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