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/types.h> 59 #include <sys/param.h> 60 #include <sys/socket.h> 61 #include <net/if.h> 62 #include <netinet/in.h> 63 #include <net/if_types.h> 64 #include <ifaddrs.h> 65 #include <sys/queue.h> 66 #ifdef INET6 67 #include <sys/sysctl.h> 68 #include <sys/ioctl.h> 69 #include <netinet6/in6_var.h> 70 #include <netinet6/nd6.h> 71 #endif 72 #include <arpa/inet.h> 73 #include <arpa/nameser.h> 74 #include <rpc/rpc.h> 75 #include <rpcsvc/yp_prot.h> 76 #include <rpcsvc/ypclnt.h> 77 #include <netdb.h> 78 #include <resolv.h> 79 #include <string.h> 80 #include <stdlib.h> 81 #include <stddef.h> 82 #include <ctype.h> 83 #include <unistd.h> 84 #include <stdio.h> 85 #include <errno.h> 86 87 #include "res_config.h" 88 89 #ifdef DEBUG 90 #include <syslog.h> 91 #endif 92 93 #include <stdarg.h> 94 #include <nsswitch.h> 95 #include "un-namespace.h" 96 #include "netdb_private.h" 97 #include "libc_private.h" 98 #ifdef NS_CACHING 99 #include "nscache.h" 100 #endif 101 102 #define ANY 0 103 #define YES 1 104 #define NO 0 105 106 static const char in_addrany[] = { 0, 0, 0, 0 }; 107 static const char in_loopback[] = { 127, 0, 0, 1 }; 108 #ifdef INET6 109 static const char in6_addrany[] = { 110 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 111 }; 112 static const char in6_loopback[] = { 113 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 114 }; 115 #endif 116 117 struct policyqueue { 118 TAILQ_ENTRY(policyqueue) pc_entry; 119 #ifdef INET6 120 struct in6_addrpolicy pc_policy; 121 #endif 122 }; 123 TAILQ_HEAD(policyhead, policyqueue); 124 125 static const struct afd { 126 int a_af; 127 int a_addrlen; 128 socklen_t a_socklen; 129 int a_off; 130 const char *a_addrany; 131 const char *a_loopback; 132 int a_scoped; 133 } afdl [] = { 134 #ifdef INET6 135 #define N_INET6 0 136 {PF_INET6, sizeof(struct in6_addr), 137 sizeof(struct sockaddr_in6), 138 offsetof(struct sockaddr_in6, sin6_addr), 139 in6_addrany, in6_loopback, 1}, 140 #define N_INET 1 141 #define N_LOCAL 2 142 #else 143 #define N_INET 0 144 #define N_LOCAL 1 145 #endif 146 {PF_INET, sizeof(struct in_addr), 147 sizeof(struct sockaddr_in), 148 offsetof(struct sockaddr_in, sin_addr), 149 in_addrany, in_loopback, 0}, 150 #define sizeofmember(type, member) (sizeof(((type *)0)->member)) 151 {PF_LOCAL, sizeofmember(struct sockaddr_un, sun_path), 152 sizeof(struct sockaddr_un), 153 offsetof(struct sockaddr_un, sun_path), 154 NULL, NULL, 0}, 155 {0, 0, 0, 0, NULL, NULL, 0}, 156 }; 157 158 struct explore { 159 int e_af; 160 int e_socktype; 161 int e_protocol; 162 int e_wild; 163 #define AF_ANY 0x01 164 #define SOCKTYPE_ANY 0x02 165 #define PROTOCOL_ANY 0x04 166 #define WILD_AF(ex) ((ex)->e_wild & AF_ANY) 167 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & SOCKTYPE_ANY) 168 #define WILD_PROTOCOL(ex) ((ex)->e_wild & PROTOCOL_ANY) 169 }; 170 171 static const struct explore explore[] = { 172 #ifdef INET6 173 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 174 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 175 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, 176 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 177 { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 178 AF_ANY | SOCKTYPE_ANY }, 179 { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 180 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 181 { PF_INET6, SOCK_DGRAM, IPPROTO_UDPLITE, 182 AF_ANY | SOCKTYPE_ANY }, 183 { PF_INET6, SOCK_RAW, ANY, 184 AF_ANY | PROTOCOL_ANY }, 185 #endif 186 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, 187 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 188 { PF_INET, SOCK_STREAM, IPPROTO_TCP, 189 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 190 { PF_INET, SOCK_STREAM, IPPROTO_SCTP, 191 AF_ANY | SOCKTYPE_ANY }, 192 { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 193 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 194 { PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE, 195 AF_ANY | SOCKTYPE_ANY }, 196 { PF_INET, SOCK_RAW, ANY, 197 AF_ANY | PROTOCOL_ANY }, 198 { PF_LOCAL, SOCK_DGRAM, ANY, 199 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 200 { PF_LOCAL, SOCK_STREAM, ANY, 201 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 202 { PF_LOCAL, SOCK_SEQPACKET, ANY, 203 AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, 204 { -1, 0, 0, 0 }, 205 }; 206 207 #ifdef INET6 208 #define PTON_MAX 16 209 #else 210 #define PTON_MAX 4 211 #endif 212 213 #define AIO_SRCFLAG_DEPRECATED 0x1 214 215 struct ai_order { 216 union { 217 struct sockaddr_storage aiou_ss; 218 struct sockaddr aiou_sa; 219 } aio_src_un; 220 #define aio_srcsa aio_src_un.aiou_sa 221 u_int32_t aio_srcflag; 222 int aio_srcscope; 223 int aio_dstscope; 224 struct policyqueue *aio_srcpolicy; 225 struct policyqueue *aio_dstpolicy; 226 struct addrinfo *aio_ai; 227 int aio_matchlen; 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[sizeof(afdl)/sizeof(afdl[0])]; 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 * occassions. 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 = malloc(sizeof(*aio) * n)) == NULL) 695 return(n); /* give up reordering */ 696 memset(aio, 0, sizeof(*aio) * n); 697 698 /* retrieve address selection policy from the kernel */ 699 TAILQ_INIT(&policyhead); 700 if (!get_addrselectpolicy(&policyhead)) { 701 /* no policy is installed into kernel, we don't sort. */ 702 free(aio); 703 return (n); 704 } 705 706 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 707 aio[i].aio_ai = ai; 708 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 709 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 710 &policyhead); 711 set_source(&aio[i], &policyhead); 712 } 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, sizeof(mib) / sizeof(mib[0]), 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, sizeof(mib) / sizeof(mib[0]), 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 < addrlen * 8) { 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 return(-1); 1071 } 1072 1073 /* 1074 * Copy from scope.c. 1075 * XXX: we should standardize the functions and link them as standard 1076 * library. 1077 */ 1078 static int 1079 gai_addr2scopetype(struct sockaddr *sa) 1080 { 1081 #ifdef INET6 1082 struct sockaddr_in6 *sa6; 1083 #endif 1084 struct sockaddr_in *sa4; 1085 1086 switch(sa->sa_family) { 1087 #ifdef INET6 1088 case AF_INET6: 1089 sa6 = (struct sockaddr_in6 *)sa; 1090 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1091 /* just use the scope field of the multicast address */ 1092 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1093 } 1094 /* 1095 * Unicast addresses: map scope type to corresponding scope 1096 * value defined for multcast addresses. 1097 * XXX: hardcoded scope type values are bad... 1098 */ 1099 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1100 return(1); /* node local scope */ 1101 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1102 return(2); /* link-local scope */ 1103 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1104 return(5); /* site-local scope */ 1105 return(14); /* global scope */ 1106 break; 1107 #endif 1108 case AF_INET: 1109 /* 1110 * IPv4 pseudo scoping according to RFC 3484. 1111 */ 1112 sa4 = (struct sockaddr_in *)sa; 1113 /* IPv4 autoconfiguration addresses have link-local scope. */ 1114 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1115 ((u_char *)&sa4->sin_addr)[1] == 254) 1116 return(2); 1117 /* Private addresses have site-local scope. */ 1118 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1119 (((u_char *)&sa4->sin_addr)[0] == 172 && 1120 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1121 (((u_char *)&sa4->sin_addr)[0] == 192 && 1122 ((u_char *)&sa4->sin_addr)[1] == 168)) 1123 return(14); /* XXX: It should be 5 unless NAT */ 1124 /* Loopback addresses have link-local scope. */ 1125 if (((u_char *)&sa4->sin_addr)[0] == 127) 1126 return(2); 1127 return(14); 1128 break; 1129 default: 1130 errno = EAFNOSUPPORT; /* is this a good error? */ 1131 return(-1); 1132 } 1133 } 1134 1135 static int 1136 explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1137 struct addrinfo **res) 1138 { 1139 int error; 1140 struct addrinfo sentinel, *cur; 1141 const struct addrinfo *src; 1142 1143 error = 0; 1144 sentinel.ai_next = NULL; 1145 cur = &sentinel; 1146 1147 for (src = src0; src != NULL; src = src->ai_next) { 1148 if (src->ai_family != pai->ai_family) 1149 continue; 1150 1151 cur->ai_next = copy_ai(src); 1152 if (!cur->ai_next) { 1153 error = EAI_MEMORY; 1154 goto fail; 1155 } 1156 1157 cur->ai_next->ai_socktype = pai->ai_socktype; 1158 cur->ai_next->ai_protocol = pai->ai_protocol; 1159 cur = cur->ai_next; 1160 } 1161 1162 *res = sentinel.ai_next; 1163 return 0; 1164 1165 fail: 1166 freeaddrinfo(sentinel.ai_next); 1167 return error; 1168 } 1169 1170 /* 1171 * hostname == NULL. 1172 * passive socket -> anyaddr (0.0.0.0 or ::) 1173 * non-passive socket -> localhost (127.0.0.1 or ::1) 1174 */ 1175 static int 1176 explore_null(const struct addrinfo *pai, const char *servname, 1177 struct addrinfo **res) 1178 { 1179 int s; 1180 const struct afd *afd; 1181 struct addrinfo *ai; 1182 int error; 1183 1184 *res = NULL; 1185 ai = NULL; 1186 1187 if (pai->ai_family == PF_LOCAL) 1188 return (0); 1189 1190 /* 1191 * filter out AFs that are not supported by the kernel 1192 * XXX errno? 1193 */ 1194 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1195 if (s < 0) { 1196 if (errno != EMFILE) 1197 return 0; 1198 } else 1199 _close(s); 1200 1201 afd = find_afd(pai->ai_family); 1202 if (afd == NULL) 1203 return 0; 1204 1205 if (pai->ai_flags & AI_PASSIVE) { 1206 GET_AI(ai, afd, afd->a_addrany); 1207 GET_PORT(ai, servname); 1208 } else { 1209 GET_AI(ai, afd, afd->a_loopback); 1210 GET_PORT(ai, servname); 1211 } 1212 1213 *res = ai; 1214 return 0; 1215 1216 free: 1217 if (ai != NULL) 1218 freeaddrinfo(ai); 1219 return error; 1220 } 1221 1222 /* 1223 * numeric hostname 1224 */ 1225 static int 1226 explore_numeric(const struct addrinfo *pai, const char *hostname, 1227 const char *servname, struct addrinfo **res, const char *canonname) 1228 { 1229 const struct afd *afd; 1230 struct addrinfo *ai, ai0; 1231 int error; 1232 char pton[PTON_MAX], path[PATH_MAX], *p; 1233 1234 #ifdef CTASSERT 1235 CTASSERT(sizeofmember(struct sockaddr_un, sun_path) <= PATH_MAX); 1236 #endif 1237 *res = NULL; 1238 ai = NULL; 1239 1240 afd = find_afd(pai->ai_family); 1241 if (afd == NULL) 1242 return 0; 1243 1244 switch (afd->a_af) { 1245 case AF_LOCAL: 1246 if (hostname[0] != '/') 1247 ERR(EAI_NONAME); 1248 if (strlen(hostname) > afd->a_addrlen) 1249 ERR(EAI_MEMORY); 1250 /* NUL-termination does not need to be guaranteed. */ 1251 strncpy(path, hostname, afd->a_addrlen); 1252 p = &path[0]; 1253 break; 1254 case AF_INET: 1255 /* 1256 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1257 * that are accepted by inet_addr() and its family. The 1258 * accepted forms includes the "classful" one, which inet_pton 1259 * does not accept. So we need to separate the case for 1260 * AF_INET. 1261 */ 1262 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1263 return 0; 1264 p = pton; 1265 break; 1266 default: 1267 if (inet_pton(afd->a_af, hostname, pton) != 1) { 1268 if (pai->ai_family != AF_INET6 || 1269 (pai->ai_flags & AI_V4MAPPED) != AI_V4MAPPED) 1270 return 0; 1271 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1272 return 0; 1273 afd = &afdl[N_INET]; 1274 ai0 = *pai; 1275 ai0.ai_family = AF_INET; 1276 pai = &ai0; 1277 } 1278 p = pton; 1279 break; 1280 } 1281 1282 if (pai->ai_family == afd->a_af) { 1283 GET_AI(ai, afd, p); 1284 GET_PORT(ai, servname); 1285 if ((pai->ai_family == AF_INET || 1286 pai->ai_family == AF_INET6) && 1287 (pai->ai_flags & AI_CANONNAME)) { 1288 /* 1289 * Set the numeric address itself as the canonical 1290 * name, based on a clarification in RFC3493. 1291 */ 1292 GET_CANONNAME(ai, canonname); 1293 } 1294 } else { 1295 /* 1296 * XXX: This should not happen since we already matched the AF 1297 * by find_afd. 1298 */ 1299 ERR(EAI_FAMILY); 1300 } 1301 1302 *res = ai; 1303 return 0; 1304 1305 free: 1306 bad: 1307 if (ai != NULL) 1308 freeaddrinfo(ai); 1309 return error; 1310 } 1311 1312 /* 1313 * numeric hostname with scope 1314 */ 1315 static int 1316 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1317 const char *servname, struct addrinfo **res) 1318 { 1319 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 1320 return explore_numeric(pai, hostname, servname, res, hostname); 1321 #else 1322 const struct afd *afd; 1323 struct addrinfo *cur; 1324 int error; 1325 char *cp, *hostname2 = NULL, *scope, *addr; 1326 struct sockaddr_in6 *sin6; 1327 1328 afd = find_afd(pai->ai_family); 1329 if (afd == NULL) 1330 return 0; 1331 1332 if (!afd->a_scoped) 1333 return explore_numeric(pai, hostname, servname, res, hostname); 1334 1335 cp = strchr(hostname, SCOPE_DELIMITER); 1336 if (cp == NULL) 1337 return explore_numeric(pai, hostname, servname, res, hostname); 1338 1339 /* 1340 * Handle special case of <scoped_address><delimiter><scope id> 1341 */ 1342 hostname2 = strdup(hostname); 1343 if (hostname2 == NULL) 1344 return EAI_MEMORY; 1345 /* terminate at the delimiter */ 1346 hostname2[cp - hostname] = '\0'; 1347 addr = hostname2; 1348 scope = cp + 1; 1349 1350 error = explore_numeric(pai, addr, servname, res, hostname); 1351 if (error == 0) { 1352 u_int32_t scopeid; 1353 1354 for (cur = *res; cur; cur = cur->ai_next) { 1355 if (cur->ai_family != AF_INET6) 1356 continue; 1357 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1358 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1359 free(hostname2); 1360 freeaddrinfo(*res); 1361 *res = NULL; 1362 return(EAI_NONAME); /* XXX: is return OK? */ 1363 } 1364 sin6->sin6_scope_id = scopeid; 1365 } 1366 } 1367 1368 free(hostname2); 1369 1370 if (error && *res) { 1371 freeaddrinfo(*res); 1372 *res = NULL; 1373 } 1374 return error; 1375 #endif 1376 } 1377 1378 static int 1379 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1380 { 1381 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1382 ai->ai_canonname = strdup(str); 1383 if (ai->ai_canonname == NULL) 1384 return EAI_MEMORY; 1385 } 1386 return 0; 1387 } 1388 1389 static struct addrinfo * 1390 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1391 { 1392 char *p; 1393 struct addrinfo *ai; 1394 #ifdef INET6 1395 struct in6_addr mapaddr; 1396 1397 if (afd->a_af == AF_INET && (pai->ai_flags & AI_V4MAPPED) != 0) { 1398 afd = &afdl[N_INET6]; 1399 _map_v4v6_address(addr, (char *)&mapaddr); 1400 addr = (char *)&mapaddr; 1401 } 1402 #endif 1403 1404 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1405 + (afd->a_socklen)); 1406 if (ai == NULL) 1407 return NULL; 1408 1409 memcpy(ai, pai, sizeof(struct addrinfo)); 1410 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1411 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1412 ai->ai_addr->sa_len = afd->a_socklen; 1413 ai->ai_addrlen = afd->a_socklen; 1414 if (ai->ai_family == PF_LOCAL) { 1415 size_t n = strnlen(addr, afd->a_addrlen); 1416 1417 ai->ai_addrlen -= afd->a_addrlen - n; 1418 ai->ai_addr->sa_len -= afd->a_addrlen - n; 1419 } 1420 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1421 p = (char *)(void *)(ai->ai_addr); 1422 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1423 return ai; 1424 } 1425 1426 /* XXX need to malloc() the same way we do from other functions! */ 1427 static struct addrinfo * 1428 copy_ai(const struct addrinfo *pai) 1429 { 1430 struct addrinfo *ai; 1431 size_t l; 1432 1433 l = sizeof(*ai) + pai->ai_addrlen; 1434 if ((ai = (struct addrinfo *)malloc(l)) == NULL) 1435 return NULL; 1436 memset(ai, 0, l); 1437 memcpy(ai, pai, sizeof(*ai)); 1438 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1439 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1440 1441 if (pai->ai_canonname) { 1442 l = strlen(pai->ai_canonname) + 1; 1443 if ((ai->ai_canonname = malloc(l)) == NULL) { 1444 free(ai); 1445 return NULL; 1446 } 1447 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1448 } else { 1449 /* just to make sure */ 1450 ai->ai_canonname = NULL; 1451 } 1452 1453 ai->ai_next = NULL; 1454 1455 return ai; 1456 } 1457 1458 static int 1459 get_portmatch(const struct addrinfo *ai, const char *servname) 1460 { 1461 1462 /* get_port does not touch first argument when matchonly == 1. */ 1463 /* LINTED const cast */ 1464 return get_port((struct addrinfo *)ai, servname, 1); 1465 } 1466 1467 static int 1468 get_port(struct addrinfo *ai, const char *servname, int matchonly) 1469 { 1470 const char *proto; 1471 struct servent *sp; 1472 int port, error; 1473 int allownumeric; 1474 1475 if (servname == NULL) 1476 return 0; 1477 switch (ai->ai_family) { 1478 case AF_LOCAL: 1479 /* AF_LOCAL ignores servname silently. */ 1480 return (0); 1481 case AF_INET: 1482 #ifdef AF_INET6 1483 case AF_INET6: 1484 #endif 1485 break; 1486 default: 1487 return 0; 1488 } 1489 1490 switch (ai->ai_socktype) { 1491 case SOCK_RAW: 1492 return EAI_SERVICE; 1493 case SOCK_DGRAM: 1494 case SOCK_STREAM: 1495 case SOCK_SEQPACKET: 1496 allownumeric = 1; 1497 break; 1498 case ANY: 1499 switch (ai->ai_family) { 1500 case AF_INET: 1501 #ifdef AF_INET6 1502 case AF_INET6: 1503 #endif 1504 allownumeric = 1; 1505 break; 1506 default: 1507 allownumeric = 0; 1508 break; 1509 } 1510 break; 1511 default: 1512 return EAI_SOCKTYPE; 1513 } 1514 1515 error = str2number(servname, &port); 1516 if (error == 0) { 1517 if (!allownumeric) 1518 return EAI_SERVICE; 1519 if (port < 0 || port > 65535) 1520 return EAI_SERVICE; 1521 port = htons(port); 1522 } else { 1523 if (ai->ai_flags & AI_NUMERICSERV) 1524 return EAI_NONAME; 1525 1526 switch (ai->ai_protocol) { 1527 case IPPROTO_UDP: 1528 proto = "udp"; 1529 break; 1530 case IPPROTO_TCP: 1531 proto = "tcp"; 1532 break; 1533 case IPPROTO_SCTP: 1534 proto = "sctp"; 1535 break; 1536 case IPPROTO_UDPLITE: 1537 proto = "udplite"; 1538 break; 1539 default: 1540 proto = NULL; 1541 break; 1542 } 1543 1544 if ((sp = getservbyname(servname, proto)) == NULL) 1545 return EAI_SERVICE; 1546 port = sp->s_port; 1547 } 1548 1549 if (!matchonly) { 1550 switch (ai->ai_family) { 1551 case AF_INET: 1552 ((struct sockaddr_in *)(void *) 1553 ai->ai_addr)->sin_port = port; 1554 break; 1555 #ifdef INET6 1556 case AF_INET6: 1557 ((struct sockaddr_in6 *)(void *) 1558 ai->ai_addr)->sin6_port = port; 1559 break; 1560 #endif 1561 } 1562 } 1563 1564 return 0; 1565 } 1566 1567 static const struct afd * 1568 find_afd(int af) 1569 { 1570 const struct afd *afd; 1571 1572 if (af == PF_UNSPEC) 1573 return NULL; 1574 for (afd = afdl; afd->a_af; afd++) { 1575 if (afd->a_af == af) 1576 return afd; 1577 } 1578 return NULL; 1579 } 1580 1581 /* 1582 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are 1583 * configured on the local system and correlates with pai->ai_family value. 1584 * If an address family is not configured on the system, it will not be 1585 * queried for. For this purpose, loopback addresses are not considered 1586 * configured addresses. 1587 * 1588 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1589 * _dns_getaddrinfo. 1590 */ 1591 static int 1592 addrconfig(struct addrinfo *pai) 1593 { 1594 struct ifaddrs *ifaddrs, *ifa; 1595 struct sockaddr_in *sin; 1596 #ifdef INET6 1597 struct sockaddr_in6 *sin6; 1598 #endif 1599 int seen_inet = 0, seen_inet6 = 0; 1600 1601 if (getifaddrs(&ifaddrs) != 0) 1602 return (0); 1603 1604 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1605 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1606 continue; 1607 switch (ifa->ifa_addr->sa_family) { 1608 case AF_INET: 1609 if (seen_inet) 1610 continue; 1611 sin = (struct sockaddr_in *)(ifa->ifa_addr); 1612 if (htonl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) 1613 continue; 1614 seen_inet = 1; 1615 break; 1616 #ifdef INET6 1617 case AF_INET6: 1618 if (seen_inet6) 1619 continue; 1620 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); 1621 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 1622 continue; 1623 if ((ifa->ifa_flags & IFT_LOOP) != 0 && 1624 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 1625 continue; 1626 if (is_ifdisabled(ifa->ifa_name)) 1627 continue; 1628 seen_inet6 = 1; 1629 break; 1630 #endif 1631 } 1632 } 1633 freeifaddrs(ifaddrs); 1634 1635 switch(pai->ai_family) { 1636 case AF_INET6: 1637 return (seen_inet6); 1638 case AF_INET: 1639 return (seen_inet); 1640 case AF_UNSPEC: 1641 if (seen_inet == seen_inet6) 1642 return (seen_inet); 1643 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1644 return (1); 1645 } 1646 return (1); 1647 } 1648 1649 #ifdef INET6 1650 static int 1651 is_ifdisabled(char *name) 1652 { 1653 struct in6_ndireq nd; 1654 int fd; 1655 1656 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1657 return (-1); 1658 memset(&nd, 0, sizeof(nd)); 1659 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1660 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1661 _close(fd); 1662 return (-1); 1663 } 1664 _close(fd); 1665 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1666 } 1667 1668 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1669 static int 1670 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1671 { 1672 u_long lscopeid; 1673 struct in6_addr *a6; 1674 char *ep; 1675 1676 a6 = &sin6->sin6_addr; 1677 1678 /* empty scopeid portion is invalid */ 1679 if (*scope == '\0') 1680 return -1; 1681 1682 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1683 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1684 /* 1685 * We currently assume a one-to-one mapping between links 1686 * and interfaces, so we simply use interface indices for 1687 * like-local scopes. 1688 */ 1689 *scopeid = if_nametoindex(scope); 1690 if (*scopeid == 0) 1691 goto trynumeric; 1692 return 0; 1693 } 1694 1695 /* still unclear about literal, allow numeric only - placeholder */ 1696 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1697 goto trynumeric; 1698 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1699 goto trynumeric; 1700 else 1701 goto trynumeric; /* global */ 1702 1703 /* try to convert to a numeric id as a last resort */ 1704 trynumeric: 1705 errno = 0; 1706 lscopeid = strtoul(scope, &ep, 10); 1707 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1708 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1709 return 0; 1710 else 1711 return -1; 1712 } 1713 #endif 1714 1715 1716 #ifdef NS_CACHING 1717 static int 1718 addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1719 void *cache_mdata) 1720 { 1721 res_state statp; 1722 u_long res_options; 1723 1724 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1725 char *hostname; 1726 struct addrinfo *hints; 1727 1728 char *p; 1729 int ai_flags, ai_family, ai_socktype, ai_protocol; 1730 size_t desired_size, size; 1731 1732 statp = __res_state(); 1733 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1734 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1735 1736 hostname = va_arg(ap, char *); 1737 hints = va_arg(ap, struct addrinfo *); 1738 1739 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1740 if (hostname != NULL) { 1741 size = strlen(hostname); 1742 desired_size += size + 1; 1743 } else 1744 size = 0; 1745 1746 if (desired_size > *buffer_size) { 1747 *buffer_size = desired_size; 1748 return (NS_RETURN); 1749 } 1750 1751 if (hints == NULL) 1752 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1753 else { 1754 ai_flags = hints->ai_flags; 1755 ai_family = hints->ai_family; 1756 ai_socktype = hints->ai_socktype; 1757 ai_protocol = hints->ai_protocol; 1758 } 1759 1760 p = buffer; 1761 memcpy(p, &res_options, sizeof(res_options)); 1762 p += sizeof(res_options); 1763 1764 memcpy(p, &op_id, sizeof(int)); 1765 p += sizeof(int); 1766 1767 memcpy(p, &ai_flags, sizeof(int)); 1768 p += sizeof(int); 1769 1770 memcpy(p, &ai_family, sizeof(int)); 1771 p += sizeof(int); 1772 1773 memcpy(p, &ai_socktype, sizeof(int)); 1774 p += sizeof(int); 1775 1776 memcpy(p, &ai_protocol, sizeof(int)); 1777 p += sizeof(int); 1778 1779 if (hostname != NULL) 1780 memcpy(p, hostname, size); 1781 1782 *buffer_size = desired_size; 1783 return (NS_SUCCESS); 1784 } 1785 1786 static int 1787 addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1788 va_list ap, void *cache_mdata) 1789 { 1790 struct addrinfo *ai, *cai; 1791 char *p; 1792 size_t desired_size, size, ai_size; 1793 1794 ai = *((struct addrinfo **)retval); 1795 1796 desired_size = sizeof(size_t); 1797 ai_size = 0; 1798 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1799 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1800 if (cai->ai_canonname != NULL) 1801 desired_size += sizeof(size_t) + 1802 strlen(cai->ai_canonname); 1803 ++ai_size; 1804 } 1805 1806 if (desired_size > *buffer_size) { 1807 /* this assignment is here for future use */ 1808 errno = ERANGE; 1809 *buffer_size = desired_size; 1810 return (NS_RETURN); 1811 } 1812 1813 memset(buffer, 0, desired_size); 1814 p = buffer; 1815 1816 memcpy(p, &ai_size, sizeof(size_t)); 1817 p += sizeof(size_t); 1818 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1819 memcpy(p, cai, sizeof(struct addrinfo)); 1820 p += sizeof(struct addrinfo); 1821 1822 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1823 p += cai->ai_addrlen; 1824 1825 if (cai->ai_canonname != NULL) { 1826 size = strlen(cai->ai_canonname); 1827 memcpy(p, &size, sizeof(size_t)); 1828 p += sizeof(size_t); 1829 1830 memcpy(p, cai->ai_canonname, size); 1831 p += size; 1832 } 1833 } 1834 1835 return (NS_SUCCESS); 1836 } 1837 1838 static int 1839 addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1840 va_list ap, void *cache_mdata) 1841 { 1842 struct addrinfo new_ai, *result, *sentinel, *lasts; 1843 1844 char *p; 1845 size_t ai_size, ai_i, size; 1846 1847 p = buffer; 1848 memcpy(&ai_size, p, sizeof(size_t)); 1849 p += sizeof(size_t); 1850 1851 result = NULL; 1852 lasts = NULL; 1853 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1854 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1855 p += sizeof(struct addrinfo); 1856 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1857 _ALIGNBYTES; 1858 1859 sentinel = (struct addrinfo *)malloc(size); 1860 memset(sentinel, 0, size); 1861 1862 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1863 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1864 sizeof(struct addrinfo)); 1865 1866 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1867 p += new_ai.ai_addrlen; 1868 1869 if (new_ai.ai_canonname != NULL) { 1870 memcpy(&size, p, sizeof(size_t)); 1871 p += sizeof(size_t); 1872 1873 sentinel->ai_canonname = (char *)malloc(size + 1); 1874 memset(sentinel->ai_canonname, 0, size + 1); 1875 1876 memcpy(sentinel->ai_canonname, p, size); 1877 p += size; 1878 } 1879 1880 if (result == NULL) { 1881 result = sentinel; 1882 lasts = sentinel; 1883 } else { 1884 lasts->ai_next = sentinel; 1885 lasts = sentinel; 1886 } 1887 } 1888 1889 *((struct addrinfo **)retval) = result; 1890 return (NS_SUCCESS); 1891 } 1892 #endif /* NS_CACHING */ 1893 1894 /* 1895 * FQDN hostname, DNS lookup 1896 */ 1897 static int 1898 explore_fqdn(const struct addrinfo *pai, const char *hostname, 1899 const char *servname, struct addrinfo **res) 1900 { 1901 struct addrinfo *result; 1902 struct addrinfo *cur; 1903 int error = 0; 1904 1905 #ifdef NS_CACHING 1906 static const nss_cache_info cache_info = 1907 NS_COMMON_CACHE_INFO_INITIALIZER( 1908 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1909 addrinfo_unmarshal_func); 1910 #endif 1911 static const ns_dtab dtab[] = { 1912 NS_FILES_CB(_files_getaddrinfo, NULL) 1913 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1914 NS_NIS_CB(_yp_getaddrinfo, NULL) 1915 #ifdef NS_CACHING 1916 NS_CACHE_CB(&cache_info) 1917 #endif 1918 { 0 } 1919 }; 1920 1921 result = NULL; 1922 1923 /* 1924 * if the servname does not match socktype/protocol, ignore it. 1925 */ 1926 if (get_portmatch(pai, servname) != 0) 1927 return 0; 1928 1929 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1930 default_dns_files, hostname, pai)) { 1931 case NS_TRYAGAIN: 1932 error = EAI_AGAIN; 1933 goto free; 1934 case NS_UNAVAIL: 1935 error = EAI_FAIL; 1936 goto free; 1937 case NS_NOTFOUND: 1938 error = EAI_NONAME; 1939 goto free; 1940 case NS_SUCCESS: 1941 error = 0; 1942 for (cur = result; cur; cur = cur->ai_next) { 1943 GET_PORT(cur, servname); 1944 /* canonname should be filled already */ 1945 } 1946 break; 1947 } 1948 1949 *res = result; 1950 1951 return 0; 1952 1953 free: 1954 if (result) 1955 freeaddrinfo(result); 1956 return error; 1957 } 1958 1959 #ifdef DEBUG 1960 static const char AskedForGot[] = 1961 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1962 #endif 1963 1964 static struct addrinfo * 1965 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1966 const struct addrinfo *pai, res_state res) 1967 { 1968 struct addrinfo sentinel, *cur; 1969 struct addrinfo ai; 1970 const struct afd *afd; 1971 char *canonname; 1972 const HEADER *hp; 1973 const u_char *cp; 1974 int n; 1975 const u_char *eom; 1976 char *bp, *ep; 1977 int type, class, ancount, qdcount; 1978 int haveanswer, had_error; 1979 char tbuf[MAXDNAME]; 1980 int (*name_ok)(const char *); 1981 char hostbuf[8*1024]; 1982 1983 memset(&sentinel, 0, sizeof(sentinel)); 1984 cur = &sentinel; 1985 1986 canonname = NULL; 1987 eom = answer->buf + anslen; 1988 switch (qtype) { 1989 case T_A: 1990 case T_AAAA: 1991 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1992 name_ok = res_hnok; 1993 break; 1994 default: 1995 return (NULL); /* XXX should be abort(); */ 1996 } 1997 /* 1998 * find first satisfactory answer 1999 */ 2000 hp = &answer->hdr; 2001 ancount = ntohs(hp->ancount); 2002 qdcount = ntohs(hp->qdcount); 2003 bp = hostbuf; 2004 ep = hostbuf + sizeof hostbuf; 2005 cp = answer->buf + HFIXEDSZ; 2006 if (qdcount != 1) { 2007 RES_SET_H_ERRNO(res, NO_RECOVERY); 2008 return (NULL); 2009 } 2010 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2011 if ((n < 0) || !(*name_ok)(bp)) { 2012 RES_SET_H_ERRNO(res, NO_RECOVERY); 2013 return (NULL); 2014 } 2015 cp += n + QFIXEDSZ; 2016 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 2017 /* res_send() has already verified that the query name is the 2018 * same as the one we sent; this just gets the expanded name 2019 * (i.e., with the succeeding search-domain tacked on). 2020 */ 2021 n = strlen(bp) + 1; /* for the \0 */ 2022 if (n >= MAXHOSTNAMELEN) { 2023 RES_SET_H_ERRNO(res, NO_RECOVERY); 2024 return (NULL); 2025 } 2026 canonname = bp; 2027 bp += n; 2028 /* The qname can be abbreviated, but h_name is now absolute. */ 2029 qname = canonname; 2030 } 2031 haveanswer = 0; 2032 had_error = 0; 2033 while (ancount-- > 0 && cp < eom && !had_error) { 2034 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 2035 if ((n < 0) || !(*name_ok)(bp)) { 2036 had_error++; 2037 continue; 2038 } 2039 cp += n; /* name */ 2040 type = _getshort(cp); 2041 cp += INT16SZ; /* type */ 2042 class = _getshort(cp); 2043 cp += INT16SZ + INT32SZ; /* class, TTL */ 2044 n = _getshort(cp); 2045 cp += INT16SZ; /* len */ 2046 if (class != C_IN) { 2047 /* XXX - debug? syslog? */ 2048 cp += n; 2049 continue; /* XXX - had_error++ ? */ 2050 } 2051 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 2052 type == T_CNAME) { 2053 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 2054 if ((n < 0) || !(*name_ok)(tbuf)) { 2055 had_error++; 2056 continue; 2057 } 2058 cp += n; 2059 /* Get canonical name. */ 2060 n = strlen(tbuf) + 1; /* for the \0 */ 2061 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 2062 had_error++; 2063 continue; 2064 } 2065 strlcpy(bp, tbuf, ep - bp); 2066 canonname = bp; 2067 bp += n; 2068 continue; 2069 } 2070 if (qtype == T_ANY) { 2071 if (!(type == T_A || type == T_AAAA)) { 2072 cp += n; 2073 continue; 2074 } 2075 } else if (type != qtype) { 2076 #ifdef DEBUG 2077 if (type != T_KEY && type != T_SIG && 2078 type != ns_t_dname) 2079 syslog(LOG_NOTICE|LOG_AUTH, 2080 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2081 qname, p_class(C_IN), p_type(qtype), 2082 p_type(type)); 2083 #endif 2084 cp += n; 2085 continue; /* XXX - had_error++ ? */ 2086 } 2087 switch (type) { 2088 case T_A: 2089 case T_AAAA: 2090 if (strcasecmp(canonname, bp) != 0) { 2091 #ifdef DEBUG 2092 syslog(LOG_NOTICE|LOG_AUTH, 2093 AskedForGot, canonname, bp); 2094 #endif 2095 cp += n; 2096 continue; /* XXX - had_error++ ? */ 2097 } 2098 if (type == T_A && n != INADDRSZ) { 2099 cp += n; 2100 continue; 2101 } 2102 if (type == T_AAAA && n != IN6ADDRSZ) { 2103 cp += n; 2104 continue; 2105 } 2106 #ifdef FILTER_V4MAPPED 2107 if (type == T_AAAA) { 2108 struct in6_addr in6; 2109 memcpy(&in6, cp, sizeof(in6)); 2110 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2111 cp += n; 2112 continue; 2113 } 2114 } 2115 #endif 2116 if (!haveanswer) { 2117 int nn; 2118 2119 canonname = bp; 2120 nn = strlen(bp) + 1; /* for the \0 */ 2121 bp += nn; 2122 } 2123 2124 /* don't overwrite pai */ 2125 ai = *pai; 2126 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2127 afd = find_afd(ai.ai_family); 2128 if (afd == NULL) { 2129 cp += n; 2130 continue; 2131 } 2132 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2133 if (cur->ai_next == NULL) 2134 had_error++; 2135 while (cur && cur->ai_next) 2136 cur = cur->ai_next; 2137 cp += n; 2138 break; 2139 default: 2140 abort(); 2141 } 2142 if (!had_error) 2143 haveanswer++; 2144 } 2145 if (haveanswer) { 2146 #if defined(RESOLVSORT) 2147 /* 2148 * We support only IPv4 address for backward 2149 * compatibility against gethostbyname(3). 2150 */ 2151 if (res->nsort && qtype == T_A) { 2152 if (addr4sort(&sentinel, res) < 0) { 2153 freeaddrinfo(sentinel.ai_next); 2154 RES_SET_H_ERRNO(res, NO_RECOVERY); 2155 return NULL; 2156 } 2157 } 2158 #endif /*RESOLVSORT*/ 2159 if (!canonname) 2160 (void)get_canonname(pai, sentinel.ai_next, qname); 2161 else 2162 (void)get_canonname(pai, sentinel.ai_next, canonname); 2163 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2164 return sentinel.ai_next; 2165 } 2166 2167 /* 2168 * We could have walked a CNAME chain, but the ultimate target 2169 * may not have what we looked for. 2170 */ 2171 RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : NO_RECOVERY); 2172 return NULL; 2173 } 2174 2175 #ifdef RESOLVSORT 2176 struct addr_ptr { 2177 struct addrinfo *ai; 2178 int aval; 2179 }; 2180 2181 static int 2182 addr4sort(struct addrinfo *sentinel, res_state res) 2183 { 2184 struct addrinfo *ai; 2185 struct addr_ptr *addrs, addr; 2186 struct sockaddr_in *sin; 2187 int naddrs, i, j; 2188 int needsort = 0; 2189 2190 if (!sentinel) 2191 return -1; 2192 naddrs = 0; 2193 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2194 naddrs++; 2195 if (naddrs < 2) 2196 return 0; /* We don't need sorting. */ 2197 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2198 return -1; 2199 i = 0; 2200 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2201 sin = (struct sockaddr_in *)ai->ai_addr; 2202 for (j = 0; (unsigned)j < res->nsort; j++) { 2203 if (res->sort_list[j].addr.s_addr == 2204 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2205 break; 2206 } 2207 addrs[i].ai = ai; 2208 addrs[i].aval = j; 2209 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2210 needsort = i; 2211 i++; 2212 } 2213 if (!needsort) { 2214 free(addrs); 2215 return 0; 2216 } 2217 2218 while (needsort < naddrs) { 2219 for (j = needsort - 1; j >= 0; j--) { 2220 if (addrs[j].aval > addrs[j+1].aval) { 2221 addr = addrs[j]; 2222 addrs[j] = addrs[j + 1]; 2223 addrs[j + 1] = addr; 2224 } else 2225 break; 2226 } 2227 needsort++; 2228 } 2229 2230 ai = sentinel; 2231 for (i = 0; i < naddrs; ++i) { 2232 ai->ai_next = addrs[i].ai; 2233 ai = ai->ai_next; 2234 } 2235 ai->ai_next = NULL; 2236 free(addrs); 2237 return 0; 2238 } 2239 #endif /*RESOLVSORT*/ 2240 2241 /*ARGSUSED*/ 2242 static int 2243 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2244 { 2245 struct addrinfo *ai, ai0; 2246 querybuf *buf, *buf2; 2247 const char *hostname; 2248 const struct addrinfo *pai; 2249 struct addrinfo sentinel, *cur; 2250 struct res_target q, q2; 2251 res_state res; 2252 2253 hostname = va_arg(ap, char *); 2254 pai = va_arg(ap, const struct addrinfo *); 2255 2256 memset(&q, 0, sizeof(q)); 2257 memset(&q2, 0, sizeof(q2)); 2258 memset(&sentinel, 0, sizeof(sentinel)); 2259 cur = &sentinel; 2260 2261 res = __res_state(); 2262 2263 buf = malloc(sizeof(*buf)); 2264 if (!buf) { 2265 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2266 return NS_NOTFOUND; 2267 } 2268 buf2 = malloc(sizeof(*buf2)); 2269 if (!buf2) { 2270 free(buf); 2271 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2272 return NS_NOTFOUND; 2273 } 2274 2275 if (pai->ai_family == AF_INET6 && 2276 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) { 2277 ai0 = *pai; 2278 ai0.ai_family = AF_UNSPEC; 2279 pai = &ai0; 2280 } 2281 2282 switch (pai->ai_family) { 2283 case AF_UNSPEC: 2284 q.name = hostname; 2285 q.qclass = C_IN; 2286 q.qtype = T_A; 2287 q.answer = buf->buf; 2288 q.anslen = sizeof(buf->buf); 2289 q.next = &q2; 2290 q2.name = hostname; 2291 q2.qclass = C_IN; 2292 q2.qtype = T_AAAA; 2293 q2.answer = buf2->buf; 2294 q2.anslen = sizeof(buf2->buf); 2295 break; 2296 case AF_INET: 2297 q.name = hostname; 2298 q.qclass = C_IN; 2299 q.qtype = T_A; 2300 q.answer = buf->buf; 2301 q.anslen = sizeof(buf->buf); 2302 break; 2303 case AF_INET6: 2304 q.name = hostname; 2305 q.qclass = C_IN; 2306 q.qtype = T_AAAA; 2307 q.answer = buf->buf; 2308 q.anslen = sizeof(buf->buf); 2309 break; 2310 default: 2311 free(buf); 2312 free(buf2); 2313 return NS_UNAVAIL; 2314 } 2315 2316 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2317 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2318 free(buf); 2319 free(buf2); 2320 return NS_NOTFOUND; 2321 } 2322 2323 if (res_searchN(hostname, &q, res) < 0) { 2324 free(buf); 2325 free(buf2); 2326 return NS_NOTFOUND; 2327 } 2328 /* prefer IPv6 */ 2329 if (q.next) { 2330 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2331 if (ai) { 2332 cur->ai_next = ai; 2333 while (cur && cur->ai_next) 2334 cur = cur->ai_next; 2335 } 2336 } 2337 if (!ai || pai->ai_family != AF_UNSPEC || 2338 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) != AI_V4MAPPED) { 2339 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2340 if (ai) 2341 cur->ai_next = ai; 2342 } 2343 free(buf); 2344 free(buf2); 2345 if (sentinel.ai_next == NULL) 2346 switch (res->res_h_errno) { 2347 case HOST_NOT_FOUND: 2348 case NO_DATA: 2349 return NS_NOTFOUND; 2350 case TRY_AGAIN: 2351 return NS_TRYAGAIN; 2352 default: 2353 return NS_UNAVAIL; 2354 } 2355 *((struct addrinfo **)rv) = sentinel.ai_next; 2356 return NS_SUCCESS; 2357 } 2358 2359 static void 2360 _sethtent(FILE **hostf) 2361 { 2362 if (!*hostf) 2363 *hostf = fopen(_PATH_HOSTS, "re"); 2364 else 2365 rewind(*hostf); 2366 } 2367 2368 static void 2369 _endhtent(FILE **hostf) 2370 { 2371 if (*hostf) { 2372 (void) fclose(*hostf); 2373 *hostf = NULL; 2374 } 2375 } 2376 2377 static struct addrinfo * 2378 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2379 { 2380 char *p; 2381 char *cp, *tname, *cname; 2382 struct addrinfo hints, *res0, *res; 2383 int error; 2384 const char *addr; 2385 char hostbuf[8*1024]; 2386 2387 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2388 return (NULL); 2389 again: 2390 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2391 return (NULL); 2392 if (*p == '#') 2393 goto again; 2394 cp = strpbrk(p, "#\n"); 2395 if (cp != NULL) 2396 *cp = '\0'; 2397 if (!(cp = strpbrk(p, " \t"))) 2398 goto again; 2399 *cp++ = '\0'; 2400 addr = p; 2401 cname = NULL; 2402 /* if this is not something we're looking for, skip it. */ 2403 while (cp && *cp) { 2404 if (*cp == ' ' || *cp == '\t') { 2405 cp++; 2406 continue; 2407 } 2408 tname = cp; 2409 if (cname == NULL) 2410 cname = cp; 2411 if ((cp = strpbrk(cp, " \t")) != NULL) 2412 *cp++ = '\0'; 2413 if (strcasecmp(name, tname) == 0) 2414 goto found; 2415 } 2416 goto again; 2417 2418 found: 2419 /* we should not glob socktype/protocol here */ 2420 memset(&hints, 0, sizeof(hints)); 2421 hints.ai_family = pai->ai_family; 2422 hints.ai_socktype = SOCK_DGRAM; 2423 hints.ai_protocol = 0; 2424 hints.ai_flags = AI_NUMERICHOST; 2425 if (pai->ai_family == AF_INET6 && 2426 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2427 hints.ai_flags |= AI_V4MAPPED; 2428 error = getaddrinfo(addr, "0", &hints, &res0); 2429 if (error) 2430 goto again; 2431 #ifdef FILTER_V4MAPPED 2432 /* XXX should check all items in the chain */ 2433 if (res0->ai_family == AF_INET6 && 2434 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2435 freeaddrinfo(res0); 2436 goto again; 2437 } 2438 #endif 2439 for (res = res0; res; res = res->ai_next) { 2440 /* cover it up */ 2441 res->ai_flags = pai->ai_flags; 2442 res->ai_socktype = pai->ai_socktype; 2443 res->ai_protocol = pai->ai_protocol; 2444 2445 if (pai->ai_flags & AI_CANONNAME) { 2446 if (get_canonname(pai, res, cname) != 0) { 2447 freeaddrinfo(res0); 2448 goto again; 2449 } 2450 } 2451 } 2452 return res0; 2453 } 2454 2455 static struct addrinfo * 2456 _getht(FILE **hostf, const char *name, const struct addrinfo *pai, 2457 struct addrinfo *cur) 2458 { 2459 struct addrinfo *p; 2460 2461 while ((p = _gethtent(hostf, name, pai)) != NULL) { 2462 cur->ai_next = p; 2463 while (cur && cur->ai_next) 2464 cur = cur->ai_next; 2465 } 2466 return (cur); 2467 } 2468 2469 /*ARGSUSED*/ 2470 static int 2471 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2472 { 2473 const char *name; 2474 const struct addrinfo *pai; 2475 struct addrinfo sentinel, *cur; 2476 FILE *hostf = NULL; 2477 2478 name = va_arg(ap, char *); 2479 pai = va_arg(ap, struct addrinfo *); 2480 2481 memset(&sentinel, 0, sizeof(sentinel)); 2482 cur = &sentinel; 2483 2484 _sethtent(&hostf); 2485 if (pai->ai_family == AF_INET6 && 2486 (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) == AI_V4MAPPED) { 2487 struct addrinfo ai0 = *pai; 2488 2489 ai0.ai_flags &= ~AI_V4MAPPED; 2490 cur = _getht(&hostf, name, &ai0, cur); 2491 if (sentinel.ai_next == NULL) { 2492 _sethtent(&hostf); 2493 ai0.ai_flags |= AI_V4MAPPED; 2494 cur = _getht(&hostf, name, &ai0, cur); 2495 } 2496 } else 2497 cur = _getht(&hostf, name, pai, cur); 2498 _endhtent(&hostf); 2499 2500 *((struct addrinfo **)rv) = sentinel.ai_next; 2501 if (sentinel.ai_next == NULL) 2502 return NS_NOTFOUND; 2503 return NS_SUCCESS; 2504 } 2505 2506 #ifdef YP 2507 /*ARGSUSED*/ 2508 static struct addrinfo * 2509 _yphostent(char *line, const struct addrinfo *pai) 2510 { 2511 struct addrinfo sentinel, *cur; 2512 struct addrinfo hints, *res, *res0; 2513 int error; 2514 char *p = line; 2515 const char *addr, *canonname; 2516 char *nextline; 2517 char *cp; 2518 2519 addr = canonname = NULL; 2520 2521 memset(&sentinel, 0, sizeof(sentinel)); 2522 cur = &sentinel; 2523 2524 nextline: 2525 /* terminate line */ 2526 cp = strchr(p, '\n'); 2527 if (cp) { 2528 *cp++ = '\0'; 2529 nextline = cp; 2530 } else 2531 nextline = NULL; 2532 2533 cp = strpbrk(p, " \t"); 2534 if (cp == NULL) { 2535 if (canonname == NULL) 2536 return (NULL); 2537 else 2538 goto done; 2539 } 2540 *cp++ = '\0'; 2541 2542 addr = p; 2543 2544 while (cp && *cp) { 2545 if (*cp == ' ' || *cp == '\t') { 2546 cp++; 2547 continue; 2548 } 2549 if (!canonname) 2550 canonname = cp; 2551 if ((cp = strpbrk(cp, " \t")) != NULL) 2552 *cp++ = '\0'; 2553 } 2554 2555 hints = *pai; 2556 hints.ai_flags = AI_NUMERICHOST; 2557 if (pai->ai_family == AF_INET6 && 2558 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) 2559 hints.ai_flags |= AI_V4MAPPED; 2560 error = getaddrinfo(addr, NULL, &hints, &res0); 2561 if (error == 0) { 2562 for (res = res0; res; res = res->ai_next) { 2563 /* cover it up */ 2564 res->ai_flags = pai->ai_flags; 2565 2566 if (pai->ai_flags & AI_CANONNAME) 2567 (void)get_canonname(pai, res, canonname); 2568 } 2569 } else 2570 res0 = NULL; 2571 if (res0) { 2572 cur->ai_next = res0; 2573 while (cur && cur->ai_next) 2574 cur = cur->ai_next; 2575 } 2576 2577 if (nextline) { 2578 p = nextline; 2579 goto nextline; 2580 } 2581 2582 done: 2583 return sentinel.ai_next; 2584 } 2585 2586 /*ARGSUSED*/ 2587 static int 2588 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2589 { 2590 struct addrinfo sentinel, *cur; 2591 struct addrinfo *ai = NULL; 2592 char *ypbuf; 2593 int ypbuflen, r; 2594 const char *name; 2595 const struct addrinfo *pai; 2596 char *ypdomain; 2597 2598 if (_yp_check(&ypdomain) == 0) 2599 return NS_UNAVAIL; 2600 2601 name = va_arg(ap, char *); 2602 pai = va_arg(ap, const struct addrinfo *); 2603 2604 memset(&sentinel, 0, sizeof(sentinel)); 2605 cur = &sentinel; 2606 2607 /* ipnodes.byname can hold both IPv4/v6 */ 2608 r = yp_match(ypdomain, "ipnodes.byname", name, 2609 (int)strlen(name), &ypbuf, &ypbuflen); 2610 if (r == 0) { 2611 ai = _yphostent(ypbuf, pai); 2612 if (ai) { 2613 cur->ai_next = ai; 2614 while (cur && cur->ai_next) 2615 cur = cur->ai_next; 2616 } 2617 free(ypbuf); 2618 } 2619 2620 if (ai != NULL) { 2621 struct sockaddr_in6 *sin6; 2622 2623 switch (ai->ai_family) { 2624 case AF_INET: 2625 goto done; 2626 case AF_INET6: 2627 sin6 = (struct sockaddr_in6 *)ai->ai_addr; 2628 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 2629 goto done; 2630 break; 2631 } 2632 } 2633 2634 /* hosts.byname is only for IPv4 (Solaris8) */ 2635 if (pai->ai_family == AF_UNSPEC || pai->ai_family == AF_INET || 2636 ((pai->ai_family == AF_INET6 && 2637 (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) && 2638 (ai == NULL || (pai->ai_flags & AI_ALL) == AI_ALL))) { 2639 r = yp_match(ypdomain, "hosts.byname", name, 2640 (int)strlen(name), &ypbuf, &ypbuflen); 2641 if (r == 0) { 2642 struct addrinfo ai4; 2643 2644 ai4 = *pai; 2645 if (pai->ai_family == AF_UNSPEC) 2646 ai4.ai_family = AF_INET; 2647 ai = _yphostent(ypbuf, &ai4); 2648 if (ai) { 2649 cur->ai_next = ai; 2650 while (cur && cur->ai_next) 2651 cur = cur->ai_next; 2652 } 2653 free(ypbuf); 2654 } 2655 } 2656 2657 done: 2658 if (sentinel.ai_next == NULL) { 2659 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2660 return NS_NOTFOUND; 2661 } 2662 *((struct addrinfo **)rv) = sentinel.ai_next; 2663 return NS_SUCCESS; 2664 } 2665 #endif 2666 2667 /* resolver logic */ 2668 2669 /* 2670 * Formulate a normal query, send, and await answer. 2671 * Returned answer is placed in supplied buffer "answer". 2672 * Perform preliminary check of answer, returning success only 2673 * if no error is indicated and the answer count is nonzero. 2674 * Return the size of the response on success, -1 on error. 2675 * Error number is left in h_errno. 2676 * 2677 * Caller must parse answer and determine whether it answers the question. 2678 */ 2679 static int 2680 res_queryN(const char *name, struct res_target *target, res_state res) 2681 { 2682 u_char *buf; 2683 HEADER *hp; 2684 int n; 2685 u_int oflags; 2686 struct res_target *t; 2687 int rcode; 2688 int ancount; 2689 2690 rcode = NOERROR; 2691 ancount = 0; 2692 2693 buf = malloc(MAXPACKET); 2694 if (!buf) { 2695 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2696 return -1; 2697 } 2698 2699 for (t = target; t; t = t->next) { 2700 int class, type; 2701 u_char *answer; 2702 int anslen; 2703 2704 hp = (HEADER *)(void *)t->answer; 2705 2706 /* make it easier... */ 2707 class = t->qclass; 2708 type = t->qtype; 2709 answer = t->answer; 2710 anslen = t->anslen; 2711 2712 oflags = res->_flags; 2713 2714 again: 2715 hp->rcode = NOERROR; /* default */ 2716 2717 #ifdef DEBUG 2718 if (res->options & RES_DEBUG) 2719 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2720 #endif 2721 2722 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2723 buf, MAXPACKET); 2724 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2725 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2726 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2727 if (n <= 0) { 2728 #ifdef DEBUG 2729 if (res->options & RES_DEBUG) 2730 printf(";; res_query: mkquery failed\n"); 2731 #endif 2732 free(buf); 2733 RES_SET_H_ERRNO(res, NO_RECOVERY); 2734 return (n); 2735 } 2736 n = res_nsend(res, buf, n, answer, anslen); 2737 if (n < 0) { 2738 /* 2739 * if the query choked with EDNS0, retry 2740 * without EDNS0 2741 */ 2742 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2743 != 0U && 2744 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2745 res->_flags |= RES_F_EDNS0ERR; 2746 if (res->options & RES_DEBUG) 2747 printf(";; res_nquery: retry without EDNS0\n"); 2748 goto again; 2749 } 2750 rcode = hp->rcode; /* record most recent error */ 2751 #ifdef DEBUG 2752 if (res->options & RES_DEBUG) 2753 printf(";; res_query: send error\n"); 2754 #endif 2755 continue; 2756 } 2757 2758 if (n > anslen) 2759 hp->rcode = FORMERR; /* XXX not very informative */ 2760 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2761 rcode = hp->rcode; /* record most recent error */ 2762 #ifdef DEBUG 2763 if (res->options & RES_DEBUG) 2764 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2765 ntohs(hp->ancount)); 2766 #endif 2767 continue; 2768 } 2769 2770 ancount += ntohs(hp->ancount); 2771 2772 t->n = n; 2773 } 2774 2775 free(buf); 2776 2777 if (ancount == 0) { 2778 switch (rcode) { 2779 case NXDOMAIN: 2780 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2781 break; 2782 case SERVFAIL: 2783 RES_SET_H_ERRNO(res, TRY_AGAIN); 2784 break; 2785 case NOERROR: 2786 RES_SET_H_ERRNO(res, NO_DATA); 2787 break; 2788 case FORMERR: 2789 case NOTIMP: 2790 case REFUSED: 2791 default: 2792 RES_SET_H_ERRNO(res, NO_RECOVERY); 2793 break; 2794 } 2795 return (-1); 2796 } 2797 return (ancount); 2798 } 2799 2800 /* 2801 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2802 * Return the size of the response on success, -1 on error. 2803 * If enabled, implement search rules until answer or unrecoverable failure 2804 * is detected. Error code, if any, is left in h_errno. 2805 */ 2806 static int 2807 res_searchN(const char *name, struct res_target *target, res_state res) 2808 { 2809 const char *cp, * const *domain; 2810 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2811 u_int dots; 2812 int trailing_dot, ret, saved_herrno; 2813 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2814 int tried_as_is = 0; 2815 int searched = 0; 2816 char abuf[MAXDNAME]; 2817 2818 errno = 0; 2819 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2820 dots = 0; 2821 for (cp = name; *cp; cp++) 2822 dots += (*cp == '.'); 2823 trailing_dot = 0; 2824 if (cp > name && *--cp == '.') 2825 trailing_dot++; 2826 2827 /* 2828 * if there aren't any dots, it could be a user-level alias 2829 */ 2830 if (!dots && 2831 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2832 return (res_queryN(cp, target, res)); 2833 2834 /* 2835 * If there are enough dots in the name, let's just give it a 2836 * try 'as is'. The threshold can be set with the "ndots" option. 2837 * Also, query 'as is', if there is a trailing dot in the name. 2838 */ 2839 saved_herrno = -1; 2840 if (dots >= res->ndots || trailing_dot) { 2841 ret = res_querydomainN(name, NULL, target, res); 2842 if (ret > 0 || trailing_dot) 2843 return (ret); 2844 if (errno == ECONNREFUSED) { 2845 RES_SET_H_ERRNO(res, TRY_AGAIN); 2846 return (-1); 2847 } 2848 switch (res->res_h_errno) { 2849 case NO_DATA: 2850 case HOST_NOT_FOUND: 2851 break; 2852 case TRY_AGAIN: 2853 if (hp->rcode == SERVFAIL) 2854 break; 2855 /* FALLTHROUGH */ 2856 default: 2857 return (-1); 2858 } 2859 saved_herrno = res->res_h_errno; 2860 tried_as_is++; 2861 } 2862 2863 /* 2864 * We do at least one level of search if 2865 * - there is no dot and RES_DEFNAME is set, or 2866 * - there is at least one dot, there is no trailing dot, 2867 * and RES_DNSRCH is set. 2868 */ 2869 if ((!dots && (res->options & RES_DEFNAMES)) || 2870 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2871 int done = 0; 2872 2873 for (domain = (const char * const *)res->dnsrch; 2874 *domain && !done; 2875 domain++) { 2876 searched = 1; 2877 2878 if (domain[0][0] == '\0' || 2879 (domain[0][0] == '.' && domain[0][1] == '\0')) 2880 root_on_list++; 2881 2882 if (root_on_list && tried_as_is) 2883 continue; 2884 2885 ret = res_querydomainN(name, *domain, target, res); 2886 if (ret > 0) 2887 return (ret); 2888 2889 /* 2890 * If no server present, give up. 2891 * If name isn't found in this domain, 2892 * keep trying higher domains in the search list 2893 * (if that's enabled). 2894 * On a NO_DATA error, keep trying, otherwise 2895 * a wildcard entry of another type could keep us 2896 * from finding this entry higher in the domain. 2897 * If we get some other error (negative answer or 2898 * server failure), then stop searching up, 2899 * but try the input name below in case it's 2900 * fully-qualified. 2901 */ 2902 if (errno == ECONNREFUSED) { 2903 RES_SET_H_ERRNO(res, TRY_AGAIN); 2904 return (-1); 2905 } 2906 2907 switch (res->res_h_errno) { 2908 case NO_DATA: 2909 got_nodata++; 2910 /* FALLTHROUGH */ 2911 case HOST_NOT_FOUND: 2912 /* keep trying */ 2913 break; 2914 case TRY_AGAIN: 2915 got_servfail++; 2916 if (hp->rcode == SERVFAIL) { 2917 /* try next search element, if any */ 2918 break; 2919 } 2920 /* FALLTHROUGH */ 2921 default: 2922 /* anything else implies that we're done */ 2923 done++; 2924 } 2925 /* 2926 * if we got here for some reason other than DNSRCH, 2927 * we only wanted one iteration of the loop, so stop. 2928 */ 2929 if (!(res->options & RES_DNSRCH)) 2930 done++; 2931 } 2932 } 2933 2934 switch (res->res_h_errno) { 2935 case NO_DATA: 2936 case HOST_NOT_FOUND: 2937 break; 2938 case TRY_AGAIN: 2939 if (hp->rcode == SERVFAIL) 2940 break; 2941 /* FALLTHROUGH */ 2942 default: 2943 goto giveup; 2944 } 2945 2946 /* 2947 * If the query has not already been tried as is then try it 2948 * unless RES_NOTLDQUERY is set and there were no dots. 2949 */ 2950 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2951 !(tried_as_is || root_on_list)) { 2952 ret = res_querydomainN(name, NULL, target, res); 2953 if (ret > 0) 2954 return (ret); 2955 } 2956 2957 /* 2958 * if we got here, we didn't satisfy the search. 2959 * if we did an initial full query, return that query's h_errno 2960 * (note that we wouldn't be here if that query had succeeded). 2961 * else if we ever got a nodata, send that back as the reason. 2962 * else send back meaningless h_errno, that being the one from 2963 * the last DNSRCH we did. 2964 */ 2965 giveup: 2966 if (saved_herrno != -1) 2967 RES_SET_H_ERRNO(res, saved_herrno); 2968 else if (got_nodata) 2969 RES_SET_H_ERRNO(res, NO_DATA); 2970 else if (got_servfail) 2971 RES_SET_H_ERRNO(res, TRY_AGAIN); 2972 return (-1); 2973 } 2974 2975 /* 2976 * Perform a call on res_query on the concatenation of name and domain, 2977 * removing a trailing dot from name if domain is NULL. 2978 */ 2979 static int 2980 res_querydomainN(const char *name, const char *domain, 2981 struct res_target *target, res_state res) 2982 { 2983 char nbuf[MAXDNAME]; 2984 const char *longname = nbuf; 2985 size_t n, d; 2986 2987 #ifdef DEBUG 2988 if (res->options & RES_DEBUG) 2989 printf(";; res_querydomain(%s, %s)\n", 2990 name, domain?domain:"<Nil>"); 2991 #endif 2992 if (domain == NULL) { 2993 /* 2994 * Check for trailing '.'; 2995 * copy without '.' if present. 2996 */ 2997 n = strlen(name); 2998 if (n >= MAXDNAME) { 2999 RES_SET_H_ERRNO(res, NO_RECOVERY); 3000 return (-1); 3001 } 3002 if (n > 0 && name[--n] == '.') { 3003 strncpy(nbuf, name, n); 3004 nbuf[n] = '\0'; 3005 } else 3006 longname = name; 3007 } else { 3008 n = strlen(name); 3009 d = strlen(domain); 3010 if (n + d + 1 >= MAXDNAME) { 3011 RES_SET_H_ERRNO(res, NO_RECOVERY); 3012 return (-1); 3013 } 3014 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 3015 } 3016 return (res_queryN(longname, target, res)); 3017 } 3018