sfrim.c

著名的入侵检测系统snort的最新版本的源码

/****************************************************************************
 *
 * Copyright (C) 2005-2007 Sourcefire, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License Version 2 as
 * published by the Free Software Foundation.  You may not use, modify or
 * distribute this program under any other version of the GNU General
 * Public License.
 *
 * 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.
 *
 ****************************************************************************/

/*
 *   sfrim.c    
 *
 *   Rule Index Map
 *
 *   author: marc norton
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include "sfrim.h"

/*
 * Return Sid associated with index
 * author: marc norton
 */
unsigned RuleIndexMapSid( rule_index_map_t * map, int index )
{
    if( ! map )
        return 0;
    
    if( index < map->num_rules )
    {
        return map->map[index].sid;
    }
    return 0;
}
/*
 * Return Gid associated with index
 * author: marc norton
 */
unsigned RuleIndexMapGid(rule_index_map_t * map, int index )
{
    if( ! map )
    {
        return 0;
    }
    if( index < map->num_rules )
    {
        return map->map[index].gid;
    }
    return 0;
}
/*
 * Create a rule index map table 
 * author: marc norton
 */
rule_index_map_t * RuleIndexMapCreate( int max_rules )
{
        rule_index_map_t *p = calloc( 1, sizeof(rule_index_map_t) );
        if(!p)
        {
            return 0;
        }
        p->max_rules=max_rules;
        p->num_rules=0;
        p->map = calloc( max_rules, sizeof(rule_number_t));
        if(!p->map )
        {
            free(p);
            return 0;
        }
        return p;
}
/*
 * Free a rule index map table 
 * author: marc norton
 */
void RuleIndexMapFree( rule_index_map_t ** p )
{
    if( !p || !*p )
    {
      return ;
    }
    if( (*p)->map )
    {
        free((*p)->map);
    }
    free( *p );

    *p = 0;
}

/*
 * Add a rule to a rule index map table 
 * author: marc norton
 */
int RuleIndexMapAdd( rule_index_map_t * p, unsigned gid, unsigned sid )
{
        int index;
       
        if( !p ) 
        {
            return -1;
        }
        if( p->num_rules == (p->max_rules - 1) )
        {
            return -1;
        }
        index = p->num_rules  ;   
        p->map[ index ].gid = gid;
        p->map[ index ].sid = sid;
        p->num_rules++;

        //printf("RuleIndexMapping: index=%d gid=%u sid=%u\n",index,gid,sid);
        return index;
}
/*
 * print a rule index map table to stdout 
 * author: marc norton
 */
void print_rule_index_map( rule_index_map_t * p )
{
    int i;
    printf("***\n*** Rule Index Map (%d entries)\n***\n",p->num_rules);
    for(i=0;i<p->num_rules;i++)
    {
         printf("rule-index-map[%d] { gid:%u sid:%u }\n",i,p->map[i].gid,p->map[i].sid);
    }
    printf("***end rule index map ***\n");
}