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