From 7e79e69eae63a97c9b8464202adc34aa1ceaeeaf Mon Sep 17 00:00:00 2001
From: Paul Chote <pchote@users.noreply.github.com>
Date: Wed, 5 May 2021 22:47:36 +0100
Subject: [PATCH] Remove public mutable state from Connection.

---
 OpenRA.Game/Server/Connection.cs | 58 +++++++++++++++++++-------------
 OpenRA.Game/Server/Server.cs     | 15 ++++-----
 2 files changed, 40 insertions(+), 33 deletions(-)

diff --git a/OpenRA.Game/Server/Connection.cs b/OpenRA.Game/Server/Connection.cs
index bf337587ded3..c3971cc850e7 100644
--- a/OpenRA.Game/Server/Connection.cs
+++ b/OpenRA.Game/Server/Connection.cs
@@ -19,21 +19,29 @@ namespace OpenRA.Server
 	public class Connection
 	{
 		public const int MaxOrderLength = 131072;
-		public Socket Socket;
-		public List<byte> Data = new List<byte>();
-		public ReceiveState State = ReceiveState.Header;
-		public int ExpectLength = 8;
-		public int Frame = 0;
-		public int MostRecentFrame = 0;
-		public bool Validated;
+
+		public readonly Socket Socket;
+		public readonly List<byte> Data = new List<byte>();
+		public readonly int PlayerIndex;
+		public readonly string AuthToken;
 
 		public long TimeSinceLastResponse => Game.RunTime - lastReceivedTime;
-		public bool TimeoutMessageShown = false;
+		public int MostRecentFrame { get; private set; }
+
+		public bool TimeoutMessageShown;
+		public bool Validated;
+
+		ReceiveState state = ReceiveState.Header;
+		int expectLength = 8;
+		int frame = 0;
 		long lastReceivedTime = 0;
 
-		/* client data */
-		public int PlayerIndex;
-		public string AuthToken;
+		public Connection(Socket socket, int playerIndex, string authToken)
+		{
+			Socket = socket;
+			PlayerIndex = playerIndex;
+			AuthToken = authToken;
+		}
 
 		public byte[] PopBytes(int n)
 		{
@@ -85,21 +93,22 @@ bool ReadDataInner(Server server)
 		public void ReadData(Server server)
 		{
 			if (ReadDataInner(server))
-				while (Data.Count >= ExpectLength)
+			{
+				while (Data.Count >= expectLength)
 				{
-					var bytes = PopBytes(ExpectLength);
-					switch (State)
+					var bytes = PopBytes(expectLength);
+					switch (state)
 					{
 						case ReceiveState.Header:
 							{
-								ExpectLength = BitConverter.ToInt32(bytes, 0) - 4;
-								Frame = BitConverter.ToInt32(bytes, 4);
-								State = ReceiveState.Data;
+								expectLength = BitConverter.ToInt32(bytes, 0) - 4;
+								frame = BitConverter.ToInt32(bytes, 4);
+								state = ReceiveState.Data;
 
-								if (ExpectLength < 0 || ExpectLength > MaxOrderLength)
+								if (expectLength < 0 || expectLength > MaxOrderLength)
 								{
 									server.DropClient(this);
-									Log.Write("server", "Dropping client {0} for excessive order length = {1}", PlayerIndex, ExpectLength);
+									Log.Write("server", "Dropping client {0} for excessive order length = {1}", PlayerIndex, expectLength);
 									return;
 								}
 
@@ -108,17 +117,18 @@ public void ReadData(Server server)
 
 						case ReceiveState.Data:
 							{
-								if (MostRecentFrame < Frame)
-									MostRecentFrame = Frame;
+								if (MostRecentFrame < frame)
+									MostRecentFrame = frame;
 
-								server.DispatchOrders(this, Frame, bytes);
-								ExpectLength = 8;
-								State = ReceiveState.Header;
+								server.DispatchOrders(this, frame, bytes);
+								expectLength = 8;
+								state = ReceiveState.Header;
 
 								break;
 							}
 					}
 				}
+			}
 		}
 	}
 
diff --git a/OpenRA.Game/Server/Server.cs b/OpenRA.Game/Server/Server.cs
index 79f6b2bc459e..80aa2a83bac5 100644
--- a/OpenRA.Game/Server/Server.cs
+++ b/OpenRA.Game/Server/Server.cs
@@ -374,20 +374,17 @@ void AcceptConnection(TcpListener listener)
 				return;
 			}
 
-			var newConn = new Connection { Socket = newSocket };
+
+			// Validate player identity by asking them to sign a random blob of data
+			// which we can then verify against the player public key database
+			var token = Convert.ToBase64String(OpenRA.Exts.MakeArray(256, _ => (byte)Random.Next()));
+
+			var newConn = new Connection(newSocket, ChooseFreePlayerIndex(), token);
 			try
 			{
 				newConn.Socket.Blocking = false;
 				newConn.Socket.NoDelay = true;
 
-				// Validate player identity by asking them to sign a random blob of data
-				// which we can then verify against the player public key database
-				var token = Convert.ToBase64String(OpenRA.Exts.MakeArray(256, _ => (byte)Random.Next()));
-
-				// Assign the player number.
-				newConn.PlayerIndex = ChooseFreePlayerIndex();
-				newConn.AuthToken = token;
-
 				// Send handshake and client index.
 				var ms = new MemoryStream(8);
 				ms.WriteArray(BitConverter.GetBytes(ProtocolVersion.Handshake));