static async Task CopyAsync(TcpStream src,
TcpStream dst,
CancellationToken ct)
{
await src.CopyToAsync(dst, 4096, ct);
dst.Shutdown(SocketShutdown.Send);
}
static async Task <TcpClient> ForwardAsync(TcpClient src,
IPEndPoint dstEP,
CancellationToken ct,
int timeout)
{
var srcEP = src.Client.RemoteEndPoint;
var dst = new TcpClient();
try
{
await dst.ConnectAsync(dstEP, ct, timeout);
Trace.TraceInformation("Connect: {0} -> {1}",
dst.Client.LocalEndPoint, dstEP);
using (TcpStream ss = new TcpStream(src, timeout, timeout),
ds = new TcpStream(dst, timeout, timeout))
{
await Task.WhenAll(CopyAsync(ss, ds, ct),
CopyAsync(ds, ss, ct));
}
Trace.TraceInformation("Closed: {0} -> {1}",
srcEP, dstEP);
}
catch (OperationCanceledException ex)
{
Trace.TraceWarning(ex.Message);
}
catch (TimeoutException ex)
{
Trace.TraceWarning(ex.Message);
}
catch (Exception ex)
{
Trace.TraceError("Forward failed: {0}", ex.Message);
}
src.Close();
dst.Close();
return(null);
}