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