carpet client synchronizations and protocols

src/main/java/carpet/CarpetServer.java

@@ -6,7 +6,7 @@ import java.util.List;
 import java.util.Random;
 
 import carpet.commands.*;
-import carpet.helpers.ServerNetworkHandler;
+import carpet.network.ServerNetworkHandler;
 import carpet.helpers.TickSpeed;
 import carpet.logging.LoggerRegistry;
 import carpet.script.CarpetScriptServer;
@@ -18,7 +18,6 @@ import net.fabricmc.loader.api.FabricLoader;
 import net.minecraft.server.command.ServerCommandSource;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.network.ServerPlayerEntity;
-import net.minecraft.util.Identifier;
 
 public class CarpetServer // static for now - easier to handle all around the code, its one anyways
 {
@@ -28,7 +27,6 @@ public class CarpetServer // static for now - easier to handle all around the co
     public static CarpetScriptServer scriptServer;
     public static SettingsManager settingsManager;
     public static final List<CarpetExtension> extensions = new ArrayList<>();
-    public static final Identifier CARPET_CHANNEL = new Identifier("carpet:info");
 
     // Separate from onServerLoaded, because a server can be loaded multiple times in singleplayer
     public static void manageExtension(CarpetExtension extension)
@@ -48,9 +46,6 @@ public class CarpetServer // static for now - easier to handle all around the co
         settingsManager = new SettingsManager(CarpetSettings.carpetVersion, "carpet", "Carpet Mod");
         settingsManager.parseSettingsClass(CarpetSettings.class);
         extensions.forEach(CarpetExtension::onGameStarted);
-        CarpetServer.settingsManager.addRuleObserver((source, parsedRule, s) -> {
-            ServerNetworkHandler.sendUpdateToClient(parsedRule.name, parsedRule.getAsString(), source);
-        });
     }
 
     public static void onServerLoaded(MinecraftServer server)
@@ -66,6 +61,7 @@ public class CarpetServer // static for now - easier to handle all around the co
         scriptServer.loadAllWorldScripts();
         MobAI.resetTrackers();
         LoggerRegistry.initLoggers();
+        //TickSpeed.reset();
     }
 
     public static void tick(MinecraftServer server)
@@ -108,31 +104,41 @@ public class CarpetServer // static for now - easier to handle all around the co
 
     public static void onPlayerLoggedIn(ServerPlayerEntity player)
     {
+        ServerNetworkHandler.onPlayerJoin(player);
         LoggerRegistry.playerConnected(player);
         extensions.forEach(e -> e.onPlayerLoggedIn(player));
-        ServerNetworkHandler.onPlayerJoin(player);
+
     }
 
     public static void onPlayerLoggedOut(ServerPlayerEntity player)
     {
+        ServerNetworkHandler.onPlayerLoggedOut(player);
         LoggerRegistry.playerDisconnected(player);
         extensions.forEach(e -> e.onPlayerLoggedOut(player));
     }
 
     public static void onServerClosed(MinecraftServer server)
     {
+        ServerNetworkHandler.close();
         currentCommandDispatcher = null;
         if (scriptServer != null) scriptServer.onClose();
-        settingsManager.detachServer();
+
         LoggerRegistry.stopLoggers();
-        TickSpeed.reset();
         extensions.forEach(e -> e.onServerClosed(server));
         minecraft_server = null;
+        disconnect();
     }
 
     public static void registerExtensionLoggers()
     {
         extensions.forEach(CarpetExtension::registerLoggers);
     }
+
+    public static void disconnect()
+    {
+        // this for whatever reason gets called multiple times even when joining;
+        TickSpeed.reset();
+        settingsManager.detachServer();
+    }
 }
 

src/main/java/carpet/CarpetSettings.java

@@ -44,7 +44,7 @@ public class CarpetSettings
 
     private static class LanguageValidator extends Validator<String> {
         @Override public String validate(ServerCommandSource source, ParsedRule<String> currentRule, String newValue, String string) {
-            if (currentRule.get().equals(newValue))
+            if (currentRule.get().equals(newValue) || source == null)
             {
                 return newValue;
             }
@@ -487,7 +487,7 @@ public class CarpetSettings
     {
         @Override public Integer validate(ServerCommandSource source, ParsedRule<Integer> currentRule, Integer newValue, String string)
         {
-            if (currentRule.get().equals(newValue))
+            if (currentRule.get().equals(newValue) || source == null)
             {
                 return newValue;
             }
@@ -538,6 +538,7 @@ public class CarpetSettings
             }
         }
         @Override public Integer validate(ServerCommandSource source, ParsedRule<Integer> currentRule, Integer newValue, String string) {
+            if (source == null) return newValue;
             if (newValue < 0 || newValue > 32)
             {
                 Messenger.m(source, "r spawn chunk size has to be between 0 and 32");

src/main/java/carpet/commands/TickCommand.java

@@ -67,7 +67,7 @@ public class TickCommand
 
     private static int setTps(ServerCommandSource source, float tps)
     {
-        TickSpeed.tickrate(tps);
+        TickSpeed.tickrate(tps, true);
         queryTps(source);
         return (int)tps;
     }

src/main/java/carpet/fakes/CustomPayloadC2SPacketInterface.java

@@ -0,0 +1,10 @@
+package carpet.fakes;
+
+import net.minecraft.util.Identifier;
+import net.minecraft.util.PacketByteBuf;
+
+public interface CustomPayloadC2SPacketInterface
+{
+    Identifier getPacketChannel();
+    PacketByteBuf getPacketData();
+}

src/main/java/carpet/helpers/ClientNetworkHandler.java

@@ -1,59 +0,0 @@
-package carpet.helpers;
-
-import carpet.CarpetServer;
-import carpet.CarpetSettings;
-import carpet.settings.ParsedRule;
-import net.minecraft.client.MinecraftClient;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.ListTag;
-import net.minecraft.nbt.Tag;
-import net.minecraft.util.Identifier;
-import net.minecraft.util.PacketByteBuf;
-
-public class ClientNetworkHandler
-{
-    public static void handleData(Identifier channel, PacketByteBuf data)
-    {
-        if (CarpetServer.CARPET_CHANNEL.equals(channel) && data != null)
-        {
-            int id = data.readVarInt();
-            
-            if (id == 1)
-                setOnJoinInfo(data);
-            else if (id == 2)
-                updateRule(data);
-            else if (id == 3)
-                updateTickRateClient(data);
-        }
-    }
-    
-    private static void setOnJoinInfo(PacketByteBuf data)
-    {
-        CompoundTag compound = data.readCompoundTag();
-        if (compound == null) return;
-        
-        TickSpeed.tickrate(compound.getFloat("Tickrate"));
-        
-        ListTag rulesList = compound.getList("rules", 10);
-        for (Tag tag : rulesList)
-        {
-            CompoundTag ruleNBT = (CompoundTag) tag;
-            String rule = ruleNBT.getString("rule");
-            String value = ruleNBT.getString("value");
-            CarpetServer.settingsManager.getRule(rule).set(null, value);
-        }
-    }
-    
-    private static void updateRule(PacketByteBuf data)
-    {
-        String rule = data.readString();
-        String newValue = data.readString();
-        CarpetServer.settingsManager.getRule(rule).set(null, newValue);
-    }
-    
-    private static void updateTickRateClient(PacketByteBuf data)
-    {
-        float rate = data.readFloat();
-        TickSpeed.tickrate(rate);
-    }
-}

src/main/java/carpet/helpers/ServerNetworkHandler.java

@@ -1,66 +0,0 @@
-package carpet.helpers;
-
-import carpet.CarpetServer;
-import carpet.CarpetSettings;
-import carpet.settings.ParsedRule;
-import io.netty.buffer.Unpooled;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.ListTag;
-import net.minecraft.network.packet.s2c.play.CustomPayloadS2CPacket;
-import net.minecraft.server.MinecraftServer;
-import net.minecraft.server.command.ServerCommandSource;
-import net.minecraft.server.network.ServerPlayerEntity;
-import net.minecraft.util.PacketByteBuf;
-
-public class ServerNetworkHandler
-{
-    public static void onPlayerJoin(ServerPlayerEntity playerEntity)
-    {
-        CompoundTag data = new CompoundTag();
-        
-        data.putFloat("Tickrate", TickSpeed.tickrate);
-        
-        ListTag rulesList = new ListTag();
-        for (ParsedRule<?> rule : CarpetServer.settingsManager.getRules())
-        {
-            CompoundTag ruleNBT = new CompoundTag();
-            
-            ruleNBT.putString("rule" ,rule.name);
-            ruleNBT.putString("value", rule.getAsString());
-            ruleNBT.putString("default", rule.defaultAsString);
-            rulesList.add(ruleNBT);
-        }
-        data.put("rules", rulesList);
-        PacketByteBuf packetBuf = new PacketByteBuf(Unpooled.buffer());
-        packetBuf.writeVarInt(1);
-        packetBuf.writeCompoundTag(data);
-        playerEntity.networkHandler.sendPacket(new CustomPayloadS2CPacket(CarpetServer.CARPET_CHANNEL, packetBuf));
-    }
-    
-    public static void sendUpdateToClient(String rule, String newValue, ServerCommandSource source)
-    {
-        PacketByteBuf data = new PacketByteBuf(Unpooled.buffer());
-        
-        data.writeVarInt(2);
-        data.writeString(rule);
-        data.writeString(newValue);
-        for (ServerPlayerEntity player : source.getMinecraftServer().getPlayerManager().getPlayerList())
-        {
-            player.networkHandler.sendPacket(new CustomPayloadS2CPacket(CarpetServer.CARPET_CHANNEL, data));
-        }
-    }
-    
-    public static void sendTickRateToPlayers(float rate)
-    {
-        PacketByteBuf data = new PacketByteBuf(Unpooled.buffer());
-        data.writeVarInt(3);
-        data.writeFloat(rate);
-        if (CarpetServer.minecraft_server != null)
-        {
-            for (ServerPlayerEntity player : CarpetServer.minecraft_server.getPlayerManager().getPlayerList())
-            {
-                player.networkHandler.sendPacket(new CustomPayloadS2CPacket(CarpetServer.CARPET_CHANNEL, data));
-            }
-        }
-    }
-}

src/main/java/carpet/helpers/TickSpeed.java

@@ -5,6 +5,7 @@ import java.util.Map;
 import java.util.function.BiConsumer;
 
 import carpet.CarpetServer;
+import carpet.network.ServerNetworkHandler;
 import carpet.utils.Messenger;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.server.MinecraftServer;
@@ -177,7 +178,7 @@ public class TickSpeed
         }
     }
     
-    public static void tickrate(float rate)
+    public static void tickrate(float rate, boolean update)
     {
         tickrate = rate;
         long mspt = (long)(1000.0 / tickrate);
@@ -189,7 +190,7 @@ public class TickSpeed
         
         TickSpeed.mspt = (float)mspt;
         
-        notifyTickrateListeners("carpet");
+        if (update) notifyTickrateListeners("carpet");
     }
     
     private static void tickrateChanged(String modId, float rate)
@@ -221,7 +222,7 @@ public class TickSpeed
 	            }
 	        }
         }
-        ServerNetworkHandler.sendTickRateToPlayers(tickrate);
+        ServerNetworkHandler.updateTickSpeedToConnectedPlayers();
     }
     
     public static BiConsumer<String, Float> addTickrateListener(String modId, BiConsumer<String, Float> tickrateListener) 

src/main/java/carpet/mixins/ClientPlayNetworkHandlerMixin.java

@@ -1,44 +1,43 @@
 package carpet.mixins;
 
-import carpet.CarpetServer;
-import carpet.helpers.ClientNetworkHandler;
+import carpet.network.CarpetClient;
+import carpet.network.ClientNetworkHandler;
 import net.minecraft.client.MinecraftClient;
 import net.minecraft.client.network.ClientPlayNetworkHandler;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.ListTag;
-import net.minecraft.nbt.Tag;
 import net.minecraft.network.packet.s2c.play.CustomPayloadS2CPacket;
-import net.minecraft.util.Identifier;
-import net.minecraft.util.PacketByteBuf;
+import net.minecraft.network.packet.s2c.play.GameJoinS2CPacket;
+import net.minecraft.text.Text;
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
-import org.spongepowered.asm.mixin.injection.callback.LocalCapture;
 
 @Mixin(ClientPlayNetworkHandler.class)
 public abstract class ClientPlayNetworkHandlerMixin
 {
-    @Inject(method = "onCustomPayload", at = @At(value = "CONSTANT", args = "stringValue=Unknown custom packed identifier: {}"), cancellable = true, locals = LocalCapture.CAPTURE_FAILSOFT, require = 0)
-    private void onCustomPayloadNotFound(CustomPayloadS2CPacket packet, CallbackInfo ci, Identifier id, PacketByteBuf buf)
-    {
-        if (CarpetServer.CARPET_CHANNEL.equals(id))
-        {
-            if (buf.refCnt() > 0)
-            {
-                buf.release();
-            }
-            
-            ci.cancel();
-        }
-    }
-    
+    @Shadow private MinecraftClient client;
+
     @Inject(method = "onCustomPayload", at = @At("HEAD"), cancellable = true)
     private void onOnCustomPayload(CustomPayloadS2CPacket packet, CallbackInfo ci)
     {
-        Identifier channel = packet.getChannel();
-        PacketByteBuf buf = packet.getData();
-        ClientNetworkHandler.handleData(channel, buf);
-        ci.cancel();
+        if (CarpetClient.CARPET_CHANNEL.equals(packet.getChannel()))
+        {
+            ClientNetworkHandler.handleData(packet.getData(), client.player);
+            ci.cancel();
+        }
     }
+
+    @Inject(method = "onGameJoin", at = @At("RETURN"))
+    private void onGameJoined(GameJoinS2CPacket packet, CallbackInfo info)
+    {
+        CarpetClient.gameJoined(client.player);
+    }
+
+    @Inject(method = "onDisconnected", at = @At("HEAD"))
+    private void onCMDisconnected(Text reason, CallbackInfo ci)
+    {
+        CarpetClient.disconnect();
+    }
+
 }

src/main/java/carpet/mixins/ClientPlayerEntity_clientCommandMixin.java

@@ -1,6 +1,7 @@
 package carpet.mixins;
 
 import carpet.CarpetServer;
+import carpet.network.CarpetClient;
 import net.minecraft.client.network.ClientPlayerEntity;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
@@ -13,8 +14,10 @@ public class ClientPlayerEntity_clientCommandMixin
     @Inject(method = "sendChatMessage", at = @At("HEAD"))
     private void inspectMessage(String string, CallbackInfo ci)
     {
-        ClientPlayerEntity playerSource = (ClientPlayerEntity)(Object) this;
-        if (CarpetServer.minecraft_server == null)
+        if (CarpetServer.minecraft_server == null && !CarpetClient.isCarpet())
+        {
+            ClientPlayerEntity playerSource = (ClientPlayerEntity)(Object) this;
             CarpetServer.settingsManager.inspectClientsideCommand(playerSource.getCommandSource(), string);
+        }
     }
 }

src/main/java/carpet/mixins/CustomPayloadC2SPacketMixin.java

@@ -0,0 +1,27 @@
+package carpet.mixins;
+
+import carpet.fakes.CustomPayloadC2SPacketInterface;
+import net.minecraft.network.packet.c2s.play.CustomPayloadC2SPacket;
+import net.minecraft.util.Identifier;
+import net.minecraft.util.PacketByteBuf;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+@Mixin(CustomPayloadC2SPacket.class)
+public class CustomPayloadC2SPacketMixin implements CustomPayloadC2SPacketInterface
+{
+    @Shadow
+    private Identifier channel;
+    @Shadow
+    private PacketByteBuf data;
+
+    @Override
+    public Identifier getPacketChannel() {
+        return channel;
+    }
+
+    @Override
+    public PacketByteBuf getPacketData() {
+        return new PacketByteBuf(this.data.copy());
+    }
+}

src/main/java/carpet/mixins/MinecraftClientMixin.java

@@ -1,7 +1,9 @@
 package carpet.mixins;
 
 import carpet.CarpetServer;
+import carpet.network.CarpetClient;
 import net.minecraft.client.MinecraftClient;
+import net.minecraft.client.gui.screen.Screen;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
@@ -18,4 +20,10 @@ public class MinecraftClientMixin
         //CM start game hook
         CarpetServer.onGameStarted();
     }
+
+    @Inject(method = "disconnect(Lnet/minecraft/client/gui/screen/Screen;)V", at = @At("HEAD"))
+    private void onCloseGame(Screen screen, CallbackInfo ci)
+    {
+        CarpetClient.disconnect();
+    }
 }

src/main/java/carpet/mixins/ServerPlayNetworkHandlerMixin.java

@@ -0,0 +1,31 @@
+package carpet.mixins;
+
+import carpet.fakes.CustomPayloadC2SPacketInterface;
+import carpet.network.CarpetClient;
+import carpet.network.ServerNetworkHandler;
+import net.minecraft.network.packet.c2s.play.CustomPayloadC2SPacket;
+import net.minecraft.server.network.ServerPlayNetworkHandler;
+import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.util.Identifier;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(ServerPlayNetworkHandler.class)
+public class ServerPlayNetworkHandlerMixin
+{
+    @Shadow public ServerPlayerEntity player;
+
+    @Inject(method = "onCustomPayload", at = @At("HEAD"), cancellable = true)
+    private void onCustomCarpetPayload(CustomPayloadC2SPacket packet, CallbackInfo ci)
+    {
+        Identifier channel = ((CustomPayloadC2SPacketInterface) packet).getPacketChannel();
+        if (CarpetClient.CARPET_CHANNEL.equals(channel))
+        {
+            ServerNetworkHandler.handleData(((CustomPayloadC2SPacketInterface) packet).getPacketData(), player);
+            ci.cancel();
+        }
+    }
+}

src/main/java/carpet/network/CarpetClient.java

@@ -0,0 +1,52 @@
+package carpet.network;
+
+import carpet.CarpetServer;
+import net.minecraft.client.network.ClientPlayerEntity;
+import net.minecraft.util.Identifier;
+
+public class CarpetClient
+{
+    public static final Object sync = new Object();
+    public static final int HI = 69;
+    public static final int HELLO = 420;
+    public static final int DATA = 1;
+
+    private static ClientPlayerEntity clientPlayer = null;
+    private static boolean isServerCarpet = false;
+    public static String serverCarpetVersion;
+    public static final Identifier CARPET_CHANNEL = new Identifier("carpet:hello");
+
+    public static void gameJoined(ClientPlayerEntity player)
+    {
+        synchronized (sync)
+        {
+            clientPlayer = player;
+            // client didn't say hi back yet
+            if (isServerCarpet)
+                ClientNetworkHandler.respondHello();
+
+        }
+    }
+
+    public static void disconnect()
+    {
+        isServerCarpet = false;
+        clientPlayer = null;
+        CarpetServer.disconnect();
+    }
+
+    public static void setCarpet()
+    {
+        isServerCarpet = true;
+    }
+
+    public static ClientPlayerEntity getPlayer()
+    {
+        return clientPlayer;
+    }
+
+    public static boolean isCarpet()
+    {
+        return isServerCarpet;
+    }
+}

src/main/java/carpet/network/ClientNetworkHandler.java

@@ -0,0 +1,93 @@
+package carpet.network;
+
+import carpet.CarpetServer;
+import carpet.CarpetSettings;
+import carpet.helpers.TickSpeed;
+import carpet.settings.ParsedRule;
+import io.netty.buffer.Unpooled;
+import net.minecraft.client.network.ClientPlayerEntity;
+import net.minecraft.nbt.AbstractNumberTag;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.Tag;
+import net.minecraft.network.packet.c2s.play.CustomPayloadC2SPacket;
+import net.minecraft.util.PacketByteBuf;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.BiConsumer;
+
+public class ClientNetworkHandler
+{
+    private static Map<String, BiConsumer<ClientPlayerEntity, Tag>> dataHandlers = new HashMap<String, BiConsumer<ClientPlayerEntity, Tag>>(){{
+        put("Rules", (p, t) -> {
+            CompoundTag ruleset = (CompoundTag)t;
+            for (String ruleName: ruleset.getKeys())
+            {
+                ParsedRule<?> rule = CarpetServer.settingsManager.getRule(ruleName);
+                if (rule == null)
+                    CarpetSettings.LOG.error("Received unknown rule: "+ruleName);
+                else
+                {
+                    CompoundTag ruleNBT = (CompoundTag) ruleset.get(ruleName);
+                    String value = ruleNBT.getString("Value");
+                    rule.set(null, value);
+                }
+            }
+        });
+        put("TickRate", (p, t) -> TickSpeed.tickrate(((AbstractNumberTag)t).getFloat(), false));
+    }};
+
+
+    public static void handleData(PacketByteBuf data, ClientPlayerEntity player)
+    {
+        if (data != null)
+        {
+            int id = data.readVarInt();
+            if (id == CarpetClient.HI)
+                onHi(data);
+            if (id == CarpetClient.DATA)
+                onSyncData(data, player);
+        }
+    }
+
+    private static void onHi(PacketByteBuf data)
+    {
+        synchronized (CarpetClient.sync)
+        {
+            CarpetClient.setCarpet();
+            CarpetClient.serverCarpetVersion = data.readString(64);
+            if (CarpetSettings.carpetVersion.equals(CarpetClient.serverCarpetVersion))
+            {
+                CarpetSettings.LOG.info("Joined carpet server with matching carpet version");
+            }
+            else
+            {
+                CarpetSettings.LOG.warn("Joined carpet server with another carpet version: "+CarpetClient.serverCarpetVersion);
+            }
+            if (CarpetClient.getPlayer() != null)
+                respondHello();
+
+        }
+    }
+
+    public static void respondHello()
+    {
+        CarpetClient.getPlayer().networkHandler.sendPacket(new CustomPayloadC2SPacket(
+                CarpetClient.CARPET_CHANNEL,
+                (new PacketByteBuf(Unpooled.buffer())).writeVarInt(CarpetClient.HELLO).writeString(CarpetSettings.carpetVersion)
+        ));
+    }
+
+    private static void onSyncData(PacketByteBuf data, ClientPlayerEntity player)
+    {
+        CompoundTag compound = data.readCompoundTag();
+        if (compound == null) return;
+        for (String key: compound.getKeys())
+        {
+            if (dataHandlers.containsKey(key))
+                dataHandlers.get(key).accept(player, compound.get(key));
+            else
+                CarpetSettings.LOG.error("Unknown carpet data: "+key);
+        }
+    }
+}

src/main/java/carpet/network/ServerNetworkHandler.java

@@ -0,0 +1,123 @@
+package carpet.network;
+
+import carpet.CarpetServer;
+import carpet.CarpetSettings;
+import carpet.helpers.TickSpeed;
+import carpet.settings.ParsedRule;
+import io.netty.buffer.Unpooled;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.packet.s2c.play.CustomPayloadS2CPacket;
+import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.util.PacketByteBuf;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ServerNetworkHandler
+{
+    private static List<ServerPlayerEntity> carpetPlayers = new ArrayList<>();
+
+    public static void handleData(PacketByteBuf data, ServerPlayerEntity player)
+    {
+        if (data != null)
+        {
+            int id = data.readVarInt();
+            if (id == CarpetClient.HELLO)
+                onHello(player, data);
+        }
+    }
+    public static void onPlayerJoin(ServerPlayerEntity playerEntity)
+    {
+        if (!playerEntity.networkHandler.connection.isLocal())
+        {
+            playerEntity.networkHandler.sendPacket(new CustomPayloadS2CPacket(
+                    CarpetClient.CARPET_CHANNEL,
+                    (new PacketByteBuf(Unpooled.buffer())).writeVarInt(CarpetClient.HI).writeString(CarpetSettings.carpetVersion)
+            ));
+        }
+    }
+
+    public static void onHello(ServerPlayerEntity playerEntity, PacketByteBuf packetData)
+    {
+        carpetPlayers.add(playerEntity);
+        String clientVersion = packetData.readString(64);
+        if (clientVersion.equals(CarpetSettings.carpetVersion))
+            CarpetSettings.LOG.info("Player "+playerEntity.getName().getString()+" joined with a matching carpet client");
+        else
+            CarpetSettings.LOG.warn("Player "+playerEntity.getName().getString()+" joined with another carpet version: "+clientVersion);
+        DataBuilder data = DataBuilder.create().withTickRate();
+        CarpetServer.settingsManager.getRules().forEach(data::withRule);
+        playerEntity.networkHandler.sendPacket(new CustomPayloadS2CPacket(CarpetClient.CARPET_CHANNEL, data.build() ));
+    }
+    
+    public static void updateRuleWithConnectedClients(ParsedRule<?> rule)
+    {
+        for (ServerPlayerEntity player : carpetPlayers)
+        {
+            player.networkHandler.sendPacket(new CustomPayloadS2CPacket(
+                    CarpetClient.CARPET_CHANNEL,
+                    DataBuilder.create().withRule(rule).build()
+            ));
+        }
+    }
+    
+    public static void updateTickSpeedToConnectedPlayers()
+    {
+        for (ServerPlayerEntity player : carpetPlayers)
+        {
+            player.networkHandler.sendPacket(new CustomPayloadS2CPacket(
+                    CarpetClient.CARPET_CHANNEL,
+                    DataBuilder.create().withTickRate().build()
+            ));
+        }
+    }
+
+    public static void onPlayerLoggedOut(ServerPlayerEntity player)
+    {
+        if (!player.networkHandler.connection.isLocal())
+            carpetPlayers.remove(player);
+    }
+
+    public static void close()
+    {
+        carpetPlayers.clear();
+    }
+
+    private static class DataBuilder
+    {
+        private CompoundTag tag;
+        private static DataBuilder create()
+        {
+            return new DataBuilder();
+        }
+        private DataBuilder()
+        {
+            tag = new CompoundTag();
+        }
+        private DataBuilder withTickRate()
+        {
+            tag.putFloat("TickRate", TickSpeed.tickrate);
+            return this;
+        }
+        private DataBuilder withRule(ParsedRule<?> rule)
+        {
+            CompoundTag rules = (CompoundTag) tag.get("Rules");
+            if (rules == null)
+            {
+                rules = new CompoundTag();
+                tag.put("Rules", rules);
+            }
+            CompoundTag ruleNBT = new CompoundTag();
+            ruleNBT.putString("Value", rule.getAsString());
+            rules.put(rule.name, ruleNBT);
+            return this;
+        }
+        private PacketByteBuf build()
+        {
+            PacketByteBuf packetBuf = new PacketByteBuf(Unpooled.buffer());
+            packetBuf.writeVarInt(CarpetClient.DATA);
+            packetBuf.writeCompoundTag(tag);
+            return packetBuf;
+        }
+    }
+}

src/main/java/carpet/settings/SettingsManager.java

@@ -2,6 +2,7 @@ package carpet.settings;
 
 import carpet.CarpetServer;
 import carpet.CarpetSettings;
+import carpet.network.ServerNetworkHandler;
 import carpet.utils.Translations;
 import carpet.utils.Messenger;
 import com.google.common.collect.ImmutableList;
@@ -80,7 +81,7 @@ public class SettingsManager
 
     public void detachServer()
     {
-        for (ParsedRule<?> rule : rules.values()) rule.resetToDefault(server.getCommandSource());
+        for (ParsedRule<?> rule : rules.values()) rule.resetToDefault(null);
         server = null;
     }
 
@@ -103,6 +104,7 @@ public class SettingsManager
     void notifyRuleChanged(ServerCommandSource source, ParsedRule<?> rule, String userTypedValue)
     {
         observers.forEach(observer -> observer.accept(source, rule, userTypedValue));
+        ServerNetworkHandler.updateRuleWithConnectedClients(rule);
     }
 
     public Iterable<String> getCategories()
@@ -584,8 +586,6 @@ public class SettingsManager
                     rules.get(setting).set(source, strOption);
                 }
             }
-
-
         }
     }
 }

src/main/java/carpet/settings/Validator.java

@@ -22,7 +22,7 @@ public abstract class Validator<T>
         @Override
         public T validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string)
         {
-            if (CarpetServer.settingsManager != null)
+            if (CarpetServer.settingsManager != null && source != null)
                 CarpetServer.settingsManager.notifyPlayersCommandsChanged();
             return newValue;
         }

src/main/java/carpet/utils/Messenger.java

@@ -231,7 +231,8 @@ public class Messenger
     //message source
     public static void m(ServerCommandSource source, Object ... fields)
     {
-        source.sendFeedback(Messenger.c(fields),source.getMinecraftServer() != null && source.getMinecraftServer().getWorld(DimensionType.OVERWORLD) != null);
+        if (source != null)
+            source.sendFeedback(Messenger.c(fields),source.getMinecraftServer() != null && source.getMinecraftServer().getWorld(DimensionType.OVERWORLD) != null);
     }
     public static void m(PlayerEntity player, Object ... fields)
     {