1 /* $NetBSD: gethnamaddr.c,v 1.68 2006/01/24 17:29:33 christos Exp $ */ 2 3 /* 4 * ++Copyright++ 1985, 1988, 1993 5 * - 6 * Copyright (c) 1985, 1988, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * - 33 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 34 * 35 * Permission to use, copy, modify, and distribute this software for any 36 * purpose with or without fee is hereby granted, provided that the above 37 * copyright notice and this permission notice appear in all copies, and that 38 * the name of Digital Equipment Corporation not be used in advertising or 39 * publicity pertaining to distribution of the document or software without 40 * specific, written prior permission. 41 * 42 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 43 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 44 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 45 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 46 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 47 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 48 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 49 * SOFTWARE. 50 * - 51 * --Copyright-- 52 */ 53 54 #include <sys/cdefs.h> 55 #if defined(LIBC_SCCS) && !defined(lint) 56 #if 0 57 static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93"; 58 static char rcsid[] = "Id: gethnamaddr.c,v 8.21 1997/06/01 20:34:37 vixie Exp "; 59 #else 60 __RCSID("$NetBSD: gethnamaddr.c,v 1.68 2006/01/24 17:29:33 christos Exp $"); 61 #endif 62 #endif /* LIBC_SCCS and not lint */ 63 64 #if defined(_LIBC) 65 #include "namespace.h" 66 #endif 67 #include <sys/param.h> 68 #include <sys/socket.h> 69 #include <netinet/in.h> 70 #include <arpa/inet.h> 71 #include <arpa/nameser.h> 72 73 #include <assert.h> 74 #include <ctype.h> 75 #include <errno.h> 76 #include <netdb.h> 77 #include <resolv.h> 78 #include <stdarg.h> 79 #include <stdio.h> 80 #include <syslog.h> 81 82 #ifndef LOG_AUTH 83 # define LOG_AUTH 0 84 #endif 85 86 #define MULTI_PTRS_ARE_ALIASES 1 /* XXX - experimental */ 87 88 #include <nsswitch.h> 89 #include <stdlib.h> 90 #include <string.h> 91 92 #ifdef YP 93 #include <rpc/rpc.h> 94 #include <rpcsvc/yp_prot.h> 95 #include <rpcsvc/ypclnt.h> 96 #endif 97 98 #if defined(_LIBC) && defined(__weak_alias) 99 __weak_alias(gethostbyaddr,_gethostbyaddr) 100 __weak_alias(gethostbyname,_gethostbyname) 101 __weak_alias(gethostent,_gethostent) 102 #endif 103 104 #define MAXALIASES 35 105 #define MAXADDRS 35 106 107 static const char AskedForGot[] = 108 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 109 110 static char *h_addr_ptrs[MAXADDRS + 1]; 111 112 #ifdef YP 113 static char *__ypdomain; 114 #endif 115 116 static struct hostent host; 117 static char *host_aliases[MAXALIASES]; 118 static char hostbuf[8*1024]; 119 static u_int32_t host_addr[16 / sizeof(u_int32_t)]; /* IPv4 or IPv6 */ 120 static FILE *hostf = NULL; 121 static int stayopen = 0; 122 123 #define MAXPACKET (64*1024) 124 125 typedef union { 126 HEADER hdr; 127 u_char buf[MAXPACKET]; 128 } querybuf; 129 130 typedef union { 131 int32_t al; 132 char ac; 133 } align; 134 135 #ifdef DEBUG 136 static void dprintf(const char *, res_state, ...) 137 __attribute__((__format__(__printf__, 1, 3))); 138 #endif 139 static struct hostent *getanswer(const querybuf *, int, const char *, int, 140 res_state); 141 static void map_v4v6_address(const char *, char *); 142 static void map_v4v6_hostent(struct hostent *, char **, char *); 143 static void addrsort(char **, int, res_state); 144 145 void _sethtent(int); 146 void _endhtent(void); 147 struct hostent *_gethtent(void); 148 void ht_sethostent(int); 149 void ht_endhostent(void); 150 struct hostent *ht_gethostbyname(char *); 151 struct hostent *ht_gethostbyaddr(const char *, int, int); 152 void dns_service(void); 153 #undef dn_skipname 154 int dn_skipname(const u_char *, const u_char *); 155 int _gethtbyaddr(void *, void *, va_list); 156 int _gethtbyname(void *, void *, va_list); 157 struct hostent *_gethtbyname2(const char *, int); 158 int _dns_gethtbyaddr(void *, void *, va_list); 159 int _dns_gethtbyname(void *, void *, va_list); 160 #ifdef YP 161 struct hostent *_yphostent(char *, int); 162 int _yp_gethtbyaddr(void *, void *, va_list); 163 int _yp_gethtbyname(void *, void *, va_list); 164 #endif 165 166 static struct hostent *gethostbyname_internal(const char *, int, res_state); 167 168 static const ns_src default_dns_files[] = { 169 { NSSRC_FILES, NS_SUCCESS }, 170 { NSSRC_DNS, NS_SUCCESS }, 171 { 0 } 172 }; 173 174 175 #ifdef DEBUG 176 static void 177 dprintf(const char *msg, res_state res, ...) 178 { 179 _DIAGASSERT(msg != NULL); 180 181 if (res->options & RES_DEBUG) { 182 int save = errno; 183 va_list ap; 184 185 va_start (ap, res); 186 vprintf(msg, ap); 187 va_end (ap); 188 189 errno = save; 190 } 191 } 192 #else 193 # define dprintf(msg, res, num) /*nada*/ 194 #endif 195 196 #define BOUNDED_INCR(x) \ 197 do { \ 198 cp += (x); \ 199 if (cp > eom) { \ 200 h_errno = NO_RECOVERY; \ 201 return NULL; \ 202 } \ 203 } while (/*CONSTCOND*/0) 204 205 #define BOUNDS_CHECK(ptr, count) \ 206 do { \ 207 if ((ptr) + (count) > eom) { \ 208 h_errno = NO_RECOVERY; \ 209 return NULL; \ 210 } \ 211 } while (/*CONSTCOND*/0) 212 213 static struct hostent * 214 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 215 res_state res) 216 { 217 const HEADER *hp; 218 const u_char *cp; 219 int n; 220 const u_char *eom, *erdata; 221 char *bp, **ap, **hap, *ep; 222 int type, class, ancount, qdcount; 223 int haveanswer, had_error; 224 int toobig = 0; 225 char tbuf[MAXDNAME]; 226 const char *tname; 227 int (*name_ok)(const char *); 228 229 _DIAGASSERT(answer != NULL); 230 _DIAGASSERT(qname != NULL); 231 232 tname = qname; 233 host.h_name = NULL; 234 eom = answer->buf + anslen; 235 switch (qtype) { 236 case T_A: 237 case T_AAAA: 238 name_ok = res_hnok; 239 break; 240 case T_PTR: 241 name_ok = res_dnok; 242 break; 243 default: 244 return NULL; /* XXX should be abort(); */ 245 } 246 /* 247 * find first satisfactory answer 248 */ 249 hp = &answer->hdr; 250 ancount = ntohs(hp->ancount); 251 qdcount = ntohs(hp->qdcount); 252 bp = hostbuf; 253 ep = hostbuf + sizeof hostbuf; 254 cp = answer->buf; 255 BOUNDED_INCR(HFIXEDSZ); 256 if (qdcount != 1) { 257 h_errno = NO_RECOVERY; 258 return NULL; 259 } 260 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 261 if ((n < 0) || !(*name_ok)(bp)) { 262 h_errno = NO_RECOVERY; 263 return NULL; 264 } 265 BOUNDED_INCR(n + QFIXEDSZ); 266 if (qtype == T_A || qtype == T_AAAA) { 267 /* res_send() has already verified that the query name is the 268 * same as the one we sent; this just gets the expanded name 269 * (i.e., with the succeeding search-domain tacked on). 270 */ 271 n = strlen(bp) + 1; /* for the \0 */ 272 if (n >= MAXHOSTNAMELEN) { 273 h_errno = NO_RECOVERY; 274 return NULL; 275 } 276 host.h_name = bp; 277 bp += n; 278 /* The qname can be abbreviated, but h_name is now absolute. */ 279 qname = host.h_name; 280 } 281 ap = host_aliases; 282 *ap = NULL; 283 host.h_aliases = host_aliases; 284 hap = h_addr_ptrs; 285 *hap = NULL; 286 host.h_addr_list = h_addr_ptrs; 287 haveanswer = 0; 288 had_error = 0; 289 while (ancount-- > 0 && cp < eom && !had_error) { 290 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 291 if ((n < 0) || !(*name_ok)(bp)) { 292 had_error++; 293 continue; 294 } 295 cp += n; /* name */ 296 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 297 type = _getshort(cp); 298 cp += INT16SZ; /* type */ 299 class = _getshort(cp); 300 cp += INT16SZ + INT32SZ; /* class, TTL */ 301 n = _getshort(cp); 302 cp += INT16SZ; /* len */ 303 BOUNDS_CHECK(cp, n); 304 erdata = cp + n; 305 if (class != C_IN) { 306 /* XXX - debug? syslog? */ 307 cp += n; 308 continue; /* XXX - had_error++ ? */ 309 } 310 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 311 if (ap >= &host_aliases[MAXALIASES-1]) 312 continue; 313 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 314 if ((n < 0) || !(*name_ok)(tbuf)) { 315 had_error++; 316 continue; 317 } 318 cp += n; 319 if (cp != erdata) { 320 h_errno = NO_RECOVERY; 321 return NULL; 322 } 323 /* Store alias. */ 324 *ap++ = bp; 325 n = strlen(bp) + 1; /* for the \0 */ 326 if (n >= MAXHOSTNAMELEN) { 327 had_error++; 328 continue; 329 } 330 bp += n; 331 /* Get canonical name. */ 332 n = strlen(tbuf) + 1; /* for the \0 */ 333 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 334 had_error++; 335 continue; 336 } 337 strlcpy(bp, tbuf, (size_t)(ep - bp)); 338 host.h_name = bp; 339 bp += n; 340 continue; 341 } 342 if (qtype == T_PTR && type == T_CNAME) { 343 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 344 if (n < 0 || !res_dnok(tbuf)) { 345 had_error++; 346 continue; 347 } 348 cp += n; 349 if (cp != erdata) { 350 h_errno = NO_RECOVERY; 351 return NULL; 352 } 353 /* Get canonical name. */ 354 n = strlen(tbuf) + 1; /* for the \0 */ 355 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 356 had_error++; 357 continue; 358 } 359 strlcpy(bp, tbuf, (size_t)(ep - bp)); 360 tname = bp; 361 bp += n; 362 continue; 363 } 364 if (type != qtype) { 365 if (type != T_KEY && type != T_SIG) 366 syslog(LOG_NOTICE|LOG_AUTH, 367 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 368 qname, p_class(C_IN), p_type(qtype), 369 p_type(type)); 370 cp += n; 371 continue; /* XXX - had_error++ ? */ 372 } 373 switch (type) { 374 case T_PTR: 375 if (strcasecmp(tname, bp) != 0) { 376 syslog(LOG_NOTICE|LOG_AUTH, 377 AskedForGot, qname, bp); 378 cp += n; 379 continue; /* XXX - had_error++ ? */ 380 } 381 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 382 if ((n < 0) || !res_hnok(bp)) { 383 had_error++; 384 break; 385 } 386 #if MULTI_PTRS_ARE_ALIASES 387 cp += n; 388 if (cp != erdata) { 389 h_errno = NO_RECOVERY; 390 return NULL; 391 } 392 if (!haveanswer) 393 host.h_name = bp; 394 else if (ap < &host_aliases[MAXALIASES-1]) 395 *ap++ = bp; 396 else 397 n = -1; 398 if (n != -1) { 399 n = strlen(bp) + 1; /* for the \0 */ 400 if (n >= MAXHOSTNAMELEN) { 401 had_error++; 402 break; 403 } 404 bp += n; 405 } 406 break; 407 #else 408 host.h_name = bp; 409 if (res->options & RES_USE_INET6) { 410 n = strlen(bp) + 1; /* for the \0 */ 411 if (n >= MAXHOSTNAMELEN) { 412 had_error++; 413 break; 414 } 415 bp += n; 416 map_v4v6_hostent(&host, &bp, ep); 417 } 418 h_errno = NETDB_SUCCESS; 419 return &host; 420 #endif 421 case T_A: 422 case T_AAAA: 423 if (strcasecmp(host.h_name, bp) != 0) { 424 syslog(LOG_NOTICE|LOG_AUTH, 425 AskedForGot, host.h_name, bp); 426 cp += n; 427 continue; /* XXX - had_error++ ? */ 428 } 429 if (n != host.h_length) { 430 cp += n; 431 continue; 432 } 433 if (type == T_AAAA) { 434 struct in6_addr in6; 435 memcpy(&in6, cp, IN6ADDRSZ); 436 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 437 cp += n; 438 continue; 439 } 440 } 441 if (!haveanswer) { 442 int nn; 443 444 host.h_name = bp; 445 nn = strlen(bp) + 1; /* for the \0 */ 446 bp += nn; 447 } 448 449 bp += sizeof(align) - 450 (size_t)((u_long)bp % sizeof(align)); 451 452 if (bp + n >= &hostbuf[sizeof hostbuf]) { 453 dprintf("size (%d) too big\n", res, n); 454 had_error++; 455 continue; 456 } 457 if (hap >= &h_addr_ptrs[MAXADDRS-1]) { 458 if (!toobig++) 459 dprintf("Too many addresses (%d)\n", 460 res, MAXADDRS); 461 cp += n; 462 continue; 463 } 464 (void)memcpy(*hap++ = bp, cp, (size_t)n); 465 bp += n; 466 cp += n; 467 if (cp != erdata) { 468 h_errno = NO_RECOVERY; 469 return NULL; 470 } 471 break; 472 default: 473 abort(); 474 } 475 if (!had_error) 476 haveanswer++; 477 } 478 if (haveanswer) { 479 *ap = NULL; 480 *hap = NULL; 481 /* 482 * Note: we sort even if host can take only one address 483 * in its return structures - should give it the "best" 484 * address in that case, not some random one 485 */ 486 if (res->nsort && haveanswer > 1 && qtype == T_A) 487 addrsort(h_addr_ptrs, haveanswer, res); 488 if (!host.h_name) { 489 n = strlen(qname) + 1; /* for the \0 */ 490 if (n > ep - bp || n >= MAXHOSTNAMELEN) 491 goto no_recovery; 492 strlcpy(bp, qname, (size_t)(ep - bp)); 493 host.h_name = bp; 494 bp += n; 495 } 496 if (res->options & RES_USE_INET6) 497 map_v4v6_hostent(&host, &bp, ep); 498 h_errno = NETDB_SUCCESS; 499 return &host; 500 } 501 no_recovery: 502 h_errno = NO_RECOVERY; 503 return NULL; 504 } 505 506 struct hostent * 507 gethostbyname(const char *name) 508 { 509 struct hostent *hp; 510 res_state res = __res_get_state(); 511 512 if (res == NULL) 513 return NULL; 514 515 _DIAGASSERT(name != NULL); 516 517 if (res->options & RES_USE_INET6) { 518 hp = gethostbyname_internal(name, AF_INET6, res); 519 if (hp) { 520 __res_put_state(res); 521 return hp; 522 } 523 } 524 hp = gethostbyname_internal(name, AF_INET, res); 525 __res_put_state(res); 526 return hp; 527 } 528 529 struct hostent * 530 gethostbyname2(const char *name, int af) 531 { 532 struct hostent *hp; 533 res_state res = __res_get_state(); 534 535 if (res == NULL) 536 return NULL; 537 hp = gethostbyname_internal(name, af, res); 538 __res_put_state(res); 539 return hp; 540 } 541 542 static struct hostent * 543 gethostbyname_internal(const char *name, int af, res_state res) 544 { 545 const char *cp; 546 char *bp, *ep; 547 int size; 548 struct hostent *hp; 549 static const ns_dtab dtab[] = { 550 NS_FILES_CB(_gethtbyname, NULL) 551 { NSSRC_DNS, _dns_gethtbyname, NULL }, /* force -DHESIOD */ 552 NS_NIS_CB(_yp_gethtbyname, NULL) 553 { 0 } 554 }; 555 556 _DIAGASSERT(name != NULL); 557 558 switch (af) { 559 case AF_INET: 560 size = INADDRSZ; 561 break; 562 case AF_INET6: 563 size = IN6ADDRSZ; 564 break; 565 default: 566 h_errno = NETDB_INTERNAL; 567 errno = EAFNOSUPPORT; 568 return NULL; 569 } 570 571 host.h_addrtype = af; 572 host.h_length = size; 573 574 /* 575 * if there aren't any dots, it could be a user-level alias. 576 * this is also done in res_nquery() since we are not the only 577 * function that looks up host names. 578 */ 579 if (!strchr(name, '.') && (cp = __hostalias(name))) 580 name = cp; 581 582 /* 583 * disallow names consisting only of digits/dots, unless 584 * they end in a dot. 585 */ 586 if (isdigit((u_char) name[0])) 587 for (cp = name;; ++cp) { 588 if (!*cp) { 589 if (*--cp == '.') 590 break; 591 /* 592 * All-numeric, no dot at the end. 593 * Fake up a hostent as if we'd actually 594 * done a lookup. 595 */ 596 if (inet_pton(af, name, 597 (char *)(void *)host_addr) <= 0) { 598 h_errno = HOST_NOT_FOUND; 599 return NULL; 600 } 601 strncpy(hostbuf, name, MAXDNAME); 602 hostbuf[MAXDNAME] = '\0'; 603 bp = hostbuf + MAXDNAME; 604 ep = hostbuf + sizeof hostbuf; 605 host.h_name = hostbuf; 606 host.h_aliases = host_aliases; 607 host_aliases[0] = NULL; 608 h_addr_ptrs[0] = (char *)(void *)host_addr; 609 h_addr_ptrs[1] = NULL; 610 host.h_addr_list = h_addr_ptrs; 611 if (res->options & RES_USE_INET6) 612 map_v4v6_hostent(&host, &bp, ep); 613 h_errno = NETDB_SUCCESS; 614 return &host; 615 } 616 if (!isdigit((u_char) *cp) && *cp != '.') 617 break; 618 } 619 if ((isxdigit((u_char) name[0]) && strchr(name, ':') != NULL) || 620 name[0] == ':') 621 for (cp = name;; ++cp) { 622 if (!*cp) { 623 if (*--cp == '.') 624 break; 625 /* 626 * All-IPv6-legal, no dot at the end. 627 * Fake up a hostent as if we'd actually 628 * done a lookup. 629 */ 630 if (inet_pton(af, name, 631 (char *)(void *)host_addr) <= 0) { 632 h_errno = HOST_NOT_FOUND; 633 return NULL; 634 } 635 strncpy(hostbuf, name, MAXDNAME); 636 hostbuf[MAXDNAME] = '\0'; 637 bp = hostbuf + MAXDNAME; 638 ep = hostbuf + sizeof hostbuf; 639 host.h_name = hostbuf; 640 host.h_aliases = host_aliases; 641 host_aliases[0] = NULL; 642 h_addr_ptrs[0] = (char *)(void *)host_addr; 643 h_addr_ptrs[1] = NULL; 644 host.h_addr_list = h_addr_ptrs; 645 h_errno = NETDB_SUCCESS; 646 return &host; 647 } 648 if (!isxdigit((u_char) *cp) && *cp != ':' && *cp != '.') 649 break; 650 } 651 652 hp = NULL; 653 h_errno = NETDB_INTERNAL; 654 if (nsdispatch(&hp, dtab, NSDB_HOSTS, "gethostbyname", 655 default_dns_files, name, strlen(name), af) != NS_SUCCESS) 656 return NULL; 657 h_errno = NETDB_SUCCESS; 658 return hp; 659 } 660 661 struct hostent * 662 gethostbyaddr(const char *addr, /* XXX should have been def'd as u_char! */ 663 socklen_t len, int af) 664 { 665 const u_char *uaddr = (const u_char *)addr; 666 socklen_t size; 667 struct hostent *hp; 668 static const ns_dtab dtab[] = { 669 NS_FILES_CB(_gethtbyaddr, NULL) 670 { NSSRC_DNS, _dns_gethtbyaddr, NULL }, /* force -DHESIOD */ 671 NS_NIS_CB(_yp_gethtbyaddr, NULL) 672 { 0 } 673 }; 674 675 _DIAGASSERT(addr != NULL); 676 677 if (af == AF_INET6 && len == IN6ADDRSZ && 678 (IN6_IS_ADDR_LINKLOCAL((const struct in6_addr *)(const void *)uaddr) || 679 IN6_IS_ADDR_SITELOCAL((const struct in6_addr *)(const void *)uaddr))) { 680 h_errno = HOST_NOT_FOUND; 681 return NULL; 682 } 683 if (af == AF_INET6 && len == IN6ADDRSZ && 684 (IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)(const void *)uaddr) || 685 IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)(const void *)uaddr))) { 686 /* Unmap. */ 687 addr += IN6ADDRSZ - INADDRSZ; 688 uaddr += IN6ADDRSZ - INADDRSZ; 689 af = AF_INET; 690 len = INADDRSZ; 691 } 692 switch (af) { 693 case AF_INET: 694 size = INADDRSZ; 695 break; 696 case AF_INET6: 697 size = IN6ADDRSZ; 698 break; 699 default: 700 errno = EAFNOSUPPORT; 701 h_errno = NETDB_INTERNAL; 702 return NULL; 703 } 704 if (size != len) { 705 errno = EINVAL; 706 h_errno = NETDB_INTERNAL; 707 return NULL; 708 } 709 hp = NULL; 710 h_errno = NETDB_INTERNAL; 711 if (nsdispatch(&hp, dtab, NSDB_HOSTS, "gethostbyaddr", 712 default_dns_files, uaddr, len, af) != NS_SUCCESS) 713 return NULL; 714 h_errno = NETDB_SUCCESS; 715 return hp; 716 } 717 718 void 719 _sethtent(int f) 720 { 721 if (!hostf) 722 hostf = fopen(_PATH_HOSTS, "r" ); 723 else 724 rewind(hostf); 725 stayopen = f; 726 } 727 728 void 729 _endhtent(void) 730 { 731 if (hostf && !stayopen) { 732 (void) fclose(hostf); 733 hostf = NULL; 734 } 735 } 736 737 struct hostent * 738 _gethtent(void) 739 { 740 char *p; 741 char *cp, **q; 742 int af, len; 743 744 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) { 745 h_errno = NETDB_INTERNAL; 746 return NULL; 747 } 748 again: 749 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) { 750 h_errno = HOST_NOT_FOUND; 751 return NULL; 752 } 753 if (*p == '#') 754 goto again; 755 if (!(cp = strpbrk(p, "#\n"))) 756 goto again; 757 *cp = '\0'; 758 if (!(cp = strpbrk(p, " \t"))) 759 goto again; 760 *cp++ = '\0'; 761 if (inet_pton(AF_INET6, p, (char *)(void *)host_addr) > 0) { 762 af = AF_INET6; 763 len = IN6ADDRSZ; 764 } else if (inet_pton(AF_INET, p, (char *)(void *)host_addr) > 0) { 765 res_state res = __res_get_state(); 766 if (res == NULL) 767 return NULL; 768 if (res->options & RES_USE_INET6) { 769 map_v4v6_address((char *)(void *)host_addr, 770 (char *)(void *)host_addr); 771 af = AF_INET6; 772 len = IN6ADDRSZ; 773 } else { 774 af = AF_INET; 775 len = INADDRSZ; 776 } 777 __res_put_state(res); 778 } else { 779 goto again; 780 } 781 /* if this is not something we're looking for, skip it. */ 782 if (host.h_addrtype != 0 && host.h_addrtype != af) 783 goto again; 784 if (host.h_length != 0 && host.h_length != len) 785 goto again; 786 h_addr_ptrs[0] = (char *)(void *)host_addr; 787 h_addr_ptrs[1] = NULL; 788 host.h_addr_list = h_addr_ptrs; 789 host.h_length = len; 790 host.h_addrtype = af; 791 while (*cp == ' ' || *cp == '\t') 792 cp++; 793 host.h_name = cp; 794 q = host.h_aliases = host_aliases; 795 if ((cp = strpbrk(cp, " \t")) != NULL) 796 *cp++ = '\0'; 797 while (cp && *cp) { 798 if (*cp == ' ' || *cp == '\t') { 799 cp++; 800 continue; 801 } 802 if (q < &host_aliases[MAXALIASES - 1]) 803 *q++ = cp; 804 if ((cp = strpbrk(cp, " \t")) != NULL) 805 *cp++ = '\0'; 806 } 807 *q = NULL; 808 h_errno = NETDB_SUCCESS; 809 return &host; 810 } 811 812 /*ARGSUSED*/ 813 int 814 _gethtbyname(void *rv, void *cb_data, va_list ap) 815 { 816 struct hostent *hp; 817 const char *name; 818 int af; 819 820 _DIAGASSERT(rv != NULL); 821 822 name = va_arg(ap, char *); 823 /* NOSTRICT skip len */(void)va_arg(ap, int); 824 af = va_arg(ap, int); 825 826 hp = NULL; 827 #if 0 828 { 829 res_state res = __res_get_state(); 830 if (res == NULL) 831 return NS_NOTFOUND; 832 if (res->options & RES_USE_INET6) 833 hp = _gethtbyname2(name, AF_INET6); 834 if (hp==NULL) 835 hp = _gethtbyname2(name, AF_INET); 836 __res_put_state(res); 837 } 838 #else 839 hp = _gethtbyname2(name, af); 840 #endif 841 *((struct hostent **)rv) = hp; 842 if (hp == NULL) { 843 h_errno = HOST_NOT_FOUND; 844 return NS_NOTFOUND; 845 } 846 return NS_SUCCESS; 847 } 848 849 struct hostent * 850 _gethtbyname2(const char *name, int af) 851 { 852 struct hostent *p; 853 char *tmpbuf, *ptr, **cp; 854 int num; 855 size_t len; 856 857 _DIAGASSERT(name != NULL); 858 859 _sethtent(stayopen); 860 ptr = tmpbuf = NULL; 861 num = 0; 862 while ((p = _gethtent()) != NULL && num < MAXADDRS) { 863 if (p->h_addrtype != af) 864 continue; 865 if (strcasecmp(p->h_name, name) != 0) { 866 for (cp = p->h_aliases; *cp != NULL; cp++) 867 if (strcasecmp(*cp, name) == 0) 868 break; 869 if (*cp == NULL) continue; 870 } 871 872 if (num == 0) { 873 size_t bufsize; 874 char *src; 875 876 bufsize = strlen(p->h_name) + 2 + 877 MAXADDRS * p->h_length + 878 ALIGNBYTES; 879 for (cp = p->h_aliases; *cp != NULL; cp++) 880 bufsize += strlen(*cp) + 1; 881 882 if ((tmpbuf = malloc(bufsize)) == NULL) { 883 h_errno = NETDB_INTERNAL; 884 return NULL; 885 } 886 887 ptr = tmpbuf; 888 src = p->h_name; 889 while ((*ptr++ = *src++) != '\0'); 890 for (cp = p->h_aliases; *cp != NULL; cp++) { 891 src = *cp; 892 while ((*ptr++ = *src++) != '\0'); 893 } 894 *ptr++ = '\0'; 895 896 ptr = (char *)(void *)ALIGN(ptr); 897 } 898 899 (void)memcpy(ptr, p->h_addr_list[0], (size_t)p->h_length); 900 ptr += p->h_length; 901 num++; 902 } 903 _endhtent(); 904 if (num == 0) return NULL; 905 906 len = ptr - tmpbuf; 907 if (len > (sizeof(hostbuf) - ALIGNBYTES)) { 908 free(tmpbuf); 909 errno = ENOSPC; 910 h_errno = NETDB_INTERNAL; 911 return NULL; 912 } 913 ptr = memcpy((void *)ALIGN(hostbuf), tmpbuf, len); 914 free(tmpbuf); 915 916 host.h_name = ptr; 917 while (*ptr++); 918 919 cp = host_aliases; 920 while (*ptr) { 921 *cp++ = ptr; 922 while (*ptr++); 923 } 924 ptr++; 925 *cp = NULL; 926 927 ptr = (char *)(void *)ALIGN(ptr); 928 cp = h_addr_ptrs; 929 while (num--) { 930 *cp++ = ptr; 931 ptr += host.h_length; 932 } 933 *cp = NULL; 934 935 return &host; 936 } 937 938 /*ARGSUSED*/ 939 int 940 _gethtbyaddr(void *rv, void *cb_data, va_list ap) 941 { 942 struct hostent *p; 943 const unsigned char *addr; 944 int len, af; 945 946 _DIAGASSERT(rv != NULL); 947 948 addr = va_arg(ap, unsigned char *); 949 len = va_arg(ap, int); 950 af = va_arg(ap, int); 951 952 host.h_length = len; 953 host.h_addrtype = af; 954 955 _sethtent(stayopen); 956 while ((p = _gethtent()) != NULL) 957 if (p->h_addrtype == af && !memcmp(p->h_addr, addr, 958 (size_t)len)) 959 break; 960 _endhtent(); 961 *((struct hostent **)rv) = p; 962 if (p==NULL) { 963 h_errno = HOST_NOT_FOUND; 964 return NS_NOTFOUND; 965 } 966 return NS_SUCCESS; 967 } 968 969 static void 970 map_v4v6_address(const char *src, char *dst) 971 { 972 u_char *p = (u_char *)dst; 973 char tmp[INADDRSZ]; 974 int i; 975 976 _DIAGASSERT(src != NULL); 977 _DIAGASSERT(dst != NULL); 978 979 /* Stash a temporary copy so our caller can update in place. */ 980 (void)memcpy(tmp, src, INADDRSZ); 981 /* Mark this ipv6 addr as a mapped ipv4. */ 982 for (i = 0; i < 10; i++) 983 *p++ = 0x00; 984 *p++ = 0xff; 985 *p++ = 0xff; 986 /* Retrieve the saved copy and we're done. */ 987 (void)memcpy((void *)p, tmp, INADDRSZ); 988 } 989 990 static void 991 map_v4v6_hostent(struct hostent *hp, char **bpp, char *ep) 992 { 993 char **ap; 994 995 _DIAGASSERT(hp != NULL); 996 _DIAGASSERT(bpp != NULL); 997 _DIAGASSERT(ep != NULL); 998 999 if (hp->h_addrtype != AF_INET || hp->h_length != INADDRSZ) 1000 return; 1001 hp->h_addrtype = AF_INET6; 1002 hp->h_length = IN6ADDRSZ; 1003 for (ap = hp->h_addr_list; *ap; ap++) { 1004 int i = sizeof(align) - (size_t)((u_long)*bpp % sizeof(align)); 1005 1006 if (ep - *bpp < (i + IN6ADDRSZ)) { 1007 /* Out of memory. Truncate address list here. XXX */ 1008 *ap = NULL; 1009 return; 1010 } 1011 *bpp += i; 1012 map_v4v6_address(*ap, *bpp); 1013 *ap = *bpp; 1014 *bpp += IN6ADDRSZ; 1015 } 1016 } 1017 1018 static void 1019 addrsort(char **ap, int num, res_state res) 1020 { 1021 int i, j; 1022 char **p; 1023 short aval[MAXADDRS]; 1024 int needsort = 0; 1025 1026 _DIAGASSERT(ap != NULL); 1027 1028 p = ap; 1029 for (i = 0; i < num; i++, p++) { 1030 for (j = 0 ; (unsigned)j < res->nsort; j++) 1031 if (res->sort_list[j].addr.s_addr == 1032 (((struct in_addr *)(void *)(*p))->s_addr & 1033 res->sort_list[j].mask)) 1034 break; 1035 aval[i] = j; 1036 if (needsort == 0 && i > 0 && j < aval[i-1]) 1037 needsort = i; 1038 } 1039 if (!needsort) 1040 return; 1041 1042 while (needsort < num) { 1043 for (j = needsort - 1; j >= 0; j--) { 1044 if (aval[j] > aval[j+1]) { 1045 char *hp; 1046 1047 i = aval[j]; 1048 aval[j] = aval[j+1]; 1049 aval[j+1] = i; 1050 1051 hp = ap[j]; 1052 ap[j] = ap[j+1]; 1053 ap[j+1] = hp; 1054 } else 1055 break; 1056 } 1057 needsort++; 1058 } 1059 } 1060 1061 struct hostent * 1062 gethostent(void) 1063 { 1064 host.h_addrtype = 0; 1065 host.h_length = 0; 1066 return _gethtent(); 1067 } 1068 1069 /*ARGSUSED*/ 1070 int 1071 _dns_gethtbyname(void *rv, void *cb_data, va_list ap) 1072 { 1073 querybuf *buf; 1074 int n, type; 1075 struct hostent *hp; 1076 const char *name; 1077 int af; 1078 res_state res; 1079 1080 _DIAGASSERT(rv != NULL); 1081 1082 name = va_arg(ap, char *); 1083 /* NOSTRICT skip len */(void)va_arg(ap, int); 1084 af = va_arg(ap, int); 1085 1086 switch (af) { 1087 case AF_INET: 1088 type = T_A; 1089 break; 1090 case AF_INET6: 1091 type = T_AAAA; 1092 break; 1093 default: 1094 return NS_UNAVAIL; 1095 } 1096 buf = malloc(sizeof(*buf)); 1097 if (buf == NULL) { 1098 h_errno = NETDB_INTERNAL; 1099 return NS_NOTFOUND; 1100 } 1101 res = __res_get_state(); 1102 if (res == NULL) 1103 return NS_NOTFOUND; 1104 n = res_nsearch(res, name, C_IN, type, buf->buf, sizeof(buf->buf)); 1105 if (n < 0) { 1106 free(buf); 1107 dprintf("res_nsearch failed (%d)\n", res, n); 1108 __res_put_state(res); 1109 return NS_NOTFOUND; 1110 } 1111 hp = getanswer(buf, n, name, type, res); 1112 free(buf); 1113 __res_put_state(res); 1114 if (hp == NULL) 1115 switch (h_errno) { 1116 case HOST_NOT_FOUND: 1117 return NS_NOTFOUND; 1118 case TRY_AGAIN: 1119 return NS_TRYAGAIN; 1120 default: 1121 return NS_UNAVAIL; 1122 } 1123 *((struct hostent **)rv) = hp; 1124 return NS_SUCCESS; 1125 } 1126 1127 /*ARGSUSED*/ 1128 int 1129 _dns_gethtbyaddr(void *rv, void *cb_data, va_list ap) 1130 { 1131 char qbuf[MAXDNAME + 1], *qp, *ep; 1132 int n; 1133 querybuf *buf; 1134 struct hostent *hp; 1135 const unsigned char *uaddr; 1136 int len, af, advance; 1137 res_state res; 1138 1139 _DIAGASSERT(rv != NULL); 1140 1141 uaddr = va_arg(ap, unsigned char *); 1142 len = va_arg(ap, int); 1143 af = va_arg(ap, int); 1144 1145 switch (af) { 1146 case AF_INET: 1147 (void)snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa", 1148 (uaddr[3] & 0xff), (uaddr[2] & 0xff), 1149 (uaddr[1] & 0xff), (uaddr[0] & 0xff)); 1150 break; 1151 1152 case AF_INET6: 1153 qp = qbuf; 1154 ep = qbuf + sizeof(qbuf) - 1; 1155 for (n = IN6ADDRSZ - 1; n >= 0; n--) { 1156 advance = snprintf(qp, (size_t)(ep - qp), "%x.%x.", 1157 uaddr[n] & 0xf, 1158 ((unsigned int)uaddr[n] >> 4) & 0xf); 1159 if (advance > 0 && qp + advance < ep) 1160 qp += advance; 1161 else { 1162 h_errno = NETDB_INTERNAL; 1163 return NS_NOTFOUND; 1164 } 1165 } 1166 if (strlcat(qbuf, "ip6.arpa", sizeof(qbuf)) >= sizeof(qbuf)) { 1167 h_errno = NETDB_INTERNAL; 1168 return NS_NOTFOUND; 1169 } 1170 break; 1171 default: 1172 abort(); 1173 } 1174 1175 buf = malloc(sizeof(*buf)); 1176 if (buf == NULL) { 1177 h_errno = NETDB_INTERNAL; 1178 return NS_NOTFOUND; 1179 } 1180 res = __res_get_state(); 1181 if (res == NULL) 1182 return NS_NOTFOUND; 1183 n = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf)); 1184 if (n < 0) { 1185 free(buf); 1186 dprintf("res_nquery failed (%d)\n", res, n); 1187 __res_put_state(res); 1188 return NS_NOTFOUND; 1189 } 1190 hp = getanswer(buf, n, qbuf, T_PTR, res); 1191 free(buf); 1192 if (hp == NULL) { 1193 __res_put_state(res); 1194 switch (h_errno) { 1195 case HOST_NOT_FOUND: 1196 return NS_NOTFOUND; 1197 case TRY_AGAIN: 1198 return NS_TRYAGAIN; 1199 default: 1200 return NS_UNAVAIL; 1201 } 1202 } 1203 hp->h_addrtype = af; 1204 hp->h_length = len; 1205 (void)memcpy(host_addr, uaddr, (size_t)len); 1206 h_addr_ptrs[0] = (char *)(void *)host_addr; 1207 h_addr_ptrs[1] = NULL; 1208 if (af == AF_INET && (res->options & RES_USE_INET6)) { 1209 map_v4v6_address((char *)(void *)host_addr, 1210 (char *)(void *)host_addr); 1211 hp->h_addrtype = AF_INET6; 1212 hp->h_length = IN6ADDRSZ; 1213 } 1214 1215 __res_put_state(res); 1216 *((struct hostent **)rv) = hp; 1217 h_errno = NETDB_SUCCESS; 1218 return NS_SUCCESS; 1219 } 1220 1221 #ifdef YP 1222 /*ARGSUSED*/ 1223 struct hostent * 1224 _yphostent(char *line, int af) 1225 { 1226 static struct in_addr host_addrs[MAXADDRS]; 1227 static struct in6_addr host6_addrs[MAXADDRS]; 1228 char *p = line; 1229 char *cp, **q; 1230 char **hap; 1231 int addrok; 1232 int more; 1233 size_t naddrs; 1234 1235 _DIAGASSERT(line != NULL); 1236 1237 host.h_name = NULL; 1238 host.h_addr_list = h_addr_ptrs; 1239 host.h_addrtype = af; 1240 switch (af) { 1241 case AF_INET: 1242 host.h_length = INADDRSZ; 1243 break; 1244 case AF_INET6: 1245 host.h_length = IN6ADDRSZ; 1246 break; 1247 default: 1248 return NULL; 1249 } 1250 hap = h_addr_ptrs; 1251 q = host.h_aliases = host_aliases; 1252 naddrs = 0; 1253 1254 nextline: 1255 /* check for host_addrs overflow */ 1256 if (naddrs >= sizeof(host_addrs) / sizeof(host_addrs[0])) 1257 goto done; 1258 if (naddrs >= sizeof(host6_addrs) / sizeof(host6_addrs[0])) 1259 goto done; 1260 1261 more = 0; 1262 cp = strpbrk(p, " \t"); 1263 if (cp == NULL) 1264 goto done; 1265 *cp++ = '\0'; 1266 1267 /* p has should have an address */ 1268 addrok = 0; 1269 switch (af) { 1270 case AF_INET: 1271 addrok = inet_aton(p, &host_addrs[naddrs]); 1272 break; 1273 case AF_INET6: 1274 addrok = inet_pton(af, p, &host6_addrs[naddrs]); 1275 break; 1276 } 1277 if (addrok != 1) { 1278 /* skip to the next line */ 1279 while (cp && *cp) { 1280 if (*cp == '\n') { 1281 cp++; 1282 goto nextline; 1283 } 1284 cp++; 1285 } 1286 1287 goto done; 1288 } 1289 1290 switch (af) { 1291 case AF_INET: 1292 *hap++ = (char *)(void *)&host_addrs[naddrs++]; 1293 break; 1294 case AF_INET6: 1295 *hap++ = (char *)(void *)&host6_addrs[naddrs++]; 1296 break; 1297 } 1298 1299 while (*cp == ' ' || *cp == '\t') 1300 cp++; 1301 p = cp; 1302 cp = strpbrk(p, " \t\n"); 1303 if (cp != NULL) { 1304 if (*cp == '\n') 1305 more = 1; 1306 *cp++ = '\0'; 1307 } 1308 if (!host.h_name) 1309 host.h_name = p; 1310 else if (strcmp(host.h_name, p)==0) 1311 ; 1312 else if (q < &host_aliases[MAXALIASES - 1]) 1313 *q++ = p; 1314 p = cp; 1315 if (more) 1316 goto nextline; 1317 1318 while (cp && *cp) { 1319 if (*cp == ' ' || *cp == '\t') { 1320 cp++; 1321 continue; 1322 } 1323 if (*cp == '\n') { 1324 cp++; 1325 goto nextline; 1326 } 1327 if (q < &host_aliases[MAXALIASES - 1]) 1328 *q++ = cp; 1329 cp = strpbrk(cp, " \t"); 1330 if (cp != NULL) 1331 *cp++ = '\0'; 1332 } 1333 1334 done: 1335 if (host.h_name == NULL) 1336 return NULL; 1337 *q = NULL; 1338 *hap = NULL; 1339 return &host; 1340 } 1341 1342 /*ARGSUSED*/ 1343 int 1344 _yp_gethtbyaddr(void *rv, void *cb_data, va_list ap) 1345 { 1346 struct hostent *hp = NULL; 1347 static char *__ypcurrent; 1348 int __ypcurrentlen, r; 1349 char name[INET6_ADDRSTRLEN]; /* XXX enough? */ 1350 const unsigned char *uaddr; 1351 int af; 1352 const char *map; 1353 1354 _DIAGASSERT(rv != NULL); 1355 1356 uaddr = va_arg(ap, unsigned char *); 1357 /* NOSTRICT skip len */(void)va_arg(ap, int); 1358 af = va_arg(ap, int); 1359 1360 if (!__ypdomain) { 1361 if (_yp_check(&__ypdomain) == 0) 1362 return NS_UNAVAIL; 1363 } 1364 /* 1365 * XXX unfortunately, we cannot support IPv6 extended scoped address 1366 * notation here. gethostbyaddr() is not scope-aware. too bad. 1367 */ 1368 if (inet_ntop(af, uaddr, name, sizeof(name)) == NULL) 1369 return NS_UNAVAIL; 1370 if (__ypcurrent) 1371 free(__ypcurrent); 1372 __ypcurrent = NULL; 1373 switch (af) { 1374 case AF_INET: 1375 map = "hosts.byaddr"; 1376 break; 1377 default: 1378 map = "ipnodes.byaddr"; 1379 break; 1380 } 1381 r = yp_match(__ypdomain, map, name, 1382 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1383 if (r == 0) 1384 hp = _yphostent(__ypcurrent, af); 1385 if (hp == NULL) { 1386 h_errno = HOST_NOT_FOUND; 1387 return NS_NOTFOUND; 1388 } 1389 *((struct hostent **)rv) = hp; 1390 return NS_SUCCESS; 1391 } 1392 1393 /*ARGSUSED*/ 1394 int 1395 _yp_gethtbyname(void *rv, void *cb_data, va_list ap) 1396 { 1397 struct hostent *hp = NULL; 1398 static char *__ypcurrent; 1399 int __ypcurrentlen, r; 1400 const char *name; 1401 int af; 1402 const char *map; 1403 1404 _DIAGASSERT(rv != NULL); 1405 1406 name = va_arg(ap, char *); 1407 /* NOSTRICT skip len */(void)va_arg(ap, int); 1408 af = va_arg(ap, int); 1409 1410 if (!__ypdomain) { 1411 if (_yp_check(&__ypdomain) == 0) 1412 return NS_UNAVAIL; 1413 } 1414 if (__ypcurrent) 1415 free(__ypcurrent); 1416 __ypcurrent = NULL; 1417 switch (af) { 1418 case AF_INET: 1419 map = "hosts.byname"; 1420 break; 1421 default: 1422 map = "ipnodes.byname"; 1423 break; 1424 } 1425 r = yp_match(__ypdomain, map, name, 1426 (int)strlen(name), &__ypcurrent, &__ypcurrentlen); 1427 if (r == 0) 1428 hp = _yphostent(__ypcurrent, af); 1429 if (hp == NULL) { 1430 h_errno = HOST_NOT_FOUND; 1431 return NS_NOTFOUND; 1432 } 1433 *((struct hostent **)rv) = hp; 1434 return NS_SUCCESS; 1435 } 1436 #endif 1437