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Fix enhanced routing ack handling #3922

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Fix enhanced routing ack handling #3922

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8916abd
Correct behavior.
mdaigle Jan 29, 2026
e68c0aa
Update tests to reduce redundancy.
mdaigle Jan 29, 2026
dc948ac
Remove duplicate feature ext ack.
mdaigle Jan 29, 2026
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18 changes: 17 additions & 1 deletion ...Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlInternalConnectionTds.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -1618,6 +1618,14 @@ private void LoginNoFailover(ServerInfo serverInfo,

if (RoutingInfo != null)
{
// Check if we received enhanced routing info, but not the ack for the feature.
// In this case, we should ignore the routing info and connect to the current server.
if (!string.IsNullOrEmpty(RoutingInfo.DatabaseName) && !IsEnhancedRoutingSupportEnabled)
{
RoutingInfo = null;
break;
}

SqlClientEventSource.Log.TryTraceEvent("<sc.SqlInternalConnectionTds.LoginNoFailover> Routed to {0}", serverInfo.ExtendedServerName);
if (routingAttempts > MaxNumberOfRedirectRoute)
{
Expand Down Expand Up @@ -1879,6 +1887,14 @@ TimeoutTimer timeout
int routingAttempts = 0;
while (RoutingInfo != null)
{
// Check if we received enhanced routing info, but not the ack for the feature.
// In this case, we should ignore the routing info and connect to the current server.
if (!string.IsNullOrEmpty(RoutingInfo.DatabaseName) && !IsEnhancedRoutingSupportEnabled)
{
RoutingInfo = null;
continue;
}

if (routingAttempts > MaxNumberOfRedirectRoute)
{
throw SQL.ROR_RecursiveRoutingNotSupported(this, MaxNumberOfRedirectRoute);
Expand Down Expand Up @@ -2723,7 +2739,7 @@ internal SqlFedAuthToken GetFedAuthToken(SqlFedAuthInfo fedAuthInfo)

internal void OnFeatureExtAck(int featureId, byte[] data)
{
if (RoutingInfo != null && featureId != TdsEnums.FEATUREEXT_SQLDNSCACHING)
if (RoutingInfo != null && featureId != TdsEnums.FEATUREEXT_SQLDNSCACHING && featureId != TdsEnums.FEATUREEXT_ENHANCEDROUTINGSUPPORT)
{
return;
}
Expand Down
18 changes: 17 additions & 1 deletion src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/SqlInternalConnectionTds.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -1648,6 +1648,14 @@ private void LoginNoFailover(ServerInfo serverInfo,

if (RoutingInfo != null)
{
// Check if we received enhanced routing info, but not the ack for the feature.
// In this case, we should ignore the routing info and connect to the current server.
if (!string.IsNullOrEmpty(RoutingInfo.DatabaseName) && !IsEnhancedRoutingSupportEnabled)
{
RoutingInfo = null;
break;
}

SqlClientEventSource.Log.TryTraceEvent("<sc.SqlInternalConnectionTds.LoginNoFailover> Routed to {0}", serverInfo.ExtendedServerName);
if (routingAttempts > MaxNumberOfRedirectRoute)
{
Expand Down Expand Up @@ -1933,6 +1941,14 @@ TimeoutTimer timeout
int routingAttempts = 0;
while (RoutingInfo != null)
{
// Check if we received enhanced routing info, but not the ack for the feature.
// In this case, we should ignore the routing info and connect to the current server.
if (!string.IsNullOrEmpty(RoutingInfo.DatabaseName) && !IsEnhancedRoutingSupportEnabled)
{
RoutingInfo = null;
continue;
}

if (routingAttempts > MaxNumberOfRedirectRoute)
{
throw SQL.ROR_RecursiveRoutingNotSupported(this, MaxNumberOfRedirectRoute);
Expand Down Expand Up @@ -2766,7 +2782,7 @@ internal SqlFedAuthToken GetFedAuthToken(SqlFedAuthInfo fedAuthInfo)

internal void OnFeatureExtAck(int featureId, byte[] data)
{
if (RoutingInfo != null && featureId != TdsEnums.FEATUREEXT_SQLDNSCACHING)
if (RoutingInfo != null && featureId != TdsEnums.FEATUREEXT_SQLDNSCACHING && featureId != TdsEnums.FEATUREEXT_ENHANCEDROUTINGSUPPORT)
{
return;
}
Expand Down
218 changes: 72 additions & 146 deletions ...oft.Data.SqlClient/tests/UnitTests/SimulatedServerTests/ConnectionEnhancedRoutingTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -16,185 +16,111 @@ namespace Microsoft.Data.SqlClient.UnitTests.SimulatedServerTests;
[Collection("SimulatedServerTests")]
public class ConnectionEnhancedRoutingTests
{
[Fact]
public void RoutedConnection()
/// <summary>
/// Tests that a connection is routed to the target server when enhanced routing is enabled.
/// Uses Theory to test both sync and async code paths.
/// </summary>
[Theory]
[InlineData(false)]
[InlineData(true)]
public async Task RoutedConnection(bool useAsync)
{
// Arrange
using TdsServer server = new(new());
server.Start();
using TestRoutingServers servers = new(FeatureExtensionBehavior.Enabled);

string routingDatabaseName = Guid.NewGuid().ToString();
bool clientProvidedCorrectDatabase = false;
server.OnLogin7Validated = loginToken =>
servers.TargetServer.OnLogin7Validated = loginToken =>
{
clientProvidedCorrectDatabase = routingDatabaseName == loginToken.Database;
clientProvidedCorrectDatabase = servers.RoutingDatabaseName == loginToken.Database;
};

RoutingTdsServer router = new(
new RoutingTdsServerArguments()
{
RoutingTCPHost = "localhost",
RoutingTCPPort = (ushort)server.EndPoint.Port,
RoutingDatabaseName = routingDatabaseName,
RequireReadOnly = false
});
router.Start();
router.EnhancedRoutingBehavior = FeatureExtensionBehavior.Enabled;

string connectionString = (new SqlConnectionStringBuilder()
{
DataSource = $"localhost,{router.EndPoint.Port}",
Encrypt = false,
ConnectTimeout = 10000
}).ConnectionString;

// Act
using SqlConnection connection = new(connectionString);
connection.Open();

// Assert
Assert.Equal(ConnectionState.Open, connection.State);
Assert.Equal($"localhost,{server.EndPoint.Port}", ((SqlInternalConnectionTds)connection.InnerConnection).RoutingDestination);
Assert.Equal(routingDatabaseName, connection.Database);
Assert.True(clientProvidedCorrectDatabase);

Assert.Equal(1, router.PreLoginCount);
Assert.Equal(1, server.PreLoginCount);
}

[Fact]
public async Task RoutedAsyncConnection()
{
// Arrange
using TdsServer server = new(new());
server.Start();

string routingDatabaseName = Guid.NewGuid().ToString();
bool clientProvidedCorrectDatabase = false;
server.OnLogin7Validated = loginToken =>
using SqlConnection connection = new(servers.ConnectionString);
if (useAsync)
{
clientProvidedCorrectDatabase = routingDatabaseName == loginToken.Database;
};

RoutingTdsServer router = new(
new RoutingTdsServerArguments()
{
RoutingTCPHost = "localhost",
RoutingTCPPort = (ushort)server.EndPoint.Port,
RoutingDatabaseName = routingDatabaseName,
RequireReadOnly = false
});
router.Start();
router.EnhancedRoutingBehavior = FeatureExtensionBehavior.Enabled;

string connectionString = (new SqlConnectionStringBuilder()
await connection.OpenAsync();
}
else
{
DataSource = $"localhost,{router.EndPoint.Port}",
Encrypt = false,
ConnectTimeout = 10000
}).ConnectionString;

// Act
using SqlConnection connection = new(connectionString);
await connection.OpenAsync();
connection.Open();
}

// Assert
Assert.Equal(ConnectionState.Open, connection.State);
Assert.Equal($"localhost,{server.EndPoint.Port}", ((SqlInternalConnectionTds)connection.InnerConnection).RoutingDestination);
Assert.Equal(routingDatabaseName, connection.Database);
Assert.Equal($"localhost,{servers.TargetServer.EndPoint.Port}", ((SqlInternalConnectionTds)connection.InnerConnection).RoutingDestination);
Assert.Equal(servers.RoutingDatabaseName, connection.Database);
Assert.True(clientProvidedCorrectDatabase);

Assert.Equal(1, router.PreLoginCount);
Assert.Equal(1, server.PreLoginCount);
Assert.Equal(1, servers.Router.PreLoginCount);
Assert.Equal(1, servers.TargetServer.PreLoginCount);
}

[Fact]
public void ServerIgnoresEnhancedRoutingRequest()
/// <summary>
/// Tests that a connection is NOT routed when the server does not acknowledge the enhanced routing feature
/// or has it disabled. Covers both DoNotAcknowledge and Disabled behaviors.
/// </summary>
[Theory]
[InlineData(FeatureExtensionBehavior.DoNotAcknowledge)]
[InlineData(FeatureExtensionBehavior.Disabled)]
public void ServerDoesNotRoute(FeatureExtensionBehavior behavior)
{
// Arrange
using TdsServer server = new(new());
server.Start();

string routingDatabaseName = Guid.NewGuid().ToString();
bool clientProvidedCorrectDatabase = false;
server.OnLogin7Validated = loginToken =>
{
clientProvidedCorrectDatabase = null == loginToken.Database;
};

RoutingTdsServer router = new(
new RoutingTdsServerArguments()
{
RoutingTCPHost = "localhost",
RoutingTCPPort = (ushort)server.EndPoint.Port,
RequireReadOnly = false
});
router.Start();
router.EnhancedRoutingBehavior = FeatureExtensionBehavior.DoNotAcknowledge;

string connectionString = (new SqlConnectionStringBuilder()
{
DataSource = $"localhost,{router.EndPoint.Port}",
Encrypt = false,
ConnectTimeout = 10000
}).ConnectionString;
using TestRoutingServers servers = new(behavior);

// Act
using SqlConnection connection = new(connectionString);
using SqlConnection connection = new(servers.ConnectionString);
connection.Open();

// Assert
Assert.Equal(ConnectionState.Open, connection.State);
Assert.Equal($"localhost,{server.EndPoint.Port}", ((SqlInternalConnectionTds)connection.InnerConnection).RoutingDestination);
Assert.Null(((SqlInternalConnectionTds)connection.InnerConnection).RoutingDestination);
Assert.Equal("master", connection.Database);
Assert.True(clientProvidedCorrectDatabase);

Assert.Equal(1, router.PreLoginCount);
Assert.Equal(1, server.PreLoginCount);
Assert.Equal(1, servers.Router.PreLoginCount);
Assert.Equal(0, servers.TargetServer.PreLoginCount);
}

[Fact]
public void ServerRejectsEnhancedRoutingRequest()
/// <summary>
/// Helper class that encapsulates the setup of a routing TDS server and target TDS server
/// for enhanced routing tests.
/// </summary>
private sealed class TestRoutingServers : IDisposable
{
// Arrange
using TdsServer server = new(new());
server.Start();
public TdsServer TargetServer { get; }
public RoutingTdsServer Router { get; }
public string RoutingDatabaseName { get; }
public string ConnectionString { get; }

string routingDatabaseName = Guid.NewGuid().ToString();
bool clientProvidedCorrectDatabase = false;
server.OnLogin7Validated = loginToken =>
public TestRoutingServers(FeatureExtensionBehavior enhancedRoutingBehavior)
{
clientProvidedCorrectDatabase = null == loginToken.Database;
};

RoutingTdsServer router = new(
new RoutingTdsServerArguments()
RoutingDatabaseName = Guid.NewGuid().ToString();

TargetServer = new TdsServer(new());
TargetServer.Start();

Router = new RoutingTdsServer(
new RoutingTdsServerArguments()
{
RoutingTCPHost = "localhost",
RoutingTCPPort = (ushort)TargetServer.EndPoint.Port,
RoutingDatabaseName = RoutingDatabaseName,
RequireReadOnly = false
});
Router.Start();
Router.EnhancedRoutingBehavior = enhancedRoutingBehavior;

ConnectionString = new SqlConnectionStringBuilder()
{
RoutingTCPHost = "localhost",
RoutingTCPPort = (ushort)server.EndPoint.Port,
RequireReadOnly = false
});
router.Start();
router.EnhancedRoutingBehavior = FeatureExtensionBehavior.Disabled;

string connectionString = (new SqlConnectionStringBuilder()
{
DataSource = $"localhost,{router.EndPoint.Port}",
Encrypt = false,
ConnectTimeout = 10000
}).ConnectionString;

// Act
using SqlConnection connection = new(connectionString);
connection.Open();

// Assert
Assert.Equal(ConnectionState.Open, connection.State);
Assert.Equal($"localhost,{server.EndPoint.Port}", ((SqlInternalConnectionTds)connection.InnerConnection).RoutingDestination);
Assert.Equal("master", connection.Database);
Assert.True(clientProvidedCorrectDatabase);
DataSource = $"localhost,{Router.EndPoint.Port}",
Encrypt = false,
ConnectTimeout = 10000
}.ConnectionString;
}

Assert.Equal(1, router.PreLoginCount);
Assert.Equal(1, server.PreLoginCount);
public void Dispose()
{
Router?.Dispose();
TargetServer?.Dispose();
}
}
}
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