getaddrinfo.c revision 267874
1109998Smarkm/* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 2109998Smarkm 3109998Smarkm/* 4109998Smarkm * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5109998Smarkm * All rights reserved. 6109998Smarkm * 7109998Smarkm * Redistribution and use in source and binary forms, with or without 8109998Smarkm * modification, are permitted provided that the following conditions 9109998Smarkm * are met: 10109998Smarkm * 1. Redistributions of source code must retain the above copyright 11109998Smarkm * notice, this list of conditions and the following disclaimer. 12109998Smarkm * 2. Redistributions in binary form must reproduce the above copyright 13109998Smarkm * notice, this list of conditions and the following disclaimer in the 14109998Smarkm * documentation and/or other materials provided with the distribution. 15109998Smarkm * 3. Neither the name of the project nor the names of its contributors 16109998Smarkm * may be used to endorse or promote products derived from this software 17109998Smarkm * without specific prior written permission. 18109998Smarkm * 19109998Smarkm * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20109998Smarkm * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21109998Smarkm * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22109998Smarkm * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23109998Smarkm * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24109998Smarkm * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25109998Smarkm * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26109998Smarkm * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27109998Smarkm * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28109998Smarkm * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29109998Smarkm * SUCH DAMAGE. 30109998Smarkm */ 31109998Smarkm 32109998Smarkm/* 33109998Smarkm * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator. 34109998Smarkm * 35109998Smarkm * Issues to be discussed: 36109998Smarkm * - Return values. There are nonstandard return values defined and used 37109998Smarkm * in the source code. This is because RFC2553 is silent about which error 38109998Smarkm * code must be returned for which situation. 39109998Smarkm * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 40109998Smarkm * invalid. current code - SEGV on freeaddrinfo(NULL) 41109998Smarkm * 42109998Smarkm * Note: 43109998Smarkm * - The code filters out AFs that are not supported by the kernel, 44109998Smarkm * when globbing NULL hostname (to loopback, or wildcard). Is it the right 45109998Smarkm * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 46109998Smarkm * in ai_flags? 47109998Smarkm * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 48109998Smarkm * (1) what should we do against numeric hostname (2) what should we do 49109998Smarkm * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 50109998Smarkm * non-loopback address configured? global address configured? 51109998Smarkm * 52109998Smarkm * OS specific notes for freebsd4: 53109998Smarkm * - FreeBSD supported $GAI. The code does not. 54109998Smarkm */ 55109998Smarkm 56109998Smarkm#include <sys/cdefs.h> 57109998Smarkm__FBSDID("$FreeBSD: stable/10/lib/libc/net/getaddrinfo.c 267874 2014-06-25 17:10:26Z ume $"); 58109998Smarkm 59109998Smarkm#include "namespace.h" 60109998Smarkm#include <sys/types.h> 61109998Smarkm#include <sys/param.h> 62109998Smarkm#include <sys/socket.h> 63109998Smarkm#include <net/if.h> 64109998Smarkm#include <netinet/in.h> 65109998Smarkm#include <net/if_types.h> 66109998Smarkm#include <ifaddrs.h> 67109998Smarkm#include <sys/queue.h> 68109998Smarkm#ifdef INET6 69109998Smarkm#include <net/if_var.h> 70109998Smarkm#include <sys/sysctl.h> 71109998Smarkm#include <sys/ioctl.h> 72109998Smarkm#include <netinet6/in6_var.h> 73109998Smarkm#include <netinet6/nd6.h> 74109998Smarkm#endif 75109998Smarkm#include <arpa/inet.h> 76109998Smarkm#include <arpa/nameser.h> 77109998Smarkm#include <rpc/rpc.h> 78109998Smarkm#include <rpcsvc/yp_prot.h> 79109998Smarkm#include <rpcsvc/ypclnt.h> 80109998Smarkm#include <netdb.h> 81109998Smarkm#include <resolv.h> 82109998Smarkm#include <string.h> 83109998Smarkm#include <stdlib.h> 84109998Smarkm#include <stddef.h> 85109998Smarkm#include <ctype.h> 86109998Smarkm#include <unistd.h> 87109998Smarkm#include <stdio.h> 88109998Smarkm#include <errno.h> 89109998Smarkm 90109998Smarkm#include "res_config.h" 91109998Smarkm 92109998Smarkm#ifdef DEBUG 93109998Smarkm#include <syslog.h> 94109998Smarkm#endif 95109998Smarkm 96109998Smarkm#include <stdarg.h> 97109998Smarkm#include <nsswitch.h> 98109998Smarkm#include "un-namespace.h" 99109998Smarkm#include "libc_private.h" 100109998Smarkm#ifdef NS_CACHING 101109998Smarkm#include "nscache.h" 102109998Smarkm#endif 103109998Smarkm 104109998Smarkm#if defined(__KAME__) && defined(INET6) 105109998Smarkm# define FAITH 106109998Smarkm#endif 107109998Smarkm 108109998Smarkm#define ANY 0 109109998Smarkm#define YES 1 110109998Smarkm#define NO 0 111109998Smarkm 112109998Smarkmstatic const char in_addrany[] = { 0, 0, 0, 0 }; 113109998Smarkmstatic const char in_loopback[] = { 127, 0, 0, 1 }; 114109998Smarkm#ifdef INET6 115160814Ssimonstatic const char in6_addrany[] = { 116109998Smarkm 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 117109998Smarkm}; 118109998Smarkmstatic const char in6_loopback[] = { 119109998Smarkm 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 120109998Smarkm}; 121109998Smarkm#endif 122109998Smarkm 123109998Smarkmstruct policyqueue { 124109998Smarkm TAILQ_ENTRY(policyqueue) pc_entry; 125109998Smarkm#ifdef INET6 126109998Smarkm struct in6_addrpolicy pc_policy; 127109998Smarkm#endif 128109998Smarkm}; 129109998SmarkmTAILQ_HEAD(policyhead, policyqueue); 130109998Smarkm 131109998Smarkmstatic const struct afd { 132109998Smarkm int a_af; 133109998Smarkm int a_addrlen; 134109998Smarkm socklen_t a_socklen; 135109998Smarkm int a_off; 136109998Smarkm const char *a_addrany; 137160814Ssimon const char *a_loopback; 138109998Smarkm int a_scoped; 139109998Smarkm} afdl [] = { 140109998Smarkm#ifdef INET6 141109998Smarkm#define N_INET6 0 142109998Smarkm {PF_INET6, sizeof(struct in6_addr), 143109998Smarkm sizeof(struct sockaddr_in6), 144109998Smarkm offsetof(struct sockaddr_in6, sin6_addr), 145109998Smarkm in6_addrany, in6_loopback, 1}, 146109998Smarkm#define N_INET 1 147109998Smarkm#else 148109998Smarkm#define N_INET 0 149109998Smarkm#endif 150109998Smarkm {PF_INET, sizeof(struct in_addr), 151109998Smarkm sizeof(struct sockaddr_in), 152109998Smarkm offsetof(struct sockaddr_in, sin_addr), 153109998Smarkm in_addrany, in_loopback, 0}, 154109998Smarkm {0, 0, 0, 0, NULL, NULL, 0}, 155109998Smarkm}; 156109998Smarkm 157109998Smarkmstruct explore { 158109998Smarkm int e_af; 159109998Smarkm int e_socktype; 160109998Smarkm int e_protocol; 161109998Smarkm int e_wild; 162109998Smarkm#define WILD_AF(ex) ((ex)->e_wild & 0x01) 163109998Smarkm#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 164109998Smarkm#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 165109998Smarkm}; 166109998Smarkm 167109998Smarkmstatic const struct explore explore[] = { 168109998Smarkm#if 0 169109998Smarkm { PF_LOCAL, ANY, ANY, 0x01 }, 170109998Smarkm#endif 171109998Smarkm#ifdef INET6 172237998Sjkim { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 0x07 }, 173237998Sjkim { PF_INET6, SOCK_STREAM, IPPROTO_TCP, 0x07 }, 174237998Sjkim { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 0x03 }, 175237998Sjkim { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 }, 176109998Smarkm { PF_INET6, SOCK_DGRAM, IPPROTO_UDPLITE, 0x03 }, 177109998Smarkm { PF_INET6, SOCK_RAW, ANY, 0x05 }, 178109998Smarkm#endif 179109998Smarkm { PF_INET, SOCK_DGRAM, IPPROTO_UDP, 0x07 }, 180109998Smarkm { PF_INET, SOCK_STREAM, IPPROTO_TCP, 0x07 }, 181109998Smarkm { PF_INET, SOCK_STREAM, IPPROTO_SCTP, 0x03 }, 182109998Smarkm { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 }, 183109998Smarkm { PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE, 0x03 }, 184109998Smarkm { PF_INET, SOCK_RAW, ANY, 0x05 }, 185109998Smarkm { -1, 0, 0, 0 }, 186109998Smarkm}; 187109998Smarkm 188109998Smarkm#ifdef INET6 189109998Smarkm#define PTON_MAX 16 190109998Smarkm#else 191109998Smarkm#define PTON_MAX 4 192109998Smarkm#endif 193109998Smarkm 194109998Smarkm#define AIO_SRCFLAG_DEPRECATED 0x1 195109998Smarkm 196109998Smarkmstruct ai_order { 197109998Smarkm union { 198109998Smarkm struct sockaddr_storage aiou_ss; 199109998Smarkm struct sockaddr aiou_sa; 200109998Smarkm } aio_src_un; 201109998Smarkm#define aio_srcsa aio_src_un.aiou_sa 202109998Smarkm u_int32_t aio_srcflag; 203109998Smarkm int aio_srcscope; 204109998Smarkm int aio_dstscope; 205109998Smarkm struct policyqueue *aio_srcpolicy; 206109998Smarkm struct policyqueue *aio_dstpolicy; 207109998Smarkm struct addrinfo *aio_ai; 208109998Smarkm int aio_matchlen; 209109998Smarkm}; 210109998Smarkm 211109998Smarkmstatic const ns_src default_dns_files[] = { 212109998Smarkm { NSSRC_FILES, NS_SUCCESS }, 213109998Smarkm { NSSRC_DNS, NS_SUCCESS }, 214109998Smarkm { 0 } 215109998Smarkm}; 216109998Smarkm 217109998Smarkmstruct res_target { 218109998Smarkm struct res_target *next; 219109998Smarkm const char *name; /* domain name */ 220109998Smarkm int qclass, qtype; /* class and type of query */ 221109998Smarkm u_char *answer; /* buffer to put answer */ 222109998Smarkm int anslen; /* size of answer buffer */ 223279265Sdelphij int n; /* result length */ 224279265Sdelphij}; 225279265Sdelphij 226279265Sdelphij#define MAXPACKET (64*1024) 227279265Sdelphij 228279265Sdelphijtypedef union { 229279265Sdelphij HEADER hdr; 230279265Sdelphij u_char buf[MAXPACKET]; 231279265Sdelphij} querybuf; 232279265Sdelphij 233279265Sdelphijstatic int str2number(const char *, int *); 234109998Smarkmstatic int explore_copy(const struct addrinfo *, const struct addrinfo *, 235279265Sdelphij struct addrinfo **); 236109998Smarkmstatic int explore_null(const struct addrinfo *, 237109998Smarkm const char *, struct addrinfo **); 238109998Smarkmstatic int explore_numeric(const struct addrinfo *, const char *, 239109998Smarkm const char *, struct addrinfo **, const char *); 240109998Smarkmstatic int explore_numeric_scope(const struct addrinfo *, const char *, 241109998Smarkm const char *, struct addrinfo **); 242109998Smarkmstatic int get_canonname(const struct addrinfo *, 243109998Smarkm struct addrinfo *, const char *); 244109998Smarkmstatic struct addrinfo *get_ai(const struct addrinfo *, 245109998Smarkm const struct afd *, const char *); 246109998Smarkmstatic struct addrinfo *copy_ai(const struct addrinfo *); 247109998Smarkmstatic int get_portmatch(const struct addrinfo *, const char *); 248109998Smarkmstatic int get_port(struct addrinfo *, const char *, int); 249109998Smarkmstatic const struct afd *find_afd(int); 250109998Smarkmstatic int addrconfig(struct addrinfo *); 251109998Smarkm#ifdef INET6 252109998Smarkmstatic int is_ifdisabled(char *); 253109998Smarkm#endif 254109998Smarkmstatic void set_source(struct ai_order *, struct policyhead *); 255109998Smarkmstatic int comp_dst(const void *, const void *); 256109998Smarkm#ifdef INET6 257109998Smarkmstatic int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 258109998Smarkm#endif 259109998Smarkmstatic int gai_addr2scopetype(struct sockaddr *); 260109998Smarkm 261109998Smarkmstatic int explore_fqdn(const struct addrinfo *, const char *, 262109998Smarkm const char *, struct addrinfo **); 263109998Smarkm 264109998Smarkmstatic int reorder(struct addrinfo *); 265109998Smarkmstatic int get_addrselectpolicy(struct policyhead *); 266109998Smarkmstatic void free_addrselectpolicy(struct policyhead *); 267127128Snectarstatic struct policyqueue *match_addrselectpolicy(struct sockaddr *, 268109998Smarkm struct policyhead *); 269109998Smarkmstatic int matchlen(struct sockaddr *, struct sockaddr *); 270109998Smarkm 271109998Smarkmstatic struct addrinfo *getanswer(const querybuf *, int, const char *, int, 272109998Smarkm const struct addrinfo *, res_state); 273109998Smarkm#if defined(RESOLVSORT) 274static int addr4sort(struct addrinfo *, res_state); 275#endif 276static int _dns_getaddrinfo(void *, void *, va_list); 277static void _sethtent(FILE **); 278static void _endhtent(FILE **); 279static struct addrinfo *_gethtent(FILE **, const char *, 280 const struct addrinfo *); 281static int _files_getaddrinfo(void *, void *, va_list); 282#ifdef YP 283static struct addrinfo *_yphostent(char *, const struct addrinfo *); 284static int _yp_getaddrinfo(void *, void *, va_list); 285#endif 286#ifdef NS_CACHING 287static int addrinfo_id_func(char *, size_t *, va_list, void *); 288static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 289static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 290#endif 291 292static int res_queryN(const char *, struct res_target *, res_state); 293static int res_searchN(const char *, struct res_target *, res_state); 294static int res_querydomainN(const char *, const char *, 295 struct res_target *, res_state); 296 297/* XXX macros that make external reference is BAD. */ 298 299#define GET_AI(ai, afd, addr) \ 300do { \ 301 /* external reference: pai, error, and label free */ \ 302 (ai) = get_ai(pai, (afd), (addr)); \ 303 if ((ai) == NULL) { \ 304 error = EAI_MEMORY; \ 305 goto free; \ 306 } \ 307} while (/*CONSTCOND*/0) 308 309#define GET_PORT(ai, serv) \ 310do { \ 311 /* external reference: error and label free */ \ 312 error = get_port((ai), (serv), 0); \ 313 if (error != 0) \ 314 goto free; \ 315} while (/*CONSTCOND*/0) 316 317#define GET_CANONNAME(ai, str) \ 318do { \ 319 /* external reference: pai, error and label free */ \ 320 error = get_canonname(pai, (ai), (str)); \ 321 if (error != 0) \ 322 goto free; \ 323} while (/*CONSTCOND*/0) 324 325#define ERR(err) \ 326do { \ 327 /* external reference: error, and label bad */ \ 328 error = (err); \ 329 goto bad; \ 330 /*NOTREACHED*/ \ 331} while (/*CONSTCOND*/0) 332 333#define MATCH_FAMILY(x, y, w) \ 334 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 335#define MATCH(x, y, w) \ 336 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 337 338void 339freeaddrinfo(struct addrinfo *ai) 340{ 341 struct addrinfo *next; 342 343 do { 344 next = ai->ai_next; 345 if (ai->ai_canonname) 346 free(ai->ai_canonname); 347 /* no need to free(ai->ai_addr) */ 348 free(ai); 349 ai = next; 350 } while (ai); 351} 352 353static int 354str2number(const char *p, int *portp) 355{ 356 char *ep; 357 unsigned long v; 358 359 if (*p == '\0') 360 return -1; 361 ep = NULL; 362 errno = 0; 363 v = strtoul(p, &ep, 10); 364 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 365 *portp = v; 366 return 0; 367 } else 368 return -1; 369} 370 371int 372getaddrinfo(const char *hostname, const char *servname, 373 const struct addrinfo *hints, struct addrinfo **res) 374{ 375 struct addrinfo sentinel; 376 struct addrinfo *cur; 377 int error = 0; 378 struct addrinfo ai, ai0, *afai; 379 struct addrinfo *pai; 380 const struct afd *afd; 381 const struct explore *ex; 382 struct addrinfo *afailist[sizeof(afdl)/sizeof(afdl[0])]; 383 struct addrinfo *afai_unspec; 384 int found; 385 int numeric = 0; 386 387 /* ensure we return NULL on errors */ 388 *res = NULL; 389 390 memset(&ai, 0, sizeof(ai)); 391 392 memset(afailist, 0, sizeof(afailist)); 393 afai_unspec = NULL; 394 395 memset(&sentinel, 0, sizeof(sentinel)); 396 cur = &sentinel; 397 pai = &ai; 398 pai->ai_flags = 0; 399 pai->ai_family = PF_UNSPEC; 400 pai->ai_socktype = ANY; 401 pai->ai_protocol = ANY; 402 pai->ai_addrlen = 0; 403 pai->ai_canonname = NULL; 404 pai->ai_addr = NULL; 405 pai->ai_next = NULL; 406 407 if (hostname == NULL && servname == NULL) 408 return EAI_NONAME; 409 if (hints) { 410 /* error check for hints */ 411 if (hints->ai_addrlen || hints->ai_canonname || 412 hints->ai_addr || hints->ai_next) 413 ERR(EAI_BADHINTS); /* xxx */ 414 if (hints->ai_flags & ~AI_MASK) 415 ERR(EAI_BADFLAGS); 416 switch (hints->ai_family) { 417 case PF_UNSPEC: 418 case PF_INET: 419#ifdef INET6 420 case PF_INET6: 421#endif 422 break; 423 default: 424 ERR(EAI_FAMILY); 425 } 426 memcpy(pai, hints, sizeof(*pai)); 427 428 /* 429 * if both socktype/protocol are specified, check if they 430 * are meaningful combination. 431 */ 432 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 433 for (ex = explore; ex->e_af >= 0; ex++) { 434 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 435 WILD_AF(ex))) 436 continue; 437 if (!MATCH(pai->ai_socktype, ex->e_socktype, 438 WILD_SOCKTYPE(ex))) 439 continue; 440 if (!MATCH(pai->ai_protocol, ex->e_protocol, 441 WILD_PROTOCOL(ex))) 442 continue; 443 444 /* matched */ 445 break; 446 } 447 448 if (ex->e_af < 0) 449 ERR(EAI_BADHINTS); 450 } 451 } 452 453 /* 454 * check for special cases. (1) numeric servname is disallowed if 455 * socktype/protocol are left unspecified. (2) servname is disallowed 456 * for raw and other inet{,6} sockets. 457 */ 458 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 459#ifdef PF_INET6 460 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 461#endif 462 ) { 463 ai0 = *pai; /* backup *pai */ 464 465 if (pai->ai_family == PF_UNSPEC) { 466#ifdef PF_INET6 467 pai->ai_family = PF_INET6; 468#else 469 pai->ai_family = PF_INET; 470#endif 471 } 472 error = get_portmatch(pai, servname); 473 if (error) 474 goto bad; 475 476 *pai = ai0; 477 } 478 479 ai0 = *pai; 480 481 /* 482 * NULL hostname, or numeric hostname. 483 * If numeric representation of AF1 can be interpreted as FQDN 484 * representation of AF2, we need to think again about the code below. 485 */ 486 found = 0; 487 for (afd = afdl; afd->a_af; afd++) { 488 *pai = ai0; 489 490 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 491 continue; 492 493 if (pai->ai_family == PF_UNSPEC) 494 pai->ai_family = afd->a_af; 495 496 if (hostname == NULL) { 497 error = explore_null(pai, servname, 498 &afailist[afd - afdl]); 499 500 /* 501 * Errors from explore_null should be unexpected and 502 * be caught to avoid returning an incomplete result. 503 */ 504 if (error != 0) 505 goto bad; 506 } else { 507 error = explore_numeric_scope(pai, hostname, servname, 508 &afailist[afd - afdl]); 509 510 /* 511 * explore_numeric_scope returns an error for address 512 * families that do not match that of hostname. 513 * Thus we should not catch the error at this moment. 514 */ 515 } 516 517 if (!error && afailist[afd - afdl]) 518 found++; 519 } 520 if (found) { 521 numeric = 1; 522 goto globcopy; 523 } 524 525 if (hostname == NULL) 526 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 527 if (pai->ai_flags & AI_NUMERICHOST) 528 ERR(EAI_NONAME); 529 530 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 531 ERR(EAI_FAIL); 532 533 /* 534 * hostname as alphabetical name. 535 */ 536 *pai = ai0; 537 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 538 539globcopy: 540 for (ex = explore; ex->e_af >= 0; ex++) { 541 *pai = ai0; 542 543 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 544 continue; 545 if (!MATCH(pai->ai_socktype, ex->e_socktype, 546 WILD_SOCKTYPE(ex))) 547 continue; 548 if (!MATCH(pai->ai_protocol, ex->e_protocol, 549 WILD_PROTOCOL(ex))) 550 continue; 551 552 if (pai->ai_family == PF_UNSPEC) 553 pai->ai_family = ex->e_af; 554 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 555 pai->ai_socktype = ex->e_socktype; 556 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 557 pai->ai_protocol = ex->e_protocol; 558 559 /* 560 * if the servname does not match socktype/protocol, ignore it. 561 */ 562 if (get_portmatch(pai, servname) != 0) 563 continue; 564 565 if (afai_unspec) 566 afai = afai_unspec; 567 else { 568 if ((afd = find_afd(pai->ai_family)) == NULL) 569 continue; 570 /* XXX assumes that afd points inside afdl[] */ 571 afai = afailist[afd - afdl]; 572 } 573 if (!afai) 574 continue; 575 576 error = explore_copy(pai, afai, &cur->ai_next); 577 if (error != 0) 578 goto bad; 579 580 while (cur && cur->ai_next) 581 cur = cur->ai_next; 582 } 583 584 /* 585 * ensure we return either: 586 * - error == 0, non-NULL *res 587 * - error != 0, NULL *res 588 */ 589 if (error == 0) { 590 if (sentinel.ai_next) { 591 /* 592 * If the returned entry is for an active connection, 593 * and the given name is not numeric, reorder the 594 * list, so that the application would try the list 595 * in the most efficient order. Since the head entry 596 * of the original list may contain ai_canonname and 597 * that entry may be moved elsewhere in the new list, 598 * we keep the pointer and will restore it in the new 599 * head entry. (Note that RFC3493 requires the head 600 * entry store it when requested by the caller). 601 */ 602 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 603 if (!numeric) { 604 char *canonname; 605 606 canonname = 607 sentinel.ai_next->ai_canonname; 608 sentinel.ai_next->ai_canonname = NULL; 609 (void)reorder(&sentinel); 610 if (sentinel.ai_next->ai_canonname == 611 NULL) { 612 sentinel.ai_next->ai_canonname 613 = canonname; 614 } else if (canonname != NULL) 615 free(canonname); 616 } 617 } 618 *res = sentinel.ai_next; 619 } else 620 error = EAI_FAIL; 621 } 622 623bad: 624 if (afai_unspec) 625 freeaddrinfo(afai_unspec); 626 for (afd = afdl; afd->a_af; afd++) { 627 if (afailist[afd - afdl]) 628 freeaddrinfo(afailist[afd - afdl]); 629 } 630 if (!*res) 631 if (sentinel.ai_next) 632 freeaddrinfo(sentinel.ai_next); 633 634 return (error); 635} 636 637static int 638reorder(struct addrinfo *sentinel) 639{ 640 struct addrinfo *ai, **aip; 641 struct ai_order *aio; 642 int i, n; 643 struct policyhead policyhead; 644 645 /* count the number of addrinfo elements for sorting. */ 646 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 647 ; 648 649 /* 650 * If the number is small enough, we can skip the reordering process. 651 */ 652 if (n <= 1) 653 return(n); 654 655 /* allocate a temporary array for sort and initialization of it. */ 656 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 657 return(n); /* give up reordering */ 658 memset(aio, 0, sizeof(*aio) * n); 659 660 /* retrieve address selection policy from the kernel */ 661 TAILQ_INIT(&policyhead); 662 if (!get_addrselectpolicy(&policyhead)) { 663 /* no policy is installed into kernel, we don't sort. */ 664 free(aio); 665 return (n); 666 } 667 668 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 669 aio[i].aio_ai = ai; 670 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 671 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 672 &policyhead); 673 set_source(&aio[i], &policyhead); 674 } 675 676 /* perform sorting. */ 677 qsort(aio, n, sizeof(*aio), comp_dst); 678 679 /* reorder the addrinfo chain. */ 680 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 681 *aip = aio[i].aio_ai; 682 aip = &aio[i].aio_ai->ai_next; 683 } 684 *aip = NULL; 685 686 /* cleanup and return */ 687 free(aio); 688 free_addrselectpolicy(&policyhead); 689 return(n); 690} 691 692static int 693get_addrselectpolicy(struct policyhead *head) 694{ 695#ifdef INET6 696 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 697 size_t l; 698 char *buf; 699 struct in6_addrpolicy *pol, *ep; 700 701 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 702 return (0); 703 if (l == 0) 704 return (0); 705 if ((buf = malloc(l)) == NULL) 706 return (0); 707 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 708 free(buf); 709 return (0); 710 } 711 712 ep = (struct in6_addrpolicy *)(buf + l); 713 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 714 struct policyqueue *new; 715 716 if ((new = malloc(sizeof(*new))) == NULL) { 717 free_addrselectpolicy(head); /* make the list empty */ 718 break; 719 } 720 new->pc_policy = *pol; 721 TAILQ_INSERT_TAIL(head, new, pc_entry); 722 } 723 724 free(buf); 725 return (1); 726#else 727 return (0); 728#endif 729} 730 731static void 732free_addrselectpolicy(struct policyhead *head) 733{ 734 struct policyqueue *ent, *nent; 735 736 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 737 nent = TAILQ_NEXT(ent, pc_entry); 738 TAILQ_REMOVE(head, ent, pc_entry); 739 free(ent); 740 } 741} 742 743static struct policyqueue * 744match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 745{ 746#ifdef INET6 747 struct policyqueue *ent, *bestent = NULL; 748 struct in6_addrpolicy *pol; 749 int matchlen, bestmatchlen = -1; 750 u_char *mp, *ep, *k, *p, m; 751 struct sockaddr_in6 key; 752 753 switch(addr->sa_family) { 754 case AF_INET6: 755 key = *(struct sockaddr_in6 *)addr; 756 break; 757 case AF_INET: 758 /* convert the address into IPv4-mapped IPv6 address. */ 759 memset(&key, 0, sizeof(key)); 760 key.sin6_family = AF_INET6; 761 key.sin6_len = sizeof(key); 762 key.sin6_addr.s6_addr[10] = 0xff; 763 key.sin6_addr.s6_addr[11] = 0xff; 764 memcpy(&key.sin6_addr.s6_addr[12], 765 &((struct sockaddr_in *)addr)->sin_addr, 4); 766 break; 767 default: 768 return(NULL); 769 } 770 771 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 772 pol = &ent->pc_policy; 773 matchlen = 0; 774 775 mp = (u_char *)&pol->addrmask.sin6_addr; 776 ep = mp + 16; /* XXX: scope field? */ 777 k = (u_char *)&key.sin6_addr; 778 p = (u_char *)&pol->addr.sin6_addr; 779 for (; mp < ep && *mp; mp++, k++, p++) { 780 m = *mp; 781 if ((*k & m) != *p) 782 goto next; /* not match */ 783 if (m == 0xff) /* short cut for a typical case */ 784 matchlen += 8; 785 else { 786 while (m >= 0x80) { 787 matchlen++; 788 m <<= 1; 789 } 790 } 791 } 792 793 /* matched. check if this is better than the current best. */ 794 if (matchlen > bestmatchlen) { 795 bestent = ent; 796 bestmatchlen = matchlen; 797 } 798 799 next: 800 continue; 801 } 802 803 return(bestent); 804#else 805 return(NULL); 806#endif 807 808} 809 810static void 811set_source(struct ai_order *aio, struct policyhead *ph) 812{ 813 struct addrinfo ai = *aio->aio_ai; 814 struct sockaddr_storage ss; 815 socklen_t srclen; 816 int s; 817 818 /* set unspec ("no source is available"), just in case */ 819 aio->aio_srcsa.sa_family = AF_UNSPEC; 820 aio->aio_srcscope = -1; 821 822 switch(ai.ai_family) { 823 case AF_INET: 824#ifdef INET6 825 case AF_INET6: 826#endif 827 break; 828 default: /* ignore unsupported AFs explicitly */ 829 return; 830 } 831 832 /* XXX: make a dummy addrinfo to call connect() */ 833 ai.ai_socktype = SOCK_DGRAM; 834 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 835 ai.ai_next = NULL; 836 memset(&ss, 0, sizeof(ss)); 837 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 838 ai.ai_addr = (struct sockaddr *)&ss; 839 get_port(&ai, "1", 0); 840 841 /* open a socket to get the source address for the given dst */ 842 if ((s = _socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC, 843 ai.ai_protocol)) < 0) 844 return; /* give up */ 845 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 846 goto cleanup; 847 srclen = ai.ai_addrlen; 848 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 849 aio->aio_srcsa.sa_family = AF_UNSPEC; 850 goto cleanup; 851 } 852 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 853 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 854 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 855#ifdef INET6 856 if (ai.ai_family == AF_INET6) { 857 struct in6_ifreq ifr6; 858 u_int32_t flags6; 859 860 memset(&ifr6, 0, sizeof(ifr6)); 861 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 862 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 863 flags6 = ifr6.ifr_ifru.ifru_flags6; 864 if ((flags6 & IN6_IFF_DEPRECATED)) 865 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 866 } 867 } 868#endif 869 870 cleanup: 871 _close(s); 872 return; 873} 874 875static int 876matchlen(struct sockaddr *src, struct sockaddr *dst) 877{ 878 int match = 0; 879 u_char *s, *d; 880 u_char *lim, r; 881 int addrlen; 882 883 switch (src->sa_family) { 884#ifdef INET6 885 case AF_INET6: 886 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 887 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 888 addrlen = sizeof(struct in6_addr); 889 lim = s + addrlen; 890 break; 891#endif 892 case AF_INET: 893 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 894 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 895 addrlen = sizeof(struct in_addr); 896 lim = s + addrlen; 897 break; 898 default: 899 return(0); 900 } 901 902 while (s < lim) 903 if ((r = (*d++ ^ *s++)) != 0) { 904 while (r < addrlen * 8) { 905 match++; 906 r <<= 1; 907 } 908 break; 909 } else 910 match += 8; 911 return(match); 912} 913 914static int 915comp_dst(const void *arg1, const void *arg2) 916{ 917 const struct ai_order *dst1 = arg1, *dst2 = arg2; 918 919 /* 920 * Rule 1: Avoid unusable destinations. 921 * XXX: we currently do not consider if an appropriate route exists. 922 */ 923 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 924 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 925 return(-1); 926 } 927 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 928 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 929 return(1); 930 } 931 932 /* Rule 2: Prefer matching scope. */ 933 if (dst1->aio_dstscope == dst1->aio_srcscope && 934 dst2->aio_dstscope != dst2->aio_srcscope) { 935 return(-1); 936 } 937 if (dst1->aio_dstscope != dst1->aio_srcscope && 938 dst2->aio_dstscope == dst2->aio_srcscope) { 939 return(1); 940 } 941 942 /* Rule 3: Avoid deprecated addresses. */ 943 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 944 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 945 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 946 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 947 return(-1); 948 } 949 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 950 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 951 return(1); 952 } 953 } 954 955 /* Rule 4: Prefer home addresses. */ 956 /* XXX: not implemented yet */ 957 958 /* Rule 5: Prefer matching label. */ 959#ifdef INET6 960 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 961 dst1->aio_srcpolicy->pc_policy.label == 962 dst1->aio_dstpolicy->pc_policy.label && 963 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 964 dst2->aio_srcpolicy->pc_policy.label != 965 dst2->aio_dstpolicy->pc_policy.label)) { 966 return(-1); 967 } 968 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 969 dst2->aio_srcpolicy->pc_policy.label == 970 dst2->aio_dstpolicy->pc_policy.label && 971 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 972 dst1->aio_srcpolicy->pc_policy.label != 973 dst1->aio_dstpolicy->pc_policy.label)) { 974 return(1); 975 } 976#endif 977 978 /* Rule 6: Prefer higher precedence. */ 979#ifdef INET6 980 if (dst1->aio_dstpolicy && 981 (dst2->aio_dstpolicy == NULL || 982 dst1->aio_dstpolicy->pc_policy.preced > 983 dst2->aio_dstpolicy->pc_policy.preced)) { 984 return(-1); 985 } 986 if (dst2->aio_dstpolicy && 987 (dst1->aio_dstpolicy == NULL || 988 dst2->aio_dstpolicy->pc_policy.preced > 989 dst1->aio_dstpolicy->pc_policy.preced)) { 990 return(1); 991 } 992#endif 993 994 /* Rule 7: Prefer native transport. */ 995 /* XXX: not implemented yet */ 996 997 /* Rule 8: Prefer smaller scope. */ 998 if (dst1->aio_dstscope >= 0 && 999 dst1->aio_dstscope < dst2->aio_dstscope) { 1000 return(-1); 1001 } 1002 if (dst2->aio_dstscope >= 0 && 1003 dst2->aio_dstscope < dst1->aio_dstscope) { 1004 return(1); 1005 } 1006 1007 /* 1008 * Rule 9: Use longest matching prefix. 1009 * We compare the match length in a same AF only. 1010 */ 1011 if (dst1->aio_ai->ai_addr->sa_family == 1012 dst2->aio_ai->ai_addr->sa_family) { 1013 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1014 return(-1); 1015 } 1016 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1017 return(1); 1018 } 1019 } 1020 1021 /* Rule 10: Otherwise, leave the order unchanged. */ 1022 return(-1); 1023} 1024 1025/* 1026 * Copy from scope.c. 1027 * XXX: we should standardize the functions and link them as standard 1028 * library. 1029 */ 1030static int 1031gai_addr2scopetype(struct sockaddr *sa) 1032{ 1033#ifdef INET6 1034 struct sockaddr_in6 *sa6; 1035#endif 1036 struct sockaddr_in *sa4; 1037 1038 switch(sa->sa_family) { 1039#ifdef INET6 1040 case AF_INET6: 1041 sa6 = (struct sockaddr_in6 *)sa; 1042 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1043 /* just use the scope field of the multicast address */ 1044 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1045 } 1046 /* 1047 * Unicast addresses: map scope type to corresponding scope 1048 * value defined for multcast addresses. 1049 * XXX: hardcoded scope type values are bad... 1050 */ 1051 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1052 return(1); /* node local scope */ 1053 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1054 return(2); /* link-local scope */ 1055 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1056 return(5); /* site-local scope */ 1057 return(14); /* global scope */ 1058 break; 1059#endif 1060 case AF_INET: 1061 /* 1062 * IPv4 pseudo scoping according to RFC 3484. 1063 */ 1064 sa4 = (struct sockaddr_in *)sa; 1065 /* IPv4 autoconfiguration addresses have link-local scope. */ 1066 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1067 ((u_char *)&sa4->sin_addr)[1] == 254) 1068 return(2); 1069 /* Private addresses have site-local scope. */ 1070 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1071 (((u_char *)&sa4->sin_addr)[0] == 172 && 1072 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1073 (((u_char *)&sa4->sin_addr)[0] == 192 && 1074 ((u_char *)&sa4->sin_addr)[1] == 168)) 1075 return(14); /* XXX: It should be 5 unless NAT */ 1076 /* Loopback addresses have link-local scope. */ 1077 if (((u_char *)&sa4->sin_addr)[0] == 127) 1078 return(2); 1079 return(14); 1080 break; 1081 default: 1082 errno = EAFNOSUPPORT; /* is this a good error? */ 1083 return(-1); 1084 } 1085} 1086 1087static int 1088explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1089 struct addrinfo **res) 1090{ 1091 int error; 1092 struct addrinfo sentinel, *cur; 1093 const struct addrinfo *src; 1094 1095 error = 0; 1096 sentinel.ai_next = NULL; 1097 cur = &sentinel; 1098 1099 for (src = src0; src != NULL; src = src->ai_next) { 1100 if (src->ai_family != pai->ai_family) 1101 continue; 1102 1103 cur->ai_next = copy_ai(src); 1104 if (!cur->ai_next) { 1105 error = EAI_MEMORY; 1106 goto fail; 1107 } 1108 1109 cur->ai_next->ai_socktype = pai->ai_socktype; 1110 cur->ai_next->ai_protocol = pai->ai_protocol; 1111 cur = cur->ai_next; 1112 } 1113 1114 *res = sentinel.ai_next; 1115 return 0; 1116 1117fail: 1118 freeaddrinfo(sentinel.ai_next); 1119 return error; 1120} 1121 1122/* 1123 * hostname == NULL. 1124 * passive socket -> anyaddr (0.0.0.0 or ::) 1125 * non-passive socket -> localhost (127.0.0.1 or ::1) 1126 */ 1127static int 1128explore_null(const struct addrinfo *pai, const char *servname, 1129 struct addrinfo **res) 1130{ 1131 int s; 1132 const struct afd *afd; 1133 struct addrinfo *ai; 1134 int error; 1135 1136 *res = NULL; 1137 ai = NULL; 1138 1139 /* 1140 * filter out AFs that are not supported by the kernel 1141 * XXX errno? 1142 */ 1143 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 1144 if (s < 0) { 1145 if (errno != EMFILE) 1146 return 0; 1147 } else 1148 _close(s); 1149 1150 afd = find_afd(pai->ai_family); 1151 if (afd == NULL) 1152 return 0; 1153 1154 if (pai->ai_flags & AI_PASSIVE) { 1155 GET_AI(ai, afd, afd->a_addrany); 1156 GET_PORT(ai, servname); 1157 } else { 1158 GET_AI(ai, afd, afd->a_loopback); 1159 GET_PORT(ai, servname); 1160 } 1161 1162 *res = ai; 1163 return 0; 1164 1165free: 1166 if (ai != NULL) 1167 freeaddrinfo(ai); 1168 return error; 1169} 1170 1171/* 1172 * numeric hostname 1173 */ 1174static int 1175explore_numeric(const struct addrinfo *pai, const char *hostname, 1176 const char *servname, struct addrinfo **res, const char *canonname) 1177{ 1178 const struct afd *afd; 1179 struct addrinfo *ai; 1180 int error; 1181 char pton[PTON_MAX]; 1182 1183 *res = NULL; 1184 ai = NULL; 1185 1186 afd = find_afd(pai->ai_family); 1187 if (afd == NULL) 1188 return 0; 1189 1190 switch (afd->a_af) { 1191 case AF_INET: 1192 /* 1193 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1194 * that are accepted by inet_addr() and its family. The 1195 * accepted forms includes the "classful" one, which inet_pton 1196 * does not accept. So we need to separate the case for 1197 * AF_INET. 1198 */ 1199 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1200 return 0; 1201 break; 1202 default: 1203 if (inet_pton(afd->a_af, hostname, pton) != 1) 1204 return 0; 1205 break; 1206 } 1207 1208 if (pai->ai_family == afd->a_af) { 1209 GET_AI(ai, afd, pton); 1210 GET_PORT(ai, servname); 1211 if ((pai->ai_flags & AI_CANONNAME)) { 1212 /* 1213 * Set the numeric address itself as the canonical 1214 * name, based on a clarification in RFC3493. 1215 */ 1216 GET_CANONNAME(ai, canonname); 1217 } 1218 } else { 1219 /* 1220 * XXX: This should not happen since we already matched the AF 1221 * by find_afd. 1222 */ 1223 ERR(EAI_FAMILY); 1224 } 1225 1226 *res = ai; 1227 return 0; 1228 1229free: 1230bad: 1231 if (ai != NULL) 1232 freeaddrinfo(ai); 1233 return error; 1234} 1235 1236/* 1237 * numeric hostname with scope 1238 */ 1239static int 1240explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1241 const char *servname, struct addrinfo **res) 1242{ 1243#if !defined(SCOPE_DELIMITER) || !defined(INET6) 1244 return explore_numeric(pai, hostname, servname, res, hostname); 1245#else 1246 const struct afd *afd; 1247 struct addrinfo *cur; 1248 int error; 1249 char *cp, *hostname2 = NULL, *scope, *addr; 1250 struct sockaddr_in6 *sin6; 1251 1252 afd = find_afd(pai->ai_family); 1253 if (afd == NULL) 1254 return 0; 1255 1256 if (!afd->a_scoped) 1257 return explore_numeric(pai, hostname, servname, res, hostname); 1258 1259 cp = strchr(hostname, SCOPE_DELIMITER); 1260 if (cp == NULL) 1261 return explore_numeric(pai, hostname, servname, res, hostname); 1262 1263 /* 1264 * Handle special case of <scoped_address><delimiter><scope id> 1265 */ 1266 hostname2 = strdup(hostname); 1267 if (hostname2 == NULL) 1268 return EAI_MEMORY; 1269 /* terminate at the delimiter */ 1270 hostname2[cp - hostname] = '\0'; 1271 addr = hostname2; 1272 scope = cp + 1; 1273 1274 error = explore_numeric(pai, addr, servname, res, hostname); 1275 if (error == 0) { 1276 u_int32_t scopeid; 1277 1278 for (cur = *res; cur; cur = cur->ai_next) { 1279 if (cur->ai_family != AF_INET6) 1280 continue; 1281 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1282 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1283 free(hostname2); 1284 freeaddrinfo(*res); 1285 *res = NULL; 1286 return(EAI_NONAME); /* XXX: is return OK? */ 1287 } 1288 sin6->sin6_scope_id = scopeid; 1289 } 1290 } 1291 1292 free(hostname2); 1293 1294 if (error && *res) { 1295 freeaddrinfo(*res); 1296 *res = NULL; 1297 } 1298 return error; 1299#endif 1300} 1301 1302static int 1303get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1304{ 1305 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1306 ai->ai_canonname = strdup(str); 1307 if (ai->ai_canonname == NULL) 1308 return EAI_MEMORY; 1309 } 1310 return 0; 1311} 1312 1313static struct addrinfo * 1314get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1315{ 1316 char *p; 1317 struct addrinfo *ai; 1318#ifdef FAITH 1319 struct in6_addr faith_prefix; 1320 char *fp_str; 1321 int translate = 0; 1322#endif 1323 1324#ifdef FAITH 1325 /* 1326 * Transfrom an IPv4 addr into a special IPv6 addr format for 1327 * IPv6->IPv4 translation gateway. (only TCP is supported now) 1328 * 1329 * +-----------------------------------+------------+ 1330 * | faith prefix part (12 bytes) | embedded | 1331 * | | IPv4 addr part (4 bytes) 1332 * +-----------------------------------+------------+ 1333 * 1334 * faith prefix part is specified as ascii IPv6 addr format 1335 * in environmental variable GAI. 1336 * For FAITH to work correctly, routing to faith prefix must be 1337 * setup toward a machine where a FAITH daemon operates. 1338 * Also, the machine must enable some mechanizm 1339 * (e.g. faith interface hack) to divert those packet with 1340 * faith prefixed destination addr to user-land FAITH daemon. 1341 */ 1342 fp_str = getenv("GAI"); 1343 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 1344 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 1345 u_int32_t v4a; 1346 u_int8_t v4a_top; 1347 1348 memcpy(&v4a, addr, sizeof v4a); 1349 v4a_top = v4a >> IN_CLASSA_NSHIFT; 1350 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 1351 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 1352 afd = &afdl[N_INET6]; 1353 memcpy(&faith_prefix.s6_addr[12], addr, 1354 sizeof(struct in_addr)); 1355 translate = 1; 1356 } 1357 } 1358#endif 1359 1360 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1361 + (afd->a_socklen)); 1362 if (ai == NULL) 1363 return NULL; 1364 1365 memcpy(ai, pai, sizeof(struct addrinfo)); 1366 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1367 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1368 ai->ai_addr->sa_len = afd->a_socklen; 1369 ai->ai_addrlen = afd->a_socklen; 1370 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1371 p = (char *)(void *)(ai->ai_addr); 1372#ifdef FAITH 1373 if (translate == 1) 1374 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 1375 else 1376#endif 1377 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1378 return ai; 1379} 1380 1381/* XXX need to malloc() the same way we do from other functions! */ 1382static struct addrinfo * 1383copy_ai(const struct addrinfo *pai) 1384{ 1385 struct addrinfo *ai; 1386 size_t l; 1387 1388 l = sizeof(*ai) + pai->ai_addrlen; 1389 if ((ai = (struct addrinfo *)malloc(l)) == NULL) 1390 return NULL; 1391 memset(ai, 0, l); 1392 memcpy(ai, pai, sizeof(*ai)); 1393 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1394 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1395 1396 if (pai->ai_canonname) { 1397 l = strlen(pai->ai_canonname) + 1; 1398 if ((ai->ai_canonname = malloc(l)) == NULL) { 1399 free(ai); 1400 return NULL; 1401 } 1402 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1403 } else { 1404 /* just to make sure */ 1405 ai->ai_canonname = NULL; 1406 } 1407 1408 ai->ai_next = NULL; 1409 1410 return ai; 1411} 1412 1413static int 1414get_portmatch(const struct addrinfo *ai, const char *servname) 1415{ 1416 1417 /* get_port does not touch first argument when matchonly == 1. */ 1418 /* LINTED const cast */ 1419 return get_port((struct addrinfo *)ai, servname, 1); 1420} 1421 1422static int 1423get_port(struct addrinfo *ai, const char *servname, int matchonly) 1424{ 1425 const char *proto; 1426 struct servent *sp; 1427 int port, error; 1428 int allownumeric; 1429 1430 if (servname == NULL) 1431 return 0; 1432 switch (ai->ai_family) { 1433 case AF_INET: 1434#ifdef AF_INET6 1435 case AF_INET6: 1436#endif 1437 break; 1438 default: 1439 return 0; 1440 } 1441 1442 switch (ai->ai_socktype) { 1443 case SOCK_RAW: 1444 return EAI_SERVICE; 1445 case SOCK_DGRAM: 1446 case SOCK_STREAM: 1447 case SOCK_SEQPACKET: 1448 allownumeric = 1; 1449 break; 1450 case ANY: 1451 switch (ai->ai_family) { 1452 case AF_INET: 1453#ifdef AF_INET6 1454 case AF_INET6: 1455#endif 1456 allownumeric = 1; 1457 break; 1458 default: 1459 allownumeric = 0; 1460 break; 1461 } 1462 break; 1463 default: 1464 return EAI_SOCKTYPE; 1465 } 1466 1467 error = str2number(servname, &port); 1468 if (error == 0) { 1469 if (!allownumeric) 1470 return EAI_SERVICE; 1471 if (port < 0 || port > 65535) 1472 return EAI_SERVICE; 1473 port = htons(port); 1474 } else { 1475 if (ai->ai_flags & AI_NUMERICSERV) 1476 return EAI_NONAME; 1477 1478 switch (ai->ai_protocol) { 1479 case IPPROTO_UDP: 1480 proto = "udp"; 1481 break; 1482 case IPPROTO_TCP: 1483 proto = "tcp"; 1484 break; 1485 case IPPROTO_SCTP: 1486 proto = "sctp"; 1487 break; 1488 case IPPROTO_UDPLITE: 1489 proto = "udplite"; 1490 break; 1491 default: 1492 proto = NULL; 1493 break; 1494 } 1495 1496 if ((sp = getservbyname(servname, proto)) == NULL) 1497 return EAI_SERVICE; 1498 port = sp->s_port; 1499 } 1500 1501 if (!matchonly) { 1502 switch (ai->ai_family) { 1503 case AF_INET: 1504 ((struct sockaddr_in *)(void *) 1505 ai->ai_addr)->sin_port = port; 1506 break; 1507#ifdef INET6 1508 case AF_INET6: 1509 ((struct sockaddr_in6 *)(void *) 1510 ai->ai_addr)->sin6_port = port; 1511 break; 1512#endif 1513 } 1514 } 1515 1516 return 0; 1517} 1518 1519static const struct afd * 1520find_afd(int af) 1521{ 1522 const struct afd *afd; 1523 1524 if (af == PF_UNSPEC) 1525 return NULL; 1526 for (afd = afdl; afd->a_af; afd++) { 1527 if (afd->a_af == af) 1528 return afd; 1529 } 1530 return NULL; 1531} 1532 1533/* 1534 * post-2553: AI_ADDRCONFIG check. Determines which address families are 1535 * configured on the local system and correlates with pai->ai_family value. 1536 * If an address family is not configured on the system, it will not be 1537 * queried for. For this purpose, loopback addresses are not considered 1538 * configured addresses. 1539 * 1540 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1541 * _dns_getaddrinfo. 1542 */ 1543static int 1544addrconfig(struct addrinfo *pai) 1545{ 1546 struct ifaddrs *ifaddrs, *ifa; 1547 int seen_inet = 0, seen_inet6 = 0; 1548 1549 if (getifaddrs(&ifaddrs) != 0) 1550 return 0; 1551 1552 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 1553 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) 1554 continue; 1555 if ((ifa->ifa_flags & IFT_LOOP) != 0) 1556 continue; 1557 switch (ifa->ifa_addr->sa_family) { 1558 case AF_INET: 1559 seen_inet = 1; 1560 break; 1561#ifdef INET6 1562 case AF_INET6: 1563 if (!seen_inet6 && !is_ifdisabled(ifa->ifa_name)) 1564 seen_inet6 = 1; 1565 break; 1566#endif 1567 } 1568 } 1569 freeifaddrs(ifaddrs); 1570 1571 switch(pai->ai_family) { 1572 case AF_INET6: 1573 return seen_inet6; 1574 case AF_INET: 1575 return seen_inet; 1576 case AF_UNSPEC: 1577 if (seen_inet == seen_inet6) 1578 return seen_inet; 1579 pai->ai_family = seen_inet ? AF_INET : AF_INET6; 1580 return 1; 1581 } 1582 return 1; 1583} 1584 1585#ifdef INET6 1586static int 1587is_ifdisabled(char *name) 1588{ 1589 struct in6_ndireq nd; 1590 int fd; 1591 1592 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 1593 return -1; 1594 memset(&nd, 0, sizeof(nd)); 1595 strlcpy(nd.ifname, name, sizeof(nd.ifname)); 1596 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { 1597 _close(fd); 1598 return -1; 1599 } 1600 _close(fd); 1601 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); 1602} 1603 1604/* convert a string to a scope identifier. XXX: IPv6 specific */ 1605static int 1606ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1607{ 1608 u_long lscopeid; 1609 struct in6_addr *a6; 1610 char *ep; 1611 1612 a6 = &sin6->sin6_addr; 1613 1614 /* empty scopeid portion is invalid */ 1615 if (*scope == '\0') 1616 return -1; 1617 1618 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1619 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1620 /* 1621 * We currently assume a one-to-one mapping between links 1622 * and interfaces, so we simply use interface indices for 1623 * like-local scopes. 1624 */ 1625 *scopeid = if_nametoindex(scope); 1626 if (*scopeid == 0) 1627 goto trynumeric; 1628 return 0; 1629 } 1630 1631 /* still unclear about literal, allow numeric only - placeholder */ 1632 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1633 goto trynumeric; 1634 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1635 goto trynumeric; 1636 else 1637 goto trynumeric; /* global */ 1638 1639 /* try to convert to a numeric id as a last resort */ 1640 trynumeric: 1641 errno = 0; 1642 lscopeid = strtoul(scope, &ep, 10); 1643 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1644 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1645 return 0; 1646 else 1647 return -1; 1648} 1649#endif 1650 1651 1652#ifdef NS_CACHING 1653static int 1654addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1655 void *cache_mdata) 1656{ 1657 res_state statp; 1658 u_long res_options; 1659 1660 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1661 char *hostname; 1662 struct addrinfo *hints; 1663 1664 char *p; 1665 int ai_flags, ai_family, ai_socktype, ai_protocol; 1666 size_t desired_size, size; 1667 1668 statp = __res_state(); 1669 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1670 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1671 1672 hostname = va_arg(ap, char *); 1673 hints = va_arg(ap, struct addrinfo *); 1674 1675 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1676 if (hostname != NULL) { 1677 size = strlen(hostname); 1678 desired_size += size + 1; 1679 } else 1680 size = 0; 1681 1682 if (desired_size > *buffer_size) { 1683 *buffer_size = desired_size; 1684 return (NS_RETURN); 1685 } 1686 1687 if (hints == NULL) 1688 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1689 else { 1690 ai_flags = hints->ai_flags; 1691 ai_family = hints->ai_family; 1692 ai_socktype = hints->ai_socktype; 1693 ai_protocol = hints->ai_protocol; 1694 } 1695 1696 p = buffer; 1697 memcpy(p, &res_options, sizeof(res_options)); 1698 p += sizeof(res_options); 1699 1700 memcpy(p, &op_id, sizeof(int)); 1701 p += sizeof(int); 1702 1703 memcpy(p, &ai_flags, sizeof(int)); 1704 p += sizeof(int); 1705 1706 memcpy(p, &ai_family, sizeof(int)); 1707 p += sizeof(int); 1708 1709 memcpy(p, &ai_socktype, sizeof(int)); 1710 p += sizeof(int); 1711 1712 memcpy(p, &ai_protocol, sizeof(int)); 1713 p += sizeof(int); 1714 1715 if (hostname != NULL) 1716 memcpy(p, hostname, size); 1717 1718 *buffer_size = desired_size; 1719 return (NS_SUCCESS); 1720} 1721 1722static int 1723addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1724 va_list ap, void *cache_mdata) 1725{ 1726 struct addrinfo *ai, *cai; 1727 char *p; 1728 size_t desired_size, size, ai_size; 1729 1730 ai = *((struct addrinfo **)retval); 1731 1732 desired_size = sizeof(size_t); 1733 ai_size = 0; 1734 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1735 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1736 if (cai->ai_canonname != NULL) 1737 desired_size += sizeof(size_t) + 1738 strlen(cai->ai_canonname); 1739 ++ai_size; 1740 } 1741 1742 if (desired_size > *buffer_size) { 1743 /* this assignment is here for future use */ 1744 errno = ERANGE; 1745 *buffer_size = desired_size; 1746 return (NS_RETURN); 1747 } 1748 1749 memset(buffer, 0, desired_size); 1750 p = buffer; 1751 1752 memcpy(p, &ai_size, sizeof(size_t)); 1753 p += sizeof(size_t); 1754 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1755 memcpy(p, cai, sizeof(struct addrinfo)); 1756 p += sizeof(struct addrinfo); 1757 1758 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1759 p += cai->ai_addrlen; 1760 1761 if (cai->ai_canonname != NULL) { 1762 size = strlen(cai->ai_canonname); 1763 memcpy(p, &size, sizeof(size_t)); 1764 p += sizeof(size_t); 1765 1766 memcpy(p, cai->ai_canonname, size); 1767 p += size; 1768 } 1769 } 1770 1771 return (NS_SUCCESS); 1772} 1773 1774static int 1775addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1776 va_list ap, void *cache_mdata) 1777{ 1778 struct addrinfo new_ai, *result, *sentinel, *lasts; 1779 1780 char *p; 1781 size_t ai_size, ai_i, size; 1782 1783 p = buffer; 1784 memcpy(&ai_size, p, sizeof(size_t)); 1785 p += sizeof(size_t); 1786 1787 result = NULL; 1788 lasts = NULL; 1789 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1790 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1791 p += sizeof(struct addrinfo); 1792 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1793 _ALIGNBYTES; 1794 1795 sentinel = (struct addrinfo *)malloc(size); 1796 memset(sentinel, 0, size); 1797 1798 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1799 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1800 sizeof(struct addrinfo)); 1801 1802 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1803 p += new_ai.ai_addrlen; 1804 1805 if (new_ai.ai_canonname != NULL) { 1806 memcpy(&size, p, sizeof(size_t)); 1807 p += sizeof(size_t); 1808 1809 sentinel->ai_canonname = (char *)malloc(size + 1); 1810 memset(sentinel->ai_canonname, 0, size + 1); 1811 1812 memcpy(sentinel->ai_canonname, p, size); 1813 p += size; 1814 } 1815 1816 if (result == NULL) { 1817 result = sentinel; 1818 lasts = sentinel; 1819 } else { 1820 lasts->ai_next = sentinel; 1821 lasts = sentinel; 1822 } 1823 } 1824 1825 *((struct addrinfo **)retval) = result; 1826 return (NS_SUCCESS); 1827} 1828#endif /* NS_CACHING */ 1829 1830/* 1831 * FQDN hostname, DNS lookup 1832 */ 1833static int 1834explore_fqdn(const struct addrinfo *pai, const char *hostname, 1835 const char *servname, struct addrinfo **res) 1836{ 1837 struct addrinfo *result; 1838 struct addrinfo *cur; 1839 int error = 0; 1840 1841#ifdef NS_CACHING 1842 static const nss_cache_info cache_info = 1843 NS_COMMON_CACHE_INFO_INITIALIZER( 1844 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1845 addrinfo_unmarshal_func); 1846#endif 1847 static const ns_dtab dtab[] = { 1848 NS_FILES_CB(_files_getaddrinfo, NULL) 1849 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1850 NS_NIS_CB(_yp_getaddrinfo, NULL) 1851#ifdef NS_CACHING 1852 NS_CACHE_CB(&cache_info) 1853#endif 1854 { 0 } 1855 }; 1856 1857 result = NULL; 1858 1859 /* 1860 * if the servname does not match socktype/protocol, ignore it. 1861 */ 1862 if (get_portmatch(pai, servname) != 0) 1863 return 0; 1864 1865 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1866 default_dns_files, hostname, pai)) { 1867 case NS_TRYAGAIN: 1868 error = EAI_AGAIN; 1869 goto free; 1870 case NS_UNAVAIL: 1871 error = EAI_FAIL; 1872 goto free; 1873 case NS_NOTFOUND: 1874 error = EAI_NONAME; 1875 goto free; 1876 case NS_SUCCESS: 1877 error = 0; 1878 for (cur = result; cur; cur = cur->ai_next) { 1879 GET_PORT(cur, servname); 1880 /* canonname should be filled already */ 1881 } 1882 break; 1883 } 1884 1885 *res = result; 1886 1887 return 0; 1888 1889free: 1890 if (result) 1891 freeaddrinfo(result); 1892 return error; 1893} 1894 1895#ifdef DEBUG 1896static const char AskedForGot[] = 1897 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1898#endif 1899 1900static struct addrinfo * 1901getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1902 const struct addrinfo *pai, res_state res) 1903{ 1904 struct addrinfo sentinel, *cur; 1905 struct addrinfo ai; 1906 const struct afd *afd; 1907 char *canonname; 1908 const HEADER *hp; 1909 const u_char *cp; 1910 int n; 1911 const u_char *eom; 1912 char *bp, *ep; 1913 int type, class, ancount, qdcount; 1914 int haveanswer, had_error; 1915 char tbuf[MAXDNAME]; 1916 int (*name_ok)(const char *); 1917 char hostbuf[8*1024]; 1918 1919 memset(&sentinel, 0, sizeof(sentinel)); 1920 cur = &sentinel; 1921 1922 canonname = NULL; 1923 eom = answer->buf + anslen; 1924 switch (qtype) { 1925 case T_A: 1926 case T_AAAA: 1927 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1928 name_ok = res_hnok; 1929 break; 1930 default: 1931 return (NULL); /* XXX should be abort(); */ 1932 } 1933 /* 1934 * find first satisfactory answer 1935 */ 1936 hp = &answer->hdr; 1937 ancount = ntohs(hp->ancount); 1938 qdcount = ntohs(hp->qdcount); 1939 bp = hostbuf; 1940 ep = hostbuf + sizeof hostbuf; 1941 cp = answer->buf + HFIXEDSZ; 1942 if (qdcount != 1) { 1943 RES_SET_H_ERRNO(res, NO_RECOVERY); 1944 return (NULL); 1945 } 1946 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1947 if ((n < 0) || !(*name_ok)(bp)) { 1948 RES_SET_H_ERRNO(res, NO_RECOVERY); 1949 return (NULL); 1950 } 1951 cp += n + QFIXEDSZ; 1952 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1953 /* res_send() has already verified that the query name is the 1954 * same as the one we sent; this just gets the expanded name 1955 * (i.e., with the succeeding search-domain tacked on). 1956 */ 1957 n = strlen(bp) + 1; /* for the \0 */ 1958 if (n >= MAXHOSTNAMELEN) { 1959 RES_SET_H_ERRNO(res, NO_RECOVERY); 1960 return (NULL); 1961 } 1962 canonname = bp; 1963 bp += n; 1964 /* The qname can be abbreviated, but h_name is now absolute. */ 1965 qname = canonname; 1966 } 1967 haveanswer = 0; 1968 had_error = 0; 1969 while (ancount-- > 0 && cp < eom && !had_error) { 1970 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1971 if ((n < 0) || !(*name_ok)(bp)) { 1972 had_error++; 1973 continue; 1974 } 1975 cp += n; /* name */ 1976 type = _getshort(cp); 1977 cp += INT16SZ; /* type */ 1978 class = _getshort(cp); 1979 cp += INT16SZ + INT32SZ; /* class, TTL */ 1980 n = _getshort(cp); 1981 cp += INT16SZ; /* len */ 1982 if (class != C_IN) { 1983 /* XXX - debug? syslog? */ 1984 cp += n; 1985 continue; /* XXX - had_error++ ? */ 1986 } 1987 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1988 type == T_CNAME) { 1989 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1990 if ((n < 0) || !(*name_ok)(tbuf)) { 1991 had_error++; 1992 continue; 1993 } 1994 cp += n; 1995 /* Get canonical name. */ 1996 n = strlen(tbuf) + 1; /* for the \0 */ 1997 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1998 had_error++; 1999 continue; 2000 } 2001 strlcpy(bp, tbuf, ep - bp); 2002 canonname = bp; 2003 bp += n; 2004 continue; 2005 } 2006 if (qtype == T_ANY) { 2007 if (!(type == T_A || type == T_AAAA)) { 2008 cp += n; 2009 continue; 2010 } 2011 } else if (type != qtype) { 2012#ifdef DEBUG 2013 if (type != T_KEY && type != T_SIG && 2014 type != ns_t_dname) 2015 syslog(LOG_NOTICE|LOG_AUTH, 2016 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 2017 qname, p_class(C_IN), p_type(qtype), 2018 p_type(type)); 2019#endif 2020 cp += n; 2021 continue; /* XXX - had_error++ ? */ 2022 } 2023 switch (type) { 2024 case T_A: 2025 case T_AAAA: 2026 if (strcasecmp(canonname, bp) != 0) { 2027#ifdef DEBUG 2028 syslog(LOG_NOTICE|LOG_AUTH, 2029 AskedForGot, canonname, bp); 2030#endif 2031 cp += n; 2032 continue; /* XXX - had_error++ ? */ 2033 } 2034 if (type == T_A && n != INADDRSZ) { 2035 cp += n; 2036 continue; 2037 } 2038 if (type == T_AAAA && n != IN6ADDRSZ) { 2039 cp += n; 2040 continue; 2041 } 2042#ifdef FILTER_V4MAPPED 2043 if (type == T_AAAA) { 2044 struct in6_addr in6; 2045 memcpy(&in6, cp, sizeof(in6)); 2046 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2047 cp += n; 2048 continue; 2049 } 2050 } 2051#endif 2052 if (!haveanswer) { 2053 int nn; 2054 2055 canonname = bp; 2056 nn = strlen(bp) + 1; /* for the \0 */ 2057 bp += nn; 2058 } 2059 2060 /* don't overwrite pai */ 2061 ai = *pai; 2062 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2063 afd = find_afd(ai.ai_family); 2064 if (afd == NULL) { 2065 cp += n; 2066 continue; 2067 } 2068 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2069 if (cur->ai_next == NULL) 2070 had_error++; 2071 while (cur && cur->ai_next) 2072 cur = cur->ai_next; 2073 cp += n; 2074 break; 2075 default: 2076 abort(); 2077 } 2078 if (!had_error) 2079 haveanswer++; 2080 } 2081 if (haveanswer) { 2082#if defined(RESOLVSORT) 2083 /* 2084 * We support only IPv4 address for backward 2085 * compatibility against gethostbyname(3). 2086 */ 2087 if (res->nsort && qtype == T_A) { 2088 if (addr4sort(&sentinel, res) < 0) { 2089 freeaddrinfo(sentinel.ai_next); 2090 RES_SET_H_ERRNO(res, NO_RECOVERY); 2091 return NULL; 2092 } 2093 } 2094#endif /*RESOLVSORT*/ 2095 if (!canonname) 2096 (void)get_canonname(pai, sentinel.ai_next, qname); 2097 else 2098 (void)get_canonname(pai, sentinel.ai_next, canonname); 2099 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2100 return sentinel.ai_next; 2101 } 2102 2103 RES_SET_H_ERRNO(res, NO_RECOVERY); 2104 return NULL; 2105} 2106 2107#ifdef RESOLVSORT 2108struct addr_ptr { 2109 struct addrinfo *ai; 2110 int aval; 2111}; 2112 2113static int 2114addr4sort(struct addrinfo *sentinel, res_state res) 2115{ 2116 struct addrinfo *ai; 2117 struct addr_ptr *addrs, addr; 2118 struct sockaddr_in *sin; 2119 int naddrs, i, j; 2120 int needsort = 0; 2121 2122 if (!sentinel) 2123 return -1; 2124 naddrs = 0; 2125 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2126 naddrs++; 2127 if (naddrs < 2) 2128 return 0; /* We don't need sorting. */ 2129 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2130 return -1; 2131 i = 0; 2132 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2133 sin = (struct sockaddr_in *)ai->ai_addr; 2134 for (j = 0; (unsigned)j < res->nsort; j++) { 2135 if (res->sort_list[j].addr.s_addr == 2136 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2137 break; 2138 } 2139 addrs[i].ai = ai; 2140 addrs[i].aval = j; 2141 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2142 needsort = i; 2143 i++; 2144 } 2145 if (!needsort) { 2146 free(addrs); 2147 return 0; 2148 } 2149 2150 while (needsort < naddrs) { 2151 for (j = needsort - 1; j >= 0; j--) { 2152 if (addrs[j].aval > addrs[j+1].aval) { 2153 addr = addrs[j]; 2154 addrs[j] = addrs[j + 1]; 2155 addrs[j + 1] = addr; 2156 } else 2157 break; 2158 } 2159 needsort++; 2160 } 2161 2162 ai = sentinel; 2163 for (i = 0; i < naddrs; ++i) { 2164 ai->ai_next = addrs[i].ai; 2165 ai = ai->ai_next; 2166 } 2167 ai->ai_next = NULL; 2168 free(addrs); 2169 return 0; 2170} 2171#endif /*RESOLVSORT*/ 2172 2173/*ARGSUSED*/ 2174static int 2175_dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2176{ 2177 struct addrinfo *ai; 2178 querybuf *buf, *buf2; 2179 const char *hostname; 2180 const struct addrinfo *pai; 2181 struct addrinfo sentinel, *cur; 2182 struct res_target q, q2; 2183 res_state res; 2184 2185 hostname = va_arg(ap, char *); 2186 pai = va_arg(ap, const struct addrinfo *); 2187 2188 memset(&q, 0, sizeof(q)); 2189 memset(&q2, 0, sizeof(q2)); 2190 memset(&sentinel, 0, sizeof(sentinel)); 2191 cur = &sentinel; 2192 2193 buf = malloc(sizeof(*buf)); 2194 if (!buf) { 2195 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2196 return NS_NOTFOUND; 2197 } 2198 buf2 = malloc(sizeof(*buf2)); 2199 if (!buf2) { 2200 free(buf); 2201 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2202 return NS_NOTFOUND; 2203 } 2204 2205 switch (pai->ai_family) { 2206 case AF_UNSPEC: 2207 q.name = hostname; 2208 q.qclass = C_IN; 2209 q.qtype = T_A; 2210 q.answer = buf->buf; 2211 q.anslen = sizeof(buf->buf); 2212 q.next = &q2; 2213 q2.name = hostname; 2214 q2.qclass = C_IN; 2215 q2.qtype = T_AAAA; 2216 q2.answer = buf2->buf; 2217 q2.anslen = sizeof(buf2->buf); 2218 break; 2219 case AF_INET: 2220 q.name = hostname; 2221 q.qclass = C_IN; 2222 q.qtype = T_A; 2223 q.answer = buf->buf; 2224 q.anslen = sizeof(buf->buf); 2225 break; 2226 case AF_INET6: 2227 q.name = hostname; 2228 q.qclass = C_IN; 2229 q.qtype = T_AAAA; 2230 q.answer = buf->buf; 2231 q.anslen = sizeof(buf->buf); 2232 break; 2233 default: 2234 free(buf); 2235 free(buf2); 2236 return NS_UNAVAIL; 2237 } 2238 2239 res = __res_state(); 2240 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2241 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2242 free(buf); 2243 free(buf2); 2244 return NS_NOTFOUND; 2245 } 2246 2247 if (res_searchN(hostname, &q, res) < 0) { 2248 free(buf); 2249 free(buf2); 2250 return NS_NOTFOUND; 2251 } 2252 /* prefer IPv6 */ 2253 if (q.next) { 2254 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2255 if (ai) { 2256 cur->ai_next = ai; 2257 while (cur && cur->ai_next) 2258 cur = cur->ai_next; 2259 } 2260 } 2261 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2262 if (ai) 2263 cur->ai_next = ai; 2264 free(buf); 2265 free(buf2); 2266 if (sentinel.ai_next == NULL) 2267 switch (res->res_h_errno) { 2268 case HOST_NOT_FOUND: 2269 return NS_NOTFOUND; 2270 case TRY_AGAIN: 2271 return NS_TRYAGAIN; 2272 default: 2273 return NS_UNAVAIL; 2274 } 2275 *((struct addrinfo **)rv) = sentinel.ai_next; 2276 return NS_SUCCESS; 2277} 2278 2279static void 2280_sethtent(FILE **hostf) 2281{ 2282 if (!*hostf) 2283 *hostf = fopen(_PATH_HOSTS, "re"); 2284 else 2285 rewind(*hostf); 2286} 2287 2288static void 2289_endhtent(FILE **hostf) 2290{ 2291 if (*hostf) { 2292 (void) fclose(*hostf); 2293 *hostf = NULL; 2294 } 2295} 2296 2297static struct addrinfo * 2298_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2299{ 2300 char *p; 2301 char *cp, *tname, *cname; 2302 struct addrinfo hints, *res0, *res; 2303 int error; 2304 const char *addr; 2305 char hostbuf[8*1024]; 2306 2307 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2308 return (NULL); 2309again: 2310 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2311 return (NULL); 2312 if (*p == '#') 2313 goto again; 2314 cp = strpbrk(p, "#\n"); 2315 if (cp != NULL) 2316 *cp = '\0'; 2317 if (!(cp = strpbrk(p, " \t"))) 2318 goto again; 2319 *cp++ = '\0'; 2320 addr = p; 2321 cname = NULL; 2322 /* if this is not something we're looking for, skip it. */ 2323 while (cp && *cp) { 2324 if (*cp == ' ' || *cp == '\t') { 2325 cp++; 2326 continue; 2327 } 2328 tname = cp; 2329 if (cname == NULL) 2330 cname = cp; 2331 if ((cp = strpbrk(cp, " \t")) != NULL) 2332 *cp++ = '\0'; 2333 if (strcasecmp(name, tname) == 0) 2334 goto found; 2335 } 2336 goto again; 2337 2338found: 2339 /* we should not glob socktype/protocol here */ 2340 memset(&hints, 0, sizeof(hints)); 2341 hints.ai_family = pai->ai_family; 2342 hints.ai_socktype = SOCK_DGRAM; 2343 hints.ai_protocol = 0; 2344 hints.ai_flags = AI_NUMERICHOST; 2345 error = getaddrinfo(addr, "0", &hints, &res0); 2346 if (error) 2347 goto again; 2348#ifdef FILTER_V4MAPPED 2349 /* XXX should check all items in the chain */ 2350 if (res0->ai_family == AF_INET6 && 2351 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2352 freeaddrinfo(res0); 2353 goto again; 2354 } 2355#endif 2356 for (res = res0; res; res = res->ai_next) { 2357 /* cover it up */ 2358 res->ai_flags = pai->ai_flags; 2359 res->ai_socktype = pai->ai_socktype; 2360 res->ai_protocol = pai->ai_protocol; 2361 2362 if (pai->ai_flags & AI_CANONNAME) { 2363 if (get_canonname(pai, res, cname) != 0) { 2364 freeaddrinfo(res0); 2365 goto again; 2366 } 2367 } 2368 } 2369 return res0; 2370} 2371 2372/*ARGSUSED*/ 2373static int 2374_files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2375{ 2376 const char *name; 2377 const struct addrinfo *pai; 2378 struct addrinfo sentinel, *cur; 2379 struct addrinfo *p; 2380 FILE *hostf = NULL; 2381 2382 name = va_arg(ap, char *); 2383 pai = va_arg(ap, struct addrinfo *); 2384 2385 memset(&sentinel, 0, sizeof(sentinel)); 2386 cur = &sentinel; 2387 2388 _sethtent(&hostf); 2389 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 2390 cur->ai_next = p; 2391 while (cur && cur->ai_next) 2392 cur = cur->ai_next; 2393 } 2394 _endhtent(&hostf); 2395 2396 *((struct addrinfo **)rv) = sentinel.ai_next; 2397 if (sentinel.ai_next == NULL) 2398 return NS_NOTFOUND; 2399 return NS_SUCCESS; 2400} 2401 2402#ifdef YP 2403/*ARGSUSED*/ 2404static struct addrinfo * 2405_yphostent(char *line, const struct addrinfo *pai) 2406{ 2407 struct addrinfo sentinel, *cur; 2408 struct addrinfo hints, *res, *res0; 2409 int error; 2410 char *p = line; 2411 const char *addr, *canonname; 2412 char *nextline; 2413 char *cp; 2414 2415 addr = canonname = NULL; 2416 2417 memset(&sentinel, 0, sizeof(sentinel)); 2418 cur = &sentinel; 2419 2420nextline: 2421 /* terminate line */ 2422 cp = strchr(p, '\n'); 2423 if (cp) { 2424 *cp++ = '\0'; 2425 nextline = cp; 2426 } else 2427 nextline = NULL; 2428 2429 cp = strpbrk(p, " \t"); 2430 if (cp == NULL) { 2431 if (canonname == NULL) 2432 return (NULL); 2433 else 2434 goto done; 2435 } 2436 *cp++ = '\0'; 2437 2438 addr = p; 2439 2440 while (cp && *cp) { 2441 if (*cp == ' ' || *cp == '\t') { 2442 cp++; 2443 continue; 2444 } 2445 if (!canonname) 2446 canonname = cp; 2447 if ((cp = strpbrk(cp, " \t")) != NULL) 2448 *cp++ = '\0'; 2449 } 2450 2451 hints = *pai; 2452 hints.ai_flags = AI_NUMERICHOST; 2453 error = getaddrinfo(addr, NULL, &hints, &res0); 2454 if (error == 0) { 2455 for (res = res0; res; res = res->ai_next) { 2456 /* cover it up */ 2457 res->ai_flags = pai->ai_flags; 2458 2459 if (pai->ai_flags & AI_CANONNAME) 2460 (void)get_canonname(pai, res, canonname); 2461 } 2462 } else 2463 res0 = NULL; 2464 if (res0) { 2465 cur->ai_next = res0; 2466 while (cur && cur->ai_next) 2467 cur = cur->ai_next; 2468 } 2469 2470 if (nextline) { 2471 p = nextline; 2472 goto nextline; 2473 } 2474 2475done: 2476 return sentinel.ai_next; 2477} 2478 2479/*ARGSUSED*/ 2480static int 2481_yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2482{ 2483 struct addrinfo sentinel, *cur; 2484 struct addrinfo *ai = NULL; 2485 char *ypbuf; 2486 int ypbuflen, r; 2487 const char *name; 2488 const struct addrinfo *pai; 2489 char *ypdomain; 2490 2491 if (_yp_check(&ypdomain) == 0) 2492 return NS_UNAVAIL; 2493 2494 name = va_arg(ap, char *); 2495 pai = va_arg(ap, const struct addrinfo *); 2496 2497 memset(&sentinel, 0, sizeof(sentinel)); 2498 cur = &sentinel; 2499 2500 /* hosts.byname is only for IPv4 (Solaris8) */ 2501 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 2502 r = yp_match(ypdomain, "hosts.byname", name, 2503 (int)strlen(name), &ypbuf, &ypbuflen); 2504 if (r == 0) { 2505 struct addrinfo ai4; 2506 2507 ai4 = *pai; 2508 ai4.ai_family = AF_INET; 2509 ai = _yphostent(ypbuf, &ai4); 2510 if (ai) { 2511 cur->ai_next = ai; 2512 while (cur && cur->ai_next) 2513 cur = cur->ai_next; 2514 } 2515 free(ypbuf); 2516 } 2517 } 2518 2519 /* ipnodes.byname can hold both IPv4/v6 */ 2520 r = yp_match(ypdomain, "ipnodes.byname", name, 2521 (int)strlen(name), &ypbuf, &ypbuflen); 2522 if (r == 0) { 2523 ai = _yphostent(ypbuf, pai); 2524 if (ai) 2525 cur->ai_next = ai; 2526 free(ypbuf); 2527 } 2528 2529 if (sentinel.ai_next == NULL) { 2530 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2531 return NS_NOTFOUND; 2532 } 2533 *((struct addrinfo **)rv) = sentinel.ai_next; 2534 return NS_SUCCESS; 2535} 2536#endif 2537 2538/* resolver logic */ 2539 2540/* 2541 * Formulate a normal query, send, and await answer. 2542 * Returned answer is placed in supplied buffer "answer". 2543 * Perform preliminary check of answer, returning success only 2544 * if no error is indicated and the answer count is nonzero. 2545 * Return the size of the response on success, -1 on error. 2546 * Error number is left in h_errno. 2547 * 2548 * Caller must parse answer and determine whether it answers the question. 2549 */ 2550static int 2551res_queryN(const char *name, struct res_target *target, res_state res) 2552{ 2553 u_char *buf; 2554 HEADER *hp; 2555 int n; 2556 u_int oflags; 2557 struct res_target *t; 2558 int rcode; 2559 int ancount; 2560 2561 rcode = NOERROR; 2562 ancount = 0; 2563 2564 buf = malloc(MAXPACKET); 2565 if (!buf) { 2566 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2567 return -1; 2568 } 2569 2570 for (t = target; t; t = t->next) { 2571 int class, type; 2572 u_char *answer; 2573 int anslen; 2574 2575 hp = (HEADER *)(void *)t->answer; 2576 2577 /* make it easier... */ 2578 class = t->qclass; 2579 type = t->qtype; 2580 answer = t->answer; 2581 anslen = t->anslen; 2582 2583 oflags = res->_flags; 2584 2585again: 2586 hp->rcode = NOERROR; /* default */ 2587 2588#ifdef DEBUG 2589 if (res->options & RES_DEBUG) 2590 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2591#endif 2592 2593 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2594 buf, MAXPACKET); 2595 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2596 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2597 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2598 if (n <= 0) { 2599#ifdef DEBUG 2600 if (res->options & RES_DEBUG) 2601 printf(";; res_query: mkquery failed\n"); 2602#endif 2603 free(buf); 2604 RES_SET_H_ERRNO(res, NO_RECOVERY); 2605 return (n); 2606 } 2607 n = res_nsend(res, buf, n, answer, anslen); 2608 if (n < 0) { 2609 /* 2610 * if the query choked with EDNS0, retry 2611 * without EDNS0 2612 */ 2613 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2614 != 0U && 2615 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2616 res->_flags |= RES_F_EDNS0ERR; 2617 if (res->options & RES_DEBUG) 2618 printf(";; res_nquery: retry without EDNS0\n"); 2619 goto again; 2620 } 2621 rcode = hp->rcode; /* record most recent error */ 2622#ifdef DEBUG 2623 if (res->options & RES_DEBUG) 2624 printf(";; res_query: send error\n"); 2625#endif 2626 continue; 2627 } 2628 2629 if (n > anslen) 2630 hp->rcode = FORMERR; /* XXX not very informative */ 2631 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2632 rcode = hp->rcode; /* record most recent error */ 2633#ifdef DEBUG 2634 if (res->options & RES_DEBUG) 2635 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2636 ntohs(hp->ancount)); 2637#endif 2638 continue; 2639 } 2640 2641 ancount += ntohs(hp->ancount); 2642 2643 t->n = n; 2644 } 2645 2646 free(buf); 2647 2648 if (ancount == 0) { 2649 switch (rcode) { 2650 case NXDOMAIN: 2651 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2652 break; 2653 case SERVFAIL: 2654 RES_SET_H_ERRNO(res, TRY_AGAIN); 2655 break; 2656 case NOERROR: 2657 RES_SET_H_ERRNO(res, NO_DATA); 2658 break; 2659 case FORMERR: 2660 case NOTIMP: 2661 case REFUSED: 2662 default: 2663 RES_SET_H_ERRNO(res, NO_RECOVERY); 2664 break; 2665 } 2666 return (-1); 2667 } 2668 return (ancount); 2669} 2670 2671/* 2672 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2673 * Return the size of the response on success, -1 on error. 2674 * If enabled, implement search rules until answer or unrecoverable failure 2675 * is detected. Error code, if any, is left in h_errno. 2676 */ 2677static int 2678res_searchN(const char *name, struct res_target *target, res_state res) 2679{ 2680 const char *cp, * const *domain; 2681 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2682 u_int dots; 2683 int trailing_dot, ret, saved_herrno; 2684 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2685 int tried_as_is = 0; 2686 int searched = 0; 2687 char abuf[MAXDNAME]; 2688 2689 errno = 0; 2690 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2691 dots = 0; 2692 for (cp = name; *cp; cp++) 2693 dots += (*cp == '.'); 2694 trailing_dot = 0; 2695 if (cp > name && *--cp == '.') 2696 trailing_dot++; 2697 2698 /* 2699 * if there aren't any dots, it could be a user-level alias 2700 */ 2701 if (!dots && 2702 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2703 return (res_queryN(cp, target, res)); 2704 2705 /* 2706 * If there are enough dots in the name, let's just give it a 2707 * try 'as is'. The threshold can be set with the "ndots" option. 2708 * Also, query 'as is', if there is a trailing dot in the name. 2709 */ 2710 saved_herrno = -1; 2711 if (dots >= res->ndots || trailing_dot) { 2712 ret = res_querydomainN(name, NULL, target, res); 2713 if (ret > 0 || trailing_dot) 2714 return (ret); 2715 if (errno == ECONNREFUSED) { 2716 RES_SET_H_ERRNO(res, TRY_AGAIN); 2717 return (-1); 2718 } 2719 switch (res->res_h_errno) { 2720 case NO_DATA: 2721 case HOST_NOT_FOUND: 2722 break; 2723 case TRY_AGAIN: 2724 if (hp->rcode == SERVFAIL) 2725 break; 2726 /* FALLTHROUGH */ 2727 default: 2728 return (-1); 2729 } 2730 saved_herrno = res->res_h_errno; 2731 tried_as_is++; 2732 } 2733 2734 /* 2735 * We do at least one level of search if 2736 * - there is no dot and RES_DEFNAME is set, or 2737 * - there is at least one dot, there is no trailing dot, 2738 * and RES_DNSRCH is set. 2739 */ 2740 if ((!dots && (res->options & RES_DEFNAMES)) || 2741 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2742 int done = 0; 2743 2744 for (domain = (const char * const *)res->dnsrch; 2745 *domain && !done; 2746 domain++) { 2747 searched = 1; 2748 2749 if (domain[0][0] == '\0' || 2750 (domain[0][0] == '.' && domain[0][1] == '\0')) 2751 root_on_list++; 2752 2753 if (root_on_list && tried_as_is) 2754 continue; 2755 2756 ret = res_querydomainN(name, *domain, target, res); 2757 if (ret > 0) 2758 return (ret); 2759 2760 /* 2761 * If no server present, give up. 2762 * If name isn't found in this domain, 2763 * keep trying higher domains in the search list 2764 * (if that's enabled). 2765 * On a NO_DATA error, keep trying, otherwise 2766 * a wildcard entry of another type could keep us 2767 * from finding this entry higher in the domain. 2768 * If we get some other error (negative answer or 2769 * server failure), then stop searching up, 2770 * but try the input name below in case it's 2771 * fully-qualified. 2772 */ 2773 if (errno == ECONNREFUSED) { 2774 RES_SET_H_ERRNO(res, TRY_AGAIN); 2775 return (-1); 2776 } 2777 2778 switch (res->res_h_errno) { 2779 case NO_DATA: 2780 got_nodata++; 2781 /* FALLTHROUGH */ 2782 case HOST_NOT_FOUND: 2783 /* keep trying */ 2784 break; 2785 case TRY_AGAIN: 2786 got_servfail++; 2787 if (hp->rcode == SERVFAIL) { 2788 /* try next search element, if any */ 2789 break; 2790 } 2791 /* FALLTHROUGH */ 2792 default: 2793 /* anything else implies that we're done */ 2794 done++; 2795 } 2796 /* 2797 * if we got here for some reason other than DNSRCH, 2798 * we only wanted one iteration of the loop, so stop. 2799 */ 2800 if (!(res->options & RES_DNSRCH)) 2801 done++; 2802 } 2803 } 2804 2805 switch (res->res_h_errno) { 2806 case NO_DATA: 2807 case HOST_NOT_FOUND: 2808 break; 2809 case TRY_AGAIN: 2810 if (hp->rcode == SERVFAIL) 2811 break; 2812 /* FALLTHROUGH */ 2813 default: 2814 goto giveup; 2815 } 2816 2817 /* 2818 * If the query has not already been tried as is then try it 2819 * unless RES_NOTLDQUERY is set and there were no dots. 2820 */ 2821 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2822 !(tried_as_is || root_on_list)) { 2823 ret = res_querydomainN(name, NULL, target, res); 2824 if (ret > 0) 2825 return (ret); 2826 } 2827 2828 /* 2829 * if we got here, we didn't satisfy the search. 2830 * if we did an initial full query, return that query's h_errno 2831 * (note that we wouldn't be here if that query had succeeded). 2832 * else if we ever got a nodata, send that back as the reason. 2833 * else send back meaningless h_errno, that being the one from 2834 * the last DNSRCH we did. 2835 */ 2836giveup: 2837 if (saved_herrno != -1) 2838 RES_SET_H_ERRNO(res, saved_herrno); 2839 else if (got_nodata) 2840 RES_SET_H_ERRNO(res, NO_DATA); 2841 else if (got_servfail) 2842 RES_SET_H_ERRNO(res, TRY_AGAIN); 2843 return (-1); 2844} 2845 2846/* 2847 * Perform a call on res_query on the concatenation of name and domain, 2848 * removing a trailing dot from name if domain is NULL. 2849 */ 2850static int 2851res_querydomainN(const char *name, const char *domain, 2852 struct res_target *target, res_state res) 2853{ 2854 char nbuf[MAXDNAME]; 2855 const char *longname = nbuf; 2856 size_t n, d; 2857 2858#ifdef DEBUG 2859 if (res->options & RES_DEBUG) 2860 printf(";; res_querydomain(%s, %s)\n", 2861 name, domain?domain:"<Nil>"); 2862#endif 2863 if (domain == NULL) { 2864 /* 2865 * Check for trailing '.'; 2866 * copy without '.' if present. 2867 */ 2868 n = strlen(name); 2869 if (n >= MAXDNAME) { 2870 RES_SET_H_ERRNO(res, NO_RECOVERY); 2871 return (-1); 2872 } 2873 if (n > 0 && name[--n] == '.') { 2874 strncpy(nbuf, name, n); 2875 nbuf[n] = '\0'; 2876 } else 2877 longname = name; 2878 } else { 2879 n = strlen(name); 2880 d = strlen(domain); 2881 if (n + d + 1 >= MAXDNAME) { 2882 RES_SET_H_ERRNO(res, NO_RECOVERY); 2883 return (-1); 2884 } 2885 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2886 } 2887 return (res_queryN(longname, target, res)); 2888} 2889