1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1994, Garrett Wollman 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include "namespace.h" 32 #include "reentrant.h" 33 #include <sys/param.h> 34 #include <sys/socket.h> 35 #include <netinet/in.h> 36 #include <arpa/inet.h> 37 #include <netdb.h> 38 #include <stdio.h> 39 #include <ctype.h> 40 #include <errno.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include <stdarg.h> 44 #include <nsswitch.h> 45 #include <arpa/nameser.h> /* XXX hack for _res */ 46 #include <resolv.h> /* XXX hack for _res */ 47 #include "un-namespace.h" 48 #include "netdb_private.h" 49 #ifdef NS_CACHING 50 #include "nscache.h" 51 #endif 52 53 static int gethostbyname_internal(const char *, int, struct hostent *, char *, 54 size_t, struct hostent **, int *, res_state); 55 56 /* Host lookup order if nsswitch.conf is broken or nonexistent */ 57 static const ns_src default_src[] = { 58 { NSSRC_FILES, NS_SUCCESS }, 59 { NSSRC_DNS, NS_SUCCESS }, 60 { 0 } 61 }; 62 #ifdef NS_CACHING 63 static int host_id_func(char *, size_t *, va_list, void *); 64 static int host_marshal_func(char *, size_t *, void *, va_list, void *); 65 static int host_unmarshal_func(char *, size_t, void *, va_list, void *); 66 #endif 67 68 NETDB_THREAD_ALLOC(hostent) 69 NETDB_THREAD_ALLOC(hostent_data) 70 NETDB_THREAD_ALLOC(hostdata) 71 72 static void 73 hostent_free(void *ptr) 74 { 75 free(ptr); 76 } 77 78 static void 79 hostent_data_free(void *ptr) 80 { 81 struct hostent_data *hed = ptr; 82 83 if (hed == NULL) 84 return; 85 hed->stayopen = 0; 86 _endhosthtent(hed); 87 free(hed); 88 } 89 90 static void 91 hostdata_free(void *ptr) 92 { 93 free(ptr); 94 } 95 96 int 97 __copy_hostent(struct hostent *he, struct hostent *hptr, char *buf, 98 size_t buflen) 99 { 100 char *cp; 101 char **ptr; 102 int i, n; 103 int nptr, len; 104 105 /* Find out the amount of space required to store the answer. */ 106 nptr = 2; /* NULL ptrs */ 107 len = (char *)ALIGN(buf) - buf; 108 for (i = 0; he->h_addr_list[i]; i++, nptr++) { 109 len += he->h_length; 110 } 111 for (i = 0; he->h_aliases[i]; i++, nptr++) { 112 len += strlen(he->h_aliases[i]) + 1; 113 } 114 len += strlen(he->h_name) + 1; 115 len += nptr * sizeof(char*); 116 117 if (len > buflen) { 118 errno = ERANGE; 119 return (-1); 120 } 121 122 /* copy address size and type */ 123 hptr->h_addrtype = he->h_addrtype; 124 n = hptr->h_length = he->h_length; 125 126 ptr = (char **)ALIGN(buf); 127 cp = (char *)ALIGN(buf) + nptr * sizeof(char *); 128 129 /* copy address list */ 130 hptr->h_addr_list = ptr; 131 for (i = 0; he->h_addr_list[i]; i++ , ptr++) { 132 memcpy(cp, he->h_addr_list[i], n); 133 hptr->h_addr_list[i] = cp; 134 cp += n; 135 } 136 hptr->h_addr_list[i] = NULL; 137 ptr++; 138 139 /* copy official name */ 140 n = strlen(he->h_name) + 1; 141 strcpy(cp, he->h_name); 142 hptr->h_name = cp; 143 cp += n; 144 145 /* copy aliases */ 146 hptr->h_aliases = ptr; 147 for (i = 0 ; he->h_aliases[i]; i++) { 148 n = strlen(he->h_aliases[i]) + 1; 149 strcpy(cp, he->h_aliases[i]); 150 hptr->h_aliases[i] = cp; 151 cp += n; 152 } 153 hptr->h_aliases[i] = NULL; 154 155 return (0); 156 } 157 158 #ifdef NS_CACHING 159 static int 160 host_id_func(char *buffer, size_t *buffer_size, va_list ap, void *cache_mdata) 161 { 162 res_state statp; 163 u_long res_options; 164 165 const int op_id = 1; 166 char *str; 167 void *addr; 168 socklen_t len; 169 int type; 170 171 size_t desired_size, size; 172 enum nss_lookup_type lookup_type; 173 char *p; 174 int res = NS_UNAVAIL; 175 176 statp = __res_state(); 177 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES | 178 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6); 179 180 lookup_type = (enum nss_lookup_type)(uintptr_t)cache_mdata; 181 switch (lookup_type) { 182 case nss_lt_name: 183 str = va_arg(ap, char *); 184 type = va_arg(ap, int); 185 186 size = strlen(str); 187 desired_size = sizeof(res_options) + sizeof(int) + 188 sizeof(enum nss_lookup_type) + sizeof(int) + size + 1; 189 190 if (desired_size > *buffer_size) { 191 res = NS_RETURN; 192 goto fin; 193 } 194 195 p = buffer; 196 197 memcpy(p, &res_options, sizeof(res_options)); 198 p += sizeof(res_options); 199 200 memcpy(p, &op_id, sizeof(int)); 201 p += sizeof(int); 202 203 memcpy(p, &lookup_type, sizeof(enum nss_lookup_type)); 204 p += sizeof(int); 205 206 memcpy(p, &type, sizeof(int)); 207 p += sizeof(int); 208 209 memcpy(p, str, size + 1); 210 211 res = NS_SUCCESS; 212 break; 213 case nss_lt_id: 214 addr = va_arg(ap, void *); 215 len = va_arg(ap, socklen_t); 216 type = va_arg(ap, int); 217 218 desired_size = sizeof(res_options) + sizeof(int) + 219 sizeof(enum nss_lookup_type) + sizeof(int) + 220 sizeof(socklen_t) + len; 221 222 if (desired_size > *buffer_size) { 223 res = NS_RETURN; 224 goto fin; 225 } 226 227 p = buffer; 228 memcpy(p, &res_options, sizeof(res_options)); 229 p += sizeof(res_options); 230 231 memcpy(p, &op_id, sizeof(int)); 232 p += sizeof(int); 233 234 memcpy(p, &lookup_type, sizeof(enum nss_lookup_type)); 235 p += sizeof(int); 236 237 memcpy(p, &type, sizeof(int)); 238 p += sizeof(int); 239 240 memcpy(p, &len, sizeof(socklen_t)); 241 p += sizeof(socklen_t); 242 243 memcpy(p, addr, len); 244 245 res = NS_SUCCESS; 246 break; 247 default: 248 /* should be unreachable */ 249 return (NS_UNAVAIL); 250 } 251 252 fin: 253 *buffer_size = desired_size; 254 return (res); 255 } 256 257 static int 258 host_marshal_func(char *buffer, size_t *buffer_size, void *retval, va_list ap, 259 void *cache_mdata) 260 { 261 char *str __unused; 262 void *addr __unused; 263 socklen_t len __unused; 264 int type __unused; 265 struct hostent *ht; 266 267 struct hostent new_ht; 268 size_t desired_size, aliases_size, addr_size, size; 269 char *p, **iter; 270 271 switch ((enum nss_lookup_type)(uintptr_t)cache_mdata) { 272 case nss_lt_name: 273 str = va_arg(ap, char *); 274 type = va_arg(ap, int); 275 break; 276 case nss_lt_id: 277 addr = va_arg(ap, void *); 278 len = va_arg(ap, socklen_t); 279 type = va_arg(ap, int); 280 break; 281 default: 282 /* should be unreachable */ 283 return (NS_UNAVAIL); 284 } 285 ht = va_arg(ap, struct hostent *); 286 287 desired_size = _ALIGNBYTES + sizeof(struct hostent) + sizeof(char *); 288 if (ht->h_name != NULL) 289 desired_size += strlen(ht->h_name) + 1; 290 291 if (ht->h_aliases != NULL) { 292 aliases_size = 0; 293 for (iter = ht->h_aliases; *iter; ++iter) { 294 desired_size += strlen(*iter) + 1; 295 ++aliases_size; 296 } 297 298 desired_size += _ALIGNBYTES + 299 (aliases_size + 1) * sizeof(char *); 300 } 301 302 if (ht->h_addr_list != NULL) { 303 addr_size = 0; 304 for (iter = ht->h_addr_list; *iter; ++iter) 305 ++addr_size; 306 307 desired_size += addr_size * _ALIGN(ht->h_length); 308 desired_size += _ALIGNBYTES + (addr_size + 1) * sizeof(char *); 309 } 310 311 if (desired_size > *buffer_size) { 312 /* this assignment is here for future use */ 313 *buffer_size = desired_size; 314 return (NS_RETURN); 315 } 316 317 memcpy(&new_ht, ht, sizeof(struct hostent)); 318 memset(buffer, 0, desired_size); 319 320 *buffer_size = desired_size; 321 p = buffer + sizeof(struct hostent) + sizeof(char *); 322 memcpy(buffer + sizeof(struct hostent), &p, sizeof(char *)); 323 p = (char *)_ALIGN(p); 324 325 if (new_ht.h_name != NULL) { 326 size = strlen(new_ht.h_name); 327 memcpy(p, new_ht.h_name, size); 328 new_ht.h_name = p; 329 p += size + 1; 330 } 331 332 if (new_ht.h_aliases != NULL) { 333 p = (char *)_ALIGN(p); 334 memcpy(p, new_ht.h_aliases, sizeof(char *) * aliases_size); 335 new_ht.h_aliases = (char **)p; 336 p += sizeof(char *) * (aliases_size + 1); 337 338 for (iter = new_ht.h_aliases; *iter; ++iter) { 339 size = strlen(*iter); 340 memcpy(p, *iter, size); 341 *iter = p; 342 p += size + 1; 343 } 344 } 345 346 if (new_ht.h_addr_list != NULL) { 347 p = (char *)_ALIGN(p); 348 memcpy(p, new_ht.h_addr_list, sizeof(char *) * addr_size); 349 new_ht.h_addr_list = (char **)p; 350 p += sizeof(char *) * (addr_size + 1); 351 352 size = _ALIGN(new_ht.h_length); 353 for (iter = new_ht.h_addr_list; *iter; ++iter) { 354 memcpy(p, *iter, size); 355 *iter = p; 356 p += size + 1; 357 } 358 } 359 memcpy(buffer, &new_ht, sizeof(struct hostent)); 360 return (NS_SUCCESS); 361 } 362 363 static int 364 host_unmarshal_func(char *buffer, size_t buffer_size, void *retval, va_list ap, 365 void *cache_mdata) 366 { 367 char *str __unused; 368 void *addr __unused; 369 socklen_t len __unused; 370 int type __unused; 371 struct hostent *ht; 372 373 char *p; 374 char **iter; 375 char *orig_buf; 376 size_t orig_buf_size; 377 378 switch ((enum nss_lookup_type)(uintptr_t)cache_mdata) { 379 case nss_lt_name: 380 str = va_arg(ap, char *); 381 type = va_arg(ap, int); 382 break; 383 case nss_lt_id: 384 addr = va_arg(ap, void *); 385 len = va_arg(ap, socklen_t); 386 type = va_arg(ap, int); 387 break; 388 default: 389 /* should be unreachable */ 390 return (NS_UNAVAIL); 391 } 392 393 ht = va_arg(ap, struct hostent *); 394 orig_buf = va_arg(ap, char *); 395 orig_buf_size = va_arg(ap, size_t); 396 397 if (orig_buf_size < 398 buffer_size - sizeof(struct hostent) - sizeof(char *)) { 399 errno = ERANGE; 400 return (NS_RETURN); 401 } 402 403 memcpy(ht, buffer, sizeof(struct hostent)); 404 memcpy(&p, buffer + sizeof(struct hostent), sizeof(char *)); 405 406 orig_buf = (char *)_ALIGN(orig_buf); 407 memcpy(orig_buf, buffer + sizeof(struct hostent) + sizeof(char *) + 408 _ALIGN(p) - (size_t)p, 409 buffer_size - sizeof(struct hostent) - sizeof(char *) - 410 _ALIGN(p) + (size_t)p); 411 p = (char *)_ALIGN(p); 412 413 NS_APPLY_OFFSET(ht->h_name, orig_buf, p, char *); 414 if (ht->h_aliases != NULL) { 415 NS_APPLY_OFFSET(ht->h_aliases, orig_buf, p, char **); 416 417 for (iter = ht->h_aliases; *iter; ++iter) 418 NS_APPLY_OFFSET(*iter, orig_buf, p, char *); 419 } 420 421 if (ht->h_addr_list != NULL) { 422 NS_APPLY_OFFSET(ht->h_addr_list, orig_buf, p, char **); 423 424 for (iter = ht->h_addr_list; *iter; ++iter) 425 NS_APPLY_OFFSET(*iter, orig_buf, p, char *); 426 } 427 428 *((struct hostent **)retval) = ht; 429 return (NS_SUCCESS); 430 } 431 #endif /* NS_CACHING */ 432 433 static int 434 fakeaddr(const char *name, int af, struct hostent *hp, char *buf, 435 size_t buflen, res_state statp) 436 { 437 struct hostent_data *hed; 438 struct hostent he; 439 440 if ((hed = __hostent_data_init()) == NULL) { 441 errno = ENOMEM; 442 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 443 return (-1); 444 } 445 446 if ((af != AF_INET || 447 inet_aton(name, (struct in_addr *)hed->host_addr) != 1) && 448 inet_pton(af, name, hed->host_addr) != 1) { 449 RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); 450 return (-1); 451 } 452 strncpy(hed->hostbuf, name, MAXDNAME); 453 hed->hostbuf[MAXDNAME] = '\0'; 454 if (af == AF_INET && (statp->options & RES_USE_INET6) != 0U) { 455 _map_v4v6_address((char *)hed->host_addr, 456 (char *)hed->host_addr); 457 af = AF_INET6; 458 } 459 he.h_addrtype = af; 460 switch(af) { 461 case AF_INET: 462 he.h_length = NS_INADDRSZ; 463 break; 464 case AF_INET6: 465 he.h_length = NS_IN6ADDRSZ; 466 break; 467 default: 468 errno = EAFNOSUPPORT; 469 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 470 return (-1); 471 } 472 he.h_name = hed->hostbuf; 473 he.h_aliases = hed->host_aliases; 474 hed->host_aliases[0] = NULL; 475 hed->h_addr_ptrs[0] = (char *)hed->host_addr; 476 hed->h_addr_ptrs[1] = NULL; 477 he.h_addr_list = hed->h_addr_ptrs; 478 if (__copy_hostent(&he, hp, buf, buflen) != 0) { 479 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 480 return (-1); 481 } 482 RES_SET_H_ERRNO(statp, NETDB_SUCCESS); 483 return (0); 484 } 485 486 int 487 gethostbyname_r(const char *name, struct hostent *he, char *buffer, 488 size_t buflen, struct hostent **result, int *h_errnop) 489 { 490 res_state statp; 491 492 statp = __res_state(); 493 if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) { 494 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 495 return (-1); 496 } 497 if (statp->options & RES_USE_INET6) { 498 if (fakeaddr(name, AF_INET, he, buffer, buflen, statp) == 0) { 499 *result = he; 500 return (0); 501 } 502 if (gethostbyname_internal(name, AF_INET6, he, buffer, buflen, 503 result, h_errnop, statp) == 0) 504 return (0); 505 } 506 return (gethostbyname_internal(name, AF_INET, he, buffer, buflen, 507 result, h_errnop, statp)); 508 } 509 510 int 511 gethostbyname2_r(const char *name, int af, struct hostent *he, char *buffer, 512 size_t buflen, struct hostent **result, int *h_errnop) 513 { 514 res_state statp; 515 516 statp = __res_state(); 517 if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) { 518 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 519 return (-1); 520 } 521 return (gethostbyname_internal(name, af, he, buffer, buflen, result, 522 h_errnop, statp)); 523 } 524 525 int 526 gethostbyname_internal(const char *name, int af, struct hostent *hp, char *buf, 527 size_t buflen, struct hostent **result, int *h_errnop, res_state statp) 528 { 529 const char *cp; 530 int rval, ret_errno = 0; 531 char abuf[MAXDNAME]; 532 533 #ifdef NS_CACHING 534 static const nss_cache_info cache_info = 535 NS_COMMON_CACHE_INFO_INITIALIZER( 536 hosts, (void *)nss_lt_name, 537 host_id_func, host_marshal_func, host_unmarshal_func); 538 #endif 539 static const ns_dtab dtab[] = { 540 NS_FILES_CB(_ht_gethostbyname, NULL) 541 { NSSRC_DNS, _dns_gethostbyname, NULL }, 542 NS_NIS_CB(_nis_gethostbyname, NULL) /* force -DHESIOD */ 543 #ifdef NS_CACHING 544 NS_CACHE_CB(&cache_info) 545 #endif 546 { 0 } 547 }; 548 549 switch (af) { 550 case AF_INET: 551 case AF_INET6: 552 break; 553 default: 554 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 555 *h_errnop = statp->res_h_errno; 556 errno = EAFNOSUPPORT; 557 return (-1); 558 } 559 560 /* 561 * if there aren't any dots, it could be a user-level alias. 562 * this is also done in res_query() since we are not the only 563 * function that looks up host names. 564 */ 565 if (!strchr(name, '.') && 566 (cp = res_hostalias(statp, name, abuf, sizeof abuf))) 567 name = cp; 568 569 if (fakeaddr(name, af, hp, buf, buflen, statp) == 0) { 570 *result = hp; 571 return (0); 572 } 573 574 rval = _nsdispatch((void *)result, dtab, NSDB_HOSTS, 575 "gethostbyname2_r", default_src, name, af, hp, buf, buflen, 576 &ret_errno, h_errnop); 577 578 if (rval != NS_SUCCESS) { 579 errno = ret_errno; 580 return ((ret_errno != 0) ? ret_errno : -1); 581 } 582 return (0); 583 } 584 585 int 586 gethostbyaddr_r(const void *addr, socklen_t len, int af, struct hostent *hp, 587 char *buf, size_t buflen, struct hostent **result, int *h_errnop) 588 { 589 const u_char *uaddr = (const u_char *)addr; 590 const struct in6_addr *addr6; 591 socklen_t size; 592 int rval, ret_errno = 0; 593 res_state statp; 594 595 #ifdef NS_CACHING 596 static const nss_cache_info cache_info = 597 NS_COMMON_CACHE_INFO_INITIALIZER( 598 hosts, (void *)nss_lt_id, 599 host_id_func, host_marshal_func, host_unmarshal_func); 600 #endif 601 static const ns_dtab dtab[] = { 602 NS_FILES_CB(_ht_gethostbyaddr, NULL) 603 { NSSRC_DNS, _dns_gethostbyaddr, NULL }, 604 NS_NIS_CB(_nis_gethostbyaddr, NULL) /* force -DHESIOD */ 605 #ifdef NS_CACHING 606 NS_CACHE_CB(&cache_info) 607 #endif 608 { 0 } 609 }; 610 611 statp = __res_state(); 612 if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) { 613 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 614 *h_errnop = statp->res_h_errno; 615 return (-1); 616 } 617 618 if (af == AF_INET6 && len == NS_IN6ADDRSZ) { 619 addr6 = (const struct in6_addr *)addr; 620 if (IN6_IS_ADDR_LINKLOCAL(addr6)) { 621 RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); 622 *h_errnop = statp->res_h_errno; 623 return (-1); 624 } 625 if (IN6_IS_ADDR_V4MAPPED(addr6) || 626 IN6_IS_ADDR_V4COMPAT(addr6)) { 627 /* Unmap. */ 628 uaddr += NS_IN6ADDRSZ - NS_INADDRSZ; 629 af = AF_INET; 630 len = NS_INADDRSZ; 631 } 632 } 633 switch (af) { 634 case AF_INET: 635 size = NS_INADDRSZ; 636 break; 637 case AF_INET6: 638 size = NS_IN6ADDRSZ; 639 break; 640 default: 641 errno = EAFNOSUPPORT; 642 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 643 *h_errnop = statp->res_h_errno; 644 return (-1); 645 } 646 if (size != len) { 647 errno = EINVAL; 648 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 649 *h_errnop = statp->res_h_errno; 650 return (-1); 651 } 652 653 rval = _nsdispatch((void *)result, dtab, NSDB_HOSTS, 654 "gethostbyaddr_r", default_src, uaddr, len, af, hp, buf, buflen, 655 &ret_errno, h_errnop); 656 657 if (rval != NS_SUCCESS) { 658 errno = ret_errno; 659 return ((ret_errno != 0) ? ret_errno : -1); 660 } 661 return (0); 662 } 663 664 struct hostent * 665 gethostbyname(const char *name) 666 { 667 struct hostdata *hd; 668 struct hostent *rval; 669 int ret_h_errno; 670 671 if ((hd = __hostdata_init()) == NULL) 672 return (NULL); 673 if (gethostbyname_r(name, &hd->host, hd->data, sizeof(hd->data), &rval, 674 &ret_h_errno) != 0) 675 return (NULL); 676 return (rval); 677 } 678 679 struct hostent * 680 gethostbyname2(const char *name, int af) 681 { 682 struct hostdata *hd; 683 struct hostent *rval; 684 int ret_h_errno; 685 686 if ((hd = __hostdata_init()) == NULL) 687 return (NULL); 688 if (gethostbyname2_r(name, af, &hd->host, hd->data, sizeof(hd->data), 689 &rval, &ret_h_errno) != 0) 690 return (NULL); 691 return (rval); 692 } 693 694 struct hostent * 695 gethostbyaddr(const void *addr, socklen_t len, int af) 696 { 697 struct hostdata *hd; 698 struct hostent *rval; 699 int ret_h_errno; 700 701 if ((hd = __hostdata_init()) == NULL) 702 return (NULL); 703 if (gethostbyaddr_r(addr, len, af, &hd->host, hd->data, 704 sizeof(hd->data), &rval, &ret_h_errno) != 0) 705 return (NULL); 706 return (rval); 707 } 708 709 void 710 sethostent(int stayopen) 711 { 712 struct hostent_data *hed; 713 714 if ((hed = __hostent_data_init()) == NULL) 715 return; 716 _sethosthtent(stayopen, hed); 717 _sethostdnsent(stayopen); 718 } 719 720 void 721 endhostent(void) 722 { 723 struct hostent_data *hed; 724 725 if ((hed = __hostent_data_init()) == NULL) 726 return; 727 _endhosthtent(hed); 728 _endhostdnsent(); 729 } 730