/*
* 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;
}