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 /*

  * Copyright (C) 2008 The Android Open Source Project

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions

  * are met:

  *  * Redistributions of source code must retain the above copyright

  *    notice, this list of conditions and the following disclaimer.

  *  * Redistributions in binary form must reproduce the above copyright

  *    notice, this list of conditions and the following disclaimer in

  *    the documentation and/or other materials provided with the

  *    distribution.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE

  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,

  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,

  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS

  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT

  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

  * SUCH DAMAGE.

  */

 /*

  * This version of this file is derived from Android 2.3 "Gingerbread",

  * which contains uncredited changes by Android/Google developers.  It has

  * been modified in 2011 for use in the Android build of Mozilla Firefox by

  * Mozilla contributors (including Michael Edwards <m.k.edwards@gmail.com>,

  * and Steve Workman <sjhworkman@gmail.com>).

  * These changes are offered under the same license as the original NetBSD

  * file, whose copyright and license are unchanged above.

  */

 /*

  * This version of this file is derived from Android 2.3 "Gingerbread",

  * which contains uncredited changes by Android/Google developers.  It has

  * been modified in 2011 for use in the Android build of Mozilla Firefox by

  * Mozilla contributors (including Michael Edwards <m.k.edwards@gmail.com>,

  * and Steve Workman <sjhworkman@gmail.com>).

  * These changes are offered under the same license as the original NetBSD

  * file, whose copyright and license are unchanged above.

  */

 #define ANDROID_CHANGES 1

 #define MOZILLA_NECKO_EXCLUDE_CODE 1

 #include <sys/cdefs.h>

 #include <sys/types.h>

 #include <arpa/inet.h>

 #include "arpa_nameser.h"

 #include <netdb.h>

 #include "resolv_private.h"

 #include "resolv_cache.h"

 #include <pthread.h>

 #include <stdlib.h>

 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_

 #include <sys/_system_properties.h>

 static pthread_key_t   _res_key;

 static pthread_once_t  _res_once;

 typedef struct {

     int                    _h_errno;

     struct __res_state     _nres[1];

     unsigned               _serial;

     struct prop_info*      _pi;

     struct res_static      _rstatic[1];

 } _res_thread;

 static _res_thread*

 _res_thread_alloc(void)

 {

     _res_thread*  rt = malloc(sizeof(*rt));

     if (rt) {

         rt->_h_errno = 0;

         /* Special system property which tracks any changes to 'net.*'. */

         rt->_serial = 0;

         rt->_pi = (struct prop_info*) __system_property_find("net.change");

         if (rt->_pi) {

             rt->_serial = rt->_pi->serial;

         }

         if ( res_ninit( rt->_nres ) < 0 ) {

             free(rt);

             rt = NULL;

         } else {

             memset(rt->_rstatic, 0, sizeof rt->_rstatic);

         }

     }

     return rt;

 }

 static void

 _res_static_done( res_static  rs )

 {

     /* fortunately, there is nothing to do here, since the

      * points in h_addr_ptrs and host_aliases should all

      * point to 'hostbuf'

      */

     if (rs->hostf) {  /* should not happen in theory, but just be safe */

         fclose(rs->hostf);

         rs->hostf = NULL;

     }

     free(rs->servent.s_aliases);

 }

 static void

 _res_thread_free( void*  _rt )

 {

     _res_thread*  rt = _rt;

     _res_static_done(rt->_rstatic);

     res_ndestroy(rt->_nres);

     free(rt);

 }

 static void

 _res_init_key( void )

 {

     pthread_key_create( &_res_key, _res_thread_free );

 }

 static _res_thread*

 _res_thread_get(void)

 {

     _res_thread*  rt;

     pthread_once( &_res_once, _res_init_key );

     rt = pthread_getspecific( _res_key );

     if (rt == NULL) {

         if ((rt = _res_thread_alloc()) == NULL) {

             return NULL;

         }

         rt->_h_errno = 0;

         rt->_serial = 0;

         pthread_setspecific( _res_key, rt );

     }

     /* Check the serial value for any chanes to net.* properties. */

     if (rt->_pi == NULL) {

         rt->_pi = (struct prop_info*) __system_property_find("net.change");

     }

     if (rt->_pi == NULL || rt->_serial == rt->_pi->serial) {

         return rt;

     }

     rt->_serial = rt->_pi->serial;

     /* Reload from system properties. */

     if ( res_ninit( rt->_nres ) < 0 ) {

         free(rt);

         rt = NULL;

         pthread_setspecific( _res_key, rt );

     }

 #ifdef USE_RESOLV_CACHE

     _resolv_cache_reset(rt->_serial);

 #endif

     return rt;

 }

 struct __res_state _nres;

 #if 0

 struct resolv_cache*

 __get_res_cache(void)

 {

     _res_thread*  rt = _res_thread_get();

     if (!rt)

         return NULL;

     if (!rt->_cache) {

         rt->_cache = _resolv_cache_create();

     }

     return rt->_cache;

 }

 #endif

 int*

 __get_h_errno(void)

 {

     _res_thread*  rt    = _res_thread_get();

     static int    panic = NETDB_INTERNAL;

     return rt ? &rt->_h_errno : &panic;

 }

 res_state

 __res_get_state(void)

 {

     _res_thread*  rt = _res_thread_get();

     return rt ? rt->_nres : NULL;

 }

 void

 __res_put_state(res_state res)

 {

     /* nothing to do */

     res=res;

 }

 res_static

 __res_get_static(void)

 {

     _res_thread*  rt = _res_thread_get();

     return rt ? rt->_rstatic : NULL;

 }