dnscache.h

/*-
 * Copyright (c) 2012 Nikolay Denev <ndenev@gmail.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. The name of the author may not be used to endorse or promote products
 * derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 DNSCACHE_H_INCLUDED
#define DNSCACHE_H_INCLUDED

#include <limits.h>

#define DNSCACHESIZE 4096
#define DNSCACHETTL 300
struct dnscache_entry_t {
        u_int32_t       from;
        char    host[_POSIX_HOST_NAME_MAX+1];
        int     ts;
};

struct dnscache_t {
        struct  dnscache_entry_t entry[DNSCACHESIZE];
        int     size;
        int     hit;
        int     miss;
        int     full;
        pthread_rwlock_t *lock;
};


void trytogetrdns(pthread_mutex_t *stat_mtx, struct sockaddr *from, char *host, struct dnscache_t *cache);
void dnscache_expire(void *arg);

#endif