From c144890bc3485a7dfd32268a4128c058cc291c39 Mon Sep 17 00:00:00 2001 From: Cheena Malhotra <13396919+cheenamalhotra@users.noreply.github.com> Date: Tue, 7 Apr 2026 14:45:53 -0700 Subject: [PATCH] Enable User Agent feature extension (#4124) --- .../Data/SqlClient/LocalAppContextSwitches.cs | 24 --------- .../src/Microsoft/Data/SqlClient/TdsParser.cs | 2 +- .../Common/LocalAppContextSwitchesHelper.cs | 15 ------ .../SqlClient/LocalAppContextSwitchesTest.cs | 1 - .../SimulatedServerTests/ConnectionTests.cs | 54 ------------------- 5 files changed, 1 insertion(+), 95 deletions(-) diff --git a/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/LocalAppContextSwitches.cs b/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/LocalAppContextSwitches.cs index 7694092907..16e0abb7ec 100644 --- a/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/LocalAppContextSwitches.cs +++ b/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/LocalAppContextSwitches.cs @@ -36,13 +36,6 @@ internal static class LocalAppContextSwitches private const string EnableMultiSubnetFailoverByDefaultString = "Switch.Microsoft.Data.SqlClient.EnableMultiSubnetFailoverByDefault"; - /// - /// The name of the app context switch that controls whether - /// the user agent feature is enabled. - /// - private const string EnableUserAgentString = - "Switch.Microsoft.Data.SqlClient.EnableUserAgent"; - #if NET /// /// The name of the app context switch that controls whether @@ -177,11 +170,6 @@ private enum SwitchValue : byte /// private static SwitchValue s_enableMultiSubnetFailoverByDefault = SwitchValue.None; - /// - /// The cached value of the EnableUserAgent switch. - /// - private static SwitchValue s_enableUserAgent = SwitchValue.None; - #if NET /// /// The cached value of the GlobalizationInvariantMode switch. @@ -319,18 +307,6 @@ static LocalAppContextSwitches() defaultValue: false, ref s_enableMultiSubnetFailoverByDefault); - /// - /// When set to true, the user agent feature is enabled and the driver will - /// send the user agent string to the server. - /// - /// The default value of this switch is false. - /// - public static bool EnableUserAgent => - AcquireAndReturn( - EnableUserAgentString, - defaultValue: false, - ref s_enableUserAgent); - #if NET /// /// .NET Core 2.0 and up supports Globalization Invariant mode, which diff --git a/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParser.cs b/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParser.cs index 94281b4998..088d41d94d 100644 --- a/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParser.cs +++ b/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParser.cs @@ -9663,7 +9663,7 @@ private int ApplyFeatureExData(TdsEnums.FeatureExtension requestedFeatures, checked { // NOTE: As part of TDS spec UserAgent feature extension should be the first feature extension in the list. - if (LocalAppContextSwitches.EnableUserAgent && ((requestedFeatures & TdsEnums.FeatureExtension.UserAgent) != 0)) + if ((requestedFeatures & TdsEnums.FeatureExtension.UserAgent) != 0) { length += WriteUserAgentFeatureRequest(userAgent, write); } diff --git a/src/Microsoft.Data.SqlClient/tests/Common/LocalAppContextSwitchesHelper.cs b/src/Microsoft.Data.SqlClient/tests/Common/LocalAppContextSwitchesHelper.cs index 4a0cdf67de..8102f47d51 100644 --- a/src/Microsoft.Data.SqlClient/tests/Common/LocalAppContextSwitchesHelper.cs +++ b/src/Microsoft.Data.SqlClient/tests/Common/LocalAppContextSwitchesHelper.cs @@ -43,7 +43,6 @@ public sealed class LocalAppContextSwitchesHelper : IDisposable private readonly bool? _disableTnirByDefaultOriginal; #endif private readonly bool? _enableMultiSubnetFailoverByDefaultOriginal; - private readonly bool? _enableUserAgentOriginal; #if NET private readonly bool? _globalizationInvariantModeOriginal; #endif @@ -93,8 +92,6 @@ public LocalAppContextSwitchesHelper() #endif _enableMultiSubnetFailoverByDefaultOriginal = GetSwitchValue("s_enableMultiSubnetFailoverByDefault"); - _enableUserAgentOriginal = - GetSwitchValue("s_enableUserAgent"); #if NET _globalizationInvariantModeOriginal = GetSwitchValue("s_globalizationInvariantMode"); @@ -149,9 +146,6 @@ public void Dispose() SetSwitchValue( "s_enableMultiSubnetFailoverByDefault", _enableMultiSubnetFailoverByDefaultOriginal); - SetSwitchValue( - "s_enableUserAgent", - _enableUserAgentOriginal); #if NET SetSwitchValue( "s_globalizationInvariantMode", @@ -228,15 +222,6 @@ public bool? EnableMultiSubnetFailoverByDefault set => SetSwitchValue("s_enableMultiSubnetFailoverByDefault", value); } - /// - /// Get or set the EnableUserAgent switch value. - /// - public bool? EnableUserAgent - { - get => GetSwitchValue("s_enableUserAgent"); - set => SetSwitchValue("s_enableUserAgent", value); - } - #if NET /// /// Get or set the GlobalizationInvariantMode switch value. diff --git a/src/Microsoft.Data.SqlClient/tests/UnitTests/Microsoft/Data/SqlClient/LocalAppContextSwitchesTest.cs b/src/Microsoft.Data.SqlClient/tests/UnitTests/Microsoft/Data/SqlClient/LocalAppContextSwitchesTest.cs index 59445a26b6..a5db02faa0 100644 --- a/src/Microsoft.Data.SqlClient/tests/UnitTests/Microsoft/Data/SqlClient/LocalAppContextSwitchesTest.cs +++ b/src/Microsoft.Data.SqlClient/tests/UnitTests/Microsoft/Data/SqlClient/LocalAppContextSwitchesTest.cs @@ -28,7 +28,6 @@ public void TestDefaultAppContextSwitchValues() Assert.False(LocalAppContextSwitches.UseConnectionPoolV2); Assert.False(LocalAppContextSwitches.TruncateScaledDecimal); Assert.False(LocalAppContextSwitches.IgnoreServerProvidedFailoverPartner); - Assert.False(LocalAppContextSwitches.EnableUserAgent); Assert.False(LocalAppContextSwitches.EnableMultiSubnetFailoverByDefault); #if NET Assert.False(LocalAppContextSwitches.GlobalizationInvariantMode); diff --git a/src/Microsoft.Data.SqlClient/tests/UnitTests/SimulatedServerTests/ConnectionTests.cs b/src/Microsoft.Data.SqlClient/tests/UnitTests/SimulatedServerTests/ConnectionTests.cs index a729e6afe2..06553b11f5 100644 --- a/src/Microsoft.Data.SqlClient/tests/UnitTests/SimulatedServerTests/ConnectionTests.cs +++ b/src/Microsoft.Data.SqlClient/tests/UnitTests/SimulatedServerTests/ConnectionTests.cs @@ -840,10 +840,6 @@ public void TestConnWithVectorFeatExtVersionNegotiation(bool expectedConnectionR [InlineData(false)] public void TestConnWithUserAgentFeatureExtension(bool sendAck) { - // Enable sending the UserAgent if desired. - using LocalAppContextSwitchesHelper switchesHelper = new(); - switchesHelper.EnableUserAgent = true; - // Start the test server. using TdsServer server = new(); server.Start(); @@ -904,55 +900,5 @@ public void TestConnWithUserAgentFeatureExtension(bool sendAck) // TODO: Confirm the server sent an Ack by reading log message from SqlInternalConnectionTds } - - /// - /// Test to verify no UserAgent relevant information is sent when EnableUserAgentField switch is disabled. - /// - [Fact] - public void TestConnWithoutUserAgentFeatureExtension() - { - // Disable the client-side UserAgent field entirely - using LocalAppContextSwitchesHelper switchesHelper = new(); - switchesHelper.EnableUserAgent = false; - - using var server = new TdsServer(); - server.Start(); - - // Do not advertise or force the UserAgent feature on the server - server.ServerSupportedUserAgentFeatureExtVersion = 0x00; // no support - server.EnableUserAgentFeatureExt = false; // no forced ACK - - bool loginValidated = false; - bool userAgentFeatureSeen = false; - - // Inspect the LOGIN7 packet captured by the test server - server.OnLogin7Validated = loginToken => - { - var featureExtTokens = loginToken.FeatureExt - .OfType() - .ToArray(); - - // Ensure there is no UserAgentSupport token at all - var uaToken = featureExtTokens.FirstOrDefault(t => t.FeatureID == TDSFeatureID.UserAgentSupport); - userAgentFeatureSeen = uaToken is not null; - - loginValidated = true; - }; - - // Connect to the test TDS server with a basic connection string - var connStr = new SqlConnectionStringBuilder - { - DataSource = $"localhost,{server.EndPoint.Port}", - Encrypt = SqlConnectionEncryptOption.Optional, - }.ConnectionString; - - using var connection = new SqlConnection(connStr); - connection.Open(); - - // Verify that the connection succeeded and no UserAgent data was sent - Assert.Equal(ConnectionState.Open, connection.State); - Assert.True(loginValidated, "Expected LOGIN7 to be validated by the test server"); - Assert.False(userAgentFeatureSeen, "Did not expect a UserAgentSupport feature token in LOGIN7"); - } } }