Refactor code.

Introduce asynchronous message processing

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,46 @@
+---
+name: Bug report
+about: Create a report to help us improve.
+title: ''
+labels: 'bug'
+assignees: ''
+
+---
+
+### Describe the bug
+A clear and concise description of what the bug is.
+
+### Which project is your bug related to?
+<!-- Remove the items which don't apply from the following list -->
+- Client
+- ManagedClient
+- MQTTnet.Server standalone
+- Server
+- Generic
+
+### To Reproduce
+Steps to reproduce the behavior:
+1. Using this version of MQTTnet '...'.
+2. Run this code '....'.
+3. With these arguments '....'.
+4. See error.
+
+### Expected behavior
+A clear and concise description of what you expected to happen.
+
+### Screenshots
+If applicable, add screenshots to help explain your problem.
+
+### Additional context / logging
+Add any other context about the problem here.
+Include debugging or logging information here:
+
+```batch
+\\ Put your logging output here.
+```
+### Code example
+ Please provide full code examples below where possible to make it easier for the developers to check your issues.
+ 
+```csharp
+\\ Put your code here.
+```

.github/ISSUE_TEMPLATE/custom.md

@@ -0,0 +1,19 @@
+---
+name: Custom issue template
+about: Do you have a question related to the project? Use this template.
+title: ''
+labels: 'question'
+assignees: ''
+
+---
+
+### Describe your question
+A clear and concise description of what you want to know.
+
+### Which project is your question related to?
+<!-- Remove the items which don't apply from the following list -->
+- Client
+- ManagedClient
+- MQTTnet.Server standalone
+- Server
+- Generic

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,29 @@
+---
+name: Feature request
+about: Suggest an idea for this project.
+title: ''
+labels: 'feature-request'
+assignees: ''
+
+---
+
+### Describe the feature request
+Is your feature request related to a problem? Please describe.
+A clear and concise description of what the problem is. Example. I'm am trying to do [...] but [...]
+
+### Which project is your feature request related to?
+<!-- Remove the items which don't apply from the following list -->
+- Client
+- ManagedClient
+- MQTTnet.Server standalone
+- Server
+- Generic
+
+### Describe the solution you'd like
+A clear and concise description of what you want to happen.
+
+### Describe alternatives you've considered
+A clear and concise description of any alternative solutions or features you've considered.
+
+### Additional context
+Add any other context or screenshots about the feature request here.

.gitignore

@@ -292,3 +292,5 @@ __pycache__/
 *.map
 
 /Tests/MQTTnet.TestApp.NetCore/RetainedMessages.json
+
+Build/NuGet/

Build/MQTTnet.AspNetCore.nuspec

@@ -8,18 +8,19 @@
     <license type="file">LICENSE</license>
     <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
     <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
+    <icon>images\Logo_128x128.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>This is a support library to integrate MQTTnet into AspNetCore.</description>
     <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
+    <copyright>Copyright Christian Kratky 2016-2020</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>
     <dependencies>
       <dependency id="MQTTnet" version="$nugetVersion" />
 
-      <dependency id="Microsoft.AspNetCore.Connections.Abstractions" version="2.1.3" />
+      <dependency id="Microsoft.AspNetCore.Connections.Abstractions" version="3.1.3" />
-      <dependency id="Microsoft.AspNetCore.Http.Connections" version="1.0.3"  />
+      <dependency id="Microsoft.AspNetCore.Http.Connections" version="1.1.0"  />
-      <dependency id="Microsoft.AspNetCore.WebSockets" version="2.1.1" />
+      <dependency id="Microsoft.AspNetCore.WebSockets" version="2.2.1" />
-      <dependency id="Microsoft.Extensions.Hosting.Abstractions" version="2.1.1" />
+      <dependency id="Microsoft.Extensions.Hosting.Abstractions" version="3.1.3" />
     </dependencies>
   </metadata>
 
@@ -27,6 +28,9 @@
     <!-- License -->
     <file src="..\LICENSE" />
 
+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
     <!-- .NET Standard 2.0 -->
     <file src="..\Source\MQTTnet.AspNetCore\bin\Release\netstandard2.0\MQTTnet.AspNetCore.*" target="lib\netstandard2.0\"/>
   </files>

Build/MQTTnet.Extensions.ManagedClient.nuspec

@@ -8,10 +8,11 @@
     <license type="file">LICENSE</license>
     <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
     <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
+    <icon>images\Logo_128x128.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>This is an extension library which provides a managed MQTT client with additional features using MQTTnet.</description>
     <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
+    <copyright>Copyright Christian Kratky 2016-2020</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> 
     <dependencies>
       <dependency id="MQTTnet" version="$nugetVersion" />
@@ -22,6 +23,9 @@
     <!-- License -->
     <file src="..\LICENSE" />
 
+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
     <!-- .NET Standard 1.3 -->
     <file src="..\Source\MQTTnet.Extensions.ManagedClient\bin\Release\netstandard1.3\MQTTnet.Extensions.ManagedClient.*" target="lib\netstandard1.3\"/>
 

Build/MQTTnet.Extensions.Rpc.nuspec

@@ -8,10 +8,11 @@
     <license type="file">LICENSE</license>
     <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
     <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
+    <icon>images\Logo_128x128.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>This is an extension library which allows executing synchronous device calls including a response using MQTTnet.</description>
     <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
+    <copyright>Copyright Christian Kratky 2016-2020</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> 
     <dependencies>
       <dependency id="MQTTnet" version="$nugetVersion" />
@@ -22,6 +23,9 @@
     <!-- License -->
     <file src="..\LICENSE" />
 
+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
     <!-- .NET Standard 1.3 -->
     <file src="..\Source\MQTTnet.Extensions.Rpc\bin\Release\netstandard1.3\MQTTnet.Extensions.Rpc.*" target="lib\netstandard1.3\"/>
 

Build/MQTTnet.Extensions.WebSocket4Net.nuspec

@@ -8,10 +8,11 @@
     <license type="file">LICENSE</license>
     <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
     <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
+    <icon>images\Logo_128x128.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>This is an extension library which allows using _WebSocket4Net_ as transport for MQTTnet clients.</description>
     <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
+    <copyright>Copyright Christian Kratky 2016-2020</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> 
     <dependencies>
       <dependency id="MQTTnet" version="$nugetVersion" />
@@ -22,6 +23,9 @@
     <!-- License -->
     <file src="..\LICENSE" />
 
+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
     <!-- .NET Standard 1.3 -->
     <file src="..\Source\MQTTnet.Extensions.WebSocket4Net\bin\Release\netstandard1.3\MQTTnet.Extensions.WebSocket4Net.*" target="lib\netstandard1.3\"/>
 

Build/MQTTnet.NETStandard.nuspec

@@ -8,10 +8,11 @@
     <license type="file">LICENSE</license>
     <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
     <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
+    <icon>images\Logo_128x128.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>This package contains the .NET Standard version of MQTTnet only.</description>
     <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
+    <copyright>Copyright Christian Kratky 2016-2020</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> 
     <dependencies>
       <group targetFramework="netstandard1.3">
@@ -33,6 +34,9 @@
     <!-- License -->
     <file src="..\LICENSE" />
 
+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
     <!-- .NET Standard 1.3 -->
     <file src="..\Source\MQTTnet\bin\Release\netstandard1.3\MQTTnet.*" target="lib\netstandard1.3\"/>
 

Build/MQTTnet.nuspec

@@ -8,27 +8,32 @@
     <license type="file">LICENSE</license>
     <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
     <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
+    <icon>images\Logo_128x128.png</icon>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker) and supports v3.1.0, v3.1.1 and v5.0.0 of the MQTT protocol.</description>
     <releaseNotes>
-* [Core] Fixed issues in MQTTv5 message encoding and decoding.
+* [All] Due to a merge issue not all changes are included in 3.0.8. All these changes are now included in this version.
-* [Core] Added extension method to allow usage of _WebSocket4Net_ in clients to fix issues with AWS and Xamarin.
+* [Core] Updated all nuget references.
-* [Core] Fixed usage of wrong data type for passwords (string -> byte[]).
+* [Core] Added MqttApplicationMessage.GetUserProperty() convenience method (thanks to @PMExtra).
-* [Core] Fixed an _ObjectDisposedException_ when sending data using a WebSocket channel.
+* [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.
-* [Core] Performance optimizations.
+* [Client] Improve connection stability (thanks to @jltjohanlindqvist).
-* [Client] Added support for extended authentication exchange.
+* [Client] Support WithConnectionUri to configure client (thanks to @PMExtra).
-* [Client] Exposed MQTTv5 CONNACK values to client.
+* [Client] Support PublishAsync with QoS 1 and QoS 2 from within an ApplicationMessageReceivedHandler (#648, #587, thanks to @PSanetra).
-* [Client] Added _MqttClientSubscribeOptionsBuilder_.
+* [Client] Fixed MqttCommunicationTimedOutExceptions, caused by a long running ApplicationMessageReceivedHandler, which blocked MQTT packets from being processed (#829, thanks to @PSanetra).
-* [Client] The disconnected handler is now executed in a new task to prevent deadlocks when reconnecting etc. (thanks to @lizziebeans).
+* [ManagedClient] Added builder class for MqttClientUnsubscribeOptions (thanks to @dominikviererbe).
-* [Client] Converted option _DualMode_ into nullable boolean to preserve original value and avoid exceptions in IPv4 only networks (thanks to @lavaflo).
+* [ManagedClient] Added support for persisted sessions (thansk to @PMExtra).
-* [Server] Exposed _ClientCertificateRequired_ and _CheckCertificateRevocation_ at TLS options.
+* [ManagedClient] Fixed a memory leak (thanks to @zawodskoj).
-* [Server] Exposed client certificate at client connection validator.
+* [ManagedClient] Improved internal subscription management (#569, thanks to @cstichlberger).
-* [Server] The subscription interceptor now supports altering the entire topic filter.
+* [ManagedClient] Refactored log messages (thanks to @cstichlberger).
-* [Server] Exposed more properties to the connection validator context.
+* [Server] Added support for assigned client IDs (MQTTv5 only) (thanks to @bcrosnier).
-* [MQTTnet.Server] Added authentication support via Python script file.
+* [Server] Added interceptor for unsubscriptions.
-* [MQTTnet.Server] Migrated the result of connection validations to _ReasonCode_ (MQTTv5) instead of _ReturnCode_ (MQTTv3 only) (BREAKING CHANGE!).
+* [Server] Removed exceptions when user properties are set with MQTT protocol version 3.1
+* [Server] Added custom session items to the client status.
+* [Server] Added option to check whether the server is already started properly or not.
+* [MQTTnet.AspNetCore] improved compatibility with AspNetCore 3.1
+* [MQTTnet.Server] Added interceptor for unsubscriptions.
     </releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
+    <copyright>Copyright Christian Kratky 2016-2020</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> 
     <dependencies>
       <group targetFramework="netstandard1.3">
@@ -44,7 +49,7 @@
         <dependency id="System.Net.WebSockets.Client" version="4.3.2" />
       </group>
       <group targetFramework="uap10.0">
-        <dependency id="Microsoft.NETCore.UniversalWindowsPlatform" version="6.2.8" />
+        <dependency id="Microsoft.NETCore.UniversalWindowsPlatform" version="6.2.10" />
       </group>
     </dependencies>
   </metadata>
@@ -53,6 +58,9 @@
     <!-- License -->
     <file src="..\LICENSE" />
 
+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
     <!-- .NET Standard 1.3 -->
     <file src="..\Source\MQTTnet\bin\Release\netstandard1.3\MQTTnet.*" target="lib\netstandard1.3\"/>
     

Build/build.ps1

@@ -12,6 +12,17 @@ Write-Host "Nuget version    = $nugetVersion"
 Write-Host "MSBuild path     = $msbuild"
 Write-Host
 
+Invoke-WebRequest -Uri "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe" -OutFile "nuget.exe"
+
+.\nuget.exe restore ..\MQTTnet.sln
+
+# Build and execute tests
+&$msbuild ..\Tests\MQTTnet.Core.Tests\MQTTnet.Tests.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netcoreapp3.1" /verbosity:m
+&$msbuild ..\Tests\MQTTnet.AspNetCore.Tests\MQTTnet.AspNetCore.Tests.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netcoreapp3.1" /verbosity:m
+
+vstest.console.exe ..\Tests\MQTTnet.Core.Tests\bin\Release\netcoreapp3.1\MQTTnet.Tests.dll
+vstest.console.exe ..\Tests\MQTTnet.AspNetCore.Tests\bin\Release\netcoreapp3.1\MQTTnet.AspNetCore.Tests.dll
+
 # Build the core library
 &$msbuild ..\Source\MQTTnet\MQTTnet.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net452" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet\MQTTnet.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net461" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
@@ -43,56 +54,8 @@ Write-Host
 &$msbuild ..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="uap10.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 
-####################################################################
-
-# Build MQTTnet.Server Portable
-&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion
-
-$source = "..\Source\MQTTnet.Server\bin\Release\netcoreapp2.2\publish"
-$destination = "..\Source\MQTTnet.Server\bin\MQTTnet.Server-Portable-v$nugetVersion.zip"
-If(Test-path $destination) {Remove-item $destination}
- Add-Type -assembly "system.io.compression.filesystem"
-[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
-
-####################################################################
-
-# Build MQTTnet.Server Linux-x64
-&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime linux-x64 
-
-$source = "..\Source\MQTTnet.Server\bin\Release\netcoreapp2.2\linux-x64\publish"
-$destination = "..\Source\MQTTnet.Server\bin\MQTTnet.Server-Linux-x64-v$nugetVersion.zip"
-If(Test-path $destination) {Remove-item $destination}
- Add-Type -assembly "system.io.compression.filesystem"
-[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
-
-####################################################################
-
-# Build MQTTnet.Server Linux-ARM
-&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime linux-arm 
-
-$source = "..\Source\MQTTnet.Server\bin\Release\netcoreapp2.2\linux-ARM\publish"
-$destination = "..\Source\MQTTnet.Server\bin\MQTTnet.Server-Linux-ARM-v$nugetVersion.zip"
-If(Test-path $destination) {Remove-item $destination}
- Add-Type -assembly "system.io.compression.filesystem"
-[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
-
-####################################################################
-
-# Build MQTTnet.Server Windows-x64
-&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime win-x64
-
-$source = "..\Source\MQTTnet.Server\bin\Release\netcoreapp2.2\win-x64\publish"
-$destination = "..\Source\MQTTnet.Server\bin\MQTTnet.Server-Windows-x64-v$nugetVersion.zip"
-If(Test-path $destination) {Remove-item $destination}
- Add-Type -assembly "system.io.compression.filesystem"
-[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
-
-####################################################################
-
 # Create NuGet packages.
 
-Invoke-WebRequest -Uri "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe" -OutFile "nuget.exe"
-
 Remove-Item .\NuGet -Force -Recurse -ErrorAction SilentlyContinue
 
 Copy-Item MQTTnet.AspNetCore.nuspec -Destination MQTTnet.AspNetCore.nuspec.old -Force
@@ -105,12 +68,12 @@ Copy-Item MQTTnet.Extensions.WebSocket4Net.nuspec -Destination MQTTnet.Extension
 (Get-Content MQTTnet.Extensions.WebSocket4Net.nuspec) -replace '\$nugetVersion', $nugetVersion | Set-Content MQTTnet.Extensions.WebSocket4Net.nuspec
 
 New-Item -ItemType Directory -Force -Path .\NuGet
-.\nuget.exe pack MQTTnet.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion
-.\nuget.exe pack MQTTnet.NETStandard.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.NETStandard.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion
-.\nuget.exe pack MQTTnet.AspNetCore.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.AspNetCore.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion
-.\nuget.exe pack MQTTnet.Extensions.Rpc.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.Extensions.Rpc.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion
-.\nuget.exe pack MQTTnet.Extensions.ManagedClient.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.Extensions.ManagedClient.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion
-.\nuget.exe pack MQTTnet.Extensions.WebSocket4Net.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.Extensions.WebSocket4Net.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion
 
 Move-Item MQTTnet.AspNetCore.nuspec.old -Destination MQTTnet.AspNetCore.nuspec -Force
 Move-Item MQTTnet.Extensions.Rpc.nuspec.old -Destination MQTTnet.Extensions.Rpc.nuspec -Force
@@ -118,3 +81,49 @@ Move-Item MQTTnet.Extensions.ManagedClient.nuspec.old -Destination MQTTnet.Exten
 Move-Item MQTTnet.Extensions.WebSocket4Net.nuspec.old -Destination MQTTnet.Extensions.WebSocket4Net.nuspec -Force
 
 Remove-Item "nuget.exe" -Force -Recurse -ErrorAction SilentlyContinue
+
+####################################################################
+
+# Build MQTTnet.Server Portable
+&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion
+
+$source = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\Release\netcoreapp3.1\publish"
+$destination = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\MQTTnet.Server-Portable-v$nugetVersion.zip"
+If(Test-path $destination) {Remove-item $destination}
+ Add-Type -assembly "system.io.compression.filesystem"
+[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
+
+####################################################################
+
+# Build MQTTnet.Server Linux-x64
+&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime linux-x64 
+
+$source = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\Release\netcoreapp3.1\linux-x64\publish"
+$destination = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\MQTTnet.Server-Linux-x64-v$nugetVersion.zip"
+If(Test-path $destination) {Remove-item $destination}
+ Add-Type -assembly "system.io.compression.filesystem"
+[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
+
+####################################################################
+
+# Build MQTTnet.Server Linux-ARM
+&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime linux-arm 
+
+$source = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\Release\netcoreapp3.1\linux-ARM\publish"
+$destination = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\MQTTnet.Server-Linux-ARM-v$nugetVersion.zip"
+If(Test-path $destination) {Remove-item $destination}
+ Add-Type -assembly "system.io.compression.filesystem"
+[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
+
+####################################################################
+
+# Build MQTTnet.Server Windows-x64
+&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime win-x64
+
+$source = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\Release\netcoreapp3.1\win-x64\publish"
+$destination = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\MQTTnet.Server-Windows-x64-v$nugetVersion.zip"
+If(Test-path $destination) {Remove-item $destination}
+ Add-Type -assembly "system.io.compression.filesystem"
+[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
+
+####################################################################

Build/upload.ps1

@@ -7,7 +7,7 @@ foreach ($file in $files)
 {
 	Write-Host "Uploading: " $file
 
-	.\nuget.exe push $file.Fullname $apiKey -NoSymbols -Source https://api.nuget.org/v3/index.json
+	.\nuget.exe push $file.Fullname $apiKey -Source https://api.nuget.org/v3/index.json
 }
 
 Remove-Item "nuget.exe" -Force -Recurse -ErrorAction SilentlyContinue

Documents/Import_CodeSigningKey.md

@@ -1,9 +1,9 @@
 # Import codeSigningKey.pfx
 In order to import the key for code signing on a new developer machine use the following command within the VS developer command line:
 
-> sn –i codeSigningKey.pfx VS_KEY_EFCA4C5B6DFD4B4F
+sn –i .\codeSigningKey.pfx VS_KEY_62CA73019ED23333
 
 The container name may be different.
 
 # Check if the assembly has a strong name
-> sn -vf MQTTnet.dll
+sn -vf MQTTnet.dll

Images/MQTT.svg

@@ -0,0 +1,239 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   width="210mm"
+   height="297mm"
+   viewBox="0 0 210 297"
+   version="1.1"
+   id="svg8"
+   inkscape:version="0.92.4 (5da689c313, 2019-01-14)"
+   sodipodi:docname="MQTT.svg">
+  <defs
+     id="defs2">
+    <filter
+       inkscape:label="Blur Double"
+       inkscape:menu="Blurs"
+       inkscape:menu-tooltip="Overlays two copies with different blur amounts and modifiable blend and composite"
+       style="color-interpolation-filters:sRGB;"
+       id="filter3801">
+      <feGaussianBlur
+         stdDeviation="5"
+         result="fbSourceGraphic"
+         id="feGaussianBlur3793" />
+      <feGaussianBlur
+         stdDeviation="0.01"
+         in="SourceGraphic"
+         result="result1"
+         id="feGaussianBlur3795" />
+      <feComposite
+         in2="result1"
+         operator="arithmetic"
+         in="fbSourceGraphic"
+         k2="0.5"
+         k3="0.5"
+         result="result2"
+         id="feComposite3797" />
+      <feBlend
+         in2="fbSourceGraphic"
+         mode="normal"
+         result="result3"
+         id="feBlend3799" />
+    </filter>
+  </defs>
+  <sodipodi:namedview
+     id="base"
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1.0"
+     inkscape:pageopacity="0.0"
+     inkscape:pageshadow="2"
+     inkscape:zoom="0.24748737"
+     inkscape:cx="955.72999"
+     inkscape:cy="295.38958"
+     inkscape:document-units="mm"
+     inkscape:current-layer="layer1"
+     showgrid="false"
+     inkscape:window-width="3840"
+     inkscape:window-height="2066"
+     inkscape:window-x="2989"
+     inkscape:window-y="-11"
+     inkscape:window-maximized="1" />
+  <metadata
+     id="metadata5">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title />
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <g
+     inkscape:label="Layer 1"
+     inkscape:groupmode="layer"
+     id="layer1">
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+       inkscape:export-xdpi="2.6500001"
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+       inkscape:connector-curvature="0"
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+       style="fill:#ce0000;fill-opacity:0.60591131;stroke-width:0.59952348"
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+       inkscape:connector-curvature="0"
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+       inkscape:export-ydpi="2.6500001" />
+    <path
+       style="fill:#ce0000;fill-opacity:0.60591131;stroke-width:2.26591563"
+       d="M 464.66602,532.89453 542.01562,669.92969 1595.373,1648.873 a 995.76487,866.17896 0 0 1 14.0293,-12.6835 995.76487,866.17896 0 0 1 23.6231,-17.4727 z"
+       id="rect3806-2"
+       inkscape:connector-curvature="0"
+       transform="scale(0.26458333)"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:10.58333302px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
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+       inkscape:export-xdpi="2.6500001"
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+         x="102.34985"
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+    <ellipse
+       ry="33.94323"
+       rx="39.021355"
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+       cx="124.47787"
+       id="ellipse3768"
+       style="fill:#d40000;stroke-width:0.06901014"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
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+       style="fill:#d40000;stroke-width:0.06901014"
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+       cx="234.9953"
+       cy="556.91571"
+       rx="39.021355"
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+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <text
+       id="text3778"
+       y="474.73837"
+       x="194.57605"
+       style="font-style:normal;font-weight:normal;font-size:10.58333302px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       xml:space="preserve"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001"><tspan
+         style="font-size:141.1111145px;fill:#ffffff;stroke-width:0.26458332"
+         y="474.73837"
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+         id="tspan3776"
+         sodipodi:role="line">net</tspan></text>
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+       ry="50"
+       rx="50"
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+       inkscape:connector-curvature="0"
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+       d="m -160.18302,381.97945 a 263.46279,229.17652 0 0 0 -222.88457,226.0446 263.46279,229.17652 0 0 0 0.0791,1.32549 h 172.80546 c 27.70002,0 50.00005,-22.30004 50.00005,-50.00004 z"
+       style="fill:#d40000;stroke-width:0.46593982"
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+       id="text4656"
+       y="329.30466"
+       x="-639.42944"
+       style="font-style:normal;font-weight:normal;font-size:10.58333302px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       xml:space="preserve"
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+         style="font-weight:bold;font-size:141.1111145px;fill:#ffffff;stroke-width:0.26458332"
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+         id="tspan4654"
+         sodipodi:role="line">MQTT</tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:10.58333302px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       x="-550.90747"
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+       inkscape:export-xdpi="6.3499999"
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+         sodipodi:role="line"
+         id="tspan4662"
+         x="-550.90747"
+         y="482.23267"
+         style="font-weight:bold;font-size:141.1111145px;fill:#ffffff;stroke-width:0.26458332">net</tspan></text>
+  </g>
+</svg>

MQTTnet.sln

@@ -53,6 +53,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Server", "Source\MQ
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Extensions.WebSocket4Net", "Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj", "{2BD01D53-4CA5-4142-BE8D-313876395E3E}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Apps", "Apps", "{A56E3128-1639-4F31-873A-325E14BB6295}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -270,7 +272,7 @@ Global
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{A7FF0C91-25DE-4BA6-B39E-F54E8DADF1CC} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
-		{FF1F72D6-9524-4422-9497-3CC0002216ED} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
+		{FF1F72D6-9524-4422-9497-3CC0002216ED} = {A56E3128-1639-4F31-873A-325E14BB6295}
 		{3587E506-55A2-4EB3-99C7-DC01E42D25D2} = {32A630A7-2598-41D7-B625-204CD906F5FB}
 		{3D283AAD-AAA8-4339-8394-52F80B6304DB} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
 		{C6FF8AEA-0855-41EC-A1F3-AC262225BAB9} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
@@ -279,7 +281,7 @@ Global
 		{998D04DD-7CB0-45F5-A393-E2495C16399E} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
 		{C400533A-8EBA-4F0B-BF4D-295C3708604B} = {12816BCC-AF9E-44A9-9AE5-C246AF2A0587}
 		{61B62223-F5D0-48E4-BBD6-2CBA9353CB5E} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
-		{5699FB8C-838C-4AB0-80A5-9CA809F9B65B} = {32A630A7-2598-41D7-B625-204CD906F5FB}
+		{5699FB8C-838C-4AB0-80A5-9CA809F9B65B} = {A56E3128-1639-4F31-873A-325E14BB6295}
 		{2BD01D53-4CA5-4142-BE8D-313876395E3E} = {12816BCC-AF9E-44A9-9AE5-C246AF2A0587}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution

README.md

@@ -1,5 +1,5 @@
 <p align="center">
-<img src="https://github.com/chkr1011/MQTTnet/blob/master/Images/Logo_128x128.png?raw=true" width="128">
+<img src="https://github.com/chkr1011/MQTTnet/blob/master/Images/icon_det_256.png?raw=true" width="196">
 <br/>
 <br/>
 </p>
@@ -7,8 +7,8 @@
 [![NuGet Badge](https://buildstats.info/nuget/MQTTnet)](https://www.nuget.org/packages/MQTTnet)
 [![Build status](https://ci.appveyor.com/api/projects/status/ycit86voxfevm2aa/branch/master?svg=true)](https://ci.appveyor.com/project/chkr1011/mqttnet)
 [![BCH compliance](https://bettercodehub.com/edge/badge/chkr1011/MQTTnet?branch=master)](https://bettercodehub.com/)
-[![OpenCollective](https://opencollective.com/mqttnet/backers/badge.svg)](https://opencollective.com/mqttnet) 
+[![Join the chat at https://gitter.im/MQTTnet/community](https://badges.gitter.im/MQTTnet/community.svg)](https://gitter.im/MQTTnet/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![OpenCollective](https://opencollective.com/mqttnet/sponsors/badge.svg)](https://opencollective.com/mqttnet) [![Join the chat at https://gitter.im/MQTTnet/community](https://badges.gitter.im/MQTTnet/community.svg)](https://gitter.im/MQTTnet/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://raw.githubusercontent.com/chkr1011/MQTTnet/master/LICENSE)
 
 # MQTTnet
 
@@ -92,8 +92,6 @@ Please find examples and the documentation at the Wiki of this repository (<http
 If you want to contribute to this project just create a pull request. But only pull requests which are matching the code style of this library will be accepted. Before creating a pull request please have a look at the library to get an overview of the required style.
 Also additions and updates in the Wiki are welcome.
 
-**This project, like all projects requires time and money.  If you feel compelled to support the development team, you can do so through Open Collective (https://opencollective.com/mqttnet)**.
-
 ## References
 
 This library is used in the following projects:
@@ -104,6 +102,8 @@ This library is used in the following projects:
 * MQTT Tester (MQTT client test app for [Android](https://play.google.com/store/apps/details?id=com.liveowl.mqtttester) and [iOS](https://itunes.apple.com/us/app/mqtt-tester/id1278621826?mt=8))
 * Wirehome.Core (Open Source Home Automation system for .NET Core, <https://github.com/chkr1011/Wirehome.Core>)
 
+Further projects using this project can be found under https://github.com/chkr1011/MQTTnet/network/dependents.
+
 If you use this library and want to see your project here please create a pull request.
 
 ## License

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/Client/Tcp/TcpConnection.cs

@@ -1,13 +1,13 @@
-using System;
+using Microsoft.AspNetCore.Connections;
+using Microsoft.AspNetCore.Http.Features;
+using MQTTnet.Exceptions;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.IO.Pipelines;
 using System.Net;
 using System.Net.Sockets;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Connections;
-using Microsoft.AspNetCore.Http.Features;
-using MQTTnet.Exceptions;
 
 namespace MQTTnet.AspNetCore.Client.Tcp
 {
@@ -40,8 +40,11 @@ namespace MQTTnet.AspNetCore.Client.Tcp
             _sender = new SocketSender(_socket, PipeScheduler.ThreadPool);
             _receiver = new SocketReceiver(_socket, PipeScheduler.ThreadPool);
         }
-
+#if NETCOREAPP3_1
-        public Task DisposeAsync()
+        public override ValueTask DisposeAsync()
+#else
+        public new Task DisposeAsync()
+#endif
         {
             IsConnected = false;
 
@@ -50,8 +53,15 @@ namespace MQTTnet.AspNetCore.Client.Tcp
 
             _socket?.Dispose();
 
+#if NETCOREAPP3_1
+
+            return base.DisposeAsync();
+        }
+#else
+
             return Task.CompletedTask;
         }
+#endif
 
         public async Task StartAsync()
         {

Source/MQTTnet.AspnetCore/Extensions/ApplicationBuilderExtensions.cs

@@ -1,14 +1,13 @@
 using System;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
-using System.Linq;
 using MQTTnet.Server;
-using System.Collections.Generic;
 
 namespace MQTTnet.AspNetCore
 {
     public static class ApplicationBuilderExtensions
     {
+        [Obsolete("This class is obsolete and will be removed in a future version. The recommended alternative is to use MapMqtt inside Microsoft.AspNetCore.Builder.UseEndpoints(...).")]
         public static IApplicationBuilder UseMqttEndpoint(this IApplicationBuilder app, string path = "/mqtt")
         {
             app.UseWebSockets();
@@ -24,7 +23,7 @@ namespace MQTTnet.AspNetCore
 
                 if (context.Request.Headers.TryGetValue("Sec-WebSocket-Protocol", out var requestedSubProtocolValues))
                 {
-                    subProtocol = SelectSubProtocol(requestedSubProtocolValues);
+                    subProtocol = MqttSubProtocolSelector.SelectSubProtocol(requestedSubProtocolValues);
                 }
 
                 var adapter = app.ApplicationServices.GetRequiredService<MqttWebSocketServerAdapter>();
@@ -37,14 +36,6 @@ namespace MQTTnet.AspNetCore
             return app;
         }
 
-        public static string SelectSubProtocol(IList<string> requestedSubProtocolValues)
-        {
-            // Order the protocols to also match "mqtt", "mqttv-3.1", "mqttv-3.11" etc.
-            return requestedSubProtocolValues
-                .OrderByDescending(p => p.Length)
-                .FirstOrDefault(p => p.ToLower().StartsWith("mqtt"));
-        }
-
         public static IApplicationBuilder UseMqttServer(this IApplicationBuilder app, Action<IMqttServer> configure)
         {
             var server = app.ApplicationServices.GetRequiredService<IMqttServer>();

Source/MQTTnet.AspnetCore/Extensions/ConnectionRouteBuilderExtensions.cs

@@ -0,0 +1,20 @@
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Http.Connections;
+using System;
+
+namespace MQTTnet.AspNetCore
+{
+    public static class ConnectionRouteBuilderExtensions
+    {
+#if NETCOREAPP3_1
+        [Obsolete("This class is obsolete and will be removed in a future version. The recommended alternative is to use MapMqtt inside Microsoft.AspNetCore.Builder.UseEndpoints(...).")]
+#endif
+        public static void MapMqtt(this ConnectionsRouteBuilder connection, PathString path)
+        {
+            connection.MapConnectionHandler<MqttConnectionHandler>(path, options =>
+            {
+                options.WebSockets.SubProtocolSelector = MqttSubProtocolSelector.SelectSubProtocol;
+            });
+        }
+    }
+}

Source/MQTTnet.AspnetCore/Extensions/EndpointRouterExtensions.cs

@@ -0,0 +1,21 @@
+
+#if NETCOREAPP3_1
+
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Routing;
+
+namespace MQTTnet.AspNetCore
+{
+    public static class EndpointRouterExtensions
+    {
+        public static void MapMqtt(this IEndpointRouteBuilder endpoints, string pattern) 
+        {
+            endpoints.MapConnectionHandler<MqttConnectionHandler>(pattern, options =>
+            {
+                options.WebSockets.SubProtocolSelector = MqttSubProtocolSelector.SelectSubProtocol;
+            });
+        }
+    }
+}
+
+#endif

Source/MQTTnet.AspnetCore/Extensions/ReaderExtensions.cs

@@ -80,7 +80,7 @@ namespace MQTTnet.AspNetCore
             headerLength = 0;
             bodyLength = 0;
             
-            var temp = input.Slice(0, Math.Min(5, input.Length)).GetMemory();
+            var temp = input.Slice(0, Math.Min(5, input.Length)).GetMemory().Span;
 
             do
             {
@@ -88,7 +88,7 @@ namespace MQTTnet.AspNetCore
                 {
                     return false;
                 }
-                encodedByte = temp.Span[index];
+                encodedByte = temp[index];
                 index++;
 
                 value += (byte)(encodedByte & 127) * multiplier;

Source/MQTTnet.AspnetCore/Extensions/ServiceCollectionExtensions.cs

@@ -1,10 +1,10 @@
-using System;
+using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using MQTTnet.Adapter;
 using MQTTnet.Diagnostics;
-using MQTTnet.Server;
 using MQTTnet.Implementations;
+using MQTTnet.Server;
+using System;
 
 namespace MQTTnet.AspNetCore
 {
@@ -23,7 +23,8 @@ namespace MQTTnet.AspNetCore
 
         public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, Action<MqttServerOptionsBuilder> configure)
         {
-            services.AddSingleton<IMqttServerOptions>(s => {
+            services.AddSingleton<IMqttServerOptions>(s =>
+            {
                 var builder = new MqttServerOptionsBuilder();
                 configure(builder);
                 return builder.Build();
@@ -36,7 +37,8 @@ namespace MQTTnet.AspNetCore
 
         public static IServiceCollection AddHostedMqttServerWithServices(this IServiceCollection services, Action<AspNetMqttServerOptionsBuilder> configure)
         {
-            services.AddSingleton<IMqttServerOptions>(s => {
+            services.AddSingleton<IMqttServerOptions>(s =>
+            {
                 var builder = new AspNetMqttServerOptionsBuilder(s);
                 configure(builder);
                 return builder.Build();
@@ -60,10 +62,8 @@ namespace MQTTnet.AspNetCore
         private static IServiceCollection AddHostedMqttServer(this IServiceCollection services)
         {
             var logger = new MqttNetLogger();
-            var childLogger = logger.CreateChildLogger();
 
             services.AddSingleton<IMqttNetLogger>(logger);
-            services.AddSingleton(childLogger);
             services.AddSingleton<MqttHostedServer>();
             services.AddSingleton<IHostedService>(s => s.GetService<MqttHostedServer>());
             services.AddSingleton<IMqttServer>(s => s.GetService<MqttHostedServer>());

Source/MQTTnet.AspnetCore/MQTTnet.AspNetCore.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;netcoreapp2.1</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;netcoreapp2.1;netcoreapp3.1</TargetFrameworks>
     <Product />
     <Company />
     <Authors />
@@ -14,11 +14,17 @@
     <DefineConstants>RELEASE;NETSTANDARD2_0</DefineConstants>
   </PropertyGroup>
 
-  <ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1'">
-    <PackageReference Include="Microsoft.AspNetCore.Connections.Abstractions" Version="2.1.3" />
+    <FrameworkReference Include="Microsoft.AspNetCore.App" />
-    <PackageReference Include="Microsoft.AspNetCore.Http.Connections" Version="1.0.3" />
+
-    <PackageReference Include="Microsoft.AspNetCore.WebSockets" Version="2.1.1" />
+    <PackageReference Include="System.IO.Pipelines" Version="4.7.1" />
-    <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="2.1.1" />
+  </ItemGroup>
+    
+  <ItemGroup Condition="'$(TargetFramework)' != 'netcoreapp3.1'">
+    <PackageReference Include="Microsoft.AspNetCore.Connections.Abstractions" Version="3.1.3" />
+    <PackageReference Include="Microsoft.AspNetCore.Http.Connections" Version="1.1.0" />
+    <PackageReference Include="Microsoft.AspNetCore.WebSockets" Version="2.2.1" />
+    <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="3.1.3" />
   </ItemGroup>
 
   <ItemGroup>

Source/MQTTnet.AspnetCore/MqttConnectionContext.cs

@@ -162,11 +162,12 @@ namespace MQTTnet.AspNetCore
                 var buffer = formatter.Encode(packet);
                 var msg = buffer.AsMemory();
                 var output = _output;
-                msg.CopyTo(output.GetMemory(msg.Length));
+                var result = await output.WriteAsync(msg, cancellationToken).ConfigureAwait(false);
-                BytesSent += msg.Length;
+                if (result.IsCompleted)
+                {
+                    BytesSent += msg.Length;
+                }
                 PacketFormatterAdapter.FreeBuffer();
-                output.Advance(msg.Length);
-                await output.FlushAsync().ConfigureAwait(false);
             }
             finally
             {

Source/MQTTnet.AspnetCore/MqttHostedServer.cs

@@ -21,7 +21,8 @@ namespace MQTTnet.AspNetCore
 
         public Task StartAsync(CancellationToken cancellationToken)
         {
-            return StartAsync(_options);
+            _ = StartAsync(_options);
+            return Task.CompletedTask;
         }
 
         public Task StopAsync(CancellationToken cancellationToken)

Source/MQTTnet.AspnetCore/MqttSubProtocolSelector.cs

@@ -0,0 +1,16 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace MQTTnet.AspNetCore
+{
+    public static class MqttSubProtocolSelector
+    {
+        public static string SelectSubProtocol(IList<string> requestedSubProtocolValues)
+        {
+            // Order the protocols to also match "mqtt", "mqttv-3.1", "mqttv-3.11" etc.
+            return requestedSubProtocolValues
+                .OrderByDescending(p => p.Length)
+                .FirstOrDefault(p => p.ToLower().StartsWith("mqtt"));
+        }
+    }
+}

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.AspnetCore/SpanBasedMqttPacketWriter.cs

@@ -64,7 +64,6 @@ namespace MQTTnet.AspNetCore
 
             GrowIfNeeded(propertyWriter.Length);
             Write(propertyWriter.GetBuffer(), 0, propertyWriter.Length);
-            Commit(propertyWriter.Length);
         }
 
         public void Write(byte[] payload, int start, int length)

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;
@@ -13,17 +8,34 @@ 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
 {
-    public class ManagedMqttClient : IManagedMqttClient
+    public class ManagedMqttClient : Disposable, IManagedMqttClient
     {
         private readonly BlockingQueue<ManagedMqttApplicationMessage> _messageQueue = new BlockingQueue<ManagedMqttApplicationMessage>();
+
+        /// <summary>
+        /// The subscriptions are managed in 2 separate buckets:
+        /// <see cref="_subscriptions"/> and <see cref="_unsubscriptions"/> are processed during normal operation
+        /// and are moved to the <see cref="_reconnectSubscriptions"/> when they get processed. They can be accessed by
+        /// any thread and are therefore mutex'ed. <see cref="_reconnectSubscriptions"/> get sent to the broker
+        ///  at reconnect and are solely owned by <see cref="MaintainConnectionAsync"/>.
+        /// </summary>
+        private readonly Dictionary<string, MqttQualityOfServiceLevel> _reconnectSubscriptions = new Dictionary<string, MqttQualityOfServiceLevel>();
         private readonly Dictionary<string, MqttQualityOfServiceLevel> _subscriptions = new Dictionary<string, MqttQualityOfServiceLevel>();
         private readonly HashSet<string> _unsubscriptions = new HashSet<string>();
+        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();
 
         private CancellationTokenSource _connectionCancellationToken;
         private CancellationTokenSource _publishingCancellationToken;
@@ -31,10 +43,7 @@ namespace MQTTnet.Extensions.ManagedClient
 
         private ManagedMqttClientStorageManager _storageManager;
 
-        private bool _disposed;
+        public ManagedMqttClient(IMqttClient mqttClient, IMqttNetLogger logger)
-        private bool _subscriptionsNotPushed;
-
-        public ManagedMqttClient(IMqttClient mqttClient, IMqttNetChildLogger logger)
         {
             _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
 
@@ -80,10 +89,6 @@ namespace MQTTnet.Extensions.ManagedClient
             if (options == null) throw new ArgumentNullException(nameof(options));
             if (options.ClientOptions == null) throw new ArgumentException("The client options are not set.", nameof(options));
 
-            if (!options.ClientOptions.CleanSession)
-            {
-                throw new NotSupportedException("The managed client does not support existing sessions.");
-            }
 
             if (!_maintainConnectionTask?.IsCompleted ?? false) throw new InvalidOperationException("The managed client is already started.");
 
@@ -139,6 +144,7 @@ namespace MQTTnet.Extensions.ManagedClient
             ThrowIfDisposed();
 
             if (applicationMessage == null) throw new ArgumentNullException(nameof(applicationMessage));
+            if (Options == null) throw new InvalidOperationException("call StartAsync before publishing messages");
 
             MqttTopicValidator.ThrowIfInvalid(applicationMessage.ApplicationMessage.Topic);
 
@@ -147,7 +153,7 @@ namespace MQTTnet.Extensions.ManagedClient
 
             try
             {
-                lock (_messageQueue)
+                using (await _messageQueueLock.WaitAsync(CancellationToken.None).ConfigureAwait(false))
                 {
                     if (_messageQueue.Count >= Options.MaxPendingMessages)
                     {
@@ -167,6 +173,16 @@ namespace MQTTnet.Extensions.ManagedClient
                     }
 
                     _messageQueue.Enqueue(applicationMessage);
+
+                    if (_storageManager != null)
+                    {
+                        if (removedMessage != null)
+                        {
+                            await _storageManager.RemoveAsync(removedMessage).ConfigureAwait(false);
+                        }
+
+                        await _storageManager.AddAsync(applicationMessage).ConfigureAwait(false);
+                    }
                 }
             }
             finally
@@ -181,16 +197,6 @@ namespace MQTTnet.Extensions.ManagedClient
                 }
 
             }
-            
-            if (_storageManager != null)
-            {
-                if (removedMessage != null)
-                {
-                    await _storageManager.RemoveAsync(removedMessage).ConfigureAwait(false);
-                }
-
-                await _storageManager.AddAsync(applicationMessage).ConfigureAwait(false);
-            }
         }
 
         public Task SubscribeAsync(IEnumerable<TopicFilter> topicFilters)
@@ -204,9 +210,10 @@ namespace MQTTnet.Extensions.ManagedClient
                 foreach (var topicFilter in topicFilters)
                 {
                     _subscriptions[topicFilter.Topic] = topicFilter.QualityOfServiceLevel;
-                    _subscriptionsNotPushed = true;
+                    _unsubscriptions.Remove(topicFilter.Topic);
                 }
             }
+            _subscriptionsQueuedSignal.Release();
 
             return Task.FromResult(0);
         }
@@ -221,44 +228,34 @@ namespace MQTTnet.Extensions.ManagedClient
             {
                 foreach (var topic in topics)
                 {
-                    if (_subscriptions.Remove(topic))
+                    _subscriptions.Remove(topic);
-                    {
+                    _unsubscriptions.Add(topic);
-                        _unsubscriptions.Add(topic);
-                        _subscriptionsNotPushed = true;
-                    }
                 }
             }
+            _subscriptionsQueuedSignal.Release();
 
             return Task.FromResult(0);
         }
 
-        public void Dispose()
+        protected override void Dispose(bool disposing)
         {
-            if (_disposed)
+            if (disposing)
             {
-                return;
+                StopPublishing();
-            }
+                StopMaintainingConnection();
-
+
-            _disposed = true;
+                if (_maintainConnectionTask != null)
-
+                {
-            StopPublishing();
+                    _maintainConnectionTask.GetAwaiter().GetResult();
-            StopMaintainingConnection();
+                    _maintainConnectionTask = null;
-
+                }
-            if (_maintainConnectionTask != null)
+
-            {
+                _messageQueue.Dispose();
-                Task.WaitAny(_maintainConnectionTask);
+                _messageQueueLock.Dispose();
-                _maintainConnectionTask = null;
+                _mqttClient.Dispose();
-            }
+                _subscriptionsQueuedSignal.Dispose();
-
-            _mqttClient.Dispose();
-        }
-
-        private void ThrowIfDisposed()
-        {
-            if (_disposed)
-            {
-                throw new ObjectDisposedException(nameof(ManagedMqttClient));
             }
+            base.Dispose(disposing);
         }
 
         private async Task MaintainConnectionAsync(CancellationToken cancellationToken)
@@ -275,11 +272,11 @@ namespace MQTTnet.Extensions.ManagedClient
             }
             catch (Exception exception)
             {
-                _logger.Error(exception, "Unhandled exception while maintaining connection.");
+                _logger.Error(exception, "Error exception while maintaining connection.");
             }
             finally
             {
-                if (!_disposed)
+                if (!IsDisposed)
                 {
                     try
                     {
@@ -292,6 +289,12 @@ namespace MQTTnet.Extensions.ManagedClient
 
                     _logger.Info("Stopped");
                 }
+                _reconnectSubscriptions.Clear();
+                lock (_subscriptions)
+                {
+                    _subscriptions.Clear();
+                    _unsubscriptions.Clear();
+                }
             }
         }
 
@@ -307,16 +310,22 @@ namespace MQTTnet.Extensions.ManagedClient
                     return;
                 }
 
-                if (connectionState == ReconnectionResult.Reconnected || _subscriptionsNotPushed)
+                if (connectionState == ReconnectionResult.Reconnected)
+                {
+                    await PublishReconnectSubscriptionsAsync().ConfigureAwait(false);
+                    StartPublishing();
+                    return;
+                }
+
+                if (connectionState == ReconnectionResult.Recovered)
                 {
-                    await SynchronizeSubscriptionsAsync().ConfigureAwait(false);
                     StartPublishing();
                     return;
                 }
 
                 if (connectionState == ReconnectionResult.StillConnected)
                 {
-                    await Task.Delay(Options.ConnectionCheckInterval, cancellationToken).ConfigureAwait(false);
+                    await PublishSubscriptionsAsync(Options.ConnectionCheckInterval, cancellationToken).ConfigureAwait(false);
                 }
             }
             catch (OperationCanceledException)
@@ -324,11 +333,11 @@ namespace MQTTnet.Extensions.ManagedClient
             }
             catch (MqttCommunicationException exception)
             {
-                _logger.Warning(exception, "Communication exception while maintaining connection.");
+                _logger.Warning(exception, "Communication error while maintaining connection.");
             }
             catch (Exception exception)
             {
-                _logger.Error(exception, "Unhandled exception while maintaining connection.");
+                _logger.Error(exception, "Error exception while maintaining connection.");
             }
         }
 
@@ -346,7 +355,7 @@ namespace MQTTnet.Extensions.ManagedClient
                     // of the messages, the DropOldestQueuedMessage strategy would
                     // be unable to know which message is actually the oldest and would
                     // instead drop the first item in the queue.
-                    var message = _messageQueue.PeekAndWait();
+                    var message = _messageQueue.PeekAndWait(cancellationToken);
                     if (message == null)
                     {
                         continue;
@@ -362,7 +371,7 @@ namespace MQTTnet.Extensions.ManagedClient
             }
             catch (Exception exception)
             {
-                _logger.Error(exception, "Unhandled exception while publishing queued application messages.");
+                _logger.Error(exception, "Error while publishing queued application messages.");
             }
             finally
             {
@@ -377,7 +386,7 @@ namespace MQTTnet.Extensions.ManagedClient
             {
                 await _mqttClient.PublishAsync(message.ApplicationMessage).ConfigureAwait(false);
 
-                lock (_messageQueue) //lock to avoid conflict with this.PublishAsync
+                using (await _messageQueueLock.WaitAsync(CancellationToken.None).ConfigureAwait(false)) //lock to avoid conflict with this.PublishAsync
                 {
                     // While publishing this message, this.PublishAsync could have booted this
                     // message off the queue to make room for another (when using a cap
@@ -386,11 +395,11 @@ namespace MQTTnet.Extensions.ManagedClient
                     // it from the queue.  If not, that means this.PublishAsync has already
                     // removed it, in which case we don't want to do anything.
                     _messageQueue.RemoveFirst(i => i.Id.Equals(message.Id));
-                }
 
-                if (_storageManager != null)
+                    if (_storageManager != null)
-                {
+                    {
-                    await _storageManager.RemoveAsync(message).ConfigureAwait(false);
+                        await _storageManager.RemoveAsync(message).ConfigureAwait(false);
+                    }
                 }
             }
             catch (MqttCommunicationException exception)
@@ -408,21 +417,21 @@ namespace MQTTnet.Extensions.ManagedClient
                     //contradict the expected behavior of QoS 1 and 2, that's also true
                     //for the usage of a message queue cap, so it's still consistent
                     //with prior behavior in that way.
-                    lock (_messageQueue) //lock to avoid conflict with this.PublishAsync
+                    using (await _messageQueueLock.WaitAsync(CancellationToken.None).ConfigureAwait(false)) //lock to avoid conflict with this.PublishAsync
                     {
                         _messageQueue.RemoveFirst(i => i.Id.Equals(message.Id));
-                    }
 
-                    if (_storageManager != null)
+                        if (_storageManager != null)
-                    {
+                        {
-                        await _storageManager.RemoveAsync(message).ConfigureAwait(false);
+                            await _storageManager.RemoveAsync(message).ConfigureAwait(false);
+                        }
                     }
                 }
             }
             catch (Exception exception)
             {
                 transmitException = exception;
-                _logger.Error(exception, $"Unhandled exception while publishing application message ({message.Id}).");
+                _logger.Error(exception, $"Error while publishing application message ({message.Id}).");
             }
             finally
             {
@@ -435,50 +444,84 @@ namespace MQTTnet.Extensions.ManagedClient
             }
         }
 
-        private async Task SynchronizeSubscriptionsAsync()
+        private async Task PublishSubscriptionsAsync(TimeSpan timeout, CancellationToken cancellationToken)
         {
-            _logger.Info("Synchronizing subscriptions");
+            var endTime = DateTime.UtcNow + timeout;
-
+            while (await _subscriptionsQueuedSignal.WaitAsync(GetRemainingTime(endTime), cancellationToken).ConfigureAwait(false))
-            List<TopicFilter> subscriptions;
-            HashSet<string> unsubscriptions;
-
-            lock (_subscriptions)
             {
-                subscriptions = _subscriptions.Select(i => new TopicFilter { Topic = i.Key, QualityOfServiceLevel = i.Value }).ToList();
+                List<TopicFilter> subscriptions;
+                HashSet<string> unsubscriptions;
 
-                unsubscriptions = new HashSet<string>(_unsubscriptions);
+                lock (_subscriptions)
-                _unsubscriptions.Clear();
+                {
+                    subscriptions = _subscriptions.Select(i => new TopicFilter { Topic = i.Key, QualityOfServiceLevel = i.Value }).ToList();
+                    _subscriptions.Clear();
+                    unsubscriptions = new HashSet<string>(_unsubscriptions);
+                    _unsubscriptions.Clear();
+                }
 
-                _subscriptionsNotPushed = false;
+                if (!subscriptions.Any() && !unsubscriptions.Any())
+                {
+                    continue;
+                }
+
+                _logger.Verbose($"Publishing subscriptions ({subscriptions.Count} subscriptions and {unsubscriptions.Count} unsubscriptions)");
+
+                foreach (var unsubscription in unsubscriptions)
+                {
+                    _reconnectSubscriptions.Remove(unsubscription);
+                }
+
+                foreach (var subscription in subscriptions)
+                {
+                    _reconnectSubscriptions[subscription.Topic] = subscription.QualityOfServiceLevel;
+                }
+
+                try
+                {
+                    if (unsubscriptions.Any())
+                    {
+                        await _mqttClient.UnsubscribeAsync(unsubscriptions.ToArray()).ConfigureAwait(false);
+                    }
+
+                    if (subscriptions.Any())
+                    {
+                        await _mqttClient.SubscribeAsync(subscriptions.ToArray()).ConfigureAwait(false);
+                    }
+                }
+                catch (Exception exception)
+                {
+                    await HandleSubscriptionExceptionAsync(exception).ConfigureAwait(false);
+                }
             }
+        }
 
-            if (!subscriptions.Any() && !unsubscriptions.Any())
+        private async Task PublishReconnectSubscriptionsAsync()
-            {
+        {
-                return;
+            _logger.Info("Publishing subscriptions at reconnect");
-            }
 
             try
             {
-                if (unsubscriptions.Any())
+                if (_reconnectSubscriptions.Any())
-                {
-                    await _mqttClient.UnsubscribeAsync(unsubscriptions.ToArray()).ConfigureAwait(false);
-                }
-
-                if (subscriptions.Any())
                 {
+                    var subscriptions = _reconnectSubscriptions.Select(i => new TopicFilter { Topic = i.Key, QualityOfServiceLevel = i.Value });
                     await _mqttClient.SubscribeAsync(subscriptions.ToArray()).ConfigureAwait(false);
                 }
             }
             catch (Exception exception)
             {
-                _logger.Warning(exception, "Synchronizing subscriptions failed.");
+                await HandleSubscriptionExceptionAsync(exception).ConfigureAwait(false);
-                _subscriptionsNotPushed = true;
+            }
+        }
 
-                var synchronizingSubscriptionsFailedHandler = SynchronizingSubscriptionsFailedHandler;
+        private async Task HandleSubscriptionExceptionAsync(Exception exception)
-                if (SynchronizingSubscriptionsFailedHandler != null)
+        {
-                {
+            _logger.Warning(exception, "Synchronizing subscriptions failed.");
-                    await synchronizingSubscriptionsFailedHandler.HandleSynchronizingSubscriptionsFailedAsync(new ManagedProcessFailedEventArgs(exception)).ConfigureAwait(false);
+
-                }
+            var synchronizingSubscriptionsFailedHandler = SynchronizingSubscriptionsFailedHandler;
+            if (SynchronizingSubscriptionsFailedHandler != null)
+            {
+                await synchronizingSubscriptionsFailedHandler.HandleSynchronizingSubscriptionsFailedAsync(new ManagedProcessFailedEventArgs(exception)).ConfigureAwait(false);
             }
         }
 
@@ -491,8 +534,8 @@ namespace MQTTnet.Extensions.ManagedClient
 
             try
             {
-                await _mqttClient.ConnectAsync(Options.ClientOptions).ConfigureAwait(false);
+                var result = await _mqttClient.ConnectAsync(Options.ClientOptions).ConfigureAwait(false);
-                return ReconnectionResult.Reconnected;
+                return result.IsSessionPresent ? ReconnectionResult.Recovered : ReconnectionResult.Reconnected;
             }
             catch (Exception exception)
             {
@@ -532,5 +575,11 @@ namespace MQTTnet.Extensions.ManagedClient
             _connectionCancellationToken?.Dispose();
             _connectionCancellationToken = null;
         }
+
+        private TimeSpan GetRemainingTime(DateTime endTime)
+        {
+            var remainingTime = endTime - DateTime.UtcNow;
+            return remainingTime < TimeSpan.Zero ? TimeSpan.Zero : remainingTime;
+        }
     }
 }

Source/MQTTnet.Extensions.ManagedClient/MqttFactoryExtensions.cs

@@ -1,5 +1,5 @@
-using System;
+using MQTTnet.Diagnostics;
-using MQTTnet.Diagnostics;
+using System;
 
 namespace MQTTnet.Extensions.ManagedClient
 {
@@ -9,7 +9,7 @@ namespace MQTTnet.Extensions.ManagedClient
         {
             if (factory == null) throw new ArgumentNullException(nameof(factory));
 
-            return new ManagedMqttClient(factory.CreateMqttClient(), factory.DefaultLogger.CreateChildLogger());
+            return new ManagedMqttClient(factory.CreateMqttClient(), factory.DefaultLogger);
         }
 
         public static IManagedMqttClient CreateManagedMqttClient(this IMqttFactory factory, IMqttNetLogger logger)
@@ -17,7 +17,7 @@ namespace MQTTnet.Extensions.ManagedClient
             if (factory == null) throw new ArgumentNullException(nameof(factory));
             if (logger == null) throw new ArgumentNullException(nameof(logger));
 
-            return new ManagedMqttClient(factory.CreateMqttClient(logger), logger.CreateChildLogger());
+            return new ManagedMqttClient(factory.CreateMqttClient(logger), logger);
         }
     }
 }

Source/MQTTnet.Extensions.ManagedClient/ReconnectionResult.cs

@@ -4,6 +4,7 @@
     {
         StillConnected,
         Reconnected,
+        Recovered,
         NotConnected
     }
 }

Source/MQTTnet.Extensions.Rpc/MqttRpcClient.cs

@@ -1,23 +1,32 @@
-using System;
+using MQTTnet.Client;
+using MQTTnet.Exceptions;
+using MQTTnet.Extensions.Rpc.Options;
+using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+using MQTTnet.Protocol;
+using System;
 using System.Collections.Concurrent;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Client;
-using MQTTnet.Exceptions;
-using MQTTnet.Protocol;
 
 namespace MQTTnet.Extensions.Rpc
 {
-    public class MqttRpcClient : IDisposable
+    public sealed class MqttRpcClient : IDisposable
     {
         private readonly ConcurrentDictionary<string, TaskCompletionSource<byte[]>> _waitingCalls = new ConcurrentDictionary<string, TaskCompletionSource<byte[]>>();
         private readonly IMqttClient _mqttClient;
+        private readonly IMqttRpcClientOptions _options;
         private readonly RpcAwareApplicationMessageReceivedHandler _applicationMessageReceivedHandler;
 
-        public MqttRpcClient(IMqttClient mqttClient)
+        [Obsolete("Use MqttRpcClient(IMqttClient mqttClient, IMqttRpcClientOptions options).")]
+        public MqttRpcClient(IMqttClient mqttClient) : this(mqttClient, new MqttRpcClientOptions())
+        {
+        }
+
+        public MqttRpcClient(IMqttClient mqttClient, IMqttRpcClientOptions options)
         {
             _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
+            _options = options ?? throw new ArgumentNullException(nameof(options));
 
             _applicationMessageReceivedHandler = new RpcAwareApplicationMessageReceivedHandler(
                 mqttClient.ApplicationMessageReceivedHandler,
@@ -55,8 +64,26 @@ namespace MQTTnet.Extensions.Rpc
                 throw new InvalidOperationException("The application message received handler was modified.");
             }
 
-            var requestTopic = $"MQTTnet.RPC/{Guid.NewGuid():N}/{methodName}";
+            var topicNames = _options.TopicGenerationStrategy.CreateRpcTopics(new TopicGenerationContext
-            var responseTopic = requestTopic + "/response";
+            {
+                MethodName = methodName,
+                QualityOfServiceLevel = qualityOfServiceLevel,
+                MqttClient = _mqttClient,
+                Options = _options
+            });
+
+            var requestTopic = topicNames.RequestTopic;
+            var responseTopic = topicNames.ResponseTopic;
+
+            if (string.IsNullOrWhiteSpace(requestTopic))
+            {
+                throw new MqttProtocolViolationException("RPC request topic is empty.");
+            }
+
+            if (string.IsNullOrWhiteSpace(responseTopic))
+            {
+                throw new MqttProtocolViolationException("RPC response topic is empty.");
+            }
 
             var requestMessage = new MqttApplicationMessageBuilder()
                 .WithTopic(requestTopic)

Source/MQTTnet.Extensions.Rpc/Options/IMqttRpcClientOptions.cs

@@ -0,0 +1,9 @@
+using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+
+namespace MQTTnet.Extensions.Rpc.Options
+{
+    public interface IMqttRpcClientOptions
+    {
+        IMqttRpcClientTopicGenerationStrategy TopicGenerationStrategy { get; set; }
+    }
+}

Source/MQTTnet.Extensions.Rpc/Options/MqttRpcClientOptions.cs

@@ -0,0 +1,9 @@
+using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+
+namespace MQTTnet.Extensions.Rpc.Options
+{
+    public class MqttRpcClientOptions : IMqttRpcClientOptions
+    {
+        public IMqttRpcClientTopicGenerationStrategy TopicGenerationStrategy { get; set; } = new DefaultMqttRpcClientTopicGenerationStrategy();
+    }
+}

Source/MQTTnet.Extensions.Rpc/Options/MqttRpcClientOptionsBuilder.cs

@@ -0,0 +1,25 @@
+using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+using System;
+
+namespace MQTTnet.Extensions.Rpc.Options
+{
+    public class MqttRpcClientOptionsBuilder
+    {
+        IMqttRpcClientTopicGenerationStrategy _topicGenerationStrategy = new DefaultMqttRpcClientTopicGenerationStrategy();
+
+        public MqttRpcClientOptionsBuilder WithTopicGenerationStrategy(IMqttRpcClientTopicGenerationStrategy value)
+        {
+            _topicGenerationStrategy = value ?? throw new ArgumentNullException(nameof(value));
+
+            return this;
+        }
+
+        public IMqttRpcClientOptions Build()
+        {
+            return new MqttRpcClientOptions
+            {
+                TopicGenerationStrategy = _topicGenerationStrategy
+            };
+        }
+    }
+}

Source/MQTTnet.Extensions.Rpc/Options/MqttRpcTopicPair.cs

@@ -0,0 +1,9 @@
+namespace MQTTnet.Extensions.Rpc.Options
+{
+    public class MqttRpcTopicPair
+    {
+        public string RequestTopic { get; set; }
+
+        public string ResponseTopic { get; set; }
+    }
+}

Source/MQTTnet.Extensions.Rpc/Options/TopicGeneration/DefaultMqttRpcClientTopicGenerationStrategy.cs

@@ -0,0 +1,20 @@
+using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+using System;
+
+namespace MQTTnet.Extensions.Rpc.Options
+{
+    public class DefaultMqttRpcClientTopicGenerationStrategy : IMqttRpcClientTopicGenerationStrategy
+    {
+        public MqttRpcTopicPair CreateRpcTopics(TopicGenerationContext context)
+        {
+            var requestTopic = $"MQTTnet.RPC/{Guid.NewGuid():N}/{context.MethodName}";
+            var responseTopic = requestTopic + "/response";
+
+            return new MqttRpcTopicPair
+            {
+                RequestTopic = requestTopic,
+                ResponseTopic = responseTopic
+            };
+        }
+    }
+}

Source/MQTTnet.Extensions.Rpc/Options/TopicGeneration/IMqttRpcClientTopicGenerationStrategy.cs

@@ -0,0 +1,7 @@
+namespace MQTTnet.Extensions.Rpc.Options.TopicGeneration
+{
+    public interface IMqttRpcClientTopicGenerationStrategy
+    {
+        MqttRpcTopicPair CreateRpcTopics(TopicGenerationContext context);
+    }
+}

Source/MQTTnet.Extensions.Rpc/Options/TopicGeneration/TopicGenerationContext.cs

@@ -0,0 +1,16 @@
+using MQTTnet.Client;
+using MQTTnet.Protocol;
+
+namespace MQTTnet.Extensions.Rpc.Options.TopicGeneration
+{
+    public class TopicGenerationContext
+    {
+        public string MethodName { get; set; }
+
+        public MqttQualityOfServiceLevel QualityOfServiceLevel { get; set; }
+
+        public IMqttClient MqttClient { get; set; }
+
+        public IMqttRpcClientOptions Options { get; set; }
+    }
+}

Source/MQTTnet.Extensions.WebSocket4Net/WebSocket4NetMqttChannel.cs

@@ -85,7 +85,12 @@ namespace MQTTnet.Extensions.WebSocket4Net
             {
                 foreach (var certificate in _webSocketOptions.TlsOptions.Certificates)
                 {
+#if WINDOWS_UWP
                     certificates.Add(new X509Certificate(certificate));
+#else
+                    certificates.Add(certificate);
+#endif
+                    
                 }
             }
 

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/Configuration/CertificateSettingsModel.cs

@@ -0,0 +1,35 @@
+using System.IO;
+
+namespace MQTTnet.Server.Configuration
+{
+    public class CertificateSettingsModel
+    {
+        /// <summary>
+        /// Path to certificate.
+        /// </summary>
+        public string Path { get; set; }
+        
+        /// <summary>
+        /// Password of certificate.
+        /// </summary>
+        public string Password { get; set; }
+
+        /// <summary>
+        /// Read certificate file.
+        /// </summary>
+        public byte[] ReadCertificate()
+        {
+            if (string.IsNullOrEmpty(Path) || string.IsNullOrWhiteSpace(Path))
+            {
+                throw new FileNotFoundException("No path set");
+            }
+
+            if (!File.Exists(Path))
+            {
+                throw new FileNotFoundException($"Could not find Certificate in path: {Path}");
+            }
+
+            return File.ReadAllBytes(Path);
+        }
+    }
+}

Source/MQTTnet.Server/Configuration/TcpEndpointModel.cs

@@ -9,9 +9,9 @@ namespace MQTTnet.Server.Configuration
     public class TcpEndPointModel
     {
         /// <summary>
-        /// Path to Certificate
+        /// Certificate settings.
         /// </summary>
-        public string CertificatePath { get; set; }
+        public CertificateSettingsModel Certificate { get; set; }
 
         /// <summary>
         /// Enabled / Disable
@@ -33,25 +33,6 @@ namespace MQTTnet.Server.Configuration
         /// </summary>
         public int Port { get; set; } = 1883;
 
-        /// <summary>
-        /// Read Certificate file
-        /// </summary>
-        /// <returns></returns>
-        public byte[] ReadCertificate()
-        {
-            if (string.IsNullOrEmpty(CertificatePath) || string.IsNullOrWhiteSpace(CertificatePath))
-            {
-                throw new FileNotFoundException("No path set");
-            }
-
-            if (!File.Exists(CertificatePath))
-            {
-                throw new FileNotFoundException($"Could not find Certificate in path: {CertificatePath}");
-            }
-
-            return File.ReadAllBytes(CertificatePath);
-        }
-
         /// <summary>
         /// Read IPv4
         /// </summary>

Source/MQTTnet.Server/Controllers/ClientsController.cs

@@ -13,7 +13,7 @@ namespace MQTTnet.Server.Controllers
 {
     [Authorize]
     [ApiController]
-    public class ClientsController : ControllerBase
+    public class ClientsController : Controller
     {
         private readonly MqttServerService _mqttServerService;
 

Source/MQTTnet.Server/Controllers/MessagesController.cs

@@ -0,0 +1,51 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using MQTTnet.Protocol;
+using MQTTnet.Server.Mqtt;
+
+namespace MQTTnet.Server.Controllers
+{
+    [Authorize]
+    [ApiController]
+    public class MessagesController : Controller
+    {
+        private readonly MqttServerService _mqttServerService;
+
+        public MessagesController(MqttServerService mqttServerService)
+        {
+            _mqttServerService = mqttServerService ?? throw new ArgumentNullException(nameof(mqttServerService));
+        }
+
+        [Route("api/v1/messages")]
+        [HttpPost]
+        public async Task<ActionResult> PostMessage(MqttApplicationMessage message)
+        {
+            await _mqttServerService.PublishAsync(message);
+            return Ok();
+        }
+
+        [Route("api/v1/messages/{*topic}")]
+        [HttpPost]
+        public async Task<ActionResult> PostMessage(string topic, int qosLevel = 0)
+        {
+            byte[] payload;
+
+            using (var memoryStream = new MemoryStream())
+            {
+                await HttpContext.Request.Body.CopyToAsync(memoryStream);
+                payload = memoryStream.ToArray();
+            }
+
+            var message = new MqttApplicationMessageBuilder()
+                .WithTopic(topic)
+                .WithPayload(payload)
+                .WithQualityOfServiceLevel((MqttQualityOfServiceLevel)qosLevel)
+                .Build();
+
+            return await PostMessage(message);
+        }
+    }
+}

Source/MQTTnet.Server/Controllers/RetainedApplicationMessagesController.cs

@@ -12,7 +12,7 @@ namespace MQTTnet.Server.Controllers
 {
     [Authorize]
     [ApiController]
-    public class RetainedApplicationMessagesController : ControllerBase
+    public class RetainedApplicationMessagesController : Controller
     {
         private readonly MqttServerService _mqttServerService;
 

Source/MQTTnet.Server/Controllers/ServerController.cs

@@ -0,0 +1,18 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using System.Reflection;
+
+namespace MQTTnet.Server.Controllers
+{
+    [Authorize]
+    [ApiController]
+    public class ServerController : Controller
+    {
+        [Route("api/v1/server/version")]
+        [HttpGet]
+        public ActionResult<string> GetVersion()
+        {
+            return Assembly.GetExecutingAssembly().GetCustomAttribute<AssemblyInformationalVersionAttribute>().InformationalVersion;
+        }
+    }
+}

Source/MQTTnet.Server/Controllers/SessionsController.cs

@@ -13,7 +13,7 @@ namespace MQTTnet.Server.Controllers
 {
     [Authorize]
     [ApiController]
-    public class SessionsController : ControllerBase
+    public class SessionsController : Controller
     {
         private readonly MqttServerService _mqttServerService;
 

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

@@ -1,13 +1,13 @@
-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
 {
     public class MqttNetLoggerWrapper : IMqttNetLogger
     {
-        private readonly ILogger<MqttServer> _logger;
+        readonly ILogger<MqttServer> _logger;
 
         public MqttNetLoggerWrapper(ILogger<MqttServer> logger)
         {
@@ -16,25 +16,39 @@ namespace MQTTnet.Server.Logging
 
         public event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
 
-        public IMqttNetChildLogger CreateChildLogger(string source = null)
+        public IMqttNetLogger CreateChildLogger(string source)
         {
-            return new MqttNetChildLoggerWrapper(source, this);
+            return new MqttNetLogger(source);
         }
 
-        public void Publish(MqttNetLogLevel logLevel, string source, string message, object[] parameters, Exception exception)
+        public void Publish(MqttNetLogLevel level, string source, string message, object[] parameters, Exception exception)
         {
-            var convertedLogLevel = ConvertLogLevel(logLevel);
+            var convertedLogLevel = ConvertLogLevel(level);
             _logger.Log(convertedLogLevel, exception, message, parameters);
 
             var logMessagePublishedEvent = LogMessagePublished;
             if (logMessagePublishedEvent != null)
             {
-                var logMessage = new MqttNetLogMessage(null, DateTime.UtcNow, Thread.CurrentThread.ManagedThreadId, source, logLevel, message, exception);
+                var logMessage = new MqttNetLogMessage
+                {
+                    Timestamp = DateTime.UtcNow,
+                    ThreadId = Thread.CurrentThread.ManagedThreadId,
+                    Source = source,
+                    Level = level,
+                    Message = message,
+                    Exception = exception
+                };
+
                 logMessagePublishedEvent.Invoke(this, new MqttNetLogMessagePublishedEventArgs(logMessage));
             }
         }
 
-        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.Server/MQTTnet.Server.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.2</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
     <AssemblyName>MQTTnet.Server</AssemblyName>
     <RootNamespace>MQTTnet.Server</RootNamespace>
@@ -43,14 +43,12 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="IronPython" Version="2.7.9" />
+    <PackageReference Include="IronPython" Version="2.7.10-candidate1" />
-    <PackageReference Include="IronPython.StdLib" Version="2.7.9" />
+    <PackageReference Include="IronPython.StdLib" Version="2.7.10-candidate1" />
-    <PackageReference Include="Microsoft.AspNetCore.App" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.3" />
-    <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.2.0" PrivateAssets="All" />
+    <PackageReference Include="MSTest.TestAdapter" Version="2.1.1" />
-    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.2.0" />
+    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="5.3.1" />
-    <PackageReference Include="Microsoft.AspNetCore.WebSockets" Version="2.2.1" />
+    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" Version="5.3.1" />
-    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="5.0.0-rc2" />
-    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" Version="5.0.0-rc2" />
   </ItemGroup>
 
   <ItemGroup>

Source/MQTTnet.Server/Mqtt/MqttApplicationMessageInterceptor.cs

@@ -22,14 +22,18 @@ namespace MQTTnet.Server.Mqtt
         {
             try
             {
+                // This might be not set when a message was published by the server instead of a client.
+                context.SessionItems.TryGetValue(MqttServerConnectionValidator.WrappedSessionItemsKey, out var sessionItems);
+
                 var pythonContext = new PythonDictionary
                 {
+                    { "client_id", context.ClientId },
+                    { "session_items", sessionItems },
+                    { "retain", context.ApplicationMessage.Retain },
                     { "accept_publish", context.AcceptPublish },
                     { "close_connection", context.CloseConnection },
-                    { "client_id", context.ClientId },
                     { "topic", context.ApplicationMessage.Topic },
-                    { "qos", (int)context.ApplicationMessage.QualityOfServiceLevel },
+                    { "qos", (int)context.ApplicationMessage.QualityOfServiceLevel }
-                    { "retain", context.ApplicationMessage.Retain }
                 };
                 
                 _pythonScriptHostService.InvokeOptionalFunction("on_intercept_application_message", pythonContext);

Source/MQTTnet.Server/Mqtt/MqttServerConnectionValidator.cs

@@ -9,6 +9,8 @@ namespace MQTTnet.Server.Mqtt
 {
     public class MqttServerConnectionValidator : IMqttServerConnectionValidator
     {
+        public const string WrappedSessionItemsKey = "WRAPPED_ITEMS";
+
         private readonly PythonScriptHostService _pythonScriptHostService;
         private readonly ILogger _logger;
 
@@ -22,6 +24,8 @@ namespace MQTTnet.Server.Mqtt
         {
             try
             {
+                var sessionItems = new PythonDictionary();
+
                 var pythonContext = new PythonDictionary
                 {
                     { "endpoint", context.Endpoint },
@@ -33,6 +37,7 @@ namespace MQTTnet.Server.Mqtt
                     { "clean_session", context.CleanSession},
                     { "authentication_method", context.AuthenticationMethod},
                     { "authentication_data", new Bytes(context.AuthenticationData ?? new byte[0]) },
+                    { "session_items", sessionItems },
 
                     { "result", PythonConvert.Pythonfy(context.ReasonCode) }
                 };
@@ -40,6 +45,8 @@ namespace MQTTnet.Server.Mqtt
                 _pythonScriptHostService.InvokeOptionalFunction("on_validate_client_connection", pythonContext);
 
                 context.ReasonCode = PythonConvert.ParseEnum<MqttConnectReasonCode>((string)pythonContext["result"]);
+
+                context.SessionItems[WrappedSessionItemsKey] = sessionItems;
             }
             catch (Exception exception)
             {

Source/MQTTnet.Server/Mqtt/MqttServerService.cs

@@ -1,11 +1,4 @@
-using System;
+using IronPython.Runtime;
-using System.Collections.Generic;
-using System.Linq;
-using System.Net.WebSockets;
-using System.Security.Authentication;
-using System.Text;
-using System.Threading.Tasks;
-using IronPython.Runtime;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Logging;
 using MQTTnet.Adapter;
@@ -16,25 +9,33 @@ using MQTTnet.Protocol;
 using MQTTnet.Server.Configuration;
 using MQTTnet.Server.Scripting;
 using MQTTnet.Server.Status;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.WebSockets;
+using System.Security.Authentication;
+using System.Text;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Server.Mqtt
 {
     public class MqttServerService
     {
-        private readonly ILogger<MqttServerService> _logger;
+        readonly ILogger<MqttServerService> _logger;
 
-        private readonly MqttSettingsModel _settings;
+        readonly MqttSettingsModel _settings;
-        private readonly MqttApplicationMessageInterceptor _mqttApplicationMessageInterceptor;
+        readonly MqttApplicationMessageInterceptor _mqttApplicationMessageInterceptor;
-        private readonly MqttServerStorage _mqttServerStorage;
+        readonly MqttServerStorage _mqttServerStorage;
-        private readonly MqttClientConnectedHandler _mqttClientConnectedHandler;
+        readonly MqttClientConnectedHandler _mqttClientConnectedHandler;
-        private readonly MqttClientDisconnectedHandler _mqttClientDisconnectedHandler;
+        readonly MqttClientDisconnectedHandler _mqttClientDisconnectedHandler;
-        private readonly MqttClientSubscribedTopicHandler _mqttClientSubscribedTopicHandler;
+        readonly MqttClientSubscribedTopicHandler _mqttClientSubscribedTopicHandler;
-        private readonly MqttClientUnsubscribedTopicHandler _mqttClientUnsubscribedTopicHandler;
+        readonly MqttClientUnsubscribedTopicHandler _mqttClientUnsubscribedTopicHandler;
-        private readonly MqttServerConnectionValidator _mqttConnectionValidator;
+        readonly MqttServerConnectionValidator _mqttConnectionValidator;
-        private readonly IMqttServer _mqttServer;
+        readonly IMqttServer _mqttServer;
-        private readonly MqttSubscriptionInterceptor _mqttSubscriptionInterceptor;
+        readonly MqttSubscriptionInterceptor _mqttSubscriptionInterceptor;
-        private readonly PythonScriptHostService _pythonScriptHostService;
+        readonly MqttUnsubscriptionInterceptor _mqttUnsubscriptionInterceptor;
-        private readonly MqttWebSocketServerAdapter _webSocketServerAdapter;
+        readonly PythonScriptHostService _pythonScriptHostService;
+        readonly MqttWebSocketServerAdapter _webSocketServerAdapter;
 
         public MqttServerService(
             MqttSettingsModel mqttSettings,
@@ -45,6 +46,7 @@ namespace MQTTnet.Server.Mqtt
             MqttClientUnsubscribedTopicHandler mqttClientUnsubscribedTopicHandler,
             MqttServerConnectionValidator mqttConnectionValidator,
             MqttSubscriptionInterceptor mqttSubscriptionInterceptor,
+            MqttUnsubscriptionInterceptor mqttUnsubscriptionInterceptor,
             MqttApplicationMessageInterceptor mqttApplicationMessageInterceptor,
             MqttServerStorage mqttServerStorage,
             PythonScriptHostService pythonScriptHostService,
@@ -57,16 +59,17 @@ namespace MQTTnet.Server.Mqtt
             _mqttClientUnsubscribedTopicHandler = mqttClientUnsubscribedTopicHandler ?? throw new ArgumentNullException(nameof(mqttClientUnsubscribedTopicHandler));
             _mqttConnectionValidator = mqttConnectionValidator ?? throw new ArgumentNullException(nameof(mqttConnectionValidator));
             _mqttSubscriptionInterceptor = mqttSubscriptionInterceptor ?? throw new ArgumentNullException(nameof(mqttSubscriptionInterceptor));
+            _mqttUnsubscriptionInterceptor = mqttUnsubscriptionInterceptor ?? throw new ArgumentNullException(nameof(mqttUnsubscriptionInterceptor));
             _mqttApplicationMessageInterceptor = mqttApplicationMessageInterceptor ?? throw new ArgumentNullException(nameof(mqttApplicationMessageInterceptor));
             _mqttServerStorage = mqttServerStorage ?? throw new ArgumentNullException(nameof(mqttServerStorage));
             _pythonScriptHostService = pythonScriptHostService ?? throw new ArgumentNullException(nameof(pythonScriptHostService));
             _logger = logger ?? throw new ArgumentNullException(nameof(logger));
 
-            _webSocketServerAdapter = new MqttWebSocketServerAdapter(mqttFactory.Logger.CreateChildLogger());
+            _webSocketServerAdapter = new MqttWebSocketServerAdapter(mqttFactory.Logger);
 
             var adapters = new List<IMqttServerAdapter>
             {
-                new MqttTcpServerAdapter(mqttFactory.Logger.CreateChildLogger())
+                new MqttTcpServerAdapter(mqttFactory.Logger)
                 {
                     TreatSocketOpeningErrorAsWarning = true // Opening other ports than for HTTP is not allows in Azure App Services.
                 },
@@ -124,7 +127,7 @@ namespace MQTTnet.Server.Mqtt
             return _mqttServer.PublishAsync(applicationMessage);
         }
 
-        private void Publish(PythonDictionary parameters)
+        void Publish(PythonDictionary parameters)
         {
             try
             {
@@ -170,7 +173,7 @@ namespace MQTTnet.Server.Mqtt
             }
         }
 
-        private IMqttServerOptions CreateMqttServerOptions()
+        IMqttServerOptions CreateMqttServerOptions()
         {
             var options = new MqttServerOptionsBuilder()
                 .WithMaxPendingMessagesPerClient(_settings.MaxPendingMessagesPerClient)
@@ -178,6 +181,7 @@ namespace MQTTnet.Server.Mqtt
                 .WithConnectionValidator(_mqttConnectionValidator)
                 .WithApplicationMessageInterceptor(_mqttApplicationMessageInterceptor)
                 .WithSubscriptionInterceptor(_mqttSubscriptionInterceptor)
+                .WithUnsubscriptionInterceptor(_mqttUnsubscriptionInterceptor)
                 .WithStorage(_mqttServerStorage);
 
             // Configure unencrypted connections
@@ -210,8 +214,22 @@ namespace MQTTnet.Server.Mqtt
             {
                 options
                     .WithEncryptedEndpoint()
-                    .WithEncryptionSslProtocol(SslProtocols.Tls12)
+                    .WithEncryptionSslProtocol(SslProtocols.Tls12);
-                    .WithEncryptionCertificate(_settings.EncryptedTcpEndPoint.ReadCertificate());
+
+                if (!string.IsNullOrEmpty(_settings.EncryptedTcpEndPoint?.Certificate?.Path))
+                {
+                    IMqttServerCertificateCredentials certificateCredentials = null;
+
+                    if (!string.IsNullOrEmpty(_settings.EncryptedTcpEndPoint?.Certificate?.Password))
+                    {
+                        certificateCredentials = new MqttServerCertificateCredentials
+                        {
+                            Password = _settings.EncryptedTcpEndPoint.Certificate.Password
+                        };
+                    }
+
+                    options.WithEncryptionCertificate(_settings.EncryptedTcpEndPoint.Certificate.ReadCertificate(), certificateCredentials);
+                }
 
                 if (_settings.EncryptedTcpEndPoint.TryReadIPv4(out var address4))
                 {

Source/MQTTnet.Server/Mqtt/MqttSubscriptionInterceptor.cs

@@ -21,14 +21,16 @@ namespace MQTTnet.Server.Mqtt
         {
             try
             {
+                var sessionItems = (PythonDictionary)context.SessionItems[MqttServerConnectionValidator.WrappedSessionItemsKey];
+
                 var pythonContext = new PythonDictionary
                 {
-                    { "accept_subscription", context.AcceptSubscription },
-                    { "close_connection", context.CloseConnection },
-
                     { "client_id", context.ClientId },
+                    { "session_items", sessionItems },
                     { "topic", context.TopicFilter.Topic },
-                    { "qos", (int)context.TopicFilter.QualityOfServiceLevel }
+                    { "qos", (int)context.TopicFilter.QualityOfServiceLevel },
+                    { "accept_subscription", context.AcceptSubscription },
+                    { "close_connection", context.CloseConnection }
                 };
 
                 _pythonScriptHostService.InvokeOptionalFunction("on_intercept_subscription", pythonContext);

Source/MQTTnet.Server/Mqtt/MqttUnsubscriptionInterceptor.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Threading.Tasks;
+using IronPython.Runtime;
+using Microsoft.Extensions.Logging;
+using MQTTnet.Server.Scripting;
+
+namespace MQTTnet.Server.Mqtt
+{
+    public class MqttUnsubscriptionInterceptor : IMqttServerUnsubscriptionInterceptor
+    {
+        private readonly PythonScriptHostService _pythonScriptHostService;
+        private readonly ILogger _logger;
+
+        public MqttUnsubscriptionInterceptor(PythonScriptHostService pythonScriptHostService, ILogger<MqttUnsubscriptionInterceptor> logger)
+        {
+            _pythonScriptHostService = pythonScriptHostService ?? throw new ArgumentNullException(nameof(pythonScriptHostService));
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }
+
+        public Task InterceptUnsubscriptionAsync(MqttUnsubscriptionInterceptorContext context)
+        {
+            try
+            {
+                var sessionItems = (PythonDictionary)context.SessionItems[MqttServerConnectionValidator.WrappedSessionItemsKey];
+
+                var pythonContext = new PythonDictionary
+                {
+                    { "client_id", context.ClientId },
+                    { "session_items", sessionItems },
+                    { "topic", context.Topic },
+                    { "accept_unsubscription", context.AcceptUnsubscription },
+                    { "close_connection", context.CloseConnection }
+                };
+
+                _pythonScriptHostService.InvokeOptionalFunction("on_intercept_unsubscription", pythonContext);
+
+                context.AcceptUnsubscription = (bool)pythonContext["accept_unsubscription"];
+                context.CloseConnection = (bool)pythonContext["close_connection"];
+            }
+            catch (Exception exception)
+            {
+                _logger.LogError(exception, "Error while intercepting unsubscription.");
+            }
+
+            return Task.CompletedTask;
+        }
+    }
+}

Source/MQTTnet.Server/Program.cs

@@ -1,8 +1,8 @@
-using System;
+using Microsoft.AspNetCore.Hosting;
-using System.Reflection;
+using Microsoft.Extensions.Hosting;
-using Microsoft.AspNetCore;
-using Microsoft.AspNetCore.Hosting;
 using MQTTnet.Server.Web;
+using System;
+using System.Reflection;
 
 namespace MQTTnet.Server
 {
@@ -14,7 +14,15 @@ namespace MQTTnet.Server
             {
                 PrintLogo();
 
-                WebHost.CreateDefaultBuilder(args).UseStartup<Startup>().Build().Run();
+                Host.CreateDefaultBuilder(args)
+                    .ConfigureWebHostDefaults(webBuilder =>
+                    {
+                        webBuilder.ConfigureKestrel(serverOptions =>
+                        {
+                        })
+                        .UseStartup<Startup>();
+
+                    }).Build().Run();
 
                 return 0;
             }
@@ -25,7 +33,7 @@ namespace MQTTnet.Server
             }
         }
 
-        private static void PrintLogo()
+        static void PrintLogo()
         {
             Console.ResetColor();
             Console.ForegroundColor = ConsoleColor.Red;
@@ -46,9 +54,7 @@ namespace MQTTnet.Server
             Console.WriteLine();
             Console.ForegroundColor = ConsoleColor.White;
             Console.WriteLine("The official MQTT server implementation of MQTTnet");
-            Console.WriteLine("Copyright (c) 2017-2019 The MQTTnet Team");
+            Console.WriteLine("Copyright (c) 2017-2020 The MQTTnet Team");
-
-            Console.ForegroundColor = ConsoleColor.Blue;
             Console.WriteLine(@"https://github.com/chkr1011/MQTTnet");
 
             Console.ForegroundColor = ConsoleColor.White;

Source/MQTTnet.Server/Scripting/DataSharing/DataSharingService.cs

@@ -1,14 +1,14 @@
-using System;
+using Microsoft.Extensions.Logging;
+using System;
 using System.Collections.Generic;
-using Microsoft.Extensions.Logging;
 
 namespace MQTTnet.Server.Scripting.DataSharing
 {
     public class DataSharingService
     {
-        private readonly Dictionary<string, object> _storage = new Dictionary<string, object>();
+        readonly Dictionary<string, object> _storage = new Dictionary<string, object>();
-        private readonly PythonScriptHostService _pythonScriptHostService;
+        readonly PythonScriptHostService _pythonScriptHostService;
-        private readonly ILogger<DataSharingService> _logger;
+        readonly ILogger<DataSharingService> _logger;
 
         public DataSharingService(PythonScriptHostService pythonScriptHostService, ILogger<DataSharingService> logger)
         {

Source/MQTTnet.Server/Scripting/PythonIOStream.cs

@@ -1,14 +1,14 @@
-using System;
+using Microsoft.Extensions.Logging;
+using System;
 using System.IO;
 using System.Text;
-using Microsoft.Extensions.Logging;
 
 namespace MQTTnet.Server.Scripting
 {
     public class PythonIOStream : Stream
     {
-        private readonly ILogger _logger;
+        readonly ILogger _logger;
-        private readonly Encoding _encoder = Encoding.UTF8;
+        readonly Encoding _encoder = Encoding.UTF8;
 
         public PythonIOStream(ILogger<PythonIOStream> logger)
         {

Source/MQTTnet.Server/Scripting/PythonScriptHostService.cs

@@ -1,4 +1,8 @@
-using System;
+using Microsoft.Extensions.Logging;
+using Microsoft.Scripting;
+using Microsoft.Scripting.Hosting;
+using MQTTnet.Server.Configuration;
+using System;
 using System.Collections.Generic;
 using System.Dynamic;
 using System.IO;
@@ -6,21 +10,17 @@ using System.Linq;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.Logging;
-using Microsoft.Scripting;
-using Microsoft.Scripting.Hosting;
-using MQTTnet.Server.Configuration;
 
 namespace MQTTnet.Server.Scripting
 {
     public class PythonScriptHostService
     {
-        private readonly IDictionary<string, object> _proxyObjects = new ExpandoObject();
+        readonly IDictionary<string, object> _proxyObjects = new ExpandoObject();
-        private readonly List<PythonScriptInstance> _scriptInstances = new List<PythonScriptInstance>();
+        readonly List<PythonScriptInstance> _scriptInstances = new List<PythonScriptInstance>();
-        private readonly string _scriptsPath;
+        readonly string _scriptsPath;
-        private readonly ScriptingSettingsModel _scriptingSettings;
+        readonly ScriptingSettingsModel _scriptingSettings;
-        private readonly ILogger<PythonScriptHostService> _logger;
+        readonly ILogger<PythonScriptHostService> _logger;
-        private readonly ScriptEngine _scriptEngine;
+        readonly ScriptEngine _scriptEngine;
 
         public PythonScriptHostService(ScriptingSettingsModel scriptingSettings, PythonIOStream pythonIOStream, ILogger<PythonScriptHostService> logger)
         {
@@ -139,7 +139,7 @@ namespace MQTTnet.Server.Scripting
             }
         }
 
-        private async Task TryInitializeScriptAsync(string path)
+        async Task TryInitializeScriptAsync(string path)
         {
             var uid = new FileInfo(path).Name.Replace(".py", string.Empty, StringComparison.OrdinalIgnoreCase);
 
@@ -164,7 +164,7 @@ namespace MQTTnet.Server.Scripting
             }
         }
 
-        private PythonScriptInstance CreateScriptInstance(string uid, string path, string code)
+        PythonScriptInstance CreateScriptInstance(string uid, string path, string code)
         {
             var scriptScope = _scriptEngine.CreateScope();
 
@@ -177,7 +177,7 @@ namespace MQTTnet.Server.Scripting
             return new PythonScriptInstance(uid, path, scriptScope);
         }
 
-        private void AddSearchPaths(ScriptEngine scriptEngine)
+        void AddSearchPaths(ScriptEngine scriptEngine)
         {
             if (_scriptingSettings.IncludePaths?.Any() != true)
             {

Source/MQTTnet.Server/Scripting/PythonScriptInstance.cs

@@ -1,12 +1,12 @@
-using System;
+using IronPython.Runtime;
-using IronPython.Runtime;
 using Microsoft.Scripting.Hosting;
+using System;
 
 namespace MQTTnet.Server.Scripting
 {
     public class PythonScriptInstance
     {
-        private readonly ScriptScope _scriptScope;
+        readonly ScriptScope _scriptScope;
 
         public PythonScriptInstance(string uid, string path, ScriptScope scriptScope)
         {

Source/MQTTnet.Server/Web/Startup.cs

@@ -1,10 +1,5 @@
-using System;
+using Microsoft.AspNetCore.Authentication;
-using System.Collections.Generic;
-using System.Linq;
-using System.Net;
-using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
@@ -16,7 +11,12 @@ using MQTTnet.Server.Logging;
 using MQTTnet.Server.Mqtt;
 using MQTTnet.Server.Scripting;
 using MQTTnet.Server.Scripting.DataSharing;
+using Newtonsoft.Json.Converters;
 using Swashbuckle.AspNetCore.SwaggerUI;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
 
 namespace MQTTnet.Server.Web
 {
@@ -35,33 +35,27 @@ namespace MQTTnet.Server.Web
 
         public void Configure(
             IApplicationBuilder application,
-            IHostingEnvironment environment,
             MqttServerService mqttServerService,
             PythonScriptHostService pythonScriptHostService,
             DataSharingService dataSharingService,
             MqttSettingsModel mqttSettings)
         {
-            if (environment.IsDevelopment())
+            application.UseHsts();
-            {
+            application.UseRouting();
-                application.UseDeveloperExceptionPage();
-            }
-            else
-            {
-                application.UseHsts();
-            }
-
             application.UseCors(x => x
                 .AllowAnyOrigin()
                 .AllowAnyMethod()
-                .AllowAnyHeader()
+                .AllowAnyHeader());
-                .AllowCredentials());
 
             application.UseAuthentication();
+            application.UseAuthorization();
 
             application.UseStaticFiles();
 
-            application.UseHttpsRedirection();
+            application.UseEndpoints(endpoints =>
-            application.UseMvc();
+            {
+                endpoints.MapControllers();
+            });
 
             ConfigureWebSocketEndpoint(application, mqttServerService, mqttSettings);
 
@@ -87,11 +81,14 @@ namespace MQTTnet.Server.Web
         {
             services.AddCors();
 
+
+            services.AddControllers();
+
             services.AddMvc()
-                .SetCompatibilityVersion(CompatibilityVersion.Version_2_2)
+                .SetCompatibilityVersion(CompatibilityVersion.Version_3_0)
-                .AddJsonOptions(options =>
+                .AddNewtonsoftJson(o =>
                 {
-                    options.SerializerSettings.Converters.Add(new Newtonsoft.Json.Converters.StringEnumConverter());
+                    o.SerializerSettings.Converters.Add(new StringEnumConverter());
                 });
 
             ReadMqttSettings(services);
@@ -111,12 +108,11 @@ namespace MQTTnet.Server.Web
             services.AddSingleton<MqttClientUnsubscribedTopicHandler>();
             services.AddSingleton<MqttServerConnectionValidator>();
             services.AddSingleton<MqttSubscriptionInterceptor>();
+            services.AddSingleton<MqttUnsubscriptionInterceptor>();
             services.AddSingleton<MqttApplicationMessageInterceptor>();
 
             services.AddSwaggerGen(c =>
             {
-                c.DescribeAllEnumsAsStrings();
-                
                 var securityScheme = new OpenApiSecurityScheme
                 {
                     Scheme = "Basic",
@@ -156,7 +152,7 @@ namespace MQTTnet.Server.Web
                 .AddCookie();
         }
 
-        private void ReadMqttSettings(IServiceCollection services)
+        void ReadMqttSettings(IServiceCollection services)
         {
             var mqttSettings = new MqttSettingsModel();
             Configuration.Bind("MQTT", mqttSettings);
@@ -167,7 +163,7 @@ namespace MQTTnet.Server.Web
             services.AddSingleton(scriptingSettings);
         }
 
-        private static void ConfigureWebSocketEndpoint(
+        static void ConfigureWebSocketEndpoint(
             IApplicationBuilder application,
             MqttServerService mqttServerService,
             MqttSettingsModel mqttSettings)

Source/MQTTnet.Server/appsettings.json

@@ -27,7 +27,10 @@
             "IPv4": "*",
             "IPv6": "*",
             "Port": 8883,
-            "CertificatePath": "/absolute/path/to/pfx"
+            "Certificate": {
+                "Path": "/absolute/path/to/pfx",
+                "Password": ""
+            }
         },
         "WebSocketEndPoint": {
             "Enabled": true,
@@ -49,11 +52,7 @@
     },
     "Scripting": {
         "ScriptsPath": "Scripts",
-        "IncludePaths": [
+        "IncludePaths": []
-            "Lib",
-            "/usr/lib/python2.7",
-            "C:\\Python27\\Lib"
-        ]
     },
     "Logging": {
         "LogLevel": {

Source/MQTTnet.Server/package.json

@@ -1,12 +0,0 @@
-{
-  "version": "1.0.0",
-  "name": "mqtt.test",
-  "private": true,
-  "devDependencies": {},
-  "dependencies": {
-    "@types/node": "^8.0.46",
-    "mqtt": "^2.15.1",
-    "systemjs": "^0.20.19",
-    "typescript": "^2.3.4"
-  }
-}

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;
@@ -5,34 +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 : 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 IMqttNetLogger _logger;
+        readonly IMqttChannel _channel;
+        readonly MqttPacketReader _packetReader;
 
-        private readonly IMqttNetChildLogger _logger;
+        readonly byte[] _fixedHeaderBuffer = new byte[2];
-        private readonly IMqttChannel _channel;
-        private readonly MqttPacketReader _packetReader;
 
-        private readonly byte[] _fixedHeaderBuffer = new byte[2];
+        SemaphoreSlim _writerSemaphore = new SemaphoreSlim(1, 1);
 
-        private bool _isDisposed;
+        long _bytesReceived;
+        long _bytesSent;
 
-        private long _bytesReceived;
+        public MqttChannelAdapter(IMqttChannel channel, MqttPacketFormatterAdapter packetFormatterAdapter, IMqttNetLogger logger)
-        private long _bytesSent;
-
-        public MqttChannelAdapter(IMqttChannel channel, MqttPacketFormatterAdapter packetFormatterAdapter, IMqttNetChildLogger logger)
         {
             if (logger == null) throw new ArgumentNullException(nameof(logger));
 
@@ -145,7 +143,7 @@ namespace MQTTnet.Adapter
             }
             finally
             {
-                _writerSemaphore.Release();
+                _writerSemaphore?.Release();
             }
         }
 
@@ -209,7 +207,20 @@ 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();
+                _writerSemaphore = null;
+            }
+
+            base.Dispose(disposing);
+        }
+
+        async Task<ReceivedMqttPacket> ReceiveAsync(CancellationToken cancellationToken)
         {
             var readFixedHeaderResult = await _packetReader.ReadFixedHeaderAsync(_fixedHeaderBuffer, cancellationToken).ConfigureAwait(false);
 
@@ -269,29 +280,14 @@ namespace MQTTnet.Adapter
             }
         }
 
-        public void Dispose()
+        static bool IsWrappedException(Exception exception)
-        {
-            _isDisposed = true;
-
-            _channel?.Dispose();
-        }
-
-        private void ThrowIfDisposed()
-        {
-            if (_isDisposed)
-            {
-                throw new ObjectDisposedException(nameof(MqttChannelAdapter));
-            }
-        }
-
-        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/Adapter/MqttConnectingFailedException.cs

@@ -5,12 +5,13 @@ namespace MQTTnet.Adapter
 {
     public class MqttConnectingFailedException : MqttCommunicationException
     {
-        public MqttConnectingFailedException(MqttClientConnectResultCode resultCode)
+        public MqttConnectingFailedException(MqttClientAuthenticateResult result)
-            : base($"Connecting with MQTT server failed ({resultCode.ToString()}).")
+            : base($"Connecting with MQTT server failed ({result.ResultCode.ToString()}).")
         {
-            ResultCode = resultCode;
+            Result = result;
         }
 
-        public MqttClientConnectResultCode ResultCode { get; }
+        public MqttClientAuthenticateResult Result { get; }
+        public MqttClientConnectResultCode ResultCode => Result.ResultCode;
     }
 }

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;
@@ -17,26 +13,34 @@ 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
 {
-    public class MqttClient : IMqttClient
+    public class MqttClient : Disposable, IMqttClient
     {
-        private readonly MqttPacketIdentifierProvider _packetIdentifierProvider = new MqttPacketIdentifierProvider();
+        readonly MqttPacketIdentifierProvider _packetIdentifierProvider = new MqttPacketIdentifierProvider();
-        private readonly MqttPacketDispatcher _packetDispatcher = new MqttPacketDispatcher();
+        readonly MqttPacketDispatcher _packetDispatcher = new MqttPacketDispatcher();
-        private readonly Stopwatch _sendTracker = new Stopwatch();
+        readonly Stopwatch _sendTracker = new Stopwatch();
-        private readonly object _disconnectLock = new object();
+        readonly Stopwatch _receiveTracker = new Stopwatch();
+        readonly object _disconnectLock = new object();
 
-        private readonly IMqttClientAdapterFactory _adapterFactory;
+        readonly IMqttClientAdapterFactory _adapterFactory;
-        private readonly IMqttNetChildLogger _logger;
+        readonly IMqttNetLogger _logger;
 
-        private CancellationTokenSource _backgroundCancellationTokenSource;
+        CancellationTokenSource _backgroundCancellationTokenSource;
-        private Task _packetReceiverTask;
+        Task _packetReceiverTask;
-        private Task _keepAlivePacketsSenderTask;
+        Task _keepAlivePacketsSenderTask;
+        Task _publishPacketReceiverTask;
 
-        private IMqttChannelAdapter _adapter;
+        AsyncQueue<MqttPublishPacket> _publishPacketReceiverQueue;
-        private bool _cleanDisconnectInitiated;
+
-        private long _disconnectGate;
+        IMqttChannelAdapter _adapter;
+        bool _cleanDisconnectInitiated;
+        long _disconnectGate;
 
         public MqttClient(IMqttClientAdapterFactory channelFactory, IMqttNetLogger logger)
         {
@@ -63,6 +67,8 @@ namespace MQTTnet.Client
 
             ThrowIfConnected("It is not allowed to connect with a server after the connection is established.");
 
+            ThrowIfDisposed();
+
             MqttClientAuthenticateResult authenticateResult = null;
 
             try
@@ -79,15 +85,22 @@ namespace MQTTnet.Client
                 var adapter = _adapterFactory.CreateClientAdapter(options, _logger);
                 _adapter = adapter;
 
-                _logger.Verbose($"Trying to connect with server '{options.ChannelOptions}' (Timeout={options.CommunicationTimeout}).");
+                using (var combined = CancellationTokenSource.CreateLinkedTokenSource(backgroundCancellationToken, cancellationToken))
-                await _adapter.ConnectAsync(options.CommunicationTimeout, cancellationToken).ConfigureAwait(false);
+                {
-                _logger.Verbose("Connection with server established.");
+                    _logger.Verbose($"Trying to connect with server '{options.ChannelOptions}' (Timeout={options.CommunicationTimeout}).");
+                    await _adapter.ConnectAsync(options.CommunicationTimeout, combined.Token).ConfigureAwait(false);
+                    _logger.Verbose("Connection with server established.");
 
-                _packetReceiverTask = Task.Run(() => TryReceivePacketsAsync(backgroundCancellationToken), backgroundCancellationToken);
+                    _publishPacketReceiverQueue = new AsyncQueue<MqttPublishPacket>();
+                    _publishPacketReceiverTask = Task.Run(() => ProcessReceivedPublishPackets(backgroundCancellationToken), backgroundCancellationToken);
 
-                authenticateResult = await AuthenticateAsync(adapter, options.WillMessage, cancellationToken).ConfigureAwait(false);
+                    _packetReceiverTask = Task.Run(() => TryReceivePacketsAsync(backgroundCancellationToken), backgroundCancellationToken);
+
+                    authenticateResult = await AuthenticateAsync(adapter, options.WillMessage, combined.Token).ConfigureAwait(false);
+                }
 
                 _sendTracker.Restart();
+                _receiveTracker.Restart();
 
                 if (Options.KeepAlivePeriod != TimeSpan.Zero)
                 {
@@ -121,6 +134,10 @@ namespace MQTTnet.Client
 
         public async Task DisconnectAsync(MqttClientDisconnectOptions options, CancellationToken cancellationToken)
         {
+            if (options is null) throw new ArgumentNullException(nameof(options));
+
+            ThrowIfDisposed();
+
             try
             {
                 _cleanDisconnectInitiated = true;
@@ -144,6 +161,9 @@ namespace MQTTnet.Client
         {
             if (data == null) throw new ArgumentNullException(nameof(data));
 
+            ThrowIfDisposed();
+            ThrowIfNotConnected();
+
             return SendAsync(new MqttAuthPacket
             {
                 Properties = new MqttAuthPacketProperties
@@ -161,6 +181,7 @@ namespace MQTTnet.Client
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
 
+            ThrowIfDisposed();
             ThrowIfNotConnected();
 
             var subscribePacket = _adapter.PacketFormatterAdapter.DataConverter.CreateSubscribePacket(options);
@@ -174,6 +195,7 @@ namespace MQTTnet.Client
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
 
+            ThrowIfDisposed();
             ThrowIfNotConnected();
 
             var unsubscribePacket = _adapter.PacketFormatterAdapter.DataConverter.CreateUnsubscribePacket(options);
@@ -189,6 +211,7 @@ namespace MQTTnet.Client
 
             MqttTopicValidator.ThrowIfInvalid(applicationMessage.Topic);
 
+            ThrowIfDisposed();
             ThrowIfNotConnected();
 
             var publishPacket = _adapter.PacketFormatterAdapter.DataConverter.CreatePublishPacket(applicationMessage);
@@ -214,17 +237,32 @@ namespace MQTTnet.Client
             }
         }
 
-        public void Dispose()
+        void Cleanup()
         {
             _backgroundCancellationTokenSource?.Cancel(false);
             _backgroundCancellationTokenSource?.Dispose();
             _backgroundCancellationTokenSource = null;
 
+            _publishPacketReceiverQueue?.Dispose();
+            _publishPacketReceiverQueue = null;
+
             _adapter?.Dispose();
-            _adapter = null;
         }
 
-        private async Task<MqttClientAuthenticateResult> AuthenticateAsync(IMqttChannelAdapter channelAdapter, MqttApplicationMessage willApplicationMessage, CancellationToken cancellationToken)
+
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                Cleanup();
+
+                DisconnectedHandler = null;
+            }
+
+            base.Dispose(disposing);
+        }
+
+        async Task<MqttClientAuthenticateResult> AuthenticateAsync(IMqttChannelAdapter channelAdapter, MqttApplicationMessage willApplicationMessage, CancellationToken cancellationToken)
         {
             var connectPacket = channelAdapter.PacketFormatterAdapter.DataConverter.CreateConnectPacket(
                 willApplicationMessage,
@@ -235,7 +273,7 @@ namespace MQTTnet.Client
 
             if (result.ResultCode != MqttClientConnectResultCode.Success)
             {
-                throw new MqttConnectingFailedException(result.ResultCode);
+                throw new MqttConnectingFailedException(result);
             }
 
             _logger.Verbose("Authenticated MQTT connection with server established.");
@@ -243,22 +281,21 @@ namespace MQTTnet.Client
             return result;
         }
 
-        private void ThrowIfNotConnected()
+        void ThrowIfNotConnected()
         {
             if (!IsConnected || Interlocked.Read(ref _disconnectGate) == 1) throw new MqttCommunicationException("The client is not connected.");
         }
 
-        private void ThrowIfConnected(string message)
+        void ThrowIfConnected(string message)
         {
             if (IsConnected) throw new MqttProtocolViolationException(message);
         }
 
-        private async Task DisconnectInternalAsync(Task sender, Exception exception, MqttClientAuthenticateResult authenticateResult)
+        async Task DisconnectInternalAsync(Task sender, Exception exception, MqttClientAuthenticateResult authenticateResult)
         {
             var clientWasConnected = IsConnected;
 
-            InitiateDisconnect();
+            TryInitiateDisconnect();
-
             IsConnected = false;
 
             try
@@ -269,18 +306,30 @@ namespace MQTTnet.Client
                     await _adapter.DisconnectAsync(Options.CommunicationTimeout, CancellationToken.None).ConfigureAwait(false);
                 }
 
-                await WaitForTaskAsync(_packetReceiverTask, sender).ConfigureAwait(false);
-                await WaitForTaskAsync(_keepAlivePacketsSenderTask, sender).ConfigureAwait(false);
-
                 _logger.Verbose("Disconnected from adapter.");
             }
             catch (Exception adapterException)
             {
                 _logger.Warning(adapterException, "Error while disconnecting from adapter.");
             }
+
+            try
+            {
+                var receiverTask = WaitForTaskAsync(_packetReceiverTask, sender);
+                var publishPacketReceiverTask = WaitForTaskAsync(_publishPacketReceiverTask, sender);
+                var keepAliveTask = WaitForTaskAsync(_keepAlivePacketsSenderTask, sender);
+
+                await Task.WhenAll(receiverTask, publishPacketReceiverTask, keepAliveTask).ConfigureAwait(false);
+
+                _publishPacketReceiverQueue.Dispose();
+            }
+            catch (Exception e)
+            {
+                _logger.Warning(e, "Error while waiting for internal tasks.");
+            }
             finally
             {
-                Dispose();
+                Cleanup();
                 _cleanDisconnectInitiated = false;
 
                 _logger.Info("Disconnected.");
@@ -295,7 +344,7 @@ namespace MQTTnet.Client
             }
         }
 
-        private void InitiateDisconnect()
+        void TryInitiateDisconnect()
         {
             lock (_disconnectLock)
             {
@@ -327,7 +376,7 @@ namespace MQTTnet.Client
             return _adapter.SendPacketAsync(packet, Options.CommunicationTimeout, cancellationToken);
         }
 
-        private async Task<TResponsePacket> SendAndReceiveAsync<TResponsePacket>(MqttBasePacket requestPacket, CancellationToken cancellationToken) where TResponsePacket : MqttBasePacket
+        async Task<TResponsePacket> SendAndReceiveAsync<TResponsePacket>(MqttBasePacket requestPacket, CancellationToken cancellationToken) where TResponsePacket : MqttBasePacket
         {
             cancellationToken.ThrowIfCancellationRequested();
 
@@ -344,17 +393,32 @@ namespace MQTTnet.Client
                 try
                 {
                     await _adapter.SendPacketAsync(requestPacket, Options.CommunicationTimeout, cancellationToken).ConfigureAwait(false);
-                    return await packetAwaiter.WaitOneAsync(Options.CommunicationTimeout).ConfigureAwait(false);
                 }
-                catch (MqttCommunicationTimedOutException)
+                catch (Exception e)
                 {
-                    _logger.Warning(null, "Timeout while waiting for packet of type '{0}'.", typeof(TResponsePacket).Name);
+                    _logger.Warning(e, "Error when sending packet of type '{0}'.", typeof(TResponsePacket).Name);
+                    packetAwaiter.Cancel();
+                }
+
+                try
+                {
+                    var response = await packetAwaiter.WaitOneAsync(Options.CommunicationTimeout).ConfigureAwait(false);
+                    _receiveTracker.Restart();
+                    return response;
+                }
+                catch (Exception exception)
+                {
+                    if (exception is MqttCommunicationTimedOutException)
+                    {
+                        _logger.Warning(null, "Timeout while waiting for packet of type '{0}'.", typeof(TResponsePacket).Name);
+                    }
+
                     throw;
                 }
             }
         }
 
-        private async Task TrySendKeepAliveMessagesAsync(CancellationToken cancellationToken)
+        async Task TrySendKeepAliveMessagesAsync(CancellationToken cancellationToken)
         {
             try
             {
@@ -369,14 +433,14 @@ namespace MQTTnet.Client
                         keepAliveSendInterval = Options.KeepAliveSendInterval.Value;
                     }
 
-                    var waitTime = keepAliveSendInterval - _sendTracker.Elapsed;
+                    var waitTimeSend = keepAliveSendInterval - _sendTracker.Elapsed;
-                    if (waitTime <= TimeSpan.Zero)
+                    var waitTimeReceive = keepAliveSendInterval - _receiveTracker.Elapsed;
+                    if (waitTimeSend <= TimeSpan.Zero || waitTimeReceive <= TimeSpan.Zero)
                     {
                         await SendAndReceiveAsync<MqttPingRespPacket>(new MqttPingReqPacket(), cancellationToken).ConfigureAwait(false);
-                        waitTime = keepAliveSendInterval;
                     }
 
-                    await Task.Delay(waitTime, cancellationToken).ConfigureAwait(false);
+                    await Task.Delay(keepAliveSendInterval, cancellationToken).ConfigureAwait(false);
                 }
             }
             catch (Exception exception)
@@ -391,11 +455,11 @@ namespace MQTTnet.Client
                 }
                 else if (exception is MqttCommunicationException)
                 {
-                    _logger.Warning(exception, "MQTT communication exception while sending/receiving keep alive packets.");
+                    _logger.Warning(exception, "Communication error while sending/receiving keep alive packets.");
                 }
                 else
                 {
-                    _logger.Error(exception, "Unhandled exception while sending/receiving keep alive packets.");
+                    _logger.Error(exception, "Error exception while sending/receiving keep alive packets.");
                 }
 
                 if (!DisconnectIsPending())
@@ -409,7 +473,7 @@ namespace MQTTnet.Client
             }
         }
 
-        private async Task TryReceivePacketsAsync(CancellationToken cancellationToken)
+        async Task TryReceivePacketsAsync(CancellationToken cancellationToken)
         {
             try
             {
@@ -449,11 +513,11 @@ namespace MQTTnet.Client
                 }
                 else if (exception is MqttCommunicationException)
                 {
-                    _logger.Warning(exception, "MQTT communication exception while receiving packets.");
+                    _logger.Warning(exception, "Communication error while receiving packets.");
                 }
                 else
                 {
-                    _logger.Error(exception, "Unhandled exception while receiving packets.");
+                    _logger.Error(exception, "Error while receiving packets.");
                 }
 
                 _packetDispatcher.Dispatch(exception);
@@ -469,13 +533,15 @@ namespace MQTTnet.Client
             }
         }
 
-        private async Task TryProcessReceivedPacketAsync(MqttBasePacket packet, CancellationToken cancellationToken)
+        async Task TryProcessReceivedPacketAsync(MqttBasePacket packet, CancellationToken cancellationToken)
         {
             try
             {
+                _receiveTracker.Restart();
+
                 if (packet is MqttPublishPacket publishPacket)
                 {
-                    await TryProcessReceivedPublishPacketAsync(publishPacket, cancellationToken).ConfigureAwait(false);
+                    EnqueueReceivedPublishPacket(publishPacket);
                 }
                 else if (packet is MqttPubRelPacket pubRelPacket)
                 {
@@ -521,11 +587,11 @@ namespace MQTTnet.Client
                 }
                 else if (exception is MqttCommunicationException)
                 {
-                    _logger.Warning(exception, "MQTT communication exception while receiving packets.");
+                    _logger.Warning(exception, "Communication error while receiving packets.");
                 }
                 else
                 {
-                    _logger.Error(exception, "Unhandled exception while receiving packets.");
+                    _logger.Error(exception, "Error while receiving packets.");
                 }
 
                 _packetDispatcher.Dispatch(exception);
@@ -537,64 +603,88 @@ namespace MQTTnet.Client
             }
         }
 
-        private async Task TryProcessReceivedPublishPacketAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
+        void EnqueueReceivedPublishPacket(MqttPublishPacket publishPacket)
         {
             try
             {
-                if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtMostOnce)
+                _publishPacketReceiverQueue.Enqueue(publishPacket);
-                {
-                    await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false);
-                }
-                else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtLeastOnce)
-                {
-                    if (await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false))
-                    {
-                        await SendAsync(new MqttPubAckPacket
-                        {
-                            PacketIdentifier = publishPacket.PacketIdentifier,
-                            ReasonCode = MqttPubAckReasonCode.Success
-                        }, cancellationToken).ConfigureAwait(false);
-                    }
-                }
-                else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
-                {
-                    if (await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false))
-                    {
-                        var pubRecPacket = new MqttPubRecPacket
-                        {
-                            PacketIdentifier = publishPacket.PacketIdentifier,
-                            ReasonCode = MqttPubRecReasonCode.Success
-                        };
-
-                        await SendAsync(pubRecPacket, cancellationToken).ConfigureAwait(false);
-                    }                    
-                }
-                else
-                {
-                    throw new MqttProtocolViolationException("Received a not supported QoS level.");
-                }
             }
             catch (Exception exception)
             {
-                _logger.Error(exception, "Unhandled exception while handling application message.");
+                _logger.Error(exception, "Error while enqueueing application message.");
             }
         }
 
-        private async Task<MqttClientPublishResult> PublishAtMostOnce(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
+        async Task ProcessReceivedPublishPackets(CancellationToken cancellationToken)
+        {
+            while (!cancellationToken.IsCancellationRequested)
+            {
+                try
+                {
+                    var publishPacketDequeueResult = await _publishPacketReceiverQueue.TryDequeueAsync(cancellationToken);
+
+                    if (!publishPacketDequeueResult.IsSuccess)
+                    {
+                        return;
+                    }
+
+                    var publishPacket = publishPacketDequeueResult.Item;
+
+                    if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtMostOnce)
+                    {
+                        await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false);
+                    }
+                    else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtLeastOnce)
+                    {
+                        if (await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false))
+                        {
+                            await SendAsync(new MqttPubAckPacket
+                            {
+                                PacketIdentifier = publishPacket.PacketIdentifier,
+                                ReasonCode = MqttPubAckReasonCode.Success
+                            }, cancellationToken).ConfigureAwait(false);
+                        }
+                    }
+                    else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
+                    {
+                        if (await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false))
+                        {
+                            var pubRecPacket = new MqttPubRecPacket
+                            {
+                                PacketIdentifier = publishPacket.PacketIdentifier,
+                                ReasonCode = MqttPubRecReasonCode.Success
+                            };
+
+                            await SendAsync(pubRecPacket, cancellationToken).ConfigureAwait(false);
+                        }
+                    }
+                    else
+                    {
+                        throw new MqttProtocolViolationException("Received a not supported QoS level.");
+                    }
+                }
+                catch (Exception exception)
+                {
+                    _logger.Error(exception, "Error while handling application message.");
+                }
+            }
+        }
+
+        async Task<MqttClientPublishResult> PublishAtMostOnce(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
         {
             // No packet identifier is used for QoS 0 [3.3.2.2 Packet Identifier]
             await SendAsync(publishPacket, cancellationToken).ConfigureAwait(false);
             return _adapter.PacketFormatterAdapter.DataConverter.CreatePublishResult(null);
         }
 
-        private async Task<MqttClientPublishResult> PublishAtLeastOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
+        async Task<MqttClientPublishResult> PublishAtLeastOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
         {
             publishPacket.PacketIdentifier = _packetIdentifierProvider.GetNextPacketIdentifier();
             var response = await SendAndReceiveAsync<MqttPubAckPacket>(publishPacket, cancellationToken).ConfigureAwait(false);
             return _adapter.PacketFormatterAdapter.DataConverter.CreatePublishResult(response);
         }
 
-        private async Task<MqttClientPublishResult> PublishExactlyOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
+        async Task<MqttClientPublishResult> PublishExactlyOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
         {
             publishPacket.PacketIdentifier = _packetIdentifierProvider.GetNextPacketIdentifier();
 
@@ -611,7 +701,7 @@ namespace MQTTnet.Client
             return _adapter.PacketFormatterAdapter.DataConverter.CreatePublishResult(pubRecPacket, pubCompPacket);
         }
 
-        private async Task<bool> HandleReceivedApplicationMessageAsync(MqttPublishPacket publishPacket)
+        async Task<bool> HandleReceivedApplicationMessageAsync(MqttPublishPacket publishPacket)
         {
             var applicationMessage = _adapter.PacketFormatterAdapter.DataConverter.CreateApplicationMessage(publishPacket);
 
@@ -626,15 +716,25 @@ namespace MQTTnet.Client
             return true;
         }
 
-        private static async Task WaitForTaskAsync(Task task, Task sender)
+        async Task WaitForTaskAsync(Task task, Task sender)
         {
-            if (task == sender || task == null)
+            if (task == null)
             {
                 return;
             }
 
-            if (task.IsCanceled || task.IsCompleted || task.IsFaulted)
+            if (task == sender)
             {
+                // Return here to avoid deadlocks, but first any eventual exception in the task
+                // must be handled to avoid not getting an unhandled task exception
+                if (!task.IsFaulted)
+                {
+                    return;
+                }
+
+                // By accessing the Exception property the exception is considered handled and will
+                // not result in an unhandled task exception later by the finalizer
+                _logger.Warning(task.Exception, "Error while waiting for background task.");
                 return;
             }
 
@@ -647,7 +747,7 @@ namespace MQTTnet.Client
             }
         }
 
-        private bool DisconnectIsPending()
+        bool DisconnectIsPending()
         {
             return Interlocked.CompareExchange(ref _disconnectGate, 1, 0) != 0;
         }

Source/MQTTnet/Client/MqttClientExtensions.cs

@@ -1,8 +1,4 @@
-using System;
+using MQTTnet.Client.Connecting;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
 using MQTTnet.Client.ExtendedAuthenticationExchange;
 using MQTTnet.Client.Options;
@@ -11,6 +7,10 @@ using MQTTnet.Client.Receiving;
 using MQTTnet.Client.Subscribing;
 using MQTTnet.Client.Unsubscribing;
 using MQTTnet.Protocol;
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace MQTTnet.Client
 {
@@ -128,7 +128,7 @@ namespace MQTTnet.Client
         {
             if (client == null) throw new ArgumentNullException(nameof(client));
 
-            return client.DisconnectAsync(null);
+            return client.DisconnectAsync(new MqttClientDisconnectOptions());
         }
 
         public static Task<MqttClientSubscribeResult> SubscribeAsync(this IMqttClient client, params TopicFilter[] topicFilters)

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)
         {
@@ -139,6 +139,13 @@ namespace MQTTnet.Client.Options
             return this;
         }
 
+        public MqttClientOptionsBuilder WithCredentials(IMqttClientCredentials credentials)
+        {
+            _options.Credentials = credentials;
+
+            return this;
+        }
+
         public MqttClientOptionsBuilder WithExtendedAuthenticationExchangeHandler(IMqttExtendedAuthenticationExchangeHandler handler)
         {
             _options.ExtendedAuthenticationExchangeHandler = handler;
@@ -249,7 +256,11 @@ namespace MQTTnet.Client.Options
                         UseTls = true,
                         SslProtocol = _tlsParameters.SslProtocol,
                         AllowUntrustedCertificates = _tlsParameters.AllowUntrustedCertificates,
+#if WINDOWS_UWP
                         Certificates = _tlsParameters.Certificates?.Select(c => c.ToArray()).ToList(),
+#else
+                        Certificates = _tlsParameters.Certificates?.ToList(),
+#endif
                         CertificateValidationCallback = _tlsParameters.CertificateValidationCallback,
                         IgnoreCertificateChainErrors = _tlsParameters.IgnoreCertificateChainErrors,
                         IgnoreCertificateRevocationErrors = _tlsParameters.IgnoreCertificateRevocationErrors

Source/MQTTnet/Client/Options/MqttClientOptionsBuilderTlsParameters.cs

@@ -18,7 +18,12 @@ namespace MQTTnet.Client.Options
 
         public SslProtocols SslProtocol { get; set; } = SslProtocols.Tls12;
 
+#if WINDOWS_UWP
         public IEnumerable<IEnumerable<byte>> Certificates { get; set; }
+#else
+        public IEnumerable<X509Certificate> Certificates { get; set; }
+#endif
+        
 
         public bool AllowUntrustedCertificates { get; set; }
 

Source/MQTTnet/Client/Options/MqttClientTlsOptions.cs

@@ -15,8 +15,11 @@ namespace MQTTnet.Client.Options
         public bool IgnoreCertificateChainErrors { get; set; }
 
         public bool AllowUntrustedCertificates { get; set; }
-
+#if WINDOWS_UWP
         public List<byte[]> Certificates { get; set; }
+#else
+        public List<X509Certificate> Certificates { get; set; }
+#endif
 
         public SslProtocols SslProtocol { get; set; } = SslProtocols.Tls12;
 

Source/MQTTnet/Client/Unsubscribing/MqttClientUnsubscribeOptionsBuilder.cs

@@ -0,0 +1,59 @@
+using MQTTnet.Packets;
+using System;
+using System.Collections.Generic;
+
+namespace MQTTnet.Client.Unsubscribing
+{
+    public class MqttClientUnsubscribeOptionsBuilder
+    {
+        private readonly MqttClientUnsubscribeOptions _unsubscribeOptions = new MqttClientUnsubscribeOptions();
+
+        public MqttClientUnsubscribeOptionsBuilder WithUserProperty(string name, string value)
+        {
+            if (name is null) throw new ArgumentNullException(nameof(name));
+            if (value is null) throw new ArgumentNullException(nameof(value));
+
+            return WithUserProperty(new MqttUserProperty(name, value));
+        }
+
+        public MqttClientUnsubscribeOptionsBuilder WithUserProperty(MqttUserProperty userProperty)
+        {
+            if (userProperty is null) throw new ArgumentNullException(nameof(userProperty));
+
+            if (_unsubscribeOptions.UserProperties is null)
+            {
+                _unsubscribeOptions.UserProperties = new List<MqttUserProperty>();
+            }
+
+            _unsubscribeOptions.UserProperties.Add(userProperty);
+
+            return this;
+        }
+
+        public MqttClientUnsubscribeOptionsBuilder WithTopicFilter(string topic)
+        {
+            if (topic is null) throw new ArgumentNullException(nameof(topic));
+
+            if (_unsubscribeOptions.TopicFilters is null)
+            {
+                _unsubscribeOptions.TopicFilters = new List<string>();
+            }
+
+            _unsubscribeOptions.TopicFilters.Add(topic);
+
+            return this;
+        }
+
+        public MqttClientUnsubscribeOptionsBuilder WithTopicFilter(TopicFilter topicFilter)
+        {
+            if (topicFilter is null) throw new ArgumentNullException(nameof(topicFilter));
+
+            return WithTopicFilter(topicFilter.Topic);
+        }
+
+        public MqttClientUnsubscribeOptions Build()
+        {
+            return _unsubscribeOptions;
+        }
+    }
+}

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);
 
-        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/MqttNetLogMessage.cs

@@ -4,30 +4,19 @@ namespace MQTTnet.Diagnostics
 {
     public class MqttNetLogMessage
     {
-        public MqttNetLogMessage(string logId, DateTime timestamp, int threadId, string source, MqttNetLogLevel level, string message, Exception exception)
+        public string LogId { get; set; }
-        {
-            LogId = logId;
-            Timestamp = timestamp;
-            ThreadId = threadId;
-            Source = source;
-            Level = level;
-            Message = message;
-            Exception = exception;
-        }
 
-        public string LogId { get; }
+        public DateTime Timestamp { get; set; }
 
-        public DateTime Timestamp { get; }
+        public int ThreadId { get; set; }
 
-        public int ThreadId { get; }
+        public string Source { get; set; }
 
-        public string Source { get; }
+        public MqttNetLogLevel Level { get; set; }
 
-        public MqttNetLogLevel Level { get; }
+        public string Message { get; set; }
 
-        public string Message { get; }
+        public Exception Exception { get; set; }
-
-        public Exception Exception { get; }
 
         public override string ToString()
         {

Source/MQTTnet/Diagnostics/MqttNetLogMessagePublishedEventArgs.cs

@@ -6,9 +6,16 @@ namespace MQTTnet.Diagnostics
     {
         public MqttNetLogMessagePublishedEventArgs(MqttNetLogMessage logMessage)
         {
+            LogMessage = logMessage ?? throw new ArgumentNullException(nameof(logMessage));
+
+#pragma warning disable CS0618 // Type or member is obsolete
             TraceMessage = logMessage ?? throw new ArgumentNullException(nameof(logMessage));
+#pragma warning restore CS0618 // Type or member is obsolete
         }
 
+        [Obsolete("Use new proeprty LogMessage instead.")]
         public MqttNetLogMessage TraceMessage { get; }
+
+        public MqttNetLogMessage LogMessage { get; }
     }
 }

Source/MQTTnet/Diagnostics/MqttNetLogger.cs

@@ -4,26 +4,51 @@ namespace MQTTnet.Diagnostics
 {
     public class MqttNetLogger : IMqttNetLogger
     {
-        private readonly string _logId;
+        readonly string _logId;
+        readonly string _source;
 
-        public MqttNetLogger(string logId = null)
+        readonly MqttNetLogger _parentLogger;
+
+        public MqttNetLogger(string source, string logId)
         {
+            _source = source;
+            _logId = logId;
+        }
+
+        public MqttNetLogger()
+        {
+        }
+
+        public MqttNetLogger(string logId)
+        {
+            _logId = logId;
+        }
+
+        MqttNetLogger(MqttNetLogger parentLogger, string logId, string source)
+        {
+            _parentLogger = parentLogger ?? throw new ArgumentNullException(nameof(parentLogger));
+            _source = source ?? throw new ArgumentNullException(nameof(source));
+
             _logId = logId;
         }
 
         public event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;
 
-        public IMqttNetChildLogger CreateChildLogger(string source = null)
+        // TODO: Consider creating a LoggerFactory which will allow creating loggers. The logger factory will
+        // be the only place which has the published event.
+        public IMqttNetLogger CreateChildLogger(string source)
         {
-            return new MqttNetChildLogger(this, source);
+            if (source is null) throw new ArgumentNullException(nameof(source));
+
+            return new MqttNetLogger(this, _logId, source);
         }
 
-        public void Publish(MqttNetLogLevel logLevel, string source, string message, object[] parameters, Exception exception)
+        public void Publish(MqttNetLogLevel level, string message, object[] parameters, Exception exception)
         {
             var hasLocalListeners = LogMessagePublished != null;
             var hasGlobalListeners = MqttNetGlobalLogger.HasListeners;
 
-            if (!hasLocalListeners && !hasGlobalListeners)
+            if (!hasLocalListeners && !hasGlobalListeners && _parentLogger == null)
             {
                 return;
             }
@@ -40,17 +65,35 @@ namespace MQTTnet.Diagnostics
                 }
             }
 
-            var traceMessage = new MqttNetLogMessage(_logId, DateTime.UtcNow, Environment.CurrentManagedThreadId, source, logLevel, message, exception);
+            var logMessage = new MqttNetLogMessage
+            {
+                LogId = _logId,
+                Timestamp = DateTime.UtcNow,
+                Source = _source,
+                ThreadId = Environment.CurrentManagedThreadId,
+                Level = level,
+                Message = message,
+                Exception = exception
+            };
 
             if (hasGlobalListeners)
             {
-                MqttNetGlobalLogger.Publish(traceMessage);
+                MqttNetGlobalLogger.Publish(logMessage);
             }
 
             if (hasLocalListeners)
             {
-                LogMessagePublished?.Invoke(this, new MqttNetLogMessagePublishedEventArgs(traceMessage));
+                LogMessagePublished?.Invoke(this, new MqttNetLogMessagePublishedEventArgs(logMessage));
             }
+
+            _parentLogger?.Publish(logMessage);
+        }
+
+        void Publish(MqttNetLogMessage logMessage)
+        {
+            LogMessagePublished?.Invoke(this, new MqttNetLogMessagePublishedEventArgs(logMessage));
+
+            _parentLogger?.Publish(logMessage);
         }
     }
 }

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/Exceptions/MqttConfigurationException.cs

@@ -0,0 +1,21 @@
+using System;
+
+namespace MQTTnet.Exceptions
+{
+    public class MqttConfigurationException : Exception
+    {
+        protected MqttConfigurationException()
+        {
+        }
+
+        public MqttConfigurationException(Exception innerException)
+            : base(innerException.Message, innerException)
+        {
+        }
+
+        public MqttConfigurationException(string message)
+            : base(message)
+        {
+        }
+    }
+}

Source/MQTTnet/Extensions/MqttClientOptionsBuilderExtension.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Linq;
+using MQTTnet.Client.Options;
+
+namespace MQTTnet.Extensions
+{
+    public static class MqttClientOptionsBuilderExtension
+    {
+        public static MqttClientOptionsBuilder WithConnectionUri(this MqttClientOptionsBuilder builder, Uri uri)
+        {
+            var port = uri.IsDefaultPort ? null : (int?) uri.Port;
+            switch (uri.Scheme.ToLower())
+            {
+                case "tcp":
+                case "mqtt":
+                    builder.WithTcpServer(uri.Host, port);
+                    break;
+
+                case "mqtts":
+                    builder.WithTcpServer(uri.Host, port).WithTls();
+                    break;
+
+                case "ws":
+                case "wss":
+                    builder.WithWebSocketServer(uri.ToString());
+                    break;
+
+                default:
+                    throw new ArgumentException("Unexpected scheme in uri.");
+            }
+            
+            if (!string.IsNullOrEmpty(uri.UserInfo))
+            {
+                var userInfo = uri.UserInfo.Split(':');
+                var username = userInfo[0];
+                var password = userInfo.Length > 1 ? userInfo[1] : "";
+                builder.WithCredentials(username, password);
+            }
+
+            return builder;
+        }
+
+        public static MqttClientOptionsBuilder WithConnectionUri(this MqttClientOptionsBuilder builder, string uri)
+        {
+            return WithConnectionUri(builder, new Uri(uri, UriKind.Absolute));
+        }
+    }
+}

Source/MQTTnet/Extensions/UserPropertyExtension.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Linq;
+
+namespace MQTTnet.Extensions
+{
+    public static class UserPropertyExtension
+    {
+        public static string GetUserProperty(this MqttApplicationMessage message, string propertyName, StringComparison comparisonType = StringComparison.Ordinal)
+        {
+            if (message == null) throw new ArgumentNullException(nameof(message));
+            if (propertyName == null) throw new ArgumentNullException(nameof(propertyName));
+
+            return message.UserProperties?.SingleOrDefault(up => up.Name.Equals(propertyName, comparisonType))?.Value;
+        }
+    }
+}

Source/MQTTnet/Formatter/IMqttPacketWriter.cs

@@ -5,15 +5,25 @@
         int Length { get; }
 
         void WriteWithLengthPrefix(string value);
-        void Write(byte returnCode);
+
-        void WriteWithLengthPrefix(byte[] payload);
+        void Write(byte value);
-        void Write(ushort keepAlivePeriod);
+
-        void Write(IMqttPacketWriter propertyWriter);
+        void WriteWithLengthPrefix(byte[] value);
-        void WriteVariableLengthInteger(uint length);
+
-        void Write(byte[] payload, int v, int length);
+        void Write(ushort value);
-        void Reset(int v);
+
-        void Seek(int v);
+        void Write(IMqttPacketWriter value);
+
+        void WriteVariableLengthInteger(uint value);
+
+        void Write(byte[] value, int offset, int length);
+
+        void Reset(int length);
+
+        void Seek(int offset);
+
         void FreeBuffer();
+
         byte[] GetBuffer();
     }
 }

Source/MQTTnet/Formatter/MqttPacketReader.cs

@@ -21,8 +21,6 @@ namespace MQTTnet.Formatter
         {
             // The MQTT fixed header contains 1 byte of flags and at least 1 byte for the remaining data length.
             // So in all cases at least 2 bytes must be read for a complete MQTT packet.
-            // async/await is used here because the next packet is received in a couple of minutes so the performance
-            // impact is acceptable according to a useless waiting thread.
             var buffer = fixedHeaderBuffer;
             var totalBytesRead = 0;
 
@@ -55,16 +53,7 @@ namespace MQTTnet.Formatter
                 };
             }
 
-#if WINDOWS_UWP
-            // UWP will have a dead lock when calling this not async.
             var bodyLength = await ReadBodyLengthAsync(buffer[1], cancellationToken).ConfigureAwait(false);
-#else
-            // Here the async/await pattern is not used because the overhead of context switches
-            // is too big for reading 1 byte in a row. We expect that the remaining data was sent
-            // directly after the initial bytes. If the client disconnects just in this moment we
-            // will get an exception anyway.
-            var bodyLength = ReadBodyLength(buffer[1], cancellationToken);
-#endif
 
             if (!bodyLength.HasValue)
             {
@@ -81,49 +70,6 @@ namespace MQTTnet.Formatter
             };
         }
 
-#if !WINDOWS_UWP
-        private int? ReadBodyLength(byte initialEncodedByte, CancellationToken cancellationToken)
-        {
-            var offset = 0;
-            var multiplier = 128;
-            var value = initialEncodedByte & 127;
-            int encodedByte = initialEncodedByte;
-
-            while ((encodedByte & 128) != 0)
-            {
-                offset++;
-                if (offset > 3)
-                {
-                    throw new MqttProtocolViolationException("Remaining length is invalid.");
-                }
-
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return null;
-                }
-
-                var readCount = _channel.ReadAsync(_singleByteBuffer, 0, 1, cancellationToken).GetAwaiter().GetResult();
-
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return null;
-                }
-
-                if (readCount == 0)
-                {
-                    return null;
-                }
-
-                encodedByte = _singleByteBuffer[0];
-
-                value += (encodedByte & 127) * multiplier;
-                multiplier *= 128;
-            }
-
-            return value;
-        }
-#else
-
         private async Task<int?> ReadBodyLengthAsync(byte initialEncodedByte, CancellationToken cancellationToken)
         {
             var offset = 0;
@@ -164,6 +110,5 @@ namespace MQTTnet.Formatter
 
             return value;
         }
-#endif
     }
 }

Source/MQTTnet/Formatter/V3/MqttV310DataConverter.cs

@@ -1,6 +1,4 @@
-using System;
+using MQTTnet.Client.Connecting;
-using System.Linq;
-using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
 using MQTTnet.Client.Options;
 using MQTTnet.Client.Publishing;
@@ -10,6 +8,8 @@ using MQTTnet.Exceptions;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using MQTTnet.Server;
+using System;
+using System.Linq;
 using MqttClientSubscribeResult = MQTTnet.Client.Subscribing.MqttClientSubscribeResult;
 
 namespace MQTTnet.Formatter.V3
@@ -20,11 +20,6 @@ namespace MQTTnet.Formatter.V3
         {
             if (applicationMessage == null) throw new ArgumentNullException(nameof(applicationMessage));
 
-            if (applicationMessage.UserProperties?.Any() == true)
-            {
-                throw new MqttProtocolViolationException("User properties are not supported in MQTT version 3.");
-            }
-
             return new MqttPublishPacket
             {
                 Topic = applicationMessage.Topic,
@@ -171,11 +166,6 @@ namespace MQTTnet.Formatter.V3
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
 
-            if (options.UserProperties?.Any() == true)
-            {
-                throw new MqttProtocolViolationException("User properties are not supported in MQTT version 3.");
-            }
-
             var subscribePacket = new MqttSubscribePacket();
             subscribePacket.TopicFilters.AddRange(options.TopicFilters);
 
@@ -186,11 +176,6 @@ namespace MQTTnet.Formatter.V3
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
 
-            if (options.UserProperties?.Any() == true)
-            {
-                throw new MqttProtocolViolationException("User properties are not supported in MQTT version 3.");
-            }
-
             var unsubscribePacket = new MqttUnsubscribePacket();
             unsubscribePacket.TopicFilters.AddRange(options.TopicFilters);
 
@@ -199,9 +184,9 @@ namespace MQTTnet.Formatter.V3
 
         public MqttDisconnectPacket CreateDisconnectPacket(MqttClientDisconnectOptions options)
         {
-            if (options != null)
+            if (options.ReasonCode != MqttClientDisconnectReason.NormalDisconnection || options.ReasonString != null)
             {
-                throw new MqttProtocolViolationException("Reason codes for disconnect are only supported for MQTTv5.");
+                throw new MqttProtocolViolationException("Reason codes and reason string for disconnect are only supported for MQTTv5.");
             }
 
             return new MqttDisconnectPacket();

Source/MQTTnet/Formatter/V5/MqttV500DataConverter.cs

@@ -139,7 +139,7 @@ namespace MQTTnet.Formatter.V5
                 ReasonCode = connectionValidatorContext.ReasonCode,
                 Properties = new MqttConnAckPacketProperties
                 {
-                    UserProperties = connectionValidatorContext.UserProperties,
+                    UserProperties = connectionValidatorContext.ResponseUserProperties,
                     AuthenticationMethod = connectionValidatorContext.AuthenticationMethod,
                     AuthenticationData = connectionValidatorContext.ResponseAuthenticationData,
                     AssignedClientIdentifier = connectionValidatorContext.AssignedClientIdentifier,

Source/MQTTnet/Formatter/V5/MqttV500PacketEncoder.cs

@@ -329,9 +329,6 @@ namespace MQTTnet.Formatter.V5
                 ThrowReasonCodeNotSetException();
             }
            
-            packetWriter.Write(packet.PacketIdentifier.Value);
-            packetWriter.Write((byte)packet.ReasonCode.Value);
-
             var propertiesWriter = new MqttV500PropertiesWriter();
             if (packet.Properties != null)
             {
@@ -339,6 +336,8 @@ namespace MQTTnet.Formatter.V5
                 propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
             }
 
+            packetWriter.Write(packet.PacketIdentifier.Value);
+
             if (packetWriter.Length > 0 || packet.ReasonCode.Value != MqttPubRecReasonCode.Success)
             {
                 packetWriter.Write((byte)packet.ReasonCode.Value);

Source/MQTTnet/Implementations/CrossPlatformSocket.cs

@@ -0,0 +1,229 @@
+using System;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MQTTnet.Implementations
+{
+    public sealed class CrossPlatformSocket : IDisposable
+    {
+        readonly Socket _socket;
+
+        public CrossPlatformSocket(AddressFamily addressFamily)
+        {
+            _socket = new Socket(addressFamily, SocketType.Stream, ProtocolType.Tcp);
+        }
+
+        public CrossPlatformSocket()
+        {
+            // Having this contructor is important because avoiding the address family as parameter
+            // will make use of dual mode in the .net framework.
+            _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
+        }
+
+        public CrossPlatformSocket(Socket socket)
+        {
+            _socket = socket ?? throw new ArgumentNullException(nameof(socket));
+        }
+
+        public bool NoDelay
+        {
+            get
+            {
+                return (int)_socket.GetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.NoDelay) > 0;
+            }
+
+            set
+            {
+                _socket.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.NoDelay, value ? 1 : 0);
+            }
+        }
+
+        public bool DualMode
+        {
+            get
+            {
+                return _socket.DualMode;
+            }
+
+            set
+            {
+                _socket.DualMode = value;
+            }
+        }
+
+        public int ReceiveBufferSize
+        {
+            get
+            {
+                return _socket.ReceiveBufferSize;
+            }
+
+            set
+            {
+                _socket.ReceiveBufferSize = value;
+            }
+        }
+
+        public int SendBufferSize
+        {
+            get
+            {
+                return _socket.SendBufferSize;
+            }
+
+            set
+            {
+                _socket.SendBufferSize = value;
+            }
+        }
+
+        public EndPoint RemoteEndPoint
+        {
+            get
+            {
+                return _socket.RemoteEndPoint;
+            }
+        }
+
+        public bool ReuseAddress
+        {
+            get
+            {
+                return (int)_socket.GetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress) != 0;
+            }
+
+            set
+            {
+                _socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, value ? 1 : 0);
+            }
+        }
+
+        public async Task<CrossPlatformSocket> AcceptAsync()
+        {
+            try
+            {
+#if NET452 || NET461
+                var clientSocket = await Task.Factory.FromAsync(_socket.BeginAccept, _socket.EndAccept, null).ConfigureAwait(false);
+                return new CrossPlatformSocket(clientSocket);
+#else
+                var clientSocket = await _socket.AcceptAsync().ConfigureAwait(false);
+                return new CrossPlatformSocket(clientSocket);
+#endif
+            }
+            catch (ObjectDisposedException)
+            {
+                // This will happen when _socket.EndAccept gets called by Task library but the socket is already disposed.
+                return null;
+            }
+        }
+
+        public void Bind(EndPoint localEndPoint)
+        {
+            if (localEndPoint is null) throw new ArgumentNullException(nameof(localEndPoint));
+
+            _socket.Bind(localEndPoint);
+        }
+
+        public void Listen(int connectionBacklog)
+        {
+            _socket.Listen(connectionBacklog);
+        }
+
+        public async Task ConnectAsync(string host, int port, CancellationToken cancellationToken)
+        {
+            if (host is null) throw new ArgumentNullException(nameof(host));
+
+            try
+            {
+                // Workaround for: workaround for https://github.com/dotnet/corefx/issues/24430
+                using (cancellationToken.Register(() => _socket.Dispose()))
+                {
+                    cancellationToken.ThrowIfCancellationRequested();
+
+#if NET452 || NET461
+                    await Task.Factory.FromAsync(_socket.BeginConnect, _socket.EndConnect, host, port, null).ConfigureAwait(false);
+#else
+                    await _socket.ConnectAsync(host, port).ConfigureAwait(false);
+#endif
+                }
+            }
+            catch (ObjectDisposedException)
+            {
+                // This will happen when _socket.EndConnect gets called by Task library but the socket is already disposed.
+            }
+        }
+
+        public async Task SendAsync(ArraySegment<byte> buffer, SocketFlags socketFlags)
+        {
+            try
+            {
+#if NET452 || NET461
+                await Task.Factory.FromAsync(SocketWrapper.BeginSend, _socket.EndSend, new SocketWrapper(_socket, buffer, socketFlags)).ConfigureAwait(false);
+#else
+                await _socket.SendAsync(buffer, socketFlags).ConfigureAwait(false);
+#endif
+            }
+            catch (ObjectDisposedException)
+            {
+                // This will happen when _socket.EndConnect gets called by Task library but the socket is already disposed.
+            }
+        }
+
+        public async Task<int> ReceiveAsync(ArraySegment<byte> buffer, SocketFlags socketFlags)
+        {
+            try
+            {
+#if NET452 || NET461
+                return await Task.Factory.FromAsync(SocketWrapper.BeginReceive, _socket.EndReceive, new SocketWrapper(_socket, buffer, socketFlags)).ConfigureAwait(false);
+#else
+                return await _socket.ReceiveAsync(buffer, socketFlags).ConfigureAwait(false);
+#endif
+            }
+            catch (ObjectDisposedException)
+            {
+                // This will happen when _socket.EndReceive gets called by Task library but the socket is already disposed.
+                return -1;
+            }
+        }
+
+        public NetworkStream GetStream()
+        {
+            return new NetworkStream(_socket, true);
+        }
+
+        public void Dispose()
+        {
+            _socket?.Dispose();
+        }
+
+#if NET452 || NET461
+        class SocketWrapper
+        {
+            readonly Socket _socket;
+            readonly ArraySegment<byte> _buffer;
+            readonly SocketFlags _socketFlags;
+
+            public SocketWrapper(Socket socket, ArraySegment<byte> buffer, SocketFlags socketFlags)
+            {
+                _socket = socket;
+                _buffer = buffer;
+                _socketFlags = socketFlags;
+            }
+
+            public static IAsyncResult BeginSend(AsyncCallback callback, object state)
+            {
+                var socketWrapper = (SocketWrapper)state;
+                return socketWrapper._socket.BeginSend(socketWrapper._buffer.Array, socketWrapper._buffer.Offset, socketWrapper._buffer.Count, socketWrapper._socketFlags, callback, state);
+            }
+
+            public static IAsyncResult BeginReceive(AsyncCallback callback, object state)
+            {
+                var socketWrapper = (SocketWrapper)state;
+                return socketWrapper._socket.BeginReceive(socketWrapper._buffer.Array, socketWrapper._buffer.Offset, socketWrapper._buffer.Count, socketWrapper._socketFlags, callback, state);
+            }
+        }
+#endif
+    }
+}

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));