other-licenses/android/res_state.c

   1 /*
   2  * Copyright (C) 2008 The Android Open Source Project
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *  * Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  *  * Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in
  12  *    the documentation and/or other materials provided with the
  13  *    distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
  22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 /*
  30  * This version of this file is derived from Android 2.3 "Gingerbread",
  31  * which contains uncredited changes by Android/Google developers.  It has
  32  * been modified in 2011 for use in the Android build of Mozilla Firefox by
  33  * Mozilla contributors (including Michael Edwards <m.k.edwards@gmail.com>,
  34  * and Steve Workman <sjhworkman@gmail.com>).
  35  * These changes are offered under the same license as the original NetBSD
  36  * file, whose copyright and license are unchanged above.
  37  */
  38
  39 /*
  40  * This version of this file is derived from Android 2.3 "Gingerbread",
  41  * which contains uncredited changes by Android/Google developers.  It has
  42  * been modified in 2011 for use in the Android build of Mozilla Firefox by
  43  * Mozilla contributors (including Michael Edwards <m.k.edwards@gmail.com>,
  44  * and Steve Workman <sjhworkman@gmail.com>).
  45  * These changes are offered under the same license as the original NetBSD
  46  * file, whose copyright and license are unchanged above.
  47  */
  48
  49 #define ANDROID_CHANGES 1
  50 #define MOZILLA_NECKO_EXCLUDE_CODE 1
  51
  52 #include <sys/cdefs.h>
  53 #include <sys/types.h>
  54 #include <arpa/inet.h>
  55 #include "arpa_nameser.h"
  56 #include <netdb.h>
  57 #include "resolv_private.h"
  58 #include "resolv_cache.h"
  59 #include <pthread.h>
  60 #include <stdlib.h>
  61
  62 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
  63 #include <sys/_system_properties.h>
  64
  65 static pthread_key_t   _res_key;
  66 static pthread_once_t  _res_once;
  67
  68 typedef struct {
  69     int                    _h_errno;
  70     struct __res_state     _nres[1];
  71     unsigned               _serial;
  72     struct prop_info*      _pi;
  73     struct res_static      _rstatic[1];
  74 } _res_thread;
  75
  76 static _res_thread*
  77 _res_thread_alloc(void)
  78 {
  79     _res_thread*  rt = malloc(sizeof(*rt));
  80
  81     if (rt) {
  82         rt->_h_errno = 0;
  83         /* Special system property which tracks any changes to 'net.*'. */
  84         rt->_serial = 0;
  85         rt->_pi = (struct prop_info*) __system_property_find("net.change");
  86         if (rt->_pi) {
  87             rt->_serial = rt->_pi->serial;
  88         }
  89         if ( res_ninit( rt->_nres ) < 0 ) {
  90             free(rt);
  91             rt = NULL;
  92         } else {
  93             memset(rt->_rstatic, 0, sizeof rt->_rstatic);
  94         }
  95     }
  96     return rt;
  97 }
  98
  99 static void
 100 _res_static_done( res_static  rs )
 101 {
 102     /* fortunately, there is nothing to do here, since the
 103      * points in h_addr_ptrs and host_aliases should all
 104      * point to 'hostbuf'
 105      */
 106     if (rs->hostf) {  /* should not happen in theory, but just be safe */
 107         fclose(rs->hostf);
 108         rs->hostf = NULL;
 109     }
 110     free(rs->servent.s_aliases);
 111 }
 112
 113 static void
 114 _res_thread_free( void*  _rt )
 115 {
 116     _res_thread*  rt = _rt;
 117
 118     _res_static_done(rt->_rstatic);
 119     res_ndestroy(rt->_nres);
 120     free(rt);
 121 }
 122
 123 static void
 124 _res_init_key( void )
 125 {
 126     pthread_key_create( &_res_key, _res_thread_free );
 127 }
 128
 129 static _res_thread*
 130 _res_thread_get(void)
 131 {
 132     _res_thread*  rt;
 133     pthread_once( &_res_once, _res_init_key );
 134     rt = pthread_getspecific( _res_key );
 135     if (rt == NULL) {
 136         if ((rt = _res_thread_alloc()) == NULL) {
 137             return NULL;
 138         }
 139         rt->_h_errno = 0;
 140         rt->_serial = 0;
 141         pthread_setspecific( _res_key, rt );
 142     }
 143     /* Check the serial value for any chanes to net.* properties. */
 144     if (rt->_pi == NULL) {
 145         rt->_pi = (struct prop_info*) __system_property_find("net.change");
 146     }
 147     if (rt->_pi == NULL || rt->_serial == rt->_pi->serial) {
 148         return rt;
 149     }
 150     rt->_serial = rt->_pi->serial;
 151     /* Reload from system properties. */
 152     if ( res_ninit( rt->_nres ) < 0 ) {
 153         free(rt);
 154         rt = NULL;
 155         pthread_setspecific( _res_key, rt );
 156     }
 157 #ifdef USE_RESOLV_CACHE
 158     _resolv_cache_reset(rt->_serial);
 159 #endif
 160     return rt;
 161 }
 162
 163 struct __res_state _nres;
 164
 165 #if 0
 166 struct resolv_cache*
 167 __get_res_cache(void)
 168 {
 169     _res_thread*  rt = _res_thread_get();
 170
 171     if (!rt)
 172         return NULL;
 173
 174     if (!rt->_cache) {
 175         rt->_cache = _resolv_cache_create();
 176     }
 177     return rt->_cache;
 178 }
 179 #endif
 180
 181 int*
 182 __get_h_errno(void)
 183 {
 184     _res_thread*  rt    = _res_thread_get();
 185     static int    panic = NETDB_INTERNAL;
 186
 187     return rt ? &rt->_h_errno : &panic;
 188 }
 189
 190 res_state
 191 __res_get_state(void)
 192 {
 193     _res_thread*  rt = _res_thread_get();
 194
 195     return rt ? rt->_nres : NULL;
 196 }
 197
 198 void
 199 __res_put_state(res_state res)
 200 {
 201     /* nothing to do */
 202     res=res;
 203 }
 204
 205 res_static
 206 __res_get_static(void)
 207 {
 208     _res_thread*  rt = _res_thread_get();
 209
 210     return rt ? rt->_rstatic : NULL;
 211 }