Implement HeaderTableSize for HTTP/2

Author: John Luo

src/Kestrel.Core/Http2Limits.cs

@@ -11,9 +11,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core
     public class Http2Limits
     {
         private int _maxStreamsPerConnection = 100;
+        private int _headerTableSize = MaxAllowedHeaderTableSize;
         private int _maxFrameSize = MinAllowedMaxFrameSize;
 
         // These are limits defined by the RFC https://tools.ietf.org/html/rfc7540#section-4.2
+        public const int MaxAllowedHeaderTableSize = 4096;
         public const int MinAllowedMaxFrameSize = 16 * 1024;
         public const int MaxAllowedMaxFrameSize = 16 * 1024 * 1024 - 1;
 
@@ -37,6 +39,26 @@ public int MaxStreamsPerConnection
             }
         }
 
+        /// <summary>
+        /// Limits the size of the header compression table, in octets, the HPACK decoder on the server can use.
+        /// <para>
+        /// Defaults to 4096
+        /// </para>
+        /// </summary>
+        public int HeaderTableSize
+        {
+            get => _headerTableSize;
+            set
+            {
+                if (value <= 0 || value > MaxAllowedHeaderTableSize)
+                {
+                    throw new ArgumentOutOfRangeException(nameof(value), value, CoreStrings.FormatArgumentOutOfRange(0, MaxAllowedHeaderTableSize));
+                }
+
+                _headerTableSize = value;
+            }
+        }
+
         /// <summary>
         /// Indicates the size of the largest frame payload that is allowed to be received, in octets. The size must be between 2^14 and 2^24-1.
         /// <para>

src/Kestrel.Core/Internal/Http2/Http2Connection.cs

@@ -87,9 +87,10 @@ public Http2Connection(Http2ConnectionContext context)
         {
             _context = context;
             _frameWriter = new Http2FrameWriter(context.Transport.Output, context.ConnectionContext, _outputFlowControl, this, context.ConnectionId, context.ServiceContext.Log);
-            _hpackDecoder = new HPackDecoder((int)_serverSettings.HeaderTableSize);
             _serverSettings.MaxConcurrentStreams = (uint)context.ServiceContext.ServerOptions.Limits.Http2.MaxStreamsPerConnection;
             _serverSettings.MaxFrameSize = (uint)context.ServiceContext.ServerOptions.Limits.Http2.MaxFrameSize;
+            _serverSettings.HeaderTableSize = (uint)context.ServiceContext.ServerOptions.Limits.Http2.HeaderTableSize;
+            _hpackDecoder = new HPackDecoder((int)_serverSettings.HeaderTableSize);
             _incomingFrame = new Http2Frame(_serverSettings.MaxFrameSize);
         }
 

test/Kestrel.Core.Tests/KestrelServerLimitsTests.cs

@@ -318,7 +318,22 @@ public void Http2MaxFrameSizeDefault()
         [InlineData(1 << 14 - 1)]
         [InlineData(1 << 24)]
         [InlineData(-1)]
-        public void Http2MaxFrameSizeInvalide(int value)
+        public void Http2MaxFrameSizeInvalid(int value)
+        {
+            var ex = Assert.Throws<ArgumentOutOfRangeException>(() => new KestrelServerLimits().Http2.MaxFrameSize = value);
+            Assert.Contains("A value between", ex.Message);
+        }
+
+        [Fact]
+        public void Http2HeaderTableSizeDefault()
+        {
+            Assert.Equal(4096, new KestrelServerLimits().Http2.HeaderTableSize);
+        }
+
+        [Theory]
+        [InlineData(4097)]
+        [InlineData(-1)]
+        public void Http2HeaderTableSizeInvalid(int value)
         {
             var ex = Assert.Throws<ArgumentOutOfRangeException>(() => new KestrelServerLimits().Http2.MaxFrameSize = value);
             Assert.Contains("A value between", ex.Message);

test/Kestrel.InMemory.FunctionalTests/Http2/Http2ConnectionTests.cs

@@ -2100,6 +2100,7 @@ await WaitForConnectionErrorAsync<Http2ConnectionErrorException>(
         [InlineData(Http2SettingsParameter.SETTINGS_MAX_FRAME_SIZE, 16 * 1024 - 1, Http2ErrorCode.PROTOCOL_ERROR)]
         [InlineData(Http2SettingsParameter.SETTINGS_MAX_FRAME_SIZE, 16 * 1024 * 1024, Http2ErrorCode.PROTOCOL_ERROR)]
         [InlineData(Http2SettingsParameter.SETTINGS_MAX_FRAME_SIZE, uint.MaxValue, Http2ErrorCode.PROTOCOL_ERROR)]
+        [InlineData(Http2SettingsParameter.SETTINGS_HEADER_TABLE_SIZE, 4097, Http2ErrorCode.PROTOCOL_ERROR)]
         public async Task SETTINGS_Received_InvalidParameterValue_ConnectionError(Http2SettingsParameter parameter, uint value, Http2ErrorCode expectedErrorCode)
         {
             await InitializeConnectionAsync(_noopApplication);