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 return 0; 1282 p = pton; 1283 break; 1284 default: 1285 if (inet_pton(afd->a_af, hostname, pton) != 1) { 1286 if (pai->ai_family != AF_INET6 || 1287 (pai->ai_flags & AI_V4MAPPED) != AI_V4MAPPED) 1288 return 0; 1289 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1290 return 0; 1291 afd = &afdl[N_INET]; 1292 ai0 = *pai; 1293 ai0.ai_family = AF_INET; 1294 pai = &ai0; 1295 } 1296 p = pton; 1297 break; 1298 } 1299 1300 if (pai->ai_family == afd->a_af) { 1301 GET_AI(ai, afd, p); 1302 GET_PORT(ai, servname); 1303 if ((pai->ai_family == AF_INET || 1304 pai->ai_family == AF_INET6) && 1305 (pai->ai_flags & AI_CANONNAME)) { 1306 /* 1307 * Set the numeric address itself as the canonical 1308 * name, based on a clarification in RFC3493. 1309 */ 1310 GET_CANONNAME(ai, canonname); 1311 } 1312 } else { 1313 /* 1314 * XXX: This should not happen since we already matched the AF 1315 * by find_afd. 1316 */ 1317 ERR(EAI_FAMILY); 1318 } 1319 1320 *res = ai; 1321 return 0; 1322 1323 free: 1324 bad: 1325 if (ai != NULL) 1326 freeaddrinfo(ai); 1327 return error; 1328 } 1329 1330 /* 1331 * numeric hostname with scope 1332 */ 1333 static int 1334 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1335 const char *servname, struct addrinfo **res) 1336 { 1337 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 1338 return explore_numeric(pai, hostname, servname, res, hostname); 1339 #else 1340 const struct afd *afd; 1341 struct addrinfo *cur; 1342 int error; 1343 char *cp, *hostname2 = NULL, *scope, *addr; 1344 struct sockaddr_in6 *sin6; 1345 1346 afd = find_afd(pai->ai_family); 1347 if (afd == NULL) 1348 return 0; 1349 1350 if (!afd->a_scoped) 1351 return explore_numeric(pai, hostname, servname, res, hostname); 1352 1353 cp = strchr(hostname, SCOPE_DELIMITER); 1354 if (cp == NULL) 1355 return explore_numeric(pai, hostname, servname, res, hostname); 1356 1357 /* 1358 * Handle special case of <scoped_address><delimiter><scope id> 1359 */ 1360 hostname2 = strdup(hostname); 1361 if (hostname2 == NULL) 1362 return EAI_MEMORY; 1363 /* terminate at the delimiter */ 1364 hostname2[cp - hostname] = '\0'; 1365 addr = hostname2; 1366 scope = cp + 1; 1367 1368 error = explore_numeric(pai, addr, servname, res, hostname); 1369 if (error == 0) { 1370 u_int32_t scopeid; 1371 1372 for (cur = *res; cur; cur = cur->ai_next) { 1373 if (cur->ai_family != AF_INET6) 1374 continue; 1375 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1376 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1377 free(hostname2); 1378 freeaddrinfo(*res); 1379 *res = NULL; 1380 return(EAI_NONAME); /* XXX: is return OK? */ 1381 } 1382 sin6->sin6_scope_id = scopeid; 1383 } 1384 } 1385 1386 free(hostname2); 1387 1388 if (error && *res) { 1389 freeaddrinfo(*res); 1390 *res = NULL; 1391 } 1392 return error; 1393 #endif 1394 } 1395 1396 static int 1397 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1398 { 1399 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1400 ai->ai_canonname = strdup(str); 1401 if (ai->ai_canonname == NULL) 1402 return EAI_MEMORY; 1403 } 1404 return 0; 1405 } 1406 1407 static struct addrinfo * 1408 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1409 { 1410 char *p; 1411 struct addrinfo *ai; 1412 #ifdef INET6 1413 struct in6_addr mapaddr; 1414 1415 if (afd->a_af == AF_INET && (pai->ai_flags & AI_V4MAPPED) != 0) { 1416 afd = &afdl[N_INET6]; 1417 _map_v4v6_address(addr, (char *)&mapaddr); 1418 addr = (char *)&mapaddr; 1419 } 1420 #endif 1421 1422 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1423 + (afd->a_socklen)); 1424 if (ai == NULL) 1425 return NULL; 1426 1427 memcpy(ai, pai, sizeof(struct addrinfo)); 1428 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1429 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1430 ai->ai_addr->sa_len = afd->a_socklen; 1431 ai->ai_addrlen = afd->a_socklen; 1432 if (ai->ai_family == PF_LOCAL) { 1433 size_t n = strnlen(addr, afd->a_addrlen); 1434 1435 ai->ai_addrlen -= afd->a_addrlen - n; 1436 ai->ai_addr->sa_len -= afd->a_addrlen - n; 1437 } 1438 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1439 p = (char *)(void *)(ai->ai_addr); 1440 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1441 return ai; 1442 } 1443 1444 /* XXX need to malloc() the same way we do from other functions! */ 1445 static struct addrinfo * 1446 copy_ai(const struct addrinfo *pai) 1447 { 1448 struct addrinfo *ai; 1449 size_t l; 1450 1451 l = sizeof(*ai) + pai->ai_addrlen; 1452 if ((ai = calloc(1, l)) == NULL) 1453 return NULL; 1454 memcpy(ai, pai, sizeof(*ai)); 1455 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1456 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1457 1458 if (pai->ai_canonname) { 1459 l = strlen(pai->ai_canonname) + 1; 1460 if ((ai->ai_canonname = malloc(l)) == NULL) { 1461 free(ai); 1462 return NULL; 1463 } 1464 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1465 } else { 1466 /* just to make sure */ 1467 ai->ai_canonname = NULL; 1468 } 1469 1470 ai->ai_next = NULL; 1471 1472 return ai; 1473 } 1474 1475 static int 1476 get_portmatch(const struct addrinfo *ai, const char *servname) 1477 { 1478 1479 /* get_port does not touch first argument when matchonly == 1. */ 1480 /* LINTED const cast */ 1481 return get_port((struct addrinfo *)ai, servname, 1); 1482 } 1483 1484 static int 1485 get_port(struct addrinfo *ai, const char *servname, int matchonly) 1486 { 1487 const char *proto; 1488 struct servent *sp; 1489 int port, error; 1490 int allownumeric; 1491 1492 if (servname == NULL) 1493 return 0; 1494 switch (ai->ai_family) { 1495 case AF_LOCAL: 1496 /* AF_LOCAL ignores servname silently. */ 1497 return (0); 1498 case AF_INET: 1499 #ifdef AF_INET6 1500 case AF_INET6: 1501 #endif 1502 break; 1503 default: 1504 return 0; 1505 } 1506 1507 switch (ai->ai_socktype) { 1508 case SOCK_RAW: 1509 return EAI_SERVICE; 1510 case SOCK_DGRAM: 1511 case SOCK_STREAM: 1512 case SOCK_SEQPACKET: 1513 allownumeric = 1; 1514 break; 1515 case ANY: 1516 switch (ai->ai_family) { 1517 case AF_INET: 1518 #ifdef AF_INET6 1519 case AF_INET6: 1520 #endif 1521 allownumeric = 1; 1522 break; 1523 default: 1524 allownumeric = 0; 1525 break; 1526 } 1527 break; 1528 default: 1529 return EAI_SOCKTYPE; 1530 } 1531 1532 error = str2number(servname, &port); 1533 if (error == 0) { 1534 if (!allownumeric) 1535 return EAI_SERVICE; 1536 if (port < 0 || port > 65535) 1537 return EAI_SERVICE; 1538 port = htons(port); 1539 } else { 1540 if (ai->ai_flags & AI_NUMERICSERV) 1541 return EAI_NONAME; 1542 1543 switch (ai->ai_protocol) { 1544 case IPPROTO_UDP: 1545 proto = "udp"; 1546 break; 1547 case IPPROTO_TCP: 1548 proto = "tcp"; 1549 break; 1550 case IPPROTO_SCTP: 1551 proto = "sctp"; 1552 break; 1553 case IPPROTO_UDPLITE: 1554 proto = "udplite"; 1555 break; 1556 default: 1557 proto = NULL; 1558 break; 1559 } 1560 1561 if ((sp = getservbyname(servname, proto)) == NULL) 1562 return EAI_SERVICE; 1563 port = sp->s_port; 1564 } 1565 1566 if (!matchonly) { 1567 switch (ai->ai_family) { 1568 case AF_INET: 1569 ((struct sockaddr_in *)(void *) 1570 ai->ai_addr)->sin_port = port; 1571 break; 1572 #ifdef INET6 1573 case AF_INET6: 1574 ((struct sockaddr_in6 *)(void *) 1575 ai->ai_addr)->sin6_port = port; 1576 break; 1577 #endif 1578 } 1579 } 1580 1581 return 0; 1582 } 1583 1584 static const struct afd * 1585 find_afd(int af) 1586 { 1587 const struct afd *afd; 1588 1589 if (af == PF_UNSPEC) 1590 return NULL; 1591 for (afd = afdl; afd->a_af; afd++) { 1592 if (afd->a_af == af) 1593 return afd; 1594 } 1595 return NULL; 1596 } 1597 1598 /* 1599 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are 1600 * configured on the local system and correlates with pai->ai_family value. 1601 * If an address family is not configured on the system, it will not be 1602 * queried for. For this purpose, loopback addresses are not considered 1603 * configured addresses. 1604 * 1605 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1606 * _dns_getaddrinfo. 1607 */ 1608 static int 1609 addrconfig(struct addrinfo *pai) 1610 { 1611 struct ifaddrs *ifaddrs, *ifa; 1612 struct sockaddr_in *sin; 1613 #ifdef INET6 1614 struct sockaddr_in6 *sin6; 1615 #endif 1616 int seen_inet = 0, seen_inet6 = 0; 1617 1618 if (getifaddrs(&ifaddrs) != 0) 1619 return (0); 1620 1621 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1622 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1623 continue; 1624 switch (ifa->ifa_addr->sa_family) { 1625 case AF_INET: 1626 if (seen_inet) 1627 continue; 1628 sin = (struct sockaddr_in *)(ifa->ifa_addr); 1629 if (htonl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) 1630 continue; 1631 seen_inet = 1; 1632 break; 1633 #ifdef INET6 1634 case AF_INET6: 1635 if (seen_inet6) 1636 continue; 1637 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); 1638 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 1639 continue; 1640 if ((ifa->ifa_flags & IFT_LOOP) != 0 && 1641 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 1642 continue; 1643 if (is_ifdisabled(ifa->ifa_name)) 1644 continue; 1645 seen_inet6 = 1; 1646 break; 1647 #endif 1648 } 1649 } 1650 freeifaddrs(ifaddrs); 1651 1652 switch(pai->ai_family) { 1653 case AF_INET6: 1654 return (seen_inet6); 1655 case AF_INET: 1656 return (seen_inet); 1657 case AF_UNSPEC: 1658 if (seen_inet == seen_inet6) 1659 return (seen_inet); 1660 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1661 return (1); 1662 } 1663 return (1); 1664 } 1665 1666 #ifdef INET6 1667 static int 1668 is_ifdisabled(char *name) 1669 { 1670 struct in6_ndireq nd; 1671 int fd; 1672 1673 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1674 return (-1); 1675 memset(&nd, 0, sizeof(nd)); 1676 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1677 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1678 _close(fd); 1679 return (-1); 1680 } 1681 _close(fd); 1682 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1683 } 1684 1685 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1686 static int 1687 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1688 { 1689 u_long lscopeid; 1690 struct in6_addr *a6; 1691 char *ep; 1692 1693 a6 = &sin6->sin6_addr; 1694 1695 /* empty scopeid portion is invalid */ 1696 if (*scope == '\0') 1697 return -1; 1698 1699 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1700 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1701 /* 1702 * We currently assume a one-to-one mapping between links 1703 * and interfaces, so we simply use interface indices for 1704 * like-local scopes. 1705 */ 1706 *scopeid = if_nametoindex(scope); 1707 if (*scopeid == 0) 1708 goto trynumeric; 1709 return 0; 1710 } 1711 1712 /* still unclear about literal, allow numeric only - placeholder */ 1713 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1714 goto trynumeric; 1715 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1716 goto trynumeric; 1717 else 1718 goto trynumeric; /* global */ 1719 1720 /* try to convert to a numeric id as a last resort */ 1721 trynumeric: 1722 errno = 0; 1723 lscopeid = strtoul(scope, &ep, 10); 1724 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1725 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1726 return 0; 1727 else 1728 return -1; 1729 } 1730 #endif 1731 1732 1733 #ifdef NS_CACHING 1734 static int 1735 addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1736 void *cache_mdata) 1737 { 1738 res_state statp; 1739 u_long res_options; 1740 1741 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1742 char *hostname; 1743 struct addrinfo *hints; 1744 1745 char *p; 1746 int ai_flags, ai_family, ai_socktype, ai_protocol; 1747 size_t desired_size, size; 1748 1749 statp = __res_state(); 1750 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1751 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1752 1753 hostname = va_arg(ap, char *); 1754 hints = va_arg(ap, struct addrinfo *); 1755 1756 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1757 if (hostname != NULL) { 1758 size = strlen(hostname); 1759 desired_size += size + 1; 1760 } else 1761 size = 0; 1762 1763 if (desired_size > *buffer_size) { 1764 *buffer_size = desired_size; 1765 return (NS_RETURN); 1766 } 1767 1768 if (hints == NULL) 1769 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1770 else { 1771 ai_flags = hints->ai_flags; 1772 ai_family = hints->ai_family; 1773 ai_socktype = hints->ai_socktype; 1774 ai_protocol = hints->ai_protocol; 1775 } 1776 1777 p = buffer; 1778 memcpy(p, &res_options, sizeof(res_options)); 1779 p += sizeof(res_options); 1780 1781 memcpy(p, &op_id, sizeof(int)); 1782 p += sizeof(int); 1783 1784 memcpy(p, &ai_flags, sizeof(int)); 1785 p += sizeof(int); 1786 1787 memcpy(p, &ai_family, sizeof(int)); 1788 p += sizeof(int); 1789 1790 memcpy(p, &ai_socktype, sizeof(int)); 1791 p += sizeof(int); 1792 1793 memcpy(p, &ai_protocol, sizeof(int)); 1794 p += sizeof(int); 1795 1796 if (hostname != NULL) 1797 memcpy(p, hostname, size); 1798 1799 *buffer_size = desired_size; 1800 return (NS_SUCCESS); 1801 } 1802 1803 static int 1804 addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1805 va_list ap, void *cache_mdata) 1806 { 1807 struct addrinfo *ai, *cai; 1808 char *p; 1809 size_t desired_size, size, ai_size; 1810 1811 ai = *((struct addrinfo **)retval); 1812 1813 desired_size = sizeof(size_t); 1814 ai_size = 0; 1815 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1816 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1817 if (cai->ai_canonname != NULL) 1818 desired_size += sizeof(size_t) + 1819 strlen(cai->ai_canonname); 1820 ++ai_size; 1821 } 1822 1823 if (desired_size > *buffer_size) { 1824 /* this assignment is here for future use */ 1825 errno = ERANGE; 1826 *buffer_size = desired_size; 1827 return (NS_RETURN); 1828 } 1829 1830 memset(buffer, 0, desired_size); 1831 p = buffer; 1832 1833 memcpy(p, &ai_size, sizeof(size_t)); 1834 p += sizeof(size_t); 1835 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1836 memcpy(p, cai, sizeof(struct addrinfo)); 1837 p += sizeof(struct addrinfo); 1838 1839 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1840 p += cai->ai_addrlen; 1841 1842 if (cai->ai_canonname != NULL) { 1843 size = strlen(cai->ai_canonname); 1844 memcpy(p, &size, sizeof(size_t)); 1845 p += sizeof(size_t); 1846 1847 memcpy(p, cai->ai_canonname, size); 1848 p += size; 1849 } 1850 } 1851 1852 return (NS_SUCCESS); 1853 } 1854 1855 static int 1856 addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1857 va_list ap, void *cache_mdata) 1858 { 1859 struct addrinfo new_ai, *result, *sentinel, *lasts; 1860 1861 char *p; 1862 size_t ai_size, ai_i, size; 1863 1864 p = buffer; 1865 memcpy(&ai_size, p, sizeof(size_t)); 1866 p += sizeof(size_t); 1867 1868 result = NULL; 1869 lasts = NULL; 1870 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1871 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1872 p += sizeof(struct addrinfo); 1873 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1874 _ALIGNBYTES; 1875 1876 sentinel = calloc(1, size); 1877 1878 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1879 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1880 sizeof(struct addrinfo)); 1881 1882 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1883 p += new_ai.ai_addrlen; 1884 1885 if (new_ai.ai_canonname != NULL) { 1886 memcpy(&size, p, sizeof(size_t)); 1887 p += sizeof(size_t); 1888 1889 sentinel->ai_canonname = calloc(1, size + 1); 1890 1891 memcpy(sentinel->ai_canonname, p, size); 1892 p += size; 1893 } 1894 1895 if (result == NULL) { 1896 result = sentinel; 1897 lasts = sentinel; 1898 } else { 1899 lasts->ai_next = sentinel; 1900 lasts = sentinel; 1901 } 1902 } 1903 1904 *((struct addrinfo **)retval) = result; 1905 return (NS_SUCCESS); 1906 } 1907 #endif /* NS_CACHING */ 1908 1909 /* 1910 * FQDN hostname, DNS lookup 1911 */ 1912 static int 1913 explore_fqdn(const struct addrinfo *pai, const char *hostname, 1914 const char *servname, struct addrinfo **res) 1915 { 1916 struct addrinfo *result; 1917 struct addrinfo *cur; 1918 int error = 0; 1919 1920 #ifdef NS_CACHING 1921 static const nss_cache_info cache_info = 1922 NS_COMMON_CACHE_INFO_INITIALIZER( 1923 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1924 addrinfo_unmarshal_func); 1925 #endif 1926 static const ns_dtab dtab[] = { 1927 NS_FILES_CB(_files_getaddrinfo, NULL) 1928 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1929 NS_NIS_CB(_yp_getaddrinfo, NULL) 1930 #ifdef NS_CACHING 1931 NS_CACHE_CB(&cache_info) 1932 #endif 1933 { 0 } 1934 }; 1935 1936 result = NULL; 1937 1938 /* 1939 * if the servname does not match socktype/protocol, ignore it. 1940 */ 1941 if (get_portmatch(pai, servname) != 0) 1942 return 0; 1943 1944 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1945 default_dns_files, hostname, pai)) { 1946 case NS_TRYAGAIN: 1947 error = EAI_AGAIN; 1948 goto free; 1949 case NS_UNAVAIL: 1950 error = EAI_FAIL; 1951 goto free; 1952 case NS_NOTFOUND: 1953 error = EAI_NONAME; 1954 goto free; 1955 case NS_SUCCESS: 1956 error = 0; 1957 for (cur = result; cur; cur = cur->ai_next) { 1958 GET_PORT(cur, servname); 1959 /* canonname should be filled already */ 1960 } 1961 break; 1962 } 1963 1964 *res = result; 1965 1966 return 0; 1967 1968 free: 1969 if (result) 1970 freeaddrinfo(result); 1971 return error; 1972 } 1973 1974 #ifdef DEBUG 1975 static const char AskedForGot[] = 1976 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1977 #endif 1978 1979 static struct addrinfo * 1980 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1981 const struct addrinfo *pai, res_state res) 1982 { 1983 struct addrinfo sentinel, *cur; 1984 struct addrinfo ai; 1985 const struct afd *afd; 1986 char *canonname; 1987 const HEADER *hp; 1988 const u_char *cp; 1989 int n; 1990 const u_char *eom; 1991 char *bp, *ep; 1992 int type, class, ancount, qdcount; 1993 int haveanswer, had_error; 1994 char tbuf[MAXDNAME]; 1995 int (*name_ok)(const char *); 1996 char hostbuf[8*1024]; 1997 1998 memset(&sentinel, 0, sizeof(sentinel)); 1999 cur = &sentinel; 2000 2001 canonname = NULL; 2002 eom = answer->buf + anslen; 2003 switch (qtype) { 2004 case T_A: 2005 case T_AAAA: 2006 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 2007 name_ok = res_hnok; 2008 break; 2009 default: 2010 return (NULL); /* XXX should be abort(); */ 2011 } 2012 /* 2013 * find first satisfactory answer 2014 */ 2015 hp = &answer->hdr; 2016 ancount = ntohs(hp->ancount); 2017 qdcount = ntohs(hp->qdcount); 2018 bp = hostbuf; 2019 ep = hostbuf + sizeof hostbuf; 2020 cp = answer->buf + HFIXEDSZ; 2021 if (qdcount != 1) { 2022 RES_SET_H_ERRNO(res, NO_RECOVERY); 2023 return (NULL); 2024 } 2025 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2026 if ((n < 0) || !(*name_ok)(bp)) { 2027 RES_SET_H_ERRNO(res, NO_RECOVERY); 2028 return (NULL); 2029 } 2030 cp += n + QFIXEDSZ; 2031 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 2032 /* res_send() has already verified that the query name is the 2033 * same as the one we sent; this just gets the expanded name 2034 * (i.e., with the succeeding search-domain tacked on). 2035 */ 2036 n = strlen(bp) + 1; /* for the \0 */ 2037 if (n >= MAXHOSTNAMELEN) { 2038 RES_SET_H_ERRNO(res, NO_RECOVERY); 2039 return (NULL); 2040 } 2041 canonname = bp; 2042 bp += n; 2043 /* The qname can be abbreviated, but h_name is now absolute. */ 2044 qname = canonname; 2045 } 2046 haveanswer = 0; 2047 had_error = 0; 2048 while (ancount-- > 0 && cp < eom && !had_error) { 2049 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2050 if ((n < 0) || !(*name_ok)(bp)) { 2051 had_error++; 2052 continue; 2053 } 2054 cp += n; /* name */ 2055 type = _getshort(cp); 2056 cp += INT16SZ; /* type */ 2057 class = _getshort(cp); 2058 cp += INT16SZ + INT32SZ; /* class, TTL */ 2059 n = _getshort(cp); 2060 cp += INT16SZ; /* len */ 2061 if (class != C_IN) { 2062 /* XXX - debug? syslog? */ 2063 cp += n; 2064 continue; /* XXX - had_error++ ? */ 2065 } 2066 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 2067 type == T_CNAME) { 2068 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 2069 if ((n < 0) || !(*name_ok)(tbuf)) { 2070 had_error++; 2071 continue; 2072 } 2073 cp += n; 2074 /* Get canonical name. */ 2075 n = strlen(tbuf) + 1; /* for the \0 */ 2076 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 2077 had_error++; 2078 continue; 2079 } 2080 strlcpy(bp, tbuf, ep - bp); 2081 canonname = bp; 2082 bp += n; 2083 continue; 2084 } 2085 if (qtype == T_ANY) { 2086 if (!(type == T_A || type == T_AAAA)) { 2087 cp += n; 2088 continue; 2089 } 2090 } else if (type != qtype) { 2091 #ifdef DEBUG 2092 if (type != T_KEY && type != T_SIG && 2093 type != ns_t_dname) 2094 syslog(LOG_NOTICE|LOG_AUTH, 2095 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2096 qname, p_class(C_IN), p_type(qtype), 2097 p_type(type)); 2098 #endif 2099 cp += n; 2100 continue; /* XXX - had_error++ ? */ 2101 } 2102 switch (type) { 2103 case T_A: 2104 case T_AAAA: 2105 if (strcasecmp(canonname, bp) != 0) { 2106 #ifdef DEBUG 2107 syslog(LOG_NOTICE|LOG_AUTH, 2108 AskedForGot, canonname, bp); 2109 #endif 2110 cp += n; 2111 continue; /* XXX - had_error++ ? */ 2112 } 2113 if (type == T_A && n != INADDRSZ) { 2114 cp += n; 2115 continue; 2116 } 2117 if (type == T_AAAA && n != IN6ADDRSZ) { 2118 cp += n; 2119 continue; 2120 } 2121 #ifdef FILTER_V4MAPPED 2122 if (type == T_AAAA) { 2123 struct in6_addr in6; 2124 memcpy(&in6, cp, sizeof(in6)); 2125 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2126 cp += n; 2127 continue; 2128 } 2129 } 2130 #endif 2131 if (!haveanswer) { 2132 int nn; 2133 2134 canonname = bp; 2135 nn = strlen(bp) + 1; /* for the \0 */ 2136 bp += nn; 2137 } 2138 2139 /* don't overwrite pai */ 2140 ai = *pai; 2141 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2142 afd = find_afd(ai.ai_family); 2143 if (afd == NULL) { 2144 cp += n; 2145 continue; 2146 } 2147 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2148 if (cur->ai_next == NULL) 2149 had_error++; 2150 while (cur && cur->ai_next) 2151 cur = cur->ai_next; 2152 cp += n; 2153 break; 2154 default: 2155 abort(); 2156 } 2157 if (!had_error) 2158 haveanswer++; 2159 } 2160 if (haveanswer) { 2161 #if defined(RESOLVSORT) 2162 /* 2163 * We support only IPv4 address for backward 2164 * compatibility against gethostbyname(3). 2165 */ 2166 if (res->nsort && qtype == T_A) { 2167 if (addr4sort(&sentinel, res) < 0) { 2168 freeaddrinfo(sentinel.ai_next); 2169 RES_SET_H_ERRNO(res, NO_RECOVERY); 2170 return NULL; 2171 } 2172 } 2173 #endif /*RESOLVSORT*/ 2174 if (!canonname) 2175 (void)get_canonname(pai, sentinel.ai_next, qname); 2176 else 2177 (void)get_canonname(pai, sentinel.ai_next, canonname); 2178 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2179 return sentinel.ai_next; 2180 } 2181 2182 /* 2183 * We could have walked a CNAME chain, but the ultimate target 2184 * may not have what we looked for. 2185 */ 2186 RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : NO_RECOVERY); 2187 return NULL; 2188 } 2189 2190 #ifdef RESOLVSORT 2191 struct addr_ptr { 2192 struct addrinfo *ai; 2193 int aval; 2194 }; 2195 2196 static int 2197 addr4sort(struct addrinfo *sentinel, res_state res) 2198 { 2199 struct addrinfo *ai; 2200 struct addr_ptr *addrs, addr; 2201 struct sockaddr_in *sin; 2202 int naddrs, i, j; 2203 int needsort = 0; 2204 2205 if (!sentinel) 2206 return -1; 2207 naddrs = 0; 2208 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2209 naddrs++; 2210 if (naddrs < 2) 2211 return 0; /* We don't need sorting. */ 2212 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2213 return -1; 2214 i = 0; 2215 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2216 sin = (struct sockaddr_in *)ai->ai_addr; 2217 for (j = 0; (unsigned)j < res->nsort; j++) { 2218 if (res->sort_list[j].addr.s_addr == 2219 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2220 break; 2221 } 2222 addrs[i].ai = ai; 2223 addrs[i].aval = j; 2224 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2225 needsort = i; 2226 i++; 2227 } 2228 if (!needsort) { 2229 free(addrs); 2230 return 0; 2231 } 2232 2233 while (needsort < naddrs) { 2234 for (j = needsort - 1; j >= 0; j--) { 2235 if (addrs[j].aval > addrs[j+1].aval) { 2236 addr = addrs[j]; 2237 addrs[j] = addrs[j + 1]; 2238 addrs[j + 1] = addr; 2239 } else 2240 break; 2241 } 2242 needsort++; 2243 } 2244 2245 ai = sentinel; 2246 for (i = 0; i < naddrs; ++i) { 2247 ai->ai_next = addrs[i].ai; 2248 ai = ai->ai_next; 2249 } 2250 ai->ai_next = NULL; 2251 free(addrs); 2252 return 0; 2253 } 2254 #endif /*RESOLVSORT*/ 2255 2256 /*ARGSUSED*/ 2257 static int 2258 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2259 { 2260 struct addrinfo *ai, ai0; 2261 querybuf *buf, *buf2; 2262 const char *hostname; 2263 const struct addrinfo *pai; 2264 struct addrinfo sentinel, *cur; 2265 struct res_target q, q2; 2266 res_state res; 2267 2268 ai = NULL; 2269 2270 hostname = va_arg(ap, char *); 2271 pai = va_arg(ap, const struct addrinfo *); 2272 2273 memset(&q, 0, sizeof(q)); 2274 memset(&q2, 0, sizeof(q2)); 2275 memset(&sentinel, 0, sizeof(sentinel)); 2276 cur = &sentinel; 2277 2278 res = __res_state(); 2279 2280 buf = malloc(sizeof(*buf)); 2281 if (!buf) { 2282 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2283 return NS_NOTFOUND; 2284 } 2285 buf2 = malloc(sizeof(*buf2)); 2286 if (!buf2) { 2287 free(buf); 2288 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2289 return NS_NOTFOUND; 2290 } 2291 2292 if (pai->ai_family == AF_INET6 && 2293 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) { 2294 ai0 = *pai; 2295 ai0.ai_family = AF_UNSPEC; 2296 pai = &ai0; 2297 } 2298 2299 switch (pai->ai_family) { 2300 case AF_UNSPEC: 2301 q.name = hostname; 2302 q.qclass = C_IN; 2303 q.qtype = T_A; 2304 q.answer = buf->buf; 2305 q.anslen = sizeof(buf->buf); 2306 q.next = &q2; 2307 q2.name = hostname; 2308 q2.qclass = C_IN; 2309 q2.qtype = T_AAAA; 2310 q2.answer = buf2->buf; 2311 q2.anslen = sizeof(buf2->buf); 2312 break; 2313 case AF_INET: 2314 q.name = hostname; 2315 q.qclass = C_IN; 2316 q.qtype = T_A; 2317 q.answer = buf->buf; 2318 q.anslen = sizeof(buf->buf); 2319 break; 2320 case AF_INET6: 2321 q.name = hostname; 2322 q.qclass = C_IN; 2323 q.qtype = T_AAAA; 2324 q.answer = buf->buf; 2325 q.anslen = sizeof(buf->buf); 2326 break; 2327 default: 2328 free(buf); 2329 free(buf2); 2330 return NS_UNAVAIL; 2331 } 2332 2333 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2334 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2335 free(buf); 2336 free(buf2); 2337 return NS_NOTFOUND; 2338 } 2339 2340 if (res_searchN(hostname, &q, res) < 0) { 2341 free(buf); 2342 free(buf2); 2343 return NS_NOTFOUND; 2344 } 2345 /* prefer IPv6 */ 2346 if (q.next) { 2347 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2348 if (ai != NULL) { 2349 cur->ai_next = ai; 2350 while (cur && cur->ai_next) 2351 cur = cur->ai_next; 2352 } 2353 } 2354 if (ai == NULL || pai->ai_family != AF_UNSPEC || 2355 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) != AI_V4MAPPED) { 2356 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2357 if (ai != NULL) 2358 cur->ai_next = ai; 2359 } 2360 free(buf); 2361 free(buf2); 2362 if (sentinel.ai_next == NULL) 2363 switch (res->res_h_errno) { 2364 case HOST_NOT_FOUND: 2365 case NO_DATA: 2366 return NS_NOTFOUND; 2367 case TRY_AGAIN: 2368 return NS_TRYAGAIN; 2369 default: 2370 return NS_UNAVAIL; 2371 } 2372 *((struct addrinfo **)rv) = sentinel.ai_next; 2373 return NS_SUCCESS; 2374 } 2375 2376 static void 2377 _sethtent(FILE **hostf) 2378 { 2379 if (!*hostf) 2380 *hostf = fopen(_PATH_HOSTS, "re"); 2381 else 2382 rewind(*hostf); 2383 } 2384 2385 static void 2386 _endhtent(FILE **hostf) 2387 { 2388 if (*hostf) { 2389 (void) fclose(*hostf); 2390 *hostf = NULL; 2391 } 2392 } 2393 2394 static struct addrinfo * 2395 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2396 { 2397 char *p; 2398 char *cp, *tname, *cname; 2399 struct addrinfo hints, *res0, *res; 2400 int error; 2401 const char *addr; 2402 char hostbuf[8*1024]; 2403 2404 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2405 return (NULL); 2406 again: 2407 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2408 return (NULL); 2409 if (*p == '#') 2410 goto again; 2411 cp = strpbrk(p, "#\n"); 2412 if (cp != NULL) 2413 *cp = '\0'; 2414 if (!(cp = strpbrk(p, " \t"))) 2415 goto again; 2416 *cp++ = '\0'; 2417 addr = p; 2418 cname = NULL; 2419 /* if this is not something we're looking for, skip it. */ 2420 while (cp && *cp) { 2421 if (*cp == ' ' || *cp == '\t') { 2422 cp++; 2423 continue; 2424 } 2425 tname = cp; 2426 if (cname == NULL) 2427 cname = cp; 2428 if ((cp = strpbrk(cp, " \t")) != NULL) 2429 *cp++ = '\0'; 2430 if (strcasecmp(name, tname) == 0) 2431 goto found; 2432 } 2433 goto again; 2434 2435 found: 2436 /* we should not glob socktype/protocol here */ 2437 memset(&hints, 0, sizeof(hints)); 2438 hints.ai_family = pai->ai_family; 2439 hints.ai_socktype = SOCK_DGRAM; 2440 hints.ai_protocol = 0; 2441 hints.ai_flags = AI_NUMERICHOST; 2442 if (pai->ai_family == AF_INET6 && 2443 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2444 hints.ai_flags |= AI_V4MAPPED; 2445 error = getaddrinfo(addr, "0", &hints, &res0); 2446 if (error) 2447 goto again; 2448 #ifdef FILTER_V4MAPPED 2449 /* XXX should check all items in the chain */ 2450 if (res0->ai_family == AF_INET6 && 2451 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2452 freeaddrinfo(res0); 2453 goto again; 2454 } 2455 #endif 2456 for (res = res0; res; res = res->ai_next) { 2457 /* cover it up */ 2458 res->ai_flags = pai->ai_flags; 2459 res->ai_socktype = pai->ai_socktype; 2460 res->ai_protocol = pai->ai_protocol; 2461 2462 if (pai->ai_flags & AI_CANONNAME) { 2463 if (get_canonname(pai, res, cname) != 0) { 2464 freeaddrinfo(res0); 2465 goto again; 2466 } 2467 } 2468 } 2469 return res0; 2470 } 2471 2472 static struct addrinfo * 2473 _getht(FILE **hostf, const char *name, const struct addrinfo *pai, 2474 struct addrinfo *cur) 2475 { 2476 struct addrinfo *p; 2477 2478 while ((p = _gethtent(hostf, name, pai)) != NULL) { 2479 cur->ai_next = p; 2480 while (cur && cur->ai_next) 2481 cur = cur->ai_next; 2482 } 2483 return (cur); 2484 } 2485 2486 /*ARGSUSED*/ 2487 static int 2488 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2489 { 2490 const char *name; 2491 const struct addrinfo *pai; 2492 struct addrinfo sentinel, *cur; 2493 FILE *hostf = NULL; 2494 2495 name = va_arg(ap, char *); 2496 pai = va_arg(ap, struct addrinfo *); 2497 2498 memset(&sentinel, 0, sizeof(sentinel)); 2499 cur = &sentinel; 2500 2501 _sethtent(&hostf); 2502 if (pai->ai_family == AF_INET6 && 2503 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) == AI_V4MAPPED) { 2504 struct addrinfo ai0 = *pai; 2505 2506 ai0.ai_flags &= ~AI_V4MAPPED; 2507 cur = _getht(&hostf, name, &ai0, cur); 2508 if (sentinel.ai_next == NULL) { 2509 _sethtent(&hostf); 2510 ai0.ai_flags |= AI_V4MAPPED; 2511 cur = _getht(&hostf, name, &ai0, cur); 2512 } 2513 } else 2514 cur = _getht(&hostf, name, pai, cur); 2515 _endhtent(&hostf); 2516 2517 *((struct addrinfo **)rv) = sentinel.ai_next; 2518 if (sentinel.ai_next == NULL) 2519 return NS_NOTFOUND; 2520 return NS_SUCCESS; 2521 } 2522 2523 #ifdef YP 2524 /*ARGSUSED*/ 2525 static struct addrinfo * 2526 _yphostent(char *line, const struct addrinfo *pai) 2527 { 2528 struct addrinfo sentinel, *cur; 2529 struct addrinfo hints, *res, *res0; 2530 int error; 2531 char *p = line; 2532 const char *addr, *canonname; 2533 char *nextline; 2534 char *cp; 2535 2536 addr = canonname = NULL; 2537 2538 memset(&sentinel, 0, sizeof(sentinel)); 2539 cur = &sentinel; 2540 2541 nextline: 2542 /* terminate line */ 2543 cp = strchr(p, '\n'); 2544 if (cp) { 2545 *cp++ = '\0'; 2546 nextline = cp; 2547 } else 2548 nextline = NULL; 2549 2550 cp = strpbrk(p, " \t"); 2551 if (cp == NULL) { 2552 if (canonname == NULL) 2553 return (NULL); 2554 else 2555 goto done; 2556 } 2557 *cp++ = '\0'; 2558 2559 addr = p; 2560 2561 while (cp && *cp) { 2562 if (*cp == ' ' || *cp == '\t') { 2563 cp++; 2564 continue; 2565 } 2566 if (!canonname) 2567 canonname = cp; 2568 if ((cp = strpbrk(cp, " \t")) != NULL) 2569 *cp++ = '\0'; 2570 } 2571 2572 hints = *pai; 2573 hints.ai_flags = AI_NUMERICHOST; 2574 if (pai->ai_family == AF_INET6 && 2575 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2576 hints.ai_flags |= AI_V4MAPPED; 2577 error = getaddrinfo(addr, NULL, &hints, &res0); 2578 if (error == 0) { 2579 for (res = res0; res; res = res->ai_next) { 2580 /* cover it up */ 2581 res->ai_flags = pai->ai_flags; 2582 2583 if (pai->ai_flags & AI_CANONNAME) 2584 (void)get_canonname(pai, res, canonname); 2585 } 2586 } else 2587 res0 = NULL; 2588 if (res0) { 2589 cur->ai_next = res0; 2590 while (cur && cur->ai_next) 2591 cur = cur->ai_next; 2592 } 2593 2594 if (nextline) { 2595 p = nextline; 2596 goto nextline; 2597 } 2598 2599 done: 2600 return sentinel.ai_next; 2601 } 2602 2603 /*ARGSUSED*/ 2604 static int 2605 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2606 { 2607 struct addrinfo sentinel, *cur; 2608 struct addrinfo *ai = NULL; 2609 char *ypbuf; 2610 int ypbuflen, r; 2611 const char *name; 2612 const struct addrinfo *pai; 2613 char *ypdomain; 2614 2615 if (_yp_check(&ypdomain) == 0) 2616 return NS_UNAVAIL; 2617 2618 name = va_arg(ap, char *); 2619 pai = va_arg(ap, const struct addrinfo *); 2620 2621 memset(&sentinel, 0, sizeof(sentinel)); 2622 cur = &sentinel; 2623 2624 /* ipnodes.byname can hold both IPv4/v6 */ 2625 r = yp_match(ypdomain, "ipnodes.byname", name, 2626 (int)strlen(name), &ypbuf, &ypbuflen); 2627 if (r == 0) { 2628 ai = _yphostent(ypbuf, pai); 2629 if (ai) { 2630 cur->ai_next = ai; 2631 while (cur && cur->ai_next) 2632 cur = cur->ai_next; 2633 } 2634 free(ypbuf); 2635 } 2636 2637 if (ai != NULL) { 2638 struct sockaddr_in6 *sin6; 2639 2640 switch (ai->ai_family) { 2641 case AF_INET: 2642 goto done; 2643 case AF_INET6: 2644 sin6 = (struct sockaddr_in6 *)ai->ai_addr; 2645 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 2646 goto done; 2647 break; 2648 } 2649 } 2650 2651 /* hosts.byname is only for IPv4 (Solaris8) */ 2652 if (pai->ai_family == AF_UNSPEC || pai->ai_family == AF_INET || 2653 ((pai->ai_family == AF_INET6 && 2654 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) && 2655 (ai == NULL || (pai->ai_flags & AI_ALL) == AI_ALL))) { 2656 r = yp_match(ypdomain, "hosts.byname", name, 2657 (int)strlen(name), &ypbuf, &ypbuflen); 2658 if (r == 0) { 2659 struct addrinfo ai4; 2660 2661 ai4 = *pai; 2662 if (pai->ai_family == AF_UNSPEC) 2663 ai4.ai_family = AF_INET; 2664 ai = _yphostent(ypbuf, &ai4); 2665 if (ai) { 2666 cur->ai_next = ai; 2667 while (cur && cur->ai_next) 2668 cur = cur->ai_next; 2669 } 2670 free(ypbuf); 2671 } 2672 } 2673 2674 done: 2675 if (sentinel.ai_next == NULL) { 2676 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2677 return NS_NOTFOUND; 2678 } 2679 *((struct addrinfo **)rv) = sentinel.ai_next; 2680 return NS_SUCCESS; 2681 } 2682 #endif 2683 2684 /* resolver logic */ 2685 2686 /* 2687 * Formulate a normal query, send, and await answer. 2688 * Returned answer is placed in supplied buffer "answer". 2689 * Perform preliminary check of answer, returning success only 2690 * if no error is indicated and the answer count is nonzero. 2691 * Return the size of the response on success, -1 on error. 2692 * Error number is left in h_errno. 2693 * 2694 * Caller must parse answer and determine whether it answers the question. 2695 */ 2696 static int 2697 res_queryN(const char *name, struct res_target *target, res_state res) 2698 { 2699 u_char *buf; 2700 HEADER *hp; 2701 int n; 2702 u_int oflags; 2703 struct res_target *t; 2704 int rcode; 2705 int ancount; 2706 2707 rcode = NOERROR; 2708 ancount = 0; 2709 2710 buf = malloc(MAXPACKET); 2711 if (!buf) { 2712 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2713 return -1; 2714 } 2715 2716 for (t = target; t; t = t->next) { 2717 int class, type; 2718 u_char *answer; 2719 int anslen; 2720 2721 hp = (HEADER *)(void *)t->answer; 2722 2723 /* make it easier... */ 2724 class = t->qclass; 2725 type = t->qtype; 2726 answer = t->answer; 2727 anslen = t->anslen; 2728 2729 oflags = res->_flags; 2730 2731 again: 2732 hp->rcode = NOERROR; /* default */ 2733 2734 #ifdef DEBUG 2735 if (res->options & RES_DEBUG) 2736 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2737 #endif 2738 2739 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2740 buf, MAXPACKET); 2741 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2742 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2743 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2744 if (n <= 0) { 2745 #ifdef DEBUG 2746 if (res->options & RES_DEBUG) 2747 printf(";; res_query: mkquery failed\n"); 2748 #endif 2749 free(buf); 2750 RES_SET_H_ERRNO(res, NO_RECOVERY); 2751 return (n); 2752 } 2753 n = res_nsend(res, buf, n, answer, anslen); 2754 if (n < 0) { 2755 /* 2756 * if the query choked with EDNS0, retry 2757 * without EDNS0 2758 */ 2759 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2760 != 0U && 2761 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2762 res->_flags |= RES_F_EDNS0ERR; 2763 if (res->options & RES_DEBUG) 2764 printf(";; res_nquery: retry without EDNS0\n"); 2765 goto again; 2766 } 2767 rcode = hp->rcode; /* record most recent error */ 2768 #ifdef DEBUG 2769 if (res->options & RES_DEBUG) 2770 printf(";; res_query: send error\n"); 2771 #endif 2772 continue; 2773 } 2774 2775 if (n > anslen) 2776 hp->rcode = FORMERR; /* XXX not very informative */ 2777 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2778 rcode = hp->rcode; /* record most recent error */ 2779 #ifdef DEBUG 2780 if (res->options & RES_DEBUG) 2781 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2782 ntohs(hp->ancount)); 2783 #endif 2784 continue; 2785 } 2786 2787 ancount += ntohs(hp->ancount); 2788 2789 t->n = n; 2790 } 2791 2792 free(buf); 2793 2794 if (ancount == 0) { 2795 switch (rcode) { 2796 case NXDOMAIN: 2797 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2798 break; 2799 case SERVFAIL: 2800 RES_SET_H_ERRNO(res, TRY_AGAIN); 2801 break; 2802 case NOERROR: 2803 RES_SET_H_ERRNO(res, NO_DATA); 2804 break; 2805 case FORMERR: 2806 case NOTIMP: 2807 case REFUSED: 2808 default: 2809 RES_SET_H_ERRNO(res, NO_RECOVERY); 2810 break; 2811 } 2812 return (-1); 2813 } 2814 return (ancount); 2815 } 2816 2817 /* 2818 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2819 * Return the size of the response on success, -1 on error. 2820 * If enabled, implement search rules until answer or unrecoverable failure 2821 * is detected. Error code, if any, is left in h_errno. 2822 */ 2823 static int 2824 res_searchN(const char *name, struct res_target *target, res_state res) 2825 { 2826 const char *cp, * const *domain; 2827 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2828 u_int dots; 2829 int trailing_dot, ret, saved_herrno; 2830 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2831 int tried_as_is = 0; 2832 int searched = 0; 2833 char abuf[MAXDNAME]; 2834 2835 errno = 0; 2836 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2837 dots = 0; 2838 for (cp = name; *cp; cp++) 2839 dots += (*cp == '.'); 2840 trailing_dot = 0; 2841 if (cp > name && *--cp == '.') 2842 trailing_dot++; 2843 2844 /* 2845 * if there aren't any dots, it could be a user-level alias 2846 */ 2847 if (!dots && 2848 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2849 return (res_queryN(cp, target, res)); 2850 2851 /* 2852 * If there are enough dots in the name, let's just give it a 2853 * try 'as is'. The threshold can be set with the "ndots" option. 2854 * Also, query 'as is', if there is a trailing dot in the name. 2855 */ 2856 saved_herrno = -1; 2857 if (dots >= res->ndots || trailing_dot) { 2858 ret = res_querydomainN(name, NULL, target, res); 2859 if (ret > 0 || trailing_dot) 2860 return (ret); 2861 if (errno == ECONNREFUSED) { 2862 RES_SET_H_ERRNO(res, TRY_AGAIN); 2863 return (-1); 2864 } 2865 switch (res->res_h_errno) { 2866 case NO_DATA: 2867 case HOST_NOT_FOUND: 2868 break; 2869 case TRY_AGAIN: 2870 if (hp->rcode == SERVFAIL) 2871 break; 2872 /* FALLTHROUGH */ 2873 default: 2874 return (-1); 2875 } 2876 saved_herrno = res->res_h_errno; 2877 tried_as_is++; 2878 } 2879 2880 /* 2881 * We do at least one level of search if 2882 * - there is no dot and RES_DEFNAME is set, or 2883 * - there is at least one dot, there is no trailing dot, 2884 * and RES_DNSRCH is set. 2885 */ 2886 if ((!dots && (res->options & RES_DEFNAMES)) || 2887 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2888 int done = 0; 2889 2890 for (domain = (const char * const *)res->dnsrch; 2891 *domain && !done; 2892 domain++) { 2893 searched = 1; 2894 2895 if (domain[0][0] == '\0' || 2896 (domain[0][0] == '.' && domain[0][1] == '\0')) 2897 root_on_list++; 2898 2899 if (root_on_list && tried_as_is) 2900 continue; 2901 2902 ret = res_querydomainN(name, *domain, target, res); 2903 if (ret > 0) 2904 return (ret); 2905 2906 /* 2907 * If no server present, give up. 2908 * If name isn't found in this domain, 2909 * keep trying higher domains in the search list 2910 * (if that's enabled). 2911 * On a NO_DATA error, keep trying, otherwise 2912 * a wildcard entry of another type could keep us 2913 * from finding this entry higher in the domain. 2914 * If we get some other error (negative answer or 2915 * server failure), then stop searching up, 2916 * but try the input name below in case it's 2917 * fully-qualified. 2918 */ 2919 if (errno == ECONNREFUSED) { 2920 RES_SET_H_ERRNO(res, TRY_AGAIN); 2921 return (-1); 2922 } 2923 2924 switch (res->res_h_errno) { 2925 case NO_DATA: 2926 got_nodata++; 2927 /* FALLTHROUGH */ 2928 case HOST_NOT_FOUND: 2929 /* keep trying */ 2930 break; 2931 case TRY_AGAIN: 2932 got_servfail++; 2933 if (hp->rcode == SERVFAIL) { 2934 /* try next search element, if any */ 2935 break; 2936 } 2937 /* FALLTHROUGH */ 2938 default: 2939 /* anything else implies that we're done */ 2940 done++; 2941 } 2942 /* 2943 * if we got here for some reason other than DNSRCH, 2944 * we only wanted one iteration of the loop, so stop. 2945 */ 2946 if (!(res->options & RES_DNSRCH)) 2947 done++; 2948 } 2949 } 2950 2951 switch (res->res_h_errno) { 2952 case NO_DATA: 2953 case HOST_NOT_FOUND: 2954 break; 2955 case TRY_AGAIN: 2956 if (hp->rcode == SERVFAIL) 2957 break; 2958 /* FALLTHROUGH */ 2959 default: 2960 goto giveup; 2961 } 2962 2963 /* 2964 * If the query has not already been tried as is then try it 2965 * unless RES_NOTLDQUERY is set and there were no dots. 2966 */ 2967 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2968 !(tried_as_is || root_on_list)) { 2969 ret = res_querydomainN(name, NULL, target, res); 2970 if (ret > 0) 2971 return (ret); 2972 } 2973 2974 /* 2975 * if we got here, we didn't satisfy the search. 2976 * if we did an initial full query, return that query's h_errno 2977 * (note that we wouldn't be here if that query had succeeded). 2978 * else if we ever got a nodata, send that back as the reason. 2979 * else send back meaningless h_errno, that being the one from 2980 * the last DNSRCH we did. 2981 */ 2982 giveup: 2983 if (saved_herrno != -1) 2984 RES_SET_H_ERRNO(res, saved_herrno); 2985 else if (got_nodata) 2986 RES_SET_H_ERRNO(res, NO_DATA); 2987 else if (got_servfail) 2988 RES_SET_H_ERRNO(res, TRY_AGAIN); 2989 return (-1); 2990 } 2991 2992 /* 2993 * Perform a call on res_query on the concatenation of name and domain, 2994 * removing a trailing dot from name if domain is NULL. 2995 */ 2996 static int 2997 res_querydomainN(const char *name, const char *domain, 2998 struct res_target *target, res_state res) 2999 { 3000 char nbuf[MAXDNAME]; 3001 const char *longname = nbuf; 3002 size_t n, d; 3003 3004 #ifdef DEBUG 3005 if (res->options & RES_DEBUG) 3006 printf(";; res_querydomain(%s, %s)\n", 3007 name, domain?domain:"<Nil>"); 3008 #endif 3009 if (domain == NULL) { 3010 /* 3011 * Check for trailing '.'; 3012 * copy without '.' if present. 3013 */ 3014 n = strlen(name); 3015 if (n >= MAXDNAME) { 3016 RES_SET_H_ERRNO(res, NO_RECOVERY); 3017 return (-1); 3018 } 3019 if (n > 0 && name[--n] == '.') { 3020 strncpy(nbuf, name, n); 3021 nbuf[n] = '\0'; 3022 } else 3023 longname = name; 3024 } else { 3025 n = strlen(name); 3026 d = strlen(domain); 3027 if (n + d + 1 >= MAXDNAME) { 3028 RES_SET_H_ERRNO(res, NO_RECOVERY); 3029 return (-1); 3030 } 3031 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 3032 } 3033 return (res_queryN(longname, target, res)); 3034 } 3035