fix: Fixes crashing due to bad packet assumptions. (#1829)

### Summary
- Fixes various exploits that can crash the shard when the client misbehaves.
- Clients will now be disconnected if they send packets that are marked as out of game only (new flag), while they are in-game.


> [!Note]
> **Developer Note**
> Added an `OutOfGameOnly` which should be used to flag packets as only available out of the game.
> This is the opposite of, yet not the converse to `InGameOnly`.

Projects/UOContent/Network/Packets/IncomingAccountPackets.cs

@@ -57,18 +57,17 @@ public static class IncomingAccountPackets
 
     public static unsafe void Configure()
     {
-        IncomingPackets.Register(0x00, 104, false, &CreateCharacter);
-        IncomingPackets.Register(0x5D, 73, false, &PlayCharacter);
-        IncomingPackets.Register(0x80, 62, false, &AccountLogin);
-        IncomingPackets.Register(0x83, 39, false, &DeleteCharacter);
-        IncomingPackets.Register(0x91, 65, false, &GameLogin);
-        IncomingPackets.Register(0xA0, 3, false, &PlayServer);
-        IncomingPackets.Register(0xBB, 9, false, &AccountID);
-        IncomingPackets.Register(0xBD, 0, false, &ClientVersion);
-        IncomingPackets.Register(0xCF, 0, false, &AccountLogin);
-        IncomingPackets.Register(0xE1, 0, false, &ClientType);
-        IncomingPackets.Register(0xEF, 21, false, &LoginServerSeed);
-        IncomingPackets.Register(0xF8, 106, false, &CreateCharacter);
+        IncomingPackets.Register(0x00, &CreateCharacter, 104, outgameOnly: true);
+        IncomingPackets.Register(0x5D, &PlayCharacter, 73, outgameOnly: true);
+        IncomingPackets.Register(0x80, &AccountLogin, 62, outgameOnly: true);
+        IncomingPackets.Register(0x83, &DeleteCharacter, 39, outgameOnly: true);
+        IncomingPackets.Register(0x91, &GameLogin, 65, outgameOnly: true);
+        IncomingPackets.Register(0xA0, &PlayServer, 3, outgameOnly: true);
+        IncomingPackets.Register(0xBD, &ClientVersion);
+        IncomingPackets.Register(0xCF, &AccountLogin, outgameOnly: true);
+        IncomingPackets.Register(0xE1, &ClientType);
+        IncomingPackets.Register(0xEF, &LoginServerSeed, 21, outgameOnly: true);
+        IncomingPackets.Register(0xF8, &CreateCharacter, 106, outgameOnly: true);
     }
 
     public static void CreateCharacter(NetState state, SpanReader reader)

Projects/UOContent/Network/Packets/IncomingExtendedCommandPackets.cs

@@ -14,6 +14,7 @@
  *************************************************************************/
 
 using System.Buffers;
+using System.Runtime.CompilerServices;
 using Server.ContextMenus;
 using Server.Items;
 using Server.Mobiles;
@@ -70,12 +71,18 @@ public static class IncomingExtendedCommandPackets
     {
     }
 
-    public static unsafe void RegisterExtended(int packetID, bool ingame,
-        delegate*<NetState, SpanReader, void> onReceive)
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static unsafe void RegisterExtended(
+        int packetID, bool ingame, delegate*<NetState, SpanReader, void> onReceive
+    ) => RegisterExtended(packetID, ingame, false, onReceive);
+
+    public static unsafe void RegisterExtended(
+        int packetID, bool ingame, bool outgame, delegate*<NetState, SpanReader, void> onReceive
+    )
     {
         if (packetID is >= 0 and < 0x100)
         {
-            _extendedHandlers[packetID] = new PacketHandler(packetID, 0, ingame, onReceive);
+            _extendedHandlers[packetID] = new PacketHandler(packetID, onReceive, inGameOnly: ingame, outGameOnly: outgame);
         }
     }
 
@@ -102,21 +109,30 @@ public static class IncomingExtendedCommandPackets
             return;
         }
 
-        if (ph.Ingame && state.Mobile?.Deleted != false)
+        var from = state.Mobile;
+
+        if (ph.InGameOnly)
         {
-            if (state.Mobile == null)
+            if (from == null)
             {
-                state.LogInfo(
-                    $"Sent in-game packet (0xBFx{packetId:X2}) before having been attached to a mobile"
-                );
+                state.Disconnect($"Received packet 0x{packetId:X2} before having been attached to a mobile.");
+                return;
             }
 
-            state.Disconnect($"Sent in-game packet(0xBFx{packetId:X2}) but mobile is deleted.");
+            if (from.Deleted)
+            {
+                state.Disconnect($"Received packet 0x{packetId:X2} after having been attached to a deleted mobile.");
+                return;
+            }
         }
-        else
+
+        if (ph.OutOfGameOnly && from?.Deleted == false)
         {
-            ph.OnReceive(state, reader);
+            state.Disconnect($"Received packet 0x{packetId:X2} after having been attached to a mobile.");
+            return;
         }
+
+        ph.OnReceive(state, reader);
     }
 
     public static void ScreenSize(NetState state, SpanReader reader)

Projects/UOContent/Network/Packets/IncomingItemPackets.cs

@@ -26,7 +26,7 @@ public static class IncomingItemPackets
     public static unsafe void Configure()
     {
         IncomingPackets.Register(0x07, 7, true, &LiftReq);
-        IncomingPackets.Register(new ContainerGridPacketHandler(0x08, 14, true, &DropReq));
+        IncomingPackets.Register(new ContainerGridPacketHandler(0x08, 14, &DropReq));
         IncomingPackets.Register(0x13, 10, true, &EquipReq);
         IncomingPackets.Register(0xEC, 0, false, &EquipMacro);
         IncomingPackets.Register(0xED, 0, false, &UnequipMacro);