1 /* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-3-Clause 5 * 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Issues to be discussed: 36 * - Return values. There are nonstandard return values defined and used 37 * in the source code. This is because RFC2553 is silent about which error 38 * code must be returned for which situation. 39 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 40 * invalid. Current code accepts NULL to be compatible with other OSes. 41 * 42 * Note: 43 * - The code filters out AFs that are not supported by the kernel, 44 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 45 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 46 * in ai_flags? 47 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 48 * (1) what should we do against numeric hostname (2) what should we do 49 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 50 * non-loopback address configured? global address configured? 51 * 52 * OS specific notes for freebsd4: 53 * - FreeBSD supported $GAI. The code does not. 54 */ 55 56 #include <sys/cdefs.h> 57 __FBSDID("$FreeBSD$"); 58 59 #include "namespace.h" 60 #include <sys/param.h> 61 #include <sys/socket.h> 62 #include <net/if.h> 63 #include <netinet/in.h> 64 #include <net/if_types.h> 65 #include <ifaddrs.h> 66 #include <sys/queue.h> 67 #ifdef INET6 68 #include <sys/sysctl.h> 69 #include <sys/ioctl.h> 70 #include <netinet6/in6_var.h> 71 #include <netinet6/nd6.h> 72 #endif 73 #include <arpa/inet.h> 74 #include <arpa/nameser.h> 75 #include <rpc/rpc.h> 76 #include <rpcsvc/yp_prot.h> 77 #include <rpcsvc/ypclnt.h> 78 #include <netdb.h> 79 #include <resolv.h> 80 #include <string.h> 81 #include <stdlib.h> 82 #include <stddef.h> 83 #include <ctype.h> 84 #include <unistd.h> 85 #include <stdio.h> 86 #include <errno.h> 87 88 #include "res_config.h" 89 90 #ifdef DEBUG 91 #include <syslog.h> 92 #endif 93 94 #include <stdarg.h> 95 #include <nsswitch.h> 96 #include "un-namespace.h" 97 #include "netdb_private.h" 98 #include "libc_private.h" 99 #ifdef NS_CACHING 100 #include "nscache.h" 101 #endif 102 103 #define ANY 0 104 #define YES 1 105 #define NO 0 106 107 static const char in_addrany[] = { 0, 0, 0, 0 }; 108 static const char in_loopback[] = { 127, 0, 0, 1 }; 109 #ifdef INET6 110 static const char in6_addrany[] = { 111 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 112 }; 113 static const char in6_loopback[] = { 114 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 115 }; 116 #endif 117 118 struct policyqueue { 119 TAILQ_ENTRY(policyqueue) pc_entry; 120 #ifdef INET6 121 struct in6_addrpolicy pc_policy; 122 #endif 123 }; 124 TAILQ_HEAD(policyhead, policyqueue); 125 126 static const struct afd { 127 int a_af; 128 int a_addrlen; 129 socklen_t a_socklen; 130 int a_off; 131 const char *a_addrany; 132 const char *a_loopback; 133 int a_scoped; 134 } afdl [] = { 135 #ifdef INET6 136 #define N_INET6 0 137 {PF_INET6, sizeof(struct in6_addr), 138 sizeof(struct sockaddr_in6), 139 offsetof(struct sockaddr_in6, sin6_addr), 140 in6_addrany, in6_loopback, 1}, 141 #define N_INET 1 142 #define N_LOCAL 2 143 #else 144 #define N_INET 0 145 #define N_LOCAL 1 146 #endif 147 {PF_INET, sizeof(struct in_addr), 148 sizeof(struct sockaddr_in), 149 offsetof(struct sockaddr_in, sin_addr), 150 in_addrany, in_loopback, 0}, 151 #define sizeofmember(type, member) (sizeof(((type *)0)->member)) 152 {PF_LOCAL, sizeofmember(struct sockaddr_un, sun_path), 153 sizeof(struct sockaddr_un), 154 offsetof(struct sockaddr_un, sun_path), 155 NULL, NULL, 0}, 156 {0, 0, 0, 0, NULL, NULL, 0}, 157 }; 158 159 struct explore { 160 int e_af; 161 int e_socktype; 162 int e_protocol; 163 int e_wild; 164 #define AF_ANY 0x01 165 #define SOCKTYPE_ANY 0x02 166 #define PROTOCOL_ANY 0x04 167 #define WILD_AF(ex) ((ex)->e_wild & AF_ANY) 168 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & SOCKTYPE_ANY) 169 #define WILD_PROTOCOL(ex) ((ex)->e_wild & PROTOCOL_ANY) 170 }; 171 172 static const struct explore explore[] = { 173 #ifdef INET6 174 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 175 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 176 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, 177 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 178 { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 179 AF_ANY | SOCKTYPE_ANY }, 180 { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 181 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 182 { PF_INET6, SOCK_DGRAM, IPPROTO_UDPLITE, 183 AF_ANY | SOCKTYPE_ANY }, 184 { PF_INET6, SOCK_RAW, ANY, 185 AF_ANY | PROTOCOL_ANY }, 186 #endif 187 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, 188 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 189 { PF_INET, SOCK_STREAM, IPPROTO_TCP, 190 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 191 { PF_INET, SOCK_STREAM, IPPROTO_SCTP, 192 AF_ANY | SOCKTYPE_ANY }, 193 { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 194 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 195 { PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE, 196 AF_ANY | SOCKTYPE_ANY }, 197 { PF_INET, SOCK_RAW, ANY, 198 AF_ANY | PROTOCOL_ANY }, 199 { PF_LOCAL, SOCK_DGRAM, ANY, 200 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 201 { PF_LOCAL, SOCK_STREAM, ANY, 202 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 203 { PF_LOCAL, SOCK_SEQPACKET, ANY, 204 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 205 { -1, 0, 0, 0 }, 206 }; 207 208 #ifdef INET6 209 #define PTON_MAX 16 210 #else 211 #define PTON_MAX 4 212 #endif 213 214 #define AIO_SRCFLAG_DEPRECATED 0x1 215 216 struct ai_order { 217 union { 218 struct sockaddr_storage aiou_ss; 219 struct sockaddr aiou_sa; 220 } aio_src_un; 221 #define aio_srcsa aio_src_un.aiou_sa 222 u_int32_t aio_srcflag; 223 int aio_srcscope; 224 int aio_dstscope; 225 struct policyqueue *aio_srcpolicy; 226 struct policyqueue *aio_dstpolicy; 227 struct addrinfo *aio_ai; 228 int aio_matchlen; 229 int aio_initial_sequence; 230 }; 231 232 static const ns_src default_dns_files[] = { 233 { NSSRC_FILES, NS_SUCCESS }, 234 { NSSRC_DNS, NS_SUCCESS }, 235 { 0 } 236 }; 237 238 struct res_target { 239 struct res_target *next; 240 const char *name; /* domain name */ 241 int qclass, qtype; /* class and type of query */ 242 u_char *answer; /* buffer to put answer */ 243 int anslen; /* size of answer buffer */ 244 int n; /* result length */ 245 }; 246 247 #define MAXPACKET (64*1024) 248 249 typedef union { 250 HEADER hdr; 251 u_char buf[MAXPACKET]; 252 } querybuf; 253 254 static int str2number(const char *, int *); 255 static int explore_copy(const struct addrinfo *, const struct addrinfo *, 256 struct addrinfo **); 257 static int explore_null(const struct addrinfo *, 258 const char *, struct addrinfo **); 259 static int explore_numeric(const struct addrinfo *, const char *, 260 const char *, struct addrinfo **, const char *); 261 static int explore_numeric_scope(const struct addrinfo *, const char *, 262 const char *, struct addrinfo **); 263 static int get_canonname(const struct addrinfo *, 264 struct addrinfo *, const char *); 265 static struct addrinfo *get_ai(const struct addrinfo *, 266 const struct afd *, const char *); 267 static struct addrinfo *copy_ai(const struct addrinfo *); 268 static int get_portmatch(const struct addrinfo *, const char *); 269 static int get_port(struct addrinfo *, const char *, int); 270 static const struct afd *find_afd(int); 271 static int addrconfig(struct addrinfo *); 272 #ifdef INET6 273 static int is_ifdisabled(char *); 274 #endif 275 static void set_source(struct ai_order *, struct policyhead *); 276 static int comp_dst(const void *, const void *); 277 #ifdef INET6 278 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 279 #endif 280 static int gai_addr2scopetype(struct sockaddr *); 281 282 static int explore_fqdn(const struct addrinfo *, const char *, 283 const char *, struct addrinfo **); 284 285 static int reorder(struct addrinfo *); 286 static int get_addrselectpolicy(struct policyhead *); 287 static void free_addrselectpolicy(struct policyhead *); 288 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 289 struct policyhead *); 290 static int matchlen(struct sockaddr *, struct sockaddr *); 291 292 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 293 const struct addrinfo *, res_state); 294 #if defined(RESOLVSORT) 295 static int addr4sort(struct addrinfo *, res_state); 296 #endif 297 static int _dns_getaddrinfo(void *, void *, va_list); 298 static void _sethtent(FILE **); 299 static void _endhtent(FILE **); 300 static struct addrinfo *_gethtent(FILE **, const char *, 301 const struct addrinfo *); 302 static int _files_getaddrinfo(void *, void *, va_list); 303 #ifdef YP 304 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 305 static int _yp_getaddrinfo(void *, void *, va_list); 306 #endif 307 #ifdef NS_CACHING 308 static int addrinfo_id_func(char *, size_t *, va_list, void *); 309 static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 310 static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 311 #endif 312 313 static int res_queryN(const char *, struct res_target *, res_state); 314 static int res_searchN(const char *, struct res_target *, res_state); 315 static int res_querydomainN(const char *, const char *, 316 struct res_target *, res_state); 317 318 /* XXX macros that make external reference is BAD. */ 319 320 #define GET_AI(ai, afd, addr) \ 321 do { \ 322 /* external reference: pai, error, and label free */ \ 323 (ai) = get_ai(pai, (afd), (addr)); \ 324 if ((ai) == NULL) { \ 325 error = EAI_MEMORY; \ 326 goto free; \ 327 } \ 328 } while (/*CONSTCOND*/0) 329 330 #define GET_PORT(ai, serv) \ 331 do { \ 332 /* external reference: error and label free */ \ 333 error = get_port((ai), (serv), 0); \ 334 if (error != 0) \ 335 goto free; \ 336 } while (/*CONSTCOND*/0) 337 338 #define GET_CANONNAME(ai, str) \ 339 do { \ 340 /* external reference: pai, error and label free */ \ 341 error = get_canonname(pai, (ai), (str)); \ 342 if (error != 0) \ 343 goto free; \ 344 } while (/*CONSTCOND*/0) 345 346 #define ERR(err) \ 347 do { \ 348 /* external reference: error, and label bad */ \ 349 error = (err); \ 350 goto bad; \ 351 /*NOTREACHED*/ \ 352 } while (/*CONSTCOND*/0) 353 354 #define MATCH_FAMILY(x, y, w) \ 355 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 356 #define MATCH(x, y, w) \ 357 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 358 359 void 360 freeaddrinfo(struct addrinfo *ai) 361 { 362 struct addrinfo *next; 363 364 while (ai != NULL) { 365 next = ai->ai_next; 366 free(ai->ai_canonname); 367 /* no need to free(ai->ai_addr) */ 368 free(ai); 369 ai = next; 370 } 371 } 372 373 static int 374 str2number(const char *p, int *portp) 375 { 376 char *ep; 377 unsigned long v; 378 379 if (*p == '\0') 380 return -1; 381 ep = NULL; 382 errno = 0; 383 v = strtoul(p, &ep, 10); 384 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 385 *portp = v; 386 return 0; 387 } else 388 return -1; 389 } 390 391 int 392 getaddrinfo(const char *hostname, const char *servname, 393 const struct addrinfo *hints, struct addrinfo **res) 394 { 395 struct addrinfo sentinel; 396 struct addrinfo *cur; 397 int error = 0; 398 struct addrinfo ai, ai0, *afai; 399 struct addrinfo *pai; 400 const struct afd *afd; 401 const struct explore *ex; 402 struct addrinfo *afailist[nitems(afdl)]; 403 struct addrinfo *afai_unspec; 404 int found; 405 int numeric = 0; 406 407 /* ensure we return NULL on errors */ 408 *res = NULL; 409 410 memset(&ai, 0, sizeof(ai)); 411 412 memset(afailist, 0, sizeof(afailist)); 413 afai_unspec = NULL; 414 415 memset(&sentinel, 0, sizeof(sentinel)); 416 cur = &sentinel; 417 pai = &ai; 418 pai->ai_flags = 0; 419 pai->ai_family = PF_UNSPEC; 420 pai->ai_socktype = ANY; 421 pai->ai_protocol = ANY; 422 pai->ai_addrlen = 0; 423 pai->ai_canonname = NULL; 424 pai->ai_addr = NULL; 425 pai->ai_next = NULL; 426 427 if (hostname == NULL && servname == NULL) 428 return EAI_NONAME; 429 if (hints) { 430 /* error check for hints */ 431 if (hints->ai_addrlen || hints->ai_canonname || 432 hints->ai_addr || hints->ai_next) 433 ERR(EAI_BADHINTS); /* xxx */ 434 if (hints->ai_flags & ~AI_MASK) 435 ERR(EAI_BADFLAGS); 436 switch (hints->ai_family) { 437 case PF_UNSPEC: 438 case PF_LOCAL: 439 case PF_INET: 440 #ifdef INET6 441 case PF_INET6: 442 #endif 443 break; 444 default: 445 ERR(EAI_FAMILY); 446 } 447 memcpy(pai, hints, sizeof(*pai)); 448 449 /* 450 * if both socktype/protocol are specified, check if they 451 * are meaningful combination. 452 */ 453 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 454 for (ex = explore; ex->e_af >= 0; ex++) { 455 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 456 WILD_AF(ex))) 457 continue; 458 if (!MATCH(pai->ai_socktype, ex->e_socktype, 459 WILD_SOCKTYPE(ex))) 460 continue; 461 if (!MATCH(pai->ai_protocol, ex->e_protocol, 462 WILD_PROTOCOL(ex))) 463 continue; 464 465 /* matched */ 466 break; 467 } 468 469 if (ex->e_af < 0) 470 ERR(EAI_BADHINTS); 471 } 472 } 473 474 /* 475 * RFC 3493: AI_ALL and AI_V4MAPPED are effective only against 476 * AF_INET6 query. They need to be ignored if specified in other 477 * occasions. 478 */ 479 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 480 case AI_V4MAPPED: 481 case AI_ALL | AI_V4MAPPED: 482 #ifdef INET6 483 if (pai->ai_family != AF_INET6) 484 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 485 break; 486 #endif 487 case AI_ALL: 488 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 489 break; 490 } 491 492 /* 493 * check for special cases. (1) numeric servname is disallowed if 494 * socktype/protocol are left unspecified. (2) servname is disallowed 495 * for raw and other inet{,6} sockets. 496 */ 497 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 498 #ifdef PF_INET6 499 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 500 #endif 501 ) { 502 ai0 = *pai; /* backup *pai */ 503 504 if (pai->ai_family == PF_UNSPEC) { 505 #ifdef PF_INET6 506 pai->ai_family = PF_INET6; 507 #else 508 pai->ai_family = PF_INET; 509 #endif 510 } 511 error = get_portmatch(pai, servname); 512 if (error) 513 goto bad; 514 515 *pai = ai0; 516 } 517 518 ai0 = *pai; 519 520 /* 521 * NULL hostname, or numeric hostname. 522 * If numeric representation of AF1 can be interpreted as FQDN 523 * representation of AF2, we need to think again about the code below. 524 */ 525 found = 0; 526 for (afd = afdl; afd->a_af; afd++) { 527 *pai = ai0; 528 529 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 530 continue; 531 532 if (pai->ai_family == PF_UNSPEC) 533 pai->ai_family = afd->a_af; 534 535 if (hostname == NULL) { 536 error = explore_null(pai, servname, 537 &afailist[afd - afdl]); 538 539 /* 540 * Errors from explore_null should be unexpected and 541 * be caught to avoid returning an incomplete result. 542 */ 543 if (error != 0) 544 goto bad; 545 } else { 546 error = explore_numeric_scope(pai, hostname, servname, 547 &afailist[afd - afdl]); 548 549 /* 550 * explore_numeric_scope returns an error for address 551 * families that do not match that of hostname. 552 * Thus we should not catch the error at this moment. 553 */ 554 } 555 556 if (!error && afailist[afd - afdl]) 557 found++; 558 } 559 if (found) { 560 numeric = 1; 561 goto globcopy; 562 } 563 564 if (hostname == NULL) 565 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 566 if (pai->ai_flags & AI_NUMERICHOST) 567 ERR(EAI_NONAME); 568 569 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 570 ERR(EAI_FAIL); 571 572 /* 573 * hostname as alphabetical name. 574 */ 575 *pai = ai0; 576 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 577 578 globcopy: 579 for (ex = explore; ex->e_af >= 0; ex++) { 580 *pai = ai0; 581 582 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 583 continue; 584 if (!MATCH(pai->ai_socktype, ex->e_socktype, 585 WILD_SOCKTYPE(ex))) 586 continue; 587 if (!MATCH(pai->ai_protocol, ex->e_protocol, 588 WILD_PROTOCOL(ex))) 589 continue; 590 591 if (pai->ai_family == PF_UNSPEC) 592 pai->ai_family = ex->e_af; 593 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 594 pai->ai_socktype = ex->e_socktype; 595 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 596 pai->ai_protocol = ex->e_protocol; 597 598 /* 599 * if the servname does not match socktype/protocol, ignore it. 600 */ 601 if (get_portmatch(pai, servname) != 0) 602 continue; 603 604 if (afai_unspec) 605 afai = afai_unspec; 606 else { 607 if ((afd = find_afd(pai->ai_family)) == NULL) 608 continue; 609 /* XXX assumes that afd points inside afdl[] */ 610 afai = afailist[afd - afdl]; 611 } 612 if (!afai) 613 continue; 614 615 error = explore_copy(pai, afai, &cur->ai_next); 616 if (error != 0) 617 goto bad; 618 619 while (cur && cur->ai_next) 620 cur = cur->ai_next; 621 } 622 623 /* 624 * ensure we return either: 625 * - error == 0, non-NULL *res 626 * - error != 0, NULL *res 627 */ 628 if (error == 0) { 629 if (sentinel.ai_next) { 630 /* 631 * If the returned entry is for an active connection, 632 * and the given name is not numeric, reorder the 633 * list, so that the application would try the list 634 * in the most efficient order. Since the head entry 635 * of the original list may contain ai_canonname and 636 * that entry may be moved elsewhere in the new list, 637 * we keep the pointer and will restore it in the new 638 * head entry. (Note that RFC3493 requires the head 639 * entry store it when requested by the caller). 640 */ 641 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 642 if (!numeric) { 643 char *canonname; 644 645 canonname = 646 sentinel.ai_next->ai_canonname; 647 sentinel.ai_next->ai_canonname = NULL; 648 (void)reorder(&sentinel); 649 if (sentinel.ai_next->ai_canonname == 650 NULL) { 651 sentinel.ai_next->ai_canonname 652 = canonname; 653 } else if (canonname != NULL) 654 free(canonname); 655 } 656 } 657 *res = sentinel.ai_next; 658 } else 659 error = EAI_FAIL; 660 } 661 662 bad: 663 if (afai_unspec) 664 freeaddrinfo(afai_unspec); 665 for (afd = afdl; afd->a_af; afd++) { 666 if (afailist[afd - afdl]) 667 freeaddrinfo(afailist[afd - afdl]); 668 } 669 if (!*res) 670 if (sentinel.ai_next) 671 freeaddrinfo(sentinel.ai_next); 672 673 return (error); 674 } 675 676 static int 677 reorder(struct addrinfo *sentinel) 678 { 679 struct addrinfo *ai, **aip; 680 struct ai_order *aio; 681 int i, n; 682 struct policyhead policyhead; 683 684 /* count the number of addrinfo elements for sorting. */ 685 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 686 ; 687 688 /* 689 * If the number is small enough, we can skip the reordering process. 690 */ 691 if (n <= 1) 692 return(n); 693 694 /* allocate a temporary array for sort and initialization of it. */ 695 if ((aio = calloc(n, sizeof(*aio))) == NULL) 696 return(n); /* give up reordering */ 697 698 /* retrieve address selection policy from the kernel */ 699 TAILQ_INIT(&policyhead); 700 if (!get_addrselectpolicy(&policyhead)) { 701 /* no policy is installed into kernel, we don't sort. */ 702 free(aio); 703 return (n); 704 } 705 706 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 707 aio[i].aio_ai = ai; 708 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 709 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 710 &policyhead); 711 set_source(&aio[i], &policyhead); 712 aio[i].aio_initial_sequence = i; 713 } 714 715 /* perform sorting. */ 716 qsort(aio, n, sizeof(*aio), comp_dst); 717 718 /* reorder the addrinfo chain. */ 719 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 720 *aip = aio[i].aio_ai; 721 aip = &aio[i].aio_ai->ai_next; 722 } 723 *aip = NULL; 724 725 /* cleanup and return */ 726 free(aio); 727 free_addrselectpolicy(&policyhead); 728 return(n); 729 } 730 731 static int 732 get_addrselectpolicy(struct policyhead *head) 733 { 734 #ifdef INET6 735 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 736 size_t l; 737 char *buf; 738 struct in6_addrpolicy *pol, *ep; 739 740 if (sysctl(mib, nitems(mib), NULL, &l, NULL, 0) < 0) 741 return (0); 742 if (l == 0) 743 return (0); 744 if ((buf = malloc(l)) == NULL) 745 return (0); 746 if (sysctl(mib, nitems(mib), buf, &l, NULL, 0) < 0) { 747 free(buf); 748 return (0); 749 } 750 751 ep = (struct in6_addrpolicy *)(buf + l); 752 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 753 struct policyqueue *new; 754 755 if ((new = malloc(sizeof(*new))) == NULL) { 756 free_addrselectpolicy(head); /* make the list empty */ 757 break; 758 } 759 new->pc_policy = *pol; 760 TAILQ_INSERT_TAIL(head, new, pc_entry); 761 } 762 763 free(buf); 764 return (1); 765 #else 766 return (0); 767 #endif 768 } 769 770 static void 771 free_addrselectpolicy(struct policyhead *head) 772 { 773 struct policyqueue *ent, *nent; 774 775 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 776 nent = TAILQ_NEXT(ent, pc_entry); 777 TAILQ_REMOVE(head, ent, pc_entry); 778 free(ent); 779 } 780 } 781 782 static struct policyqueue * 783 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 784 { 785 #ifdef INET6 786 struct policyqueue *ent, *bestent = NULL; 787 struct in6_addrpolicy *pol; 788 int matchlen, bestmatchlen = -1; 789 u_char *mp, *ep, *k, *p, m; 790 struct sockaddr_in6 key; 791 792 switch(addr->sa_family) { 793 case AF_INET6: 794 key = *(struct sockaddr_in6 *)addr; 795 break; 796 case AF_INET: 797 /* convert the address into IPv4-mapped IPv6 address. */ 798 memset(&key, 0, sizeof(key)); 799 key.sin6_family = AF_INET6; 800 key.sin6_len = sizeof(key); 801 _map_v4v6_address( 802 (char *)&((struct sockaddr_in *)addr)->sin_addr, 803 (char *)&key.sin6_addr); 804 break; 805 default: 806 return(NULL); 807 } 808 809 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 810 pol = &ent->pc_policy; 811 matchlen = 0; 812 813 mp = (u_char *)&pol->addrmask.sin6_addr; 814 ep = mp + 16; /* XXX: scope field? */ 815 k = (u_char *)&key.sin6_addr; 816 p = (u_char *)&pol->addr.sin6_addr; 817 for (; mp < ep && *mp; mp++, k++, p++) { 818 m = *mp; 819 if ((*k & m) != *p) 820 goto next; /* not match */ 821 if (m == 0xff) /* short cut for a typical case */ 822 matchlen += 8; 823 else { 824 while (m >= 0x80) { 825 matchlen++; 826 m <<= 1; 827 } 828 } 829 } 830 831 /* matched. check if this is better than the current best. */ 832 if (matchlen > bestmatchlen) { 833 bestent = ent; 834 bestmatchlen = matchlen; 835 } 836 837 next: 838 continue; 839 } 840 841 return(bestent); 842 #else 843 return(NULL); 844 #endif 845 846 } 847 848 static void 849 set_source(struct ai_order *aio, struct policyhead *ph) 850 { 851 struct addrinfo ai = *aio->aio_ai; 852 struct sockaddr_storage ss; 853 socklen_t srclen; 854 int s; 855 856 /* set unspec ("no source is available"), just in case */ 857 aio->aio_srcsa.sa_family = AF_UNSPEC; 858 aio->aio_srcscope = -1; 859 860 switch(ai.ai_family) { 861 case AF_INET: 862 #ifdef INET6 863 case AF_INET6: 864 #endif 865 break; 866 default: /* ignore unsupported AFs explicitly */ 867 return; 868 } 869 870 /* XXX: make a dummy addrinfo to call connect() */ 871 ai.ai_socktype = SOCK_DGRAM; 872 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 873 ai.ai_next = NULL; 874 memset(&ss, 0, sizeof(ss)); 875 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 876 ai.ai_addr = (struct sockaddr *)&ss; 877 get_port(&ai, "1", 0); 878 879 /* open a socket to get the source address for the given dst */ 880 if ((s = _socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC, 881 ai.ai_protocol)) < 0) 882 return; /* give up */ 883 #ifdef INET6 884 if (ai.ai_family == AF_INET6) { 885 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ai.ai_addr; 886 int off = 0; 887 888 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 889 (void)_setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, 890 (char *)&off, sizeof(off)); 891 } 892 #endif 893 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 894 goto cleanup; 895 srclen = ai.ai_addrlen; 896 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 897 aio->aio_srcsa.sa_family = AF_UNSPEC; 898 goto cleanup; 899 } 900 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 901 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 902 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 903 #ifdef INET6 904 if (ai.ai_family == AF_INET6) { 905 struct in6_ifreq ifr6; 906 u_int32_t flags6; 907 908 memset(&ifr6, 0, sizeof(ifr6)); 909 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 910 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 911 flags6 = ifr6.ifr_ifru.ifru_flags6; 912 if ((flags6 & IN6_IFF_DEPRECATED)) 913 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 914 } 915 } 916 #endif 917 918 cleanup: 919 _close(s); 920 return; 921 } 922 923 static int 924 matchlen(struct sockaddr *src, struct sockaddr *dst) 925 { 926 int match = 0; 927 u_char *s, *d; 928 u_char *lim, r; 929 int addrlen; 930 931 switch (src->sa_family) { 932 #ifdef INET6 933 case AF_INET6: 934 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 935 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 936 addrlen = sizeof(struct in6_addr); 937 lim = s + addrlen; 938 break; 939 #endif 940 case AF_INET: 941 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 942 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 943 addrlen = sizeof(struct in_addr); 944 lim = s + addrlen; 945 break; 946 default: 947 return(0); 948 } 949 950 while (s < lim) 951 if ((r = (*d++ ^ *s++)) != 0) { 952 while ((r & 0x80) == 0) { 953 match++; 954 r <<= 1; 955 } 956 break; 957 } else 958 match += 8; 959 return(match); 960 } 961 962 static int 963 comp_dst(const void *arg1, const void *arg2) 964 { 965 const struct ai_order *dst1 = arg1, *dst2 = arg2; 966 967 /* 968 * Rule 1: Avoid unusable destinations. 969 * XXX: we currently do not consider if an appropriate route exists. 970 */ 971 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 972 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 973 return(-1); 974 } 975 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 976 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 977 return(1); 978 } 979 980 /* Rule 2: Prefer matching scope. */ 981 if (dst1->aio_dstscope == dst1->aio_srcscope && 982 dst2->aio_dstscope != dst2->aio_srcscope) { 983 return(-1); 984 } 985 if (dst1->aio_dstscope != dst1->aio_srcscope && 986 dst2->aio_dstscope == dst2->aio_srcscope) { 987 return(1); 988 } 989 990 /* Rule 3: Avoid deprecated addresses. */ 991 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 992 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 993 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 994 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 995 return(-1); 996 } 997 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 998 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 999 return(1); 1000 } 1001 } 1002 1003 /* Rule 4: Prefer home addresses. */ 1004 /* XXX: not implemented yet */ 1005 1006 /* Rule 5: Prefer matching label. */ 1007 #ifdef INET6 1008 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 1009 dst1->aio_srcpolicy->pc_policy.label == 1010 dst1->aio_dstpolicy->pc_policy.label && 1011 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 1012 dst2->aio_srcpolicy->pc_policy.label != 1013 dst2->aio_dstpolicy->pc_policy.label)) { 1014 return(-1); 1015 } 1016 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 1017 dst2->aio_srcpolicy->pc_policy.label == 1018 dst2->aio_dstpolicy->pc_policy.label && 1019 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 1020 dst1->aio_srcpolicy->pc_policy.label != 1021 dst1->aio_dstpolicy->pc_policy.label)) { 1022 return(1); 1023 } 1024 #endif 1025 1026 /* Rule 6: Prefer higher precedence. */ 1027 #ifdef INET6 1028 if (dst1->aio_dstpolicy && 1029 (dst2->aio_dstpolicy == NULL || 1030 dst1->aio_dstpolicy->pc_policy.preced > 1031 dst2->aio_dstpolicy->pc_policy.preced)) { 1032 return(-1); 1033 } 1034 if (dst2->aio_dstpolicy && 1035 (dst1->aio_dstpolicy == NULL || 1036 dst2->aio_dstpolicy->pc_policy.preced > 1037 dst1->aio_dstpolicy->pc_policy.preced)) { 1038 return(1); 1039 } 1040 #endif 1041 1042 /* Rule 7: Prefer native transport. */ 1043 /* XXX: not implemented yet */ 1044 1045 /* Rule 8: Prefer smaller scope. */ 1046 if (dst1->aio_dstscope >= 0 && 1047 dst1->aio_dstscope < dst2->aio_dstscope) { 1048 return(-1); 1049 } 1050 if (dst2->aio_dstscope >= 0 && 1051 dst2->aio_dstscope < dst1->aio_dstscope) { 1052 return(1); 1053 } 1054 1055 /* 1056 * Rule 9: Use longest matching prefix. 1057 * We compare the match length in a same AF only. 1058 */ 1059 if (dst1->aio_ai->ai_addr->sa_family == 1060 dst2->aio_ai->ai_addr->sa_family && 1061 dst1->aio_ai->ai_addr->sa_family != AF_INET) { 1062 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1063 return(-1); 1064 } 1065 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1066 return(1); 1067 } 1068 } 1069 1070 /* Rule 10: Otherwise, leave the order unchanged. */ 1071 1072 /* 1073 * Note that qsort is unstable; so, we can't return zero and 1074 * expect the order to be unchanged. 1075 * That also means we can't depend on the current position of 1076 * dst2 being after dst1. We must enforce the initial order 1077 * with an explicit compare on the original position. 1078 * The qsort specification requires that "When the same objects 1079 * (consisting of width bytes, irrespective of their current 1080 * positions in the array) are passed more than once to the 1081 * comparison function, the results shall be consistent with one 1082 * another." 1083 * In other words, If A < B, then we must also return B > A. 1084 */ 1085 if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) 1086 return(1); 1087 1088 return(-1); 1089 } 1090 1091 /* 1092 * Copy from scope.c. 1093 * XXX: we should standardize the functions and link them as standard 1094 * library. 1095 */ 1096 static int 1097 gai_addr2scopetype(struct sockaddr *sa) 1098 { 1099 #ifdef INET6 1100 struct sockaddr_in6 *sa6; 1101 #endif 1102 struct sockaddr_in *sa4; 1103 1104 switch(sa->sa_family) { 1105 #ifdef INET6 1106 case AF_INET6: 1107 sa6 = (struct sockaddr_in6 *)sa; 1108 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1109 /* just use the scope field of the multicast address */ 1110 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1111 } 1112 /* 1113 * Unicast addresses: map scope type to corresponding scope 1114 * value defined for multcast addresses. 1115 * XXX: hardcoded scope type values are bad... 1116 */ 1117 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1118 return(1); /* node local scope */ 1119 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1120 return(2); /* link-local scope */ 1121 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1122 return(5); /* site-local scope */ 1123 return(14); /* global scope */ 1124 break; 1125 #endif 1126 case AF_INET: 1127 /* 1128 * IPv4 pseudo scoping according to RFC 3484. 1129 */ 1130 sa4 = (struct sockaddr_in *)sa; 1131 /* IPv4 autoconfiguration addresses have link-local scope. */ 1132 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1133 ((u_char *)&sa4->sin_addr)[1] == 254) 1134 return(2); 1135 /* Private addresses have site-local scope. */ 1136 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1137 (((u_char *)&sa4->sin_addr)[0] == 172 && 1138 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1139 (((u_char *)&sa4->sin_addr)[0] == 192 && 1140 ((u_char *)&sa4->sin_addr)[1] == 168)) 1141 return(14); /* XXX: It should be 5 unless NAT */ 1142 /* Loopback addresses have link-local scope. */ 1143 if (((u_char *)&sa4->sin_addr)[0] == 127) 1144 return(2); 1145 return(14); 1146 break; 1147 default: 1148 errno = EAFNOSUPPORT; /* is this a good error? */ 1149 return(-1); 1150 } 1151 } 1152 1153 static int 1154 explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1155 struct addrinfo **res) 1156 { 1157 int error; 1158 struct addrinfo sentinel, *cur; 1159 const struct addrinfo *src; 1160 1161 error = 0; 1162 sentinel.ai_next = NULL; 1163 cur = &sentinel; 1164 1165 for (src = src0; src != NULL; src = src->ai_next) { 1166 if (src->ai_family != pai->ai_family) 1167 continue; 1168 1169 cur->ai_next = copy_ai(src); 1170 if (!cur->ai_next) { 1171 error = EAI_MEMORY; 1172 goto fail; 1173 } 1174 1175 cur->ai_next->ai_socktype = pai->ai_socktype; 1176 cur->ai_next->ai_protocol = pai->ai_protocol; 1177 cur = cur->ai_next; 1178 } 1179 1180 *res = sentinel.ai_next; 1181 return 0; 1182 1183 fail: 1184 freeaddrinfo(sentinel.ai_next); 1185 return error; 1186 } 1187 1188 /* 1189 * hostname == NULL. 1190 * passive socket -> anyaddr (0.0.0.0 or ::) 1191 * non-passive socket -> localhost (127.0.0.1 or ::1) 1192 */ 1193 static int 1194 explore_null(const struct addrinfo *pai, const char *servname, 1195 struct addrinfo **res) 1196 { 1197 int s; 1198 const struct afd *afd; 1199 struct addrinfo *ai; 1200 int error; 1201 1202 *res = NULL; 1203 ai = NULL; 1204 1205 if (pai->ai_family == PF_LOCAL) 1206 return (0); 1207 1208 /* 1209 * filter out AFs that are not supported by the kernel 1210 * XXX errno? 1211 */ 1212 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1213 if (s < 0) { 1214 if (errno != EMFILE) 1215 return 0; 1216 } else 1217 _close(s); 1218 1219 afd = find_afd(pai->ai_family); 1220 if (afd == NULL) 1221 return 0; 1222 1223 if (pai->ai_flags & AI_PASSIVE) { 1224 GET_AI(ai, afd, afd->a_addrany); 1225 GET_PORT(ai, servname); 1226 } else { 1227 GET_AI(ai, afd, afd->a_loopback); 1228 GET_PORT(ai, servname); 1229 } 1230 1231 *res = ai; 1232 return 0; 1233 1234 free: 1235 if (ai != NULL) 1236 freeaddrinfo(ai); 1237 return error; 1238 } 1239 1240 /* 1241 * numeric hostname 1242 */ 1243 static int 1244 explore_numeric(const struct addrinfo *pai, const char *hostname, 1245 const char *servname, struct addrinfo **res, const char *canonname) 1246 { 1247 const struct afd *afd; 1248 struct addrinfo *ai, ai0; 1249 int error; 1250 char pton[PTON_MAX], path[PATH_MAX], *p; 1251 1252 #ifdef CTASSERT 1253 CTASSERT(sizeofmember(struct sockaddr_un, sun_path) <= PATH_MAX); 1254 #endif 1255 *res = NULL; 1256 ai = NULL; 1257 1258 afd = find_afd(pai->ai_family); 1259 if (afd == NULL) 1260 return 0; 1261 1262 switch (afd->a_af) { 1263 case AF_LOCAL: 1264 if (hostname[0] != '/') 1265 ERR(EAI_NONAME); 1266 if (strlen(hostname) > afd->a_addrlen) 1267 ERR(EAI_MEMORY); 1268 /* NUL-termination does not need to be guaranteed. */ 1269 strncpy(path, hostname, afd->a_addrlen); 1270 p = &path[0]; 1271 break; 1272 case AF_INET: 1273 /* 1274 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1275 * that are accepted by inet_addr() and its family. The 1276 * accepted forms includes the "classful" one, which inet_pton 1277 * does not accept. So we need to separate the case for 1278 * AF_INET. 1279 */ 1280 if (inet_aton(hostname, (struct in_addr *)pton) != 1 || 1281 hostname[strspn(hostname, "0123456789.xabcdefXABCDEF")] != '\0') 1282 return 0; 1283 p = pton; 1284 break; 1285 default: 1286 if (inet_pton(afd->a_af, hostname, pton) != 1) { 1287 if (pai->ai_family != AF_INET6 || 1288 (pai->ai_flags & AI_V4MAPPED) != AI_V4MAPPED) 1289 return 0; 1290 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1291 return 0; 1292 afd = &afdl[N_INET]; 1293 ai0 = *pai; 1294 ai0.ai_family = AF_INET; 1295 pai = &ai0; 1296 } 1297 p = pton; 1298 break; 1299 } 1300 1301 if (pai->ai_family == afd->a_af) { 1302 GET_AI(ai, afd, p); 1303 GET_PORT(ai, servname); 1304 if ((pai->ai_family == AF_INET || 1305 pai->ai_family == AF_INET6) && 1306 (pai->ai_flags & AI_CANONNAME)) { 1307 /* 1308 * Set the numeric address itself as the canonical 1309 * name, based on a clarification in RFC3493. 1310 */ 1311 GET_CANONNAME(ai, canonname); 1312 } 1313 } else { 1314 /* 1315 * XXX: This should not happen since we already matched the AF 1316 * by find_afd. 1317 */ 1318 ERR(EAI_FAMILY); 1319 } 1320 1321 *res = ai; 1322 return 0; 1323 1324 free: 1325 bad: 1326 if (ai != NULL) 1327 freeaddrinfo(ai); 1328 return error; 1329 } 1330 1331 /* 1332 * numeric hostname with scope 1333 */ 1334 static int 1335 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1336 const char *servname, struct addrinfo **res) 1337 { 1338 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 1339 return explore_numeric(pai, hostname, servname, res, hostname); 1340 #else 1341 const struct afd *afd; 1342 struct addrinfo *cur; 1343 int error; 1344 char *cp, *hostname2 = NULL, *scope, *addr; 1345 struct sockaddr_in6 *sin6; 1346 1347 afd = find_afd(pai->ai_family); 1348 if (afd == NULL) 1349 return 0; 1350 1351 if (!afd->a_scoped) 1352 return explore_numeric(pai, hostname, servname, res, hostname); 1353 1354 cp = strchr(hostname, SCOPE_DELIMITER); 1355 if (cp == NULL) 1356 return explore_numeric(pai, hostname, servname, res, hostname); 1357 1358 /* 1359 * Handle special case of <scoped_address><delimiter><scope id> 1360 */ 1361 hostname2 = strdup(hostname); 1362 if (hostname2 == NULL) 1363 return EAI_MEMORY; 1364 /* terminate at the delimiter */ 1365 hostname2[cp - hostname] = '\0'; 1366 addr = hostname2; 1367 scope = cp + 1; 1368 1369 error = explore_numeric(pai, addr, servname, res, hostname); 1370 if (error == 0) { 1371 u_int32_t scopeid; 1372 1373 for (cur = *res; cur; cur = cur->ai_next) { 1374 if (cur->ai_family != AF_INET6) 1375 continue; 1376 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1377 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1378 free(hostname2); 1379 freeaddrinfo(*res); 1380 *res = NULL; 1381 return(EAI_NONAME); /* XXX: is return OK? */ 1382 } 1383 sin6->sin6_scope_id = scopeid; 1384 } 1385 } 1386 1387 free(hostname2); 1388 1389 if (error && *res) { 1390 freeaddrinfo(*res); 1391 *res = NULL; 1392 } 1393 return error; 1394 #endif 1395 } 1396 1397 static int 1398 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1399 { 1400 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1401 ai->ai_canonname = strdup(str); 1402 if (ai->ai_canonname == NULL) 1403 return EAI_MEMORY; 1404 } 1405 return 0; 1406 } 1407 1408 static struct addrinfo * 1409 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1410 { 1411 char *p; 1412 struct addrinfo *ai; 1413 #ifdef INET6 1414 struct in6_addr mapaddr; 1415 1416 if (afd->a_af == AF_INET && (pai->ai_flags & AI_V4MAPPED) != 0) { 1417 afd = &afdl[N_INET6]; 1418 _map_v4v6_address(addr, (char *)&mapaddr); 1419 addr = (char *)&mapaddr; 1420 } 1421 #endif 1422 1423 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1424 + (afd->a_socklen)); 1425 if (ai == NULL) 1426 return NULL; 1427 1428 memcpy(ai, pai, sizeof(struct addrinfo)); 1429 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1430 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1431 ai->ai_addr->sa_len = afd->a_socklen; 1432 ai->ai_addrlen = afd->a_socklen; 1433 if (ai->ai_family == PF_LOCAL) { 1434 size_t n = strnlen(addr, afd->a_addrlen); 1435 1436 ai->ai_addrlen -= afd->a_addrlen - n; 1437 ai->ai_addr->sa_len -= afd->a_addrlen - n; 1438 } 1439 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1440 p = (char *)(void *)(ai->ai_addr); 1441 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1442 return ai; 1443 } 1444 1445 /* XXX need to malloc() the same way we do from other functions! */ 1446 static struct addrinfo * 1447 copy_ai(const struct addrinfo *pai) 1448 { 1449 struct addrinfo *ai; 1450 size_t l; 1451 1452 l = sizeof(*ai) + pai->ai_addrlen; 1453 if ((ai = calloc(1, l)) == NULL) 1454 return NULL; 1455 memcpy(ai, pai, sizeof(*ai)); 1456 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1457 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1458 1459 if (pai->ai_canonname) { 1460 l = strlen(pai->ai_canonname) + 1; 1461 if ((ai->ai_canonname = malloc(l)) == NULL) { 1462 free(ai); 1463 return NULL; 1464 } 1465 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1466 } else { 1467 /* just to make sure */ 1468 ai->ai_canonname = NULL; 1469 } 1470 1471 ai->ai_next = NULL; 1472 1473 return ai; 1474 } 1475 1476 static int 1477 get_portmatch(const struct addrinfo *ai, const char *servname) 1478 { 1479 1480 /* get_port does not touch first argument when matchonly == 1. */ 1481 /* LINTED const cast */ 1482 return get_port((struct addrinfo *)ai, servname, 1); 1483 } 1484 1485 static int 1486 get_port(struct addrinfo *ai, const char *servname, int matchonly) 1487 { 1488 const char *proto; 1489 struct servent *sp; 1490 int port, error; 1491 int allownumeric; 1492 1493 if (servname == NULL) 1494 return 0; 1495 switch (ai->ai_family) { 1496 case AF_LOCAL: 1497 /* AF_LOCAL ignores servname silently. */ 1498 return (0); 1499 case AF_INET: 1500 #ifdef AF_INET6 1501 case AF_INET6: 1502 #endif 1503 break; 1504 default: 1505 return 0; 1506 } 1507 1508 switch (ai->ai_socktype) { 1509 case SOCK_RAW: 1510 return EAI_SERVICE; 1511 case SOCK_DGRAM: 1512 case SOCK_STREAM: 1513 case SOCK_SEQPACKET: 1514 allownumeric = 1; 1515 break; 1516 case ANY: 1517 switch (ai->ai_family) { 1518 case AF_INET: 1519 #ifdef AF_INET6 1520 case AF_INET6: 1521 #endif 1522 allownumeric = 1; 1523 break; 1524 default: 1525 allownumeric = 0; 1526 break; 1527 } 1528 break; 1529 default: 1530 return EAI_SOCKTYPE; 1531 } 1532 1533 error = str2number(servname, &port); 1534 if (error == 0) { 1535 if (!allownumeric) 1536 return EAI_SERVICE; 1537 if (port < 0 || port > 65535) 1538 return EAI_SERVICE; 1539 port = htons(port); 1540 } else { 1541 if (ai->ai_flags & AI_NUMERICSERV) 1542 return EAI_NONAME; 1543 1544 switch (ai->ai_protocol) { 1545 case IPPROTO_UDP: 1546 proto = "udp"; 1547 break; 1548 case IPPROTO_TCP: 1549 proto = "tcp"; 1550 break; 1551 case IPPROTO_SCTP: 1552 proto = "sctp"; 1553 break; 1554 case IPPROTO_UDPLITE: 1555 proto = "udplite"; 1556 break; 1557 default: 1558 proto = NULL; 1559 break; 1560 } 1561 1562 if ((sp = getservbyname(servname, proto)) == NULL) 1563 return EAI_SERVICE; 1564 port = sp->s_port; 1565 } 1566 1567 if (!matchonly) { 1568 switch (ai->ai_family) { 1569 case AF_INET: 1570 ((struct sockaddr_in *)(void *) 1571 ai->ai_addr)->sin_port = port; 1572 break; 1573 #ifdef INET6 1574 case AF_INET6: 1575 ((struct sockaddr_in6 *)(void *) 1576 ai->ai_addr)->sin6_port = port; 1577 break; 1578 #endif 1579 } 1580 } 1581 1582 return 0; 1583 } 1584 1585 static const struct afd * 1586 find_afd(int af) 1587 { 1588 const struct afd *afd; 1589 1590 if (af == PF_UNSPEC) 1591 return NULL; 1592 for (afd = afdl; afd->a_af; afd++) { 1593 if (afd->a_af == af) 1594 return afd; 1595 } 1596 return NULL; 1597 } 1598 1599 /* 1600 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are 1601 * configured on the local system and correlates with pai->ai_family value. 1602 * If an address family is not configured on the system, it will not be 1603 * queried for. For this purpose, loopback addresses are not considered 1604 * configured addresses. 1605 * 1606 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1607 * _dns_getaddrinfo. 1608 */ 1609 static int 1610 addrconfig(struct addrinfo *pai) 1611 { 1612 struct ifaddrs *ifaddrs, *ifa; 1613 struct sockaddr_in *sin; 1614 #ifdef INET6 1615 struct sockaddr_in6 *sin6; 1616 #endif 1617 int seen_inet = 0, seen_inet6 = 0; 1618 1619 if (getifaddrs(&ifaddrs) != 0) 1620 return (0); 1621 1622 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1623 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1624 continue; 1625 switch (ifa->ifa_addr->sa_family) { 1626 case AF_INET: 1627 if (seen_inet) 1628 continue; 1629 sin = (struct sockaddr_in *)(ifa->ifa_addr); 1630 if (htonl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) 1631 continue; 1632 seen_inet = 1; 1633 break; 1634 #ifdef INET6 1635 case AF_INET6: 1636 if (seen_inet6) 1637 continue; 1638 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); 1639 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 1640 continue; 1641 if ((ifa->ifa_flags & IFT_LOOP) != 0 && 1642 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 1643 continue; 1644 if (is_ifdisabled(ifa->ifa_name)) 1645 continue; 1646 seen_inet6 = 1; 1647 break; 1648 #endif 1649 } 1650 } 1651 freeifaddrs(ifaddrs); 1652 1653 switch(pai->ai_family) { 1654 case AF_INET6: 1655 return (seen_inet6); 1656 case AF_INET: 1657 return (seen_inet); 1658 case AF_UNSPEC: 1659 if (seen_inet == seen_inet6) 1660 return (seen_inet); 1661 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1662 return (1); 1663 } 1664 return (1); 1665 } 1666 1667 #ifdef INET6 1668 static int 1669 is_ifdisabled(char *name) 1670 { 1671 struct in6_ndireq nd; 1672 int fd; 1673 1674 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1675 return (-1); 1676 memset(&nd, 0, sizeof(nd)); 1677 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1678 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1679 _close(fd); 1680 return (-1); 1681 } 1682 _close(fd); 1683 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1684 } 1685 1686 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1687 static int 1688 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1689 { 1690 u_long lscopeid; 1691 struct in6_addr *a6; 1692 char *ep; 1693 1694 a6 = &sin6->sin6_addr; 1695 1696 /* empty scopeid portion is invalid */ 1697 if (*scope == '\0') 1698 return -1; 1699 1700 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1701 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1702 /* 1703 * We currently assume a one-to-one mapping between links 1704 * and interfaces, so we simply use interface indices for 1705 * like-local scopes. 1706 */ 1707 *scopeid = if_nametoindex(scope); 1708 if (*scopeid == 0) 1709 goto trynumeric; 1710 return 0; 1711 } 1712 1713 /* still unclear about literal, allow numeric only - placeholder */ 1714 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1715 goto trynumeric; 1716 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1717 goto trynumeric; 1718 else 1719 goto trynumeric; /* global */ 1720 1721 /* try to convert to a numeric id as a last resort */ 1722 trynumeric: 1723 errno = 0; 1724 lscopeid = strtoul(scope, &ep, 10); 1725 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1726 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1727 return 0; 1728 else 1729 return -1; 1730 } 1731 #endif 1732 1733 1734 #ifdef NS_CACHING 1735 static int 1736 addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1737 void *cache_mdata) 1738 { 1739 res_state statp; 1740 u_long res_options; 1741 1742 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1743 char *hostname; 1744 struct addrinfo *hints; 1745 1746 char *p; 1747 int ai_flags, ai_family, ai_socktype, ai_protocol; 1748 size_t desired_size, size; 1749 1750 statp = __res_state(); 1751 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1752 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1753 1754 hostname = va_arg(ap, char *); 1755 hints = va_arg(ap, struct addrinfo *); 1756 1757 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1758 if (hostname != NULL) { 1759 size = strlen(hostname); 1760 desired_size += size + 1; 1761 } else 1762 size = 0; 1763 1764 if (desired_size > *buffer_size) { 1765 *buffer_size = desired_size; 1766 return (NS_RETURN); 1767 } 1768 1769 if (hints == NULL) 1770 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1771 else { 1772 ai_flags = hints->ai_flags; 1773 ai_family = hints->ai_family; 1774 ai_socktype = hints->ai_socktype; 1775 ai_protocol = hints->ai_protocol; 1776 } 1777 1778 p = buffer; 1779 memcpy(p, &res_options, sizeof(res_options)); 1780 p += sizeof(res_options); 1781 1782 memcpy(p, &op_id, sizeof(int)); 1783 p += sizeof(int); 1784 1785 memcpy(p, &ai_flags, sizeof(int)); 1786 p += sizeof(int); 1787 1788 memcpy(p, &ai_family, sizeof(int)); 1789 p += sizeof(int); 1790 1791 memcpy(p, &ai_socktype, sizeof(int)); 1792 p += sizeof(int); 1793 1794 memcpy(p, &ai_protocol, sizeof(int)); 1795 p += sizeof(int); 1796 1797 if (hostname != NULL) 1798 memcpy(p, hostname, size); 1799 1800 *buffer_size = desired_size; 1801 return (NS_SUCCESS); 1802 } 1803 1804 static int 1805 addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1806 va_list ap, void *cache_mdata) 1807 { 1808 struct addrinfo *ai, *cai; 1809 char *p; 1810 size_t desired_size, size, ai_size; 1811 1812 ai = *((struct addrinfo **)retval); 1813 1814 desired_size = sizeof(size_t); 1815 ai_size = 0; 1816 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1817 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1818 if (cai->ai_canonname != NULL) 1819 desired_size += sizeof(size_t) + 1820 strlen(cai->ai_canonname); 1821 ++ai_size; 1822 } 1823 1824 if (desired_size > *buffer_size) { 1825 /* this assignment is here for future use */ 1826 errno = ERANGE; 1827 *buffer_size = desired_size; 1828 return (NS_RETURN); 1829 } 1830 1831 memset(buffer, 0, desired_size); 1832 p = buffer; 1833 1834 memcpy(p, &ai_size, sizeof(size_t)); 1835 p += sizeof(size_t); 1836 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1837 memcpy(p, cai, sizeof(struct addrinfo)); 1838 p += sizeof(struct addrinfo); 1839 1840 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1841 p += cai->ai_addrlen; 1842 1843 if (cai->ai_canonname != NULL) { 1844 size = strlen(cai->ai_canonname); 1845 memcpy(p, &size, sizeof(size_t)); 1846 p += sizeof(size_t); 1847 1848 memcpy(p, cai->ai_canonname, size); 1849 p += size; 1850 } 1851 } 1852 1853 return (NS_SUCCESS); 1854 } 1855 1856 static int 1857 addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1858 va_list ap, void *cache_mdata) 1859 { 1860 struct addrinfo new_ai, *result, *sentinel, *lasts; 1861 1862 char *p; 1863 size_t ai_size, ai_i, size; 1864 1865 p = buffer; 1866 memcpy(&ai_size, p, sizeof(size_t)); 1867 p += sizeof(size_t); 1868 1869 result = NULL; 1870 lasts = NULL; 1871 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1872 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1873 p += sizeof(struct addrinfo); 1874 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1875 _ALIGNBYTES; 1876 1877 sentinel = calloc(1, size); 1878 1879 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1880 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1881 sizeof(struct addrinfo)); 1882 1883 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1884 p += new_ai.ai_addrlen; 1885 1886 if (new_ai.ai_canonname != NULL) { 1887 memcpy(&size, p, sizeof(size_t)); 1888 p += sizeof(size_t); 1889 1890 sentinel->ai_canonname = calloc(1, size + 1); 1891 1892 memcpy(sentinel->ai_canonname, p, size); 1893 p += size; 1894 } 1895 1896 if (result == NULL) { 1897 result = sentinel; 1898 lasts = sentinel; 1899 } else { 1900 lasts->ai_next = sentinel; 1901 lasts = sentinel; 1902 } 1903 } 1904 1905 *((struct addrinfo **)retval) = result; 1906 return (NS_SUCCESS); 1907 } 1908 #endif /* NS_CACHING */ 1909 1910 /* 1911 * FQDN hostname, DNS lookup 1912 */ 1913 static int 1914 explore_fqdn(const struct addrinfo *pai, const char *hostname, 1915 const char *servname, struct addrinfo **res) 1916 { 1917 struct addrinfo *result; 1918 struct addrinfo *cur; 1919 int error = 0; 1920 1921 #ifdef NS_CACHING 1922 static const nss_cache_info cache_info = 1923 NS_COMMON_CACHE_INFO_INITIALIZER( 1924 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1925 addrinfo_unmarshal_func); 1926 #endif 1927 static const ns_dtab dtab[] = { 1928 NS_FILES_CB(_files_getaddrinfo, NULL) 1929 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1930 NS_NIS_CB(_yp_getaddrinfo, NULL) 1931 #ifdef NS_CACHING 1932 NS_CACHE_CB(&cache_info) 1933 #endif 1934 { 0 } 1935 }; 1936 1937 result = NULL; 1938 1939 /* 1940 * if the servname does not match socktype/protocol, ignore it. 1941 */ 1942 if (get_portmatch(pai, servname) != 0) 1943 return 0; 1944 1945 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1946 default_dns_files, hostname, pai)) { 1947 case NS_TRYAGAIN: 1948 error = EAI_AGAIN; 1949 goto free; 1950 case NS_UNAVAIL: 1951 error = EAI_FAIL; 1952 goto free; 1953 case NS_NOTFOUND: 1954 error = EAI_NONAME; 1955 goto free; 1956 case NS_SUCCESS: 1957 error = 0; 1958 for (cur = result; cur; cur = cur->ai_next) { 1959 GET_PORT(cur, servname); 1960 /* canonname should be filled already */ 1961 } 1962 break; 1963 } 1964 1965 *res = result; 1966 1967 return 0; 1968 1969 free: 1970 if (result) 1971 freeaddrinfo(result); 1972 return error; 1973 } 1974 1975 #ifdef DEBUG 1976 static const char AskedForGot[] = 1977 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1978 #endif 1979 1980 static struct addrinfo * 1981 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1982 const struct addrinfo *pai, res_state res) 1983 { 1984 struct addrinfo sentinel, *cur; 1985 struct addrinfo ai; 1986 const struct afd *afd; 1987 char *canonname; 1988 const HEADER *hp; 1989 const u_char *cp; 1990 int n; 1991 const u_char *eom; 1992 char *bp, *ep; 1993 int type, class, ancount, qdcount; 1994 int haveanswer, had_error; 1995 char tbuf[MAXDNAME]; 1996 int (*name_ok)(const char *); 1997 char hostbuf[8*1024]; 1998 1999 memset(&sentinel, 0, sizeof(sentinel)); 2000 cur = &sentinel; 2001 2002 canonname = NULL; 2003 eom = answer->buf + anslen; 2004 switch (qtype) { 2005 case T_A: 2006 case T_AAAA: 2007 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 2008 name_ok = res_hnok; 2009 break; 2010 default: 2011 return (NULL); /* XXX should be abort(); */ 2012 } 2013 /* 2014 * find first satisfactory answer 2015 */ 2016 hp = &answer->hdr; 2017 ancount = ntohs(hp->ancount); 2018 qdcount = ntohs(hp->qdcount); 2019 bp = hostbuf; 2020 ep = hostbuf + sizeof hostbuf; 2021 cp = answer->buf + HFIXEDSZ; 2022 if (qdcount != 1) { 2023 RES_SET_H_ERRNO(res, NO_RECOVERY); 2024 return (NULL); 2025 } 2026 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2027 if ((n < 0) || !(*name_ok)(bp)) { 2028 RES_SET_H_ERRNO(res, NO_RECOVERY); 2029 return (NULL); 2030 } 2031 cp += n + QFIXEDSZ; 2032 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 2033 /* res_send() has already verified that the query name is the 2034 * same as the one we sent; this just gets the expanded name 2035 * (i.e., with the succeeding search-domain tacked on). 2036 */ 2037 n = strlen(bp) + 1; /* for the \0 */ 2038 if (n >= MAXHOSTNAMELEN) { 2039 RES_SET_H_ERRNO(res, NO_RECOVERY); 2040 return (NULL); 2041 } 2042 canonname = bp; 2043 bp += n; 2044 /* The qname can be abbreviated, but h_name is now absolute. */ 2045 qname = canonname; 2046 } 2047 haveanswer = 0; 2048 had_error = 0; 2049 while (ancount-- > 0 && cp < eom && !had_error) { 2050 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2051 if ((n < 0) || !(*name_ok)(bp)) { 2052 had_error++; 2053 continue; 2054 } 2055 cp += n; /* name */ 2056 type = _getshort(cp); 2057 cp += INT16SZ; /* type */ 2058 class = _getshort(cp); 2059 cp += INT16SZ + INT32SZ; /* class, TTL */ 2060 n = _getshort(cp); 2061 cp += INT16SZ; /* len */ 2062 if (class != C_IN) { 2063 /* XXX - debug? syslog? */ 2064 cp += n; 2065 continue; /* XXX - had_error++ ? */ 2066 } 2067 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 2068 type == T_CNAME) { 2069 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 2070 if ((n < 0) || !(*name_ok)(tbuf)) { 2071 had_error++; 2072 continue; 2073 } 2074 cp += n; 2075 /* Get canonical name. */ 2076 n = strlen(tbuf) + 1; /* for the \0 */ 2077 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 2078 had_error++; 2079 continue; 2080 } 2081 strlcpy(bp, tbuf, ep - bp); 2082 canonname = bp; 2083 bp += n; 2084 continue; 2085 } 2086 if (qtype == T_ANY) { 2087 if (!(type == T_A || type == T_AAAA)) { 2088 cp += n; 2089 continue; 2090 } 2091 } else if (type != qtype) { 2092 #ifdef DEBUG 2093 if (type != T_KEY && type != T_SIG && 2094 type != ns_t_dname) 2095 syslog(LOG_NOTICE|LOG_AUTH, 2096 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2097 qname, p_class(C_IN), p_type(qtype), 2098 p_type(type)); 2099 #endif 2100 cp += n; 2101 continue; /* XXX - had_error++ ? */ 2102 } 2103 switch (type) { 2104 case T_A: 2105 case T_AAAA: 2106 if (strcasecmp(canonname, bp) != 0) { 2107 #ifdef DEBUG 2108 syslog(LOG_NOTICE|LOG_AUTH, 2109 AskedForGot, canonname, bp); 2110 #endif 2111 cp += n; 2112 continue; /* XXX - had_error++ ? */ 2113 } 2114 if (type == T_A && n != INADDRSZ) { 2115 cp += n; 2116 continue; 2117 } 2118 if (type == T_AAAA && n != IN6ADDRSZ) { 2119 cp += n; 2120 continue; 2121 } 2122 #ifdef FILTER_V4MAPPED 2123 if (type == T_AAAA) { 2124 struct in6_addr in6; 2125 memcpy(&in6, cp, sizeof(in6)); 2126 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2127 cp += n; 2128 continue; 2129 } 2130 } 2131 #endif 2132 if (!haveanswer) { 2133 int nn; 2134 2135 canonname = bp; 2136 nn = strlen(bp) + 1; /* for the \0 */ 2137 bp += nn; 2138 } 2139 2140 /* don't overwrite pai */ 2141 ai = *pai; 2142 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2143 afd = find_afd(ai.ai_family); 2144 if (afd == NULL) { 2145 cp += n; 2146 continue; 2147 } 2148 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2149 if (cur->ai_next == NULL) 2150 had_error++; 2151 while (cur && cur->ai_next) 2152 cur = cur->ai_next; 2153 cp += n; 2154 break; 2155 default: 2156 abort(); 2157 } 2158 if (!had_error) 2159 haveanswer++; 2160 } 2161 if (haveanswer) { 2162 #if defined(RESOLVSORT) 2163 /* 2164 * We support only IPv4 address for backward 2165 * compatibility against gethostbyname(3). 2166 */ 2167 if (res->nsort && qtype == T_A) { 2168 if (addr4sort(&sentinel, res) < 0) { 2169 freeaddrinfo(sentinel.ai_next); 2170 RES_SET_H_ERRNO(res, NO_RECOVERY); 2171 return NULL; 2172 } 2173 } 2174 #endif /*RESOLVSORT*/ 2175 if (!canonname) 2176 (void)get_canonname(pai, sentinel.ai_next, qname); 2177 else 2178 (void)get_canonname(pai, sentinel.ai_next, canonname); 2179 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2180 return sentinel.ai_next; 2181 } 2182 2183 /* 2184 * We could have walked a CNAME chain, but the ultimate target 2185 * may not have what we looked for. 2186 */ 2187 RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : NO_RECOVERY); 2188 return NULL; 2189 } 2190 2191 #ifdef RESOLVSORT 2192 struct addr_ptr { 2193 struct addrinfo *ai; 2194 int aval; 2195 }; 2196 2197 static int 2198 addr4sort(struct addrinfo *sentinel, res_state res) 2199 { 2200 struct addrinfo *ai; 2201 struct addr_ptr *addrs, addr; 2202 struct sockaddr_in *sin; 2203 int naddrs, i, j; 2204 int needsort = 0; 2205 2206 if (!sentinel) 2207 return -1; 2208 naddrs = 0; 2209 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2210 naddrs++; 2211 if (naddrs < 2) 2212 return 0; /* We don't need sorting. */ 2213 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2214 return -1; 2215 i = 0; 2216 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2217 sin = (struct sockaddr_in *)ai->ai_addr; 2218 for (j = 0; (unsigned)j < res->nsort; j++) { 2219 if (res->sort_list[j].addr.s_addr == 2220 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2221 break; 2222 } 2223 addrs[i].ai = ai; 2224 addrs[i].aval = j; 2225 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2226 needsort = i; 2227 i++; 2228 } 2229 if (!needsort) { 2230 free(addrs); 2231 return 0; 2232 } 2233 2234 while (needsort < naddrs) { 2235 for (j = needsort - 1; j >= 0; j--) { 2236 if (addrs[j].aval > addrs[j+1].aval) { 2237 addr = addrs[j]; 2238 addrs[j] = addrs[j + 1]; 2239 addrs[j + 1] = addr; 2240 } else 2241 break; 2242 } 2243 needsort++; 2244 } 2245 2246 ai = sentinel; 2247 for (i = 0; i < naddrs; ++i) { 2248 ai->ai_next = addrs[i].ai; 2249 ai = ai->ai_next; 2250 } 2251 ai->ai_next = NULL; 2252 free(addrs); 2253 return 0; 2254 } 2255 #endif /*RESOLVSORT*/ 2256 2257 /*ARGSUSED*/ 2258 static int 2259 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2260 { 2261 struct addrinfo *ai, ai0; 2262 querybuf *buf, *buf2; 2263 const char *hostname; 2264 const struct addrinfo *pai; 2265 struct addrinfo sentinel, *cur; 2266 struct res_target q, q2; 2267 res_state res; 2268 2269 ai = NULL; 2270 2271 hostname = va_arg(ap, char *); 2272 pai = va_arg(ap, const struct addrinfo *); 2273 2274 memset(&q, 0, sizeof(q)); 2275 memset(&q2, 0, sizeof(q2)); 2276 memset(&sentinel, 0, sizeof(sentinel)); 2277 cur = &sentinel; 2278 2279 res = __res_state(); 2280 2281 buf = malloc(sizeof(*buf)); 2282 if (!buf) { 2283 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2284 return NS_NOTFOUND; 2285 } 2286 buf2 = malloc(sizeof(*buf2)); 2287 if (!buf2) { 2288 free(buf); 2289 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2290 return NS_NOTFOUND; 2291 } 2292 2293 if (pai->ai_family == AF_INET6 && 2294 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) { 2295 ai0 = *pai; 2296 ai0.ai_family = AF_UNSPEC; 2297 pai = &ai0; 2298 } 2299 2300 switch (pai->ai_family) { 2301 case AF_UNSPEC: 2302 q.name = hostname; 2303 q.qclass = C_IN; 2304 q.qtype = T_A; 2305 q.answer = buf->buf; 2306 q.anslen = sizeof(buf->buf); 2307 q.next = &q2; 2308 q2.name = hostname; 2309 q2.qclass = C_IN; 2310 q2.qtype = T_AAAA; 2311 q2.answer = buf2->buf; 2312 q2.anslen = sizeof(buf2->buf); 2313 break; 2314 case AF_INET: 2315 q.name = hostname; 2316 q.qclass = C_IN; 2317 q.qtype = T_A; 2318 q.answer = buf->buf; 2319 q.anslen = sizeof(buf->buf); 2320 break; 2321 case AF_INET6: 2322 q.name = hostname; 2323 q.qclass = C_IN; 2324 q.qtype = T_AAAA; 2325 q.answer = buf->buf; 2326 q.anslen = sizeof(buf->buf); 2327 break; 2328 default: 2329 free(buf); 2330 free(buf2); 2331 return NS_UNAVAIL; 2332 } 2333 2334 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2335 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2336 free(buf); 2337 free(buf2); 2338 return NS_NOTFOUND; 2339 } 2340 2341 if (res_searchN(hostname, &q, res) < 0) { 2342 free(buf); 2343 free(buf2); 2344 return NS_NOTFOUND; 2345 } 2346 /* prefer IPv6 */ 2347 if (q.next) { 2348 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2349 if (ai != NULL) { 2350 cur->ai_next = ai; 2351 while (cur && cur->ai_next) 2352 cur = cur->ai_next; 2353 } 2354 } 2355 if (ai == NULL || pai->ai_family != AF_UNSPEC || 2356 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) != AI_V4MAPPED) { 2357 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2358 if (ai != NULL) 2359 cur->ai_next = ai; 2360 } 2361 free(buf); 2362 free(buf2); 2363 if (sentinel.ai_next == NULL) 2364 switch (res->res_h_errno) { 2365 case HOST_NOT_FOUND: 2366 case NO_DATA: 2367 return NS_NOTFOUND; 2368 case TRY_AGAIN: 2369 return NS_TRYAGAIN; 2370 default: 2371 return NS_UNAVAIL; 2372 } 2373 *((struct addrinfo **)rv) = sentinel.ai_next; 2374 return NS_SUCCESS; 2375 } 2376 2377 static void 2378 _sethtent(FILE **hostf) 2379 { 2380 if (!*hostf) 2381 *hostf = fopen(_PATH_HOSTS, "re"); 2382 else 2383 rewind(*hostf); 2384 } 2385 2386 static void 2387 _endhtent(FILE **hostf) 2388 { 2389 if (*hostf) { 2390 (void) fclose(*hostf); 2391 *hostf = NULL; 2392 } 2393 } 2394 2395 static struct addrinfo * 2396 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2397 { 2398 char *p; 2399 char *cp, *tname, *cname; 2400 struct addrinfo hints, *res0, *res; 2401 int error; 2402 const char *addr; 2403 char hostbuf[8*1024]; 2404 2405 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2406 return (NULL); 2407 again: 2408 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2409 return (NULL); 2410 if (*p == '#') 2411 goto again; 2412 cp = strpbrk(p, "#\n"); 2413 if (cp != NULL) 2414 *cp = '\0'; 2415 if (!(cp = strpbrk(p, " \t"))) 2416 goto again; 2417 *cp++ = '\0'; 2418 addr = p; 2419 cname = NULL; 2420 /* if this is not something we're looking for, skip it. */ 2421 while (cp && *cp) { 2422 if (*cp == ' ' || *cp == '\t') { 2423 cp++; 2424 continue; 2425 } 2426 tname = cp; 2427 if (cname == NULL) 2428 cname = cp; 2429 if ((cp = strpbrk(cp, " \t")) != NULL) 2430 *cp++ = '\0'; 2431 if (strcasecmp(name, tname) == 0) 2432 goto found; 2433 } 2434 goto again; 2435 2436 found: 2437 /* we should not glob socktype/protocol here */ 2438 memset(&hints, 0, sizeof(hints)); 2439 hints.ai_family = pai->ai_family; 2440 hints.ai_socktype = SOCK_DGRAM; 2441 hints.ai_protocol = 0; 2442 hints.ai_flags = AI_NUMERICHOST; 2443 if (pai->ai_family == AF_INET6 && 2444 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2445 hints.ai_flags |= AI_V4MAPPED; 2446 error = getaddrinfo(addr, "0", &hints, &res0); 2447 if (error) 2448 goto again; 2449 #ifdef FILTER_V4MAPPED 2450 /* XXX should check all items in the chain */ 2451 if (res0->ai_family == AF_INET6 && 2452 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2453 freeaddrinfo(res0); 2454 goto again; 2455 } 2456 #endif 2457 for (res = res0; res; res = res->ai_next) { 2458 /* cover it up */ 2459 res->ai_flags = pai->ai_flags; 2460 res->ai_socktype = pai->ai_socktype; 2461 res->ai_protocol = pai->ai_protocol; 2462 2463 if (pai->ai_flags & AI_CANONNAME) { 2464 if (get_canonname(pai, res, cname) != 0) { 2465 freeaddrinfo(res0); 2466 goto again; 2467 } 2468 } 2469 } 2470 return res0; 2471 } 2472 2473 static struct addrinfo * 2474 _getht(FILE **hostf, const char *name, const struct addrinfo *pai, 2475 struct addrinfo *cur) 2476 { 2477 struct addrinfo *p; 2478 2479 while ((p = _gethtent(hostf, name, pai)) != NULL) { 2480 cur->ai_next = p; 2481 while (cur && cur->ai_next) 2482 cur = cur->ai_next; 2483 } 2484 return (cur); 2485 } 2486 2487 /*ARGSUSED*/ 2488 static int 2489 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2490 { 2491 const char *name; 2492 const struct addrinfo *pai; 2493 struct addrinfo sentinel, *cur; 2494 FILE *hostf = NULL; 2495 2496 name = va_arg(ap, char *); 2497 pai = va_arg(ap, struct addrinfo *); 2498 2499 memset(&sentinel, 0, sizeof(sentinel)); 2500 cur = &sentinel; 2501 2502 _sethtent(&hostf); 2503 if (pai->ai_family == AF_INET6 && 2504 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) == AI_V4MAPPED) { 2505 struct addrinfo ai0 = *pai; 2506 2507 ai0.ai_flags &= ~AI_V4MAPPED; 2508 cur = _getht(&hostf, name, &ai0, cur); 2509 if (sentinel.ai_next == NULL) { 2510 _sethtent(&hostf); 2511 ai0.ai_flags |= AI_V4MAPPED; 2512 cur = _getht(&hostf, name, &ai0, cur); 2513 } 2514 } else 2515 cur = _getht(&hostf, name, pai, cur); 2516 _endhtent(&hostf); 2517 2518 *((struct addrinfo **)rv) = sentinel.ai_next; 2519 if (sentinel.ai_next == NULL) 2520 return NS_NOTFOUND; 2521 return NS_SUCCESS; 2522 } 2523 2524 #ifdef YP 2525 /*ARGSUSED*/ 2526 static struct addrinfo * 2527 _yphostent(char *line, const struct addrinfo *pai) 2528 { 2529 struct addrinfo sentinel, *cur; 2530 struct addrinfo hints, *res, *res0; 2531 int error; 2532 char *p = line; 2533 const char *addr, *canonname; 2534 char *nextline; 2535 char *cp; 2536 2537 addr = canonname = NULL; 2538 2539 memset(&sentinel, 0, sizeof(sentinel)); 2540 cur = &sentinel; 2541 2542 nextline: 2543 /* terminate line */ 2544 cp = strchr(p, '\n'); 2545 if (cp) { 2546 *cp++ = '\0'; 2547 nextline = cp; 2548 } else 2549 nextline = NULL; 2550 2551 cp = strpbrk(p, " \t"); 2552 if (cp == NULL) { 2553 if (canonname == NULL) 2554 return (NULL); 2555 else 2556 goto done; 2557 } 2558 *cp++ = '\0'; 2559 2560 addr = p; 2561 2562 while (cp && *cp) { 2563 if (*cp == ' ' || *cp == '\t') { 2564 cp++; 2565 continue; 2566 } 2567 if (!canonname) 2568 canonname = cp; 2569 if ((cp = strpbrk(cp, " \t")) != NULL) 2570 *cp++ = '\0'; 2571 } 2572 2573 hints = *pai; 2574 hints.ai_flags = AI_NUMERICHOST; 2575 if (pai->ai_family == AF_INET6 && 2576 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2577 hints.ai_flags |= AI_V4MAPPED; 2578 error = getaddrinfo(addr, NULL, &hints, &res0); 2579 if (error == 0) { 2580 for (res = res0; res; res = res->ai_next) { 2581 /* cover it up */ 2582 res->ai_flags = pai->ai_flags; 2583 2584 if (pai->ai_flags & AI_CANONNAME) 2585 (void)get_canonname(pai, res, canonname); 2586 } 2587 } else 2588 res0 = NULL; 2589 if (res0) { 2590 cur->ai_next = res0; 2591 while (cur && cur->ai_next) 2592 cur = cur->ai_next; 2593 } 2594 2595 if (nextline) { 2596 p = nextline; 2597 goto nextline; 2598 } 2599 2600 done: 2601 return sentinel.ai_next; 2602 } 2603 2604 /*ARGSUSED*/ 2605 static int 2606 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2607 { 2608 struct addrinfo sentinel, *cur; 2609 struct addrinfo *ai = NULL; 2610 char *ypbuf; 2611 int ypbuflen, r; 2612 const char *name; 2613 const struct addrinfo *pai; 2614 char *ypdomain; 2615 2616 if (_yp_check(&ypdomain) == 0) 2617 return NS_UNAVAIL; 2618 2619 name = va_arg(ap, char *); 2620 pai = va_arg(ap, const struct addrinfo *); 2621 2622 memset(&sentinel, 0, sizeof(sentinel)); 2623 cur = &sentinel; 2624 2625 /* ipnodes.byname can hold both IPv4/v6 */ 2626 r = yp_match(ypdomain, "ipnodes.byname", name, 2627 (int)strlen(name), &ypbuf, &ypbuflen); 2628 if (r == 0) { 2629 ai = _yphostent(ypbuf, pai); 2630 if (ai) { 2631 cur->ai_next = ai; 2632 while (cur && cur->ai_next) 2633 cur = cur->ai_next; 2634 } 2635 free(ypbuf); 2636 } 2637 2638 if (ai != NULL) { 2639 struct sockaddr_in6 *sin6; 2640 2641 switch (ai->ai_family) { 2642 case AF_INET: 2643 goto done; 2644 case AF_INET6: 2645 sin6 = (struct sockaddr_in6 *)ai->ai_addr; 2646 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 2647 goto done; 2648 break; 2649 } 2650 } 2651 2652 /* hosts.byname is only for IPv4 (Solaris8) */ 2653 if (pai->ai_family == AF_UNSPEC || pai->ai_family == AF_INET || 2654 ((pai->ai_family == AF_INET6 && 2655 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) && 2656 (ai == NULL || (pai->ai_flags & AI_ALL) == AI_ALL))) { 2657 r = yp_match(ypdomain, "hosts.byname", name, 2658 (int)strlen(name), &ypbuf, &ypbuflen); 2659 if (r == 0) { 2660 struct addrinfo ai4; 2661 2662 ai4 = *pai; 2663 if (pai->ai_family == AF_UNSPEC) 2664 ai4.ai_family = AF_INET; 2665 ai = _yphostent(ypbuf, &ai4); 2666 if (ai) { 2667 cur->ai_next = ai; 2668 while (cur && cur->ai_next) 2669 cur = cur->ai_next; 2670 } 2671 free(ypbuf); 2672 } 2673 } 2674 2675 done: 2676 if (sentinel.ai_next == NULL) { 2677 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2678 return NS_NOTFOUND; 2679 } 2680 *((struct addrinfo **)rv) = sentinel.ai_next; 2681 return NS_SUCCESS; 2682 } 2683 #endif 2684 2685 /* resolver logic */ 2686 2687 /* 2688 * Formulate a normal query, send, and await answer. 2689 * Returned answer is placed in supplied buffer "answer". 2690 * Perform preliminary check of answer, returning success only 2691 * if no error is indicated and the answer count is nonzero. 2692 * Return the size of the response on success, -1 on error. 2693 * Error number is left in h_errno. 2694 * 2695 * Caller must parse answer and determine whether it answers the question. 2696 */ 2697 static int 2698 res_queryN(const char *name, struct res_target *target, res_state res) 2699 { 2700 u_char *buf; 2701 HEADER *hp; 2702 int n; 2703 u_int oflags; 2704 struct res_target *t; 2705 int rcode; 2706 int ancount; 2707 2708 rcode = NOERROR; 2709 ancount = 0; 2710 2711 buf = malloc(MAXPACKET); 2712 if (!buf) { 2713 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2714 return -1; 2715 } 2716 2717 for (t = target; t; t = t->next) { 2718 int class, type; 2719 u_char *answer; 2720 int anslen; 2721 2722 hp = (HEADER *)(void *)t->answer; 2723 2724 /* make it easier... */ 2725 class = t->qclass; 2726 type = t->qtype; 2727 answer = t->answer; 2728 anslen = t->anslen; 2729 2730 oflags = res->_flags; 2731 2732 again: 2733 hp->rcode = NOERROR; /* default */ 2734 2735 #ifdef DEBUG 2736 if (res->options & RES_DEBUG) 2737 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2738 #endif 2739 2740 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2741 buf, MAXPACKET); 2742 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2743 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2744 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2745 if (n <= 0) { 2746 #ifdef DEBUG 2747 if (res->options & RES_DEBUG) 2748 printf(";; res_query: mkquery failed\n"); 2749 #endif 2750 free(buf); 2751 RES_SET_H_ERRNO(res, NO_RECOVERY); 2752 return (n); 2753 } 2754 n = res_nsend(res, buf, n, answer, anslen); 2755 if (n < 0) { 2756 /* 2757 * if the query choked with EDNS0, retry 2758 * without EDNS0 2759 */ 2760 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2761 != 0U && 2762 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2763 res->_flags |= RES_F_EDNS0ERR; 2764 if (res->options & RES_DEBUG) 2765 printf(";; res_nquery: retry without EDNS0\n"); 2766 goto again; 2767 } 2768 rcode = hp->rcode; /* record most recent error */ 2769 #ifdef DEBUG 2770 if (res->options & RES_DEBUG) 2771 printf(";; res_query: send error\n"); 2772 #endif 2773 continue; 2774 } 2775 2776 if (n > anslen) 2777 hp->rcode = FORMERR; /* XXX not very informative */ 2778 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2779 rcode = hp->rcode; /* record most recent error */ 2780 #ifdef DEBUG 2781 if (res->options & RES_DEBUG) 2782 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2783 ntohs(hp->ancount)); 2784 #endif 2785 continue; 2786 } 2787 2788 ancount += ntohs(hp->ancount); 2789 2790 t->n = n; 2791 } 2792 2793 free(buf); 2794 2795 if (ancount == 0) { 2796 switch (rcode) { 2797 case NXDOMAIN: 2798 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2799 break; 2800 case SERVFAIL: 2801 RES_SET_H_ERRNO(res, TRY_AGAIN); 2802 break; 2803 case NOERROR: 2804 RES_SET_H_ERRNO(res, NO_DATA); 2805 break; 2806 case FORMERR: 2807 case NOTIMP: 2808 case REFUSED: 2809 default: 2810 RES_SET_H_ERRNO(res, NO_RECOVERY); 2811 break; 2812 } 2813 return (-1); 2814 } 2815 return (ancount); 2816 } 2817 2818 /* 2819 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2820 * Return the size of the response on success, -1 on error. 2821 * If enabled, implement search rules until answer or unrecoverable failure 2822 * is detected. Error code, if any, is left in h_errno. 2823 */ 2824 static int 2825 res_searchN(const char *name, struct res_target *target, res_state res) 2826 { 2827 const char *cp, * const *domain; 2828 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2829 u_int dots; 2830 int trailing_dot, ret, saved_herrno; 2831 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2832 int tried_as_is = 0; 2833 int searched = 0; 2834 char abuf[MAXDNAME]; 2835 2836 errno = 0; 2837 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2838 dots = 0; 2839 for (cp = name; *cp; cp++) 2840 dots += (*cp == '.'); 2841 trailing_dot = 0; 2842 if (cp > name && *--cp == '.') 2843 trailing_dot++; 2844 2845 /* 2846 * if there aren't any dots, it could be a user-level alias 2847 */ 2848 if (!dots && 2849 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2850 return (res_queryN(cp, target, res)); 2851 2852 /* 2853 * If there are enough dots in the name, let's just give it a 2854 * try 'as is'. The threshold can be set with the "ndots" option. 2855 * Also, query 'as is', if there is a trailing dot in the name. 2856 */ 2857 saved_herrno = -1; 2858 if (dots >= res->ndots || trailing_dot) { 2859 ret = res_querydomainN(name, NULL, target, res); 2860 if (ret > 0 || trailing_dot) 2861 return (ret); 2862 if (errno == ECONNREFUSED) { 2863 RES_SET_H_ERRNO(res, TRY_AGAIN); 2864 return (-1); 2865 } 2866 switch (res->res_h_errno) { 2867 case NO_DATA: 2868 case HOST_NOT_FOUND: 2869 break; 2870 case TRY_AGAIN: 2871 if (hp->rcode == SERVFAIL) 2872 break; 2873 /* FALLTHROUGH */ 2874 default: 2875 return (-1); 2876 } 2877 saved_herrno = res->res_h_errno; 2878 tried_as_is++; 2879 } 2880 2881 /* 2882 * We do at least one level of search if 2883 * - there is no dot and RES_DEFNAME is set, or 2884 * - there is at least one dot, there is no trailing dot, 2885 * and RES_DNSRCH is set. 2886 */ 2887 if ((!dots && (res->options & RES_DEFNAMES)) || 2888 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2889 int done = 0; 2890 2891 for (domain = (const char * const *)res->dnsrch; 2892 *domain && !done; 2893 domain++) { 2894 searched = 1; 2895 2896 if (domain[0][0] == '\0' || 2897 (domain[0][0] == '.' && domain[0][1] == '\0')) 2898 root_on_list++; 2899 2900 if (root_on_list && tried_as_is) 2901 continue; 2902 2903 ret = res_querydomainN(name, *domain, target, res); 2904 if (ret > 0) 2905 return (ret); 2906 2907 /* 2908 * If no server present, give up. 2909 * If name isn't found in this domain, 2910 * keep trying higher domains in the search list 2911 * (if that's enabled). 2912 * On a NO_DATA error, keep trying, otherwise 2913 * a wildcard entry of another type could keep us 2914 * from finding this entry higher in the domain. 2915 * If we get some other error (negative answer or 2916 * server failure), then stop searching up, 2917 * but try the input name below in case it's 2918 * fully-qualified. 2919 */ 2920 if (errno == ECONNREFUSED) { 2921 RES_SET_H_ERRNO(res, TRY_AGAIN); 2922 return (-1); 2923 } 2924 2925 switch (res->res_h_errno) { 2926 case NO_DATA: 2927 got_nodata++; 2928 /* FALLTHROUGH */ 2929 case HOST_NOT_FOUND: 2930 /* keep trying */ 2931 break; 2932 case TRY_AGAIN: 2933 got_servfail++; 2934 if (hp->rcode == SERVFAIL) { 2935 /* try next search element, if any */ 2936 break; 2937 } 2938 /* FALLTHROUGH */ 2939 default: 2940 /* anything else implies that we're done */ 2941 done++; 2942 } 2943 /* 2944 * if we got here for some reason other than DNSRCH, 2945 * we only wanted one iteration of the loop, so stop. 2946 */ 2947 if (!(res->options & RES_DNSRCH)) 2948 done++; 2949 } 2950 } 2951 2952 switch (res->res_h_errno) { 2953 case NO_DATA: 2954 case HOST_NOT_FOUND: 2955 break; 2956 case TRY_AGAIN: 2957 if (hp->rcode == SERVFAIL) 2958 break; 2959 /* FALLTHROUGH */ 2960 default: 2961 goto giveup; 2962 } 2963 2964 /* 2965 * If the query has not already been tried as is then try it 2966 * unless RES_NOTLDQUERY is set and there were no dots. 2967 */ 2968 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2969 !(tried_as_is || root_on_list)) { 2970 ret = res_querydomainN(name, NULL, target, res); 2971 if (ret > 0) 2972 return (ret); 2973 } 2974 2975 /* 2976 * if we got here, we didn't satisfy the search. 2977 * if we did an initial full query, return that query's h_errno 2978 * (note that we wouldn't be here if that query had succeeded). 2979 * else if we ever got a nodata, send that back as the reason. 2980 * else send back meaningless h_errno, that being the one from 2981 * the last DNSRCH we did. 2982 */ 2983 giveup: 2984 if (saved_herrno != -1) 2985 RES_SET_H_ERRNO(res, saved_herrno); 2986 else if (got_nodata) 2987 RES_SET_H_ERRNO(res, NO_DATA); 2988 else if (got_servfail) 2989 RES_SET_H_ERRNO(res, TRY_AGAIN); 2990 return (-1); 2991 } 2992 2993 /* 2994 * Perform a call on res_query on the concatenation of name and domain, 2995 * removing a trailing dot from name if domain is NULL. 2996 */ 2997 static int 2998 res_querydomainN(const char *name, const char *domain, 2999 struct res_target *target, res_state res) 3000 { 3001 char nbuf[MAXDNAME]; 3002 const char *longname = nbuf; 3003 size_t n, d; 3004 3005 #ifdef DEBUG 3006 if (res->options & RES_DEBUG) 3007 printf(";; res_querydomain(%s, %s)\n", 3008 name, domain?domain:"<Nil>"); 3009 #endif 3010 if (domain == NULL) { 3011 /* 3012 * Check for trailing '.'; 3013 * copy without '.' if present. 3014 */ 3015 n = strlen(name); 3016 if (n >= MAXDNAME) { 3017 RES_SET_H_ERRNO(res, NO_RECOVERY); 3018 return (-1); 3019 } 3020 if (n > 0 && name[--n] == '.') { 3021 strncpy(nbuf, name, n); 3022 nbuf[n] = '\0'; 3023 } else 3024 longname = name; 3025 } else { 3026 n = strlen(name); 3027 d = strlen(domain); 3028 if (n + d + 1 >= MAXDNAME) { 3029 RES_SET_H_ERRNO(res, NO_RECOVERY); 3030 return (-1); 3031 } 3032 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 3033 } 3034 return (res_queryN(longname, target, res)); 3035 } 3036