1 /* $FreeBSD: src/lib/libc/net/getaddrinfo.c,v 1.87 2008/02/03 19:07:55 ume Exp $ */ 2 /* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Issues to be discussed: 35 * - Return values. There are nonstandard return values defined and used 36 * in the source code. This is because RFC2553 is silent about which error 37 * code must be returned for which situation. 38 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 39 * invalid. current code - SEGV on freeaddrinfo(NULL) 40 * 41 * Note: 42 * - The code filters out AFs that are not supported by the kernel, 43 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 44 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 45 * in ai_flags? 46 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 47 * (1) what should we do against numeric hostname (2) what should we do 48 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 49 * non-loopback address configured? global address configured? 50 */ 51 52 #include "namespace.h" 53 #include <sys/types.h> 54 #include <sys/param.h> 55 #include <sys/socket.h> 56 #include <net/if.h> 57 #include <netinet/in.h> 58 #include <sys/queue.h> 59 #ifdef INET6 60 #include <net/if_var.h> 61 #include <sys/sysctl.h> 62 #include <sys/ioctl.h> 63 #include <netinet6/in6_var.h> /* XXX */ 64 #endif 65 #include <arpa/inet.h> 66 #include <arpa/nameser.h> 67 #include <rpc/rpc.h> 68 #include <rpcsvc/yp_prot.h> 69 #include <rpcsvc/ypclnt.h> 70 #include <netdb.h> 71 #include <resolv.h> 72 #include <string.h> 73 #include <stdlib.h> 74 #include <stddef.h> 75 #include <ctype.h> 76 #include <unistd.h> 77 #include <stdio.h> 78 #include <errno.h> 79 80 #include "res_config.h" 81 82 #ifdef DEBUG 83 #include <syslog.h> 84 #endif 85 86 #include <stdarg.h> 87 #include <nsswitch.h> 88 #include "un-namespace.h" 89 #include "libc_private.h" 90 #ifdef NS_CACHING 91 #include "nscache.h" 92 #endif 93 94 #define SUCCESS 0 95 #define ANY 0 96 #define YES 1 97 #define NO 0 98 99 static const char in_addrany[] = { 0, 0, 0, 0 }; 100 static const char in_loopback[] = { 127, 0, 0, 1 }; 101 #ifdef INET6 102 static const char in6_addrany[] = { 103 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 104 }; 105 static const char in6_loopback[] = { 106 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 107 }; 108 #endif 109 110 struct policyqueue { 111 TAILQ_ENTRY(policyqueue) pc_entry; 112 #ifdef INET6 113 struct in6_addrpolicy pc_policy; 114 #endif 115 }; 116 TAILQ_HEAD(policyhead, policyqueue); 117 118 static const struct afd { 119 int a_af; 120 int a_addrlen; 121 socklen_t a_socklen; 122 int a_off; 123 const char *a_addrany; 124 const char *a_loopback; 125 int a_scoped; 126 } afdl [] = { 127 #ifdef INET6 128 #define N_INET6 0 129 {PF_INET6, sizeof(struct in6_addr), 130 sizeof(struct sockaddr_in6), 131 offsetof(struct sockaddr_in6, sin6_addr), 132 in6_addrany, in6_loopback, 1}, 133 #define N_INET 1 134 #else 135 #define N_INET 0 136 #endif 137 {PF_INET, sizeof(struct in_addr), 138 sizeof(struct sockaddr_in), 139 offsetof(struct sockaddr_in, sin_addr), 140 in_addrany, in_loopback, 0}, 141 {0, 0, 0, 0, NULL, NULL, 0}, 142 }; 143 144 struct explore { 145 int e_af; 146 int e_socktype; 147 int e_protocol; 148 const char *e_protostr; 149 int e_wild; 150 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 151 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 152 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 153 }; 154 155 static const struct explore explore[] = { 156 #if 0 157 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 158 #endif 159 #ifdef INET6 160 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 161 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 162 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 163 #endif 164 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 165 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 166 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 167 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 168 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 169 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 170 { -1, 0, 0, NULL, 0 }, 171 }; 172 173 #ifdef INET6 174 #define PTON_MAX 16 175 #else 176 #define PTON_MAX 4 177 #endif 178 179 #define AIO_SRCFLAG_DEPRECATED 0x1 180 181 struct ai_order { 182 union { 183 struct sockaddr_storage aiou_ss; 184 struct sockaddr aiou_sa; 185 } aio_src_un; 186 #define aio_srcsa aio_src_un.aiou_sa 187 u_int32_t aio_srcflag; 188 int aio_srcscope; 189 int aio_dstscope; 190 struct policyqueue *aio_srcpolicy; 191 struct policyqueue *aio_dstpolicy; 192 struct addrinfo *aio_ai; 193 int aio_matchlen; 194 }; 195 196 static const ns_src default_dns_files[] = { 197 { NSSRC_FILES, NS_SUCCESS }, 198 { NSSRC_DNS, NS_SUCCESS }, 199 { 0 } 200 }; 201 202 struct res_target { 203 struct res_target *next; 204 const char *name; /* domain name */ 205 int qclass, qtype; /* class and type of query */ 206 u_char *answer; /* buffer to put answer */ 207 int anslen; /* size of answer buffer */ 208 int n; /* result length */ 209 }; 210 211 #define MAXPACKET (64*1024) 212 213 typedef union { 214 HEADER hdr; 215 u_char buf[MAXPACKET]; 216 } querybuf; 217 218 static int str2number(const char *, int *); 219 static int explore_null(const struct addrinfo *, 220 const char *, struct addrinfo **); 221 static int explore_numeric(const struct addrinfo *, const char *, 222 const char *, struct addrinfo **, const char *); 223 static int explore_numeric_scope(const struct addrinfo *, const char *, 224 const char *, struct addrinfo **); 225 static int get_canonname(const struct addrinfo *, 226 struct addrinfo *, const char *); 227 static struct addrinfo *get_ai(const struct addrinfo *, 228 const struct afd *, const char *); 229 static int get_portmatch(const struct addrinfo *, const char *); 230 static int get_port(struct addrinfo *, const char *, int); 231 static const struct afd *find_afd(int); 232 static int addrconfig(struct addrinfo *); 233 static void set_source(struct ai_order *, struct policyhead *); 234 static int comp_dst(const void *, const void *); 235 #ifdef INET6 236 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 237 #endif 238 static int gai_addr2scopetype(struct sockaddr *); 239 240 static int explore_fqdn(const struct addrinfo *, const char *, 241 const char *, struct addrinfo **); 242 243 static int reorder(struct addrinfo *); 244 static int get_addrselectpolicy(struct policyhead *); 245 static void free_addrselectpolicy(struct policyhead *); 246 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 247 struct policyhead *); 248 static int matchlen(struct sockaddr *, struct sockaddr *); 249 250 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 251 const struct addrinfo *, res_state); 252 #if defined(RESOLVSORT) 253 static int addr4sort(struct addrinfo *, res_state); 254 #endif 255 static int _dns_getaddrinfo(void *, void *, va_list); 256 static void _sethtent(FILE **); 257 static void _endhtent(FILE **); 258 static struct addrinfo *_gethtent(FILE **, const char *, 259 const struct addrinfo *); 260 static int _files_getaddrinfo(void *, void *, va_list); 261 #ifdef YP 262 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 263 static int _yp_getaddrinfo(void *, void *, va_list); 264 #endif 265 #ifdef NS_CACHING 266 static int addrinfo_id_func(char *, size_t *, va_list, void *); 267 static int addrinfo_marshal_func(char *, size_t *, void *, va_list, 268 void *); 269 static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, 270 void *); 271 #endif 272 273 static int res_queryN(const char *, struct res_target *, res_state); 274 static int res_searchN(const char *, struct res_target *, res_state); 275 static int res_querydomainN(const char *, const char *, 276 struct res_target *, res_state); 277 278 /* XXX macros that make external reference is BAD. */ 279 280 #define GET_AI(ai, afd, addr) \ 281 do { \ 282 /* external reference: pai, error, and label free */ \ 283 (ai) = get_ai(pai, (afd), (addr)); \ 284 if ((ai) == NULL) { \ 285 error = EAI_MEMORY; \ 286 goto free; \ 287 } \ 288 } while (/*CONSTCOND*/0) 289 290 #define GET_PORT(ai, serv) \ 291 do { \ 292 /* external reference: error and label free */ \ 293 error = get_port((ai), (serv), 0); \ 294 if (error != 0) \ 295 goto free; \ 296 } while (/*CONSTCOND*/0) 297 298 #define GET_CANONNAME(ai, str) \ 299 do { \ 300 /* external reference: pai, error and label free */ \ 301 error = get_canonname(pai, (ai), (str)); \ 302 if (error != 0) \ 303 goto free; \ 304 } while (/*CONSTCOND*/0) 305 306 #define ERR(err) \ 307 do { \ 308 /* external reference: error, and label bad */ \ 309 error = (err); \ 310 goto bad; \ 311 /*NOTREACHED*/ \ 312 } while (/*CONSTCOND*/0) 313 314 #define MATCH_FAMILY(x, y, w) \ 315 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 316 #define MATCH(x, y, w) \ 317 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 318 319 void 320 freeaddrinfo(struct addrinfo *ai) 321 { 322 struct addrinfo *next; 323 324 do { 325 next = ai->ai_next; 326 if (ai->ai_canonname) 327 free(ai->ai_canonname); 328 /* no need to free(ai->ai_addr) */ 329 free(ai); 330 ai = next; 331 } while (ai); 332 } 333 334 static int 335 str2number(const char *p, int *portp) 336 { 337 char *ep; 338 unsigned long v; 339 340 if (*p == '\0') 341 return -1; 342 ep = NULL; 343 errno = 0; 344 v = strtoul(p, &ep, 10); 345 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 346 *portp = v; 347 return 0; 348 } else 349 return -1; 350 } 351 352 int 353 getaddrinfo(const char * __restrict hostname, const char * __restrict servname, 354 const struct addrinfo * __restrict hints, struct addrinfo ** __restrict res) 355 { 356 struct addrinfo sentinel; 357 struct addrinfo *cur; 358 int error = 0; 359 struct addrinfo ai; 360 struct addrinfo ai0; 361 struct addrinfo *pai; 362 const struct explore *ex; 363 int numeric = 0; 364 365 memset(&sentinel, 0, sizeof(sentinel)); 366 cur = &sentinel; 367 pai = &ai; 368 pai->ai_flags = 0; 369 pai->ai_family = PF_UNSPEC; 370 pai->ai_socktype = ANY; 371 pai->ai_protocol = ANY; 372 pai->ai_addrlen = 0; 373 pai->ai_canonname = NULL; 374 pai->ai_addr = NULL; 375 pai->ai_next = NULL; 376 377 if (hostname == NULL && servname == NULL) 378 return EAI_NONAME; 379 if (hints) { 380 /* error check for hints */ 381 if (hints->ai_addrlen || hints->ai_canonname || 382 hints->ai_addr || hints->ai_next) 383 ERR(EAI_BADHINTS); /* xxx */ 384 if (hints->ai_flags & ~AI_MASK) 385 ERR(EAI_BADFLAGS); 386 switch (hints->ai_family) { 387 case PF_UNSPEC: 388 case PF_INET: 389 #ifdef INET6 390 case PF_INET6: 391 #endif 392 break; 393 default: 394 ERR(EAI_FAMILY); 395 } 396 memcpy(pai, hints, sizeof(*pai)); 397 398 /* 399 * if both socktype/protocol are specified, check if they 400 * are meaningful combination. 401 */ 402 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 403 for (ex = explore; ex->e_af >= 0; ex++) { 404 if (pai->ai_family != ex->e_af) 405 continue; 406 if (ex->e_socktype == ANY) 407 continue; 408 if (ex->e_protocol == ANY) 409 continue; 410 if (pai->ai_socktype == ex->e_socktype && 411 pai->ai_protocol != ex->e_protocol) { 412 ERR(EAI_BADHINTS); 413 } 414 } 415 } 416 } 417 418 /* 419 * check for special cases. (1) numeric servname is disallowed if 420 * socktype/protocol are left unspecified. (2) servname is disallowed 421 * for raw and other inet{,6} sockets. 422 */ 423 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 424 #ifdef PF_INET6 425 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 426 #endif 427 ) { 428 ai0 = *pai; /* backup *pai */ 429 430 if (pai->ai_family == PF_UNSPEC) { 431 #ifdef PF_INET6 432 pai->ai_family = PF_INET6; 433 #else 434 pai->ai_family = PF_INET; 435 #endif 436 } 437 error = get_portmatch(pai, servname); 438 if (error) 439 ERR(error); 440 441 *pai = ai0; 442 } 443 444 ai0 = *pai; 445 446 /* NULL hostname, or numeric hostname */ 447 for (ex = explore; ex->e_af >= 0; ex++) { 448 *pai = ai0; 449 450 /* PF_UNSPEC entries are prepared for DNS queries only */ 451 if (ex->e_af == PF_UNSPEC) 452 continue; 453 454 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 455 continue; 456 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 457 continue; 458 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 459 continue; 460 461 if (pai->ai_family == PF_UNSPEC) 462 pai->ai_family = ex->e_af; 463 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 464 pai->ai_socktype = ex->e_socktype; 465 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 466 pai->ai_protocol = ex->e_protocol; 467 468 if (hostname == NULL) 469 error = explore_null(pai, servname, &cur->ai_next); 470 else 471 error = explore_numeric_scope(pai, hostname, servname, 472 &cur->ai_next); 473 474 if (error) 475 goto free; 476 477 while (cur && cur->ai_next) 478 cur = cur->ai_next; 479 } 480 481 /* 482 * XXX 483 * If numreic representation of AF1 can be interpreted as FQDN 484 * representation of AF2, we need to think again about the code below. 485 */ 486 if (sentinel.ai_next) { 487 numeric = 1; 488 goto good; 489 } 490 491 if (hostname == NULL) 492 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 493 if (pai->ai_flags & AI_NUMERICHOST) 494 ERR(EAI_NONAME); 495 496 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 497 ERR(EAI_FAIL); 498 499 /* 500 * hostname as alphabetical name. 501 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 502 * outer loop by AFs. 503 */ 504 for (ex = explore; ex->e_af >= 0; ex++) { 505 *pai = ai0; 506 507 /* require exact match for family field */ 508 if (pai->ai_family != ex->e_af) 509 continue; 510 511 if (!MATCH(pai->ai_socktype, ex->e_socktype, 512 WILD_SOCKTYPE(ex))) { 513 continue; 514 } 515 if (!MATCH(pai->ai_protocol, ex->e_protocol, 516 WILD_PROTOCOL(ex))) { 517 continue; 518 } 519 520 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 521 pai->ai_socktype = ex->e_socktype; 522 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 523 pai->ai_protocol = ex->e_protocol; 524 525 error = explore_fqdn(pai, hostname, servname, &cur->ai_next); 526 527 while (cur && cur->ai_next) 528 cur = cur->ai_next; 529 } 530 531 /* XXX inhibit errors if we have the result */ 532 if (sentinel.ai_next) 533 error = 0; 534 535 good: 536 /* 537 * ensure we return either: 538 * - error == 0, non-NULL *res 539 * - error != 0, NULL *res 540 */ 541 if (error == 0) { 542 if (sentinel.ai_next) { 543 /* 544 * If the returned entry is for an active connection, 545 * and the given name is not numeric, reorder the 546 * list, so that the application would try the list 547 * in the most efficient order. Since the head entry 548 * of the original list may contain ai_canonname and 549 * that entry may be moved elsewhere in the new list, 550 * we keep the pointer and will restore it in the new 551 * head entry. (Note that RFC3493 requires the head 552 * entry store it when requested by the caller). 553 */ 554 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 555 if (!numeric) { 556 char *canonname; 557 558 canonname = 559 sentinel.ai_next->ai_canonname; 560 sentinel.ai_next->ai_canonname = NULL; 561 reorder(&sentinel); 562 if (sentinel.ai_next->ai_canonname == 563 NULL) { 564 sentinel.ai_next->ai_canonname 565 = canonname; 566 } else if (canonname != NULL) 567 free(canonname); 568 } 569 } 570 *res = sentinel.ai_next; 571 return SUCCESS; 572 } else 573 error = EAI_FAIL; 574 } 575 free: 576 bad: 577 if (sentinel.ai_next) 578 freeaddrinfo(sentinel.ai_next); 579 *res = NULL; 580 return error; 581 } 582 583 static int 584 reorder(struct addrinfo *sentinel) 585 { 586 struct addrinfo *ai, **aip; 587 struct ai_order *aio; 588 int i, n; 589 struct policyhead policyhead; 590 591 /* count the number of addrinfo elements for sorting. */ 592 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 593 ; 594 595 /* 596 * If the number is small enough, we can skip the reordering process. 597 */ 598 if (n <= 1) 599 return(n); 600 601 /* allocate a temporary array for sort and initialization of it. */ 602 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 603 return(n); /* give up reordering */ 604 memset(aio, 0, sizeof(*aio) * n); 605 606 /* retrieve address selection policy from the kernel */ 607 TAILQ_INIT(&policyhead); 608 if (!get_addrselectpolicy(&policyhead)) { 609 /* no policy is installed into kernel, we don't sort. */ 610 free(aio); 611 return (n); 612 } 613 614 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 615 aio[i].aio_ai = ai; 616 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 617 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 618 &policyhead); 619 set_source(&aio[i], &policyhead); 620 } 621 622 /* perform sorting. */ 623 qsort(aio, n, sizeof(*aio), comp_dst); 624 625 /* reorder the addrinfo chain. */ 626 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 627 *aip = aio[i].aio_ai; 628 aip = &aio[i].aio_ai->ai_next; 629 } 630 *aip = NULL; 631 632 /* cleanup and return */ 633 free(aio); 634 free_addrselectpolicy(&policyhead); 635 return(n); 636 } 637 638 static int 639 get_addrselectpolicy(struct policyhead *head) 640 { 641 #ifdef INET6 642 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 643 size_t l; 644 char *buf; 645 struct in6_addrpolicy *pol, *ep; 646 647 if (sysctl(mib, NELEM(mib), NULL, &l, NULL, 0) < 0) 648 return (0); 649 if ((buf = malloc(l)) == NULL) 650 return (0); 651 if (sysctl(mib, NELEM(mib), buf, &l, NULL, 0) < 0) { 652 free(buf); 653 return (0); 654 } 655 656 ep = (struct in6_addrpolicy *)(buf + l); 657 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 658 struct policyqueue *new; 659 660 if ((new = malloc(sizeof(*new))) == NULL) { 661 free_addrselectpolicy(head); /* make the list empty */ 662 break; 663 } 664 new->pc_policy = *pol; 665 TAILQ_INSERT_TAIL(head, new, pc_entry); 666 } 667 668 free(buf); 669 return (1); 670 #else 671 return (0); 672 #endif 673 } 674 675 static void 676 free_addrselectpolicy(struct policyhead *head) 677 { 678 struct policyqueue *ent, *nent; 679 680 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 681 nent = TAILQ_NEXT(ent, pc_entry); 682 TAILQ_REMOVE(head, ent, pc_entry); 683 free(ent); 684 } 685 } 686 687 static struct policyqueue * 688 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 689 { 690 #ifdef INET6 691 struct policyqueue *ent, *bestent = NULL; 692 struct in6_addrpolicy *pol; 693 int matchlen, bestmatchlen = -1; 694 u_char *mp, *ep, *k, *p, m; 695 struct sockaddr_in6 key; 696 697 switch(addr->sa_family) { 698 case AF_INET6: 699 key = *(struct sockaddr_in6 *)addr; 700 break; 701 case AF_INET: 702 /* convert the address into IPv4-mapped IPv6 address. */ 703 memset(&key, 0, sizeof(key)); 704 key.sin6_family = AF_INET6; 705 key.sin6_len = sizeof(key); 706 key.sin6_addr.s6_addr[10] = 0xff; 707 key.sin6_addr.s6_addr[11] = 0xff; 708 memcpy(&key.sin6_addr.s6_addr[12], 709 &((struct sockaddr_in *)addr)->sin_addr, 4); 710 break; 711 default: 712 return(NULL); 713 } 714 715 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 716 pol = &ent->pc_policy; 717 matchlen = 0; 718 719 mp = (u_char *)&pol->addrmask.sin6_addr; 720 ep = mp + 16; /* XXX: scope field? */ 721 k = (u_char *)&key.sin6_addr; 722 p = (u_char *)&pol->addr.sin6_addr; 723 for (; mp < ep && *mp; mp++, k++, p++) { 724 m = *mp; 725 if ((*k & m) != *p) 726 goto next; /* not match */ 727 if (m == 0xff) /* short cut for a typical case */ 728 matchlen += 8; 729 else { 730 while (m >= 0x80) { 731 matchlen++; 732 m <<= 1; 733 } 734 } 735 } 736 737 /* matched. check if this is better than the current best. */ 738 if (matchlen > bestmatchlen) { 739 bestent = ent; 740 bestmatchlen = matchlen; 741 } 742 743 next: 744 continue; 745 } 746 747 return(bestent); 748 #else 749 return(NULL); 750 #endif 751 752 } 753 754 static void 755 set_source(struct ai_order *aio, struct policyhead *ph) 756 { 757 struct addrinfo ai = *aio->aio_ai; 758 struct sockaddr_storage ss; 759 socklen_t srclen; 760 int s; 761 762 /* set unspec ("no source is available"), just in case */ 763 aio->aio_srcsa.sa_family = AF_UNSPEC; 764 aio->aio_srcscope = -1; 765 766 switch(ai.ai_family) { 767 case AF_INET: 768 #ifdef INET6 769 case AF_INET6: 770 #endif 771 break; 772 default: /* ignore unsupported AFs explicitly */ 773 return; 774 } 775 776 /* XXX: make a dummy addrinfo to call connect() */ 777 ai.ai_socktype = SOCK_DGRAM; 778 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 779 ai.ai_next = NULL; 780 memset(&ss, 0, sizeof(ss)); 781 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 782 ai.ai_addr = (struct sockaddr *)&ss; 783 get_port(&ai, "1", 0); 784 785 /* open a socket to get the source address for the given dst */ 786 if ((s = _socket(ai.ai_family, ai.ai_socktype, ai.ai_protocol)) < 0) 787 return; /* give up */ 788 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 789 goto cleanup; 790 srclen = ai.ai_addrlen; 791 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 792 aio->aio_srcsa.sa_family = AF_UNSPEC; 793 goto cleanup; 794 } 795 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 796 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 797 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 798 #ifdef INET6 799 if (ai.ai_family == AF_INET6) { 800 struct in6_ifreq ifr6; 801 u_int32_t flags6; 802 803 /* XXX: interface name should not be hardcoded */ 804 strncpy(ifr6.ifr_name, "lo0", sizeof(ifr6.ifr_name)); 805 memset(&ifr6, 0, sizeof(ifr6)); 806 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 807 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 808 flags6 = ifr6.ifr_ifru.ifru_flags6; 809 if ((flags6 & IN6_IFF_DEPRECATED)) 810 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 811 } 812 } 813 #endif 814 815 cleanup: 816 _close(s); 817 return; 818 } 819 820 static int 821 matchlen(struct sockaddr *src, struct sockaddr *dst) 822 { 823 int match = 0; 824 u_char *s, *d; 825 u_char *lim, r; 826 int addrlen; 827 828 switch (src->sa_family) { 829 #ifdef INET6 830 case AF_INET6: 831 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 832 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 833 addrlen = sizeof(struct in6_addr); 834 lim = s + addrlen; 835 break; 836 #endif 837 case AF_INET: 838 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 839 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 840 addrlen = sizeof(struct in_addr); 841 lim = s + addrlen; 842 break; 843 default: 844 return(0); 845 } 846 847 while (s < lim) 848 if ((r = (*d++ ^ *s++)) != 0) { 849 while (r < addrlen * 8) { 850 match++; 851 r <<= 1; 852 } 853 break; 854 } else 855 match += 8; 856 return(match); 857 } 858 859 static int 860 comp_dst(const void *arg1, const void *arg2) 861 { 862 const struct ai_order *dst1 = arg1, *dst2 = arg2; 863 864 /* 865 * Rule 1: Avoid unusable destinations. 866 * XXX: we currently do not consider if an appropriate route exists. 867 */ 868 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 869 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 870 return(-1); 871 } 872 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 873 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 874 return(1); 875 } 876 877 /* Rule 2: Prefer matching scope. */ 878 if (dst1->aio_dstscope == dst1->aio_srcscope && 879 dst2->aio_dstscope != dst2->aio_srcscope) { 880 return(-1); 881 } 882 if (dst1->aio_dstscope != dst1->aio_srcscope && 883 dst2->aio_dstscope == dst2->aio_srcscope) { 884 return(1); 885 } 886 887 /* Rule 3: Avoid deprecated addresses. */ 888 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 889 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 890 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 891 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 892 return(-1); 893 } 894 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 895 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 896 return(1); 897 } 898 } 899 900 /* Rule 4: Prefer home addresses. */ 901 /* XXX: not implemented yet */ 902 903 /* Rule 5: Prefer matching label. */ 904 #ifdef INET6 905 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 906 dst1->aio_srcpolicy->pc_policy.label == 907 dst1->aio_dstpolicy->pc_policy.label && 908 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 909 dst2->aio_srcpolicy->pc_policy.label != 910 dst2->aio_dstpolicy->pc_policy.label)) { 911 return(-1); 912 } 913 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 914 dst2->aio_srcpolicy->pc_policy.label == 915 dst2->aio_dstpolicy->pc_policy.label && 916 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 917 dst1->aio_srcpolicy->pc_policy.label != 918 dst1->aio_dstpolicy->pc_policy.label)) { 919 return(1); 920 } 921 #endif 922 923 /* Rule 6: Prefer higher precedence. */ 924 #ifdef INET6 925 if (dst1->aio_dstpolicy && 926 (dst2->aio_dstpolicy == NULL || 927 dst1->aio_dstpolicy->pc_policy.preced > 928 dst2->aio_dstpolicy->pc_policy.preced)) { 929 return(-1); 930 } 931 if (dst2->aio_dstpolicy && 932 (dst1->aio_dstpolicy == NULL || 933 dst2->aio_dstpolicy->pc_policy.preced > 934 dst1->aio_dstpolicy->pc_policy.preced)) { 935 return(1); 936 } 937 #endif 938 939 /* Rule 7: Prefer native transport. */ 940 /* XXX: not implemented yet */ 941 942 /* Rule 8: Prefer smaller scope. */ 943 if (dst1->aio_dstscope >= 0 && 944 dst1->aio_dstscope < dst2->aio_dstscope) { 945 return(-1); 946 } 947 if (dst2->aio_dstscope >= 0 && 948 dst2->aio_dstscope < dst1->aio_dstscope) { 949 return(1); 950 } 951 952 /* 953 * Rule 9: Use longest matching prefix. 954 * We compare the match length in a same AF only. 955 */ 956 if (dst1->aio_ai->ai_addr->sa_family == 957 dst2->aio_ai->ai_addr->sa_family) { 958 if (dst1->aio_matchlen > dst2->aio_matchlen) { 959 return(-1); 960 } 961 if (dst1->aio_matchlen < dst2->aio_matchlen) { 962 return(1); 963 } 964 } 965 966 /* Rule 10: Otherwise, leave the order unchanged. */ 967 return(-1); 968 } 969 970 /* 971 * Copy from scope.c. 972 * XXX: we should standardize the functions and link them as standard 973 * library. 974 */ 975 static int 976 gai_addr2scopetype(struct sockaddr *sa) 977 { 978 #ifdef INET6 979 struct sockaddr_in6 *sa6; 980 #endif 981 struct sockaddr_in *sa4; 982 983 switch(sa->sa_family) { 984 #ifdef INET6 985 case AF_INET6: 986 sa6 = (struct sockaddr_in6 *)sa; 987 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 988 /* just use the scope field of the multicast address */ 989 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 990 } 991 /* 992 * Unicast addresses: map scope type to corresponding scope 993 * value defined for multcast addresses. 994 * XXX: hardcoded scope type values are bad... 995 */ 996 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 997 return(1); /* node local scope */ 998 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 999 return(2); /* link-local scope */ 1000 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1001 return(5); /* site-local scope */ 1002 return(14); /* global scope */ 1003 break; 1004 #endif 1005 case AF_INET: 1006 /* 1007 * IPv4 pseudo scoping according to RFC 3484. 1008 */ 1009 sa4 = (struct sockaddr_in *)sa; 1010 /* IPv4 autoconfiguration addresses have link-local scope. */ 1011 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1012 ((u_char *)&sa4->sin_addr)[1] == 254) 1013 return(2); 1014 /* Private addresses have site-local scope. */ 1015 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1016 (((u_char *)&sa4->sin_addr)[0] == 172 && 1017 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1018 (((u_char *)&sa4->sin_addr)[0] == 192 && 1019 ((u_char *)&sa4->sin_addr)[1] == 168)) 1020 return(14); /* XXX: It should be 5 unless NAT */ 1021 /* Loopback addresses have link-local scope. */ 1022 if (((u_char *)&sa4->sin_addr)[0] == 127) 1023 return(2); 1024 return(14); 1025 break; 1026 default: 1027 errno = EAFNOSUPPORT; /* is this a good error? */ 1028 return(-1); 1029 } 1030 } 1031 1032 /* 1033 * hostname == NULL. 1034 * passive socket -> anyaddr (0.0.0.0 or ::) 1035 * non-passive socket -> localhost (127.0.0.1 or ::1) 1036 */ 1037 static int 1038 explore_null(const struct addrinfo *pai, const char *servname, 1039 struct addrinfo **res) 1040 { 1041 int s; 1042 const struct afd *afd; 1043 struct addrinfo *ai; 1044 int error; 1045 1046 *res = NULL; 1047 ai = NULL; 1048 1049 /* 1050 * filter out AFs that are not supported by the kernel 1051 * XXX errno? 1052 */ 1053 s = _socket(pai->ai_family, SOCK_DGRAM, 0); 1054 if (s < 0) { 1055 if (errno != EMFILE) 1056 return 0; 1057 } else 1058 _close(s); 1059 1060 /* 1061 * if the servname does not match socktype/protocol, ignore it. 1062 */ 1063 if (get_portmatch(pai, servname) != 0) 1064 return 0; 1065 1066 afd = find_afd(pai->ai_family); 1067 if (afd == NULL) 1068 return 0; 1069 1070 if (pai->ai_flags & AI_PASSIVE) { 1071 GET_AI(ai, afd, afd->a_addrany); 1072 GET_PORT(ai, servname); 1073 } else { 1074 GET_AI(ai, afd, afd->a_loopback); 1075 GET_PORT(ai, servname); 1076 } 1077 1078 *res = ai; 1079 return 0; 1080 1081 free: 1082 if (ai != NULL) 1083 freeaddrinfo(ai); 1084 return error; 1085 } 1086 1087 /* 1088 * numeric hostname 1089 */ 1090 static int 1091 explore_numeric(const struct addrinfo *pai, const char *hostname, 1092 const char *servname, struct addrinfo **res, 1093 const char *canonname) 1094 { 1095 const struct afd *afd; 1096 struct addrinfo *ai; 1097 int error; 1098 char pton[PTON_MAX]; 1099 1100 *res = NULL; 1101 ai = NULL; 1102 1103 /* 1104 * if the servname does not match socktype/protocol, ignore it. 1105 */ 1106 if (get_portmatch(pai, servname) != 0) 1107 return 0; 1108 1109 afd = find_afd(pai->ai_family); 1110 if (afd == NULL) 1111 return 0; 1112 1113 switch (afd->a_af) { 1114 case AF_INET: 1115 /* 1116 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1117 * that are accepted by inet_addr() and its family. The 1118 * accepted forms includes the "classful" one, which inet_pton 1119 * does not accept. So we need to separate the case for 1120 * AF_INET. 1121 */ 1122 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1123 return 0; 1124 break; 1125 default: 1126 if (inet_pton(afd->a_af, hostname, pton) != 1) 1127 return 0; 1128 break; 1129 } 1130 1131 if (pai->ai_family == afd->a_af) { 1132 GET_AI(ai, afd, pton); 1133 GET_PORT(ai, servname); 1134 if ((pai->ai_flags & AI_CANONNAME)) { 1135 /* 1136 * Set the numeric address itself as the canonical 1137 * name, based on a clarification in RFC3493. 1138 */ 1139 GET_CANONNAME(ai, canonname); 1140 } 1141 } else { 1142 /* 1143 * XXX: This should not happen since we already matched the AF 1144 * by find_afd. 1145 */ 1146 ERR(EAI_FAMILY); 1147 } 1148 1149 *res = ai; 1150 return 0; 1151 1152 free: 1153 bad: 1154 if (ai != NULL) 1155 freeaddrinfo(ai); 1156 return error; 1157 } 1158 1159 /* 1160 * numeric hostname with scope 1161 */ 1162 static int 1163 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1164 const char *servname, struct addrinfo **res) 1165 { 1166 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 1167 return explore_numeric(pai, hostname, servname, res, hostname); 1168 #else 1169 const struct afd *afd; 1170 struct addrinfo *cur; 1171 int error; 1172 char *cp, *hostname2 = NULL, *scope, *addr; 1173 struct sockaddr_in6 *sin6; 1174 1175 /* 1176 * if the servname does not match socktype/protocol, ignore it. 1177 */ 1178 if (get_portmatch(pai, servname) != 0) 1179 return 0; 1180 1181 afd = find_afd(pai->ai_family); 1182 if (afd == NULL) 1183 return 0; 1184 1185 if (!afd->a_scoped) 1186 return explore_numeric(pai, hostname, servname, res, hostname); 1187 1188 cp = strchr(hostname, SCOPE_DELIMITER); 1189 if (cp == NULL) 1190 return explore_numeric(pai, hostname, servname, res, hostname); 1191 1192 /* 1193 * Handle special case of <scoped_address><delimiter><scope id> 1194 */ 1195 hostname2 = strdup(hostname); 1196 if (hostname2 == NULL) 1197 return EAI_MEMORY; 1198 /* terminate at the delimiter */ 1199 hostname2[cp - hostname] = '\0'; 1200 addr = hostname2; 1201 scope = cp + 1; 1202 1203 error = explore_numeric(pai, addr, servname, res, hostname); 1204 if (error == 0) { 1205 u_int32_t scopeid; 1206 1207 for (cur = *res; cur; cur = cur->ai_next) { 1208 if (cur->ai_family != AF_INET6) 1209 continue; 1210 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1211 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1212 free(hostname2); 1213 return(EAI_NONAME); /* XXX: is return OK? */ 1214 } 1215 sin6->sin6_scope_id = scopeid; 1216 } 1217 } 1218 1219 free(hostname2); 1220 1221 return error; 1222 #endif 1223 } 1224 1225 static int 1226 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1227 { 1228 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1229 ai->ai_canonname = strdup(str); 1230 if (ai->ai_canonname == NULL) 1231 return EAI_MEMORY; 1232 } 1233 return 0; 1234 } 1235 1236 static struct addrinfo * 1237 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1238 { 1239 char *p; 1240 struct addrinfo *ai; 1241 1242 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1243 + (afd->a_socklen)); 1244 if (ai == NULL) 1245 return NULL; 1246 1247 memcpy(ai, pai, sizeof(struct addrinfo)); 1248 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1249 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1250 ai->ai_addr->sa_len = afd->a_socklen; 1251 ai->ai_addrlen = afd->a_socklen; 1252 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1253 p = (char *)(void *)(ai->ai_addr); 1254 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1255 return ai; 1256 } 1257 1258 static int 1259 get_portmatch(const struct addrinfo *ai, const char *servname) 1260 { 1261 1262 /* get_port does not touch first argument when matchonly == 1. */ 1263 /* LINTED const cast */ 1264 return get_port((struct addrinfo *)ai, servname, 1); 1265 } 1266 1267 static int 1268 get_port(struct addrinfo *ai, const char *servname, int matchonly) 1269 { 1270 const char *proto; 1271 struct servent *sp; 1272 int port, error; 1273 int allownumeric; 1274 1275 if (servname == NULL) 1276 return 0; 1277 switch (ai->ai_family) { 1278 case AF_INET: 1279 #ifdef AF_INET6 1280 case AF_INET6: 1281 #endif 1282 break; 1283 default: 1284 return 0; 1285 } 1286 1287 switch (ai->ai_socktype) { 1288 case SOCK_RAW: 1289 return EAI_SERVICE; 1290 case SOCK_DGRAM: 1291 case SOCK_STREAM: 1292 allownumeric = 1; 1293 break; 1294 case ANY: 1295 allownumeric = 0; 1296 break; 1297 default: 1298 return EAI_SOCKTYPE; 1299 } 1300 1301 error = str2number(servname, &port); 1302 if (error == 0) { 1303 if (!allownumeric) 1304 return EAI_SERVICE; 1305 if (port < 0 || port > 65535) 1306 return EAI_SERVICE; 1307 port = htons(port); 1308 } else { 1309 if (ai->ai_flags & AI_NUMERICSERV) 1310 return EAI_NONAME; 1311 switch (ai->ai_socktype) { 1312 case SOCK_DGRAM: 1313 proto = "udp"; 1314 break; 1315 case SOCK_STREAM: 1316 proto = "tcp"; 1317 break; 1318 default: 1319 proto = NULL; 1320 break; 1321 } 1322 1323 if ((sp = getservbyname(servname, proto)) == NULL) 1324 return EAI_SERVICE; 1325 port = sp->s_port; 1326 } 1327 1328 if (!matchonly) { 1329 switch (ai->ai_family) { 1330 case AF_INET: 1331 ((struct sockaddr_in *)(void *) 1332 ai->ai_addr)->sin_port = port; 1333 break; 1334 #ifdef INET6 1335 case AF_INET6: 1336 ((struct sockaddr_in6 *)(void *) 1337 ai->ai_addr)->sin6_port = port; 1338 break; 1339 #endif 1340 } 1341 } 1342 1343 return 0; 1344 } 1345 1346 static const struct afd * 1347 find_afd(int af) 1348 { 1349 const struct afd *afd; 1350 1351 if (af == PF_UNSPEC) 1352 return NULL; 1353 for (afd = afdl; afd->a_af; afd++) { 1354 if (afd->a_af == af) 1355 return afd; 1356 } 1357 return NULL; 1358 } 1359 1360 /* 1361 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1362 * will take care of it. 1363 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1364 * if the code is right or not. 1365 * 1366 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1367 * _dns_getaddrinfo. 1368 */ 1369 static int 1370 addrconfig(struct addrinfo *pai) 1371 { 1372 int s, af; 1373 1374 /* 1375 * TODO: 1376 * Note that implementation dependent test for address 1377 * configuration should be done everytime called 1378 * (or apropriate interval), 1379 * because addresses will be dynamically assigned or deleted. 1380 */ 1381 af = pai->ai_family; 1382 if (af == AF_UNSPEC) { 1383 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 1384 af = AF_INET; 1385 else { 1386 _close(s); 1387 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) 1388 af = AF_INET6; 1389 else 1390 _close(s); 1391 } 1392 } 1393 if (af != AF_UNSPEC) { 1394 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 1395 return 0; 1396 _close(s); 1397 } 1398 pai->ai_family = af; 1399 return 1; 1400 } 1401 1402 #ifdef INET6 1403 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1404 static int 1405 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1406 { 1407 u_long lscopeid; 1408 struct in6_addr *a6; 1409 char *ep; 1410 1411 a6 = &sin6->sin6_addr; 1412 1413 /* empty scopeid portion is invalid */ 1414 if (*scope == '\0') 1415 return -1; 1416 1417 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1418 /* 1419 * We currently assume a one-to-one mapping between links 1420 * and interfaces, so we simply use interface indices for 1421 * like-local scopes. 1422 */ 1423 *scopeid = if_nametoindex(scope); 1424 if (*scopeid == 0) 1425 goto trynumeric; 1426 return 0; 1427 } 1428 1429 /* still unclear about literal, allow numeric only - placeholder */ 1430 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1431 goto trynumeric; 1432 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1433 goto trynumeric; 1434 else 1435 goto trynumeric; /* global */ 1436 1437 /* try to convert to a numeric id as a last resort */ 1438 trynumeric: 1439 errno = 0; 1440 lscopeid = strtoul(scope, &ep, 10); 1441 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1442 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1443 return 0; 1444 else 1445 return -1; 1446 } 1447 #endif 1448 1449 1450 #ifdef NS_CACHING 1451 static int 1452 addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1453 void *cache_mdata __unused) 1454 { 1455 res_state statp; 1456 u_long res_options; 1457 1458 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1459 char *hostname; 1460 struct addrinfo *hints; 1461 1462 char *p; 1463 int ai_flags, ai_family, ai_socktype, ai_protocol; 1464 size_t desired_size, size; 1465 1466 statp = __res_state(); 1467 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1468 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1469 1470 hostname = va_arg(ap, char *); 1471 hints = va_arg(ap, struct addrinfo *); 1472 1473 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1474 if (hostname != NULL) { 1475 size = strlen(hostname); 1476 desired_size += size + 1; 1477 } else 1478 size = 0; 1479 1480 if (desired_size > *buffer_size) { 1481 *buffer_size = desired_size; 1482 return (NS_RETURN); 1483 } 1484 1485 if (hints == NULL) 1486 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1487 else { 1488 ai_flags = hints->ai_flags; 1489 ai_family = hints->ai_family; 1490 ai_socktype = hints->ai_socktype; 1491 ai_protocol = hints->ai_protocol; 1492 } 1493 1494 p = buffer; 1495 memcpy(p, &res_options, sizeof(res_options)); 1496 p += sizeof(res_options); 1497 1498 memcpy(p, &op_id, sizeof(int)); 1499 p += sizeof(int); 1500 1501 memcpy(p, &ai_flags, sizeof(int)); 1502 p += sizeof(int); 1503 1504 memcpy(p, &ai_family, sizeof(int)); 1505 p += sizeof(int); 1506 1507 memcpy(p, &ai_socktype, sizeof(int)); 1508 p += sizeof(int); 1509 1510 memcpy(p, &ai_protocol, sizeof(int)); 1511 p += sizeof(int); 1512 1513 if (hostname != NULL) 1514 memcpy(p, hostname, size); 1515 1516 *buffer_size = desired_size; 1517 return (NS_SUCCESS); 1518 } 1519 1520 static int 1521 addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1522 va_list ap __unused, void *cache_mdata __unused) 1523 { 1524 struct addrinfo *ai, *cai; 1525 char *p; 1526 size_t desired_size, size, ai_size; 1527 1528 ai = *((struct addrinfo **)retval); 1529 1530 desired_size = sizeof(size_t); 1531 ai_size = 0; 1532 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1533 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1534 if (cai->ai_canonname != NULL) 1535 desired_size += sizeof(size_t) + 1536 strlen(cai->ai_canonname); 1537 ++ai_size; 1538 } 1539 1540 if (desired_size > *buffer_size) { 1541 /* this assignment is here for future use */ 1542 errno = ERANGE; 1543 *buffer_size = desired_size; 1544 return (NS_RETURN); 1545 } 1546 1547 memset(buffer, 0, desired_size); 1548 p = buffer; 1549 1550 memcpy(p, &ai_size, sizeof(size_t)); 1551 p += sizeof(size_t); 1552 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1553 memcpy(p, cai, sizeof(struct addrinfo)); 1554 p += sizeof(struct addrinfo); 1555 1556 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1557 p += cai->ai_addrlen; 1558 1559 if (cai->ai_canonname != NULL) { 1560 size = strlen(cai->ai_canonname); 1561 memcpy(p, &size, sizeof(size_t)); 1562 p += sizeof(size_t); 1563 1564 memcpy(p, cai->ai_canonname, size); 1565 p += size; 1566 } 1567 } 1568 1569 return (NS_SUCCESS); 1570 } 1571 1572 static int 1573 addrinfo_unmarshal_func(char *buffer, size_t buffer_size __unused, void *retval, 1574 va_list ap __unused, void *cache_mdata __unused) 1575 { 1576 struct addrinfo new_ai, *result, *sentinel, *lasts; 1577 1578 char *p; 1579 size_t ai_size, ai_i, size; 1580 1581 p = buffer; 1582 memcpy(&ai_size, p, sizeof(size_t)); 1583 p += sizeof(size_t); 1584 1585 result = NULL; 1586 lasts = NULL; 1587 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1588 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1589 p += sizeof(struct addrinfo); 1590 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1591 _ALIGNBYTES; 1592 1593 sentinel = (struct addrinfo *)malloc(size); 1594 memset(sentinel, 0, size); 1595 1596 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1597 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1598 sizeof(struct addrinfo)); 1599 1600 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1601 p += new_ai.ai_addrlen; 1602 1603 if (new_ai.ai_canonname != NULL) { 1604 memcpy(&size, p, sizeof(size_t)); 1605 p += sizeof(size_t); 1606 1607 sentinel->ai_canonname = (char *)malloc(size + 1); 1608 memset(sentinel->ai_canonname, 0, size + 1); 1609 1610 memcpy(sentinel->ai_canonname, p, size); 1611 p += size; 1612 } 1613 1614 if (result == NULL) { 1615 result = sentinel; 1616 lasts = sentinel; 1617 } else { 1618 lasts->ai_next = sentinel; 1619 lasts = sentinel; 1620 } 1621 } 1622 1623 *((struct addrinfo **)retval) = result; 1624 return (NS_SUCCESS); 1625 } 1626 #endif /* NS_CACHING */ 1627 1628 /* 1629 * FQDN hostname, DNS lookup 1630 */ 1631 static int 1632 explore_fqdn(const struct addrinfo *pai, const char *hostname, 1633 const char *servname, struct addrinfo **res) 1634 { 1635 struct addrinfo *result; 1636 struct addrinfo *cur; 1637 int error = 0; 1638 1639 #ifdef NS_CACHING 1640 static const nss_cache_info cache_info = 1641 NS_COMMON_CACHE_INFO_INITIALIZER( 1642 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1643 addrinfo_unmarshal_func); 1644 #endif 1645 static const ns_dtab dtab[] = { 1646 NS_FILES_CB(_files_getaddrinfo, NULL) 1647 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1648 NS_NIS_CB(_yp_getaddrinfo, NULL) 1649 #ifdef NS_CACHING 1650 NS_CACHE_CB(&cache_info) 1651 #endif 1652 { 0 } 1653 }; 1654 1655 result = NULL; 1656 1657 /* 1658 * if the servname does not match socktype/protocol, ignore it. 1659 */ 1660 if (get_portmatch(pai, servname) != 0) 1661 return 0; 1662 1663 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1664 default_dns_files, hostname, pai)) { 1665 case NS_TRYAGAIN: 1666 error = EAI_AGAIN; 1667 goto free; 1668 case NS_UNAVAIL: 1669 error = EAI_FAIL; 1670 goto free; 1671 case NS_NOTFOUND: 1672 error = EAI_NONAME; 1673 goto free; 1674 case NS_SUCCESS: 1675 error = 0; 1676 for (cur = result; cur; cur = cur->ai_next) { 1677 GET_PORT(cur, servname); 1678 /* canonname should be filled already */ 1679 } 1680 break; 1681 } 1682 1683 *res = result; 1684 1685 return 0; 1686 1687 free: 1688 if (result) 1689 freeaddrinfo(result); 1690 return error; 1691 } 1692 1693 #ifdef DEBUG 1694 static const char AskedForGot[] = 1695 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1696 #endif 1697 1698 static struct addrinfo * 1699 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1700 const struct addrinfo *pai, res_state res) 1701 { 1702 struct addrinfo sentinel, *cur; 1703 struct addrinfo ai; 1704 const struct afd *afd; 1705 char *canonname; 1706 const HEADER *hp; 1707 const u_char *cp; 1708 int n; 1709 const u_char *eom; 1710 char *bp, *ep; 1711 int type, class, ancount, qdcount; 1712 int haveanswer, had_error; 1713 char tbuf[MAXDNAME]; 1714 int (*name_ok)(const char *); 1715 char hostbuf[8*1024]; 1716 1717 memset(&sentinel, 0, sizeof(sentinel)); 1718 cur = &sentinel; 1719 1720 canonname = NULL; 1721 eom = answer->buf + anslen; 1722 switch (qtype) { 1723 case T_A: 1724 case T_AAAA: 1725 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1726 name_ok = res_hnok; 1727 break; 1728 default: 1729 return (NULL); /* XXX should be abort(); */ 1730 } 1731 /* 1732 * find first satisfactory answer 1733 */ 1734 hp = &answer->hdr; 1735 ancount = ntohs(hp->ancount); 1736 qdcount = ntohs(hp->qdcount); 1737 bp = hostbuf; 1738 ep = hostbuf + sizeof hostbuf; 1739 cp = answer->buf + HFIXEDSZ; 1740 if (qdcount != 1) { 1741 RES_SET_H_ERRNO(res, NO_RECOVERY); 1742 return (NULL); 1743 } 1744 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1745 if ((n < 0) || !(*name_ok)(bp)) { 1746 RES_SET_H_ERRNO(res, NO_RECOVERY); 1747 return (NULL); 1748 } 1749 cp += n + QFIXEDSZ; 1750 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1751 /* res_send() has already verified that the query name is the 1752 * same as the one we sent; this just gets the expanded name 1753 * (i.e., with the succeeding search-domain tacked on). 1754 */ 1755 n = strlen(bp) + 1; /* for the \0 */ 1756 if (n >= MAXHOSTNAMELEN) { 1757 RES_SET_H_ERRNO(res, NO_RECOVERY); 1758 return (NULL); 1759 } 1760 canonname = bp; 1761 bp += n; 1762 /* The qname can be abbreviated, but h_name is now absolute. */ 1763 qname = canonname; 1764 } 1765 haveanswer = 0; 1766 had_error = 0; 1767 while (ancount-- > 0 && cp < eom && !had_error) { 1768 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1769 if ((n < 0) || !(*name_ok)(bp)) { 1770 had_error++; 1771 continue; 1772 } 1773 cp += n; /* name */ 1774 type = _getshort(cp); 1775 cp += INT16SZ; /* type */ 1776 class = _getshort(cp); 1777 cp += INT16SZ + INT32SZ; /* class, TTL */ 1778 n = _getshort(cp); 1779 cp += INT16SZ; /* len */ 1780 if (class != C_IN) { 1781 /* XXX - debug? syslog? */ 1782 cp += n; 1783 continue; /* XXX - had_error++ ? */ 1784 } 1785 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1786 type == T_CNAME) { 1787 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1788 if ((n < 0) || !(*name_ok)(tbuf)) { 1789 had_error++; 1790 continue; 1791 } 1792 cp += n; 1793 /* Get canonical name. */ 1794 n = strlen(tbuf) + 1; /* for the \0 */ 1795 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1796 had_error++; 1797 continue; 1798 } 1799 strlcpy(bp, tbuf, ep - bp); 1800 canonname = bp; 1801 bp += n; 1802 continue; 1803 } 1804 if (qtype == T_ANY) { 1805 if (!(type == T_A || type == T_AAAA)) { 1806 cp += n; 1807 continue; 1808 } 1809 } else if (type != qtype) { 1810 #ifdef DEBUG 1811 if (type != T_KEY && type != T_SIG) 1812 syslog(LOG_NOTICE|LOG_AUTH, 1813 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1814 qname, p_class(C_IN), p_type(qtype), 1815 p_type(type)); 1816 #endif 1817 cp += n; 1818 continue; /* XXX - had_error++ ? */ 1819 } 1820 switch (type) { 1821 case T_A: 1822 case T_AAAA: 1823 if (strcasecmp(canonname, bp) != 0) { 1824 #ifdef DEBUG 1825 syslog(LOG_NOTICE|LOG_AUTH, 1826 AskedForGot, canonname, bp); 1827 #endif 1828 cp += n; 1829 continue; /* XXX - had_error++ ? */ 1830 } 1831 if (type == T_A && n != INADDRSZ) { 1832 cp += n; 1833 continue; 1834 } 1835 if (type == T_AAAA && n != IN6ADDRSZ) { 1836 cp += n; 1837 continue; 1838 } 1839 #ifdef FILTER_V4MAPPED 1840 if (type == T_AAAA) { 1841 struct in6_addr in6; 1842 memcpy(&in6, cp, sizeof(in6)); 1843 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1844 cp += n; 1845 continue; 1846 } 1847 } 1848 #endif 1849 if (!haveanswer) { 1850 int nn; 1851 1852 canonname = bp; 1853 nn = strlen(bp) + 1; /* for the \0 */ 1854 bp += nn; 1855 } 1856 1857 /* don't overwrite pai */ 1858 ai = *pai; 1859 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1860 afd = find_afd(ai.ai_family); 1861 if (afd == NULL) { 1862 cp += n; 1863 continue; 1864 } 1865 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1866 if (cur->ai_next == NULL) 1867 had_error++; 1868 while (cur && cur->ai_next) 1869 cur = cur->ai_next; 1870 cp += n; 1871 break; 1872 default: 1873 abort(); 1874 } 1875 if (!had_error) 1876 haveanswer++; 1877 } 1878 if (haveanswer) { 1879 #if defined(RESOLVSORT) 1880 /* 1881 * We support only IPv4 address for backward 1882 * compatibility against gethostbyname(3). 1883 */ 1884 if (res->nsort && qtype == T_A) { 1885 if (addr4sort(&sentinel, res) < 0) { 1886 freeaddrinfo(sentinel.ai_next); 1887 RES_SET_H_ERRNO(res, NO_RECOVERY); 1888 return NULL; 1889 } 1890 } 1891 #endif /*RESOLVSORT*/ 1892 if (!canonname) 1893 get_canonname(pai, sentinel.ai_next, qname); 1894 else 1895 get_canonname(pai, sentinel.ai_next, canonname); 1896 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 1897 return sentinel.ai_next; 1898 } 1899 1900 RES_SET_H_ERRNO(res, NO_RECOVERY); 1901 return NULL; 1902 } 1903 1904 #ifdef RESOLVSORT 1905 struct addr_ptr { 1906 struct addrinfo *ai; 1907 int aval; 1908 }; 1909 1910 static int 1911 addr4sort(struct addrinfo *sentinel, res_state res) 1912 { 1913 struct addrinfo *ai; 1914 struct addr_ptr *addrs, addr; 1915 struct sockaddr_in *sin; 1916 int naddrs, i, j; 1917 int needsort = 0; 1918 1919 if (!sentinel) 1920 return -1; 1921 naddrs = 0; 1922 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 1923 naddrs++; 1924 if (naddrs < 2) 1925 return 0; /* We don't need sorting. */ 1926 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 1927 return -1; 1928 i = 0; 1929 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 1930 sin = (struct sockaddr_in *)ai->ai_addr; 1931 for (j = 0; (unsigned)j < res->nsort; j++) { 1932 if (res->sort_list[j].addr.s_addr == 1933 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 1934 break; 1935 } 1936 addrs[i].ai = ai; 1937 addrs[i].aval = j; 1938 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 1939 needsort = i; 1940 i++; 1941 } 1942 if (!needsort) { 1943 free(addrs); 1944 return 0; 1945 } 1946 1947 while (needsort < naddrs) { 1948 for (j = needsort - 1; j >= 0; j--) { 1949 if (addrs[j].aval > addrs[j+1].aval) { 1950 addr = addrs[j]; 1951 addrs[j] = addrs[j + 1]; 1952 addrs[j + 1] = addr; 1953 } else 1954 break; 1955 } 1956 needsort++; 1957 } 1958 1959 ai = sentinel; 1960 for (i = 0; i < naddrs; ++i) { 1961 ai->ai_next = addrs[i].ai; 1962 ai = ai->ai_next; 1963 } 1964 ai->ai_next = NULL; 1965 free(addrs); 1966 return 0; 1967 } 1968 #endif /*RESOLVSORT*/ 1969 1970 /*ARGSUSED*/ 1971 static int 1972 _dns_getaddrinfo(void *rv, void *cb_data __unused, va_list ap) 1973 { 1974 struct addrinfo *ai; 1975 querybuf *buf, *buf2; 1976 const char *hostname; 1977 const struct addrinfo *pai; 1978 struct addrinfo sentinel, *cur; 1979 struct res_target q, q2; 1980 res_state res; 1981 1982 hostname = va_arg(ap, char *); 1983 pai = va_arg(ap, const struct addrinfo *); 1984 1985 memset(&q, 0, sizeof(q)); 1986 memset(&q2, 0, sizeof(q2)); 1987 memset(&sentinel, 0, sizeof(sentinel)); 1988 cur = &sentinel; 1989 1990 buf = malloc(sizeof(*buf)); 1991 if (!buf) { 1992 h_errno = NETDB_INTERNAL; 1993 return NS_NOTFOUND; 1994 } 1995 buf2 = malloc(sizeof(*buf2)); 1996 if (!buf2) { 1997 free(buf); 1998 h_errno = NETDB_INTERNAL; 1999 return NS_NOTFOUND; 2000 } 2001 2002 switch (pai->ai_family) { 2003 case AF_UNSPEC: 2004 q.name = hostname; 2005 q.qclass = C_IN; 2006 q.qtype = T_A; 2007 q.answer = buf->buf; 2008 q.anslen = sizeof(buf->buf); 2009 q.next = &q2; 2010 q2.name = hostname; 2011 q2.qclass = C_IN; 2012 q2.qtype = T_AAAA; 2013 q2.answer = buf2->buf; 2014 q2.anslen = sizeof(buf2->buf); 2015 break; 2016 case AF_INET: 2017 q.name = hostname; 2018 q.qclass = C_IN; 2019 q.qtype = T_A; 2020 q.answer = buf->buf; 2021 q.anslen = sizeof(buf->buf); 2022 break; 2023 case AF_INET6: 2024 q.name = hostname; 2025 q.qclass = C_IN; 2026 q.qtype = T_AAAA; 2027 q.answer = buf->buf; 2028 q.anslen = sizeof(buf->buf); 2029 break; 2030 default: 2031 free(buf); 2032 free(buf2); 2033 return NS_UNAVAIL; 2034 } 2035 2036 res = __res_state(); 2037 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2038 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2039 free(buf); 2040 free(buf2); 2041 return NS_NOTFOUND; 2042 } 2043 2044 if (res_searchN(hostname, &q, res) < 0) { 2045 free(buf); 2046 free(buf2); 2047 return NS_NOTFOUND; 2048 } 2049 /* prefer IPv6 */ 2050 if (q.next) { 2051 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2052 if (ai) { 2053 cur->ai_next = ai; 2054 while (cur && cur->ai_next) 2055 cur = cur->ai_next; 2056 } 2057 } 2058 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2059 if (ai) 2060 cur->ai_next = ai; 2061 free(buf); 2062 free(buf2); 2063 if (sentinel.ai_next == NULL) 2064 switch (res->res_h_errno) { 2065 case HOST_NOT_FOUND: 2066 return NS_NOTFOUND; 2067 case TRY_AGAIN: 2068 return NS_TRYAGAIN; 2069 default: 2070 return NS_UNAVAIL; 2071 } 2072 *((struct addrinfo **)rv) = sentinel.ai_next; 2073 return NS_SUCCESS; 2074 } 2075 2076 static void 2077 _sethtent(FILE **hostf) 2078 { 2079 if (!*hostf) 2080 *hostf = fopen(_PATH_HOSTS, "r"); 2081 else 2082 rewind(*hostf); 2083 } 2084 2085 static void 2086 _endhtent(FILE **hostf) 2087 { 2088 if (*hostf) { 2089 fclose(*hostf); 2090 *hostf = NULL; 2091 } 2092 } 2093 2094 static struct addrinfo * 2095 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2096 { 2097 char *p; 2098 char *cp, *tname, *cname; 2099 struct addrinfo hints, *res0, *res; 2100 int error; 2101 const char *addr; 2102 char hostbuf[8*1024]; 2103 2104 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r"))) 2105 return (NULL); 2106 again: 2107 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2108 return (NULL); 2109 if (*p == '#') 2110 goto again; 2111 cp = strpbrk(p, "#\n"); 2112 if (cp != NULL) 2113 *cp = '\0'; 2114 if (!(cp = strpbrk(p, " \t"))) 2115 goto again; 2116 *cp++ = '\0'; 2117 addr = p; 2118 cname = NULL; 2119 /* if this is not something we're looking for, skip it. */ 2120 while (cp && *cp) { 2121 if (*cp == ' ' || *cp == '\t') { 2122 cp++; 2123 continue; 2124 } 2125 tname = cp; 2126 if (cname == NULL) 2127 cname = cp; 2128 if ((cp = strpbrk(cp, " \t")) != NULL) 2129 *cp++ = '\0'; 2130 if (strcasecmp(name, tname) == 0) 2131 goto found; 2132 } 2133 goto again; 2134 2135 found: 2136 /* we should not glob socktype/protocol here */ 2137 memset(&hints, 0, sizeof(hints)); 2138 hints.ai_family = pai->ai_family; 2139 hints.ai_socktype = SOCK_DGRAM; 2140 hints.ai_protocol = 0; 2141 hints.ai_flags = AI_NUMERICHOST; 2142 error = getaddrinfo(addr, "0", &hints, &res0); 2143 if (error) 2144 goto again; 2145 #ifdef FILTER_V4MAPPED 2146 /* XXX should check all items in the chain */ 2147 if (res0->ai_family == AF_INET6 && 2148 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2149 freeaddrinfo(res0); 2150 goto again; 2151 } 2152 #endif 2153 for (res = res0; res; res = res->ai_next) { 2154 /* cover it up */ 2155 res->ai_flags = pai->ai_flags; 2156 res->ai_socktype = pai->ai_socktype; 2157 res->ai_protocol = pai->ai_protocol; 2158 2159 if (pai->ai_flags & AI_CANONNAME) { 2160 if (get_canonname(pai, res, cname) != 0) { 2161 freeaddrinfo(res0); 2162 goto again; 2163 } 2164 } 2165 } 2166 return res0; 2167 } 2168 2169 /*ARGSUSED*/ 2170 static int 2171 _files_getaddrinfo(void *rv, void *cb_data __unused, va_list ap) 2172 { 2173 const char *name; 2174 const struct addrinfo *pai; 2175 struct addrinfo sentinel, *cur; 2176 struct addrinfo *p; 2177 FILE *hostf = NULL; 2178 2179 name = va_arg(ap, char *); 2180 pai = va_arg(ap, struct addrinfo *); 2181 2182 memset(&sentinel, 0, sizeof(sentinel)); 2183 cur = &sentinel; 2184 2185 _sethtent(&hostf); 2186 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 2187 cur->ai_next = p; 2188 while (cur && cur->ai_next) 2189 cur = cur->ai_next; 2190 } 2191 _endhtent(&hostf); 2192 2193 *((struct addrinfo **)rv) = sentinel.ai_next; 2194 if (sentinel.ai_next == NULL) 2195 return NS_NOTFOUND; 2196 return NS_SUCCESS; 2197 } 2198 2199 #ifdef YP 2200 /*ARGSUSED*/ 2201 static struct addrinfo * 2202 _yphostent(char *line, const struct addrinfo *pai) 2203 { 2204 struct addrinfo sentinel, *cur; 2205 struct addrinfo hints, *res, *res0; 2206 int error; 2207 char *p = line; 2208 const char *addr, *canonname; 2209 char *nextline; 2210 char *cp; 2211 2212 addr = canonname = NULL; 2213 2214 memset(&sentinel, 0, sizeof(sentinel)); 2215 cur = &sentinel; 2216 2217 nextline: 2218 /* terminate line */ 2219 cp = strchr(p, '\n'); 2220 if (cp) { 2221 *cp++ = '\0'; 2222 nextline = cp; 2223 } else 2224 nextline = NULL; 2225 2226 cp = strpbrk(p, " \t"); 2227 if (cp == NULL) { 2228 if (canonname == NULL) 2229 return (NULL); 2230 else 2231 goto done; 2232 } 2233 *cp++ = '\0'; 2234 2235 addr = p; 2236 2237 while (cp && *cp) { 2238 if (*cp == ' ' || *cp == '\t') { 2239 cp++; 2240 continue; 2241 } 2242 if (!canonname) 2243 canonname = cp; 2244 if ((cp = strpbrk(cp, " \t")) != NULL) 2245 *cp++ = '\0'; 2246 } 2247 2248 hints = *pai; 2249 hints.ai_flags = AI_NUMERICHOST; 2250 error = getaddrinfo(addr, NULL, &hints, &res0); 2251 if (error == 0) { 2252 for (res = res0; res; res = res->ai_next) { 2253 /* cover it up */ 2254 res->ai_flags = pai->ai_flags; 2255 2256 if (pai->ai_flags & AI_CANONNAME) 2257 get_canonname(pai, res, canonname); 2258 } 2259 } else 2260 res0 = NULL; 2261 if (res0) { 2262 cur->ai_next = res0; 2263 while (cur && cur->ai_next) 2264 cur = cur->ai_next; 2265 } 2266 2267 if (nextline) { 2268 p = nextline; 2269 goto nextline; 2270 } 2271 2272 done: 2273 return sentinel.ai_next; 2274 } 2275 2276 /*ARGSUSED*/ 2277 static int 2278 _yp_getaddrinfo(void *rv, void *cb_data __unused, va_list ap) 2279 { 2280 struct addrinfo sentinel, *cur; 2281 struct addrinfo *ai = NULL; 2282 char *ypbuf; 2283 int ypbuflen, r; 2284 const char *name; 2285 const struct addrinfo *pai; 2286 char *ypdomain; 2287 2288 if (_yp_check(&ypdomain) == 0) 2289 return NS_UNAVAIL; 2290 2291 name = va_arg(ap, char *); 2292 pai = va_arg(ap, const struct addrinfo *); 2293 2294 memset(&sentinel, 0, sizeof(sentinel)); 2295 cur = &sentinel; 2296 2297 /* hosts.byname is only for IPv4 (Solaris8) */ 2298 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 2299 r = yp_match(ypdomain, "hosts.byname", name, 2300 (int)strlen(name), &ypbuf, &ypbuflen); 2301 if (r == 0) { 2302 struct addrinfo ai4; 2303 2304 ai4 = *pai; 2305 ai4.ai_family = AF_INET; 2306 ai = _yphostent(ypbuf, &ai4); 2307 if (ai) { 2308 cur->ai_next = ai; 2309 while (cur && cur->ai_next) 2310 cur = cur->ai_next; 2311 } 2312 free(ypbuf); 2313 } 2314 } 2315 2316 /* ipnodes.byname can hold both IPv4/v6 */ 2317 r = yp_match(ypdomain, "ipnodes.byname", name, 2318 (int)strlen(name), &ypbuf, &ypbuflen); 2319 if (r == 0) { 2320 ai = _yphostent(ypbuf, pai); 2321 if (ai) 2322 cur->ai_next = ai; 2323 free(ypbuf); 2324 } 2325 2326 if (sentinel.ai_next == NULL) { 2327 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2328 return NS_NOTFOUND; 2329 } 2330 *((struct addrinfo **)rv) = sentinel.ai_next; 2331 return NS_SUCCESS; 2332 } 2333 #endif 2334 2335 /* resolver logic */ 2336 2337 /* 2338 * Formulate a normal query, send, and await answer. 2339 * Returned answer is placed in supplied buffer "answer". 2340 * Perform preliminary check of answer, returning success only 2341 * if no error is indicated and the answer count is nonzero. 2342 * Return the size of the response on success, -1 on error. 2343 * Error number is left in h_errno. 2344 * 2345 * Caller must parse answer and determine whether it answers the question. 2346 */ 2347 static int 2348 res_queryN(const char *name, struct res_target *target, res_state res) 2349 { 2350 u_char *buf; 2351 HEADER *hp; 2352 int n; 2353 u_int oflags; 2354 struct res_target *t; 2355 int rcode; 2356 int ancount; 2357 2358 rcode = NOERROR; 2359 ancount = 0; 2360 2361 buf = malloc(MAXPACKET); 2362 if (!buf) { 2363 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2364 return -1; 2365 } 2366 2367 for (t = target; t; t = t->next) { 2368 int class, type; 2369 u_char *answer; 2370 int anslen; 2371 2372 hp = (HEADER *)(void *)t->answer; 2373 2374 /* make it easier... */ 2375 class = t->qclass; 2376 type = t->qtype; 2377 answer = t->answer; 2378 anslen = t->anslen; 2379 2380 oflags = res->_flags; 2381 2382 again: 2383 hp->rcode = NOERROR; /* default */ 2384 2385 #ifdef DEBUG 2386 if (res->options & RES_DEBUG) 2387 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2388 #endif 2389 2390 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2391 buf, MAXPACKET); 2392 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2393 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2394 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2395 if (n <= 0) { 2396 #ifdef DEBUG 2397 if (res->options & RES_DEBUG) 2398 printf(";; res_query: mkquery failed\n"); 2399 #endif 2400 free(buf); 2401 RES_SET_H_ERRNO(res, NO_RECOVERY); 2402 return (n); 2403 } 2404 n = res_nsend(res, buf, n, answer, anslen); 2405 if (n < 0) { 2406 /* 2407 * if the query choked with EDNS0, retry 2408 * without EDNS0 2409 */ 2410 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2411 != 0U && 2412 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2413 res->_flags |= RES_F_EDNS0ERR; 2414 if (res->options & RES_DEBUG) 2415 printf(";; res_nquery: retry without EDNS0\n"); 2416 goto again; 2417 } 2418 rcode = hp->rcode; /* record most recent error */ 2419 #ifdef DEBUG 2420 if (res->options & RES_DEBUG) 2421 printf(";; res_query: send error\n"); 2422 #endif 2423 continue; 2424 } 2425 2426 if (n > anslen) 2427 hp->rcode = FORMERR; /* XXX not very informative */ 2428 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2429 rcode = hp->rcode; /* record most recent error */ 2430 #ifdef DEBUG 2431 if (res->options & RES_DEBUG) 2432 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2433 ntohs(hp->ancount)); 2434 #endif 2435 continue; 2436 } 2437 2438 ancount += ntohs(hp->ancount); 2439 2440 t->n = n; 2441 } 2442 2443 free(buf); 2444 2445 if (ancount == 0) { 2446 switch (rcode) { 2447 case NXDOMAIN: 2448 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2449 break; 2450 case SERVFAIL: 2451 RES_SET_H_ERRNO(res, TRY_AGAIN); 2452 break; 2453 case NOERROR: 2454 RES_SET_H_ERRNO(res, NO_DATA); 2455 break; 2456 case FORMERR: 2457 case NOTIMP: 2458 case REFUSED: 2459 default: 2460 RES_SET_H_ERRNO(res, NO_RECOVERY); 2461 break; 2462 } 2463 return (-1); 2464 } 2465 return (ancount); 2466 } 2467 2468 /* 2469 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2470 * Return the size of the response on success, -1 on error. 2471 * If enabled, implement search rules until answer or unrecoverable failure 2472 * is detected. Error code, if any, is left in h_errno. 2473 */ 2474 static int 2475 res_searchN(const char *name, struct res_target *target, res_state res) 2476 { 2477 const char *cp, * const *domain; 2478 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2479 u_int dots; 2480 int trailing_dot, ret, saved_herrno; 2481 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2482 int tried_as_is = 0; 2483 int searched = 0; 2484 char abuf[MAXDNAME]; 2485 2486 errno = 0; 2487 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2488 dots = 0; 2489 for (cp = name; *cp; cp++) 2490 dots += (*cp == '.'); 2491 trailing_dot = 0; 2492 if (cp > name && *--cp == '.') 2493 trailing_dot++; 2494 2495 /* 2496 * if there aren't any dots, it could be a user-level alias 2497 */ 2498 if (!dots && 2499 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2500 return (res_queryN(cp, target, res)); 2501 2502 /* 2503 * If there are enough dots in the name, let's just give it a 2504 * try 'as is'. The threshold can be set with the "ndots" option. 2505 * Also, query 'as is', if there is a trailing dot in the name. 2506 */ 2507 saved_herrno = -1; 2508 if (dots >= res->ndots || trailing_dot) { 2509 ret = res_querydomainN(name, NULL, target, res); 2510 if (ret > 0 || trailing_dot) 2511 return (ret); 2512 if (errno == ECONNREFUSED) { 2513 RES_SET_H_ERRNO(res, TRY_AGAIN); 2514 return (-1); 2515 } 2516 switch (res->res_h_errno) { 2517 case NO_DATA: 2518 case HOST_NOT_FOUND: 2519 break; 2520 case TRY_AGAIN: 2521 if (hp->rcode == SERVFAIL) 2522 break; 2523 /* FALLTHROUGH */ 2524 default: 2525 return (-1); 2526 } 2527 saved_herrno = res->res_h_errno; 2528 tried_as_is++; 2529 } 2530 2531 /* 2532 * We do at least one level of search if 2533 * - there is no dot and RES_DEFNAME is set, or 2534 * - there is at least one dot, there is no trailing dot, 2535 * and RES_DNSRCH is set. 2536 */ 2537 if ((!dots && (res->options & RES_DEFNAMES)) || 2538 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2539 int done = 0; 2540 2541 for (domain = (const char * const *)res->dnsrch; 2542 *domain && !done; 2543 domain++) { 2544 searched = 1; 2545 2546 if (domain[0][0] == '\0' || 2547 (domain[0][0] == '.' && domain[0][1] == '\0')) 2548 root_on_list++; 2549 2550 if (root_on_list && tried_as_is) 2551 continue; 2552 2553 ret = res_querydomainN(name, *domain, target, res); 2554 if (ret > 0) 2555 return (ret); 2556 2557 /* 2558 * If no server present, give up. 2559 * If name isn't found in this domain, 2560 * keep trying higher domains in the search list 2561 * (if that's enabled). 2562 * On a NO_DATA error, keep trying, otherwise 2563 * a wildcard entry of another type could keep us 2564 * from finding this entry higher in the domain. 2565 * If we get some other error (negative answer or 2566 * server failure), then stop searching up, 2567 * but try the input name below in case it's 2568 * fully-qualified. 2569 */ 2570 if (errno == ECONNREFUSED) { 2571 RES_SET_H_ERRNO(res, TRY_AGAIN); 2572 return (-1); 2573 } 2574 2575 switch (res->res_h_errno) { 2576 case NO_DATA: 2577 got_nodata++; 2578 /* FALLTHROUGH */ 2579 case HOST_NOT_FOUND: 2580 /* keep trying */ 2581 break; 2582 case TRY_AGAIN: 2583 got_servfail++; 2584 if (hp->rcode == SERVFAIL) { 2585 /* try next search element, if any */ 2586 break; 2587 } 2588 /* FALLTHROUGH */ 2589 default: 2590 /* anything else implies that we're done */ 2591 done++; 2592 } 2593 /* 2594 * if we got here for some reason other than DNSRCH, 2595 * we only wanted one iteration of the loop, so stop. 2596 */ 2597 if (!(res->options & RES_DNSRCH)) 2598 done++; 2599 } 2600 } 2601 2602 switch (res->res_h_errno) { 2603 case NO_DATA: 2604 case HOST_NOT_FOUND: 2605 break; 2606 case TRY_AGAIN: 2607 if (hp->rcode == SERVFAIL) 2608 break; 2609 /* FALLTHROUGH */ 2610 default: 2611 goto giveup; 2612 } 2613 2614 /* 2615 * If the query has not already been tried as is then try it 2616 * unless RES_NOTLDQUERY is set and there were no dots. 2617 */ 2618 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2619 !(tried_as_is || root_on_list)) { 2620 ret = res_querydomainN(name, NULL, target, res); 2621 if (ret > 0) 2622 return (ret); 2623 } 2624 2625 /* 2626 * if we got here, we didn't satisfy the search. 2627 * if we did an initial full query, return that query's h_errno 2628 * (note that we wouldn't be here if that query had succeeded). 2629 * else if we ever got a nodata, send that back as the reason. 2630 * else send back meaningless h_errno, that being the one from 2631 * the last DNSRCH we did. 2632 */ 2633 giveup: 2634 if (saved_herrno != -1) 2635 RES_SET_H_ERRNO(res, saved_herrno); 2636 else if (got_nodata) 2637 RES_SET_H_ERRNO(res, NO_DATA); 2638 else if (got_servfail) 2639 RES_SET_H_ERRNO(res, TRY_AGAIN); 2640 return (-1); 2641 } 2642 2643 /* 2644 * Perform a call on res_query on the concatenation of name and domain, 2645 * removing a trailing dot from name if domain is NULL. 2646 */ 2647 static int 2648 res_querydomainN(const char *name, const char *domain, 2649 struct res_target *target, res_state res) 2650 { 2651 char nbuf[MAXDNAME]; 2652 const char *longname = nbuf; 2653 size_t n, d; 2654 2655 #ifdef DEBUG 2656 if (res->options & RES_DEBUG) 2657 printf(";; res_querydomain(%s, %s)\n", 2658 name, domain?domain:"<Nil>"); 2659 #endif 2660 if (domain == NULL) { 2661 /* 2662 * Check for trailing '.'; 2663 * copy without '.' if present. 2664 */ 2665 n = strlen(name); 2666 if (n >= MAXDNAME) { 2667 RES_SET_H_ERRNO(res, NO_RECOVERY); 2668 return (-1); 2669 } 2670 if (n > 0 && name[--n] == '.') { 2671 strncpy(nbuf, name, n); 2672 nbuf[n] = '\0'; 2673 } else 2674 longname = name; 2675 } else { 2676 n = strlen(name); 2677 d = strlen(domain); 2678 if (n + d + 1 >= MAXDNAME) { 2679 RES_SET_H_ERRNO(res, NO_RECOVERY); 2680 return (-1); 2681 } 2682 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2683 } 2684 return (res_queryN(longname, target, res)); 2685 } 2686