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 /* gets the cache for the default interface. Might be NULL*/ 34 extern struct resolv_cache* __get_res_cache(void); 35 36 /* get the cache for a specified interface. Can be NULL*/ 37 extern struct resolv_cache* __get_res_cache_for_iface(const char* ifname); 38 39 /* this gets called everytime we detect some changes in the DNS configuration 40 * and will flush the cache */ 41 extern void _resolv_cache_reset( unsigned generation ); 42 43 /* Gets the address of the n:th name server for the default interface 44 * Return length of address on success else 0. 45 * Note: The first name server is at n = 1 */ 46 extern int _resolv_cache_get_nameserver(int n, char* addr, int addrLen); 47 48 /* Gets the address of the n:th name server for a certain interface 49 * Return length of address on success else 0. 50 * Note: The first name server is at n = 1 */ 51 extern int _resolv_cache_get_nameserver_for_iface(const char* ifname, int n, 52 char* addr, int addrLen); 53 54 /* Gets addrinfo of the n:th name server associated with an interface. 55 * NULL is returned if no address if found. 56 * Note: The first name server is at n = 1. */ 57 extern struct addrinfo* _resolv_cache_get_nameserver_addr_for_iface(const char* ifname, int n); 58 59 /* Gets addrinfo of the n:th name server associated with the default interface 60 * NULL is returned if no address if found. 61 * Note: The first name server is at n = 1. */ 62 extern struct addrinfo* _resolv_cache_get_nameserver_addr(int n); 63 64 /* gets the address associated with the default interface */ 65 extern struct in_addr* _resolv_get_addr_of_default_iface(); 66 67 /* gets the address associated with the specified interface */ 68 extern struct in_addr* _resolv_get_addr_of_iface(const char* ifname); 69 70 /* Get name of default interface */ 71 extern char* _resolv_get_default_iface(); 72 73 typedef enum { 74 RESOLV_CACHE_UNSUPPORTED, /* the cache can't handle that kind of queries */ 75 /* or the answer buffer is too small */ 76 RESOLV_CACHE_NOTFOUND, /* the cache doesn't know about this query */ 77 RESOLV_CACHE_FOUND /* the cache found the answer */ 78 } ResolvCacheStatus; 79 80 extern ResolvCacheStatus 81 _resolv_cache_lookup( struct resolv_cache* cache, 82 const void* query, 83 int querylen, 84 void* answer, 85 int answersize, 86 int *answerlen ); 87 88 /* add a (query,answer) to the cache, only call if _resolv_cache_lookup 89 * did return RESOLV_CACHE_NOTFOUND 90 */ 91 extern void 92 _resolv_cache_add( struct resolv_cache* cache, 93 const void* query, 94 int querylen, 95 const void* answer, 96 int answerlen ); 97 98 #endif /* _RESOLV_CACHE_H_ */ 99