1 /* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator. 34 * 35 * Issues to be discussed: 36 * - Return values. There are nonstandard return values defined and used 37 * in the source code. This is because RFC2553 is silent about which error 38 * code must be returned for which situation. 39 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 40 * invalid. current code - SEGV on freeaddrinfo(NULL) 41 * 42 * Note: 43 * - The code filters out AFs that are not supported by the kernel, 44 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 45 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 46 * in ai_flags? 47 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 48 * (1) what should we do against numeric hostname (2) what should we do 49 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 50 * non-loopback address configured? global address configured? 51 * 52 * OS specific notes for freebsd4: 53 * - FreeBSD supported $GAI. The code does not. 54 */ 55 56 #include <sys/cdefs.h> 57 __FBSDID("$FreeBSD$"); 58 59 #include "namespace.h" 60 #include <sys/types.h> 61 #include <sys/param.h> 62 #include <sys/socket.h> 63 #include <net/if.h> 64 #include <netinet/in.h> 65 #include <sys/queue.h> 66 #ifdef INET6 67 #include <net/if_var.h> 68 #include <sys/sysctl.h> 69 #include <sys/ioctl.h> 70 #include <netinet6/in6_var.h> /* XXX */ 71 #endif 72 #include <arpa/inet.h> 73 #include <arpa/nameser.h> 74 #include <rpc/rpc.h> 75 #include <rpcsvc/yp_prot.h> 76 #include <rpcsvc/ypclnt.h> 77 #include <netdb.h> 78 #include <resolv.h> 79 #include <string.h> 80 #include <stdlib.h> 81 #include <stddef.h> 82 #include <ctype.h> 83 #include <unistd.h> 84 #include <stdio.h> 85 #include <errno.h> 86 87 #include "res_config.h" 88 89 #ifdef DEBUG 90 #include <syslog.h> 91 #endif 92 93 #include <stdarg.h> 94 #include <nsswitch.h> 95 #include "un-namespace.h" 96 #include "libc_private.h" 97 #ifdef NS_CACHING 98 #include "nscache.h" 99 #endif 100 101 #if defined(__KAME__) && defined(INET6) 102 # define FAITH 103 #endif 104 105 #define ANY 0 106 #define YES 1 107 #define NO 0 108 109 static const char in_addrany[] = { 0, 0, 0, 0 }; 110 static const char in_loopback[] = { 127, 0, 0, 1 }; 111 #ifdef INET6 112 static const char in6_addrany[] = { 113 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 114 }; 115 static const char in6_loopback[] = { 116 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 117 }; 118 #endif 119 120 struct policyqueue { 121 TAILQ_ENTRY(policyqueue) pc_entry; 122 #ifdef INET6 123 struct in6_addrpolicy pc_policy; 124 #endif 125 }; 126 TAILQ_HEAD(policyhead, policyqueue); 127 128 static const struct afd { 129 int a_af; 130 int a_addrlen; 131 socklen_t a_socklen; 132 int a_off; 133 const char *a_addrany; 134 const char *a_loopback; 135 int a_scoped; 136 } afdl [] = { 137 #ifdef INET6 138 #define N_INET6 0 139 {PF_INET6, sizeof(struct in6_addr), 140 sizeof(struct sockaddr_in6), 141 offsetof(struct sockaddr_in6, sin6_addr), 142 in6_addrany, in6_loopback, 1}, 143 #define N_INET 1 144 #else 145 #define N_INET 0 146 #endif 147 {PF_INET, sizeof(struct in_addr), 148 sizeof(struct sockaddr_in), 149 offsetof(struct sockaddr_in, sin_addr), 150 in_addrany, in_loopback, 0}, 151 {0, 0, 0, 0, NULL, NULL, 0}, 152 }; 153 154 struct explore { 155 int e_af; 156 int e_socktype; 157 int e_protocol; 158 int e_wild; 159 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 160 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 161 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 162 }; 163 164 static const struct explore explore[] = { 165 #if 0 166 { PF_LOCAL, ANY, ANY, 0x01 }, 167 #endif 168 #ifdef INET6 169 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 0x07 }, 170 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, 0x07 }, 171 { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 0x03 }, 172 { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 }, 173 { PF_INET6, SOCK_RAW, ANY, 0x05 }, 174 #endif 175 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, 0x07 }, 176 { PF_INET, SOCK_STREAM, IPPROTO_TCP, 0x07 }, 177 { PF_INET, SOCK_STREAM, IPPROTO_SCTP, 0x03 }, 178 { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 }, 179 { PF_INET, SOCK_RAW, ANY, 0x05 }, 180 { -1, 0, 0, 0 }, 181 }; 182 183 #ifdef INET6 184 #define PTON_MAX 16 185 #else 186 #define PTON_MAX 4 187 #endif 188 189 #define AIO_SRCFLAG_DEPRECATED 0x1 190 191 struct ai_order { 192 union { 193 struct sockaddr_storage aiou_ss; 194 struct sockaddr aiou_sa; 195 } aio_src_un; 196 #define aio_srcsa aio_src_un.aiou_sa 197 u_int32_t aio_srcflag; 198 int aio_srcscope; 199 int aio_dstscope; 200 struct policyqueue *aio_srcpolicy; 201 struct policyqueue *aio_dstpolicy; 202 struct addrinfo *aio_ai; 203 int aio_matchlen; 204 }; 205 206 static const ns_src default_dns_files[] = { 207 { NSSRC_FILES, NS_SUCCESS }, 208 { NSSRC_DNS, NS_SUCCESS }, 209 { 0 } 210 }; 211 212 struct res_target { 213 struct res_target *next; 214 const char *name; /* domain name */ 215 int qclass, qtype; /* class and type of query */ 216 u_char *answer; /* buffer to put answer */ 217 int anslen; /* size of answer buffer */ 218 int n; /* result length */ 219 }; 220 221 #define MAXPACKET (64*1024) 222 223 typedef union { 224 HEADER hdr; 225 u_char buf[MAXPACKET]; 226 } querybuf; 227 228 static int str2number(const char *, int *); 229 static int explore_copy(const struct addrinfo *, const struct addrinfo *, 230 struct addrinfo **); 231 static int explore_null(const struct addrinfo *, 232 const char *, struct addrinfo **); 233 static int explore_numeric(const struct addrinfo *, const char *, 234 const char *, struct addrinfo **, const char *); 235 static int explore_numeric_scope(const struct addrinfo *, const char *, 236 const char *, struct addrinfo **); 237 static int get_canonname(const struct addrinfo *, 238 struct addrinfo *, const char *); 239 static struct addrinfo *get_ai(const struct addrinfo *, 240 const struct afd *, const char *); 241 static struct addrinfo *copy_ai(const struct addrinfo *); 242 static int get_portmatch(const struct addrinfo *, const char *); 243 static int get_port(struct addrinfo *, const char *, int); 244 static const struct afd *find_afd(int); 245 static int addrconfig(struct addrinfo *); 246 static void set_source(struct ai_order *, struct policyhead *); 247 static int comp_dst(const void *, const void *); 248 #ifdef INET6 249 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 250 #endif 251 static int gai_addr2scopetype(struct sockaddr *); 252 253 static int explore_fqdn(const struct addrinfo *, const char *, 254 const char *, struct addrinfo **); 255 256 static int reorder(struct addrinfo *); 257 static int get_addrselectpolicy(struct policyhead *); 258 static void free_addrselectpolicy(struct policyhead *); 259 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 260 struct policyhead *); 261 static int matchlen(struct sockaddr *, struct sockaddr *); 262 263 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 264 const struct addrinfo *, res_state); 265 #if defined(RESOLVSORT) 266 static int addr4sort(struct addrinfo *, res_state); 267 #endif 268 static int _dns_getaddrinfo(void *, void *, va_list); 269 static void _sethtent(FILE **); 270 static void _endhtent(FILE **); 271 static struct addrinfo *_gethtent(FILE **, const char *, 272 const struct addrinfo *); 273 static int _files_getaddrinfo(void *, void *, va_list); 274 #ifdef YP 275 static struct addrinfo *_yphostent(char *, const struct addrinfo *); 276 static int _yp_getaddrinfo(void *, void *, va_list); 277 #endif 278 #ifdef NS_CACHING 279 static int addrinfo_id_func(char *, size_t *, va_list, void *); 280 static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *); 281 static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *); 282 #endif 283 284 static int res_queryN(const char *, struct res_target *, res_state); 285 static int res_searchN(const char *, struct res_target *, res_state); 286 static int res_querydomainN(const char *, const char *, 287 struct res_target *, res_state); 288 289 /* XXX macros that make external reference is BAD. */ 290 291 #define GET_AI(ai, afd, addr) \ 292 do { \ 293 /* external reference: pai, error, and label free */ \ 294 (ai) = get_ai(pai, (afd), (addr)); \ 295 if ((ai) == NULL) { \ 296 error = EAI_MEMORY; \ 297 goto free; \ 298 } \ 299 } while (/*CONSTCOND*/0) 300 301 #define GET_PORT(ai, serv) \ 302 do { \ 303 /* external reference: error and label free */ \ 304 error = get_port((ai), (serv), 0); \ 305 if (error != 0) \ 306 goto free; \ 307 } while (/*CONSTCOND*/0) 308 309 #define GET_CANONNAME(ai, str) \ 310 do { \ 311 /* external reference: pai, error and label free */ \ 312 error = get_canonname(pai, (ai), (str)); \ 313 if (error != 0) \ 314 goto free; \ 315 } while (/*CONSTCOND*/0) 316 317 #define ERR(err) \ 318 do { \ 319 /* external reference: error, and label bad */ \ 320 error = (err); \ 321 goto bad; \ 322 /*NOTREACHED*/ \ 323 } while (/*CONSTCOND*/0) 324 325 #define MATCH_FAMILY(x, y, w) \ 326 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) 327 #define MATCH(x, y, w) \ 328 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 329 330 void 331 freeaddrinfo(struct addrinfo *ai) 332 { 333 struct addrinfo *next; 334 335 do { 336 next = ai->ai_next; 337 if (ai->ai_canonname) 338 free(ai->ai_canonname); 339 /* no need to free(ai->ai_addr) */ 340 free(ai); 341 ai = next; 342 } while (ai); 343 } 344 345 static int 346 str2number(const char *p, int *portp) 347 { 348 char *ep; 349 unsigned long v; 350 351 if (*p == '\0') 352 return -1; 353 ep = NULL; 354 errno = 0; 355 v = strtoul(p, &ep, 10); 356 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) { 357 *portp = v; 358 return 0; 359 } else 360 return -1; 361 } 362 363 int 364 getaddrinfo(const char *hostname, const char *servname, 365 const struct addrinfo *hints, struct addrinfo **res) 366 { 367 struct addrinfo sentinel; 368 struct addrinfo *cur; 369 int error = 0; 370 struct addrinfo ai, ai0, *afai; 371 struct addrinfo *pai; 372 const struct afd *afd; 373 const struct explore *ex; 374 struct addrinfo *afailist[sizeof(afdl)/sizeof(afdl[0])]; 375 struct addrinfo *afai_unspec; 376 int found; 377 int numeric = 0; 378 379 /* ensure we return NULL on errors */ 380 *res = NULL; 381 382 memset(&ai, 0, sizeof(ai)); 383 384 memset(afailist, 0, sizeof(afailist)); 385 afai_unspec = NULL; 386 387 memset(&sentinel, 0, sizeof(sentinel)); 388 cur = &sentinel; 389 pai = &ai; 390 pai->ai_flags = 0; 391 pai->ai_family = PF_UNSPEC; 392 pai->ai_socktype = ANY; 393 pai->ai_protocol = ANY; 394 pai->ai_addrlen = 0; 395 pai->ai_canonname = NULL; 396 pai->ai_addr = NULL; 397 pai->ai_next = NULL; 398 399 if (hostname == NULL && servname == NULL) 400 return EAI_NONAME; 401 if (hints) { 402 /* error check for hints */ 403 if (hints->ai_addrlen || hints->ai_canonname || 404 hints->ai_addr || hints->ai_next) 405 ERR(EAI_BADHINTS); /* xxx */ 406 if (hints->ai_flags & ~AI_MASK) 407 ERR(EAI_BADFLAGS); 408 switch (hints->ai_family) { 409 case PF_UNSPEC: 410 case PF_INET: 411 #ifdef INET6 412 case PF_INET6: 413 #endif 414 break; 415 default: 416 ERR(EAI_FAMILY); 417 } 418 memcpy(pai, hints, sizeof(*pai)); 419 420 /* 421 * if both socktype/protocol are specified, check if they 422 * are meaningful combination. 423 */ 424 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 425 for (ex = explore; ex->e_af >= 0; ex++) { 426 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, 427 WILD_AF(ex))) 428 continue; 429 if (!MATCH(pai->ai_socktype, ex->e_socktype, 430 WILD_SOCKTYPE(ex))) 431 continue; 432 if (!MATCH(pai->ai_protocol, ex->e_protocol, 433 WILD_PROTOCOL(ex))) 434 continue; 435 436 /* matched */ 437 break; 438 } 439 440 if (ex->e_af < 0) 441 ERR(EAI_BADHINTS); 442 } 443 } 444 445 /* 446 * check for special cases. (1) numeric servname is disallowed if 447 * socktype/protocol are left unspecified. (2) servname is disallowed 448 * for raw and other inet{,6} sockets. 449 */ 450 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 451 #ifdef PF_INET6 452 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 453 #endif 454 ) { 455 ai0 = *pai; /* backup *pai */ 456 457 if (pai->ai_family == PF_UNSPEC) { 458 #ifdef PF_INET6 459 pai->ai_family = PF_INET6; 460 #else 461 pai->ai_family = PF_INET; 462 #endif 463 } 464 error = get_portmatch(pai, servname); 465 if (error) 466 goto bad; 467 468 *pai = ai0; 469 } 470 471 ai0 = *pai; 472 473 /* 474 * NULL hostname, or numeric hostname. 475 * If numeric representation of AF1 can be interpreted as FQDN 476 * representation of AF2, we need to think again about the code below. 477 */ 478 found = 0; 479 for (afd = afdl; afd->a_af; afd++) { 480 *pai = ai0; 481 482 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) 483 continue; 484 485 if (pai->ai_family == PF_UNSPEC) 486 pai->ai_family = afd->a_af; 487 488 if (hostname == NULL) { 489 error = explore_null(pai, servname, 490 &afailist[afd - afdl]); 491 492 /* 493 * Errors from explore_null should be unexpected and 494 * be caught to avoid returning an incomplete result. 495 */ 496 if (error != 0) 497 goto bad; 498 } else { 499 error = explore_numeric_scope(pai, hostname, servname, 500 &afailist[afd - afdl]); 501 502 /* 503 * explore_numeric_scope returns an error for address 504 * families that do not match that of hostname. 505 * Thus we should not catch the error at this moment. 506 */ 507 } 508 509 if (!error && afailist[afd - afdl]) 510 found++; 511 } 512 if (found) { 513 numeric = 1; 514 goto globcopy; 515 } 516 517 if (hostname == NULL) 518 ERR(EAI_NONAME); /* used to be EAI_NODATA */ 519 if (pai->ai_flags & AI_NUMERICHOST) 520 ERR(EAI_NONAME); 521 522 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) 523 ERR(EAI_FAIL); 524 525 /* 526 * hostname as alphabetical name. 527 */ 528 *pai = ai0; 529 error = explore_fqdn(pai, hostname, servname, &afai_unspec); 530 531 globcopy: 532 for (ex = explore; ex->e_af >= 0; ex++) { 533 *pai = ai0; 534 535 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 536 continue; 537 if (!MATCH(pai->ai_socktype, ex->e_socktype, 538 WILD_SOCKTYPE(ex))) 539 continue; 540 if (!MATCH(pai->ai_protocol, ex->e_protocol, 541 WILD_PROTOCOL(ex))) 542 continue; 543 544 if (pai->ai_family == PF_UNSPEC) 545 pai->ai_family = ex->e_af; 546 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 547 pai->ai_socktype = ex->e_socktype; 548 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 549 pai->ai_protocol = ex->e_protocol; 550 551 /* 552 * if the servname does not match socktype/protocol, ignore it. 553 */ 554 if (get_portmatch(pai, servname) != 0) 555 continue; 556 557 if (afai_unspec) 558 afai = afai_unspec; 559 else { 560 if ((afd = find_afd(pai->ai_family)) == NULL) 561 continue; 562 /* XXX assumes that afd points inside afdl[] */ 563 afai = afailist[afd - afdl]; 564 } 565 if (!afai) 566 continue; 567 568 error = explore_copy(pai, afai, &cur->ai_next); 569 if (error != 0) 570 goto bad; 571 572 while (cur && cur->ai_next) 573 cur = cur->ai_next; 574 } 575 576 /* 577 * ensure we return either: 578 * - error == 0, non-NULL *res 579 * - error != 0, NULL *res 580 */ 581 if (error == 0) { 582 if (sentinel.ai_next) { 583 /* 584 * If the returned entry is for an active connection, 585 * and the given name is not numeric, reorder the 586 * list, so that the application would try the list 587 * in the most efficient order. Since the head entry 588 * of the original list may contain ai_canonname and 589 * that entry may be moved elsewhere in the new list, 590 * we keep the pointer and will restore it in the new 591 * head entry. (Note that RFC3493 requires the head 592 * entry store it when requested by the caller). 593 */ 594 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) { 595 if (!numeric) { 596 char *canonname; 597 598 canonname = 599 sentinel.ai_next->ai_canonname; 600 sentinel.ai_next->ai_canonname = NULL; 601 (void)reorder(&sentinel); 602 if (sentinel.ai_next->ai_canonname == 603 NULL) { 604 sentinel.ai_next->ai_canonname 605 = canonname; 606 } else if (canonname != NULL) 607 free(canonname); 608 } 609 } 610 *res = sentinel.ai_next; 611 } else 612 error = EAI_FAIL; 613 } 614 615 bad: 616 if (afai_unspec) 617 freeaddrinfo(afai_unspec); 618 for (afd = afdl; afd->a_af; afd++) { 619 if (afailist[afd - afdl]) 620 freeaddrinfo(afailist[afd - afdl]); 621 } 622 if (!*res) 623 if (sentinel.ai_next) 624 freeaddrinfo(sentinel.ai_next); 625 626 return (error); 627 } 628 629 static int 630 reorder(struct addrinfo *sentinel) 631 { 632 struct addrinfo *ai, **aip; 633 struct ai_order *aio; 634 int i, n; 635 struct policyhead policyhead; 636 637 /* count the number of addrinfo elements for sorting. */ 638 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++) 639 ; 640 641 /* 642 * If the number is small enough, we can skip the reordering process. 643 */ 644 if (n <= 1) 645 return(n); 646 647 /* allocate a temporary array for sort and initialization of it. */ 648 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 649 return(n); /* give up reordering */ 650 memset(aio, 0, sizeof(*aio) * n); 651 652 /* retrieve address selection policy from the kernel */ 653 TAILQ_INIT(&policyhead); 654 if (!get_addrselectpolicy(&policyhead)) { 655 /* no policy is installed into kernel, we don't sort. */ 656 free(aio); 657 return (n); 658 } 659 660 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) { 661 aio[i].aio_ai = ai; 662 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr); 663 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr, 664 &policyhead); 665 set_source(&aio[i], &policyhead); 666 } 667 668 /* perform sorting. */ 669 qsort(aio, n, sizeof(*aio), comp_dst); 670 671 /* reorder the addrinfo chain. */ 672 for (i = 0, aip = &sentinel->ai_next; i < n; i++) { 673 *aip = aio[i].aio_ai; 674 aip = &aio[i].aio_ai->ai_next; 675 } 676 *aip = NULL; 677 678 /* cleanup and return */ 679 free(aio); 680 free_addrselectpolicy(&policyhead); 681 return(n); 682 } 683 684 static int 685 get_addrselectpolicy(struct policyhead *head) 686 { 687 #ifdef INET6 688 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 689 size_t l; 690 char *buf; 691 struct in6_addrpolicy *pol, *ep; 692 693 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 694 return (0); 695 if (l == 0) 696 return (0); 697 if ((buf = malloc(l)) == NULL) 698 return (0); 699 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 700 free(buf); 701 return (0); 702 } 703 704 ep = (struct in6_addrpolicy *)(buf + l); 705 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 706 struct policyqueue *new; 707 708 if ((new = malloc(sizeof(*new))) == NULL) { 709 free_addrselectpolicy(head); /* make the list empty */ 710 break; 711 } 712 new->pc_policy = *pol; 713 TAILQ_INSERT_TAIL(head, new, pc_entry); 714 } 715 716 free(buf); 717 return (1); 718 #else 719 return (0); 720 #endif 721 } 722 723 static void 724 free_addrselectpolicy(struct policyhead *head) 725 { 726 struct policyqueue *ent, *nent; 727 728 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 729 nent = TAILQ_NEXT(ent, pc_entry); 730 TAILQ_REMOVE(head, ent, pc_entry); 731 free(ent); 732 } 733 } 734 735 static struct policyqueue * 736 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 737 { 738 #ifdef INET6 739 struct policyqueue *ent, *bestent = NULL; 740 struct in6_addrpolicy *pol; 741 int matchlen, bestmatchlen = -1; 742 u_char *mp, *ep, *k, *p, m; 743 struct sockaddr_in6 key; 744 745 switch(addr->sa_family) { 746 case AF_INET6: 747 key = *(struct sockaddr_in6 *)addr; 748 break; 749 case AF_INET: 750 /* convert the address into IPv4-mapped IPv6 address. */ 751 memset(&key, 0, sizeof(key)); 752 key.sin6_family = AF_INET6; 753 key.sin6_len = sizeof(key); 754 key.sin6_addr.s6_addr[10] = 0xff; 755 key.sin6_addr.s6_addr[11] = 0xff; 756 memcpy(&key.sin6_addr.s6_addr[12], 757 &((struct sockaddr_in *)addr)->sin_addr, 4); 758 break; 759 default: 760 return(NULL); 761 } 762 763 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 764 pol = &ent->pc_policy; 765 matchlen = 0; 766 767 mp = (u_char *)&pol->addrmask.sin6_addr; 768 ep = mp + 16; /* XXX: scope field? */ 769 k = (u_char *)&key.sin6_addr; 770 p = (u_char *)&pol->addr.sin6_addr; 771 for (; mp < ep && *mp; mp++, k++, p++) { 772 m = *mp; 773 if ((*k & m) != *p) 774 goto next; /* not match */ 775 if (m == 0xff) /* short cut for a typical case */ 776 matchlen += 8; 777 else { 778 while (m >= 0x80) { 779 matchlen++; 780 m <<= 1; 781 } 782 } 783 } 784 785 /* matched. check if this is better than the current best. */ 786 if (matchlen > bestmatchlen) { 787 bestent = ent; 788 bestmatchlen = matchlen; 789 } 790 791 next: 792 continue; 793 } 794 795 return(bestent); 796 #else 797 return(NULL); 798 #endif 799 800 } 801 802 static void 803 set_source(struct ai_order *aio, struct policyhead *ph) 804 { 805 struct addrinfo ai = *aio->aio_ai; 806 struct sockaddr_storage ss; 807 socklen_t srclen; 808 int s; 809 810 /* set unspec ("no source is available"), just in case */ 811 aio->aio_srcsa.sa_family = AF_UNSPEC; 812 aio->aio_srcscope = -1; 813 814 switch(ai.ai_family) { 815 case AF_INET: 816 #ifdef INET6 817 case AF_INET6: 818 #endif 819 break; 820 default: /* ignore unsupported AFs explicitly */ 821 return; 822 } 823 824 /* XXX: make a dummy addrinfo to call connect() */ 825 ai.ai_socktype = SOCK_DGRAM; 826 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */ 827 ai.ai_next = NULL; 828 memset(&ss, 0, sizeof(ss)); 829 memcpy(&ss, ai.ai_addr, ai.ai_addrlen); 830 ai.ai_addr = (struct sockaddr *)&ss; 831 get_port(&ai, "1", 0); 832 833 /* open a socket to get the source address for the given dst */ 834 if ((s = _socket(ai.ai_family, ai.ai_socktype, ai.ai_protocol)) < 0) 835 return; /* give up */ 836 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0) 837 goto cleanup; 838 srclen = ai.ai_addrlen; 839 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 840 aio->aio_srcsa.sa_family = AF_UNSPEC; 841 goto cleanup; 842 } 843 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 844 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 845 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr); 846 #ifdef INET6 847 if (ai.ai_family == AF_INET6) { 848 struct in6_ifreq ifr6; 849 u_int32_t flags6; 850 851 memset(&ifr6, 0, sizeof(ifr6)); 852 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen); 853 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 854 flags6 = ifr6.ifr_ifru.ifru_flags6; 855 if ((flags6 & IN6_IFF_DEPRECATED)) 856 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 857 } 858 } 859 #endif 860 861 cleanup: 862 _close(s); 863 return; 864 } 865 866 static int 867 matchlen(struct sockaddr *src, struct sockaddr *dst) 868 { 869 int match = 0; 870 u_char *s, *d; 871 u_char *lim, r; 872 int addrlen; 873 874 switch (src->sa_family) { 875 #ifdef INET6 876 case AF_INET6: 877 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 878 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 879 addrlen = sizeof(struct in6_addr); 880 lim = s + addrlen; 881 break; 882 #endif 883 case AF_INET: 884 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 885 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 886 addrlen = sizeof(struct in_addr); 887 lim = s + addrlen; 888 break; 889 default: 890 return(0); 891 } 892 893 while (s < lim) 894 if ((r = (*d++ ^ *s++)) != 0) { 895 while (r < addrlen * 8) { 896 match++; 897 r <<= 1; 898 } 899 break; 900 } else 901 match += 8; 902 return(match); 903 } 904 905 static int 906 comp_dst(const void *arg1, const void *arg2) 907 { 908 const struct ai_order *dst1 = arg1, *dst2 = arg2; 909 910 /* 911 * Rule 1: Avoid unusable destinations. 912 * XXX: we currently do not consider if an appropriate route exists. 913 */ 914 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 915 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 916 return(-1); 917 } 918 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 919 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 920 return(1); 921 } 922 923 /* Rule 2: Prefer matching scope. */ 924 if (dst1->aio_dstscope == dst1->aio_srcscope && 925 dst2->aio_dstscope != dst2->aio_srcscope) { 926 return(-1); 927 } 928 if (dst1->aio_dstscope != dst1->aio_srcscope && 929 dst2->aio_dstscope == dst2->aio_srcscope) { 930 return(1); 931 } 932 933 /* Rule 3: Avoid deprecated addresses. */ 934 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 935 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 936 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 937 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 938 return(-1); 939 } 940 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 941 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 942 return(1); 943 } 944 } 945 946 /* Rule 4: Prefer home addresses. */ 947 /* XXX: not implemented yet */ 948 949 /* Rule 5: Prefer matching label. */ 950 #ifdef INET6 951 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 952 dst1->aio_srcpolicy->pc_policy.label == 953 dst1->aio_dstpolicy->pc_policy.label && 954 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 955 dst2->aio_srcpolicy->pc_policy.label != 956 dst2->aio_dstpolicy->pc_policy.label)) { 957 return(-1); 958 } 959 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 960 dst2->aio_srcpolicy->pc_policy.label == 961 dst2->aio_dstpolicy->pc_policy.label && 962 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 963 dst1->aio_srcpolicy->pc_policy.label != 964 dst1->aio_dstpolicy->pc_policy.label)) { 965 return(1); 966 } 967 #endif 968 969 /* Rule 6: Prefer higher precedence. */ 970 #ifdef INET6 971 if (dst1->aio_dstpolicy && 972 (dst2->aio_dstpolicy == NULL || 973 dst1->aio_dstpolicy->pc_policy.preced > 974 dst2->aio_dstpolicy->pc_policy.preced)) { 975 return(-1); 976 } 977 if (dst2->aio_dstpolicy && 978 (dst1->aio_dstpolicy == NULL || 979 dst2->aio_dstpolicy->pc_policy.preced > 980 dst1->aio_dstpolicy->pc_policy.preced)) { 981 return(1); 982 } 983 #endif 984 985 /* Rule 7: Prefer native transport. */ 986 /* XXX: not implemented yet */ 987 988 /* Rule 8: Prefer smaller scope. */ 989 if (dst1->aio_dstscope >= 0 && 990 dst1->aio_dstscope < dst2->aio_dstscope) { 991 return(-1); 992 } 993 if (dst2->aio_dstscope >= 0 && 994 dst2->aio_dstscope < dst1->aio_dstscope) { 995 return(1); 996 } 997 998 /* 999 * Rule 9: Use longest matching prefix. 1000 * We compare the match length in a same AF only. 1001 */ 1002 if (dst1->aio_ai->ai_addr->sa_family == 1003 dst2->aio_ai->ai_addr->sa_family) { 1004 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1005 return(-1); 1006 } 1007 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1008 return(1); 1009 } 1010 } 1011 1012 /* Rule 10: Otherwise, leave the order unchanged. */ 1013 return(-1); 1014 } 1015 1016 /* 1017 * Copy from scope.c. 1018 * XXX: we should standardize the functions and link them as standard 1019 * library. 1020 */ 1021 static int 1022 gai_addr2scopetype(struct sockaddr *sa) 1023 { 1024 #ifdef INET6 1025 struct sockaddr_in6 *sa6; 1026 #endif 1027 struct sockaddr_in *sa4; 1028 1029 switch(sa->sa_family) { 1030 #ifdef INET6 1031 case AF_INET6: 1032 sa6 = (struct sockaddr_in6 *)sa; 1033 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1034 /* just use the scope field of the multicast address */ 1035 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1036 } 1037 /* 1038 * Unicast addresses: map scope type to corresponding scope 1039 * value defined for multcast addresses. 1040 * XXX: hardcoded scope type values are bad... 1041 */ 1042 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1043 return(1); /* node local scope */ 1044 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1045 return(2); /* link-local scope */ 1046 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1047 return(5); /* site-local scope */ 1048 return(14); /* global scope */ 1049 break; 1050 #endif 1051 case AF_INET: 1052 /* 1053 * IPv4 pseudo scoping according to RFC 3484. 1054 */ 1055 sa4 = (struct sockaddr_in *)sa; 1056 /* IPv4 autoconfiguration addresses have link-local scope. */ 1057 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1058 ((u_char *)&sa4->sin_addr)[1] == 254) 1059 return(2); 1060 /* Private addresses have site-local scope. */ 1061 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1062 (((u_char *)&sa4->sin_addr)[0] == 172 && 1063 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1064 (((u_char *)&sa4->sin_addr)[0] == 192 && 1065 ((u_char *)&sa4->sin_addr)[1] == 168)) 1066 return(14); /* XXX: It should be 5 unless NAT */ 1067 /* Loopback addresses have link-local scope. */ 1068 if (((u_char *)&sa4->sin_addr)[0] == 127) 1069 return(2); 1070 return(14); 1071 break; 1072 default: 1073 errno = EAFNOSUPPORT; /* is this a good error? */ 1074 return(-1); 1075 } 1076 } 1077 1078 static int 1079 explore_copy(const struct addrinfo *pai, const struct addrinfo *src0, 1080 struct addrinfo **res) 1081 { 1082 int error; 1083 struct addrinfo sentinel, *cur; 1084 const struct addrinfo *src; 1085 1086 error = 0; 1087 sentinel.ai_next = NULL; 1088 cur = &sentinel; 1089 1090 for (src = src0; src != NULL; src = src->ai_next) { 1091 if (src->ai_family != pai->ai_family) 1092 continue; 1093 1094 cur->ai_next = copy_ai(src); 1095 if (!cur->ai_next) { 1096 error = EAI_MEMORY; 1097 goto fail; 1098 } 1099 1100 cur->ai_next->ai_socktype = pai->ai_socktype; 1101 cur->ai_next->ai_protocol = pai->ai_protocol; 1102 cur = cur->ai_next; 1103 } 1104 1105 *res = sentinel.ai_next; 1106 return 0; 1107 1108 fail: 1109 freeaddrinfo(sentinel.ai_next); 1110 return error; 1111 } 1112 1113 /* 1114 * hostname == NULL. 1115 * passive socket -> anyaddr (0.0.0.0 or ::) 1116 * non-passive socket -> localhost (127.0.0.1 or ::1) 1117 */ 1118 static int 1119 explore_null(const struct addrinfo *pai, const char *servname, 1120 struct addrinfo **res) 1121 { 1122 int s; 1123 const struct afd *afd; 1124 struct addrinfo *ai; 1125 int error; 1126 1127 *res = NULL; 1128 ai = NULL; 1129 1130 /* 1131 * filter out AFs that are not supported by the kernel 1132 * XXX errno? 1133 */ 1134 s = _socket(pai->ai_family, SOCK_DGRAM, 0); 1135 if (s < 0) { 1136 if (errno != EMFILE) 1137 return 0; 1138 } else 1139 _close(s); 1140 1141 afd = find_afd(pai->ai_family); 1142 if (afd == NULL) 1143 return 0; 1144 1145 if (pai->ai_flags & AI_PASSIVE) { 1146 GET_AI(ai, afd, afd->a_addrany); 1147 GET_PORT(ai, servname); 1148 } else { 1149 GET_AI(ai, afd, afd->a_loopback); 1150 GET_PORT(ai, servname); 1151 } 1152 1153 *res = ai; 1154 return 0; 1155 1156 free: 1157 if (ai != NULL) 1158 freeaddrinfo(ai); 1159 return error; 1160 } 1161 1162 /* 1163 * numeric hostname 1164 */ 1165 static int 1166 explore_numeric(const struct addrinfo *pai, const char *hostname, 1167 const char *servname, struct addrinfo **res, const char *canonname) 1168 { 1169 const struct afd *afd; 1170 struct addrinfo *ai; 1171 int error; 1172 char pton[PTON_MAX]; 1173 1174 *res = NULL; 1175 ai = NULL; 1176 1177 afd = find_afd(pai->ai_family); 1178 if (afd == NULL) 1179 return 0; 1180 1181 switch (afd->a_af) { 1182 case AF_INET: 1183 /* 1184 * RFC3493 requires getaddrinfo() to accept AF_INET formats 1185 * that are accepted by inet_addr() and its family. The 1186 * accepted forms includes the "classful" one, which inet_pton 1187 * does not accept. So we need to separate the case for 1188 * AF_INET. 1189 */ 1190 if (inet_aton(hostname, (struct in_addr *)pton) != 1) 1191 return 0; 1192 break; 1193 default: 1194 if (inet_pton(afd->a_af, hostname, pton) != 1) 1195 return 0; 1196 break; 1197 } 1198 1199 if (pai->ai_family == afd->a_af) { 1200 GET_AI(ai, afd, pton); 1201 GET_PORT(ai, servname); 1202 if ((pai->ai_flags & AI_CANONNAME)) { 1203 /* 1204 * Set the numeric address itself as the canonical 1205 * name, based on a clarification in RFC3493. 1206 */ 1207 GET_CANONNAME(ai, canonname); 1208 } 1209 } else { 1210 /* 1211 * XXX: This should not happen since we already matched the AF 1212 * by find_afd. 1213 */ 1214 ERR(EAI_FAMILY); 1215 } 1216 1217 *res = ai; 1218 return 0; 1219 1220 free: 1221 bad: 1222 if (ai != NULL) 1223 freeaddrinfo(ai); 1224 return error; 1225 } 1226 1227 /* 1228 * numeric hostname with scope 1229 */ 1230 static int 1231 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1232 const char *servname, struct addrinfo **res) 1233 { 1234 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 1235 return explore_numeric(pai, hostname, servname, res, hostname); 1236 #else 1237 const struct afd *afd; 1238 struct addrinfo *cur; 1239 int error; 1240 char *cp, *hostname2 = NULL, *scope, *addr; 1241 struct sockaddr_in6 *sin6; 1242 1243 afd = find_afd(pai->ai_family); 1244 if (afd == NULL) 1245 return 0; 1246 1247 if (!afd->a_scoped) 1248 return explore_numeric(pai, hostname, servname, res, hostname); 1249 1250 cp = strchr(hostname, SCOPE_DELIMITER); 1251 if (cp == NULL) 1252 return explore_numeric(pai, hostname, servname, res, hostname); 1253 1254 /* 1255 * Handle special case of <scoped_address><delimiter><scope id> 1256 */ 1257 hostname2 = strdup(hostname); 1258 if (hostname2 == NULL) 1259 return EAI_MEMORY; 1260 /* terminate at the delimiter */ 1261 hostname2[cp - hostname] = '\0'; 1262 addr = hostname2; 1263 scope = cp + 1; 1264 1265 error = explore_numeric(pai, addr, servname, res, hostname); 1266 if (error == 0) { 1267 u_int32_t scopeid; 1268 1269 for (cur = *res; cur; cur = cur->ai_next) { 1270 if (cur->ai_family != AF_INET6) 1271 continue; 1272 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1273 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1274 free(hostname2); 1275 freeaddrinfo(*res); 1276 *res = NULL; 1277 return(EAI_NONAME); /* XXX: is return OK? */ 1278 } 1279 sin6->sin6_scope_id = scopeid; 1280 } 1281 } 1282 1283 free(hostname2); 1284 1285 if (error && *res) { 1286 freeaddrinfo(*res); 1287 *res = NULL; 1288 } 1289 return error; 1290 #endif 1291 } 1292 1293 static int 1294 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1295 { 1296 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1297 ai->ai_canonname = strdup(str); 1298 if (ai->ai_canonname == NULL) 1299 return EAI_MEMORY; 1300 } 1301 return 0; 1302 } 1303 1304 static struct addrinfo * 1305 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1306 { 1307 char *p; 1308 struct addrinfo *ai; 1309 #ifdef FAITH 1310 struct in6_addr faith_prefix; 1311 char *fp_str; 1312 int translate = 0; 1313 #endif 1314 1315 #ifdef FAITH 1316 /* 1317 * Transfrom an IPv4 addr into a special IPv6 addr format for 1318 * IPv6->IPv4 translation gateway. (only TCP is supported now) 1319 * 1320 * +-----------------------------------+------------+ 1321 * | faith prefix part (12 bytes) | embedded | 1322 * | | IPv4 addr part (4 bytes) 1323 * +-----------------------------------+------------+ 1324 * 1325 * faith prefix part is specified as ascii IPv6 addr format 1326 * in environmental variable GAI. 1327 * For FAITH to work correctly, routing to faith prefix must be 1328 * setup toward a machine where a FAITH daemon operates. 1329 * Also, the machine must enable some mechanizm 1330 * (e.g. faith interface hack) to divert those packet with 1331 * faith prefixed destination addr to user-land FAITH daemon. 1332 */ 1333 fp_str = getenv("GAI"); 1334 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && 1335 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { 1336 u_int32_t v4a; 1337 u_int8_t v4a_top; 1338 1339 memcpy(&v4a, addr, sizeof v4a); 1340 v4a_top = v4a >> IN_CLASSA_NSHIFT; 1341 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && 1342 v4a_top != 0 && v4a != IN_LOOPBACKNET) { 1343 afd = &afdl[N_INET6]; 1344 memcpy(&faith_prefix.s6_addr[12], addr, 1345 sizeof(struct in_addr)); 1346 translate = 1; 1347 } 1348 } 1349 #endif 1350 1351 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1352 + (afd->a_socklen)); 1353 if (ai == NULL) 1354 return NULL; 1355 1356 memcpy(ai, pai, sizeof(struct addrinfo)); 1357 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1358 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1359 ai->ai_addr->sa_len = afd->a_socklen; 1360 ai->ai_addrlen = afd->a_socklen; 1361 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1362 p = (char *)(void *)(ai->ai_addr); 1363 #ifdef FAITH 1364 if (translate == 1) 1365 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); 1366 else 1367 #endif 1368 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1369 return ai; 1370 } 1371 1372 /* XXX need to malloc() the same way we do from other functions! */ 1373 static struct addrinfo * 1374 copy_ai(const struct addrinfo *pai) 1375 { 1376 struct addrinfo *ai; 1377 size_t l; 1378 1379 l = sizeof(*ai) + pai->ai_addrlen; 1380 if ((ai = (struct addrinfo *)malloc(l)) == NULL) 1381 return NULL; 1382 memset(ai, 0, l); 1383 memcpy(ai, pai, sizeof(*ai)); 1384 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1385 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen); 1386 1387 if (pai->ai_canonname) { 1388 l = strlen(pai->ai_canonname) + 1; 1389 if ((ai->ai_canonname = malloc(l)) == NULL) { 1390 free(ai); 1391 return NULL; 1392 } 1393 strlcpy(ai->ai_canonname, pai->ai_canonname, l); 1394 } else { 1395 /* just to make sure */ 1396 ai->ai_canonname = NULL; 1397 } 1398 1399 ai->ai_next = NULL; 1400 1401 return ai; 1402 } 1403 1404 static int 1405 get_portmatch(const struct addrinfo *ai, const char *servname) 1406 { 1407 1408 /* get_port does not touch first argument when matchonly == 1. */ 1409 /* LINTED const cast */ 1410 return get_port((struct addrinfo *)ai, servname, 1); 1411 } 1412 1413 static int 1414 get_port(struct addrinfo *ai, const char *servname, int matchonly) 1415 { 1416 const char *proto; 1417 struct servent *sp; 1418 int port, error; 1419 int allownumeric; 1420 1421 if (servname == NULL) 1422 return 0; 1423 switch (ai->ai_family) { 1424 case AF_INET: 1425 #ifdef AF_INET6 1426 case AF_INET6: 1427 #endif 1428 break; 1429 default: 1430 return 0; 1431 } 1432 1433 switch (ai->ai_socktype) { 1434 case SOCK_RAW: 1435 return EAI_SERVICE; 1436 case SOCK_DGRAM: 1437 case SOCK_STREAM: 1438 case SOCK_SEQPACKET: 1439 allownumeric = 1; 1440 break; 1441 case ANY: 1442 switch (ai->ai_family) { 1443 case AF_INET: 1444 #ifdef AF_INET6 1445 case AF_INET6: 1446 #endif 1447 allownumeric = 1; 1448 break; 1449 default: 1450 allownumeric = 0; 1451 break; 1452 } 1453 break; 1454 default: 1455 return EAI_SOCKTYPE; 1456 } 1457 1458 error = str2number(servname, &port); 1459 if (error == 0) { 1460 if (!allownumeric) 1461 return EAI_SERVICE; 1462 if (port < 0 || port > 65535) 1463 return EAI_SERVICE; 1464 port = htons(port); 1465 } else { 1466 if (ai->ai_flags & AI_NUMERICSERV) 1467 return EAI_NONAME; 1468 1469 switch (ai->ai_protocol) { 1470 case IPPROTO_UDP: 1471 proto = "udp"; 1472 break; 1473 case IPPROTO_TCP: 1474 proto = "tcp"; 1475 break; 1476 case IPPROTO_SCTP: 1477 proto = "sctp"; 1478 break; 1479 default: 1480 proto = NULL; 1481 break; 1482 } 1483 1484 if ((sp = getservbyname(servname, proto)) == NULL) 1485 return EAI_SERVICE; 1486 port = sp->s_port; 1487 } 1488 1489 if (!matchonly) { 1490 switch (ai->ai_family) { 1491 case AF_INET: 1492 ((struct sockaddr_in *)(void *) 1493 ai->ai_addr)->sin_port = port; 1494 break; 1495 #ifdef INET6 1496 case AF_INET6: 1497 ((struct sockaddr_in6 *)(void *) 1498 ai->ai_addr)->sin6_port = port; 1499 break; 1500 #endif 1501 } 1502 } 1503 1504 return 0; 1505 } 1506 1507 static const struct afd * 1508 find_afd(int af) 1509 { 1510 const struct afd *afd; 1511 1512 if (af == PF_UNSPEC) 1513 return NULL; 1514 for (afd = afdl; afd->a_af; afd++) { 1515 if (afd->a_af == af) 1516 return afd; 1517 } 1518 return NULL; 1519 } 1520 1521 /* 1522 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend 1523 * will take care of it. 1524 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure 1525 * if the code is right or not. 1526 * 1527 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with 1528 * _dns_getaddrinfo. 1529 */ 1530 static int 1531 addrconfig(struct addrinfo *pai) 1532 { 1533 int s, af; 1534 1535 /* 1536 * TODO: 1537 * Note that implementation dependent test for address 1538 * configuration should be done everytime called 1539 * (or apropriate interval), 1540 * because addresses will be dynamically assigned or deleted. 1541 */ 1542 af = pai->ai_family; 1543 if (af == AF_UNSPEC) { 1544 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 1545 af = AF_INET; 1546 else { 1547 _close(s); 1548 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) 1549 af = AF_INET6; 1550 else 1551 _close(s); 1552 } 1553 } 1554 if (af != AF_UNSPEC) { 1555 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 1556 return 0; 1557 _close(s); 1558 } 1559 pai->ai_family = af; 1560 return 1; 1561 } 1562 1563 #ifdef INET6 1564 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1565 static int 1566 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1567 { 1568 u_long lscopeid; 1569 struct in6_addr *a6; 1570 char *ep; 1571 1572 a6 = &sin6->sin6_addr; 1573 1574 /* empty scopeid portion is invalid */ 1575 if (*scope == '\0') 1576 return -1; 1577 1578 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 1579 IN6_IS_ADDR_MC_NODELOCAL(a6)) { 1580 /* 1581 * We currently assume a one-to-one mapping between links 1582 * and interfaces, so we simply use interface indices for 1583 * like-local scopes. 1584 */ 1585 *scopeid = if_nametoindex(scope); 1586 if (*scopeid == 0) 1587 goto trynumeric; 1588 return 0; 1589 } 1590 1591 /* still unclear about literal, allow numeric only - placeholder */ 1592 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1593 goto trynumeric; 1594 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1595 goto trynumeric; 1596 else 1597 goto trynumeric; /* global */ 1598 1599 /* try to convert to a numeric id as a last resort */ 1600 trynumeric: 1601 errno = 0; 1602 lscopeid = strtoul(scope, &ep, 10); 1603 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1604 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1605 return 0; 1606 else 1607 return -1; 1608 } 1609 #endif 1610 1611 1612 #ifdef NS_CACHING 1613 static int 1614 addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap, 1615 void *cache_mdata) 1616 { 1617 res_state statp; 1618 u_long res_options; 1619 1620 const int op_id = 0; /* identifies the getaddrinfo for the cache */ 1621 char *hostname; 1622 struct addrinfo *hints; 1623 1624 char *p; 1625 int ai_flags, ai_family, ai_socktype, ai_protocol; 1626 size_t desired_size, size; 1627 1628 statp = __res_state(); 1629 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 1630 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 1631 1632 hostname = va_arg(ap, char *); 1633 hints = va_arg(ap, struct addrinfo *); 1634 1635 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4; 1636 if (hostname != NULL) { 1637 size = strlen(hostname); 1638 desired_size += size + 1; 1639 } else 1640 size = 0; 1641 1642 if (desired_size > *buffer_size) { 1643 *buffer_size = desired_size; 1644 return (NS_RETURN); 1645 } 1646 1647 if (hints == NULL) 1648 ai_flags = ai_family = ai_socktype = ai_protocol = 0; 1649 else { 1650 ai_flags = hints->ai_flags; 1651 ai_family = hints->ai_family; 1652 ai_socktype = hints->ai_socktype; 1653 ai_protocol = hints->ai_protocol; 1654 } 1655 1656 p = buffer; 1657 memcpy(p, &res_options, sizeof(res_options)); 1658 p += sizeof(res_options); 1659 1660 memcpy(p, &op_id, sizeof(int)); 1661 p += sizeof(int); 1662 1663 memcpy(p, &ai_flags, sizeof(int)); 1664 p += sizeof(int); 1665 1666 memcpy(p, &ai_family, sizeof(int)); 1667 p += sizeof(int); 1668 1669 memcpy(p, &ai_socktype, sizeof(int)); 1670 p += sizeof(int); 1671 1672 memcpy(p, &ai_protocol, sizeof(int)); 1673 p += sizeof(int); 1674 1675 if (hostname != NULL) 1676 memcpy(p, hostname, size); 1677 1678 *buffer_size = desired_size; 1679 return (NS_SUCCESS); 1680 } 1681 1682 static int 1683 addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval, 1684 va_list ap, void *cache_mdata) 1685 { 1686 struct addrinfo *ai, *cai; 1687 char *p; 1688 size_t desired_size, size, ai_size; 1689 1690 ai = *((struct addrinfo **)retval); 1691 1692 desired_size = sizeof(size_t); 1693 ai_size = 0; 1694 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1695 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen; 1696 if (cai->ai_canonname != NULL) 1697 desired_size += sizeof(size_t) + 1698 strlen(cai->ai_canonname); 1699 ++ai_size; 1700 } 1701 1702 if (desired_size > *buffer_size) { 1703 /* this assignment is here for future use */ 1704 errno = ERANGE; 1705 *buffer_size = desired_size; 1706 return (NS_RETURN); 1707 } 1708 1709 memset(buffer, 0, desired_size); 1710 p = buffer; 1711 1712 memcpy(p, &ai_size, sizeof(size_t)); 1713 p += sizeof(size_t); 1714 for (cai = ai; cai != NULL; cai = cai->ai_next) { 1715 memcpy(p, cai, sizeof(struct addrinfo)); 1716 p += sizeof(struct addrinfo); 1717 1718 memcpy(p, cai->ai_addr, cai->ai_addrlen); 1719 p += cai->ai_addrlen; 1720 1721 if (cai->ai_canonname != NULL) { 1722 size = strlen(cai->ai_canonname); 1723 memcpy(p, &size, sizeof(size_t)); 1724 p += sizeof(size_t); 1725 1726 memcpy(p, cai->ai_canonname, size); 1727 p += size; 1728 } 1729 } 1730 1731 return (NS_SUCCESS); 1732 } 1733 1734 static int 1735 addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval, 1736 va_list ap, void *cache_mdata) 1737 { 1738 struct addrinfo new_ai, *result, *sentinel, *lasts; 1739 1740 char *p; 1741 size_t ai_size, ai_i, size; 1742 1743 p = buffer; 1744 memcpy(&ai_size, p, sizeof(size_t)); 1745 p += sizeof(size_t); 1746 1747 result = NULL; 1748 lasts = NULL; 1749 for (ai_i = 0; ai_i < ai_size; ++ai_i) { 1750 memcpy(&new_ai, p, sizeof(struct addrinfo)); 1751 p += sizeof(struct addrinfo); 1752 size = new_ai.ai_addrlen + sizeof(struct addrinfo) + 1753 _ALIGNBYTES; 1754 1755 sentinel = (struct addrinfo *)malloc(size); 1756 memset(sentinel, 0, size); 1757 1758 memcpy(sentinel, &new_ai, sizeof(struct addrinfo)); 1759 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel + 1760 sizeof(struct addrinfo)); 1761 1762 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen); 1763 p += new_ai.ai_addrlen; 1764 1765 if (new_ai.ai_canonname != NULL) { 1766 memcpy(&size, p, sizeof(size_t)); 1767 p += sizeof(size_t); 1768 1769 sentinel->ai_canonname = (char *)malloc(size + 1); 1770 memset(sentinel->ai_canonname, 0, size + 1); 1771 1772 memcpy(sentinel->ai_canonname, p, size); 1773 p += size; 1774 } 1775 1776 if (result == NULL) { 1777 result = sentinel; 1778 lasts = sentinel; 1779 } else { 1780 lasts->ai_next = sentinel; 1781 lasts = sentinel; 1782 } 1783 } 1784 1785 *((struct addrinfo **)retval) = result; 1786 return (NS_SUCCESS); 1787 } 1788 #endif /* NS_CACHING */ 1789 1790 /* 1791 * FQDN hostname, DNS lookup 1792 */ 1793 static int 1794 explore_fqdn(const struct addrinfo *pai, const char *hostname, 1795 const char *servname, struct addrinfo **res) 1796 { 1797 struct addrinfo *result; 1798 struct addrinfo *cur; 1799 int error = 0; 1800 1801 #ifdef NS_CACHING 1802 static const nss_cache_info cache_info = 1803 NS_COMMON_CACHE_INFO_INITIALIZER( 1804 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func, 1805 addrinfo_unmarshal_func); 1806 #endif 1807 static const ns_dtab dtab[] = { 1808 NS_FILES_CB(_files_getaddrinfo, NULL) 1809 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 1810 NS_NIS_CB(_yp_getaddrinfo, NULL) 1811 #ifdef NS_CACHING 1812 NS_CACHE_CB(&cache_info) 1813 #endif 1814 { 0 } 1815 }; 1816 1817 result = NULL; 1818 1819 /* 1820 * if the servname does not match socktype/protocol, ignore it. 1821 */ 1822 if (get_portmatch(pai, servname) != 0) 1823 return 0; 1824 1825 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 1826 default_dns_files, hostname, pai)) { 1827 case NS_TRYAGAIN: 1828 error = EAI_AGAIN; 1829 goto free; 1830 case NS_UNAVAIL: 1831 error = EAI_FAIL; 1832 goto free; 1833 case NS_NOTFOUND: 1834 error = EAI_NONAME; 1835 goto free; 1836 case NS_SUCCESS: 1837 error = 0; 1838 for (cur = result; cur; cur = cur->ai_next) { 1839 GET_PORT(cur, servname); 1840 /* canonname should be filled already */ 1841 } 1842 break; 1843 } 1844 1845 *res = result; 1846 1847 return 0; 1848 1849 free: 1850 if (result) 1851 freeaddrinfo(result); 1852 return error; 1853 } 1854 1855 #ifdef DEBUG 1856 static const char AskedForGot[] = 1857 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1858 #endif 1859 1860 static struct addrinfo * 1861 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1862 const struct addrinfo *pai, res_state res) 1863 { 1864 struct addrinfo sentinel, *cur; 1865 struct addrinfo ai; 1866 const struct afd *afd; 1867 char *canonname; 1868 const HEADER *hp; 1869 const u_char *cp; 1870 int n; 1871 const u_char *eom; 1872 char *bp, *ep; 1873 int type, class, ancount, qdcount; 1874 int haveanswer, had_error; 1875 char tbuf[MAXDNAME]; 1876 int (*name_ok)(const char *); 1877 char hostbuf[8*1024]; 1878 1879 memset(&sentinel, 0, sizeof(sentinel)); 1880 cur = &sentinel; 1881 1882 canonname = NULL; 1883 eom = answer->buf + anslen; 1884 switch (qtype) { 1885 case T_A: 1886 case T_AAAA: 1887 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1888 name_ok = res_hnok; 1889 break; 1890 default: 1891 return (NULL); /* XXX should be abort(); */ 1892 } 1893 /* 1894 * find first satisfactory answer 1895 */ 1896 hp = &answer->hdr; 1897 ancount = ntohs(hp->ancount); 1898 qdcount = ntohs(hp->qdcount); 1899 bp = hostbuf; 1900 ep = hostbuf + sizeof hostbuf; 1901 cp = answer->buf + HFIXEDSZ; 1902 if (qdcount != 1) { 1903 RES_SET_H_ERRNO(res, NO_RECOVERY); 1904 return (NULL); 1905 } 1906 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1907 if ((n < 0) || !(*name_ok)(bp)) { 1908 RES_SET_H_ERRNO(res, NO_RECOVERY); 1909 return (NULL); 1910 } 1911 cp += n + QFIXEDSZ; 1912 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1913 /* res_send() has already verified that the query name is the 1914 * same as the one we sent; this just gets the expanded name 1915 * (i.e., with the succeeding search-domain tacked on). 1916 */ 1917 n = strlen(bp) + 1; /* for the \0 */ 1918 if (n >= MAXHOSTNAMELEN) { 1919 RES_SET_H_ERRNO(res, NO_RECOVERY); 1920 return (NULL); 1921 } 1922 canonname = bp; 1923 bp += n; 1924 /* The qname can be abbreviated, but h_name is now absolute. */ 1925 qname = canonname; 1926 } 1927 haveanswer = 0; 1928 had_error = 0; 1929 while (ancount-- > 0 && cp < eom && !had_error) { 1930 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1931 if ((n < 0) || !(*name_ok)(bp)) { 1932 had_error++; 1933 continue; 1934 } 1935 cp += n; /* name */ 1936 type = _getshort(cp); 1937 cp += INT16SZ; /* type */ 1938 class = _getshort(cp); 1939 cp += INT16SZ + INT32SZ; /* class, TTL */ 1940 n = _getshort(cp); 1941 cp += INT16SZ; /* len */ 1942 if (class != C_IN) { 1943 /* XXX - debug? syslog? */ 1944 cp += n; 1945 continue; /* XXX - had_error++ ? */ 1946 } 1947 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1948 type == T_CNAME) { 1949 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1950 if ((n < 0) || !(*name_ok)(tbuf)) { 1951 had_error++; 1952 continue; 1953 } 1954 cp += n; 1955 /* Get canonical name. */ 1956 n = strlen(tbuf) + 1; /* for the \0 */ 1957 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1958 had_error++; 1959 continue; 1960 } 1961 strlcpy(bp, tbuf, ep - bp); 1962 canonname = bp; 1963 bp += n; 1964 continue; 1965 } 1966 if (qtype == T_ANY) { 1967 if (!(type == T_A || type == T_AAAA)) { 1968 cp += n; 1969 continue; 1970 } 1971 } else if (type != qtype) { 1972 #ifdef DEBUG 1973 if (type != T_KEY && type != T_SIG && 1974 type != ns_t_dname) 1975 syslog(LOG_NOTICE|LOG_AUTH, 1976 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1977 qname, p_class(C_IN), p_type(qtype), 1978 p_type(type)); 1979 #endif 1980 cp += n; 1981 continue; /* XXX - had_error++ ? */ 1982 } 1983 switch (type) { 1984 case T_A: 1985 case T_AAAA: 1986 if (strcasecmp(canonname, bp) != 0) { 1987 #ifdef DEBUG 1988 syslog(LOG_NOTICE|LOG_AUTH, 1989 AskedForGot, canonname, bp); 1990 #endif 1991 cp += n; 1992 continue; /* XXX - had_error++ ? */ 1993 } 1994 if (type == T_A && n != INADDRSZ) { 1995 cp += n; 1996 continue; 1997 } 1998 if (type == T_AAAA && n != IN6ADDRSZ) { 1999 cp += n; 2000 continue; 2001 } 2002 #ifdef FILTER_V4MAPPED 2003 if (type == T_AAAA) { 2004 struct in6_addr in6; 2005 memcpy(&in6, cp, sizeof(in6)); 2006 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 2007 cp += n; 2008 continue; 2009 } 2010 } 2011 #endif 2012 if (!haveanswer) { 2013 int nn; 2014 2015 canonname = bp; 2016 nn = strlen(bp) + 1; /* for the \0 */ 2017 bp += nn; 2018 } 2019 2020 /* don't overwrite pai */ 2021 ai = *pai; 2022 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 2023 afd = find_afd(ai.ai_family); 2024 if (afd == NULL) { 2025 cp += n; 2026 continue; 2027 } 2028 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 2029 if (cur->ai_next == NULL) 2030 had_error++; 2031 while (cur && cur->ai_next) 2032 cur = cur->ai_next; 2033 cp += n; 2034 break; 2035 default: 2036 abort(); 2037 } 2038 if (!had_error) 2039 haveanswer++; 2040 } 2041 if (haveanswer) { 2042 #if defined(RESOLVSORT) 2043 /* 2044 * We support only IPv4 address for backward 2045 * compatibility against gethostbyname(3). 2046 */ 2047 if (res->nsort && qtype == T_A) { 2048 if (addr4sort(&sentinel, res) < 0) { 2049 freeaddrinfo(sentinel.ai_next); 2050 RES_SET_H_ERRNO(res, NO_RECOVERY); 2051 return NULL; 2052 } 2053 } 2054 #endif /*RESOLVSORT*/ 2055 if (!canonname) 2056 (void)get_canonname(pai, sentinel.ai_next, qname); 2057 else 2058 (void)get_canonname(pai, sentinel.ai_next, canonname); 2059 RES_SET_H_ERRNO(res, NETDB_SUCCESS); 2060 return sentinel.ai_next; 2061 } 2062 2063 RES_SET_H_ERRNO(res, NO_RECOVERY); 2064 return NULL; 2065 } 2066 2067 #ifdef RESOLVSORT 2068 struct addr_ptr { 2069 struct addrinfo *ai; 2070 int aval; 2071 }; 2072 2073 static int 2074 addr4sort(struct addrinfo *sentinel, res_state res) 2075 { 2076 struct addrinfo *ai; 2077 struct addr_ptr *addrs, addr; 2078 struct sockaddr_in *sin; 2079 int naddrs, i, j; 2080 int needsort = 0; 2081 2082 if (!sentinel) 2083 return -1; 2084 naddrs = 0; 2085 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) 2086 naddrs++; 2087 if (naddrs < 2) 2088 return 0; /* We don't need sorting. */ 2089 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL) 2090 return -1; 2091 i = 0; 2092 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) { 2093 sin = (struct sockaddr_in *)ai->ai_addr; 2094 for (j = 0; (unsigned)j < res->nsort; j++) { 2095 if (res->sort_list[j].addr.s_addr == 2096 (sin->sin_addr.s_addr & res->sort_list[j].mask)) 2097 break; 2098 } 2099 addrs[i].ai = ai; 2100 addrs[i].aval = j; 2101 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval) 2102 needsort = i; 2103 i++; 2104 } 2105 if (!needsort) { 2106 free(addrs); 2107 return 0; 2108 } 2109 2110 while (needsort < naddrs) { 2111 for (j = needsort - 1; j >= 0; j--) { 2112 if (addrs[j].aval > addrs[j+1].aval) { 2113 addr = addrs[j]; 2114 addrs[j] = addrs[j + 1]; 2115 addrs[j + 1] = addr; 2116 } else 2117 break; 2118 } 2119 needsort++; 2120 } 2121 2122 ai = sentinel; 2123 for (i = 0; i < naddrs; ++i) { 2124 ai->ai_next = addrs[i].ai; 2125 ai = ai->ai_next; 2126 } 2127 ai->ai_next = NULL; 2128 free(addrs); 2129 return 0; 2130 } 2131 #endif /*RESOLVSORT*/ 2132 2133 /*ARGSUSED*/ 2134 static int 2135 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 2136 { 2137 struct addrinfo *ai; 2138 querybuf *buf, *buf2; 2139 const char *hostname; 2140 const struct addrinfo *pai; 2141 struct addrinfo sentinel, *cur; 2142 struct res_target q, q2; 2143 res_state res; 2144 2145 hostname = va_arg(ap, char *); 2146 pai = va_arg(ap, const struct addrinfo *); 2147 2148 memset(&q, 0, sizeof(q)); 2149 memset(&q2, 0, sizeof(q2)); 2150 memset(&sentinel, 0, sizeof(sentinel)); 2151 cur = &sentinel; 2152 2153 buf = malloc(sizeof(*buf)); 2154 if (!buf) { 2155 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2156 return NS_NOTFOUND; 2157 } 2158 buf2 = malloc(sizeof(*buf2)); 2159 if (!buf2) { 2160 free(buf); 2161 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2162 return NS_NOTFOUND; 2163 } 2164 2165 switch (pai->ai_family) { 2166 case AF_UNSPEC: 2167 q.name = hostname; 2168 q.qclass = C_IN; 2169 q.qtype = T_A; 2170 q.answer = buf->buf; 2171 q.anslen = sizeof(buf->buf); 2172 q.next = &q2; 2173 q2.name = hostname; 2174 q2.qclass = C_IN; 2175 q2.qtype = T_AAAA; 2176 q2.answer = buf2->buf; 2177 q2.anslen = sizeof(buf2->buf); 2178 break; 2179 case AF_INET: 2180 q.name = hostname; 2181 q.qclass = C_IN; 2182 q.qtype = T_A; 2183 q.answer = buf->buf; 2184 q.anslen = sizeof(buf->buf); 2185 break; 2186 case AF_INET6: 2187 q.name = hostname; 2188 q.qclass = C_IN; 2189 q.qtype = T_AAAA; 2190 q.answer = buf->buf; 2191 q.anslen = sizeof(buf->buf); 2192 break; 2193 default: 2194 free(buf); 2195 free(buf2); 2196 return NS_UNAVAIL; 2197 } 2198 2199 res = __res_state(); 2200 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) { 2201 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2202 free(buf); 2203 free(buf2); 2204 return NS_NOTFOUND; 2205 } 2206 2207 if (res_searchN(hostname, &q, res) < 0) { 2208 free(buf); 2209 free(buf2); 2210 return NS_NOTFOUND; 2211 } 2212 /* prefer IPv6 */ 2213 if (q.next) { 2214 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res); 2215 if (ai) { 2216 cur->ai_next = ai; 2217 while (cur && cur->ai_next) 2218 cur = cur->ai_next; 2219 } 2220 } 2221 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); 2222 if (ai) 2223 cur->ai_next = ai; 2224 free(buf); 2225 free(buf2); 2226 if (sentinel.ai_next == NULL) 2227 switch (res->res_h_errno) { 2228 case HOST_NOT_FOUND: 2229 return NS_NOTFOUND; 2230 case TRY_AGAIN: 2231 return NS_TRYAGAIN; 2232 default: 2233 return NS_UNAVAIL; 2234 } 2235 *((struct addrinfo **)rv) = sentinel.ai_next; 2236 return NS_SUCCESS; 2237 } 2238 2239 static void 2240 _sethtent(FILE **hostf) 2241 { 2242 if (!*hostf) 2243 *hostf = fopen(_PATH_HOSTS, "r"); 2244 else 2245 rewind(*hostf); 2246 } 2247 2248 static void 2249 _endhtent(FILE **hostf) 2250 { 2251 if (*hostf) { 2252 (void) fclose(*hostf); 2253 *hostf = NULL; 2254 } 2255 } 2256 2257 static struct addrinfo * 2258 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2259 { 2260 char *p; 2261 char *cp, *tname, *cname; 2262 struct addrinfo hints, *res0, *res; 2263 int error; 2264 const char *addr; 2265 char hostbuf[8*1024]; 2266 2267 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r"))) 2268 return (NULL); 2269 again: 2270 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2271 return (NULL); 2272 if (*p == '#') 2273 goto again; 2274 cp = strpbrk(p, "#\n"); 2275 if (cp != NULL) 2276 *cp = '\0'; 2277 if (!(cp = strpbrk(p, " \t"))) 2278 goto again; 2279 *cp++ = '\0'; 2280 addr = p; 2281 cname = NULL; 2282 /* if this is not something we're looking for, skip it. */ 2283 while (cp && *cp) { 2284 if (*cp == ' ' || *cp == '\t') { 2285 cp++; 2286 continue; 2287 } 2288 tname = cp; 2289 if (cname == NULL) 2290 cname = cp; 2291 if ((cp = strpbrk(cp, " \t")) != NULL) 2292 *cp++ = '\0'; 2293 if (strcasecmp(name, tname) == 0) 2294 goto found; 2295 } 2296 goto again; 2297 2298 found: 2299 /* we should not glob socktype/protocol here */ 2300 memset(&hints, 0, sizeof(hints)); 2301 hints.ai_family = pai->ai_family; 2302 hints.ai_socktype = SOCK_DGRAM; 2303 hints.ai_protocol = 0; 2304 hints.ai_flags = AI_NUMERICHOST; 2305 error = getaddrinfo(addr, "0", &hints, &res0); 2306 if (error) 2307 goto again; 2308 #ifdef FILTER_V4MAPPED 2309 /* XXX should check all items in the chain */ 2310 if (res0->ai_family == AF_INET6 && 2311 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { 2312 freeaddrinfo(res0); 2313 goto again; 2314 } 2315 #endif 2316 for (res = res0; res; res = res->ai_next) { 2317 /* cover it up */ 2318 res->ai_flags = pai->ai_flags; 2319 res->ai_socktype = pai->ai_socktype; 2320 res->ai_protocol = pai->ai_protocol; 2321 2322 if (pai->ai_flags & AI_CANONNAME) { 2323 if (get_canonname(pai, res, cname) != 0) { 2324 freeaddrinfo(res0); 2325 goto again; 2326 } 2327 } 2328 } 2329 return res0; 2330 } 2331 2332 /*ARGSUSED*/ 2333 static int 2334 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2335 { 2336 const char *name; 2337 const struct addrinfo *pai; 2338 struct addrinfo sentinel, *cur; 2339 struct addrinfo *p; 2340 FILE *hostf = NULL; 2341 2342 name = va_arg(ap, char *); 2343 pai = va_arg(ap, struct addrinfo *); 2344 2345 memset(&sentinel, 0, sizeof(sentinel)); 2346 cur = &sentinel; 2347 2348 _sethtent(&hostf); 2349 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 2350 cur->ai_next = p; 2351 while (cur && cur->ai_next) 2352 cur = cur->ai_next; 2353 } 2354 _endhtent(&hostf); 2355 2356 *((struct addrinfo **)rv) = sentinel.ai_next; 2357 if (sentinel.ai_next == NULL) 2358 return NS_NOTFOUND; 2359 return NS_SUCCESS; 2360 } 2361 2362 #ifdef YP 2363 /*ARGSUSED*/ 2364 static struct addrinfo * 2365 _yphostent(char *line, const struct addrinfo *pai) 2366 { 2367 struct addrinfo sentinel, *cur; 2368 struct addrinfo hints, *res, *res0; 2369 int error; 2370 char *p = line; 2371 const char *addr, *canonname; 2372 char *nextline; 2373 char *cp; 2374 2375 addr = canonname = NULL; 2376 2377 memset(&sentinel, 0, sizeof(sentinel)); 2378 cur = &sentinel; 2379 2380 nextline: 2381 /* terminate line */ 2382 cp = strchr(p, '\n'); 2383 if (cp) { 2384 *cp++ = '\0'; 2385 nextline = cp; 2386 } else 2387 nextline = NULL; 2388 2389 cp = strpbrk(p, " \t"); 2390 if (cp == NULL) { 2391 if (canonname == NULL) 2392 return (NULL); 2393 else 2394 goto done; 2395 } 2396 *cp++ = '\0'; 2397 2398 addr = p; 2399 2400 while (cp && *cp) { 2401 if (*cp == ' ' || *cp == '\t') { 2402 cp++; 2403 continue; 2404 } 2405 if (!canonname) 2406 canonname = cp; 2407 if ((cp = strpbrk(cp, " \t")) != NULL) 2408 *cp++ = '\0'; 2409 } 2410 2411 hints = *pai; 2412 hints.ai_flags = AI_NUMERICHOST; 2413 error = getaddrinfo(addr, NULL, &hints, &res0); 2414 if (error == 0) { 2415 for (res = res0; res; res = res->ai_next) { 2416 /* cover it up */ 2417 res->ai_flags = pai->ai_flags; 2418 2419 if (pai->ai_flags & AI_CANONNAME) 2420 (void)get_canonname(pai, res, canonname); 2421 } 2422 } else 2423 res0 = NULL; 2424 if (res0) { 2425 cur->ai_next = res0; 2426 while (cur && cur->ai_next) 2427 cur = cur->ai_next; 2428 } 2429 2430 if (nextline) { 2431 p = nextline; 2432 goto nextline; 2433 } 2434 2435 done: 2436 return sentinel.ai_next; 2437 } 2438 2439 /*ARGSUSED*/ 2440 static int 2441 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap) 2442 { 2443 struct addrinfo sentinel, *cur; 2444 struct addrinfo *ai = NULL; 2445 char *ypbuf; 2446 int ypbuflen, r; 2447 const char *name; 2448 const struct addrinfo *pai; 2449 char *ypdomain; 2450 2451 if (_yp_check(&ypdomain) == 0) 2452 return NS_UNAVAIL; 2453 2454 name = va_arg(ap, char *); 2455 pai = va_arg(ap, const struct addrinfo *); 2456 2457 memset(&sentinel, 0, sizeof(sentinel)); 2458 cur = &sentinel; 2459 2460 /* hosts.byname is only for IPv4 (Solaris8) */ 2461 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { 2462 r = yp_match(ypdomain, "hosts.byname", name, 2463 (int)strlen(name), &ypbuf, &ypbuflen); 2464 if (r == 0) { 2465 struct addrinfo ai4; 2466 2467 ai4 = *pai; 2468 ai4.ai_family = AF_INET; 2469 ai = _yphostent(ypbuf, &ai4); 2470 if (ai) { 2471 cur->ai_next = ai; 2472 while (cur && cur->ai_next) 2473 cur = cur->ai_next; 2474 } 2475 free(ypbuf); 2476 } 2477 } 2478 2479 /* ipnodes.byname can hold both IPv4/v6 */ 2480 r = yp_match(ypdomain, "ipnodes.byname", name, 2481 (int)strlen(name), &ypbuf, &ypbuflen); 2482 if (r == 0) { 2483 ai = _yphostent(ypbuf, pai); 2484 if (ai) 2485 cur->ai_next = ai; 2486 free(ypbuf); 2487 } 2488 2489 if (sentinel.ai_next == NULL) { 2490 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND); 2491 return NS_NOTFOUND; 2492 } 2493 *((struct addrinfo **)rv) = sentinel.ai_next; 2494 return NS_SUCCESS; 2495 } 2496 #endif 2497 2498 /* resolver logic */ 2499 2500 /* 2501 * Formulate a normal query, send, and await answer. 2502 * Returned answer is placed in supplied buffer "answer". 2503 * Perform preliminary check of answer, returning success only 2504 * if no error is indicated and the answer count is nonzero. 2505 * Return the size of the response on success, -1 on error. 2506 * Error number is left in h_errno. 2507 * 2508 * Caller must parse answer and determine whether it answers the question. 2509 */ 2510 static int 2511 res_queryN(const char *name, struct res_target *target, res_state res) 2512 { 2513 u_char *buf; 2514 HEADER *hp; 2515 int n; 2516 u_int oflags; 2517 struct res_target *t; 2518 int rcode; 2519 int ancount; 2520 2521 rcode = NOERROR; 2522 ancount = 0; 2523 2524 buf = malloc(MAXPACKET); 2525 if (!buf) { 2526 RES_SET_H_ERRNO(res, NETDB_INTERNAL); 2527 return -1; 2528 } 2529 2530 for (t = target; t; t = t->next) { 2531 int class, type; 2532 u_char *answer; 2533 int anslen; 2534 2535 hp = (HEADER *)(void *)t->answer; 2536 2537 /* make it easier... */ 2538 class = t->qclass; 2539 type = t->qtype; 2540 answer = t->answer; 2541 anslen = t->anslen; 2542 2543 oflags = res->_flags; 2544 2545 again: 2546 hp->rcode = NOERROR; /* default */ 2547 2548 #ifdef DEBUG 2549 if (res->options & RES_DEBUG) 2550 printf(";; res_query(%s, %d, %d)\n", name, class, type); 2551 #endif 2552 2553 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2554 buf, MAXPACKET); 2555 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 && 2556 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U) 2557 n = res_nopt(res, n, buf, MAXPACKET, anslen); 2558 if (n <= 0) { 2559 #ifdef DEBUG 2560 if (res->options & RES_DEBUG) 2561 printf(";; res_query: mkquery failed\n"); 2562 #endif 2563 free(buf); 2564 RES_SET_H_ERRNO(res, NO_RECOVERY); 2565 return (n); 2566 } 2567 n = res_nsend(res, buf, n, answer, anslen); 2568 if (n < 0) { 2569 /* 2570 * if the query choked with EDNS0, retry 2571 * without EDNS0 2572 */ 2573 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) 2574 != 0U && 2575 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) { 2576 res->_flags |= RES_F_EDNS0ERR; 2577 if (res->options & RES_DEBUG) 2578 printf(";; res_nquery: retry without EDNS0\n"); 2579 goto again; 2580 } 2581 rcode = hp->rcode; /* record most recent error */ 2582 #ifdef DEBUG 2583 if (res->options & RES_DEBUG) 2584 printf(";; res_query: send error\n"); 2585 #endif 2586 continue; 2587 } 2588 2589 if (n > anslen) 2590 hp->rcode = FORMERR; /* XXX not very informative */ 2591 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2592 rcode = hp->rcode; /* record most recent error */ 2593 #ifdef DEBUG 2594 if (res->options & RES_DEBUG) 2595 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2596 ntohs(hp->ancount)); 2597 #endif 2598 continue; 2599 } 2600 2601 ancount += ntohs(hp->ancount); 2602 2603 t->n = n; 2604 } 2605 2606 free(buf); 2607 2608 if (ancount == 0) { 2609 switch (rcode) { 2610 case NXDOMAIN: 2611 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); 2612 break; 2613 case SERVFAIL: 2614 RES_SET_H_ERRNO(res, TRY_AGAIN); 2615 break; 2616 case NOERROR: 2617 RES_SET_H_ERRNO(res, NO_DATA); 2618 break; 2619 case FORMERR: 2620 case NOTIMP: 2621 case REFUSED: 2622 default: 2623 RES_SET_H_ERRNO(res, NO_RECOVERY); 2624 break; 2625 } 2626 return (-1); 2627 } 2628 return (ancount); 2629 } 2630 2631 /* 2632 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2633 * Return the size of the response on success, -1 on error. 2634 * If enabled, implement search rules until answer or unrecoverable failure 2635 * is detected. Error code, if any, is left in h_errno. 2636 */ 2637 static int 2638 res_searchN(const char *name, struct res_target *target, res_state res) 2639 { 2640 const char *cp, * const *domain; 2641 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ 2642 u_int dots; 2643 int trailing_dot, ret, saved_herrno; 2644 int got_nodata = 0, got_servfail = 0, root_on_list = 0; 2645 int tried_as_is = 0; 2646 int searched = 0; 2647 char abuf[MAXDNAME]; 2648 2649 errno = 0; 2650 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */ 2651 dots = 0; 2652 for (cp = name; *cp; cp++) 2653 dots += (*cp == '.'); 2654 trailing_dot = 0; 2655 if (cp > name && *--cp == '.') 2656 trailing_dot++; 2657 2658 /* 2659 * if there aren't any dots, it could be a user-level alias 2660 */ 2661 if (!dots && 2662 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL) 2663 return (res_queryN(cp, target, res)); 2664 2665 /* 2666 * If there are enough dots in the name, let's just give it a 2667 * try 'as is'. The threshold can be set with the "ndots" option. 2668 * Also, query 'as is', if there is a trailing dot in the name. 2669 */ 2670 saved_herrno = -1; 2671 if (dots >= res->ndots || trailing_dot) { 2672 ret = res_querydomainN(name, NULL, target, res); 2673 if (ret > 0 || trailing_dot) 2674 return (ret); 2675 if (errno == ECONNREFUSED) { 2676 RES_SET_H_ERRNO(res, TRY_AGAIN); 2677 return (-1); 2678 } 2679 switch (res->res_h_errno) { 2680 case NO_DATA: 2681 case HOST_NOT_FOUND: 2682 break; 2683 case TRY_AGAIN: 2684 if (hp->rcode == SERVFAIL) 2685 break; 2686 /* FALLTHROUGH */ 2687 default: 2688 return (-1); 2689 } 2690 saved_herrno = res->res_h_errno; 2691 tried_as_is++; 2692 } 2693 2694 /* 2695 * We do at least one level of search if 2696 * - there is no dot and RES_DEFNAME is set, or 2697 * - there is at least one dot, there is no trailing dot, 2698 * and RES_DNSRCH is set. 2699 */ 2700 if ((!dots && (res->options & RES_DEFNAMES)) || 2701 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2702 int done = 0; 2703 2704 for (domain = (const char * const *)res->dnsrch; 2705 *domain && !done; 2706 domain++) { 2707 searched = 1; 2708 2709 if (domain[0][0] == '\0' || 2710 (domain[0][0] == '.' && domain[0][1] == '\0')) 2711 root_on_list++; 2712 2713 if (root_on_list && tried_as_is) 2714 continue; 2715 2716 ret = res_querydomainN(name, *domain, target, res); 2717 if (ret > 0) 2718 return (ret); 2719 2720 /* 2721 * If no server present, give up. 2722 * If name isn't found in this domain, 2723 * keep trying higher domains in the search list 2724 * (if that's enabled). 2725 * On a NO_DATA error, keep trying, otherwise 2726 * a wildcard entry of another type could keep us 2727 * from finding this entry higher in the domain. 2728 * If we get some other error (negative answer or 2729 * server failure), then stop searching up, 2730 * but try the input name below in case it's 2731 * fully-qualified. 2732 */ 2733 if (errno == ECONNREFUSED) { 2734 RES_SET_H_ERRNO(res, TRY_AGAIN); 2735 return (-1); 2736 } 2737 2738 switch (res->res_h_errno) { 2739 case NO_DATA: 2740 got_nodata++; 2741 /* FALLTHROUGH */ 2742 case HOST_NOT_FOUND: 2743 /* keep trying */ 2744 break; 2745 case TRY_AGAIN: 2746 got_servfail++; 2747 if (hp->rcode == SERVFAIL) { 2748 /* try next search element, if any */ 2749 break; 2750 } 2751 /* FALLTHROUGH */ 2752 default: 2753 /* anything else implies that we're done */ 2754 done++; 2755 } 2756 /* 2757 * if we got here for some reason other than DNSRCH, 2758 * we only wanted one iteration of the loop, so stop. 2759 */ 2760 if (!(res->options & RES_DNSRCH)) 2761 done++; 2762 } 2763 } 2764 2765 switch (res->res_h_errno) { 2766 case NO_DATA: 2767 case HOST_NOT_FOUND: 2768 break; 2769 case TRY_AGAIN: 2770 if (hp->rcode == SERVFAIL) 2771 break; 2772 /* FALLTHROUGH */ 2773 default: 2774 goto giveup; 2775 } 2776 2777 /* 2778 * If the query has not already been tried as is then try it 2779 * unless RES_NOTLDQUERY is set and there were no dots. 2780 */ 2781 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) && 2782 !(tried_as_is || root_on_list)) { 2783 ret = res_querydomainN(name, NULL, target, res); 2784 if (ret > 0) 2785 return (ret); 2786 } 2787 2788 /* 2789 * if we got here, we didn't satisfy the search. 2790 * if we did an initial full query, return that query's h_errno 2791 * (note that we wouldn't be here if that query had succeeded). 2792 * else if we ever got a nodata, send that back as the reason. 2793 * else send back meaningless h_errno, that being the one from 2794 * the last DNSRCH we did. 2795 */ 2796 giveup: 2797 if (saved_herrno != -1) 2798 RES_SET_H_ERRNO(res, saved_herrno); 2799 else if (got_nodata) 2800 RES_SET_H_ERRNO(res, NO_DATA); 2801 else if (got_servfail) 2802 RES_SET_H_ERRNO(res, TRY_AGAIN); 2803 return (-1); 2804 } 2805 2806 /* 2807 * Perform a call on res_query on the concatenation of name and domain, 2808 * removing a trailing dot from name if domain is NULL. 2809 */ 2810 static int 2811 res_querydomainN(const char *name, const char *domain, 2812 struct res_target *target, res_state res) 2813 { 2814 char nbuf[MAXDNAME]; 2815 const char *longname = nbuf; 2816 size_t n, d; 2817 2818 #ifdef DEBUG 2819 if (res->options & RES_DEBUG) 2820 printf(";; res_querydomain(%s, %s)\n", 2821 name, domain?domain:"<Nil>"); 2822 #endif 2823 if (domain == NULL) { 2824 /* 2825 * Check for trailing '.'; 2826 * copy without '.' if present. 2827 */ 2828 n = strlen(name); 2829 if (n >= MAXDNAME) { 2830 RES_SET_H_ERRNO(res, NO_RECOVERY); 2831 return (-1); 2832 } 2833 if (n > 0 && name[--n] == '.') { 2834 strncpy(nbuf, name, n); 2835 nbuf[n] = '\0'; 2836 } else 2837 longname = name; 2838 } else { 2839 n = strlen(name); 2840 d = strlen(domain); 2841 if (n + d + 1 >= MAXDNAME) { 2842 RES_SET_H_ERRNO(res, NO_RECOVERY); 2843 return (-1); 2844 } 2845 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2846 } 2847 return (res_queryN(longname, target, res)); 2848 } 2849