getaddrinfo.c revision 158115
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 158115 2006-04-28 12:03:38Z 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 *cur; 1066 struct addrinfo sentinel; 1067 int error; 1068 1069 *res = NULL; 1070 sentinel.ai_next = NULL; 1071 cur = &sentinel; 1072 1073 /* 1074 * filter out AFs that are not supported by the kernel 1075 * XXX errno? 1076 */ 1077 s = _socket(pai->ai_family, SOCK_DGRAM, 0); 1078 if (s < 0) { 1079 if (errno != EMFILE) 1080 return 0; 1081 } else 1082 _close(s); 1083 1084 /* 1085 * if the servname does not match socktype/protocol, ignore it. 1086 */ 1087 if (get_portmatch(pai, servname) != 0) 1088 return 0; 1089 1090 afd = find_afd(pai->ai_family); 1091 if (afd == NULL) 1092 return 0; 1093 1094 if (pai->ai_flags & AI_PASSIVE) { 1095 GET_AI(cur->ai_next, afd, afd->a_addrany); 1096 /* xxx meaningless? 1097 * GET_CANONNAME(cur->ai_next, "anyaddr"); 1098 */ 1099 GET_PORT(cur->ai_next, servname); 1100 } else { 1101 GET_AI(cur->ai_next, afd, afd->a_loopback); 1102 /* xxx meaningless? 1103 * GET_CANONNAME(cur->ai_next, "localhost"); 1104 */ 1105 GET_PORT(cur->ai_next, servname); 1106 } 1107 cur = cur->ai_next; 1108 1109 *res = sentinel.ai_next; 1110 return 0; 1111 1112free: 1113 if (sentinel.ai_next) 1114 freeaddrinfo(sentinel.ai_next); 1115 return error; 1116} 1117 1118/* 1119 * numeric hostname 1120 */ 1121static int 1122explore_numeric(const struct addrinfo *pai, const char *hostname, 1123 const char *servname, struct addrinfo **res, const char *canonname) 1124{ 1125 const struct afd *afd; 1126 struct addrinfo *cur; 1127 struct addrinfo sentinel; 1128 int error; 1129 char pton[PTON_MAX]; 1130 1131 *res = NULL; 1132 sentinel.ai_next = NULL; 1133 cur = &sentinel; 1134 1135 /* 1136 * if the servname does not match socktype/protocol, ignore it. 1137 */ 1138 if (get_portmatch(pai, servname) != 0) 1139 return 0; 1140 1141 afd = find_afd(pai->ai_family); 1142 if (afd == NULL) 1143 return 0; 1144 1145 switch (afd->a_af) { 1146#if 1 /*X/Open spec*/ 1147 case AF_INET: 1148 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 1149 if (pai->ai_family == afd->a_af || 1150 pai->ai_family == PF_UNSPEC /*?*/) { 1151 GET_AI(cur->ai_next, afd, pton); 1152 GET_PORT(cur->ai_next, servname); 1153 if ((pai->ai_flags & AI_CANONNAME)) { 1154 /* 1155 * Set the numeric address itself as 1156 * the canonical name, based on a 1157 * clarification in rfc3493. 1158 */ 1159 GET_CANONNAME(cur->ai_next, canonname); 1160 } 1161 while (cur && cur->ai_next) 1162 cur = cur->ai_next; 1163 } else 1164 ERR(EAI_FAMILY); /*xxx*/ 1165 } 1166 break; 1167#endif 1168 default: 1169 if (inet_pton(afd->a_af, hostname, pton) == 1) { 1170 if (pai->ai_family == afd->a_af || 1171 pai->ai_family == PF_UNSPEC /*?*/) { 1172 GET_AI(cur->ai_next, afd, pton); 1173 GET_PORT(cur->ai_next, servname); 1174 if ((pai->ai_flags & AI_CANONNAME)) { 1175 /* 1176 * Set the numeric address itself as 1177 * the canonical name, based on a 1178 * clarification in rfc3493. 1179 */ 1180 GET_CANONNAME(cur->ai_next, canonname); 1181 } 1182 while (cur && cur->ai_next) 1183 cur = cur->ai_next; 1184 } else 1185 ERR(EAI_FAMILY); /* XXX */ 1186 } 1187 break; 1188 } 1189 1190 *res = sentinel.ai_next; 1191 return 0; 1192 1193free: 1194bad: 1195 if (sentinel.ai_next) 1196 freeaddrinfo(sentinel.ai_next); 1197 return error; 1198} 1199 1200/* 1201 * numeric hostname with scope 1202 */ 1203static int 1204explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1205 const char *servname, struct addrinfo **res) 1206{ 1207#if !defined(SCOPE_DELIMITER) || !defined(INET6) 1208 return explore_numeric(pai, hostname, servname, res, hostname); 1209#else 1210 const struct afd *afd; 1211 struct addrinfo *cur; 1212 int error; 1213 char *cp, *hostname2 = NULL, *scope, *addr; 1214 struct sockaddr_in6 *sin6; 1215 1216 /* 1217 * if the servname does not match socktype/protocol, ignore it. 1218 */ 1219 if (get_portmatch(pai, servname) != 0) 1220 return 0; 1221 1222 afd = find_afd(pai->ai_family); 1223 if (afd == NULL) 1224 return 0; 1225 1226 if (!afd->a_scoped) 1227 return explore_numeric(pai, hostname, servname, res, hostname); 1228 1229 cp = strchr(hostname, SCOPE_DELIMITER); 1230 if (cp == NULL) 1231 return explore_numeric(pai, hostname, servname, res, hostname); 1232 1233 /* 1234 * Handle special case of <scoped_address><delimiter><scope id> 1235 */ 1236 hostname2 = strdup(hostname); 1237 if (hostname2 == NULL) 1238 return EAI_MEMORY; 1239 /* terminate at the delimiter */ 1240 hostname2[cp - hostname] = '\0'; 1241 addr = hostname2; 1242 scope = cp + 1; 1243 1244 error = explore_numeric(pai, addr, servname, res, hostname); 1245 if (error == 0) { 1246 u_int32_t scopeid; 1247 1248 for (cur = *res; cur; cur = cur->ai_next) { 1249 if (cur->ai_family != AF_INET6) 1250 continue; 1251 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1252 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1253 free(hostname2); 1254 return(EAI_NONAME); /* XXX: is return OK? */ 1255 } 1256 sin6->sin6_scope_id = scopeid; 1257 } 1258 } 1259 1260 free(hostname2); 1261 1262 return error; 1263#endif 1264} 1265 1266static int 1267get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1268{ 1269 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1270 ai->ai_canonname = strdup(str); 1271 if (ai->ai_canonname == NULL) 1272 return EAI_MEMORY; 1273 } 1274 return 0; 1275} 1276 1277static struct addrinfo * 1278get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1279{ 1280 char *p; 1281 struct addrinfo *ai; 1282#ifdef FAITH 1283 struct in6_addr faith_prefix; 1284 char *fp_str; 1285 int translate = 0; 1286#endif 1287 1288#ifdef FAITH 1289 /* 1290 * Transfrom an IPv4 addr into a special IPv6 addr format for 1291 * IPv6->IPv4 translation gateway. (only TCP is supported now) 1292 * 1293 * +-----------------------------------+------------+ 1294 * | faith prefix part (12 bytes) | embedded | 1295 * | | IPv4 addr part (4 bytes) 1296 * +-----------------------------------+------------+ 1297 * 1298 * faith prefix part is specified as ascii IPv6 addr format 1299 * in environmental variable GAI. 1300 * For FAITH to work correctly, routing to faith prefix must be 1301 * setup toward a machine where a FAITH daemon operates. 1302 * Also, the machine must enable some mechanizm 1303 * (e.g. faith interface hack) to divert those packet with 1304 * faith prefixed destination addr to user-land FAITH daemon. 1305 */ 1306 fp_str = getenv("GAI"); 1307 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 1308 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 1309 u_int32_t v4a; 1310 u_int8_t v4a_top; 1311 1312 memcpy(&v4a, addr, sizeof v4a); 1313 v4a_top = v4a >> IN_CLASSA_NSHIFT; 1314 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 1315 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 1316 afd = &afdl[N_INET6]; 1317 memcpy(&faith_prefix.s6_addr[12], addr, 1318 sizeof(struct in_addr)); 1319 translate = 1; 1320 } 1321 } 1322#endif 1323 1324 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1325 + (afd->a_socklen)); 1326 if (ai == NULL) 1327 return NULL; 1328 1329 memcpy(ai, pai, sizeof(struct addrinfo)); 1330 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1331 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1332 ai->ai_addr->sa_len = afd->a_socklen; 1333 ai->ai_addrlen = afd->a_socklen; 1334 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1335 p = (char *)(void *)(ai->ai_addr); 1336#ifdef FAITH 1337 if (translate == 1) 1338 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 1339 else 1340#endif 1341 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1342 return ai; 1343} 1344 1345static int 1346get_portmatch(const struct addrinfo *ai, const char *servname) 1347{ 1348 1349 /* get_port does not touch first argument when matchonly == 1. */ 1350 /* LINTED const cast */ 1351 return get_port((struct addrinfo *)ai, servname, 1); 1352} 1353 1354static int 1355get_port(struct addrinfo *ai, const char *servname, int matchonly) 1356{ 1357 const char *proto; 1358 struct servent *sp; 1359 int port; 1360 int allownumeric; 1361 1362 if (servname == NULL) 1363 return 0; 1364 switch (ai->ai_family) { 1365 case AF_INET: 1366#ifdef AF_INET6 1367 case AF_INET6: 1368#endif 1369 break; 1370 default: 1371 return 0; 1372 } 1373 1374 switch (ai->ai_socktype) { 1375 case SOCK_RAW: 1376 return EAI_SERVICE; 1377 case SOCK_DGRAM: 1378 case SOCK_STREAM: 1379 allownumeric = 1; 1380 break; 1381 case ANY: 1382 allownumeric = 0; 1383 break; 1384 default: 1385 return EAI_SOCKTYPE; 1386 } 1387 1388 port = str2number(servname); 1389 if (port >= 0) { 1390 if (!allownumeric) 1391 return EAI_SERVICE; 1392 if (port < 0 || port > 65535) 1393 return EAI_SERVICE; 1394 port = htons(port); 1395 } else { 1396 if (ai->ai_flags & AI_NUMERICSERV) 1397 return EAI_NONAME; 1398 switch (ai->ai_socktype) { 1399 case SOCK_DGRAM: 1400 proto = "udp"; 1401 break; 1402 case SOCK_STREAM: 1403 proto = "tcp"; 1404 break; 1405 default: 1406 proto = NULL; 1407 break; 1408 } 1409 1410 if ((sp = getservbyname(servname, proto)) == NULL) 1411 return EAI_SERVICE; 1412 port = sp->s_port; 1413 } 1414 1415 if (!matchonly) { 1416 switch (ai->ai_family) { 1417 case AF_INET: 1418 ((struct sockaddr_in *)(void *) 1419 ai->ai_addr)->sin_port = port; 1420 break; 1421#ifdef INET6 1422 case AF_INET6: 1423 ((struct sockaddr_in6 *)(void *) 1424 ai->ai_addr)->sin6_port = port; 1425 break; 1426#endif 1427 } 1428 } 1429 1430 return 0; 1431} 1432 1433static const struct afd * 1434find_afd(int af) 1435{ 1436 const struct afd *afd; 1437 1438 if (af == PF_UNSPEC) 1439 return NULL; 1440 for (afd = afdl; afd->a_af; afd++) { 1441 if (afd->a_af == af) 1442 return afd; 1443 } 1444 return NULL; 1445} 1446 1447/* 1448 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1449 * will take care of it. 1450 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1451 * if the code is right or not. 1452 * 1453 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1454 * _dns_getaddrinfo. 1455 */ 1456static int 1457addrconfig(struct addrinfo *pai) 1458{ 1459 int s, af; 1460 1461 /* 1462 * TODO: 1463 * Note that implementation dependent test for address 1464 * configuration should be done everytime called 1465 * (or apropriate interval), 1466 * because addresses will be dynamically assigned or deleted. 1467 */ 1468 af = pai->ai_family; 1469 if (af == AF_UNSPEC) { 1470 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 1471 af = AF_INET; 1472 else { 1473 _close(s); 1474 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) 1475 af = AF_INET6; 1476 else 1477 _close(s); 1478 } 1479 } 1480 if (af != AF_UNSPEC) { 1481 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 1482 return 0; 1483 _close(s); 1484 } 1485 pai->ai_family = af; 1486 return 1; 1487} 1488 1489#ifdef INET6 1490/* convert a string to a scope identifier. XXX: IPv6 specific */ 1491static int 1492ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1493{ 1494 u_long lscopeid; 1495 struct in6_addr *a6; 1496 char *ep; 1497 1498 a6 = &sin6->sin6_addr; 1499 1500 /* empty scopeid portion is invalid */ 1501 if (*scope == '\0') 1502 return -1; 1503 1504 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1505 /* 1506 * We currently assume a one-to-one mapping between links 1507 * and interfaces, so we simply use interface indices for 1508 * like-local scopes. 1509 */ 1510 *scopeid = if_nametoindex(scope); 1511 if (*scopeid == 0) 1512 goto trynumeric; 1513 return 0; 1514 } 1515 1516 /* still unclear about literal, allow numeric only - placeholder */ 1517 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1518 goto trynumeric; 1519 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1520 goto trynumeric; 1521 else 1522 goto trynumeric; /* global */ 1523 1524 /* try to convert to a numeric id as a last resort */ 1525 trynumeric: 1526 errno = 0; 1527 lscopeid = strtoul(scope, &ep, 10); 1528 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1529 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1530 return 0; 1531 else 1532 return -1; 1533} 1534#endif 1535 1536 1537#ifdef NS_CACHING 1538static int 1539addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1540 void *cache_mdata) 1541{ 1542 res_state statp; 1543 u_long res_options; 1544 1545 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1546 char *hostname; 1547 struct addrinfo *hints; 1548 1549 char *p; 1550 int ai_flags, ai_family, ai_socktype, ai_protocol; 1551 size_t desired_size, size; 1552 1553 statp = __res_state(); 1554 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1555 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1556 1557 hostname = va_arg(ap, char *); 1558 hints = va_arg(ap, struct addrinfo *); 1559 1560 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1561 if (hostname != NULL) { 1562 size = strlen(hostname); 1563 desired_size += size + 1; 1564 } else 1565 size = 0; 1566 1567 if (desired_size > *buffer_size) { 1568 *buffer_size = desired_size; 1569 return (NS_RETURN); 1570 } 1571 1572 if (hints == NULL) 1573 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1574 else { 1575 ai_flags = hints->ai_flags; 1576 ai_family = hints->ai_family; 1577 ai_socktype = hints->ai_socktype; 1578 ai_protocol = hints->ai_protocol; 1579 } 1580 1581 p = buffer; 1582 memcpy(p, &res_options, sizeof(res_options)); 1583 p += sizeof(res_options); 1584 1585 memcpy(p, &op_id, sizeof(int)); 1586 p += sizeof(int); 1587 1588 memcpy(p, &ai_flags, sizeof(int)); 1589 p += sizeof(int); 1590 1591 memcpy(p, &ai_family, sizeof(int)); 1592 p += sizeof(int); 1593 1594 memcpy(p, &ai_socktype, sizeof(int)); 1595 p += sizeof(int); 1596 1597 memcpy(p, &ai_protocol, sizeof(int)); 1598 p += sizeof(int); 1599 1600 if (hostname != NULL) 1601 memcpy(p, hostname, size); 1602 1603 *buffer_size = desired_size; 1604 return (NS_SUCCESS); 1605} 1606 1607static int 1608addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1609 va_list ap, void *cache_mdata) 1610{ 1611 struct addrinfo *ai, *cai; 1612 char *p; 1613 size_t desired_size, size, ai_size; 1614 1615 ai = *((struct addrinfo **)retval); 1616 1617 desired_size = sizeof(size_t); 1618 ai_size = 0; 1619 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1620 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1621 if (cai->ai_canonname != NULL) 1622 desired_size += sizeof(size_t) + 1623 strlen(cai->ai_canonname); 1624 ++ai_size; 1625 } 1626 1627 if (desired_size > *buffer_size) { 1628 /* this assignment is here for future use */ 1629 errno = ERANGE; 1630 *buffer_size = desired_size; 1631 return (NS_RETURN); 1632 } 1633 1634 memset(buffer, 0, desired_size); 1635 p = buffer; 1636 1637 memcpy(p, &ai_size, sizeof(size_t)); 1638 p += sizeof(size_t); 1639 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1640 memcpy(p, cai, sizeof(struct addrinfo)); 1641 p += sizeof(struct addrinfo); 1642 1643 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1644 p += cai->ai_addrlen; 1645 1646 if (cai->ai_canonname != NULL) { 1647 size = strlen(cai->ai_canonname); 1648 memcpy(p, &size, sizeof(size_t)); 1649 p += sizeof(size_t); 1650 1651 memcpy(p, cai->ai_canonname, size); 1652 p += size; 1653 } 1654 } 1655 1656 return (NS_SUCCESS); 1657} 1658 1659static int 1660addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1661 va_list ap, void *cache_mdata) 1662{ 1663 struct addrinfo new_ai, *result, *sentinel, *lasts; 1664 1665 char *p; 1666 size_t ai_size, ai_i, size; 1667 1668 p = buffer; 1669 memcpy(&ai_size, p, sizeof(size_t)); 1670 p += sizeof(size_t); 1671 1672 result = NULL; 1673 lasts = NULL; 1674 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1675 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1676 p += sizeof(struct addrinfo); 1677 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1678 _ALIGNBYTES; 1679 1680 sentinel = (struct addrinfo *)malloc(size); 1681 memset(sentinel, 0, size); 1682 1683 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1684 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1685 sizeof(struct addrinfo)); 1686 1687 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1688 p += new_ai.ai_addrlen; 1689 1690 if (new_ai.ai_canonname != NULL) { 1691 memcpy(&size, p, sizeof(size_t)); 1692 p += sizeof(size_t); 1693 1694 sentinel->ai_canonname = (char *)malloc(size + 1); 1695 memset(sentinel->ai_canonname, 0, size + 1); 1696 1697 memcpy(sentinel->ai_canonname, p, size); 1698 p += size; 1699 } 1700 1701 if (result == NULL) { 1702 result = sentinel; 1703 lasts = sentinel; 1704 } else { 1705 lasts->ai_next = sentinel; 1706 lasts = sentinel; 1707 } 1708 } 1709 1710 *((struct addrinfo **)retval) = result; 1711 return (NS_SUCCESS); 1712} 1713#endif /* NS_CACHING */ 1714 1715/* 1716 * FQDN hostname, DNS lookup 1717 */ 1718static int 1719explore_fqdn(const struct addrinfo *pai, const char *hostname, 1720 const char *servname, struct addrinfo **res) 1721{ 1722 struct addrinfo *result; 1723 struct addrinfo *cur; 1724 int error = 0; 1725 1726#ifdef NS_CACHING 1727 static const nss_cache_info cache_info = 1728 NS_COMMON_CACHE_INFO_INITIALIZER( 1729 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1730 addrinfo_unmarshal_func); 1731#endif 1732 static const ns_dtab dtab[] = { 1733 NS_FILES_CB(_files_getaddrinfo, NULL) 1734 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1735 NS_NIS_CB(_yp_getaddrinfo, NULL) 1736#ifdef NS_CACHING 1737 NS_CACHE_CB(&cache_info) 1738#endif 1739 { 0 } 1740 }; 1741 1742 result = NULL; 1743 1744 /* 1745 * if the servname does not match socktype/protocol, ignore it. 1746 */ 1747 if (get_portmatch(pai, servname) != 0) 1748 return 0; 1749 1750 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1751 default_dns_files, hostname, pai)) { 1752 case NS_TRYAGAIN: 1753 error = EAI_AGAIN; 1754 goto free; 1755 case NS_UNAVAIL: 1756 error = EAI_FAIL; 1757 goto free; 1758 case NS_NOTFOUND: 1759 error = EAI_NONAME; 1760 goto free; 1761 case NS_SUCCESS: 1762 error = 0; 1763 for (cur = result; cur; cur = cur->ai_next) { 1764 GET_PORT(cur, servname); 1765 /* canonname should be filled already */ 1766 } 1767 break; 1768 } 1769 1770 *res = result; 1771 1772 return 0; 1773 1774free: 1775 if (result) 1776 freeaddrinfo(result); 1777 return error; 1778} 1779 1780#ifdef DEBUG 1781static const char AskedForGot[] = 1782 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1783#endif 1784 1785static struct addrinfo * 1786getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1787 const struct addrinfo *pai, res_state res) 1788{ 1789 struct addrinfo sentinel, *cur; 1790 struct addrinfo ai; 1791 const struct afd *afd; 1792 char *canonname; 1793 const HEADER *hp; 1794 const u_char *cp; 1795 int n; 1796 const u_char *eom; 1797 char *bp, *ep; 1798 int type, class, ancount, qdcount; 1799 int haveanswer, had_error; 1800 char tbuf[MAXDNAME]; 1801 int (*name_ok)(const char *); 1802 char hostbuf[8*1024]; 1803 1804 memset(&sentinel, 0, sizeof(sentinel)); 1805 cur = &sentinel; 1806 1807 canonname = NULL; 1808 eom = answer->buf + anslen; 1809 switch (qtype) { 1810 case T_A: 1811 case T_AAAA: 1812 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1813 name_ok = res_hnok; 1814 break; 1815 default: 1816 return (NULL); /* XXX should be abort(); */ 1817 } 1818 /* 1819 * find first satisfactory answer 1820 */ 1821 hp = &answer->hdr; 1822 ancount = ntohs(hp->ancount); 1823 qdcount = ntohs(hp->qdcount); 1824 bp = hostbuf; 1825 ep = hostbuf + sizeof hostbuf; 1826 cp = answer->buf + HFIXEDSZ; 1827 if (qdcount != 1) { 1828 RES_SET_H_ERRNO(res, NO_RECOVERY); 1829 return (NULL); 1830 } 1831 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1832 if ((n < 0) || !(*name_ok)(bp)) { 1833 RES_SET_H_ERRNO(res, NO_RECOVERY); 1834 return (NULL); 1835 } 1836 cp += n + QFIXEDSZ; 1837 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1838 /* res_send() has already verified that the query name is the 1839 * same as the one we sent; this just gets the expanded name 1840 * (i.e., with the succeeding search-domain tacked on). 1841 */ 1842 n = strlen(bp) + 1; /* for the \0 */ 1843 if (n >= MAXHOSTNAMELEN) { 1844 RES_SET_H_ERRNO(res, NO_RECOVERY); 1845 return (NULL); 1846 } 1847 canonname = bp; 1848 bp += n; 1849 /* The qname can be abbreviated, but h_name is now absolute. */ 1850 qname = canonname; 1851 } 1852 haveanswer = 0; 1853 had_error = 0; 1854 while (ancount-- > 0 && cp < eom && !had_error) { 1855 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1856 if ((n < 0) || !(*name_ok)(bp)) { 1857 had_error++; 1858 continue; 1859 } 1860 cp += n; /* name */ 1861 type = _getshort(cp); 1862 cp += INT16SZ; /* type */ 1863 class = _getshort(cp); 1864 cp += INT16SZ + INT32SZ; /* class, TTL */ 1865 n = _getshort(cp); 1866 cp += INT16SZ; /* len */ 1867 if (class != C_IN) { 1868 /* XXX - debug? syslog? */ 1869 cp += n; 1870 continue; /* XXX - had_error++ ? */ 1871 } 1872 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1873 type == T_CNAME) { 1874 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1875 if ((n < 0) || !(*name_ok)(tbuf)) { 1876 had_error++; 1877 continue; 1878 } 1879 cp += n; 1880 /* Get canonical name. */ 1881 n = strlen(tbuf) + 1; /* for the \0 */ 1882 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1883 had_error++; 1884 continue; 1885 } 1886 strlcpy(bp, tbuf, ep - bp); 1887 canonname = bp; 1888 bp += n; 1889 continue; 1890 } 1891 if (qtype == T_ANY) { 1892 if (!(type == T_A || type == T_AAAA)) { 1893 cp += n; 1894 continue; 1895 } 1896 } else if (type != qtype) { 1897#ifdef DEBUG 1898 if (type != T_KEY && type != T_SIG) 1899 syslog(LOG_NOTICE|LOG_AUTH, 1900 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1901 qname, p_class(C_IN), p_type(qtype), 1902 p_type(type)); 1903#endif 1904 cp += n; 1905 continue; /* XXX - had_error++ ? */ 1906 } 1907 switch (type) { 1908 case T_A: 1909 case T_AAAA: 1910 if (strcasecmp(canonname, bp) != 0) { 1911#ifdef DEBUG 1912 syslog(LOG_NOTICE|LOG_AUTH, 1913 AskedForGot, canonname, bp); 1914#endif 1915 cp += n; 1916 continue; /* XXX - had_error++ ? */ 1917 } 1918 if (type == T_A && n != INADDRSZ) { 1919 cp += n; 1920 continue; 1921 } 1922 if (type == T_AAAA && n != IN6ADDRSZ) { 1923 cp += n; 1924 continue; 1925 } 1926#ifdef FILTER_V4MAPPED 1927 if (type == T_AAAA) { 1928 struct in6_addr in6; 1929 memcpy(&in6, cp, sizeof(in6)); 1930 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1931 cp += n; 1932 continue; 1933 } 1934 } 1935#endif 1936 if (!haveanswer) { 1937 int nn; 1938 1939 canonname = bp; 1940 nn = strlen(bp) + 1; /* for the \0 */ 1941 bp += nn; 1942 } 1943 1944 /* don't overwrite pai */ 1945 ai = *pai; 1946 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1947 afd = find_afd(ai.ai_family); 1948 if (afd == NULL) { 1949 cp += n; 1950 continue; 1951 } 1952 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1953 if (cur->ai_next == NULL) 1954 had_error++; 1955 while (cur && cur->ai_next) 1956 cur = cur->ai_next; 1957 cp += n; 1958 break; 1959 default: 1960 abort(); 1961 } 1962 if (!had_error) 1963 haveanswer++; 1964 } 1965 if (haveanswer) { 1966#if defined(RESOLVSORT) 1967 /* 1968 * We support only IPv4 address for backward 1969 * compatibility against gethostbyname(3). 1970 */ 1971 if (res->nsort && qtype == T_A) { 1972 if (addr4sort(&sentinel, res) < 0) { 1973 freeaddrinfo(sentinel.ai_next); 1974 RES_SET_H_ERRNO(res, NO_RECOVERY); 1975 return NULL; 1976 } 1977 } 1978#endif /*RESOLVSORT*/ 1979 if (!canonname) 1980 (void)get_canonname(pai, sentinel.ai_next, qname); 1981 else 1982 (void)get_canonname(pai, sentinel.ai_next, canonname); 1983 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 1984 return sentinel.ai_next; 1985 } 1986 1987 RES_SET_H_ERRNO(res, NO_RECOVERY); 1988 return NULL; 1989} 1990 1991#ifdef RESOLVSORT 1992struct addr_ptr { 1993 struct addrinfo *ai; 1994 int aval; 1995}; 1996 1997static int 1998addr4sort(struct addrinfo *sentinel, res_state res) 1999{ 2000 struct addrinfo *ai; 2001 struct addr_ptr *addrs, addr; 2002 struct sockaddr_in *sin; 2003 int naddrs, i, j; 2004 int needsort = 0; 2005 2006 if (!sentinel) 2007 return -1; 2008 naddrs = 0; 2009 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2010 naddrs++; 2011 if (naddrs < 2) 2012 return 0; /* We don't need sorting. */ 2013 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2014 return -1; 2015 i = 0; 2016 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2017 sin = (struct sockaddr_in *)ai->ai_addr; 2018 for (j = 0; (unsigned)j < res->nsort; j++) { 2019 if (res->sort_list[j].addr.s_addr == 2020 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2021 break; 2022 } 2023 addrs[i].ai = ai; 2024 addrs[i].aval = j; 2025 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2026 needsort = i; 2027 i++; 2028 } 2029 if (!needsort) { 2030 free(addrs); 2031 return 0; 2032 } 2033 2034 while (needsort < naddrs) { 2035 for (j = needsort - 1; j >= 0; j--) { 2036 if (addrs[j].aval > addrs[j+1].aval) { 2037 addr = addrs[j]; 2038 addrs[j] = addrs[j + 1]; 2039 addrs[j + 1] = addr; 2040 } else 2041 break; 2042 } 2043 needsort++; 2044 } 2045 2046 ai = sentinel; 2047 for (i = 0; i < naddrs; ++i) { 2048 ai->ai_next = addrs[i].ai; 2049 ai = ai->ai_next; 2050 } 2051 ai->ai_next = NULL; 2052 free(addrs); 2053 return 0; 2054} 2055#endif /*RESOLVSORT*/ 2056 2057/*ARGSUSED*/ 2058static int 2059_dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2060{ 2061 struct addrinfo *ai; 2062 querybuf *buf, *buf2; 2063 const char *hostname; 2064 const struct addrinfo *pai; 2065 struct addrinfo sentinel, *cur; 2066 struct res_target q, q2; 2067 res_state res; 2068 2069 hostname = va_arg(ap, char *); 2070 pai = va_arg(ap, const struct addrinfo *); 2071 2072 memset(&q, 0, sizeof(q)); 2073 memset(&q2, 0, sizeof(q2)); 2074 memset(&sentinel, 0, sizeof(sentinel)); 2075 cur = &sentinel; 2076 2077 buf = malloc(sizeof(*buf)); 2078 if (!buf) { 2079 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2080 return NS_NOTFOUND; 2081 } 2082 buf2 = malloc(sizeof(*buf2)); 2083 if (!buf2) { 2084 free(buf); 2085 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2086 return NS_NOTFOUND; 2087 } 2088 2089 switch (pai->ai_family) { 2090 case AF_UNSPEC: 2091 q.name = hostname; 2092 q.qclass = C_IN; 2093 q.qtype = T_A; 2094 q.answer = buf->buf; 2095 q.anslen = sizeof(buf->buf); 2096 q.next = &q2; 2097 q2.name = hostname; 2098 q2.qclass = C_IN; 2099 q2.qtype = T_AAAA; 2100 q2.answer = buf2->buf; 2101 q2.anslen = sizeof(buf2->buf); 2102 break; 2103 case AF_INET: 2104 q.name = hostname; 2105 q.qclass = C_IN; 2106 q.qtype = T_A; 2107 q.answer = buf->buf; 2108 q.anslen = sizeof(buf->buf); 2109 break; 2110 case AF_INET6: 2111 q.name = hostname; 2112 q.qclass = C_IN; 2113 q.qtype = T_AAAA; 2114 q.answer = buf->buf; 2115 q.anslen = sizeof(buf->buf); 2116 break; 2117 default: 2118 free(buf); 2119 free(buf2); 2120 return NS_UNAVAIL; 2121 } 2122 2123 res = __res_state(); 2124 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2125 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2126 free(buf); 2127 free(buf2); 2128 return NS_NOTFOUND; 2129 } 2130 2131 if (res_searchN(hostname, &q, res) < 0) { 2132 free(buf); 2133 free(buf2); 2134 return NS_NOTFOUND; 2135 } 2136 /* prefer IPv6 */ 2137 if (q.next) { 2138 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2139 if (ai) { 2140 cur->ai_next = ai; 2141 while (cur && cur->ai_next) 2142 cur = cur->ai_next; 2143 } 2144 } 2145 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2146 if (ai) 2147 cur->ai_next = ai; 2148 free(buf); 2149 free(buf2); 2150 if (sentinel.ai_next == NULL) 2151 switch (res->res_h_errno) { 2152 case HOST_NOT_FOUND: 2153 return NS_NOTFOUND; 2154 case TRY_AGAIN: 2155 return NS_TRYAGAIN; 2156 default: 2157 return NS_UNAVAIL; 2158 } 2159 *((struct addrinfo **)rv) = sentinel.ai_next; 2160 return NS_SUCCESS; 2161} 2162 2163static void 2164_sethtent(FILE **hostf) 2165{ 2166 if (!*hostf) 2167 *hostf = fopen(_PATH_HOSTS, "r"); 2168 else 2169 rewind(*hostf); 2170} 2171 2172static void 2173_endhtent(FILE **hostf) 2174{ 2175 if (*hostf) { 2176 (void) fclose(*hostf); 2177 *hostf = NULL; 2178 } 2179} 2180 2181static struct addrinfo * 2182_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2183{ 2184 char *p; 2185 char *cp, *tname, *cname; 2186 struct addrinfo hints, *res0, *res; 2187 int error; 2188 const char *addr; 2189 char hostbuf[8*1024]; 2190 2191 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r"))) 2192 return (NULL); 2193again: 2194 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2195 return (NULL); 2196 if (*p == '#') 2197 goto again; 2198 cp = strpbrk(p, "#\n"); 2199 if (cp != NULL) 2200 *cp = '\0'; 2201 if (!(cp = strpbrk(p, " \t"))) 2202 goto again; 2203 *cp++ = '\0'; 2204 addr = p; 2205 cname = NULL; 2206 /* if this is not something we're looking for, skip it. */ 2207 while (cp && *cp) { 2208 if (*cp == ' ' || *cp == '\t') { 2209 cp++; 2210 continue; 2211 } 2212 tname = cp; 2213 if (cname == NULL) 2214 cname = cp; 2215 if ((cp = strpbrk(cp, " \t")) != NULL) 2216 *cp++ = '\0'; 2217 if (strcasecmp(name, tname) == 0) 2218 goto found; 2219 } 2220 goto again; 2221 2222found: 2223 /* we should not glob socktype/protocol here */ 2224 memset(&hints, 0, sizeof(hints)); 2225 hints.ai_family = pai->ai_family; 2226 hints.ai_socktype = SOCK_DGRAM; 2227 hints.ai_protocol = 0; 2228 hints.ai_flags = AI_NUMERICHOST; 2229 error = getaddrinfo(addr, "0", &hints, &res0); 2230 if (error) 2231 goto again; 2232#ifdef FILTER_V4MAPPED 2233 /* XXX should check all items in the chain */ 2234 if (res0->ai_family == AF_INET6 && 2235 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2236 freeaddrinfo(res0); 2237 goto again; 2238 } 2239#endif 2240 for (res = res0; res; res = res->ai_next) { 2241 /* cover it up */ 2242 res->ai_flags = pai->ai_flags; 2243 res->ai_socktype = pai->ai_socktype; 2244 res->ai_protocol = pai->ai_protocol; 2245 2246 if (pai->ai_flags & AI_CANONNAME) { 2247 if (get_canonname(pai, res, cname) != 0) { 2248 freeaddrinfo(res0); 2249 goto again; 2250 } 2251 } 2252 } 2253 return res0; 2254} 2255 2256/*ARGSUSED*/ 2257static int 2258_files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2259{ 2260 const char *name; 2261 const struct addrinfo *pai; 2262 struct addrinfo sentinel, *cur; 2263 struct addrinfo *p; 2264 FILE *hostf = NULL; 2265 2266 name = va_arg(ap, char *); 2267 pai = va_arg(ap, struct addrinfo *); 2268 2269 memset(&sentinel, 0, sizeof(sentinel)); 2270 cur = &sentinel; 2271 2272 _sethtent(&hostf); 2273 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 2274 cur->ai_next = p; 2275 while (cur && cur->ai_next) 2276 cur = cur->ai_next; 2277 } 2278 _endhtent(&hostf); 2279 2280 *((struct addrinfo **)rv) = sentinel.ai_next; 2281 if (sentinel.ai_next == NULL) 2282 return NS_NOTFOUND; 2283 return NS_SUCCESS; 2284} 2285 2286#ifdef YP 2287/*ARGSUSED*/ 2288static struct addrinfo * 2289_yphostent(char *line, const struct addrinfo *pai) 2290{ 2291 struct addrinfo sentinel, *cur; 2292 struct addrinfo hints, *res, *res0; 2293 int error; 2294 char *p = line; 2295 const char *addr, *canonname; 2296 char *nextline; 2297 char *cp; 2298 2299 addr = canonname = NULL; 2300 2301 memset(&sentinel, 0, sizeof(sentinel)); 2302 cur = &sentinel; 2303 2304nextline: 2305 /* terminate line */ 2306 cp = strchr(p, '\n'); 2307 if (cp) { 2308 *cp++ = '\0'; 2309 nextline = cp; 2310 } else 2311 nextline = NULL; 2312 2313 cp = strpbrk(p, " \t"); 2314 if (cp == NULL) { 2315 if (canonname == NULL) 2316 return (NULL); 2317 else 2318 goto done; 2319 } 2320 *cp++ = '\0'; 2321 2322 addr = p; 2323 2324 while (cp && *cp) { 2325 if (*cp == ' ' || *cp == '\t') { 2326 cp++; 2327 continue; 2328 } 2329 if (!canonname) 2330 canonname = cp; 2331 if ((cp = strpbrk(cp, " \t")) != NULL) 2332 *cp++ = '\0'; 2333 } 2334 2335 hints = *pai; 2336 hints.ai_flags = AI_NUMERICHOST; 2337 error = getaddrinfo(addr, NULL, &hints, &res0); 2338 if (error == 0) { 2339 for (res = res0; res; res = res->ai_next) { 2340 /* cover it up */ 2341 res->ai_flags = pai->ai_flags; 2342 2343 if (pai->ai_flags & AI_CANONNAME) 2344 (void)get_canonname(pai, res, canonname); 2345 } 2346 } else 2347 res0 = NULL; 2348 if (res0) { 2349 cur->ai_next = res0; 2350 while (cur && cur->ai_next) 2351 cur = cur->ai_next; 2352 } 2353 2354 if (nextline) { 2355 p = nextline; 2356 goto nextline; 2357 } 2358 2359done: 2360 return sentinel.ai_next; 2361} 2362 2363/*ARGSUSED*/ 2364static int 2365_yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2366{ 2367 struct addrinfo sentinel, *cur; 2368 struct addrinfo *ai = NULL; 2369 char *ypbuf; 2370 int ypbuflen, r; 2371 const char *name; 2372 const struct addrinfo *pai; 2373 char *ypdomain; 2374 2375 if (_yp_check(&ypdomain) == 0) 2376 return NS_UNAVAIL; 2377 2378 name = va_arg(ap, char *); 2379 pai = va_arg(ap, const struct addrinfo *); 2380 2381 memset(&sentinel, 0, sizeof(sentinel)); 2382 cur = &sentinel; 2383 2384 /* hosts.byname is only for IPv4 (Solaris8) */ 2385 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 2386 r = yp_match(ypdomain, "hosts.byname", name, 2387 (int)strlen(name), &ypbuf, &ypbuflen); 2388 if (r == 0) { 2389 struct addrinfo ai4; 2390 2391 ai4 = *pai; 2392 ai4.ai_family = AF_INET; 2393 ai = _yphostent(ypbuf, &ai4); 2394 if (ai) { 2395 cur->ai_next = ai; 2396 while (cur && cur->ai_next) 2397 cur = cur->ai_next; 2398 } 2399 free(ypbuf); 2400 } 2401 } 2402 2403 /* ipnodes.byname can hold both IPv4/v6 */ 2404 r = yp_match(ypdomain, "ipnodes.byname", name, 2405 (int)strlen(name), &ypbuf, &ypbuflen); 2406 if (r == 0) { 2407 ai = _yphostent(ypbuf, pai); 2408 if (ai) 2409 cur->ai_next = ai; 2410 free(ypbuf); 2411 } 2412 2413 if (sentinel.ai_next == NULL) { 2414 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2415 return NS_NOTFOUND; 2416 } 2417 *((struct addrinfo **)rv) = sentinel.ai_next; 2418 return NS_SUCCESS; 2419} 2420#endif 2421 2422/* resolver logic */ 2423 2424/* 2425 * Formulate a normal query, send, and await answer. 2426 * Returned answer is placed in supplied buffer "answer". 2427 * Perform preliminary check of answer, returning success only 2428 * if no error is indicated and the answer count is nonzero. 2429 * Return the size of the response on success, -1 on error. 2430 * Error number is left in h_errno. 2431 * 2432 * Caller must parse answer and determine whether it answers the question. 2433 */ 2434static int 2435res_queryN(const char *name, struct res_target *target, res_state res) 2436{ 2437 u_char *buf; 2438 HEADER *hp; 2439 int n; 2440 u_int oflags; 2441 struct res_target *t; 2442 int rcode; 2443 int ancount; 2444 2445 rcode = NOERROR; 2446 ancount = 0; 2447 2448 buf = malloc(MAXPACKET); 2449 if (!buf) { 2450 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2451 return -1; 2452 } 2453 2454 for (t = target; t; t = t->next) { 2455 int class, type; 2456 u_char *answer; 2457 int anslen; 2458 2459 hp = (HEADER *)(void *)t->answer; 2460 2461 /* make it easier... */ 2462 class = t->qclass; 2463 type = t->qtype; 2464 answer = t->answer; 2465 anslen = t->anslen; 2466 2467 oflags = res->_flags; 2468 2469again: 2470 hp->rcode = NOERROR; /* default */ 2471 2472#ifdef DEBUG 2473 if (res->options & RES_DEBUG) 2474 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2475#endif 2476 2477 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2478 buf, MAXPACKET); 2479 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2480 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2481 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2482 if (n <= 0) { 2483#ifdef DEBUG 2484 if (res->options & RES_DEBUG) 2485 printf(";; res_query: mkquery failed\n"); 2486#endif 2487 free(buf); 2488 RES_SET_H_ERRNO(res, NO_RECOVERY); 2489 return (n); 2490 } 2491 n = res_nsend(res, buf, n, answer, anslen); 2492 if (n < 0) { 2493 /* 2494 * if the query choked with EDNS0, retry 2495 * without EDNS0 2496 */ 2497 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2498 != 0U && 2499 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2500 res->_flags |= RES_F_EDNS0ERR; 2501 if (res->options & RES_DEBUG) 2502 printf(";; res_nquery: retry without EDNS0\n"); 2503 goto again; 2504 } 2505 rcode = hp->rcode; /* record most recent error */ 2506#ifdef DEBUG 2507 if (res->options & RES_DEBUG) 2508 printf(";; res_query: send error\n"); 2509#endif 2510 continue; 2511 } 2512 2513 if (n > anslen) 2514 hp->rcode = FORMERR; /* XXX not very informative */ 2515 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2516 rcode = hp->rcode; /* record most recent error */ 2517#ifdef DEBUG 2518 if (res->options & RES_DEBUG) 2519 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2520 ntohs(hp->ancount)); 2521#endif 2522 continue; 2523 } 2524 2525 ancount += ntohs(hp->ancount); 2526 2527 t->n = n; 2528 } 2529 2530 free(buf); 2531 2532 if (ancount == 0) { 2533 switch (rcode) { 2534 case NXDOMAIN: 2535 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2536 break; 2537 case SERVFAIL: 2538 RES_SET_H_ERRNO(res, TRY_AGAIN); 2539 break; 2540 case NOERROR: 2541 RES_SET_H_ERRNO(res, NO_DATA); 2542 break; 2543 case FORMERR: 2544 case NOTIMP: 2545 case REFUSED: 2546 default: 2547 RES_SET_H_ERRNO(res, NO_RECOVERY); 2548 break; 2549 } 2550 return (-1); 2551 } 2552 return (ancount); 2553} 2554 2555/* 2556 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2557 * Return the size of the response on success, -1 on error. 2558 * If enabled, implement search rules until answer or unrecoverable failure 2559 * is detected. Error code, if any, is left in h_errno. 2560 */ 2561static int 2562res_searchN(const char *name, struct res_target *target, res_state res) 2563{ 2564 const char *cp, * const *domain; 2565 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2566 u_int dots; 2567 int trailing_dot, ret, saved_herrno; 2568 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2569 int tried_as_is = 0; 2570 int searched = 0; 2571 char abuf[MAXDNAME]; 2572 2573 errno = 0; 2574 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2575 dots = 0; 2576 for (cp = name; *cp; cp++) 2577 dots += (*cp == '.'); 2578 trailing_dot = 0; 2579 if (cp > name && *--cp == '.') 2580 trailing_dot++; 2581 2582 /* 2583 * if there aren't any dots, it could be a user-level alias 2584 */ 2585 if (!dots && 2586 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2587 return (res_queryN(cp, target, res)); 2588 2589 /* 2590 * If there are enough dots in the name, let's just give it a 2591 * try 'as is'. The threshold can be set with the "ndots" option. 2592 * Also, query 'as is', if there is a trailing dot in the name. 2593 */ 2594 saved_herrno = -1; 2595 if (dots >= res->ndots || trailing_dot) { 2596 ret = res_querydomainN(name, NULL, target, res); 2597 if (ret > 0 || trailing_dot) 2598 return (ret); 2599 if (errno == ECONNREFUSED) { 2600 RES_SET_H_ERRNO(res, TRY_AGAIN); 2601 return (-1); 2602 } 2603 switch (res->res_h_errno) { 2604 case NO_DATA: 2605 case HOST_NOT_FOUND: 2606 break; 2607 case TRY_AGAIN: 2608 if (hp->rcode == SERVFAIL) 2609 break; 2610 /* FALLTHROUGH */ 2611 default: 2612 return (-1); 2613 } 2614 saved_herrno = res->res_h_errno; 2615 tried_as_is++; 2616 } 2617 2618 /* 2619 * We do at least one level of search if 2620 * - there is no dot and RES_DEFNAME is set, or 2621 * - there is at least one dot, there is no trailing dot, 2622 * and RES_DNSRCH is set. 2623 */ 2624 if ((!dots && (res->options & RES_DEFNAMES)) || 2625 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2626 int done = 0; 2627 2628 for (domain = (const char * const *)res->dnsrch; 2629 *domain && !done; 2630 domain++) { 2631 searched = 1; 2632 2633 if (domain[0][0] == '\0' || 2634 (domain[0][0] == '.' && domain[0][1] == '\0')) 2635 root_on_list++; 2636 2637 if (root_on_list && tried_as_is) 2638 continue; 2639 2640 ret = res_querydomainN(name, *domain, target, res); 2641 if (ret > 0) 2642 return (ret); 2643 2644 /* 2645 * If no server present, give up. 2646 * If name isn't found in this domain, 2647 * keep trying higher domains in the search list 2648 * (if that's enabled). 2649 * On a NO_DATA error, keep trying, otherwise 2650 * a wildcard entry of another type could keep us 2651 * from finding this entry higher in the domain. 2652 * If we get some other error (negative answer or 2653 * server failure), then stop searching up, 2654 * but try the input name below in case it's 2655 * fully-qualified. 2656 */ 2657 if (errno == ECONNREFUSED) { 2658 RES_SET_H_ERRNO(res, TRY_AGAIN); 2659 return (-1); 2660 } 2661 2662 switch (res->res_h_errno) { 2663 case NO_DATA: 2664 got_nodata++; 2665 /* FALLTHROUGH */ 2666 case HOST_NOT_FOUND: 2667 /* keep trying */ 2668 break; 2669 case TRY_AGAIN: 2670 got_servfail++; 2671 if (hp->rcode == SERVFAIL) { 2672 /* try next search element, if any */ 2673 break; 2674 } 2675 /* FALLTHROUGH */ 2676 default: 2677 /* anything else implies that we're done */ 2678 done++; 2679 } 2680 /* 2681 * if we got here for some reason other than DNSRCH, 2682 * we only wanted one iteration of the loop, so stop. 2683 */ 2684 if (!(res->options & RES_DNSRCH)) 2685 done++; 2686 } 2687 } 2688 2689 switch (res->res_h_errno) { 2690 case NO_DATA: 2691 case HOST_NOT_FOUND: 2692 break; 2693 case TRY_AGAIN: 2694 if (hp->rcode == SERVFAIL) 2695 break; 2696 /* FALLTHROUGH */ 2697 default: 2698 goto giveup; 2699 } 2700 2701 /* 2702 * If the query has not already been tried as is then try it 2703 * unless RES_NOTLDQUERY is set and there were no dots. 2704 */ 2705 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2706 !(tried_as_is || root_on_list)) { 2707 ret = res_querydomainN(name, NULL, target, res); 2708 if (ret > 0) 2709 return (ret); 2710 } 2711 2712 /* 2713 * if we got here, we didn't satisfy the search. 2714 * if we did an initial full query, return that query's h_errno 2715 * (note that we wouldn't be here if that query had succeeded). 2716 * else if we ever got a nodata, send that back as the reason. 2717 * else send back meaningless h_errno, that being the one from 2718 * the last DNSRCH we did. 2719 */ 2720giveup: 2721 if (saved_herrno != -1) 2722 RES_SET_H_ERRNO(res, saved_herrno); 2723 else if (got_nodata) 2724 RES_SET_H_ERRNO(res, NO_DATA); 2725 else if (got_servfail) 2726 RES_SET_H_ERRNO(res, TRY_AGAIN); 2727 return (-1); 2728} 2729 2730/* 2731 * Perform a call on res_query on the concatenation of name and domain, 2732 * removing a trailing dot from name if domain is NULL. 2733 */ 2734static int 2735res_querydomainN(const char *name, const char *domain, 2736 struct res_target *target, res_state res) 2737{ 2738 char nbuf[MAXDNAME]; 2739 const char *longname = nbuf; 2740 size_t n, d; 2741 2742#ifdef DEBUG 2743 if (res->options & RES_DEBUG) 2744 printf(";; res_querydomain(%s, %s)\n", 2745 name, domain?domain:"<Nil>"); 2746#endif 2747 if (domain == NULL) { 2748 /* 2749 * Check for trailing '.'; 2750 * copy without '.' if present. 2751 */ 2752 n = strlen(name); 2753 if (n >= MAXDNAME) { 2754 RES_SET_H_ERRNO(res, NO_RECOVERY); 2755 return (-1); 2756 } 2757 if (n > 0 && name[--n] == '.') { 2758 strncpy(nbuf, name, n); 2759 nbuf[n] = '\0'; 2760 } else 2761 longname = name; 2762 } else { 2763 n = strlen(name); 2764 d = strlen(domain); 2765 if (n + d + 1 >= MAXDNAME) { 2766 RES_SET_H_ERRNO(res, NO_RECOVERY); 2767 return (-1); 2768 } 2769 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2770 } 2771 return (res_queryN(longname, target, res)); 2772} 2773