/// <summary>
/// WaitCallback method for performing a byte[] scan on an independent thread using System.Treading.QueueUserWorkItem.
/// </summary>
/// <exception cref="ArgumentException">Throws argument "o" is not an instance of StreamScanArgs.</exception>
/// <param name="o">Instance of StreamScanArgs.</param>
protected virtual void DoStreamScan(object o)
{
if (!(o is StreamScanArgs))
{
throw new ArgumentException(ResourceManagers.Strings.GetString(STR_DO_BYTE_SCAN_ARG_EX));
}
StreamScanArgs scanArgs = (StreamScanArgs)o;
StreamScan(scanArgs);
}
/// <summary>
/// Scan a byte[] bag.
/// </summary>
/// <param name="id">Unique identifier for the buffer (eg. filename, url or database key, etc.)</param>
/// <param name="stream">Stream to scan</param>
public override void Scan(string id, Stream stream)
{
StreamScanArgs args = new StreamScanArgs(id, stream);
switch (_threadModel)
{
case VirusScanAgent.ThreadingModel.AsynchronousThreadPool:
ThreadPool.QueueUserWorkItem(new WaitCallback(this.DoStreamScan), args);
break;
case VirusScanAgent.ThreadingModel.SynchronousSingleThread:
StreamScan(args);
break;
default:
throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, ResourceManagers.Strings.GetString(STR_SCAN_NOT_SUPPORTED_EX_THREADING), _threadModel));
}
}
/// <summary>
/// Method scans a byte[] by passing it to clamd over a dynamically allocated port. The real magic happens here.
/// The ItemScanCompleted event is raised whenever this method completes. If a virus is found, this method raises
/// the VirusFound event.
/// </summary>
/// <param name="args">StreamScanArgs instance.</param>
protected virtual void StreamScan(StreamScanArgs args)
{
string outstr = null;
try
{
using (TcpClient tcpclient = new TcpClient(this.ClamdHost, this.ClamdPort))
using (NetworkStream netStream = tcpclient.GetStream())
using (StreamWriter outputStream = new StreamWriter(netStream))
using (StreamReader inputStream = new StreamReader(netStream))
{
outputStream.WriteLine(SCAN_VERB);
outputStream.Flush();
string portstr = inputStream.ReadLine();
string[] daemonargs = portstr.Split(' ');
SendStream(args.Stream, int.Parse(daemonargs[daemonargs.Length - 1], CultureInfo.InvariantCulture));
outstr = inputStream.ReadLine();
outputStream.Close();
inputStream.Close();
netStream.Close();
tcpclient.Close();
}
if (outstr != null && outstr.IndexOf(FOUND) > -1)
{
this.OnVirusFound(new ScanCompletedEventArgs(args.Id, outstr));
}
this.OnItemScanCompleted(new ScanCompletedEventArgs(args.Id, outstr));
//reset retry counter
_netRetryCount = 0;
}
catch (Exception ex)
{
if (ex is SocketException || ex is IOException)
{
if (_netRetryCount < MAX_NET_RETRY)
{
//increment retry count and try again
_netRetryCount++;
StreamScan(args);
}
else
{
//reset retry count log error and return
_netRetryCount = 0;
if (_logger.IsDebugEnabled)
{
_logger.Error(ex);
}
else
{
_logger.Error(ex.Message);
}
}
}
else
{
throw;
}
}
}
/// <summary>
/// Scan a byte[] bag.
/// </summary>
/// <param name="id">Unique identifier for the buffer (eg. filename, url or database key, etc.)</param>
/// <param name="stream">Stream to scan</param>
public override void Scan(string id, Stream stream)
{
StreamScanArgs args = new StreamScanArgs(id,stream);
switch(_threadModel)
{
case VirusScanAgent.ThreadingModel.AsynchronousThreadPool :
ThreadPool.QueueUserWorkItem( new WaitCallback( this.DoStreamScan ), args );
break;
case VirusScanAgent.ThreadingModel.SynchronousSingleThread :
StreamScan(args);
break;
default :
throw new NotSupportedException( string.Format(CultureInfo.CurrentCulture, ResourceManagers.Strings.GetString(STR_SCAN_NOT_SUPPORTED_EX_THREADING), _threadModel) );
}
}
/// <summary>
/// Method scans a byte[] by passing it to clamd over a dynamically allocated port. The real magic happens here.
/// The ItemScanCompleted event is raised whenever this method completes. If a virus is found, this method raises
/// the VirusFound event.
/// </summary>
/// <param name="args">StreamScanArgs instance.</param>
protected virtual void StreamScan(StreamScanArgs args)
{
string outstr = null;
try
{
using ( TcpClient tcpclient = new TcpClient( this.ClamdHost, this.ClamdPort ) )
using (NetworkStream netStream = tcpclient.GetStream() )
using (StreamWriter outputStream = new StreamWriter(netStream) )
using (StreamReader inputStream = new StreamReader(netStream) )
{
outputStream.WriteLine( SCAN_VERB );
outputStream.Flush();
string portstr = inputStream.ReadLine();
string[] daemonargs = portstr.Split(' ');
SendStream ( args.Stream, int.Parse (daemonargs[daemonargs.Length-1], CultureInfo.InvariantCulture ) );
outstr = inputStream.ReadLine();
outputStream.Close();
inputStream.Close();
netStream.Close();
tcpclient.Close();
}
if(outstr!=null && outstr.IndexOf(FOUND)>-1)
this.OnVirusFound( new ScanCompletedEventArgs( args.Id, outstr ) );
this.OnItemScanCompleted( new ScanCompletedEventArgs( args.Id, outstr ) );
//reset retry counter
_netRetryCount = 0;
}
catch(Exception ex)
{
if(ex is SocketException || ex is IOException)
{
if (_netRetryCount < MAX_NET_RETRY)
{
//increment retry count and try again
_netRetryCount++;
StreamScan( args );
}
else
{
//reset retry count log error and return
_netRetryCount = 0;
if(_logger.IsDebugEnabled)
_logger.Error(ex);
else
_logger.Error(ex.Message);
}
}
else
throw;
}
}
