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 1.5 2005/09/19 09:34:53 asmodai 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 74 #include "res_config.h" 75 76 #define SPRINTF(x) ((size_t)sprintf x) 77 78 #define MAXALIASES 35 79 #define MAXADDRS 35 80 81 static const char AskedForGot[] = 82 "gethostby*.gethostanswer: asked for \"%s\", got \"%s\""; 83 84 static char *h_addr_ptrs[MAXADDRS + 1]; 85 86 static struct hostent host; 87 static char *host_aliases[MAXALIASES]; 88 static char hostbuf[8*1024]; 89 static u_char host_addr[16]; /* IPv4 or IPv6 */ 90 91 #ifdef RESOLVSORT 92 static void addrsort (char **, int); 93 #endif 94 95 #define MAXPACKET (64*1024) 96 97 typedef union { 98 HEADER hdr; 99 u_char buf[MAXPACKET]; 100 } querybuf; 101 102 typedef union { 103 int32_t al; 104 char ac; 105 } align; 106 107 extern int h_errno; 108 int _dns_ttl_; 109 110 #ifdef DEBUG 111 static void 112 dprintf(msg, num) 113 char *msg; 114 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(answer, anslen, qname, qtype) 146 const querybuf *answer; 147 int anslen; 148 const char *qname; 149 int qtype; 150 { 151 const HEADER *hp; 152 const u_char *cp; 153 int n; 154 const u_char *eom, *erdata; 155 char *bp, **ap, **hap; 156 int type, class, buflen, ancount, qdcount; 157 int haveanswer, had_error; 158 int toobig = 0; 159 char tbuf[MAXDNAME]; 160 const char *tname; 161 int (*name_ok) (const char *); 162 163 tname = qname; 164 host.h_name = NULL; 165 eom = answer->buf + anslen; 166 switch (qtype) { 167 case T_A: 168 case T_AAAA: 169 name_ok = res_hnok; 170 break; 171 case T_PTR: 172 name_ok = res_dnok; 173 break; 174 default: 175 h_errno = NO_RECOVERY; 176 return (NULL); /* XXX should be abort(); */ 177 } 178 /* 179 * find first satisfactory answer 180 */ 181 hp = &answer->hdr; 182 ancount = ntohs(hp->ancount); 183 qdcount = ntohs(hp->qdcount); 184 bp = hostbuf; 185 buflen = sizeof hostbuf; 186 cp = answer->buf; 187 BOUNDED_INCR(HFIXEDSZ); 188 if (qdcount != 1) { 189 h_errno = NO_RECOVERY; 190 return (NULL); 191 } 192 n = dn_expand(answer->buf, eom, cp, bp, buflen); 193 if ((n < 0) || !(*name_ok)(bp)) { 194 h_errno = NO_RECOVERY; 195 return (NULL); 196 } 197 BOUNDED_INCR(n + QFIXEDSZ); 198 if (qtype == T_A || qtype == T_AAAA) { 199 /* res_send() has already verified that the query name is the 200 * same as the one we sent; this just gets the expanded name 201 * (i.e., with the succeeding search-domain tacked on). 202 */ 203 n = strlen(bp) + 1; /* for the \0 */ 204 if (n >= MAXHOSTNAMELEN) { 205 h_errno = NO_RECOVERY; 206 return (NULL); 207 } 208 host.h_name = bp; 209 bp += n; 210 buflen -= n; 211 /* The qname can be abbreviated, but h_name is now absolute. */ 212 qname = host.h_name; 213 } 214 ap = host_aliases; 215 *ap = NULL; 216 host.h_aliases = host_aliases; 217 hap = h_addr_ptrs; 218 *hap = NULL; 219 host.h_addr_list = h_addr_ptrs; 220 haveanswer = 0; 221 had_error = 0; 222 _dns_ttl_ = -1; 223 while (ancount-- > 0 && cp < eom && !had_error) { 224 n = dn_expand(answer->buf, eom, cp, bp, buflen); 225 if ((n < 0) || !(*name_ok)(bp)) { 226 had_error++; 227 continue; 228 } 229 cp += n; /* name */ 230 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 231 type = _getshort(cp); 232 cp += INT16SZ; /* type */ 233 class = _getshort(cp); 234 cp += INT16SZ; /* class */ 235 if (qtype == T_A && type == T_A) 236 _dns_ttl_ = _getlong(cp); 237 cp += INT32SZ; /* TTL */ 238 n = _getshort(cp); 239 cp += INT16SZ; /* len */ 240 BOUNDS_CHECK(cp, n); 241 erdata = cp + n; 242 if (class != C_IN) { 243 /* XXX - debug? syslog? */ 244 cp += n; 245 continue; /* XXX - had_error++ ? */ 246 } 247 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 248 if (ap >= &host_aliases[MAXALIASES-1]) 249 continue; 250 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 251 if ((n < 0) || !(*name_ok)(tbuf)) { 252 had_error++; 253 continue; 254 } 255 cp += n; 256 if (cp != erdata) { 257 h_errno = NO_RECOVERY; 258 return (NULL); 259 } 260 /* Store alias. */ 261 *ap++ = bp; 262 n = strlen(bp) + 1; /* for the \0 */ 263 if (n >= MAXHOSTNAMELEN) { 264 had_error++; 265 continue; 266 } 267 bp += n; 268 buflen -= n; 269 /* Get canonical name. */ 270 n = strlen(tbuf) + 1; /* for the \0 */ 271 if (n > buflen || n >= MAXHOSTNAMELEN) { 272 had_error++; 273 continue; 274 } 275 strcpy(bp, tbuf); 276 host.h_name = bp; 277 bp += n; 278 buflen -= n; 279 continue; 280 } 281 if (qtype == T_PTR && type == T_CNAME) { 282 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 283 if (n < 0 || !res_dnok(tbuf)) { 284 had_error++; 285 continue; 286 } 287 cp += n; 288 if (cp != erdata) { 289 h_errno = NO_RECOVERY; 290 return (NULL); 291 } 292 /* Get canonical name. */ 293 n = strlen(tbuf) + 1; /* for the \0 */ 294 if (n > buflen || n >= MAXHOSTNAMELEN) { 295 had_error++; 296 continue; 297 } 298 strcpy(bp, tbuf); 299 tname = bp; 300 bp += n; 301 buflen -= n; 302 continue; 303 } 304 if (type != qtype) { 305 if (type != T_SIG) 306 syslog(LOG_NOTICE|LOG_AUTH, 307 "gethostby*.gethostanswer: asked for \"%s %s %s\", got type \"%s\"", 308 qname, p_class(C_IN), p_type(qtype), 309 p_type(type)); 310 cp += n; 311 continue; /* XXX - had_error++ ? */ 312 } 313 switch (type) { 314 case T_PTR: 315 if (strcasecmp(tname, bp) != 0) { 316 syslog(LOG_NOTICE|LOG_AUTH, 317 AskedForGot, qname, bp); 318 cp += n; 319 continue; /* XXX - had_error++ ? */ 320 } 321 n = dn_expand(answer->buf, eom, cp, bp, buflen); 322 if ((n < 0) || !res_hnok(bp)) { 323 had_error++; 324 break; 325 } 326 #if MULTI_PTRS_ARE_ALIASES 327 cp += n; 328 if (cp != erdata) { 329 h_errno = NO_RECOVERY; 330 return (NULL); 331 } 332 if (!haveanswer) 333 host.h_name = bp; 334 else if (ap < &host_aliases[MAXALIASES-1]) 335 *ap++ = bp; 336 else 337 n = -1; 338 if (n != -1) { 339 n = strlen(bp) + 1; /* for the \0 */ 340 if (n >= MAXHOSTNAMELEN) { 341 had_error++; 342 break; 343 } 344 bp += n; 345 buflen -= n; 346 } 347 break; 348 #else 349 host.h_name = bp; 350 if (_res.options & RES_USE_INET6) { 351 n = strlen(bp) + 1; /* for the \0 */ 352 if (n >= MAXHOSTNAMELEN) { 353 had_error++; 354 break; 355 } 356 bp += n; 357 buflen -= n; 358 _map_v4v6_hostent(&host, &bp, &buflen); 359 } 360 h_errno = NETDB_SUCCESS; 361 return (&host); 362 #endif 363 case T_A: 364 case T_AAAA: 365 if (strcasecmp(host.h_name, bp) != 0) { 366 syslog(LOG_NOTICE|LOG_AUTH, 367 AskedForGot, host.h_name, bp); 368 cp += n; 369 continue; /* XXX - had_error++ ? */ 370 } 371 if (n != host.h_length) { 372 cp += n; 373 continue; 374 } 375 if (!haveanswer) { 376 int nn; 377 378 host.h_name = bp; 379 nn = strlen(bp) + 1; /* for the \0 */ 380 bp += nn; 381 buflen -= nn; 382 } 383 384 buflen -= sizeof(align) - ((u_long)bp % sizeof(align)); 385 bp += sizeof(align) - ((u_long)bp % sizeof(align)); 386 387 if (bp + n >= &hostbuf[sizeof hostbuf]) { 388 dprintf("size (%d) too big\n", n); 389 had_error++; 390 continue; 391 } 392 if (hap >= &h_addr_ptrs[MAXADDRS-1]) { 393 if (!toobig++) 394 dprintf("Too many addresses (%d)\n", 395 MAXADDRS); 396 cp += n; 397 continue; 398 } 399 bcopy(cp, *hap++ = bp, n); 400 bp += n; 401 buflen -= n; 402 cp += n; 403 if (cp != erdata) { 404 h_errno = NO_RECOVERY; 405 return (NULL); 406 } 407 break; 408 default: 409 dprintf("Impossible condition (type=%d)\n", type); 410 h_errno = NO_RECOVERY; 411 return (NULL); 412 /* BIND has abort() here, too risky on bad data */ 413 } 414 if (!had_error) 415 haveanswer++; 416 } 417 if (haveanswer) { 418 *ap = NULL; 419 *hap = NULL; 420 # if defined(RESOLVSORT) 421 /* 422 * Note: we sort even if host can take only one address 423 * in its return structures - should give it the "best" 424 * address in that case, not some random one 425 */ 426 if (_res.nsort && haveanswer > 1 && qtype == T_A) 427 addrsort(h_addr_ptrs, haveanswer); 428 # endif /*RESOLVSORT*/ 429 if (!host.h_name) { 430 n = strlen(qname) + 1; /* for the \0 */ 431 if (n > buflen || n >= MAXHOSTNAMELEN) 432 goto no_recovery; 433 strcpy(bp, qname); 434 host.h_name = bp; 435 bp += n; 436 buflen -= n; 437 } 438 if (_res.options & RES_USE_INET6) 439 _map_v4v6_hostent(&host, &bp, &buflen); 440 h_errno = NETDB_SUCCESS; 441 return (&host); 442 } 443 no_recovery: 444 h_errno = NO_RECOVERY; 445 return (NULL); 446 } 447 448 struct hostent * 449 __dns_getanswer(answer, anslen, qname, qtype) 450 const char *answer; 451 int anslen; 452 const char *qname; 453 int qtype; 454 { 455 switch(qtype) { 456 case T_AAAA: 457 host.h_addrtype = AF_INET6; 458 host.h_length = IN6ADDRSZ; 459 break; 460 case T_A: 461 default: 462 host.h_addrtype = AF_INET; 463 host.h_length = INADDRSZ; 464 break; 465 } 466 467 return(gethostanswer((const querybuf *)answer, anslen, qname, qtype)); 468 } 469 470 struct hostent * 471 _gethostbydnsname(name, af) 472 const char *name; 473 int af; 474 { 475 querybuf *buf; 476 const char *cp; 477 char *bp; 478 int n, size, type, len; 479 struct hostent *hp; 480 481 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 482 h_errno = NETDB_INTERNAL; 483 return (NULL); 484 } 485 486 switch (af) { 487 case AF_INET: 488 size = INADDRSZ; 489 type = T_A; 490 break; 491 case AF_INET6: 492 size = IN6ADDRSZ; 493 type = T_AAAA; 494 break; 495 default: 496 h_errno = NETDB_INTERNAL; 497 errno = EAFNOSUPPORT; 498 return (NULL); 499 } 500 501 host.h_addrtype = af; 502 host.h_length = size; 503 504 /* 505 * if there aren't any dots, it could be a user-level alias. 506 * this is also done in res_query() since we are not the only 507 * function that looks up host names. 508 */ 509 if (!strchr(name, '.') && (cp = __hostalias(name))) 510 name = cp; 511 512 /* 513 * disallow names consisting only of digits/dots, unless 514 * they end in a dot. 515 */ 516 if (isdigit((unsigned char)name[0])) 517 for (cp = name;; ++cp) { 518 if (!*cp) { 519 if (*--cp == '.') 520 break; 521 /* 522 * All-numeric, no dot at the end. 523 * Fake up a hostent as if we'd actually 524 * done a lookup. 525 */ 526 if (inet_pton(af, name, host_addr) <= 0) { 527 h_errno = HOST_NOT_FOUND; 528 return (NULL); 529 } 530 strncpy(hostbuf, name, MAXDNAME); 531 hostbuf[MAXDNAME] = '\0'; 532 bp = hostbuf + MAXDNAME; 533 len = sizeof hostbuf - MAXDNAME; 534 host.h_name = hostbuf; 535 host.h_aliases = host_aliases; 536 host_aliases[0] = NULL; 537 h_addr_ptrs[0] = (char *)host_addr; 538 h_addr_ptrs[1] = NULL; 539 host.h_addr_list = h_addr_ptrs; 540 if (_res.options & RES_USE_INET6) 541 _map_v4v6_hostent(&host, &bp, &len); 542 h_errno = NETDB_SUCCESS; 543 return (&host); 544 } 545 if (!isdigit((unsigned char)*cp) && *cp != '.') 546 break; 547 } 548 if ((isxdigit((unsigned char)name[0]) && strchr(name, ':') != NULL) || 549 name[0] == ':') 550 for (cp = name;; ++cp) { 551 if (!*cp) { 552 if (*--cp == '.') 553 break; 554 /* 555 * All-IPv6-legal, no dot at the end. 556 * Fake up a hostent as if we'd actually 557 * done a lookup. 558 */ 559 if (inet_pton(af, name, host_addr) <= 0) { 560 h_errno = HOST_NOT_FOUND; 561 return (NULL); 562 } 563 strncpy(hostbuf, name, MAXDNAME); 564 hostbuf[MAXDNAME] = '\0'; 565 bp = hostbuf + MAXDNAME; 566 len = sizeof hostbuf - MAXDNAME; 567 host.h_name = hostbuf; 568 host.h_aliases = host_aliases; 569 host_aliases[0] = NULL; 570 h_addr_ptrs[0] = (char *)host_addr; 571 h_addr_ptrs[1] = NULL; 572 host.h_addr_list = h_addr_ptrs; 573 h_errno = NETDB_SUCCESS; 574 return (&host); 575 } 576 if (!isxdigit((unsigned char)*cp) && *cp != ':' && *cp != '.') 577 break; 578 } 579 580 if ((buf = malloc(sizeof(*buf))) == NULL) { 581 h_errno = NETDB_INTERNAL; 582 return (NULL); 583 } 584 n = res_search(name, C_IN, type, buf->buf, sizeof(buf->buf)); 585 if (n < 0) { 586 free(buf); 587 dprintf("res_search failed (%d)\n", n); 588 return (NULL); 589 } else if (n > sizeof(buf->buf)) { 590 free(buf); 591 dprintf("static buffer is too small (%d)\n", n); 592 return (NULL); 593 } 594 hp = gethostanswer(buf, n, name, type); 595 free(buf); 596 return (hp); 597 } 598 599 struct hostent * 600 _gethostbydnsaddr(addr, len, af) 601 const char *addr; /* XXX should have been def'd as u_char! */ 602 int len, af; 603 { 604 const u_char *uaddr = (const u_char *)addr; 605 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff }; 606 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 }; 607 int n, size; 608 querybuf *buf; 609 struct hostent *hp; 610 char qbuf[MAXDNAME+1], *qp; 611 #ifdef SUNSECURITY 612 struct hostent *rhp; 613 char **haddr; 614 u_long old_options; 615 char hname2[MAXDNAME+1]; 616 #endif /*SUNSECURITY*/ 617 618 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 619 h_errno = NETDB_INTERNAL; 620 return (NULL); 621 } 622 if (af == AF_INET6 && len == IN6ADDRSZ && 623 (!bcmp(uaddr, mapped, sizeof mapped) || 624 !bcmp(uaddr, tunnelled, sizeof tunnelled))) { 625 /* Unmap. */ 626 addr += sizeof mapped; 627 uaddr += sizeof mapped; 628 af = AF_INET; 629 len = INADDRSZ; 630 } 631 switch (af) { 632 case AF_INET: 633 size = INADDRSZ; 634 break; 635 case AF_INET6: 636 size = IN6ADDRSZ; 637 break; 638 default: 639 errno = EAFNOSUPPORT; 640 h_errno = NETDB_INTERNAL; 641 return (NULL); 642 } 643 if (size != len) { 644 errno = EINVAL; 645 h_errno = NETDB_INTERNAL; 646 return (NULL); 647 } 648 switch (af) { 649 case AF_INET: 650 (void) sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", 651 (uaddr[3] & 0xff), 652 (uaddr[2] & 0xff), 653 (uaddr[1] & 0xff), 654 (uaddr[0] & 0xff)); 655 break; 656 case AF_INET6: 657 qp = qbuf; 658 for (n = IN6ADDRSZ - 1; n >= 0; n--) { 659 qp += SPRINTF((qp, "%x.%x.", 660 uaddr[n] & 0xf, 661 (uaddr[n] >> 4) & 0xf)); 662 } 663 strlcat(qbuf, "ip6.arpa", sizeof(qbuf)); 664 break; 665 default: 666 abort(); 667 } 668 if ((buf = malloc(sizeof(*buf))) == NULL) { 669 h_errno = NETDB_INTERNAL; 670 return (NULL); 671 } 672 n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf->buf, sizeof buf->buf); 673 if (n < 0 && af == AF_INET6) { 674 *qp = '\0'; 675 strlcat(qbuf, "ip6.int", sizeof(qbuf)); 676 n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf->buf, 677 sizeof buf->buf); 678 } 679 if (n < 0) { 680 free(buf); 681 dprintf("res_query failed (%d)\n", n); 682 return (NULL); 683 } 684 if (n > sizeof buf->buf) { 685 free(buf); 686 dprintf("static buffer is too small (%d)\n", n); 687 return (NULL); 688 } 689 if (!(hp = gethostanswer(buf, n, qbuf, T_PTR))) { 690 free(buf); 691 return (NULL); /* h_errno was set by gethostanswer() */ 692 } 693 free(buf); 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 (NULL); 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 (NULL); 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 return (hp); 738 } 739 740 #ifdef RESOLVSORT 741 static void 742 addrsort(ap, num) 743 char **ap; 744 int num; 745 { 746 int i, j; 747 char **p; 748 short aval[MAXADDRS]; 749 int needsort = 0; 750 751 p = ap; 752 for (i = 0; i < num; i++, p++) { 753 for (j = 0 ; (unsigned)j < _res.nsort; j++) 754 if (_res.sort_list[j].addr.s_addr == 755 (((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask)) 756 break; 757 aval[i] = j; 758 if (needsort == 0 && i > 0 && j < aval[i-1]) 759 needsort = i; 760 } 761 if (!needsort) 762 return; 763 764 while (needsort < num) { 765 for (j = needsort - 1; j >= 0; j--) { 766 if (aval[j] > aval[j+1]) { 767 char *hp; 768 769 i = aval[j]; 770 aval[j] = aval[j+1]; 771 aval[j+1] = i; 772 773 hp = ap[j]; 774 ap[j] = ap[j+1]; 775 ap[j+1] = hp; 776 777 } else 778 break; 779 } 780 needsort++; 781 } 782 } 783 #endif 784 void 785 _sethostdnsent(stayopen) 786 int stayopen; 787 { 788 if ((_res.options & RES_INIT) == 0 && res_init() == -1) 789 return; 790 if (stayopen) 791 _res.options |= RES_STAYOPEN | RES_USEVC; 792 } 793 794 void 795 _endhostdnsent() 796 { 797 _res.options &= ~(RES_STAYOPEN | RES_USEVC); 798 res_close(); 799 } 800