getaddrinfo.c revision 160551
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 * - Thread safe-ness must be checked. 37 * - Return values. There are nonstandard return values defined and used 38 * in the source code. This is because RFC2553 is silent about which error 39 * code must be returned for which situation. 40 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 41 * invalid. current code - SEGV on freeaddrinfo(NULL) 42 * 43 * Note: 44 * - The code filters out AFs that are not supported by the kernel, 45 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 46 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 47 * in ai_flags? 48 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 49 * (1) what should we do against numeric hostname (2) what should we do 50 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 51 * non-loopback address configured? global address configured? 52 * 53 * OS specific notes for netbsd/openbsd/freebsd4/bsdi4: 54 * - To avoid search order issue, we have a big amount of code duplicate 55 * from gethnamaddr.c and some other places. The issues that there's no 56 * lower layer function to lookup "IPv4 or IPv6" record. Calling 57 * gethostbyname2 from getaddrinfo will end up in wrong search order, as 58 * presented above. 59 * 60 * OS specific notes for freebsd4: 61 * - FreeBSD supported $GAI. The code does not. 62 * - FreeBSD allowed classful IPv4 numeric (127.1), the code does not. 63 */ 64 65#include <sys/cdefs.h> 66__FBSDID("$FreeBSD: head/lib/libc/net/getaddrinfo.c 160551 2006-07-21 18:57:44Z ume $"); 67 68#include "namespace.h" 69#include <sys/types.h> 70#include <sys/param.h> 71#include <sys/socket.h> 72#include <net/if.h> 73#include <netinet/in.h> 74#include <sys/queue.h> 75#ifdef INET6 76#include <net/if_var.h> 77#include <sys/sysctl.h> 78#include <sys/ioctl.h> 79#include <netinet6/in6_var.h> /* XXX */ 80#endif 81#include <arpa/inet.h> 82#include <arpa/nameser.h> 83#include <rpc/rpc.h> 84#include <rpcsvc/yp_prot.h> 85#include <rpcsvc/ypclnt.h> 86#include <netdb.h> 87#include <resolv.h> 88#include <string.h> 89#include <stdlib.h> 90#include <stddef.h> 91#include <ctype.h> 92#include <unistd.h> 93#include <stdio.h> 94#include <errno.h> 95 96#include "res_config.h" 97 98#ifdef DEBUG 99#include <syslog.h> 100#endif 101 102#include <stdarg.h> 103#include <nsswitch.h> 104#include "un-namespace.h" 105#include "libc_private.h" 106#ifdef NS_CACHING 107#include "nscache.h" 108#endif 109 110#if defined(__KAME__) && defined(INET6) 111# define FAITH 112#endif 113 114#define SUCCESS 0 115#define ANY 0 116#define YES 1 117#define NO 0 118 119static const char in_addrany[] = { 0, 0, 0, 0 }; 120static const char in_loopback[] = { 127, 0, 0, 1 }; 121#ifdef INET6 122static const char in6_addrany[] = { 123 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 124}; 125static const char in6_loopback[] = { 126 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 127}; 128#endif 129 130struct policyqueue { 131 TAILQ_ENTRY(policyqueue) pc_entry; 132#ifdef INET6 133 struct in6_addrpolicy pc_policy; 134#endif 135}; 136TAILQ_HEAD(policyhead, policyqueue); 137 138static const struct afd { 139 int a_af; 140 int a_addrlen; 141 socklen_t a_socklen; 142 int a_off; 143 const char *a_addrany; 144 const char *a_loopback; 145 int a_scoped; 146} afdl [] = { 147#ifdef INET6 148#define N_INET6 0 149 {PF_INET6, sizeof(struct in6_addr), 150 sizeof(struct sockaddr_in6), 151 offsetof(struct sockaddr_in6, sin6_addr), 152 in6_addrany, in6_loopback, 1}, 153#define N_INET 1 154#else 155#define N_INET 0 156#endif 157 {PF_INET, sizeof(struct in_addr), 158 sizeof(struct sockaddr_in), 159 offsetof(struct sockaddr_in, sin_addr), 160 in_addrany, in_loopback, 0}, 161 {0, 0, 0, 0, NULL, NULL, 0}, 162}; 163 164struct explore { 165 int e_af; 166 int e_socktype; 167 int e_protocol; 168 const char *e_protostr; 169 int e_wild; 170#define WILD_AF(ex) ((ex)->e_wild & 0x01) 171#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 172#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 173}; 174 175static const struct explore explore[] = { 176#if 0 177 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 178#endif 179#ifdef INET6 180 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 181 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 182 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 183#endif 184 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 185 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 186 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 187 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 188 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 189 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 190 { -1, 0, 0, NULL, 0 }, 191}; 192 193#ifdef INET6 194#define PTON_MAX 16 195#else 196#define PTON_MAX 4 197#endif 198 199#define AIO_SRCFLAG_DEPRECATED 0x1 200 201struct ai_order { 202 union { 203 struct sockaddr_storage aiou_ss; 204 struct sockaddr aiou_sa; 205 } aio_src_un; 206#define aio_srcsa aio_src_un.aiou_sa 207 u_int32_t aio_srcflag; 208 int aio_srcscope; 209 int aio_dstscope; 210 struct policyqueue *aio_srcpolicy; 211 struct policyqueue *aio_dstpolicy; 212 struct addrinfo *aio_ai; 213 int aio_matchlen; 214}; 215 216static const ns_src default_dns_files[] = { 217 { NSSRC_FILES, NS_SUCCESS }, 218 { NSSRC_DNS, NS_SUCCESS }, 219 { 0 } 220}; 221 222struct res_target { 223 struct res_target *next; 224 const char *name; /* domain name */ 225 int qclass, qtype; /* class and type of query */ 226 u_char *answer; /* buffer to put answer */ 227 int anslen; /* size of answer buffer */ 228 int n; /* result length */ 229}; 230 231#define MAXPACKET (64*1024) 232 233typedef union { 234 HEADER hdr; 235 u_char buf[MAXPACKET]; 236} querybuf; 237 238static int str2number(const char *); 239static int explore_null(const struct addrinfo *, 240 const char *, struct addrinfo **); 241static int explore_numeric(const struct addrinfo *, const char *, 242 const char *, struct addrinfo **, const char *); 243static int explore_numeric_scope(const struct addrinfo *, const char *, 244 const char *, struct addrinfo **); 245static int get_canonname(const struct addrinfo *, 246 struct addrinfo *, const char *); 247static struct addrinfo *get_ai(const struct addrinfo *, 248 const struct afd *, const char *); 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 *); 253static void set_source(struct ai_order *, struct policyhead *); 254static int comp_dst(const void *, const void *); 255#ifdef INET6 256static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 257#endif 258static int gai_addr2scopetype(struct sockaddr *); 259 260static int explore_fqdn(const struct addrinfo *, const char *, 261 const char *, struct addrinfo **); 262 263static int reorder(struct addrinfo *); 264static int get_addrselectpolicy(struct policyhead *); 265static void free_addrselectpolicy(struct policyhead *); 266static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 267 struct policyhead *); 268static int matchlen(struct sockaddr *, struct sockaddr *); 269 270static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 271 const struct addrinfo *, res_state); 272#if defined(RESOLVSORT) 273static int addr4sort(struct addrinfo *, res_state); 274#endif 275static int _dns_getaddrinfo(void *, void *, va_list); 276static void _sethtent(FILE **); 277static void _endhtent(FILE **); 278static struct addrinfo *_gethtent(FILE **, const char *, 279 const struct addrinfo *); 280static int _files_getaddrinfo(void *, void *, va_list); 281#ifdef YP 282static struct addrinfo *_yphostent(char *, const struct addrinfo *); 283static int _yp_getaddrinfo(void *, void *, va_list); 284#endif 285#ifdef NS_CACHING 286static int addrinfo_id_func(char *, size_t *, va_list, void *); 287static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 288static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 289#endif 290 291static int res_queryN(const char *, struct res_target *, res_state); 292static int res_searchN(const char *, struct res_target *, res_state); 293static int res_querydomainN(const char *, const char *, 294 struct res_target *, res_state); 295 296/* XXX macros that make external reference is BAD. */ 297 298#define GET_AI(ai, afd, addr) \ 299do { \ 300 /* external reference: pai, error, and label free */ \ 301 (ai) = get_ai(pai, (afd), (addr)); \ 302 if ((ai) == NULL) { \ 303 error = EAI_MEMORY; \ 304 goto free; \ 305 } \ 306} while (/*CONSTCOND*/0) 307 308#define GET_PORT(ai, serv) \ 309do { \ 310 /* external reference: error and label free */ \ 311 error = get_port((ai), (serv), 0); \ 312 if (error != 0) \ 313 goto free; \ 314} while (/*CONSTCOND*/0) 315 316#define GET_CANONNAME(ai, str) \ 317do { \ 318 /* external reference: pai, error and label free */ \ 319 error = get_canonname(pai, (ai), (str)); \ 320 if (error != 0) \ 321 goto free; \ 322} while (/*CONSTCOND*/0) 323 324#define ERR(err) \ 325do { \ 326 /* external reference: error, and label bad */ \ 327 error = (err); \ 328 goto bad; \ 329 /*NOTREACHED*/ \ 330} while (/*CONSTCOND*/0) 331 332#define MATCH_FAMILY(x, y, w) \ 333 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 334#define MATCH(x, y, w) \ 335 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 336 337void 338freeaddrinfo(struct addrinfo *ai) 339{ 340 struct addrinfo *next; 341 342 do { 343 next = ai->ai_next; 344 if (ai->ai_canonname) 345 free(ai->ai_canonname); 346 /* no need to free(ai->ai_addr) */ 347 free(ai); 348 ai = next; 349 } while (ai); 350} 351 352static int 353str2number(const char *p) 354{ 355 char *ep; 356 unsigned long v; 357 358 if (*p == '\0') 359 return -1; 360 ep = NULL; 361 errno = 0; 362 v = strtoul(p, &ep, 10); 363 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) 364 return v; 365 else 366 return -1; 367} 368 369int 370getaddrinfo(const char *hostname, const char *servname, 371 const struct addrinfo *hints, struct addrinfo **res) 372{ 373 struct addrinfo sentinel; 374 struct addrinfo *cur; 375 int error = 0; 376 struct addrinfo ai; 377 struct addrinfo ai0; 378 struct addrinfo *pai; 379 const struct explore *ex; 380 int numeric = 0; 381 382 memset(&sentinel, 0, sizeof(sentinel)); 383 cur = &sentinel; 384 pai = &ai; 385 pai->ai_flags = 0; 386 pai->ai_family = PF_UNSPEC; 387 pai->ai_socktype = ANY; 388 pai->ai_protocol = ANY; 389 pai->ai_addrlen = 0; 390 pai->ai_canonname = NULL; 391 pai->ai_addr = NULL; 392 pai->ai_next = NULL; 393 394 if (hostname == NULL && servname == NULL) 395 return EAI_NONAME; 396 if (hints) { 397 /* error check for hints */ 398 if (hints->ai_addrlen || hints->ai_canonname || 399 hints->ai_addr || hints->ai_next) 400 ERR(EAI_BADHINTS); /* xxx */ 401 if (hints->ai_flags & ~AI_MASK) 402 ERR(EAI_BADFLAGS); 403 switch (hints->ai_family) { 404 case PF_UNSPEC: 405 case PF_INET: 406#ifdef INET6 407 case PF_INET6: 408#endif 409 break; 410 default: 411 ERR(EAI_FAMILY); 412 } 413 memcpy(pai, hints, sizeof(*pai)); 414 415 /* 416 * if both socktype/protocol are specified, check if they 417 * are meaningful combination. 418 */ 419 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 420 for (ex = explore; ex->e_af >= 0; ex++) { 421 if (pai->ai_family != ex->e_af) 422 continue; 423 if (ex->e_socktype == ANY) 424 continue; 425 if (ex->e_protocol == ANY) 426 continue; 427 if (pai->ai_socktype == ex->e_socktype && 428 pai->ai_protocol != ex->e_protocol) { 429 ERR(EAI_BADHINTS); 430 } 431 } 432 } 433 } 434 435 /* 436 * post-2553: AI_ALL and AI_V4MAPPED are effective only against 437 * AF_INET6 query. They need to be ignored if specified in other 438 * occassions. 439 */ 440 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 441 case AI_V4MAPPED: 442 case AI_ALL | AI_V4MAPPED: 443 if (pai->ai_family != AF_INET6) 444 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 445 break; 446 case AI_ALL: 447#if 1 448 /* illegal */ 449 ERR(EAI_BADFLAGS); 450#else 451 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 452#endif 453 break; 454 } 455 456 /* 457 * check for special cases. (1) numeric servname is disallowed if 458 * socktype/protocol are left unspecified. (2) servname is disallowed 459 * for raw and other inet{,6} sockets. 460 */ 461 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 462#ifdef PF_INET6 463 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 464#endif 465 ) { 466 ai0 = *pai; /* backup *pai */ 467 468 if (pai->ai_family == PF_UNSPEC) { 469#ifdef PF_INET6 470 pai->ai_family = PF_INET6; 471#else 472 pai->ai_family = PF_INET; 473#endif 474 } 475 error = get_portmatch(pai, servname); 476 if (error) 477 ERR(error); 478 479 *pai = ai0; 480 } 481 482 ai0 = *pai; 483 484 /* NULL hostname, or numeric hostname */ 485 for (ex = explore; ex->e_af >= 0; ex++) { 486 *pai = ai0; 487 488 /* PF_UNSPEC entries are prepared for DNS queries only */ 489 if (ex->e_af == PF_UNSPEC) 490 continue; 491 492 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 493 continue; 494 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 495 continue; 496 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 497 continue; 498 499 if (pai->ai_family == PF_UNSPEC) 500 pai->ai_family = ex->e_af; 501 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 502 pai->ai_socktype = ex->e_socktype; 503 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 504 pai->ai_protocol = ex->e_protocol; 505 506 if (hostname == NULL) 507 error = explore_null(pai, servname, &cur->ai_next); 508 else 509 error = explore_numeric_scope(pai, hostname, servname, 510 &cur->ai_next); 511 512 if (error) 513 goto free; 514 515 while (cur && cur->ai_next) 516 cur = cur->ai_next; 517 } 518 519 /* 520 * XXX 521 * If numreic representation of AF1 can be interpreted as FQDN 522 * representation of AF2, we need to think again about the code below. 523 */ 524 if (sentinel.ai_next) { 525 numeric = 1; 526 goto good; 527 } 528 529 if (hostname == NULL) 530 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 531 if (pai->ai_flags & AI_NUMERICHOST) 532 ERR(EAI_NONAME); 533 534 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 535 ERR(EAI_FAIL); 536 537 /* 538 * hostname as alphabetical name. 539 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 540 * outer loop by AFs. 541 */ 542 for (ex = explore; ex->e_af >= 0; ex++) { 543 *pai = ai0; 544 545 /* require exact match for family field */ 546 if (pai->ai_family != ex->e_af) 547 continue; 548 549 if (!MATCH(pai->ai_socktype, ex->e_socktype, 550 WILD_SOCKTYPE(ex))) { 551 continue; 552 } 553 if (!MATCH(pai->ai_protocol, ex->e_protocol, 554 WILD_PROTOCOL(ex))) { 555 continue; 556 } 557 558 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 559 pai->ai_socktype = ex->e_socktype; 560 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 561 pai->ai_protocol = ex->e_protocol; 562 563 error = explore_fqdn(pai, hostname, servname, 564 &cur->ai_next); 565 566 while (cur && cur->ai_next) 567 cur = cur->ai_next; 568 } 569 570 /* XXX inhibit errors if we have the result */ 571 if (sentinel.ai_next) 572 error = 0; 573 574good: 575 /* 576 * ensure we return either: 577 * - error == 0, non-NULL *res 578 * - error != 0, NULL *res 579 */ 580 if (error == 0) { 581 if (sentinel.ai_next) { 582 /* 583 * If the returned entry is for an active connection, 584 * and the given name is not numeric, reorder the 585 * list, so that the application would try the list 586 * in the most efficient order. 587 */ 588 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 589 if (!numeric) 590 (void)reorder(&sentinel); 591 } 592 *res = sentinel.ai_next; 593 return SUCCESS; 594 } else 595 error = EAI_FAIL; 596 } 597free: 598bad: 599 if (sentinel.ai_next) 600 freeaddrinfo(sentinel.ai_next); 601 *res = NULL; 602 return error; 603} 604 605static int 606reorder(struct addrinfo *sentinel) 607{ 608 struct addrinfo *ai, **aip; 609 struct ai_order *aio; 610 int i, n; 611 struct policyhead policyhead; 612 613 /* count the number of addrinfo elements for sorting. */ 614 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 615 ; 616 617 /* 618 * If the number is small enough, we can skip the reordering process. 619 */ 620 if (n <= 1) 621 return(n); 622 623 /* allocate a temporary array for sort and initialization of it. */ 624 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 625 return(n); /* give up reordering */ 626 memset(aio, 0, sizeof(*aio) * n); 627 628 /* retrieve address selection policy from the kernel */ 629 TAILQ_INIT(&policyhead); 630 if (!get_addrselectpolicy(&policyhead)) { 631 /* no policy is installed into kernel, we don't sort. */ 632 free(aio); 633 return (n); 634 } 635 636 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 637 aio[i].aio_ai = ai; 638 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 639 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 640 &policyhead); 641 set_source(&aio[i], &policyhead); 642 } 643 644 /* perform sorting. */ 645 qsort(aio, n, sizeof(*aio), comp_dst); 646 647 /* reorder the addrinfo chain. */ 648 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 649 *aip = aio[i].aio_ai; 650 aip = &aio[i].aio_ai->ai_next; 651 } 652 *aip = NULL; 653 654 /* cleanup and return */ 655 free(aio); 656 free_addrselectpolicy(&policyhead); 657 return(n); 658} 659 660static int 661get_addrselectpolicy(struct policyhead *head) 662{ 663#ifdef INET6 664 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 665 size_t l; 666 char *buf; 667 struct in6_addrpolicy *pol, *ep; 668 669 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 670 return (0); 671 if ((buf = malloc(l)) == NULL) 672 return (0); 673 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 674 free(buf); 675 return (0); 676 } 677 678 ep = (struct in6_addrpolicy *)(buf + l); 679 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 680 struct policyqueue *new; 681 682 if ((new = malloc(sizeof(*new))) == NULL) { 683 free_addrselectpolicy(head); /* make the list empty */ 684 break; 685 } 686 new->pc_policy = *pol; 687 TAILQ_INSERT_TAIL(head, new, pc_entry); 688 } 689 690 free(buf); 691 return (1); 692#else 693 return (0); 694#endif 695} 696 697static void 698free_addrselectpolicy(struct policyhead *head) 699{ 700 struct policyqueue *ent, *nent; 701 702 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 703 nent = TAILQ_NEXT(ent, pc_entry); 704 TAILQ_REMOVE(head, ent, pc_entry); 705 free(ent); 706 } 707} 708 709static struct policyqueue * 710match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 711{ 712#ifdef INET6 713 struct policyqueue *ent, *bestent = NULL; 714 struct in6_addrpolicy *pol; 715 int matchlen, bestmatchlen = -1; 716 u_char *mp, *ep, *k, *p, m; 717 struct sockaddr_in6 key; 718 719 switch(addr->sa_family) { 720 case AF_INET6: 721 key = *(struct sockaddr_in6 *)addr; 722 break; 723 case AF_INET: 724 /* convert the address into IPv4-mapped IPv6 address. */ 725 memset(&key, 0, sizeof(key)); 726 key.sin6_family = AF_INET6; 727 key.sin6_len = sizeof(key); 728 key.sin6_addr.s6_addr[10] = 0xff; 729 key.sin6_addr.s6_addr[11] = 0xff; 730 memcpy(&key.sin6_addr.s6_addr[12], 731 &((struct sockaddr_in *)addr)->sin_addr, 4); 732 break; 733 default: 734 return(NULL); 735 } 736 737 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 738 pol = &ent->pc_policy; 739 matchlen = 0; 740 741 mp = (u_char *)&pol->addrmask.sin6_addr; 742 ep = mp + 16; /* XXX: scope field? */ 743 k = (u_char *)&key.sin6_addr; 744 p = (u_char *)&pol->addr.sin6_addr; 745 for (; mp < ep && *mp; mp++, k++, p++) { 746 m = *mp; 747 if ((*k & m) != *p) 748 goto next; /* not match */ 749 if (m == 0xff) /* short cut for a typical case */ 750 matchlen += 8; 751 else { 752 while (m >= 0x80) { 753 matchlen++; 754 m <<= 1; 755 } 756 } 757 } 758 759 /* matched. check if this is better than the current best. */ 760 if (matchlen > bestmatchlen) { 761 bestent = ent; 762 bestmatchlen = matchlen; 763 } 764 765 next: 766 continue; 767 } 768 769 return(bestent); 770#else 771 return(NULL); 772#endif 773 774} 775 776static void 777set_source(struct ai_order *aio, struct policyhead *ph) 778{ 779 struct addrinfo ai = *aio->aio_ai; 780 struct sockaddr_storage ss; 781 socklen_t srclen; 782 int s; 783 784 /* set unspec ("no source is available"), just in case */ 785 aio->aio_srcsa.sa_family = AF_UNSPEC; 786 aio->aio_srcscope = -1; 787 788 switch(ai.ai_family) { 789 case AF_INET: 790#ifdef INET6 791 case AF_INET6: 792#endif 793 break; 794 default: /* ignore unsupported AFs explicitly */ 795 return; 796 } 797 798 /* XXX: make a dummy addrinfo to call connect() */ 799 ai.ai_socktype = SOCK_DGRAM; 800 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 801 ai.ai_next = NULL; 802 memset(&ss, 0, sizeof(ss)); 803 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 804 ai.ai_addr = (struct sockaddr *)&ss; 805 get_port(&ai, "1", 0); 806 807 /* open a socket to get the source address for the given dst */ 808 if ((s = _socket(ai.ai_family, ai.ai_socktype, ai.ai_protocol)) < 0) 809 return; /* give up */ 810 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 811 goto cleanup; 812 srclen = ai.ai_addrlen; 813 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 814 aio->aio_srcsa.sa_family = AF_UNSPEC; 815 goto cleanup; 816 } 817 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 818 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 819 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 820#ifdef INET6 821 if (ai.ai_family == AF_INET6) { 822 struct in6_ifreq ifr6; 823 u_int32_t flags6; 824 825 /* XXX: interface name should not be hardcoded */ 826 strncpy(ifr6.ifr_name, "lo0", sizeof(ifr6.ifr_name)); 827 memset(&ifr6, 0, sizeof(ifr6)); 828 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 829 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 830 flags6 = ifr6.ifr_ifru.ifru_flags6; 831 if ((flags6 & IN6_IFF_DEPRECATED)) 832 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 833 } 834 } 835#endif 836 837 cleanup: 838 _close(s); 839 return; 840} 841 842static int 843matchlen(struct sockaddr *src, struct sockaddr *dst) 844{ 845 int match = 0; 846 u_char *s, *d; 847 u_char *lim, r; 848 int addrlen; 849 850 switch (src->sa_family) { 851#ifdef INET6 852 case AF_INET6: 853 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 854 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 855 addrlen = sizeof(struct in6_addr); 856 lim = s + addrlen; 857 break; 858#endif 859 case AF_INET: 860 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 861 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 862 addrlen = sizeof(struct in_addr); 863 lim = s + addrlen; 864 break; 865 default: 866 return(0); 867 } 868 869 while (s < lim) 870 if ((r = (*d++ ^ *s++)) != 0) { 871 while (r < addrlen * 8) { 872 match++; 873 r <<= 1; 874 } 875 break; 876 } else 877 match += 8; 878 return(match); 879} 880 881static int 882comp_dst(const void *arg1, const void *arg2) 883{ 884 const struct ai_order *dst1 = arg1, *dst2 = arg2; 885 886 /* 887 * Rule 1: Avoid unusable destinations. 888 * XXX: we currently do not consider if an appropriate route exists. 889 */ 890 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 891 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 892 return(-1); 893 } 894 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 895 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 896 return(1); 897 } 898 899 /* Rule 2: Prefer matching scope. */ 900 if (dst1->aio_dstscope == dst1->aio_srcscope && 901 dst2->aio_dstscope != dst2->aio_srcscope) { 902 return(-1); 903 } 904 if (dst1->aio_dstscope != dst1->aio_srcscope && 905 dst2->aio_dstscope == dst2->aio_srcscope) { 906 return(1); 907 } 908 909 /* Rule 3: Avoid deprecated addresses. */ 910 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 911 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 912 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 913 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 914 return(-1); 915 } 916 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 917 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 918 return(1); 919 } 920 } 921 922 /* Rule 4: Prefer home addresses. */ 923 /* XXX: not implemented yet */ 924 925 /* Rule 5: Prefer matching label. */ 926#ifdef INET6 927 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 928 dst1->aio_srcpolicy->pc_policy.label == 929 dst1->aio_dstpolicy->pc_policy.label && 930 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 931 dst2->aio_srcpolicy->pc_policy.label != 932 dst2->aio_dstpolicy->pc_policy.label)) { 933 return(-1); 934 } 935 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 936 dst2->aio_srcpolicy->pc_policy.label == 937 dst2->aio_dstpolicy->pc_policy.label && 938 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 939 dst1->aio_srcpolicy->pc_policy.label != 940 dst1->aio_dstpolicy->pc_policy.label)) { 941 return(1); 942 } 943#endif 944 945 /* Rule 6: Prefer higher precedence. */ 946#ifdef INET6 947 if (dst1->aio_dstpolicy && 948 (dst2->aio_dstpolicy == NULL || 949 dst1->aio_dstpolicy->pc_policy.preced > 950 dst2->aio_dstpolicy->pc_policy.preced)) { 951 return(-1); 952 } 953 if (dst2->aio_dstpolicy && 954 (dst1->aio_dstpolicy == NULL || 955 dst2->aio_dstpolicy->pc_policy.preced > 956 dst1->aio_dstpolicy->pc_policy.preced)) { 957 return(1); 958 } 959#endif 960 961 /* Rule 7: Prefer native transport. */ 962 /* XXX: not implemented yet */ 963 964 /* Rule 8: Prefer smaller scope. */ 965 if (dst1->aio_dstscope >= 0 && 966 dst1->aio_dstscope < dst2->aio_dstscope) { 967 return(-1); 968 } 969 if (dst2->aio_dstscope >= 0 && 970 dst2->aio_dstscope < dst1->aio_dstscope) { 971 return(1); 972 } 973 974 /* 975 * Rule 9: Use longest matching prefix. 976 * We compare the match length in a same AF only. 977 */ 978 if (dst1->aio_ai->ai_addr->sa_family == 979 dst2->aio_ai->ai_addr->sa_family) { 980 if (dst1->aio_matchlen > dst2->aio_matchlen) { 981 return(-1); 982 } 983 if (dst1->aio_matchlen < dst2->aio_matchlen) { 984 return(1); 985 } 986 } 987 988 /* Rule 10: Otherwise, leave the order unchanged. */ 989 return(-1); 990} 991 992/* 993 * Copy from scope.c. 994 * XXX: we should standardize the functions and link them as standard 995 * library. 996 */ 997static int 998gai_addr2scopetype(struct sockaddr *sa) 999{ 1000#ifdef INET6 1001 struct sockaddr_in6 *sa6; 1002#endif 1003 struct sockaddr_in *sa4; 1004 1005 switch(sa->sa_family) { 1006#ifdef INET6 1007 case AF_INET6: 1008 sa6 = (struct sockaddr_in6 *)sa; 1009 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1010 /* just use the scope field of the multicast address */ 1011 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1012 } 1013 /* 1014 * Unicast addresses: map scope type to corresponding scope 1015 * value defined for multcast addresses. 1016 * XXX: hardcoded scope type values are bad... 1017 */ 1018 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1019 return(1); /* node local scope */ 1020 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1021 return(2); /* link-local scope */ 1022 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1023 return(5); /* site-local scope */ 1024 return(14); /* global scope */ 1025 break; 1026#endif 1027 case AF_INET: 1028 /* 1029 * IPv4 pseudo scoping according to RFC 3484. 1030 */ 1031 sa4 = (struct sockaddr_in *)sa; 1032 /* IPv4 autoconfiguration addresses have link-local scope. */ 1033 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1034 ((u_char *)&sa4->sin_addr)[1] == 254) 1035 return(2); 1036 /* Private addresses have site-local scope. */ 1037 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1038 (((u_char *)&sa4->sin_addr)[0] == 172 && 1039 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1040 (((u_char *)&sa4->sin_addr)[0] == 192 && 1041 ((u_char *)&sa4->sin_addr)[1] == 168)) 1042 return(14); /* XXX: It should be 5 unless NAT */ 1043 /* Loopback addresses have link-local scope. */ 1044 if (((u_char *)&sa4->sin_addr)[0] == 127) 1045 return(2); 1046 return(14); 1047 break; 1048 default: 1049 errno = EAFNOSUPPORT; /* is this a good error? */ 1050 return(-1); 1051 } 1052} 1053 1054/* 1055 * hostname == NULL. 1056 * passive socket -> anyaddr (0.0.0.0 or ::) 1057 * non-passive socket -> localhost (127.0.0.1 or ::1) 1058 */ 1059static int 1060explore_null(const struct addrinfo *pai, const char *servname, 1061 struct addrinfo **res) 1062{ 1063 int s; 1064 const struct afd *afd; 1065 struct addrinfo *ai; 1066 int error; 1067 1068 *res = NULL; 1069 ai = NULL; 1070 1071 /* 1072 * filter out AFs that are not supported by the kernel 1073 * XXX errno? 1074 */ 1075 s = _socket(pai->ai_family, SOCK_DGRAM, 0); 1076 if (s < 0) { 1077 if (errno != EMFILE) 1078 return 0; 1079 } else 1080 _close(s); 1081 1082 /* 1083 * if the servname does not match socktype/protocol, ignore it. 1084 */ 1085 if (get_portmatch(pai, servname) != 0) 1086 return 0; 1087 1088 afd = find_afd(pai->ai_family); 1089 if (afd == NULL) 1090 return 0; 1091 1092 if (pai->ai_flags & AI_PASSIVE) { 1093 GET_AI(ai, afd, afd->a_addrany); 1094 GET_PORT(ai, servname); 1095 } else { 1096 GET_AI(ai, afd, afd->a_loopback); 1097 GET_PORT(ai, servname); 1098 } 1099 1100 *res = ai; 1101 return 0; 1102 1103free: 1104 if (ai != NULL) 1105 freeaddrinfo(ai); 1106 return error; 1107} 1108 1109/* 1110 * numeric hostname 1111 */ 1112static int 1113explore_numeric(const struct addrinfo *pai, const char *hostname, 1114 const char *servname, struct addrinfo **res, const char *canonname) 1115{ 1116 const struct afd *afd; 1117 struct addrinfo *ai; 1118 int error; 1119 char pton[PTON_MAX]; 1120 1121 *res = NULL; 1122 ai = NULL; 1123 1124 /* 1125 * if the servname does not match socktype/protocol, ignore it. 1126 */ 1127 if (get_portmatch(pai, servname) != 0) 1128 return 0; 1129 1130 afd = find_afd(pai->ai_family); 1131 if (afd == NULL) 1132 return 0; 1133 1134 switch (afd->a_af) { 1135#if 1 /*X/Open spec*/ 1136 case AF_INET: 1137 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 1138 if (pai->ai_family == afd->a_af || 1139 pai->ai_family == PF_UNSPEC /*?*/) { 1140 GET_AI(ai, afd, pton); 1141 GET_PORT(ai, servname); 1142 if ((pai->ai_flags & AI_CANONNAME)) { 1143 /* 1144 * Set the numeric address itself as 1145 * the canonical name, based on a 1146 * clarification in rfc3493. 1147 */ 1148 GET_CANONNAME(ai, canonname); 1149 } 1150 } else 1151 ERR(EAI_FAMILY); /*xxx*/ 1152 } 1153 break; 1154#endif 1155 default: 1156 if (inet_pton(afd->a_af, hostname, pton) == 1) { 1157 if (pai->ai_family == afd->a_af || 1158 pai->ai_family == PF_UNSPEC /*?*/) { 1159 GET_AI(ai, afd, pton); 1160 GET_PORT(ai, servname); 1161 if ((pai->ai_flags & AI_CANONNAME)) { 1162 /* 1163 * Set the numeric address itself as 1164 * the canonical name, based on a 1165 * clarification in rfc3493. 1166 */ 1167 GET_CANONNAME(ai, canonname); 1168 } 1169 } else 1170 ERR(EAI_FAMILY); /* XXX */ 1171 } 1172 break; 1173 } 1174 1175 *res = ai; 1176 return 0; 1177 1178free: 1179bad: 1180 if (ai != NULL) 1181 freeaddrinfo(ai); 1182 return error; 1183} 1184 1185/* 1186 * numeric hostname with scope 1187 */ 1188static int 1189explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1190 const char *servname, struct addrinfo **res) 1191{ 1192#if !defined(SCOPE_DELIMITER) || !defined(INET6) 1193 return explore_numeric(pai, hostname, servname, res, hostname); 1194#else 1195 const struct afd *afd; 1196 struct addrinfo *cur; 1197 int error; 1198 char *cp, *hostname2 = NULL, *scope, *addr; 1199 struct sockaddr_in6 *sin6; 1200 1201 /* 1202 * if the servname does not match socktype/protocol, ignore it. 1203 */ 1204 if (get_portmatch(pai, servname) != 0) 1205 return 0; 1206 1207 afd = find_afd(pai->ai_family); 1208 if (afd == NULL) 1209 return 0; 1210 1211 if (!afd->a_scoped) 1212 return explore_numeric(pai, hostname, servname, res, hostname); 1213 1214 cp = strchr(hostname, SCOPE_DELIMITER); 1215 if (cp == NULL) 1216 return explore_numeric(pai, hostname, servname, res, hostname); 1217 1218 /* 1219 * Handle special case of <scoped_address><delimiter><scope id> 1220 */ 1221 hostname2 = strdup(hostname); 1222 if (hostname2 == NULL) 1223 return EAI_MEMORY; 1224 /* terminate at the delimiter */ 1225 hostname2[cp - hostname] = '\0'; 1226 addr = hostname2; 1227 scope = cp + 1; 1228 1229 error = explore_numeric(pai, addr, servname, res, hostname); 1230 if (error == 0) { 1231 u_int32_t scopeid; 1232 1233 for (cur = *res; cur; cur = cur->ai_next) { 1234 if (cur->ai_family != AF_INET6) 1235 continue; 1236 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1237 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1238 free(hostname2); 1239 return(EAI_NONAME); /* XXX: is return OK? */ 1240 } 1241 sin6->sin6_scope_id = scopeid; 1242 } 1243 } 1244 1245 free(hostname2); 1246 1247 return error; 1248#endif 1249} 1250 1251static int 1252get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1253{ 1254 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1255 ai->ai_canonname = strdup(str); 1256 if (ai->ai_canonname == NULL) 1257 return EAI_MEMORY; 1258 } 1259 return 0; 1260} 1261 1262static struct addrinfo * 1263get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1264{ 1265 char *p; 1266 struct addrinfo *ai; 1267#ifdef FAITH 1268 struct in6_addr faith_prefix; 1269 char *fp_str; 1270 int translate = 0; 1271#endif 1272 1273#ifdef FAITH 1274 /* 1275 * Transfrom an IPv4 addr into a special IPv6 addr format for 1276 * IPv6->IPv4 translation gateway. (only TCP is supported now) 1277 * 1278 * +-----------------------------------+------------+ 1279 * | faith prefix part (12 bytes) | embedded | 1280 * | | IPv4 addr part (4 bytes) 1281 * +-----------------------------------+------------+ 1282 * 1283 * faith prefix part is specified as ascii IPv6 addr format 1284 * in environmental variable GAI. 1285 * For FAITH to work correctly, routing to faith prefix must be 1286 * setup toward a machine where a FAITH daemon operates. 1287 * Also, the machine must enable some mechanizm 1288 * (e.g. faith interface hack) to divert those packet with 1289 * faith prefixed destination addr to user-land FAITH daemon. 1290 */ 1291 fp_str = getenv("GAI"); 1292 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 1293 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 1294 u_int32_t v4a; 1295 u_int8_t v4a_top; 1296 1297 memcpy(&v4a, addr, sizeof v4a); 1298 v4a_top = v4a >> IN_CLASSA_NSHIFT; 1299 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 1300 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 1301 afd = &afdl[N_INET6]; 1302 memcpy(&faith_prefix.s6_addr[12], addr, 1303 sizeof(struct in_addr)); 1304 translate = 1; 1305 } 1306 } 1307#endif 1308 1309 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1310 + (afd->a_socklen)); 1311 if (ai == NULL) 1312 return NULL; 1313 1314 memcpy(ai, pai, sizeof(struct addrinfo)); 1315 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1316 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1317 ai->ai_addr->sa_len = afd->a_socklen; 1318 ai->ai_addrlen = afd->a_socklen; 1319 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1320 p = (char *)(void *)(ai->ai_addr); 1321#ifdef FAITH 1322 if (translate == 1) 1323 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 1324 else 1325#endif 1326 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1327 return ai; 1328} 1329 1330static int 1331get_portmatch(const struct addrinfo *ai, const char *servname) 1332{ 1333 1334 /* get_port does not touch first argument when matchonly == 1. */ 1335 /* LINTED const cast */ 1336 return get_port((struct addrinfo *)ai, servname, 1); 1337} 1338 1339static int 1340get_port(struct addrinfo *ai, const char *servname, int matchonly) 1341{ 1342 const char *proto; 1343 struct servent *sp; 1344 int port; 1345 int allownumeric; 1346 1347 if (servname == NULL) 1348 return 0; 1349 switch (ai->ai_family) { 1350 case AF_INET: 1351#ifdef AF_INET6 1352 case AF_INET6: 1353#endif 1354 break; 1355 default: 1356 return 0; 1357 } 1358 1359 switch (ai->ai_socktype) { 1360 case SOCK_RAW: 1361 return EAI_SERVICE; 1362 case SOCK_DGRAM: 1363 case SOCK_STREAM: 1364 allownumeric = 1; 1365 break; 1366 case ANY: 1367 allownumeric = 0; 1368 break; 1369 default: 1370 return EAI_SOCKTYPE; 1371 } 1372 1373 port = str2number(servname); 1374 if (port >= 0) { 1375 if (!allownumeric) 1376 return EAI_SERVICE; 1377 if (port < 0 || port > 65535) 1378 return EAI_SERVICE; 1379 port = htons(port); 1380 } else { 1381 if (ai->ai_flags & AI_NUMERICSERV) 1382 return EAI_NONAME; 1383 switch (ai->ai_socktype) { 1384 case SOCK_DGRAM: 1385 proto = "udp"; 1386 break; 1387 case SOCK_STREAM: 1388 proto = "tcp"; 1389 break; 1390 default: 1391 proto = NULL; 1392 break; 1393 } 1394 1395 if ((sp = getservbyname(servname, proto)) == NULL) 1396 return EAI_SERVICE; 1397 port = sp->s_port; 1398 } 1399 1400 if (!matchonly) { 1401 switch (ai->ai_family) { 1402 case AF_INET: 1403 ((struct sockaddr_in *)(void *) 1404 ai->ai_addr)->sin_port = port; 1405 break; 1406#ifdef INET6 1407 case AF_INET6: 1408 ((struct sockaddr_in6 *)(void *) 1409 ai->ai_addr)->sin6_port = port; 1410 break; 1411#endif 1412 } 1413 } 1414 1415 return 0; 1416} 1417 1418static const struct afd * 1419find_afd(int af) 1420{ 1421 const struct afd *afd; 1422 1423 if (af == PF_UNSPEC) 1424 return NULL; 1425 for (afd = afdl; afd->a_af; afd++) { 1426 if (afd->a_af == af) 1427 return afd; 1428 } 1429 return NULL; 1430} 1431 1432/* 1433 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1434 * will take care of it. 1435 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1436 * if the code is right or not. 1437 * 1438 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1439 * _dns_getaddrinfo. 1440 */ 1441static int 1442addrconfig(struct addrinfo *pai) 1443{ 1444 int s, af; 1445 1446 /* 1447 * TODO: 1448 * Note that implementation dependent test for address 1449 * configuration should be done everytime called 1450 * (or apropriate interval), 1451 * because addresses will be dynamically assigned or deleted. 1452 */ 1453 af = pai->ai_family; 1454 if (af == AF_UNSPEC) { 1455 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 1456 af = AF_INET; 1457 else { 1458 _close(s); 1459 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) 1460 af = AF_INET6; 1461 else 1462 _close(s); 1463 } 1464 } 1465 if (af != AF_UNSPEC) { 1466 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 1467 return 0; 1468 _close(s); 1469 } 1470 pai->ai_family = af; 1471 return 1; 1472} 1473 1474#ifdef INET6 1475/* convert a string to a scope identifier. XXX: IPv6 specific */ 1476static int 1477ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1478{ 1479 u_long lscopeid; 1480 struct in6_addr *a6; 1481 char *ep; 1482 1483 a6 = &sin6->sin6_addr; 1484 1485 /* empty scopeid portion is invalid */ 1486 if (*scope == '\0') 1487 return -1; 1488 1489 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1490 /* 1491 * We currently assume a one-to-one mapping between links 1492 * and interfaces, so we simply use interface indices for 1493 * like-local scopes. 1494 */ 1495 *scopeid = if_nametoindex(scope); 1496 if (*scopeid == 0) 1497 goto trynumeric; 1498 return 0; 1499 } 1500 1501 /* still unclear about literal, allow numeric only - placeholder */ 1502 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1503 goto trynumeric; 1504 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1505 goto trynumeric; 1506 else 1507 goto trynumeric; /* global */ 1508 1509 /* try to convert to a numeric id as a last resort */ 1510 trynumeric: 1511 errno = 0; 1512 lscopeid = strtoul(scope, &ep, 10); 1513 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1514 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1515 return 0; 1516 else 1517 return -1; 1518} 1519#endif 1520 1521 1522#ifdef NS_CACHING 1523static int 1524addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1525 void *cache_mdata) 1526{ 1527 res_state statp; 1528 u_long res_options; 1529 1530 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1531 char *hostname; 1532 struct addrinfo *hints; 1533 1534 char *p; 1535 int ai_flags, ai_family, ai_socktype, ai_protocol; 1536 size_t desired_size, size; 1537 1538 statp = __res_state(); 1539 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1540 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1541 1542 hostname = va_arg(ap, char *); 1543 hints = va_arg(ap, struct addrinfo *); 1544 1545 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1546 if (hostname != NULL) { 1547 size = strlen(hostname); 1548 desired_size += size + 1; 1549 } else 1550 size = 0; 1551 1552 if (desired_size > *buffer_size) { 1553 *buffer_size = desired_size; 1554 return (NS_RETURN); 1555 } 1556 1557 if (hints == NULL) 1558 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1559 else { 1560 ai_flags = hints->ai_flags; 1561 ai_family = hints->ai_family; 1562 ai_socktype = hints->ai_socktype; 1563 ai_protocol = hints->ai_protocol; 1564 } 1565 1566 p = buffer; 1567 memcpy(p, &res_options, sizeof(res_options)); 1568 p += sizeof(res_options); 1569 1570 memcpy(p, &op_id, sizeof(int)); 1571 p += sizeof(int); 1572 1573 memcpy(p, &ai_flags, sizeof(int)); 1574 p += sizeof(int); 1575 1576 memcpy(p, &ai_family, sizeof(int)); 1577 p += sizeof(int); 1578 1579 memcpy(p, &ai_socktype, sizeof(int)); 1580 p += sizeof(int); 1581 1582 memcpy(p, &ai_protocol, sizeof(int)); 1583 p += sizeof(int); 1584 1585 if (hostname != NULL) 1586 memcpy(p, hostname, size); 1587 1588 *buffer_size = desired_size; 1589 return (NS_SUCCESS); 1590} 1591 1592static int 1593addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1594 va_list ap, void *cache_mdata) 1595{ 1596 struct addrinfo *ai, *cai; 1597 char *p; 1598 size_t desired_size, size, ai_size; 1599 1600 ai = *((struct addrinfo **)retval); 1601 1602 desired_size = sizeof(size_t); 1603 ai_size = 0; 1604 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1605 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1606 if (cai->ai_canonname != NULL) 1607 desired_size += sizeof(size_t) + 1608 strlen(cai->ai_canonname); 1609 ++ai_size; 1610 } 1611 1612 if (desired_size > *buffer_size) { 1613 /* this assignment is here for future use */ 1614 errno = ERANGE; 1615 *buffer_size = desired_size; 1616 return (NS_RETURN); 1617 } 1618 1619 memset(buffer, 0, desired_size); 1620 p = buffer; 1621 1622 memcpy(p, &ai_size, sizeof(size_t)); 1623 p += sizeof(size_t); 1624 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1625 memcpy(p, cai, sizeof(struct addrinfo)); 1626 p += sizeof(struct addrinfo); 1627 1628 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1629 p += cai->ai_addrlen; 1630 1631 if (cai->ai_canonname != NULL) { 1632 size = strlen(cai->ai_canonname); 1633 memcpy(p, &size, sizeof(size_t)); 1634 p += sizeof(size_t); 1635 1636 memcpy(p, cai->ai_canonname, size); 1637 p += size; 1638 } 1639 } 1640 1641 return (NS_SUCCESS); 1642} 1643 1644static int 1645addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1646 va_list ap, void *cache_mdata) 1647{ 1648 struct addrinfo new_ai, *result, *sentinel, *lasts; 1649 1650 char *p; 1651 size_t ai_size, ai_i, size; 1652 1653 p = buffer; 1654 memcpy(&ai_size, p, sizeof(size_t)); 1655 p += sizeof(size_t); 1656 1657 result = NULL; 1658 lasts = NULL; 1659 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1660 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1661 p += sizeof(struct addrinfo); 1662 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1663 _ALIGNBYTES; 1664 1665 sentinel = (struct addrinfo *)malloc(size); 1666 memset(sentinel, 0, size); 1667 1668 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1669 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1670 sizeof(struct addrinfo)); 1671 1672 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1673 p += new_ai.ai_addrlen; 1674 1675 if (new_ai.ai_canonname != NULL) { 1676 memcpy(&size, p, sizeof(size_t)); 1677 p += sizeof(size_t); 1678 1679 sentinel->ai_canonname = (char *)malloc(size + 1); 1680 memset(sentinel->ai_canonname, 0, size + 1); 1681 1682 memcpy(sentinel->ai_canonname, p, size); 1683 p += size; 1684 } 1685 1686 if (result == NULL) { 1687 result = sentinel; 1688 lasts = sentinel; 1689 } else { 1690 lasts->ai_next = sentinel; 1691 lasts = sentinel; 1692 } 1693 } 1694 1695 *((struct addrinfo **)retval) = result; 1696 return (NS_SUCCESS); 1697} 1698#endif /* NS_CACHING */ 1699 1700/* 1701 * FQDN hostname, DNS lookup 1702 */ 1703static int 1704explore_fqdn(const struct addrinfo *pai, const char *hostname, 1705 const char *servname, struct addrinfo **res) 1706{ 1707 struct addrinfo *result; 1708 struct addrinfo *cur; 1709 int error = 0; 1710 1711#ifdef NS_CACHING 1712 static const nss_cache_info cache_info = 1713 NS_COMMON_CACHE_INFO_INITIALIZER( 1714 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1715 addrinfo_unmarshal_func); 1716#endif 1717 static const ns_dtab dtab[] = { 1718 NS_FILES_CB(_files_getaddrinfo, NULL) 1719 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1720 NS_NIS_CB(_yp_getaddrinfo, NULL) 1721#ifdef NS_CACHING 1722 NS_CACHE_CB(&cache_info) 1723#endif 1724 { 0 } 1725 }; 1726 1727 result = NULL; 1728 1729 /* 1730 * if the servname does not match socktype/protocol, ignore it. 1731 */ 1732 if (get_portmatch(pai, servname) != 0) 1733 return 0; 1734 1735 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1736 default_dns_files, hostname, pai)) { 1737 case NS_TRYAGAIN: 1738 error = EAI_AGAIN; 1739 goto free; 1740 case NS_UNAVAIL: 1741 error = EAI_FAIL; 1742 goto free; 1743 case NS_NOTFOUND: 1744 error = EAI_NONAME; 1745 goto free; 1746 case NS_SUCCESS: 1747 error = 0; 1748 for (cur = result; cur; cur = cur->ai_next) { 1749 GET_PORT(cur, servname); 1750 /* canonname should be filled already */ 1751 } 1752 break; 1753 } 1754 1755 *res = result; 1756 1757 return 0; 1758 1759free: 1760 if (result) 1761 freeaddrinfo(result); 1762 return error; 1763} 1764 1765#ifdef DEBUG 1766static const char AskedForGot[] = 1767 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1768#endif 1769 1770static struct addrinfo * 1771getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1772 const struct addrinfo *pai, res_state res) 1773{ 1774 struct addrinfo sentinel, *cur; 1775 struct addrinfo ai; 1776 const struct afd *afd; 1777 char *canonname; 1778 const HEADER *hp; 1779 const u_char *cp; 1780 int n; 1781 const u_char *eom; 1782 char *bp, *ep; 1783 int type, class, ancount, qdcount; 1784 int haveanswer, had_error; 1785 char tbuf[MAXDNAME]; 1786 int (*name_ok)(const char *); 1787 char hostbuf[8*1024]; 1788 1789 memset(&sentinel, 0, sizeof(sentinel)); 1790 cur = &sentinel; 1791 1792 canonname = NULL; 1793 eom = answer->buf + anslen; 1794 switch (qtype) { 1795 case T_A: 1796 case T_AAAA: 1797 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1798 name_ok = res_hnok; 1799 break; 1800 default: 1801 return (NULL); /* XXX should be abort(); */ 1802 } 1803 /* 1804 * find first satisfactory answer 1805 */ 1806 hp = &answer->hdr; 1807 ancount = ntohs(hp->ancount); 1808 qdcount = ntohs(hp->qdcount); 1809 bp = hostbuf; 1810 ep = hostbuf + sizeof hostbuf; 1811 cp = answer->buf + HFIXEDSZ; 1812 if (qdcount != 1) { 1813 RES_SET_H_ERRNO(res, NO_RECOVERY); 1814 return (NULL); 1815 } 1816 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1817 if ((n < 0) || !(*name_ok)(bp)) { 1818 RES_SET_H_ERRNO(res, NO_RECOVERY); 1819 return (NULL); 1820 } 1821 cp += n + QFIXEDSZ; 1822 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1823 /* res_send() has already verified that the query name is the 1824 * same as the one we sent; this just gets the expanded name 1825 * (i.e., with the succeeding search-domain tacked on). 1826 */ 1827 n = strlen(bp) + 1; /* for the \0 */ 1828 if (n >= MAXHOSTNAMELEN) { 1829 RES_SET_H_ERRNO(res, NO_RECOVERY); 1830 return (NULL); 1831 } 1832 canonname = bp; 1833 bp += n; 1834 /* The qname can be abbreviated, but h_name is now absolute. */ 1835 qname = canonname; 1836 } 1837 haveanswer = 0; 1838 had_error = 0; 1839 while (ancount-- > 0 && cp < eom && !had_error) { 1840 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1841 if ((n < 0) || !(*name_ok)(bp)) { 1842 had_error++; 1843 continue; 1844 } 1845 cp += n; /* name */ 1846 type = _getshort(cp); 1847 cp += INT16SZ; /* type */ 1848 class = _getshort(cp); 1849 cp += INT16SZ + INT32SZ; /* class, TTL */ 1850 n = _getshort(cp); 1851 cp += INT16SZ; /* len */ 1852 if (class != C_IN) { 1853 /* XXX - debug? syslog? */ 1854 cp += n; 1855 continue; /* XXX - had_error++ ? */ 1856 } 1857 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1858 type == T_CNAME) { 1859 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1860 if ((n < 0) || !(*name_ok)(tbuf)) { 1861 had_error++; 1862 continue; 1863 } 1864 cp += n; 1865 /* Get canonical name. */ 1866 n = strlen(tbuf) + 1; /* for the \0 */ 1867 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1868 had_error++; 1869 continue; 1870 } 1871 strlcpy(bp, tbuf, ep - bp); 1872 canonname = bp; 1873 bp += n; 1874 continue; 1875 } 1876 if (qtype == T_ANY) { 1877 if (!(type == T_A || type == T_AAAA)) { 1878 cp += n; 1879 continue; 1880 } 1881 } else if (type != qtype) { 1882#ifdef DEBUG 1883 if (type != T_KEY && type != T_SIG) 1884 syslog(LOG_NOTICE|LOG_AUTH, 1885 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1886 qname, p_class(C_IN), p_type(qtype), 1887 p_type(type)); 1888#endif 1889 cp += n; 1890 continue; /* XXX - had_error++ ? */ 1891 } 1892 switch (type) { 1893 case T_A: 1894 case T_AAAA: 1895 if (strcasecmp(canonname, bp) != 0) { 1896#ifdef DEBUG 1897 syslog(LOG_NOTICE|LOG_AUTH, 1898 AskedForGot, canonname, bp); 1899#endif 1900 cp += n; 1901 continue; /* XXX - had_error++ ? */ 1902 } 1903 if (type == T_A && n != INADDRSZ) { 1904 cp += n; 1905 continue; 1906 } 1907 if (type == T_AAAA && n != IN6ADDRSZ) { 1908 cp += n; 1909 continue; 1910 } 1911#ifdef FILTER_V4MAPPED 1912 if (type == T_AAAA) { 1913 struct in6_addr in6; 1914 memcpy(&in6, cp, sizeof(in6)); 1915 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1916 cp += n; 1917 continue; 1918 } 1919 } 1920#endif 1921 if (!haveanswer) { 1922 int nn; 1923 1924 canonname = bp; 1925 nn = strlen(bp) + 1; /* for the \0 */ 1926 bp += nn; 1927 } 1928 1929 /* don't overwrite pai */ 1930 ai = *pai; 1931 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1932 afd = find_afd(ai.ai_family); 1933 if (afd == NULL) { 1934 cp += n; 1935 continue; 1936 } 1937 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1938 if (cur->ai_next == NULL) 1939 had_error++; 1940 while (cur && cur->ai_next) 1941 cur = cur->ai_next; 1942 cp += n; 1943 break; 1944 default: 1945 abort(); 1946 } 1947 if (!had_error) 1948 haveanswer++; 1949 } 1950 if (haveanswer) { 1951#if defined(RESOLVSORT) 1952 /* 1953 * We support only IPv4 address for backward 1954 * compatibility against gethostbyname(3). 1955 */ 1956 if (res->nsort && qtype == T_A) { 1957 if (addr4sort(&sentinel, res) < 0) { 1958 freeaddrinfo(sentinel.ai_next); 1959 RES_SET_H_ERRNO(res, NO_RECOVERY); 1960 return NULL; 1961 } 1962 } 1963#endif /*RESOLVSORT*/ 1964 if (!canonname) 1965 (void)get_canonname(pai, sentinel.ai_next, qname); 1966 else 1967 (void)get_canonname(pai, sentinel.ai_next, canonname); 1968 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 1969 return sentinel.ai_next; 1970 } 1971 1972 RES_SET_H_ERRNO(res, NO_RECOVERY); 1973 return NULL; 1974} 1975 1976#ifdef RESOLVSORT 1977struct addr_ptr { 1978 struct addrinfo *ai; 1979 int aval; 1980}; 1981 1982static int 1983addr4sort(struct addrinfo *sentinel, res_state res) 1984{ 1985 struct addrinfo *ai; 1986 struct addr_ptr *addrs, addr; 1987 struct sockaddr_in *sin; 1988 int naddrs, i, j; 1989 int needsort = 0; 1990 1991 if (!sentinel) 1992 return -1; 1993 naddrs = 0; 1994 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 1995 naddrs++; 1996 if (naddrs < 2) 1997 return 0; /* We don't need sorting. */ 1998 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 1999 return -1; 2000 i = 0; 2001 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2002 sin = (struct sockaddr_in *)ai->ai_addr; 2003 for (j = 0; (unsigned)j < res->nsort; j++) { 2004 if (res->sort_list[j].addr.s_addr == 2005 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2006 break; 2007 } 2008 addrs[i].ai = ai; 2009 addrs[i].aval = j; 2010 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2011 needsort = i; 2012 i++; 2013 } 2014 if (!needsort) { 2015 free(addrs); 2016 return 0; 2017 } 2018 2019 while (needsort < naddrs) { 2020 for (j = needsort - 1; j >= 0; j--) { 2021 if (addrs[j].aval > addrs[j+1].aval) { 2022 addr = addrs[j]; 2023 addrs[j] = addrs[j + 1]; 2024 addrs[j + 1] = addr; 2025 } else 2026 break; 2027 } 2028 needsort++; 2029 } 2030 2031 ai = sentinel; 2032 for (i = 0; i < naddrs; ++i) { 2033 ai->ai_next = addrs[i].ai; 2034 ai = ai->ai_next; 2035 } 2036 ai->ai_next = NULL; 2037 free(addrs); 2038 return 0; 2039} 2040#endif /*RESOLVSORT*/ 2041 2042/*ARGSUSED*/ 2043static int 2044_dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2045{ 2046 struct addrinfo *ai; 2047 querybuf *buf, *buf2; 2048 const char *hostname; 2049 const struct addrinfo *pai; 2050 struct addrinfo sentinel, *cur; 2051 struct res_target q, q2; 2052 res_state res; 2053 2054 hostname = va_arg(ap, char *); 2055 pai = va_arg(ap, const struct addrinfo *); 2056 2057 memset(&q, 0, sizeof(q)); 2058 memset(&q2, 0, sizeof(q2)); 2059 memset(&sentinel, 0, sizeof(sentinel)); 2060 cur = &sentinel; 2061 2062 buf = malloc(sizeof(*buf)); 2063 if (!buf) { 2064 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2065 return NS_NOTFOUND; 2066 } 2067 buf2 = malloc(sizeof(*buf2)); 2068 if (!buf2) { 2069 free(buf); 2070 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2071 return NS_NOTFOUND; 2072 } 2073 2074 switch (pai->ai_family) { 2075 case AF_UNSPEC: 2076 q.name = hostname; 2077 q.qclass = C_IN; 2078 q.qtype = T_A; 2079 q.answer = buf->buf; 2080 q.anslen = sizeof(buf->buf); 2081 q.next = &q2; 2082 q2.name = hostname; 2083 q2.qclass = C_IN; 2084 q2.qtype = T_AAAA; 2085 q2.answer = buf2->buf; 2086 q2.anslen = sizeof(buf2->buf); 2087 break; 2088 case AF_INET: 2089 q.name = hostname; 2090 q.qclass = C_IN; 2091 q.qtype = T_A; 2092 q.answer = buf->buf; 2093 q.anslen = sizeof(buf->buf); 2094 break; 2095 case AF_INET6: 2096 q.name = hostname; 2097 q.qclass = C_IN; 2098 q.qtype = T_AAAA; 2099 q.answer = buf->buf; 2100 q.anslen = sizeof(buf->buf); 2101 break; 2102 default: 2103 free(buf); 2104 free(buf2); 2105 return NS_UNAVAIL; 2106 } 2107 2108 res = __res_state(); 2109 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2110 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2111 free(buf); 2112 free(buf2); 2113 return NS_NOTFOUND; 2114 } 2115 2116 if (res_searchN(hostname, &q, res) < 0) { 2117 free(buf); 2118 free(buf2); 2119 return NS_NOTFOUND; 2120 } 2121 /* prefer IPv6 */ 2122 if (q.next) { 2123 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2124 if (ai) { 2125 cur->ai_next = ai; 2126 while (cur && cur->ai_next) 2127 cur = cur->ai_next; 2128 } 2129 } 2130 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2131 if (ai) 2132 cur->ai_next = ai; 2133 free(buf); 2134 free(buf2); 2135 if (sentinel.ai_next == NULL) 2136 switch (res->res_h_errno) { 2137 case HOST_NOT_FOUND: 2138 return NS_NOTFOUND; 2139 case TRY_AGAIN: 2140 return NS_TRYAGAIN; 2141 default: 2142 return NS_UNAVAIL; 2143 } 2144 *((struct addrinfo **)rv) = sentinel.ai_next; 2145 return NS_SUCCESS; 2146} 2147 2148static void 2149_sethtent(FILE **hostf) 2150{ 2151 if (!*hostf) 2152 *hostf = fopen(_PATH_HOSTS, "r"); 2153 else 2154 rewind(*hostf); 2155} 2156 2157static void 2158_endhtent(FILE **hostf) 2159{ 2160 if (*hostf) { 2161 (void) fclose(*hostf); 2162 *hostf = NULL; 2163 } 2164} 2165 2166static struct addrinfo * 2167_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2168{ 2169 char *p; 2170 char *cp, *tname, *cname; 2171 struct addrinfo hints, *res0, *res; 2172 int error; 2173 const char *addr; 2174 char hostbuf[8*1024]; 2175 2176 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r"))) 2177 return (NULL); 2178again: 2179 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2180 return (NULL); 2181 if (*p == '#') 2182 goto again; 2183 cp = strpbrk(p, "#\n"); 2184 if (cp != NULL) 2185 *cp = '\0'; 2186 if (!(cp = strpbrk(p, " \t"))) 2187 goto again; 2188 *cp++ = '\0'; 2189 addr = p; 2190 cname = NULL; 2191 /* if this is not something we're looking for, skip it. */ 2192 while (cp && *cp) { 2193 if (*cp == ' ' || *cp == '\t') { 2194 cp++; 2195 continue; 2196 } 2197 tname = cp; 2198 if (cname == NULL) 2199 cname = cp; 2200 if ((cp = strpbrk(cp, " \t")) != NULL) 2201 *cp++ = '\0'; 2202 if (strcasecmp(name, tname) == 0) 2203 goto found; 2204 } 2205 goto again; 2206 2207found: 2208 /* we should not glob socktype/protocol here */ 2209 memset(&hints, 0, sizeof(hints)); 2210 hints.ai_family = pai->ai_family; 2211 hints.ai_socktype = SOCK_DGRAM; 2212 hints.ai_protocol = 0; 2213 hints.ai_flags = AI_NUMERICHOST; 2214 error = getaddrinfo(addr, "0", &hints, &res0); 2215 if (error) 2216 goto again; 2217#ifdef FILTER_V4MAPPED 2218 /* XXX should check all items in the chain */ 2219 if (res0->ai_family == AF_INET6 && 2220 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2221 freeaddrinfo(res0); 2222 goto again; 2223 } 2224#endif 2225 for (res = res0; res; res = res->ai_next) { 2226 /* cover it up */ 2227 res->ai_flags = pai->ai_flags; 2228 res->ai_socktype = pai->ai_socktype; 2229 res->ai_protocol = pai->ai_protocol; 2230 2231 if (pai->ai_flags & AI_CANONNAME) { 2232 if (get_canonname(pai, res, cname) != 0) { 2233 freeaddrinfo(res0); 2234 goto again; 2235 } 2236 } 2237 } 2238 return res0; 2239} 2240 2241/*ARGSUSED*/ 2242static int 2243_files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2244{ 2245 const char *name; 2246 const struct addrinfo *pai; 2247 struct addrinfo sentinel, *cur; 2248 struct addrinfo *p; 2249 FILE *hostf = NULL; 2250 2251 name = va_arg(ap, char *); 2252 pai = va_arg(ap, struct addrinfo *); 2253 2254 memset(&sentinel, 0, sizeof(sentinel)); 2255 cur = &sentinel; 2256 2257 _sethtent(&hostf); 2258 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 2259 cur->ai_next = p; 2260 while (cur && cur->ai_next) 2261 cur = cur->ai_next; 2262 } 2263 _endhtent(&hostf); 2264 2265 *((struct addrinfo **)rv) = sentinel.ai_next; 2266 if (sentinel.ai_next == NULL) 2267 return NS_NOTFOUND; 2268 return NS_SUCCESS; 2269} 2270 2271#ifdef YP 2272/*ARGSUSED*/ 2273static struct addrinfo * 2274_yphostent(char *line, const struct addrinfo *pai) 2275{ 2276 struct addrinfo sentinel, *cur; 2277 struct addrinfo hints, *res, *res0; 2278 int error; 2279 char *p = line; 2280 const char *addr, *canonname; 2281 char *nextline; 2282 char *cp; 2283 2284 addr = canonname = NULL; 2285 2286 memset(&sentinel, 0, sizeof(sentinel)); 2287 cur = &sentinel; 2288 2289nextline: 2290 /* terminate line */ 2291 cp = strchr(p, '\n'); 2292 if (cp) { 2293 *cp++ = '\0'; 2294 nextline = cp; 2295 } else 2296 nextline = NULL; 2297 2298 cp = strpbrk(p, " \t"); 2299 if (cp == NULL) { 2300 if (canonname == NULL) 2301 return (NULL); 2302 else 2303 goto done; 2304 } 2305 *cp++ = '\0'; 2306 2307 addr = p; 2308 2309 while (cp && *cp) { 2310 if (*cp == ' ' || *cp == '\t') { 2311 cp++; 2312 continue; 2313 } 2314 if (!canonname) 2315 canonname = cp; 2316 if ((cp = strpbrk(cp, " \t")) != NULL) 2317 *cp++ = '\0'; 2318 } 2319 2320 hints = *pai; 2321 hints.ai_flags = AI_NUMERICHOST; 2322 error = getaddrinfo(addr, NULL, &hints, &res0); 2323 if (error == 0) { 2324 for (res = res0; res; res = res->ai_next) { 2325 /* cover it up */ 2326 res->ai_flags = pai->ai_flags; 2327 2328 if (pai->ai_flags & AI_CANONNAME) 2329 (void)get_canonname(pai, res, canonname); 2330 } 2331 } else 2332 res0 = NULL; 2333 if (res0) { 2334 cur->ai_next = res0; 2335 while (cur && cur->ai_next) 2336 cur = cur->ai_next; 2337 } 2338 2339 if (nextline) { 2340 p = nextline; 2341 goto nextline; 2342 } 2343 2344done: 2345 return sentinel.ai_next; 2346} 2347 2348/*ARGSUSED*/ 2349static int 2350_yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2351{ 2352 struct addrinfo sentinel, *cur; 2353 struct addrinfo *ai = NULL; 2354 char *ypbuf; 2355 int ypbuflen, r; 2356 const char *name; 2357 const struct addrinfo *pai; 2358 char *ypdomain; 2359 2360 if (_yp_check(&ypdomain) == 0) 2361 return NS_UNAVAIL; 2362 2363 name = va_arg(ap, char *); 2364 pai = va_arg(ap, const struct addrinfo *); 2365 2366 memset(&sentinel, 0, sizeof(sentinel)); 2367 cur = &sentinel; 2368 2369 /* hosts.byname is only for IPv4 (Solaris8) */ 2370 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 2371 r = yp_match(ypdomain, "hosts.byname", name, 2372 (int)strlen(name), &ypbuf, &ypbuflen); 2373 if (r == 0) { 2374 struct addrinfo ai4; 2375 2376 ai4 = *pai; 2377 ai4.ai_family = AF_INET; 2378 ai = _yphostent(ypbuf, &ai4); 2379 if (ai) { 2380 cur->ai_next = ai; 2381 while (cur && cur->ai_next) 2382 cur = cur->ai_next; 2383 } 2384 free(ypbuf); 2385 } 2386 } 2387 2388 /* ipnodes.byname can hold both IPv4/v6 */ 2389 r = yp_match(ypdomain, "ipnodes.byname", name, 2390 (int)strlen(name), &ypbuf, &ypbuflen); 2391 if (r == 0) { 2392 ai = _yphostent(ypbuf, pai); 2393 if (ai) 2394 cur->ai_next = ai; 2395 free(ypbuf); 2396 } 2397 2398 if (sentinel.ai_next == NULL) { 2399 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2400 return NS_NOTFOUND; 2401 } 2402 *((struct addrinfo **)rv) = sentinel.ai_next; 2403 return NS_SUCCESS; 2404} 2405#endif 2406 2407/* resolver logic */ 2408 2409/* 2410 * Formulate a normal query, send, and await answer. 2411 * Returned answer is placed in supplied buffer "answer". 2412 * Perform preliminary check of answer, returning success only 2413 * if no error is indicated and the answer count is nonzero. 2414 * Return the size of the response on success, -1 on error. 2415 * Error number is left in h_errno. 2416 * 2417 * Caller must parse answer and determine whether it answers the question. 2418 */ 2419static int 2420res_queryN(const char *name, struct res_target *target, res_state res) 2421{ 2422 u_char *buf; 2423 HEADER *hp; 2424 int n; 2425 u_int oflags; 2426 struct res_target *t; 2427 int rcode; 2428 int ancount; 2429 2430 rcode = NOERROR; 2431 ancount = 0; 2432 2433 buf = malloc(MAXPACKET); 2434 if (!buf) { 2435 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2436 return -1; 2437 } 2438 2439 for (t = target; t; t = t->next) { 2440 int class, type; 2441 u_char *answer; 2442 int anslen; 2443 2444 hp = (HEADER *)(void *)t->answer; 2445 2446 /* make it easier... */ 2447 class = t->qclass; 2448 type = t->qtype; 2449 answer = t->answer; 2450 anslen = t->anslen; 2451 2452 oflags = res->_flags; 2453 2454again: 2455 hp->rcode = NOERROR; /* default */ 2456 2457#ifdef DEBUG 2458 if (res->options & RES_DEBUG) 2459 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2460#endif 2461 2462 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2463 buf, MAXPACKET); 2464 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2465 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2466 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2467 if (n <= 0) { 2468#ifdef DEBUG 2469 if (res->options & RES_DEBUG) 2470 printf(";; res_query: mkquery failed\n"); 2471#endif 2472 free(buf); 2473 RES_SET_H_ERRNO(res, NO_RECOVERY); 2474 return (n); 2475 } 2476 n = res_nsend(res, buf, n, answer, anslen); 2477 if (n < 0) { 2478 /* 2479 * if the query choked with EDNS0, retry 2480 * without EDNS0 2481 */ 2482 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2483 != 0U && 2484 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2485 res->_flags |= RES_F_EDNS0ERR; 2486 if (res->options & RES_DEBUG) 2487 printf(";; res_nquery: retry without EDNS0\n"); 2488 goto again; 2489 } 2490 rcode = hp->rcode; /* record most recent error */ 2491#ifdef DEBUG 2492 if (res->options & RES_DEBUG) 2493 printf(";; res_query: send error\n"); 2494#endif 2495 continue; 2496 } 2497 2498 if (n > anslen) 2499 hp->rcode = FORMERR; /* XXX not very informative */ 2500 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2501 rcode = hp->rcode; /* record most recent error */ 2502#ifdef DEBUG 2503 if (res->options & RES_DEBUG) 2504 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2505 ntohs(hp->ancount)); 2506#endif 2507 continue; 2508 } 2509 2510 ancount += ntohs(hp->ancount); 2511 2512 t->n = n; 2513 } 2514 2515 free(buf); 2516 2517 if (ancount == 0) { 2518 switch (rcode) { 2519 case NXDOMAIN: 2520 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2521 break; 2522 case SERVFAIL: 2523 RES_SET_H_ERRNO(res, TRY_AGAIN); 2524 break; 2525 case NOERROR: 2526 RES_SET_H_ERRNO(res, NO_DATA); 2527 break; 2528 case FORMERR: 2529 case NOTIMP: 2530 case REFUSED: 2531 default: 2532 RES_SET_H_ERRNO(res, NO_RECOVERY); 2533 break; 2534 } 2535 return (-1); 2536 } 2537 return (ancount); 2538} 2539 2540/* 2541 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2542 * Return the size of the response on success, -1 on error. 2543 * If enabled, implement search rules until answer or unrecoverable failure 2544 * is detected. Error code, if any, is left in h_errno. 2545 */ 2546static int 2547res_searchN(const char *name, struct res_target *target, res_state res) 2548{ 2549 const char *cp, * const *domain; 2550 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2551 u_int dots; 2552 int trailing_dot, ret, saved_herrno; 2553 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2554 int tried_as_is = 0; 2555 int searched = 0; 2556 char abuf[MAXDNAME]; 2557 2558 errno = 0; 2559 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2560 dots = 0; 2561 for (cp = name; *cp; cp++) 2562 dots += (*cp == '.'); 2563 trailing_dot = 0; 2564 if (cp > name && *--cp == '.') 2565 trailing_dot++; 2566 2567 /* 2568 * if there aren't any dots, it could be a user-level alias 2569 */ 2570 if (!dots && 2571 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2572 return (res_queryN(cp, target, res)); 2573 2574 /* 2575 * If there are enough dots in the name, let's just give it a 2576 * try 'as is'. The threshold can be set with the "ndots" option. 2577 * Also, query 'as is', if there is a trailing dot in the name. 2578 */ 2579 saved_herrno = -1; 2580 if (dots >= res->ndots || trailing_dot) { 2581 ret = res_querydomainN(name, NULL, target, res); 2582 if (ret > 0 || trailing_dot) 2583 return (ret); 2584 if (errno == ECONNREFUSED) { 2585 RES_SET_H_ERRNO(res, TRY_AGAIN); 2586 return (-1); 2587 } 2588 switch (res->res_h_errno) { 2589 case NO_DATA: 2590 case HOST_NOT_FOUND: 2591 break; 2592 case TRY_AGAIN: 2593 if (hp->rcode == SERVFAIL) 2594 break; 2595 /* FALLTHROUGH */ 2596 default: 2597 return (-1); 2598 } 2599 saved_herrno = res->res_h_errno; 2600 tried_as_is++; 2601 } 2602 2603 /* 2604 * We do at least one level of search if 2605 * - there is no dot and RES_DEFNAME is set, or 2606 * - there is at least one dot, there is no trailing dot, 2607 * and RES_DNSRCH is set. 2608 */ 2609 if ((!dots && (res->options & RES_DEFNAMES)) || 2610 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2611 int done = 0; 2612 2613 for (domain = (const char * const *)res->dnsrch; 2614 *domain && !done; 2615 domain++) { 2616 searched = 1; 2617 2618 if (domain[0][0] == '\0' || 2619 (domain[0][0] == '.' && domain[0][1] == '\0')) 2620 root_on_list++; 2621 2622 if (root_on_list && tried_as_is) 2623 continue; 2624 2625 ret = res_querydomainN(name, *domain, target, res); 2626 if (ret > 0) 2627 return (ret); 2628 2629 /* 2630 * If no server present, give up. 2631 * If name isn't found in this domain, 2632 * keep trying higher domains in the search list 2633 * (if that's enabled). 2634 * On a NO_DATA error, keep trying, otherwise 2635 * a wildcard entry of another type could keep us 2636 * from finding this entry higher in the domain. 2637 * If we get some other error (negative answer or 2638 * server failure), then stop searching up, 2639 * but try the input name below in case it's 2640 * fully-qualified. 2641 */ 2642 if (errno == ECONNREFUSED) { 2643 RES_SET_H_ERRNO(res, TRY_AGAIN); 2644 return (-1); 2645 } 2646 2647 switch (res->res_h_errno) { 2648 case NO_DATA: 2649 got_nodata++; 2650 /* FALLTHROUGH */ 2651 case HOST_NOT_FOUND: 2652 /* keep trying */ 2653 break; 2654 case TRY_AGAIN: 2655 got_servfail++; 2656 if (hp->rcode == SERVFAIL) { 2657 /* try next search element, if any */ 2658 break; 2659 } 2660 /* FALLTHROUGH */ 2661 default: 2662 /* anything else implies that we're done */ 2663 done++; 2664 } 2665 /* 2666 * if we got here for some reason other than DNSRCH, 2667 * we only wanted one iteration of the loop, so stop. 2668 */ 2669 if (!(res->options & RES_DNSRCH)) 2670 done++; 2671 } 2672 } 2673 2674 switch (res->res_h_errno) { 2675 case NO_DATA: 2676 case HOST_NOT_FOUND: 2677 break; 2678 case TRY_AGAIN: 2679 if (hp->rcode == SERVFAIL) 2680 break; 2681 /* FALLTHROUGH */ 2682 default: 2683 goto giveup; 2684 } 2685 2686 /* 2687 * If the query has not already been tried as is then try it 2688 * unless RES_NOTLDQUERY is set and there were no dots. 2689 */ 2690 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2691 !(tried_as_is || root_on_list)) { 2692 ret = res_querydomainN(name, NULL, target, res); 2693 if (ret > 0) 2694 return (ret); 2695 } 2696 2697 /* 2698 * if we got here, we didn't satisfy the search. 2699 * if we did an initial full query, return that query's h_errno 2700 * (note that we wouldn't be here if that query had succeeded). 2701 * else if we ever got a nodata, send that back as the reason. 2702 * else send back meaningless h_errno, that being the one from 2703 * the last DNSRCH we did. 2704 */ 2705giveup: 2706 if (saved_herrno != -1) 2707 RES_SET_H_ERRNO(res, saved_herrno); 2708 else if (got_nodata) 2709 RES_SET_H_ERRNO(res, NO_DATA); 2710 else if (got_servfail) 2711 RES_SET_H_ERRNO(res, TRY_AGAIN); 2712 return (-1); 2713} 2714 2715/* 2716 * Perform a call on res_query on the concatenation of name and domain, 2717 * removing a trailing dot from name if domain is NULL. 2718 */ 2719static int 2720res_querydomainN(const char *name, const char *domain, 2721 struct res_target *target, res_state res) 2722{ 2723 char nbuf[MAXDNAME]; 2724 const char *longname = nbuf; 2725 size_t n, d; 2726 2727#ifdef DEBUG 2728 if (res->options & RES_DEBUG) 2729 printf(";; res_querydomain(%s, %s)\n", 2730 name, domain?domain:"<Nil>"); 2731#endif 2732 if (domain == NULL) { 2733 /* 2734 * Check for trailing '.'; 2735 * copy without '.' if present. 2736 */ 2737 n = strlen(name); 2738 if (n >= MAXDNAME) { 2739 RES_SET_H_ERRNO(res, NO_RECOVERY); 2740 return (-1); 2741 } 2742 if (n > 0 && name[--n] == '.') { 2743 strncpy(nbuf, name, n); 2744 nbuf[n] = '\0'; 2745 } else 2746 longname = name; 2747 } else { 2748 n = strlen(name); 2749 d = strlen(domain); 2750 if (n + d + 1 >= MAXDNAME) { 2751 RES_SET_H_ERRNO(res, NO_RECOVERY); 2752 return (-1); 2753 } 2754 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2755 } 2756 return (res_queryN(longname, target, res)); 2757} 2758