| The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame^] | 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 | struct resolv_cache; /* forward */ |
| 32 | |
| 33 | /* get cache instance, can be NULL if cache is disabled |
| 34 | * (e.g. through an environment variable) */ |
| 35 | extern struct resolv_cache* __get_res_cache(void); |
| 36 | |
| 37 | /* this gets called everytime we detect some changes in the DNS configuration |
| 38 | * and will flush the cache */ |
| 39 | extern void _resolv_cache_reset( unsigned generation ); |
| 40 | |
| 41 | typedef enum { |
| 42 | RESOLV_CACHE_UNSUPPORTED, /* the cache can't handle that kind of queries */ |
| 43 | /* or the answer buffer is too small */ |
| 44 | RESOLV_CACHE_NOTFOUND, /* the cache doesn't know about this query */ |
| 45 | RESOLV_CACHE_FOUND /* the cache found the answer */ |
| 46 | } ResolvCacheStatus; |
| 47 | |
| 48 | extern ResolvCacheStatus |
| 49 | _resolv_cache_lookup( struct resolv_cache* cache, |
| 50 | const void* query, |
| 51 | int querylen, |
| 52 | void* answer, |
| 53 | int answersize, |
| 54 | int *answerlen ); |
| 55 | |
| 56 | /* add a (query,answer) to the cache, only call if _resolv_cache_lookup |
| 57 | * did return RESOLV_CACHE_NOTFOUND |
| 58 | */ |
| 59 | extern void |
| 60 | _resolv_cache_add( struct resolv_cache* cache, |
| 61 | const void* query, |
| 62 | int querylen, |
| 63 | const void* answer, |
| 64 | int answerlen ); |
| 65 | |
| 66 | #endif /* _RESOLV_CACHE_H_ */ |