Snort_AIPreproc/cluster.c

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2010-08-14 14:30:41 +02:00
/*
* =====================================================================================
*
* Filename: cluster.c
*
* Description: Module for managing alarm clustering and cluter hierarchies
*
* Version: 1.0
* Created: 12/08/2010 12:43:28
* Revision: none
* Compiler: gcc
*
* Author: BlackLight (http://0x00.ath.cx), <blacklight@autistici.org>
* Licence: GNU GPL v.3
* Company: DO WHAT YOU WANT CAUSE A PIRATE IS FREE, YOU ARE A PIRATE!
*
* =====================================================================================
*/
#include "spp_ai.h"
#include <stdio.h>
#include <unistd.h>
#include <pthread.h>
PRIVATE hierarchy_node *src_port_root = NULL;
PRIVATE hierarchy_node *src_addr_root = NULL;
PRIVATE hierarchy_node *dst_port_root = NULL;
PRIVATE hierarchy_node *dst_addr_root = NULL;
PRIVATE AI_config *_config = NULL;
PRIVATE AI_snort_alert *alert_log = NULL;
/**
* FUNCTION: _hierarchy_node_new
* \brief Create a new clustering hierarchy node
* \param label Label for the node
* \param min_val Minimum value for the range represented by the node
* \param max_val Maximum value for the range represented by the node
* \return The brand new node if the allocation was ok, otherwise abort the application
*/
PRIVATE hierarchy_node*
_hierarchy_node_new ( char *label, int min_val, int max_val )
{
hierarchy_node *n = NULL;
if ( !( n = ( hierarchy_node* ) malloc ( sizeof ( hierarchy_node )) ))
{
_dpd.fatalMsg ( "Dynamic memory allocation failure at %s:%d\n", __FILE__, __LINE__ );
}
n->min_val = min_val;
n->max_val = max_val;
n->nchildren = 0;
n->children = NULL;
n->parent = NULL;
strncpy ( n->label, label, sizeof ( n->label ));
return n;
} /* ----- end of function _hierarchy_node_new ----- */
/**
* FUNCTION: _hierarchy_node_append
* \brief Append a node to a clustering hierarchy node
* \param parent Parent node
* \param child Child node
*/
PRIVATE void
_hierarchy_node_append ( hierarchy_node *parent, hierarchy_node *child )
{
if ( !( parent->children = ( hierarchy_node** ) realloc ( parent->children, (++(parent->nchildren)) * sizeof ( hierarchy_node* )) ))
{
_dpd.fatalMsg ( "Dynamic memory allocation failure at %s:%d\n", __FILE__, __LINE__ );
}
parent->children[ parent->nchildren - 1 ] = child;
child->parent = parent;
} /* ----- end of function _hierarchy_node_append ----- */
/* PRIVATE void */
/* _hierarchy_node_free ( hierarchy_node *n ) */
/* { */
/* int i; */
/* */
/* if ( !n ) */
/* return; */
/* */
/* for ( i=0; i < n->nchildren; i++ ) */
/* { */
/* if ( n->children[i] ) */
/* _hierarchy_node_free ( n->children[i] ); */
/* } */
/* */
/* free ( n ); */
/* n = NULL; */
/* } */
/**
* FUNCTION: _AI_get_min_hierarchy_node
* \brief Get the minimum node in a hierarchy tree that matches a certain value
* \param val Value to be matched in the range
* \param root Root of the hierarchy
* \return The minimum node that matches the value if any, NULL otherwise
*/
PRIVATE hierarchy_node*
_AI_get_min_hierarchy_node ( int val, hierarchy_node *root )
{
int i;
hierarchy_node *next = NULL;
if ( !root )
{
return NULL;
}
if ( (unsigned) val < (unsigned) root->min_val || (unsigned) val > (unsigned) root->max_val )
{
return NULL;
}
for ( i=0; i < root->nchildren && !next; i++ )
{
if ( root->children[i]->min_val <= val && root->children[i]->max_val >= val )
{
next = root->children[i];
}
}
if ( !next )
return root;
return _AI_get_min_hierarchy_node ( val, next );
} /* ----- end of function _AI_get_min_hierarchy_node ----- */
/**
* FUNCTION: _AI_cluster_thread
* \brief Thread for periodically clustering the log information
*/
PRIVATE void*
_AI_cluster_thread ( void* arg )
{
AI_snort_alert *tmp;
hierarchy_node *node, *child;
char label[256];
while ( 1 )
{
sleep ( _config->alertClusteringInterval );
if ( !( alert_log = AI_get_alerts() ))
{
continue;
}
FILE *fp = fopen ( "/home/blacklight/LOG", "a" );
for ( tmp = alert_log; tmp; tmp = tmp->next )
{
if ( src_addr_root && !tmp->src_addr_node )
{
node = _AI_get_min_hierarchy_node ( ntohl ( tmp->src_addr ), src_addr_root );
if ( node )
{
if ( node->min_val < node->max_val )
{
inet_ntop ( AF_INET, &(tmp->src_addr), label, INET_ADDRSTRLEN );
child = _hierarchy_node_new ( label, ntohl ( tmp->src_addr ), ntohl ( tmp->src_addr ));
_hierarchy_node_append ( node, child );
node = child;
}
tmp->src_addr_node = node;
fprintf ( fp, "minimum range holding %s: %s (prev: %s)\n", label, tmp->src_addr_node->label, tmp->src_addr_node->parent->label );
}
}
if ( dst_addr_root && !tmp->dst_addr_node )
{
node = _AI_get_min_hierarchy_node ( ntohl ( tmp->dst_addr ), dst_addr_root );
if ( node )
{
if ( node->min_val < node->max_val )
{
/* snprintf ( label, sizeof(label), "%d", ntohl ( tmp->dst_addr )); */
inet_ntop ( AF_INET, &(tmp->src_addr), label, INET_ADDRSTRLEN );
child = _hierarchy_node_new ( label, ntohl ( tmp->dst_addr ), ntohl ( tmp->dst_addr ));
_hierarchy_node_append ( node, child );
node = child;
}
tmp->dst_addr_node = node;
}
}
if ( src_port_root && !tmp->src_port_node )
{
node = _AI_get_min_hierarchy_node ( ntohs ( tmp->src_port ), src_port_root );
if ( node )
{
if ( node->min_val < node->max_val )
{
snprintf ( label, sizeof(label), "%d", ntohs ( tmp->src_port ));
child = _hierarchy_node_new ( label, ntohs ( tmp->src_port ), ntohs ( tmp->src_port ));
_hierarchy_node_append ( node, child );
node = child;
}
tmp->src_port_node = node;
fprintf ( fp, "minimum range holding %d: %s (prev: %s)\n", ntohs(tmp->src_port), tmp->src_port_node->label, tmp->src_port_node->parent->label );
}
}
if ( dst_port_root && !tmp->dst_port_node )
{
node = _AI_get_min_hierarchy_node ( ntohs ( tmp->dst_port ), dst_port_root );
if ( node )
{
if ( node->min_val < node->max_val )
{
snprintf ( label, sizeof(label), "%d", ntohs ( tmp->dst_port ));
child = _hierarchy_node_new ( label, ntohs ( tmp->dst_port ), ntohs ( tmp->dst_port ));
_hierarchy_node_append ( node, child );
node = child;
}
tmp->dst_port_node = node;
fprintf ( fp, "minimum range holding %d: %s (prev: %s)\n", ntohs(tmp->dst_port), tmp->dst_port_node->label, tmp->dst_port_node->parent->label );
}
}
}
fclose ( fp );
}
return (void*) 0;
} /* ----- end of function AI_cluster_thread ----- */
/**
* FUNCTION: AI_hierarchies_build
* \brief Build the clustering hierarchy trees
* \param conf Reference to the configuration of the module
* \param nodes Nodes containing the information about the clustering ranges
* \param n_nodes Number of nodes
*/
void
AI_hierarchies_build ( AI_config *conf, hierarchy_node **nodes, int n_nodes )
{
int i, j;
int min_range = 0;
pthread_t cluster_thread;
hierarchy_node *root = NULL;
hierarchy_node *cover = NULL;
_config = conf;
for ( i=0; i < n_nodes; i++ )
{
switch ( nodes[i]->type )
{
case src_port:
if ( !src_port_root )
src_port_root = _hierarchy_node_new ( "1-65535", 1, 65535 );
root = src_port_root;
min_range = 65534;
break;
case dst_port:
if ( !dst_port_root )
dst_port_root = _hierarchy_node_new ( "1-65535", 1, 65535 );
root = dst_port_root;
min_range = 65534;
break;
case src_addr:
if ( !src_addr_root )
src_addr_root = _hierarchy_node_new ( "0.0.0.0/0",
0x0, 0xffffffff );
root = src_addr_root;
min_range = 0xffffffff;
break;
case dst_addr:
if ( !dst_addr_root )
dst_addr_root = _hierarchy_node_new ( "0.0.0.0/0",
0x0, 0xffffffff );
root = dst_addr_root;
min_range = 0xffffffff;
break;
/* TODO Manage range for timestamps (and something more?) */
default:
break;
}
cover = NULL;
for ( j=0; j < n_nodes; j++ )
{
if ( i != j )
{
if ( (unsigned) nodes[j]->min_val <= (unsigned) nodes[i]->min_val &&
(unsigned) nodes[j]->max_val >= (unsigned) nodes[i]->max_val )
{
if (( (unsigned) nodes[i]->min_val - (unsigned) nodes[j]->min_val +
(unsigned) nodes[j]->max_val - (unsigned) nodes[i]->max_val ) <= min_range )
{
cover = nodes[j];
min_range = nodes[i]->min_val - nodes[j]->min_val +
nodes[j]->max_val - nodes[i]->max_val;
}
}
}
}
if ( cover )
{
_hierarchy_node_append ( cover, nodes[i] );
} else {
if ( (unsigned) nodes[i]->min_val >= (unsigned) root->min_val && (unsigned) nodes[i]->max_val <= (unsigned) root->max_val &&
( (unsigned) nodes[i]->min_val != (unsigned) root->min_val || (unsigned) nodes[i]->max_val != (unsigned) root->max_val ))
{
_hierarchy_node_append ( root, nodes[i] );
}
}
}
if ( pthread_create ( &cluster_thread, NULL, _AI_cluster_thread, NULL ) != 0 )
{
_dpd.fatalMsg ( "Failed to create the hash cleanup thread\n" );
}
} /* ----- end of function AI_hierarchies_build ----- */