1 /* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * Issues to be discussed: 34 * - Return values. There are nonstandard return values defined and used 35 * in the source code. This is because RFC2553 is silent about which error 36 * code must be returned for which situation. 37 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 38 * invalid. current code - SEGV on freeaddrinfo(NULL) 39 * 40 * Note: 41 * - The code filters out AFs that are not supported by the kernel, 42 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 43 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 44 * in ai_flags? 45 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 46 * (1) what should we do against numeric hostname (2) what should we do 47 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 48 * non-loopback address configured? global address configured? 49 * 50 * OS specific notes for freebsd4: 51 * - FreeBSD supported $GAI. The code does not. 52 */ 53 54 #include <sys/cdefs.h> 55 __FBSDID("$FreeBSD$"); 56 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 }; 228 229 static const ns_src default_dns_files[] = { 230 { NSSRC_FILES, NS_SUCCESS }, 231 { NSSRC_DNS, NS_SUCCESS }, 232 { 0 } 233 }; 234 235 struct res_target { 236 struct res_target *next; 237 const char *name; /* domain name */ 238 int qclass, qtype; /* class and type of query */ 239 u_char *answer; /* buffer to put answer */ 240 int anslen; /* size of answer buffer */ 241 int n; /* result length */ 242 }; 243 244 #define MAXPACKET (64*1024) 245 246 typedef union { 247 HEADER hdr; 248 u_char buf[MAXPACKET]; 249 } querybuf; 250 251 static int str2number(const char *, int *); 252 static int explore_copy(const struct addrinfo *, const struct addrinfo *, 253 struct addrinfo **); 254 static int explore_null(const struct addrinfo *, 255 const char *, struct addrinfo **); 256 static int explore_numeric(const struct addrinfo *, const char *, 257 const char *, struct addrinfo **, const char *); 258 static int explore_numeric_scope(const struct addrinfo *, const char *, 259 const char *, struct addrinfo **); 260 static int get_canonname(const struct addrinfo *, 261 struct addrinfo *, const char *); 262 static struct addrinfo *get_ai(const struct addrinfo *, 263 const struct afd *, const char *); 264 static struct addrinfo *copy_ai(const struct addrinfo *); 265 static int get_portmatch(const struct addrinfo *, const char *); 266 static int get_port(struct addrinfo *, const char *, int); 267 static const struct afd *find_afd(int); 268 static int addrconfig(struct addrinfo *); 269 #ifdef INET6 270 static int is_ifdisabled(char *); 271 #endif 272 static void set_source(struct ai_order *, struct policyhead *); 273 static int comp_dst(const void *, const void *); 274 #ifdef INET6 275 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 276 #endif 277 static int gai_addr2scopetype(struct sockaddr *); 278 279 static int explore_fqdn(const struct addrinfo *, const char *, 280 const char *, struct addrinfo **); 281 282 static int reorder(struct addrinfo *); 283 static int get_addrselectpolicy(struct policyhead *); 284 static void free_addrselectpolicy(struct policyhead *); 285 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 286 struct policyhead *); 287 static int matchlen(struct sockaddr *, struct sockaddr *); 288 289 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 290 const struct addrinfo *, res_state); 291 #if defined(RESOLVSORT) 292 static int addr4sort(struct addrinfo *, res_state); 293 #endif 294 static int _dns_getaddrinfo(void *, void *, va_list); 295 static void _sethtent(FILE **); 296 static void _endhtent(FILE **); 297 static struct addrinfo *_gethtent(FILE **, const char *, 298 const struct addrinfo *); 299 static int _files_getaddrinfo(void *, void *, va_list); 300 #ifdef YP 301 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 302 static int _yp_getaddrinfo(void *, void *, va_list); 303 #endif 304 #ifdef NS_CACHING 305 static int addrinfo_id_func(char *, size_t *, va_list, void *); 306 static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 307 static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 308 #endif 309 310 static int res_queryN(const char *, struct res_target *, res_state); 311 static int res_searchN(const char *, struct res_target *, res_state); 312 static int res_querydomainN(const char *, const char *, 313 struct res_target *, res_state); 314 315 /* XXX macros that make external reference is BAD. */ 316 317 #define GET_AI(ai, afd, addr) \ 318 do { \ 319 /* external reference: pai, error, and label free */ \ 320 (ai) = get_ai(pai, (afd), (addr)); \ 321 if ((ai) == NULL) { \ 322 error = EAI_MEMORY; \ 323 goto free; \ 324 } \ 325 } while (/*CONSTCOND*/0) 326 327 #define GET_PORT(ai, serv) \ 328 do { \ 329 /* external reference: error and label free */ \ 330 error = get_port((ai), (serv), 0); \ 331 if (error != 0) \ 332 goto free; \ 333 } while (/*CONSTCOND*/0) 334 335 #define GET_CANONNAME(ai, str) \ 336 do { \ 337 /* external reference: pai, error and label free */ \ 338 error = get_canonname(pai, (ai), (str)); \ 339 if (error != 0) \ 340 goto free; \ 341 } while (/*CONSTCOND*/0) 342 343 #define ERR(err) \ 344 do { \ 345 /* external reference: error, and label bad */ \ 346 error = (err); \ 347 goto bad; \ 348 /*NOTREACHED*/ \ 349 } while (/*CONSTCOND*/0) 350 351 #define MATCH_FAMILY(x, y, w) \ 352 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 353 #define MATCH(x, y, w) \ 354 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 355 356 void 357 freeaddrinfo(struct addrinfo *ai) 358 { 359 struct addrinfo *next; 360 361 do { 362 next = ai->ai_next; 363 if (ai->ai_canonname) 364 free(ai->ai_canonname); 365 /* no need to free(ai->ai_addr) */ 366 free(ai); 367 ai = next; 368 } while (ai); 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 = malloc(sizeof(*aio) * n)) == NULL) 694 return(n); /* give up reordering */ 695 memset(aio, 0, sizeof(*aio) * n); 696 697 /* retrieve address selection policy from the kernel */ 698 TAILQ_INIT(&policyhead); 699 if (!get_addrselectpolicy(&policyhead)) { 700 /* no policy is installed into kernel, we don't sort. */ 701 free(aio); 702 return (n); 703 } 704 705 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 706 aio[i].aio_ai = ai; 707 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 708 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 709 &policyhead); 710 set_source(&aio[i], &policyhead); 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 < addrlen * 8) { 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 return(-1); 1070 } 1071 1072 /* 1073 * Copy from scope.c. 1074 * XXX: we should standardize the functions and link them as standard 1075 * library. 1076 */ 1077 static int 1078 gai_addr2scopetype(struct sockaddr *sa) 1079 { 1080 #ifdef INET6 1081 struct sockaddr_in6 *sa6; 1082 #endif 1083 struct sockaddr_in *sa4; 1084 1085 switch(sa->sa_family) { 1086 #ifdef INET6 1087 case AF_INET6: 1088 sa6 = (struct sockaddr_in6 *)sa; 1089 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1090 /* just use the scope field of the multicast address */ 1091 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1092 } 1093 /* 1094 * Unicast addresses: map scope type to corresponding scope 1095 * value defined for multcast addresses. 1096 * XXX: hardcoded scope type values are bad... 1097 */ 1098 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1099 return(1); /* node local scope */ 1100 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1101 return(2); /* link-local scope */ 1102 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1103 return(5); /* site-local scope */ 1104 return(14); /* global scope */ 1105 break; 1106 #endif 1107 case AF_INET: 1108 /* 1109 * IPv4 pseudo scoping according to RFC 3484. 1110 */ 1111 sa4 = (struct sockaddr_in *)sa; 1112 /* IPv4 autoconfiguration addresses have link-local scope. */ 1113 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1114 ((u_char *)&sa4->sin_addr)[1] == 254) 1115 return(2); 1116 /* Private addresses have site-local scope. */ 1117 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1118 (((u_char *)&sa4->sin_addr)[0] == 172 && 1119 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1120 (((u_char *)&sa4->sin_addr)[0] == 192 && 1121 ((u_char *)&sa4->sin_addr)[1] == 168)) 1122 return(14); /* XXX: It should be 5 unless NAT */ 1123 /* Loopback addresses have link-local scope. */ 1124 if (((u_char *)&sa4->sin_addr)[0] == 127) 1125 return(2); 1126 return(14); 1127 break; 1128 default: 1129 errno = EAFNOSUPPORT; /* is this a good error? */ 1130 return(-1); 1131 } 1132 } 1133 1134 static int 1135 explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1136 struct addrinfo **res) 1137 { 1138 int error; 1139 struct addrinfo sentinel, *cur; 1140 const struct addrinfo *src; 1141 1142 error = 0; 1143 sentinel.ai_next = NULL; 1144 cur = &sentinel; 1145 1146 for (src = src0; src != NULL; src = src->ai_next) { 1147 if (src->ai_family != pai->ai_family) 1148 continue; 1149 1150 cur->ai_next = copy_ai(src); 1151 if (!cur->ai_next) { 1152 error = EAI_MEMORY; 1153 goto fail; 1154 } 1155 1156 cur->ai_next->ai_socktype = pai->ai_socktype; 1157 cur->ai_next->ai_protocol = pai->ai_protocol; 1158 cur = cur->ai_next; 1159 } 1160 1161 *res = sentinel.ai_next; 1162 return 0; 1163 1164 fail: 1165 freeaddrinfo(sentinel.ai_next); 1166 return error; 1167 } 1168 1169 /* 1170 * hostname == NULL. 1171 * passive socket -> anyaddr (0.0.0.0 or ::) 1172 * non-passive socket -> localhost (127.0.0.1 or ::1) 1173 */ 1174 static int 1175 explore_null(const struct addrinfo *pai, const char *servname, 1176 struct addrinfo **res) 1177 { 1178 int s; 1179 const struct afd *afd; 1180 struct addrinfo *ai; 1181 int error; 1182 1183 *res = NULL; 1184 ai = NULL; 1185 1186 if (pai->ai_family == PF_LOCAL) 1187 return (0); 1188 1189 /* 1190 * filter out AFs that are not supported by the kernel 1191 * XXX errno? 1192 */ 1193 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1194 if (s < 0) { 1195 if (errno != EMFILE) 1196 return 0; 1197 } else 1198 _close(s); 1199 1200 afd = find_afd(pai->ai_family); 1201 if (afd == NULL) 1202 return 0; 1203 1204 if (pai->ai_flags & AI_PASSIVE) { 1205 GET_AI(ai, afd, afd->a_addrany); 1206 GET_PORT(ai, servname); 1207 } else { 1208 GET_AI(ai, afd, afd->a_loopback); 1209 GET_PORT(ai, servname); 1210 } 1211 1212 *res = ai; 1213 return 0; 1214 1215 free: 1216 if (ai != NULL) 1217 freeaddrinfo(ai); 1218 return error; 1219 } 1220 1221 /* 1222 * numeric hostname 1223 */ 1224 static int 1225 explore_numeric(const struct addrinfo *pai, const char *hostname, 1226 const char *servname, struct addrinfo **res, const char *canonname) 1227 { 1228 const struct afd *afd; 1229 struct addrinfo *ai, ai0; 1230 int error; 1231 char pton[PTON_MAX], path[PATH_MAX], *p; 1232 1233 #ifdef CTASSERT 1234 CTASSERT(sizeofmember(struct sockaddr_un, sun_path) <= PATH_MAX); 1235 #endif 1236 *res = NULL; 1237 ai = NULL; 1238 1239 afd = find_afd(pai->ai_family); 1240 if (afd == NULL) 1241 return 0; 1242 1243 switch (afd->a_af) { 1244 case AF_LOCAL: 1245 if (hostname[0] != '/') 1246 ERR(EAI_NONAME); 1247 if (strlen(hostname) > afd->a_addrlen) 1248 ERR(EAI_MEMORY); 1249 /* NUL-termination does not need to be guaranteed. */ 1250 strncpy(path, hostname, afd->a_addrlen); 1251 p = &path[0]; 1252 break; 1253 case AF_INET: 1254 /* 1255 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1256 * that are accepted by inet_addr() and its family. The 1257 * accepted forms includes the "classful" one, which inet_pton 1258 * does not accept. So we need to separate the case for 1259 * AF_INET. 1260 */ 1261 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1262 return 0; 1263 p = pton; 1264 break; 1265 default: 1266 if (inet_pton(afd->a_af, hostname, pton) != 1) { 1267 if (pai->ai_family != AF_INET6 || 1268 (pai->ai_flags & AI_V4MAPPED) != AI_V4MAPPED) 1269 return 0; 1270 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1271 return 0; 1272 afd = &afdl[N_INET]; 1273 ai0 = *pai; 1274 ai0.ai_family = AF_INET; 1275 pai = &ai0; 1276 } 1277 p = pton; 1278 break; 1279 } 1280 1281 if (pai->ai_family == afd->a_af) { 1282 GET_AI(ai, afd, p); 1283 GET_PORT(ai, servname); 1284 if ((pai->ai_family == AF_INET || 1285 pai->ai_family == AF_INET6) && 1286 (pai->ai_flags & AI_CANONNAME)) { 1287 /* 1288 * Set the numeric address itself as the canonical 1289 * name, based on a clarification in RFC3493. 1290 */ 1291 GET_CANONNAME(ai, canonname); 1292 } 1293 } else { 1294 /* 1295 * XXX: This should not happen since we already matched the AF 1296 * by find_afd. 1297 */ 1298 ERR(EAI_FAMILY); 1299 } 1300 1301 *res = ai; 1302 return 0; 1303 1304 free: 1305 bad: 1306 if (ai != NULL) 1307 freeaddrinfo(ai); 1308 return error; 1309 } 1310 1311 /* 1312 * numeric hostname with scope 1313 */ 1314 static int 1315 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1316 const char *servname, struct addrinfo **res) 1317 { 1318 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 1319 return explore_numeric(pai, hostname, servname, res, hostname); 1320 #else 1321 const struct afd *afd; 1322 struct addrinfo *cur; 1323 int error; 1324 char *cp, *hostname2 = NULL, *scope, *addr; 1325 struct sockaddr_in6 *sin6; 1326 1327 afd = find_afd(pai->ai_family); 1328 if (afd == NULL) 1329 return 0; 1330 1331 if (!afd->a_scoped) 1332 return explore_numeric(pai, hostname, servname, res, hostname); 1333 1334 cp = strchr(hostname, SCOPE_DELIMITER); 1335 if (cp == NULL) 1336 return explore_numeric(pai, hostname, servname, res, hostname); 1337 1338 /* 1339 * Handle special case of <scoped_address><delimiter><scope id> 1340 */ 1341 hostname2 = strdup(hostname); 1342 if (hostname2 == NULL) 1343 return EAI_MEMORY; 1344 /* terminate at the delimiter */ 1345 hostname2[cp - hostname] = '\0'; 1346 addr = hostname2; 1347 scope = cp + 1; 1348 1349 error = explore_numeric(pai, addr, servname, res, hostname); 1350 if (error == 0) { 1351 u_int32_t scopeid; 1352 1353 for (cur = *res; cur; cur = cur->ai_next) { 1354 if (cur->ai_family != AF_INET6) 1355 continue; 1356 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1357 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1358 free(hostname2); 1359 freeaddrinfo(*res); 1360 *res = NULL; 1361 return(EAI_NONAME); /* XXX: is return OK? */ 1362 } 1363 sin6->sin6_scope_id = scopeid; 1364 } 1365 } 1366 1367 free(hostname2); 1368 1369 if (error && *res) { 1370 freeaddrinfo(*res); 1371 *res = NULL; 1372 } 1373 return error; 1374 #endif 1375 } 1376 1377 static int 1378 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1379 { 1380 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1381 ai->ai_canonname = strdup(str); 1382 if (ai->ai_canonname == NULL) 1383 return EAI_MEMORY; 1384 } 1385 return 0; 1386 } 1387 1388 static struct addrinfo * 1389 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1390 { 1391 char *p; 1392 struct addrinfo *ai; 1393 #ifdef INET6 1394 struct in6_addr mapaddr; 1395 1396 if (afd->a_af == AF_INET && (pai->ai_flags & AI_V4MAPPED) != 0) { 1397 afd = &afdl[N_INET6]; 1398 _map_v4v6_address(addr, (char *)&mapaddr); 1399 addr = (char *)&mapaddr; 1400 } 1401 #endif 1402 1403 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1404 + (afd->a_socklen)); 1405 if (ai == NULL) 1406 return NULL; 1407 1408 memcpy(ai, pai, sizeof(struct addrinfo)); 1409 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1410 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1411 ai->ai_addr->sa_len = afd->a_socklen; 1412 ai->ai_addrlen = afd->a_socklen; 1413 if (ai->ai_family == PF_LOCAL) { 1414 size_t n = strnlen(addr, afd->a_addrlen); 1415 1416 ai->ai_addrlen -= afd->a_addrlen - n; 1417 ai->ai_addr->sa_len -= afd->a_addrlen - n; 1418 } 1419 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1420 p = (char *)(void *)(ai->ai_addr); 1421 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1422 return ai; 1423 } 1424 1425 /* XXX need to malloc() the same way we do from other functions! */ 1426 static struct addrinfo * 1427 copy_ai(const struct addrinfo *pai) 1428 { 1429 struct addrinfo *ai; 1430 size_t l; 1431 1432 l = sizeof(*ai) + pai->ai_addrlen; 1433 if ((ai = (struct addrinfo *)malloc(l)) == NULL) 1434 return NULL; 1435 memset(ai, 0, l); 1436 memcpy(ai, pai, sizeof(*ai)); 1437 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1438 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1439 1440 if (pai->ai_canonname) { 1441 l = strlen(pai->ai_canonname) + 1; 1442 if ((ai->ai_canonname = malloc(l)) == NULL) { 1443 free(ai); 1444 return NULL; 1445 } 1446 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1447 } else { 1448 /* just to make sure */ 1449 ai->ai_canonname = NULL; 1450 } 1451 1452 ai->ai_next = NULL; 1453 1454 return ai; 1455 } 1456 1457 static int 1458 get_portmatch(const struct addrinfo *ai, const char *servname) 1459 { 1460 1461 /* get_port does not touch first argument when matchonly == 1. */ 1462 /* LINTED const cast */ 1463 return get_port((struct addrinfo *)ai, servname, 1); 1464 } 1465 1466 static int 1467 get_port(struct addrinfo *ai, const char *servname, int matchonly) 1468 { 1469 const char *proto; 1470 struct servent *sp; 1471 int port, error; 1472 int allownumeric; 1473 1474 if (servname == NULL) 1475 return 0; 1476 switch (ai->ai_family) { 1477 case AF_LOCAL: 1478 /* AF_LOCAL ignores servname silently. */ 1479 return (0); 1480 case AF_INET: 1481 #ifdef AF_INET6 1482 case AF_INET6: 1483 #endif 1484 break; 1485 default: 1486 return 0; 1487 } 1488 1489 switch (ai->ai_socktype) { 1490 case SOCK_RAW: 1491 return EAI_SERVICE; 1492 case SOCK_DGRAM: 1493 case SOCK_STREAM: 1494 case SOCK_SEQPACKET: 1495 allownumeric = 1; 1496 break; 1497 case ANY: 1498 switch (ai->ai_family) { 1499 case AF_INET: 1500 #ifdef AF_INET6 1501 case AF_INET6: 1502 #endif 1503 allownumeric = 1; 1504 break; 1505 default: 1506 allownumeric = 0; 1507 break; 1508 } 1509 break; 1510 default: 1511 return EAI_SOCKTYPE; 1512 } 1513 1514 error = str2number(servname, &port); 1515 if (error == 0) { 1516 if (!allownumeric) 1517 return EAI_SERVICE; 1518 if (port < 0 || port > 65535) 1519 return EAI_SERVICE; 1520 port = htons(port); 1521 } else { 1522 if (ai->ai_flags & AI_NUMERICSERV) 1523 return EAI_NONAME; 1524 1525 switch (ai->ai_protocol) { 1526 case IPPROTO_UDP: 1527 proto = "udp"; 1528 break; 1529 case IPPROTO_TCP: 1530 proto = "tcp"; 1531 break; 1532 case IPPROTO_SCTP: 1533 proto = "sctp"; 1534 break; 1535 case IPPROTO_UDPLITE: 1536 proto = "udplite"; 1537 break; 1538 default: 1539 proto = NULL; 1540 break; 1541 } 1542 1543 if ((sp = getservbyname(servname, proto)) == NULL) 1544 return EAI_SERVICE; 1545 port = sp->s_port; 1546 } 1547 1548 if (!matchonly) { 1549 switch (ai->ai_family) { 1550 case AF_INET: 1551 ((struct sockaddr_in *)(void *) 1552 ai->ai_addr)->sin_port = port; 1553 break; 1554 #ifdef INET6 1555 case AF_INET6: 1556 ((struct sockaddr_in6 *)(void *) 1557 ai->ai_addr)->sin6_port = port; 1558 break; 1559 #endif 1560 } 1561 } 1562 1563 return 0; 1564 } 1565 1566 static const struct afd * 1567 find_afd(int af) 1568 { 1569 const struct afd *afd; 1570 1571 if (af == PF_UNSPEC) 1572 return NULL; 1573 for (afd = afdl; afd->a_af; afd++) { 1574 if (afd->a_af == af) 1575 return afd; 1576 } 1577 return NULL; 1578 } 1579 1580 /* 1581 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are 1582 * configured on the local system and correlates with pai->ai_family value. 1583 * If an address family is not configured on the system, it will not be 1584 * queried for. For this purpose, loopback addresses are not considered 1585 * configured addresses. 1586 * 1587 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1588 * _dns_getaddrinfo. 1589 */ 1590 static int 1591 addrconfig(struct addrinfo *pai) 1592 { 1593 struct ifaddrs *ifaddrs, *ifa; 1594 struct sockaddr_in *sin; 1595 #ifdef INET6 1596 struct sockaddr_in6 *sin6; 1597 #endif 1598 int seen_inet = 0, seen_inet6 = 0; 1599 1600 if (getifaddrs(&ifaddrs) != 0) 1601 return (0); 1602 1603 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1604 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1605 continue; 1606 switch (ifa->ifa_addr->sa_family) { 1607 case AF_INET: 1608 if (seen_inet) 1609 continue; 1610 sin = (struct sockaddr_in *)(ifa->ifa_addr); 1611 if (htonl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) 1612 continue; 1613 seen_inet = 1; 1614 break; 1615 #ifdef INET6 1616 case AF_INET6: 1617 if (seen_inet6) 1618 continue; 1619 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); 1620 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 1621 continue; 1622 if ((ifa->ifa_flags & IFT_LOOP) != 0 && 1623 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 1624 continue; 1625 if (is_ifdisabled(ifa->ifa_name)) 1626 continue; 1627 seen_inet6 = 1; 1628 break; 1629 #endif 1630 } 1631 } 1632 freeifaddrs(ifaddrs); 1633 1634 switch(pai->ai_family) { 1635 case AF_INET6: 1636 return (seen_inet6); 1637 case AF_INET: 1638 return (seen_inet); 1639 case AF_UNSPEC: 1640 if (seen_inet == seen_inet6) 1641 return (seen_inet); 1642 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1643 return (1); 1644 } 1645 return (1); 1646 } 1647 1648 #ifdef INET6 1649 static int 1650 is_ifdisabled(char *name) 1651 { 1652 struct in6_ndireq nd; 1653 int fd; 1654 1655 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1656 return (-1); 1657 memset(&nd, 0, sizeof(nd)); 1658 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1659 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1660 _close(fd); 1661 return (-1); 1662 } 1663 _close(fd); 1664 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1665 } 1666 1667 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1668 static int 1669 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1670 { 1671 u_long lscopeid; 1672 struct in6_addr *a6; 1673 char *ep; 1674 1675 a6 = &sin6->sin6_addr; 1676 1677 /* empty scopeid portion is invalid */ 1678 if (*scope == '\0') 1679 return -1; 1680 1681 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1682 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1683 /* 1684 * We currently assume a one-to-one mapping between links 1685 * and interfaces, so we simply use interface indices for 1686 * like-local scopes. 1687 */ 1688 *scopeid = if_nametoindex(scope); 1689 if (*scopeid == 0) 1690 goto trynumeric; 1691 return 0; 1692 } 1693 1694 /* still unclear about literal, allow numeric only - placeholder */ 1695 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1696 goto trynumeric; 1697 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1698 goto trynumeric; 1699 else 1700 goto trynumeric; /* global */ 1701 1702 /* try to convert to a numeric id as a last resort */ 1703 trynumeric: 1704 errno = 0; 1705 lscopeid = strtoul(scope, &ep, 10); 1706 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1707 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1708 return 0; 1709 else 1710 return -1; 1711 } 1712 #endif 1713 1714 1715 #ifdef NS_CACHING 1716 static int 1717 addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1718 void *cache_mdata) 1719 { 1720 res_state statp; 1721 u_long res_options; 1722 1723 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1724 char *hostname; 1725 struct addrinfo *hints; 1726 1727 char *p; 1728 int ai_flags, ai_family, ai_socktype, ai_protocol; 1729 size_t desired_size, size; 1730 1731 statp = __res_state(); 1732 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1733 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1734 1735 hostname = va_arg(ap, char *); 1736 hints = va_arg(ap, struct addrinfo *); 1737 1738 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1739 if (hostname != NULL) { 1740 size = strlen(hostname); 1741 desired_size += size + 1; 1742 } else 1743 size = 0; 1744 1745 if (desired_size > *buffer_size) { 1746 *buffer_size = desired_size; 1747 return (NS_RETURN); 1748 } 1749 1750 if (hints == NULL) 1751 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1752 else { 1753 ai_flags = hints->ai_flags; 1754 ai_family = hints->ai_family; 1755 ai_socktype = hints->ai_socktype; 1756 ai_protocol = hints->ai_protocol; 1757 } 1758 1759 p = buffer; 1760 memcpy(p, &res_options, sizeof(res_options)); 1761 p += sizeof(res_options); 1762 1763 memcpy(p, &op_id, sizeof(int)); 1764 p += sizeof(int); 1765 1766 memcpy(p, &ai_flags, sizeof(int)); 1767 p += sizeof(int); 1768 1769 memcpy(p, &ai_family, sizeof(int)); 1770 p += sizeof(int); 1771 1772 memcpy(p, &ai_socktype, sizeof(int)); 1773 p += sizeof(int); 1774 1775 memcpy(p, &ai_protocol, sizeof(int)); 1776 p += sizeof(int); 1777 1778 if (hostname != NULL) 1779 memcpy(p, hostname, size); 1780 1781 *buffer_size = desired_size; 1782 return (NS_SUCCESS); 1783 } 1784 1785 static int 1786 addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1787 va_list ap, void *cache_mdata) 1788 { 1789 struct addrinfo *ai, *cai; 1790 char *p; 1791 size_t desired_size, size, ai_size; 1792 1793 ai = *((struct addrinfo **)retval); 1794 1795 desired_size = sizeof(size_t); 1796 ai_size = 0; 1797 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1798 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1799 if (cai->ai_canonname != NULL) 1800 desired_size += sizeof(size_t) + 1801 strlen(cai->ai_canonname); 1802 ++ai_size; 1803 } 1804 1805 if (desired_size > *buffer_size) { 1806 /* this assignment is here for future use */ 1807 errno = ERANGE; 1808 *buffer_size = desired_size; 1809 return (NS_RETURN); 1810 } 1811 1812 memset(buffer, 0, desired_size); 1813 p = buffer; 1814 1815 memcpy(p, &ai_size, sizeof(size_t)); 1816 p += sizeof(size_t); 1817 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1818 memcpy(p, cai, sizeof(struct addrinfo)); 1819 p += sizeof(struct addrinfo); 1820 1821 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1822 p += cai->ai_addrlen; 1823 1824 if (cai->ai_canonname != NULL) { 1825 size = strlen(cai->ai_canonname); 1826 memcpy(p, &size, sizeof(size_t)); 1827 p += sizeof(size_t); 1828 1829 memcpy(p, cai->ai_canonname, size); 1830 p += size; 1831 } 1832 } 1833 1834 return (NS_SUCCESS); 1835 } 1836 1837 static int 1838 addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1839 va_list ap, void *cache_mdata) 1840 { 1841 struct addrinfo new_ai, *result, *sentinel, *lasts; 1842 1843 char *p; 1844 size_t ai_size, ai_i, size; 1845 1846 p = buffer; 1847 memcpy(&ai_size, p, sizeof(size_t)); 1848 p += sizeof(size_t); 1849 1850 result = NULL; 1851 lasts = NULL; 1852 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1853 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1854 p += sizeof(struct addrinfo); 1855 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1856 _ALIGNBYTES; 1857 1858 sentinel = (struct addrinfo *)malloc(size); 1859 memset(sentinel, 0, size); 1860 1861 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1862 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1863 sizeof(struct addrinfo)); 1864 1865 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1866 p += new_ai.ai_addrlen; 1867 1868 if (new_ai.ai_canonname != NULL) { 1869 memcpy(&size, p, sizeof(size_t)); 1870 p += sizeof(size_t); 1871 1872 sentinel->ai_canonname = (char *)malloc(size + 1); 1873 memset(sentinel->ai_canonname, 0, size + 1); 1874 1875 memcpy(sentinel->ai_canonname, p, size); 1876 p += size; 1877 } 1878 1879 if (result == NULL) { 1880 result = sentinel; 1881 lasts = sentinel; 1882 } else { 1883 lasts->ai_next = sentinel; 1884 lasts = sentinel; 1885 } 1886 } 1887 1888 *((struct addrinfo **)retval) = result; 1889 return (NS_SUCCESS); 1890 } 1891 #endif /* NS_CACHING */ 1892 1893 /* 1894 * FQDN hostname, DNS lookup 1895 */ 1896 static int 1897 explore_fqdn(const struct addrinfo *pai, const char *hostname, 1898 const char *servname, struct addrinfo **res) 1899 { 1900 struct addrinfo *result; 1901 struct addrinfo *cur; 1902 int error = 0; 1903 1904 #ifdef NS_CACHING 1905 static const nss_cache_info cache_info = 1906 NS_COMMON_CACHE_INFO_INITIALIZER( 1907 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1908 addrinfo_unmarshal_func); 1909 #endif 1910 static const ns_dtab dtab[] = { 1911 NS_FILES_CB(_files_getaddrinfo, NULL) 1912 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1913 NS_NIS_CB(_yp_getaddrinfo, NULL) 1914 #ifdef NS_CACHING 1915 NS_CACHE_CB(&cache_info) 1916 #endif 1917 { 0 } 1918 }; 1919 1920 result = NULL; 1921 1922 /* 1923 * if the servname does not match socktype/protocol, ignore it. 1924 */ 1925 if (get_portmatch(pai, servname) != 0) 1926 return 0; 1927 1928 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1929 default_dns_files, hostname, pai)) { 1930 case NS_TRYAGAIN: 1931 error = EAI_AGAIN; 1932 goto free; 1933 case NS_UNAVAIL: 1934 error = EAI_FAIL; 1935 goto free; 1936 case NS_NOTFOUND: 1937 error = EAI_NONAME; 1938 goto free; 1939 case NS_SUCCESS: 1940 error = 0; 1941 for (cur = result; cur; cur = cur->ai_next) { 1942 GET_PORT(cur, servname); 1943 /* canonname should be filled already */ 1944 } 1945 break; 1946 } 1947 1948 *res = result; 1949 1950 return 0; 1951 1952 free: 1953 if (result) 1954 freeaddrinfo(result); 1955 return error; 1956 } 1957 1958 #ifdef DEBUG 1959 static const char AskedForGot[] = 1960 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1961 #endif 1962 1963 static struct addrinfo * 1964 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1965 const struct addrinfo *pai, res_state res) 1966 { 1967 struct addrinfo sentinel, *cur; 1968 struct addrinfo ai; 1969 const struct afd *afd; 1970 char *canonname; 1971 const HEADER *hp; 1972 const u_char *cp; 1973 int n; 1974 const u_char *eom; 1975 char *bp, *ep; 1976 int type, class, ancount, qdcount; 1977 int haveanswer, had_error; 1978 char tbuf[MAXDNAME]; 1979 int (*name_ok)(const char *); 1980 char hostbuf[8*1024]; 1981 1982 memset(&sentinel, 0, sizeof(sentinel)); 1983 cur = &sentinel; 1984 1985 canonname = NULL; 1986 eom = answer->buf + anslen; 1987 switch (qtype) { 1988 case T_A: 1989 case T_AAAA: 1990 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1991 name_ok = res_hnok; 1992 break; 1993 default: 1994 return (NULL); /* XXX should be abort(); */ 1995 } 1996 /* 1997 * find first satisfactory answer 1998 */ 1999 hp = &answer->hdr; 2000 ancount = ntohs(hp->ancount); 2001 qdcount = ntohs(hp->qdcount); 2002 bp = hostbuf; 2003 ep = hostbuf + sizeof hostbuf; 2004 cp = answer->buf + HFIXEDSZ; 2005 if (qdcount != 1) { 2006 RES_SET_H_ERRNO(res, NO_RECOVERY); 2007 return (NULL); 2008 } 2009 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2010 if ((n < 0) || !(*name_ok)(bp)) { 2011 RES_SET_H_ERRNO(res, NO_RECOVERY); 2012 return (NULL); 2013 } 2014 cp += n + QFIXEDSZ; 2015 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 2016 /* res_send() has already verified that the query name is the 2017 * same as the one we sent; this just gets the expanded name 2018 * (i.e., with the succeeding search-domain tacked on). 2019 */ 2020 n = strlen(bp) + 1; /* for the \0 */ 2021 if (n >= MAXHOSTNAMELEN) { 2022 RES_SET_H_ERRNO(res, NO_RECOVERY); 2023 return (NULL); 2024 } 2025 canonname = bp; 2026 bp += n; 2027 /* The qname can be abbreviated, but h_name is now absolute. */ 2028 qname = canonname; 2029 } 2030 haveanswer = 0; 2031 had_error = 0; 2032 while (ancount-- > 0 && cp < eom && !had_error) { 2033 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2034 if ((n < 0) || !(*name_ok)(bp)) { 2035 had_error++; 2036 continue; 2037 } 2038 cp += n; /* name */ 2039 type = _getshort(cp); 2040 cp += INT16SZ; /* type */ 2041 class = _getshort(cp); 2042 cp += INT16SZ + INT32SZ; /* class, TTL */ 2043 n = _getshort(cp); 2044 cp += INT16SZ; /* len */ 2045 if (class != C_IN) { 2046 /* XXX - debug? syslog? */ 2047 cp += n; 2048 continue; /* XXX - had_error++ ? */ 2049 } 2050 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 2051 type == T_CNAME) { 2052 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 2053 if ((n < 0) || !(*name_ok)(tbuf)) { 2054 had_error++; 2055 continue; 2056 } 2057 cp += n; 2058 /* Get canonical name. */ 2059 n = strlen(tbuf) + 1; /* for the \0 */ 2060 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 2061 had_error++; 2062 continue; 2063 } 2064 strlcpy(bp, tbuf, ep - bp); 2065 canonname = bp; 2066 bp += n; 2067 continue; 2068 } 2069 if (qtype == T_ANY) { 2070 if (!(type == T_A || type == T_AAAA)) { 2071 cp += n; 2072 continue; 2073 } 2074 } else if (type != qtype) { 2075 #ifdef DEBUG 2076 if (type != T_KEY && type != T_SIG && 2077 type != ns_t_dname) 2078 syslog(LOG_NOTICE|LOG_AUTH, 2079 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2080 qname, p_class(C_IN), p_type(qtype), 2081 p_type(type)); 2082 #endif 2083 cp += n; 2084 continue; /* XXX - had_error++ ? */ 2085 } 2086 switch (type) { 2087 case T_A: 2088 case T_AAAA: 2089 if (strcasecmp(canonname, bp) != 0) { 2090 #ifdef DEBUG 2091 syslog(LOG_NOTICE|LOG_AUTH, 2092 AskedForGot, canonname, bp); 2093 #endif 2094 cp += n; 2095 continue; /* XXX - had_error++ ? */ 2096 } 2097 if (type == T_A && n != INADDRSZ) { 2098 cp += n; 2099 continue; 2100 } 2101 if (type == T_AAAA && n != IN6ADDRSZ) { 2102 cp += n; 2103 continue; 2104 } 2105 #ifdef FILTER_V4MAPPED 2106 if (type == T_AAAA) { 2107 struct in6_addr in6; 2108 memcpy(&in6, cp, sizeof(in6)); 2109 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2110 cp += n; 2111 continue; 2112 } 2113 } 2114 #endif 2115 if (!haveanswer) { 2116 int nn; 2117 2118 canonname = bp; 2119 nn = strlen(bp) + 1; /* for the \0 */ 2120 bp += nn; 2121 } 2122 2123 /* don't overwrite pai */ 2124 ai = *pai; 2125 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2126 afd = find_afd(ai.ai_family); 2127 if (afd == NULL) { 2128 cp += n; 2129 continue; 2130 } 2131 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2132 if (cur->ai_next == NULL) 2133 had_error++; 2134 while (cur && cur->ai_next) 2135 cur = cur->ai_next; 2136 cp += n; 2137 break; 2138 default: 2139 abort(); 2140 } 2141 if (!had_error) 2142 haveanswer++; 2143 } 2144 if (haveanswer) { 2145 #if defined(RESOLVSORT) 2146 /* 2147 * We support only IPv4 address for backward 2148 * compatibility against gethostbyname(3). 2149 */ 2150 if (res->nsort && qtype == T_A) { 2151 if (addr4sort(&sentinel, res) < 0) { 2152 freeaddrinfo(sentinel.ai_next); 2153 RES_SET_H_ERRNO(res, NO_RECOVERY); 2154 return NULL; 2155 } 2156 } 2157 #endif /*RESOLVSORT*/ 2158 if (!canonname) 2159 (void)get_canonname(pai, sentinel.ai_next, qname); 2160 else 2161 (void)get_canonname(pai, sentinel.ai_next, canonname); 2162 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2163 return sentinel.ai_next; 2164 } 2165 2166 /* 2167 * We could have walked a CNAME chain, but the ultimate target 2168 * may not have what we looked for. 2169 */ 2170 RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : NO_RECOVERY); 2171 return NULL; 2172 } 2173 2174 #ifdef RESOLVSORT 2175 struct addr_ptr { 2176 struct addrinfo *ai; 2177 int aval; 2178 }; 2179 2180 static int 2181 addr4sort(struct addrinfo *sentinel, res_state res) 2182 { 2183 struct addrinfo *ai; 2184 struct addr_ptr *addrs, addr; 2185 struct sockaddr_in *sin; 2186 int naddrs, i, j; 2187 int needsort = 0; 2188 2189 if (!sentinel) 2190 return -1; 2191 naddrs = 0; 2192 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2193 naddrs++; 2194 if (naddrs < 2) 2195 return 0; /* We don't need sorting. */ 2196 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2197 return -1; 2198 i = 0; 2199 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2200 sin = (struct sockaddr_in *)ai->ai_addr; 2201 for (j = 0; (unsigned)j < res->nsort; j++) { 2202 if (res->sort_list[j].addr.s_addr == 2203 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2204 break; 2205 } 2206 addrs[i].ai = ai; 2207 addrs[i].aval = j; 2208 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2209 needsort = i; 2210 i++; 2211 } 2212 if (!needsort) { 2213 free(addrs); 2214 return 0; 2215 } 2216 2217 while (needsort < naddrs) { 2218 for (j = needsort - 1; j >= 0; j--) { 2219 if (addrs[j].aval > addrs[j+1].aval) { 2220 addr = addrs[j]; 2221 addrs[j] = addrs[j + 1]; 2222 addrs[j + 1] = addr; 2223 } else 2224 break; 2225 } 2226 needsort++; 2227 } 2228 2229 ai = sentinel; 2230 for (i = 0; i < naddrs; ++i) { 2231 ai->ai_next = addrs[i].ai; 2232 ai = ai->ai_next; 2233 } 2234 ai->ai_next = NULL; 2235 free(addrs); 2236 return 0; 2237 } 2238 #endif /*RESOLVSORT*/ 2239 2240 /*ARGSUSED*/ 2241 static int 2242 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2243 { 2244 struct addrinfo *ai, ai0; 2245 querybuf *buf, *buf2; 2246 const char *hostname; 2247 const struct addrinfo *pai; 2248 struct addrinfo sentinel, *cur; 2249 struct res_target q, q2; 2250 res_state res; 2251 2252 hostname = va_arg(ap, char *); 2253 pai = va_arg(ap, const struct addrinfo *); 2254 2255 memset(&q, 0, sizeof(q)); 2256 memset(&q2, 0, sizeof(q2)); 2257 memset(&sentinel, 0, sizeof(sentinel)); 2258 cur = &sentinel; 2259 2260 res = __res_state(); 2261 2262 buf = malloc(sizeof(*buf)); 2263 if (!buf) { 2264 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2265 return NS_NOTFOUND; 2266 } 2267 buf2 = malloc(sizeof(*buf2)); 2268 if (!buf2) { 2269 free(buf); 2270 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2271 return NS_NOTFOUND; 2272 } 2273 2274 if (pai->ai_family == AF_INET6 && 2275 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) { 2276 ai0 = *pai; 2277 ai0.ai_family = AF_UNSPEC; 2278 pai = &ai0; 2279 } 2280 2281 switch (pai->ai_family) { 2282 case AF_UNSPEC: 2283 q.name = hostname; 2284 q.qclass = C_IN; 2285 q.qtype = T_A; 2286 q.answer = buf->buf; 2287 q.anslen = sizeof(buf->buf); 2288 q.next = &q2; 2289 q2.name = hostname; 2290 q2.qclass = C_IN; 2291 q2.qtype = T_AAAA; 2292 q2.answer = buf2->buf; 2293 q2.anslen = sizeof(buf2->buf); 2294 break; 2295 case AF_INET: 2296 q.name = hostname; 2297 q.qclass = C_IN; 2298 q.qtype = T_A; 2299 q.answer = buf->buf; 2300 q.anslen = sizeof(buf->buf); 2301 break; 2302 case AF_INET6: 2303 q.name = hostname; 2304 q.qclass = C_IN; 2305 q.qtype = T_AAAA; 2306 q.answer = buf->buf; 2307 q.anslen = sizeof(buf->buf); 2308 break; 2309 default: 2310 free(buf); 2311 free(buf2); 2312 return NS_UNAVAIL; 2313 } 2314 2315 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2316 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2317 free(buf); 2318 free(buf2); 2319 return NS_NOTFOUND; 2320 } 2321 2322 if (res_searchN(hostname, &q, res) < 0) { 2323 free(buf); 2324 free(buf2); 2325 return NS_NOTFOUND; 2326 } 2327 /* prefer IPv6 */ 2328 if (q.next) { 2329 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2330 if (ai) { 2331 cur->ai_next = ai; 2332 while (cur && cur->ai_next) 2333 cur = cur->ai_next; 2334 } 2335 } 2336 if (!ai || pai->ai_family != AF_UNSPEC || 2337 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) != AI_V4MAPPED) { 2338 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2339 if (ai) 2340 cur->ai_next = ai; 2341 } 2342 free(buf); 2343 free(buf2); 2344 if (sentinel.ai_next == NULL) 2345 switch (res->res_h_errno) { 2346 case HOST_NOT_FOUND: 2347 case NO_DATA: 2348 return NS_NOTFOUND; 2349 case TRY_AGAIN: 2350 return NS_TRYAGAIN; 2351 default: 2352 return NS_UNAVAIL; 2353 } 2354 *((struct addrinfo **)rv) = sentinel.ai_next; 2355 return NS_SUCCESS; 2356 } 2357 2358 static void 2359 _sethtent(FILE **hostf) 2360 { 2361 if (!*hostf) 2362 *hostf = fopen(_PATH_HOSTS, "re"); 2363 else 2364 rewind(*hostf); 2365 } 2366 2367 static void 2368 _endhtent(FILE **hostf) 2369 { 2370 if (*hostf) { 2371 (void) fclose(*hostf); 2372 *hostf = NULL; 2373 } 2374 } 2375 2376 static struct addrinfo * 2377 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2378 { 2379 char *p; 2380 char *cp, *tname, *cname; 2381 struct addrinfo hints, *res0, *res; 2382 int error; 2383 const char *addr; 2384 char hostbuf[8*1024]; 2385 2386 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2387 return (NULL); 2388 again: 2389 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2390 return (NULL); 2391 if (*p == '#') 2392 goto again; 2393 cp = strpbrk(p, "#\n"); 2394 if (cp != NULL) 2395 *cp = '\0'; 2396 if (!(cp = strpbrk(p, " \t"))) 2397 goto again; 2398 *cp++ = '\0'; 2399 addr = p; 2400 cname = NULL; 2401 /* if this is not something we're looking for, skip it. */ 2402 while (cp && *cp) { 2403 if (*cp == ' ' || *cp == '\t') { 2404 cp++; 2405 continue; 2406 } 2407 tname = cp; 2408 if (cname == NULL) 2409 cname = cp; 2410 if ((cp = strpbrk(cp, " \t")) != NULL) 2411 *cp++ = '\0'; 2412 if (strcasecmp(name, tname) == 0) 2413 goto found; 2414 } 2415 goto again; 2416 2417 found: 2418 /* we should not glob socktype/protocol here */ 2419 memset(&hints, 0, sizeof(hints)); 2420 hints.ai_family = pai->ai_family; 2421 hints.ai_socktype = SOCK_DGRAM; 2422 hints.ai_protocol = 0; 2423 hints.ai_flags = AI_NUMERICHOST; 2424 if (pai->ai_family == AF_INET6 && 2425 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2426 hints.ai_flags |= AI_V4MAPPED; 2427 error = getaddrinfo(addr, "0", &hints, &res0); 2428 if (error) 2429 goto again; 2430 #ifdef FILTER_V4MAPPED 2431 /* XXX should check all items in the chain */ 2432 if (res0->ai_family == AF_INET6 && 2433 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2434 freeaddrinfo(res0); 2435 goto again; 2436 } 2437 #endif 2438 for (res = res0; res; res = res->ai_next) { 2439 /* cover it up */ 2440 res->ai_flags = pai->ai_flags; 2441 res->ai_socktype = pai->ai_socktype; 2442 res->ai_protocol = pai->ai_protocol; 2443 2444 if (pai->ai_flags & AI_CANONNAME) { 2445 if (get_canonname(pai, res, cname) != 0) { 2446 freeaddrinfo(res0); 2447 goto again; 2448 } 2449 } 2450 } 2451 return res0; 2452 } 2453 2454 static struct addrinfo * 2455 _getht(FILE **hostf, const char *name, const struct addrinfo *pai, 2456 struct addrinfo *cur) 2457 { 2458 struct addrinfo *p; 2459 2460 while ((p = _gethtent(hostf, name, pai)) != NULL) { 2461 cur->ai_next = p; 2462 while (cur && cur->ai_next) 2463 cur = cur->ai_next; 2464 } 2465 return (cur); 2466 } 2467 2468 /*ARGSUSED*/ 2469 static int 2470 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2471 { 2472 const char *name; 2473 const struct addrinfo *pai; 2474 struct addrinfo sentinel, *cur; 2475 FILE *hostf = NULL; 2476 2477 name = va_arg(ap, char *); 2478 pai = va_arg(ap, struct addrinfo *); 2479 2480 memset(&sentinel, 0, sizeof(sentinel)); 2481 cur = &sentinel; 2482 2483 _sethtent(&hostf); 2484 if (pai->ai_family == AF_INET6 && 2485 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) == AI_V4MAPPED) { 2486 struct addrinfo ai0 = *pai; 2487 2488 ai0.ai_flags &= ~AI_V4MAPPED; 2489 cur = _getht(&hostf, name, &ai0, cur); 2490 if (sentinel.ai_next == NULL) { 2491 _sethtent(&hostf); 2492 ai0.ai_flags |= AI_V4MAPPED; 2493 cur = _getht(&hostf, name, &ai0, cur); 2494 } 2495 } else 2496 cur = _getht(&hostf, name, pai, cur); 2497 _endhtent(&hostf); 2498 2499 *((struct addrinfo **)rv) = sentinel.ai_next; 2500 if (sentinel.ai_next == NULL) 2501 return NS_NOTFOUND; 2502 return NS_SUCCESS; 2503 } 2504 2505 #ifdef YP 2506 /*ARGSUSED*/ 2507 static struct addrinfo * 2508 _yphostent(char *line, const struct addrinfo *pai) 2509 { 2510 struct addrinfo sentinel, *cur; 2511 struct addrinfo hints, *res, *res0; 2512 int error; 2513 char *p = line; 2514 const char *addr, *canonname; 2515 char *nextline; 2516 char *cp; 2517 2518 addr = canonname = NULL; 2519 2520 memset(&sentinel, 0, sizeof(sentinel)); 2521 cur = &sentinel; 2522 2523 nextline: 2524 /* terminate line */ 2525 cp = strchr(p, '\n'); 2526 if (cp) { 2527 *cp++ = '\0'; 2528 nextline = cp; 2529 } else 2530 nextline = NULL; 2531 2532 cp = strpbrk(p, " \t"); 2533 if (cp == NULL) { 2534 if (canonname == NULL) 2535 return (NULL); 2536 else 2537 goto done; 2538 } 2539 *cp++ = '\0'; 2540 2541 addr = p; 2542 2543 while (cp && *cp) { 2544 if (*cp == ' ' || *cp == '\t') { 2545 cp++; 2546 continue; 2547 } 2548 if (!canonname) 2549 canonname = cp; 2550 if ((cp = strpbrk(cp, " \t")) != NULL) 2551 *cp++ = '\0'; 2552 } 2553 2554 hints = *pai; 2555 hints.ai_flags = AI_NUMERICHOST; 2556 if (pai->ai_family == AF_INET6 && 2557 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2558 hints.ai_flags |= AI_V4MAPPED; 2559 error = getaddrinfo(addr, NULL, &hints, &res0); 2560 if (error == 0) { 2561 for (res = res0; res; res = res->ai_next) { 2562 /* cover it up */ 2563 res->ai_flags = pai->ai_flags; 2564 2565 if (pai->ai_flags & AI_CANONNAME) 2566 (void)get_canonname(pai, res, canonname); 2567 } 2568 } else 2569 res0 = NULL; 2570 if (res0) { 2571 cur->ai_next = res0; 2572 while (cur && cur->ai_next) 2573 cur = cur->ai_next; 2574 } 2575 2576 if (nextline) { 2577 p = nextline; 2578 goto nextline; 2579 } 2580 2581 done: 2582 return sentinel.ai_next; 2583 } 2584 2585 /*ARGSUSED*/ 2586 static int 2587 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2588 { 2589 struct addrinfo sentinel, *cur; 2590 struct addrinfo *ai = NULL; 2591 char *ypbuf; 2592 int ypbuflen, r; 2593 const char *name; 2594 const struct addrinfo *pai; 2595 char *ypdomain; 2596 2597 if (_yp_check(&ypdomain) == 0) 2598 return NS_UNAVAIL; 2599 2600 name = va_arg(ap, char *); 2601 pai = va_arg(ap, const struct addrinfo *); 2602 2603 memset(&sentinel, 0, sizeof(sentinel)); 2604 cur = &sentinel; 2605 2606 /* ipnodes.byname can hold both IPv4/v6 */ 2607 r = yp_match(ypdomain, "ipnodes.byname", name, 2608 (int)strlen(name), &ypbuf, &ypbuflen); 2609 if (r == 0) { 2610 ai = _yphostent(ypbuf, pai); 2611 if (ai) { 2612 cur->ai_next = ai; 2613 while (cur && cur->ai_next) 2614 cur = cur->ai_next; 2615 } 2616 free(ypbuf); 2617 } 2618 2619 if (ai != NULL) { 2620 struct sockaddr_in6 *sin6; 2621 2622 switch (ai->ai_family) { 2623 case AF_INET: 2624 goto done; 2625 case AF_INET6: 2626 sin6 = (struct sockaddr_in6 *)ai->ai_addr; 2627 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 2628 goto done; 2629 break; 2630 } 2631 } 2632 2633 /* hosts.byname is only for IPv4 (Solaris8) */ 2634 if (pai->ai_family == AF_UNSPEC || pai->ai_family == AF_INET || 2635 ((pai->ai_family == AF_INET6 && 2636 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) && 2637 (ai == NULL || (pai->ai_flags & AI_ALL) == AI_ALL))) { 2638 r = yp_match(ypdomain, "hosts.byname", name, 2639 (int)strlen(name), &ypbuf, &ypbuflen); 2640 if (r == 0) { 2641 struct addrinfo ai4; 2642 2643 ai4 = *pai; 2644 if (pai->ai_family == AF_UNSPEC) 2645 ai4.ai_family = AF_INET; 2646 ai = _yphostent(ypbuf, &ai4); 2647 if (ai) { 2648 cur->ai_next = ai; 2649 while (cur && cur->ai_next) 2650 cur = cur->ai_next; 2651 } 2652 free(ypbuf); 2653 } 2654 } 2655 2656 done: 2657 if (sentinel.ai_next == NULL) { 2658 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2659 return NS_NOTFOUND; 2660 } 2661 *((struct addrinfo **)rv) = sentinel.ai_next; 2662 return NS_SUCCESS; 2663 } 2664 #endif 2665 2666 /* resolver logic */ 2667 2668 /* 2669 * Formulate a normal query, send, and await answer. 2670 * Returned answer is placed in supplied buffer "answer". 2671 * Perform preliminary check of answer, returning success only 2672 * if no error is indicated and the answer count is nonzero. 2673 * Return the size of the response on success, -1 on error. 2674 * Error number is left in h_errno. 2675 * 2676 * Caller must parse answer and determine whether it answers the question. 2677 */ 2678 static int 2679 res_queryN(const char *name, struct res_target *target, res_state res) 2680 { 2681 u_char *buf; 2682 HEADER *hp; 2683 int n; 2684 u_int oflags; 2685 struct res_target *t; 2686 int rcode; 2687 int ancount; 2688 2689 rcode = NOERROR; 2690 ancount = 0; 2691 2692 buf = malloc(MAXPACKET); 2693 if (!buf) { 2694 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2695 return -1; 2696 } 2697 2698 for (t = target; t; t = t->next) { 2699 int class, type; 2700 u_char *answer; 2701 int anslen; 2702 2703 hp = (HEADER *)(void *)t->answer; 2704 2705 /* make it easier... */ 2706 class = t->qclass; 2707 type = t->qtype; 2708 answer = t->answer; 2709 anslen = t->anslen; 2710 2711 oflags = res->_flags; 2712 2713 again: 2714 hp->rcode = NOERROR; /* default */ 2715 2716 #ifdef DEBUG 2717 if (res->options & RES_DEBUG) 2718 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2719 #endif 2720 2721 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2722 buf, MAXPACKET); 2723 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2724 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2725 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2726 if (n <= 0) { 2727 #ifdef DEBUG 2728 if (res->options & RES_DEBUG) 2729 printf(";; res_query: mkquery failed\n"); 2730 #endif 2731 free(buf); 2732 RES_SET_H_ERRNO(res, NO_RECOVERY); 2733 return (n); 2734 } 2735 n = res_nsend(res, buf, n, answer, anslen); 2736 if (n < 0) { 2737 /* 2738 * if the query choked with EDNS0, retry 2739 * without EDNS0 2740 */ 2741 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2742 != 0U && 2743 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2744 res->_flags |= RES_F_EDNS0ERR; 2745 if (res->options & RES_DEBUG) 2746 printf(";; res_nquery: retry without EDNS0\n"); 2747 goto again; 2748 } 2749 rcode = hp->rcode; /* record most recent error */ 2750 #ifdef DEBUG 2751 if (res->options & RES_DEBUG) 2752 printf(";; res_query: send error\n"); 2753 #endif 2754 continue; 2755 } 2756 2757 if (n > anslen) 2758 hp->rcode = FORMERR; /* XXX not very informative */ 2759 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2760 rcode = hp->rcode; /* record most recent error */ 2761 #ifdef DEBUG 2762 if (res->options & RES_DEBUG) 2763 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2764 ntohs(hp->ancount)); 2765 #endif 2766 continue; 2767 } 2768 2769 ancount += ntohs(hp->ancount); 2770 2771 t->n = n; 2772 } 2773 2774 free(buf); 2775 2776 if (ancount == 0) { 2777 switch (rcode) { 2778 case NXDOMAIN: 2779 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2780 break; 2781 case SERVFAIL: 2782 RES_SET_H_ERRNO(res, TRY_AGAIN); 2783 break; 2784 case NOERROR: 2785 RES_SET_H_ERRNO(res, NO_DATA); 2786 break; 2787 case FORMERR: 2788 case NOTIMP: 2789 case REFUSED: 2790 default: 2791 RES_SET_H_ERRNO(res, NO_RECOVERY); 2792 break; 2793 } 2794 return (-1); 2795 } 2796 return (ancount); 2797 } 2798 2799 /* 2800 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2801 * Return the size of the response on success, -1 on error. 2802 * If enabled, implement search rules until answer or unrecoverable failure 2803 * is detected. Error code, if any, is left in h_errno. 2804 */ 2805 static int 2806 res_searchN(const char *name, struct res_target *target, res_state res) 2807 { 2808 const char *cp, * const *domain; 2809 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2810 u_int dots; 2811 int trailing_dot, ret, saved_herrno; 2812 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2813 int tried_as_is = 0; 2814 int searched = 0; 2815 char abuf[MAXDNAME]; 2816 2817 errno = 0; 2818 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2819 dots = 0; 2820 for (cp = name; *cp; cp++) 2821 dots += (*cp == '.'); 2822 trailing_dot = 0; 2823 if (cp > name && *--cp == '.') 2824 trailing_dot++; 2825 2826 /* 2827 * if there aren't any dots, it could be a user-level alias 2828 */ 2829 if (!dots && 2830 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2831 return (res_queryN(cp, target, res)); 2832 2833 /* 2834 * If there are enough dots in the name, let's just give it a 2835 * try 'as is'. The threshold can be set with the "ndots" option. 2836 * Also, query 'as is', if there is a trailing dot in the name. 2837 */ 2838 saved_herrno = -1; 2839 if (dots >= res->ndots || trailing_dot) { 2840 ret = res_querydomainN(name, NULL, target, res); 2841 if (ret > 0 || trailing_dot) 2842 return (ret); 2843 if (errno == ECONNREFUSED) { 2844 RES_SET_H_ERRNO(res, TRY_AGAIN); 2845 return (-1); 2846 } 2847 switch (res->res_h_errno) { 2848 case NO_DATA: 2849 case HOST_NOT_FOUND: 2850 break; 2851 case TRY_AGAIN: 2852 if (hp->rcode == SERVFAIL) 2853 break; 2854 /* FALLTHROUGH */ 2855 default: 2856 return (-1); 2857 } 2858 saved_herrno = res->res_h_errno; 2859 tried_as_is++; 2860 } 2861 2862 /* 2863 * We do at least one level of search if 2864 * - there is no dot and RES_DEFNAME is set, or 2865 * - there is at least one dot, there is no trailing dot, 2866 * and RES_DNSRCH is set. 2867 */ 2868 if ((!dots && (res->options & RES_DEFNAMES)) || 2869 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2870 int done = 0; 2871 2872 for (domain = (const char * const *)res->dnsrch; 2873 *domain && !done; 2874 domain++) { 2875 searched = 1; 2876 2877 if (domain[0][0] == '\0' || 2878 (domain[0][0] == '.' && domain[0][1] == '\0')) 2879 root_on_list++; 2880 2881 if (root_on_list && tried_as_is) 2882 continue; 2883 2884 ret = res_querydomainN(name, *domain, target, res); 2885 if (ret > 0) 2886 return (ret); 2887 2888 /* 2889 * If no server present, give up. 2890 * If name isn't found in this domain, 2891 * keep trying higher domains in the search list 2892 * (if that's enabled). 2893 * On a NO_DATA error, keep trying, otherwise 2894 * a wildcard entry of another type could keep us 2895 * from finding this entry higher in the domain. 2896 * If we get some other error (negative answer or 2897 * server failure), then stop searching up, 2898 * but try the input name below in case it's 2899 * fully-qualified. 2900 */ 2901 if (errno == ECONNREFUSED) { 2902 RES_SET_H_ERRNO(res, TRY_AGAIN); 2903 return (-1); 2904 } 2905 2906 switch (res->res_h_errno) { 2907 case NO_DATA: 2908 got_nodata++; 2909 /* FALLTHROUGH */ 2910 case HOST_NOT_FOUND: 2911 /* keep trying */ 2912 break; 2913 case TRY_AGAIN: 2914 got_servfail++; 2915 if (hp->rcode == SERVFAIL) { 2916 /* try next search element, if any */ 2917 break; 2918 } 2919 /* FALLTHROUGH */ 2920 default: 2921 /* anything else implies that we're done */ 2922 done++; 2923 } 2924 /* 2925 * if we got here for some reason other than DNSRCH, 2926 * we only wanted one iteration of the loop, so stop. 2927 */ 2928 if (!(res->options & RES_DNSRCH)) 2929 done++; 2930 } 2931 } 2932 2933 switch (res->res_h_errno) { 2934 case NO_DATA: 2935 case HOST_NOT_FOUND: 2936 break; 2937 case TRY_AGAIN: 2938 if (hp->rcode == SERVFAIL) 2939 break; 2940 /* FALLTHROUGH */ 2941 default: 2942 goto giveup; 2943 } 2944 2945 /* 2946 * If the query has not already been tried as is then try it 2947 * unless RES_NOTLDQUERY is set and there were no dots. 2948 */ 2949 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2950 !(tried_as_is || root_on_list)) { 2951 ret = res_querydomainN(name, NULL, target, res); 2952 if (ret > 0) 2953 return (ret); 2954 } 2955 2956 /* 2957 * if we got here, we didn't satisfy the search. 2958 * if we did an initial full query, return that query's h_errno 2959 * (note that we wouldn't be here if that query had succeeded). 2960 * else if we ever got a nodata, send that back as the reason. 2961 * else send back meaningless h_errno, that being the one from 2962 * the last DNSRCH we did. 2963 */ 2964 giveup: 2965 if (saved_herrno != -1) 2966 RES_SET_H_ERRNO(res, saved_herrno); 2967 else if (got_nodata) 2968 RES_SET_H_ERRNO(res, NO_DATA); 2969 else if (got_servfail) 2970 RES_SET_H_ERRNO(res, TRY_AGAIN); 2971 return (-1); 2972 } 2973 2974 /* 2975 * Perform a call on res_query on the concatenation of name and domain, 2976 * removing a trailing dot from name if domain is NULL. 2977 */ 2978 static int 2979 res_querydomainN(const char *name, const char *domain, 2980 struct res_target *target, res_state res) 2981 { 2982 char nbuf[MAXDNAME]; 2983 const char *longname = nbuf; 2984 size_t n, d; 2985 2986 #ifdef DEBUG 2987 if (res->options & RES_DEBUG) 2988 printf(";; res_querydomain(%s, %s)\n", 2989 name, domain?domain:"<Nil>"); 2990 #endif 2991 if (domain == NULL) { 2992 /* 2993 * Check for trailing '.'; 2994 * copy without '.' if present. 2995 */ 2996 n = strlen(name); 2997 if (n >= MAXDNAME) { 2998 RES_SET_H_ERRNO(res, NO_RECOVERY); 2999 return (-1); 3000 } 3001 if (n > 0 && name[--n] == '.') { 3002 strncpy(nbuf, name, n); 3003 nbuf[n] = '\0'; 3004 } else 3005 longname = name; 3006 } else { 3007 n = strlen(name); 3008 d = strlen(domain); 3009 if (n + d + 1 >= MAXDNAME) { 3010 RES_SET_H_ERRNO(res, NO_RECOVERY); 3011 return (-1); 3012 } 3013 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 3014 } 3015 return (res_queryN(longname, target, res)); 3016 } 3017