getaddrinfo.c revision 160553
1210284Sjmallett/* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 2232812Sjmallett 3215990Sjmallett/* 4210284Sjmallett * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5210284Sjmallett * All rights reserved. 6215990Sjmallett * 7215990Sjmallett * Redistribution and use in source and binary forms, with or without 8215990Sjmallett * modification, are permitted provided that the following conditions 9210284Sjmallett * are met: 10215990Sjmallett * 1. Redistributions of source code must retain the above copyright 11215990Sjmallett * notice, this list of conditions and the following disclaimer. 12210284Sjmallett * 2. Redistributions in binary form must reproduce the above copyright 13215990Sjmallett * notice, this list of conditions and the following disclaimer in the 14215990Sjmallett * documentation and/or other materials provided with the distribution. 15215990Sjmallett * 3. Neither the name of the project nor the names of its contributors 16215990Sjmallett * may be used to endorse or promote products derived from this software 17215990Sjmallett * without specific prior written permission. 18232812Sjmallett * 19215990Sjmallett * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20215990Sjmallett * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21215990Sjmallett * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22215990Sjmallett * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23215990Sjmallett * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24215990Sjmallett * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25215990Sjmallett * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26215990Sjmallett * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27215990Sjmallett * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28215990Sjmallett * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29232812Sjmallett * SUCH DAMAGE. 30215990Sjmallett */ 31215990Sjmallett 32215990Sjmallett/* 33215990Sjmallett * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator. 34215990Sjmallett * 35215990Sjmallett * Issues to be discussed: 36215990Sjmallett * - Thread safe-ness must be checked. 37215990Sjmallett * - Return values. There are nonstandard return values defined and used 38210284Sjmallett * in the source code. This is because RFC2553 is silent about which error 39210284Sjmallett * code must be returned for which situation. 40210284Sjmallett * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 41210284Sjmallett * invalid. current code - SEGV on freeaddrinfo(NULL) 42210284Sjmallett * 43210284Sjmallett * Note: 44210284Sjmallett * - The code filters out AFs that are not supported by the kernel, 45215990Sjmallett * when globbing NULL hostname (to loopback, or wildcard). Is it the right 46210284Sjmallett * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 47210284Sjmallett * in ai_flags? 48210284Sjmallett * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 49210284Sjmallett * (1) what should we do against numeric hostname (2) what should we do 50210284Sjmallett * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 51210284Sjmallett * non-loopback address configured? global address configured? 52232812Sjmallett * 53210284Sjmallett * OS specific notes for netbsd/openbsd/freebsd4/bsdi4: 54210284Sjmallett * - To avoid search order issue, we have a big amount of code duplicate 55210284Sjmallett * from gethnamaddr.c and some other places. The issues that there's no 56210284Sjmallett * lower layer function to lookup "IPv4 or IPv6" record. Calling 57210284Sjmallett * gethostbyname2 from getaddrinfo will end up in wrong search order, as 58210284Sjmallett * presented above. 59210284Sjmallett * 60210284Sjmallett * OS specific notes for freebsd4: 61210284Sjmallett * - FreeBSD supported $GAI. The code does not. 62210284Sjmallett */ 63210284Sjmallett 64210284Sjmallett#include <sys/cdefs.h> 65210284Sjmallett__FBSDID("$FreeBSD: head/lib/libc/net/getaddrinfo.c 160553 2006-07-21 19:02:28Z ume $"); 66210284Sjmallett 67210284Sjmallett#include "namespace.h" 68210284Sjmallett#include <sys/types.h> 69210284Sjmallett#include <sys/param.h> 70210284Sjmallett#include <sys/socket.h> 71210284Sjmallett#include <net/if.h> 72210284Sjmallett#include <netinet/in.h> 73210284Sjmallett#include <sys/queue.h> 74210284Sjmallett#ifdef INET6 75210284Sjmallett#include <net/if_var.h> 76210284Sjmallett#include <sys/sysctl.h> 77210284Sjmallett#include <sys/ioctl.h> 78210284Sjmallett#include <netinet6/in6_var.h> /* XXX */ 79210284Sjmallett#endif 80210284Sjmallett#include <arpa/inet.h> 81210284Sjmallett#include <arpa/nameser.h> 82210284Sjmallett#include <rpc/rpc.h> 83210284Sjmallett#include <rpcsvc/yp_prot.h> 84210284Sjmallett#include <rpcsvc/ypclnt.h> 85210284Sjmallett#include <netdb.h> 86210284Sjmallett#include <resolv.h> 87210284Sjmallett#include <string.h> 88210284Sjmallett#include <stdlib.h> 89210284Sjmallett#include <stddef.h> 90210284Sjmallett#include <ctype.h> 91210284Sjmallett#include <unistd.h> 92210284Sjmallett#include <stdio.h> 93210284Sjmallett#include <errno.h> 94210284Sjmallett 95210284Sjmallett#include "res_config.h" 96210284Sjmallett 97210284Sjmallett#ifdef DEBUG 98210284Sjmallett#include <syslog.h> 99210284Sjmallett#endif 100210284Sjmallett 101210284Sjmallett#include <stdarg.h> 102210284Sjmallett#include <nsswitch.h> 103210284Sjmallett#include "un-namespace.h" 104210284Sjmallett#include "libc_private.h" 105210284Sjmallett#ifdef NS_CACHING 106210284Sjmallett#include "nscache.h" 107210284Sjmallett#endif 108210311Sjmallett 109215990Sjmallett#if defined(__KAME__) && defined(INET6) 110210284Sjmallett# define FAITH 111210284Sjmallett#endif 112210284Sjmallett 113210284Sjmallett#define SUCCESS 0 114210284Sjmallett#define ANY 0 115210284Sjmallett#define YES 1 116210284Sjmallett#define NO 0 117210284Sjmallett 118210284Sjmallettstatic const char in_addrany[] = { 0, 0, 0, 0 }; 119210284Sjmallettstatic const char in_loopback[] = { 127, 0, 0, 1 }; 120210284Sjmallett#ifdef INET6 121210284Sjmallettstatic const char in6_addrany[] = { 122210284Sjmallett 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 123210284Sjmallett}; 124215990Sjmallettstatic const char in6_loopback[] = { 125210311Sjmallett 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 126210311Sjmallett}; 127215990Sjmallett#endif 128210284Sjmallett 129215990Sjmallettstruct policyqueue { 130215990Sjmallett TAILQ_ENTRY(policyqueue) pc_entry; 131210311Sjmallett#ifdef INET6 132215990Sjmallett struct in6_addrpolicy pc_policy; 133210284Sjmallett#endif 134210284Sjmallett}; 135210284SjmallettTAILQ_HEAD(policyhead, policyqueue); 136210284Sjmallett 137210284Sjmallettstatic const struct afd { 138210284Sjmallett int a_af; 139210284Sjmallett int a_addrlen; 140210284Sjmallett socklen_t a_socklen; 141210284Sjmallett int a_off; 142210284Sjmallett const char *a_addrany; 143210284Sjmallett const char *a_loopback; 144210284Sjmallett int a_scoped; 145210284Sjmallett} afdl [] = { 146210284Sjmallett#ifdef INET6 147210284Sjmallett#define N_INET6 0 148210284Sjmallett {PF_INET6, sizeof(struct in6_addr), 149210284Sjmallett sizeof(struct sockaddr_in6), 150210284Sjmallett offsetof(struct sockaddr_in6, sin6_addr), 151210284Sjmallett in6_addrany, in6_loopback, 1}, 152210284Sjmallett#define N_INET 1 153210284Sjmallett#else 154210284Sjmallett#define N_INET 0 155210284Sjmallett#endif 156210284Sjmallett {PF_INET, sizeof(struct in_addr), 157210284Sjmallett sizeof(struct sockaddr_in), 158215990Sjmallett offsetof(struct sockaddr_in, sin_addr), 159215990Sjmallett in_addrany, in_loopback, 0}, 160215990Sjmallett {0, 0, 0, 0, NULL, NULL, 0}, 161215990Sjmallett}; 162210284Sjmallett 163215990Sjmallettstruct explore { 164215990Sjmallett int e_af; 165215990Sjmallett int e_socktype; 166215990Sjmallett int e_protocol; 167215990Sjmallett const char *e_protostr; 168215990Sjmallett int e_wild; 169215990Sjmallett#define WILD_AF(ex) ((ex)->e_wild & 0x01) 170215990Sjmallett#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 171215990Sjmallett#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 172215990Sjmallett}; 173215990Sjmallett 174215990Sjmallettstatic const struct explore explore[] = { 175215990Sjmallett#if 0 176215990Sjmallett { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 177215990Sjmallett#endif 178215990Sjmallett#ifdef INET6 179215990Sjmallett { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 180215990Sjmallett { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 181215990Sjmallett { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 182215990Sjmallett#endif 183215990Sjmallett { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 184215990Sjmallett { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 185215990Sjmallett { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 186215990Sjmallett { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 187215990Sjmallett { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 188210284Sjmallett { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 189210284Sjmallett { -1, 0, 0, NULL, 0 }, 190210284Sjmallett}; 191210284Sjmallett 192210284Sjmallett#ifdef INET6 193210284Sjmallett#define PTON_MAX 16 194210284Sjmallett#else 195210284Sjmallett#define PTON_MAX 4 196210284Sjmallett#endif 197210284Sjmallett 198210284Sjmallett#define AIO_SRCFLAG_DEPRECATED 0x1 199210284Sjmallett 200210284Sjmallettstruct ai_order { 201210284Sjmallett union { 202210284Sjmallett struct sockaddr_storage aiou_ss; 203210284Sjmallett struct sockaddr aiou_sa; 204210284Sjmallett } aio_src_un; 205210284Sjmallett#define aio_srcsa aio_src_un.aiou_sa 206210284Sjmallett u_int32_t aio_srcflag; 207210284Sjmallett int aio_srcscope; 208210284Sjmallett int aio_dstscope; 209210284Sjmallett struct policyqueue *aio_srcpolicy; 210210284Sjmallett struct policyqueue *aio_dstpolicy; 211210284Sjmallett struct addrinfo *aio_ai; 212210284Sjmallett int aio_matchlen; 213210284Sjmallett}; 214210284Sjmallett 215210284Sjmallettstatic const ns_src default_dns_files[] = { 216210284Sjmallett { NSSRC_FILES, NS_SUCCESS }, 217210284Sjmallett { NSSRC_DNS, NS_SUCCESS }, 218210284Sjmallett { 0 } 219210284Sjmallett}; 220210284Sjmallett 221210284Sjmallettstruct res_target { 222232812Sjmallett struct res_target *next; 223210284Sjmallett const char *name; /* domain name */ 224210284Sjmallett int qclass, qtype; /* class and type of query */ 225210284Sjmallett u_char *answer; /* buffer to put answer */ 226210284Sjmallett int anslen; /* size of answer buffer */ 227210284Sjmallett int n; /* result length */ 228210284Sjmallett}; 229210284Sjmallett 230232812Sjmallett#define MAXPACKET (64*1024) 231232812Sjmallett 232210284Sjmalletttypedef union { 233215990Sjmallett HEADER hdr; 234210311Sjmallett u_char buf[MAXPACKET]; 235210311Sjmallett} querybuf; 236210311Sjmallett 237210284Sjmallettstatic int str2number(const char *); 238210284Sjmallettstatic int explore_null(const struct addrinfo *, 239210284Sjmallett const char *, struct addrinfo **); 240210284Sjmallettstatic int explore_numeric(const struct addrinfo *, const char *, 241210284Sjmallett const char *, struct addrinfo **, const char *); 242210284Sjmallettstatic int explore_numeric_scope(const struct addrinfo *, const char *, 243210284Sjmallett const char *, struct addrinfo **); 244static int get_canonname(const struct addrinfo *, 245 struct addrinfo *, const char *); 246static struct addrinfo *get_ai(const struct addrinfo *, 247 const struct afd *, const char *); 248static int get_portmatch(const struct addrinfo *, const char *); 249static int get_port(struct addrinfo *, const char *, int); 250static const struct afd *find_afd(int); 251static int addrconfig(struct addrinfo *); 252static void set_source(struct ai_order *, struct policyhead *); 253static int comp_dst(const void *, const void *); 254#ifdef INET6 255static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 256#endif 257static int gai_addr2scopetype(struct sockaddr *); 258 259static int explore_fqdn(const struct addrinfo *, const char *, 260 const char *, struct addrinfo **); 261 262static int reorder(struct addrinfo *); 263static int get_addrselectpolicy(struct policyhead *); 264static void free_addrselectpolicy(struct policyhead *); 265static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 266 struct policyhead *); 267static int matchlen(struct sockaddr *, struct sockaddr *); 268 269static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 270 const struct addrinfo *, res_state); 271#if defined(RESOLVSORT) 272static int addr4sort(struct addrinfo *, res_state); 273#endif 274static int _dns_getaddrinfo(void *, void *, va_list); 275static void _sethtent(FILE **); 276static void _endhtent(FILE **); 277static struct addrinfo *_gethtent(FILE **, const char *, 278 const struct addrinfo *); 279static int _files_getaddrinfo(void *, void *, va_list); 280#ifdef YP 281static struct addrinfo *_yphostent(char *, const struct addrinfo *); 282static int _yp_getaddrinfo(void *, void *, va_list); 283#endif 284#ifdef NS_CACHING 285static int addrinfo_id_func(char *, size_t *, va_list, void *); 286static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 287static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 288#endif 289 290static int res_queryN(const char *, struct res_target *, res_state); 291static int res_searchN(const char *, struct res_target *, res_state); 292static int res_querydomainN(const char *, const char *, 293 struct res_target *, res_state); 294 295/* XXX macros that make external reference is BAD. */ 296 297#define GET_AI(ai, afd, addr) \ 298do { \ 299 /* external reference: pai, error, and label free */ \ 300 (ai) = get_ai(pai, (afd), (addr)); \ 301 if ((ai) == NULL) { \ 302 error = EAI_MEMORY; \ 303 goto free; \ 304 } \ 305} while (/*CONSTCOND*/0) 306 307#define GET_PORT(ai, serv) \ 308do { \ 309 /* external reference: error and label free */ \ 310 error = get_port((ai), (serv), 0); \ 311 if (error != 0) \ 312 goto free; \ 313} while (/*CONSTCOND*/0) 314 315#define GET_CANONNAME(ai, str) \ 316do { \ 317 /* external reference: pai, error and label free */ \ 318 error = get_canonname(pai, (ai), (str)); \ 319 if (error != 0) \ 320 goto free; \ 321} while (/*CONSTCOND*/0) 322 323#define ERR(err) \ 324do { \ 325 /* external reference: error, and label bad */ \ 326 error = (err); \ 327 goto bad; \ 328 /*NOTREACHED*/ \ 329} while (/*CONSTCOND*/0) 330 331#define MATCH_FAMILY(x, y, w) \ 332 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 333#define MATCH(x, y, w) \ 334 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 335 336void 337freeaddrinfo(struct addrinfo *ai) 338{ 339 struct addrinfo *next; 340 341 do { 342 next = ai->ai_next; 343 if (ai->ai_canonname) 344 free(ai->ai_canonname); 345 /* no need to free(ai->ai_addr) */ 346 free(ai); 347 ai = next; 348 } while (ai); 349} 350 351static int 352str2number(const char *p) 353{ 354 char *ep; 355 unsigned long v; 356 357 if (*p == '\0') 358 return -1; 359 ep = NULL; 360 errno = 0; 361 v = strtoul(p, &ep, 10); 362 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) 363 return v; 364 else 365 return -1; 366} 367 368int 369getaddrinfo(const char *hostname, const char *servname, 370 const struct addrinfo *hints, struct addrinfo **res) 371{ 372 struct addrinfo sentinel; 373 struct addrinfo *cur; 374 int error = 0; 375 struct addrinfo ai; 376 struct addrinfo ai0; 377 struct addrinfo *pai; 378 const struct explore *ex; 379 int numeric = 0; 380 381 memset(&sentinel, 0, sizeof(sentinel)); 382 cur = &sentinel; 383 pai = &ai; 384 pai->ai_flags = 0; 385 pai->ai_family = PF_UNSPEC; 386 pai->ai_socktype = ANY; 387 pai->ai_protocol = ANY; 388 pai->ai_addrlen = 0; 389 pai->ai_canonname = NULL; 390 pai->ai_addr = NULL; 391 pai->ai_next = NULL; 392 393 if (hostname == NULL && servname == NULL) 394 return EAI_NONAME; 395 if (hints) { 396 /* error check for hints */ 397 if (hints->ai_addrlen || hints->ai_canonname || 398 hints->ai_addr || hints->ai_next) 399 ERR(EAI_BADHINTS); /* xxx */ 400 if (hints->ai_flags & ~AI_MASK) 401 ERR(EAI_BADFLAGS); 402 switch (hints->ai_family) { 403 case PF_UNSPEC: 404 case PF_INET: 405#ifdef INET6 406 case PF_INET6: 407#endif 408 break; 409 default: 410 ERR(EAI_FAMILY); 411 } 412 memcpy(pai, hints, sizeof(*pai)); 413 414 /* 415 * if both socktype/protocol are specified, check if they 416 * are meaningful combination. 417 */ 418 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 419 for (ex = explore; ex->e_af >= 0; ex++) { 420 if (pai->ai_family != ex->e_af) 421 continue; 422 if (ex->e_socktype == ANY) 423 continue; 424 if (ex->e_protocol == ANY) 425 continue; 426 if (pai->ai_socktype == ex->e_socktype && 427 pai->ai_protocol != ex->e_protocol) { 428 ERR(EAI_BADHINTS); 429 } 430 } 431 } 432 } 433 434 /* 435 * post-2553: AI_ALL and AI_V4MAPPED are effective only against 436 * AF_INET6 query. They need to be ignored if specified in other 437 * occassions. 438 */ 439 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { 440 case AI_V4MAPPED: 441 case AI_ALL | AI_V4MAPPED: 442 if (pai->ai_family != AF_INET6) 443 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 444 break; 445 case AI_ALL: 446#if 1 447 /* illegal */ 448 ERR(EAI_BADFLAGS); 449#else 450 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 451#endif 452 break; 453 } 454 455 /* 456 * check for special cases. (1) numeric servname is disallowed if 457 * socktype/protocol are left unspecified. (2) servname is disallowed 458 * for raw and other inet{,6} sockets. 459 */ 460 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 461#ifdef PF_INET6 462 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 463#endif 464 ) { 465 ai0 = *pai; /* backup *pai */ 466 467 if (pai->ai_family == PF_UNSPEC) { 468#ifdef PF_INET6 469 pai->ai_family = PF_INET6; 470#else 471 pai->ai_family = PF_INET; 472#endif 473 } 474 error = get_portmatch(pai, servname); 475 if (error) 476 ERR(error); 477 478 *pai = ai0; 479 } 480 481 ai0 = *pai; 482 483 /* NULL hostname, or numeric hostname */ 484 for (ex = explore; ex->e_af >= 0; ex++) { 485 *pai = ai0; 486 487 /* PF_UNSPEC entries are prepared for DNS queries only */ 488 if (ex->e_af == PF_UNSPEC) 489 continue; 490 491 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 492 continue; 493 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 494 continue; 495 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 496 continue; 497 498 if (pai->ai_family == PF_UNSPEC) 499 pai->ai_family = ex->e_af; 500 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 501 pai->ai_socktype = ex->e_socktype; 502 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 503 pai->ai_protocol = ex->e_protocol; 504 505 if (hostname == NULL) 506 error = explore_null(pai, servname, &cur->ai_next); 507 else 508 error = explore_numeric_scope(pai, hostname, servname, 509 &cur->ai_next); 510 511 if (error) 512 goto free; 513 514 while (cur && cur->ai_next) 515 cur = cur->ai_next; 516 } 517 518 /* 519 * XXX 520 * If numreic representation of AF1 can be interpreted as FQDN 521 * representation of AF2, we need to think again about the code below. 522 */ 523 if (sentinel.ai_next) { 524 numeric = 1; 525 goto good; 526 } 527 528 if (hostname == NULL) 529 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 530 if (pai->ai_flags & AI_NUMERICHOST) 531 ERR(EAI_NONAME); 532 533 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 534 ERR(EAI_FAIL); 535 536 /* 537 * hostname as alphabetical name. 538 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 539 * outer loop by AFs. 540 */ 541 for (ex = explore; ex->e_af >= 0; ex++) { 542 *pai = ai0; 543 544 /* require exact match for family field */ 545 if (pai->ai_family != ex->e_af) 546 continue; 547 548 if (!MATCH(pai->ai_socktype, ex->e_socktype, 549 WILD_SOCKTYPE(ex))) { 550 continue; 551 } 552 if (!MATCH(pai->ai_protocol, ex->e_protocol, 553 WILD_PROTOCOL(ex))) { 554 continue; 555 } 556 557 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 558 pai->ai_socktype = ex->e_socktype; 559 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 560 pai->ai_protocol = ex->e_protocol; 561 562 error = explore_fqdn(pai, hostname, servname, 563 &cur->ai_next); 564 565 while (cur && cur->ai_next) 566 cur = cur->ai_next; 567 } 568 569 /* XXX inhibit errors if we have the result */ 570 if (sentinel.ai_next) 571 error = 0; 572 573good: 574 /* 575 * ensure we return either: 576 * - error == 0, non-NULL *res 577 * - error != 0, NULL *res 578 */ 579 if (error == 0) { 580 if (sentinel.ai_next) { 581 /* 582 * If the returned entry is for an active connection, 583 * and the given name is not numeric, reorder the 584 * list, so that the application would try the list 585 * in the most efficient order. 586 */ 587 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 588 if (!numeric) 589 (void)reorder(&sentinel); 590 } 591 *res = sentinel.ai_next; 592 return SUCCESS; 593 } else 594 error = EAI_FAIL; 595 } 596free: 597bad: 598 if (sentinel.ai_next) 599 freeaddrinfo(sentinel.ai_next); 600 *res = NULL; 601 return error; 602} 603 604static int 605reorder(struct addrinfo *sentinel) 606{ 607 struct addrinfo *ai, **aip; 608 struct ai_order *aio; 609 int i, n; 610 struct policyhead policyhead; 611 612 /* count the number of addrinfo elements for sorting. */ 613 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 614 ; 615 616 /* 617 * If the number is small enough, we can skip the reordering process. 618 */ 619 if (n <= 1) 620 return(n); 621 622 /* allocate a temporary array for sort and initialization of it. */ 623 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 624 return(n); /* give up reordering */ 625 memset(aio, 0, sizeof(*aio) * n); 626 627 /* retrieve address selection policy from the kernel */ 628 TAILQ_INIT(&policyhead); 629 if (!get_addrselectpolicy(&policyhead)) { 630 /* no policy is installed into kernel, we don't sort. */ 631 free(aio); 632 return (n); 633 } 634 635 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 636 aio[i].aio_ai = ai; 637 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 638 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 639 &policyhead); 640 set_source(&aio[i], &policyhead); 641 } 642 643 /* perform sorting. */ 644 qsort(aio, n, sizeof(*aio), comp_dst); 645 646 /* reorder the addrinfo chain. */ 647 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 648 *aip = aio[i].aio_ai; 649 aip = &aio[i].aio_ai->ai_next; 650 } 651 *aip = NULL; 652 653 /* cleanup and return */ 654 free(aio); 655 free_addrselectpolicy(&policyhead); 656 return(n); 657} 658 659static int 660get_addrselectpolicy(struct policyhead *head) 661{ 662#ifdef INET6 663 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 664 size_t l; 665 char *buf; 666 struct in6_addrpolicy *pol, *ep; 667 668 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 669 return (0); 670 if ((buf = malloc(l)) == NULL) 671 return (0); 672 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 673 free(buf); 674 return (0); 675 } 676 677 ep = (struct in6_addrpolicy *)(buf + l); 678 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 679 struct policyqueue *new; 680 681 if ((new = malloc(sizeof(*new))) == NULL) { 682 free_addrselectpolicy(head); /* make the list empty */ 683 break; 684 } 685 new->pc_policy = *pol; 686 TAILQ_INSERT_TAIL(head, new, pc_entry); 687 } 688 689 free(buf); 690 return (1); 691#else 692 return (0); 693#endif 694} 695 696static void 697free_addrselectpolicy(struct policyhead *head) 698{ 699 struct policyqueue *ent, *nent; 700 701 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 702 nent = TAILQ_NEXT(ent, pc_entry); 703 TAILQ_REMOVE(head, ent, pc_entry); 704 free(ent); 705 } 706} 707 708static struct policyqueue * 709match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 710{ 711#ifdef INET6 712 struct policyqueue *ent, *bestent = NULL; 713 struct in6_addrpolicy *pol; 714 int matchlen, bestmatchlen = -1; 715 u_char *mp, *ep, *k, *p, m; 716 struct sockaddr_in6 key; 717 718 switch(addr->sa_family) { 719 case AF_INET6: 720 key = *(struct sockaddr_in6 *)addr; 721 break; 722 case AF_INET: 723 /* convert the address into IPv4-mapped IPv6 address. */ 724 memset(&key, 0, sizeof(key)); 725 key.sin6_family = AF_INET6; 726 key.sin6_len = sizeof(key); 727 key.sin6_addr.s6_addr[10] = 0xff; 728 key.sin6_addr.s6_addr[11] = 0xff; 729 memcpy(&key.sin6_addr.s6_addr[12], 730 &((struct sockaddr_in *)addr)->sin_addr, 4); 731 break; 732 default: 733 return(NULL); 734 } 735 736 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 737 pol = &ent->pc_policy; 738 matchlen = 0; 739 740 mp = (u_char *)&pol->addrmask.sin6_addr; 741 ep = mp + 16; /* XXX: scope field? */ 742 k = (u_char *)&key.sin6_addr; 743 p = (u_char *)&pol->addr.sin6_addr; 744 for (; mp < ep && *mp; mp++, k++, p++) { 745 m = *mp; 746 if ((*k & m) != *p) 747 goto next; /* not match */ 748 if (m == 0xff) /* short cut for a typical case */ 749 matchlen += 8; 750 else { 751 while (m >= 0x80) { 752 matchlen++; 753 m <<= 1; 754 } 755 } 756 } 757 758 /* matched. check if this is better than the current best. */ 759 if (matchlen > bestmatchlen) { 760 bestent = ent; 761 bestmatchlen = matchlen; 762 } 763 764 next: 765 continue; 766 } 767 768 return(bestent); 769#else 770 return(NULL); 771#endif 772 773} 774 775static void 776set_source(struct ai_order *aio, struct policyhead *ph) 777{ 778 struct addrinfo ai = *aio->aio_ai; 779 struct sockaddr_storage ss; 780 socklen_t srclen; 781 int s; 782 783 /* set unspec ("no source is available"), just in case */ 784 aio->aio_srcsa.sa_family = AF_UNSPEC; 785 aio->aio_srcscope = -1; 786 787 switch(ai.ai_family) { 788 case AF_INET: 789#ifdef INET6 790 case AF_INET6: 791#endif 792 break; 793 default: /* ignore unsupported AFs explicitly */ 794 return; 795 } 796 797 /* XXX: make a dummy addrinfo to call connect() */ 798 ai.ai_socktype = SOCK_DGRAM; 799 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 800 ai.ai_next = NULL; 801 memset(&ss, 0, sizeof(ss)); 802 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 803 ai.ai_addr = (struct sockaddr *)&ss; 804 get_port(&ai, "1", 0); 805 806 /* open a socket to get the source address for the given dst */ 807 if ((s = _socket(ai.ai_family, ai.ai_socktype, ai.ai_protocol)) < 0) 808 return; /* give up */ 809 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 810 goto cleanup; 811 srclen = ai.ai_addrlen; 812 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 813 aio->aio_srcsa.sa_family = AF_UNSPEC; 814 goto cleanup; 815 } 816 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 817 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 818 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 819#ifdef INET6 820 if (ai.ai_family == AF_INET6) { 821 struct in6_ifreq ifr6; 822 u_int32_t flags6; 823 824 /* XXX: interface name should not be hardcoded */ 825 strncpy(ifr6.ifr_name, "lo0", sizeof(ifr6.ifr_name)); 826 memset(&ifr6, 0, sizeof(ifr6)); 827 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 828 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 829 flags6 = ifr6.ifr_ifru.ifru_flags6; 830 if ((flags6 & IN6_IFF_DEPRECATED)) 831 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 832 } 833 } 834#endif 835 836 cleanup: 837 _close(s); 838 return; 839} 840 841static int 842matchlen(struct sockaddr *src, struct sockaddr *dst) 843{ 844 int match = 0; 845 u_char *s, *d; 846 u_char *lim, r; 847 int addrlen; 848 849 switch (src->sa_family) { 850#ifdef INET6 851 case AF_INET6: 852 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 853 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 854 addrlen = sizeof(struct in6_addr); 855 lim = s + addrlen; 856 break; 857#endif 858 case AF_INET: 859 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 860 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 861 addrlen = sizeof(struct in_addr); 862 lim = s + addrlen; 863 break; 864 default: 865 return(0); 866 } 867 868 while (s < lim) 869 if ((r = (*d++ ^ *s++)) != 0) { 870 while (r < addrlen * 8) { 871 match++; 872 r <<= 1; 873 } 874 break; 875 } else 876 match += 8; 877 return(match); 878} 879 880static int 881comp_dst(const void *arg1, const void *arg2) 882{ 883 const struct ai_order *dst1 = arg1, *dst2 = arg2; 884 885 /* 886 * Rule 1: Avoid unusable destinations. 887 * XXX: we currently do not consider if an appropriate route exists. 888 */ 889 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 890 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 891 return(-1); 892 } 893 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 894 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 895 return(1); 896 } 897 898 /* Rule 2: Prefer matching scope. */ 899 if (dst1->aio_dstscope == dst1->aio_srcscope && 900 dst2->aio_dstscope != dst2->aio_srcscope) { 901 return(-1); 902 } 903 if (dst1->aio_dstscope != dst1->aio_srcscope && 904 dst2->aio_dstscope == dst2->aio_srcscope) { 905 return(1); 906 } 907 908 /* Rule 3: Avoid deprecated addresses. */ 909 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 910 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 911 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 912 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 913 return(-1); 914 } 915 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 916 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 917 return(1); 918 } 919 } 920 921 /* Rule 4: Prefer home addresses. */ 922 /* XXX: not implemented yet */ 923 924 /* Rule 5: Prefer matching label. */ 925#ifdef INET6 926 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 927 dst1->aio_srcpolicy->pc_policy.label == 928 dst1->aio_dstpolicy->pc_policy.label && 929 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 930 dst2->aio_srcpolicy->pc_policy.label != 931 dst2->aio_dstpolicy->pc_policy.label)) { 932 return(-1); 933 } 934 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 935 dst2->aio_srcpolicy->pc_policy.label == 936 dst2->aio_dstpolicy->pc_policy.label && 937 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 938 dst1->aio_srcpolicy->pc_policy.label != 939 dst1->aio_dstpolicy->pc_policy.label)) { 940 return(1); 941 } 942#endif 943 944 /* Rule 6: Prefer higher precedence. */ 945#ifdef INET6 946 if (dst1->aio_dstpolicy && 947 (dst2->aio_dstpolicy == NULL || 948 dst1->aio_dstpolicy->pc_policy.preced > 949 dst2->aio_dstpolicy->pc_policy.preced)) { 950 return(-1); 951 } 952 if (dst2->aio_dstpolicy && 953 (dst1->aio_dstpolicy == NULL || 954 dst2->aio_dstpolicy->pc_policy.preced > 955 dst1->aio_dstpolicy->pc_policy.preced)) { 956 return(1); 957 } 958#endif 959 960 /* Rule 7: Prefer native transport. */ 961 /* XXX: not implemented yet */ 962 963 /* Rule 8: Prefer smaller scope. */ 964 if (dst1->aio_dstscope >= 0 && 965 dst1->aio_dstscope < dst2->aio_dstscope) { 966 return(-1); 967 } 968 if (dst2->aio_dstscope >= 0 && 969 dst2->aio_dstscope < dst1->aio_dstscope) { 970 return(1); 971 } 972 973 /* 974 * Rule 9: Use longest matching prefix. 975 * We compare the match length in a same AF only. 976 */ 977 if (dst1->aio_ai->ai_addr->sa_family == 978 dst2->aio_ai->ai_addr->sa_family) { 979 if (dst1->aio_matchlen > dst2->aio_matchlen) { 980 return(-1); 981 } 982 if (dst1->aio_matchlen < dst2->aio_matchlen) { 983 return(1); 984 } 985 } 986 987 /* Rule 10: Otherwise, leave the order unchanged. */ 988 return(-1); 989} 990 991/* 992 * Copy from scope.c. 993 * XXX: we should standardize the functions and link them as standard 994 * library. 995 */ 996static int 997gai_addr2scopetype(struct sockaddr *sa) 998{ 999#ifdef INET6 1000 struct sockaddr_in6 *sa6; 1001#endif 1002 struct sockaddr_in *sa4; 1003 1004 switch(sa->sa_family) { 1005#ifdef INET6 1006 case AF_INET6: 1007 sa6 = (struct sockaddr_in6 *)sa; 1008 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1009 /* just use the scope field of the multicast address */ 1010 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1011 } 1012 /* 1013 * Unicast addresses: map scope type to corresponding scope 1014 * value defined for multcast addresses. 1015 * XXX: hardcoded scope type values are bad... 1016 */ 1017 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1018 return(1); /* node local scope */ 1019 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1020 return(2); /* link-local scope */ 1021 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1022 return(5); /* site-local scope */ 1023 return(14); /* global scope */ 1024 break; 1025#endif 1026 case AF_INET: 1027 /* 1028 * IPv4 pseudo scoping according to RFC 3484. 1029 */ 1030 sa4 = (struct sockaddr_in *)sa; 1031 /* IPv4 autoconfiguration addresses have link-local scope. */ 1032 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1033 ((u_char *)&sa4->sin_addr)[1] == 254) 1034 return(2); 1035 /* Private addresses have site-local scope. */ 1036 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1037 (((u_char *)&sa4->sin_addr)[0] == 172 && 1038 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1039 (((u_char *)&sa4->sin_addr)[0] == 192 && 1040 ((u_char *)&sa4->sin_addr)[1] == 168)) 1041 return(14); /* XXX: It should be 5 unless NAT */ 1042 /* Loopback addresses have link-local scope. */ 1043 if (((u_char *)&sa4->sin_addr)[0] == 127) 1044 return(2); 1045 return(14); 1046 break; 1047 default: 1048 errno = EAFNOSUPPORT; /* is this a good error? */ 1049 return(-1); 1050 } 1051} 1052 1053/* 1054 * hostname == NULL. 1055 * passive socket -> anyaddr (0.0.0.0 or ::) 1056 * non-passive socket -> localhost (127.0.0.1 or ::1) 1057 */ 1058static int 1059explore_null(const struct addrinfo *pai, const char *servname, 1060 struct addrinfo **res) 1061{ 1062 int s; 1063 const struct afd *afd; 1064 struct addrinfo *ai; 1065 int error; 1066 1067 *res = NULL; 1068 ai = NULL; 1069 1070 /* 1071 * filter out AFs that are not supported by the kernel 1072 * XXX errno? 1073 */ 1074 s = _socket(pai->ai_family, SOCK_DGRAM, 0); 1075 if (s < 0) { 1076 if (errno != EMFILE) 1077 return 0; 1078 } else 1079 _close(s); 1080 1081 /* 1082 * if the servname does not match socktype/protocol, ignore it. 1083 */ 1084 if (get_portmatch(pai, servname) != 0) 1085 return 0; 1086 1087 afd = find_afd(pai->ai_family); 1088 if (afd == NULL) 1089 return 0; 1090 1091 if (pai->ai_flags & AI_PASSIVE) { 1092 GET_AI(ai, afd, afd->a_addrany); 1093 GET_PORT(ai, servname); 1094 } else { 1095 GET_AI(ai, afd, afd->a_loopback); 1096 GET_PORT(ai, servname); 1097 } 1098 1099 *res = ai; 1100 return 0; 1101 1102free: 1103 if (ai != NULL) 1104 freeaddrinfo(ai); 1105 return error; 1106} 1107 1108/* 1109 * numeric hostname 1110 */ 1111static int 1112explore_numeric(const struct addrinfo *pai, const char *hostname, 1113 const char *servname, struct addrinfo **res, const char *canonname) 1114{ 1115 const struct afd *afd; 1116 struct addrinfo *ai; 1117 int error; 1118 char pton[PTON_MAX]; 1119 1120 *res = NULL; 1121 ai = NULL; 1122 1123 /* 1124 * if the servname does not match socktype/protocol, ignore it. 1125 */ 1126 if (get_portmatch(pai, servname) != 0) 1127 return 0; 1128 1129 afd = find_afd(pai->ai_family); 1130 if (afd == NULL) 1131 return 0; 1132 1133 switch (afd->a_af) { 1134 case AF_INET: 1135 /* 1136 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1137 * that are accepted by inet_addr() and its family. The 1138 * accepted forms includes the "classful" one, which inet_pton 1139 * does not accept. So we need to separate the case for 1140 * AF_INET. 1141 */ 1142 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1143 return 0; 1144 break; 1145 default: 1146 if (inet_pton(afd->a_af, hostname, pton) != 1) 1147 return 0; 1148 break; 1149 } 1150 1151 if (pai->ai_family == afd->a_af) { 1152 GET_AI(ai, afd, pton); 1153 GET_PORT(ai, servname); 1154 if ((pai->ai_flags & AI_CANONNAME)) { 1155 /* 1156 * Set the numeric address itself as the canonical 1157 * name, based on a clarification in RFC3493. 1158 */ 1159 GET_CANONNAME(ai, canonname); 1160 } 1161 } else { 1162 /* 1163 * XXX: This should not happen since we already matched the AF 1164 * by find_afd. 1165 */ 1166 ERR(EAI_FAMILY); 1167 } 1168 1169 *res = ai; 1170 return 0; 1171 1172free: 1173bad: 1174 if (ai != NULL) 1175 freeaddrinfo(ai); 1176 return error; 1177} 1178 1179/* 1180 * numeric hostname with scope 1181 */ 1182static int 1183explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1184 const char *servname, struct addrinfo **res) 1185{ 1186#if !defined(SCOPE_DELIMITER) || !defined(INET6) 1187 return explore_numeric(pai, hostname, servname, res, hostname); 1188#else 1189 const struct afd *afd; 1190 struct addrinfo *cur; 1191 int error; 1192 char *cp, *hostname2 = NULL, *scope, *addr; 1193 struct sockaddr_in6 *sin6; 1194 1195 /* 1196 * if the servname does not match socktype/protocol, ignore it. 1197 */ 1198 if (get_portmatch(pai, servname) != 0) 1199 return 0; 1200 1201 afd = find_afd(pai->ai_family); 1202 if (afd == NULL) 1203 return 0; 1204 1205 if (!afd->a_scoped) 1206 return explore_numeric(pai, hostname, servname, res, hostname); 1207 1208 cp = strchr(hostname, SCOPE_DELIMITER); 1209 if (cp == NULL) 1210 return explore_numeric(pai, hostname, servname, res, hostname); 1211 1212 /* 1213 * Handle special case of <scoped_address><delimiter><scope id> 1214 */ 1215 hostname2 = strdup(hostname); 1216 if (hostname2 == NULL) 1217 return EAI_MEMORY; 1218 /* terminate at the delimiter */ 1219 hostname2[cp - hostname] = '\0'; 1220 addr = hostname2; 1221 scope = cp + 1; 1222 1223 error = explore_numeric(pai, addr, servname, res, hostname); 1224 if (error == 0) { 1225 u_int32_t scopeid; 1226 1227 for (cur = *res; cur; cur = cur->ai_next) { 1228 if (cur->ai_family != AF_INET6) 1229 continue; 1230 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1231 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1232 free(hostname2); 1233 return(EAI_NONAME); /* XXX: is return OK? */ 1234 } 1235 sin6->sin6_scope_id = scopeid; 1236 } 1237 } 1238 1239 free(hostname2); 1240 1241 return error; 1242#endif 1243} 1244 1245static int 1246get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1247{ 1248 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1249 ai->ai_canonname = strdup(str); 1250 if (ai->ai_canonname == NULL) 1251 return EAI_MEMORY; 1252 } 1253 return 0; 1254} 1255 1256static struct addrinfo * 1257get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1258{ 1259 char *p; 1260 struct addrinfo *ai; 1261#ifdef FAITH 1262 struct in6_addr faith_prefix; 1263 char *fp_str; 1264 int translate = 0; 1265#endif 1266 1267#ifdef FAITH 1268 /* 1269 * Transfrom an IPv4 addr into a special IPv6 addr format for 1270 * IPv6->IPv4 translation gateway. (only TCP is supported now) 1271 * 1272 * +-----------------------------------+------------+ 1273 * | faith prefix part (12 bytes) | embedded | 1274 * | | IPv4 addr part (4 bytes) 1275 * +-----------------------------------+------------+ 1276 * 1277 * faith prefix part is specified as ascii IPv6 addr format 1278 * in environmental variable GAI. 1279 * For FAITH to work correctly, routing to faith prefix must be 1280 * setup toward a machine where a FAITH daemon operates. 1281 * Also, the machine must enable some mechanizm 1282 * (e.g. faith interface hack) to divert those packet with 1283 * faith prefixed destination addr to user-land FAITH daemon. 1284 */ 1285 fp_str = getenv("GAI"); 1286 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 1287 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 1288 u_int32_t v4a; 1289 u_int8_t v4a_top; 1290 1291 memcpy(&v4a, addr, sizeof v4a); 1292 v4a_top = v4a >> IN_CLASSA_NSHIFT; 1293 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 1294 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 1295 afd = &afdl[N_INET6]; 1296 memcpy(&faith_prefix.s6_addr[12], addr, 1297 sizeof(struct in_addr)); 1298 translate = 1; 1299 } 1300 } 1301#endif 1302 1303 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1304 + (afd->a_socklen)); 1305 if (ai == NULL) 1306 return NULL; 1307 1308 memcpy(ai, pai, sizeof(struct addrinfo)); 1309 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1310 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1311 ai->ai_addr->sa_len = afd->a_socklen; 1312 ai->ai_addrlen = afd->a_socklen; 1313 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1314 p = (char *)(void *)(ai->ai_addr); 1315#ifdef FAITH 1316 if (translate == 1) 1317 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 1318 else 1319#endif 1320 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1321 return ai; 1322} 1323 1324static int 1325get_portmatch(const struct addrinfo *ai, const char *servname) 1326{ 1327 1328 /* get_port does not touch first argument when matchonly == 1. */ 1329 /* LINTED const cast */ 1330 return get_port((struct addrinfo *)ai, servname, 1); 1331} 1332 1333static int 1334get_port(struct addrinfo *ai, const char *servname, int matchonly) 1335{ 1336 const char *proto; 1337 struct servent *sp; 1338 int port; 1339 int allownumeric; 1340 1341 if (servname == NULL) 1342 return 0; 1343 switch (ai->ai_family) { 1344 case AF_INET: 1345#ifdef AF_INET6 1346 case AF_INET6: 1347#endif 1348 break; 1349 default: 1350 return 0; 1351 } 1352 1353 switch (ai->ai_socktype) { 1354 case SOCK_RAW: 1355 return EAI_SERVICE; 1356 case SOCK_DGRAM: 1357 case SOCK_STREAM: 1358 allownumeric = 1; 1359 break; 1360 case ANY: 1361 allownumeric = 0; 1362 break; 1363 default: 1364 return EAI_SOCKTYPE; 1365 } 1366 1367 port = str2number(servname); 1368 if (port >= 0) { 1369 if (!allownumeric) 1370 return EAI_SERVICE; 1371 if (port < 0 || port > 65535) 1372 return EAI_SERVICE; 1373 port = htons(port); 1374 } else { 1375 if (ai->ai_flags & AI_NUMERICSERV) 1376 return EAI_NONAME; 1377 switch (ai->ai_socktype) { 1378 case SOCK_DGRAM: 1379 proto = "udp"; 1380 break; 1381 case SOCK_STREAM: 1382 proto = "tcp"; 1383 break; 1384 default: 1385 proto = NULL; 1386 break; 1387 } 1388 1389 if ((sp = getservbyname(servname, proto)) == NULL) 1390 return EAI_SERVICE; 1391 port = sp->s_port; 1392 } 1393 1394 if (!matchonly) { 1395 switch (ai->ai_family) { 1396 case AF_INET: 1397 ((struct sockaddr_in *)(void *) 1398 ai->ai_addr)->sin_port = port; 1399 break; 1400#ifdef INET6 1401 case AF_INET6: 1402 ((struct sockaddr_in6 *)(void *) 1403 ai->ai_addr)->sin6_port = port; 1404 break; 1405#endif 1406 } 1407 } 1408 1409 return 0; 1410} 1411 1412static const struct afd * 1413find_afd(int af) 1414{ 1415 const struct afd *afd; 1416 1417 if (af == PF_UNSPEC) 1418 return NULL; 1419 for (afd = afdl; afd->a_af; afd++) { 1420 if (afd->a_af == af) 1421 return afd; 1422 } 1423 return NULL; 1424} 1425 1426/* 1427 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1428 * will take care of it. 1429 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1430 * if the code is right or not. 1431 * 1432 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1433 * _dns_getaddrinfo. 1434 */ 1435static int 1436addrconfig(struct addrinfo *pai) 1437{ 1438 int s, af; 1439 1440 /* 1441 * TODO: 1442 * Note that implementation dependent test for address 1443 * configuration should be done everytime called 1444 * (or apropriate interval), 1445 * because addresses will be dynamically assigned or deleted. 1446 */ 1447 af = pai->ai_family; 1448 if (af == AF_UNSPEC) { 1449 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 1450 af = AF_INET; 1451 else { 1452 _close(s); 1453 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) 1454 af = AF_INET6; 1455 else 1456 _close(s); 1457 } 1458 } 1459 if (af != AF_UNSPEC) { 1460 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 1461 return 0; 1462 _close(s); 1463 } 1464 pai->ai_family = af; 1465 return 1; 1466} 1467 1468#ifdef INET6 1469/* convert a string to a scope identifier. XXX: IPv6 specific */ 1470static int 1471ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1472{ 1473 u_long lscopeid; 1474 struct in6_addr *a6; 1475 char *ep; 1476 1477 a6 = &sin6->sin6_addr; 1478 1479 /* empty scopeid portion is invalid */ 1480 if (*scope == '\0') 1481 return -1; 1482 1483 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1484 /* 1485 * We currently assume a one-to-one mapping between links 1486 * and interfaces, so we simply use interface indices for 1487 * like-local scopes. 1488 */ 1489 *scopeid = if_nametoindex(scope); 1490 if (*scopeid == 0) 1491 goto trynumeric; 1492 return 0; 1493 } 1494 1495 /* still unclear about literal, allow numeric only - placeholder */ 1496 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1497 goto trynumeric; 1498 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1499 goto trynumeric; 1500 else 1501 goto trynumeric; /* global */ 1502 1503 /* try to convert to a numeric id as a last resort */ 1504 trynumeric: 1505 errno = 0; 1506 lscopeid = strtoul(scope, &ep, 10); 1507 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1508 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1509 return 0; 1510 else 1511 return -1; 1512} 1513#endif 1514 1515 1516#ifdef NS_CACHING 1517static int 1518addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1519 void *cache_mdata) 1520{ 1521 res_state statp; 1522 u_long res_options; 1523 1524 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1525 char *hostname; 1526 struct addrinfo *hints; 1527 1528 char *p; 1529 int ai_flags, ai_family, ai_socktype, ai_protocol; 1530 size_t desired_size, size; 1531 1532 statp = __res_state(); 1533 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1534 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1535 1536 hostname = va_arg(ap, char *); 1537 hints = va_arg(ap, struct addrinfo *); 1538 1539 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1540 if (hostname != NULL) { 1541 size = strlen(hostname); 1542 desired_size += size + 1; 1543 } else 1544 size = 0; 1545 1546 if (desired_size > *buffer_size) { 1547 *buffer_size = desired_size; 1548 return (NS_RETURN); 1549 } 1550 1551 if (hints == NULL) 1552 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1553 else { 1554 ai_flags = hints->ai_flags; 1555 ai_family = hints->ai_family; 1556 ai_socktype = hints->ai_socktype; 1557 ai_protocol = hints->ai_protocol; 1558 } 1559 1560 p = buffer; 1561 memcpy(p, &res_options, sizeof(res_options)); 1562 p += sizeof(res_options); 1563 1564 memcpy(p, &op_id, sizeof(int)); 1565 p += sizeof(int); 1566 1567 memcpy(p, &ai_flags, sizeof(int)); 1568 p += sizeof(int); 1569 1570 memcpy(p, &ai_family, sizeof(int)); 1571 p += sizeof(int); 1572 1573 memcpy(p, &ai_socktype, sizeof(int)); 1574 p += sizeof(int); 1575 1576 memcpy(p, &ai_protocol, sizeof(int)); 1577 p += sizeof(int); 1578 1579 if (hostname != NULL) 1580 memcpy(p, hostname, size); 1581 1582 *buffer_size = desired_size; 1583 return (NS_SUCCESS); 1584} 1585 1586static int 1587addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1588 va_list ap, void *cache_mdata) 1589{ 1590 struct addrinfo *ai, *cai; 1591 char *p; 1592 size_t desired_size, size, ai_size; 1593 1594 ai = *((struct addrinfo **)retval); 1595 1596 desired_size = sizeof(size_t); 1597 ai_size = 0; 1598 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1599 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1600 if (cai->ai_canonname != NULL) 1601 desired_size += sizeof(size_t) + 1602 strlen(cai->ai_canonname); 1603 ++ai_size; 1604 } 1605 1606 if (desired_size > *buffer_size) { 1607 /* this assignment is here for future use */ 1608 errno = ERANGE; 1609 *buffer_size = desired_size; 1610 return (NS_RETURN); 1611 } 1612 1613 memset(buffer, 0, desired_size); 1614 p = buffer; 1615 1616 memcpy(p, &ai_size, sizeof(size_t)); 1617 p += sizeof(size_t); 1618 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1619 memcpy(p, cai, sizeof(struct addrinfo)); 1620 p += sizeof(struct addrinfo); 1621 1622 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1623 p += cai->ai_addrlen; 1624 1625 if (cai->ai_canonname != NULL) { 1626 size = strlen(cai->ai_canonname); 1627 memcpy(p, &size, sizeof(size_t)); 1628 p += sizeof(size_t); 1629 1630 memcpy(p, cai->ai_canonname, size); 1631 p += size; 1632 } 1633 } 1634 1635 return (NS_SUCCESS); 1636} 1637 1638static int 1639addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1640 va_list ap, void *cache_mdata) 1641{ 1642 struct addrinfo new_ai, *result, *sentinel, *lasts; 1643 1644 char *p; 1645 size_t ai_size, ai_i, size; 1646 1647 p = buffer; 1648 memcpy(&ai_size, p, sizeof(size_t)); 1649 p += sizeof(size_t); 1650 1651 result = NULL; 1652 lasts = NULL; 1653 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1654 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1655 p += sizeof(struct addrinfo); 1656 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1657 _ALIGNBYTES; 1658 1659 sentinel = (struct addrinfo *)malloc(size); 1660 memset(sentinel, 0, size); 1661 1662 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1663 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1664 sizeof(struct addrinfo)); 1665 1666 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1667 p += new_ai.ai_addrlen; 1668 1669 if (new_ai.ai_canonname != NULL) { 1670 memcpy(&size, p, sizeof(size_t)); 1671 p += sizeof(size_t); 1672 1673 sentinel->ai_canonname = (char *)malloc(size + 1); 1674 memset(sentinel->ai_canonname, 0, size + 1); 1675 1676 memcpy(sentinel->ai_canonname, p, size); 1677 p += size; 1678 } 1679 1680 if (result == NULL) { 1681 result = sentinel; 1682 lasts = sentinel; 1683 } else { 1684 lasts->ai_next = sentinel; 1685 lasts = sentinel; 1686 } 1687 } 1688 1689 *((struct addrinfo **)retval) = result; 1690 return (NS_SUCCESS); 1691} 1692#endif /* NS_CACHING */ 1693 1694/* 1695 * FQDN hostname, DNS lookup 1696 */ 1697static int 1698explore_fqdn(const struct addrinfo *pai, const char *hostname, 1699 const char *servname, struct addrinfo **res) 1700{ 1701 struct addrinfo *result; 1702 struct addrinfo *cur; 1703 int error = 0; 1704 1705#ifdef NS_CACHING 1706 static const nss_cache_info cache_info = 1707 NS_COMMON_CACHE_INFO_INITIALIZER( 1708 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1709 addrinfo_unmarshal_func); 1710#endif 1711 static const ns_dtab dtab[] = { 1712 NS_FILES_CB(_files_getaddrinfo, NULL) 1713 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1714 NS_NIS_CB(_yp_getaddrinfo, NULL) 1715#ifdef NS_CACHING 1716 NS_CACHE_CB(&cache_info) 1717#endif 1718 { 0 } 1719 }; 1720 1721 result = NULL; 1722 1723 /* 1724 * if the servname does not match socktype/protocol, ignore it. 1725 */ 1726 if (get_portmatch(pai, servname) != 0) 1727 return 0; 1728 1729 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1730 default_dns_files, hostname, pai)) { 1731 case NS_TRYAGAIN: 1732 error = EAI_AGAIN; 1733 goto free; 1734 case NS_UNAVAIL: 1735 error = EAI_FAIL; 1736 goto free; 1737 case NS_NOTFOUND: 1738 error = EAI_NONAME; 1739 goto free; 1740 case NS_SUCCESS: 1741 error = 0; 1742 for (cur = result; cur; cur = cur->ai_next) { 1743 GET_PORT(cur, servname); 1744 /* canonname should be filled already */ 1745 } 1746 break; 1747 } 1748 1749 *res = result; 1750 1751 return 0; 1752 1753free: 1754 if (result) 1755 freeaddrinfo(result); 1756 return error; 1757} 1758 1759#ifdef DEBUG 1760static const char AskedForGot[] = 1761 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1762#endif 1763 1764static struct addrinfo * 1765getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1766 const struct addrinfo *pai, res_state res) 1767{ 1768 struct addrinfo sentinel, *cur; 1769 struct addrinfo ai; 1770 const struct afd *afd; 1771 char *canonname; 1772 const HEADER *hp; 1773 const u_char *cp; 1774 int n; 1775 const u_char *eom; 1776 char *bp, *ep; 1777 int type, class, ancount, qdcount; 1778 int haveanswer, had_error; 1779 char tbuf[MAXDNAME]; 1780 int (*name_ok)(const char *); 1781 char hostbuf[8*1024]; 1782 1783 memset(&sentinel, 0, sizeof(sentinel)); 1784 cur = &sentinel; 1785 1786 canonname = NULL; 1787 eom = answer->buf + anslen; 1788 switch (qtype) { 1789 case T_A: 1790 case T_AAAA: 1791 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1792 name_ok = res_hnok; 1793 break; 1794 default: 1795 return (NULL); /* XXX should be abort(); */ 1796 } 1797 /* 1798 * find first satisfactory answer 1799 */ 1800 hp = &answer->hdr; 1801 ancount = ntohs(hp->ancount); 1802 qdcount = ntohs(hp->qdcount); 1803 bp = hostbuf; 1804 ep = hostbuf + sizeof hostbuf; 1805 cp = answer->buf + HFIXEDSZ; 1806 if (qdcount != 1) { 1807 RES_SET_H_ERRNO(res, NO_RECOVERY); 1808 return (NULL); 1809 } 1810 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1811 if ((n < 0) || !(*name_ok)(bp)) { 1812 RES_SET_H_ERRNO(res, NO_RECOVERY); 1813 return (NULL); 1814 } 1815 cp += n + QFIXEDSZ; 1816 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1817 /* res_send() has already verified that the query name is the 1818 * same as the one we sent; this just gets the expanded name 1819 * (i.e., with the succeeding search-domain tacked on). 1820 */ 1821 n = strlen(bp) + 1; /* for the \0 */ 1822 if (n >= MAXHOSTNAMELEN) { 1823 RES_SET_H_ERRNO(res, NO_RECOVERY); 1824 return (NULL); 1825 } 1826 canonname = bp; 1827 bp += n; 1828 /* The qname can be abbreviated, but h_name is now absolute. */ 1829 qname = canonname; 1830 } 1831 haveanswer = 0; 1832 had_error = 0; 1833 while (ancount-- > 0 && cp < eom && !had_error) { 1834 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1835 if ((n < 0) || !(*name_ok)(bp)) { 1836 had_error++; 1837 continue; 1838 } 1839 cp += n; /* name */ 1840 type = _getshort(cp); 1841 cp += INT16SZ; /* type */ 1842 class = _getshort(cp); 1843 cp += INT16SZ + INT32SZ; /* class, TTL */ 1844 n = _getshort(cp); 1845 cp += INT16SZ; /* len */ 1846 if (class != C_IN) { 1847 /* XXX - debug? syslog? */ 1848 cp += n; 1849 continue; /* XXX - had_error++ ? */ 1850 } 1851 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1852 type == T_CNAME) { 1853 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1854 if ((n < 0) || !(*name_ok)(tbuf)) { 1855 had_error++; 1856 continue; 1857 } 1858 cp += n; 1859 /* Get canonical name. */ 1860 n = strlen(tbuf) + 1; /* for the \0 */ 1861 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1862 had_error++; 1863 continue; 1864 } 1865 strlcpy(bp, tbuf, ep - bp); 1866 canonname = bp; 1867 bp += n; 1868 continue; 1869 } 1870 if (qtype == T_ANY) { 1871 if (!(type == T_A || type == T_AAAA)) { 1872 cp += n; 1873 continue; 1874 } 1875 } else if (type != qtype) { 1876#ifdef DEBUG 1877 if (type != T_KEY && type != T_SIG) 1878 syslog(LOG_NOTICE|LOG_AUTH, 1879 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1880 qname, p_class(C_IN), p_type(qtype), 1881 p_type(type)); 1882#endif 1883 cp += n; 1884 continue; /* XXX - had_error++ ? */ 1885 } 1886 switch (type) { 1887 case T_A: 1888 case T_AAAA: 1889 if (strcasecmp(canonname, bp) != 0) { 1890#ifdef DEBUG 1891 syslog(LOG_NOTICE|LOG_AUTH, 1892 AskedForGot, canonname, bp); 1893#endif 1894 cp += n; 1895 continue; /* XXX - had_error++ ? */ 1896 } 1897 if (type == T_A && n != INADDRSZ) { 1898 cp += n; 1899 continue; 1900 } 1901 if (type == T_AAAA && n != IN6ADDRSZ) { 1902 cp += n; 1903 continue; 1904 } 1905#ifdef FILTER_V4MAPPED 1906 if (type == T_AAAA) { 1907 struct in6_addr in6; 1908 memcpy(&in6, cp, sizeof(in6)); 1909 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1910 cp += n; 1911 continue; 1912 } 1913 } 1914#endif 1915 if (!haveanswer) { 1916 int nn; 1917 1918 canonname = bp; 1919 nn = strlen(bp) + 1; /* for the \0 */ 1920 bp += nn; 1921 } 1922 1923 /* don't overwrite pai */ 1924 ai = *pai; 1925 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1926 afd = find_afd(ai.ai_family); 1927 if (afd == NULL) { 1928 cp += n; 1929 continue; 1930 } 1931 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1932 if (cur->ai_next == NULL) 1933 had_error++; 1934 while (cur && cur->ai_next) 1935 cur = cur->ai_next; 1936 cp += n; 1937 break; 1938 default: 1939 abort(); 1940 } 1941 if (!had_error) 1942 haveanswer++; 1943 } 1944 if (haveanswer) { 1945#if defined(RESOLVSORT) 1946 /* 1947 * We support only IPv4 address for backward 1948 * compatibility against gethostbyname(3). 1949 */ 1950 if (res->nsort && qtype == T_A) { 1951 if (addr4sort(&sentinel, res) < 0) { 1952 freeaddrinfo(sentinel.ai_next); 1953 RES_SET_H_ERRNO(res, NO_RECOVERY); 1954 return NULL; 1955 } 1956 } 1957#endif /*RESOLVSORT*/ 1958 if (!canonname) 1959 (void)get_canonname(pai, sentinel.ai_next, qname); 1960 else 1961 (void)get_canonname(pai, sentinel.ai_next, canonname); 1962 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 1963 return sentinel.ai_next; 1964 } 1965 1966 RES_SET_H_ERRNO(res, NO_RECOVERY); 1967 return NULL; 1968} 1969 1970#ifdef RESOLVSORT 1971struct addr_ptr { 1972 struct addrinfo *ai; 1973 int aval; 1974}; 1975 1976static int 1977addr4sort(struct addrinfo *sentinel, res_state res) 1978{ 1979 struct addrinfo *ai; 1980 struct addr_ptr *addrs, addr; 1981 struct sockaddr_in *sin; 1982 int naddrs, i, j; 1983 int needsort = 0; 1984 1985 if (!sentinel) 1986 return -1; 1987 naddrs = 0; 1988 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 1989 naddrs++; 1990 if (naddrs < 2) 1991 return 0; /* We don't need sorting. */ 1992 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 1993 return -1; 1994 i = 0; 1995 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 1996 sin = (struct sockaddr_in *)ai->ai_addr; 1997 for (j = 0; (unsigned)j < res->nsort; j++) { 1998 if (res->sort_list[j].addr.s_addr == 1999 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2000 break; 2001 } 2002 addrs[i].ai = ai; 2003 addrs[i].aval = j; 2004 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2005 needsort = i; 2006 i++; 2007 } 2008 if (!needsort) { 2009 free(addrs); 2010 return 0; 2011 } 2012 2013 while (needsort < naddrs) { 2014 for (j = needsort - 1; j >= 0; j--) { 2015 if (addrs[j].aval > addrs[j+1].aval) { 2016 addr = addrs[j]; 2017 addrs[j] = addrs[j + 1]; 2018 addrs[j + 1] = addr; 2019 } else 2020 break; 2021 } 2022 needsort++; 2023 } 2024 2025 ai = sentinel; 2026 for (i = 0; i < naddrs; ++i) { 2027 ai->ai_next = addrs[i].ai; 2028 ai = ai->ai_next; 2029 } 2030 ai->ai_next = NULL; 2031 free(addrs); 2032 return 0; 2033} 2034#endif /*RESOLVSORT*/ 2035 2036/*ARGSUSED*/ 2037static int 2038_dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2039{ 2040 struct addrinfo *ai; 2041 querybuf *buf, *buf2; 2042 const char *hostname; 2043 const struct addrinfo *pai; 2044 struct addrinfo sentinel, *cur; 2045 struct res_target q, q2; 2046 res_state res; 2047 2048 hostname = va_arg(ap, char *); 2049 pai = va_arg(ap, const struct addrinfo *); 2050 2051 memset(&q, 0, sizeof(q)); 2052 memset(&q2, 0, sizeof(q2)); 2053 memset(&sentinel, 0, sizeof(sentinel)); 2054 cur = &sentinel; 2055 2056 buf = malloc(sizeof(*buf)); 2057 if (!buf) { 2058 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2059 return NS_NOTFOUND; 2060 } 2061 buf2 = malloc(sizeof(*buf2)); 2062 if (!buf2) { 2063 free(buf); 2064 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2065 return NS_NOTFOUND; 2066 } 2067 2068 switch (pai->ai_family) { 2069 case AF_UNSPEC: 2070 q.name = hostname; 2071 q.qclass = C_IN; 2072 q.qtype = T_A; 2073 q.answer = buf->buf; 2074 q.anslen = sizeof(buf->buf); 2075 q.next = &q2; 2076 q2.name = hostname; 2077 q2.qclass = C_IN; 2078 q2.qtype = T_AAAA; 2079 q2.answer = buf2->buf; 2080 q2.anslen = sizeof(buf2->buf); 2081 break; 2082 case AF_INET: 2083 q.name = hostname; 2084 q.qclass = C_IN; 2085 q.qtype = T_A; 2086 q.answer = buf->buf; 2087 q.anslen = sizeof(buf->buf); 2088 break; 2089 case AF_INET6: 2090 q.name = hostname; 2091 q.qclass = C_IN; 2092 q.qtype = T_AAAA; 2093 q.answer = buf->buf; 2094 q.anslen = sizeof(buf->buf); 2095 break; 2096 default: 2097 free(buf); 2098 free(buf2); 2099 return NS_UNAVAIL; 2100 } 2101 2102 res = __res_state(); 2103 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2104 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2105 free(buf); 2106 free(buf2); 2107 return NS_NOTFOUND; 2108 } 2109 2110 if (res_searchN(hostname, &q, res) < 0) { 2111 free(buf); 2112 free(buf2); 2113 return NS_NOTFOUND; 2114 } 2115 /* prefer IPv6 */ 2116 if (q.next) { 2117 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2118 if (ai) { 2119 cur->ai_next = ai; 2120 while (cur && cur->ai_next) 2121 cur = cur->ai_next; 2122 } 2123 } 2124 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2125 if (ai) 2126 cur->ai_next = ai; 2127 free(buf); 2128 free(buf2); 2129 if (sentinel.ai_next == NULL) 2130 switch (res->res_h_errno) { 2131 case HOST_NOT_FOUND: 2132 return NS_NOTFOUND; 2133 case TRY_AGAIN: 2134 return NS_TRYAGAIN; 2135 default: 2136 return NS_UNAVAIL; 2137 } 2138 *((struct addrinfo **)rv) = sentinel.ai_next; 2139 return NS_SUCCESS; 2140} 2141 2142static void 2143_sethtent(FILE **hostf) 2144{ 2145 if (!*hostf) 2146 *hostf = fopen(_PATH_HOSTS, "r"); 2147 else 2148 rewind(*hostf); 2149} 2150 2151static void 2152_endhtent(FILE **hostf) 2153{ 2154 if (*hostf) { 2155 (void) fclose(*hostf); 2156 *hostf = NULL; 2157 } 2158} 2159 2160static struct addrinfo * 2161_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2162{ 2163 char *p; 2164 char *cp, *tname, *cname; 2165 struct addrinfo hints, *res0, *res; 2166 int error; 2167 const char *addr; 2168 char hostbuf[8*1024]; 2169 2170 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r"))) 2171 return (NULL); 2172again: 2173 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2174 return (NULL); 2175 if (*p == '#') 2176 goto again; 2177 cp = strpbrk(p, "#\n"); 2178 if (cp != NULL) 2179 *cp = '\0'; 2180 if (!(cp = strpbrk(p, " \t"))) 2181 goto again; 2182 *cp++ = '\0'; 2183 addr = p; 2184 cname = NULL; 2185 /* if this is not something we're looking for, skip it. */ 2186 while (cp && *cp) { 2187 if (*cp == ' ' || *cp == '\t') { 2188 cp++; 2189 continue; 2190 } 2191 tname = cp; 2192 if (cname == NULL) 2193 cname = cp; 2194 if ((cp = strpbrk(cp, " \t")) != NULL) 2195 *cp++ = '\0'; 2196 if (strcasecmp(name, tname) == 0) 2197 goto found; 2198 } 2199 goto again; 2200 2201found: 2202 /* we should not glob socktype/protocol here */ 2203 memset(&hints, 0, sizeof(hints)); 2204 hints.ai_family = pai->ai_family; 2205 hints.ai_socktype = SOCK_DGRAM; 2206 hints.ai_protocol = 0; 2207 hints.ai_flags = AI_NUMERICHOST; 2208 error = getaddrinfo(addr, "0", &hints, &res0); 2209 if (error) 2210 goto again; 2211#ifdef FILTER_V4MAPPED 2212 /* XXX should check all items in the chain */ 2213 if (res0->ai_family == AF_INET6 && 2214 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2215 freeaddrinfo(res0); 2216 goto again; 2217 } 2218#endif 2219 for (res = res0; res; res = res->ai_next) { 2220 /* cover it up */ 2221 res->ai_flags = pai->ai_flags; 2222 res->ai_socktype = pai->ai_socktype; 2223 res->ai_protocol = pai->ai_protocol; 2224 2225 if (pai->ai_flags & AI_CANONNAME) { 2226 if (get_canonname(pai, res, cname) != 0) { 2227 freeaddrinfo(res0); 2228 goto again; 2229 } 2230 } 2231 } 2232 return res0; 2233} 2234 2235/*ARGSUSED*/ 2236static int 2237_files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2238{ 2239 const char *name; 2240 const struct addrinfo *pai; 2241 struct addrinfo sentinel, *cur; 2242 struct addrinfo *p; 2243 FILE *hostf = NULL; 2244 2245 name = va_arg(ap, char *); 2246 pai = va_arg(ap, struct addrinfo *); 2247 2248 memset(&sentinel, 0, sizeof(sentinel)); 2249 cur = &sentinel; 2250 2251 _sethtent(&hostf); 2252 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 2253 cur->ai_next = p; 2254 while (cur && cur->ai_next) 2255 cur = cur->ai_next; 2256 } 2257 _endhtent(&hostf); 2258 2259 *((struct addrinfo **)rv) = sentinel.ai_next; 2260 if (sentinel.ai_next == NULL) 2261 return NS_NOTFOUND; 2262 return NS_SUCCESS; 2263} 2264 2265#ifdef YP 2266/*ARGSUSED*/ 2267static struct addrinfo * 2268_yphostent(char *line, const struct addrinfo *pai) 2269{ 2270 struct addrinfo sentinel, *cur; 2271 struct addrinfo hints, *res, *res0; 2272 int error; 2273 char *p = line; 2274 const char *addr, *canonname; 2275 char *nextline; 2276 char *cp; 2277 2278 addr = canonname = NULL; 2279 2280 memset(&sentinel, 0, sizeof(sentinel)); 2281 cur = &sentinel; 2282 2283nextline: 2284 /* terminate line */ 2285 cp = strchr(p, '\n'); 2286 if (cp) { 2287 *cp++ = '\0'; 2288 nextline = cp; 2289 } else 2290 nextline = NULL; 2291 2292 cp = strpbrk(p, " \t"); 2293 if (cp == NULL) { 2294 if (canonname == NULL) 2295 return (NULL); 2296 else 2297 goto done; 2298 } 2299 *cp++ = '\0'; 2300 2301 addr = p; 2302 2303 while (cp && *cp) { 2304 if (*cp == ' ' || *cp == '\t') { 2305 cp++; 2306 continue; 2307 } 2308 if (!canonname) 2309 canonname = cp; 2310 if ((cp = strpbrk(cp, " \t")) != NULL) 2311 *cp++ = '\0'; 2312 } 2313 2314 hints = *pai; 2315 hints.ai_flags = AI_NUMERICHOST; 2316 error = getaddrinfo(addr, NULL, &hints, &res0); 2317 if (error == 0) { 2318 for (res = res0; res; res = res->ai_next) { 2319 /* cover it up */ 2320 res->ai_flags = pai->ai_flags; 2321 2322 if (pai->ai_flags & AI_CANONNAME) 2323 (void)get_canonname(pai, res, canonname); 2324 } 2325 } else 2326 res0 = NULL; 2327 if (res0) { 2328 cur->ai_next = res0; 2329 while (cur && cur->ai_next) 2330 cur = cur->ai_next; 2331 } 2332 2333 if (nextline) { 2334 p = nextline; 2335 goto nextline; 2336 } 2337 2338done: 2339 return sentinel.ai_next; 2340} 2341 2342/*ARGSUSED*/ 2343static int 2344_yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2345{ 2346 struct addrinfo sentinel, *cur; 2347 struct addrinfo *ai = NULL; 2348 char *ypbuf; 2349 int ypbuflen, r; 2350 const char *name; 2351 const struct addrinfo *pai; 2352 char *ypdomain; 2353 2354 if (_yp_check(&ypdomain) == 0) 2355 return NS_UNAVAIL; 2356 2357 name = va_arg(ap, char *); 2358 pai = va_arg(ap, const struct addrinfo *); 2359 2360 memset(&sentinel, 0, sizeof(sentinel)); 2361 cur = &sentinel; 2362 2363 /* hosts.byname is only for IPv4 (Solaris8) */ 2364 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 2365 r = yp_match(ypdomain, "hosts.byname", name, 2366 (int)strlen(name), &ypbuf, &ypbuflen); 2367 if (r == 0) { 2368 struct addrinfo ai4; 2369 2370 ai4 = *pai; 2371 ai4.ai_family = AF_INET; 2372 ai = _yphostent(ypbuf, &ai4); 2373 if (ai) { 2374 cur->ai_next = ai; 2375 while (cur && cur->ai_next) 2376 cur = cur->ai_next; 2377 } 2378 free(ypbuf); 2379 } 2380 } 2381 2382 /* ipnodes.byname can hold both IPv4/v6 */ 2383 r = yp_match(ypdomain, "ipnodes.byname", name, 2384 (int)strlen(name), &ypbuf, &ypbuflen); 2385 if (r == 0) { 2386 ai = _yphostent(ypbuf, pai); 2387 if (ai) 2388 cur->ai_next = ai; 2389 free(ypbuf); 2390 } 2391 2392 if (sentinel.ai_next == NULL) { 2393 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2394 return NS_NOTFOUND; 2395 } 2396 *((struct addrinfo **)rv) = sentinel.ai_next; 2397 return NS_SUCCESS; 2398} 2399#endif 2400 2401/* resolver logic */ 2402 2403/* 2404 * Formulate a normal query, send, and await answer. 2405 * Returned answer is placed in supplied buffer "answer". 2406 * Perform preliminary check of answer, returning success only 2407 * if no error is indicated and the answer count is nonzero. 2408 * Return the size of the response on success, -1 on error. 2409 * Error number is left in h_errno. 2410 * 2411 * Caller must parse answer and determine whether it answers the question. 2412 */ 2413static int 2414res_queryN(const char *name, struct res_target *target, res_state res) 2415{ 2416 u_char *buf; 2417 HEADER *hp; 2418 int n; 2419 u_int oflags; 2420 struct res_target *t; 2421 int rcode; 2422 int ancount; 2423 2424 rcode = NOERROR; 2425 ancount = 0; 2426 2427 buf = malloc(MAXPACKET); 2428 if (!buf) { 2429 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2430 return -1; 2431 } 2432 2433 for (t = target; t; t = t->next) { 2434 int class, type; 2435 u_char *answer; 2436 int anslen; 2437 2438 hp = (HEADER *)(void *)t->answer; 2439 2440 /* make it easier... */ 2441 class = t->qclass; 2442 type = t->qtype; 2443 answer = t->answer; 2444 anslen = t->anslen; 2445 2446 oflags = res->_flags; 2447 2448again: 2449 hp->rcode = NOERROR; /* default */ 2450 2451#ifdef DEBUG 2452 if (res->options & RES_DEBUG) 2453 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2454#endif 2455 2456 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2457 buf, MAXPACKET); 2458 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2459 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2460 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2461 if (n <= 0) { 2462#ifdef DEBUG 2463 if (res->options & RES_DEBUG) 2464 printf(";; res_query: mkquery failed\n"); 2465#endif 2466 free(buf); 2467 RES_SET_H_ERRNO(res, NO_RECOVERY); 2468 return (n); 2469 } 2470 n = res_nsend(res, buf, n, answer, anslen); 2471 if (n < 0) { 2472 /* 2473 * if the query choked with EDNS0, retry 2474 * without EDNS0 2475 */ 2476 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2477 != 0U && 2478 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2479 res->_flags |= RES_F_EDNS0ERR; 2480 if (res->options & RES_DEBUG) 2481 printf(";; res_nquery: retry without EDNS0\n"); 2482 goto again; 2483 } 2484 rcode = hp->rcode; /* record most recent error */ 2485#ifdef DEBUG 2486 if (res->options & RES_DEBUG) 2487 printf(";; res_query: send error\n"); 2488#endif 2489 continue; 2490 } 2491 2492 if (n > anslen) 2493 hp->rcode = FORMERR; /* XXX not very informative */ 2494 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2495 rcode = hp->rcode; /* record most recent error */ 2496#ifdef DEBUG 2497 if (res->options & RES_DEBUG) 2498 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2499 ntohs(hp->ancount)); 2500#endif 2501 continue; 2502 } 2503 2504 ancount += ntohs(hp->ancount); 2505 2506 t->n = n; 2507 } 2508 2509 free(buf); 2510 2511 if (ancount == 0) { 2512 switch (rcode) { 2513 case NXDOMAIN: 2514 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2515 break; 2516 case SERVFAIL: 2517 RES_SET_H_ERRNO(res, TRY_AGAIN); 2518 break; 2519 case NOERROR: 2520 RES_SET_H_ERRNO(res, NO_DATA); 2521 break; 2522 case FORMERR: 2523 case NOTIMP: 2524 case REFUSED: 2525 default: 2526 RES_SET_H_ERRNO(res, NO_RECOVERY); 2527 break; 2528 } 2529 return (-1); 2530 } 2531 return (ancount); 2532} 2533 2534/* 2535 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2536 * Return the size of the response on success, -1 on error. 2537 * If enabled, implement search rules until answer or unrecoverable failure 2538 * is detected. Error code, if any, is left in h_errno. 2539 */ 2540static int 2541res_searchN(const char *name, struct res_target *target, res_state res) 2542{ 2543 const char *cp, * const *domain; 2544 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2545 u_int dots; 2546 int trailing_dot, ret, saved_herrno; 2547 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2548 int tried_as_is = 0; 2549 int searched = 0; 2550 char abuf[MAXDNAME]; 2551 2552 errno = 0; 2553 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2554 dots = 0; 2555 for (cp = name; *cp; cp++) 2556 dots += (*cp == '.'); 2557 trailing_dot = 0; 2558 if (cp > name && *--cp == '.') 2559 trailing_dot++; 2560 2561 /* 2562 * if there aren't any dots, it could be a user-level alias 2563 */ 2564 if (!dots && 2565 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2566 return (res_queryN(cp, target, res)); 2567 2568 /* 2569 * If there are enough dots in the name, let's just give it a 2570 * try 'as is'. The threshold can be set with the "ndots" option. 2571 * Also, query 'as is', if there is a trailing dot in the name. 2572 */ 2573 saved_herrno = -1; 2574 if (dots >= res->ndots || trailing_dot) { 2575 ret = res_querydomainN(name, NULL, target, res); 2576 if (ret > 0 || trailing_dot) 2577 return (ret); 2578 if (errno == ECONNREFUSED) { 2579 RES_SET_H_ERRNO(res, TRY_AGAIN); 2580 return (-1); 2581 } 2582 switch (res->res_h_errno) { 2583 case NO_DATA: 2584 case HOST_NOT_FOUND: 2585 break; 2586 case TRY_AGAIN: 2587 if (hp->rcode == SERVFAIL) 2588 break; 2589 /* FALLTHROUGH */ 2590 default: 2591 return (-1); 2592 } 2593 saved_herrno = res->res_h_errno; 2594 tried_as_is++; 2595 } 2596 2597 /* 2598 * We do at least one level of search if 2599 * - there is no dot and RES_DEFNAME is set, or 2600 * - there is at least one dot, there is no trailing dot, 2601 * and RES_DNSRCH is set. 2602 */ 2603 if ((!dots && (res->options & RES_DEFNAMES)) || 2604 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2605 int done = 0; 2606 2607 for (domain = (const char * const *)res->dnsrch; 2608 *domain && !done; 2609 domain++) { 2610 searched = 1; 2611 2612 if (domain[0][0] == '\0' || 2613 (domain[0][0] == '.' && domain[0][1] == '\0')) 2614 root_on_list++; 2615 2616 if (root_on_list && tried_as_is) 2617 continue; 2618 2619 ret = res_querydomainN(name, *domain, target, res); 2620 if (ret > 0) 2621 return (ret); 2622 2623 /* 2624 * If no server present, give up. 2625 * If name isn't found in this domain, 2626 * keep trying higher domains in the search list 2627 * (if that's enabled). 2628 * On a NO_DATA error, keep trying, otherwise 2629 * a wildcard entry of another type could keep us 2630 * from finding this entry higher in the domain. 2631 * If we get some other error (negative answer or 2632 * server failure), then stop searching up, 2633 * but try the input name below in case it's 2634 * fully-qualified. 2635 */ 2636 if (errno == ECONNREFUSED) { 2637 RES_SET_H_ERRNO(res, TRY_AGAIN); 2638 return (-1); 2639 } 2640 2641 switch (res->res_h_errno) { 2642 case NO_DATA: 2643 got_nodata++; 2644 /* FALLTHROUGH */ 2645 case HOST_NOT_FOUND: 2646 /* keep trying */ 2647 break; 2648 case TRY_AGAIN: 2649 got_servfail++; 2650 if (hp->rcode == SERVFAIL) { 2651 /* try next search element, if any */ 2652 break; 2653 } 2654 /* FALLTHROUGH */ 2655 default: 2656 /* anything else implies that we're done */ 2657 done++; 2658 } 2659 /* 2660 * if we got here for some reason other than DNSRCH, 2661 * we only wanted one iteration of the loop, so stop. 2662 */ 2663 if (!(res->options & RES_DNSRCH)) 2664 done++; 2665 } 2666 } 2667 2668 switch (res->res_h_errno) { 2669 case NO_DATA: 2670 case HOST_NOT_FOUND: 2671 break; 2672 case TRY_AGAIN: 2673 if (hp->rcode == SERVFAIL) 2674 break; 2675 /* FALLTHROUGH */ 2676 default: 2677 goto giveup; 2678 } 2679 2680 /* 2681 * If the query has not already been tried as is then try it 2682 * unless RES_NOTLDQUERY is set and there were no dots. 2683 */ 2684 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2685 !(tried_as_is || root_on_list)) { 2686 ret = res_querydomainN(name, NULL, target, res); 2687 if (ret > 0) 2688 return (ret); 2689 } 2690 2691 /* 2692 * if we got here, we didn't satisfy the search. 2693 * if we did an initial full query, return that query's h_errno 2694 * (note that we wouldn't be here if that query had succeeded). 2695 * else if we ever got a nodata, send that back as the reason. 2696 * else send back meaningless h_errno, that being the one from 2697 * the last DNSRCH we did. 2698 */ 2699giveup: 2700 if (saved_herrno != -1) 2701 RES_SET_H_ERRNO(res, saved_herrno); 2702 else if (got_nodata) 2703 RES_SET_H_ERRNO(res, NO_DATA); 2704 else if (got_servfail) 2705 RES_SET_H_ERRNO(res, TRY_AGAIN); 2706 return (-1); 2707} 2708 2709/* 2710 * Perform a call on res_query on the concatenation of name and domain, 2711 * removing a trailing dot from name if domain is NULL. 2712 */ 2713static int 2714res_querydomainN(const char *name, const char *domain, 2715 struct res_target *target, res_state res) 2716{ 2717 char nbuf[MAXDNAME]; 2718 const char *longname = nbuf; 2719 size_t n, d; 2720 2721#ifdef DEBUG 2722 if (res->options & RES_DEBUG) 2723 printf(";; res_querydomain(%s, %s)\n", 2724 name, domain?domain:"<Nil>"); 2725#endif 2726 if (domain == NULL) { 2727 /* 2728 * Check for trailing '.'; 2729 * copy without '.' if present. 2730 */ 2731 n = strlen(name); 2732 if (n >= MAXDNAME) { 2733 RES_SET_H_ERRNO(res, NO_RECOVERY); 2734 return (-1); 2735 } 2736 if (n > 0 && name[--n] == '.') { 2737 strncpy(nbuf, name, n); 2738 nbuf[n] = '\0'; 2739 } else 2740 longname = name; 2741 } else { 2742 n = strlen(name); 2743 d = strlen(domain); 2744 if (n + d + 1 >= MAXDNAME) { 2745 RES_SET_H_ERRNO(res, NO_RECOVERY); 2746 return (-1); 2747 } 2748 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2749 } 2750 return (res_queryN(longname, target, res)); 2751} 2752