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_ */ 67
