struct addrinfo sentinel, *cur; 1140 const struct addrinfo *src; 1141 1142 error = 0; 1143 sentinel.ai_next = NULL; 1144 cur = &sentinel; 1145 1146 for (src = src0; src != NULL; src = src->ai_next) { 1147 if (src->ai_family != pai->ai_family) 1148 continue; 1149 1150 cur->ai_next = copy_ai(src); 1151 if (!cur->ai_next) { 1152 error = EAI_MEMORY; 1153 goto fail; 1154 } 1155 1156 cur->ai_next->ai_socktype = pai->ai_socktype; 1157 cur->ai_next->ai_protocol = pai->ai_protocol; 1158 cur = cur->ai_next; 1159 } 1160 1161 *res = sentinel.ai_next; 1162 return 0; 1163 1164fail: 1165 freeaddrinfo(sentinel.ai_next); 1166 return error; 1167} 1168 1169/* 1170 * hostname == NULL. 1171 * passive socket -> anyaddr (0.0.0.0 or ::) 1172 * non-passive socket -> localhost (127.0.0.1 or ::1) 1173 */ 1174static int 1175explore_null(const struct addrinfo *pai, const char *servname, 1176 struct addrinfo **res) 1177{ 1178 int s; 1179 const struct afd *afd; 1180 struct addrinfo *ai; 1181 int error; 1182 1183 *res = NULL; 1184 ai = NULL; 1185 1186 /* 1187 * filter out AFs that are not supported by the kernel 1188 * XXX errno? 1189 */ 1190 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1191 if (s < 0) { 1192 if (errno != EMFILE) 1193 return 0; 1194 } else 1195 _close(s); 1196 1197 afd = find_afd(pai->ai_family); 1198 if (afd == NULL) 1199 return 0; 1200 1201 if (pai->ai_flags & AI_PASSIVE) { 1202 GET_AI(ai, afd, afd->a_addrany); 1203 GET_PORT(ai, servname); 1204 } else { 1205 GET_AI(ai, afd, afd->a_loopback); 1206 GET_PORT(ai, servname); 1207 } 1208 1209 *res = ai; 1210 return 0; 1211 1212free: 1213 if (ai != NULL) 1214 freeaddrinfo(ai); 1215 return error; 1216} 1217 1218/* 1219 * numeric hostname 1220 */ 1221static int 1222explore_numeric(const struct addrinfo *pai, const char *hostname, 1223 const char *servname, struct addrinfo **res, const char *canonname) 1224{ 1225 const struct afd *afd; 1226 struct addrinfo *ai, ai0; 1227 int error; 1228 char pton[PTON_MAX]; 1229 1230 *res = NULL; 1231 ai = NULL; 1232 1233 afd = find_afd(pai->ai_family); 1234 if (afd == NULL) 1235 return 0; 1236 1237 switch (afd->a_af) { 1238 case AF_INET: 1239 /* 1240 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1241 * that are accepted by inet_addr() and its family. The 1242 * accepted forms includes the "classful" one, which inet_pton 1243 * does not accept. So we need to separate the case for 1244 * AF_INET. 1245 */ 1246 if (inet_aton(hostname, (struct in_addr *)pton) != 1 || 1247 hostname[strspn(hostname, "0123456789.xabcdefXABCDEF")] != '\0') 1248 return 0; 1249 break; 1250 default: 1251 if (inet_pton(afd->a_af, hostname, pton) != 1) { 1252 if (pai->ai_family != AF_INET6 || 1253 (pai->ai_flags & AI_V4MAPPED) != AI_V4MAPPED) 1254 return 0; 1255 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1256 return 0; 1257 afd = &afdl[N_INET]; 1258 ai0 = *pai; 1259 ai0.ai_family = AF_INET; 1260 pai = &ai0; 1261 } 1262 break; 1263 } 1264 1265 if (pai->ai_family == afd->a_af) { 1266 GET_AI(ai, afd, pton); 1267 GET_PORT(ai, servname); 1268 if ((pai->ai_flags & AI_CANONNAME)) { 1269 /* 1270 * Set the numeric address itself as the canonical 1271 * name, based on a clarification in RFC3493. 1272 */ 1273 GET_CANONNAME(ai, canonname); 1274 } 1275 } else { 1276 /* 1277 * XXX: This should not happen since we already matched the AF 1278 * by find_afd. 1279 */ 1280 ERR(EAI_FAMILY); 1281 } 1282 1283 *res = ai; 1284 return 0; 1285 1286free: 1287bad: 1288 if (ai != NULL) 1289 freeaddrinfo(ai); 1290 return error; 1291} 1292 1293/* 1294 * numeric hostname with scope 1295 */ 1296static int 1297explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1298 const char *servname, struct addrinfo **res) 1299{ 1300#if !defined(SCOPE_DELIMITER) || !defined(INET6) 1301 return explore_numeric(pai, hostname, servname, res, hostname); 1302#else 1303 const struct afd *afd; 1304 struct addrinfo *cur; 1305 int error; 1306 char *cp, *hostname2 = NULL, *scope, *addr; 1307 struct sockaddr_in6 *sin6; 1308 1309 afd = find_afd(pai->ai_family); 1310 if (afd == NULL) 1311 return 0; 1312 1313 if (!afd->a_scoped) 1314 return explore_numeric(pai, hostname, servname, res, hostname); 1315 1316 cp = strchr(hostname, SCOPE_DELIMITER); 1317 if (cp == NULL) 1318 return explore_numeric(pai, hostname, servname, res, hostname); 1319 1320 /* 1321 * Handle special case of <scoped_address><delimiter><scope id> 1322 */ 1323 hostname2 = strdup(hostname); 1324 if (hostname2 == NULL) 1325 return EAI_MEMORY; 1326 /* terminate at the delimiter */ 1327 hostname2[cp - hostname] = '\0'; 1328 addr = hostname2; 1329 scope = cp + 1; 1330 1331 error = explore_numeric(pai, addr, servname, res, hostname); 1332 if (error == 0) { 1333 u_int32_t scopeid; 1334 1335 for (cur = *res; cur; cur = cur->ai_next) { 1336 if (cur->ai_family != AF_INET6) 1337 continue; 1338 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1339 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1340 free(hostname2); 1341 freeaddrinfo(*res); 1342 *res = NULL; 1343 return(EAI_NONAME); /* XXX: is return OK? */ 1344 } 1345 sin6->sin6_scope_id = scopeid; 1346 } 1347 } 1348 1349 free(hostname2); 1350 1351 if (error && *res) { 1352 freeaddrinfo(*res); 1353 *res = NULL; 1354 } 1355 return error; 1356#endif 1357} 1358 1359static int 1360get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1361{ 1362 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1363 ai->ai_canonname = strdup(str); 1364 if (ai->ai_canonname == NULL) 1365 return EAI_MEMORY; 1366 } 1367 return 0; 1368} 1369 1370static struct addrinfo * 1371get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1372{ 1373 char *p; 1374 struct addrinfo *ai; 1375#ifdef FAITH 1376 struct in6_addr faith_prefix; 1377 char *fp_str; 1378 int translate = 0; 1379#endif 1380#ifdef INET6 1381 struct in6_addr mapaddr; 1382#endif 1383 1384#ifdef FAITH 1385 /* 1386 * Transfrom an IPv4 addr into a special IPv6 addr format for 1387 * IPv6->IPv4 translation gateway. (only TCP is supported now) 1388 * 1389 * +-----------------------------------+------------+ 1390 * | faith prefix part (12 bytes) | embedded | 1391 * | | IPv4 addr part (4 bytes) 1392 * +-----------------------------------+------------+ 1393 * 1394 * faith prefix part is specified as ascii IPv6 addr format 1395 * in environmental variable GAI. 1396 * For FAITH to work correctly, routing to faith prefix must be 1397 * setup toward a machine where a FAITH daemon operates. 1398 * Also, the machine must enable some mechanizm 1399 * (e.g. faith interface hack) to divert those packet with 1400 * faith prefixed destination addr to user-land FAITH daemon. 1401 */ 1402 fp_str = getenv("GAI"); 1403 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 1404 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 1405 u_int32_t v4a; 1406 u_int8_t v4a_top; 1407 1408 memcpy(&v4a, addr, sizeof v4a); 1409 v4a_top = v4a >> IN_CLASSA_NSHIFT; 1410 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 1411 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 1412 afd = &afdl[N_INET6]; 1413 memcpy(&faith_prefix.s6_addr[12], addr, 1414 sizeof(struct in_addr)); 1415 translate = 1; 1416 } 1417 } 1418#endif 1419 1420#ifdef INET6 1421 if (afd->a_af == AF_INET && (pai->ai_flags & AI_V4MAPPED) != 0) { 1422 afd = &afdl[N_INET6]; 1423 _map_v4v6_address(addr, (char *)&mapaddr); 1424 addr = (char *)&mapaddr; 1425 } 1426#endif 1427 1428 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1429 + (afd->a_socklen)); 1430 if (ai == NULL) 1431 return NULL; 1432 1433 memcpy(ai, pai, sizeof(struct addrinfo)); 1434 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1435 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1436 ai->ai_addr->sa_len = afd->a_socklen; 1437 ai->ai_addrlen = afd->a_socklen; 1438 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1439 p = (char *)(void *)(ai->ai_addr); 1440#ifdef FAITH 1441 if (translate == 1) 1442 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 1443 else 1444#endif 1445 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1446 return ai; 1447} 1448 1449/* XXX need to malloc() the same way we do from other functions! */ 1450static struct addrinfo * 1451copy_ai(const struct addrinfo *pai) 1452{ 1453 struct addrinfo *ai; 1454 size_t l; 1455 1456 l = sizeof(*ai) + pai->ai_addrlen; 1457 if ((ai = calloc(1, l)) == NULL) 1458 return NULL; 1459 memcpy(ai, pai, sizeof(*ai)); 1460 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1461 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1462 1463 if (pai->ai_canonname) { 1464 l = strlen(pai->ai_canonname) + 1; 1465 if ((ai->ai_canonname = malloc(l)) == NULL) { 1466 free(ai); 1467 return NULL; 1468 } 1469 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1470 } else { 1471 /* just to make sure */ 1472 ai->ai_canonname = NULL; 1473 } 1474 1475 ai->ai_next = NULL; 1476 1477 return ai; 1478} 1479 1480static int 1481get_portmatch(const struct addrinfo *ai, const char *servname) 1482{ 1483 1484 /* get_port does not touch first argument when matchonly == 1. */ 1485 /* LINTED const cast */ 1486 return get_port((struct addrinfo *)ai, servname, 1); 1487} 1488 1489static int 1490get_port(struct addrinfo *ai, const char *servname, int matchonly) 1491{ 1492 const char *proto; 1493 struct servent *sp; 1494 int port, error; 1495 int allownumeric; 1496 1497 if (servname == NULL) 1498 return 0; 1499 switch (ai->ai_family) { 1500 case AF_INET: 1501#ifdef AF_INET6 1502 case AF_INET6: 1503#endif 1504 break; 1505 default: 1506 return 0; 1507 } 1508 1509 switch (ai->ai_socktype) { 1510 case SOCK_RAW: 1511 return EAI_SERVICE; 1512 case SOCK_DGRAM: 1513 case SOCK_STREAM: 1514 case SOCK_SEQPACKET: 1515 allownumeric = 1; 1516 break; 1517 case ANY: 1518 switch (ai->ai_family) { 1519 case AF_INET: 1520#ifdef AF_INET6 1521 case AF_INET6: 1522#endif 1523 allownumeric = 1; 1524 break; 1525 default: 1526 allownumeric = 0; 1527 break; 1528 } 1529 break; 1530 default: 1531 return EAI_SOCKTYPE; 1532 } 1533 1534 error = str2number(servname, &port); 1535 if (error == 0) { 1536 if (!allownumeric) 1537 return EAI_SERVICE; 1538 if (port < 0 || port > 65535) 1539 return EAI_SERVICE; 1540 port = htons(port); 1541 } else { 1542 if (ai->ai_flags & AI_NUMERICSERV) 1543 return EAI_NONAME; 1544 1545 switch (ai->ai_protocol) { 1546 case IPPROTO_UDP: 1547 proto = "udp"; 1548 break; 1549 case IPPROTO_TCP: 1550 proto = "tcp"; 1551 break; 1552 case IPPROTO_SCTP: 1553 proto = "sctp"; 1554 break; 1555 case IPPROTO_UDPLITE: 1556 proto = "udplite"; 1557 break; 1558 default: 1559 proto = NULL; 1560 break; 1561 } 1562 1563 if ((sp = getservbyname(servname, proto)) == NULL) 1564 return EAI_SERVICE; 1565 port = sp->s_port; 1566 } 1567 1568 if (!matchonly) { 1569 switch (ai->ai_family) { 1570 case AF_INET: 1571 ((struct sockaddr_in *)(void *) 1572 ai->ai_addr)->sin_port = port; 1573 break; 1574#ifdef INET6 1575 case AF_INET6: 1576 ((struct sockaddr_in6 *)(void *) 1577 ai->ai_addr)->sin6_port = port; 1578 break; 1579#endif 1580 } 1581 } 1582 1583 return 0; 1584} 1585 1586static const struct afd * 1587find_afd(int af) 1588{ 1589 const struct afd *afd; 1590 1591 if (af == PF_UNSPEC) 1592 return NULL; 1593 for (afd = afdl; afd->a_af; afd++) { 1594 if (afd->a_af == af) 1595 return afd; 1596 } 1597 return NULL; 1598} 1599 1600/* 1601 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are 1602 * configured on the local system and correlates with pai->ai_family value. 1603 * If an address family is not configured on the system, it will not be 1604 * queried for. For this purpose, loopback addresses are not considered 1605 * configured addresses. 1606 * 1607 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1608 * _dns_getaddrinfo. 1609 */ 1610static int 1611addrconfig(struct addrinfo *pai) 1612{ 1613 struct ifaddrs *ifaddrs, *ifa; 1614 struct sockaddr_in *sin; 1615#ifdef INET6 1616 struct sockaddr_in6 *sin6; 1617#endif 1618 int seen_inet = 0, seen_inet6 = 0; 1619 1620 if (getifaddrs(&ifaddrs) != 0) 1621 return (0); 1622 1623 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1624 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1625 continue; 1626 switch (ifa->ifa_addr->sa_family) { 1627 case AF_INET: 1628 if (seen_inet) 1629 continue; 1630 sin = (struct sockaddr_in *)(ifa->ifa_addr); 1631 if (htonl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) 1632 continue; 1633 seen_inet = 1; 1634 break; 1635#ifdef INET6 1636 case AF_INET6: 1637 if (seen_inet6) 1638 continue; 1639 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); 1640 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 1641 continue; 1642 if ((ifa->ifa_flags & IFT_LOOP) != 0 && 1643 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 1644 continue; 1645 if (is_ifdisabled(ifa->ifa_name)) 1646 continue; 1647 seen_inet6 = 1; 1648 break; 1649#endif 1650 } 1651 } 1652 freeifaddrs(ifaddrs); 1653 1654 switch(pai->ai_family) { 1655 case AF_INET6: 1656 return (seen_inet6); 1657 case AF_INET: 1658 return (seen_inet); 1659 case AF_UNSPEC: 1660 if (seen_inet == seen_inet6) 1661 return (seen_inet); 1662 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1663 return (1); 1664 } 1665 return (1); 1666} 1667 1668#ifdef INET6 1669static int 1670is_ifdisabled(char *name) 1671{ 1672 struct in6_ndireq nd; 1673 int fd; 1674 1675 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1676 return (-1); 1677 memset(&nd, 0, sizeof(nd)); 1678 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1679 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1680 _close(fd); 1681 return (-1); 1682 } 1683 _close(fd); 1684 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1685} 1686 1687/* convert a string to a scope identifier. XXX: IPv6 specific */ 1688static int 1689ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1690{ 1691 u_long lscopeid; 1692 struct in6_addr *a6; 1693 char *ep; 1694 1695 a6 = &sin6->sin6_addr; 1696 1697 /* empty scopeid portion is invalid */ 1698 if (*scope == '\0') 1699 return -1; 1700 1701 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1702 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1703 /* 1704 * We currently assume a one-to-one mapping between links 1705 * and interfaces, so we simply use interface indices for 1706 * like-local scopes. 1707 */ 1708 *scopeid = if_nametoindex(scope); 1709 if (*scopeid == 0) 1710 goto trynumeric; 1711 return 0; 1712 } 1713 1714 /* still unclear about literal, allow numeric only - placeholder */ 1715 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1716 goto trynumeric; 1717 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1718 goto trynumeric; 1719 else 1720 goto trynumeric; /* global */ 1721 1722 /* try to convert to a numeric id as a last resort */ 1723 trynumeric: 1724 errno = 0; 1725 lscopeid = strtoul(scope, &ep, 10); 1726 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1727 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1728 return 0; 1729 else 1730 return -1; 1731} 1732#endif 1733 1734 1735#ifdef NS_CACHING 1736static int 1737addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1738 void *cache_mdata) 1739{ 1740 res_state statp; 1741 u_long res_options; 1742 1743 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1744 char *hostname; 1745 struct addrinfo *hints; 1746 1747 char *p; 1748 int ai_flags, ai_family, ai_socktype, ai_protocol; 1749 size_t desired_size, size; 1750 1751 statp = __res_state(); 1752 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1753 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1754 1755 hostname = va_arg(ap, char *); 1756 hints = va_arg(ap, struct addrinfo *); 1757 1758 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1759 if (hostname != NULL) { 1760 size = strlen(hostname); 1761 desired_size += size + 1; 1762 } else 1763 size = 0; 1764 1765 if (desired_size > *buffer_size) { 1766 *buffer_size = desired_size; 1767 return (NS_RETURN); 1768 } 1769 1770 if (hints == NULL) 1771 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1772 else { 1773 ai_flags = hints->ai_flags; 1774 ai_family = hints->ai_family; 1775 ai_socktype = hints->ai_socktype; 1776 ai_protocol = hints->ai_protocol; 1777 } 1778 1779 p = buffer; 1780 memcpy(p, &res_options, sizeof(res_options)); 1781 p += sizeof(res_options); 1782 1783 memcpy(p, &op_id, sizeof(int)); 1784 p += sizeof(int); 1785 1786 memcpy(p, &ai_flags, sizeof(int)); 1787 p += sizeof(int); 1788 1789 memcpy(p, &ai_family, sizeof(int)); 1790 p += sizeof(int); 1791 1792 memcpy(p, &ai_socktype, sizeof(int)); 1793 p += sizeof(int); 1794 1795 memcpy(p, &ai_protocol, sizeof(int)); 1796 p += sizeof(int); 1797 1798 if (hostname != NULL) 1799 memcpy(p, hostname, size); 1800 1801 *buffer_size = desired_size; 1802 return (NS_SUCCESS); 1803} 1804 1805static int 1806addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1807 va_list ap, void *cache_mdata) 1808{ 1809 struct addrinfo *ai, *cai; 1810 char *p; 1811 size_t desired_size, size, ai_size; 1812 1813 ai = *((struct addrinfo **)retval); 1814 1815 desired_size = sizeof(size_t); 1816 ai_size = 0; 1817 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1818 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1819 if (cai->ai_canonname != NULL) 1820 desired_size += sizeof(size_t) + 1821 strlen(cai->ai_canonname); 1822 ++ai_size; 1823 } 1824 1825 if (desired_size > *buffer_size) { 1826 /* this assignment is here for future use */ 1827 errno = ERANGE; 1828 *buffer_size = desired_size; 1829 return (NS_RETURN); 1830 } 1831 1832 memset(buffer, 0, desired_size); 1833 p = buffer; 1834 1835 memcpy(p, &ai_size, sizeof(size_t)); 1836 p += sizeof(size_t); 1837 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1838 memcpy(p, cai, sizeof(struct addrinfo)); 1839 p += sizeof(struct addrinfo); 1840 1841 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1842 p += cai->ai_addrlen; 1843 1844 if (cai->ai_canonname != NULL) { 1845 size = strlen(cai->ai_canonname); 1846 memcpy(p, &size, sizeof(size_t)); 1847 p += sizeof(size_t); 1848 1849 memcpy(p, cai->ai_canonname, size); 1850 p += size; 1851 } 1852 } 1853 1854 return (NS_SUCCESS); 1855} 1856 1857static int 1858addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1859 va_list ap, void *cache_mdata) 1860{ 1861 struct addrinfo new_ai, *result, *sentinel, *lasts; 1862 1863 char *p; 1864 size_t ai_size, ai_i, size; 1865 1866 p = buffer; 1867 memcpy(&ai_size, p, sizeof(size_t)); 1868 p += sizeof(size_t); 1869 1870 result = NULL; 1871 lasts = NULL; 1872 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1873 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1874 p += sizeof(struct addrinfo); 1875 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1876 _ALIGNBYTES; 1877 1878 sentinel = calloc(1, size); 1879 1880 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1881 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1882 sizeof(struct addrinfo)); 1883 1884 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1885 p += new_ai.ai_addrlen; 1886 1887 if (new_ai.ai_canonname != NULL) { 1888 memcpy(&size, p, sizeof(size_t)); 1889 p += sizeof(size_t); 1890 1891 sentinel->ai_canonname = calloc(1, size + 1); 1892 1893 memcpy(sentinel->ai_canonname, p, size); 1894 p += size; 1895 } 1896 1897 if (result == NULL) { 1898 result = sentinel; 1899 lasts = sentinel; 1900 } else { 1901 lasts->ai_next = sentinel; 1902 lasts = sentinel; 1903 } 1904 } 1905 1906 *((struct addrinfo **)retval) = result; 1907 return (NS_SUCCESS); 1908} 1909#endif /* NS_CACHING */ 1910 1911/* 1912 * FQDN hostname, DNS lookup 1913 */ 1914static int 1915explore_fqdn(const struct addrinfo *pai, const char *hostname, 1916 const char *servname, struct addrinfo **res) 1917{ 1918 struct addrinfo *result; 1919 struct addrinfo *cur; 1920 int error = 0; 1921 1922#ifdef NS_CACHING 1923 static const nss_cache_info cache_info = 1924 NS_COMMON_CACHE_INFO_INITIALIZER( 1925 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1926 addrinfo_unmarshal_func); 1927#endif 1928 static const ns_dtab dtab[] = { 1929 NS_FILES_CB(_files_getaddrinfo, NULL) 1930 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1931 NS_NIS_CB(_yp_getaddrinfo, NULL) 1932#ifdef NS_CACHING 1933 NS_CACHE_CB(&cache_info) 1934#endif 1935 { 0 } 1936 }; 1937 1938 result = NULL; 1939 1940 /* 1941 * if the servname does not match socktype/protocol, ignore it. 1942 */ 1943 if (get_portmatch(pai, servname) != 0) 1944 return 0; 1945 1946 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1947 default_dns_files, hostname, pai)) { 1948 case NS_TRYAGAIN: 1949 error = EAI_AGAIN; 1950 goto free; 1951 case NS_UNAVAIL: 1952 error = EAI_FAIL; 1953 goto free; 1954 case NS_NOTFOUND: 1955 error = EAI_NONAME; 1956 goto free; 1957 case NS_SUCCESS: 1958 error = 0; 1959 for (cur = result; cur; cur = cur->ai_next) { 1960 GET_PORT(cur, servname); 1961 /* canonname should be filled already */ 1962 } 1963 break; 1964 } 1965 1966 *res = result; 1967 1968 return 0; 1969 1970free: 1971 if (result) 1972 freeaddrinfo(result); 1973 return error; 1974} 1975 1976#ifdef DEBUG 1977static const char AskedForGot[] = 1978 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1979#endif 1980 1981static struct addrinfo * 1982getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1983 const struct addrinfo *pai, res_state res) 1984{ 1985 struct addrinfo sentinel, *cur; 1986 struct addrinfo ai; 1987 const struct afd *afd; 1988 char *canonname; 1989 const HEADER *hp; 1990 const u_char *cp; 1991 int n; 1992 const u_char *eom; 1993 char *bp, *ep; 1994 int type, class, ancount, qdcount; 1995 int haveanswer, had_error; 1996 char tbuf[MAXDNAME]; 1997 int (*name_ok)(const char *); 1998 char hostbuf[8*1024]; 1999 2000 memset(&sentinel, 0, sizeof(sentinel)); 2001 cur = &sentinel; 2002 2003 canonname = NULL; 2004 eom = answer->buf + anslen; 2005 switch (qtype) { 2006 case T_A: 2007 case T_AAAA: 2008 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 2009 name_ok = res_hnok; 2010 break; 2011 default: 2012 return (NULL); /* XXX should be abort(); */ 2013 } 2014 /* 2015 * find first satisfactory answer 2016 */ 2017 hp = &answer->hdr; 2018 ancount = ntohs(hp->ancount); 2019 qdcount = ntohs(hp->qdcount); 2020 bp = hostbuf; 2021 ep = hostbuf + sizeof hostbuf; 2022 cp = answer->buf + HFIXEDSZ; 2023 if (qdcount != 1) { 2024 RES_SET_H_ERRNO(res, NO_RECOVERY); 2025 return (NULL); 2026 } 2027 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2028 if ((n < 0) || !(*name_ok)(bp)) { 2029 RES_SET_H_ERRNO(res, NO_RECOVERY); 2030 return (NULL); 2031 } 2032 cp += n + QFIXEDSZ; 2033 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 2034 /* res_send() has already verified that the query name is the 2035 * same as the one we sent; this just gets the expanded name 2036 * (i.e., with the succeeding search-domain tacked on). 2037 */ 2038 n = strlen(bp) + 1; /* for the \0 */ 2039 if (n >= MAXHOSTNAMELEN) { 2040 RES_SET_H_ERRNO(res, NO_RECOVERY); 2041 return (NULL); 2042 } 2043 canonname = bp; 2044 bp += n; 2045 /* The qname can be abbreviated, but h_name is now absolute. */ 2046 qname = canonname; 2047 } 2048 haveanswer = 0; 2049 had_error = 0; 2050 while (ancount-- > 0 && cp < eom && !had_error) { 2051 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2052 if ((n < 0) || !(*name_ok)(bp)) { 2053 had_error++; 2054 continue; 2055 } 2056 cp += n; /* name */ 2057 type = _getshort(cp); 2058 cp += INT16SZ; /* type */ 2059 class = _getshort(cp); 2060 cp += INT16SZ + INT32SZ; /* class, TTL */ 2061 n = _getshort(cp); 2062 cp += INT16SZ; /* len */ 2063 if (class != C_IN) { 2064 /* XXX - debug? syslog? */ 2065 cp += n; 2066 continue; /* XXX - had_error++ ? */ 2067 } 2068 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 2069 type == T_CNAME) { 2070 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 2071 if ((n < 0) || !(*name_ok)(tbuf)) { 2072 had_error++; 2073 continue; 2074 } 2075 cp += n; 2076 /* Get canonical name. */ 2077 n = strlen(tbuf) + 1; /* for the \0 */ 2078 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 2079 had_error++; 2080 continue; 2081 } 2082 strlcpy(bp, tbuf, ep - bp); 2083 canonname = bp; 2084 bp += n; 2085 continue; 2086 } 2087 if (qtype == T_ANY) { 2088 if (!(type == T_A || type == T_AAAA)) { 2089 cp += n; 2090 continue; 2091 } 2092 } else if (type != qtype) { 2093#ifdef DEBUG 2094 if (type != T_KEY && type != T_SIG && 2095 type != ns_t_dname) 2096 syslog(LOG_NOTICE|LOG_AUTH, 2097 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2098 qname, p_class(C_IN), p_type(qtype), 2099 p_type(type)); 2100#endif 2101 cp += n; 2102 continue; /* XXX - had_error++ ? */ 2103 } 2104 switch (type) { 2105 case T_A: 2106 case T_AAAA: 2107 if (strcasecmp(canonname, bp) != 0) { 2108#ifdef DEBUG 2109 syslog(LOG_NOTICE|LOG_AUTH, 2110 AskedForGot, canonname, bp); 2111#endif 2112 cp += n; 2113 continue; /* XXX - had_error++ ? */ 2114 } 2115 if (type == T_A && n != INADDRSZ) { 2116 cp += n; 2117 continue; 2118 } 2119 if (type == T_AAAA && n != IN6ADDRSZ) { 2120 cp += n; 2121 continue; 2122 } 2123#ifdef FILTER_V4MAPPED 2124 if (type == T_AAAA) { 2125 struct in6_addr in6; 2126 memcpy(&in6, cp, sizeof(in6)); 2127 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2128 cp += n; 2129 continue; 2130 } 2131 } 2132#endif 2133 if (!haveanswer) { 2134 int nn; 2135 2136 canonname = bp; 2137 nn = strlen(bp) + 1; /* for the \0 */ 2138 bp += nn; 2139 } 2140 2141 /* don't overwrite pai */ 2142 ai = *pai; 2143 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2144 afd = find_afd(ai.ai_family); 2145 if (afd == NULL) { 2146 cp += n; 2147 continue; 2148 } 2149 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2150 if (cur->ai_next == NULL) 2151 had_error++; 2152 while (cur && cur->ai_next) 2153 cur = cur->ai_next; 2154 cp += n; 2155 break; 2156 default: 2157 abort(); 2158 } 2159 if (!had_error) 2160 haveanswer++; 2161 } 2162 if (haveanswer) { 2163#if defined(RESOLVSORT) 2164 /* 2165 * We support only IPv4 address for backward 2166 * compatibility against gethostbyname(3). 2167 */ 2168 if (res->nsort && qtype == T_A) { 2169 if (addr4sort(&sentinel, res) < 0) { 2170 freeaddrinfo(sentinel.ai_next); 2171 RES_SET_H_ERRNO(res, NO_RECOVERY); 2172 return NULL; 2173 } 2174 } 2175#endif /*RESOLVSORT*/ 2176 if (!canonname) 2177 (void)get_canonname(pai, sentinel.ai_next, qname); 2178 else 2179 (void)get_canonname(pai, sentinel.ai_next, canonname); 2180 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2181 return sentinel.ai_next; 2182 } 2183 2184 /* 2185 * We could have walked a CNAME chain, but the ultimate target 2186 * may not have what we looked for. 2187 */ 2188 RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : NO_RECOVERY); 2189 return NULL; 2190} 2191 2192#ifdef RESOLVSORT 2193struct addr_ptr { 2194 struct addrinfo *ai; 2195 int aval; 2196}; 2197 2198static int 2199addr4sort(struct addrinfo *sentinel, res_state res) 2200{ 2201 struct addrinfo *ai; 2202 struct addr_ptr *addrs, addr; 2203 struct sockaddr_in *sin; 2204 int naddrs, i, j; 2205 int needsort = 0; 2206 2207 if (!sentinel) 2208 return -1; 2209 naddrs = 0; 2210 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2211 naddrs++; 2212 if (naddrs < 2) 2213 return 0; /* We don't need sorting. */ 2214 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2215 return -1; 2216 i = 0; 2217 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2218 sin = (struct sockaddr_in *)ai->ai_addr; 2219 for (j = 0; (unsigned)j < res->nsort; j++) { 2220 if (res->sort_list[j].addr.s_addr == 2221 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2222 break; 2223 } 2224 addrs[i].ai = ai; 2225 addrs[i].aval = j; 2226 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2227 needsort = i; 2228 i++; 2229 } 2230 if (!needsort) { 2231 free(addrs); 2232 return 0; 2233 } 2234 2235 while (needsort < naddrs) { 2236 for (j = needsort - 1; j >= 0; j--) { 2237 if (addrs[j].aval > addrs[j+1].aval) { 2238 addr = addrs[j]; 2239 addrs[j] = addrs[j + 1]; 2240 addrs[j + 1] = addr; 2241 } else 2242 break; 2243 } 2244 needsort++; 2245 } 2246 2247 ai = sentinel; 2248 for (i = 0; i < naddrs; ++i) { 2249 ai->ai_next = addrs[i].ai; 2250 ai = ai->ai_next; 2251 } 2252 ai->ai_next = NULL; 2253 free(addrs); 2254 return 0; 2255} 2256#endif /*RESOLVSORT*/ 2257 2258/*ARGSUSED*/ 2259static int 2260_dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2261{ 2262 struct addrinfo *ai, ai0; 2263 querybuf *buf, *buf2; 2264 const char *hostname; 2265 const struct addrinfo *pai; 2266 struct addrinfo sentinel, *cur; 2267 struct res_target q, q2; 2268 res_state res; 2269 2270 ai = NULL; 2271 2272 hostname = va_arg(ap, char *); 2273 pai = va_arg(ap, const struct addrinfo *); 2274 2275 memset(&q, 0, sizeof(q)); 2276 memset(&q2, 0, sizeof(q2)); 2277 memset(&sentinel, 0, sizeof(sentinel)); 2278 cur = &sentinel; 2279 2280 res = __res_state(); 2281 2282 buf = malloc(sizeof(*buf)); 2283 if (!buf) { 2284 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2285 return NS_NOTFOUND; 2286 } 2287 buf2 = malloc(sizeof(*buf2)); 2288 if (!buf2) { 2289 free(buf); 2290 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2291 return NS_NOTFOUND; 2292 } 2293 2294 if (pai->ai_family == AF_INET6 && 2295 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) { 2296 ai0 = *pai; 2297 ai0.ai_family = AF_UNSPEC; 2298 pai = &ai0; 2299 } 2300 2301 switch (pai->ai_family) { 2302 case AF_UNSPEC: 2303 q.name = hostname; 2304 q.qclass = C_IN; 2305 q.qtype = T_A; 2306 q.answer = buf->buf; 2307 q.anslen = sizeof(buf->buf); 2308 q.next = &q2; 2309 q2.name = hostname; 2310 q2.qclass = C_IN; 2311 q2.qtype = T_AAAA; 2312 q2.answer = buf2->buf; 2313 q2.anslen = sizeof(buf2->buf); 2314 break; 2315 case AF_INET: 2316 q.name = hostname; 2317 q.qclass = C_IN; 2318 q.qtype = T_A; 2319 q.answer = buf->buf; 2320 q.anslen = sizeof(buf->buf); 2321 break; 2322 case AF_INET6: 2323 q.name = hostname; 2324 q.qclass = C_IN; 2325 q.qtype = T_AAAA; 2326 q.answer = buf->buf; 2327 q.anslen = sizeof(buf->buf); 2328 break; 2329 default: 2330 free(buf); 2331 free(buf2); 2332 return NS_UNAVAIL; 2333 } 2334 2335 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2336 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2337 free(buf); 2338 free(buf2); 2339 return NS_NOTFOUND; 2340 } 2341 2342 if (res_searchN(hostname, &q, res) < 0) { 2343 free(buf); 2344 free(buf2); 2345 return NS_NOTFOUND; 2346 } 2347 /* prefer IPv6 */ 2348 if (q.next) { 2349 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2350 if (ai != NULL) { 2351 cur->ai_next = ai; 2352 while (cur && cur->ai_next) 2353 cur = cur->ai_next; 2354 } 2355 } 2356 if (ai == NULL || pai->ai_family != AF_UNSPEC || 2357 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) != AI_V4MAPPED) { 2358 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2359 if (ai != NULL) 2360 cur->ai_next = ai; 2361 } 2362 free(buf); 2363 free(buf2); 2364 if (sentinel.ai_next == NULL) 2365 switch (res->res_h_errno) { 2366 case HOST_NOT_FOUND: 2367 case NO_DATA: 2368 return NS_NOTFOUND; 2369 case TRY_AGAIN: 2370 return NS_TRYAGAIN; 2371 default: 2372 return NS_UNAVAIL; 2373 } 2374 *((struct addrinfo **)rv) = sentinel.ai_next; 2375 return NS_SUCCESS; 2376} 2377 2378static void 2379_sethtent(FILE **hostf) 2380{ 2381 if (!*hostf) 2382 *hostf = fopen(_PATH_HOSTS, "re"); 2383 else 2384 rewind(*hostf); 2385} 2386 2387static void 2388_endhtent(FILE **hostf) 2389{ 2390 if (*hostf) { 2391 (void) fclose(*hostf); 2392 *hostf = NULL; 2393 } 2394} 2395 2396static struct addrinfo * 2397_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2398{ 2399 char *p; 2400 char *cp, *tname, *cname; 2401 struct addrinfo hints, *res0, *res; 2402 int error; 2403 const char *addr; 2404 char hostbuf[8*1024]; 2405 2406 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2407 return (NULL); 2408again: 2409 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2410 return (NULL); 2411 if (*p == '#') 2412 goto again; 2413 cp = strpbrk(p, "#\n"); 2414 if (cp != NULL) 2415 *cp = '\0'; 2416 if (!(cp = strpbrk(p, " \t"))) 2417 goto again; 2418 *cp++ = '\0'; 2419 addr = p; 2420 cname = NULL; 2421 /* if this is not something we're looking for, skip it. */ 2422 while (cp && *cp) { 2423 if (*cp == ' ' || *cp == '\t') { 2424 cp++; 2425 continue; 2426 } 2427 tname = cp; 2428 if (cname == NULL) 2429 cname = cp; 2430 if ((cp = strpbrk(cp, " \t")) != NULL) 2431 *cp++ = '\0'; 2432 if (strcasecmp(name, tname) == 0) 2433 goto found; 2434 } 2435 goto again; 2436 2437found: 2438 /* we should not glob socktype/protocol here */ 2439 memset(&hints, 0, sizeof(hints)); 2440 hints.ai_family = pai->ai_family; 2441 hints.ai_socktype = SOCK_DGRAM; 2442 hints.ai_protocol = 0; 2443 hints.ai_flags = AI_NUMERICHOST; 2444 if (pai->ai_family == AF_INET6 && 2445 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2446 hints.ai_flags |= AI_V4MAPPED; 2447 error = getaddrinfo(addr, "0", &hints, &res0); 2448 if (error) 2449 goto again; 2450#ifdef FILTER_V4MAPPED 2451 /* XXX should check all items in the chain */ 2452 if (res0->ai_family == AF_INET6 && 2453 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2454 freeaddrinfo(res0); 2455 goto again; 2456 } 2457#endif 2458 for (res = res0; res; res = res->ai_next) { 2459 /* cover it up */ 2460 res->ai_flags = pai->ai_flags; 2461 res->ai_socktype = pai->ai_socktype; 2462 res->ai_protocol = pai->ai_protocol; 2463 2464 if (pai->ai_flags & AI_CANONNAME) { 2465 if (get_canonname(pai, res, cname) != 0) { 2466 freeaddrinfo(res0); 2467 goto again; 2468 } 2469 } 2470 } 2471 return res0; 2472} 2473 2474static struct addrinfo * 2475_getht(FILE **hostf, const char *name, const struct addrinfo *pai, 2476 struct addrinfo *cur) 2477{ 2478 struct addrinfo *p; 2479 2480 while ((p = _gethtent(hostf, name, pai)) != NULL) { 2481 cur->ai_next = p; 2482 while (cur && cur->ai_next) 2483 cur = cur->ai_next; 2484 } 2485 return (cur); 2486} 2487 2488/*ARGSUSED*/ 2489static int 2490_files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2491{ 2492 const char *name; 2493 const struct addrinfo *pai; 2494 struct addrinfo sentinel, *cur; 2495 FILE *hostf = NULL; 2496 2497 name = va_arg(ap, char *); 2498 pai = va_arg(ap, struct addrinfo *); 2499 2500 memset(&sentinel, 0, sizeof(sentinel)); 2501 cur = &sentinel; 2502 2503 _sethtent(&hostf); 2504 if (pai->ai_family == AF_INET6 && 2505 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) == AI_V4MAPPED) { 2506 struct addrinfo ai0 = *pai; 2507 2508 ai0.ai_flags &= ~AI_V4MAPPED; 2509 cur = _getht(&hostf, name, &ai0, cur); 2510 if (sentinel.ai_next == NULL) { 2511 _sethtent(&hostf); 2512 ai0.ai_flags |= AI_V4MAPPED; 2513 cur = _getht(&hostf, name, &ai0, cur); 2514 } 2515 } else 2516 cur = _getht(&hostf, name, pai, cur); 2517 _endhtent(&hostf); 2518 2519 *((struct addrinfo **)rv) = sentinel.ai_next; 2520 if (sentinel.ai_next == NULL) 2521 return NS_NOTFOUND; 2522 return NS_SUCCESS; 2523} 2524 2525#ifdef YP 2526/*ARGSUSED*/ 2527static struct addrinfo * 2528_yphostent(char *line, const struct addrinfo *pai) 2529{ 2530 struct addrinfo sentinel, *cur; 2531 struct addrinfo hints, *res, *res0; 2532 int error; 2533 char *p = line; 2534 const char *addr, *canonname; 2535 char *nextline; 2536 char *cp; 2537 2538 addr = canonname = NULL; 2539 2540 memset(&sentinel, 0, sizeof(sentinel)); 2541 cur = &sentinel; 2542 2543nextline: 2544 /* terminate line */ 2545 cp = strchr(p, '\n'); 2546 if (cp) { 2547 *cp++ = '\0'; 2548 nextline = cp; 2549 } else 2550 nextline = NULL; 2551 2552 cp = strpbrk(p, " \t"); 2553 if (cp == NULL) { 2554 if (canonname == NULL) 2555 return (NULL); 2556 else 2557 goto done; 2558 } 2559 *cp++ = '\0'; 2560 2561 addr = p; 2562 2563 while (cp && *cp) { 2564 if (*cp == ' ' || *cp == '\t') { 2565 cp++; 2566 continue; 2567 } 2568 if (!canonname) 2569 canonname = cp; 2570 if ((cp = strpbrk(cp, " \t")) != NULL) 2571 *cp++ = '\0'; 2572 } 2573 2574 hints = *pai; 2575 hints.ai_flags = AI_NUMERICHOST; 2576 if (pai->ai_family == AF_INET6 && 2577 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2578 hints.ai_flags |= AI_V4MAPPED; 2579 error = getaddrinfo(addr, NULL, &hints, &res0); 2580 if (error == 0) { 2581 for (res = res0; res; res = res->ai_next) { 2582 /* cover it up */ 2583 res->ai_flags = pai->ai_flags; 2584 2585 if (pai->ai_flags & AI_CANONNAME) 2586 (void)get_canonname(pai, res, canonname); 2587 } 2588 } else 2589 res0 = NULL; 2590 if (res0) { 2591 cur->ai_next = res0; 2592 while (cur && cur->ai_next) 2593 cur = cur->ai_next; 2594 } 2595 2596 if (nextline) { 2597 p = nextline; 2598 goto nextline; 2599 } 2600 2601done: 2602 return sentinel.ai_next; 2603} 2604 2605/*ARGSUSED*/ 2606static int 2607_yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2608{ 2609 struct addrinfo sentinel, *cur; 2610 struct addrinfo *ai = NULL; 2611 char *ypbuf; 2612 int ypbuflen, r; 2613 const char *name; 2614 const struct addrinfo *pai; 2615 char *ypdomain; 2616 2617 if (_yp_check(&ypdomain) == 0) 2618 return NS_UNAVAIL; 2619 2620 name = va_arg(ap, char *); 2621 pai = va_arg(ap, const struct addrinfo *); 2622 2623 memset(&sentinel, 0, sizeof(sentinel)); 2624 cur = &sentinel; 2625 2626 /* ipnodes.byname can hold both IPv4/v6 */ 2627 r = yp_match(ypdomain, "ipnodes.byname", name, 2628 (int)strlen(name), &ypbuf, &ypbuflen); 2629 if (r == 0) { 2630 ai = _yphostent(ypbuf, pai); 2631 if (ai) { 2632 cur->ai_next = ai; 2633 while (cur && cur->ai_next) 2634 cur = cur->ai_next; 2635 } 2636 free(ypbuf); 2637 } 2638 2639 if (ai != NULL) { 2640 struct sockaddr_in6 *sin6; 2641 2642 switch (ai->ai_family) { 2643 case AF_INET: 2644 goto done; 2645 case AF_INET6: 2646 sin6 = (struct sockaddr_in6 *)ai->ai_addr; 2647 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 2648 goto done; 2649 break; 2650 } 2651 } 2652 2653 /* hosts.byname is only for IPv4 (Solaris8) */ 2654 if (pai->ai_family == AF_UNSPEC || pai->ai_family == AF_INET || 2655 ((pai->ai_family == AF_INET6 && 2656 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) && 2657 (ai == NULL || (pai->ai_flags & AI_ALL) == AI_ALL))) { 2658 r = yp_match(ypdomain, "hosts.byname", name, 2659 (int)strlen(name), &ypbuf, &ypbuflen); 2660 if (r == 0) { 2661 struct addrinfo ai4; 2662 2663 ai4 = *pai; 2664 if (pai->ai_family == AF_UNSPEC) 2665 ai4.ai_family = AF_INET; 2666 ai = _yphostent(ypbuf, &ai4); 2667 if (ai) { 2668 cur->ai_next = ai; 2669 while (cur && cur->ai_next) 2670 cur = cur->ai_next; 2671 } 2672 free(ypbuf); 2673 } 2674 } 2675 2676done: 2677 if (sentinel.ai_next == NULL) { 2678 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2679 return NS_NOTFOUND; 2680 } 2681 *((struct addrinfo **)rv) = sentinel.ai_next; 2682 return NS_SUCCESS; 2683} 2684#endif 2685 2686/* resolver logic */ 2687 2688/* 2689 * Formulate a normal query, send, and await answer. 2690 * Returned answer is placed in supplied buffer "answer". 2691 * Perform preliminary check of answer, returning success only 2692 * if no error is indicated and the answer count is nonzero. 2693 * Return the size of the response on success, -1 on error. 2694 * Error number is left in h_errno. 2695 * 2696 * Caller must parse answer and determine whether it answers the question. 2697 */ 2698static int 2699res_queryN(const char *name, struct res_target *target, res_state res) 2700{ 2701 u_char *buf; 2702 HEADER *hp; 2703 int n; 2704 u_int oflags; 2705 struct res_target *t; 2706 int rcode; 2707 int ancount; 2708 2709 rcode = NOERROR; 2710 ancount = 0; 2711 2712 buf = malloc(MAXPACKET); 2713 if (!buf) { 2714 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2715 return -1; 2716 } 2717 2718 for (t = target; t; t = t->next) { 2719 int class, type; 2720 u_char *answer; 2721 int anslen; 2722 2723 hp = (HEADER *)(void *)t->answer; 2724 2725 /* make it easier... */ 2726 class = t->qclass; 2727 type = t->qtype; 2728 answer = t->answer; 2729 anslen = t->anslen; 2730 2731 oflags = res->_flags; 2732 2733again: 2734 hp->rcode = NOERROR; /* default */ 2735 2736#ifdef DEBUG 2737 if (res->options & RES_DEBUG) 2738 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2739#endif 2740 2741 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2742 buf, MAXPACKET); 2743 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2744 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2745 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2746 if (n <= 0) { 2747#ifdef DEBUG 2748 if (res->options & RES_DEBUG) 2749 printf(";; res_query: mkquery failed\n"); 2750#endif 2751 free(buf); 2752 RES_SET_H_ERRNO(res, NO_RECOVERY); 2753 return (n); 2754 } 2755 n = res_nsend(res, buf, n, answer, anslen); 2756 if (n < 0) { 2757 /* 2758 * if the query choked with EDNS0, retry 2759 * without EDNS0 2760 */ 2761 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2762 != 0U && 2763 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2764 res->_flags |= RES_F_EDNS0ERR; 2765 if (res->options & RES_DEBUG) 2766 printf(";; res_nquery: retry without EDNS0\n"); 2767 goto again; 2768 } 2769 rcode = hp->rcode; /* record most recent error */ 2770#ifdef DEBUG 2771 if (res->options & RES_DEBUG) 2772 printf(";; res_query: send error\n"); 2773#endif 2774 continue; 2775 } 2776 2777 if (n > anslen) 2778 hp->rcode = FORMERR; /* XXX not very informative */ 2779 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2780 rcode = hp->rcode; /* record most recent error */ 2781#ifdef DEBUG 2782 if (res->options & RES_DEBUG) 2783 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2784 ntohs(hp->ancount)); 2785#endif 2786 continue; 2787 } 2788 2789 ancount += ntohs(hp->ancount); 2790 2791 t->n = n; 2792 } 2793 2794 free(buf); 2795 2796 if (ancount == 0) { 2797 switch (rcode) { 2798 case NXDOMAIN: 2799 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2800 break; 2801 case SERVFAIL: 2802 RES_SET_H_ERRNO(res, TRY_AGAIN); 2803 break; 2804 case NOERROR: 2805 RES_SET_H_ERRNO(res, NO_DATA); 2806 break; 2807 case FORMERR: 2808 case NOTIMP: 2809 case REFUSED: 2810 default: 2811 RES_SET_H_ERRNO(res, NO_RECOVERY); 2812 break; 2813 } 2814 return (-1); 2815 } 2816 return (ancount); 2817} 2818 2819/* 2820 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2821 * Return the size of the response on success, -1 on error. 2822 * If enabled, implement search rules until answer or unrecoverable failure 2823 * is detected. Error code, if any, is left in h_errno. 2824 */ 2825static int 2826res_searchN(const char *name, struct res_target *target, res_state res) 2827{ 2828 const char *cp, * const *domain; 2829 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2830 u_int dots; 2831 int trailing_dot, ret, saved_herrno; 2832 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2833 int tried_as_is = 0; 2834 int searched = 0; 2835 char abuf[MAXDNAME]; 2836 2837 errno = 0; 2838 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2839 dots = 0; 2840 for (cp = name; *cp; cp++) 2841 dots += (*cp == '.'); 2842 trailing_dot = 0; 2843 if (cp > name && *--cp == '.') 2844 trailing_dot++; 2845 2846 /* 2847 * if there aren't any dots, it could be a user-level alias 2848 */ 2849 if (!dots && 2850 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2851 return (res_queryN(cp, target, res)); 2852 2853 /* 2854 * If there are enough dots in the name, let's just give it a 2855 * try 'as is'. The threshold can be set with the "ndots" option. 2856 * Also, query 'as is', if there is a trailing dot in the name. 2857 */ 2858 saved_herrno = -1; 2859 if (dots >= res->ndots || trailing_dot) { 2860 ret = res_querydomainN(name, NULL, target, res); 2861 if (ret > 0 || trailing_dot) 2862 return (ret); 2863 if (errno == ECONNREFUSED) { 2864 RES_SET_H_ERRNO(res, TRY_AGAIN); 2865 return (-1); 2866 } 2867 switch (res->res_h_errno) { 2868 case NO_DATA: 2869 case HOST_NOT_FOUND: 2870 break; 2871 case TRY_AGAIN: 2872 if (hp->rcode == SERVFAIL) 2873 break; 2874 /* FALLTHROUGH */ 2875 default: 2876 return (-1); 2877 } 2878 saved_herrno = res->res_h_errno; 2879 tried_as_is++; 2880 } 2881 2882 /* 2883 * We do at least one level of search if 2884 * - there is no dot and RES_DEFNAME is set, or 2885 * - there is at least one dot, there is no trailing dot, 2886 * and RES_DNSRCH is set. 2887 */ 2888 if ((!dots && (res->options & RES_DEFNAMES)) || 2889 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2890 int done = 0; 2891 2892 for (domain = (const char * const *)res->dnsrch; 2893 *domain && !done; 2894 domain++) { 2895 searched = 1; 2896 2897 if (domain[0][0] == '\0' || 2898 (domain[0][0] == '.' && domain[0][1] == '\0')) 2899 root_on_list++; 2900 2901 if (root_on_list && tried_as_is) 2902 continue; 2903 2904 ret = res_querydomainN(name, *domain, target, res); 2905 if (ret > 0) 2906 return (ret); 2907 2908 /* 2909 * If no server present, give up. 2910 * If name isn't found in this domain, 2911 * keep trying higher domains in the search list 2912 * (if that's enabled). 2913 * On a NO_DATA error, keep trying, otherwise 2914 * a wildcard entry of another type could keep us 2915 * from finding this entry higher in the domain. 2916 * If we get some other error (negative answer or 2917 * server failure), then stop searching up, 2918 * but try the input name below in case it's 2919 * fully-qualified. 2920 */ 2921 if (errno == ECONNREFUSED) { 2922 RES_SET_H_ERRNO(res, TRY_AGAIN); 2923 return (-1); 2924 } 2925 2926 switch (res->res_h_errno) { 2927 case NO_DATA: 2928 got_nodata++; 2929 /* FALLTHROUGH */ 2930 case HOST_NOT_FOUND: 2931 /* keep trying */ 2932 break; 2933 case TRY_AGAIN: 2934 got_servfail++; 2935 if (hp->rcode == SERVFAIL) { 2936 /* try next search element, if any */ 2937 break; 2938 } 2939 /* FALLTHROUGH */ 2940 default: 2941 /* anything else implies that we're done */ 2942 done++; 2943 } 2944 /* 2945 * if we got here for some reason other than DNSRCH, 2946 * we only wanted one iteration of the loop, so stop. 2947 */ 2948 if (!(res->options & RES_DNSRCH)) 2949 done++; 2950 } 2951 } 2952 2953 switch (res->res_h_errno) { 2954 case NO_DATA: 2955 case HOST_NOT_FOUND: 2956 break; 2957 case TRY_AGAIN: 2958 if (hp->rcode == SERVFAIL) 2959 break; 2960 /* FALLTHROUGH */ 2961 default: 2962 goto giveup; 2963 } 2964 2965 /* 2966 * If the query has not already been tried as is then try it 2967 * unless RES_NOTLDQUERY is set and there were no dots. 2968 */ 2969 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2970 !(tried_as_is || root_on_list)) { 2971 ret = res_querydomainN(name, NULL, target, res); 2972 if (ret > 0) 2973 return (ret); 2974 } 2975 2976 /* 2977 * if we got here, we didn't satisfy the search. 2978 * if we did an initial full query, return that query's h_errno 2979 * (note that we wouldn't be here if that query had succeeded). 2980 * else if we ever got a nodata, send that back as the reason. 2981 * else send back meaningless h_errno, that being the one from 2982 * the last DNSRCH we did. 2983 */ 2984giveup: 2985 if (saved_herrno != -1) 2986 RES_SET_H_ERRNO(res, saved_herrno); 2987 else if (got_nodata) 2988 RES_SET_H_ERRNO(res, NO_DATA); 2989 else if (got_servfail) 2990 RES_SET_H_ERRNO(res, TRY_AGAIN); 2991 return (-1); 2992} 2993 2994/* 2995 * Perform a call on res_query on the concatenation of name and domain, 2996 * removing a trailing dot from name if domain is NULL. 2997 */ 2998static int 2999res_querydomainN(const char *name, const char *domain, 3000 struct res_target *target, res_state res) 3001{ 3002 char nbuf[MAXDNAME]; 3003 const char *longname = nbuf; 3004 size_t n, d; 3005 3006#ifdef DEBUG 3007 if (res->options & RES_DEBUG) 3008 printf(";; res_querydomain(%s, %s)\n", 3009 name, domain?domain:"<Nil>"); 3010#endif 3011 if (domain == NULL) { 3012 /* 3013 * Check for trailing '.'; 3014 * copy without '.' if present. 3015 */ 3016 n = strlen(name); 3017 if (n >= MAXDNAME) { 3018 RES_SET_H_ERRNO(res, NO_RECOVERY); 3019 return (-1); 3020 } 3021 if (n > 0 && name[--n] == '.') { 3022 strncpy(nbuf, name, n); 3023 nbuf[n] = '\0'; 3024 } else 3025 longname = name; 3026 } else { 3027 n = strlen(name); 3028 d = strlen(domain); 3029 if (n + d + 1 >= MAXDNAME) { 3030 RES_SET_H_ERRNO(res, NO_RECOVERY); 3031 return (-1); 3032 } 3033 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 3034 } 3035 return (res_queryN(longname, target, res)); 3036} 3037