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 #ifdef RESOLVSORT 100 static void addrsort(char **, int); 101 #endif 102 103 #ifdef DEBUG 104 static void dprintf(char *, int) __printflike(1, 0); 105 #endif 106 107 #define MAXPACKET (64*1024) 108 109 typedef union { 110 HEADER hdr; 111 u_char buf[MAXPACKET]; 112 } querybuf; 113 114 typedef union { 115 int32_t al; 116 char ac; 117 } align; 118 119 extern int h_errno; 120 int _dns_ttl_; 121 122 #ifdef DEBUG 123 static void 124 dprintf(msg, num) 125 char *msg; 126 int num; 127 { 128 if (_res.options & RES_DEBUG) { 129 int save = errno; 130 131 printf(msg, num); 132 errno = save; 133 } 134 } 135 #else 136 # define dprintf(msg, num) /*nada*/ 137 #endif 138 139 #define BOUNDED_INCR(x) \ 140 do { \ 141 cp += x; \ 142 if (cp > eom) { \ 143 h_errno = NO_RECOVERY; \ 144 return (NULL); \ 145 } \ 146 } while (0) 147 148 #define BOUNDS_CHECK(ptr, count) \ 149 do { \ 150 if ((ptr) + (count) > eom) { \ 151 h_errno = NO_RECOVERY; \ 152 return (NULL); \ 153 } \ 154 } while (0) 155 156 static struct hostent * 157 gethostanswer(answer, anslen, qname, qtype) 158 const querybuf *answer; 159 int anslen; 160 const char *qname; 161 int qtype; 162 { 163 const HEADER *hp; 164 const u_char *cp; 165 int n; 166 const u_char *eom, *erdata; 167 char *bp, *ep, **ap, **hap; 168 int type, class, ancount, qdcount; 169 int haveanswer, had_error; 170 int toobig = 0; 171 char tbuf[MAXDNAME]; 172 const char *tname; 173 int (*name_ok)(const char *); 174 175 tname = qname; 176 host.h_name = NULL; 177 eom = answer->buf + anslen; 178 switch (qtype) { 179 case T_A: 180 case T_AAAA: 181 name_ok = res_hnok; 182 break; 183 case T_PTR: 184 name_ok = res_dnok; 185 break; 186 default: 187 h_errno = NO_RECOVERY; 188 return (NULL); /* XXX should be abort(); */ 189 } 190 /* 191 * find first satisfactory answer 192 */ 193 hp = &answer->hdr; 194 ancount = ntohs(hp->ancount); 195 qdcount = ntohs(hp->qdcount); 196 bp = hostbuf; 197 ep = hostbuf + sizeof hostbuf; 198 cp = answer->buf; 199 BOUNDED_INCR(HFIXEDSZ); 200 if (qdcount != 1) { 201 h_errno = NO_RECOVERY; 202 return (NULL); 203 } 204 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 205 if ((n < 0) || !(*name_ok)(bp)) { 206 h_errno = NO_RECOVERY; 207 return (NULL); 208 } 209 BOUNDED_INCR(n + QFIXEDSZ); 210 if (qtype == T_A || qtype == T_AAAA) { 211 /* res_send() has already verified that the query name is the 212 * same as the one we sent; this just gets the expanded name 213 * (i.e., with the succeeding search-domain tacked on). 214 */ 215 n = strlen(bp) + 1; /* for the \0 */ 216 if (n >= MAXHOSTNAMELEN) { 217 h_errno = NO_RECOVERY; 218 return (NULL); 219 } 220 host.h_name = bp; 221 bp += n; 222 /* The qname can be abbreviated, but h_name is now absolute. */ 223 qname = host.h_name; 224 } 225 ap = host_aliases; 226 *ap = NULL; 227 host.h_aliases = host_aliases; 228 hap = h_addr_ptrs; 229 *hap = NULL; 230 host.h_addr_list = h_addr_ptrs; 231 haveanswer = 0; 232 had_error = 0; 233 _dns_ttl_ = -1; 234 while (ancount-- > 0 && cp < eom && !had_error) { 235 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 236 if ((n < 0) || !(*name_ok)(bp)) { 237 had_error++; 238 continue; 239 } 240 cp += n; /* name */ 241 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 242 type = _getshort(cp); 243 cp += INT16SZ; /* type */ 244 class = _getshort(cp); 245 cp += INT16SZ; /* class */ 246 if (qtype == T_A && type == T_A) 247 _dns_ttl_ = _getlong(cp); 248 cp += INT32SZ; /* TTL */ 249 n = _getshort(cp); 250 cp += INT16SZ; /* len */ 251 BOUNDS_CHECK(cp, n); 252 erdata = cp + n; 253 if (class != C_IN) { 254 /* XXX - debug? syslog? */ 255 cp += n; 256 continue; /* XXX - had_error++ ? */ 257 } 258 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 259 if (ap >= &host_aliases[MAXALIASES-1]) 260 continue; 261 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 262 if ((n < 0) || !(*name_ok)(tbuf)) { 263 had_error++; 264 continue; 265 } 266 cp += n; 267 if (cp != erdata) { 268 h_errno = NO_RECOVERY; 269 return (NULL); 270 } 271 /* Store alias. */ 272 *ap++ = bp; 273 n = strlen(bp) + 1; /* for the \0 */ 274 if (n >= MAXHOSTNAMELEN) { 275 had_error++; 276 continue; 277 } 278 bp += n; 279 /* Get canonical name. */ 280 n = strlen(tbuf) + 1; /* for the \0 */ 281 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 282 had_error++; 283 continue; 284 } 285 strcpy(bp, tbuf); 286 host.h_name = bp; 287 bp += n; 288 continue; 289 } 290 if (qtype == T_PTR && type == T_CNAME) { 291 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 292 if (n < 0 || !res_dnok(tbuf)) { 293 had_error++; 294 continue; 295 } 296 cp += n; 297 if (cp != erdata) { 298 h_errno = NO_RECOVERY; 299 return (NULL); 300 } 301 /* Get canonical name. */ 302 n = strlen(tbuf) + 1; /* for the \0 */ 303 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 304 had_error++; 305 continue; 306 } 307 strcpy(bp, tbuf); 308 tname = bp; 309 bp += n; 310 continue; 311 } 312 if (type != qtype) { 313 if (type != T_SIG) 314 syslog(LOG_NOTICE|LOG_AUTH, 315 "gethostby*.gethostanswer: asked for \"%s %s %s\", got type \"%s\"", 316 qname, p_class(C_IN), p_type(qtype), 317 p_type(type)); 318 cp += n; 319 continue; /* XXX - had_error++ ? */ 320 } 321 switch (type) { 322 case T_PTR: 323 if (strcasecmp(tname, bp) != 0) { 324 syslog(LOG_NOTICE|LOG_AUTH, 325 AskedForGot, qname, bp); 326 cp += n; 327 continue; /* XXX - had_error++ ? */ 328 } 329 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 330 if ((n < 0) || !res_hnok(bp)) { 331 had_error++; 332 break; 333 } 334 #if MULTI_PTRS_ARE_ALIASES 335 cp += n; 336 if (cp != erdata) { 337 h_errno = NO_RECOVERY; 338 return (NULL); 339 } 340 if (!haveanswer) 341 host.h_name = bp; 342 else if (ap < &host_aliases[MAXALIASES-1]) 343 *ap++ = bp; 344 else 345 n = -1; 346 if (n != -1) { 347 n = strlen(bp) + 1; /* for the \0 */ 348 if (n >= MAXHOSTNAMELEN) { 349 had_error++; 350 break; 351 } 352 bp += n; 353 } 354 break; 355 #else 356 host.h_name = bp; 357 if (_res.options & RES_USE_INET6) { 358 n = strlen(bp) + 1; /* for the \0 */ 359 if (n >= MAXHOSTNAMELEN) { 360 had_error++; 361 break; 362 } 363 bp += n; 364 _map_v4v6_hostent(&host, &bp, &ep); 365 } 366 h_errno = NETDB_SUCCESS; 367 return (&host); 368 #endif 369 case T_A: 370 case T_AAAA: 371 if (strcasecmp(host.h_name, bp) != 0) { 372 syslog(LOG_NOTICE|LOG_AUTH, 373 AskedForGot, host.h_name, bp); 374 cp += n; 375 continue; /* XXX - had_error++ ? */ 376 } 377 if (n != host.h_length) { 378 cp += n; 379 continue; 380 } 381 if (!haveanswer) { 382 int nn; 383 384 host.h_name = bp; 385 nn = strlen(bp) + 1; /* for the \0 */ 386 bp += nn; 387 } 388 389 bp += sizeof(align) - ((u_long)bp % sizeof(align)); 390 391 if (bp + n >= ep) { 392 dprintf("size (%d) too big\n", n); 393 had_error++; 394 continue; 395 } 396 if (hap >= &h_addr_ptrs[MAXADDRS-1]) { 397 if (!toobig++) 398 dprintf("Too many addresses (%d)\n", 399 MAXADDRS); 400 cp += n; 401 continue; 402 } 403 bcopy(cp, *hap++ = bp, n); 404 bp += n; 405 cp += n; 406 if (cp != erdata) { 407 h_errno = NO_RECOVERY; 408 return (NULL); 409 } 410 break; 411 default: 412 dprintf("Impossible condition (type=%d)\n", type); 413 h_errno = NO_RECOVERY; 414 return (NULL); 415 /* BIND has abort() here, too risky on bad data */ 416 } 417 if (!had_error) 418 haveanswer++; 419 } 420 if (haveanswer) { 421 *ap = NULL; 422 *hap = NULL; 423 # if defined(RESOLVSORT) 424 /* 425 * Note: we sort even if host can take only one address 426 * in its return structures - should give it the "best" 427 * address in that case, not some random one 428 */ 429 if (_res.nsort && haveanswer > 1 && qtype == T_A) 430 addrsort(h_addr_ptrs, haveanswer); 431 # endif /*RESOLVSORT*/ 432 if (!host.h_name) { 433 n = strlen(qname) + 1; /* for the \0 */ 434 if (n > ep - bp || n >= MAXHOSTNAMELEN) 435 goto no_recovery; 436 strcpy(bp, qname); 437 host.h_name = bp; 438 bp += n; 439 } 440 if (_res.options & RES_USE_INET6) 441 _map_v4v6_hostent(&host, &bp, &ep); 442 h_errno = NETDB_SUCCESS; 443 return (&host); 444 } 445 no_recovery: 446 h_errno = NO_RECOVERY; 447 return (NULL); 448 } 449 450 struct hostent * 451 __dns_getanswer(answer, anslen, qname, qtype) 452 const char *answer; 453 int anslen; 454 const char *qname; 455 int qtype; 456 { 457 switch(qtype) { 458 case T_AAAA: 459 host.h_addrtype = AF_INET6; 460 host.h_length = IN6ADDRSZ; 461 break; 462 case T_A: 463 default: 464 host.h_addrtype = AF_INET; 465 host.h_length = INADDRSZ; 466 break; 467 } 468 469 return(gethostanswer((const querybuf *)answer, anslen, qname, qtype)); 470 } 471 472 int 473 _dns_gethostbyname(void *rval, void *cb_data, va_list ap) 474 { 475 const char *name; 476 int af; 477 querybuf *buf; 478 const char *cp; 479 char *bp, *ep; 480 int n, size, type, len; 481 482 name = va_arg(ap, const char *); 483 af = va_arg(ap, int); 484 *(struct hostent **)rval = NULL; 485 486 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 487 h_errno = NETDB_INTERNAL; 488 return NS_UNAVAIL; 489 } 490 491 switch (af) { 492 case AF_INET: 493 size = INADDRSZ; 494 type = T_A; 495 break; 496 case AF_INET6: 497 size = IN6ADDRSZ; 498 type = T_AAAA; 499 break; 500 default: 501 h_errno = NETDB_INTERNAL; 502 errno = EAFNOSUPPORT; 503 return NS_UNAVAIL; 504 } 505 506 host.h_addrtype = af; 507 host.h_length = size; 508 509 /* 510 * if there aren't any dots, it could be a user-level alias. 511 * this is also done in res_query() since we are not the only 512 * function that looks up host names. 513 */ 514 if (!strchr(name, '.') && (cp = __hostalias(name))) 515 name = cp; 516 517 /* 518 * disallow names consisting only of digits/dots, unless 519 * they end in a dot. 520 */ 521 if (isdigit((unsigned char)name[0])) 522 for (cp = name;; ++cp) { 523 if (!*cp) { 524 if (*--cp == '.') 525 break; 526 /* 527 * All-numeric, no dot at the end. 528 * Fake up a hostent as if we'd actually 529 * done a lookup. 530 */ 531 if (inet_pton(af, name, host_addr) <= 0) { 532 h_errno = HOST_NOT_FOUND; 533 return NS_NOTFOUND; 534 } 535 strncpy(hostbuf, name, MAXDNAME); 536 hostbuf[MAXDNAME] = '\0'; 537 bp = hostbuf + MAXDNAME; 538 ep = hostbuf + sizeof hostbuf; 539 host.h_name = hostbuf; 540 host.h_aliases = host_aliases; 541 host_aliases[0] = NULL; 542 h_addr_ptrs[0] = (char *)host_addr; 543 h_addr_ptrs[1] = NULL; 544 host.h_addr_list = h_addr_ptrs; 545 if (_res.options & RES_USE_INET6) 546 _map_v4v6_hostent(&host, &bp, &ep); 547 h_errno = NETDB_SUCCESS; 548 *(struct hostent **)rval = &host; 549 return NS_SUCCESS; 550 } 551 if (!isdigit((unsigned char)*cp) && *cp != '.') 552 break; 553 } 554 if ((isxdigit((unsigned char)name[0]) && strchr(name, ':') != NULL) || 555 name[0] == ':') 556 for (cp = name;; ++cp) { 557 if (!*cp) { 558 if (*--cp == '.') 559 break; 560 /* 561 * All-IPv6-legal, no dot at the end. 562 * Fake up a hostent as if we'd actually 563 * done a lookup. 564 */ 565 if (inet_pton(af, name, host_addr) <= 0) { 566 h_errno = HOST_NOT_FOUND; 567 return NS_NOTFOUND; 568 } 569 strncpy(hostbuf, name, MAXDNAME); 570 hostbuf[MAXDNAME] = '\0'; 571 bp = hostbuf + MAXDNAME; 572 len = sizeof hostbuf - MAXDNAME; 573 host.h_name = hostbuf; 574 host.h_aliases = host_aliases; 575 host_aliases[0] = NULL; 576 h_addr_ptrs[0] = (char *)host_addr; 577 h_addr_ptrs[1] = NULL; 578 host.h_addr_list = h_addr_ptrs; 579 h_errno = NETDB_SUCCESS; 580 *(struct hostent **)rval = &host; 581 return NS_SUCCESS; 582 } 583 if (!isxdigit((unsigned char)*cp) && *cp != ':' && *cp != '.') 584 break; 585 } 586 587 if ((buf = malloc(sizeof(*buf))) == NULL) { 588 h_errno = NETDB_INTERNAL; 589 return NS_NOTFOUND; 590 } 591 n = res_search(name, C_IN, type, buf->buf, sizeof(buf->buf)); 592 if (n < 0) { 593 free(buf); 594 dprintf("res_search failed (%d)\n", n); 595 return (NULL); 596 } else if (n > sizeof(buf->buf)) { 597 free(buf); 598 dprintf("static buffer is too small (%d)\n", n); 599 return (NULL); 600 } 601 *(struct hostent **)rval = gethostanswer(buf, n, name, type); 602 free(buf); 603 return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND; 604 } 605 606 int 607 _dns_gethostbyaddr(void *rval, void *cb_data, va_list ap) 608 { 609 const char *addr; /* XXX should have been def'd as u_char! */ 610 int len, af; 611 const u_char *uaddr; 612 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff }; 613 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 }; 614 int n, size; 615 querybuf *buf; 616 struct hostent *hp; 617 char qbuf[MAXDNAME+1], *qp; 618 #ifdef SUNSECURITY 619 struct hostent *rhp; 620 char **haddr; 621 u_long old_options; 622 char hname2[MAXDNAME+1]; 623 #endif /*SUNSECURITY*/ 624 625 addr = va_arg(ap, const char *); 626 uaddr = (const u_char *)addr; 627 len = va_arg(ap, int); 628 af = va_arg(ap, int); 629 630 *(struct hostent **)rval = NULL; 631 632 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 633 h_errno = NETDB_INTERNAL; 634 return NS_UNAVAIL; 635 } 636 if (af == AF_INET6 && len == IN6ADDRSZ && 637 (!bcmp(uaddr, mapped, sizeof mapped) || 638 !bcmp(uaddr, tunnelled, sizeof tunnelled))) { 639 /* Unmap. */ 640 addr += sizeof mapped; 641 uaddr += sizeof mapped; 642 af = AF_INET; 643 len = INADDRSZ; 644 } 645 switch (af) { 646 case AF_INET: 647 size = INADDRSZ; 648 break; 649 case AF_INET6: 650 size = IN6ADDRSZ; 651 break; 652 default: 653 errno = EAFNOSUPPORT; 654 h_errno = NETDB_INTERNAL; 655 return NS_UNAVAIL; 656 } 657 if (size != len) { 658 errno = EINVAL; 659 h_errno = NETDB_INTERNAL; 660 return NS_UNAVAIL; 661 } 662 switch (af) { 663 case AF_INET: 664 (void) sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", 665 (uaddr[3] & 0xff), 666 (uaddr[2] & 0xff), 667 (uaddr[1] & 0xff), 668 (uaddr[0] & 0xff)); 669 break; 670 case AF_INET6: 671 qp = qbuf; 672 for (n = IN6ADDRSZ - 1; n >= 0; n--) { 673 qp += SPRINTF((qp, "%x.%x.", 674 uaddr[n] & 0xf, 675 (uaddr[n] >> 4) & 0xf)); 676 } 677 strlcat(qbuf, "ip6.arpa", sizeof(qbuf)); 678 break; 679 default: 680 abort(); 681 } 682 if ((buf = malloc(sizeof(*buf))) == NULL) { 683 h_errno = NETDB_INTERNAL; 684 return NS_NOTFOUND; 685 } 686 n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf->buf, sizeof buf->buf); 687 if (n < 0 && af == AF_INET6) { 688 *qp = '\0'; 689 strlcat(qbuf, "ip6.int", sizeof(qbuf)); 690 n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf->buf, 691 sizeof buf->buf); 692 } 693 if (n < 0) { 694 free(buf); 695 dprintf("res_query failed (%d)\n", n); 696 return NS_UNAVAIL; 697 } 698 if (n > sizeof buf->buf) { 699 free(buf); 700 dprintf("static buffer is too small (%d)\n", n); 701 return NS_UNAVAIL; 702 } 703 if (!(hp = gethostanswer(buf, n, qbuf, T_PTR))) { 704 free(buf); 705 return NS_NOTFOUND; /* h_errno was set by gethostanswer() */ 706 } 707 free(buf); 708 #ifdef SUNSECURITY 709 if (af == AF_INET) { 710 /* 711 * turn off search as the name should be absolute, 712 * 'localhost' should be matched by defnames 713 */ 714 strncpy(hname2, hp->h_name, MAXDNAME); 715 hname2[MAXDNAME] = '\0'; 716 old_options = _res.options; 717 _res.options &= ~RES_DNSRCH; 718 _res.options |= RES_DEFNAMES; 719 if (!(rhp = gethostbyname(hname2))) { 720 syslog(LOG_NOTICE|LOG_AUTH, 721 "gethostbyaddr: No A record for %s (verifying [%s])", 722 hname2, inet_ntoa(*((struct in_addr *)addr))); 723 _res.options = old_options; 724 h_errno = HOST_NOT_FOUND; 725 return NS_NOTFOUND; 726 } 727 _res.options = old_options; 728 for (haddr = rhp->h_addr_list; *haddr; haddr++) 729 if (!memcmp(*haddr, addr, INADDRSZ)) 730 break; 731 if (!*haddr) { 732 syslog(LOG_NOTICE|LOG_AUTH, 733 "gethostbyaddr: A record of %s != PTR record [%s]", 734 hname2, inet_ntoa(*((struct in_addr *)addr))); 735 h_errno = HOST_NOT_FOUND; 736 return NS_NOTFOUND; 737 } 738 } 739 #endif /*SUNSECURITY*/ 740 hp->h_addrtype = af; 741 hp->h_length = len; 742 bcopy(addr, host_addr, len); 743 h_addr_ptrs[0] = (char *)host_addr; 744 h_addr_ptrs[1] = NULL; 745 if (af == AF_INET && (_res.options & RES_USE_INET6)) { 746 _map_v4v6_address((char*)host_addr, (char*)host_addr); 747 hp->h_addrtype = AF_INET6; 748 hp->h_length = IN6ADDRSZ; 749 } 750 h_errno = NETDB_SUCCESS; 751 *(struct hostent **)rval = hp; 752 return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND; 753 } 754 755 #ifdef RESOLVSORT 756 static void 757 addrsort(ap, num) 758 char **ap; 759 int num; 760 { 761 int i, j; 762 char **p; 763 short aval[MAXADDRS]; 764 int needsort = 0; 765 766 p = ap; 767 for (i = 0; i < num; i++, p++) { 768 for (j = 0 ; (unsigned)j < _res.nsort; j++) 769 if (_res.sort_list[j].addr.s_addr == 770 (((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask)) 771 break; 772 aval[i] = j; 773 if (needsort == 0 && i > 0 && j < aval[i-1]) 774 needsort = i; 775 } 776 if (!needsort) 777 return; 778 779 while (needsort < num) { 780 for (j = needsort - 1; j >= 0; j--) { 781 if (aval[j] > aval[j+1]) { 782 char *hp; 783 784 i = aval[j]; 785 aval[j] = aval[j+1]; 786 aval[j+1] = i; 787 788 hp = ap[j]; 789 ap[j] = ap[j+1]; 790 ap[j+1] = hp; 791 792 } else 793 break; 794 } 795 needsort++; 796 } 797 } 798 #endif 799 void 800 _sethostdnsent(stayopen) 801 int stayopen; 802 { 803 if ((_res.options & RES_INIT) == 0 && res_init() == -1) 804 return; 805 if (stayopen) 806 _res.options |= RES_STAYOPEN | RES_USEVC; 807 } 808 809 void 810 _endhostdnsent() 811 { 812 _res.options &= ~(RES_STAYOPEN | RES_USEVC); 813 res_close(); 814 } 815