private async Task HandleWebsocketRequest(WebSocketContext context)
{
string key = null;
try
{
var timeout = new CancellationTokenSource(new TimeSpan(0, 0, 3));
string filename = await context.WebSocket.ReceiveString(timeout.Token);
long?filesize = null; if (long.TryParse(await context.WebSocket.ReceiveString(timeout.Token), out long size))
{
filesize = size;
}
string mimetype = await context.WebSocket.ReceiveString(timeout.Token);
SocketRelay relay = new SocketRelay(context.WebSocket, filename, filesize, mimetype);
key = AddRelay(relay);
await context.WebSocket.SendString($"code={key}", timeout.Token);
OnSocketRelay?.Invoke(filename, filesize, key, relay);
await relay.HandleUpload();
}
catch (TaskCanceledException)
{
await context.WebSocket.CloseOutputAsync(WebSocketCloseStatus.Empty, null, CancellationToken.None);
}
// client disconnects without closing
catch (WebSocketException) { }
catch (Exception e) when(e.InnerException is WebSocketException)
{
}
finally
{
if (key != null)
{
activeRelays.TryRemove(key, out IRelay x);
}
}
}
private async void ProcessLocalConnection(object state)
{
var connection = (ConnectionInfo)state;
var buffer = new byte[BufferSize];
try
{
var bytesRead = connection.LocalSocket.Receive(buffer);
if (bytesRead < 1 || buffer[0] != Protocol.Socks4.Version)
{
connection.Terminate();
return;
}
OnLogMessage?.Invoke(this, $"Got {bytesRead} bytes from ");
}
catch (SocketException ex)
{
OnLogMessage?.Invoke(this, $"Caught SocketException in ProcessLocalConnection with error code {ex.SocketErrorCode}");
}
try
{
switch (buffer[1])
{
case Protocol.Socks4.CommandStreamConnection:
{
var portBuffer = new[] { buffer[2], buffer[3] };
var port = (ushort)(portBuffer[0] << 8 | portBuffer[1]);
var address = new[] { buffer[4], buffer[5], buffer[6], buffer[7] };
var destAddress = new IPAddress(address).ToString();
var destAddressFamily = AddressFamily.InterNetwork;
if (IsSocks4AProtocol(address))
{
var hostBuffer = new byte[256];
Buffer.BlockCopy(buffer, 9, hostBuffer, 0, 100);
// Resolve hostname, fallback to remote proxy dns resolution
var hostname = Encoding.ASCII.GetString(hostBuffer).TrimEnd((char)0);
if (!ResolveHostnamesRemotely)
{
var resolvedHostname = await DnsResolver.TryResolve(hostname);
if (resolvedHostname == null)
{
OnLogMessage?.Invoke(this, $"DNS resolution failed for {hostname}");
SendSocks4Reply(connection.LocalSocket, Protocol.Socks4.StatusRequestGranted, address, portBuffer);
connection.Terminate();
break;
}
destAddress = resolvedHostname.ToString();
destAddressFamily = resolvedHostname.AddressFamily;
}
else
{
destAddress = hostname;
destAddressFamily = AddressFamily.Unspecified;
}
}
connection.RemoteSocket = Socks5Client.Connect(
RemotEndPoint.Address.ToString(),
RemotEndPoint.Port,
destAddress,
port,
Username,
Password,
SendTimeout,
ReceiveTimeout);
OnRemoteConnect?.Invoke(this, new DnsEndPoint(destAddress, port, destAddressFamily));
if (connection.RemoteSocket.Connected)
{
OnLogMessage?.Invoke(this, "RelayBiDirectionally between server and client started");
SendSocks4Reply(connection.LocalSocket, Protocol.Socks4.StatusRequestGranted, address, portBuffer);
SocketRelay.RelayBiDirectionally(connection.RemoteSocket, connection.LocalSocket);
}
else
{
OnLogMessage?.Invoke(this, "RemoteSocket connection failed");
SendSocks4Reply(connection.LocalSocket, Protocol.Socks4.StatusRequestFailed, address, portBuffer);
connection.Terminate();
}
break;
}
case Protocol.Socks4.CommandBindingConnection:
{
var portBuffer = new[] { buffer[2], buffer[3] };
var address = new[] { buffer[4], buffer[5], buffer[6], buffer[7] };
// TCP/IP port binding not supported
SendSocks4Reply(connection.LocalSocket, Protocol.Socks4.StatusRequestFailed, address, portBuffer);
connection.Terminate();
break;
}
default:
OnLogMessage?.Invoke(this, "Unknown protocol on LocalSocket");
connection.Terminate();
break;
}
}
catch (SocketException ex)
{
OnLogMessage?.Invoke(this, $"Caught SocketException in ProcessLocalConnection with error code {ex.SocketErrorCode.ToString()}");
}
catch (Socks5Exception ex)
{
var portBuffer = new[] { buffer[2], buffer[3] };
var address = new[] { buffer[4], buffer[5], buffer[6], buffer[7] };
SendSocks4Reply(connection.LocalSocket, Protocol.Socks4.StatusRequestFailed, address, portBuffer);
connection.Terminate();
OnLogMessage?.Invoke(this, $"Caught Socks5Exception in ProcessLocalConnection with message {ex.Message}");
}
}
private void AcceptCallback(IAsyncResult ar)
{
Socket sktActive = null;
try
{
var state = (Tuple<Socket, EventWaitHandle>)ar.AsyncState;
state.Item2.Set();
sktActive = state.Item1.EndAccept(ar);
}
catch (ObjectDisposedException)
{
// Accept has been cancelled.
return;
}
try
{
// 安全验证
//if (!m_confirm.Confirm(sktActive))
//{
// sktActive.Close();
// return;
//}
Socket sktPassive = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
sktPassive.Connect(m_epDest);
SocketRelay relay = new SocketRelay(sktActive, sktPassive);
relay.OnFinished += OnSocketRelayFinished;
relay.Run();
lock (m_listSR) m_listSR.Add(relay);
}
catch (SocketException ex)
{
string strbuf = String.Format("{0}({1})", ex.Message, ex.ErrorCode);
byte[] buf = Encoding.Default.GetBytes(strbuf);
sktActive.Send(buf);
sktActive.Shutdown(SocketShutdown.Both);
sktActive.Close();
}
}
private void OnSocketRelayFinished(SocketRelay item)
{
lock (m_listSR)
{
if (m_listSR.Contains(item))
m_listSR.Remove(item);
}
}
