public static AppFunc Middleware(AppFunc app)
{
return env =>
{
var request = new OwinRequest(env);
var websocketVersion = request.Get<string>(OwinConstants.WebSocket.Version);
WebSocketAccept webSocketAccept = request.Get<WebSocketAccept>(OwinConstants.WebSocket.Accept);
if (request.CanUpgrade && websocketVersion == null) // If we have opaque support and no WebSocket support yet
{
if (IsWebSocketRequest(env))
{
// TODO: check for correct requested version of WebSocket protocol
IDictionary<string, object> acceptOptions = null;
WebSocketFunc webSocketFunc = null;
// Announce websocket support
env[OwinConstants.WebSocket.Accept] = new WebSocketAccept(
(options, callback) =>
{
acceptOptions = options;
webSocketFunc = callback;
env[OwinConstants.ResponseStatusCode] = 101;
});
return app(env).ContinueWith(t =>
{
OwinResponse response = new OwinResponse(env);
if (response.StatusCode == 101
&& webSocketFunc != null)
{
SetWebSocketResponseHeaders(env, acceptOptions);
request.UpgradeDelegate(acceptOptions, opaqueEnv =>
{
WebSocketLayer webSocket = new WebSocketLayer(opaqueEnv);
return webSocketFunc(webSocket.Environment)
.ContinueWith(tt => webSocket.CleanupAsync());
});
}
});
}
}
// else
return app(env);
};
}
private async Task<Http2ServerSession> CreateUpgradeSessionAsync(OwinRequest owinRequest)
{
// Create a new Http2Session object with the following:
// A reference to AppFunc _next
// Client cert (if any)
// Stream with ID 1 containing request headers & properties copied from the current environment, queued for dispatch to _next AppFunc once upgrade is complete.
// Misc extra keys? local & remote IPAddress & ports, IsLocal, capabilities, (not send-file? might still work with careful flushing)
X509Certificate clientCert = null;
if (string.Equals(owinRequest.Scheme, "https", StringComparison.OrdinalIgnoreCase))
{
Func<Task> loadCertAsync = owinRequest.Get<Func<Task>>("ssl.LoadClientCert");
if (loadCertAsync != null)
{
await loadCertAsync();
}
clientCert = owinRequest.Get<X509Certificate>("ssl.ClientCertificate");
}
// The opaque stream and CancellationToken will be provided after the opaque upgrade.
return new Http2ServerSession(_nextHttp2, CreateTransportInfo(clientCert, owinRequest), CopyHandshakeRequest(owinRequest));
}
