feat: Added command line option support for overriding the port (#2708)

* Added command line option support for overriding the port

* Formatting fixes

* Updated port command line argument to use DedicatedServer.Arguments when available

---------

Co-authored-by: Noel Stephens <[email protected]>

Author: samlucas-unity

com.unity.netcode.gameobjects/Runtime/Core/NetworkManager.cs

@@ -412,6 +412,19 @@ public NetworkPrefabHandler PrefabHandler
         internal NetworkConnectionManager ConnectionManager = new NetworkConnectionManager();
         internal NetworkMessageManager MessageManager = null;
 
+        internal struct Override<T>
+        {
+            private T m_Value;
+            public bool Overidden { get; private set; }
+            internal T Value
+            {
+                get { return Overidden ? m_Value : default(T); }
+                set { Overidden = true; m_Value = value; }
+            }
+        };
+
+        internal Override<ushort> PortOverride;
+
 #if UNITY_EDITOR
         internal static INetworkManagerHelper NetworkManagerHelper;
 
@@ -658,6 +671,8 @@ internal void Initialize(bool server)
                 return;
             }
 
+            ParseCommandLineOptions();
+
             if (NetworkConfig.NetworkTransport == null)
             {
                 if (NetworkLog.CurrentLogLevel <= LogLevel.Error)
@@ -1100,5 +1115,39 @@ private void OnDestroy()
                 Singleton = null;
             }
         }
+
+        // Command line options
+        private const string k_OverridePortArg = "-port";
+
+        private string GetArg(string[] commandLineArgs, string arg)
+        {
+            var argIndex = Array.IndexOf(commandLineArgs, arg);
+            if (argIndex >= 0 && argIndex < commandLineArgs.Length - 1)
+            {
+                return commandLineArgs[argIndex + 1];
+            }
+
+            return null;
+        }
+
+        private void ParseArg<T>(string arg, ref Override<T> value)
+        {
+            if (GetArg(Environment.GetCommandLineArgs(), arg) is string argValue)
+            {
+                value.Value = (T)Convert.ChangeType(argValue, typeof(T));
+            }
+        }
+
+        private void ParseCommandLineOptions()
+        {
+#if UNITY_SERVER && UNITY_DEDICATED_SERVER_ARGUMENTS_PRESENT
+            if ( UnityEngine.DedicatedServer.Arguments.Port != null)
+            {
+                PortOverride.Value = (ushort)UnityEngine.DedicatedServer.Arguments.Port;
+            }
+#else
+            ParseArg(k_OverridePortArg, ref PortOverride);
+#endif
+        }
     }
 }

com.unity.netcode.gameobjects/Runtime/Transports/UNET/UNetTransport.cs

@@ -199,15 +199,15 @@ public override NetworkEvent PollEvent(out ulong clientId, out ArraySegment<byte
         public override bool StartClient()
         {
             m_ServerHostId = UnityEngine.Networking.NetworkTransport.AddHost(new HostTopology(GetConfig(), 1), 0, null);
-            m_ServerConnectionId = UnityEngine.Networking.NetworkTransport.Connect(m_ServerHostId, ConnectAddress, ConnectPort, 0, out byte error);
+            m_ServerConnectionId = UnityEngine.Networking.NetworkTransport.Connect(m_ServerHostId, ConnectAddress, GetConnectPort(), 0, out byte error);
             return (NetworkError)error == NetworkError.Ok;
         }
 
         public override bool StartServer()
         {
             var topology = new HostTopology(GetConfig(), MaxConnections);
             // Undocumented, but AddHost returns -1 in case of any type of failure. See UNET::NetLibraryManager::AddHost
-            return -1 != UnityEngine.Networking.NetworkTransport.AddHost(topology, ServerListenPort, null);
+            return -1 != UnityEngine.Networking.NetworkTransport.AddHost(topology, GetServerListenPort(), null);
         }
 
         public override void DisconnectRemoteClient(ulong clientId)
@@ -281,6 +281,26 @@ private ConnectionConfig GetConfig()
 
             return connectionConfig;
         }
+
+        public int GetConnectPort()
+        {
+            if (NetworkManager && NetworkManager.PortOverride.Overidden)
+            {
+                return NetworkManager.PortOverride.Value;
+            }
+
+            return ConnectPort;
+        }
+
+        public int GetServerListenPort()
+        {
+            if (NetworkManager && NetworkManager.PortOverride.Overidden)
+            {
+                return NetworkManager.PortOverride.Value;
+            }
+
+            return ServerListenPort;
+        }
     }
 }
 #pragma warning restore CS1591 // Missing XML comment for publicly visible type or member

com.unity.netcode.gameobjects/Runtime/Transports/UTP/UnityTransport.cs

@@ -402,6 +402,7 @@ public struct SimulatorParameters
         /// - packet jitter (variances in latency, see: https://en.wikipedia.org/wiki/Jitter)
         /// - packet drop rate (packet loss)
         /// </summary>
+
 #if UTP_TRANSPORT_2_0_ABOVE
         [Obsolete("DebugSimulator is no longer supported and has no effect. Use Network Simulator from the Multiplayer Tools package.", false)]
 #endif
@@ -685,9 +686,11 @@ public void SetConnectionData(NetworkEndpoint endPoint, NetworkEndpoint listenEn
         /// <param name="packetDelay">Packet delay in milliseconds.</param>
         /// <param name="packetJitter">Packet jitter in milliseconds.</param>
         /// <param name="dropRate">Packet drop percentage.</param>
+
 #if UTP_TRANSPORT_2_0_ABOVE
         [Obsolete("SetDebugSimulatorParameters is no longer supported and has no effect. Use Network Simulator from the Multiplayer Tools package.", false)]
 #endif
+
         public void SetDebugSimulatorParameters(int packetDelay, int packetJitter, int dropRate)
         {
             if (m_Driver.IsCreated)
@@ -1209,6 +1212,11 @@ public override void Initialize(NetworkManager networkManager = null)
 
             NetworkManager = networkManager;
 
+            if (NetworkManager && NetworkManager.PortOverride.Overidden)
+            {
+                ConnectionData.Port = NetworkManager.PortOverride.Value;
+            }
+
             m_RealTimeProvider = NetworkManager ? NetworkManager.RealTimeProvider : new RealTimeProvider();
 
             m_NetworkSettings = new NetworkSettings(Allocator.Persistent);

com.unity.netcode.gameobjects/Runtime/com.unity.netcode.runtime.asmdef

@@ -41,6 +41,11 @@
             "name": "com.unity.transport",
             "expression": "2.1.0",
             "define": "UTP_TRANSPORT_2_1_ABOVE"
+        },
+        {
+            "name": "Unity",
+            "expression": "2023",
+            "define": "UNITY_DEDICATED_SERVER_ARGUMENTS_PRESENT"
         }
     ]
 }