1 /*- 2 * Copyright (c) 2006 The FreeBSD Project. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 * 25 * $FreeBSD$ 26 */ 27 28 #include <sys/types.h> 29 #include <netinet/in.h> 30 #include <arpa/nameser.h> 31 #include <resolv.h> 32 #include <stdlib.h> 33 34 #include "namespace.h" 35 #include "reentrant.h" 36 #include "un-namespace.h" 37 38 #undef _res 39 40 struct __res_state _res; 41 42 static thread_key_t res_key; 43 static once_t res_init_once = ONCE_INITIALIZER; 44 static int res_thr_keycreated = 0; 45 46 static void 47 free_res(void *ptr) 48 { 49 res_state statp = ptr; 50 51 if (statp->_u._ext.ext != NULL) 52 res_ndestroy(statp); 53 free(statp); 54 } 55 56 static void 57 res_keycreate(void) 58 { 59 res_thr_keycreated = thr_keycreate(&res_key, free_res) == 0; 60 } 61 62 res_state 63 __res_state(void) 64 { 65 res_state statp; 66 67 if (thr_main() != 0) 68 return (&_res); 69 70 if (thr_once(&res_init_once, res_keycreate) != 0 || 71 !res_thr_keycreated) 72 return (&_res); 73 74 statp = thr_getspecific(res_key); 75 if (statp != NULL) 76 return (statp); 77 statp = calloc(1, sizeof(*statp)); 78 if (statp == NULL) 79 return (&_res); 80 #ifdef __BIND_RES_TEXT 81 statp->options = RES_TIMEOUT; /* Motorola, et al. */ 82 #endif 83 if (thr_setspecific(res_key, statp) == 0) 84 return (statp); 85 free(statp); 86 return (&_res); 87 } 88