Mod version validation

- Game.CurrentMods property to query the current mods when no orderManager accessible
- Server sends mod versions to master server on ping
- Client sends mod versions on handshake response
- Validate match on server side of handshake, not client side

OpenRA.Game/Game.cs

@@ -195,6 +195,11 @@ namespace OpenRA
 			get { return orderManager.Connection.LocalClientId == 0; }
 		}
 		
+		public static Dictionary<String, Mod> CurrentMods
+		{
+			get { return Mod.AllMods.Where( k => orderManager.LobbyInfo.GlobalSettings.Mods.Contains( k.Key )).ToDictionary( k => k.Key, k => k.Value ); }
+		}
+
 		static Modifiers modifiers;
 		public static Modifiers GetModifierKeys() { return modifiers; }
 		internal static void HandleModifierKeys(Modifiers mods) { modifiers = mods; }

OpenRA.Game/Network/UnitOrders.cs

@@ -103,37 +103,6 @@ namespace OpenRA.Network
 				{
 					var request = HandshakeRequest.Deserialize(order.TargetString);
 				
-					// Check valid mods/versions
-					var serverMods = request.Mods;
-					var localMods = orderManager.LobbyInfo.GlobalSettings.Mods;
-					
-					bool valid = true;
-					if (localMods.Length != serverMods.Length)
-						valid = false;
-					else
-						foreach (var m in serverMods)
-						{
-							var parts = m.Split('@');
-							if (!localMods.Contains(parts[0]))
-							{
-								valid = false;
-								break;
-							}
-							if (parts[1] == "{DEV_VERSION}" || Mod.AllMods[parts[0]].Version == "{DEV_VERSION}")
-								continue;
-					
-							if (parts[1] != Mod.AllMods[parts[0]].Version)
-							{
-								valid = false;
-								break;
-							}
-						}
-
-					if (!valid)
-						throw new InvalidOperationException("Mod/Version mismatch. Client: `{0}`, Server: `{1}`".F(
-					                                           string.Join(",",localMods.Select(m => "{0}@{1}".F(m, Mod.AllMods[m].Version)).ToArray()),
-					                                           string.Join(",",serverMods)));
-					
 					// Check that the map exists on the client
 					if (!Game.modData.AvailableMaps.ContainsKey(request.Map))
 						throw new InvalidOperationException("Missing map {0}".F(request.Map));
@@ -149,6 +118,7 @@ namespace OpenRA.Network
 						State = Session.ClientState.NotReady
 					};
 				
+					var localMods = orderManager.LobbyInfo.GlobalSettings.Mods.Select(m => "{0}@{1}".F(m,Mod.AllMods[m].Version)).ToArray();
 					var response = new HandshakeResponse()
 					{
 						Client = info,

OpenRA.Game/Server/Server.cs

@@ -189,7 +189,23 @@ namespace OpenRA.Server
 					return;
 				}
 				
-				var client = HandshakeResponse.Deserialize(data).Client;
+				var handshake = HandshakeResponse.Deserialize(data);
+				var client = handshake.Client;
+				var mods = handshake.Mods;
+				
+				// Check that the client has compatable mods
+				
+				var valid = mods.All( m => m.Contains('@')) && //valid format
+				            mods.Count() == Game.CurrentMods.Count() &&  //same number
+				            mods.Select( m => Pair.New(m.Split('@')[0], m.Split('@')[1])).All(kv => Game.CurrentMods.ContainsKey(kv.First) &&
+				     		(kv.Second == "{DEV_VERSION}" || Game.CurrentMods[kv.First].Version == "{DEV_VERSION}" || kv.Second == Game.CurrentMods[kv.First].Version));
+				if (!valid) 
+				{
+					Log.Write("server", "Rejected connection from {0}; mods do not match.", 
+						newConn.socket.RemoteEndPoint);
+					DropClient(newConn);
+					return;
+				}
 				
 				// Promote connection to a valid client
 				preConns.Remove(newConn);

OpenRA.Mods.RA/ServerTraits/MasterServerPinger.cs

@@ -13,6 +13,7 @@ using System.Collections.Generic;
 using System.Net;
 using OpenRA.Server;
 using S = OpenRA.Server.Server;
+using System.Linq;
 
 namespace OpenRA.Mods.RA.Server
 {
@@ -67,7 +68,7 @@ namespace OpenRA.Mods.RA.Server
 								externalPort, Uri.EscapeUriString(server.Name),
 								server.GameStarted ? 2 : 1,	// todo: post-game states, etc.
 								server.lobbyInfo.Clients.Count,
-							   string.Join(",", server.lobbyInfo.GlobalSettings.Mods),
+								string.Join(",", Game.CurrentMods.Select(f => "{0}@{1}".F(f.Key, f.Value.Version)).ToArray()),
 								server.lobbyInfo.GlobalSettings.Map));
 
 							if (isInitialPing)

OpenRA.Mods.RA/Widgets/Delegates/ServerBrowserDelegate.cs

@@ -149,8 +149,7 @@ namespace OpenRA.Mods.RA.Widgets.Delegates
 				return;
 			}
 
-            // only "waiting for players"
-            var gamesWaiting = games.Where(g => g.State == 1);
+            var gamesWaiting = games.Where(g => CanJoin(g));
 
             if (gamesWaiting.Count() == 0)
 			{
@@ -179,6 +178,22 @@ namespace OpenRA.Mods.RA.Widgets.Delegates
 				i++;
 			}
 		}
+		
+		bool CanJoin(GameServer game)
+		{
+			//"waiting for players"
+			if (game.State != 1)
+				return false;
+			
+			// Mods won't match if there are a different number
+			if (Game.CurrentMods.Count != game.Mods.Count())
+				return false;
+			
+			return game.Mods.All( m => m.Contains('@')) &&  game.Mods.Select( m => Pair.New(m.Split('@')[0], m.Split('@')[1]))
+				.All(kv => Game.CurrentMods.ContainsKey(kv.First) &&
+				     (kv.Second == "{DEV_VERSION}" || Game.CurrentMods[kv.First].Version == "{DEV_VERSION}" || kv.Second == Game.CurrentMods[kv.First].Version));
+		}
+		
 	}
 
 	public class DirectConnectDelegate : IWidgetDelegate