Add low level client.

Build/MQTTnet.nuspec

@@ -21,6 +21,7 @@
 * [Server] Added interceptor for unsubscriptions.
 * [MQTTnet.Server] Added interceptor for unsubscriptions.
 * [MQTTnet.AspNetCore] improved compatibility with AspNetCore 3.1
+* [LowLevelMqttClient] Added low level MQTT client in order to provide more flexibility when using the MQTT protocol. This client requires detailed knowledge about the MQTT protocol.
     </releaseNotes>
     <copyright>Copyright Christian Kratky 2016-2019</copyright>
     <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 

Source/MQTTnet.AspnetCore/Client/MqttClientConnectionContextFactory.cs

@@ -1,17 +1,16 @@
-using System;
+using MQTTnet.Adapter;
-using System.Net;
-using MQTTnet.Adapter;
 using MQTTnet.AspNetCore.Client.Tcp;
-using MQTTnet.Client;
 using MQTTnet.Client.Options;
 using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
+using System;
+using System.Net;
 
 namespace MQTTnet.AspNetCore.Client
 {
     public class MqttClientConnectionContextFactory : IMqttClientAdapterFactory
     {
-        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetChildLogger logger)
+        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetLogger logger)
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
 

Source/MQTTnet.AspnetCore/MqttWebSocketServerAdapter.cs

@@ -1,20 +1,20 @@
-using System;
+using Microsoft.AspNetCore.Http;
-using System.Net.WebSockets;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Http;
 using MQTTnet.Adapter;
 using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
 using MQTTnet.Implementations;
 using MQTTnet.Server;
+using System;
+using System.Net.WebSockets;
+using System.Threading.Tasks;
 
 namespace MQTTnet.AspNetCore
 {
     public class MqttWebSocketServerAdapter : IMqttServerAdapter
     {
-        private readonly IMqttNetChildLogger _logger;
+        private readonly IMqttNetLogger _logger;
 
-        public MqttWebSocketServerAdapter(IMqttNetChildLogger logger)
+        public MqttWebSocketServerAdapter(IMqttNetLogger logger)
         {
             if (logger == null) throw new ArgumentNullException(nameof(logger));
 

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttClient.cs

@@ -1,9 +1,4 @@
-using System;
+using MQTTnet.Client;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Client;
 using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
 using MQTTnet.Client.Publishing;
@@ -13,6 +8,11 @@ using MQTTnet.Exceptions;
 using MQTTnet.Internal;
 using MQTTnet.Protocol;
 using MQTTnet.Server;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Extensions.ManagedClient
 {
@@ -33,7 +33,7 @@ namespace MQTTnet.Extensions.ManagedClient
         private readonly SemaphoreSlim _subscriptionsQueuedSignal = new SemaphoreSlim(0);
 
         private readonly IMqttClient _mqttClient;
-        private readonly IMqttNetChildLogger _logger;
+        private readonly IMqttNetLogger _logger;
 
         private readonly AsyncLock _messageQueueLock = new AsyncLock();
 
@@ -43,7 +43,7 @@ namespace MQTTnet.Extensions.ManagedClient
 
         private ManagedMqttClientStorageManager _storageManager;
 
-        public ManagedMqttClient(IMqttClient mqttClient, IMqttNetChildLogger logger)
+        public ManagedMqttClient(IMqttClient mqttClient, IMqttNetLogger logger)
         {
             _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
 

Source/MQTTnet.Extensions.WebSocket4Net/WebSocket4NetMqttClientAdapterFactory.cs

@@ -1,15 +1,15 @@
-using System;
+using MQTTnet.Adapter;
-using MQTTnet.Adapter;
 using MQTTnet.Client.Options;
 using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
 using MQTTnet.Implementations;
+using System;
 
 namespace MQTTnet.Extensions.WebSocket4Net
 {
     public class WebSocket4NetMqttClientAdapterFactory : IMqttClientAdapterFactory
     {
-        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetChildLogger logger)
+        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetLogger logger)
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
             if (logger == null) throw new ArgumentNullException(nameof(logger));
@@ -17,19 +17,19 @@ namespace MQTTnet.Extensions.WebSocket4Net
             switch (options.ChannelOptions)
             {
                 case MqttClientTcpOptions _:
-                {
+                    {
-                    return new MqttChannelAdapter(new MqttTcpChannel(options), new MqttPacketFormatterAdapter(options.ProtocolVersion), logger);
+                        return new MqttChannelAdapter(new MqttTcpChannel(options), new MqttPacketFormatterAdapter(options.ProtocolVersion), logger);
-                }
+                    }
 
                 case MqttClientWebSocketOptions webSocketOptions:
-                {
+                    {
-                    return new MqttChannelAdapter(new WebSocket4NetMqttChannel(options, webSocketOptions), new MqttPacketFormatterAdapter(options.ProtocolVersion), logger);
+                        return new MqttChannelAdapter(new WebSocket4NetMqttChannel(options, webSocketOptions), new MqttPacketFormatterAdapter(options.ProtocolVersion), logger);
-                }
+                    }
 
                 default:
-                {
+                    {
-                    throw new NotSupportedException();
+                        throw new NotSupportedException();
-                }
+                    }
             }
         }
     }

Source/MQTTnet.Server/Logging/MqttNetChildLoggerWrapper.cs

@@ -1,43 +1,43 @@
-using System;
+//using MQTTnet.Diagnostics;
-using MQTTnet.Diagnostics;
+//using System;
 
-namespace MQTTnet.Server.Logging
+//namespace MQTTnet.Server.Logging
-{
+//{
-    public class MqttNetChildLoggerWrapper : IMqttNetChildLogger
+//    public class MqttNetChildLoggerWrapper : IMqttNetChildLogger
-    {
+//    {
-        private readonly MqttNetLoggerWrapper _logger;
+//        private readonly MqttNetLoggerWrapper _logger;
-        private readonly string _source;
+//        private readonly string _source;
 
-        public MqttNetChildLoggerWrapper(string source, MqttNetLoggerWrapper logger)
+//        public MqttNetChildLoggerWrapper(string source, MqttNetLoggerWrapper logger)
-        {
+//        {
-            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+//            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
 
-            _source = source;
+//            _source = source;
-        }
+//        }
 
-        public IMqttNetChildLogger CreateChildLogger(string source = null)
+//        public IMqttNetLogger CreateChildLogger(string source = null)
-        {
+//        {
-            return _logger.CreateChildLogger(source);
+//            return _logger.CreateChildLogger(source);
-        }
+//        }
 
-        public void Verbose(string message, params object[] parameters)
+//        public void Verbose(string message, params object[] parameters)
-        {
+//        {
-            _logger.Publish(MqttNetLogLevel.Verbose, _source, message, parameters, null);
+//            _logger.Publish(MqttNetLogLevel.Verbose, _source, message, parameters, null);
-        }
+//        }
 
-        public void Info(string message, params object[] parameters)
+//        public void Info(string message, params object[] parameters)
-        {
+//        {
-            _logger.Publish(MqttNetLogLevel.Info, _source, message, parameters, null);
+//            _logger.Publish(MqttNetLogLevel.Info, _source, message, parameters, null);
-        }
+//        }
 
-        public void Warning(Exception exception, string message, params object[] parameters)
+//        public void Warning(Exception exception, string message, params object[] parameters)
-        {
+//        {
-            _logger.Publish(MqttNetLogLevel.Warning, _source, message, parameters, exception);
+//            _logger.Publish(MqttNetLogLevel.Warning, _source, message, parameters, exception);
-        }
+//        }
 
-        public void Error(Exception exception, string message, params object[] parameters)
+//        public void Error(Exception exception, string message, params object[] parameters)
-        {
+//        {
-            _logger.Publish(MqttNetLogLevel.Error, _source, message, parameters, exception);
+//            _logger.Publish(MqttNetLogLevel.Error, _source, message, parameters, exception);
-        }
+//        }
-    }
+//    }
-}
+//}

Source/MQTTnet.Server/Logging/MqttNetLoggerWrapper.cs

@@ -1,7 +1,7 @@
-using System;
+using Microsoft.Extensions.Logging;
-using System.Threading;
-using Microsoft.Extensions.Logging;
 using MQTTnet.Diagnostics;
+using System;
+using System.Threading;
 
 namespace MQTTnet.Server.Logging
 {
@@ -16,9 +16,9 @@ namespace MQTTnet.Server.Logging
 
         public event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
 
-        public IMqttNetChildLogger CreateChildLogger(string source = null)
+        public IMqttNetLogger CreateChildLogger(string source = null)
         {
-            return new MqttNetChildLoggerWrapper(source, this);
+            return new MqttNetLogger(source);
         }
 
         public void Publish(MqttNetLogLevel logLevel, string source, string message, object[] parameters, Exception exception)
@@ -34,7 +34,12 @@ namespace MQTTnet.Server.Logging
             }
         }
 
-        private static LogLevel ConvertLogLevel(MqttNetLogLevel logLevel)
+        public void Publish(MqttNetLogLevel logLevel, string message, object[] parameters, Exception exception)
+        {
+            Publish(logLevel, null, message, parameters, exception);
+        }
+
+        static LogLevel ConvertLogLevel(MqttNetLogLevel logLevel)
         {
             switch (logLevel)
             {

Source/MQTTnet/Adapter/IMqttClientAdapterFactory.cs

@@ -5,6 +5,6 @@ namespace MQTTnet.Adapter
 {
     public interface IMqttClientAdapterFactory
     {
-        IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetChildLogger logger);
+        IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetLogger logger);
     }
 }

Source/MQTTnet/Adapter/MqttChannelAdapter.cs

@@ -1,3 +1,9 @@
+using MQTTnet.Channel;
+using MQTTnet.Diagnostics;
+using MQTTnet.Exceptions;
+using MQTTnet.Formatter;
+using MQTTnet.Internal;
+using MQTTnet.Packets;
 using System;
 using System.IO;
 using System.Net.Sockets;
@@ -5,32 +11,26 @@ using System.Runtime.InteropServices;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Channel;
-using MQTTnet.Diagnostics;
-using MQTTnet.Exceptions;
-using MQTTnet.Formatter;
-using MQTTnet.Internal;
-using MQTTnet.Packets;
 
 namespace MQTTnet.Adapter
 {
-    public class MqttChannelAdapter : Disposable, IMqttChannelAdapter
+    public sealed class MqttChannelAdapter : Disposable, IMqttChannelAdapter
     {
-        private const uint ErrorOperationAborted = 0x800703E3;
+        const uint ErrorOperationAborted = 0x800703E3;
-        private const int ReadBufferSize = 4096;  // TODO: Move buffer size to config
+        const int ReadBufferSize = 4096;  // TODO: Move buffer size to config
 
-        private readonly SemaphoreSlim _writerSemaphore = new SemaphoreSlim(1, 1);
+        readonly SemaphoreSlim _writerSemaphore = new SemaphoreSlim(1, 1);
 
-        private readonly IMqttNetChildLogger _logger;
+        readonly IMqttNetLogger _logger;
-        private readonly IMqttChannel _channel;
+        readonly IMqttChannel _channel;
-        private readonly MqttPacketReader _packetReader;
+        readonly MqttPacketReader _packetReader;
 
-        private readonly byte[] _fixedHeaderBuffer = new byte[2];
+        readonly byte[] _fixedHeaderBuffer = new byte[2];
 
-        private long _bytesReceived;
+        long _bytesReceived;
-        private long _bytesSent;
+        long _bytesSent;
 
-        public MqttChannelAdapter(IMqttChannel channel, MqttPacketFormatterAdapter packetFormatterAdapter, IMqttNetChildLogger logger)
+        public MqttChannelAdapter(IMqttChannel channel, MqttPacketFormatterAdapter packetFormatterAdapter, IMqttNetLogger logger)
         {
             if (logger == null) throw new ArgumentNullException(nameof(logger));
 
@@ -207,7 +207,18 @@ namespace MQTTnet.Adapter
             Interlocked.Exchange(ref _bytesSent, 0L);
         }
 
-        private async Task<ReceivedMqttPacket> ReceiveAsync(CancellationToken cancellationToken)
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                _channel?.Dispose();
+                _writerSemaphore?.Dispose();
+            }
+
+            base.Dispose(disposing);
+        }
+
+        async Task<ReceivedMqttPacket> ReceiveAsync(CancellationToken cancellationToken)
         {
             var readFixedHeaderResult = await _packetReader.ReadFixedHeaderAsync(_fixedHeaderBuffer, cancellationToken).ConfigureAwait(false);
 
@@ -267,25 +278,14 @@ namespace MQTTnet.Adapter
             }
         }
 
-        protected override void Dispose(bool disposing)
+        static bool IsWrappedException(Exception exception)
-        {
-            if (disposing)
-            {
-                _channel?.Dispose();
-                _writerSemaphore?.Dispose();
-            }
-            
-            base.Dispose(disposing);
-        }
-
-        private static bool IsWrappedException(Exception exception)
         {
             return exception is OperationCanceledException ||
                    exception is MqttCommunicationTimedOutException ||
                    exception is MqttCommunicationException;
         }
 
-        private static void WrapException(Exception exception)
+        static void WrapException(Exception exception)
         {
             if (exception is IOException && exception.InnerException is SocketException innerException)
             {

Source/MQTTnet/Client/MqttClient.cs

@@ -1,7 +1,3 @@
-using System;
-using System.Diagnostics;
-using System.Threading;
-using System.Threading.Tasks;
 using MQTTnet.Adapter;
 using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
@@ -17,6 +13,10 @@ using MQTTnet.Internal;
 using MQTTnet.PacketDispatcher;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
+using System;
+using System.Diagnostics;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Client
 {
@@ -29,7 +29,7 @@ namespace MQTTnet.Client
         private readonly object _disconnectLock = new object();
 
         private readonly IMqttClientAdapterFactory _adapterFactory;
-        private readonly IMqttNetChildLogger _logger;
+        private readonly IMqttNetLogger _logger;
 
         private CancellationTokenSource _backgroundCancellationTokenSource;
         private Task _packetReceiverTask;

Source/MQTTnet/Client/Options/MqttClientOptionsBuilder.cs

@@ -1,19 +1,19 @@
-using System;
+using MQTTnet.Client.ExtendedAuthenticationExchange;
+using MQTTnet.Formatter;
+using System;
 using System.Linq;
 using System.Text;
-using MQTTnet.Client.ExtendedAuthenticationExchange;
-using MQTTnet.Formatter;
 
 namespace MQTTnet.Client.Options
 {
     public class MqttClientOptionsBuilder
     {
-        private readonly MqttClientOptions _options = new MqttClientOptions();
+        readonly MqttClientOptions _options = new MqttClientOptions();
 
-        private MqttClientTcpOptions _tcpOptions;
+        MqttClientTcpOptions _tcpOptions;
-        private MqttClientWebSocketOptions _webSocketOptions;
+        MqttClientWebSocketOptions _webSocketOptions;
-        private MqttClientOptionsBuilderTlsParameters _tlsParameters;
+        MqttClientOptionsBuilderTlsParameters _tlsParameters;
-        private MqttClientWebSocketProxyOptions _proxyOptions;
+        MqttClientWebSocketProxyOptions _proxyOptions;
 
         public MqttClientOptionsBuilder WithProtocolVersion(MqttProtocolVersion value)
         {

Source/MQTTnet/Diagnostics/IMqttNetChildLogger.cs

@@ -1,17 +0,0 @@
-using System;
-
-namespace MQTTnet.Diagnostics
-{
-    public interface IMqttNetChildLogger
-    {
-        IMqttNetChildLogger CreateChildLogger(string source = null);
-
-        void Verbose(string message, params object[] parameters);
-
-        void Info(string message, params object[] parameters);
-
-        void Warning(Exception exception, string message, params object[] parameters);
-
-        void Error(Exception exception, string message, params object[] parameters);
-    }
-}

Source/MQTTnet/Diagnostics/IMqttNetLogger.cs

@@ -6,8 +6,8 @@ namespace MQTTnet.Diagnostics
     {
         event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
 
-        IMqttNetChildLogger CreateChildLogger(string source = null);
+        IMqttNetLogger CreateChildLogger(string source = null);
 
-        void Publish(MqttNetLogLevel logLevel, string source, string message, object[] parameters, Exception exception);
+        void Publish(MqttNetLogLevel logLevel, string message, object[] parameters, Exception exception);
     }
 }

Source/MQTTnet/Diagnostics/MqttNetChildLogger.cs

@@ -1,51 +0,0 @@
-using System;
-
-namespace MQTTnet.Diagnostics
-{
-    public class MqttNetChildLogger : IMqttNetChildLogger
-    {
-        private readonly IMqttNetLogger _logger;
-        private readonly string _source;
-
-        public MqttNetChildLogger(IMqttNetLogger logger, string source)
-        {
-            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
-            _source = source;
-        }
-
-        public IMqttNetChildLogger CreateChildLogger(string source)
-        {
-            string childSource;
-            if (!string.IsNullOrEmpty(_source))
-            {
-                childSource = _source + "." + source;
-            }
-            else
-            {
-                childSource = source;
-            }
-
-            return new MqttNetChildLogger(_logger, childSource);
-        }
-
-        public void Verbose(string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Verbose, _source, message, parameters, null);
-        }
-
-        public void Info(string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Info, _source, message, parameters, null);
-        }
-
-        public void Warning(Exception exception, string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Warning, _source, message, parameters, exception);
-        }
-
-        public void Error(Exception exception, string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Error, _source, message, parameters, exception);
-        }
-    }
-}

Source/MQTTnet/Diagnostics/MqttNetLogMessagePublishedEventArgs.cs

@@ -7,8 +7,12 @@ namespace MQTTnet.Diagnostics
         public MqttNetLogMessagePublishedEventArgs(MqttNetLogMessage logMessage)
         {
             TraceMessage = logMessage ?? throw new ArgumentNullException(nameof(logMessage));
+            LogMessage = logMessage ?? throw new ArgumentNullException(nameof(logMessage));
         }
 
+        [Obsolete("Use new proeprty LogMessage instead.")]
         public MqttNetLogMessage TraceMessage { get; }
+
+        public MqttNetLogMessage LogMessage { get; }
     }
 }

Source/MQTTnet/Diagnostics/MqttNetLogger.cs

@@ -4,21 +4,27 @@ namespace MQTTnet.Diagnostics
 {
     public class MqttNetLogger : IMqttNetLogger
     {
-        private readonly string _logId;
+        readonly string _logId;
+        readonly string _source;
 
-        public MqttNetLogger(string logId = null)
+        public MqttNetLogger(string source, string logId = null)
         {
+            _source = source;
             _logId = logId;
         }
 
+        public MqttNetLogger()
+        {
+        }
+
         public event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
 
-        public IMqttNetChildLogger CreateChildLogger(string source = null)
+        public IMqttNetLogger CreateChildLogger(string source = null)
         {
-            return new MqttNetChildLogger(this, source);
+            return new MqttNetLogger(source, _logId);
         }
 
-        public void Publish(MqttNetLogLevel logLevel, string source, string message, object[] parameters, Exception exception)
+        public void Publish(MqttNetLogLevel logLevel, string message, object[] parameters, Exception exception)
         {
             var hasLocalListeners = LogMessagePublished != null;
             var hasGlobalListeners = MqttNetGlobalLogger.HasListeners;
@@ -40,7 +46,7 @@ namespace MQTTnet.Diagnostics
                 }
             }
 
-            var traceMessage = new MqttNetLogMessage(_logId, DateTime.UtcNow, Environment.CurrentManagedThreadId, source, logLevel, message, exception);
+            var traceMessage = new MqttNetLogMessage(_logId, DateTime.UtcNow, Environment.CurrentManagedThreadId, _source, logLevel, message, exception);
 
             if (hasGlobalListeners)
             {

Source/MQTTnet/Diagnostics/MqttNetLoggerExtensions.cs

@@ -0,0 +1,35 @@
+using System;
+
+namespace MQTTnet.Diagnostics
+{
+    public static class MqttNetLoggerExtensions
+    {
+        public static void Verbose(this IMqttNetLogger logger, string message, params object[] parameters)
+        {
+            if (logger is null) throw new ArgumentNullException(nameof(logger));
+
+            logger.Publish(MqttNetLogLevel.Verbose, message, parameters, null);
+        }
+
+        public static void Info(this IMqttNetLogger logger, string message, params object[] parameters)
+        {
+            if (logger is null) throw new ArgumentNullException(nameof(logger));
+
+            logger.Publish(MqttNetLogLevel.Info, message, parameters, null);
+        }
+
+        public static void Warning(this IMqttNetLogger logger, Exception exception, string message, params object[] parameters)
+        {
+            if (logger is null) throw new ArgumentNullException(nameof(logger));
+
+            logger.Publish(MqttNetLogLevel.Warning, message, parameters, exception);
+        }
+
+        public static void Error(this IMqttNetLogger logger, Exception exception, string message, params object[] parameters)
+        {
+            if (logger is null) throw new ArgumentNullException(nameof(logger));
+
+            logger.Publish(MqttNetLogLevel.Error, message, parameters, exception);
+        }
+    }
+}

Source/MQTTnet/Diagnostics/TargetFrameworkProvider.cs

@@ -1,6 +1,6 @@
 namespace MQTTnet.Diagnostics
 {
-    public static class TargetFrameworkInfoProvider
+    public static class TargetFrameworkProvider
     {
         public static string TargetFramework
         {

Source/MQTTnet/Implementations/MqttClientAdapterFactory.cs

@@ -1,14 +1,14 @@
-using System;
+using MQTTnet.Adapter;
-using MQTTnet.Adapter;
 using MQTTnet.Client.Options;
 using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
+using System;
 
 namespace MQTTnet.Implementations
 {
     public class MqttClientAdapterFactory : IMqttClientAdapterFactory
     {
-        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetChildLogger logger)
+        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetLogger logger)
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
 

Source/MQTTnet/Implementations/MqttTcpServerAdapter.Uwp.cs

@@ -11,14 +11,14 @@ using System.Threading.Tasks;
 
 namespace MQTTnet.Implementations
 {
-    public class MqttTcpServerAdapter : IMqttServerAdapter
+    public sealed class MqttTcpServerAdapter : IMqttServerAdapter
     {
-        private readonly IMqttNetChildLogger _logger;
+        readonly IMqttNetLogger _logger;
 
-        private IMqttServerOptions _options;
+        IMqttServerOptions _options;
-        private StreamSocketListener _listener;
+        StreamSocketListener _listener;
 
-        public MqttTcpServerAdapter(IMqttNetChildLogger logger)
+        public MqttTcpServerAdapter(IMqttNetLogger logger)
         {
             if (logger == null) throw new ArgumentNullException(nameof(logger));
 
@@ -68,7 +68,7 @@ namespace MQTTnet.Implementations
             _listener = null;
         }
 
-        private async void OnConnectionReceivedAsync(StreamSocketListener sender, StreamSocketListenerConnectionReceivedEventArgs args)
+        async void OnConnectionReceivedAsync(StreamSocketListener sender, StreamSocketListenerConnectionReceivedEventArgs args)
         {
             try
             {

Source/MQTTnet/Implementations/MqttTcpServerAdapter.cs

@@ -1,4 +1,8 @@
 #if !WINDOWS_UWP
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
+using MQTTnet.Internal;
+using MQTTnet.Server;
 using System;
 using System.Collections.Generic;
 using System.Net;
@@ -6,21 +10,17 @@ using System.Net.Sockets;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Adapter;
-using MQTTnet.Diagnostics;
-using MQTTnet.Internal;
-using MQTTnet.Server;
 
 namespace MQTTnet.Implementations
 {
-    public class MqttTcpServerAdapter : Disposable, IMqttServerAdapter
+    public sealed class MqttTcpServerAdapter : Disposable, IMqttServerAdapter
     {
-        private readonly List<MqttTcpServerListener> _listeners = new List<MqttTcpServerListener>();
+        readonly List<MqttTcpServerListener> _listeners = new List<MqttTcpServerListener>();
-        private readonly IMqttNetChildLogger _logger;
+        readonly IMqttNetLogger _logger;
 
-        private CancellationTokenSource _cancellationTokenSource;
+        CancellationTokenSource _cancellationTokenSource;
 
-        public MqttTcpServerAdapter(IMqttNetChildLogger logger)
+        public MqttTcpServerAdapter(IMqttNetLogger logger)
         {
             if (logger == null) throw new ArgumentNullException(nameof(logger));
 
@@ -77,7 +77,17 @@ namespace MQTTnet.Implementations
             return Task.FromResult(0);
         }
 
-        private void Cleanup()
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                Cleanup();
+            }
+
+            base.Dispose(disposing);
+        }
+
+        void Cleanup()
         {
             _cancellationTokenSource?.Cancel(false);
             _cancellationTokenSource?.Dispose();
@@ -91,16 +101,7 @@ namespace MQTTnet.Implementations
             _listeners.Clear();
         }
 
-        protected override void Dispose(bool disposing)
+        void RegisterListeners(MqttServerTcpEndpointBaseOptions options, X509Certificate2 tlsCertificate, CancellationToken cancellationToken)
-        {
-            if (disposing)
-            {
-                Cleanup();
-            }
-            base.Dispose(disposing);
-        }
-
-        private void RegisterListeners(MqttServerTcpEndpointBaseOptions options, X509Certificate2 tlsCertificate, CancellationToken cancellationToken)
         {
             if (!options.BoundInterNetworkAddress.Equals(IPAddress.None))
             {

Source/MQTTnet/Implementations/MqttTcpServerListener.cs

@@ -1,4 +1,9 @@
 #if !WINDOWS_UWP
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
+using MQTTnet.Formatter;
+using MQTTnet.Internal;
+using MQTTnet.Server;
 using System;
 using System.IO;
 using System.Net;
@@ -7,21 +12,16 @@ using System.Net.Sockets;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Adapter;
-using MQTTnet.Diagnostics;
-using MQTTnet.Formatter;
-using MQTTnet.Internal;
-using MQTTnet.Server;
 
 namespace MQTTnet.Implementations
 {
-    public class MqttTcpServerListener : IDisposable
+    public sealed class MqttTcpServerListener : IDisposable
     {
-        private readonly IMqttNetChildLogger _logger;
+        readonly IMqttNetLogger _logger;
-        private readonly AddressFamily _addressFamily;
+        readonly AddressFamily _addressFamily;
-        private readonly MqttServerTcpEndpointBaseOptions _options;
+        readonly MqttServerTcpEndpointBaseOptions _options;
-        private readonly MqttServerTlsTcpEndpointOptions _tlsOptions;
+        readonly MqttServerTlsTcpEndpointOptions _tlsOptions;
-        private readonly X509Certificate2 _tlsCertificate;
+        readonly X509Certificate2 _tlsCertificate;
 
         private Socket _socket;
         private IPEndPoint _localEndPoint;
@@ -30,7 +30,7 @@ namespace MQTTnet.Implementations
             AddressFamily addressFamily,
             MqttServerTcpEndpointBaseOptions options,
             X509Certificate2 tlsCertificate,
-            IMqttNetChildLogger logger)
+            IMqttNetLogger logger)
         {
             _addressFamily = addressFamily;
             _options = options;
@@ -87,7 +87,7 @@ namespace MQTTnet.Implementations
                     throw;
                 }
 
-                _logger.Warning(exception,"Error while creating listener socket for local end point '{0}'.", _localEndPoint);
+                _logger.Warning(exception, "Error while creating listener socket for local end point '{0}'.", _localEndPoint);
                 return false;
             }
         }
@@ -101,7 +101,7 @@ namespace MQTTnet.Implementations
 #endif
         }
 
-        private async Task AcceptClientConnectionsAsync(CancellationToken cancellationToken)
+        async Task AcceptClientConnectionsAsync(CancellationToken cancellationToken)
         {
             while (!cancellationToken.IsCancellationRequested)
             {
@@ -135,7 +135,7 @@ namespace MQTTnet.Implementations
             }
         }
 
-        private async Task TryHandleClientConnectionAsync(Socket clientSocket)
+        async Task TryHandleClientConnectionAsync(Socket clientSocket)
         {
             Stream stream = null;
             string remoteEndPoint = null;

Source/MQTTnet/Internal/TaskExtensions.cs

@@ -1,11 +1,11 @@
-using System.Threading.Tasks;
+using MQTTnet.Diagnostics;
-using MQTTnet.Diagnostics;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Internal
 {
     public static class TaskExtensions
     {
-        public static void Forget(this Task task, IMqttNetChildLogger logger)
+        public static void Forget(this Task task, IMqttNetLogger logger)
         {
             task?.ContinueWith(t =>
                 {

Source/MQTTnet/LowLevelClient/ILowLevelMqttClient.cs

@@ -0,0 +1,19 @@
+using MQTTnet.Client.Options;
+using MQTTnet.Packets;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MQTTnet.LowLevelClient
+{
+    public interface ILowLevelMqttClient : IDisposable
+    {
+        Task ConnectAsync(IMqttClientOptions options, CancellationToken cancellationToken);
+
+        Task DisconnectAsync(CancellationToken cancellationToken);
+
+        Task SendAsync(MqttBasePacket packet, CancellationToken cancellationToken);
+
+        Task<MqttBasePacket> ReceiveAsync(CancellationToken cancellationToken);
+    }
+}

Source/MQTTnet/LowLevelClient/LowLevelMqttClient.cs

@@ -0,0 +1,128 @@
+using MQTTnet.Adapter;
+using MQTTnet.Client.Options;
+using MQTTnet.Diagnostics;
+using MQTTnet.Packets;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MQTTnet.LowLevelClient
+{
+    public sealed class LowLevelMqttClient : ILowLevelMqttClient
+    {
+        readonly IMqttNetLogger _logger;
+        readonly IMqttClientAdapterFactory _clientAdapterFactory;
+
+        IMqttChannelAdapter _adapter;
+        IMqttClientOptions _options;
+
+        public LowLevelMqttClient(IMqttClientAdapterFactory clientAdapterFactory, IMqttNetLogger logger)
+        {
+            if (clientAdapterFactory is null) throw new ArgumentNullException(nameof(clientAdapterFactory));
+            if (logger is null) throw new ArgumentNullException(nameof(logger));
+
+            _clientAdapterFactory = clientAdapterFactory;
+            _logger = logger.CreateChildLogger(nameof(LowLevelMqttClient));
+        }
+
+        bool IsConnected => _adapter != null;
+
+        public async Task ConnectAsync(IMqttClientOptions options, CancellationToken cancellationToken)
+        {
+            if (options is null) throw new ArgumentNullException(nameof(options));
+
+            if (_adapter != null)
+            {
+                throw new InvalidOperationException("Low level MQTT client is already connected. Disconnect first before connecting again.");
+            }
+
+            var newAdapter = _clientAdapterFactory.CreateClientAdapter(options, _logger);
+
+            try
+            {
+                _logger.Verbose($"Trying to connect with server '{options.ChannelOptions}' (Timeout={options.CommunicationTimeout}).");
+                await newAdapter.ConnectAsync(options.CommunicationTimeout, cancellationToken).ConfigureAwait(false);
+                _logger.Verbose("Connection with server established.");
+
+                _options = options;
+            }
+            catch (Exception)
+            {
+                _adapter.Dispose();
+                throw;
+            }
+
+            _adapter = newAdapter;
+        }
+
+        public async Task DisconnectAsync(CancellationToken cancellationToken)
+        {
+            if (_adapter == null)
+            {
+                return;
+            }
+
+            await SafeDisconnect(cancellationToken).ConfigureAwait(false);
+            _adapter = null;
+        }
+
+        public async Task SendAsync(MqttBasePacket packet, CancellationToken cancellationToken)
+        {
+            if (packet is null) throw new ArgumentNullException(nameof(packet));
+
+            if (_adapter == null)
+            {
+                throw new InvalidOperationException("Low level MQTT client is not connected.");
+            }
+
+            try
+            {
+                await _adapter.SendPacketAsync(packet, _options.CommunicationTimeout, cancellationToken).ConfigureAwait(false);
+            }
+            catch (Exception)
+            {
+                await SafeDisconnect(cancellationToken).ConfigureAwait(false);
+                throw;
+            }
+        }
+
+        public async Task<MqttBasePacket> ReceiveAsync(CancellationToken cancellationToken)
+        {
+            if (_adapter == null)
+            {
+                throw new InvalidOperationException("Low level MQTT client is not connected.");
+            }
+
+            try
+            {
+                return await _adapter.ReceivePacketAsync(_options.CommunicationTimeout, cancellationToken).ConfigureAwait(false);
+            }
+            catch (Exception)
+            {
+                await SafeDisconnect(cancellationToken).ConfigureAwait(false);
+                throw;
+            }
+        }
+
+        public void Dispose()
+        {
+            _adapter?.Dispose();
+        }
+
+        async Task SafeDisconnect(CancellationToken cancellationToken)
+        {
+            try
+            {
+                await _adapter.DisconnectAsync(_options.CommunicationTimeout, cancellationToken).ConfigureAwait(false);
+            }
+            catch (Exception exception)
+            {
+                _logger.Error(exception, "Error while disconnecting.");
+            }
+            finally
+            {
+                _adapter.Dispose();
+            }
+        }
+    }
+}

Source/MQTTnet/MqttFactory.cs

@@ -1,18 +1,19 @@
-using System;
+using MQTTnet.Adapter;
-using System.Collections.Generic;
-using MQTTnet.Adapter;
 using MQTTnet.Client;
 using MQTTnet.Diagnostics;
 using MQTTnet.Implementations;
+using MQTTnet.LowLevelClient;
 using MQTTnet.Server;
+using System;
+using System.Collections.Generic;
 
 namespace MQTTnet
 {
-    public class MqttFactory : IMqttFactory
+    public sealed class MqttFactory : IMqttFactory
     {
-        private IMqttClientAdapterFactory _clientAdapterFactory = new MqttClientAdapterFactory();
+        IMqttClientAdapterFactory _clientAdapterFactory = new MqttClientAdapterFactory();
 
-        public MqttFactory() : this(new MqttNetLogger())
+        public MqttFactory() : this(new MqttNetLogger(null, null))
         {
         }
 
@@ -29,6 +30,33 @@ namespace MQTTnet
             return this;
         }
 
+        public ILowLevelMqttClient CreateLowLevelMqttClient()
+        {
+            return CreateLowLevelMqttClient(DefaultLogger);
+        }
+
+        public ILowLevelMqttClient CreateLowLevelMqttClient(IMqttNetLogger logger)
+        {
+            if (logger == null) throw new ArgumentNullException(nameof(logger));
+
+            return new LowLevelMqttClient(_clientAdapterFactory, logger);
+        }
+
+        public ILowLevelMqttClient CreateLowLevelMqttClient(IMqttClientAdapterFactory clientAdapterFactory)
+        {
+            if (clientAdapterFactory == null) throw new ArgumentNullException(nameof(clientAdapterFactory));
+
+            return new LowLevelMqttClient(_clientAdapterFactory, DefaultLogger);
+        }
+
+        public ILowLevelMqttClient CreateLowLevelMqttClient(IMqttNetLogger logger, IMqttClientAdapterFactory clientAdapterFactoryy)
+        {
+            if (logger == null) throw new ArgumentNullException(nameof(logger));
+            if (clientAdapterFactoryy == null) throw new ArgumentNullException(nameof(clientAdapterFactoryy));
+
+            return new LowLevelMqttClient(_clientAdapterFactory, logger);
+        }
+
         public IMqttClient CreateMqttClient()
         {
             return CreateMqttClient(DefaultLogger);

Source/MQTTnet/Server/IMqttRetainedMessagesManager.cs

@@ -1,12 +1,12 @@
-using System.Collections.Generic;
+using MQTTnet.Diagnostics;
+using System.Collections.Generic;
 using System.Threading.Tasks;
-using MQTTnet.Diagnostics;
 
 namespace MQTTnet.Server
 {
     public interface IMqttRetainedMessagesManager
     {
-        Task Start(IMqttServerOptions options, IMqttNetChildLogger logger);
+        Task Start(IMqttServerOptions options, IMqttNetLogger logger);
 
         Task LoadMessagesAsync();
 

Source/MQTTnet/Server/MqttClientConnection.cs

@@ -1,8 +1,4 @@
-using System;
+using MQTTnet.Adapter;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Adapter;
 using MQTTnet.Client;
 using MQTTnet.Diagnostics;
 using MQTTnet.Exceptions;
@@ -12,6 +8,10 @@ using MQTTnet.PacketDispatcher;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using MQTTnet.Server.Status;
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Server
 {
@@ -25,7 +25,7 @@ namespace MQTTnet.Server
         private readonly MqttClientKeepAliveMonitor _keepAliveMonitor;
         private readonly MqttClientSessionsManager _sessionsManager;
 
-        private readonly IMqttNetChildLogger _logger;
+        private readonly IMqttNetLogger _logger;
         private readonly IMqttServerOptions _serverOptions;
 
         private readonly IMqttChannelAdapter _channelAdapter;
@@ -49,7 +49,7 @@ namespace MQTTnet.Server
             IMqttServerOptions serverOptions,
             MqttClientSessionsManager sessionsManager,
             IMqttRetainedMessagesManager retainedMessagesManager,
-            IMqttNetChildLogger logger)
+            IMqttNetLogger logger)
         {
             Session = session ?? throw new ArgumentNullException(nameof(session));
             _serverOptions = serverOptions ?? throw new ArgumentNullException(nameof(serverOptions));

Source/MQTTnet/Server/MqttClientKeepAliveMonitor.cs

@@ -1,9 +1,9 @@
-using System;
+using MQTTnet.Diagnostics;
+using MQTTnet.Internal;
+using System;
 using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Diagnostics;
-using MQTTnet.Internal;
 
 namespace MQTTnet.Server
 {
@@ -13,11 +13,11 @@ namespace MQTTnet.Server
 
         private readonly string _clientId;
         private readonly Func<Task> _keepAliveElapsedCallback;
-        private readonly IMqttNetChildLogger _logger;
+        private readonly IMqttNetLogger _logger;
 
         private bool _isPaused;
 
-        public MqttClientKeepAliveMonitor(string clientId, Func<Task> keepAliveElapsedCallback, IMqttNetChildLogger logger)
+        public MqttClientKeepAliveMonitor(string clientId, Func<Task> keepAliveElapsedCallback, IMqttNetLogger logger)
         {
             _clientId = clientId ?? throw new ArgumentNullException(nameof(clientId));
             _keepAliveElapsedCallback = keepAliveElapsedCallback ?? throw new ArgumentNullException(nameof(keepAliveElapsedCallback));

Source/MQTTnet/Server/MqttClientSession.cs

@@ -1,18 +1,18 @@
-using System;
+using MQTTnet.Diagnostics;
+using MQTTnet.Server.Status;
+using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
-using MQTTnet.Diagnostics;
-using MQTTnet.Server.Status;
 
 namespace MQTTnet.Server
 {
     public class MqttClientSession
     {
-        private readonly IMqttNetChildLogger _logger;
+        private readonly IMqttNetLogger _logger;
 
         private readonly DateTime _createdTimestamp = DateTime.UtcNow;
 
-        public MqttClientSession(string clientId, IDictionary<object, object> items, MqttServerEventDispatcher eventDispatcher, IMqttServerOptions serverOptions, IMqttNetChildLogger logger)
+        public MqttClientSession(string clientId, IDictionary<object, object> items, MqttServerEventDispatcher eventDispatcher, IMqttServerOptions serverOptions, IMqttNetLogger logger)
         {
             ClientId = clientId ?? throw new ArgumentNullException(nameof(clientId));
             Items = items ?? throw new ArgumentNullException(nameof(items));

Source/MQTTnet/Server/MqttClientSessionsManager.cs

@@ -1,15 +1,15 @@
-using System;
+using MQTTnet.Adapter;
-using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Adapter;
 using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using MQTTnet.Server.Status;
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Server
 {
@@ -27,14 +27,14 @@ namespace MQTTnet.Server
 
         private readonly IMqttRetainedMessagesManager _retainedMessagesManager;
         private readonly IMqttServerOptions _options;
-        private readonly IMqttNetChildLogger _logger;
+        private readonly IMqttNetLogger _logger;
 
         public MqttClientSessionsManager(
             IMqttServerOptions options,
             IMqttRetainedMessagesManager retainedMessagesManager,
             CancellationToken cancellationToken,
             MqttServerEventDispatcher eventDispatcher,
-            IMqttNetChildLogger logger)
+            IMqttNetLogger logger)
         {
             _cancellationToken = cancellationToken;
 

Source/MQTTnet/Server/MqttRetainedMessagesManager.cs

@@ -1,10 +1,10 @@
-using System;
+using MQTTnet.Diagnostics;
+using MQTTnet.Implementations;
+using MQTTnet.Internal;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
-using MQTTnet.Diagnostics;
-using MQTTnet.Implementations;
-using MQTTnet.Internal;
 
 namespace MQTTnet.Server
 {
@@ -14,10 +14,10 @@ namespace MQTTnet.Server
         private readonly AsyncLock _messagesLock = new AsyncLock();
         private readonly Dictionary<string, MqttApplicationMessage> _messages = new Dictionary<string, MqttApplicationMessage>();
 
-        private IMqttNetChildLogger _logger;
+        private IMqttNetLogger _logger;
         private IMqttServerOptions _options;
 
-        public Task Start(IMqttServerOptions options, IMqttNetChildLogger logger)
+        public Task Start(IMqttServerOptions options, IMqttNetLogger logger)
         {
             if (logger == null) throw new ArgumentNullException(nameof(logger));
             _logger = logger.CreateChildLogger(nameof(MqttRetainedMessagesManager));

Source/MQTTnet/Server/MqttServer.cs

@@ -17,13 +17,13 @@ namespace MQTTnet.Server
     {
         private readonly MqttServerEventDispatcher _eventDispatcher;
         private readonly ICollection<IMqttServerAdapter> _adapters;
-        private readonly IMqttNetChildLogger _logger;
+        private readonly IMqttNetLogger _logger;
 
         private MqttClientSessionsManager _clientSessionsManager;
         private IMqttRetainedMessagesManager _retainedMessagesManager;
         private CancellationTokenSource _cancellationTokenSource;
 
-        public MqttServer(IEnumerable<IMqttServerAdapter> adapters, IMqttNetChildLogger logger)
+        public MqttServer(IEnumerable<IMqttServerAdapter> adapters, IMqttNetLogger logger)
         {
             if (adapters == null) throw new ArgumentNullException(nameof(adapters));
             _adapters = adapters.ToList();

Source/MQTTnet/Server/MqttServerEventDispatcher.cs

@@ -1,15 +1,15 @@
-using System;
+using MQTTnet.Client.Receiving;
-using System.Threading.Tasks;
-using MQTTnet.Client.Receiving;
 using MQTTnet.Diagnostics;
+using System;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Server
 {
     public class MqttServerEventDispatcher
     {
-        private readonly IMqttNetChildLogger _logger;
+        private readonly IMqttNetLogger _logger;
 
-        public MqttServerEventDispatcher(IMqttNetChildLogger logger)
+        public MqttServerEventDispatcher(IMqttNetLogger logger)
         {
             _logger = logger ?? throw new ArgumentNullException(nameof(logger));
         }

Source/MQTTnet/TopicFilter.cs

@@ -2,6 +2,7 @@
 
 namespace MQTTnet
 {
+    // TODO: Consider renaming to "MqttTopicFilter"
     public class TopicFilter
     {
         public string Topic { get; set; }

Tests/MQTTnet.Benchmarks/LoggerBenchmark.cs

@@ -10,7 +10,7 @@ namespace MQTTnet.Benchmarks
     public class LoggerBenchmark
     {
         private IMqttNetLogger _logger;
-        private IMqttNetChildLogger _childLogger;
+        private IMqttNetLogger _childLogger;
         private bool _useHandler;
 
         [GlobalSetup]

Tests/MQTTnet.Benchmarks/Program.cs

@@ -9,7 +9,7 @@ namespace MQTTnet.Benchmarks
     {
         public static void Main(string[] args)
         {
-            Console.WriteLine($"MQTTnet - BenchmarkApp.{TargetFrameworkInfoProvider.TargetFramework}");
+            Console.WriteLine($"MQTTnet - BenchmarkApp.{TargetFrameworkProvider.TargetFramework}");
             Console.WriteLine("1 = MessageProcessingBenchmark");
             Console.WriteLine("2 = SerializerBenchmark");
             Console.WriteLine("3 = LoggerBenchmark");

Tests/MQTTnet.Core.Tests/LowLevelMqttClient_Tests.cs

@@ -0,0 +1,111 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.Client.Options;
+using MQTTnet.LowLevelClient;
+using MQTTnet.Packets;
+using MQTTnet.Protocol;
+using MQTTnet.Tests.Mockups;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Tests
+{
+    [TestClass]
+    public class LowLevelMqttClient_Tests
+    {
+        public TestContext TestContext { get; set; }
+
+        [TestMethod]
+        public async Task Connect_And_Disconnect()
+        {
+            using (var testEnvironment = new TestEnvironment(TestContext))
+            {
+                var server = await testEnvironment.StartServerAsync();
+
+                var factory = new MqttFactory();
+                var lowLevelClient = factory.CreateLowLevelMqttClient();
+
+                await lowLevelClient.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", testEnvironment.ServerPort).Build(), CancellationToken.None);
+
+                await lowLevelClient.DisconnectAsync(CancellationToken.None);
+            }
+        }
+
+        [TestMethod]
+        public async Task Authenticate()
+        {
+            using (var testEnvironment = new TestEnvironment(TestContext))
+            {
+                var server = await testEnvironment.StartServerAsync();
+
+                var factory = new MqttFactory();
+                var lowLevelClient = factory.CreateLowLevelMqttClient();
+
+                await lowLevelClient.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", testEnvironment.ServerPort).Build(), CancellationToken.None);
+
+                var receivedPacket = await Authenticate(lowLevelClient).ConfigureAwait(false);
+
+                await lowLevelClient.DisconnectAsync(CancellationToken.None).ConfigureAwait(false);
+
+                Assert.IsNotNull(receivedPacket);
+                Assert.AreEqual(MqttConnectReturnCode.ConnectionAccepted, receivedPacket.ReturnCode);
+            }
+        }
+
+        [TestMethod]
+        public async Task Subscribe()
+        {
+            using (var testEnvironment = new TestEnvironment(TestContext))
+            {
+                var server = await testEnvironment.StartServerAsync();
+
+                var factory = new MqttFactory();
+                var lowLevelClient = factory.CreateLowLevelMqttClient();
+
+                await lowLevelClient.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", testEnvironment.ServerPort).Build(), CancellationToken.None);
+
+                await Authenticate(lowLevelClient).ConfigureAwait(false);
+
+                var receivedPacket = await Subscribe(lowLevelClient, "a").ConfigureAwait(false);
+
+                await lowLevelClient.DisconnectAsync(CancellationToken.None).ConfigureAwait(false);
+
+                Assert.IsNotNull(receivedPacket);
+                Assert.AreEqual(MqttSubscribeReturnCode.SuccessMaximumQoS0, receivedPacket.ReturnCodes[0]);
+            }
+        }
+
+        async Task<MqttConnAckPacket> Authenticate(ILowLevelMqttClient client)
+        {
+            await client.SendAsync(new MqttConnectPacket()
+            {
+                CleanSession = true,
+                ClientId = TestContext.TestName,
+                Username = "user",
+                Password = Encoding.UTF8.GetBytes("pass")
+            },
+            CancellationToken.None).ConfigureAwait(false);
+
+            return await client.ReceiveAsync(CancellationToken.None).ConfigureAwait(false) as MqttConnAckPacket;
+        }
+
+        async Task<MqttSubAckPacket> Subscribe(ILowLevelMqttClient client, string topic)
+        {
+            await client.SendAsync(new MqttSubscribePacket
+            {
+                PacketIdentifier = 1,
+                TopicFilters = new List<TopicFilter>
+                {
+                    new TopicFilter
+                    {
+                        Topic = topic
+                    }
+                }
+            },
+            CancellationToken.None).ConfigureAwait(false);
+
+            return await client.ReceiveAsync(CancellationToken.None).ConfigureAwait(false) as MqttSubAckPacket;
+        }
+    }
+}

Tests/MQTTnet.Core.Tests/Mockups/TestClientWrapper.cs

@@ -1,6 +1,4 @@
-using System.Threading;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Client;
 using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
@@ -10,10 +8,12 @@ using MQTTnet.Client.Publishing;
 using MQTTnet.Client.Receiving;
 using MQTTnet.Client.Subscribing;
 using MQTTnet.Client.Unsubscribing;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Tests.Mockups
 {
-    public class TestClientWrapper : IMqttClient
+    public sealed class TestClientWrapper : IMqttClient
     {
         public TestClientWrapper(IMqttClient implementation, TestContext testContext)
         {
@@ -22,6 +22,7 @@ namespace MQTTnet.Tests.Mockups
         }
 
         public IMqttClient Implementation { get; }
+
         public TestContext TestContext { get; }
 
         public bool IsConnected => Implementation.IsConnected;
@@ -34,28 +35,32 @@ namespace MQTTnet.Tests.Mockups
 
         public Task<MqttClientAuthenticateResult> ConnectAsync(IMqttClientOptions options, CancellationToken cancellationToken)
         {
-            switch (options)
+            if (TestContext != null)
             {
-                case MqttClientOptionsBuilder builder:
+                switch (options)
-                    {
+                {
-                        var existingClientId = builder.Build().ClientId;
+                    case MqttClientOptionsBuilder builder:
-                        if (existingClientId != null && !existingClientId.StartsWith(TestContext.TestName))
                         {
-                            builder.WithClientId(TestContext.TestName + existingClientId);
+                            var existingClientId = builder.Build().ClientId;
+                            if (existingClientId != null && !existingClientId.StartsWith(TestContext.TestName))
+                            {
+                                builder.WithClientId(TestContext.TestName + existingClientId);
+                            }
+
+                            break;
                         }
-                    }
+
-                    break;
+                    case MqttClientOptions op:
-                case MqttClientOptions op:
-                    {
-                        var existingClientId = op.ClientId;
-                        if (existingClientId != null && !existingClientId.StartsWith(TestContext.TestName))
                         {
-                            op.ClientId = TestContext.TestName + existingClientId;
+                            var existingClientId = op.ClientId;
+                            if (existingClientId != null && !existingClientId.StartsWith(TestContext.TestName))
+                            {
+                                op.ClientId = TestContext.TestName + existingClientId;
+                            }
+
+                            break;
                         }
-                    }
+                }
-                    break;
-                default:
-                    break;
             }
 
             return Implementation.ConnectAsync(options, cancellationToken);
@@ -81,7 +86,7 @@ namespace MQTTnet.Tests.Mockups
             return Implementation.SendExtendedAuthenticationExchangeDataAsync(data, cancellationToken);
         }
 
-        public Task<Client.Subscribing.MqttClientSubscribeResult> SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken)
+        public Task<MqttClientSubscribeResult> SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken)
         {
             return Implementation.SubscribeAsync(options, cancellationToken);
         }

Tests/MQTTnet.Core.Tests/Mockups/TestEnvironment.cs

@@ -1,27 +1,27 @@
-using System;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Client;
 using MQTTnet.Client.Options;
 using MQTTnet.Diagnostics;
 using MQTTnet.Internal;
 using MQTTnet.Server;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Tests.Mockups
 {
-    public class TestEnvironment : Disposable
+    public sealed class TestEnvironment : Disposable
     {
-        private readonly MqttFactory _mqttFactory = new MqttFactory();
+        readonly MqttFactory _mqttFactory = new MqttFactory();
-        private readonly List<IMqttClient> _clients = new List<IMqttClient>();
+        readonly List<IMqttClient> _clients = new List<IMqttClient>();
-        private readonly IMqttNetLogger _serverLogger = new MqttNetLogger("server");
+        readonly IMqttNetLogger _serverLogger = new MqttNetLogger("server");
-        private readonly IMqttNetLogger _clientLogger = new MqttNetLogger("client");
+        readonly IMqttNetLogger _clientLogger = new MqttNetLogger("client");
 
-        private readonly List<string> _serverErrors = new List<string>();
+        readonly List<string> _serverErrors = new List<string>();
-        private readonly List<string> _clientErrors = new List<string>();
+        readonly List<string> _clientErrors = new List<string>();
 
-        private readonly List<Exception> _exceptions = new List<Exception>();
+        readonly List<Exception> _exceptions = new List<Exception>();
 
         public IMqttServer Server { get; private set; }
 
@@ -37,36 +37,42 @@ namespace MQTTnet.Tests.Mockups
 
         public TestContext TestContext { get; }
 
+        public TestEnvironment() : this(null)
+        {
+        }
+
         public TestEnvironment(TestContext testContext)
         {
+            TestContext = testContext;
+
             _serverLogger.LogMessagePublished += (s, e) =>
             {
-                if (e.TraceMessage.Level == MqttNetLogLevel.Error)
+                if (e.LogMessage.Level == MqttNetLogLevel.Error)
                 {
                     lock (_serverErrors)
                     {
-                        _serverErrors.Add(e.TraceMessage.ToString());
+                        _serverErrors.Add(e.LogMessage.ToString());
                     }
                 }
             };
 
             _clientLogger.LogMessagePublished += (s, e) =>
             {
-                lock (_clientErrors)
+                if (e.LogMessage.Level == MqttNetLogLevel.Error)
                 {
-                    if (e.TraceMessage.Level == MqttNetLogLevel.Error)
+                    lock (_clientErrors)
                     {
-                        _clientErrors.Add(e.TraceMessage.ToString());
+                        _clientErrors.Add(e.LogMessage.ToString());
                     }
                 }
             };
-            TestContext = testContext;
         }
 
         public IMqttClient CreateClient()
         {
             var client = _mqttFactory.CreateMqttClient(_clientLogger);
             _clients.Add(client);
+
             return new TestClientWrapper(client, TestContext);
         }
 
@@ -90,15 +96,17 @@ namespace MQTTnet.Tests.Mockups
 
         public Task<IMqttClient> ConnectClientAsync()
         {
-            return ConnectClientAsync(new MqttClientOptionsBuilder() );
+            return ConnectClientAsync(new MqttClientOptionsBuilder());
         }
 
         public async Task<IMqttClient> ConnectClientAsync(MqttClientOptionsBuilder options)
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
 
+            options = options.WithTcpServer("localhost", ServerPort);
+
             var client = CreateClient();
-            await client.ConnectAsync(options.WithTcpServer("localhost", ServerPort).Build());
+            await client.ConnectAsync(options.Build());
 
             return client;
         }
@@ -150,6 +158,7 @@ namespace MQTTnet.Tests.Mockups
                     throw new Exception($"{_exceptions.Count} exceptions tracked.\r\n" + string.Join(Environment.NewLine, _exceptions));
                 }
             }
+
             base.Dispose(disposing);
         }
 

Tests/MQTTnet.Core.Tests/Mockups/TestLogger.cs

@@ -1,20 +1,15 @@
-using System;
+using MQTTnet.Diagnostics;
-using MQTTnet.Diagnostics;
+using System;
 
 namespace MQTTnet.Tests.Mockups
 {
-    public class TestLogger : IMqttNetLogger, IMqttNetChildLogger
+    public class TestLogger : IMqttNetLogger
     {
         public event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
 
-        IMqttNetChildLogger IMqttNetLogger.CreateChildLogger(string source)
+        public IMqttNetLogger CreateChildLogger(string source = null)
         {
-            return new MqttNetChildLogger(this, source);
+            return new TestLogger();
-        }
-
-        IMqttNetChildLogger IMqttNetChildLogger.CreateChildLogger(string source)
-        {
-            return new MqttNetChildLogger(this, source);
         }
 
         public void Verbose(string message, params object[] parameters)
@@ -36,5 +31,10 @@ namespace MQTTnet.Tests.Mockups
         public void Publish(MqttNetLogLevel logLevel, string source, string message, object[] parameters, Exception exception)
         {
         }
+
+        public void Publish(MqttNetLogLevel logLevel, string message, object[] parameters, Exception exception)
+        {
+            throw new NotImplementedException();
+        }
     }
 }

Tests/MQTTnet.Core.Tests/Mockups/TestMqttCommunicationAdapterFactory.cs

@@ -13,7 +13,7 @@ namespace MQTTnet.Tests.Mockups
             _adapter = adapter;
         }
 
-        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetChildLogger logger)
+        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetLogger logger)
         {
             return _adapter;
         }

Tests/MQTTnet.Core.Tests/Mockups/TestServerWrapper.cs

@@ -1,16 +1,16 @@
-using System;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Client.Publishing;
 using MQTTnet.Client.Receiving;
 using MQTTnet.Server;
 using MQTTnet.Server.Status;
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Tests.Mockups
 {
-    public class TestServerWrapper : IMqttServer
+    public sealed class TestServerWrapper : IMqttServer
     {
         public TestServerWrapper(IMqttServer implementation, TestContext testContext, TestEnvironment testEnvironment)
         {
@@ -60,22 +60,29 @@ namespace MQTTnet.Tests.Mockups
 
         public Task StartAsync(IMqttServerOptions options)
         {
-            switch (options)
+            if (TestContext != null)
             {
-                case MqttServerOptionsBuilder builder:
+                switch (options)
-                    if (builder.Build().ConnectionValidator == null)
+                {
-                    {
+                    case MqttServerOptionsBuilder builder:
-                        builder.WithConnectionValidator(ConnectionValidator);
+                        {
-                    }
+                            if (builder.Build().ConnectionValidator == null)
-                    break;
+                            {
-                case MqttServerOptions op:
+                                builder.WithConnectionValidator(ConnectionValidator);
-                    if (op.ConnectionValidator == null)
+                            }
-                    {
+
-                        op.ConnectionValidator = new MqttServerConnectionValidatorDelegate(ConnectionValidator);
+                            break;
-                    }
+                        }
-                    break;
+                    case MqttServerOptions op:
-                default:
+                        {
-                    break;
+                            if (op.ConnectionValidator == null)
+                            {
+                                op.ConnectionValidator = new MqttServerConnectionValidatorDelegate(ConnectionValidator);
+                            }
+
+                            break;
+                        }
+                }
             }
 
             return Implementation.StartAsync(options);

Tests/MQTTnet.Core.Tests/MqttFactory_Tests.cs

@@ -17,22 +17,23 @@ namespace MQTTnet.Tests
 
             //This test compares
             //1. correct logID
-            string logId = "logId";
+            var logId = "logId";
             string invalidLogId = null;
 
             //2. if the total log calls are the same for global and local
-            int globalLogCount = 0;
+            var globalLogCount = 0;
-            int localLogCount = 0;
+            var localLogCount = 0;
 
-            MqttNetLogger logger = new MqttNetLogger(logId);
+            var logger = new MqttNetLogger(logId);
 
             //we have a theoretical bug here if a concurrent test is also logging
             var globalLog = new EventHandler<MqttNetLogMessagePublishedEventArgs>((s, e) =>
             {
-                if (logId != e.TraceMessage.LogId)
+                if (logId != e.LogMessage.LogId)
                 {
-                    invalidLogId = e.TraceMessage.LogId;
+                    invalidLogId = e.LogMessage.LogId;
                 }
+
                 Interlocked.Increment(ref globalLogCount);
             });
 
@@ -40,10 +41,11 @@ namespace MQTTnet.Tests
 
             logger.LogMessagePublished += (s, e) =>
             {
-                if (logId != e.TraceMessage.LogId)
+                if (logId != e.LogMessage.LogId)
                 {
-                    invalidLogId = e.TraceMessage.LogId;
+                    invalidLogId = e.LogMessage.LogId;
                 }
+
                 Interlocked.Increment(ref localLogCount);
             };
 

Tests/MQTTnet.Core.Tests/Server_Tests.cs

@@ -1,11 +1,4 @@
-using System;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System.Collections.Generic;
-using System.Linq;
-using System.Net.Sockets;
-using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Adapter;
 using MQTTnet.Client;
 using MQTTnet.Client.Connecting;
@@ -17,6 +10,13 @@ using MQTTnet.Implementations;
 using MQTTnet.Protocol;
 using MQTTnet.Server;
 using MQTTnet.Tests.Mockups;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Sockets;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Tests
 {
@@ -1016,7 +1016,7 @@ namespace MQTTnet.Tests
         [TestMethod]
         public async Task Same_Client_Id_Connect_Disconnect_Event_Order()
         {
-            using (var testEnvironment = new TestEnvironment(TestContext))
+            using (var testEnvironment = new TestEnvironment())
             {
                 var server = await testEnvironment.StartServerAsync(new MqttServerOptionsBuilder());
 
@@ -1038,11 +1038,11 @@ namespace MQTTnet.Tests
                     }
                 });
 
-                var clientOptions = new MqttClientOptionsBuilder()
+                var clientOptionsBuilder = new MqttClientOptionsBuilder()
-                    .WithClientId("same_id");
+                    .WithClientId(Guid.NewGuid().ToString());
 
                 // c
-                var c1 = await testEnvironment.ConnectClientAsync(clientOptions);
+                var c1 = await testEnvironment.ConnectClientAsync(clientOptionsBuilder);
 
                 await Task.Delay(500);
 
@@ -1050,7 +1050,7 @@ namespace MQTTnet.Tests
                 Assert.AreEqual("c", flow);
 
                 // dc
-                var c2 = await testEnvironment.ConnectClientAsync(clientOptions);
+                var c2 = await testEnvironment.ConnectClientAsync(clientOptionsBuilder);
 
                 c2.UseApplicationMessageReceivedHandler(_ =>
                 {
@@ -1058,8 +1058,8 @@ namespace MQTTnet.Tests
                     {
                         events.Add("r");
                     }
-
                 });
+
                 c2.SubscribeAsync("topic").Wait();
 
                 await Task.Delay(500);
@@ -1080,7 +1080,7 @@ namespace MQTTnet.Tests
 
                 Assert.AreEqual(false, c1.IsConnected);
                 await c1.DisconnectAsync();
-                Assert.AreEqual (false, c1.IsConnected);
+                Assert.AreEqual(false, c1.IsConnected);
 
                 await Task.Delay(500);
 

Tests/MQTTnet.TestApp.NetCore/Program.cs

@@ -17,7 +17,7 @@ namespace MQTTnet.TestApp.NetCore
     {
         public static void Main()
         {
-            Console.WriteLine($"MQTTnet - TestApp.{TargetFrameworkInfoProvider.TargetFramework}");
+            Console.WriteLine($"MQTTnet - TestApp.{TargetFrameworkProvider.TargetFramework}");
             Console.WriteLine("1 = Start client");
             Console.WriteLine("2 = Start server");
             Console.WriteLine("3 = Start performance test");