67 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			67 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (C) 2008 The Android Open Source Project
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *  * Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 *  * Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in
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 *    the documentation and/or other materials provided with the
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 *    distribution.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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#ifndef _RESOLV_CACHE_H_
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#define _RESOLV_CACHE_H_
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struct resolv_cache;  /* forward */
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/* get cache instance, can be NULL if cache is disabled
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 * (e.g. through an environment variable) */
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extern struct resolv_cache*  __get_res_cache(void);
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/* this gets called everytime we detect some changes in the DNS configuration
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 * and will flush the cache */
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extern void   _resolv_cache_reset( unsigned  generation );
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typedef enum {
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    RESOLV_CACHE_UNSUPPORTED,  /* the cache can't handle that kind of queries */
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                               /* or the answer buffer is too small */
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    RESOLV_CACHE_NOTFOUND,     /* the cache doesn't know about this query */
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    RESOLV_CACHE_FOUND         /* the cache found the answer */
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} ResolvCacheStatus;
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extern ResolvCacheStatus
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_resolv_cache_lookup( struct resolv_cache*  cache,
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                      const void*           query,
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                      int                   querylen,
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                      void*                 answer,
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                      int                   answersize,
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                      int                  *answerlen );
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/* add a (query,answer) to the cache, only call if _resolv_cache_lookup
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 * did return RESOLV_CACHE_NOTFOUND
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 */
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extern void
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_resolv_cache_add( struct resolv_cache*  cache,
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                   const void*           query,
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                   int                   querylen,
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                   const void*           answer,
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                   int                   answerlen );
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#endif /* _RESOLV_CACHE_H_ */
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