rd_filter.c

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/*
 * $Id: rd_filter.c 4585 2008-08-06 08:20:30Z klaus_darilion $
 *
 * Copyright (C) 2005 Voice Sistem SRL
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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.
 *
 * Kamailio 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.
 *
 *
 * History:
 * ---------
 *  2005-06-22  first version (bogdan)
 */


#include <string.h>
#include <sys/types.h> /* for regex */
#include <regex.h>

#include "../../dprint.h"
#include "rd_filter.h"

#define MAX_FILTERS 6

static int default_rule = ACCEPT_RULE;

static regex_t *rd_filters[NR_FILTER_TYPES][MAX_FILTERS];
static int nr_filters[NR_FILTER_TYPES];
static int start_filters[NR_FILTER_TYPES];


void init_filters(void)
{
   memset( rd_filters , 0, NR_FILTER_TYPES*MAX_FILTERS*sizeof(regex_t*));
   reset_filters();
}


void set_default_rule( int type )
{
   default_rule = type;
}


void reset_filters(void)
{
   nr_filters[ACCEPT_FILTER] = 1;
   nr_filters[DENY_FILTER]   = 1;
   start_filters[ACCEPT_FILTER] = 0;
   start_filters[DENY_FILTER]   = 0;
}


void add_default_filter( int type, regex_t *filter)
{
   rd_filters[type][0] = filter;
}


int add_filter( int type, regex_t *filter, int flags)
{
   if ( nr_filters[type]==MAX_FILTERS ) {
      LM_ERR("too many filters type %d\n", type);
      return -1;
   }

   /* flags? */
   if (flags&RESET_ADDED)
      nr_filters[type] = 1;
   if (flags&RESET_DEFAULT)
      start_filters[type] = 1;

   /* set filter */
   rd_filters[type][ nr_filters[type]++ ] = filter;
   return 0;
}


int run_filters(char *s)
{
   regmatch_t pmatch;
   int i;

   /* check for accept filters */
   for( i=start_filters[ACCEPT_FILTER] ; i<nr_filters[ACCEPT_FILTER] ; i++ ) {
      if (rd_filters[ACCEPT_FILTER][i]==0)
         continue;
      if (regexec(rd_filters[ACCEPT_FILTER][i], s, 1, &pmatch, 0)==0)
         return 1;
   }

   /* if default rule is deny, don' check the deny rules */
   if (default_rule!=DENY_RULE) {
      /* check for deny filters */
      for( i=start_filters[DENY_FILTER] ; i<nr_filters[DENY_FILTER] ; i++ ) {
         if (rd_filters[DENY_FILTER][i]==0)
            continue;
         if (regexec(rd_filters[DENY_FILTER][i], s, 1, &pmatch, 0)==0)
            return -1;
      }
   }

   /* return default */
   return (default_rule==ACCEPT_RULE)?1:-1;
}