/*

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 *

 * Copyrights

 *

 * Portions created by or assigned to Jabber.com, Inc. are

 * Copyright (c) 1999-2002 Jabber.com, Inc.  All Rights Reserved.  Contact

 * information for Jabber.com, Inc. is available at http://www.jabber.com/.

 *

 * Portions Copyright (c) 1998-1999 Jeremie Miller.

 *

 * Acknowledgements

 *

 * Special thanks to the Jabber Open Source Contributors for their

 * suggestions and support of Jabber.

 *

 */

/**

 * create a new instance of jlimit that is used to limit events

 *

 * limit the events to maxp points per maxt seconds

 *

 * @param maxt time interval (in seconds) after which the points are cleared

 * @param maxp maximum number of points available for the time interval given in maxt

 * @return new instance of jlimit (has to be freed with jlimit_free if not used anymore)

 */

#include "jabber.h"

jlimit jlimit_new(int maxt, int maxp)

{

    pool p;

    jlimit r;

    p = pool_new();

    r = pmalloc(p,sizeof(_jlimit));

    r->key = NULL;

    r->start = r->points = 0;

    r->maxt = maxt;

    r->maxp = maxp;

    r->p = p;

    return r;

}

/**

 * free a jlimit instance

 *

 * @param r the jlimit instance that should be freed

 */

void jlimit_free(jlimit r)

{

    if(r != NULL)

    {

        if(r->key != NULL) free(r->key);

        pool_free(r->p);

    }

}

/**

 * update/check a key in a jlimit instance

 *

 * Each jlimit instance can track many limits (that have the same setup).

 * The limit is selected by the key, which can be an IP address.

 *

 * @param r the jlimit instance

 * @param key for which key the limit should be checked

 * @param points how many points of the limit should be consumed

 * @return 1 if limit reached, 0 if we are still within the rate limit

 */

int jlimit_check(jlimit r, char *key, int points)

{

    int now = time(NULL);

    if(r == NULL) return 0;

    /* make sure we didn't go over the time frame or get a null/new key */

    if((now - r->start) > r->maxt || key == NULL || j_strcmp(key,r->key) != 0)

    { /* start a new key */

        free(r->key);

        if(key != NULL)

          /* We use strdup instead of pstrdup since r->key needs to be free'd before

             and more often than the rest of the rlimit structure */

            r->key = strdup(key);

        else

            r->key = NULL;

        r->start = now;

        r->points = 0;

    }

    r->points += points;

    /* if we're within the time frame and over the point limit */

    if(r->points > r->maxp && (now - r->start) < r->maxt)

    {

        return 1; /* we don't reset the rate here, so that it remains rated until the time runs out */

    }

    return 0;

}