From 0db2274434fc8c398191c5419e850af89419b3e6 Mon Sep 17 00:00:00 2001
From: Afsaneh Rafighi <v-afrafi@microsoft.com>
Date: Mon, 5 Nov 2018 16:31:29 -0800
Subject: [PATCH] Add TCPKeepAlive to SqlClient Sockets (#33024)

* Updating version files

* Enable keep alive on SqlClient TCP sockets

* make KeepAlive netcoreapp specific

* added condition for uapassembly

* added a new defineConstants called FEATURE_TCPKEEPALIVE

* update TCPKeepAliveInterval value

* set KeepAlive values in unix only

* add documentation and add link to Github Issue

* move SNITcpHandle.Windows.cs available in UAP

* updating csproj for SNITcpHandle

* fix in csproj for CI failure
---
 .../src/System.Data.SqlClient.csproj          |  4 ++++
 .../Data/SqlClient/SNI/SNITcpHandle.Unix.cs   | 19 +++++++++++++++++++
 .../SqlClient/SNI/SNITcpHandle.Windows.cs     | 16 ++++++++++++++++
 .../System/Data/SqlClient/SNI/SNITcpHandle.cs |  2 ++
 4 files changed, 41 insertions(+)
 create mode 100644 src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.Unix.cs
 create mode 100644 src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.Windows.cs

diff --git a/src/System.Data.SqlClient/src/System.Data.SqlClient.csproj b/src/System.Data.SqlClient/src/System.Data.SqlClient.csproj
index 2c0e366c9167..a288a3ed5c6a 100644
--- a/src/System.Data.SqlClient/src/System.Data.SqlClient.csproj
+++ b/src/System.Data.SqlClient/src/System.Data.SqlClient.csproj
@@ -9,6 +9,7 @@
     <AssemblyVersion Condition="'$(TargetGroup)' == 'netstandard1.2'">4.0.0.0</AssemblyVersion>
     <AssemblyVersion Condition="'$(TargetGroup)' == 'netstandard1.3'">4.1.0.0</AssemblyVersion>
     <DefineConstants Condition="'$(TargetsNetCoreApp)' == 'true'">$(DefineConstants);netcoreapp</DefineConstants>
+    <DefineConstants Condition="'$(TargetGroup)' == 'netcoreapp'">$(DefineConstants);FEATURE_TCPKEEPALIVE</DefineConstants>
     <Configurations>net461-Windows_NT-Debug;net461-Windows_NT-Release;netcoreapp-Debug;netcoreapp-Release;netcoreapp-Unix-Debug;netcoreapp-Unix-Release;netcoreapp-Windows_NT-Debug;netcoreapp-Windows_NT-Release;netcoreapp2.1-Debug;netcoreapp2.1-Release;netcoreapp2.1-Unix-Debug;netcoreapp2.1-Unix-Release;netcoreapp2.1-Windows_NT-Debug;netcoreapp2.1-Windows_NT-Release;netfx-Windows_NT-Debug;netfx-Windows_NT-Release;netstandard-Debug;netstandard-Release;netstandard-Unix-Debug;netstandard-Unix-Release;netstandard-Windows_NT-Debug;netstandard-Windows_NT-Release;netstandard1.2-Debug;netstandard1.2-Release;netstandard1.3-Debug;netstandard1.3-Release;uap-Windows_NT-Debug;uap-Windows_NT-Release;uap10.0.16299-Windows_NT-Debug;uap10.0.16299-Windows_NT-Release</Configurations>
   </PropertyGroup>
   <ItemGroup Condition="'$(TargetGroup)' == 'netstandard' OR '$(TargetsNetCoreApp)' == 'true' OR '$(IsUAPAssembly)' == 'true' ">
@@ -273,10 +274,12 @@
   <!-- Manage the SNI toggle for Windows netstandard and UWP -->
   <ItemGroup Condition="('$(TargetGroup)' == 'netstandard' OR '$(TargetsNetCoreApp)' == 'true') AND '$(TargetsWindows)' == 'true'">
     <!-- Manage the SNI toggle for Windows netstandard and UWP -->
+    <Compile Include="System\Data\SqlClient\SNI\SNITcpHandle.Windows.cs" />
     <Compile Include="System\Data\SqlClient\TdsParserStateObjectFactory.Windows.cs" />
     <AdditionalFiles Include="$(MSBuildProjectDirectory)/*.analyzerdata.windows" />
   </ItemGroup>
   <ItemGroup Condition="'$(IsUAPAssembly)' == 'true'">
+    <Compile Include="System\Data\SqlClient\SNI\SNITcpHandle.Windows.cs" />
     <Compile Include="System\Data\SqlClient\TdsParserStateObjectFactory.Managed.cs" />
     <Compile Include="System\Data\SqlClient\LocalDBAPI.uap.cs" />
     <Compile Include="System\Data\SqlClient\SNI\LocalDB.uap.cs" />
@@ -475,6 +478,7 @@
     <Compile Include="System\Data\SqlClient\TdsParser.Unix.cs" />
     <Compile Include="System\Data\SqlClient\LocalDBAPI.Unix.cs" />
     <Compile Include="System\Data\SqlClient\SNI\LocalDB.Unix.cs" />
+    <Compile Include="System\Data\SqlClient\SNI\SNITcpHandle.Unix.cs" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetsWindows)' == 'true' And '$(IsPartialFacadeAssembly)' != 'true' and '$(IsUAPAssembly)' != 'true'">
     <Reference Include="Microsoft.Win32.Registry" />
diff --git a/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.Unix.cs b/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.Unix.cs
new file mode 100644
index 000000000000..be2a26abcb68
--- /dev/null
+++ b/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.Unix.cs
@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Net.Sockets;
+using System.Text;
+
+namespace System.Data.SqlClient.SNI
+{
+    internal partial class SNITcpHandle
+    {
+        internal static void SetKeepAliveValues(ref Socket socket)
+        {
+#if FEATURE_TCPKEEPALIVE
+            socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.KeepAlive, true);
+            socket.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.TcpKeepAliveInterval, 1);
+            socket.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.TcpKeepAliveTime, 30);
+#endif
+        }
+    }
+}
diff --git a/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.Windows.cs b/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.Windows.cs
new file mode 100644
index 000000000000..15a8a4e98526
--- /dev/null
+++ b/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.Windows.cs
@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Net.Sockets;
+using System.Text;
+
+namespace System.Data.SqlClient.SNI
+{
+    internal partial class SNITcpHandle
+    {
+        internal static void SetKeepAliveValues(ref Socket socket)
+        {
+            //This method will later be setting the KeepAlive, TcpKeepAliveInterval and TcpKeepAliveTime based on Windows platform specific checks. 
+            // Link to issue: https://github.com/dotnet/corefx/issues/33209
+        }
+    }
+}
diff --git a/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.cs b/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.cs
index 5c49c70cb442..3e42ae78ad68 100644
--- a/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.cs
+++ b/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.cs
@@ -223,6 +223,8 @@ void Cancel()
                     if (ipAddresses[i] != null)
                     {
                         sockets[i] = new Socket(ipAddresses[i].AddressFamily, SocketType.Stream, ProtocolType.Tcp);
+                        // enable keep-alive on socket
+                        SNITcpHandle.SetKeepAliveValues(ref sockets[i]);                      
                         sockets[i].Connect(ipAddresses[i], port);
                         if (sockets[i] != null) // sockets[i] can be null if cancel callback is executed during connect()
                         {