1 /* 2 * ++Copyright++ 1985, 1988, 1993 3 * - 4 * Copyright (c) 1985, 1988, 1993 5 * The Regents of the University of California. 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 University 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 REGENTS 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 REGENTS 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 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 32 * 33 * Permission to use, copy, modify, and distribute this software for any 34 * purpose with or without fee is hereby granted, provided that the above 35 * copyright notice and this permission notice appear in all copies, and that 36 * the name of Digital Equipment Corporation not be used in advertising or 37 * publicity pertaining to distribution of the document or software without 38 * specific, written prior permission. 39 * 40 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 41 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 42 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 43 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 44 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 45 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 46 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 47 * SOFTWARE. 48 * - 49 * --Copyright-- 50 * 51 * @(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93 52 * $From: Id: gethnamaddr.c,v 8.23 1998/04/07 04:59:46 vixie Exp $ 53 * $FreeBSD: src/lib/libc/net/gethostbydns.c,v 1.27.2.5 2002/11/02 18:54:57 ume Exp $ 54 * $DragonFly: src/lib/libc/net/gethostbydns.c,v 1.6 2005/11/13 02:04:47 swildner Exp $ 55 */ 56 57 #include <sys/types.h> 58 #include <sys/param.h> 59 #include <sys/socket.h> 60 #include <netinet/in.h> 61 #include <arpa/inet.h> 62 #include <arpa/nameser.h> 63 64 #include <stdio.h> 65 #include <stdlib.h> 66 #include <unistd.h> 67 #include <string.h> 68 #include <netdb.h> 69 #include <resolv.h> 70 #include <ctype.h> 71 #include <errno.h> 72 #include <syslog.h> 73 #include <stdarg.h> 74 #include <nsswitch.h> 75 76 #include "res_config.h" 77 78 #define SPRINTF(x) ((size_t)sprintf x) 79 80 #define MAXALIASES 35 81 #define MAXADDRS 35 82 83 static const char AskedForGot[] = 84 "gethostby*.gethostanswer: asked for \"%s\", got \"%s\""; 85 86 static char *h_addr_ptrs[MAXADDRS + 1]; 87 88 static struct hostent host; 89 static char *host_aliases[MAXALIASES]; 90 static char hostbuf[8*1024]; 91 static u_char host_addr[16]; /* IPv4 or IPv6 */ 92 93 #ifdef RESOLVSORT 94 static void addrsort (char **, int); 95 #endif 96 97 #define MAXPACKET (64*1024) 98 99 typedef union { 100 HEADER hdr; 101 u_char buf[MAXPACKET]; 102 } querybuf; 103 104 typedef union { 105 int32_t al; 106 char ac; 107 } align; 108 109 extern int h_errno; 110 int _dns_ttl_; 111 112 #ifdef DEBUG 113 static void 114 dprintf(char *msg, int num) 115 { 116 if (_res.options & RES_DEBUG) { 117 int save = errno; 118 119 printf(msg, num); 120 errno = save; 121 } 122 } 123 #else 124 # define dprintf(msg, num) /*nada*/ 125 #endif 126 127 #define BOUNDED_INCR(x) \ 128 do { \ 129 cp += x; \ 130 if (cp > eom) { \ 131 h_errno = NO_RECOVERY; \ 132 return (NULL); \ 133 } \ 134 } while (0) 135 136 #define BOUNDS_CHECK(ptr, count) \ 137 do { \ 138 if ((ptr) + (count) > eom) { \ 139 h_errno = NO_RECOVERY; \ 140 return (NULL); \ 141 } \ 142 } while (0) 143 144 static struct hostent * 145 gethostanswer(const querybuf *answer, int anslen, const char *qname, int qtype) 146 { 147 const HEADER *hp; 148 const u_char *cp; 149 int n; 150 const u_char *eom, *erdata; 151 char *bp, **ap, **hap; 152 int type, class, buflen, ancount, qdcount; 153 int haveanswer, had_error; 154 int toobig = 0; 155 char tbuf[MAXDNAME]; 156 const char *tname; 157 int (*name_ok) (const char *); 158 159 tname = qname; 160 host.h_name = NULL; 161 eom = answer->buf + anslen; 162 switch (qtype) { 163 case T_A: 164 case T_AAAA: 165 name_ok = res_hnok; 166 break; 167 case T_PTR: 168 name_ok = res_dnok; 169 break; 170 default: 171 h_errno = NO_RECOVERY; 172 return (NULL); /* XXX should be abort(); */ 173 } 174 /* 175 * find first satisfactory answer 176 */ 177 hp = &answer->hdr; 178 ancount = ntohs(hp->ancount); 179 qdcount = ntohs(hp->qdcount); 180 bp = hostbuf; 181 buflen = sizeof hostbuf; 182 cp = answer->buf; 183 BOUNDED_INCR(HFIXEDSZ); 184 if (qdcount != 1) { 185 h_errno = NO_RECOVERY; 186 return (NULL); 187 } 188 n = dn_expand(answer->buf, eom, cp, bp, buflen); 189 if ((n < 0) || !(*name_ok)(bp)) { 190 h_errno = NO_RECOVERY; 191 return (NULL); 192 } 193 BOUNDED_INCR(n + QFIXEDSZ); 194 if (qtype == T_A || qtype == T_AAAA) { 195 /* res_send() has already verified that the query name is the 196 * same as the one we sent; this just gets the expanded name 197 * (i.e., with the succeeding search-domain tacked on). 198 */ 199 n = strlen(bp) + 1; /* for the \0 */ 200 if (n >= MAXHOSTNAMELEN) { 201 h_errno = NO_RECOVERY; 202 return (NULL); 203 } 204 host.h_name = bp; 205 bp += n; 206 buflen -= n; 207 /* The qname can be abbreviated, but h_name is now absolute. */ 208 qname = host.h_name; 209 } 210 ap = host_aliases; 211 *ap = NULL; 212 host.h_aliases = host_aliases; 213 hap = h_addr_ptrs; 214 *hap = NULL; 215 host.h_addr_list = h_addr_ptrs; 216 haveanswer = 0; 217 had_error = 0; 218 _dns_ttl_ = -1; 219 while (ancount-- > 0 && cp < eom && !had_error) { 220 n = dn_expand(answer->buf, eom, cp, bp, buflen); 221 if ((n < 0) || !(*name_ok)(bp)) { 222 had_error++; 223 continue; 224 } 225 cp += n; /* name */ 226 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 227 type = _getshort(cp); 228 cp += INT16SZ; /* type */ 229 class = _getshort(cp); 230 cp += INT16SZ; /* class */ 231 if (qtype == T_A && type == T_A) 232 _dns_ttl_ = _getlong(cp); 233 cp += INT32SZ; /* TTL */ 234 n = _getshort(cp); 235 cp += INT16SZ; /* len */ 236 BOUNDS_CHECK(cp, n); 237 erdata = cp + n; 238 if (class != C_IN) { 239 /* XXX - debug? syslog? */ 240 cp += n; 241 continue; /* XXX - had_error++ ? */ 242 } 243 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 244 if (ap >= &host_aliases[MAXALIASES-1]) 245 continue; 246 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 247 if ((n < 0) || !(*name_ok)(tbuf)) { 248 had_error++; 249 continue; 250 } 251 cp += n; 252 if (cp != erdata) { 253 h_errno = NO_RECOVERY; 254 return (NULL); 255 } 256 /* Store alias. */ 257 *ap++ = bp; 258 n = strlen(bp) + 1; /* for the \0 */ 259 if (n >= MAXHOSTNAMELEN) { 260 had_error++; 261 continue; 262 } 263 bp += n; 264 buflen -= n; 265 /* Get canonical name. */ 266 n = strlen(tbuf) + 1; /* for the \0 */ 267 if (n > buflen || n >= MAXHOSTNAMELEN) { 268 had_error++; 269 continue; 270 } 271 strcpy(bp, tbuf); 272 host.h_name = bp; 273 bp += n; 274 buflen -= n; 275 continue; 276 } 277 if (qtype == T_PTR && type == T_CNAME) { 278 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 279 if (n < 0 || !res_dnok(tbuf)) { 280 had_error++; 281 continue; 282 } 283 cp += n; 284 if (cp != erdata) { 285 h_errno = NO_RECOVERY; 286 return (NULL); 287 } 288 /* Get canonical name. */ 289 n = strlen(tbuf) + 1; /* for the \0 */ 290 if (n > buflen || n >= MAXHOSTNAMELEN) { 291 had_error++; 292 continue; 293 } 294 strcpy(bp, tbuf); 295 tname = bp; 296 bp += n; 297 buflen -= n; 298 continue; 299 } 300 if (type != qtype) { 301 if (type != T_SIG) 302 syslog(LOG_NOTICE|LOG_AUTH, 303 "gethostby*.gethostanswer: asked for \"%s %s %s\", got type \"%s\"", 304 qname, p_class(C_IN), p_type(qtype), 305 p_type(type)); 306 cp += n; 307 continue; /* XXX - had_error++ ? */ 308 } 309 switch (type) { 310 case T_PTR: 311 if (strcasecmp(tname, bp) != 0) { 312 syslog(LOG_NOTICE|LOG_AUTH, 313 AskedForGot, qname, bp); 314 cp += n; 315 continue; /* XXX - had_error++ ? */ 316 } 317 n = dn_expand(answer->buf, eom, cp, bp, buflen); 318 if ((n < 0) || !res_hnok(bp)) { 319 had_error++; 320 break; 321 } 322 #if MULTI_PTRS_ARE_ALIASES 323 cp += n; 324 if (cp != erdata) { 325 h_errno = NO_RECOVERY; 326 return (NULL); 327 } 328 if (!haveanswer) 329 host.h_name = bp; 330 else if (ap < &host_aliases[MAXALIASES-1]) 331 *ap++ = bp; 332 else 333 n = -1; 334 if (n != -1) { 335 n = strlen(bp) + 1; /* for the \0 */ 336 if (n >= MAXHOSTNAMELEN) { 337 had_error++; 338 break; 339 } 340 bp += n; 341 buflen -= n; 342 } 343 break; 344 #else 345 host.h_name = bp; 346 if (_res.options & RES_USE_INET6) { 347 n = strlen(bp) + 1; /* for the \0 */ 348 if (n >= MAXHOSTNAMELEN) { 349 had_error++; 350 break; 351 } 352 bp += n; 353 buflen -= n; 354 _map_v4v6_hostent(&host, &bp, &buflen); 355 } 356 h_errno = NETDB_SUCCESS; 357 return (&host); 358 #endif 359 case T_A: 360 case T_AAAA: 361 if (strcasecmp(host.h_name, bp) != 0) { 362 syslog(LOG_NOTICE|LOG_AUTH, 363 AskedForGot, host.h_name, bp); 364 cp += n; 365 continue; /* XXX - had_error++ ? */ 366 } 367 if (n != host.h_length) { 368 cp += n; 369 continue; 370 } 371 if (!haveanswer) { 372 int nn; 373 374 host.h_name = bp; 375 nn = strlen(bp) + 1; /* for the \0 */ 376 bp += nn; 377 buflen -= nn; 378 } 379 380 buflen -= sizeof(align) - ((u_long)bp % sizeof(align)); 381 bp += sizeof(align) - ((u_long)bp % sizeof(align)); 382 383 if (bp + n >= &hostbuf[sizeof hostbuf]) { 384 dprintf("size (%d) too big\n", n); 385 had_error++; 386 continue; 387 } 388 if (hap >= &h_addr_ptrs[MAXADDRS-1]) { 389 if (!toobig++) 390 dprintf("Too many addresses (%d)\n", 391 MAXADDRS); 392 cp += n; 393 continue; 394 } 395 bcopy(cp, *hap++ = bp, n); 396 bp += n; 397 buflen -= n; 398 cp += n; 399 if (cp != erdata) { 400 h_errno = NO_RECOVERY; 401 return (NULL); 402 } 403 break; 404 default: 405 dprintf("Impossible condition (type=%d)\n", type); 406 h_errno = NO_RECOVERY; 407 return (NULL); 408 /* BIND has abort() here, too risky on bad data */ 409 } 410 if (!had_error) 411 haveanswer++; 412 } 413 if (haveanswer) { 414 *ap = NULL; 415 *hap = NULL; 416 # if defined(RESOLVSORT) 417 /* 418 * Note: we sort even if host can take only one address 419 * in its return structures - should give it the "best" 420 * address in that case, not some random one 421 */ 422 if (_res.nsort && haveanswer > 1 && qtype == T_A) 423 addrsort(h_addr_ptrs, haveanswer); 424 # endif /*RESOLVSORT*/ 425 if (!host.h_name) { 426 n = strlen(qname) + 1; /* for the \0 */ 427 if (n > buflen || n >= MAXHOSTNAMELEN) 428 goto no_recovery; 429 strcpy(bp, qname); 430 host.h_name = bp; 431 bp += n; 432 buflen -= n; 433 } 434 if (_res.options & RES_USE_INET6) 435 _map_v4v6_hostent(&host, &bp, &buflen); 436 h_errno = NETDB_SUCCESS; 437 return (&host); 438 } 439 no_recovery: 440 h_errno = NO_RECOVERY; 441 return (NULL); 442 } 443 444 struct hostent * 445 __dns_getanswer(const char *answer, int anslen, const char *qname, int qtype) 446 { 447 switch(qtype) { 448 case T_AAAA: 449 host.h_addrtype = AF_INET6; 450 host.h_length = IN6ADDRSZ; 451 break; 452 case T_A: 453 default: 454 host.h_addrtype = AF_INET; 455 host.h_length = INADDRSZ; 456 break; 457 } 458 459 return(gethostanswer((const querybuf *)answer, anslen, qname, qtype)); 460 } 461 462 int 463 _dns_gethostbyname(void *rval, void *cb_data, va_list ap) 464 { 465 querybuf *buf; 466 const char *cp, *name; 467 char *bp; 468 int af, n, size, type, len; 469 struct hostent *hp; 470 471 name = va_arg(ap, const char *); 472 af = va_arg(ap, int); 473 *(struct hostent **)rval = NULL; 474 475 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 476 h_errno = NETDB_INTERNAL; 477 return NS_UNAVAIL; 478 } 479 480 switch (af) { 481 case AF_INET: 482 size = INADDRSZ; 483 type = T_A; 484 break; 485 case AF_INET6: 486 size = IN6ADDRSZ; 487 type = T_AAAA; 488 break; 489 default: 490 h_errno = NETDB_INTERNAL; 491 errno = EAFNOSUPPORT; 492 return NS_UNAVAIL; 493 } 494 495 host.h_addrtype = af; 496 host.h_length = size; 497 498 /* 499 * if there aren't any dots, it could be a user-level alias. 500 * this is also done in res_query() since we are not the only 501 * function that looks up host names. 502 */ 503 if (!strchr(name, '.') && (cp = __hostalias(name))) 504 name = cp; 505 506 /* 507 * disallow names consisting only of digits/dots, unless 508 * they end in a dot. 509 */ 510 if (isdigit((unsigned char)name[0])) 511 for (cp = name;; ++cp) { 512 if (!*cp) { 513 if (*--cp == '.') 514 break; 515 /* 516 * All-numeric, no dot at the end. 517 * Fake up a hostent as if we'd actually 518 * done a lookup. 519 */ 520 if (inet_pton(af, name, host_addr) <= 0) { 521 h_errno = HOST_NOT_FOUND; 522 return NS_NOTFOUND; 523 } 524 strncpy(hostbuf, name, MAXDNAME); 525 hostbuf[MAXDNAME] = '\0'; 526 bp = hostbuf + MAXDNAME; 527 len = sizeof hostbuf - MAXDNAME; 528 host.h_name = hostbuf; 529 host.h_aliases = host_aliases; 530 host_aliases[0] = NULL; 531 h_addr_ptrs[0] = (char *)host_addr; 532 h_addr_ptrs[1] = NULL; 533 host.h_addr_list = h_addr_ptrs; 534 if (_res.options & RES_USE_INET6) 535 _map_v4v6_hostent(&host, &bp, &len); 536 h_errno = NETDB_SUCCESS; 537 *(struct hostent **)rval = &host; 538 return NS_SUCCESS; 539 } 540 if (!isdigit((unsigned char)*cp) && *cp != '.') 541 break; 542 } 543 if ((isxdigit((unsigned char)name[0]) && strchr(name, ':') != NULL) || 544 name[0] == ':') 545 for (cp = name;; ++cp) { 546 if (!*cp) { 547 if (*--cp == '.') 548 break; 549 /* 550 * All-IPv6-legal, no dot at the end. 551 * Fake up a hostent as if we'd actually 552 * done a lookup. 553 */ 554 if (inet_pton(af, name, host_addr) <= 0) { 555 h_errno = HOST_NOT_FOUND; 556 return NS_NOTFOUND; 557 } 558 strncpy(hostbuf, name, MAXDNAME); 559 hostbuf[MAXDNAME] = '\0'; 560 bp = hostbuf + MAXDNAME; 561 len = sizeof hostbuf - MAXDNAME; 562 host.h_name = hostbuf; 563 host.h_aliases = host_aliases; 564 host_aliases[0] = NULL; 565 h_addr_ptrs[0] = (char *)host_addr; 566 h_addr_ptrs[1] = NULL; 567 host.h_addr_list = h_addr_ptrs; 568 h_errno = NETDB_SUCCESS; 569 *(struct hostent **)rval = &host; 570 return NS_SUCCESS; 571 } 572 if (!isxdigit((unsigned char)*cp) && *cp != ':' && *cp != '.') 573 break; 574 } 575 576 if ((buf = malloc(sizeof(*buf))) == NULL) { 577 h_errno = NETDB_INTERNAL; 578 return (NULL); 579 } 580 n = res_search(name, C_IN, type, buf->buf, sizeof(buf->buf)); 581 if (n < 0) { 582 free(buf); 583 dprintf("res_search failed (%d)\n", n); 584 return (NULL); 585 } else if (n > sizeof(buf->buf)) { 586 free(buf); 587 dprintf("static buffer is too small (%d)\n", n); 588 return (NULL); 589 } 590 *(struct hostent **)rval = gethostanswer(buf, n, name, type); 591 free(buf); 592 return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND; 593 } 594 595 int 596 _dns_gethostbyaddr(void *rval, void *cb_data, va_list ap) 597 { 598 const char *addr; /* XXX should have been def'd as u_char! */ 599 int len, af; 600 601 const u_char *uaddr; 602 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff }; 603 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 }; 604 int n, size; 605 querybuf *buf; 606 struct hostent *hp; 607 char qbuf[MAXDNAME+1], *qp; 608 #ifdef SUNSECURITY 609 struct hostent *rhp; 610 char **haddr; 611 u_long old_options; 612 char hname2[MAXDNAME+1]; 613 #endif /*SUNSECURITY*/ 614 615 addr = va_arg(ap, const char *); 616 uaddr = (const u_char *)addr; 617 len = va_arg(ap, int); 618 af = va_arg(ap, int); 619 620 *(struct hostent **)rval = NULL; 621 622 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 623 h_errno = NETDB_INTERNAL; 624 return NS_UNAVAIL; 625 } 626 if (af == AF_INET6 && len == IN6ADDRSZ && 627 (!bcmp(uaddr, mapped, sizeof mapped) || 628 !bcmp(uaddr, tunnelled, sizeof tunnelled))) { 629 /* Unmap. */ 630 addr += sizeof mapped; 631 uaddr += sizeof mapped; 632 af = AF_INET; 633 len = INADDRSZ; 634 } 635 switch (af) { 636 case AF_INET: 637 size = INADDRSZ; 638 break; 639 case AF_INET6: 640 size = IN6ADDRSZ; 641 break; 642 default: 643 errno = EAFNOSUPPORT; 644 h_errno = NETDB_INTERNAL; 645 return NS_UNAVAIL; 646 } 647 if (size != len) { 648 errno = EINVAL; 649 h_errno = NETDB_INTERNAL; 650 return NS_UNAVAIL; 651 } 652 switch (af) { 653 case AF_INET: 654 sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", 655 (uaddr[3] & 0xff), 656 (uaddr[2] & 0xff), 657 (uaddr[1] & 0xff), 658 (uaddr[0] & 0xff)); 659 break; 660 case AF_INET6: 661 qp = qbuf; 662 for (n = IN6ADDRSZ - 1; n >= 0; n--) { 663 qp += SPRINTF((qp, "%x.%x.", 664 uaddr[n] & 0xf, 665 (uaddr[n] >> 4) & 0xf)); 666 } 667 strlcat(qbuf, "ip6.arpa", sizeof(qbuf)); 668 break; 669 default: 670 abort(); 671 } 672 if ((buf = malloc(sizeof(*buf))) == NULL) { 673 h_errno = NETDB_INTERNAL; 674 return (NULL); 675 } 676 n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf->buf, sizeof buf->buf); 677 if (n < 0 && af == AF_INET6) { 678 *qp = '\0'; 679 strlcat(qbuf, "ip6.int", sizeof(qbuf)); 680 n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf->buf, 681 sizeof buf->buf); 682 } 683 if (n < 0) { 684 free(buf); 685 dprintf("res_query failed (%d)\n", n); 686 return NS_UNAVAIL; 687 } 688 if (n > sizeof buf->buf) { 689 free(buf); 690 dprintf("static buffer is too small (%d)\n", n); 691 return NS_UNAVAIL; 692 } 693 if (!(hp = gethostanswer(buf, n, qbuf, T_PTR))) { 694 free(buf); 695 return NS_NOTFOUND; /* h_errno was set by gethostanswer() */ 696 } 697 free(buf); 698 #ifdef SUNSECURITY 699 if (af == AF_INET) { 700 /* 701 * turn off search as the name should be absolute, 702 * 'localhost' should be matched by defnames 703 */ 704 strncpy(hname2, hp->h_name, MAXDNAME); 705 hname2[MAXDNAME] = '\0'; 706 old_options = _res.options; 707 _res.options &= ~RES_DNSRCH; 708 _res.options |= RES_DEFNAMES; 709 if (!(rhp = gethostbyname(hname2))) { 710 syslog(LOG_NOTICE|LOG_AUTH, 711 "gethostbyaddr: No A record for %s (verifying [%s])", 712 hname2, inet_ntoa(*((struct in_addr *)addr))); 713 _res.options = old_options; 714 h_errno = HOST_NOT_FOUND; 715 return NS_NOTFOUND; 716 } 717 _res.options = old_options; 718 for (haddr = rhp->h_addr_list; *haddr; haddr++) 719 if (!memcmp(*haddr, addr, INADDRSZ)) 720 break; 721 if (!*haddr) { 722 syslog(LOG_NOTICE|LOG_AUTH, 723 "gethostbyaddr: A record of %s != PTR record [%s]", 724 hname2, inet_ntoa(*((struct in_addr *)addr))); 725 h_errno = HOST_NOT_FOUND; 726 return NS_NOTFOUND; 727 } 728 } 729 #endif /*SUNSECURITY*/ 730 hp->h_addrtype = af; 731 hp->h_length = len; 732 bcopy(addr, host_addr, len); 733 h_addr_ptrs[0] = (char *)host_addr; 734 h_addr_ptrs[1] = NULL; 735 if (af == AF_INET && (_res.options & RES_USE_INET6)) { 736 _map_v4v6_address((char*)host_addr, (char*)host_addr); 737 hp->h_addrtype = AF_INET6; 738 hp->h_length = IN6ADDRSZ; 739 } 740 h_errno = NETDB_SUCCESS; 741 *(struct hostent **)rval = hp; 742 return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND; 743 } 744 745 #ifdef RESOLVSORT 746 static void 747 addrsort(char **ap, int num) 748 { 749 int i, j; 750 char **p; 751 short aval[MAXADDRS]; 752 int needsort = 0; 753 754 p = ap; 755 for (i = 0; i < num; i++, p++) { 756 for (j = 0 ; (unsigned)j < _res.nsort; j++) 757 if (_res.sort_list[j].addr.s_addr == 758 (((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask)) 759 break; 760 aval[i] = j; 761 if (needsort == 0 && i > 0 && j < aval[i-1]) 762 needsort = i; 763 } 764 if (!needsort) 765 return; 766 767 while (needsort < num) { 768 for (j = needsort - 1; j >= 0; j--) { 769 if (aval[j] > aval[j+1]) { 770 char *hp; 771 772 i = aval[j]; 773 aval[j] = aval[j+1]; 774 aval[j+1] = i; 775 776 hp = ap[j]; 777 ap[j] = ap[j+1]; 778 ap[j+1] = hp; 779 780 } else 781 break; 782 } 783 needsort++; 784 } 785 } 786 #endif 787 void 788 _sethostdnsent(int stayopen) 789 { 790 if ((_res.options & RES_INIT) == 0 && res_init() == -1) 791 return; 792 if (stayopen) 793 _res.options |= RES_STAYOPEN | RES_USEVC; 794 } 795 796 void 797 _endhostdnsent(void) 798 { 799 _res.options &= ~(RES_STAYOPEN | RES_USEVC); 800 res_close(); 801 } 802