Add KeepAliveTimeout support to WebSocketMiddleware (#57293)

Author: BrennanConroy

src/Http/Http.Features/src/PublicAPI.Unshipped.txt

@@ -1,3 +1,5 @@
 #nullable enable
 Microsoft.AspNetCore.Http.Features.IHttpMetricsTagsFeature.MetricsDisabled.get -> bool
 Microsoft.AspNetCore.Http.Features.IHttpMetricsTagsFeature.MetricsDisabled.set -> void
+Microsoft.AspNetCore.Http.WebSocketAcceptContext.KeepAliveTimeout.get -> System.TimeSpan?
+Microsoft.AspNetCore.Http.WebSocketAcceptContext.KeepAliveTimeout.set -> void

src/Http/Http.Features/src/WebSocketAcceptContext.cs

@@ -11,17 +11,44 @@ namespace Microsoft.AspNetCore.Http;
 public class WebSocketAcceptContext
 {
     private int _serverMaxWindowBits = 15;
+    private TimeSpan? _keepAliveTimeout;
 
     /// <summary>
     /// Gets or sets the subprotocol being negotiated.
     /// </summary>
     public virtual string? SubProtocol { get; set; }
 
     /// <summary>
-    /// The interval to send pong frames. This is a heart-beat that keeps the connection alive.
+    /// The interval to send keep-alive frames. This is a heart-beat that keeps the connection alive.
     /// </summary>
+    /// <remarks>
+    /// May be either a Ping or a Pong frame, depending on if <see cref="KeepAliveTimeout" /> is set.
+    /// </remarks>
     public virtual TimeSpan? KeepAliveInterval { get; set; }
 
+    /// <summary>
+    /// The time to wait for a Pong frame response after sending a Ping frame. If the time is exceeded the websocket will be aborted.
+    /// </summary>
+    /// <remarks>
+    /// <c>null</c> means use the value from <c>WebSocketOptions.KeepAliveTimeout</c>.
+    /// <see cref="Timeout.InfiniteTimeSpan"/> and <see cref="TimeSpan.Zero"/> are valid values and will disable the timeout.
+    /// </remarks>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <see cref="TimeSpan"/> is less than <see cref="TimeSpan.Zero"/>.
+    /// </exception>
+    public TimeSpan? KeepAliveTimeout
+    {
+        get => _keepAliveTimeout;
+        set
+        {
+            if (value is not null && value != Timeout.InfiniteTimeSpan)
+            {
+                ArgumentOutOfRangeException.ThrowIfLessThan(value.Value, TimeSpan.Zero);
+            }
+            _keepAliveTimeout = value;
+        }
+    }
+
     /// <summary>
     /// Enables support for the 'permessage-deflate' WebSocket extension.<para />
     /// Be aware that enabling compression over encrypted connections makes the application subject to CRIME/BREACH type attacks.

src/Middleware/WebSockets/src/AbortStream.cs

@@ -0,0 +1,129 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Net.WebSockets;
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.WebSockets;
+
+/// <summary>
+/// Used in <see cref="WebSocketMiddleware"/> to wrap the <see cref="HttpContext"/>.Request.Body stream
+/// so that we can call <see cref="HttpContext.Abort"/> when the stream is disposed and the WebSocket is in the <see cref="WebSocketState.Aborted"/> state.
+/// The Stream provided by Kestrel (and maybe other servers) noops in Dispose as it doesn't know whether it's a graceful close or not
+/// and can result in truncated responses if in the graceful case.
+///
+/// This handles explicit <see cref="WebSocket.Abort"/> calls as well as the Keep-Alive timeout setting <see cref="WebSocketState.Aborted"/> and disposing the stream.
+/// </summary>
+/// <remarks>
+/// Workaround for https://github.com/dotnet/runtime/issues/44272
+/// </remarks>
+internal sealed class AbortStream : Stream
+{
+    private readonly Stream _innerStream;
+    private readonly HttpContext _httpContext;
+
+    public WebSocket? WebSocket { get; set; }
+
+    public AbortStream(HttpContext httpContext, Stream innerStream)
+    {
+        _innerStream = innerStream;
+        _httpContext = httpContext;
+    }
+
+    public override bool CanRead => _innerStream.CanRead;
+
+    public override bool CanSeek => _innerStream.CanSeek;
+
+    public override bool CanWrite => _innerStream.CanWrite;
+
+    public override bool CanTimeout => _innerStream.CanTimeout;
+
+    public override long Length => _innerStream.Length;
+
+    public override long Position { get => _innerStream.Position; set => _innerStream.Position = value; }
+
+    public override void Flush()
+    {
+        _innerStream.Flush();
+    }
+
+    public override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+    {
+        return _innerStream.ReadAsync(buffer, offset, count, cancellationToken);
+    }
+
+    public override ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken = default)
+    {
+        return _innerStream.ReadAsync(buffer, cancellationToken);
+    }
+
+    public override int Read(byte[] buffer, int offset, int count)
+    {
+        return _innerStream.Read(buffer, offset, count);
+    }
+
+    public override IAsyncResult BeginRead(byte[] buffer, int offset, int count, AsyncCallback? callback, object? state)
+    {
+        return _innerStream.BeginRead(buffer, offset, count, callback, state);
+    }
+
+    public override int EndRead(IAsyncResult asyncResult)
+    {
+        return _innerStream.EndRead(asyncResult);
+    }
+
+    public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback? callback, object? state)
+    {
+        return _innerStream.BeginWrite(buffer, offset, count, callback, state);
+    }
+
+    public override void EndWrite(IAsyncResult asyncResult)
+    {
+        _innerStream.EndWrite(asyncResult);
+    }
+
+    public override long Seek(long offset, SeekOrigin origin)
+    {
+        return _innerStream.Seek(offset, origin);
+    }
+
+    public override void SetLength(long value)
+    {
+        _innerStream.SetLength(value);
+    }
+
+    public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+    {
+        return _innerStream.WriteAsync(buffer, offset, count, cancellationToken);
+    }
+
+    public override ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken = default)
+    {
+        return _innerStream.WriteAsync(buffer, cancellationToken);
+    }
+
+    public override void Write(byte[] buffer, int offset, int count)
+    {
+        _innerStream.Write(buffer, offset, count);
+    }
+
+    public override Task FlushAsync(CancellationToken cancellationToken)
+    {
+        return _innerStream.FlushAsync(cancellationToken);
+    }
+
+    public override ValueTask DisposeAsync()
+    {
+        return _innerStream.DisposeAsync();
+    }
+
+    protected override void Dispose(bool disposing)
+    {
+        // Currently, if ManagedWebSocket sets the Aborted state it calls Stream.Dispose after
+        if (WebSocket?.State == WebSocketState.Aborted)
+        {
+            _httpContext.Abort();
+        }
+        _innerStream.Dispose();
+    }
+}

src/Middleware/WebSockets/src/PublicAPI.Unshipped.txt

@@ -1 +1,3 @@
 #nullable enable
+Microsoft.AspNetCore.Builder.WebSocketOptions.KeepAliveTimeout.get -> System.TimeSpan
+Microsoft.AspNetCore.Builder.WebSocketOptions.KeepAliveTimeout.set -> void

src/Middleware/WebSockets/src/ServerWebSocket.cs

@@ -141,13 +141,15 @@ public async Task<WebSocket> AcceptAsync(WebSocketAcceptContext acceptContext)
             bool serverContextTakeover = true;
             int serverMaxWindowBits = 15;
             TimeSpan keepAliveInterval = _options.KeepAliveInterval;
+            TimeSpan keepAliveTimeout = _options.KeepAliveTimeout;
             if (acceptContext != null)
             {
                 subProtocol = acceptContext.SubProtocol;
                 enableCompression = acceptContext.DangerousEnableCompression;
                 serverContextTakeover = !acceptContext.DisableServerContextTakeover;
                 serverMaxWindowBits = acceptContext.ServerMaxWindowBits;
                 keepAliveInterval = acceptContext.KeepAliveInterval ?? keepAliveInterval;
+                keepAliveTimeout = acceptContext.KeepAliveTimeout ?? keepAliveTimeout;
             }
 
 #pragma warning disable CS0618 // Type or member is obsolete
@@ -208,15 +210,18 @@ public async Task<WebSocket> AcceptAsync(WebSocketAcceptContext acceptContext)
             // Disable request timeout, if there is one, after the websocket has been accepted
             _context.Features.Get<IHttpRequestTimeoutFeature>()?.DisableTimeout();
 
-            var wrappedSocket = WebSocket.CreateFromStream(opaqueTransport, new WebSocketCreationOptions()
+            var abortStream = new AbortStream(_context, opaqueTransport);
+            var wrappedSocket = WebSocket.CreateFromStream(abortStream, new WebSocketCreationOptions()
             {
                 IsServer = true,
                 KeepAliveInterval = keepAliveInterval,
+                KeepAliveTimeout = keepAliveTimeout,
                 SubProtocol = subProtocol,
                 DangerousDeflateOptions = deflateOptions
             });
 
-            return new ServerWebSocket(wrappedSocket, _context);
+            abortStream.WebSocket = wrappedSocket;
+            return wrappedSocket;
         }
 
         public static bool CheckSupportedWebSocketRequest(string method, IHeaderDictionary requestHeaders)

src/Middleware/WebSockets/src/WebSocketMiddleware.cs

@@ -8,6 +8,8 @@ namespace Microsoft.AspNetCore.Builder;
 /// </summary>
 public class WebSocketOptions
 {
+    private TimeSpan _keepAliveTimeout = Timeout.InfiniteTimeSpan;
+
     /// <summary>
     /// Constructs the <see cref="WebSocketOptions"/> class with default values.
     /// </summary>
@@ -18,11 +20,40 @@ public WebSocketOptions()
     }
 
     /// <summary>
-    /// Gets or sets the frequency at which to send Ping/Pong keep-alive control frames.
+    /// The interval to send keep-alive frames. This is a heart-beat that keeps the connection alive.
     /// The default is two minutes.
     /// </summary>
+    /// <remarks>
+    /// May be either a Ping or a Pong frame, depending on if <see cref="KeepAliveTimeout" /> is set.
+    /// </remarks>
     public TimeSpan KeepAliveInterval { get; set; }
 
+    /// <summary>
+    /// The time to wait for a Pong frame response after sending a Ping frame. If the time is exceeded the websocket will be aborted.
+    /// </summary>
+    /// <remarks>
+    /// Default value is <see cref="Timeout.InfiniteTimeSpan"/>.
+    /// <see cref="Timeout.InfiniteTimeSpan"/> and <see cref="TimeSpan.Zero"/> will disable the timeout.
+    /// </remarks>
+    /// <exception cref="ArgumentOutOfRangeException">
+    /// <see cref="TimeSpan"/> is less than <see cref="TimeSpan.Zero"/>.
+    /// </exception>
+    public TimeSpan KeepAliveTimeout
+    {
+        get
+        {
+            return _keepAliveTimeout;
+        }
+        set
+        {
+            if (value != Timeout.InfiniteTimeSpan)
+            {
+                ArgumentOutOfRangeException.ThrowIfLessThan(value, TimeSpan.Zero);
+            }
+            _keepAliveTimeout = value;
+        }
+    }
+
     /// <summary>
     /// Gets or sets the size of the protocol buffer used to receive and parse frames.
     /// The default is 4kb.

src/Middleware/WebSockets/src/WebSocketOptions.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using Microsoft.AspNetCore.Builder;
@@ -17,14 +17,22 @@ public void AddWebSocketsConfiguresOptions()
         serviceCollection.AddWebSockets(o =>
         {
             o.KeepAliveInterval = TimeSpan.FromSeconds(1000);
+            o.KeepAliveTimeout = TimeSpan.FromSeconds(1234);
             o.AllowedOrigins.Add("someString");
         });
 
         var services = serviceCollection.BuildServiceProvider();
         var socketOptions = services.GetRequiredService<IOptions<WebSocketOptions>>().Value;
 
         Assert.Equal(TimeSpan.FromSeconds(1000), socketOptions.KeepAliveInterval);
+        Assert.Equal(TimeSpan.FromSeconds(1234), socketOptions.KeepAliveTimeout);
         Assert.Single(socketOptions.AllowedOrigins);
         Assert.Equal("someString", socketOptions.AllowedOrigins[0]);
     }
+
+    [Fact]
+    public void ThrowsForBadOptions()
+    {
+        Assert.Throws<ArgumentOutOfRangeException>(() => new WebSocketOptions() { KeepAliveTimeout = TimeSpan.FromMicroseconds(-1) });
+    }
 }