Fixing a multiple access to output database bug

alert_parser.c

@@ -19,7 +19,6 @@
 
 #include	"spp_ai.h"
 
-#include 	<pthread.h>
 #include	<stdio.h>
 #include	<sys/stat.h>
 #include	<time.h>
@@ -325,7 +324,7 @@ AI_file_alertparser_thread ( void* arg )
 					free ( matches );
 					matches = NULL;
 				} else {
-					AI_fatal_err ( "Parse error: a line in the alert log cannot be associated to an alert block", __FILE__, __LINE__ );
+					_dpd.errMsg ( "Error: a line in the alert log cannot be associated to an alert block", __FILE__, __LINE__ );
 				}
 			} else if ( preg_match ( "\\[Priority:\\s*([0-9]+)\\]", line, &matches, &nmatches) > 0 ) {
 				alert->priority = (unsigned short) strtoul ( matches[0], NULL, 10 );

cluster.c

@@ -21,7 +21,6 @@
 
 #include	<limits.h>
 #include	<math.h>
-#include 	<pthread.h>
 #include	<stdio.h>
 #include	<unistd.h>
 
@@ -481,6 +480,9 @@ __AI_cluster_thread ( void* arg )
 			alert_log = NULL;
 		}
 		
+		/* get_alerts() is a function pointer that can point to the function for getting the alerts from
+		 * the plain alert log file or from the database. Calling it the source of the alerts is
+		 * completely transparent to this level */
 		if ( !( alert_log = get_alerts() ))
 		{
 			pthread_mutex_unlock ( &mutex );

correlation.c

@@ -22,7 +22,6 @@
 #include	<alloca.h>
 #include	<libxml/xmlreader.h>
 #include	<math.h>
-#include 	<pthread.h>
 #include	<stdio.h>
 #include	<stdlib.h>
 #include	<string.h>

db.c

@@ -22,7 +22,6 @@
 
 #include	"db.h"
 
-#include 	<pthread.h>
 #include	<time.h>
 #include	<unistd.h>
 

db.h

@@ -34,16 +34,26 @@
 	#define 	DB_fetch_row 		mysql_fetch_row
 	#define 	DB_free_result 	mysql_free_result
 	#define 	DB_escape_string 	mysql_do_escape_string
+	#define 	DB_do_error 		mysql_do_error
+	#define 	DB_is_gone 		mysql_is_gone
 	#define 	DB_close 			mysql_do_close
 
 	#define 	DB_out_init 			mysql_do_out_init
 	#define 	DB_is_out_init 		mysql_is_out_init
 	#define 	DB_out_query 			mysql_do_out_query
 	#define 	DB_out_escape_string 	mysql_do_out_escape_string
+	#define 	DB_do_out_error 		mysql_do_out_error
+	#define 	DB_is_out_gone 		mysql_is_out_gone
 	#define 	DB_out_close 			mysql_do_out_close
 
 	DB_result* DB_query ( const char* );
 	DB_result* DB_out_query ( const char* );
+
+	const char* DB_do_error();
+	const char* DB_do_out_error();
+
+	BOOL DB_is_gone();
+	BOOL DB_is_out_gone();
 #endif
 
 #ifdef 	HAVE_LIBPQ

mysql.c

@@ -21,6 +21,7 @@
 #ifdef 	HAVE_LIBMYSQLCLIENT
 
 #include	<mysql/mysql.h>
+#include	<mysql/errmsg.h>
 
 /** \defgroup mysql Module for the interface with a MySQL DBMS
  * @{ */
@@ -124,6 +125,18 @@ mysql_do_escape_string ( char **to, const char *from, unsigned long length )
 	return mysql_real_escape_string ( db, *to, from, length );
 }
 
+const char*
+mysql_do_error ()
+{
+	return mysql_error ( db );
+}
+
+BOOL
+mysql_is_gone ()
+{
+	return (( mysql_errno ( db ) == CR_SERVER_GONE_ERROR ) || ( mysql_errno ( db ) == CR_SERVER_LOST ));
+}
+
 void
 mysql_do_close ()
 {
@@ -156,6 +169,18 @@ mysql_do_out_escape_string ( char **to, const char *from, unsigned long length )
 	return mysql_real_escape_string ( outdb, *to, from, length );
 }
 
+const char*
+mysql_do_out_error ()
+{
+	return mysql_error ( outdb );
+}
+
+BOOL
+mysql_is_out_gone ()
+{
+	return (( mysql_errno ( outdb ) == CR_SERVER_GONE_ERROR ) || ( mysql_errno ( outdb ) == CR_SERVER_LOST ));
+}
+
 void
 mysql_do_out_close ()
 {

neural.c

@@ -30,7 +30,6 @@
 #include	<alloca.h>
 #include	<limits.h>
 #include	<math.h>
-#include	<pthread.h>
 #include	<sys/stat.h>
 #include	<time.h>
 #include	<unistd.h>
@@ -68,20 +67,24 @@ AI_neural_correlation_weight ()
 			k = (double) config->alert_correlation_weight / HYPERBOLIC_TANGENT_SOLUTION;
 	
 	snprintf ( query, sizeof ( query ), "SELECT count(*) FROM %s", outdb_config[ALERTS_TABLE] );
+	pthread_mutex_lock ( &outdb_mutex );
 
 	if ( !DB_out_init() )
 	{
+		pthread_mutex_unlock ( &outdb_mutex );
 		AI_fatal_err ( "Unable to connect to the database specified in module configuration", __FILE__, __LINE__ );
 	}
 
 	if ( !( res = (DB_result) DB_out_query ( query )))
 	{
-		AI_fatal_err ( "AIPreproc: Query error", __FILE__, __LINE__ );
+		pthread_mutex_unlock ( &outdb_mutex );
+		return 0;
 	}
 
 	row = (DB_row) DB_fetch_row ( res );
 	x = strtod ( row[0], NULL );
 	DB_free_result ( res );
+	pthread_mutex_unlock ( &outdb_mutex );
 
 	return (( exp(x/k) - exp(-x/k) ) / ( exp(x/k) + exp(-x/k) ));
 }		/* -----  end of function AI_neural_correlation_weight  ----- */
@@ -182,9 +185,12 @@ AI_alert_neural_som_correlation ( const AI_snort_alert *a, const AI_snort_alert
 	
 	/* The timestamp of this alert is computed like the average timestamp of the grouped alerts */
 	for ( i=1; i < a->grouped_alerts_count; i++ )
+	{
+		if ( a->grouped_alerts[i-1] )
 		{
 			time_sum += (unsigned long long int) a->grouped_alerts[i-1]->timestamp;
 		}
+	}
 
 	t1.timestamp = (time_t) ( time_sum / a->grouped_alerts_count );
 
@@ -198,9 +204,12 @@ AI_alert_neural_som_correlation ( const AI_snort_alert *a, const AI_snort_alert
 	time_sum = (unsigned long long int) b->timestamp;
 	
 	for ( i=1; i < b->grouped_alerts_count; i++ )
+	{
+		if ( b->grouped_alerts[i-1] )
 		{
 			time_sum += (unsigned long long int) b->grouped_alerts[i-1]->timestamp;
 		}
+	}
 
 	t2.timestamp = (time_t) ( time_sum / b->grouped_alerts_count );
 	return __AI_som_alert_distance ( t1, t2 );
@@ -224,8 +233,11 @@ __AI_som_train ()
 	DB_row    row;
 	AI_som_alert_tuple   *tuples = NULL;
 
+	pthread_mutex_lock ( &outdb_mutex );
+
 	if ( !DB_out_init() )
 	{
+		pthread_mutex_unlock ( &outdb_mutex );
 		AI_fatal_err ( "Unable to connect to the database specified in module configuration", __FILE__, __LINE__ );
 	}
 
@@ -251,9 +263,11 @@ __AI_som_train ()
 
 	if ( !( res = (DB_result) DB_out_query ( query )))
 	{
+		pthread_mutex_unlock ( &outdb_mutex );
 		return;
 	}
 
+	pthread_mutex_unlock ( &outdb_mutex );
 	num_rows = DB_num_rows ( res );
 
 	if ( num_rows == 0 )
@@ -295,7 +309,6 @@ __AI_som_train ()
 	}
 
 	DB_free_result ( res );
-
 	pthread_mutex_lock ( &neural_mutex );
 
 	if ( !net )

outdb.c

@@ -30,7 +30,6 @@
 #include	"uthash.h"
 
 #include	<alloca.h>
-#include	<pthread.h>
 
 /** Hash table built as cache for the couple of alerts already belonging to the same cluster,
  * for avoiding more queries on the database*/
@@ -41,7 +40,7 @@ typedef struct  {
 } AI_couples_cache;
 
 /** Mutex object, for managing concurrent thread access to the database */
-PRIVATE pthread_mutex_t  mutex;
+pthread_mutex_t outdb_mutex;
 PRIVATE AI_couples_cache *couples_cache = NULL;
 
 /**
@@ -51,7 +50,7 @@ PRIVATE AI_couples_cache *couples_cache = NULL;
 void
 AI_outdb_mutex_initialize ()
 {
-	pthread_mutex_init ( &mutex, NULL );
+	pthread_mutex_init ( &outdb_mutex, NULL );
 }		/* -----  end of function AI_outdb_mutex_initialize  ----- */
 
 /**
@@ -80,7 +79,7 @@ AI_store_alert_to_db_thread ( void *arg )
 	DB_row    row;
 	AI_snort_alert *alert = (AI_snort_alert*) arg;
 
-	pthread_mutex_lock ( &mutex );
+	pthread_mutex_lock ( &outdb_mutex );
 
 	if ( !DB_out_init() )
 		AI_fatal_err ( "Unable to connect to the specified output database", __FILE__, __LINE__ );
@@ -109,13 +108,14 @@ AI_store_alert_to_db_thread ( void *arg )
 	if ( !( res = (DB_result) DB_out_query ( query )))
 	{
 		_dpd.logMsg ( "AIPreproc: Warning: error in executing query: '%s'\n", query );
-		pthread_mutex_unlock ( &mutex );
+		pthread_mutex_unlock ( &outdb_mutex );
 		pthread_exit ((void*) 0);
+		return (void*) 0;
 	}
 
 	if ( !( row = (DB_row) DB_fetch_row ( res )))
 	{
-		pthread_mutex_unlock ( &mutex );
+		pthread_mutex_unlock ( &outdb_mutex );
 		pthread_exit ((void*) 0);
 	}
 
@@ -145,13 +145,13 @@ AI_store_alert_to_db_thread ( void *arg )
 		if ( !( res = (DB_result) DB_out_query ( query )))
 		{
 			_dpd.logMsg ( "AIPreproc: Warning: error in executing query: '%s'\n", query );
-			pthread_mutex_unlock ( &mutex );
+			pthread_mutex_unlock ( &outdb_mutex );
 			pthread_exit ((void*) 0);
 		}
 
 		if ( !( row = (DB_row) DB_fetch_row ( res )))
 		{
-			pthread_mutex_unlock ( &mutex );
+			pthread_mutex_unlock ( &outdb_mutex );
 			pthread_exit ((void*) 0);
 		}
 
@@ -211,13 +211,13 @@ AI_store_alert_to_db_thread ( void *arg )
 	if ( !( res = (DB_result) DB_out_query ( query )))
 	{
 		_dpd.logMsg ( "AIPreproc: Warning: error in executing query: '%s'\n", query );
-		pthread_mutex_unlock ( &mutex );
+		pthread_mutex_unlock ( &outdb_mutex );
 		pthread_exit ((void*) 0);
 	}
 
 	if ( !( row = (DB_row) DB_fetch_row ( res )))
 	{
-		pthread_mutex_unlock ( &mutex );
+		pthread_mutex_unlock ( &outdb_mutex );
 		pthread_exit ((void*) 0);
 	}
 
@@ -274,7 +274,7 @@ AI_store_alert_to_db_thread ( void *arg )
 		}
 	}
 
-	pthread_mutex_unlock ( &mutex );
+	pthread_mutex_unlock ( &outdb_mutex );
 	pthread_exit ((void*) 0);
 	return (void*) 0;
 }		/* -----  end of function AI_store_alert_to_db_thread  ----- */
@@ -303,7 +303,7 @@ AI_store_cluster_to_db_thread ( void *arg )
 	DB_row    row;
 	BOOL      new_cluster = false;
 
-	pthread_mutex_lock ( &mutex );
+	pthread_mutex_lock ( &outdb_mutex );
 
 	/* Check if the couple of alerts is already in our cache, so it already
 	 * belongs to the same cluster. If so, just return */
@@ -311,7 +311,7 @@ AI_store_cluster_to_db_thread ( void *arg )
 
 	if ( found )
 	{
-		pthread_mutex_unlock ( &mutex );
+		pthread_mutex_unlock ( &outdb_mutex );
 		pthread_exit ((void*) 0);
 		return (void*) 0;
 	}
@@ -323,7 +323,7 @@ AI_store_cluster_to_db_thread ( void *arg )
 	/* If one of the two alerts has no alert_id, simply return */
 	if ( !alerts_couple->alert1->alert_id || !alerts_couple->alert2->alert_id )
 	{
-		pthread_mutex_unlock ( &mutex );
+		pthread_mutex_unlock ( &outdb_mutex );
 		pthread_exit ((void*) 0);
 		return (void*) 0;
 	}
@@ -337,14 +337,14 @@ AI_store_cluster_to_db_thread ( void *arg )
 	if ( !( res = (DB_result) DB_out_query ( query )))
 	{
 		_dpd.logMsg ( "AIPreproc: Warning: error in executing query: '%s'\n", query );
-		pthread_mutex_unlock ( &mutex );
+		pthread_mutex_unlock ( &outdb_mutex );
 		pthread_exit ((void*) 0);
 		return (void*) 0;
 	}
 
 	if ( !( row = (DB_row) DB_fetch_row ( res )))
 	{
-		pthread_mutex_unlock ( &mutex );
+		pthread_mutex_unlock ( &outdb_mutex );
 		pthread_exit ((void*) 0);
 		return (void*) 0;
 	}
@@ -384,7 +384,7 @@ AI_store_cluster_to_db_thread ( void *arg )
 		found->alerts_couple = alerts_couple;
 		found->cluster_id = cluster1;
 		HASH_ADD ( hh, couples_cache, alerts_couple, sizeof ( AI_alerts_couple ), found );
-		pthread_mutex_unlock ( &mutex );
+		pthread_mutex_unlock ( &outdb_mutex );
 		pthread_exit ((void*) 0);
 		return (void*) 0;
 	}
@@ -417,14 +417,14 @@ AI_store_cluster_to_db_thread ( void *arg )
 		if ( !( res = (DB_result) DB_out_query ( query )))
 		{
 			_dpd.logMsg ( "AIPreproc: Warning: error in executing query: '%s'\n", query );
-			pthread_mutex_unlock ( &mutex );
+			pthread_mutex_unlock ( &outdb_mutex );
 			pthread_exit ((void*) 0);
 			return (void*) 0;
 		}
 
 		if ( !( row = (DB_row) DB_fetch_row ( res )))
 		{
-			pthread_mutex_unlock ( &mutex );
+			pthread_mutex_unlock ( &outdb_mutex );
 			pthread_exit ((void*) 0);
 			return (void*) 0;
 		}
@@ -468,7 +468,7 @@ AI_store_cluster_to_db_thread ( void *arg )
 	found->cluster_id = cluster1;
 	HASH_ADD ( hh, couples_cache, alerts_couple, sizeof ( AI_alerts_couple ), found );
 
-	pthread_mutex_unlock ( &mutex );
+	pthread_mutex_unlock ( &outdb_mutex );
 	pthread_exit ((void*) 0);
 	return (void*) 0;
 }		/* -----  end of function AI_store_cluster_to_db_thread  ----- */
@@ -485,7 +485,7 @@ AI_store_correlation_to_db_thread ( void *arg )
 	char query[1024] = { 0 };
 	AI_alert_correlation *corr = (AI_alert_correlation*) arg;
 
-	pthread_mutex_lock ( &mutex );
+	pthread_mutex_lock ( &outdb_mutex );
 
 	/* Initialize the database (it just does nothing if it is already initialized) */
 	if ( !DB_out_init() )
@@ -501,7 +501,7 @@ AI_store_correlation_to_db_thread ( void *arg )
 		corr->correlation );
 	DB_free_result ((DB_result) DB_out_query ( query ));
 
-	pthread_mutex_unlock ( &mutex );
+	pthread_mutex_unlock ( &outdb_mutex );
 	pthread_exit ((void*) 0);
 	return 0;
 }		/* -----  end of function AI_store_correlation_to_db_thread  ----- */

spp_ai.c

@@ -22,7 +22,6 @@
 #include "sf_preproc_info.h"
 
 #include <errno.h>
-#include <pthread.h>
 #include <stdlib.h>
 #include <string.h>
 

spp_ai.h

@@ -28,6 +28,8 @@
 #include 	"sf_dynamic_preprocessor.h"
 #include	"uthash.h"
 
+#include	<pthread.h>
+
 #define 	PRIVATE 		static
 
 /** Default interval in seconds for the thread cleaning up TCP streams */
@@ -524,6 +526,9 @@ extern AI_snort_alert   **alerts_pool;
 /** Number of alerts contained in the buffer to be serialized */
 extern unsigned int     alerts_pool_count;
 
+/** Mutex variable for writing on the output database */
+extern pthread_mutex_t  outdb_mutex;
+
 /** Configuration of the module */
 extern AI_config        *config;
 

stream.c

@@ -19,7 +19,6 @@
 
 #include 	"spp_ai.h"
 
-#include 	<pthread.h>
 #include	<stdio.h>
 #include	<stdlib.h>
 #include	<unistd.h>
@@ -43,18 +42,21 @@ PRIVATE void
 __AI_stream_free ( struct pkt_info* stream )
 {
 	struct pkt_info *tmp = NULL;
-	char ip [ INET_ADDRSTRLEN ];
 
+	/* If the provided stream is empty, or the hash table contains no element, just return */
 	if ( !stream || !hash || HASH_COUNT(hash) == 0 )
 		return;
 
+	/* Lock the mutex over the hash table and search for a stream having the provided key */
 	pthread_mutex_lock ( &hash_mutex );
 	HASH_FIND ( hh, hash, &(stream->key), sizeof(struct pkt_key), tmp );
 	pthread_mutex_unlock ( &hash_mutex );
 
+	/* If that key is not there, just return */
 	if ( !tmp )
 		return;
 
+	/* If the stream has no IP or TCP header, return */
 	if ( stream->pkt )
 	{
 		if ( !stream->pkt->ip4_header )
@@ -64,12 +66,12 @@ __AI_stream_free ( struct pkt_info* stream )
 			return;
 	}
 
-	inet_ntop ( AF_INET, &(stream->key.src_ip), ip, INET_ADDRSTRLEN );
+	/* Remove the stream from the hash table */
-
 	pthread_mutex_lock ( &hash_mutex );
 	HASH_DEL ( hash, stream );
 	pthread_mutex_unlock ( &hash_mutex );
 
+	/* Remove all the packets contained in the stream */
 	while ( stream )
 	{
 		tmp = stream->next;

webserv.c

@@ -20,7 +20,6 @@
 #include	"spp_ai.h"
 
 #include	<alloca.h>
-#include 	<pthread.h>
 #include	<stdio.h>
 #include	<stdlib.h>
 #include	<sys/stat.h>