/// <summary>
/// PASV Command - RFC 959 - Section 4.1.2
/// <para>进入被动模式（请求服务器等待数据连接）</para>
/// </summary>
/// <returns></returns>
private Response Passive()
{
_dataConnectionType = DataConnectionType.Passive;
IPAddress localIp = ((IPEndPoint)ControlClient.Client.LocalEndPoint).Address;
_passiveListener = PassiveListenerPool.GetListener(localIp);
try
{
_passiveListener.Start();
}
catch
{
_log.Error("No more ports available");
return(GetResponse(FtpResponses.UNABLE_TO_OPEN_DATA_CONNECTION));
}
IPEndPoint passiveListenerEndpoint = (IPEndPoint)_passiveListener.LocalEndpoint;
byte[] address = passiveListenerEndpoint.Address.GetAddressBytes();
ushort port = (ushort)passiveListenerEndpoint.Port;
byte[] portArray = BitConverter.GetBytes(port);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(portArray);
}
return(GetResponse(FtpResponses.ENTERING_PASSIVE_MODE.SetData(address[0], address[1], address[2], address[3], portArray[0], portArray[1])));
}
protected override void Dispose(bool disposing)
{
PassiveListenerPool.ReleaseAll();
if (_timer != null)
{
_timer.Dispose();
}
base.Dispose(disposing);
}
/// <summary>
/// EPSV Command - RFC 2428
/// <para>扩展被动模式（IPv6）</para>
/// </summary>
/// <returns></returns>
private Response EPassive()
{
_dataConnectionType = DataConnectionType.Passive;
IPAddress localIp = ((IPEndPoint)ControlClient.Client.LocalEndPoint).Address;
_passiveListener = PassiveListenerPool.GetListener(localIp);
try
{
_passiveListener.Start();
}
catch
{
_log.Error("No more ports available");
return(GetResponse(FtpResponses.UNABLE_TO_OPEN_DATA_CONNECTION));
}
IPEndPoint passiveListenerEndpoint = (IPEndPoint)_passiveListener.LocalEndpoint;
return(GetResponse(FtpResponses.ENTERING_EXTENDED_PASSIVE_MODE.SetData(passiveListenerEndpoint.Port)));
}
private void DoDataConnectionOperation(IAsyncResult result)
{
_performanceCounter.IncrementTotalConnectionAttempts();
_performanceCounter.IncrementCurrentConnections();
//由BeginConnect异步调用，因此需要EndConnect，EndConnect需要使用【对应的】IAsyncResult作为参数
HandleAsyncResult(result);
//取出我们传入的真正需要的DataConnectionOperation结构，内含本次要执行的方法与参数
DataConnectionOperation op = result.AsyncState as DataConnectionOperation;
Response response;
try
{
if (_dataClient == null)
{
throw new SocketException();
}
//通过上述异步过程，此时的_dataClient已经连接
if (_protected)
{
using (GnuSslStream dataStream = new GnuSslStream(_dataClient.GetStream(), false))
{
try
{
dataStream.AuthenticateAsServer(_cert, false, SslProtocols.Tls, true);
response = op.Operation(dataStream, op.Arguments);
}
catch (Exception)
{
response = GetResponse(FtpResponses.UNABLE_TO_OPEN_DATA_CONNECTION);
//throw;
}
dataStream.Close();
//response = op.Operation(dataStream, op.Arguments);
}
}
else
{
using (NetworkStream dataStream = _dataClient.GetStream())
{
response = op.Operation(dataStream, op.Arguments);
}
}
}
catch (Exception ex)
{
_log.Error(ex);
response = GetResponse(FtpResponses.TRANSFER_ABORTED);
}
if (_dataClient != null)
{
_dataClient.Close();
_dataClient = null;
}
_performanceCounter.DecrementCurrentConnections();
if (_dataConnectionType == DataConnectionType.Passive)
{
PassiveListenerPool.FreeListener(_passiveListener);
}
Write(response.ToString());
}
