Proof Of Concept initial

Adds initial files for a proof-of-concept project, including Dockerfile, .gitignore, project files, and MQTT-related services. This commit sets up the basic structure and configuration for exploring and validating the core concepts of the project.
2025-08-06 15:40:21 +02:00
parent bbc704fe6b
commit 043f504cdd
11 changed files with 1019 additions and 41 deletions
--- a/Source/ProofOfConcept/Services/MQTTServer.cs
+++ b/Source/ProofOfConcept/Services/MQTTServer.cs
@@ -1,24 +1,154 @@
+using System.Net;
+using Microsoft.Extensions.Options;
+using MQTTnet.Protocol;
+using MQTTnet.Server;
+
 namespace ProofOfConcept.Services;

-public class MQTTServer
+public class MQTTServer : IHostedService
 {
-    private ILogger<MQTTServer> logger;
-    private MQTTServerConfiguration configuration;
+    private readonly ILogger<MQTTServer> logger;
+    private readonly MQTTServerConfiguration configuration;

-    public MQTTServer(ILogger<MQTTServer> logger, IOptionsMonitor<MQTTServerConfiguration> options)
+    private readonly MqttServer server;
+    
+    public MQTTServer(ILogger<MQTTServer> logger, IOptions<MQTTServerConfiguration> options)
    {
        this.logger = logger;
-        this.configuration = options.CurrentValue;
+        this.configuration = options.Value;

-        options.OnChange(newValue =>
+        MqttServerOptions mqttServerOptions = new MqttServerOptionsBuilder().WithDefaultEndpoint().WithDefaultEndpointPort(this.configuration.Port).WithKeepAlive().Build();
+        this.server = new MqttServerFactory().CreateMqttServer(mqttServerOptions);
+
+        this.server.ClientConnectedAsync += (e) =>
        {
-            this.configuration = newValue;
-            logger.LogInformation("Configuration of {ClassName} changed", nameof(MQTTServer));
-        });
+            logger.LogInformation("Client connected from: {IPAddress}. ClientID: {ClientID}", e.RemoteEndPoint.ToString(), e.ClientId);
+            return Task.CompletedTask;
+        };
+
+        this.server.ClientDisconnectedAsync += (e) =>
+        {
+            logger.LogInformation("Client {ClientID} disconnected from: {IPAddress}. Reason: {ReasonString} ({ReasonCode})", e.ClientId, e.RemoteEndPoint.ToString(), e.ReasonString, e.ReasonCode);
+            return Task.CompletedTask;
+        };
+        
+        this.server.ClientSubscribedTopicAsync += (e) =>
+        {
+            logger.LogInformation("Client {ClientID} subscribed to topic: {Topic}", e.ClientId, e.TopicFilter.Topic);
+            return Task.CompletedTask;
+        };
+
+        this.server.ClientUnsubscribedTopicAsync += (e) =>
+        {
+            logger.LogInformation("Client {ClientID} unsubscribed from topic: {Topic}", e.ClientId, e.TopicFilter);
+            return Task.CompletedTask;
+        };
+
+        this.server.InterceptingPublishAsync += (e) =>
+        {
+            if (e.ApplicationMessage.Topic == "telemetry" && e.ClientId != this.configuration.TelemetryClient.ClientID)
+            {
+                logger.LogWarning("Client {ClientID} tried to publish to telemetry topic", e.ClientId);
+                
+                e.Response.ReasonCode = MqttPubAckReasonCode.NotAuthorized;
+                return Task.CompletedTask;
+            }
+
+            logger.LogInformation("Client {ClientID} published message to topic: {Topic}", e.ClientId, e.ApplicationMessage.Topic);
+            return Task.CompletedTask;
+        };
+
+        this.server.ValidatingConnectionAsync += (e) =>
+        {
+            //Local client (by clientID)
+            if (e.ClientId == this.configuration.LocalClient.ClientID)
+            {
+                //Not local connection (IP is not loopback)
+                if (e.RemoteEndPoint is IPEndPoint ipEndPoint && !IPAddress.IsLoopback(ipEndPoint.Address))
+                {
+                    logger.LogWarning("Local client tried to connect from non-loopback address: {IPAddress}", ipEndPoint.ToString());
+                    e.ReasonCode = MqttConnectReasonCode.NotAuthorized;
+                }
+                
+                //Invalid username or password
+                else if (e.UserName != configuration.LocalClient.Username || e.Password != configuration.LocalClient.Password)
+                {
+                    logger.LogWarning("Local client tried to connect with invalid credentials");
+                    e.ReasonCode = MqttConnectReasonCode.NotAuthorized;
+                }
+            }
+            
+            //Telemetry client
+            else if (e.ClientId == this.configuration.TelemetryClient.ClientID)
+            {
+                if (e.UserName != configuration.TelemetryClient.Username || e.Password != configuration.TelemetryClient.Password)
+                {
+                    logger.LogWarning("Telemetry client tried to connect with invalid credentials");
+                    e.ReasonCode = MqttConnectReasonCode.NotAuthorized;
+                }
+            }
+            
+            //Observer
+            else if ((this.configuration.Observer.ClientID is not null && e.ClientId == this.configuration.Observer.ClientID) || this.configuration.Observer.ClientID is null)
+            {
+                if (e.UserName != configuration.Observer.Username || e.Password != configuration.Observer.Password)
+                {
+                    logger.LogWarning("Observer tried to connect with invalid credentials");
+                    e.ReasonCode = MqttConnectReasonCode.NotAuthorized;
+                }
+            }
+
+            else
+                e.ReasonCode = MqttConnectReasonCode.Banned;
+            
+            return Task.CompletedTask;
+        };
+    }
+
+    public async Task StartAsync(CancellationToken cancellationToken)
+    {
+        this.logger.LogTrace("Starting MQTT Server...");
+
+        await this.server.StartAsync();
+       
+        this.logger.LogInformation("MQTT Server started");
+    }
+
+    public async Task StopAsync(CancellationToken cancellationToken)
+    {
+        this.logger.LogTrace("Stopping MQTT Server...");
+
+        await this.server.StopAsync();
+        
+        this.logger.LogInformation("MQTT Server stopped");
    }
 }

 public class MQTTServerConfiguration
 {
+    public ushort Port { get; set; } = 1883;
+    public MQTTAuthenticationData TelemetryClient { get; set; } = new MQTTAuthenticationData("telemetry", "fleet", "9R0FXNs5NEIEbI4"); //Must have a known client id
+    public MQTTAuthenticationData LocalClient { get; set; } = new MQTTAuthenticationData("local", "client", "xuhvoc-parrox-xuzsE4"); //Must have a known client id
+    public MQTTAuthenticationData Observer { get; set; } = new MQTTAuthenticationData("observer", "JC740d4c4E9dveh");
+}
+
+public class MQTTAuthenticationData
+{
+    public string? ClientID { get; set; }
+    public string Username { get; set; }
+    public string Password { get; set; }
+
+    public MQTTAuthenticationData(string clientId, string username, string password)
+    {
+        ClientID = clientId;
+        Username = username;
+        Password = password;
+    }
    
+    public MQTTAuthenticationData(string username, string password)
+    {
+        ClientID = null;
+        Username = username;
+        Password = password;
+    }
 }