address review feedback

Author: Katya Sokolova

src/libraries/System.Net.Http/src/System/Net/Http/Headers/HttpRequestHeaders.cs

@@ -159,12 +159,7 @@ public int? MaxForwards
             set { SetOrRemoveParsedValue(KnownHeaders.MaxForwards.Descriptor, value); }
         }
 
-        public string? Protocol
-        {
-            get { return (string?)GetSingleParsedValue(new HeaderDescriptor(":protocol")); }
-            set { SetOrRemoveParsedValue(new HeaderDescriptor(":protocol"), value); }
-        }
-
+        public string? Protocol { get; set; }
 
         public AuthenticationHeaderValue? ProxyAuthorization
         {

src/libraries/System.Net.Http/src/System/Net/Http/HttpRequestMessage.cs

@@ -168,7 +168,7 @@ public override string ToString()
 
         internal bool WasRedirected() => (_sendStatus & MessageIsRedirect) != 0;
 
-        internal bool IsWebSocketH2Request() => _version.Major == 2 && HasHeaders && Headers.Protocol == "websocket";
+        internal bool IsWebSocketH2Request() => _version.Major == 2 && Method == HttpMethod.Connect && HasHeaders && Headers.Protocol == "websocket";
 
         #region IDisposable Members
 

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs

@@ -1458,8 +1458,6 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
                 WriteBytes(":protocol"u8, ref headerBuffer);
                 Encoding? protocolEncoding = _pool.Settings._requestHeaderEncodingSelector?.Invoke(":protocol", request);
                 WriteLiteralHeaderValue(request.Headers.Protocol, protocolEncoding, ref headerBuffer);
-
-                request.Headers.Protocol = null;
             }
 
             if (request.HasHeaders)

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Stream.cs

@@ -107,6 +107,10 @@ public Http2Stream(HttpRequestMessage request, Http2Connection connection)
                 if (_request.Content == null)
                 {
                     _requestCompletionState = StreamCompletionState.Completed;
+                    if (_request.IsWebSocketH2Request())
+                    {
+                        _requestBodyCancellationSource = new CancellationTokenSource();
+                    }
                 }
                 else
                 {

src/libraries/System.Net.WebSockets.Client/src/Resources/Strings.resx

@@ -78,6 +78,9 @@
   <data name="net_WebSockets_Connect101Expected" xml:space="preserve">
     <value>The server returned status code '{0}' when status code '101' was expected.</value>
   </data>
+  <data name="net_WebSockets_Connect200Expected" xml:space="preserve">
+    <value>The server returned status code '{0}' when status code '200' was expected.</value>
+  </data>
   <data name="net_WebSockets_MissingResponseHeader" xml:space="preserve">
     <value>The server's response was missing the required header '{0}'.</value>
   </data>
@@ -129,4 +132,4 @@
   <data name="net_WebSockets_ClientWindowBitsNegotiationFailure" xml:space="preserve">
     <value>The WebSocket failed to negotiate max client window bits. The client requested {0} but the server responded with {1}.</value>
   </data>
-</root>
+</root>

src/libraries/System.Net.WebSockets.Client/src/System/Net/WebSockets/WebSocketHandle.Managed.cs

@@ -44,32 +44,36 @@ public void Abort()
 
         public async Task ConnectAsync(Uri uri, HttpMessageInvoker? invoker, CancellationToken cancellationToken, ClientWebSocketOptions options)
         {
-            invoker ??= new HttpMessageInvoker(SetupHandler(options));
+            bool disposeHandler = false;
+            invoker ??= new HttpMessageInvoker(SetupHandler(options, out disposeHandler));
             HttpResponseMessage? response = null;
 
-            // TODO setup to false
-            bool disposeHandler = true;
+            bool tryDowngrade = false;
             try
             {
-                if (options.HttpVersion.Major >= 3 && options.HttpVersionPolicy != HttpVersionPolicy.RequestVersionOrLower)
-                {
-                    throw new Exception();
-                }
-
-                var request = new HttpRequestMessage(HttpMethod.Get, uri);
-                if (options.HttpVersion.Major >= 2 || (options.HttpVersionPolicy == HttpVersionPolicy.RequestVersionOrHigher))
-                {
-                    request.Version = new Version(2, 0);
-                }
-                else
-                {
-                    request.Version = new Version(1, 1);
-                }
 
                 while (true)
                 {
                     try
                     {
+                        HttpRequestMessage request;
+                        if (!tryDowngrade && options.HttpVersion == HttpVersion.Version20
+                            || (options.HttpVersion == HttpVersion.Version11 && options.HttpVersionPolicy == HttpVersionPolicy.RequestVersionOrHigher))
+                        {
+                            request = new HttpRequestMessage(HttpMethod.Connect, uri);
+                            request.Version = new Version(2, 0);
+                            tryDowngrade = true;
+                        }
+                        else if (tryDowngrade || options.HttpVersion == HttpVersion.Version11)
+                        {
+                            request = new HttpRequestMessage(HttpMethod.Get, uri);
+                            request.Version = new Version(1, 1);
+                            tryDowngrade = false;
+                        }
+                        else
+                        {
+                            throw new WebSocketException(WebSocketError.UnsupportedProtocol);
+                        }
                         if (options._requestHeaders?.Count > 0) // use field to avoid lazily initializing the collection
                         {
                             foreach (string key in options.RequestHeaders)
@@ -107,13 +111,11 @@ public async Task ConnectAsync(Uri uri, HttpMessageInvoker? invoker, Cancellatio
                     }
                     catch (HttpRequestException ex)
                     {
-                        if (ex.Data.Contains("SETTINGS_ENABLE_CONNECT_PROTOCOL") && request.Version.Major == 2
-                            && (options.HttpVersion.Major == 2 && options.HttpVersionPolicy == HttpVersionPolicy.RequestVersionOrLower
-                            || options.HttpVersion.Major == 1 && options.HttpVersionPolicy == HttpVersionPolicy.RequestVersionOrHigher))
+                        if (!ex.Data.Contains("SETTINGS_ENABLE_CONNECT_PROTOCOL") || !tryDowngrade
+                            || (options.HttpVersion != HttpVersion.Version11 && options.HttpVersionPolicy != HttpVersionPolicy.RequestVersionOrLower))
                         {
-                            request.Version = new Version(1, 1);
+                            throw ex;
                         }
-                        else { throw ex; }
                     }
 
                 }
@@ -205,7 +207,7 @@ public async Task ConnectAsync(Uri uri, HttpMessageInvoker? invoker, Cancellatio
             }
         }
 
-        private static SocketsHttpHandler SetupHandler(ClientWebSocketOptions options)
+        private static SocketsHttpHandler SetupHandler(ClientWebSocketOptions options, out bool disposeHandler)
         {
             SocketsHttpHandler? handler;
             // Create the handler for this request and populate it with all of the options.
@@ -218,6 +220,7 @@ private static SocketsHttpHandler SetupHandler(ClientWebSocketOptions options)
                 options.RemoteCertificateValidationCallback == null &&
                 options._clientCertificates?.Count == 0)
             {
+                disposeHandler = false;
                 handler = s_defaultHandler;
                 if (handler == null)
                 {
@@ -236,6 +239,7 @@ private static SocketsHttpHandler SetupHandler(ClientWebSocketOptions options)
             }
             else
             {
+                disposeHandler = true;
                 handler = new SocketsHttpHandler();
                 handler.PooledConnectionLifetime = TimeSpan.Zero;
                 handler.CookieContainer = options.Cookies;
@@ -424,7 +428,7 @@ private static void ValidateResponse(HttpResponseMessage response, string secVal
             {
                 if (response.StatusCode != HttpStatusCode.OK)
                 {
-                    throw new WebSocketException(WebSocketError.NotAWebSocket, SR.Format(SR.net_WebSockets_Connect101Expected, (int)response.StatusCode));
+                    throw new WebSocketException(WebSocketError.NotAWebSocket, SR.Format(SR.net_WebSockets_Connect200Expected, (int)response.StatusCode));
                 }
             }