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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.
*/
#ifndef _RESOLV_CACHE_H_
#define _RESOLV_CACHE_H_
struct __res_state;
struct resolv_cache; /* forward */
/* gets the cache for an interface. Set ifname argument to NULL or
* empty buffer ('\0') to get cache for default interface.
* returned cache might be NULL*/
extern struct resolv_cache* __get_res_cache(const char* ifname);
/* this gets called everytime we detect some changes in the DNS configuration
* and will flush the cache */
extern void _resolv_cache_reset( unsigned generation );
/* Gets the address of the n:th name server for the default interface
* Return length of address on success else 0.
* Note: The first name server is at n = 1 */
extern int _resolv_cache_get_nameserver(int n, char* addr, int addrLen);
/* Gets the address of the n:th name server for a certain interface
* Return length of address on success else 0.
* Note: The first name server is at n = 1 */
extern int _resolv_cache_get_nameserver_for_iface(const char* ifname, int n,
char* addr, int addrLen);
/* Gets addrinfo of the n:th name server associated with an interface.
* NULL is returned if no address if found.
* Note: The first name server is at n = 1. */
extern struct addrinfo* _resolv_cache_get_nameserver_addr_for_iface(const char* ifname, int n);
/* Gets addrinfo of the n:th name server associated with the default interface
* NULL is returned if no address if found.
* Note: The first name server is at n = 1. */
extern struct addrinfo* _resolv_cache_get_nameserver_addr(int n);
/* gets the address associated with the default interface */
extern struct in_addr* _resolv_get_addr_of_default_iface();
/* gets the address associated with the specified interface */
extern struct in_addr* _resolv_get_addr_of_iface(const char* ifname);
/* Copy the name of the default interface to provided buffer.
* Return length of buffer on success on failure -1 is returned */
extern int _resolv_get_default_iface(char* buff, int buffLen);
/* sets the name server addresses to the provided res_state structure. The
* name servers are retrieved from the cache which is associated
* with the interface to which the res_state structure is associated */
extern int _resolv_populate_res_for_iface(struct __res_state* statp);
typedef enum {
RESOLV_CACHE_UNSUPPORTED, /* the cache can't handle that kind of queries */
/* or the answer buffer is too small */
RESOLV_CACHE_NOTFOUND, /* the cache doesn't know about this query */
RESOLV_CACHE_FOUND /* the cache found the answer */
} ResolvCacheStatus;
extern ResolvCacheStatus
_resolv_cache_lookup( struct resolv_cache* cache,
const void* query,
int querylen,
void* answer,
int answersize,
int *answerlen );
/* add a (query,answer) to the cache, only call if _resolv_cache_lookup
* did return RESOLV_CACHE_NOTFOUND
*/
extern void
_resolv_cache_add( struct resolv_cache* cache,
const void* query,
int querylen,
const void* answer,
int answerlen );
/* Notify the cache a request failed */
extern void
_resolv_cache_query_failed( struct resolv_cache* cache,
const void* query,
int querylen);
#endif /* _RESOLV_CACHE_H_ */
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