Enable Managed SNI on Windows with AppContext switch

BUILDGUIDE.md

@@ -160,6 +160,7 @@ Tests can be built and run with custom Target Frameworks. See the below examples
 # Build the tests for custom TargetFramework (.NET Core)
 # Applicable values: netcoreapp2.1 | netcoreapp2.2 | netcoreapp3.0
 ```
+
 ### Running Tests:
 
 ```bash
@@ -171,3 +172,9 @@ Tests can be built and run with custom Target Frameworks. See the below examples
 # Use above property to run Functional Tests with custom TargetFramework (.NET Core)
 # Applicable values: netcoreapp2.1 | netcoreapp2.2 | netcoreapp3.0
 ```
+
+## Using Managed SNI on Windows
+
+Managed SNI can be enabled on Windows by enabling below AppContext switch:
+
+**"Microsoft.Data.SqlClient.UseManagedNetworkingOnWindows"**

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParserStateObjectFactory.Windows.cs

@@ -9,25 +9,15 @@ namespace Microsoft.Data.SqlClient
 {
  internal sealed class TdsParserStateObjectFactory
  {
-
- private const string UseLegacyNetworkingOnWindows = "Microsoft.Data.SqlClient.UseLegacyNetworkingOnWindows";
-
  public static readonly TdsParserStateObjectFactory Singleton = new TdsParserStateObjectFactory();
 
+ private const string UseManagedNetworkingOnWindows = "Microsoft.Data.SqlClient.UseManagedNetworkingOnWindows";
 
- // Temporary disabling App Context switching for managed SNI.
- // If the appcontext switch is set then Use Managed SNI based on the value. Otherwise Managed SNI should always be used.
- //private static bool shouldUseLegacyNetorking;
- //public static bool UseManagedSNI { get; } = AppContext.TryGetSwitch(UseLegacyNetworkingOnWindows, out shouldUseLegacyNetorking) ? !shouldUseLegacyNetorking : true;
+ private static bool shouldUseManagedSNI;
 
-#if DEBUG
- private static Lazy<bool> useManagedSNIOnWindows = new Lazy<bool>(
- () => bool.TrueString.Equals(Environment.GetEnvironmentVariable("Microsoft.Data.SqlClient.UseManagedSNIOnWindows"), StringComparison.InvariantCultureIgnoreCase)
- );
- public static bool UseManagedSNI => useManagedSNIOnWindows.Value;
-#else
- public static bool UseManagedSNI { get; } = false;
-#endif
+ // If the appcontext switch is set then Use Managed SNI based on the value. Otherwise Native SNI.dll will be used by default.
+ public static bool UseManagedSNI { get; } =
+ AppContext.TryGetSwitch(UseManagedNetworkingOnWindows, out shouldUseManagedSNI) ? shouldUseManagedSNI : false;
 
  public EncryptionOptions EncryptionOptions
  {
@@ -49,10 +39,14 @@ public TdsParserStateObject CreateTdsParserStateObject(TdsParser parser)
  {
  if (UseManagedSNI)
  {
+ SqlClientEventSource.Log.TraceEvent("<sc.TdsParserStateObjectFactory.CreateTdsParserStateObject|INFO> Found AppContext switch '{0}#' enabled, managed networking implementation will be used."
+ , UseManagedNetworkingOnWindows);
  return new TdsParserStateObjectManaged(parser);
  }
  else
  {
+ SqlClientEventSource.Log.TraceEvent("<sc.TdsParserStateObjectFactory.CreateTdsParserStateObject|INFO> AppContext switch '{0}#' not enabled, native networking implementation will be used."
+ , UseManagedNetworkingOnWindows);
  return new TdsParserStateObjectNative(parser);
  }
  }

src/Microsoft.Data.SqlClient/tests/ManualTests/DataCommon/DataTestUtility.cs

@@ -45,9 +45,10 @@ public static class DataTestUtility
  public const string UdtTestDbName = "UdtTestDb";
  public const string AKVKeyName = "TestSqlClientAzureKeyVaultProvider";
 
- private static readonly Assembly MdsAssembly = typeof(Microsoft.Data.SqlClient.SqlConnection).GetTypeInfo().Assembly;
- private static readonly Type TdsParserStateObjectFactoryInstance = MdsAssembly?.GetType("Microsoft.Data.SqlClient.TdsParserStateObjectFactory");
- private static readonly PropertyInfo UseManagedSni = TdsParserStateObjectFactoryInstance?.GetProperty("UseManagedSNI", BindingFlags.Static | BindingFlags.Public);
+ private const string ManagedNetworkingAppContextSwitch = "Microsoft.Data.SqlClient.UseManagedNetworkingOnWindows";
+
+ private static bool UseManagedSNI =
+ bool.TryParse(Environment.GetEnvironmentVariable("Microsoft_Data_SqlClient_UseManagedSniOnWindows"), out UseManagedSNI) ? UseManagedSNI : false;
 
  private static readonly string[] AzureSqlServerEndpoints = {".database.windows.net",
  ".database.cloudapi.de",
@@ -76,6 +77,12 @@ private class Config
 
  static DataTestUtility()
  {
+ if (UseManagedSNI)
+ {
+ AppContext.SetSwitch(ManagedNetworkingAppContextSwitch, true);
+ Console.WriteLine($"App Context switch {ManagedNetworkingAppContextSwitch} enabled on {Environment.OSVersion}");
+ }
+
  using (StreamReader r = new StreamReader("config.json"))
  {
  string json = r.ReadToEnd();
@@ -231,7 +238,7 @@ public static bool IsAKVSetupAvailable()
  return !string.IsNullOrEmpty(AKVUrl) && !string.IsNullOrEmpty(AKVClientId) && !string.IsNullOrEmpty(AKVClientSecret);
  }
 
- public static bool IsUsingManagedSNI() => (bool)(UseManagedSni?.GetValue(null) ?? false);
+ public static bool IsUsingManagedSNI() => UseManagedSNI;
 
  public static bool IsUsingNativeSNI() => !IsUsingManagedSNI();
 

src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/IntegratedAuthenticationTest/IntegratedAuthenticationTest.cs

@@ -9,8 +9,8 @@ namespace Microsoft.Data.SqlClient.ManualTesting.Tests
  public static class IntegratedAuthenticationTest
  {
  private static bool IsIntegratedSecurityEnvironmentSet() => DataTestUtility.IsIntegratedSecuritySetup();
- private static bool AreConnectionStringsSetup() => DataTestUtility.AreConnStringsSetup();
 
+ private static bool AreConnectionStringsSetup() => DataTestUtility.AreConnStringsSetup();
 
  [ConditionalFact(nameof(IsIntegratedSecurityEnvironmentSet), nameof(AreConnectionStringsSetup))]
  public static void IntegratedAuthenticationTestWithConnectionPooling()