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 #include "namespace.h" 58 #include <sys/param.h> 59 #include <sys/socket.h> 60 #include <net/if.h> 61 #include <netinet/in.h> 62 #include <net/if_types.h> 63 #include <ifaddrs.h> 64 #include <sys/queue.h> 65 #ifdef INET6 66 #include <sys/sysctl.h> 67 #include <sys/ioctl.h> 68 #include <netinet6/in6_var.h> 69 #include <netinet6/nd6.h> 70 #endif 71 #include <arpa/inet.h> 72 #include <arpa/nameser.h> 73 #include <rpc/rpc.h> 74 #include <rpcsvc/yp_prot.h> 75 #include <rpcsvc/ypclnt.h> 76 #include <netdb.h> 77 #include <resolv.h> 78 #include <string.h> 79 #include <stdlib.h> 80 #include <stddef.h> 81 #include <ctype.h> 82 #include <unistd.h> 83 #include <stdio.h> 84 #include <errno.h> 85 86 #include "res_config.h" 87 88 #ifdef DEBUG 89 #include <syslog.h> 90 #endif 91 92 #include <stdarg.h> 93 #include <nsswitch.h> 94 #include "un-namespace.h" 95 #include "netdb_private.h" 96 #include "libc_private.h" 97 #ifdef NS_CACHING 98 #include "nscache.h" 99 #endif 100 101 #define ANY 0 102 #define YES 1 103 #define NO 0 104 105 static const char in_addrany[] = { 0, 0, 0, 0 }; 106 static const char in_loopback[] = { 127, 0, 0, 1 }; 107 #ifdef INET6 108 static const char in6_addrany[] = { 109 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 110 }; 111 static const char in6_loopback[] = { 112 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 113 }; 114 #endif 115 116 struct policyqueue { 117 TAILQ_ENTRY(policyqueue) pc_entry; 118 #ifdef INET6 119 struct in6_addrpolicy pc_policy; 120 #endif 121 }; 122 TAILQ_HEAD(policyhead, policyqueue); 123 124 static const struct afd { 125 int a_af; 126 int a_addrlen; 127 socklen_t a_socklen; 128 int a_off; 129 const char *a_addrany; 130 const char *a_loopback; 131 int a_scoped; 132 } afdl [] = { 133 #ifdef INET6 134 #define N_INET6 0 135 {PF_INET6, sizeof(struct in6_addr), 136 sizeof(struct sockaddr_in6), 137 offsetof(struct sockaddr_in6, sin6_addr), 138 in6_addrany, in6_loopback, 1}, 139 #define N_INET 1 140 #define N_LOCAL 2 141 #else 142 #define N_INET 0 143 #define N_LOCAL 1 144 #endif 145 {PF_INET, sizeof(struct in_addr), 146 sizeof(struct sockaddr_in), 147 offsetof(struct sockaddr_in, sin_addr), 148 in_addrany, in_loopback, 0}, 149 #define sizeofmember(type, member) (sizeof(((type *)0)->member)) 150 {PF_LOCAL, sizeofmember(struct sockaddr_un, sun_path), 151 sizeof(struct sockaddr_un), 152 offsetof(struct sockaddr_un, sun_path), 153 NULL, NULL, 0}, 154 {0, 0, 0, 0, NULL, NULL, 0}, 155 }; 156 157 struct explore { 158 int e_af; 159 int e_socktype; 160 int e_protocol; 161 int e_wild; 162 #define AF_ANY 0x01 163 #define SOCKTYPE_ANY 0x02 164 #define PROTOCOL_ANY 0x04 165 #define WILD_AF(ex) ((ex)->e_wild & AF_ANY) 166 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & SOCKTYPE_ANY) 167 #define WILD_PROTOCOL(ex) ((ex)->e_wild & PROTOCOL_ANY) 168 }; 169 170 static const struct explore explore[] = { 171 #ifdef INET6 172 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 173 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 174 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, 175 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 176 { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 177 AF_ANY | SOCKTYPE_ANY }, 178 { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 179 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 180 { PF_INET6, SOCK_DGRAM, IPPROTO_UDPLITE, 181 AF_ANY | SOCKTYPE_ANY }, 182 { PF_INET6, SOCK_RAW, ANY, 183 AF_ANY | PROTOCOL_ANY }, 184 #endif 185 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, 186 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 187 { PF_INET, SOCK_STREAM, IPPROTO_TCP, 188 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 189 { PF_INET, SOCK_STREAM, IPPROTO_SCTP, 190 AF_ANY | SOCKTYPE_ANY }, 191 { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 192 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 193 { PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE, 194 AF_ANY | SOCKTYPE_ANY }, 195 { PF_INET, SOCK_RAW, ANY, 196 AF_ANY | PROTOCOL_ANY }, 197 { PF_LOCAL, SOCK_DGRAM, ANY, 198 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 199 { PF_LOCAL, SOCK_STREAM, ANY, 200 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 201 { PF_LOCAL, SOCK_SEQPACKET, ANY, 202 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 203 { -1, 0, 0, 0 }, 204 }; 205 206 #ifdef INET6 207 #define PTON_MAX 16 208 #else 209 #define PTON_MAX 4 210 #endif 211 212 #define AIO_SRCFLAG_DEPRECATED 0x1 213 214 struct ai_order { 215 union { 216 struct sockaddr_storage aiou_ss; 217 struct sockaddr aiou_sa; 218 } aio_src_un; 219 #define aio_srcsa aio_src_un.aiou_sa 220 u_int32_t aio_srcflag; 221 int aio_srcscope; 222 int aio_dstscope; 223 struct policyqueue *aio_srcpolicy; 224 struct policyqueue *aio_dstpolicy; 225 struct addrinfo *aio_ai; 226 int aio_matchlen; 227 int aio_initial_sequence; 228 }; 229 230 static const ns_src default_dns_files[] = { 231 { NSSRC_FILES, NS_SUCCESS }, 232 { NSSRC_DNS, NS_SUCCESS }, 233 { 0 } 234 }; 235 236 struct res_target { 237 struct res_target *next; 238 const char *name; /* domain name */ 239 int qclass, qtype; /* class and type of query */ 240 u_char *answer; /* buffer to put answer */ 241 int anslen; /* size of answer buffer */ 242 int n; /* result length */ 243 }; 244 245 #define MAXPACKET (64*1024) 246 247 typedef union { 248 HEADER hdr; 249 u_char buf[MAXPACKET]; 250 } querybuf; 251 252 static int str2number(const char *, int *); 253 static int explore_copy(const struct addrinfo *, const struct addrinfo *, 254 struct addrinfo **); 255 static int explore_null(const struct addrinfo *, 256 const char *, struct addrinfo **); 257 static int explore_numeric(const struct addrinfo *, const char *, 258 const char *, struct addrinfo **, const char *); 259 static int explore_numeric_scope(const struct addrinfo *, const char *, 260 const char *, struct addrinfo **); 261 static int get_canonname(const struct addrinfo *, 262 struct addrinfo *, const char *); 263 static struct addrinfo *get_ai(const struct addrinfo *, 264 const struct afd *, const char *); 265 static struct addrinfo *copy_ai(const struct addrinfo *); 266 static int get_portmatch(const struct addrinfo *, const char *); 267 static int get_port(struct addrinfo *, const char *, int); 268 static const struct afd *find_afd(int); 269 static int addrconfig(struct addrinfo *); 270 #ifdef INET6 271 static int is_ifdisabled(char *); 272 #endif 273 static void set_source(struct ai_order *, struct policyhead *); 274 static int comp_dst(const void *, const void *); 275 #ifdef INET6 276 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 277 #endif 278 static int gai_addr2scopetype(struct sockaddr *); 279 280 static int explore_fqdn(const struct addrinfo *, const char *, 281 const char *, struct addrinfo **); 282 283 static int reorder(struct addrinfo *); 284 static int get_addrselectpolicy(struct policyhead *); 285 static void free_addrselectpolicy(struct policyhead *); 286 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 287 struct policyhead *); 288 static int matchlen(struct sockaddr *, struct sockaddr *); 289 290 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 291 const struct addrinfo *, res_state); 292 #if defined(RESOLVSORT) 293 static int addr4sort(struct addrinfo *, res_state); 294 #endif 295 static int _dns_getaddrinfo(void *, void *, va_list); 296 static void _sethtent(FILE **); 297 static void _endhtent(FILE **); 298 static struct addrinfo *_gethtent(FILE **, const char *, 299 const struct addrinfo *); 300 static int _files_getaddrinfo(void *, void *, va_list); 301 #ifdef YP 302 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 303 static int _yp_getaddrinfo(void *, void *, va_list); 304 #endif 305 #ifdef NS_CACHING 306 static int addrinfo_id_func(char *, size_t *, va_list, void *); 307 static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 308 static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 309 #endif 310 311 static int res_queryN(const char *, struct res_target *, res_state); 312 static int res_searchN(const char *, struct res_target *, res_state); 313 static int res_querydomainN(const char *, const char *, 314 struct res_target *, res_state); 315 316 /* XXX macros that make external reference is BAD. */ 317 318 #define GET_AI(ai, afd, addr) \ 319 do { \ 320 /* external reference: pai, error, and label free */ \ 321 (ai) = get_ai(pai, (afd), (addr)); \ 322 if ((ai) == NULL) { \ 323 error = EAI_MEMORY; \ 324 goto free; \ 325 } \ 326 } while (/*CONSTCOND*/0) 327 328 #define GET_PORT(ai, serv) \ 329 do { \ 330 /* external reference: error and label free */ \ 331 error = get_port((ai), (serv), 0); \ 332 if (error != 0) \ 333 goto free; \ 334 } while (/*CONSTCOND*/0) 335 336 #define GET_CANONNAME(ai, str) \ 337 do { \ 338 /* external reference: pai, error and label free */ \ 339 error = get_canonname(pai, (ai), (str)); \ 340 if (error != 0) \ 341 goto free; \ 342 } while (/*CONSTCOND*/0) 343 344 #define ERR(err) \ 345 do { \ 346 /* external reference: error, and label bad */ \ 347 error = (err); \ 348 goto bad; \ 349 /*NOTREACHED*/ \ 350 } while (/*CONSTCOND*/0) 351 352 #define MATCH_FAMILY(x, y, w) \ 353 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 354 #define MATCH(x, y, w) \ 355 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 356 357 void 358 freeaddrinfo(struct addrinfo *ai) 359 { 360 struct addrinfo *next; 361 362 while (ai != NULL) { 363 next = ai->ai_next; 364 free(ai->ai_canonname); 365 /* no need to free(ai->ai_addr) */ 366 free(ai); 367 ai = next; 368 } 369 } 370 371 static int 372 str2number(const char *p, int *portp) 373 { 374 char *ep; 375 unsigned long v; 376 377 if (*p == '\0') 378 return -1; 379 ep = NULL; 380 errno = 0; 381 v = strtoul(p, &ep, 10); 382 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 383 *portp = v; 384 return 0; 385 } else 386 return -1; 387 } 388 389 int 390 getaddrinfo(const char *hostname, const char *servname, 391 const struct addrinfo *hints, struct addrinfo **res) 392 { 393 struct addrinfo sentinel; 394 struct addrinfo *cur; 395 int error = 0; 396 struct addrinfo ai, ai0, *afai; 397 struct addrinfo *pai; 398 const struct afd *afd; 399 const struct explore *ex; 400 struct addrinfo *afailist[nitems(afdl)]; 401 struct addrinfo *afai_unspec; 402 int found; 403 int numeric = 0; 404 405 /* ensure we return NULL on errors */ 406 *res = NULL; 407 408 memset(&ai, 0, sizeof(ai)); 409 410 memset(afailist, 0, sizeof(afailist)); 411 afai_unspec = NULL; 412 413 memset(&sentinel, 0, sizeof(sentinel)); 414 cur = &sentinel; 415 pai = &ai; 416 pai->ai_flags = 0; 417 pai->ai_family = PF_UNSPEC; 418 pai->ai_socktype = ANY; 419 pai->ai_protocol = ANY; 420 pai->ai_addrlen = 0; 421 pai->ai_canonname = NULL; 422 pai->ai_addr = NULL; 423 pai->ai_next = NULL; 424 425 if (hostname == NULL && servname == NULL) 426 return EAI_NONAME; 427 if (hints) { 428 /* error check for hints */ 429 if (hints->ai_addrlen || hints->ai_canonname || 430 hints->ai_addr || hints->ai_next) 431 ERR(EAI_BADHINTS); /* xxx */ 432 if (hints->ai_flags & ~AI_MASK) 433 ERR(EAI_BADFLAGS); 434 switch (hints->ai_family) { 435 case PF_UNSPEC: 436 case PF_LOCAL: 437 case PF_INET: 438 #ifdef INET6 439 case PF_INET6: 440 #endif 441 break; 442 default: 443 ERR(EAI_FAMILY); 444 } 445 memcpy(pai, hints, sizeof(*pai)); 446 447 /* 448 * if both socktype/protocol are specified, check if they 449 * are meaningful combination. 450 */ 451 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 452 for (ex = explore; ex->e_af >= 0; ex++) { 453 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 454 WILD_AF(ex))) 455 continue; 456 if (!MATCH(pai->ai_socktype, ex->e_socktype, 457 WILD_SOCKTYPE(ex))) 458 continue; 459 if (!MATCH(pai->ai_protocol, ex->e_protocol, 460 WILD_PROTOCOL(ex))) 461 continue; 462 463 /* matched */ 464 break; 465 } 466 467 if (ex->e_af < 0) 468 ERR(EAI_BADHINTS); 469 } 470 } 471 472 /* 473 * RFC 3493: AI_ALL and AI_V4MAPPED are effective only against 474 * AF_INET6 query. They need to be ignored if specified in other 475 * occasions. 476 */ 477 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 478 case AI_V4MAPPED: 479 case AI_ALL | AI_V4MAPPED: 480 #ifdef INET6 481 if (pai->ai_family != AF_INET6) 482 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 483 break; 484 #endif 485 case AI_ALL: 486 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 487 break; 488 } 489 490 /* 491 * check for special cases. (1) numeric servname is disallowed if 492 * socktype/protocol are left unspecified. (2) servname is disallowed 493 * for raw and other inet{,6} sockets. 494 */ 495 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 496 #ifdef PF_INET6 497 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 498 #endif 499 ) { 500 ai0 = *pai; /* backup *pai */ 501 502 if (pai->ai_family == PF_UNSPEC) { 503 #ifdef PF_INET6 504 pai->ai_family = PF_INET6; 505 #else 506 pai->ai_family = PF_INET; 507 #endif 508 } 509 error = get_portmatch(pai, servname); 510 if (error) 511 goto bad; 512 513 *pai = ai0; 514 } 515 516 ai0 = *pai; 517 518 /* 519 * NULL hostname, or numeric hostname. 520 * If numeric representation of AF1 can be interpreted as FQDN 521 * representation of AF2, we need to think again about the code below. 522 */ 523 found = 0; 524 for (afd = afdl; afd->a_af; afd++) { 525 *pai = ai0; 526 527 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 528 continue; 529 530 if (pai->ai_family == PF_UNSPEC) 531 pai->ai_family = afd->a_af; 532 533 if (hostname == NULL) { 534 error = explore_null(pai, servname, 535 &afailist[afd - afdl]); 536 537 /* 538 * Errors from explore_null should be unexpected and 539 * be caught to avoid returning an incomplete result. 540 */ 541 if (error != 0) 542 goto bad; 543 } else { 544 error = explore_numeric_scope(pai, hostname, servname, 545 &afailist[afd - afdl]); 546 547 /* 548 * explore_numeric_scope returns an error for address 549 * families that do not match that of hostname. 550 * Thus we should not catch the error at this moment. 551 */ 552 } 553 554 if (!error && afailist[afd - afdl]) 555 found++; 556 } 557 if (found) { 558 numeric = 1; 559 goto globcopy; 560 } 561 562 if (hostname == NULL) 563 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 564 if (pai->ai_flags & AI_NUMERICHOST) 565 ERR(EAI_NONAME); 566 567 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 568 ERR(EAI_FAIL); 569 570 /* 571 * hostname as alphabetical name. 572 */ 573 *pai = ai0; 574 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 575 576 globcopy: 577 for (ex = explore; ex->e_af >= 0; ex++) { 578 *pai = ai0; 579 580 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 581 continue; 582 if (!MATCH(pai->ai_socktype, ex->e_socktype, 583 WILD_SOCKTYPE(ex))) 584 continue; 585 if (!MATCH(pai->ai_protocol, ex->e_protocol, 586 WILD_PROTOCOL(ex))) 587 continue; 588 589 if (pai->ai_family == PF_UNSPEC) 590 pai->ai_family = ex->e_af; 591 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 592 pai->ai_socktype = ex->e_socktype; 593 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 594 pai->ai_protocol = ex->e_protocol; 595 596 /* 597 * if the servname does not match socktype/protocol, ignore it. 598 */ 599 if (get_portmatch(pai, servname) != 0) 600 continue; 601 602 if (afai_unspec) 603 afai = afai_unspec; 604 else { 605 if ((afd = find_afd(pai->ai_family)) == NULL) 606 continue; 607 /* XXX assumes that afd points inside afdl[] */ 608 afai = afailist[afd - afdl]; 609 } 610 if (!afai) 611 continue; 612 613 error = explore_copy(pai, afai, &cur->ai_next); 614 if (error != 0) 615 goto bad; 616 617 while (cur && cur->ai_next) 618 cur = cur->ai_next; 619 } 620 621 /* 622 * ensure we return either: 623 * - error == 0, non-NULL *res 624 * - error != 0, NULL *res 625 */ 626 if (error == 0) { 627 if (sentinel.ai_next) { 628 /* 629 * If the returned entry is for an active connection, 630 * and the given name is not numeric, reorder the 631 * list, so that the application would try the list 632 * in the most efficient order. Since the head entry 633 * of the original list may contain ai_canonname and 634 * that entry may be moved elsewhere in the new list, 635 * we keep the pointer and will restore it in the new 636 * head entry. (Note that RFC3493 requires the head 637 * entry store it when requested by the caller). 638 */ 639 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 640 if (!numeric) { 641 char *canonname; 642 643 canonname = 644 sentinel.ai_next->ai_canonname; 645 sentinel.ai_next->ai_canonname = NULL; 646 (void)reorder(&sentinel); 647 if (sentinel.ai_next->ai_canonname == 648 NULL) { 649 sentinel.ai_next->ai_canonname 650 = canonname; 651 } else if (canonname != NULL) 652 free(canonname); 653 } 654 } 655 *res = sentinel.ai_next; 656 } else 657 error = EAI_FAIL; 658 } 659 660 bad: 661 if (afai_unspec) 662 freeaddrinfo(afai_unspec); 663 for (afd = afdl; afd->a_af; afd++) { 664 if (afailist[afd - afdl]) 665 freeaddrinfo(afailist[afd - afdl]); 666 } 667 if (!*res) 668 if (sentinel.ai_next) 669 freeaddrinfo(sentinel.ai_next); 670 671 return (error); 672 } 673 674 static int 675 reorder(struct addrinfo *sentinel) 676 { 677 struct addrinfo *ai, **aip; 678 struct ai_order *aio; 679 int i, n; 680 struct policyhead policyhead; 681 682 /* count the number of addrinfo elements for sorting. */ 683 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 684 ; 685 686 /* 687 * If the number is small enough, we can skip the reordering process. 688 */ 689 if (n <= 1) 690 return(n); 691 692 /* allocate a temporary array for sort and initialization of it. */ 693 if ((aio = calloc(n, sizeof(*aio))) == NULL) 694 return(n); /* give up reordering */ 695 696 /* retrieve address selection policy from the kernel */ 697 TAILQ_INIT(&policyhead); 698 if (!get_addrselectpolicy(&policyhead)) { 699 /* no policy is installed into kernel, we don't sort. */ 700 free(aio); 701 return (n); 702 } 703 704 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 705 aio[i].aio_ai = ai; 706 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 707 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 708 &policyhead); 709 set_source(&aio[i], &policyhead); 710 aio[i].aio_initial_sequence = i; 711 } 712 713 /* perform sorting. */ 714 qsort(aio, n, sizeof(*aio), comp_dst); 715 716 /* reorder the addrinfo chain. */ 717 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 718 *aip = aio[i].aio_ai; 719 aip = &aio[i].aio_ai->ai_next; 720 } 721 *aip = NULL; 722 723 /* cleanup and return */ 724 free(aio); 725 free_addrselectpolicy(&policyhead); 726 return(n); 727 } 728 729 static int 730 get_addrselectpolicy(struct policyhead *head) 731 { 732 #ifdef INET6 733 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 734 size_t l; 735 char *buf; 736 struct in6_addrpolicy *pol, *ep; 737 738 if (sysctl(mib, nitems(mib), NULL, &l, NULL, 0) < 0) 739 return (0); 740 if (l == 0) 741 return (0); 742 if ((buf = malloc(l)) == NULL) 743 return (0); 744 if (sysctl(mib, nitems(mib), buf, &l, NULL, 0) < 0) { 745 free(buf); 746 return (0); 747 } 748 749 ep = (struct in6_addrpolicy *)(buf + l); 750 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 751 struct policyqueue *new; 752 753 if ((new = malloc(sizeof(*new))) == NULL) { 754 free_addrselectpolicy(head); /* make the list empty */ 755 break; 756 } 757 new->pc_policy = *pol; 758 TAILQ_INSERT_TAIL(head, new, pc_entry); 759 } 760 761 free(buf); 762 return (1); 763 #else 764 return (0); 765 #endif 766 } 767 768 static void 769 free_addrselectpolicy(struct policyhead *head) 770 { 771 struct policyqueue *ent, *nent; 772 773 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 774 nent = TAILQ_NEXT(ent, pc_entry); 775 TAILQ_REMOVE(head, ent, pc_entry); 776 free(ent); 777 } 778 } 779 780 static struct policyqueue * 781 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 782 { 783 #ifdef INET6 784 struct policyqueue *ent, *bestent = NULL; 785 struct in6_addrpolicy *pol; 786 int matchlen, bestmatchlen = -1; 787 u_char *mp, *ep, *k, *p, m; 788 struct sockaddr_in6 key; 789 790 switch(addr->sa_family) { 791 case AF_INET6: 792 key = *(struct sockaddr_in6 *)addr; 793 break; 794 case AF_INET: 795 /* convert the address into IPv4-mapped IPv6 address. */ 796 memset(&key, 0, sizeof(key)); 797 key.sin6_family = AF_INET6; 798 key.sin6_len = sizeof(key); 799 _map_v4v6_address( 800 (char *)&((struct sockaddr_in *)addr)->sin_addr, 801 (char *)&key.sin6_addr); 802 break; 803 default: 804 return(NULL); 805 } 806 807 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 808 pol = &ent->pc_policy; 809 matchlen = 0; 810 811 mp = (u_char *)&pol->addrmask.sin6_addr; 812 ep = mp + 16; /* XXX: scope field? */ 813 k = (u_char *)&key.sin6_addr; 814 p = (u_char *)&pol->addr.sin6_addr; 815 for (; mp < ep && *mp; mp++, k++, p++) { 816 m = *mp; 817 if ((*k & m) != *p) 818 goto next; /* not match */ 819 if (m == 0xff) /* short cut for a typical case */ 820 matchlen += 8; 821 else { 822 while (m >= 0x80) { 823 matchlen++; 824 m <<= 1; 825 } 826 } 827 } 828 829 /* matched. check if this is better than the current best. */ 830 if (matchlen > bestmatchlen) { 831 bestent = ent; 832 bestmatchlen = matchlen; 833 } 834 835 next: 836 continue; 837 } 838 839 return(bestent); 840 #else 841 return(NULL); 842 #endif 843 844 } 845 846 static void 847 set_source(struct ai_order *aio, struct policyhead *ph) 848 { 849 struct addrinfo ai = *aio->aio_ai; 850 struct sockaddr_storage ss; 851 socklen_t srclen; 852 int s; 853 854 /* set unspec ("no source is available"), just in case */ 855 aio->aio_srcsa.sa_family = AF_UNSPEC; 856 aio->aio_srcscope = -1; 857 858 switch(ai.ai_family) { 859 case AF_INET: 860 #ifdef INET6 861 case AF_INET6: 862 #endif 863 break; 864 default: /* ignore unsupported AFs explicitly */ 865 return; 866 } 867 868 /* XXX: make a dummy addrinfo to call connect() */ 869 ai.ai_socktype = SOCK_DGRAM; 870 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 871 ai.ai_next = NULL; 872 memset(&ss, 0, sizeof(ss)); 873 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 874 ai.ai_addr = (struct sockaddr *)&ss; 875 get_port(&ai, "1", 0); 876 877 /* open a socket to get the source address for the given dst */ 878 if ((s = _socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC, 879 ai.ai_protocol)) < 0) 880 return; /* give up */ 881 #ifdef INET6 882 if (ai.ai_family == AF_INET6) { 883 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ai.ai_addr; 884 int off = 0; 885 886 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 887 (void)_setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, 888 (char *)&off, sizeof(off)); 889 } 890 #endif 891 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 892 goto cleanup; 893 srclen = ai.ai_addrlen; 894 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 895 aio->aio_srcsa.sa_family = AF_UNSPEC; 896 goto cleanup; 897 } 898 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 899 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 900 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 901 #ifdef INET6 902 if (ai.ai_family == AF_INET6) { 903 struct in6_ifreq ifr6; 904 u_int32_t flags6; 905 906 memset(&ifr6, 0, sizeof(ifr6)); 907 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 908 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 909 flags6 = ifr6.ifr_ifru.ifru_flags6; 910 if ((flags6 & IN6_IFF_DEPRECATED)) 911 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 912 } 913 } 914 #endif 915 916 cleanup: 917 _close(s); 918 return; 919 } 920 921 static int 922 matchlen(struct sockaddr *src, struct sockaddr *dst) 923 { 924 int match = 0; 925 u_char *s, *d; 926 u_char *lim, r; 927 int addrlen; 928 929 switch (src->sa_family) { 930 #ifdef INET6 931 case AF_INET6: 932 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 933 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 934 addrlen = sizeof(struct in6_addr); 935 lim = s + addrlen; 936 break; 937 #endif 938 case AF_INET: 939 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 940 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 941 addrlen = sizeof(struct in_addr); 942 lim = s + addrlen; 943 break; 944 default: 945 return(0); 946 } 947 948 while (s < lim) 949 if ((r = (*d++ ^ *s++)) != 0) { 950 while ((r & 0x80) == 0) { 951 match++; 952 r <<= 1; 953 } 954 break; 955 } else 956 match += 8; 957 return(match); 958 } 959 960 static int 961 comp_dst(const void *arg1, const void *arg2) 962 { 963 const struct ai_order *dst1 = arg1, *dst2 = arg2; 964 965 /* 966 * Rule 1: Avoid unusable destinations. 967 * XXX: we currently do not consider if an appropriate route exists. 968 */ 969 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 970 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 971 return(-1); 972 } 973 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 974 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 975 return(1); 976 } 977 978 /* Rule 2: Prefer matching scope. */ 979 if (dst1->aio_dstscope == dst1->aio_srcscope && 980 dst2->aio_dstscope != dst2->aio_srcscope) { 981 return(-1); 982 } 983 if (dst1->aio_dstscope != dst1->aio_srcscope && 984 dst2->aio_dstscope == dst2->aio_srcscope) { 985 return(1); 986 } 987 988 /* Rule 3: Avoid deprecated addresses. */ 989 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 990 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 991 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 992 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 993 return(-1); 994 } 995 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 996 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 997 return(1); 998 } 999 } 1000 1001 /* Rule 4: Prefer home addresses. */ 1002 /* XXX: not implemented yet */ 1003 1004 /* Rule 5: Prefer matching label. */ 1005 #ifdef INET6 1006 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 1007 dst1->aio_srcpolicy->pc_policy.label == 1008 dst1->aio_dstpolicy->pc_policy.label && 1009 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 1010 dst2->aio_srcpolicy->pc_policy.label != 1011 dst2->aio_dstpolicy->pc_policy.label)) { 1012 return(-1); 1013 } 1014 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 1015 dst2->aio_srcpolicy->pc_policy.label == 1016 dst2->aio_dstpolicy->pc_policy.label && 1017 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 1018 dst1->aio_srcpolicy->pc_policy.label != 1019 dst1->aio_dstpolicy->pc_policy.label)) { 1020 return(1); 1021 } 1022 #endif 1023 1024 /* Rule 6: Prefer higher precedence. */ 1025 #ifdef INET6 1026 if (dst1->aio_dstpolicy && 1027 (dst2->aio_dstpolicy == NULL || 1028 dst1->aio_dstpolicy->pc_policy.preced > 1029 dst2->aio_dstpolicy->pc_policy.preced)) { 1030 return(-1); 1031 } 1032 if (dst2->aio_dstpolicy && 1033 (dst1->aio_dstpolicy == NULL || 1034 dst2->aio_dstpolicy->pc_policy.preced > 1035 dst1->aio_dstpolicy->pc_policy.preced)) { 1036 return(1); 1037 } 1038 #endif 1039 1040 /* Rule 7: Prefer native transport. */ 1041 /* XXX: not implemented yet */ 1042 1043 /* Rule 8: Prefer smaller scope. */ 1044 if (dst1->aio_dstscope >= 0 && 1045 dst1->aio_dstscope < dst2->aio_dstscope) { 1046 return(-1); 1047 } 1048 if (dst2->aio_dstscope >= 0 && 1049 dst2->aio_dstscope < dst1->aio_dstscope) { 1050 return(1); 1051 } 1052 1053 /* 1054 * Rule 9: Use longest matching prefix. 1055 * We compare the match length in a same AF only. 1056 */ 1057 if (dst1->aio_ai->ai_addr->sa_family == 1058 dst2->aio_ai->ai_addr->sa_family && 1059 dst1->aio_ai->ai_addr->sa_family != AF_INET) { 1060 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1061 return(-1); 1062 } 1063 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1064 return(1); 1065 } 1066 } 1067 1068 /* Rule 10: Otherwise, leave the order unchanged. */ 1069 1070 /* 1071 * Note that qsort is unstable; so, we can't return zero and 1072 * expect the order to be unchanged. 1073 * That also means we can't depend on the current position of 1074 * dst2 being after dst1. We must enforce the initial order 1075 * with an explicit compare on the original position. 1076 * The qsort specification requires that "When the same objects 1077 * (consisting of width bytes, irrespective of their current 1078 * positions in the array) are passed more than once to the 1079 * comparison function, the results shall be consistent with one 1080 * another." 1081 * In other words, If A < B, then we must also return B > A. 1082 */ 1083 if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) 1084 return(1); 1085 1086 return(-1); 1087 } 1088 1089 /* 1090 * Copy from scope.c. 1091 * XXX: we should standardize the functions and link them as standard 1092 * library. 1093 */ 1094 static int 1095 gai_addr2scopetype(struct sockaddr *sa) 1096 { 1097 #ifdef INET6 1098 struct sockaddr_in6 *sa6; 1099 #endif 1100 struct sockaddr_in *sa4; 1101 1102 switch(sa->sa_family) { 1103 #ifdef INET6 1104 case AF_INET6: 1105 sa6 = (struct sockaddr_in6 *)sa; 1106 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1107 /* just use the scope field of the multicast address */ 1108 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1109 } 1110 /* 1111 * Unicast addresses: map scope type to corresponding scope 1112 * value defined for multcast addresses. 1113 * XXX: hardcoded scope type values are bad... 1114 */ 1115 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1116 return(1); /* node local scope */ 1117 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1118 return(2); /* link-local scope */ 1119 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1120 return(5); /* site-local scope */ 1121 return(14); /* global scope */ 1122 break; 1123 #endif 1124 case AF_INET: 1125 /* 1126 * IPv4 pseudo scoping according to RFC 3484. 1127 */ 1128 sa4 = (struct sockaddr_in *)sa; 1129 /* IPv4 autoconfiguration addresses have link-local scope. */ 1130 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1131 ((u_char *)&sa4->sin_addr)[1] == 254) 1132 return(2); 1133 /* Private addresses have site-local scope. */ 1134 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1135 (((u_char *)&sa4->sin_addr)[0] == 172 && 1136 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1137 (((u_char *)&sa4->sin_addr)[0] == 192 && 1138 ((u_char *)&sa4->sin_addr)[1] == 168)) 1139 return(14); /* XXX: It should be 5 unless NAT */ 1140 /* Loopback addresses have link-local scope. */ 1141 if (((u_char *)&sa4->sin_addr)[0] == 127) 1142 return(2); 1143 return(14); 1144 break; 1145 default: 1146 errno = EAFNOSUPPORT; /* is this a good error? */ 1147 return(-1); 1148 } 1149 } 1150 1151 static int 1152 explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1153 struct addrinfo **res) 1154 { 1155 int error; 1156 struct addrinfo sentinel, *cur; 1157 const struct addrinfo *src; 1158 1159 error = 0; 1160 sentinel.ai_next = NULL; 1161 cur = &sentinel; 1162 1163 for (src = src0; src != NULL; src = src->ai_next) { 1164 if (src->ai_family != pai->ai_family) 1165 continue; 1166 1167 cur->ai_next = copy_ai(src); 1168 if (!cur->ai_next) { 1169 error = EAI_MEMORY; 1170 goto fail; 1171 } 1172 1173 cur->ai_next->ai_socktype = pai->ai_socktype; 1174 cur->ai_next->ai_protocol = pai->ai_protocol; 1175 cur = cur->ai_next; 1176 } 1177 1178 *res = sentinel.ai_next; 1179 return 0; 1180 1181 fail: 1182 freeaddrinfo(sentinel.ai_next); 1183 return error; 1184 } 1185 1186 /* 1187 * hostname == NULL. 1188 * passive socket -> anyaddr (0.0.0.0 or ::) 1189 * non-passive socket -> localhost (127.0.0.1 or ::1) 1190 */ 1191 static int 1192 explore_null(const struct addrinfo *pai, const char *servname, 1193 struct addrinfo **res) 1194 { 1195 int s; 1196 const struct afd *afd; 1197 struct addrinfo *ai; 1198 int error; 1199 1200 *res = NULL; 1201 ai = NULL; 1202 1203 if (pai->ai_family == PF_LOCAL) 1204 return (0); 1205 1206 /* 1207 * filter out AFs that are not supported by the kernel 1208 * XXX errno? 1209 */ 1210 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1211 if (s < 0) { 1212 if (errno != EMFILE) 1213 return 0; 1214 } else 1215 _close(s); 1216 1217 afd = find_afd(pai->ai_family); 1218 if (afd == NULL) 1219 return 0; 1220 1221 if (pai->ai_flags & AI_PASSIVE) { 1222 GET_AI(ai, afd, afd->a_addrany); 1223 GET_PORT(ai, servname); 1224 } else { 1225 GET_AI(ai, afd, afd->a_loopback); 1226 GET_PORT(ai, servname); 1227 } 1228 1229 *res = ai; 1230 return 0; 1231 1232 free: 1233 if (ai != NULL) 1234 freeaddrinfo(ai); 1235 return error; 1236 } 1237 1238 /* 1239 * numeric hostname 1240 */ 1241 static int 1242 explore_numeric(const struct addrinfo *pai, const char *hostname, 1243 const char *servname, struct addrinfo **res, const char *canonname) 1244 { 1245 const struct afd *afd; 1246 struct addrinfo *ai, ai0; 1247 int error; 1248 char pton[PTON_MAX], path[PATH_MAX], *p; 1249 1250 #ifdef CTASSERT 1251 CTASSERT(sizeofmember(struct sockaddr_un, sun_path) <= PATH_MAX); 1252 #endif 1253 *res = NULL; 1254 ai = NULL; 1255 1256 afd = find_afd(pai->ai_family); 1257 if (afd == NULL) 1258 return 0; 1259 1260 switch (afd->a_af) { 1261 case AF_LOCAL: 1262 if (hostname[0] != '/') 1263 ERR(EAI_NONAME); 1264 if (strlen(hostname) > afd->a_addrlen) 1265 ERR(EAI_MEMORY); 1266 /* NUL-termination does not need to be guaranteed. */ 1267 strncpy(path, hostname, afd->a_addrlen); 1268 p = &path[0]; 1269 break; 1270 case AF_INET: 1271 /* 1272 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1273 * that are accepted by inet_addr() and its family. The 1274 * accepted forms includes the "classful" one, which inet_pton 1275 * does not accept. So we need to separate the case for 1276 * AF_INET. 1277 */ 1278 if (inet_aton(hostname, (struct in_addr *)pton) != 1 || 1279 hostname[strspn(hostname, "0123456789.xabcdefXABCDEF")] != '\0') 1280 return 0; 1281 p = pton; 1282 break; 1283 default: 1284 if (inet_pton(afd->a_af, hostname, pton) != 1) { 1285 if (pai->ai_family != AF_INET6 || 1286 (pai->ai_flags & AI_V4MAPPED) != AI_V4MAPPED) 1287 return 0; 1288 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1289 return 0; 1290 afd = &afdl[N_INET]; 1291 ai0 = *pai; 1292 ai0.ai_family = AF_INET; 1293 pai = &ai0; 1294 } 1295 p = pton; 1296 break; 1297 } 1298 1299 if (pai->ai_family == afd->a_af) { 1300 GET_AI(ai, afd, p); 1301 GET_PORT(ai, servname); 1302 if ((pai->ai_family == AF_INET || 1303 pai->ai_family == AF_INET6) && 1304 (pai->ai_flags & AI_CANONNAME)) { 1305 /* 1306 * Set the numeric address itself as the canonical 1307 * name, based on a clarification in RFC3493. 1308 */ 1309 GET_CANONNAME(ai, canonname); 1310 } 1311 } else { 1312 /* 1313 * XXX: This should not happen since we already matched the AF 1314 * by find_afd. 1315 */ 1316 ERR(EAI_FAMILY); 1317 } 1318 1319 *res = ai; 1320 return 0; 1321 1322 free: 1323 bad: 1324 if (ai != NULL) 1325 freeaddrinfo(ai); 1326 return error; 1327 } 1328 1329 /* 1330 * numeric hostname with scope 1331 */ 1332 static int 1333 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1334 const char *servname, struct addrinfo **res) 1335 { 1336 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 1337 return explore_numeric(pai, hostname, servname, res, hostname); 1338 #else 1339 const struct afd *afd; 1340 struct addrinfo *cur; 1341 int error; 1342 char *cp, *hostname2 = NULL, *scope, *addr; 1343 struct sockaddr_in6 *sin6; 1344 1345 afd = find_afd(pai->ai_family); 1346 if (afd == NULL) 1347 return 0; 1348 1349 if (!afd->a_scoped) 1350 return explore_numeric(pai, hostname, servname, res, hostname); 1351 1352 cp = strchr(hostname, SCOPE_DELIMITER); 1353 if (cp == NULL) 1354 return explore_numeric(pai, hostname, servname, res, hostname); 1355 1356 /* 1357 * Handle special case of <scoped_address><delimiter><scope id> 1358 */ 1359 hostname2 = strdup(hostname); 1360 if (hostname2 == NULL) 1361 return EAI_MEMORY; 1362 /* terminate at the delimiter */ 1363 hostname2[cp - hostname] = '\0'; 1364 addr = hostname2; 1365 scope = cp + 1; 1366 1367 error = explore_numeric(pai, addr, servname, res, hostname); 1368 if (error == 0) { 1369 u_int32_t scopeid; 1370 1371 for (cur = *res; cur; cur = cur->ai_next) { 1372 if (cur->ai_family != AF_INET6) 1373 continue; 1374 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1375 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1376 free(hostname2); 1377 freeaddrinfo(*res); 1378 *res = NULL; 1379 return(EAI_NONAME); /* XXX: is return OK? */ 1380 } 1381 sin6->sin6_scope_id = scopeid; 1382 } 1383 } 1384 1385 free(hostname2); 1386 1387 if (error && *res) { 1388 freeaddrinfo(*res); 1389 *res = NULL; 1390 } 1391 return error; 1392 #endif 1393 } 1394 1395 static int 1396 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1397 { 1398 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1399 ai->ai_canonname = strdup(str); 1400 if (ai->ai_canonname == NULL) 1401 return EAI_MEMORY; 1402 } 1403 return 0; 1404 } 1405 1406 static struct addrinfo * 1407 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1408 { 1409 char *p; 1410 struct addrinfo *ai; 1411 #ifdef INET6 1412 struct in6_addr mapaddr; 1413 1414 if (afd->a_af == AF_INET && (pai->ai_flags & AI_V4MAPPED) != 0) { 1415 afd = &afdl[N_INET6]; 1416 _map_v4v6_address(addr, (char *)&mapaddr); 1417 addr = (char *)&mapaddr; 1418 } 1419 #endif 1420 1421 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1422 + (afd->a_socklen)); 1423 if (ai == NULL) 1424 return NULL; 1425 1426 memcpy(ai, pai, sizeof(struct addrinfo)); 1427 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1428 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1429 ai->ai_addr->sa_len = afd->a_socklen; 1430 ai->ai_addrlen = afd->a_socklen; 1431 if (ai->ai_family == PF_LOCAL) { 1432 size_t n = strnlen(addr, afd->a_addrlen); 1433 1434 ai->ai_addrlen -= afd->a_addrlen - n; 1435 ai->ai_addr->sa_len -= afd->a_addrlen - n; 1436 } 1437 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1438 p = (char *)(void *)(ai->ai_addr); 1439 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1440 return ai; 1441 } 1442 1443 /* XXX need to malloc() the same way we do from other functions! */ 1444 static struct addrinfo * 1445 copy_ai(const struct addrinfo *pai) 1446 { 1447 struct addrinfo *ai; 1448 size_t l; 1449 1450 l = sizeof(*ai) + pai->ai_addrlen; 1451 if ((ai = calloc(1, l)) == NULL) 1452 return NULL; 1453 memcpy(ai, pai, sizeof(*ai)); 1454 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1455 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1456 1457 if (pai->ai_canonname) { 1458 l = strlen(pai->ai_canonname) + 1; 1459 if ((ai->ai_canonname = malloc(l)) == NULL) { 1460 free(ai); 1461 return NULL; 1462 } 1463 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1464 } else { 1465 /* just to make sure */ 1466 ai->ai_canonname = NULL; 1467 } 1468 1469 ai->ai_next = NULL; 1470 1471 return ai; 1472 } 1473 1474 static int 1475 get_portmatch(const struct addrinfo *ai, const char *servname) 1476 { 1477 1478 /* get_port does not touch first argument when matchonly == 1. */ 1479 /* LINTED const cast */ 1480 return get_port((struct addrinfo *)ai, servname, 1); 1481 } 1482 1483 static int 1484 get_port(struct addrinfo *ai, const char *servname, int matchonly) 1485 { 1486 const char *proto; 1487 struct servent *sp; 1488 int port, error; 1489 int allownumeric; 1490 1491 if (servname == NULL) 1492 return 0; 1493 switch (ai->ai_family) { 1494 case AF_LOCAL: 1495 /* AF_LOCAL ignores servname silently. */ 1496 return (0); 1497 case AF_INET: 1498 #ifdef AF_INET6 1499 case AF_INET6: 1500 #endif 1501 break; 1502 default: 1503 return 0; 1504 } 1505 1506 switch (ai->ai_socktype) { 1507 case SOCK_RAW: 1508 return EAI_SERVICE; 1509 case SOCK_DGRAM: 1510 case SOCK_STREAM: 1511 case SOCK_SEQPACKET: 1512 allownumeric = 1; 1513 break; 1514 case ANY: 1515 switch (ai->ai_family) { 1516 case AF_INET: 1517 #ifdef AF_INET6 1518 case AF_INET6: 1519 #endif 1520 allownumeric = 1; 1521 break; 1522 default: 1523 allownumeric = 0; 1524 break; 1525 } 1526 break; 1527 default: 1528 return EAI_SOCKTYPE; 1529 } 1530 1531 error = str2number(servname, &port); 1532 if (error == 0) { 1533 if (!allownumeric) 1534 return EAI_SERVICE; 1535 if (port < 0 || port > 65535) 1536 return EAI_SERVICE; 1537 port = htons(port); 1538 } else { 1539 if (ai->ai_flags & AI_NUMERICSERV) 1540 return EAI_NONAME; 1541 1542 switch (ai->ai_protocol) { 1543 case IPPROTO_UDP: 1544 proto = "udp"; 1545 break; 1546 case IPPROTO_TCP: 1547 proto = "tcp"; 1548 break; 1549 case IPPROTO_SCTP: 1550 proto = "sctp"; 1551 break; 1552 case IPPROTO_UDPLITE: 1553 proto = "udplite"; 1554 break; 1555 default: 1556 proto = NULL; 1557 break; 1558 } 1559 1560 if ((sp = getservbyname(servname, proto)) == NULL) 1561 return EAI_SERVICE; 1562 port = sp->s_port; 1563 } 1564 1565 if (!matchonly) { 1566 switch (ai->ai_family) { 1567 case AF_INET: 1568 ((struct sockaddr_in *)(void *) 1569 ai->ai_addr)->sin_port = port; 1570 break; 1571 #ifdef INET6 1572 case AF_INET6: 1573 ((struct sockaddr_in6 *)(void *) 1574 ai->ai_addr)->sin6_port = port; 1575 break; 1576 #endif 1577 } 1578 } 1579 1580 return 0; 1581 } 1582 1583 static const struct afd * 1584 find_afd(int af) 1585 { 1586 const struct afd *afd; 1587 1588 if (af == PF_UNSPEC) 1589 return NULL; 1590 for (afd = afdl; afd->a_af; afd++) { 1591 if (afd->a_af == af) 1592 return afd; 1593 } 1594 return NULL; 1595 } 1596 1597 /* 1598 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are 1599 * configured on the local system and correlates with pai->ai_family value. 1600 * If an address family is not configured on the system, it will not be 1601 * queried for. For this purpose, loopback addresses are not considered 1602 * configured addresses. 1603 * 1604 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1605 * _dns_getaddrinfo. 1606 */ 1607 static int 1608 addrconfig(struct addrinfo *pai) 1609 { 1610 struct ifaddrs *ifaddrs, *ifa; 1611 struct sockaddr_in *sin; 1612 #ifdef INET6 1613 struct sockaddr_in6 *sin6; 1614 #endif 1615 int seen_inet = 0, seen_inet6 = 0; 1616 1617 if (getifaddrs(&ifaddrs) != 0) 1618 return (0); 1619 1620 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1621 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1622 continue; 1623 switch (ifa->ifa_addr->sa_family) { 1624 case AF_INET: 1625 if (seen_inet) 1626 continue; 1627 sin = (struct sockaddr_in *)(ifa->ifa_addr); 1628 if (htonl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) 1629 continue; 1630 seen_inet = 1; 1631 break; 1632 #ifdef INET6 1633 case AF_INET6: 1634 if (seen_inet6) 1635 continue; 1636 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); 1637 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 1638 continue; 1639 if ((ifa->ifa_flags & IFT_LOOP) != 0 && 1640 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 1641 continue; 1642 if (is_ifdisabled(ifa->ifa_name)) 1643 continue; 1644 seen_inet6 = 1; 1645 break; 1646 #endif 1647 } 1648 } 1649 freeifaddrs(ifaddrs); 1650 1651 switch(pai->ai_family) { 1652 case AF_INET6: 1653 return (seen_inet6); 1654 case AF_INET: 1655 return (seen_inet); 1656 case AF_UNSPEC: 1657 if (seen_inet == seen_inet6) 1658 return (seen_inet); 1659 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1660 return (1); 1661 } 1662 return (1); 1663 } 1664 1665 #ifdef INET6 1666 static int 1667 is_ifdisabled(char *name) 1668 { 1669 struct in6_ndireq nd; 1670 int fd; 1671 1672 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1673 return (-1); 1674 memset(&nd, 0, sizeof(nd)); 1675 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1676 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1677 _close(fd); 1678 return (-1); 1679 } 1680 _close(fd); 1681 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1682 } 1683 1684 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1685 static int 1686 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1687 { 1688 u_long lscopeid; 1689 struct in6_addr *a6; 1690 char *ep; 1691 1692 a6 = &sin6->sin6_addr; 1693 1694 /* empty scopeid portion is invalid */ 1695 if (*scope == '\0') 1696 return -1; 1697 1698 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1699 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1700 /* 1701 * We currently assume a one-to-one mapping between links 1702 * and interfaces, so we simply use interface indices for 1703 * like-local scopes. 1704 */ 1705 *scopeid = if_nametoindex(scope); 1706 if (*scopeid == 0) 1707 goto trynumeric; 1708 return 0; 1709 } 1710 1711 /* still unclear about literal, allow numeric only - placeholder */ 1712 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1713 goto trynumeric; 1714 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1715 goto trynumeric; 1716 else 1717 goto trynumeric; /* global */ 1718 1719 /* try to convert to a numeric id as a last resort */ 1720 trynumeric: 1721 errno = 0; 1722 lscopeid = strtoul(scope, &ep, 10); 1723 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1724 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1725 return 0; 1726 else 1727 return -1; 1728 } 1729 #endif 1730 1731 1732 #ifdef NS_CACHING 1733 static int 1734 addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1735 void *cache_mdata) 1736 { 1737 res_state statp; 1738 u_long res_options; 1739 1740 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1741 char *hostname; 1742 struct addrinfo *hints; 1743 1744 char *p; 1745 int ai_flags, ai_family, ai_socktype, ai_protocol; 1746 size_t desired_size, size; 1747 1748 statp = __res_state(); 1749 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1750 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1751 1752 hostname = va_arg(ap, char *); 1753 hints = va_arg(ap, struct addrinfo *); 1754 1755 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1756 if (hostname != NULL) { 1757 size = strlen(hostname); 1758 desired_size += size + 1; 1759 } else 1760 size = 0; 1761 1762 if (desired_size > *buffer_size) { 1763 *buffer_size = desired_size; 1764 return (NS_RETURN); 1765 } 1766 1767 if (hints == NULL) 1768 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1769 else { 1770 ai_flags = hints->ai_flags; 1771 ai_family = hints->ai_family; 1772 ai_socktype = hints->ai_socktype; 1773 ai_protocol = hints->ai_protocol; 1774 } 1775 1776 p = buffer; 1777 memcpy(p, &res_options, sizeof(res_options)); 1778 p += sizeof(res_options); 1779 1780 memcpy(p, &op_id, sizeof(int)); 1781 p += sizeof(int); 1782 1783 memcpy(p, &ai_flags, sizeof(int)); 1784 p += sizeof(int); 1785 1786 memcpy(p, &ai_family, sizeof(int)); 1787 p += sizeof(int); 1788 1789 memcpy(p, &ai_socktype, sizeof(int)); 1790 p += sizeof(int); 1791 1792 memcpy(p, &ai_protocol, sizeof(int)); 1793 p += sizeof(int); 1794 1795 if (hostname != NULL) 1796 memcpy(p, hostname, size); 1797 1798 *buffer_size = desired_size; 1799 return (NS_SUCCESS); 1800 } 1801 1802 static int 1803 addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1804 va_list ap, void *cache_mdata) 1805 { 1806 struct addrinfo *ai, *cai; 1807 char *p; 1808 size_t desired_size, size, ai_size; 1809 1810 ai = *((struct addrinfo **)retval); 1811 1812 desired_size = sizeof(size_t); 1813 ai_size = 0; 1814 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1815 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1816 if (cai->ai_canonname != NULL) 1817 desired_size += sizeof(size_t) + 1818 strlen(cai->ai_canonname); 1819 ++ai_size; 1820 } 1821 1822 if (desired_size > *buffer_size) { 1823 /* this assignment is here for future use */ 1824 errno = ERANGE; 1825 *buffer_size = desired_size; 1826 return (NS_RETURN); 1827 } 1828 1829 memset(buffer, 0, desired_size); 1830 p = buffer; 1831 1832 memcpy(p, &ai_size, sizeof(size_t)); 1833 p += sizeof(size_t); 1834 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1835 memcpy(p, cai, sizeof(struct addrinfo)); 1836 p += sizeof(struct addrinfo); 1837 1838 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1839 p += cai->ai_addrlen; 1840 1841 if (cai->ai_canonname != NULL) { 1842 size = strlen(cai->ai_canonname); 1843 memcpy(p, &size, sizeof(size_t)); 1844 p += sizeof(size_t); 1845 1846 memcpy(p, cai->ai_canonname, size); 1847 p += size; 1848 } 1849 } 1850 1851 return (NS_SUCCESS); 1852 } 1853 1854 static int 1855 addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1856 va_list ap, void *cache_mdata) 1857 { 1858 struct addrinfo new_ai, *result, *sentinel, *lasts; 1859 1860 char *p; 1861 size_t ai_size, ai_i, size; 1862 1863 p = buffer; 1864 memcpy(&ai_size, p, sizeof(size_t)); 1865 p += sizeof(size_t); 1866 1867 result = NULL; 1868 lasts = NULL; 1869 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1870 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1871 p += sizeof(struct addrinfo); 1872 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1873 _ALIGNBYTES; 1874 1875 sentinel = calloc(1, size); 1876 1877 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1878 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1879 sizeof(struct addrinfo)); 1880 1881 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1882 p += new_ai.ai_addrlen; 1883 1884 if (new_ai.ai_canonname != NULL) { 1885 memcpy(&size, p, sizeof(size_t)); 1886 p += sizeof(size_t); 1887 1888 sentinel->ai_canonname = calloc(1, size + 1); 1889 1890 memcpy(sentinel->ai_canonname, p, size); 1891 p += size; 1892 } 1893 1894 if (result == NULL) { 1895 result = sentinel; 1896 lasts = sentinel; 1897 } else { 1898 lasts->ai_next = sentinel; 1899 lasts = sentinel; 1900 } 1901 } 1902 1903 *((struct addrinfo **)retval) = result; 1904 return (NS_SUCCESS); 1905 } 1906 #endif /* NS_CACHING */ 1907 1908 /* 1909 * FQDN hostname, DNS lookup 1910 */ 1911 static int 1912 explore_fqdn(const struct addrinfo *pai, const char *hostname, 1913 const char *servname, struct addrinfo **res) 1914 { 1915 struct addrinfo *result; 1916 struct addrinfo *cur; 1917 int error = 0; 1918 1919 #ifdef NS_CACHING 1920 static const nss_cache_info cache_info = 1921 NS_COMMON_CACHE_INFO_INITIALIZER( 1922 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1923 addrinfo_unmarshal_func); 1924 #endif 1925 static const ns_dtab dtab[] = { 1926 NS_FILES_CB(_files_getaddrinfo, NULL) 1927 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1928 NS_NIS_CB(_yp_getaddrinfo, NULL) 1929 #ifdef NS_CACHING 1930 NS_CACHE_CB(&cache_info) 1931 #endif 1932 { 0 } 1933 }; 1934 1935 result = NULL; 1936 1937 /* 1938 * if the servname does not match socktype/protocol, ignore it. 1939 */ 1940 if (get_portmatch(pai, servname) != 0) 1941 return 0; 1942 1943 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1944 default_dns_files, hostname, pai)) { 1945 case NS_TRYAGAIN: 1946 error = EAI_AGAIN; 1947 goto free; 1948 case NS_UNAVAIL: 1949 error = EAI_FAIL; 1950 goto free; 1951 case NS_NOTFOUND: 1952 error = EAI_NONAME; 1953 goto free; 1954 case NS_ADDRFAMILY: 1955 error = EAI_ADDRFAMILY; 1956 goto free; 1957 case NS_SUCCESS: 1958 error = 0; 1959 for (cur = result; cur; cur = cur->ai_next) { 1960 GET_PORT(cur, servname); 1961 /* canonname should be filled already */ 1962 } 1963 break; 1964 } 1965 1966 *res = result; 1967 1968 return 0; 1969 1970 free: 1971 if (result) 1972 freeaddrinfo(result); 1973 return error; 1974 } 1975 1976 #ifdef DEBUG 1977 static const char AskedForGot[] = 1978 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1979 #endif 1980 1981 static struct addrinfo * 1982 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1983 const struct addrinfo *pai, res_state res) 1984 { 1985 struct addrinfo sentinel, *cur; 1986 struct addrinfo ai; 1987 const struct afd *afd; 1988 char *canonname; 1989 const HEADER *hp; 1990 const u_char *cp; 1991 int n; 1992 const u_char *eom; 1993 char *bp, *ep; 1994 int type, class, ancount, qdcount; 1995 int haveanswer, had_error; 1996 char tbuf[MAXDNAME]; 1997 int (*name_ok)(const char *); 1998 char hostbuf[8*1024]; 1999 2000 memset(&sentinel, 0, sizeof(sentinel)); 2001 cur = &sentinel; 2002 2003 canonname = NULL; 2004 eom = answer->buf + anslen; 2005 switch (qtype) { 2006 case T_A: 2007 case T_AAAA: 2008 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 2009 name_ok = res_hnok; 2010 break; 2011 default: 2012 return (NULL); /* XXX should be abort(); */ 2013 } 2014 /* 2015 * find first satisfactory answer 2016 */ 2017 hp = &answer->hdr; 2018 ancount = ntohs(hp->ancount); 2019 qdcount = ntohs(hp->qdcount); 2020 bp = hostbuf; 2021 ep = hostbuf + sizeof hostbuf; 2022 cp = answer->buf + HFIXEDSZ; 2023 if (qdcount != 1) { 2024 RES_SET_H_ERRNO(res, NO_RECOVERY); 2025 return (NULL); 2026 } 2027 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2028 if ((n < 0) || !(*name_ok)(bp)) { 2029 RES_SET_H_ERRNO(res, NO_RECOVERY); 2030 return (NULL); 2031 } 2032 cp += n + QFIXEDSZ; 2033 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 2034 /* res_send() has already verified that the query name is the 2035 * same as the one we sent; this just gets the expanded name 2036 * (i.e., with the succeeding search-domain tacked on). 2037 */ 2038 n = strlen(bp) + 1; /* for the \0 */ 2039 if (n >= MAXHOSTNAMELEN) { 2040 RES_SET_H_ERRNO(res, NO_RECOVERY); 2041 return (NULL); 2042 } 2043 canonname = bp; 2044 bp += n; 2045 /* The qname can be abbreviated, but h_name is now absolute. */ 2046 qname = canonname; 2047 } 2048 haveanswer = 0; 2049 had_error = 0; 2050 while (ancount-- > 0 && cp < eom && !had_error) { 2051 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2052 if ((n < 0) || !(*name_ok)(bp)) { 2053 had_error++; 2054 continue; 2055 } 2056 cp += n; /* name */ 2057 type = _getshort(cp); 2058 cp += INT16SZ; /* type */ 2059 class = _getshort(cp); 2060 cp += INT16SZ + INT32SZ; /* class, TTL */ 2061 n = _getshort(cp); 2062 cp += INT16SZ; /* len */ 2063 if (class != C_IN) { 2064 /* XXX - debug? syslog? */ 2065 cp += n; 2066 continue; /* XXX - had_error++ ? */ 2067 } 2068 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 2069 type == T_CNAME) { 2070 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 2071 if ((n < 0) || !(*name_ok)(tbuf)) { 2072 had_error++; 2073 continue; 2074 } 2075 cp += n; 2076 /* Get canonical name. */ 2077 n = strlen(tbuf) + 1; /* for the \0 */ 2078 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 2079 had_error++; 2080 continue; 2081 } 2082 strlcpy(bp, tbuf, ep - bp); 2083 canonname = bp; 2084 bp += n; 2085 continue; 2086 } 2087 if (qtype == T_ANY) { 2088 if (!(type == T_A || type == T_AAAA)) { 2089 cp += n; 2090 continue; 2091 } 2092 } else if (type != qtype) { 2093 #ifdef DEBUG 2094 if (type != T_KEY && type != T_SIG && 2095 type != T_DNAME && type != T_RRSIG) 2096 syslog(LOG_NOTICE|LOG_AUTH, 2097 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2098 qname, p_class(C_IN), p_type(qtype), 2099 p_type(type)); 2100 #endif 2101 cp += n; 2102 continue; /* XXX - had_error++ ? */ 2103 } 2104 switch (type) { 2105 case T_A: 2106 case T_AAAA: 2107 if (strcasecmp(canonname, bp) != 0) { 2108 #ifdef DEBUG 2109 syslog(LOG_NOTICE|LOG_AUTH, 2110 AskedForGot, canonname, bp); 2111 #endif 2112 cp += n; 2113 continue; /* XXX - had_error++ ? */ 2114 } 2115 if (type == T_A && n != INADDRSZ) { 2116 cp += n; 2117 continue; 2118 } 2119 if (type == T_AAAA && n != IN6ADDRSZ) { 2120 cp += n; 2121 continue; 2122 } 2123 #ifdef FILTER_V4MAPPED 2124 if (type == T_AAAA) { 2125 struct in6_addr in6; 2126 memcpy(&in6, cp, sizeof(in6)); 2127 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2128 cp += n; 2129 continue; 2130 } 2131 } 2132 #endif 2133 if (!haveanswer) { 2134 int nn; 2135 2136 canonname = bp; 2137 nn = strlen(bp) + 1; /* for the \0 */ 2138 bp += nn; 2139 } 2140 2141 /* don't overwrite pai */ 2142 ai = *pai; 2143 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2144 afd = find_afd(ai.ai_family); 2145 if (afd == NULL) { 2146 cp += n; 2147 continue; 2148 } 2149 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2150 if (cur->ai_next == NULL) 2151 had_error++; 2152 while (cur && cur->ai_next) 2153 cur = cur->ai_next; 2154 cp += n; 2155 break; 2156 default: 2157 abort(); 2158 } 2159 if (!had_error) 2160 haveanswer++; 2161 } 2162 if (haveanswer) { 2163 #if defined(RESOLVSORT) 2164 /* 2165 * We support only IPv4 address for backward 2166 * compatibility against gethostbyname(3). 2167 */ 2168 if (res->nsort && qtype == T_A) { 2169 if (addr4sort(&sentinel, res) < 0) { 2170 freeaddrinfo(sentinel.ai_next); 2171 RES_SET_H_ERRNO(res, NO_RECOVERY); 2172 return NULL; 2173 } 2174 } 2175 #endif /*RESOLVSORT*/ 2176 if (!canonname) 2177 (void)get_canonname(pai, sentinel.ai_next, qname); 2178 else 2179 (void)get_canonname(pai, sentinel.ai_next, canonname); 2180 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2181 return sentinel.ai_next; 2182 } 2183 2184 /* 2185 * We could have walked a CNAME chain, but the ultimate target 2186 * may not have what we looked for. 2187 */ 2188 RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : NO_RECOVERY); 2189 return NULL; 2190 } 2191 2192 #ifdef RESOLVSORT 2193 struct addr_ptr { 2194 struct addrinfo *ai; 2195 int aval; 2196 }; 2197 2198 static int 2199 addr4sort(struct addrinfo *sentinel, res_state res) 2200 { 2201 struct addrinfo *ai; 2202 struct addr_ptr *addrs, addr; 2203 struct sockaddr_in *sin; 2204 int naddrs, i, j; 2205 int needsort = 0; 2206 2207 if (!sentinel) 2208 return -1; 2209 naddrs = 0; 2210 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2211 naddrs++; 2212 if (naddrs < 2) 2213 return 0; /* We don't need sorting. */ 2214 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2215 return -1; 2216 i = 0; 2217 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2218 sin = (struct sockaddr_in *)ai->ai_addr; 2219 for (j = 0; (unsigned)j < res->nsort; j++) { 2220 if (res->sort_list[j].addr.s_addr == 2221 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2222 break; 2223 } 2224 addrs[i].ai = ai; 2225 addrs[i].aval = j; 2226 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2227 needsort = i; 2228 i++; 2229 } 2230 if (!needsort) { 2231 free(addrs); 2232 return 0; 2233 } 2234 2235 while (needsort < naddrs) { 2236 for (j = needsort - 1; j >= 0; j--) { 2237 if (addrs[j].aval > addrs[j+1].aval) { 2238 addr = addrs[j]; 2239 addrs[j] = addrs[j + 1]; 2240 addrs[j + 1] = addr; 2241 } else 2242 break; 2243 } 2244 needsort++; 2245 } 2246 2247 ai = sentinel; 2248 for (i = 0; i < naddrs; ++i) { 2249 ai->ai_next = addrs[i].ai; 2250 ai = ai->ai_next; 2251 } 2252 ai->ai_next = NULL; 2253 free(addrs); 2254 return 0; 2255 } 2256 #endif /*RESOLVSORT*/ 2257 2258 /*ARGSUSED*/ 2259 static int 2260 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2261 { 2262 struct addrinfo *ai, ai0; 2263 querybuf *buf, *buf2; 2264 const char *hostname; 2265 const struct addrinfo *pai; 2266 struct addrinfo sentinel, *cur; 2267 struct res_target q, q2; 2268 res_state res; 2269 2270 ai = NULL; 2271 2272 hostname = va_arg(ap, char *); 2273 pai = va_arg(ap, const struct addrinfo *); 2274 2275 memset(&q, 0, sizeof(q)); 2276 memset(&q2, 0, sizeof(q2)); 2277 memset(&sentinel, 0, sizeof(sentinel)); 2278 cur = &sentinel; 2279 2280 res = __res_state(); 2281 2282 buf = malloc(sizeof(*buf)); 2283 if (!buf) { 2284 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2285 return NS_NOTFOUND; 2286 } 2287 buf2 = malloc(sizeof(*buf2)); 2288 if (!buf2) { 2289 free(buf); 2290 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2291 return NS_NOTFOUND; 2292 } 2293 2294 if (pai->ai_family == AF_INET6 && 2295 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) { 2296 ai0 = *pai; 2297 ai0.ai_family = AF_UNSPEC; 2298 pai = &ai0; 2299 } 2300 2301 switch (pai->ai_family) { 2302 case AF_UNSPEC: 2303 q.name = hostname; 2304 q.qclass = C_IN; 2305 q.qtype = T_A; 2306 q.answer = buf->buf; 2307 q.anslen = sizeof(buf->buf); 2308 q.next = &q2; 2309 q2.name = hostname; 2310 q2.qclass = C_IN; 2311 q2.qtype = T_AAAA; 2312 q2.answer = buf2->buf; 2313 q2.anslen = sizeof(buf2->buf); 2314 break; 2315 case AF_INET: 2316 q.name = hostname; 2317 q.qclass = C_IN; 2318 q.qtype = T_A; 2319 q.answer = buf->buf; 2320 q.anslen = sizeof(buf->buf); 2321 break; 2322 case AF_INET6: 2323 q.name = hostname; 2324 q.qclass = C_IN; 2325 q.qtype = T_AAAA; 2326 q.answer = buf->buf; 2327 q.anslen = sizeof(buf->buf); 2328 break; 2329 default: 2330 free(buf); 2331 free(buf2); 2332 return NS_UNAVAIL; 2333 } 2334 2335 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2336 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2337 free(buf); 2338 free(buf2); 2339 return NS_NOTFOUND; 2340 } 2341 2342 if (res_searchN(hostname, &q, res) < 0) { 2343 free(buf); 2344 free(buf2); 2345 if (res->res_h_errno == NO_DATA) 2346 return (NS_ADDRFAMILY); 2347 return (NS_NOTFOUND); 2348 } 2349 /* prefer IPv6 */ 2350 if (q.next) { 2351 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2352 if (ai != NULL) { 2353 cur->ai_next = ai; 2354 while (cur && cur->ai_next) 2355 cur = cur->ai_next; 2356 } 2357 } 2358 if (ai == NULL || pai->ai_family != AF_UNSPEC || 2359 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) != AI_V4MAPPED) { 2360 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2361 if (ai != NULL) 2362 cur->ai_next = ai; 2363 } 2364 free(buf); 2365 free(buf2); 2366 if (sentinel.ai_next == NULL) 2367 switch (res->res_h_errno) { 2368 case HOST_NOT_FOUND: 2369 return (NS_NOTFOUND); 2370 case NO_DATA: 2371 return (NS_ADDRFAMILY); 2372 case TRY_AGAIN: 2373 return (NS_TRYAGAIN); 2374 default: 2375 return (NS_UNAVAIL); 2376 } 2377 *((struct addrinfo **)rv) = sentinel.ai_next; 2378 return (NS_SUCCESS); 2379 } 2380 2381 static void 2382 _sethtent(FILE **hostf) 2383 { 2384 if (!*hostf) 2385 *hostf = fopen(_PATH_HOSTS, "re"); 2386 else 2387 rewind(*hostf); 2388 } 2389 2390 static void 2391 _endhtent(FILE **hostf) 2392 { 2393 if (*hostf) { 2394 (void) fclose(*hostf); 2395 *hostf = NULL; 2396 } 2397 } 2398 2399 static struct addrinfo * 2400 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2401 { 2402 char *p; 2403 char *cp, *tname, *cname; 2404 struct addrinfo hints, *res0, *res; 2405 int error; 2406 const char *addr; 2407 char hostbuf[8*1024]; 2408 2409 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2410 return (NULL); 2411 again: 2412 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2413 return (NULL); 2414 if (*p == '#') 2415 goto again; 2416 cp = strpbrk(p, "#\n"); 2417 if (cp != NULL) 2418 *cp = '\0'; 2419 if (!(cp = strpbrk(p, " \t"))) 2420 goto again; 2421 *cp++ = '\0'; 2422 addr = p; 2423 cname = NULL; 2424 /* if this is not something we're looking for, skip it. */ 2425 while (cp && *cp) { 2426 if (*cp == ' ' || *cp == '\t') { 2427 cp++; 2428 continue; 2429 } 2430 tname = cp; 2431 if (cname == NULL) 2432 cname = cp; 2433 if ((cp = strpbrk(cp, " \t")) != NULL) 2434 *cp++ = '\0'; 2435 if (strcasecmp(name, tname) == 0) 2436 goto found; 2437 } 2438 goto again; 2439 2440 found: 2441 /* we should not glob socktype/protocol here */ 2442 memset(&hints, 0, sizeof(hints)); 2443 hints.ai_family = pai->ai_family; 2444 hints.ai_socktype = SOCK_DGRAM; 2445 hints.ai_protocol = 0; 2446 hints.ai_flags = AI_NUMERICHOST; 2447 if (pai->ai_family == AF_INET6 && 2448 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2449 hints.ai_flags |= AI_V4MAPPED; 2450 error = getaddrinfo(addr, "0", &hints, &res0); 2451 if (error) 2452 goto again; 2453 #ifdef FILTER_V4MAPPED 2454 /* XXX should check all items in the chain */ 2455 if (res0->ai_family == AF_INET6 && 2456 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2457 freeaddrinfo(res0); 2458 goto again; 2459 } 2460 #endif 2461 for (res = res0; res; res = res->ai_next) { 2462 /* cover it up */ 2463 res->ai_flags = pai->ai_flags; 2464 res->ai_socktype = pai->ai_socktype; 2465 res->ai_protocol = pai->ai_protocol; 2466 2467 if (pai->ai_flags & AI_CANONNAME) { 2468 if (get_canonname(pai, res, cname) != 0) { 2469 freeaddrinfo(res0); 2470 goto again; 2471 } 2472 } 2473 } 2474 return res0; 2475 } 2476 2477 static struct addrinfo * 2478 _getht(FILE **hostf, const char *name, const struct addrinfo *pai, 2479 struct addrinfo *cur) 2480 { 2481 struct addrinfo *p; 2482 2483 while ((p = _gethtent(hostf, name, pai)) != NULL) { 2484 cur->ai_next = p; 2485 while (cur && cur->ai_next) 2486 cur = cur->ai_next; 2487 } 2488 return (cur); 2489 } 2490 2491 /*ARGSUSED*/ 2492 static int 2493 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2494 { 2495 const char *name; 2496 const struct addrinfo *pai; 2497 struct addrinfo sentinel, *cur; 2498 FILE *hostf = NULL; 2499 2500 name = va_arg(ap, char *); 2501 pai = va_arg(ap, struct addrinfo *); 2502 2503 memset(&sentinel, 0, sizeof(sentinel)); 2504 cur = &sentinel; 2505 2506 _sethtent(&hostf); 2507 if (pai->ai_family == AF_INET6 && 2508 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) == AI_V4MAPPED) { 2509 struct addrinfo ai0 = *pai; 2510 2511 ai0.ai_flags &= ~AI_V4MAPPED; 2512 cur = _getht(&hostf, name, &ai0, cur); 2513 if (sentinel.ai_next == NULL) { 2514 _sethtent(&hostf); 2515 ai0.ai_flags |= AI_V4MAPPED; 2516 cur = _getht(&hostf, name, &ai0, cur); 2517 } 2518 } else 2519 cur = _getht(&hostf, name, pai, cur); 2520 _endhtent(&hostf); 2521 2522 *((struct addrinfo **)rv) = sentinel.ai_next; 2523 if (sentinel.ai_next == NULL) 2524 return NS_NOTFOUND; 2525 return NS_SUCCESS; 2526 } 2527 2528 #ifdef YP 2529 /*ARGSUSED*/ 2530 static struct addrinfo * 2531 _yphostent(char *line, const struct addrinfo *pai) 2532 { 2533 struct addrinfo sentinel, *cur; 2534 struct addrinfo hints, *res, *res0; 2535 int error; 2536 char *p = line; 2537 const char *addr, *canonname; 2538 char *nextline; 2539 char *cp; 2540 2541 addr = canonname = NULL; 2542 2543 memset(&sentinel, 0, sizeof(sentinel)); 2544 cur = &sentinel; 2545 2546 nextline: 2547 /* terminate line */ 2548 cp = strchr(p, '\n'); 2549 if (cp) { 2550 *cp++ = '\0'; 2551 nextline = cp; 2552 } else 2553 nextline = NULL; 2554 2555 cp = strpbrk(p, " \t"); 2556 if (cp == NULL) { 2557 if (canonname == NULL) 2558 return (NULL); 2559 else 2560 goto done; 2561 } 2562 *cp++ = '\0'; 2563 2564 addr = p; 2565 2566 while (cp && *cp) { 2567 if (*cp == ' ' || *cp == '\t') { 2568 cp++; 2569 continue; 2570 } 2571 if (!canonname) 2572 canonname = cp; 2573 if ((cp = strpbrk(cp, " \t")) != NULL) 2574 *cp++ = '\0'; 2575 } 2576 2577 hints = *pai; 2578 hints.ai_flags = AI_NUMERICHOST; 2579 if (pai->ai_family == AF_INET6 && 2580 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2581 hints.ai_flags |= AI_V4MAPPED; 2582 error = getaddrinfo(addr, NULL, &hints, &res0); 2583 if (error == 0) { 2584 for (res = res0; res; res = res->ai_next) { 2585 /* cover it up */ 2586 res->ai_flags = pai->ai_flags; 2587 2588 if (pai->ai_flags & AI_CANONNAME) 2589 (void)get_canonname(pai, res, canonname); 2590 } 2591 } else 2592 res0 = NULL; 2593 if (res0) { 2594 cur->ai_next = res0; 2595 while (cur && cur->ai_next) 2596 cur = cur->ai_next; 2597 } 2598 2599 if (nextline) { 2600 p = nextline; 2601 goto nextline; 2602 } 2603 2604 done: 2605 return sentinel.ai_next; 2606 } 2607 2608 /*ARGSUSED*/ 2609 static int 2610 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2611 { 2612 struct addrinfo sentinel, *cur; 2613 struct addrinfo *ai = NULL; 2614 char *ypbuf; 2615 int ypbuflen, r; 2616 const char *name; 2617 const struct addrinfo *pai; 2618 char *ypdomain; 2619 2620 if (_yp_check(&ypdomain) == 0) 2621 return NS_UNAVAIL; 2622 2623 name = va_arg(ap, char *); 2624 pai = va_arg(ap, const struct addrinfo *); 2625 2626 memset(&sentinel, 0, sizeof(sentinel)); 2627 cur = &sentinel; 2628 2629 /* ipnodes.byname can hold both IPv4/v6 */ 2630 r = yp_match(ypdomain, "ipnodes.byname", name, 2631 (int)strlen(name), &ypbuf, &ypbuflen); 2632 if (r == 0) { 2633 ai = _yphostent(ypbuf, pai); 2634 if (ai) { 2635 cur->ai_next = ai; 2636 while (cur && cur->ai_next) 2637 cur = cur->ai_next; 2638 } 2639 free(ypbuf); 2640 } 2641 2642 if (ai != NULL) { 2643 struct sockaddr_in6 *sin6; 2644 2645 switch (ai->ai_family) { 2646 case AF_INET: 2647 goto done; 2648 case AF_INET6: 2649 sin6 = (struct sockaddr_in6 *)ai->ai_addr; 2650 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 2651 goto done; 2652 break; 2653 } 2654 } 2655 2656 /* hosts.byname is only for IPv4 (Solaris8) */ 2657 if (pai->ai_family == AF_UNSPEC || pai->ai_family == AF_INET || 2658 ((pai->ai_family == AF_INET6 && 2659 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) && 2660 (ai == NULL || (pai->ai_flags & AI_ALL) == AI_ALL))) { 2661 r = yp_match(ypdomain, "hosts.byname", name, 2662 (int)strlen(name), &ypbuf, &ypbuflen); 2663 if (r == 0) { 2664 struct addrinfo ai4; 2665 2666 ai4 = *pai; 2667 if (pai->ai_family == AF_UNSPEC) 2668 ai4.ai_family = AF_INET; 2669 ai = _yphostent(ypbuf, &ai4); 2670 if (ai) { 2671 cur->ai_next = ai; 2672 while (cur && cur->ai_next) 2673 cur = cur->ai_next; 2674 } 2675 free(ypbuf); 2676 } 2677 } 2678 2679 done: 2680 if (sentinel.ai_next == NULL) { 2681 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2682 return NS_NOTFOUND; 2683 } 2684 *((struct addrinfo **)rv) = sentinel.ai_next; 2685 return NS_SUCCESS; 2686 } 2687 #endif 2688 2689 /* resolver logic */ 2690 2691 /* 2692 * Formulate a normal query, send, and await answer. 2693 * Returned answer is placed in supplied buffer "answer". 2694 * Perform preliminary check of answer, returning success only 2695 * if no error is indicated and the answer count is nonzero. 2696 * Return the size of the response on success, -1 on error. 2697 * Error number is left in h_errno. 2698 * 2699 * Caller must parse answer and determine whether it answers the question. 2700 */ 2701 static int 2702 res_queryN(const char *name, struct res_target *target, res_state res) 2703 { 2704 u_char *buf; 2705 HEADER *hp; 2706 int n; 2707 u_int oflags; 2708 struct res_target *t; 2709 int rcode; 2710 int ancount; 2711 2712 rcode = NOERROR; 2713 ancount = 0; 2714 2715 buf = malloc(MAXPACKET); 2716 if (!buf) { 2717 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2718 return -1; 2719 } 2720 2721 for (t = target; t; t = t->next) { 2722 int class, type; 2723 u_char *answer; 2724 int anslen; 2725 2726 hp = (HEADER *)(void *)t->answer; 2727 2728 /* make it easier... */ 2729 class = t->qclass; 2730 type = t->qtype; 2731 answer = t->answer; 2732 anslen = t->anslen; 2733 2734 oflags = res->_flags; 2735 2736 again: 2737 hp->rcode = NOERROR; /* default */ 2738 2739 #ifdef DEBUG 2740 if (res->options & RES_DEBUG) 2741 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2742 #endif 2743 2744 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2745 buf, MAXPACKET); 2746 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2747 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2748 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2749 if (n <= 0) { 2750 #ifdef DEBUG 2751 if (res->options & RES_DEBUG) 2752 printf(";; res_query: mkquery failed\n"); 2753 #endif 2754 free(buf); 2755 RES_SET_H_ERRNO(res, NO_RECOVERY); 2756 return (n); 2757 } 2758 n = res_nsend(res, buf, n, answer, anslen); 2759 if (n < 0) { 2760 /* 2761 * if the query choked with EDNS0, retry 2762 * without EDNS0 2763 */ 2764 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2765 != 0U && 2766 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2767 res->_flags |= RES_F_EDNS0ERR; 2768 if (res->options & RES_DEBUG) 2769 printf(";; res_nquery: retry without EDNS0\n"); 2770 goto again; 2771 } 2772 rcode = hp->rcode; /* record most recent error */ 2773 #ifdef DEBUG 2774 if (res->options & RES_DEBUG) 2775 printf(";; res_query: send error\n"); 2776 #endif 2777 continue; 2778 } 2779 2780 if (n > anslen) 2781 hp->rcode = FORMERR; /* XXX not very informative */ 2782 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2783 rcode = hp->rcode; /* record most recent error */ 2784 #ifdef DEBUG 2785 if (res->options & RES_DEBUG) 2786 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2787 ntohs(hp->ancount)); 2788 #endif 2789 continue; 2790 } 2791 2792 ancount += ntohs(hp->ancount); 2793 2794 t->n = n; 2795 } 2796 2797 free(buf); 2798 2799 if (ancount == 0) { 2800 switch (rcode) { 2801 case NXDOMAIN: 2802 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2803 break; 2804 case SERVFAIL: 2805 RES_SET_H_ERRNO(res, TRY_AGAIN); 2806 break; 2807 case NOERROR: 2808 RES_SET_H_ERRNO(res, NO_DATA); 2809 break; 2810 case FORMERR: 2811 case NOTIMP: 2812 case REFUSED: 2813 default: 2814 RES_SET_H_ERRNO(res, NO_RECOVERY); 2815 break; 2816 } 2817 return (-1); 2818 } 2819 return (ancount); 2820 } 2821 2822 /* 2823 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2824 * Return the size of the response on success, -1 on error. 2825 * If enabled, implement search rules until answer or unrecoverable failure 2826 * is detected. Error code, if any, is left in h_errno. 2827 */ 2828 static int 2829 res_searchN(const char *name, struct res_target *target, res_state res) 2830 { 2831 const char *cp, * const *domain; 2832 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2833 u_int dots; 2834 int trailing_dot, ret, saved_herrno; 2835 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2836 int tried_as_is = 0; 2837 int searched = 0; 2838 char abuf[MAXDNAME]; 2839 2840 errno = 0; 2841 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2842 dots = 0; 2843 for (cp = name; *cp; cp++) 2844 dots += (*cp == '.'); 2845 trailing_dot = 0; 2846 if (cp > name && *--cp == '.') 2847 trailing_dot++; 2848 2849 /* 2850 * if there aren't any dots, it could be a user-level alias 2851 */ 2852 if (!dots && 2853 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2854 return (res_queryN(cp, target, res)); 2855 2856 /* 2857 * If there are enough dots in the name, let's just give it a 2858 * try 'as is'. The threshold can be set with the "ndots" option. 2859 * Also, query 'as is', if there is a trailing dot in the name. 2860 */ 2861 saved_herrno = -1; 2862 if (dots >= res->ndots || trailing_dot) { 2863 ret = res_querydomainN(name, NULL, target, res); 2864 if (ret > 0 || trailing_dot) 2865 return (ret); 2866 if (errno == ECONNREFUSED) { 2867 RES_SET_H_ERRNO(res, TRY_AGAIN); 2868 return (-1); 2869 } 2870 switch (res->res_h_errno) { 2871 case NO_DATA: 2872 case HOST_NOT_FOUND: 2873 break; 2874 case TRY_AGAIN: 2875 if (hp->rcode == SERVFAIL) 2876 break; 2877 /* FALLTHROUGH */ 2878 default: 2879 return (-1); 2880 } 2881 saved_herrno = res->res_h_errno; 2882 tried_as_is++; 2883 } 2884 2885 /* 2886 * We do at least one level of search if 2887 * - there is no dot and RES_DEFNAME is set, or 2888 * - there is at least one dot, there is no trailing dot, 2889 * and RES_DNSRCH is set. 2890 */ 2891 if ((!dots && (res->options & RES_DEFNAMES)) || 2892 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2893 int done = 0; 2894 2895 for (domain = (const char * const *)res->dnsrch; 2896 *domain && !done; 2897 domain++) { 2898 searched = 1; 2899 2900 if (domain[0][0] == '\0' || 2901 (domain[0][0] == '.' && domain[0][1] == '\0')) 2902 root_on_list++; 2903 2904 if (root_on_list && tried_as_is) 2905 continue; 2906 2907 ret = res_querydomainN(name, *domain, target, res); 2908 if (ret > 0) 2909 return (ret); 2910 2911 /* 2912 * If no server present, give up. 2913 * If name isn't found in this domain, 2914 * keep trying higher domains in the search list 2915 * (if that's enabled). 2916 * On a NO_DATA error, keep trying, otherwise 2917 * a wildcard entry of another type could keep us 2918 * from finding this entry higher in the domain. 2919 * If we get some other error (negative answer or 2920 * server failure), then stop searching up, 2921 * but try the input name below in case it's 2922 * fully-qualified. 2923 */ 2924 if (errno == ECONNREFUSED) { 2925 RES_SET_H_ERRNO(res, TRY_AGAIN); 2926 return (-1); 2927 } 2928 2929 switch (res->res_h_errno) { 2930 case NO_DATA: 2931 got_nodata++; 2932 /* FALLTHROUGH */ 2933 case HOST_NOT_FOUND: 2934 /* keep trying */ 2935 break; 2936 case TRY_AGAIN: 2937 got_servfail++; 2938 if (hp->rcode == SERVFAIL) { 2939 /* try next search element, if any */ 2940 break; 2941 } 2942 /* FALLTHROUGH */ 2943 default: 2944 /* anything else implies that we're done */ 2945 done++; 2946 } 2947 /* 2948 * if we got here for some reason other than DNSRCH, 2949 * we only wanted one iteration of the loop, so stop. 2950 */ 2951 if (!(res->options & RES_DNSRCH)) 2952 done++; 2953 } 2954 } 2955 2956 switch (res->res_h_errno) { 2957 case NO_DATA: 2958 case HOST_NOT_FOUND: 2959 break; 2960 case TRY_AGAIN: 2961 if (hp->rcode == SERVFAIL) 2962 break; 2963 /* FALLTHROUGH */ 2964 default: 2965 goto giveup; 2966 } 2967 2968 /* 2969 * If the query has not already been tried as is then try it 2970 * unless RES_NOTLDQUERY is set and there were no dots. 2971 */ 2972 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2973 !(tried_as_is || root_on_list)) { 2974 ret = res_querydomainN(name, NULL, target, res); 2975 if (ret > 0) 2976 return (ret); 2977 } 2978 2979 /* 2980 * if we got here, we didn't satisfy the search. 2981 * if we did an initial full query, return that query's h_errno 2982 * (note that we wouldn't be here if that query had succeeded). 2983 * else if we ever got a nodata, send that back as the reason. 2984 * else send back meaningless h_errno, that being the one from 2985 * the last DNSRCH we did. 2986 */ 2987 giveup: 2988 if (saved_herrno != -1) 2989 RES_SET_H_ERRNO(res, saved_herrno); 2990 else if (got_nodata) 2991 RES_SET_H_ERRNO(res, NO_DATA); 2992 else if (got_servfail) 2993 RES_SET_H_ERRNO(res, TRY_AGAIN); 2994 return (-1); 2995 } 2996 2997 /* 2998 * Perform a call on res_query on the concatenation of name and domain, 2999 * removing a trailing dot from name if domain is NULL. 3000 */ 3001 static int 3002 res_querydomainN(const char *name, const char *domain, 3003 struct res_target *target, res_state res) 3004 { 3005 char nbuf[MAXDNAME]; 3006 const char *longname = nbuf; 3007 size_t n, d; 3008 3009 #ifdef DEBUG 3010 if (res->options & RES_DEBUG) 3011 printf(";; res_querydomain(%s, %s)\n", 3012 name, domain?domain:"<Nil>"); 3013 #endif 3014 if (domain == NULL) { 3015 /* 3016 * Check for trailing '.'; 3017 * copy without '.' if present. 3018 */ 3019 n = strlen(name); 3020 if (n >= MAXDNAME) { 3021 RES_SET_H_ERRNO(res, NO_RECOVERY); 3022 return (-1); 3023 } 3024 if (n > 0 && name[--n] == '.') { 3025 strncpy(nbuf, name, n); 3026 nbuf[n] = '\0'; 3027 } else 3028 longname = name; 3029 } else { 3030 n = strlen(name); 3031 d = strlen(domain); 3032 if (n + d + 1 >= MAXDNAME) { 3033 RES_SET_H_ERRNO(res, NO_RECOVERY); 3034 return (-1); 3035 } 3036 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 3037 } 3038 return (res_queryN(longname, target, res)); 3039 } 3040