/// <summary>
/// Perpetually listen and relay traffic until cancelled.
/// </summary>
public Task ListenAsync(CancellationToken token)
{
// Start listening before returning from the menthod.
this.listener.Start(BacklogLength);
// All communication is then handled asynchronously.
return(Task.Run(() =>
{
using (token.Register(this.listener.Stop))
{
while (this.ClientAcceptLimit == 0 || this.ClientAcceptLimit > this.ClientsAccepted)
{
try
{
var socket = this.listener.AcceptSocket();
if (this.policy.IsClientAllowed((IPEndPoint)socket.RemoteEndPoint))
{
TraceSources.Compute.TraceInformation(
"Connection from {0} allowed by policy", socket.RemoteEndPoint);
}
else
{
TraceSources.Compute.TraceWarning(
"Connection from {0} rejected by policy", socket.RemoteEndPoint);
socket.Close();
continue;
}
var clientStream = new SocketStream(socket, this.Statistics);
var serverStream = new SshRelayStream(this.server);
OnClientConnected(clientStream.ToString());
this.ClientsAccepted++;
Task.WhenAll(
clientStream.RelayToAsync(serverStream, token),
serverStream.RelayToAsync(clientStream, token))
.ContinueWith(t =>
{
TraceSources.Compute.TraceVerbose("SshRelayListener: Closed connection");
if (t.IsFaulted)
{
OnConnectionFailed(t.Exception);
}
OnClientDisconnected(clientStream.ToString());
});
}
catch (SocketException e) when(e.SocketErrorCode == SocketError.Interrupted)
{
// Operation cancelled, terminate gracefully.
break;
}
}
}
}));
}
