Improvements bases on feedback. Fixed tests. Added documentation.

Author: desdesdes

docfx/logging.md

@@ -1,7 +1,43 @@
 Logging
 =================
 
-SSH.NET uses the [Microsoft.Extensions.Logging](https://learn.microsoft.com/dotnet/core/extensions/logging) API to log diagnostic messages. In order to access the log messages of SSH.NET in your own application for diagnosis, register your own `ILoggerFactory` before using the SSH.NET APIs, for example:
+SSH.NET uses the [Microsoft.Extensions.Logging](https://learn.microsoft.com/dotnet/core/extensions/logging) API to log diagnostic messages. 
+
+It is possible to specify a logger in the `ConnectionInfo`, for example:
+
+```cs
+using Microsoft.Extensions.Logging;
+
+ILoggerFactory loggerFactory = LoggerFactory.Create(builder =>
+{
+    builder.SetMinimumLevel(LogLevel.Debug);
+    builder.AddConsole();
+});
+
+Renci.SshNet.SshNetLoggingConfiguration.InitializeLogging(loggerFactory);
+```
+
+```cs
+using Microsoft.Extensions.Logging;
+
+ILoggerFactory loggerFactory = LoggerFactory.Create(builder =>
+{
+    builder.SetMinimumLevel(LogLevel.Debug);
+    builder.AddConsole();
+});
+
+var connectionInfo = new ConnectionInfo("sftp.foo.com",
+                                        "guest",
+                                        new PasswordAuthenticationMethod("guest", "pwd"));
+										
+connectionInfo.LoggerFactory = loggerFactory;
+using (var client = new SftpClient(connectionInfo))
+{
+    client.Connect();
+}
+```
+
+You can also register an application-wide `ILoggerFactory` before using the SSH.NET APIs, this will be used as a fallback if the `ConnectionInfo` is not set, for example:
 
 ```cs
 using Microsoft.Extensions.Logging;

src/Renci.SshNet/BaseClient.cs

@@ -20,6 +20,8 @@ public abstract class BaseClient : IBaseClient
         /// Holds value indicating whether the connection info is owned by this client.
         /// </summary>
         private readonly bool _ownsConnectionInfo;
+
+        private readonly ILogger _logger;
         private readonly IServiceFactory _serviceFactory;
         private readonly object _keepAliveLock = new object();
         private TimeSpan _keepAliveInterval;
@@ -35,14 +37,6 @@ public abstract class BaseClient : IBaseClient
         /// </value>
         internal ISession? Session { get; private set; }
 
-        internal ILogger? Logger
-        {
-            get
-            {
-                return Session?.SessionLoggerFactory?.CreateLogger(GetType());
-            }
-        }
-
         /// <summary>
         /// Gets the factory for creating new services.
         /// </summary>
@@ -198,6 +192,7 @@ private protected BaseClient(ConnectionInfo connectionInfo, bool ownsConnectionI
             _connectionInfo = connectionInfo;
             _ownsConnectionInfo = ownsConnectionInfo;
             _serviceFactory = serviceFactory;
+            _logger = (connectionInfo.LoggerFactory ?? SshNetLoggingConfiguration.LoggerFactory).CreateLogger(GetType());
             _keepAliveInterval = Timeout.InfiniteTimeSpan;
         }
 
@@ -351,7 +346,7 @@ public async Task ConnectAsync(CancellationToken cancellationToken)
         /// <exception cref="ObjectDisposedException">The method was called after the client was disposed.</exception>
         public void Disconnect()
         {
-            Logger?.LogInformation("Disconnecting client.");
+            _logger.LogInformation("Disconnecting client.");
 
             CheckDisposed();
 
@@ -450,7 +445,7 @@ protected virtual void Dispose(bool disposing)
 
             if (disposing)
             {
-                Logger?.LogDebug("Disposing client.");
+                _logger.LogDebug("Disposing client.");
 
                 Disconnect();
 
@@ -513,7 +508,7 @@ private void SendKeepAliveMessage()
                 }
                 catch (Exception ex)
                 {
-                    Logger?.LogError(ex, "Error sending keepalive message");
+                    _logger.LogError(ex, "Error sending keepalive message");
                 }
                 finally
                 {

src/Renci.SshNet/ForwardedPortDynamic.cs

@@ -21,7 +21,6 @@ namespace Renci.SshNet
     /// </summary>
     public class ForwardedPortDynamic : ForwardedPort
     {
-        private readonly ILogger _logger;
         private ForwardedPortStatus _status;
 
         /// <summary>
@@ -75,7 +74,6 @@ public ForwardedPortDynamic(string host, uint port)
             BoundHost = host;
             BoundPort = port;
             _status = ForwardedPortStatus.Stopped;
-            _logger = Session.SessionLoggerFactory.CreateLogger<ForwardedPortDynamic>();
         }
 
         /// <summary>
@@ -416,7 +414,12 @@ private void InternalStop(TimeSpan timeout)
 
             if (!_pendingChannelCountdown.Wait(timeout))
             {
-                _logger.LogInformation("Timeout waiting for pending channels in dynamic forwarded port to close.");
+                var session = Session;
+                if (session != null)
+                {
+                    var logger = session.SessionLoggerFactory.CreateLogger<ForwardedPortDynamic>();
+                    logger.LogInformation("Timeout waiting for pending channels in dynamic forwarded port to close.");
+                }
             }
         }
 

src/Renci.SshNet/ForwardedPortLocal.cs

@@ -14,7 +14,6 @@ namespace Renci.SshNet
     /// </summary>
     public partial class ForwardedPortLocal : ForwardedPort
     {
-        private readonly ILogger _logger;
         private ForwardedPortStatus _status;
         private bool _isDisposed;
         private Socket _listener;
@@ -103,7 +102,6 @@ public ForwardedPortLocal(string boundHost, uint boundPort, string host, uint po
             Host = host;
             Port = port;
             _status = ForwardedPortStatus.Stopped;
-            _logger = Session.SessionLoggerFactory.CreateLogger<ForwardedPortLocal>();
         }
 
         /// <summary>
@@ -390,7 +388,12 @@ private void InternalStop(TimeSpan timeout)
 
             if (!_pendingChannelCountdown.Wait(timeout))
             {
-                _logger.LogInformation("Timeout waiting for pending channels in local forwarded port to close.");
+                var session = Session;
+                if (session != null)
+                {
+                    var logger = session.SessionLoggerFactory.CreateLogger<ForwardedPortLocal>();
+                    logger.LogInformation("Timeout waiting for pending channels in local forwarded port to close.");
+                }
             }
         }
 

src/Renci.SshNet/ForwardedPortRemote.cs

@@ -16,7 +16,6 @@ namespace Renci.SshNet
     /// </summary>
     public class ForwardedPortRemote : ForwardedPort
     {
-        private readonly ILogger _logger;
         private ForwardedPortStatus _status;
         private bool _requestStatus;
         private EventWaitHandle _globalRequestResponse = new AutoResetEvent(initialState: false);
@@ -100,7 +99,6 @@ public ForwardedPortRemote(IPAddress boundHostAddress, uint boundPort, IPAddress
             HostAddress = hostAddress;
             Port = port;
             _status = ForwardedPortStatus.Stopped;
-            _logger = Session.SessionLoggerFactory.CreateLogger<ForwardedPortRemote>();
         }
 
         /// <summary>
@@ -212,7 +210,12 @@ protected override void StopPort(TimeSpan timeout)
 
             if (!_pendingChannelCountdown.Wait(timeout))
             {
-                _logger.LogInformation("Timeout waiting for pending channels in remote forwarded port to close.");
+                var session = Session;
+                if (session != null)
+                {
+                    var logger = session.SessionLoggerFactory.CreateLogger<ForwardedPortRemote>();
+                    logger.LogInformation("Timeout waiting for pending channels in remote forwarded port to close.");
+                }
             }
 
             _status = ForwardedPortStatus.Stopped;

src/Renci.SshNet/ISession.cs

@@ -28,7 +28,7 @@ internal interface ISession : IDisposable
         /// Gets the logger factory for this session.
         /// </summary>
         /// <value>
-        /// The logger factory for this session.
+        /// The logger factory for this session. Will never return <see langword="null"/>.
         /// </value>
         public ILoggerFactory SessionLoggerFactory { get; }
 

src/Renci.SshNet/ISubsystemSession.cs

@@ -16,7 +16,7 @@ internal interface ISubsystemSession : IDisposable
         /// Gets the logger factory for this subsystem session.
         /// </summary>
         /// <value>
-        /// The logger factory for this connection.
+        /// The logger factory for this connection. Will never return <see langword="null"/>.
         /// </value>
         public ILoggerFactory SessionLoggerFactory { get; }
 

src/Renci.SshNet/Security/KeyExchange.cs

@@ -18,7 +18,7 @@ namespace Renci.SshNet.Security
     /// </summary>
     public abstract class KeyExchange : Algorithm, IKeyExchange
     {
-        private readonly ILogger _logger;
+        private ILogger _logger;
         private Func<byte[], KeyHostAlgorithm> _hostKeyAlgorithmFactory;
         private CipherInfo _clientCipherInfo;
         private CipherInfo _serverCipherInfo;
@@ -69,13 +69,13 @@ public byte[] ExchangeHash
         /// </summary>
         protected KeyExchange()
         {
-            _logger = Session.SessionLoggerFactory.CreateLogger(GetType());
         }
 
         /// <inheritdoc/>
         public virtual void Start(Session session, KeyExchangeInitMessage message, bool sendClientInitMessage)
         {
             Session = session;
+            _logger = Session.SessionLoggerFactory.CreateLogger(GetType());
 
             if (sendClientInitMessage)
             {

test/Renci.SshNet.Tests/Classes/BaseClientTestBase.cs

@@ -1,4 +1,6 @@
-using Moq;
+using Microsoft.Extensions.Logging.Abstractions;
+
+using Moq;
 
 using Renci.SshNet.Connection;
 using Renci.SshNet.Tests.Common;
@@ -16,6 +18,7 @@ protected virtual void CreateMocks()
             ServiceFactoryMock = new Mock<IServiceFactory>(MockBehavior.Strict);
             SocketFactoryMock = new Mock<ISocketFactory>(MockBehavior.Strict);
             SessionMock = new Mock<ISession>(MockBehavior.Strict);
+            SessionMock.Setup(p => p.SessionLoggerFactory).Returns(NullLoggerFactory.Instance);
         }
 
         protected virtual void SetupData()

test/Renci.SshNet.Tests/Classes/BaseClientTest_ConnectAsync_Timeout.cs

@@ -2,6 +2,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 
+using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
 using Moq;
@@ -23,6 +24,7 @@ public class BaseClientTest_ConnectAsync_Timeout
         public void Init()
         {
             var sessionMock = new Mock<ISession>();
+            sessionMock.Setup(p => p.SessionLoggerFactory).Returns(NullLoggerFactory.Instance);
             var serviceFactoryMock = new Mock<IServiceFactory>();
             var socketFactoryMock = new Mock<ISocketFactory>();