Implement ssh keep alive success callback for C# SDK

cs/build/build.props

@@ -41,7 +41,7 @@
     <ReportGeneratorVersion>5.3.9</ReportGeneratorVersion>
     <SystemTextEncodingsWebPackageVersion>4.7.2</SystemTextEncodingsWebPackageVersion>
     <VisualStudioValidationVersion>15.5.31</VisualStudioValidationVersion>
-    <DevTunnelsSshPackageVersion>3.12.8</DevTunnelsSshPackageVersion>
+    <DevTunnelsSshPackageVersion>3.12.11</DevTunnelsSshPackageVersion>
     <XunitRunnerVisualStudioVersion>2.4.0</XunitRunnerVisualStudioVersion>
     <XunitVersion>2.4.0</XunitVersion>
   </PropertyGroup>

cs/src/Connections/ITunnelClient.cs

@@ -202,6 +202,16 @@ Task ConnectAsync(
     /// configured <see cref="TunnelConnectionOptions.KeepAliveIntervalInSeconds"/>. This callback is only invoked
     /// if the keep-alive interval is greater than 0.
     /// </remarks>
-    public event EventHandler<SshKeepAliveFailureEventArgs>? KeepAliveFailed;
+    public event EventHandler<SshKeepAliveEventArgs>? KeepAliveFailed;
+
+    /// <summary>
+    /// Event raised when a keep-alive message response is received.
+    /// </summary>
+    /// <remarks>
+    /// The event args provide the count of keep-alive messages that got a response within the
+    /// configured <see cref="TunnelConnectionOptions.KeepAliveIntervalInSeconds"/>. This callback is only invoked
+    /// if the keep-alive interval is greater than 0.
+    /// </remarks>
+    public event EventHandler<SshKeepAliveEventArgs>? KeepAliveSucceeded;
 }
 

cs/src/Connections/ITunnelHost.cs

@@ -127,7 +127,7 @@ Task ConnectAsync(
     /// ForwardedPortConnecting event will be raised.
     /// </remarks>
     event EventHandler<ForwardedPortConnectingEventArgs>? ForwardedPortConnecting;
-    
+
     /// <summary>
     /// Event raised when a keep-alive message response is not received.
     /// </summary>
@@ -136,5 +136,15 @@ Task ConnectAsync(
     /// configured <see cref="TunnelConnectionOptions.KeepAliveIntervalInSeconds"/>. This callback is only invoked
     /// if the keep-alive interval is greater than 0.
     /// </remarks>
-    public event EventHandler<SshKeepAliveFailureEventArgs>? KeepAliveFailed;
+    public event EventHandler<SshKeepAliveEventArgs>? KeepAliveFailed;
+
+    /// <summary>
+    /// Event raised when a keep-alive message response is received.
+    /// </summary>
+    /// <remarks>
+    /// The event args provide the count of keep-alive messages that got a response within the
+    /// configured <see cref="TunnelConnectionOptions.KeepAliveIntervalInSeconds"/>. This callback is only invoked
+    /// if the keep-alive interval is greater than 0.
+    /// </remarks>
+    public event EventHandler<SshKeepAliveEventArgs>? KeepAliveSucceeded;
 }

cs/src/Connections/SshKeepAliveFailureEventArgs.cs → cs/src/Connections/SshKeepAliveEventArgs.cs

@@ -1,27 +1,27 @@
-// <copyright file="SshKeepAliveFailureEventArgs.cs" company="Microsoft">
-// Copyright (c) Microsoft. All rights reserved.
-// Licensed under the MIT license.
-// </copyright>
-
-using System;
-
-namespace Microsoft.DevTunnels.Connections;
-
-/// <summary>
-/// Event raised when a keep-alive message respose is not received.
-/// </summary>
-public class SshKeepAliveFailureEventArgs : EventArgs
-{
-    /// <summary>
-    /// Create a new instance of <see cref="SshKeepAliveFailureEventArgs"/>.
-    /// </summary>
-	public SshKeepAliveFailureEventArgs(int count)
-	{
-		Count = count;
-	}
-
-	/// <summary>
-	/// The number of keep-alive messages that have been sent without a response.
-	/// </summary>
-	public int Count { get; }
-}
+// <copyright file="SshKeepAliveFailureEventArgs.cs" company="Microsoft">
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license.
+// </copyright>
+
+using System;
+
+namespace Microsoft.DevTunnels.Connections;
+
+/// <summary>
+/// Event raised when a keep-alive message respose is or is not received.
+/// </summary>
+public class SshKeepAliveEventArgs : EventArgs
+{
+    /// <summary>
+    /// Create a new instance of <see cref="SshKeepAliveEventArgs"/>.
+    /// </summary>
+	public SshKeepAliveEventArgs(int count)
+	{
+		Count = count;
+	}
+
+	/// <summary>
+	/// The number of keep-alive messages that have been sent with the same state.
+	/// </summary>
+	public int Count { get; }
+}

cs/src/Connections/TunnelClient.cs

@@ -206,10 +206,14 @@ protected async Task StartSshSessionAsync(Stream stream, TunnelConnectionOptions
 
         session = new SshClientSession(clientConfig, Trace.WithName("SSH"));
         SshSession = session;
-        session.KeepAliveRequestFailed += (_, e) =>
+        session.KeepAliveFailed += (_, e) =>
         {
             OnKeepAliveFailed(e.Count);
         };
+        session.KeepAliveSucceeded += (_, e) =>
+        {
+            OnKeepAliveSucceeded(e.Count);
+        };
         SshPortForwardingService = session.ActivateService<PortForwardingService>();
         ConfigurePortForwardingService();
         SubscribeSessionEvents(session);

cs/src/Connections/TunnelConnection.cs

@@ -265,7 +265,17 @@ protected virtual void ValidateAccessToken()
     /// configured <see cref="TunnelConnectionOptions.KeepAliveIntervalInSeconds"/>. This callback is only invoked
     /// if the keep-alive interval is greater than 0.
     /// </remarks>
-    public event EventHandler<SshKeepAliveFailureEventArgs>? KeepAliveFailed;
+    public event EventHandler<SshKeepAliveEventArgs>? KeepAliveFailed;
+
+    /// <summary>
+    /// Event raised when a keep-alive message response is received.
+    /// </summary>
+    /// <remarks>
+    /// The event args provide the count of keep-alive messages that got a response within the
+    /// configured <see cref="TunnelConnectionOptions.KeepAliveIntervalInSeconds"/>. This callback is only invoked
+    /// if the keep-alive interval is greater than 0.
+    /// </remarks>
+    public event EventHandler<SshKeepAliveEventArgs>? KeepAliveSucceeded;
 
     /// <summary>
     /// Fetch the tunnel from the service if <see cref="ManagementClient"/> and <see cref="Tunnel"/> are not null.
@@ -360,7 +370,15 @@ protected virtual async Task<bool> OnRefreshingTunnelAccessTokenAsync(Cancellati
     /// </summary>
     protected virtual void OnKeepAliveFailed(int count)
     {
-        KeepAliveFailed?.Invoke(this, new SshKeepAliveFailureEventArgs(count));
+        KeepAliveFailed?.Invoke(this, new SshKeepAliveEventArgs(count));
+    }
+
+    /// <summary>
+    /// Event raised when a keep-alive message response is not received.
+    /// </summary>
+    protected virtual void OnKeepAliveSucceeded(int count)
+    {
+        KeepAliveSucceeded?.Invoke(this, new SshKeepAliveEventArgs(count));
     }
 
     /// <inheritdoc />

cs/src/Connections/TunnelRelayTunnelHost.cs

@@ -207,10 +207,14 @@ protected override async Task ConfigureSessionAsync(Stream stream, bool isReconn
             hostPfs.MessageFactory = this;
         }
 
-        session.KeepAliveRequestFailed += (_, e) =>
+        session.KeepAliveFailed += (_, e) =>
         {
             OnKeepAliveFailed(e.Count);
         };
+        session.KeepAliveSucceeded += (_, e) =>
+        {
+            OnKeepAliveSucceeded(e.Count);
+        };
 
         SshSession = session;
         SubscribeSessionEvents(session);