gethostbydns.c revision 92986
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) 57static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93"; 58static 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: head/lib/libc/net/gethostbydns.c 92986 2002-03-22 21:53:29Z obrien $"); 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 <unistd.h> 72#include <string.h> 73#include <netdb.h> 74#include <resolv.h> 75#include <ctype.h> 76#include <errno.h> 77#include <syslog.h> 78#include <stdarg.h> 79#include <nsswitch.h> 80 81#include "res_config.h" 82 83#define SPRINTF(x) ((size_t)sprintf x) 84 85#define MAXALIASES 35 86#define MAXADDRS 35 87 88static const char AskedForGot[] = 89 "gethostby*.gethostanswer: asked for \"%s\", got \"%s\""; 90 91static char *h_addr_ptrs[MAXADDRS + 1]; 92 93static struct hostent host; 94static char *host_aliases[MAXALIASES]; 95static char hostbuf[8*1024]; 96static u_char host_addr[16]; /* IPv4 or IPv6 */ 97 98#ifdef RESOLVSORT 99static void addrsort(char **, int); 100#endif 101 102#ifdef DEBUG 103static void dprintf(char *, int) __printflike(1, 0); 104#endif 105 106#if PACKETSZ > 1024 107#define MAXPACKET PACKETSZ 108#else 109#define MAXPACKET 1024 110#endif 111 112typedef union { 113 HEADER hdr; 114 u_char buf[MAXPACKET]; 115} querybuf; 116 117typedef union { 118 int32_t al; 119 char ac; 120} align; 121 122extern int h_errno; 123int _dns_ttl_; 124 125#ifdef DEBUG 126static void 127dprintf(msg, num) 128 char *msg; 129 int num; 130{ 131 if (_res.options & RES_DEBUG) { 132 int save = errno; 133 134 printf(msg, num); 135 errno = save; 136 } 137} 138#else 139# define dprintf(msg, num) /*nada*/ 140#endif 141 142#define BOUNDED_INCR(x) \ 143 do { \ 144 cp += x; \ 145 if (cp > eom) { \ 146 h_errno = NO_RECOVERY; \ 147 return (NULL); \ 148 } \ 149 } while (0) 150 151#define BOUNDS_CHECK(ptr, count) \ 152 do { \ 153 if ((ptr) + (count) > eom) { \ 154 h_errno = NO_RECOVERY; \ 155 return (NULL); \ 156 } \ 157 } while (0) 158 159static struct hostent * 160gethostanswer(answer, anslen, qname, qtype) 161 const querybuf *answer; 162 int anslen; 163 const char *qname; 164 int qtype; 165{ 166 const HEADER *hp; 167 const u_char *cp; 168 int n; 169 const u_char *eom, *erdata; 170 char *bp, **ap, **hap; 171 int type, class, buflen, ancount, qdcount; 172 int haveanswer, had_error; 173 int toobig = 0; 174 char tbuf[MAXDNAME]; 175 const char *tname; 176 int (*name_ok)(const char *); 177 178 tname = qname; 179 host.h_name = NULL; 180 eom = answer->buf + anslen; 181 switch (qtype) { 182 case T_A: 183 case T_AAAA: 184 name_ok = res_hnok; 185 break; 186 case T_PTR: 187 name_ok = res_dnok; 188 break; 189 default: 190 h_errno = NO_RECOVERY; 191 return (NULL); /* XXX should be abort(); */ 192 } 193 /* 194 * find first satisfactory answer 195 */ 196 hp = &answer->hdr; 197 ancount = ntohs(hp->ancount); 198 qdcount = ntohs(hp->qdcount); 199 bp = hostbuf; 200 buflen = sizeof hostbuf; 201 cp = answer->buf; 202 BOUNDED_INCR(HFIXEDSZ); 203 if (qdcount != 1) { 204 h_errno = NO_RECOVERY; 205 return (NULL); 206 } 207 n = dn_expand(answer->buf, eom, cp, bp, buflen); 208 if ((n < 0) || !(*name_ok)(bp)) { 209 h_errno = NO_RECOVERY; 210 return (NULL); 211 } 212 BOUNDED_INCR(n + QFIXEDSZ); 213 if (qtype == T_A || qtype == T_AAAA) { 214 /* res_send() has already verified that the query name is the 215 * same as the one we sent; this just gets the expanded name 216 * (i.e., with the succeeding search-domain tacked on). 217 */ 218 n = strlen(bp) + 1; /* for the \0 */ 219 if (n >= MAXHOSTNAMELEN) { 220 h_errno = NO_RECOVERY; 221 return (NULL); 222 } 223 host.h_name = bp; 224 bp += n; 225 buflen -= n; 226 /* The qname can be abbreviated, but h_name is now absolute. */ 227 qname = host.h_name; 228 } 229 ap = host_aliases; 230 *ap = NULL; 231 host.h_aliases = host_aliases; 232 hap = h_addr_ptrs; 233 *hap = NULL; 234 host.h_addr_list = h_addr_ptrs; 235 haveanswer = 0; 236 had_error = 0; 237 _dns_ttl_ = -1; 238 while (ancount-- > 0 && cp < eom && !had_error) { 239 n = dn_expand(answer->buf, eom, cp, bp, buflen); 240 if ((n < 0) || !(*name_ok)(bp)) { 241 had_error++; 242 continue; 243 } 244 cp += n; /* name */ 245 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 246 type = _getshort(cp); 247 cp += INT16SZ; /* type */ 248 class = _getshort(cp); 249 cp += INT16SZ; /* class */ 250 if (qtype == T_A && type == T_A) 251 _dns_ttl_ = _getlong(cp); 252 cp += INT32SZ; /* TTL */ 253 n = _getshort(cp); 254 cp += INT16SZ; /* len */ 255 BOUNDS_CHECK(cp, n); 256 erdata = cp + n; 257 if (class != C_IN) { 258 /* XXX - debug? syslog? */ 259 cp += n; 260 continue; /* XXX - had_error++ ? */ 261 } 262 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 263 if (ap >= &host_aliases[MAXALIASES-1]) 264 continue; 265 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 266 if ((n < 0) || !(*name_ok)(tbuf)) { 267 had_error++; 268 continue; 269 } 270 cp += n; 271 if (cp != erdata) { 272 h_errno = NO_RECOVERY; 273 return (NULL); 274 } 275 /* Store alias. */ 276 *ap++ = bp; 277 n = strlen(bp) + 1; /* for the \0 */ 278 if (n >= MAXHOSTNAMELEN) { 279 had_error++; 280 continue; 281 } 282 bp += n; 283 buflen -= n; 284 /* Get canonical name. */ 285 n = strlen(tbuf) + 1; /* for the \0 */ 286 if (n > buflen || n >= MAXHOSTNAMELEN) { 287 had_error++; 288 continue; 289 } 290 strcpy(bp, tbuf); 291 host.h_name = bp; 292 bp += n; 293 buflen -= n; 294 continue; 295 } 296 if (qtype == T_PTR && type == T_CNAME) { 297 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 298 if (n < 0 || !res_dnok(tbuf)) { 299 had_error++; 300 continue; 301 } 302 cp += n; 303 if (cp != erdata) { 304 h_errno = NO_RECOVERY; 305 return (NULL); 306 } 307 /* Get canonical name. */ 308 n = strlen(tbuf) + 1; /* for the \0 */ 309 if (n > buflen || n >= MAXHOSTNAMELEN) { 310 had_error++; 311 continue; 312 } 313 strcpy(bp, tbuf); 314 tname = bp; 315 bp += n; 316 buflen -= n; 317 continue; 318 } 319 if (type != qtype) { 320 if (type != T_SIG) 321 syslog(LOG_NOTICE|LOG_AUTH, 322 "gethostby*.gethostanswer: asked for \"%s %s %s\", got type \"%s\"", 323 qname, p_class(C_IN), p_type(qtype), 324 p_type(type)); 325 cp += n; 326 continue; /* XXX - had_error++ ? */ 327 } 328 switch (type) { 329 case T_PTR: 330 if (strcasecmp(tname, bp) != 0) { 331 syslog(LOG_NOTICE|LOG_AUTH, 332 AskedForGot, qname, bp); 333 cp += n; 334 continue; /* XXX - had_error++ ? */ 335 } 336 n = dn_expand(answer->buf, eom, cp, bp, buflen); 337 if ((n < 0) || !res_hnok(bp)) { 338 had_error++; 339 break; 340 } 341#if MULTI_PTRS_ARE_ALIASES 342 cp += n; 343 if (cp != erdata) { 344 h_errno = NO_RECOVERY; 345 return (NULL); 346 } 347 if (!haveanswer) 348 host.h_name = bp; 349 else if (ap < &host_aliases[MAXALIASES-1]) 350 *ap++ = bp; 351 else 352 n = -1; 353 if (n != -1) { 354 n = strlen(bp) + 1; /* for the \0 */ 355 if (n >= MAXHOSTNAMELEN) { 356 had_error++; 357 break; 358 } 359 bp += n; 360 buflen -= n; 361 } 362 break; 363#else 364 host.h_name = bp; 365 if (_res.options & RES_USE_INET6) { 366 n = strlen(bp) + 1; /* for the \0 */ 367 if (n >= MAXHOSTNAMELEN) { 368 had_error++; 369 break; 370 } 371 bp += n; 372 buflen -= n; 373 _map_v4v6_hostent(&host, &bp, &buflen); 374 } 375 h_errno = NETDB_SUCCESS; 376 return (&host); 377#endif 378 case T_A: 379 case T_AAAA: 380 if (strcasecmp(host.h_name, bp) != 0) { 381 syslog(LOG_NOTICE|LOG_AUTH, 382 AskedForGot, host.h_name, bp); 383 cp += n; 384 continue; /* XXX - had_error++ ? */ 385 } 386 if (n != host.h_length) { 387 cp += n; 388 continue; 389 } 390 if (!haveanswer) { 391 int nn; 392 393 host.h_name = bp; 394 nn = strlen(bp) + 1; /* for the \0 */ 395 bp += nn; 396 buflen -= nn; 397 } 398 399 bp += sizeof(align) - ((u_long)bp % sizeof(align)); 400 401 if (bp + n >= &hostbuf[sizeof hostbuf]) { 402 dprintf("size (%d) too big\n", n); 403 had_error++; 404 continue; 405 } 406 if (hap >= &h_addr_ptrs[MAXADDRS-1]) { 407 if (!toobig++) 408 dprintf("Too many addresses (%d)\n", 409 MAXADDRS); 410 cp += n; 411 continue; 412 } 413 bcopy(cp, *hap++ = bp, n); 414 bp += n; 415 buflen -= n; 416 cp += n; 417 if (cp != erdata) { 418 h_errno = NO_RECOVERY; 419 return (NULL); 420 } 421 break; 422 default: 423 dprintf("Impossible condition (type=%d)\n", type); 424 h_errno = NO_RECOVERY; 425 return (NULL); 426 /* BIND has abort() here, too risky on bad data */ 427 } 428 if (!had_error) 429 haveanswer++; 430 } 431 if (haveanswer) { 432 *ap = NULL; 433 *hap = NULL; 434# if defined(RESOLVSORT) 435 /* 436 * Note: we sort even if host can take only one address 437 * in its return structures - should give it the "best" 438 * address in that case, not some random one 439 */ 440 if (_res.nsort && haveanswer > 1 && qtype == T_A) 441 addrsort(h_addr_ptrs, haveanswer); 442# endif /*RESOLVSORT*/ 443 if (!host.h_name) { 444 n = strlen(qname) + 1; /* for the \0 */ 445 if (n > buflen || n >= MAXHOSTNAMELEN) 446 goto no_recovery; 447 strcpy(bp, qname); 448 host.h_name = bp; 449 bp += n; 450 buflen -= n; 451 } 452 if (_res.options & RES_USE_INET6) 453 _map_v4v6_hostent(&host, &bp, &buflen); 454 h_errno = NETDB_SUCCESS; 455 return (&host); 456 } 457 no_recovery: 458 h_errno = NO_RECOVERY; 459 return (NULL); 460} 461 462struct hostent * 463__dns_getanswer(answer, anslen, qname, qtype) 464 const char *answer; 465 int anslen; 466 const char *qname; 467 int qtype; 468{ 469 switch(qtype) { 470 case T_AAAA: 471 host.h_addrtype = AF_INET6; 472 host.h_length = IN6ADDRSZ; 473 break; 474 case T_A: 475 default: 476 host.h_addrtype = AF_INET; 477 host.h_length = INADDRSZ; 478 break; 479 } 480 481 return(gethostanswer((const querybuf *)answer, anslen, qname, qtype)); 482} 483 484int 485_dns_gethostbyname(void *rval, void *cb_data, va_list ap) 486{ 487 const char *name; 488 int af; 489 querybuf buf; 490 const char *cp; 491 char *bp; 492 int n, size, type, len; 493 494 name = va_arg(ap, const char *); 495 af = va_arg(ap, int); 496 *(struct hostent **)rval = NULL; 497 498 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 499 h_errno = NETDB_INTERNAL; 500 return NS_UNAVAIL; 501 } 502 503 switch (af) { 504 case AF_INET: 505 size = INADDRSZ; 506 type = T_A; 507 break; 508 case AF_INET6: 509 size = IN6ADDRSZ; 510 type = T_AAAA; 511 break; 512 default: 513 h_errno = NETDB_INTERNAL; 514 errno = EAFNOSUPPORT; 515 return NS_UNAVAIL; 516 } 517 518 host.h_addrtype = af; 519 host.h_length = size; 520 521 /* 522 * if there aren't any dots, it could be a user-level alias. 523 * this is also done in res_query() since we are not the only 524 * function that looks up host names. 525 */ 526 if (!strchr(name, '.') && (cp = __hostalias(name))) 527 name = cp; 528 529 /* 530 * disallow names consisting only of digits/dots, unless 531 * they end in a dot. 532 */ 533 if (isdigit((unsigned char)name[0])) 534 for (cp = name;; ++cp) { 535 if (!*cp) { 536 if (*--cp == '.') 537 break; 538 /* 539 * All-numeric, no dot at the end. 540 * Fake up a hostent as if we'd actually 541 * done a lookup. 542 */ 543 if (inet_pton(af, name, host_addr) <= 0) { 544 h_errno = HOST_NOT_FOUND; 545 return NS_NOTFOUND; 546 } 547 strncpy(hostbuf, name, MAXDNAME); 548 hostbuf[MAXDNAME] = '\0'; 549 bp = hostbuf + MAXDNAME; 550 len = sizeof hostbuf - MAXDNAME; 551 host.h_name = hostbuf; 552 host.h_aliases = host_aliases; 553 host_aliases[0] = NULL; 554 h_addr_ptrs[0] = (char *)host_addr; 555 h_addr_ptrs[1] = NULL; 556 host.h_addr_list = h_addr_ptrs; 557 if (_res.options & RES_USE_INET6) 558 _map_v4v6_hostent(&host, &bp, &len); 559 h_errno = NETDB_SUCCESS; 560 *(struct hostent **)rval = &host; 561 return NS_SUCCESS; 562 } 563 if (!isdigit((unsigned char)*cp) && *cp != '.') 564 break; 565 } 566 if ((isxdigit((unsigned char)name[0]) && strchr(name, ':') != NULL) || 567 name[0] == ':') 568 for (cp = name;; ++cp) { 569 if (!*cp) { 570 if (*--cp == '.') 571 break; 572 /* 573 * All-IPv6-legal, no dot at the end. 574 * Fake up a hostent as if we'd actually 575 * done a lookup. 576 */ 577 if (inet_pton(af, name, host_addr) <= 0) { 578 h_errno = HOST_NOT_FOUND; 579 return NS_NOTFOUND; 580 } 581 strncpy(hostbuf, name, MAXDNAME); 582 hostbuf[MAXDNAME] = '\0'; 583 bp = hostbuf + MAXDNAME; 584 len = sizeof hostbuf - MAXDNAME; 585 host.h_name = hostbuf; 586 host.h_aliases = host_aliases; 587 host_aliases[0] = NULL; 588 h_addr_ptrs[0] = (char *)host_addr; 589 h_addr_ptrs[1] = NULL; 590 host.h_addr_list = h_addr_ptrs; 591 h_errno = NETDB_SUCCESS; 592 *(struct hostent **)rval = &host; 593 return NS_SUCCESS; 594 } 595 if (!isxdigit((unsigned char)*cp) && *cp != ':' && *cp != '.') 596 break; 597 } 598 599 if ((n = res_search(name, C_IN, type, buf.buf, sizeof(buf))) < 0) { 600 dprintf("res_search failed (%d)\n", n); 601 return NS_UNAVAIL; 602 } 603 *(struct hostent **)rval = gethostanswer(&buf, n, name, type); 604 return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND; 605} 606 607int 608_dns_gethostbyaddr(void *rval, void *cb_data, va_list ap) 609{ 610 const char *addr; /* XXX should have been def'd as u_char! */ 611 int len, af; 612 const u_char *uaddr; 613 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff }; 614 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 }; 615 int n, size; 616 querybuf buf; 617 struct hostent *hp; 618 char qbuf[MAXDNAME+1], *qp; 619#ifdef SUNSECURITY 620 struct hostent *rhp; 621 char **haddr; 622 u_long old_options; 623 char hname2[MAXDNAME+1]; 624#endif /*SUNSECURITY*/ 625 626 addr = va_arg(ap, const char *); 627 uaddr = (const u_char *)addr; 628 len = va_arg(ap, int); 629 af = va_arg(ap, int); 630 631 *(struct hostent **)rval = NULL; 632 633 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 634 h_errno = NETDB_INTERNAL; 635 return NS_UNAVAIL; 636 } 637 if (af == AF_INET6 && len == IN6ADDRSZ && 638 (!bcmp(uaddr, mapped, sizeof mapped) || 639 !bcmp(uaddr, tunnelled, sizeof tunnelled))) { 640 /* Unmap. */ 641 addr += sizeof mapped; 642 uaddr += sizeof mapped; 643 af = AF_INET; 644 len = INADDRSZ; 645 } 646 switch (af) { 647 case AF_INET: 648 size = INADDRSZ; 649 break; 650 case AF_INET6: 651 size = IN6ADDRSZ; 652 break; 653 default: 654 errno = EAFNOSUPPORT; 655 h_errno = NETDB_INTERNAL; 656 return NS_UNAVAIL; 657 } 658 if (size != len) { 659 errno = EINVAL; 660 h_errno = NETDB_INTERNAL; 661 return NS_UNAVAIL; 662 } 663 switch (af) { 664 case AF_INET: 665 (void) sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", 666 (uaddr[3] & 0xff), 667 (uaddr[2] & 0xff), 668 (uaddr[1] & 0xff), 669 (uaddr[0] & 0xff)); 670 break; 671 case AF_INET6: 672 qp = qbuf; 673 for (n = IN6ADDRSZ - 1; n >= 0; n--) { 674 qp += SPRINTF((qp, "%x.%x.", 675 uaddr[n] & 0xf, 676 (uaddr[n] >> 4) & 0xf)); 677 } 678 strcpy(qp, "ip6.int"); 679 break; 680 default: 681 abort(); 682 } 683 n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf.buf, sizeof buf.buf); 684 if (n < 0) { 685 dprintf("res_query failed (%d)\n", n); 686 return NS_UNAVAIL; 687 } 688 if (n > sizeof buf.buf) { 689 dprintf("static buffer is too small (%d)\n", n); 690 return NS_UNAVAIL; 691 } 692 if (!(hp = gethostanswer(&buf, n, qbuf, T_PTR))) 693 return NS_NOTFOUND; /* h_errno was set by gethostanswer() */ 694#ifdef SUNSECURITY 695 if (af == AF_INET) { 696 /* 697 * turn off search as the name should be absolute, 698 * 'localhost' should be matched by defnames 699 */ 700 strncpy(hname2, hp->h_name, MAXDNAME); 701 hname2[MAXDNAME] = '\0'; 702 old_options = _res.options; 703 _res.options &= ~RES_DNSRCH; 704 _res.options |= RES_DEFNAMES; 705 if (!(rhp = gethostbyname(hname2))) { 706 syslog(LOG_NOTICE|LOG_AUTH, 707 "gethostbyaddr: No A record for %s (verifying [%s])", 708 hname2, inet_ntoa(*((struct in_addr *)addr))); 709 _res.options = old_options; 710 h_errno = HOST_NOT_FOUND; 711 return NS_NOTFOUND; 712 } 713 _res.options = old_options; 714 for (haddr = rhp->h_addr_list; *haddr; haddr++) 715 if (!memcmp(*haddr, addr, INADDRSZ)) 716 break; 717 if (!*haddr) { 718 syslog(LOG_NOTICE|LOG_AUTH, 719 "gethostbyaddr: A record of %s != PTR record [%s]", 720 hname2, inet_ntoa(*((struct in_addr *)addr))); 721 h_errno = HOST_NOT_FOUND; 722 return NS_NOTFOUND; 723 } 724 } 725#endif /*SUNSECURITY*/ 726 hp->h_addrtype = af; 727 hp->h_length = len; 728 bcopy(addr, host_addr, len); 729 h_addr_ptrs[0] = (char *)host_addr; 730 h_addr_ptrs[1] = NULL; 731 if (af == AF_INET && (_res.options & RES_USE_INET6)) { 732 _map_v4v6_address((char*)host_addr, (char*)host_addr); 733 hp->h_addrtype = AF_INET6; 734 hp->h_length = IN6ADDRSZ; 735 } 736 h_errno = NETDB_SUCCESS; 737 *(struct hostent **)rval = hp; 738 return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND; 739} 740 741#ifdef RESOLVSORT 742static void 743addrsort(ap, num) 744 char **ap; 745 int num; 746{ 747 int i, j; 748 char **p; 749 short aval[MAXADDRS]; 750 int needsort = 0; 751 752 p = ap; 753 for (i = 0; i < num; i++, p++) { 754 for (j = 0 ; (unsigned)j < _res.nsort; j++) 755 if (_res.sort_list[j].addr.s_addr == 756 (((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask)) 757 break; 758 aval[i] = j; 759 if (needsort == 0 && i > 0 && j < aval[i-1]) 760 needsort = i; 761 } 762 if (!needsort) 763 return; 764 765 while (needsort < num) { 766 for (j = needsort - 1; j >= 0; j--) { 767 if (aval[j] > aval[j+1]) { 768 char *hp; 769 770 i = aval[j]; 771 aval[j] = aval[j+1]; 772 aval[j+1] = i; 773 774 hp = ap[j]; 775 ap[j] = ap[j+1]; 776 ap[j+1] = hp; 777 778 } else 779 break; 780 } 781 needsort++; 782 } 783} 784#endif 785void 786_sethostdnsent(stayopen) 787 int stayopen; 788{ 789 if ((_res.options & RES_INIT) == 0 && res_init() == -1) 790 return; 791 if (stayopen) 792 _res.options |= RES_STAYOPEN | RES_USEVC; 793} 794 795void 796_endhostdnsent() 797{ 798 _res.options &= ~(RES_STAYOPEN | RES_USEVC); 799 res_close(); 800} 801