feedback + skip tests on browser

src/libraries/System.Net.Http/src/Resources/Strings.resx

@@ -568,6 +568,6 @@
     <value>The HTTP/1.1 response chunk was too large.</value>
   </data>
     <data name="net_unsupported_extended_connect" xml:space="preserve">
-    <value>Extended CONNECT is not supported.</value>
+    <value>Failed to establish web socket connection over HTTP/2 because extended CONNECT is not supported. Try to downgrade the request version to HTTP/1.1</value>
   </data>
 </root>

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

@@ -21,6 +21,7 @@ public sealed class HttpRequestHeaders : HttpHeaders
         private HttpGeneralHeaders? _generalHeaders;
         private HttpHeaderValueCollection<NameValueWithParametersHeaderValue>? _expect;
         private bool _expectContinueSet;
+        private string? _protocol;
 
         #region Request Headers
 
@@ -159,7 +160,15 @@ public int? MaxForwards
             set { SetOrRemoveParsedValue(KnownHeaders.MaxForwards.Descriptor, value); }
         }
 
-        public string? Protocol { get; set; }
+        public string? Protocol
+        {
+            get => _protocol;
+            set
+            {
+                CheckContainsNewLine(value);
+                _protocol = value;
+            }
+        }
 
         public AuthenticationHeaderValue? ProxyAuthorization
         {

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

@@ -21,6 +21,10 @@ internal sealed partial class Http2Connection : HttpConnectionBase
         // Equivalent to the bytes returned from HPackEncoder.EncodeLiteralHeaderFieldWithoutIndexingNewNameToAllocatedArray(":protocol")
         private static ReadOnlySpan<byte> ProtocolLiteralHeaderBytes => new byte[] { 0x0, 0x9, 0x3a, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x63, 0x6f, 0x6c };
 
+        private static readonly TaskCompletionSourceWithCancellation<bool> s_settingsReceivedSingleton = CreateSuccessfullyCompletedTcs();
+
+        private TaskCompletionSourceWithCancellation<bool>? _initialSettingsReceived;
+
         private readonly HttpConnectionPool _pool;
         private readonly Stream _stream;
 
@@ -176,6 +180,13 @@ static long TimeSpanToMs(TimeSpan value) {
 
         private object SyncObject => _httpStreams;
 
+        internal TaskCompletionSourceWithCancellation<bool> InitialSettingsReceived =>
+            _initialSettingsReceived ??
+            Interlocked.CompareExchange(ref _initialSettingsReceived, new(), null) ??
+            _initialSettingsReceived;
+
+        internal bool IsConnectEnabled { get; private set; }
+
         public async ValueTask SetupAsync()
         {
             try
@@ -1468,7 +1479,6 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
             {
                 if (request.Headers.Protocol != null)
                 {
-                    HttpHeaders.CheckContainsNewLine(request.Headers.Protocol);
                     WriteBytes(ProtocolLiteralHeaderBytes, ref headerBuffer);
                     Encoding? protocolEncoding = _pool.Settings._requestHeaderEncodingSelector?.Invoke(":protocol", request);
                     WriteLiteralHeaderValue(request.Headers.Protocol, protocolEncoding, ref headerBuffer);
@@ -1918,22 +1928,12 @@ private enum SettingId : ushort
             EnableConnect = 0x8
         }
 
-        private static readonly TaskCompletionSourceWithCancellation<bool> s_settingsReceivedSingleton = CreateSuccessfullyCompleted();
-
-        internal TaskCompletionSourceWithCancellation<bool> InitialSettingsReceived =>
-            _initialSettingsReceived ??
-            Interlocked.CompareExchange(ref _initialSettingsReceived, new(), null) ??
-            _initialSettingsReceived;
-
-        private TaskCompletionSourceWithCancellation<bool>? _initialSettingsReceived;
-
-        private static TaskCompletionSourceWithCancellation<bool> CreateSuccessfullyCompleted()
+        private static TaskCompletionSourceWithCancellation<bool> CreateSuccessfullyCompletedTcs()
         {
             var tcs = new TaskCompletionSourceWithCancellation<bool>();
             tcs.TrySetResult(true);
             return tcs;
         }
-        internal bool IsConnectEnabled { get; private set; }
 
         // Note that this is safe to be called concurrently by multiple threads.
 

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

@@ -1024,7 +1024,8 @@ public async ValueTask<HttpResponseMessage> SendWithVersionDetectionAndRetryAsyn
                             {
                                 if (request.IsWebSocketH2Request())
                                 {
-                                    if (await connection.InitialSettingsReceived.WaitWithCancellationAsync(cancellationToken).ConfigureAwait(false) && !connection.IsConnectEnabled)
+                                    await connection.InitialSettingsReceived.WaitWithCancellationAsync(cancellationToken).ConfigureAwait(false);
+                                    if (!connection.IsConnectEnabled)
                                     {
                                         HttpRequestException exception = new(SR.net_unsupported_extended_connect);
                                         exception.Data["SETTINGS_ENABLE_CONNECT_PROTOCOL"] = false;

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

@@ -75,11 +75,8 @@
   <data name="net_WebSockets_ArgumentOutOfRange_TooSmall" xml:space="preserve">
     <value>The argument must be a value greater than {0}.</value>
   </data>
-  <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 name="net_WebSockets_ConnectStatusExpected" xml:space="preserve">
+    <value>The server returned status code '{0}' when status code '{1}' was expected.</value>
   </data>
   <data name="net_WebSockets_MissingResponseHeader" xml:space="preserve">
     <value>The server's response was missing the required header '{0}'.</value>

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

@@ -83,7 +83,7 @@ public async Task ConnectAsync(Uri uri, HttpMessageInvoker? invoker, Cancellatio
 
                         string? secValue = AddWebSocketHeaders(request, options);
 
-                        // Issue the request.  The response must be status code 101.
+                        // Issue the request.
                         CancellationTokenSource? linkedCancellation;
                         CancellationTokenSource externalAndAbortCancellation;
                         if (cancellationToken.CanBeCanceled) // avoid allocating linked source if external token is not cancelable
@@ -355,7 +355,6 @@ static int ParseWindowBits(ReadOnlySpan<char> value)
             else if (request.Version == HttpVersion.Version20)
             {
                 request.Headers.Protocol = "websocket";
-                request.Headers.TryAddWithoutValidation(HttpKnownHeaderNames.Origin, request.Headers.Host);
             }
 
             request.Headers.TryAddWithoutValidation(HttpKnownHeaderNames.SecWebSocketVersion, "13");
@@ -413,7 +412,7 @@ private static void ValidateResponse(HttpResponseMessage response, string? secVa
             {
                 if (response.StatusCode != HttpStatusCode.SwitchingProtocols)
                 {
-                    throw new WebSocketException(WebSocketError.NotAWebSocket, SR.Format(SR.net_WebSockets_Connect101Expected, (int)response.StatusCode));
+                    throw new WebSocketException(WebSocketError.NotAWebSocket, SR.Format(SR.net_WebSockets_ConnectStatusExpected, (int)response.StatusCode, (int)HttpStatusCode.SwitchingProtocols));
                 }
 
                 Debug.Assert(secValue != null);
@@ -427,7 +426,7 @@ private static void ValidateResponse(HttpResponseMessage response, string? secVa
             {
                 if (response.StatusCode != HttpStatusCode.OK)
                 {
-                    throw new WebSocketException(WebSocketError.NotAWebSocket, SR.Format(SR.net_WebSockets_Connect200Expected, (int)response.StatusCode));
+                    throw new WebSocketException(WebSocketError.NotAWebSocket, SR.Format(SR.net_WebSockets_ConnectStatusExpected, (int)response.StatusCode, (int)HttpStatusCode.OK));
                 }
             }
 

src/libraries/System.Net.WebSockets.Client/tests/ClientWebSocketTestBase.cs

@@ -53,7 +53,7 @@ public static IEnumerable<object[]> UnavailableWebSocketServers
                 {
                     server = System.Net.Test.Common.Configuration.Http.RemoteEchoServer;
                     var ub = new UriBuilder("ws", server.Host, server.Port, server.PathAndQuery);
-                    exceptionMessage = ResourceHelper.GetExceptionMessage("net_WebSockets_Connect101Expected", (int) HttpStatusCode.OK);
+                    exceptionMessage = ResourceHelper.GetExceptionMessage("net_WebSockets_ConnectStatusExpected", (int) HttpStatusCode.OK, (int) HttpStatusCode.SwitchingProtocols);
 
                     yield return new object[] { ub.Uri, exceptionMessage, WebSocketError.NotAWebSocket };
                 }

src/libraries/System.Net.WebSockets.Client/tests/ConnectTest.Http2.cs

@@ -18,6 +18,7 @@ public class ConnectTest_Http2 : ClientWebSocketTestBase
         public ConnectTest_Http2(ITestOutputHelper output) : base(output) { }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.Browser, "WebSocket over HTTP/2 is not supported on Browser")]
         public async Task ConnectAsync_VersionNotSupported_Throws()
         {
             await Http2LoopbackServer.CreateClientAndServerAsync(async uri =>
@@ -43,6 +44,7 @@ await Http2LoopbackServer.CreateClientAndServerAsync(async uri =>
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.Browser, "WebSocket over HTTP/2 is not supported on Browser")]
         public async Task ConnectAsync_VersionSupported_Success()
         {
             await Http2LoopbackServer.CreateClientAndServerAsync(async uri =>