MQTTunnelNet 1.0.5

MQTTunnelNet: Tunnel TCP via MQTT broker

This library is a wrapper around libmqttunnel (https://github.com/Staatsgeheim/libmqttunnel)

Changelog

v1.0.5

• Added configuration option to ignore SSL errors
• Fixed OSX x64 library, the build was corrupted in 1.0.4

v1.0.4

• Added Linux ARM64 support
• Added Linux x86 support

v1.0.3

• Changed the native library loading mechanism for cross platform compatibility
• Added MacOS x64 support
• Added MacOS ARM64 support
• Added Linux x64 support
• Added .NET 9 support

The library now supports:

Platforms:

• Windows x86
• Windows x64
• MacOS x64*
• MacOS ARM64*
• Linux x64

MacOS Notes*

Run xattr -r -d com.apple.quarantine libmqttunnel_x64.dylib or xattr -r -d com.apple.quarantine libmqttunnel_arm64.dylib to enable the libary to load unsigned

Runtimes:

• net45
• net451
• net452
• net46
• net461
• net462
• net463
• net47
• net471
• net472
• net48
• net481
• net5.0
• net6.0
• net7.0
• net8.0
• net9.0
• netstandard2.0
• netstandard2.1
• netcoreapp3.0
• netcoreapp3.1

v1.0.2

• Added 32 bits support
• Added support to load configs from memory instead of disk
• Added MQTTunnelLogLevel to give more control over the log level

enum MQTTunnelLogLevel : int
{
    None = -1,
    DebugLevel = 0,
    InfoLevel = 1,
    WarnLevel = 2,
    ErrorLevel = 3,
    PanicLevel = 4,
    FatalLevel = 5
}

• Added support for more .NET versions

net45
net451
net452
net46
net461
net462
net463
net47
net471
net472
net48
net481
net5.0
net6.0
net7.0
net8.0
net9.0
netstandard2.0
netstandard2.1
netcoreapp3.0
netcoreapp3.1

How to use

Remote and local instances use the same Config file.

Create and start a server (remote)

    var server = MQTTunnel.CreateServer("config.json");
    server.StartAsync();

Create and connect a tunnel (local)

    var tunnel = MQTTunnel.CreateTunnel("config.json", 9000, 8000)
    tunnel.StartAsync();

Create and connect multiple tunnels (local)

    var tunnel1 = MQTTunnel.CreateTunnel("config.json", 9000, 8000)
    tunnel1.StartAsync();
    var tunnel2 = MQTTunnel.CreateTunnel("config.json", 9001, 8001)
    tunnel2.StartAsync();

Using a config in memory

    var configJsonData = @"
    {
        "host": "mqttbroker.example",
        "port": 8883,
        "ignoreSslErrors": false,
        "username", "",
        "password", "",
        "caCert": "root-CA.crt",
        "clientCert": "certificate.pem.crt",
        "privateKey": "private.pem.key",
        "control": "device/1/control"
    }";

Create and start a server using a config in memory (remote)

    var server = MQTTunnel.CreateServerMem(configJsonData);
    server.StartAsync();

Create and connect a tunnel using a config in memory (local)

    var tunnel = MQTTunnel.CreateTunnelMem(configJsonData, 9000, 8000)
    tunnel.StartAsync();

Create and connect multiple tunnels using a config in memory (local)

    var tunnel1 = MQTTunnel.CreateTunnelMem(configJsonData, 9000, 8000)
    tunnel1.StartAsync();
    var tunnel2 = MQTTunnel.CreateTunnelMem(configJsonData, 9001, 8001)
    tunnel2.StartAsync();

Config file

You can use client certs as well as username/password or both in the Config file.

{
    "host": "mqttbroker.example",
    "port": 8883,
    "ignoreSslErrors": true,
    "username", "",
    "password", "",
    "caCert": "root-CA.crt",
    "clientCert": "certificate.pem.crt",
    "privateKey": "private.pem.key",
    "control": "device/1/control"
}

Other options

• clientId: MQTT ClientID. If empty, random string is generated

Info

• control: Sets the MQTT topic that is used for this instance

Architecture

Example: Local port = 2022, Remote port = 22,

sequenceDiagram

LocalTCP ->> LocalMQTTunnel: conn read from port 2022
LocalMQTTunnel ->> MQTTBroker: Publish to local port topic '/2022'
MQTTBroker ->> RemoteMQTTunnel: Recieve from local port topic '/2022'
RemoteMQTTunnel ->> RemoteTCP: conn write to port 22
RemoteTCP ->> RemoteMQTTunnel: conn read from port 22
RemoteMQTTunnel ->> MQTTBroker: Publish to local port topic '/22'
MQTTBroker ->> LocalMQTTunnel: Recieve from local port topic '/22'
LocalMQTTunnel ->> LocalTCP: conn write to port 2022

More internal architecture

sequenceDiagram

participant Remote
participant RemoteTCP
participant RemoteTCPConnection
participant RemoteMQTTunnel

RemoteMQTTunnel ->> RemoteMQTTunnel: subscribe control topic
LocalMQTTunnel ->> LocalMQTTunnel: make a Tunnel instance which includes local/remote port pair
LocalMQTTunnel ->> LocalTCP: NewTCPConnection()
LocalTCP ->> LocalTCP: start listening
Local ->> LocalTCP: connect
LocalTCP ->> LocalMQTTunnel: OpenTunnel()
LocalMQTTunnel ->> RemoteMQTTunnel: Publish control packet
RemoteMQTTunnel ->> RemoteTCPConnection: NewTCPConnection()
RemoteTCPConnection ->> RemoteTCP: connect()
RemoteTCP ->> Remote: connect()

License

• MIT