private async Task <SimpleSocket> SpawnServerFromService(string url, bool task)
{
// Ideally we would like to reuse Uri (or some other similar code), but it doesn't work without a Host
var parameterIndex = url.IndexOf('?');
var urlWithoutParameters = parameterIndex != -1 ? url.Substring(0, parameterIndex) : url;
string[] urlSegments;
string urlParameters;
RouterHelper.ParseUrl(url, out urlSegments, out urlParameters);
// Find a matching server
TaskCompletionSource <Service> serviceTcs;
lock (registeredServices)
{
if (!registeredServices.TryGetValue(urlWithoutParameters, out serviceTcs))
{
if (task)
{
throw new Exception("ConnectionRouter task not found, a task won't spawn a new service on demand instead must be started explicitly.");
}
serviceTcs = new TaskCompletionSource <Service>();
registeredServices.Add(urlWithoutParameters, serviceTcs);
if (urlSegments.Length < 4)
{
Log.Error($"{RouterMessage.ClientRequestServer} action URL {url} is invalid");
throw new InvalidOperationException();
}
var packageName = urlSegments[1];
var packageVersion = urlSegments[2];
var process = urlSegments[3];
// Find package
var package = PackageStore.Instance.FindLocalPackage(packageName, new PackageVersionRange(new PackageVersion(packageVersion)));
if (package == null)
{
Log.Error($"{RouterMessage.ClientRequestServer} action URL [{url}] could not locate NuGet package");
throw new InvalidOperationException();
}
// Locate executable
var servicePath = package.GetFiles().FirstOrDefault(x => string.Compare(Path.GetFileName(x.Path), process, true) == 0)?.FullPath;
if (servicePath == null || !File.Exists(servicePath))
{
Log.Error($"{RouterMessage.ClientRequestServer} action URL [{url}] references a process that doesn't seem to exist");
throw new InvalidOperationException();
}
RunServiceProcessAndLog(servicePath);
}
}
var service = await serviceTcs.Task;
// Generate connection Guid
var guid = Guid.NewGuid();
var serverSocketTcs = new TaskCompletionSource <SimpleSocket>();
lock (pendingServers)
{
pendingServers.Add(guid, serverSocketTcs);
}
await service.SendLock.WaitAsync();
try
{
// Notify service that we want it to establish back a new connection to us for this client
await service.Socket.WriteStream.WriteInt16Async((short)RouterMessage.ServiceRequestServer);
await service.Socket.WriteStream.WriteStringAsync(url);
await service.Socket.WriteStream.WriteGuidAsync(guid);
await service.Socket.WriteStream.FlushAsync();
}
finally
{
service.SendLock.Release();
}
// Should answer within 4 sec
var ct = new CancellationTokenSource(4000);
ct.Token.Register(() =>
{
if (!serverSocketTcs.Task.IsCompleted)
{
serverSocketTcs.TrySetException(new TimeoutException($"{RouterMessage.ServiceRequestServer} action URL [{url}] could not connect back in time"));
}
});
// Wait for such a server to be available
return(await serverSocketTcs.Task);
}
/// <summary>
/// Handles ClientRequestServer messages.
/// It will try to find a matching service (spawn it if not started yet), and ask it to establish a new "server" connection back to us.
/// </summary>
/// <param name="clientSocket">The client socket context.</param>
/// <returns></returns>
private async Task HandleMessageClientRequestServer(SimpleSocket clientSocket)
{
// Check for an existing server
// TODO: Proper Url parsing (query string)
var url = await clientSocket.ReadStream.ReadStringAsync();
Log.Info($"Client {clientSocket.RemoteAddress}:{clientSocket.RemotePort} sent message ClientRequestServer with URL {url}");
string[] urlSegments;
string urlParameters;
RouterHelper.ParseUrl(url, out urlSegments, out urlParameters);
if (urlSegments.Length == 0)
{
throw new InvalidOperationException("No URL Segments");
}
SimpleSocket serverSocket = null;
ExceptionDispatchInfo serverSocketCapturedException = null;
try
{
// For now, we handle only "service" URL
switch (urlSegments[0])
{
case "service":
{
// From the URL, start service (if not started yet) and ask it to provide a server
serverSocket = await SpawnServerFromService(url, false);
break;
}
case "task":
{
// From the URL, start service (if not started yet) and ask it to provide a server
serverSocket = await SpawnServerFromService(url, true);
break;
}
case "redirect":
{
// Redirect to a IP/port
serverSocket = new SimpleSocket();
var host = urlSegments[1];
var port = int.Parse(urlSegments[2]);
// Note: for security reasons, we currently use a whitelist
//if (host == "stridebuild.stride3d.net" && port == 1832)
// await serverSocket.StartClient(host, port, false);
//else
throw new InvalidOperationException("Trying to redirect to a non-whitelisted host/port");
//break;
}
default:
throw new InvalidOperationException("This type of URL is not supported");
}
}
catch (Exception e)
{
serverSocketCapturedException = ExceptionDispatchInfo.Capture(e);
}
if (serverSocketCapturedException != null)
{
try
{
// Notify client that there was an error
await clientSocket.WriteStream.WriteInt16Async((short)RouterMessage.ClientServerStarted);
await clientSocket.WriteStream.WriteInt32Async(1); // error code Failure
await clientSocket.WriteStream.WriteStringAsync(serverSocketCapturedException.SourceException.Message);
await clientSocket.WriteStream.FlushAsync();
}
finally
{
serverSocketCapturedException.Throw();
}
}
try
{
// Notify client that we've found a server for it
await clientSocket.WriteStream.WriteInt16Async((short)RouterMessage.ClientServerStarted);
await clientSocket.WriteStream.WriteInt32Async(0); // error code OK
await clientSocket.WriteStream.FlushAsync();
// Let's forward clientSocketContext and serverSocketContext
await await Task.WhenAny(
ForwardSocket(clientSocket, serverSocket),
ForwardSocket(serverSocket, clientSocket));
}
catch
{
serverSocket.Dispose();
throw;
}
}