Create simple networking only plugin for Bukkit

commandapi-platforms/commandapi-bukkit/commandapi-bukkit-networking-plugin/pom.xml

@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+
+	<parent>
+		<artifactId>commandapi-bukkit</artifactId>
+		<groupId>dev.jorel</groupId>
+		<version>9.4.0-SNAPSHOT</version>
+	</parent>
+
+	<modelVersion>4.0.0</modelVersion>
+
+	<artifactId>commandapi-bukkit-networking-plugin</artifactId>
+
+	<dependencies>
+		<dependency>
+			<groupId>dev.jorel</groupId>
+			<artifactId>commandapi-core</artifactId>
+			<version>${project.version}</version>
+			<scope>compile</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.spigotmc</groupId>
+			<artifactId>spigot-api</artifactId>
+			<version>${paper.version}</version>
+			<scope>provided</scope>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<resources>
+			<resource>
+				<directory>src/main/resources</directory>
+				<filtering>true</filtering> <!-- Fill ${project.version} in plugin.yml -->
+			 </resource>
+		</resources>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-shade-plugin</artifactId>
+				<executions>
+					<execution>
+						<phase>package</phase>
+						<goals>
+							<goal>shade</goal>
+						</goals>
+						<configuration>
+							<minimizeJar>true</minimizeJar>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>

commandapi-platforms/commandapi-bukkit/commandapi-bukkit-networking-plugin/src/main/java/dev/jorel/commandapi/CommandAPINetworkingMain.java

@@ -0,0 +1,24 @@
+package dev.jorel.commandapi;
+
+import org.bukkit.plugin.java.JavaPlugin;
+
+import dev.jorel.commandapi.network.BukkitNetworkingCommandAPIMessenger;
+
+/**
+ * Main CommandAPI networking plugin entrypoint
+ */
+public class CommandAPINetworkingMain extends JavaPlugin {
+	private BukkitNetworkingCommandAPIMessenger messenger;
+
+	@Override
+	public void onEnable() {
+		messenger = new BukkitNetworkingCommandAPIMessenger(this);
+	}
+
+	/**
+	 * @return The {@link BukkitNetworkingCommandAPIMessenger} handling packets.
+	 */
+	public BukkitNetworkingCommandAPIMessenger getMessenger() {
+		return messenger;
+	}
+}

commandapi-platforms/commandapi-bukkit/commandapi-bukkit-networking-plugin/src/main/java/dev/jorel/commandapi/network/BukkitHandshakePacketHandler.java

@@ -0,0 +1,21 @@
+package dev.jorel.commandapi.network;
+
+import dev.jorel.commandapi.CommandAPINetworkingMain;
+import dev.jorel.commandapi.network.packets.SetVersionPacket;
+import org.bukkit.entity.Player;
+
+/**
+ * A {@link HandshakePacketHandler} for handling {@link CommandAPIPacket}s sent to Bukkit by {@link Player} connections.
+ */
+public class BukkitHandshakePacketHandler implements HandshakePacketHandler<Player> {
+	private final CommandAPINetworkingMain plugin;
+
+	protected BukkitHandshakePacketHandler(CommandAPINetworkingMain plugin) {
+		this.plugin = plugin;
+	}
+
+	@Override
+	public void handleSetVersionPacket(Player sender, SetVersionPacket packet) {
+		plugin.getMessenger().setProtocolVersion(sender, packet.protocolVersion());
+	}
+}

commandapi-platforms/commandapi-bukkit/commandapi-bukkit-networking-plugin/src/main/java/dev/jorel/commandapi/network/BukkitNetworkingCommandAPIMessenger.java

@@ -0,0 +1,106 @@
+package dev.jorel.commandapi.network;
+
+import dev.jorel.commandapi.CommandAPINetworkingMain;
+import dev.jorel.commandapi.network.packets.SetVersionPacket;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerQuitEvent;
+import org.bukkit.event.player.PlayerRegisterChannelEvent;
+import org.bukkit.plugin.messaging.Messenger;
+import org.bukkit.plugin.messaging.PluginMessageListener;
+
+import java.util.HashMap;
+import java.util.Map;
+
+// Based on https://www.spigotmc.org/wiki/bukkit-bungee-plugin-messaging-channel/
+/**
+ * A {@link CommandAPIMessenger} for sending and receiving messages to and from CommandAPIBukkit and {@link Player}s
+ * connected to the Bukkit server.
+ */
+public class BukkitNetworkingCommandAPIMessenger extends CommandAPIMessenger<Player, Player> implements PluginMessageListener, Listener {
+	private final CommandAPINetworkingMain plugin;
+	private final Map<Player, Integer> protocolVersionPerPlayer;
+
+	/**
+	 * Creates a new {@link BukkitNetworkingCommandAPIMessenger}.
+	 *
+	 * @param plugin The plugin sending and receiving messages.
+	 */
+	public BukkitNetworkingCommandAPIMessenger(CommandAPINetworkingMain plugin) {
+		super(new BukkitNetworkingPacketHandlerProvider(plugin));
+		this.plugin = plugin;
+
+		this.protocolVersionPerPlayer = new HashMap<>();
+
+		// Register to listen for and send plugin messages on each channel
+		Messenger messenger = Bukkit.getServer().getMessenger();
+		for (String channelIdentifier : CommandAPIProtocol.getAllChannelIdentifiers()) {
+			messenger.registerIncomingPluginChannel(this.plugin, channelIdentifier, this);
+			messenger.registerOutgoingPluginChannel(this.plugin, channelIdentifier);
+		}
+		// Register to listen for player join and leave
+		Bukkit.getPluginManager().registerEvents(this, this.plugin);
+	}
+
+	@EventHandler
+	public void onPlayerRegisterChannel(PlayerRegisterChannelEvent event) {
+		// Run once the handshake channel is registered
+		//  We can't send messages until the channel is registered, so this is the earliest this can happen
+		if (!event.getChannel().equals(CommandAPIProtocol.HANDSHAKE.getChannelIdentifier())) return;
+
+		// Send SetVersionPacket to inform player of our capabilities
+		this.sendPacket(event.getPlayer(), new SetVersionPacket(CommandAPIProtocol.PROTOCOL_VERSION));
+	}
+
+	@EventHandler
+	public void onPlayerLeave(PlayerQuitEvent event) {
+		// Remove player from our protocol version map, so we don't keep track of useless data
+		this.protocolVersionPerPlayer.remove(event.getPlayer());
+	}
+
+	@Override
+	public void close() {
+		// Unregister this listener
+		Messenger messenger = Bukkit.getServer().getMessenger();
+		for (String channelIdentifier : CommandAPIProtocol.getAllChannelIdentifiers()) {
+			messenger.unregisterIncomingPluginChannel(this.plugin, channelIdentifier);
+			messenger.unregisterOutgoingPluginChannel(this.plugin, channelIdentifier);
+		}
+		HandlerList.unregisterAll(this);
+	}
+
+	/**
+	 * Sets the {@link CommandAPIProtocol#PROTOCOL_VERSION} being used by the given player. This is only intended to be
+	 * called by {@link BukkitHandshakePacketHandler#handleSetVersionPacket(Player, SetVersionPacket)} when a
+	 * {@link SetVersionPacket} is received.
+	 *
+	 * @param sender          The player that sent the {@link SetVersionPacket}.
+	 * @param protocolVersion The {@link CommandAPIProtocol#PROTOCOL_VERSION} in the {@link SetVersionPacket}.
+	 */
+	public void setProtocolVersion(Player sender, int protocolVersion) {
+		this.protocolVersionPerPlayer.put(sender, protocolVersion);
+	}
+
+	@Override
+	public int getConnectionProtocolVersion(Player target) {
+		return this.protocolVersionPerPlayer.getOrDefault(target, 0);
+	}
+
+	@Override
+	public void onPluginMessageReceived(String channel, Player player, byte[] message) {
+		// A plugin message was sent to Bukkit, check if it is for us
+		CommandAPIProtocol protocol = CommandAPIProtocol.getProtocolForChannel(channel);
+		if (protocol == null) return;
+
+		// Handle the message
+		messageReceived(protocol, player, message);
+	}
+
+	@Override
+	public void sendRawBytes(CommandAPIProtocol protocol, Player target, byte[] bytes) {
+		target.sendPluginMessage(this.plugin, protocol.getChannelIdentifier(), bytes);
+	}
+}

commandapi-platforms/commandapi-bukkit/commandapi-bukkit-networking-plugin/src/main/java/dev/jorel/commandapi/network/BukkitNetworkingPacketHandlerProvider.java

@@ -0,0 +1,28 @@
+package dev.jorel.commandapi.network;
+
+import org.bukkit.entity.Player;
+
+import dev.jorel.commandapi.CommandAPINetworkingMain;
+
+/**
+ * A {@link CommandAPIPacketHandlerProvider} for the barebones netowrking plugin for Bukkit.
+ */
+public class BukkitNetworkingPacketHandlerProvider implements CommandAPIPacketHandlerProvider<Player> {
+	private final BukkitHandshakePacketHandler handshakePacketHandler;
+	private final BukkitPlayPacketHandler playPacketHandler;
+
+	protected BukkitNetworkingPacketHandlerProvider(CommandAPINetworkingMain plugin) {
+		handshakePacketHandler = new BukkitHandshakePacketHandler(plugin);
+		playPacketHandler = new BukkitPlayPacketHandler(plugin);
+	}
+
+	@Override
+	public BukkitHandshakePacketHandler getHandshakePacketHandler() {
+		return handshakePacketHandler;
+	}
+
+	@Override
+	public BukkitPlayPacketHandler getPlayPacketHandler() {
+		return playPacketHandler;
+	}
+}

commandapi-platforms/commandapi-bukkit/commandapi-bukkit-networking-plugin/src/main/java/dev/jorel/commandapi/network/BukkitPlayPacketHandler.java

@@ -0,0 +1,21 @@
+package dev.jorel.commandapi.network;
+
+import dev.jorel.commandapi.CommandAPINetworkingMain;
+import dev.jorel.commandapi.network.packets.UpdateRequirementsPacket;
+import org.bukkit.entity.Player;
+
+/**
+ * A {@link PlayPacketHandler} for handling {@link CommandAPIPacket}s sent to Bukkit by {@link Player} connections.
+ */
+public class BukkitPlayPacketHandler implements PlayPacketHandler<Player> {
+	private final CommandAPINetworkingMain plugin;
+
+	protected BukkitPlayPacketHandler(CommandAPINetworkingMain plugin) {
+		this.plugin = plugin;
+	}
+
+	@Override
+	public void handleUpdateRequirementsPacket(Player sender, UpdateRequirementsPacket packet) {
+		sender.updateCommands();
+	}
+}

commandapi-platforms/commandapi-bukkit/commandapi-bukkit-networking-plugin/src/main/resources/plugin.yml

@@ -0,0 +1,9 @@
+name: CommandAPINetworking
+main: dev.jorel.commandapi.CommandAPINetworkingMain
+version: ${project.version}
+description: A barebones plugin that only handles plugin messages sent by the CommandAPI
+authors:
+  - Will Kroboth
+website: https://www.jorel.dev/CommandAPI/
+api-version: 1.13
+folia-supported: true

commandapi-platforms/commandapi-bukkit/pom.xml

@@ -27,6 +27,7 @@
 		<module>commandapi-bukkit-plugin</module>
 		<module>commandapi-bukkit-test</module>
 		<module>commandapi-bukkit-shade</module>
+		<module>commandapi-bukkit-networking-plugin</module>
 
 		<module>commandapi-bukkit-plugin-mojang-mapped</module>
 		<module>commandapi-bukkit-shade-mojang-mapped</module>