getaddrinfo.c revision 292824
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 292824 2015-12-28 03:26:16Z 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}; 211 212static const ns_src default_dns_files[] = { 213 { NSSRC_FILES, NS_SUCCESS }, 214 { NSSRC_DNS, NS_SUCCESS }, 215 { 0 } 216}; 217 218struct res_target { 219 struct res_target *next; 220 const char *name; /* domain name */ 221 int qclass, qtype; /* class and type of query */ 222 u_char *answer; /* buffer to put answer */ 223 int anslen; /* size of answer buffer */ 224 int n; /* result length */ 225}; 226 227#define MAXPACKET (64*1024) 228 229typedef union { 230 HEADER hdr; 231 u_char buf[MAXPACKET]; 232} querybuf; 233 234static int str2number(const char *, int *); 235static int explore_copy(const struct addrinfo *, const struct addrinfo *, 236 struct addrinfo **); 237static int explore_null(const struct addrinfo *, 238 const char *, struct addrinfo **); 239static int explore_numeric(const struct addrinfo *, const char *, 240 const char *, struct addrinfo **, const char *); 241static int explore_numeric_scope(const struct addrinfo *, const char *, 242 const char *, struct addrinfo **); 243static int get_canonname(const struct addrinfo *, 244 struct addrinfo *, const char *); 245static struct addrinfo *get_ai(const struct addrinfo *, 246 const struct afd *, const char *); 247static struct addrinfo *copy_ai(const struct addrinfo *); 248static int get_portmatch(const struct addrinfo *, const char *); 249static int get_port(struct addrinfo *, const char *, int); 250static const struct afd *find_afd(int); 251static int addrconfig(struct addrinfo *); 252#ifdef INET6 253static int is_ifdisabled(char *); 254#endif 255static void set_source(struct ai_order *, struct policyhead *); 256static int comp_dst(const void *, const void *); 257#ifdef INET6 258static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 259#endif 260static int gai_addr2scopetype(struct sockaddr *); 261 262static int explore_fqdn(const struct addrinfo *, const char *, 263 const char *, struct addrinfo **); 264 265static int reorder(struct addrinfo *); 266static int get_addrselectpolicy(struct policyhead *); 267static void free_addrselectpolicy(struct policyhead *); 268static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 269 struct policyhead *); 270static int matchlen(struct sockaddr *, struct sockaddr *); 271 272static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 273 const struct addrinfo *, res_state); 274#if defined(RESOLVSORT) 275static int addr4sort(struct addrinfo *, res_state); 276#endif 277static int _dns_getaddrinfo(void *, void *, va_list); 278static void _sethtent(FILE **); 279static void _endhtent(FILE **); 280static struct addrinfo *_gethtent(FILE **, const char *, 281 const struct addrinfo *); 282static int _files_getaddrinfo(void *, void *, va_list); 283#ifdef YP 284static struct addrinfo *_yphostent(char *, const struct addrinfo *); 285static int _yp_getaddrinfo(void *, void *, va_list); 286#endif 287#ifdef NS_CACHING 288static int addrinfo_id_func(char *, size_t *, va_list, void *); 289static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 290static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 291#endif 292 293static int res_queryN(const char *, struct res_target *, res_state); 294static int res_searchN(const char *, struct res_target *, res_state); 295static int res_querydomainN(const char *, const char *, 296 struct res_target *, res_state); 297 298/* XXX macros that make external reference is BAD. */ 299 300#define GET_AI(ai, afd, addr) \ 301do { \ 302 /* external reference: pai, error, and label free */ \ 303 (ai) = get_ai(pai, (afd), (addr)); \ 304 if ((ai) == NULL) { \ 305 error = EAI_MEMORY; \ 306 goto free; \ 307 } \ 308} while (/*CONSTCOND*/0) 309 310#define GET_PORT(ai, serv) \ 311do { \ 312 /* external reference: error and label free */ \ 313 error = get_port((ai), (serv), 0); \ 314 if (error != 0) \ 315 goto free; \ 316} while (/*CONSTCOND*/0) 317 318#define GET_CANONNAME(ai, str) \ 319do { \ 320 /* external reference: pai, error and label free */ \ 321 error = get_canonname(pai, (ai), (str)); \ 322 if (error != 0) \ 323 goto free; \ 324} while (/*CONSTCOND*/0) 325 326#define ERR(err) \ 327do { \ 328 /* external reference: error, and label bad */ \ 329 error = (err); \ 330 goto bad; \ 331 /*NOTREACHED*/ \ 332} while (/*CONSTCOND*/0) 333 334#define MATCH_FAMILY(x, y, w) \ 335 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 336#define MATCH(x, y, w) \ 337 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 338 339void 340freeaddrinfo(struct addrinfo *ai) 341{ 342 struct addrinfo *next; 343 344 do { 345 next = ai->ai_next; 346 if (ai->ai_canonname) 347 free(ai->ai_canonname); 348 /* no need to free(ai->ai_addr) */ 349 free(ai); 350 ai = next; 351 } while (ai); 352} 353 354static int 355str2number(const char *p, int *portp) 356{ 357 char *ep; 358 unsigned long v; 359 360 if (*p == '\0') 361 return -1; 362 ep = NULL; 363 errno = 0; 364 v = strtoul(p, &ep, 10); 365 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 366 *portp = v; 367 return 0; 368 } else 369 return -1; 370} 371 372int 373getaddrinfo(const char *hostname, const char *servname, 374 const struct addrinfo *hints, struct addrinfo **res) 375{ 376 struct addrinfo sentinel; 377 struct addrinfo *cur; 378 int error = 0; 379 struct addrinfo ai, ai0, *afai; 380 struct addrinfo *pai; 381 const struct afd *afd; 382 const struct explore *ex; 383 struct addrinfo *afailist[sizeof(afdl)/sizeof(afdl[0])]; 384 struct addrinfo *afai_unspec; 385 int found; 386 int numeric = 0; 387 388 /* ensure we return NULL on errors */ 389 *res = NULL; 390 391 memset(&ai, 0, sizeof(ai)); 392 393 memset(afailist, 0, sizeof(afailist)); 394 afai_unspec = NULL; 395 396 memset(&sentinel, 0, sizeof(sentinel)); 397 cur = &sentinel; 398 pai = &ai; 399 pai->ai_flags = 0; 400 pai->ai_family = PF_UNSPEC; 401 pai->ai_socktype = ANY; 402 pai->ai_protocol = ANY; 403 pai->ai_addrlen = 0; 404 pai->ai_canonname = NULL; 405 pai->ai_addr = NULL; 406 pai->ai_next = NULL; 407 408 if (hostname == NULL && servname == NULL) 409 return EAI_NONAME; 410 if (hints) { 411 /* error check for hints */ 412 if (hints->ai_addrlen || hints->ai_canonname || 413 hints->ai_addr || hints->ai_next) 414 ERR(EAI_BADHINTS); /* xxx */ 415 if (hints->ai_flags & ~AI_MASK) 416 ERR(EAI_BADFLAGS); 417 switch (hints->ai_family) { 418 case PF_UNSPEC: 419 case PF_INET: 420#ifdef INET6 421 case PF_INET6: 422#endif 423 break; 424 default: 425 ERR(EAI_FAMILY); 426 } 427 memcpy(pai, hints, sizeof(*pai)); 428 429 /* 430 * if both socktype/protocol are specified, check if they 431 * are meaningful combination. 432 */ 433 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 434 for (ex = explore; ex->e_af >= 0; ex++) { 435 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 436 WILD_AF(ex))) 437 continue; 438 if (!MATCH(pai->ai_socktype, ex->e_socktype, 439 WILD_SOCKTYPE(ex))) 440 continue; 441 if (!MATCH(pai->ai_protocol, ex->e_protocol, 442 WILD_PROTOCOL(ex))) 443 continue; 444 445 /* matched */ 446 break; 447 } 448 449 if (ex->e_af < 0) 450 ERR(EAI_BADHINTS); 451 } 452 } 453 454 /* 455 * RFC 3493: AI_ALL and AI_V4MAPPED are effective only against 456 * AF_INET6 query. They need to be ignored if specified in other 457 * occassions. 458 */ 459 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 460 case AI_V4MAPPED: 461 case AI_ALL | AI_V4MAPPED: 462#ifdef INET6 463 if (pai->ai_family != AF_INET6) 464 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 465 break; 466#endif 467 case AI_ALL: 468 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 469 break; 470 } 471 472 /* 473 * check for special cases. (1) numeric servname is disallowed if 474 * socktype/protocol are left unspecified. (2) servname is disallowed 475 * for raw and other inet{,6} sockets. 476 */ 477 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 478#ifdef PF_INET6 479 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 480#endif 481 ) { 482 ai0 = *pai; /* backup *pai */ 483 484 if (pai->ai_family == PF_UNSPEC) { 485#ifdef PF_INET6 486 pai->ai_family = PF_INET6; 487#else 488 pai->ai_family = PF_INET; 489#endif 490 } 491 error = get_portmatch(pai, servname); 492 if (error) 493 goto bad; 494 495 *pai = ai0; 496 } 497 498 ai0 = *pai; 499 500 /* 501 * NULL hostname, or numeric hostname. 502 * If numeric representation of AF1 can be interpreted as FQDN 503 * representation of AF2, we need to think again about the code below. 504 */ 505 found = 0; 506 for (afd = afdl; afd->a_af; afd++) { 507 *pai = ai0; 508 509 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 510 continue; 511 512 if (pai->ai_family == PF_UNSPEC) 513 pai->ai_family = afd->a_af; 514 515 if (hostname == NULL) { 516 error = explore_null(pai, servname, 517 &afailist[afd - afdl]); 518 519 /* 520 * Errors from explore_null should be unexpected and 521 * be caught to avoid returning an incomplete result. 522 */ 523 if (error != 0) 524 goto bad; 525 } else { 526 error = explore_numeric_scope(pai, hostname, servname, 527 &afailist[afd - afdl]); 528 529 /* 530 * explore_numeric_scope returns an error for address 531 * families that do not match that of hostname. 532 * Thus we should not catch the error at this moment. 533 */ 534 } 535 536 if (!error && afailist[afd - afdl]) 537 found++; 538 } 539 if (found) { 540 numeric = 1; 541 goto globcopy; 542 } 543 544 if (hostname == NULL) 545 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 546 if (pai->ai_flags & AI_NUMERICHOST) 547 ERR(EAI_NONAME); 548 549 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 550 ERR(EAI_FAIL); 551 552 /* 553 * hostname as alphabetical name. 554 */ 555 *pai = ai0; 556 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 557 558globcopy: 559 for (ex = explore; ex->e_af >= 0; ex++) { 560 *pai = ai0; 561 562 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 563 continue; 564 if (!MATCH(pai->ai_socktype, ex->e_socktype, 565 WILD_SOCKTYPE(ex))) 566 continue; 567 if (!MATCH(pai->ai_protocol, ex->e_protocol, 568 WILD_PROTOCOL(ex))) 569 continue; 570 571 if (pai->ai_family == PF_UNSPEC) 572 pai->ai_family = ex->e_af; 573 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 574 pai->ai_socktype = ex->e_socktype; 575 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 576 pai->ai_protocol = ex->e_protocol; 577 578 /* 579 * if the servname does not match socktype/protocol, ignore it. 580 */ 581 if (get_portmatch(pai, servname) != 0) 582 continue; 583 584 if (afai_unspec) 585 afai = afai_unspec; 586 else { 587 if ((afd = find_afd(pai->ai_family)) == NULL) 588 continue; 589 /* XXX assumes that afd points inside afdl[] */ 590 afai = afailist[afd - afdl]; 591 } 592 if (!afai) 593 continue; 594 595 error = explore_copy(pai, afai, &cur->ai_next); 596 if (error != 0) 597 goto bad; 598 599 while (cur && cur->ai_next) 600 cur = cur->ai_next; 601 } 602 603 /* 604 * ensure we return either: 605 * - error == 0, non-NULL *res 606 * - error != 0, NULL *res 607 */ 608 if (error == 0) { 609 if (sentinel.ai_next) { 610 /* 611 * If the returned entry is for an active connection, 612 * and the given name is not numeric, reorder the 613 * list, so that the application would try the list 614 * in the most efficient order. Since the head entry 615 * of the original list may contain ai_canonname and 616 * that entry may be moved elsewhere in the new list, 617 * we keep the pointer and will restore it in the new 618 * head entry. (Note that RFC3493 requires the head 619 * entry store it when requested by the caller). 620 */ 621 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 622 if (!numeric) { 623 char *canonname; 624 625 canonname = 626 sentinel.ai_next->ai_canonname; 627 sentinel.ai_next->ai_canonname = NULL; 628 (void)reorder(&sentinel); 629 if (sentinel.ai_next->ai_canonname == 630 NULL) { 631 sentinel.ai_next->ai_canonname 632 = canonname; 633 } else if (canonname != NULL) 634 free(canonname); 635 } 636 } 637 *res = sentinel.ai_next; 638 } else 639 error = EAI_FAIL; 640 } 641 642bad: 643 if (afai_unspec) 644 freeaddrinfo(afai_unspec); 645 for (afd = afdl; afd->a_af; afd++) { 646 if (afailist[afd - afdl]) 647 freeaddrinfo(afailist[afd - afdl]); 648 } 649 if (!*res) 650 if (sentinel.ai_next) 651 freeaddrinfo(sentinel.ai_next); 652 653 return (error); 654} 655 656static int 657reorder(struct addrinfo *sentinel) 658{ 659 struct addrinfo *ai, **aip; 660 struct ai_order *aio; 661 int i, n; 662 struct policyhead policyhead; 663 664 /* count the number of addrinfo elements for sorting. */ 665 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 666 ; 667 668 /* 669 * If the number is small enough, we can skip the reordering process. 670 */ 671 if (n <= 1) 672 return(n); 673 674 /* allocate a temporary array for sort and initialization of it. */ 675 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 676 return(n); /* give up reordering */ 677 memset(aio, 0, sizeof(*aio) * n); 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 } 694 695 /* perform sorting. */ 696 qsort(aio, n, sizeof(*aio), comp_dst); 697 698 /* reorder the addrinfo chain. */ 699 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 700 *aip = aio[i].aio_ai; 701 aip = &aio[i].aio_ai->ai_next; 702 } 703 *aip = NULL; 704 705 /* cleanup and return */ 706 free(aio); 707 free_addrselectpolicy(&policyhead); 708 return(n); 709} 710 711static int 712get_addrselectpolicy(struct policyhead *head) 713{ 714#ifdef INET6 715 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 716 size_t l; 717 char *buf; 718 struct in6_addrpolicy *pol, *ep; 719 720 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 721 return (0); 722 if (l == 0) 723 return (0); 724 if ((buf = malloc(l)) == NULL) 725 return (0); 726 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 727 free(buf); 728 return (0); 729 } 730 731 ep = (struct in6_addrpolicy *)(buf + l); 732 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 733 struct policyqueue *new; 734 735 if ((new = malloc(sizeof(*new))) == NULL) { 736 free_addrselectpolicy(head); /* make the list empty */ 737 break; 738 } 739 new->pc_policy = *pol; 740 TAILQ_INSERT_TAIL(head, new, pc_entry); 741 } 742 743 free(buf); 744 return (1); 745#else 746 return (0); 747#endif 748} 749 750static void 751free_addrselectpolicy(struct policyhead *head) 752{ 753 struct policyqueue *ent, *nent; 754 755 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 756 nent = TAILQ_NEXT(ent, pc_entry); 757 TAILQ_REMOVE(head, ent, pc_entry); 758 free(ent); 759 } 760} 761 762static struct policyqueue * 763match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 764{ 765#ifdef INET6 766 struct policyqueue *ent, *bestent = NULL; 767 struct in6_addrpolicy *pol; 768 int matchlen, bestmatchlen = -1; 769 u_char *mp, *ep, *k, *p, m; 770 struct sockaddr_in6 key; 771 772 switch(addr->sa_family) { 773 case AF_INET6: 774 key = *(struct sockaddr_in6 *)addr; 775 break; 776 case AF_INET: 777 /* convert the address into IPv4-mapped IPv6 address. */ 778 memset(&key, 0, sizeof(key)); 779 key.sin6_family = AF_INET6; 780 key.sin6_len = sizeof(key); 781 key.sin6_addr.s6_addr[10] = 0xff; 782 key.sin6_addr.s6_addr[11] = 0xff; 783 memcpy(&key.sin6_addr.s6_addr[12], 784 &((struct sockaddr_in *)addr)->sin_addr, 4); 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 < addrlen * 8) { 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 return(-1); 1053} 1054 1055/* 1056 * Copy from scope.c. 1057 * XXX: we should standardize the functions and link them as standard 1058 * library. 1059 */ 1060static int 1061gai_addr2scopetype(struct sockaddr *sa) 1062{ 1063#ifdef INET6 1064 struct sockaddr_in6 *sa6; 1065#endif 1066 struct sockaddr_in *sa4; 1067 1068 switch(sa->sa_family) { 1069#ifdef INET6 1070 case AF_INET6: 1071 sa6 = (struct sockaddr_in6 *)sa; 1072 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1073 /* just use the scope field of the multicast address */ 1074 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1075 } 1076 /* 1077 * Unicast addresses: map scope type to corresponding scope 1078 * value defined for multcast addresses. 1079 * XXX: hardcoded scope type values are bad... 1080 */ 1081 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1082 return(1); /* node local scope */ 1083 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1084 return(2); /* link-local scope */ 1085 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1086 return(5); /* site-local scope */ 1087 return(14); /* global scope */ 1088 break; 1089#endif 1090 case AF_INET: 1091 /* 1092 * IPv4 pseudo scoping according to RFC 3484. 1093 */ 1094 sa4 = (struct sockaddr_in *)sa; 1095 /* IPv4 autoconfiguration addresses have link-local scope. */ 1096 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1097 ((u_char *)&sa4->sin_addr)[1] == 254) 1098 return(2); 1099 /* Private addresses have site-local scope. */ 1100 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1101 (((u_char *)&sa4->sin_addr)[0] == 172 && 1102 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1103 (((u_char *)&sa4->sin_addr)[0] == 192 && 1104 ((u_char *)&sa4->sin_addr)[1] == 168)) 1105 return(14); /* XXX: It should be 5 unless NAT */ 1106 /* Loopback addresses have link-local scope. */ 1107 if (((u_char *)&sa4->sin_addr)[0] == 127) 1108 return(2); 1109 return(14); 1110 break; 1111 default: 1112 errno = EAFNOSUPPORT; /* is this a good error? */ 1113 return(-1); 1114 } 1115} 1116 1117static int 1118explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1119 struct addrinfo **res) 1120{ 1121 int error; 1122 struct addrinfo sentinel, *cur; 1123 const struct addrinfo *src; 1124 1125 error = 0; 1126 sentinel.ai_next = NULL; 1127 cur = &sentinel; 1128 1129 for (src = src0; src != NULL; src = src->ai_next) { 1130 if (src->ai_family != pai->ai_family) 1131 continue; 1132 1133 cur->ai_next = copy_ai(src); 1134 if (!cur->ai_next) { 1135 error = EAI_MEMORY; 1136 goto fail; 1137 } 1138 1139 cur->ai_next->ai_socktype = pai->ai_socktype; 1140 cur->ai_next->ai_protocol = pai->ai_protocol; 1141 cur = cur->ai_next; 1142 } 1143 1144 *res = sentinel.ai_next; 1145 return 0; 1146 1147fail: 1148 freeaddrinfo(sentinel.ai_next); 1149 return error; 1150} 1151 1152/* 1153 * hostname == NULL. 1154 * passive socket -> anyaddr (0.0.0.0 or ::) 1155 * non-passive socket -> localhost (127.0.0.1 or ::1) 1156 */ 1157static int 1158explore_null(const struct addrinfo *pai, const char *servname, 1159 struct addrinfo **res) 1160{ 1161 int s; 1162 const struct afd *afd; 1163 struct addrinfo *ai; 1164 int error; 1165 1166 *res = NULL; 1167 ai = NULL; 1168 1169 /* 1170 * filter out AFs that are not supported by the kernel 1171 * XXX errno? 1172 */ 1173 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1174 if (s < 0) { 1175 if (errno != EMFILE) 1176 return 0; 1177 } else 1178 _close(s); 1179 1180 afd = find_afd(pai->ai_family); 1181 if (afd == NULL) 1182 return 0; 1183 1184 if (pai->ai_flags & AI_PASSIVE) { 1185 GET_AI(ai, afd, afd->a_addrany); 1186 GET_PORT(ai, servname); 1187 } else { 1188 GET_AI(ai, afd, afd->a_loopback); 1189 GET_PORT(ai, servname); 1190 } 1191 1192 *res = ai; 1193 return 0; 1194 1195free: 1196 if (ai != NULL) 1197 freeaddrinfo(ai); 1198 return error; 1199} 1200 1201/* 1202 * numeric hostname 1203 */ 1204static int 1205explore_numeric(const struct addrinfo *pai, const char *hostname, 1206 const char *servname, struct addrinfo **res, const char *canonname) 1207{ 1208 const struct afd *afd; 1209 struct addrinfo *ai, ai0; 1210 int error; 1211 char pton[PTON_MAX]; 1212 1213 *res = NULL; 1214 ai = NULL; 1215 1216 afd = find_afd(pai->ai_family); 1217 if (afd == NULL) 1218 return 0; 1219 1220 switch (afd->a_af) { 1221 case AF_INET: 1222 /* 1223 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1224 * that are accepted by inet_addr() and its family. The 1225 * accepted forms includes the "classful" one, which inet_pton 1226 * does not accept. So we need to separate the case for 1227 * AF_INET. 1228 */ 1229 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1230 return 0; 1231 break; 1232 default: 1233 if (inet_pton(afd->a_af, hostname, pton) != 1) { 1234 if (pai->ai_family != AF_INET6 || 1235 (pai->ai_flags & AI_V4MAPPED) != AI_V4MAPPED) 1236 return 0; 1237 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1238 return 0; 1239 afd = &afdl[N_INET]; 1240 ai0 = *pai; 1241 ai0.ai_family = AF_INET; 1242 pai = &ai0; 1243 } 1244 break; 1245 } 1246 1247 if (pai->ai_family == afd->a_af) { 1248 GET_AI(ai, afd, pton); 1249 GET_PORT(ai, servname); 1250 if ((pai->ai_flags & AI_CANONNAME)) { 1251 /* 1252 * Set the numeric address itself as the canonical 1253 * name, based on a clarification in RFC3493. 1254 */ 1255 GET_CANONNAME(ai, canonname); 1256 } 1257 } else { 1258 /* 1259 * XXX: This should not happen since we already matched the AF 1260 * by find_afd. 1261 */ 1262 ERR(EAI_FAMILY); 1263 } 1264 1265 *res = ai; 1266 return 0; 1267 1268free: 1269bad: 1270 if (ai != NULL) 1271 freeaddrinfo(ai); 1272 return error; 1273} 1274 1275/* 1276 * numeric hostname with scope 1277 */ 1278static int 1279explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1280 const char *servname, struct addrinfo **res) 1281{ 1282#if !defined(SCOPE_DELIMITER) || !defined(INET6) 1283 return explore_numeric(pai, hostname, servname, res, hostname); 1284#else 1285 const struct afd *afd; 1286 struct addrinfo *cur; 1287 int error; 1288 char *cp, *hostname2 = NULL, *scope, *addr; 1289 struct sockaddr_in6 *sin6; 1290 1291 afd = find_afd(pai->ai_family); 1292 if (afd == NULL) 1293 return 0; 1294 1295 if (!afd->a_scoped) 1296 return explore_numeric(pai, hostname, servname, res, hostname); 1297 1298 cp = strchr(hostname, SCOPE_DELIMITER); 1299 if (cp == NULL) 1300 return explore_numeric(pai, hostname, servname, res, hostname); 1301 1302 /* 1303 * Handle special case of <scoped_address><delimiter><scope id> 1304 */ 1305 hostname2 = strdup(hostname); 1306 if (hostname2 == NULL) 1307 return EAI_MEMORY; 1308 /* terminate at the delimiter */ 1309 hostname2[cp - hostname] = '\0'; 1310 addr = hostname2; 1311 scope = cp + 1; 1312 1313 error = explore_numeric(pai, addr, servname, res, hostname); 1314 if (error == 0) { 1315 u_int32_t scopeid; 1316 1317 for (cur = *res; cur; cur = cur->ai_next) { 1318 if (cur->ai_family != AF_INET6) 1319 continue; 1320 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1321 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1322 free(hostname2); 1323 freeaddrinfo(*res); 1324 *res = NULL; 1325 return(EAI_NONAME); /* XXX: is return OK? */ 1326 } 1327 sin6->sin6_scope_id = scopeid; 1328 } 1329 } 1330 1331 free(hostname2); 1332 1333 if (error && *res) { 1334 freeaddrinfo(*res); 1335 *res = NULL; 1336 } 1337 return error; 1338#endif 1339} 1340 1341static int 1342get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1343{ 1344 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1345 ai->ai_canonname = strdup(str); 1346 if (ai->ai_canonname == NULL) 1347 return EAI_MEMORY; 1348 } 1349 return 0; 1350} 1351 1352static struct addrinfo * 1353get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1354{ 1355 char *p; 1356 struct addrinfo *ai; 1357#ifdef FAITH 1358 struct in6_addr faith_prefix; 1359 char *fp_str; 1360 int translate = 0; 1361#endif 1362#ifdef INET6 1363 struct in6_addr mapaddr; 1364#endif 1365 1366#ifdef FAITH 1367 /* 1368 * Transfrom an IPv4 addr into a special IPv6 addr format for 1369 * IPv6->IPv4 translation gateway. (only TCP is supported now) 1370 * 1371 * +-----------------------------------+------------+ 1372 * | faith prefix part (12 bytes) | embedded | 1373 * | | IPv4 addr part (4 bytes) 1374 * +-----------------------------------+------------+ 1375 * 1376 * faith prefix part is specified as ascii IPv6 addr format 1377 * in environmental variable GAI. 1378 * For FAITH to work correctly, routing to faith prefix must be 1379 * setup toward a machine where a FAITH daemon operates. 1380 * Also, the machine must enable some mechanizm 1381 * (e.g. faith interface hack) to divert those packet with 1382 * faith prefixed destination addr to user-land FAITH daemon. 1383 */ 1384 fp_str = getenv("GAI"); 1385 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 1386 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 1387 u_int32_t v4a; 1388 u_int8_t v4a_top; 1389 1390 memcpy(&v4a, addr, sizeof v4a); 1391 v4a_top = v4a >> IN_CLASSA_NSHIFT; 1392 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 1393 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 1394 afd = &afdl[N_INET6]; 1395 memcpy(&faith_prefix.s6_addr[12], addr, 1396 sizeof(struct in_addr)); 1397 translate = 1; 1398 } 1399 } 1400#endif 1401 1402#ifdef INET6 1403 if (afd->a_af == AF_INET && (pai->ai_flags & AI_V4MAPPED) != 0) { 1404 afd = &afdl[N_INET6]; 1405 _map_v4v6_address(addr, (char *)&mapaddr); 1406 addr = (char *)&mapaddr; 1407 } 1408#endif 1409 1410 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1411 + (afd->a_socklen)); 1412 if (ai == NULL) 1413 return NULL; 1414 1415 memcpy(ai, pai, sizeof(struct addrinfo)); 1416 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1417 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1418 ai->ai_addr->sa_len = afd->a_socklen; 1419 ai->ai_addrlen = afd->a_socklen; 1420 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1421 p = (char *)(void *)(ai->ai_addr); 1422#ifdef FAITH 1423 if (translate == 1) 1424 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 1425 else 1426#endif 1427 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1428 return ai; 1429} 1430 1431/* XXX need to malloc() the same way we do from other functions! */ 1432static struct addrinfo * 1433copy_ai(const struct addrinfo *pai) 1434{ 1435 struct addrinfo *ai; 1436 size_t l; 1437 1438 l = sizeof(*ai) + pai->ai_addrlen; 1439 if ((ai = (struct addrinfo *)malloc(l)) == NULL) 1440 return NULL; 1441 memset(ai, 0, l); 1442 memcpy(ai, pai, sizeof(*ai)); 1443 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1444 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1445 1446 if (pai->ai_canonname) { 1447 l = strlen(pai->ai_canonname) + 1; 1448 if ((ai->ai_canonname = malloc(l)) == NULL) { 1449 free(ai); 1450 return NULL; 1451 } 1452 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1453 } else { 1454 /* just to make sure */ 1455 ai->ai_canonname = NULL; 1456 } 1457 1458 ai->ai_next = NULL; 1459 1460 return ai; 1461} 1462 1463static int 1464get_portmatch(const struct addrinfo *ai, const char *servname) 1465{ 1466 1467 /* get_port does not touch first argument when matchonly == 1. */ 1468 /* LINTED const cast */ 1469 return get_port((struct addrinfo *)ai, servname, 1); 1470} 1471 1472static int 1473get_port(struct addrinfo *ai, const char *servname, int matchonly) 1474{ 1475 const char *proto; 1476 struct servent *sp; 1477 int port, error; 1478 int allownumeric; 1479 1480 if (servname == NULL) 1481 return 0; 1482 switch (ai->ai_family) { 1483 case AF_INET: 1484#ifdef AF_INET6 1485 case AF_INET6: 1486#endif 1487 break; 1488 default: 1489 return 0; 1490 } 1491 1492 switch (ai->ai_socktype) { 1493 case SOCK_RAW: 1494 return EAI_SERVICE; 1495 case SOCK_DGRAM: 1496 case SOCK_STREAM: 1497 case SOCK_SEQPACKET: 1498 allownumeric = 1; 1499 break; 1500 case ANY: 1501 switch (ai->ai_family) { 1502 case AF_INET: 1503#ifdef AF_INET6 1504 case AF_INET6: 1505#endif 1506 allownumeric = 1; 1507 break; 1508 default: 1509 allownumeric = 0; 1510 break; 1511 } 1512 break; 1513 default: 1514 return EAI_SOCKTYPE; 1515 } 1516 1517 error = str2number(servname, &port); 1518 if (error == 0) { 1519 if (!allownumeric) 1520 return EAI_SERVICE; 1521 if (port < 0 || port > 65535) 1522 return EAI_SERVICE; 1523 port = htons(port); 1524 } else { 1525 if (ai->ai_flags & AI_NUMERICSERV) 1526 return EAI_NONAME; 1527 1528 switch (ai->ai_protocol) { 1529 case IPPROTO_UDP: 1530 proto = "udp"; 1531 break; 1532 case IPPROTO_TCP: 1533 proto = "tcp"; 1534 break; 1535 case IPPROTO_SCTP: 1536 proto = "sctp"; 1537 break; 1538 case IPPROTO_UDPLITE: 1539 proto = "udplite"; 1540 break; 1541 default: 1542 proto = NULL; 1543 break; 1544 } 1545 1546 if ((sp = getservbyname(servname, proto)) == NULL) 1547 return EAI_SERVICE; 1548 port = sp->s_port; 1549 } 1550 1551 if (!matchonly) { 1552 switch (ai->ai_family) { 1553 case AF_INET: 1554 ((struct sockaddr_in *)(void *) 1555 ai->ai_addr)->sin_port = port; 1556 break; 1557#ifdef INET6 1558 case AF_INET6: 1559 ((struct sockaddr_in6 *)(void *) 1560 ai->ai_addr)->sin6_port = port; 1561 break; 1562#endif 1563 } 1564 } 1565 1566 return 0; 1567} 1568 1569static const struct afd * 1570find_afd(int af) 1571{ 1572 const struct afd *afd; 1573 1574 if (af == PF_UNSPEC) 1575 return NULL; 1576 for (afd = afdl; afd->a_af; afd++) { 1577 if (afd->a_af == af) 1578 return afd; 1579 } 1580 return NULL; 1581} 1582 1583/* 1584 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are 1585 * configured on the local system and correlates with pai->ai_family value. 1586 * If an address family is not configured on the system, it will not be 1587 * queried for. For this purpose, loopback addresses are not considered 1588 * configured addresses. 1589 * 1590 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1591 * _dns_getaddrinfo. 1592 */ 1593static int 1594addrconfig(struct addrinfo *pai) 1595{ 1596 struct ifaddrs *ifaddrs, *ifa; 1597 struct sockaddr_in *sin; 1598#ifdef INET6 1599 struct sockaddr_in6 *sin6; 1600#endif 1601 int seen_inet = 0, seen_inet6 = 0; 1602 1603 if (getifaddrs(&ifaddrs) != 0) 1604 return (0); 1605 1606 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1607 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1608 continue; 1609 switch (ifa->ifa_addr->sa_family) { 1610 case AF_INET: 1611 if (seen_inet) 1612 continue; 1613 sin = (struct sockaddr_in *)(ifa->ifa_addr); 1614 if (htonl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) 1615 continue; 1616 seen_inet = 1; 1617 break; 1618#ifdef INET6 1619 case AF_INET6: 1620 if (seen_inet6) 1621 continue; 1622 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); 1623 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 1624 continue; 1625 if ((ifa->ifa_flags & IFT_LOOP) != 0 && 1626 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 1627 continue; 1628 if (is_ifdisabled(ifa->ifa_name)) 1629 continue; 1630 seen_inet6 = 1; 1631 break; 1632#endif 1633 } 1634 } 1635 freeifaddrs(ifaddrs); 1636 1637 switch(pai->ai_family) { 1638 case AF_INET6: 1639 return (seen_inet6); 1640 case AF_INET: 1641 return (seen_inet); 1642 case AF_UNSPEC: 1643 if (seen_inet == seen_inet6) 1644 return (seen_inet); 1645 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1646 return (1); 1647 } 1648 return (1); 1649} 1650 1651#ifdef INET6 1652static int 1653is_ifdisabled(char *name) 1654{ 1655 struct in6_ndireq nd; 1656 int fd; 1657 1658 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1659 return (-1); 1660 memset(&nd, 0, sizeof(nd)); 1661 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1662 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1663 _close(fd); 1664 return (-1); 1665 } 1666 _close(fd); 1667 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1668} 1669 1670/* convert a string to a scope identifier. XXX: IPv6 specific */ 1671static int 1672ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1673{ 1674 u_long lscopeid; 1675 struct in6_addr *a6; 1676 char *ep; 1677 1678 a6 = &sin6->sin6_addr; 1679 1680 /* empty scopeid portion is invalid */ 1681 if (*scope == '\0') 1682 return -1; 1683 1684 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1685 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1686 /* 1687 * We currently assume a one-to-one mapping between links 1688 * and interfaces, so we simply use interface indices for 1689 * like-local scopes. 1690 */ 1691 *scopeid = if_nametoindex(scope); 1692 if (*scopeid == 0) 1693 goto trynumeric; 1694 return 0; 1695 } 1696 1697 /* still unclear about literal, allow numeric only - placeholder */ 1698 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1699 goto trynumeric; 1700 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1701 goto trynumeric; 1702 else 1703 goto trynumeric; /* global */ 1704 1705 /* try to convert to a numeric id as a last resort */ 1706 trynumeric: 1707 errno = 0; 1708 lscopeid = strtoul(scope, &ep, 10); 1709 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1710 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1711 return 0; 1712 else 1713 return -1; 1714} 1715#endif 1716 1717 1718#ifdef NS_CACHING 1719static int 1720addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1721 void *cache_mdata) 1722{ 1723 res_state statp; 1724 u_long res_options; 1725 1726 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1727 char *hostname; 1728 struct addrinfo *hints; 1729 1730 char *p; 1731 int ai_flags, ai_family, ai_socktype, ai_protocol; 1732 size_t desired_size, size; 1733 1734 statp = __res_state(); 1735 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1736 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1737 1738 hostname = va_arg(ap, char *); 1739 hints = va_arg(ap, struct addrinfo *); 1740 1741 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1742 if (hostname != NULL) { 1743 size = strlen(hostname); 1744 desired_size += size + 1; 1745 } else 1746 size = 0; 1747 1748 if (desired_size > *buffer_size) { 1749 *buffer_size = desired_size; 1750 return (NS_RETURN); 1751 } 1752 1753 if (hints == NULL) 1754 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1755 else { 1756 ai_flags = hints->ai_flags; 1757 ai_family = hints->ai_family; 1758 ai_socktype = hints->ai_socktype; 1759 ai_protocol = hints->ai_protocol; 1760 } 1761 1762 p = buffer; 1763 memcpy(p, &res_options, sizeof(res_options)); 1764 p += sizeof(res_options); 1765 1766 memcpy(p, &op_id, sizeof(int)); 1767 p += sizeof(int); 1768 1769 memcpy(p, &ai_flags, sizeof(int)); 1770 p += sizeof(int); 1771 1772 memcpy(p, &ai_family, sizeof(int)); 1773 p += sizeof(int); 1774 1775 memcpy(p, &ai_socktype, sizeof(int)); 1776 p += sizeof(int); 1777 1778 memcpy(p, &ai_protocol, sizeof(int)); 1779 p += sizeof(int); 1780 1781 if (hostname != NULL) 1782 memcpy(p, hostname, size); 1783 1784 *buffer_size = desired_size; 1785 return (NS_SUCCESS); 1786} 1787 1788static int 1789addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1790 va_list ap, void *cache_mdata) 1791{ 1792 struct addrinfo *ai, *cai; 1793 char *p; 1794 size_t desired_size, size, ai_size; 1795 1796 ai = *((struct addrinfo **)retval); 1797 1798 desired_size = sizeof(size_t); 1799 ai_size = 0; 1800 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1801 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1802 if (cai->ai_canonname != NULL) 1803 desired_size += sizeof(size_t) + 1804 strlen(cai->ai_canonname); 1805 ++ai_size; 1806 } 1807 1808 if (desired_size > *buffer_size) { 1809 /* this assignment is here for future use */ 1810 errno = ERANGE; 1811 *buffer_size = desired_size; 1812 return (NS_RETURN); 1813 } 1814 1815 memset(buffer, 0, desired_size); 1816 p = buffer; 1817 1818 memcpy(p, &ai_size, sizeof(size_t)); 1819 p += sizeof(size_t); 1820 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1821 memcpy(p, cai, sizeof(struct addrinfo)); 1822 p += sizeof(struct addrinfo); 1823 1824 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1825 p += cai->ai_addrlen; 1826 1827 if (cai->ai_canonname != NULL) { 1828 size = strlen(cai->ai_canonname); 1829 memcpy(p, &size, sizeof(size_t)); 1830 p += sizeof(size_t); 1831 1832 memcpy(p, cai->ai_canonname, size); 1833 p += size; 1834 } 1835 } 1836 1837 return (NS_SUCCESS); 1838} 1839 1840static int 1841addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1842 va_list ap, void *cache_mdata) 1843{ 1844 struct addrinfo new_ai, *result, *sentinel, *lasts; 1845 1846 char *p; 1847 size_t ai_size, ai_i, size; 1848 1849 p = buffer; 1850 memcpy(&ai_size, p, sizeof(size_t)); 1851 p += sizeof(size_t); 1852 1853 result = NULL; 1854 lasts = NULL; 1855 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1856 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1857 p += sizeof(struct addrinfo); 1858 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1859 _ALIGNBYTES; 1860 1861 sentinel = (struct addrinfo *)malloc(size); 1862 memset(sentinel, 0, size); 1863 1864 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1865 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1866 sizeof(struct addrinfo)); 1867 1868 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1869 p += new_ai.ai_addrlen; 1870 1871 if (new_ai.ai_canonname != NULL) { 1872 memcpy(&size, p, sizeof(size_t)); 1873 p += sizeof(size_t); 1874 1875 sentinel->ai_canonname = (char *)malloc(size + 1); 1876 memset(sentinel->ai_canonname, 0, size + 1); 1877 1878 memcpy(sentinel->ai_canonname, p, size); 1879 p += size; 1880 } 1881 1882 if (result == NULL) { 1883 result = sentinel; 1884 lasts = sentinel; 1885 } else { 1886 lasts->ai_next = sentinel; 1887 lasts = sentinel; 1888 } 1889 } 1890 1891 *((struct addrinfo **)retval) = result; 1892 return (NS_SUCCESS); 1893} 1894#endif /* NS_CACHING */ 1895 1896/* 1897 * FQDN hostname, DNS lookup 1898 */ 1899static int 1900explore_fqdn(const struct addrinfo *pai, const char *hostname, 1901 const char *servname, struct addrinfo **res) 1902{ 1903 struct addrinfo *result; 1904 struct addrinfo *cur; 1905 int error = 0; 1906 1907#ifdef NS_CACHING 1908 static const nss_cache_info cache_info = 1909 NS_COMMON_CACHE_INFO_INITIALIZER( 1910 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1911 addrinfo_unmarshal_func); 1912#endif 1913 static const ns_dtab dtab[] = { 1914 NS_FILES_CB(_files_getaddrinfo, NULL) 1915 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1916 NS_NIS_CB(_yp_getaddrinfo, NULL) 1917#ifdef NS_CACHING 1918 NS_CACHE_CB(&cache_info) 1919#endif 1920 { 0 } 1921 }; 1922 1923 result = NULL; 1924 1925 /* 1926 * if the servname does not match socktype/protocol, ignore it. 1927 */ 1928 if (get_portmatch(pai, servname) != 0) 1929 return 0; 1930 1931 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1932 default_dns_files, hostname, pai)) { 1933 case NS_TRYAGAIN: 1934 error = EAI_AGAIN; 1935 goto free; 1936 case NS_UNAVAIL: 1937 error = EAI_FAIL; 1938 goto free; 1939 case NS_NOTFOUND: 1940 error = EAI_NONAME; 1941 goto free; 1942 case NS_SUCCESS: 1943 error = 0; 1944 for (cur = result; cur; cur = cur->ai_next) { 1945 GET_PORT(cur, servname); 1946 /* canonname should be filled already */ 1947 } 1948 break; 1949 } 1950 1951 *res = result; 1952 1953 return 0; 1954 1955free: 1956 if (result) 1957 freeaddrinfo(result); 1958 return error; 1959} 1960 1961#ifdef DEBUG 1962static const char AskedForGot[] = 1963 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1964#endif 1965 1966static struct addrinfo * 1967getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1968 const struct addrinfo *pai, res_state res) 1969{ 1970 struct addrinfo sentinel, *cur; 1971 struct addrinfo ai; 1972 const struct afd *afd; 1973 char *canonname; 1974 const HEADER *hp; 1975 const u_char *cp; 1976 int n; 1977 const u_char *eom; 1978 char *bp, *ep; 1979 int type, class, ancount, qdcount; 1980 int haveanswer, had_error; 1981 char tbuf[MAXDNAME]; 1982 int (*name_ok)(const char *); 1983 char hostbuf[8*1024]; 1984 1985 memset(&sentinel, 0, sizeof(sentinel)); 1986 cur = &sentinel; 1987 1988 canonname = NULL; 1989 eom = answer->buf + anslen; 1990 switch (qtype) { 1991 case T_A: 1992 case T_AAAA: 1993 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1994 name_ok = res_hnok; 1995 break; 1996 default: 1997 return (NULL); /* XXX should be abort(); */ 1998 } 1999 /* 2000 * find first satisfactory answer 2001 */ 2002 hp = &answer->hdr; 2003 ancount = ntohs(hp->ancount); 2004 qdcount = ntohs(hp->qdcount); 2005 bp = hostbuf; 2006 ep = hostbuf + sizeof hostbuf; 2007 cp = answer->buf + HFIXEDSZ; 2008 if (qdcount != 1) { 2009 RES_SET_H_ERRNO(res, NO_RECOVERY); 2010 return (NULL); 2011 } 2012 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2013 if ((n < 0) || !(*name_ok)(bp)) { 2014 RES_SET_H_ERRNO(res, NO_RECOVERY); 2015 return (NULL); 2016 } 2017 cp += n + QFIXEDSZ; 2018 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 2019 /* res_send() has already verified that the query name is the 2020 * same as the one we sent; this just gets the expanded name 2021 * (i.e., with the succeeding search-domain tacked on). 2022 */ 2023 n = strlen(bp) + 1; /* for the \0 */ 2024 if (n >= MAXHOSTNAMELEN) { 2025 RES_SET_H_ERRNO(res, NO_RECOVERY); 2026 return (NULL); 2027 } 2028 canonname = bp; 2029 bp += n; 2030 /* The qname can be abbreviated, but h_name is now absolute. */ 2031 qname = canonname; 2032 } 2033 haveanswer = 0; 2034 had_error = 0; 2035 while (ancount-- > 0 && cp < eom && !had_error) { 2036 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2037 if ((n < 0) || !(*name_ok)(bp)) { 2038 had_error++; 2039 continue; 2040 } 2041 cp += n; /* name */ 2042 type = _getshort(cp); 2043 cp += INT16SZ; /* type */ 2044 class = _getshort(cp); 2045 cp += INT16SZ + INT32SZ; /* class, TTL */ 2046 n = _getshort(cp); 2047 cp += INT16SZ; /* len */ 2048 if (class != C_IN) { 2049 /* XXX - debug? syslog? */ 2050 cp += n; 2051 continue; /* XXX - had_error++ ? */ 2052 } 2053 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 2054 type == T_CNAME) { 2055 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 2056 if ((n < 0) || !(*name_ok)(tbuf)) { 2057 had_error++; 2058 continue; 2059 } 2060 cp += n; 2061 /* Get canonical name. */ 2062 n = strlen(tbuf) + 1; /* for the \0 */ 2063 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 2064 had_error++; 2065 continue; 2066 } 2067 strlcpy(bp, tbuf, ep - bp); 2068 canonname = bp; 2069 bp += n; 2070 continue; 2071 } 2072 if (qtype == T_ANY) { 2073 if (!(type == T_A || type == T_AAAA)) { 2074 cp += n; 2075 continue; 2076 } 2077 } else if (type != qtype) { 2078#ifdef DEBUG 2079 if (type != T_KEY && type != T_SIG && 2080 type != ns_t_dname) 2081 syslog(LOG_NOTICE|LOG_AUTH, 2082 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2083 qname, p_class(C_IN), p_type(qtype), 2084 p_type(type)); 2085#endif 2086 cp += n; 2087 continue; /* XXX - had_error++ ? */ 2088 } 2089 switch (type) { 2090 case T_A: 2091 case T_AAAA: 2092 if (strcasecmp(canonname, bp) != 0) { 2093#ifdef DEBUG 2094 syslog(LOG_NOTICE|LOG_AUTH, 2095 AskedForGot, canonname, bp); 2096#endif 2097 cp += n; 2098 continue; /* XXX - had_error++ ? */ 2099 } 2100 if (type == T_A && n != INADDRSZ) { 2101 cp += n; 2102 continue; 2103 } 2104 if (type == T_AAAA && n != IN6ADDRSZ) { 2105 cp += n; 2106 continue; 2107 } 2108#ifdef FILTER_V4MAPPED 2109 if (type == T_AAAA) { 2110 struct in6_addr in6; 2111 memcpy(&in6, cp, sizeof(in6)); 2112 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2113 cp += n; 2114 continue; 2115 } 2116 } 2117#endif 2118 if (!haveanswer) { 2119 int nn; 2120 2121 canonname = bp; 2122 nn = strlen(bp) + 1; /* for the \0 */ 2123 bp += nn; 2124 } 2125 2126 /* don't overwrite pai */ 2127 ai = *pai; 2128 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2129 afd = find_afd(ai.ai_family); 2130 if (afd == NULL) { 2131 cp += n; 2132 continue; 2133 } 2134 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2135 if (cur->ai_next == NULL) 2136 had_error++; 2137 while (cur && cur->ai_next) 2138 cur = cur->ai_next; 2139 cp += n; 2140 break; 2141 default: 2142 abort(); 2143 } 2144 if (!had_error) 2145 haveanswer++; 2146 } 2147 if (haveanswer) { 2148#if defined(RESOLVSORT) 2149 /* 2150 * We support only IPv4 address for backward 2151 * compatibility against gethostbyname(3). 2152 */ 2153 if (res->nsort && qtype == T_A) { 2154 if (addr4sort(&sentinel, res) < 0) { 2155 freeaddrinfo(sentinel.ai_next); 2156 RES_SET_H_ERRNO(res, NO_RECOVERY); 2157 return NULL; 2158 } 2159 } 2160#endif /*RESOLVSORT*/ 2161 if (!canonname) 2162 (void)get_canonname(pai, sentinel.ai_next, qname); 2163 else 2164 (void)get_canonname(pai, sentinel.ai_next, canonname); 2165 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2166 return sentinel.ai_next; 2167 } 2168 2169 /* 2170 * We could have walked a CNAME chain, but the ultimate target 2171 * may not have what we looked for. 2172 */ 2173 RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : NO_RECOVERY); 2174 return NULL; 2175} 2176 2177#ifdef RESOLVSORT 2178struct addr_ptr { 2179 struct addrinfo *ai; 2180 int aval; 2181}; 2182 2183static int 2184addr4sort(struct addrinfo *sentinel, res_state res) 2185{ 2186 struct addrinfo *ai; 2187 struct addr_ptr *addrs, addr; 2188 struct sockaddr_in *sin; 2189 int naddrs, i, j; 2190 int needsort = 0; 2191 2192 if (!sentinel) 2193 return -1; 2194 naddrs = 0; 2195 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2196 naddrs++; 2197 if (naddrs < 2) 2198 return 0; /* We don't need sorting. */ 2199 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2200 return -1; 2201 i = 0; 2202 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2203 sin = (struct sockaddr_in *)ai->ai_addr; 2204 for (j = 0; (unsigned)j < res->nsort; j++) { 2205 if (res->sort_list[j].addr.s_addr == 2206 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2207 break; 2208 } 2209 addrs[i].ai = ai; 2210 addrs[i].aval = j; 2211 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2212 needsort = i; 2213 i++; 2214 } 2215 if (!needsort) { 2216 free(addrs); 2217 return 0; 2218 } 2219 2220 while (needsort < naddrs) { 2221 for (j = needsort - 1; j >= 0; j--) { 2222 if (addrs[j].aval > addrs[j+1].aval) { 2223 addr = addrs[j]; 2224 addrs[j] = addrs[j + 1]; 2225 addrs[j + 1] = addr; 2226 } else 2227 break; 2228 } 2229 needsort++; 2230 } 2231 2232 ai = sentinel; 2233 for (i = 0; i < naddrs; ++i) { 2234 ai->ai_next = addrs[i].ai; 2235 ai = ai->ai_next; 2236 } 2237 ai->ai_next = NULL; 2238 free(addrs); 2239 return 0; 2240} 2241#endif /*RESOLVSORT*/ 2242 2243/*ARGSUSED*/ 2244static int 2245_dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2246{ 2247 struct addrinfo *ai, ai0; 2248 querybuf *buf, *buf2; 2249 const char *hostname; 2250 const struct addrinfo *pai; 2251 struct addrinfo sentinel, *cur; 2252 struct res_target q, q2; 2253 res_state res; 2254 2255 hostname = va_arg(ap, char *); 2256 pai = va_arg(ap, const struct addrinfo *); 2257 2258 memset(&q, 0, sizeof(q)); 2259 memset(&q2, 0, sizeof(q2)); 2260 memset(&sentinel, 0, sizeof(sentinel)); 2261 cur = &sentinel; 2262 2263 res = __res_state(); 2264 2265 buf = malloc(sizeof(*buf)); 2266 if (!buf) { 2267 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2268 return NS_NOTFOUND; 2269 } 2270 buf2 = malloc(sizeof(*buf2)); 2271 if (!buf2) { 2272 free(buf); 2273 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2274 return NS_NOTFOUND; 2275 } 2276 2277 if (pai->ai_family == AF_INET6 && 2278 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) { 2279 ai0 = *pai; 2280 ai0.ai_family = AF_UNSPEC; 2281 pai = &ai0; 2282 } 2283 2284 switch (pai->ai_family) { 2285 case AF_UNSPEC: 2286 q.name = hostname; 2287 q.qclass = C_IN; 2288 q.qtype = T_A; 2289 q.answer = buf->buf; 2290 q.anslen = sizeof(buf->buf); 2291 q.next = &q2; 2292 q2.name = hostname; 2293 q2.qclass = C_IN; 2294 q2.qtype = T_AAAA; 2295 q2.answer = buf2->buf; 2296 q2.anslen = sizeof(buf2->buf); 2297 break; 2298 case AF_INET: 2299 q.name = hostname; 2300 q.qclass = C_IN; 2301 q.qtype = T_A; 2302 q.answer = buf->buf; 2303 q.anslen = sizeof(buf->buf); 2304 break; 2305 case AF_INET6: 2306 q.name = hostname; 2307 q.qclass = C_IN; 2308 q.qtype = T_AAAA; 2309 q.answer = buf->buf; 2310 q.anslen = sizeof(buf->buf); 2311 break; 2312 default: 2313 free(buf); 2314 free(buf2); 2315 return NS_UNAVAIL; 2316 } 2317 2318 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2319 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2320 free(buf); 2321 free(buf2); 2322 return NS_NOTFOUND; 2323 } 2324 2325 if (res_searchN(hostname, &q, res) < 0) { 2326 free(buf); 2327 free(buf2); 2328 return NS_NOTFOUND; 2329 } 2330 /* prefer IPv6 */ 2331 if (q.next) { 2332 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2333 if (ai) { 2334 cur->ai_next = ai; 2335 while (cur && cur->ai_next) 2336 cur = cur->ai_next; 2337 } 2338 } 2339 if (!ai || pai->ai_family != AF_UNSPEC || 2340 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) != AI_V4MAPPED) { 2341 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2342 if (ai) 2343 cur->ai_next = ai; 2344 } 2345 free(buf); 2346 free(buf2); 2347 if (sentinel.ai_next == NULL) 2348 switch (res->res_h_errno) { 2349 case HOST_NOT_FOUND: 2350 case NO_DATA: 2351 return NS_NOTFOUND; 2352 case TRY_AGAIN: 2353 return NS_TRYAGAIN; 2354 default: 2355 return NS_UNAVAIL; 2356 } 2357 *((struct addrinfo **)rv) = sentinel.ai_next; 2358 return NS_SUCCESS; 2359} 2360 2361static void 2362_sethtent(FILE **hostf) 2363{ 2364 if (!*hostf) 2365 *hostf = fopen(_PATH_HOSTS, "re"); 2366 else 2367 rewind(*hostf); 2368} 2369 2370static void 2371_endhtent(FILE **hostf) 2372{ 2373 if (*hostf) { 2374 (void) fclose(*hostf); 2375 *hostf = NULL; 2376 } 2377} 2378 2379static struct addrinfo * 2380_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2381{ 2382 char *p; 2383 char *cp, *tname, *cname; 2384 struct addrinfo hints, *res0, *res; 2385 int error; 2386 const char *addr; 2387 char hostbuf[8*1024]; 2388 2389 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2390 return (NULL); 2391again: 2392 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2393 return (NULL); 2394 if (*p == '#') 2395 goto again; 2396 cp = strpbrk(p, "#\n"); 2397 if (cp != NULL) 2398 *cp = '\0'; 2399 if (!(cp = strpbrk(p, " \t"))) 2400 goto again; 2401 *cp++ = '\0'; 2402 addr = p; 2403 cname = NULL; 2404 /* if this is not something we're looking for, skip it. */ 2405 while (cp && *cp) { 2406 if (*cp == ' ' || *cp == '\t') { 2407 cp++; 2408 continue; 2409 } 2410 tname = cp; 2411 if (cname == NULL) 2412 cname = cp; 2413 if ((cp = strpbrk(cp, " \t")) != NULL) 2414 *cp++ = '\0'; 2415 if (strcasecmp(name, tname) == 0) 2416 goto found; 2417 } 2418 goto again; 2419 2420found: 2421 /* we should not glob socktype/protocol here */ 2422 memset(&hints, 0, sizeof(hints)); 2423 hints.ai_family = pai->ai_family; 2424 hints.ai_socktype = SOCK_DGRAM; 2425 hints.ai_protocol = 0; 2426 hints.ai_flags = AI_NUMERICHOST; 2427 if (pai->ai_family == AF_INET6 && 2428 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2429 hints.ai_flags |= AI_V4MAPPED; 2430 error = getaddrinfo(addr, "0", &hints, &res0); 2431 if (error) 2432 goto again; 2433#ifdef FILTER_V4MAPPED 2434 /* XXX should check all items in the chain */ 2435 if (res0->ai_family == AF_INET6 && 2436 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2437 freeaddrinfo(res0); 2438 goto again; 2439 } 2440#endif 2441 for (res = res0; res; res = res->ai_next) { 2442 /* cover it up */ 2443 res->ai_flags = pai->ai_flags; 2444 res->ai_socktype = pai->ai_socktype; 2445 res->ai_protocol = pai->ai_protocol; 2446 2447 if (pai->ai_flags & AI_CANONNAME) { 2448 if (get_canonname(pai, res, cname) != 0) { 2449 freeaddrinfo(res0); 2450 goto again; 2451 } 2452 } 2453 } 2454 return res0; 2455} 2456 2457static struct addrinfo * 2458_getht(FILE **hostf, const char *name, const struct addrinfo *pai, 2459 struct addrinfo *cur) 2460{ 2461 struct addrinfo *p; 2462 2463 while ((p = _gethtent(hostf, name, pai)) != NULL) { 2464 cur->ai_next = p; 2465 while (cur && cur->ai_next) 2466 cur = cur->ai_next; 2467 } 2468 return (cur); 2469} 2470 2471/*ARGSUSED*/ 2472static int 2473_files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2474{ 2475 const char *name; 2476 const struct addrinfo *pai; 2477 struct addrinfo sentinel, *cur; 2478 FILE *hostf = NULL; 2479 2480 name = va_arg(ap, char *); 2481 pai = va_arg(ap, struct addrinfo *); 2482 2483 memset(&sentinel, 0, sizeof(sentinel)); 2484 cur = &sentinel; 2485 2486 _sethtent(&hostf); 2487 if (pai->ai_family == AF_INET6 && 2488 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) == AI_V4MAPPED) { 2489 struct addrinfo ai0 = *pai; 2490 2491 ai0.ai_flags &= ~AI_V4MAPPED; 2492 cur = _getht(&hostf, name, &ai0, cur); 2493 if (sentinel.ai_next == NULL) { 2494 _sethtent(&hostf); 2495 ai0.ai_flags |= AI_V4MAPPED; 2496 cur = _getht(&hostf, name, &ai0, cur); 2497 } 2498 } else 2499 cur = _getht(&hostf, name, pai, cur); 2500 _endhtent(&hostf); 2501 2502 *((struct addrinfo **)rv) = sentinel.ai_next; 2503 if (sentinel.ai_next == NULL) 2504 return NS_NOTFOUND; 2505 return NS_SUCCESS; 2506} 2507 2508#ifdef YP 2509/*ARGSUSED*/ 2510static struct addrinfo * 2511_yphostent(char *line, const struct addrinfo *pai) 2512{ 2513 struct addrinfo sentinel, *cur; 2514 struct addrinfo hints, *res, *res0; 2515 int error; 2516 char *p = line; 2517 const char *addr, *canonname; 2518 char *nextline; 2519 char *cp; 2520 2521 addr = canonname = NULL; 2522 2523 memset(&sentinel, 0, sizeof(sentinel)); 2524 cur = &sentinel; 2525 2526nextline: 2527 /* terminate line */ 2528 cp = strchr(p, '\n'); 2529 if (cp) { 2530 *cp++ = '\0'; 2531 nextline = cp; 2532 } else 2533 nextline = NULL; 2534 2535 cp = strpbrk(p, " \t"); 2536 if (cp == NULL) { 2537 if (canonname == NULL) 2538 return (NULL); 2539 else 2540 goto done; 2541 } 2542 *cp++ = '\0'; 2543 2544 addr = p; 2545 2546 while (cp && *cp) { 2547 if (*cp == ' ' || *cp == '\t') { 2548 cp++; 2549 continue; 2550 } 2551 if (!canonname) 2552 canonname = cp; 2553 if ((cp = strpbrk(cp, " \t")) != NULL) 2554 *cp++ = '\0'; 2555 } 2556 2557 hints = *pai; 2558 hints.ai_flags = AI_NUMERICHOST; 2559 if (pai->ai_family == AF_INET6 && 2560 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2561 hints.ai_flags |= AI_V4MAPPED; 2562 error = getaddrinfo(addr, NULL, &hints, &res0); 2563 if (error == 0) { 2564 for (res = res0; res; res = res->ai_next) { 2565 /* cover it up */ 2566 res->ai_flags = pai->ai_flags; 2567 2568 if (pai->ai_flags & AI_CANONNAME) 2569 (void)get_canonname(pai, res, canonname); 2570 } 2571 } else 2572 res0 = NULL; 2573 if (res0) { 2574 cur->ai_next = res0; 2575 while (cur && cur->ai_next) 2576 cur = cur->ai_next; 2577 } 2578 2579 if (nextline) { 2580 p = nextline; 2581 goto nextline; 2582 } 2583 2584done: 2585 return sentinel.ai_next; 2586} 2587 2588/*ARGSUSED*/ 2589static int 2590_yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2591{ 2592 struct addrinfo sentinel, *cur; 2593 struct addrinfo *ai = NULL; 2594 char *ypbuf; 2595 int ypbuflen, r; 2596 const char *name; 2597 const struct addrinfo *pai; 2598 char *ypdomain; 2599 2600 if (_yp_check(&ypdomain) == 0) 2601 return NS_UNAVAIL; 2602 2603 name = va_arg(ap, char *); 2604 pai = va_arg(ap, const struct addrinfo *); 2605 2606 memset(&sentinel, 0, sizeof(sentinel)); 2607 cur = &sentinel; 2608 2609 /* ipnodes.byname can hold both IPv4/v6 */ 2610 r = yp_match(ypdomain, "ipnodes.byname", name, 2611 (int)strlen(name), &ypbuf, &ypbuflen); 2612 if (r == 0) { 2613 ai = _yphostent(ypbuf, pai); 2614 if (ai) { 2615 cur->ai_next = ai; 2616 while (cur && cur->ai_next) 2617 cur = cur->ai_next; 2618 } 2619 free(ypbuf); 2620 } 2621 2622 if (ai != NULL) { 2623 struct sockaddr_in6 *sin6; 2624 2625 switch (ai->ai_family) { 2626 case AF_INET: 2627 goto done; 2628 case AF_INET6: 2629 sin6 = (struct sockaddr_in6 *)ai->ai_addr; 2630 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 2631 goto done; 2632 break; 2633 } 2634 } 2635 2636 /* hosts.byname is only for IPv4 (Solaris8) */ 2637 if (pai->ai_family == AF_UNSPEC || pai->ai_family == AF_INET || 2638 ((pai->ai_family == AF_INET6 && 2639 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) && 2640 (ai == NULL || (pai->ai_flags & AI_ALL) == AI_ALL))) { 2641 r = yp_match(ypdomain, "hosts.byname", name, 2642 (int)strlen(name), &ypbuf, &ypbuflen); 2643 if (r == 0) { 2644 struct addrinfo ai4; 2645 2646 ai4 = *pai; 2647 if (pai->ai_family == AF_UNSPEC) 2648 ai4.ai_family = AF_INET; 2649 ai = _yphostent(ypbuf, &ai4); 2650 if (ai) { 2651 cur->ai_next = ai; 2652 while (cur && cur->ai_next) 2653 cur = cur->ai_next; 2654 } 2655 free(ypbuf); 2656 } 2657 } 2658 2659done: 2660 if (sentinel.ai_next == NULL) { 2661 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2662 return NS_NOTFOUND; 2663 } 2664 *((struct addrinfo **)rv) = sentinel.ai_next; 2665 return NS_SUCCESS; 2666} 2667#endif 2668 2669/* resolver logic */ 2670 2671/* 2672 * Formulate a normal query, send, and await answer. 2673 * Returned answer is placed in supplied buffer "answer". 2674 * Perform preliminary check of answer, returning success only 2675 * if no error is indicated and the answer count is nonzero. 2676 * Return the size of the response on success, -1 on error. 2677 * Error number is left in h_errno. 2678 * 2679 * Caller must parse answer and determine whether it answers the question. 2680 */ 2681static int 2682res_queryN(const char *name, struct res_target *target, res_state res) 2683{ 2684 u_char *buf; 2685 HEADER *hp; 2686 int n; 2687 u_int oflags; 2688 struct res_target *t; 2689 int rcode; 2690 int ancount; 2691 2692 rcode = NOERROR; 2693 ancount = 0; 2694 2695 buf = malloc(MAXPACKET); 2696 if (!buf) { 2697 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2698 return -1; 2699 } 2700 2701 for (t = target; t; t = t->next) { 2702 int class, type; 2703 u_char *answer; 2704 int anslen; 2705 2706 hp = (HEADER *)(void *)t->answer; 2707 2708 /* make it easier... */ 2709 class = t->qclass; 2710 type = t->qtype; 2711 answer = t->answer; 2712 anslen = t->anslen; 2713 2714 oflags = res->_flags; 2715 2716again: 2717 hp->rcode = NOERROR; /* default */ 2718 2719#ifdef DEBUG 2720 if (res->options & RES_DEBUG) 2721 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2722#endif 2723 2724 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2725 buf, MAXPACKET); 2726 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2727 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2728 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2729 if (n <= 0) { 2730#ifdef DEBUG 2731 if (res->options & RES_DEBUG) 2732 printf(";; res_query: mkquery failed\n"); 2733#endif 2734 free(buf); 2735 RES_SET_H_ERRNO(res, NO_RECOVERY); 2736 return (n); 2737 } 2738 n = res_nsend(res, buf, n, answer, anslen); 2739 if (n < 0) { 2740 /* 2741 * if the query choked with EDNS0, retry 2742 * without EDNS0 2743 */ 2744 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2745 != 0U && 2746 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2747 res->_flags |= RES_F_EDNS0ERR; 2748 if (res->options & RES_DEBUG) 2749 printf(";; res_nquery: retry without EDNS0\n"); 2750 goto again; 2751 } 2752 rcode = hp->rcode; /* record most recent error */ 2753#ifdef DEBUG 2754 if (res->options & RES_DEBUG) 2755 printf(";; res_query: send error\n"); 2756#endif 2757 continue; 2758 } 2759 2760 if (n > anslen) 2761 hp->rcode = FORMERR; /* XXX not very informative */ 2762 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2763 rcode = hp->rcode; /* record most recent error */ 2764#ifdef DEBUG 2765 if (res->options & RES_DEBUG) 2766 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2767 ntohs(hp->ancount)); 2768#endif 2769 continue; 2770 } 2771 2772 ancount += ntohs(hp->ancount); 2773 2774 t->n = n; 2775 } 2776 2777 free(buf); 2778 2779 if (ancount == 0) { 2780 switch (rcode) { 2781 case NXDOMAIN: 2782 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2783 break; 2784 case SERVFAIL: 2785 RES_SET_H_ERRNO(res, TRY_AGAIN); 2786 break; 2787 case NOERROR: 2788 RES_SET_H_ERRNO(res, NO_DATA); 2789 break; 2790 case FORMERR: 2791 case NOTIMP: 2792 case REFUSED: 2793 default: 2794 RES_SET_H_ERRNO(res, NO_RECOVERY); 2795 break; 2796 } 2797 return (-1); 2798 } 2799 return (ancount); 2800} 2801 2802/* 2803 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2804 * Return the size of the response on success, -1 on error. 2805 * If enabled, implement search rules until answer or unrecoverable failure 2806 * is detected. Error code, if any, is left in h_errno. 2807 */ 2808static int 2809res_searchN(const char *name, struct res_target *target, res_state res) 2810{ 2811 const char *cp, * const *domain; 2812 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2813 u_int dots; 2814 int trailing_dot, ret, saved_herrno; 2815 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2816 int tried_as_is = 0; 2817 int searched = 0; 2818 char abuf[MAXDNAME]; 2819 2820 errno = 0; 2821 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2822 dots = 0; 2823 for (cp = name; *cp; cp++) 2824 dots += (*cp == '.'); 2825 trailing_dot = 0; 2826 if (cp > name && *--cp == '.') 2827 trailing_dot++; 2828 2829 /* 2830 * if there aren't any dots, it could be a user-level alias 2831 */ 2832 if (!dots && 2833 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2834 return (res_queryN(cp, target, res)); 2835 2836 /* 2837 * If there are enough dots in the name, let's just give it a 2838 * try 'as is'. The threshold can be set with the "ndots" option. 2839 * Also, query 'as is', if there is a trailing dot in the name. 2840 */ 2841 saved_herrno = -1; 2842 if (dots >= res->ndots || trailing_dot) { 2843 ret = res_querydomainN(name, NULL, target, res); 2844 if (ret > 0 || trailing_dot) 2845 return (ret); 2846 if (errno == ECONNREFUSED) { 2847 RES_SET_H_ERRNO(res, TRY_AGAIN); 2848 return (-1); 2849 } 2850 switch (res->res_h_errno) { 2851 case NO_DATA: 2852 case HOST_NOT_FOUND: 2853 break; 2854 case TRY_AGAIN: 2855 if (hp->rcode == SERVFAIL) 2856 break; 2857 /* FALLTHROUGH */ 2858 default: 2859 return (-1); 2860 } 2861 saved_herrno = res->res_h_errno; 2862 tried_as_is++; 2863 } 2864 2865 /* 2866 * We do at least one level of search if 2867 * - there is no dot and RES_DEFNAME is set, or 2868 * - there is at least one dot, there is no trailing dot, 2869 * and RES_DNSRCH is set. 2870 */ 2871 if ((!dots && (res->options & RES_DEFNAMES)) || 2872 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2873 int done = 0; 2874 2875 for (domain = (const char * const *)res->dnsrch; 2876 *domain && !done; 2877 domain++) { 2878 searched = 1; 2879 2880 if (domain[0][0] == '\0' || 2881 (domain[0][0] == '.' && domain[0][1] == '\0')) 2882 root_on_list++; 2883 2884 if (root_on_list && tried_as_is) 2885 continue; 2886 2887 ret = res_querydomainN(name, *domain, target, res); 2888 if (ret > 0) 2889 return (ret); 2890 2891 /* 2892 * If no server present, give up. 2893 * If name isn't found in this domain, 2894 * keep trying higher domains in the search list 2895 * (if that's enabled). 2896 * On a NO_DATA error, keep trying, otherwise 2897 * a wildcard entry of another type could keep us 2898 * from finding this entry higher in the domain. 2899 * If we get some other error (negative answer or 2900 * server failure), then stop searching up, 2901 * but try the input name below in case it's 2902 * fully-qualified. 2903 */ 2904 if (errno == ECONNREFUSED) { 2905 RES_SET_H_ERRNO(res, TRY_AGAIN); 2906 return (-1); 2907 } 2908 2909 switch (res->res_h_errno) { 2910 case NO_DATA: 2911 got_nodata++; 2912 /* FALLTHROUGH */ 2913 case HOST_NOT_FOUND: 2914 /* keep trying */ 2915 break; 2916 case TRY_AGAIN: 2917 got_servfail++; 2918 if (hp->rcode == SERVFAIL) { 2919 /* try next search element, if any */ 2920 break; 2921 } 2922 /* FALLTHROUGH */ 2923 default: 2924 /* anything else implies that we're done */ 2925 done++; 2926 } 2927 /* 2928 * if we got here for some reason other than DNSRCH, 2929 * we only wanted one iteration of the loop, so stop. 2930 */ 2931 if (!(res->options & RES_DNSRCH)) 2932 done++; 2933 } 2934 } 2935 2936 switch (res->res_h_errno) { 2937 case NO_DATA: 2938 case HOST_NOT_FOUND: 2939 break; 2940 case TRY_AGAIN: 2941 if (hp->rcode == SERVFAIL) 2942 break; 2943 /* FALLTHROUGH */ 2944 default: 2945 goto giveup; 2946 } 2947 2948 /* 2949 * If the query has not already been tried as is then try it 2950 * unless RES_NOTLDQUERY is set and there were no dots. 2951 */ 2952 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2953 !(tried_as_is || root_on_list)) { 2954 ret = res_querydomainN(name, NULL, target, res); 2955 if (ret > 0) 2956 return (ret); 2957 } 2958 2959 /* 2960 * if we got here, we didn't satisfy the search. 2961 * if we did an initial full query, return that query's h_errno 2962 * (note that we wouldn't be here if that query had succeeded). 2963 * else if we ever got a nodata, send that back as the reason. 2964 * else send back meaningless h_errno, that being the one from 2965 * the last DNSRCH we did. 2966 */ 2967giveup: 2968 if (saved_herrno != -1) 2969 RES_SET_H_ERRNO(res, saved_herrno); 2970 else if (got_nodata) 2971 RES_SET_H_ERRNO(res, NO_DATA); 2972 else if (got_servfail) 2973 RES_SET_H_ERRNO(res, TRY_AGAIN); 2974 return (-1); 2975} 2976 2977/* 2978 * Perform a call on res_query on the concatenation of name and domain, 2979 * removing a trailing dot from name if domain is NULL. 2980 */ 2981static int 2982res_querydomainN(const char *name, const char *domain, 2983 struct res_target *target, res_state res) 2984{ 2985 char nbuf[MAXDNAME]; 2986 const char *longname = nbuf; 2987 size_t n, d; 2988 2989#ifdef DEBUG 2990 if (res->options & RES_DEBUG) 2991 printf(";; res_querydomain(%s, %s)\n", 2992 name, domain?domain:"<Nil>"); 2993#endif 2994 if (domain == NULL) { 2995 /* 2996 * Check for trailing '.'; 2997 * copy without '.' if present. 2998 */ 2999 n = strlen(name); 3000 if (n >= MAXDNAME) { 3001 RES_SET_H_ERRNO(res, NO_RECOVERY); 3002 return (-1); 3003 } 3004 if (n > 0 && name[--n] == '.') { 3005 strncpy(nbuf, name, n); 3006 nbuf[n] = '\0'; 3007 } else 3008 longname = name; 3009 } else { 3010 n = strlen(name); 3011 d = strlen(domain); 3012 if (n + d + 1 >= MAXDNAME) { 3013 RES_SET_H_ERRNO(res, NO_RECOVERY); 3014 return (-1); 3015 } 3016 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 3017 } 3018 return (res_queryN(longname, target, res)); 3019} 3020