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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * - 35 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 36 * 37 * Permission to use, copy, modify, and distribute this software for any 38 * purpose with or without fee is hereby granted, provided that the above 39 * copyright notice and this permission notice appear in all copies, and that 40 * the name of Digital Equipment Corporation not be used in advertising or 41 * publicity pertaining to distribution of the document or software without 42 * specific, written prior permission. 43 * 44 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 45 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 46 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 47 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 48 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 49 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 50 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 51 * SOFTWARE. 52 * - 53 * --Copyright-- 54 */ 55 56 #if defined(LIBC_SCCS) && !defined(lint) 57 static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93"; 58 static char fromrcsid[] = "From: Id: gethnamaddr.c,v 8.23 1998/04/07 04:59:46 vixie Exp $"; 59 #endif /* LIBC_SCCS and not lint */ 60 #include <sys/cdefs.h> 61 __FBSDID("$FreeBSD$"); 62 63 #include <sys/types.h> 64 #include <sys/param.h> 65 #include <sys/socket.h> 66 #include <netinet/in.h> 67 #include <arpa/inet.h> 68 #include <arpa/nameser.h> 69 70 #include <stdio.h> 71 #include <stdlib.h> 72 #include <unistd.h> 73 #include <string.h> 74 #include <netdb.h> 75 #include <resolv.h> 76 #include <ctype.h> 77 #include <errno.h> 78 #include <syslog.h> 79 #include <stdarg.h> 80 #include <nsswitch.h> 81 82 #include "res_config.h" 83 84 #define SPRINTF(x) ((size_t)sprintf x) 85 86 #define MAXALIASES 35 87 #define MAXADDRS 35 88 89 static const char AskedForGot[] = 90 "gethostby*.gethostanswer: asked for \"%s\", got \"%s\""; 91 92 static char *h_addr_ptrs[MAXADDRS + 1]; 93 94 static struct hostent host; 95 static char *host_aliases[MAXALIASES]; 96 static char hostbuf[8*1024]; 97 static u_char host_addr[16]; /* IPv4 or IPv6 */ 98 99 extern const char *_res_hostalias(const char *, char *, size_t); 100 101 #ifdef RESOLVSORT 102 static void addrsort(char **, int); 103 #endif 104 105 #ifdef DEBUG 106 static void dprintf(char *, int) __printflike(1, 0); 107 #endif 108 109 #define MAXPACKET (64*1024) 110 111 typedef union { 112 HEADER hdr; 113 u_char buf[MAXPACKET]; 114 } querybuf; 115 116 typedef union { 117 int32_t al; 118 char ac; 119 } align; 120 121 int _dns_ttl_; 122 123 #ifdef DEBUG 124 static void 125 dprintf(msg, num) 126 char *msg; 127 int num; 128 { 129 if (_res.options & RES_DEBUG) { 130 int save = errno; 131 132 printf(msg, num); 133 errno = save; 134 } 135 } 136 #else 137 # define dprintf(msg, num) /*nada*/ 138 #endif 139 140 #define BOUNDED_INCR(x) \ 141 do { \ 142 cp += x; \ 143 if (cp > eom) { \ 144 h_errno = NO_RECOVERY; \ 145 return (NULL); \ 146 } \ 147 } while (0) 148 149 #define BOUNDS_CHECK(ptr, count) \ 150 do { \ 151 if ((ptr) + (count) > eom) { \ 152 h_errno = NO_RECOVERY; \ 153 return (NULL); \ 154 } \ 155 } while (0) 156 157 static struct hostent * 158 gethostanswer(answer, anslen, qname, qtype) 159 const querybuf *answer; 160 int anslen; 161 const char *qname; 162 int qtype; 163 { 164 const HEADER *hp; 165 const u_char *cp; 166 int n; 167 const u_char *eom, *erdata; 168 char *bp, *ep, **ap, **hap; 169 int type, class, ancount, qdcount; 170 int haveanswer, had_error; 171 int toobig = 0; 172 char tbuf[MAXDNAME]; 173 const char *tname; 174 int (*name_ok)(const char *); 175 176 tname = qname; 177 host.h_name = NULL; 178 eom = answer->buf + anslen; 179 switch (qtype) { 180 case T_A: 181 case T_AAAA: 182 name_ok = res_hnok; 183 break; 184 case T_PTR: 185 name_ok = res_dnok; 186 break; 187 default: 188 h_errno = NO_RECOVERY; 189 return (NULL); /* XXX should be abort(); */ 190 } 191 /* 192 * find first satisfactory answer 193 */ 194 hp = &answer->hdr; 195 ancount = ntohs(hp->ancount); 196 qdcount = ntohs(hp->qdcount); 197 bp = hostbuf; 198 ep = hostbuf + sizeof hostbuf; 199 cp = answer->buf; 200 BOUNDED_INCR(HFIXEDSZ); 201 if (qdcount != 1) { 202 h_errno = NO_RECOVERY; 203 return (NULL); 204 } 205 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 206 if ((n < 0) || !(*name_ok)(bp)) { 207 h_errno = NO_RECOVERY; 208 return (NULL); 209 } 210 BOUNDED_INCR(n + QFIXEDSZ); 211 if (qtype == T_A || qtype == T_AAAA) { 212 /* res_send() has already verified that the query name is the 213 * same as the one we sent; this just gets the expanded name 214 * (i.e., with the succeeding search-domain tacked on). 215 */ 216 n = strlen(bp) + 1; /* for the \0 */ 217 if (n >= MAXHOSTNAMELEN) { 218 h_errno = NO_RECOVERY; 219 return (NULL); 220 } 221 host.h_name = bp; 222 bp += n; 223 /* The qname can be abbreviated, but h_name is now absolute. */ 224 qname = host.h_name; 225 } 226 ap = host_aliases; 227 *ap = NULL; 228 host.h_aliases = host_aliases; 229 hap = h_addr_ptrs; 230 *hap = NULL; 231 host.h_addr_list = h_addr_ptrs; 232 haveanswer = 0; 233 had_error = 0; 234 _dns_ttl_ = -1; 235 while (ancount-- > 0 && cp < eom && !had_error) { 236 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 237 if ((n < 0) || !(*name_ok)(bp)) { 238 had_error++; 239 continue; 240 } 241 cp += n; /* name */ 242 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 243 type = _getshort(cp); 244 cp += INT16SZ; /* type */ 245 class = _getshort(cp); 246 cp += INT16SZ; /* class */ 247 if (qtype == T_A && type == T_A) 248 _dns_ttl_ = _getlong(cp); 249 cp += INT32SZ; /* TTL */ 250 n = _getshort(cp); 251 cp += INT16SZ; /* len */ 252 BOUNDS_CHECK(cp, n); 253 erdata = cp + n; 254 if (class != C_IN) { 255 /* XXX - debug? syslog? */ 256 cp += n; 257 continue; /* XXX - had_error++ ? */ 258 } 259 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 260 if (ap >= &host_aliases[MAXALIASES-1]) 261 continue; 262 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 263 if ((n < 0) || !(*name_ok)(tbuf)) { 264 had_error++; 265 continue; 266 } 267 cp += n; 268 if (cp != erdata) { 269 h_errno = NO_RECOVERY; 270 return (NULL); 271 } 272 /* Store alias. */ 273 *ap++ = bp; 274 n = strlen(bp) + 1; /* for the \0 */ 275 if (n >= MAXHOSTNAMELEN) { 276 had_error++; 277 continue; 278 } 279 bp += n; 280 /* Get canonical name. */ 281 n = strlen(tbuf) + 1; /* for the \0 */ 282 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 283 had_error++; 284 continue; 285 } 286 strcpy(bp, tbuf); 287 host.h_name = bp; 288 bp += n; 289 continue; 290 } 291 if (qtype == T_PTR && type == T_CNAME) { 292 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 293 if (n < 0 || !res_dnok(tbuf)) { 294 had_error++; 295 continue; 296 } 297 cp += n; 298 if (cp != erdata) { 299 h_errno = NO_RECOVERY; 300 return (NULL); 301 } 302 /* Get canonical name. */ 303 n = strlen(tbuf) + 1; /* for the \0 */ 304 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 305 had_error++; 306 continue; 307 } 308 strcpy(bp, tbuf); 309 tname = bp; 310 bp += n; 311 continue; 312 } 313 if (type != qtype) { 314 if (type != T_SIG) 315 syslog(LOG_NOTICE|LOG_AUTH, 316 "gethostby*.gethostanswer: asked for \"%s %s %s\", got type \"%s\"", 317 qname, p_class(C_IN), p_type(qtype), 318 p_type(type)); 319 cp += n; 320 continue; /* XXX - had_error++ ? */ 321 } 322 switch (type) { 323 case T_PTR: 324 if (strcasecmp(tname, bp) != 0) { 325 syslog(LOG_NOTICE|LOG_AUTH, 326 AskedForGot, qname, bp); 327 cp += n; 328 continue; /* XXX - had_error++ ? */ 329 } 330 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 331 if ((n < 0) || !res_hnok(bp)) { 332 had_error++; 333 break; 334 } 335 #if MULTI_PTRS_ARE_ALIASES 336 cp += n; 337 if (cp != erdata) { 338 h_errno = NO_RECOVERY; 339 return (NULL); 340 } 341 if (!haveanswer) 342 host.h_name = bp; 343 else if (ap < &host_aliases[MAXALIASES-1]) 344 *ap++ = bp; 345 else 346 n = -1; 347 if (n != -1) { 348 n = strlen(bp) + 1; /* for the \0 */ 349 if (n >= MAXHOSTNAMELEN) { 350 had_error++; 351 break; 352 } 353 bp += n; 354 } 355 break; 356 #else 357 host.h_name = bp; 358 if (_res.options & RES_USE_INET6) { 359 n = strlen(bp) + 1; /* for the \0 */ 360 if (n >= MAXHOSTNAMELEN) { 361 had_error++; 362 break; 363 } 364 bp += n; 365 _map_v4v6_hostent(&host, &bp, &ep); 366 } 367 h_errno = NETDB_SUCCESS; 368 return (&host); 369 #endif 370 case T_A: 371 case T_AAAA: 372 if (strcasecmp(host.h_name, bp) != 0) { 373 syslog(LOG_NOTICE|LOG_AUTH, 374 AskedForGot, host.h_name, bp); 375 cp += n; 376 continue; /* XXX - had_error++ ? */ 377 } 378 if (n != host.h_length) { 379 cp += n; 380 continue; 381 } 382 if (!haveanswer) { 383 int nn; 384 385 host.h_name = bp; 386 nn = strlen(bp) + 1; /* for the \0 */ 387 bp += nn; 388 } 389 390 bp += sizeof(align) - ((u_long)bp % sizeof(align)); 391 392 if (bp + n >= ep) { 393 dprintf("size (%d) too big\n", n); 394 had_error++; 395 continue; 396 } 397 if (hap >= &h_addr_ptrs[MAXADDRS-1]) { 398 if (!toobig++) 399 dprintf("Too many addresses (%d)\n", 400 MAXADDRS); 401 cp += n; 402 continue; 403 } 404 bcopy(cp, *hap++ = bp, n); 405 bp += n; 406 cp += n; 407 if (cp != erdata) { 408 h_errno = NO_RECOVERY; 409 return (NULL); 410 } 411 break; 412 default: 413 dprintf("Impossible condition (type=%d)\n", type); 414 h_errno = NO_RECOVERY; 415 return (NULL); 416 /* BIND has abort() here, too risky on bad data */ 417 } 418 if (!had_error) 419 haveanswer++; 420 } 421 if (haveanswer) { 422 *ap = NULL; 423 *hap = NULL; 424 # if defined(RESOLVSORT) 425 /* 426 * Note: we sort even if host can take only one address 427 * in its return structures - should give it the "best" 428 * address in that case, not some random one 429 */ 430 if (_res.nsort && haveanswer > 1 && qtype == T_A) 431 addrsort(h_addr_ptrs, haveanswer); 432 # endif /*RESOLVSORT*/ 433 if (!host.h_name) { 434 n = strlen(qname) + 1; /* for the \0 */ 435 if (n > ep - bp || n >= MAXHOSTNAMELEN) 436 goto no_recovery; 437 strcpy(bp, qname); 438 host.h_name = bp; 439 bp += n; 440 } 441 if (_res.options & RES_USE_INET6) 442 _map_v4v6_hostent(&host, &bp, &ep); 443 h_errno = NETDB_SUCCESS; 444 return (&host); 445 } 446 no_recovery: 447 h_errno = NO_RECOVERY; 448 return (NULL); 449 } 450 451 struct hostent * 452 __dns_getanswer(answer, anslen, qname, qtype) 453 const char *answer; 454 int anslen; 455 const char *qname; 456 int qtype; 457 { 458 switch(qtype) { 459 case T_AAAA: 460 host.h_addrtype = AF_INET6; 461 host.h_length = IN6ADDRSZ; 462 break; 463 case T_A: 464 default: 465 host.h_addrtype = AF_INET; 466 host.h_length = INADDRSZ; 467 break; 468 } 469 470 return(gethostanswer((const querybuf *)answer, anslen, qname, qtype)); 471 } 472 473 int 474 _dns_gethostbyname(void *rval, void *cb_data, va_list ap) 475 { 476 const char *name; 477 int af; 478 querybuf *buf; 479 const char *cp; 480 char *bp, *ep; 481 int n, size, type, len; 482 char abuf[MAXDNAME]; 483 484 name = va_arg(ap, const char *); 485 af = va_arg(ap, int); 486 *(struct hostent **)rval = NULL; 487 488 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 489 h_errno = NETDB_INTERNAL; 490 return NS_UNAVAIL; 491 } 492 493 switch (af) { 494 case AF_INET: 495 size = INADDRSZ; 496 type = T_A; 497 break; 498 case AF_INET6: 499 size = IN6ADDRSZ; 500 type = T_AAAA; 501 break; 502 default: 503 h_errno = NETDB_INTERNAL; 504 errno = EAFNOSUPPORT; 505 return NS_UNAVAIL; 506 } 507 508 host.h_addrtype = af; 509 host.h_length = size; 510 511 /* 512 * if there aren't any dots, it could be a user-level alias. 513 * this is also done in res_query() since we are not the only 514 * function that looks up host names. 515 */ 516 if (!strchr(name, '.') && 517 (cp = _res_hostalias(name, abuf, sizeof abuf))) 518 name = cp; 519 520 /* 521 * disallow names consisting only of digits/dots, unless 522 * they end in a dot. 523 */ 524 if (isdigit((unsigned char)name[0])) 525 for (cp = name;; ++cp) { 526 if (!*cp) { 527 if (*--cp == '.') 528 break; 529 /* 530 * All-numeric, no dot at the end. 531 * Fake up a hostent as if we'd actually 532 * done a lookup. 533 */ 534 if (inet_pton(af, name, host_addr) <= 0) { 535 h_errno = HOST_NOT_FOUND; 536 return NS_NOTFOUND; 537 } 538 strncpy(hostbuf, name, MAXDNAME); 539 hostbuf[MAXDNAME] = '\0'; 540 bp = hostbuf + MAXDNAME; 541 ep = hostbuf + sizeof hostbuf; 542 host.h_name = hostbuf; 543 host.h_aliases = host_aliases; 544 host_aliases[0] = NULL; 545 h_addr_ptrs[0] = (char *)host_addr; 546 h_addr_ptrs[1] = NULL; 547 host.h_addr_list = h_addr_ptrs; 548 if (_res.options & RES_USE_INET6) 549 _map_v4v6_hostent(&host, &bp, &ep); 550 h_errno = NETDB_SUCCESS; 551 *(struct hostent **)rval = &host; 552 return NS_SUCCESS; 553 } 554 if (!isdigit((unsigned char)*cp) && *cp != '.') 555 break; 556 } 557 if ((isxdigit((unsigned char)name[0]) && strchr(name, ':') != NULL) || 558 name[0] == ':') 559 for (cp = name;; ++cp) { 560 if (!*cp) { 561 if (*--cp == '.') 562 break; 563 /* 564 * All-IPv6-legal, no dot at the end. 565 * Fake up a hostent as if we'd actually 566 * done a lookup. 567 */ 568 if (inet_pton(af, name, host_addr) <= 0) { 569 h_errno = HOST_NOT_FOUND; 570 return NS_NOTFOUND; 571 } 572 strncpy(hostbuf, name, MAXDNAME); 573 hostbuf[MAXDNAME] = '\0'; 574 bp = hostbuf + MAXDNAME; 575 len = sizeof hostbuf - MAXDNAME; 576 host.h_name = hostbuf; 577 host.h_aliases = host_aliases; 578 host_aliases[0] = NULL; 579 h_addr_ptrs[0] = (char *)host_addr; 580 h_addr_ptrs[1] = NULL; 581 host.h_addr_list = h_addr_ptrs; 582 h_errno = NETDB_SUCCESS; 583 *(struct hostent **)rval = &host; 584 return NS_SUCCESS; 585 } 586 if (!isxdigit((unsigned char)*cp) && *cp != ':' && *cp != '.') 587 break; 588 } 589 590 if ((buf = malloc(sizeof(*buf))) == NULL) { 591 h_errno = NETDB_INTERNAL; 592 return NS_NOTFOUND; 593 } 594 n = res_search(name, C_IN, type, buf->buf, sizeof(buf->buf)); 595 if (n < 0) { 596 free(buf); 597 dprintf("res_search failed (%d)\n", n); 598 return (0); 599 } else if (n > sizeof(buf->buf)) { 600 free(buf); 601 dprintf("static buffer is too small (%d)\n", n); 602 return (0); 603 } 604 *(struct hostent **)rval = gethostanswer(buf, n, name, type); 605 free(buf); 606 return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND; 607 } 608 609 int 610 _dns_gethostbyaddr(void *rval, void *cb_data, va_list ap) 611 { 612 const char *addr; /* XXX should have been def'd as u_char! */ 613 int len, af; 614 const u_char *uaddr; 615 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff }; 616 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 }; 617 int n, size; 618 querybuf *buf; 619 struct hostent *hp; 620 char qbuf[MAXDNAME+1], *qp; 621 #ifdef SUNSECURITY 622 struct hostent *rhp; 623 char **haddr; 624 u_long old_options; 625 char hname2[MAXDNAME+1]; 626 #endif /*SUNSECURITY*/ 627 628 addr = va_arg(ap, const char *); 629 uaddr = (const u_char *)addr; 630 len = va_arg(ap, int); 631 af = va_arg(ap, int); 632 633 *(struct hostent **)rval = NULL; 634 635 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 636 h_errno = NETDB_INTERNAL; 637 return NS_UNAVAIL; 638 } 639 if (af == AF_INET6 && len == IN6ADDRSZ && 640 (!bcmp(uaddr, mapped, sizeof mapped) || 641 !bcmp(uaddr, tunnelled, sizeof tunnelled))) { 642 /* Unmap. */ 643 addr += sizeof mapped; 644 uaddr += sizeof mapped; 645 af = AF_INET; 646 len = INADDRSZ; 647 } 648 switch (af) { 649 case AF_INET: 650 size = INADDRSZ; 651 break; 652 case AF_INET6: 653 size = IN6ADDRSZ; 654 break; 655 default: 656 errno = EAFNOSUPPORT; 657 h_errno = NETDB_INTERNAL; 658 return NS_UNAVAIL; 659 } 660 if (size != len) { 661 errno = EINVAL; 662 h_errno = NETDB_INTERNAL; 663 return NS_UNAVAIL; 664 } 665 switch (af) { 666 case AF_INET: 667 (void) sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", 668 (uaddr[3] & 0xff), 669 (uaddr[2] & 0xff), 670 (uaddr[1] & 0xff), 671 (uaddr[0] & 0xff)); 672 break; 673 case AF_INET6: 674 qp = qbuf; 675 for (n = IN6ADDRSZ - 1; n >= 0; n--) { 676 qp += SPRINTF((qp, "%x.%x.", 677 uaddr[n] & 0xf, 678 (uaddr[n] >> 4) & 0xf)); 679 } 680 strlcat(qbuf, "ip6.arpa", sizeof(qbuf)); 681 break; 682 default: 683 abort(); 684 } 685 if ((buf = malloc(sizeof(*buf))) == NULL) { 686 h_errno = NETDB_INTERNAL; 687 return NS_NOTFOUND; 688 } 689 n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf->buf, sizeof buf->buf); 690 if (n < 0) { 691 free(buf); 692 dprintf("res_query failed (%d)\n", n); 693 return NS_UNAVAIL; 694 } 695 if (n > sizeof buf->buf) { 696 free(buf); 697 dprintf("static buffer is too small (%d)\n", n); 698 return NS_UNAVAIL; 699 } 700 if (!(hp = gethostanswer(buf, n, qbuf, T_PTR))) { 701 free(buf); 702 return NS_NOTFOUND; /* h_errno was set by gethostanswer() */ 703 } 704 free(buf); 705 #ifdef SUNSECURITY 706 if (af == AF_INET) { 707 /* 708 * turn off search as the name should be absolute, 709 * 'localhost' should be matched by defnames 710 */ 711 strncpy(hname2, hp->h_name, MAXDNAME); 712 hname2[MAXDNAME] = '\0'; 713 old_options = _res.options; 714 _res.options &= ~RES_DNSRCH; 715 _res.options |= RES_DEFNAMES; 716 if (!(rhp = gethostbyname(hname2))) { 717 syslog(LOG_NOTICE|LOG_AUTH, 718 "gethostbyaddr: No A record for %s (verifying [%s])", 719 hname2, inet_ntoa(*((struct in_addr *)addr))); 720 _res.options = old_options; 721 h_errno = HOST_NOT_FOUND; 722 return NS_NOTFOUND; 723 } 724 _res.options = old_options; 725 for (haddr = rhp->h_addr_list; *haddr; haddr++) 726 if (!memcmp(*haddr, addr, INADDRSZ)) 727 break; 728 if (!*haddr) { 729 syslog(LOG_NOTICE|LOG_AUTH, 730 "gethostbyaddr: A record of %s != PTR record [%s]", 731 hname2, inet_ntoa(*((struct in_addr *)addr))); 732 h_errno = HOST_NOT_FOUND; 733 return NS_NOTFOUND; 734 } 735 } 736 #endif /*SUNSECURITY*/ 737 hp->h_addrtype = af; 738 hp->h_length = len; 739 bcopy(addr, host_addr, len); 740 h_addr_ptrs[0] = (char *)host_addr; 741 h_addr_ptrs[1] = NULL; 742 if (af == AF_INET && (_res.options & RES_USE_INET6)) { 743 _map_v4v6_address((char*)host_addr, (char*)host_addr); 744 hp->h_addrtype = AF_INET6; 745 hp->h_length = IN6ADDRSZ; 746 } 747 h_errno = NETDB_SUCCESS; 748 *(struct hostent **)rval = hp; 749 return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND; 750 } 751 752 #ifdef RESOLVSORT 753 static void 754 addrsort(ap, num) 755 char **ap; 756 int num; 757 { 758 int i, j; 759 char **p; 760 short aval[MAXADDRS]; 761 int needsort = 0; 762 763 p = ap; 764 for (i = 0; i < num; i++, p++) { 765 for (j = 0 ; (unsigned)j < _res.nsort; j++) 766 if (_res.sort_list[j].addr.s_addr == 767 (((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask)) 768 break; 769 aval[i] = j; 770 if (needsort == 0 && i > 0 && j < aval[i-1]) 771 needsort = i; 772 } 773 if (!needsort) 774 return; 775 776 while (needsort < num) { 777 for (j = needsort - 1; j >= 0; j--) { 778 if (aval[j] > aval[j+1]) { 779 char *hp; 780 781 i = aval[j]; 782 aval[j] = aval[j+1]; 783 aval[j+1] = i; 784 785 hp = ap[j]; 786 ap[j] = ap[j+1]; 787 ap[j+1] = hp; 788 789 } else 790 break; 791 } 792 needsort++; 793 } 794 } 795 #endif 796 void 797 _sethostdnsent(stayopen) 798 int stayopen; 799 { 800 if ((_res.options & RES_INIT) == 0 && res_init() == -1) 801 return; 802 if (stayopen) 803 _res.options |= RES_STAYOPEN | RES_USEVC; 804 } 805 806 void 807 _endhostdnsent() 808 { 809 _res.options &= ~(RES_STAYOPEN | RES_USEVC); 810 res_close(); 811 } 812