Home | History | Annotate | Download | only in include 
      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 #ifndef _RESOLV_CACHE_H_
     29 #define _RESOLV_CACHE_H_
     30 
     31 #include <stddef.h>
     32 #include <sys/cdefs.h>
     33 
     34 struct __res_state;
     35 
     36 /* sets the name server addresses to the provided res_state structure. The
     37  * name servers are retrieved from the cache which is associated
     38  * with the network to which the res_state structure is associated */
     39 __LIBC_HIDDEN__
     40 extern void _resolv_populate_res_for_net(struct __res_state* statp);
     41 
     42 typedef enum {
     43     RESOLV_CACHE_UNSUPPORTED,  /* the cache can't handle that kind of queries */
     44                                /* or the answer buffer is too small */
     45     RESOLV_CACHE_NOTFOUND,     /* the cache doesn't know about this query */
     46     RESOLV_CACHE_FOUND         /* the cache found the answer */
     47 } ResolvCacheStatus;
     48 
     49 __LIBC_HIDDEN__
     50 extern ResolvCacheStatus
     51 _resolv_cache_lookup( unsigned              netid,
     52                       const void*           query,
     53                       int                   querylen,
     54                       void*                 answer,
     55                       int                   answersize,
     56                       int                  *answerlen );
     57 
     58 /* add a (query,answer) to the cache, only call if _resolv_cache_lookup
     59  * did return RESOLV_CACHE_NOTFOUND
     60  */
     61 __LIBC_HIDDEN__
     62 extern void
     63 _resolv_cache_add( unsigned              netid,
     64                    const void*           query,
     65                    int                   querylen,
     66                    const void*           answer,
     67                    int                   answerlen );
     68 
     69 /* Notify the cache a request failed */
     70 __LIBC_HIDDEN__
     71 extern void
     72 _resolv_cache_query_failed( unsigned     netid,
     73                    const void* query,
     74                    int         querylen);
     75 
     76 #endif /* _RESOLV_CACHE_H_ */
     77