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 "netdb_private.h" 83 #include "res_config.h" 84 85 #define SPRINTF(x) ((size_t)sprintf x) 86 87 static const char AskedForGot[] = 88 "gethostby*.gethostanswer: asked for \"%s\", got \"%s\""; 89 90 #ifdef RESOLVSORT 91 static void addrsort(char **, int, res_state); 92 #endif 93 94 #ifdef DEBUG 95 static void dprintf(char *, int, res_state) __printflike(1, 0); 96 #endif 97 98 #define MAXPACKET (64*1024) 99 100 typedef union { 101 HEADER hdr; 102 u_char buf[MAXPACKET]; 103 } querybuf; 104 105 typedef union { 106 int32_t al; 107 char ac; 108 } align; 109 110 int _dns_ttl_; 111 112 #ifdef DEBUG 113 static void 114 dprintf(msg, num, res) 115 char *msg; 116 int num; 117 res_state res; 118 { 119 if (res->options & RES_DEBUG) { 120 int save = errno; 121 122 printf(msg, num); 123 errno = save; 124 } 125 } 126 #else 127 # define dprintf(msg, num, res) /*nada*/ 128 #endif 129 130 #define BOUNDED_INCR(x) \ 131 do { \ 132 cp += x; \ 133 if (cp > eom) { \ 134 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); \ 135 return -1; \ 136 } \ 137 } while (0) 138 139 #define BOUNDS_CHECK(ptr, count) \ 140 do { \ 141 if ((ptr) + (count) > eom) { \ 142 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); \ 143 return -1; \ 144 } \ 145 } while (0) 146 147 static int 148 gethostanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 149 struct hostent *he, struct hostent_data *hed) 150 { 151 const HEADER *hp; 152 const u_char *cp; 153 int n; 154 const u_char *eom, *erdata; 155 char *bp, *ep, **ap, **hap; 156 int type, class, 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 he->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 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); 176 return -1; /* 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 = hed->hostbuf; 185 ep = hed->hostbuf + sizeof hed->hostbuf; 186 cp = answer->buf; 187 BOUNDED_INCR(HFIXEDSZ); 188 if (qdcount != 1) { 189 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); 190 return -1; 191 } 192 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 193 if ((n < 0) || !(*name_ok)(bp)) { 194 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); 195 return -1; 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 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); 206 return -1; 207 } 208 he->h_name = bp; 209 bp += n; 210 /* The qname can be abbreviated, but h_name is now absolute. */ 211 qname = he->h_name; 212 } 213 ap = hed->host_aliases; 214 *ap = NULL; 215 he->h_aliases = hed->host_aliases; 216 hap = hed->h_addr_ptrs; 217 *hap = NULL; 218 he->h_addr_list = hed->h_addr_ptrs; 219 haveanswer = 0; 220 had_error = 0; 221 _dns_ttl_ = -1; 222 while (ancount-- > 0 && cp < eom && !had_error) { 223 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 224 if ((n < 0) || !(*name_ok)(bp)) { 225 had_error++; 226 continue; 227 } 228 cp += n; /* name */ 229 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 230 type = _getshort(cp); 231 cp += INT16SZ; /* type */ 232 class = _getshort(cp); 233 cp += INT16SZ; /* class */ 234 if (qtype == T_A && type == T_A) 235 _dns_ttl_ = _getlong(cp); 236 cp += INT32SZ; /* TTL */ 237 n = _getshort(cp); 238 cp += INT16SZ; /* len */ 239 BOUNDS_CHECK(cp, n); 240 erdata = cp + n; 241 if (class != C_IN) { 242 /* XXX - debug? syslog? */ 243 cp += n; 244 continue; /* XXX - had_error++ ? */ 245 } 246 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 247 if (ap >= &hed->host_aliases[_MAXALIASES-1]) 248 continue; 249 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 250 if ((n < 0) || !(*name_ok)(tbuf)) { 251 had_error++; 252 continue; 253 } 254 cp += n; 255 if (cp != erdata) { 256 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); 257 return -1; 258 } 259 /* Store alias. */ 260 *ap++ = bp; 261 n = strlen(bp) + 1; /* for the \0 */ 262 if (n >= MAXHOSTNAMELEN) { 263 had_error++; 264 continue; 265 } 266 bp += n; 267 /* Get canonical name. */ 268 n = strlen(tbuf) + 1; /* for the \0 */ 269 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 270 had_error++; 271 continue; 272 } 273 strcpy(bp, tbuf); 274 he->h_name = bp; 275 bp += n; 276 continue; 277 } 278 if (qtype == T_PTR && type == T_CNAME) { 279 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 280 if (n < 0 || !res_dnok(tbuf)) { 281 had_error++; 282 continue; 283 } 284 cp += n; 285 if (cp != erdata) { 286 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); 287 return -1; 288 } 289 /* Get canonical name. */ 290 n = strlen(tbuf) + 1; /* for the \0 */ 291 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 292 had_error++; 293 continue; 294 } 295 strcpy(bp, tbuf); 296 tname = bp; 297 bp += 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, ep - bp); 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 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); 326 return -1; 327 } 328 if (!haveanswer) 329 he->h_name = bp; 330 else if (ap < &hed->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 } 342 break; 343 #else 344 he->h_name = bp; 345 if (hed->res->options & RES_USE_INET6) { 346 n = strlen(bp) + 1; /* for the \0 */ 347 if (n >= MAXHOSTNAMELEN) { 348 had_error++; 349 break; 350 } 351 bp += n; 352 _map_v4v6_hostent(he, &bp, ep); 353 } 354 RES_SET_H_ERRNO(hed->res, NETDB_SUCCESS); 355 return 0; 356 #endif 357 case T_A: 358 case T_AAAA: 359 if (strcasecmp(he->h_name, bp) != 0) { 360 syslog(LOG_NOTICE|LOG_AUTH, 361 AskedForGot, he->h_name, bp); 362 cp += n; 363 continue; /* XXX - had_error++ ? */ 364 } 365 if (n != he->h_length) { 366 cp += n; 367 continue; 368 } 369 if (!haveanswer) { 370 int nn; 371 372 he->h_name = bp; 373 nn = strlen(bp) + 1; /* for the \0 */ 374 bp += nn; 375 } 376 377 bp += sizeof(align) - ((u_long)bp % sizeof(align)); 378 379 if (bp + n >= ep) { 380 dprintf("size (%d) too big\n", n, hed->res); 381 had_error++; 382 continue; 383 } 384 if (hap >= &hed->h_addr_ptrs[_MAXADDRS-1]) { 385 if (!toobig++) 386 dprintf("Too many addresses (%d)\n", 387 _MAXADDRS, hed->res); 388 cp += n; 389 continue; 390 } 391 memcpy(*hap++ = bp, cp, n); 392 bp += n; 393 cp += n; 394 if (cp != erdata) { 395 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); 396 return -1; 397 } 398 break; 399 default: 400 dprintf("Impossible condition (type=%d)\n", type, 401 hed->res); 402 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); 403 return -1; 404 /* BIND has abort() here, too risky on bad data */ 405 } 406 if (!had_error) 407 haveanswer++; 408 } 409 if (haveanswer) { 410 *ap = NULL; 411 *hap = NULL; 412 # if defined(RESOLVSORT) 413 /* 414 * Note: we sort even if host can take only one address 415 * in its return structures - should give it the "best" 416 * address in that case, not some random one 417 */ 418 if (hed->res->nsort && haveanswer > 1 && qtype == T_A) 419 addrsort(hed->h_addr_ptrs, haveanswer, hed->res); 420 # endif /*RESOLVSORT*/ 421 if (!he->h_name) { 422 n = strlen(qname) + 1; /* for the \0 */ 423 if (n > ep - bp || n >= MAXHOSTNAMELEN) 424 goto no_recovery; 425 strcpy(bp, qname); 426 he->h_name = bp; 427 bp += n; 428 } 429 if (hed->res->options & RES_USE_INET6) 430 _map_v4v6_hostent(he, &bp, ep); 431 RES_SET_H_ERRNO(hed->res, NETDB_SUCCESS); 432 return 0; 433 } 434 no_recovery: 435 RES_SET_H_ERRNO(hed->res, NO_RECOVERY); 436 return -1; 437 } 438 439 /* XXX: for async DNS resolver in ypserv */ 440 struct hostent * 441 __dns_getanswer(const char *answer, int anslen, const char *qname, int qtype) 442 { 443 struct hostdata *hd; 444 int error; 445 res_state statp; 446 447 statp = __res_state(); 448 if ((hd = __hostdata_init()) == NULL) { 449 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 450 return NULL; 451 } 452 hd->data.res = statp; 453 switch (qtype) { 454 case T_AAAA: 455 hd->host.h_addrtype = AF_INET6; 456 hd->host.h_length = IN6ADDRSZ; 457 break; 458 case T_A: 459 default: 460 hd->host.h_addrtype = AF_INET; 461 hd->host.h_length = INADDRSZ; 462 break; 463 } 464 465 error = gethostanswer((const querybuf *)answer, anslen, qname, qtype, 466 &hd->host, &hd->data); 467 return (error == 0) ? &hd->host : NULL; 468 } 469 470 int 471 _dns_gethostbyname(void *rval, void *cb_data, va_list ap) 472 { 473 const char *name; 474 int af; 475 struct hostent *he; 476 struct hostent_data *hed; 477 querybuf *buf; 478 int n, size, type, error; 479 480 name = va_arg(ap, const char *); 481 af = va_arg(ap, int); 482 he = va_arg(ap, struct hostent *); 483 hed = va_arg(ap, struct hostent_data *); 484 485 switch (af) { 486 case AF_INET: 487 size = INADDRSZ; 488 type = T_A; 489 break; 490 case AF_INET6: 491 size = IN6ADDRSZ; 492 type = T_AAAA; 493 break; 494 default: 495 RES_SET_H_ERRNO(hed->res, NETDB_INTERNAL); 496 errno = EAFNOSUPPORT; 497 return NS_UNAVAIL; 498 } 499 500 he->h_addrtype = af; 501 he->h_length = size; 502 503 if ((buf = malloc(sizeof(*buf))) == NULL) { 504 RES_SET_H_ERRNO(hed->res, NETDB_INTERNAL); 505 return NS_NOTFOUND; 506 } 507 n = res_nsearch(hed->res, name, C_IN, type, buf->buf, sizeof(buf->buf)); 508 if (n < 0) { 509 free(buf); 510 dprintf("res_nsearch failed (%d)\n", n, hed->res); 511 return (0); 512 } else if (n > sizeof(buf->buf)) { 513 free(buf); 514 dprintf("static buffer is too small (%d)\n", n, hed->res); 515 return (0); 516 } 517 error = gethostanswer(buf, n, name, type, he, hed); 518 free(buf); 519 return (error == 0) ? NS_SUCCESS : NS_NOTFOUND; 520 } 521 522 int 523 _dns_gethostbyaddr(void *rval, void *cb_data, va_list ap) 524 { 525 const u_char *uaddr; 526 int len, af; 527 struct hostent *he; 528 struct hostent_data *hed; 529 int n, error; 530 querybuf *buf; 531 char qbuf[MAXDNAME+1], *qp; 532 #ifdef SUNSECURITY 533 struct hostdata rhd; 534 struct hostent *rhe; 535 char **haddr; 536 u_long old_options; 537 char hname2[MAXDNAME+1], numaddr[46]; 538 #endif /*SUNSECURITY*/ 539 540 uaddr = va_arg(ap, const u_char *); 541 len = va_arg(ap, int); 542 af = va_arg(ap, int); 543 he = va_arg(ap, struct hostent *); 544 hed = va_arg(ap, struct hostent_data *); 545 546 switch (af) { 547 case AF_INET: 548 (void) sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", 549 (uaddr[3] & 0xff), 550 (uaddr[2] & 0xff), 551 (uaddr[1] & 0xff), 552 (uaddr[0] & 0xff)); 553 break; 554 case AF_INET6: 555 qp = qbuf; 556 for (n = IN6ADDRSZ - 1; n >= 0; n--) { 557 qp += SPRINTF((qp, "%x.%x.", 558 uaddr[n] & 0xf, 559 (uaddr[n] >> 4) & 0xf)); 560 } 561 strlcat(qbuf, "ip6.arpa", sizeof(qbuf)); 562 break; 563 default: 564 abort(); 565 } 566 if ((buf = malloc(sizeof(*buf))) == NULL) { 567 RES_SET_H_ERRNO(hed->res, NETDB_INTERNAL); 568 return NS_NOTFOUND; 569 } 570 n = res_nquery(hed->res, qbuf, C_IN, T_PTR, (u_char *)buf->buf, 571 sizeof buf->buf); 572 if (n < 0) { 573 free(buf); 574 dprintf("res_nquery failed (%d)\n", n, hed->res); 575 return NS_UNAVAIL; 576 } 577 if (n > sizeof buf->buf) { 578 free(buf); 579 dprintf("static buffer is too small (%d)\n", n, hed->res); 580 return NS_UNAVAIL; 581 } 582 if ((error = gethostanswer(buf, n, qbuf, T_PTR, he, hed)) != 0) { 583 free(buf); 584 return NS_NOTFOUND; /* h_errno was set by gethostanswer() */ 585 } 586 free(buf); 587 #ifdef SUNSECURITY 588 if (af == AF_INET) { 589 /* 590 * turn off search as the name should be absolute, 591 * 'localhost' should be matched by defnames 592 */ 593 strncpy(hname2, he->h_name, MAXDNAME); 594 hname2[MAXDNAME] = '\0'; 595 old_options = hed->res->options; 596 hed->res->options &= ~RES_DNSRCH; 597 hed->res->options |= RES_DEFNAMES; 598 memset(&rhd, 0, sizeof rhd); 599 if (!(rhe = gethostbyname_r(hname2, &rhd.host, &rhd.data))) { 600 if (inet_ntop(af, addr, numaddr, sizeof(numaddr)) == NULL) 601 strlcpy(numaddr, "UNKNOWN", sizeof(numaddr)); 602 syslog(LOG_NOTICE|LOG_AUTH, 603 "gethostbyaddr: No A record for %s (verifying [%s])", 604 hname2, numaddr); 605 hed->res->options = old_options; 606 RES_SET_H_ERRNO(hed->res, HOST_NOT_FOUND); 607 return NS_NOTFOUND; 608 } 609 hed->res->options = old_options; 610 for (haddr = rhe->h_addr_list; *haddr; haddr++) 611 if (!memcmp(*haddr, addr, INADDRSZ)) 612 break; 613 if (!*haddr) { 614 if (inet_ntop(af, addr, numaddr, sizeof(numaddr)) == NULL) 615 strlcpy(numaddr, "UNKNOWN", sizeof(numaddr)); 616 syslog(LOG_NOTICE|LOG_AUTH, 617 "gethostbyaddr: A record of %s != PTR record [%s]", 618 hname2, numaddr); 619 RES_SET_H_ERRNO(hed->res, HOST_NOT_FOUND); 620 return NS_NOTFOUND; 621 } 622 } 623 #endif /*SUNSECURITY*/ 624 he->h_addrtype = af; 625 he->h_length = len; 626 memcpy(hed->host_addr, uaddr, len); 627 hed->h_addr_ptrs[0] = (char *)hed->host_addr; 628 hed->h_addr_ptrs[1] = NULL; 629 if (af == AF_INET && (hed->res->options & RES_USE_INET6)) { 630 _map_v4v6_address((char*)hed->host_addr, (char*)hed->host_addr); 631 he->h_addrtype = AF_INET6; 632 he->h_length = IN6ADDRSZ; 633 } 634 RES_SET_H_ERRNO(hed->res, NETDB_SUCCESS); 635 return (error == 0) ? NS_SUCCESS : NS_NOTFOUND; 636 } 637 638 #ifdef RESOLVSORT 639 static void 640 addrsort(ap, num, res) 641 char **ap; 642 int num; 643 res_state res; 644 { 645 int i, j; 646 char **p; 647 short aval[_MAXADDRS]; 648 int needsort = 0; 649 650 p = ap; 651 for (i = 0; i < num; i++, p++) { 652 for (j = 0 ; (unsigned)j < res->nsort; j++) 653 if (res->sort_list[j].addr.s_addr == 654 (((struct in_addr *)(*p))->s_addr & res->sort_list[j].mask)) 655 break; 656 aval[i] = j; 657 if (needsort == 0 && i > 0 && j < aval[i-1]) 658 needsort = i; 659 } 660 if (!needsort) 661 return; 662 663 while (needsort < num) { 664 for (j = needsort - 1; j >= 0; j--) { 665 if (aval[j] > aval[j+1]) { 666 char *hp; 667 668 i = aval[j]; 669 aval[j] = aval[j+1]; 670 aval[j+1] = i; 671 672 hp = ap[j]; 673 ap[j] = ap[j+1]; 674 ap[j+1] = hp; 675 676 } else 677 break; 678 } 679 needsort++; 680 } 681 } 682 #endif 683 684 void 685 _sethostdnsent(stayopen) 686 int stayopen; 687 { 688 res_state statp; 689 690 statp = __res_state(); 691 if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) 692 return; 693 if (stayopen) 694 statp->options |= RES_STAYOPEN | RES_USEVC; 695 } 696 697 void 698 _endhostdnsent() 699 { 700 res_state statp; 701 702 statp = __res_state(); 703 statp->options &= ~(RES_STAYOPEN | RES_USEVC); 704 res_nclose(statp); 705 } 706