Expose more information in client connected event args.

Source/MQTTnet/Server/Events/ClientConnectedEventArgs.cs

@@ -4,26 +4,33 @@
 
 using System;
 using System.Collections;
+using System.Collections.Generic;
 using MQTTnet.Formatter;
+using MQTTnet.Packets;
 
 namespace MQTTnet.Server
 {
     public sealed class ClientConnectedEventArgs : EventArgs
     {
-        public ClientConnectedEventArgs(string clientId, string userName, MqttProtocolVersion protocolVersion, string endpoint, IDictionary sessionItems)
+        readonly MqttConnectPacket _connectPacket;
+
+        public ClientConnectedEventArgs(MqttConnectPacket connectPacket, MqttProtocolVersion protocolVersion, string endpoint, IDictionary sessionItems)
         {
-            ClientId = clientId ?? throw new ArgumentNullException(nameof(clientId));
-            UserName = userName;
+            _connectPacket = connectPacket ?? throw new ArgumentNullException(nameof(connectPacket));
             ProtocolVersion = protocolVersion;
             Endpoint = endpoint;
             SessionItems = sessionItems ?? throw new ArgumentNullException(nameof(sessionItems));
         }
 
+        public byte[] AuthenticationData => _connectPacket.AuthenticationData;
+
+        public string AuthenticationMethod => _connectPacket.AuthenticationMethod;
+
         /// <summary>
         ///     Gets the client identifier of the connected client.
         ///     Hint: This identifier needs to be unique over all used clients / devices on the broker to avoid connection issues.
         /// </summary>
-        public string ClientId { get; }
+        public string ClientId => _connectPacket.ClientId;
 
         /// <summary>
         ///     Gets the endpoint of the connected client.
@@ -43,6 +50,12 @@ namespace MQTTnet.Server
         /// <summary>
         ///     Gets the user name of the connected client.
         /// </summary>
-        public string UserName { get; }
+        public string UserName => _connectPacket.Username;
+
+        /// <summary>
+        ///     Gets the user properties sent by the client.
+        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
+        /// </summary>
+        public List<MqttUserProperty> UserProperties => _connectPacket?.UserProperties;
     }
 }
\ No newline at end of file

Source/MQTTnet/Server/Internal/MqttClientSessionsManager.cs

@@ -377,9 +377,7 @@ namespace MQTTnet.Server
 
                 if (_eventContainer.ClientConnectedEvent.HasHandlers)
                 {
-                    var eventArgs = new ClientConnectedEventArgs(
-                        connectPacket.ClientId,
-                        connectPacket.Username,
+                    var eventArgs = new ClientConnectedEventArgs(connectPacket,
                         channelAdapter.PacketFormatterAdapter.ProtocolVersion,
                         channelAdapter.Endpoint,
                         client.Session.Items);
@@ -614,7 +612,11 @@ namespace MQTTnet.Server
                     _sessions[connectPacket.ClientId] = session;
 
                     // Create a new client (always required).
-                    _clients.TryGetValue(connectPacket.ClientId, out oldClient);
+                    lock (_clients)
+                    {
+                        _clients.TryGetValue(connectPacket.ClientId, out oldClient);    
+                    }
+                    
                     if (oldClient != null)
                     {
                         // This will stop the current client from sending and receiving but remains the connection active
@@ -624,7 +626,10 @@ namespace MQTTnet.Server
 
                     client = CreateClient(connectPacket, channelAdapter, session);
 
-                    _clients[connectPacket.ClientId] = client;
+                    lock (_clients)
+                    {
+                        _clients[connectPacket.ClientId] = client;
+                    }
                 }
                 finally
                 {