private Task <Tunnel> ConnectIfNecessaryAsync(TunnelDestination endpoint)
{
lock (this.tunnelsLock)
{
if (!this.tunnels.TryGetValue(endpoint, out Task <Tunnel> tunnel))
{
return(ConnectAndCacheAsync(endpoint));
}
else if (tunnel.IsFaulted)
{
TraceSources.IapDesktop.TraceVerbose(
"Tunnel to {0} is faulted.. reconnecting", endpoint);
// There is no point in handing out a faulty attempt
// to create a tunnel. So start anew.
return(ConnectAndCacheAsync(endpoint));
}
else
{
TraceSources.IapDesktop.TraceVerbose(
"Reusing tunnel to {0}", endpoint);
// This tunnel is good or still in the process
// of connecting.
return(tunnel);
}
}
}
public async Task <Tunnel> ConnectAsync(TunnelDestination endpoint, TimeSpan timeout)
{
using (TraceSources.IapDesktop.TraceMethod().WithParameters(endpoint, timeout))
{
var tunnel = await ConnectIfNecessaryAsync(endpoint);
try
{
// Whether it is a new or existing tunnel, probe it first before
// handing it out. It might be broken after all (because of reauth
// or for other reasons).
await tunnel.Probe(timeout);
TraceSources.IapDesktop.TraceVerbose(
"Probing tunnel to {0} succeeded", endpoint);
}
catch (Exception e)
{
TraceSources.IapDesktop.TraceVerbose(
"Probing tunnel to {0} failed: {1}", endpoint, e.Message);
// Un-cache this broken tunnel.
await DisconnectAsync(endpoint);
throw;
}
await this.eventService.FireAsync(new TunnelOpenedEvent(endpoint));
return(tunnel);
}
}
private Task <Tunnel> ConnectAndCacheAsync(TunnelDestination endpoint)
{
var tunnel = this.tunnelService.CreateTunnelAsync(endpoint);
TraceSources.IapDesktop.TraceVerbose("Created tunnel to {0}", endpoint);
this.tunnels[endpoint] = tunnel;
return(tunnel);
}
public bool IsConnected(TunnelDestination endpoint)
{
lock (this.tunnelsLock)
{
if (this.tunnels.TryGetValue(endpoint, out Task <Tunnel> tunnel))
{
return(!tunnel.IsFaulted);
}
else
{
return(false);
}
}
}
public async Task DisconnectAsync(TunnelDestination endpoint)
{
using (TraceSources.IapDesktop.TraceMethod().WithParameters(endpoint))
{
lock (this.tunnelsLock)
{
if (!this.tunnels.TryGetValue(endpoint, out var tunnel))
{
throw new KeyNotFoundException($"No active tunnel to {endpoint}");
}
tunnel.Result.Close();
this.tunnels.Remove(endpoint);
}
await this.eventService.FireAsync(new TunnelClosedEvent(endpoint));
}
}
public Task <Tunnel> CreateTunnelAsync(TunnelDestination tunnelEndpoint)
{
using (TraceSources.IapDesktop.TraceMethod().WithParameters(tunnelEndpoint))
{
var iapEndpoint = new IapTunnelingEndpoint(
this.authorizationService.Authorization.Credential,
tunnelEndpoint.Instance,
tunnelEndpoint.RemotePort,
IapTunnelingEndpoint.DefaultNetworkInterface);
// Start listener to enable clients to connect. Do not await
// the listener as we want to continue listeining in the
// background.
var listener = SshRelayListener.CreateLocalListener(iapEndpoint);
var cts = new CancellationTokenSource();
_ = listener.ListenAsync(cts.Token);
// Return the tunnel which allows the listener to be stopped
// via the CancellationTokenSource.
return(Task.FromResult(new Tunnel(iapEndpoint, listener, cts)));
}
}
public TunnelClosedEvent(TunnelDestination destination)
{
this.Destination = destination;
}
public TunnelOpenedEvent(TunnelDestination destination)
{
this.Destination = destination;
}