Allow host only mods to send Support Flags

examples/moddedsupport/SendBAUSupportFlagsExamplePatch.cs

@@ -0,0 +1,64 @@
+using HarmonyLib;
+using Hazel;
+
+namespace BetterAmongUs.Examples;
+
+/// <summary>
+/// Example patch that demonstrates how to send BetterAmongUs modded support flags to BAU users.
+/// This patch hooks into the player info serialization process to transmit custom flags that control various BAU features.
+/// </summary>
+[HarmonyPatch]
+internal static class SendBAUSupportFlagsExamplePatch
+{
+    /// <summary>
+    /// Postfix patch that runs after NetworkedPlayerInfo.Serialize.
+    /// When the host is serializing the player data, this method writes
+    /// BAU support flags into the message stream to communicate mod capabilities to the BAU client.
+    /// </summary>
+    /// <param name="__instance">The NetworkedPlayerInfo instance being serialized.</param>
+    /// <param name="writer">The MessageWriter used for serialization.</param>
+    /// <remarks>
+    /// This example sends the "command.force.bau.prefix" flag which forces all BAU commands
+    /// to use the "bau:" prefix. The flag is hashed using GetFlagHash for efficient transmission.
+    /// <para>
+    /// <b>Important:</b> This functionality only works on protocol version +25 (modded protocol)!
+    /// </para>
+    /// </remarks>
+    [HarmonyPatch(typeof(NetworkedPlayerInfo), nameof(NetworkedPlayerInfo.Serialize))]
+    [HarmonyPriority(Priority.Last)]
+    [HarmonyPostfix]
+    internal static void Serialize_Postfix(NetworkedPlayerInfo __instance, MessageWriter writer)
+    {
+        if (!AmongUsClient.Instance.AmHost || __instance.OwnerId != -2)
+            return;
+
+        writer.Write("bau:flags"); // Mark message as BAU flags
+        writer.WritePacked(1); // Amount of flags we are sending
+        writer.WritePacked(GetFlagHash("command.force.bau.prefix")); // Send flag hash, most use GetFlagHash with the exact logic in this example!
+    }
+
+    /// <summary>
+    /// Generates a deterministic integer hash from a string for use as a flag identifier.
+    /// </summary>
+    /// <param name="input">The input string to hash</param>
+    /// <returns>
+    /// A 32-bit integer hash value. Returns 0 for null or empty strings.
+    /// </returns>
+    internal static int GetFlagHash(string input)
+    {
+        if (string.IsNullOrEmpty(input)) return 0;
+
+        int hash = 17;
+        hash = hash * 31 + input.Length;
+
+        for (int i = 0; i < input.Length; i++)
+        {
+            char c = input[i];
+            hash = hash * 31 + c;
+            hash = hash * 31 + i;
+        }
+
+        hash = hash * 31 + input.Length;
+        return hash;
+    }
+}

src/BAUPlugin.cs

@@ -18,6 +18,7 @@ using HarmonyLib;
 using Il2CppInterop.Runtime.Injection;
 using System.Reflection;
 using UnityEngine;
+using UnityEngine.SceneManagement;
 
 namespace BetterAmongUs;
 
@@ -160,6 +161,7 @@ internal class BAUPlugin : BasePlugin
         BAUModdedSupportEvents.OnBAUOptionsLoadedEvent.InvokeAll([.. OptionItem.AllOptions.Cast<object>()]);
         InstanceAttribute.RegisterAll();
         OutfitData.Initialize();
+        SceneManager.add_sceneLoaded((Action<Scene, LoadSceneMode>)OnSceneLoaded);
 
         if (File.Exists(BetterDataManager.Files.logFilePath))
             File.WriteAllText(BetterDataManager.Files.previousLogFilePath, File.ReadAllText(BetterDataManager.Files.logFilePath));
@@ -171,6 +173,17 @@ internal class BAUPlugin : BasePlugin
         Logger_.Log($"BetterAmongUs {BetterAmongUsVersion}-{ModInfo.BuildDate} - [{AppVersion} --> {SupportedVersions}] {Utils.GetPlatformName(PlatformData.Platform)}");
     }
 
+    private static void OnSceneLoaded(Scene scene, LoadSceneMode _)
+    {
+        if (AmongUsClient.Instance != null)
+        {
+            if (scene.name == AmongUsClient.Instance.MainMenuScene)
+            {
+                BAUModdedSupportFlags.ClearTempFlags();
+            }
+        }
+    }
+
     /// <summary>
     /// Sets up the console window for logging.
     /// </summary>

src/ModInfo.cs

@@ -108,5 +108,7 @@ internal static class ModInfo
     internal static class Constants
     {
         internal const int MAX_CHAT_TEXT = 120;
+        internal const string BAU_CUSTOM_RPC_FLAG = "bau:rpc";
+        internal const string BAU_MODDED_PROTOCOL_FLAG = "bau:flags";
     }
 }

src/Modules/HandshakeHandler.cs

@@ -40,7 +40,7 @@ internal sealed class HandshakeHandler
     {
         if (!BAUConfigs.SendBetterRpc.Value) yield break;
 
-        while (_extendedData._Data == null || _extendedData._Data.Object == null || PlayerControl.LocalPlayer == null)
+        while (_extendedData.BaseMono == null || _extendedData.BaseMono.Object == null || PlayerControl.LocalPlayer == null)
         {
             if (GameState.IsFreePlay) yield break;
             yield return null;
@@ -71,7 +71,7 @@ internal sealed class HandshakeHandler
     // Local client sends to client
     private void SendSecretToPlayer()
     {
-        if (_extendedData._Data.Object.IsLocalPlayer())
+        if (_extendedData.BaseMono.Object.IsLocalPlayer())
             return;
 
         if (HasSendSharedSecret)
@@ -84,7 +84,7 @@ internal sealed class HandshakeHandler
             writer.Write(SharedSecret.CryptoAvailable);
             writer.WriteBytes(SharedSecret.GetPublicKey());
             writer.Write(SharedSecret.GetTempKey());
-        }, _extendedData._Data.ClientId);
+        }, _extendedData.BaseMono.ClientId);
     }
 
     /// <summary>
@@ -94,7 +94,7 @@ internal sealed class HandshakeHandler
     // Client receives from local client
     internal void HandleSecretFromSender(MessageReader reader)
     {
-        if (_extendedData._Data?.Object?.IsLocalPlayer() == true)
+        if (_extendedData.BaseMono?.Object?.IsLocalPlayer() == true)
             return;
 
         bool senderSupportsCrypto = reader.ReadBoolean();
@@ -116,7 +116,7 @@ internal sealed class HandshakeHandler
         _extendedData.IsBetterUser = true;
 
         TryHandlePendingVerificationData();
-        SendSecretHashToSender(tempKey, _extendedData._Data.ClientId);
+        SendSecretHashToSender(tempKey, _extendedData.BaseMono.ClientId);
         ResendSecretToPlayer();
     }
 

src/Modules/Support/BAUModdedSupportFlags.cs

@@ -221,6 +221,7 @@ public static class BAUModdedSupportFlags
     public static string Disable_CustomColorBlindText = "gameplay.disable.customcolorblindtext";
 
     private static readonly HashSet<string> _flags = [];
+    private static readonly HashSet<int> _tempFlags = [];
     private static bool _initialized = false;
 
     private static readonly BAUSupportVar<string[]> BAUSupportFlags = new("bau:flags");
@@ -262,6 +263,23 @@ public static class BAUModdedSupportFlags
         _flags.Add(flag);
     }
 
+    /// <summary>
+    /// Manually adds a temporary flag to the internal temporary flag collection.
+    /// </summary>
+    /// <param name="flag">The flag hash to add to the collection.</param>
+    internal static void AddTempFlag(int flag)
+    {
+        _tempFlags.Add(flag);
+    }
+
+    /// <summary>
+    /// CLears all temporary flags.
+    /// </summary>
+    internal static void ClearTempFlags()
+    {
+        _tempFlags.Clear();
+    }
+
     /// <summary>
     /// Checks if a specific flag has been declared by any loaded mod.
     /// </summary>
@@ -269,6 +287,31 @@ public static class BAUModdedSupportFlags
     /// <returns><c>true</c> if the flag is present; otherwise, <c>false</c>.</returns>
     public static bool HasFlag(string flag)
     {
-        return _flags.Contains(flag);
+        return _flags.Contains(flag) || _tempFlags.Contains(GetFlagHash(flag));
+    }
+
+    /// <summary>
+    /// Generates a integer hash from a string for use as a flag identifier.
+    /// </summary>
+    /// <param name="input">The input string to hash. Can be null or empty.</param>
+    /// <returns>
+    /// A integer hash value. Returns 0 for null or empty strings.
+    /// </returns>
+    internal static int GetFlagHash(string input)
+    {
+        if (string.IsNullOrEmpty(input)) return 0;
+
+        int hash = 17;
+        hash = hash * 31 + input.Length;
+
+        for (int i = 0; i < input.Length; i++)
+        {
+            char c = input[i];
+            hash = hash * 31 + c;
+            hash = hash * 31 + i;
+        }
+
+        hash = hash * 31 + input.Length;
+        return hash;
     }
 }

src/Mono/Extended/ExtendedPlayerControl.cs

@@ -17,18 +17,13 @@ internal sealed class ExtendedPlayerControl : MonoBehaviour, IMonoExtension<Play
     /// </summary>
     public PlayerControl? BaseMono { get; set; }
 
-    /// <summary>
-    /// Gets the PlayerControl instance.
-    /// </summary>
-    internal PlayerControl? _Player => BaseMono;
-
     private void Awake()
     {
         if (!this.RegisterExtension())
             return;
 
         this.StartCoroutine(CoAddBetterData());
-        _Player.gameObject.AddComponent<PlayerInfoDisplay>().Init(_Player);
+        BaseMono.gameObject.AddComponent<PlayerInfoDisplay>().Init(BaseMono);
     }
 
     /// <summary>
@@ -38,12 +33,12 @@ internal sealed class ExtendedPlayerControl : MonoBehaviour, IMonoExtension<Play
     [HideFromIl2Cpp]
     private IEnumerator CoAddBetterData()
     {
-        while (_Player == null || _Player.Data == null)
+        while (BaseMono == null || BaseMono.Data == null)
         {
             yield return null;
         }
 
-        TryCreateExtendedData(_Player.Data);
+        TryCreateExtendedData(BaseMono.Data);
     }
 
     /// <summary>

src/Mono/Extended/ExtendedPlayerInfo.cs

@@ -2,6 +2,9 @@
 using BetterAmongUs.Helpers;
 using BetterAmongUs.Managers;
 using BetterAmongUs.Modules;
+using BetterAmongUs.Modules.Support;
+using HarmonyLib;
+using Hazel;
 using Il2CppInterop.Runtime.Attributes;
 using InnerNet;
 using UnityEngine;
@@ -21,15 +24,13 @@ internal sealed class ExtendedPlayerInfo : MonoBehaviour, IMonoExtension<Network
         }
         catch (Exception ex)
         {
-            Logger_.Error("Handshake disabled: " + ex.Message);
+            Logger_.Log("Handshake disabled: " + ex.Message);
             HandshakeHandler = null;
         }
     }
 
     public NetworkedPlayerInfo? BaseMono { get; set; }
 
-    internal NetworkedPlayerInfo? _Data => BaseMono;
-
     private bool hasSet = false;
 
     /// <summary>
@@ -75,17 +76,17 @@ internal sealed class ExtendedPlayerInfo : MonoBehaviour, IMonoExtension<Network
 
         if (AntiCheatInfo.RPCSentPS > 0)
         {
-            bool flag = _Data.IsCheater();
+            bool flag = BaseMono.IsCheater();
 
             if (AntiCheatInfo.RPCSentPS >= ExtendedAntiCheatInfo.MAX_RPC_SENT && !flag)
             {
                 BetterNotificationManager.NotifyCheat(
-                    _Data.Object,
+                    BaseMono.Object,
                     Translator.GetString("AntiCheat.Reason.RPCSentPS"),
                     Translator.GetString("AntiCheat.UnauthorizedAction")
                 );
 
-                Logger_.LogCheat($"{_Data.Object.ExtendedData().RealName} {AntiCheatInfo.RPCSentPS} Sent.");
+                Logger_.LogCheat($"{BaseMono.Object.ExtendedData().RealName} {AntiCheatInfo.RPCSentPS} Sent.");
             }
 
             timeAccumulator += time;
@@ -98,6 +99,28 @@ internal sealed class ExtendedPlayerInfo : MonoBehaviour, IMonoExtension<Network
         }
     }
 
+    internal void Deserialize(MessageReader reader)
+    {
+        if (BaseMono.OwnerId != -2)
+            return;
+
+        if (reader.BytesRemaining > 0)
+        {
+            try
+            {
+                if (reader.ReadString() == ModInfo.Constants.BAU_MODDED_PROTOCOL_FLAG)
+                {
+                    int flagCount = reader.ReadPackedInt32();
+                    for (int i = 0; i < flagCount; i++)
+                    {
+                        BAUModdedSupportFlags.AddTempFlag(reader.ReadPackedInt32());
+                    }
+                }
+            }
+            catch { }
+        }
+    }
+
     /// <summary>
     /// Gets the handshake handler for this player.
     /// </summary>
@@ -113,7 +136,7 @@ internal sealed class ExtendedPlayerInfo : MonoBehaviour, IMonoExtension<Network
     /// <summary>
     /// Gets the player's real name.
     /// </summary>
-    internal string RealName => _Data?.PlayerName ?? "???";
+    internal string RealName => BaseMono?.PlayerName ?? "???";
 
     /// <summary>
     /// Gets or sets the last name set for this player.
@@ -245,6 +268,18 @@ internal sealed class ExtendedRoleInfo
 /// </summary>
 internal static class PlayerControlDataExtension
 {
+    [HarmonyPatch(typeof(NetworkedPlayerInfo))]
+    class NetworkedPlayerInfoPatch
+    {
+        [HarmonyPatch(nameof(NetworkedPlayerInfo.Deserialize))]
+        [HarmonyPriority(Priority.Last)]
+        [HarmonyPostfix]
+        internal static void Deserialize_Postfix(NetworkedPlayerInfo __instance, MessageReader reader)
+        {
+            __instance.ExtendedData()?.Deserialize(reader);
+        }
+    }
+
     /// <summary>
     /// Gets extended player data from a PlayerControl.
     /// </summary>

src/Network/RPC.cs

@@ -15,10 +15,6 @@ internal static class RPC
     /// </summary>
     internal const RpcCalls CUSTOM_RPC_CALL = RpcCalls.CancelPet;
 
-    /// <summary>
-    /// The flag string used to identify custom RPC messages packed within vanilla RPC calls.
-    /// </summary>
-    internal const string CUSTOM_RPC_FLAG = "bau:rpc";
 
     /// <summary>
     /// Sends a custom RPC message packed within a vanilla SetNamePlateStr RPC call.
@@ -32,7 +28,7 @@ internal static class RPC
     {
         AmongUsClient.Instance.SendRpcImmediately(PlayerControl.LocalPlayer.NetId, CUSTOM_RPC_CALL, SendOption.Reliable, writer =>
         {
-            writer.Write(CUSTOM_RPC_FLAG); // Flag to check if its a rpc packed into SetNamePlateStr
+            writer.Write(ModInfo.Constants.BAU_CUSTOM_RPC_FLAG); // Flag to check if its a rpc packed into SetNamePlateStr
             writer.Write((byte)customRPC);
             action(writer);
         }, targetClientId);
@@ -120,7 +116,7 @@ internal static class RPC
         {
             try
             {
-                if (reader.ReadString() == CUSTOM_RPC_FLAG)
+                if (reader.ReadString() == ModInfo.Constants.BAU_CUSTOM_RPC_FLAG)
                 {
                     return true;
                 }

src/Patches/Client/ClientPatch.cs

@@ -35,7 +35,7 @@ internal static class ClientPatch
 
     [HarmonyPatch(typeof(SignInStatusComponent), nameof(SignInStatusComponent.SetOnline))]
     [HarmonyPrefix]
-    private static bool SignInStatusComponent_SetOnline_Prefix(SignInStatusComponent __instance)
+    private static bool SignInStatusComponent_SetOnline_Prefix()
     {
         // Get supported Among Us versions for BAU
         var varSupportedVersions = ModInfo.SupportedAmongUsVersions;
@@ -80,10 +80,11 @@ internal static class ClientPatch
 
     [HarmonyPatch(typeof(AmongUsClient), nameof(AmongUsClient.ExitGame))]
     [HarmonyPostfix]
-    private static void AmongUsClient_ExitGame_Postfix([HarmonyArgument(0)] DisconnectReasons reason)
+    private static void AmongUsClient_ExitGame_Postfix(DisconnectReasons reason)
     {
         // Hide custom loading bar when exiting game
         CustomLoadingBarManager.ToggleLoadingBar(false);
+
         Logger_.Log($"Client has left game for: {Enum.GetName(reason)}", "AmongUsClientPatch");
     }