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- using System;
- using System.Collections.Generic;
- using System.Text;
- using System.Net.Sockets;
- using System.Net;
- using Shadowsocks.Encryption;
- using Shadowsocks.Model;
-
- namespace Shadowsocks.Controller
- {
-
- class Local : Listener.Service
- {
- private Configuration _config;
- public Local(Configuration config)
- {
- this._config = config;
- }
-
- public bool Handle(byte[] firstPacket, int length, Socket socket)
- {
- if (length < 2 || firstPacket[0] != 5)
- {
- return false;
- }
- socket.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.NoDelay, true);
- Handler handler = new Handler();
- handler.connection = socket;
- Server server = _config.GetCurrentServer();
- handler.encryptor = EncryptorFactory.GetEncryptor(server.method, server.password);
- handler.server = server;
-
- handler.Start(firstPacket, length);
- return true;
- }
- }
-
- class Handler
- {
- //public Encryptor encryptor;
- public IEncryptor encryptor;
- public Server server;
- // Client socket.
- public Socket remote;
- public Socket connection;
-
- private byte[] _firstPacket;
- private int _firstPacketLength;
- // Size of receive buffer.
- public const int RecvSize = 16384;
- public const int BufferSize = RecvSize + 32;
- // remote receive buffer
- private byte[] remoteRecvBuffer = new byte[RecvSize];
- // remote send buffer
- private byte[] remoteSendBuffer = new byte[BufferSize];
- // connection receive buffer
- private byte[] connetionRecvBuffer = new byte[RecvSize];
- // connection send buffer
- private byte[] connetionSendBuffer = new byte[BufferSize];
- // Received data string.
-
- private bool connectionShutdown = false;
- private bool remoteShutdown = false;
- private bool closed = false;
-
- private object encryptionLock = new object();
- private object decryptionLock = new object();
-
- public void Start(byte[] firstPacket, int length)
- {
- this._firstPacket = firstPacket;
- this._firstPacketLength = length;
- try
- {
- // TODO async resolving
- IPAddress ipAddress;
- bool parsed = IPAddress.TryParse(server.server, out ipAddress);
- if (!parsed)
- {
- IPHostEntry ipHostInfo = Dns.GetHostEntry(server.server);
- ipAddress = ipHostInfo.AddressList[0];
- }
- IPEndPoint remoteEP = new IPEndPoint(ipAddress, server.server_port);
-
-
- remote = new Socket(ipAddress.AddressFamily,
- SocketType.Stream, ProtocolType.Tcp);
- remote.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.NoDelay, true);
-
- // Connect to the remote endpoint.
- remote.BeginConnect(remoteEP,
- new AsyncCallback(ConnectCallback), null);
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- this.Close();
- }
- }
-
- private void CheckClose()
- {
- if (connectionShutdown && remoteShutdown)
- {
- this.Close();
- }
- }
-
- public void Close()
- {
- lock (this)
- {
- if (closed)
- {
- return;
- }
- closed = true;
- }
- if (connection != null)
- {
- try
- {
- connection.Shutdown(SocketShutdown.Both);
- connection.Close();
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- }
- }
- if (remote != null)
- {
- try
- {
- remote.Shutdown(SocketShutdown.Both);
- remote.Close();
- }
- catch (SocketException e)
- {
- Logging.LogUsefulException(e);
- }
- }
- lock (encryptionLock)
- {
- lock (decryptionLock)
- {
- ((IDisposable)encryptor).Dispose();
- }
- }
- }
-
- private void ConnectCallback(IAsyncResult ar)
- {
- if (closed)
- {
- return;
- }
- try
- {
- // Complete the connection.
- remote.EndConnect(ar);
-
- //Console.WriteLine("Socket connected to {0}",
- // remote.RemoteEndPoint.ToString());
-
- HandshakeReceive();
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- this.Close();
- }
- }
-
- private void HandshakeReceive()
- {
- if (closed)
- {
- return;
- }
- try
- {
- int bytesRead = _firstPacketLength;
-
- if (bytesRead > 1)
- {
- byte[] response = { 5, 0 };
- if (_firstPacket[0] != 5)
- {
- // reject socks 4
- response = new byte[] { 0, 91 };
- Console.WriteLine("socks 5 protocol error");
- }
- connection.BeginSend(response, 0, response.Length, 0, new AsyncCallback(HandshakeSendCallback), null);
- }
- else
- {
- this.Close();
- }
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- this.Close();
- }
- }
-
- private void HandshakeSendCallback(IAsyncResult ar)
- {
- if (closed)
- {
- return;
- }
- try
- {
- connection.EndSend(ar);
-
- // +----+-----+-------+------+----------+----------+
- // |VER | CMD | RSV | ATYP | DST.ADDR | DST.PORT |
- // +----+-----+-------+------+----------+----------+
- // | 1 | 1 | X'00' | 1 | Variable | 2 |
- // +----+-----+-------+------+----------+----------+
- // Skip first 3 bytes
- // TODO validate
- connection.BeginReceive(connetionRecvBuffer, 0, 3, 0,
- new AsyncCallback(handshakeReceive2Callback), null);
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- this.Close();
- }
- }
-
- private void handshakeReceive2Callback(IAsyncResult ar)
- {
- if (closed)
- {
- return;
- }
- try
- {
- int bytesRead = connection.EndReceive(ar);
-
- if (bytesRead > 0)
- {
- byte[] response = { 5, 0, 0, 1, 0, 0, 0, 0, 0, 0 };
- connection.BeginSend(response, 0, response.Length, 0, new AsyncCallback(StartPipe), null);
- }
- else
- {
- Console.WriteLine("failed to recv data in handshakeReceive2Callback");
- this.Close();
- }
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- this.Close();
- }
- }
-
-
- private void StartPipe(IAsyncResult ar)
- {
- if (closed)
- {
- return;
- }
- try
- {
- connection.EndReceive(ar);
- remote.BeginReceive(remoteRecvBuffer, 0, RecvSize, 0,
- new AsyncCallback(PipeRemoteReceiveCallback), null);
- connection.BeginReceive(connetionRecvBuffer, 0, RecvSize, 0,
- new AsyncCallback(PipeConnectionReceiveCallback), null);
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- this.Close();
- }
- }
-
- private void PipeRemoteReceiveCallback(IAsyncResult ar)
- {
- if (closed)
- {
- return;
- }
- try
- {
- int bytesRead = remote.EndReceive(ar);
-
- if (bytesRead > 0)
- {
- int bytesToSend;
- lock (decryptionLock)
- {
- if (closed)
- {
- return;
- }
- encryptor.Decrypt(remoteRecvBuffer, bytesRead, remoteSendBuffer, out bytesToSend);
- }
- connection.BeginSend(remoteSendBuffer, 0, bytesToSend, 0, new AsyncCallback(PipeConnectionSendCallback), null);
- }
- else
- {
- //Console.WriteLine("bytesRead: " + bytesRead.ToString());
- connection.Shutdown(SocketShutdown.Send);
- connectionShutdown = true;
- CheckClose();
- }
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- this.Close();
- }
- }
-
- private void PipeConnectionReceiveCallback(IAsyncResult ar)
- {
- if (closed)
- {
- return;
- }
- try
- {
- int bytesRead = connection.EndReceive(ar);
-
- if (bytesRead > 0)
- {
- int bytesToSend;
- lock (encryptionLock)
- {
- if (closed)
- {
- return;
- }
- encryptor.Encrypt(connetionRecvBuffer, bytesRead, connetionSendBuffer, out bytesToSend);
- }
- remote.BeginSend(connetionSendBuffer, 0, bytesToSend, 0, new AsyncCallback(PipeRemoteSendCallback), null);
- }
- else
- {
- remote.Shutdown(SocketShutdown.Send);
- remoteShutdown = true;
- CheckClose();
- }
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- this.Close();
- }
- }
-
- private void PipeRemoteSendCallback(IAsyncResult ar)
- {
- if (closed)
- {
- return;
- }
- try
- {
- remote.EndSend(ar);
- connection.BeginReceive(this.connetionRecvBuffer, 0, RecvSize, 0,
- new AsyncCallback(PipeConnectionReceiveCallback), null);
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- this.Close();
- }
- }
-
- private void PipeConnectionSendCallback(IAsyncResult ar)
- {
- if (closed)
- {
- return;
- }
- try
- {
- connection.EndSend(ar);
- remote.BeginReceive(this.remoteRecvBuffer, 0, RecvSize, 0,
- new AsyncCallback(PipeRemoteReceiveCallback), null);
- }
- catch (Exception e)
- {
- Logging.LogUsefulException(e);
- this.Close();
- }
- }
- }
-
- }
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