wip

pom.xml

@@ -28,6 +28,10 @@
             <id>spigot-repo</id>
             <url>https://hub.spigotmc.org/nexus/content/repositories/snapshots/</url>
         </repository>
+        <repository>
+            <id>dmulloy2-repo</id>
+            <url>https://repo.dmulloy2.net/repository/public/</url>
+        </repository>
     </repositories>
 
     <dependencies>
@@ -43,5 +47,11 @@
             <version>24.1.0</version>
             <scope>compile</scope>
         </dependency>
+        <dependency>
+            <groupId>com.comphenix.protocol</groupId>
+            <artifactId>ProtocolLib</artifactId>
+            <version>5.3.0</version>
+            <scope>provided</scope>
+        </dependency>
     </dependencies>
 </project>

reflections.txt

@@ -0,0 +1,8 @@
+usage of:
+
+reflections:
+- ping/F3NameListener net.minecraft.network.protocol.common.custom.BrandPayload
+
+protocollib:
+- ping/F3NameListener sending and intercepting CUSTOM_PAYLOADs to modify brand
+- ping/PingChecker sending and intercepting COOKIE_RESPONSEs to measure ping

src/main/java/eu/m724/tweaks/TweaksPlugin.java

@@ -3,6 +3,9 @@ package eu.m724.tweaks;
 import eu.m724.tweaks.chat.ChatCommands;
 import eu.m724.tweaks.chat.ChatManager;
 import eu.m724.tweaks.door.DoorListener;
+import eu.m724.tweaks.ping.F3NameListener;
+import eu.m724.tweaks.ping.PingChecker;
+import eu.m724.tweaks.ping.PingCommands;
 import org.bukkit.plugin.java.JavaPlugin;
 
 import java.util.Objects;
@@ -18,5 +21,9 @@ public class TweaksPlugin extends JavaPlugin {
         Objects.requireNonNull(getCommand("chatmanage")).setExecutor(chatCommands);
 
         getServer().getPluginManager().registerEvents(new DoorListener(), this);
+
+        new F3NameListener(this).init();
+        new PingChecker(this).init();
+        Objects.requireNonNull(getCommand("ping")).setExecutor(new PingCommands());
     }
 }

src/main/java/eu/m724/tweaks/ping/F3NameListener.java

@@ -0,0 +1,90 @@
+package eu.m724.tweaks.ping;
+
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.ProtocolLibrary;
+import com.comphenix.protocol.events.*;
+import com.comphenix.protocol.reflect.StructureModifier;
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.scheduler.BukkitRunnable;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+public class F3NameListener {
+    private final Plugin plugin;
+    private final Class<?> brandPayloadClass;
+    private final Constructor<?> brandPayloadConstructor;
+
+    public F3NameListener(Plugin plugin) {
+        this.plugin = plugin;
+        try {
+            this.brandPayloadClass = Class.forName("net.minecraft.network.protocol.common.custom.BrandPayload");
+            this.brandPayloadConstructor = brandPayloadClass.getConstructor(String.class);
+        } catch (ClassNotFoundException | NoSuchMethodException e) {
+            throw new BrandPayloadReflectionException(e);
+        }
+    }
+
+    public void init() {
+        new BukkitRunnable() {
+            @Override
+            public void run() {
+                double mspt = PlayerPing.getMillisPerTick();
+                boolean showMspt = mspt > 50.05; // mspt is at least like 50.01 because of some measuring overheads (I think)
+                for (Player player : plugin.getServer().getOnlinePlayers()) {
+                    double ping = PlayerPing.getPingMillis(player);
+                    String brand;
+                    if (ping == 0) {
+                        brand = "wait";
+                    } else {
+                        if (showMspt) {
+                            brand = "%.2f mspt | %.2f ms".formatted(mspt, PlayerPing.getPingMillis(player));
+                        } else {
+                            brand = "%.2f ms".formatted(PlayerPing.getPingMillis(player));
+                        }
+                    }
+                    changeBrand(player, brand);
+                }
+            }
+        }.runTaskTimerAsynchronously(plugin, 0, 200); // 10 sec
+
+        // this is just to make the server not send a brand on login, it doesn't ever run after login
+        ProtocolLibrary.getProtocolManager().addPacketListener(new PacketAdapter(
+                plugin,
+                ListenerPriority.NORMAL,
+                PacketType.Configuration.Server.CUSTOM_PAYLOAD
+        ) {
+            @Override
+            public void onPacketSending(PacketEvent event) {
+                try {
+                    PacketContainer packet = event.getPacket();
+                    Object brandPayload = brandPayloadConstructor.newInstance("wait");
+                    InternalStructure structure = new InternalStructure(brandPayload, new StructureModifier<>(brandPayloadClass));
+                    packet.getStructures().write(0, structure);
+                } catch (InstantiationException | IllegalAccessException | InvocationTargetException e) {
+                    throw new BrandPayloadReflectionException(e);
+                }
+            }
+        });
+    }
+
+    private void changeBrand(Player player, String brand) {
+        PacketContainer packet = new PacketContainer(PacketType.Play.Server.CUSTOM_PAYLOAD);
+        Object brandPayload;
+        try {
+            brandPayload = brandPayloadConstructor.newInstance(brand);
+        } catch (InstantiationException | IllegalAccessException | InvocationTargetException e) {
+            throw new BrandPayloadReflectionException(e);
+        }
+        InternalStructure structure = new InternalStructure(brandPayload, new StructureModifier<>(brandPayloadClass));
+        packet.getStructures().write(0, structure);
+        ProtocolLibrary.getProtocolManager().sendServerPacket(player, packet);
+    }
+
+    public static class BrandPayloadReflectionException extends RuntimeException {
+        public BrandPayloadReflectionException(Exception e) {
+            super(e);
+        }
+    }
+}

src/main/java/eu/m724/tweaks/ping/MsptChecker.java

@@ -0,0 +1,19 @@
+package eu.m724.tweaks.ping;
+
+import org.bukkit.plugin.Plugin;
+import org.bukkit.scheduler.BukkitRunnable;
+
+public class MsptChecker extends BukkitRunnable {
+    private long lastLoop = 0;
+
+    @Override
+    public void run() {
+        long now = System.nanoTime();
+        PlayerPing.nspt = (now - lastLoop) / 100;
+        lastLoop = now;
+    }
+
+    public void init(Plugin plugin) {
+        this.runTaskTimerAsynchronously(plugin, 0, 100); // 5 secs
+    }
+}

src/main/java/eu/m724/tweaks/ping/PingChecker.java

@@ -0,0 +1,63 @@
+package eu.m724.tweaks.ping;
+
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.ProtocolLibrary;
+import com.comphenix.protocol.events.ListenerPriority;
+import com.comphenix.protocol.events.PacketAdapter;
+import com.comphenix.protocol.events.PacketContainer;
+import com.comphenix.protocol.events.PacketEvent;
+import com.comphenix.protocol.wrappers.MinecraftKey;
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.scheduler.BukkitRunnable;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class PingChecker extends BukkitRunnable {
+    private final Plugin plugin;
+
+    // TODO concurrnet too?
+    // this is in nanoseconds
+    private final Map<Player, Long> pending = new ConcurrentHashMap<>();
+
+    public PingChecker(Plugin plugin) {
+        this.plugin = plugin;
+    }
+
+    public void init() {
+        ProtocolLibrary.getProtocolManager().addPacketListener(new PacketAdapter(
+                plugin,
+                ListenerPriority.NORMAL,
+                PacketType.Play.Client.COOKIE_RESPONSE
+        ) {
+            @Override
+            public void onPacketReceiving(PacketEvent event) {
+                // below line checks, whether the first (and sole) identifier field in the packet is minecraft:chk_ping
+                if (event.getPacket().getMinecraftKeys().read(0).getKey().equals("chk_ping")) {
+                    Player player = event.getPlayer();
+
+                    long start = pending.remove(player);
+                    PlayerPing.pings.put(player, System.nanoTime() - start);
+                    // gotta cancel because the server will kick
+                    event.setCancelled(true);
+                }
+            }
+        });
+
+        this.runTaskTimerAsynchronously(plugin, 0, 200); // 10 secs
+        new MsptChecker().init(plugin); // TODO should this be here
+    }
+
+    @Override
+    public void run() {
+        plugin.getServer().getOnlinePlayers().forEach(player -> {
+            if (pending.containsKey(player)) return;
+            pending.put(player, System.nanoTime()); // here or at the bottom? probably doesn't matter
+
+            PacketContainer packet = new PacketContainer(PacketType.Play.Server.COOKIE_REQUEST);
+            packet.getMinecraftKeys().write(0, new MinecraftKey("chk_ping"));
+            ProtocolLibrary.getProtocolManager().sendServerPacket(player, packet);
+        });
+    }
+}

src/main/java/eu/m724/tweaks/ping/PingCommands.java

@@ -0,0 +1,24 @@
+package eu.m724.tweaks.ping;
+
+import net.md_5.bungee.api.ChatColor;
+import net.md_5.bungee.api.chat.BaseComponent;
+import net.md_5.bungee.api.chat.ComponentBuilder;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+
+public class PingCommands implements CommandExecutor {
+    @Override
+    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] args) {
+        if (command.getName().equals("ping")) {
+            Player player = (Player) sender;
+            BaseComponent[] component = new ComponentBuilder("Ping: ").color(ChatColor.GOLD)
+                    .append("%.2fms".formatted(PlayerPing.getPingMillis(player))).color(ChatColor.AQUA)
+                    .create();
+            player.spigot().sendMessage(component);
+        }
+        return true;
+    }
+}

src/main/java/eu/m724/tweaks/ping/PlayerPing.java

@@ -0,0 +1,30 @@
+package eu.m724.tweaks.ping;
+
+import org.bukkit.entity.Player;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class PlayerPing {
+    // TODO concurrnet?
+    // in nanos
+    static final Map<Player, Long> pings = new ConcurrentHashMap<>();
+    // nanos per tick
+    static long nspt = 0L;
+
+    public static long getPingNanos(Player player) {
+        return pings.getOrDefault(player, -1L);
+    }
+
+    public static double getPingMillis(Player player) {
+        return getPingNanos(player) / 1000000.0; // a mil ns in ms
+    }
+
+    public static long getNanosPerTick() {
+        return nspt;
+    }
+
+    public static double getMillisPerTick() {
+        return nspt / 1000000.0; // a mil ns in ms
+    }
+}

src/main/resources/plugin.yml

@@ -3,6 +3,7 @@ version: ${project.version}
 
 main: eu.m724.tweaks.TweaksPlugin
 api-version: 1.21.1
+depend: [ProtocolLib]
 
 commands:
   chat:
@@ -12,4 +13,6 @@ commands:
   chatmanage:
     description: Chatroom user management commands
     aliases: [cm, crm]
+  ping:
+    description: Your ping