diff --git a/SpigotCore/SpigotCore_Main/src/com/comphenix/tinyprotocol/Reflection.java b/SpigotCore/SpigotCore_Main/src/com/comphenix/tinyprotocol/Reflection.java new file mode 100644 index 00000000..c9bd2db3 --- /dev/null +++ b/SpigotCore/SpigotCore_Main/src/com/comphenix/tinyprotocol/Reflection.java @@ -0,0 +1,502 @@ +package com.comphenix.tinyprotocol; + +import java.lang.reflect.Constructor; +import java.lang.reflect.Field; +import java.lang.reflect.Method; +import java.lang.reflect.ParameterizedType; +import java.lang.reflect.Type; +import java.util.Arrays; +import java.util.regex.Matcher; +import java.util.regex.Pattern; + +import org.bukkit.Bukkit; + +/** + * An utility class that simplifies reflection in Bukkit plugins. + * + * @author Kristian + */ +public final class Reflection { + /** + * An interface for invoking a specific constructor. + */ + public interface ConstructorInvoker { + /** + * Invoke a constructor for a specific class. + * + * @param arguments - the arguments to pass to the constructor. + * @return The constructed object. + */ + public Object invoke(Object... arguments); + } + + /** + * An interface for invoking a specific method. + */ + public interface MethodInvoker { + /** + * Invoke a method on a specific target object. + * + * @param target - the target object, or NULL for a static method. + * @param arguments - the arguments to pass to the method. + * @return The return value, or NULL if is void. + */ + public Object invoke(Object target, Object... arguments); + } + + /** + * An interface for retrieving the field content. + * + * @param - field type. + */ + public interface FieldAccessor { + /** + * Retrieve the content of a field. + * + * @param target - the target object, or NULL for a static field. + * @return The value of the field. + */ + public T get(Object target); + + /** + * Set the content of a field. + * + * @param target - the target object, or NULL for a static field. + * @param value - the new value of the field. + */ + public void set(Object target, Object value); + + /** + * Determine if the given object has this field. + * + * @param target - the object to test. + * @return TRUE if it does, FALSE otherwise. + */ + public boolean hasField(Object target); + } + + // Deduce the net.minecraft.server.v* package + private static String OBC_PREFIX = Bukkit.getServer().getClass().getPackage().getName(); + private static String NMS_PREFIX = OBC_PREFIX.replace("org.bukkit.craftbukkit", "net.minecraft.server"); + private static String VERSION = OBC_PREFIX.replace("org.bukkit.craftbukkit", "").replace(".", ""); + + // Variable replacement + private static Pattern MATCH_VARIABLE = Pattern.compile("\\{([^\\}]+)\\}"); + + private Reflection() { + // Seal class + } + + /** + * Retrieve a field accessor for a specific field type and name. + * + * @param target - the target type. + * @param name - the name of the field, or NULL to ignore. + * @param fieldType - a compatible field type. + * @return The field accessor. + */ + public static FieldAccessor getField(Class target, String name, Class fieldType) { + return getField(target, name, fieldType, 0); + } + + /** + * Retrieve a field accessor for a specific field type and name. + * + * @param className - lookup name of the class, see {@link #getClass(String)}. + * @param name - the name of the field, or NULL to ignore. + * @param fieldType - a compatible field type. + * @return The field accessor. + */ + public static FieldAccessor getField(String className, String name, Class fieldType) { + return getField(getClass(className), name, fieldType, 0); + } + + /** + * Retrieve a field accessor for a specific field type and name. + * + * @param target - the target type. + * @param fieldType - a compatible field type. + * @param index - the number of compatible fields to skip. + * @return The field accessor. + */ + public static FieldAccessor getField(Class target, Class fieldType, int index) { + return getField(target, null, fieldType, index); + } + + /** + * Retrieve a field accessor for a specific field type and name. + * + * @param className - lookup name of the class, see {@link #getClass(String)}. + * @param fieldType - a compatible field type. + * @param index - the number of compatible fields to skip. + * @return The field accessor. + */ + public static FieldAccessor getField(String className, Class fieldType, int index) { + return getField(getClass(className), fieldType, index); + } + + // Common method + private static FieldAccessor getField(Class target, String name, Class fieldType, int index) { + for (final Field field : target.getDeclaredFields()) { + if ((name == null || field.getName().equals(name)) && fieldType.isAssignableFrom(field.getType()) && index-- <= 0) { + field.setAccessible(true); + + // A function for retrieving a specific field value + return new FieldAccessor() { + + @Override + @SuppressWarnings("unchecked") + public T get(Object target) { + try { + return (T) field.get(target); + } catch (IllegalAccessException e) { + throw new RuntimeException("Cannot access reflection.", e); + } + } + + @Override + public void set(Object target, Object value) { + try { + field.set(target, value); + } catch (IllegalAccessException e) { + throw new RuntimeException("Cannot access reflection.", e); + } + } + + @Override + public boolean hasField(Object target) { + // target instanceof DeclaringClass + return field.getDeclaringClass().isAssignableFrom(target.getClass()); + } + }; + } + } + + // Search in parent classes + if (target.getSuperclass() != null) + return getField(target.getSuperclass(), name, fieldType, index); + + throw new IllegalArgumentException("Cannot find field with type " + fieldType); + } + + /** + * Retrieves a field with a given type and parameters. This is most useful + * when dealing with Collections. + * + * @param target the target class. + * @param fieldType Type of the field + * @param params Variable length array of type parameters + * @return The field + * + * @throws IllegalArgumentException If the field cannot be found + */ + public static Field getParameterizedField(Class target, Class fieldType, Class... params) { + for (Field field : target.getDeclaredFields()) { + if (field.getType().equals(fieldType)) { + Type type = field.getGenericType(); + if (type instanceof ParameterizedType) { + if (Arrays.equals(((ParameterizedType) type).getActualTypeArguments(), params)) + return field; + } + } + } + + throw new IllegalArgumentException("Unable to find a field with type " + fieldType + " and params " + Arrays.toString(params)); + } + + /** + * Search for the first publicly and privately defined method of the given name and parameter count. + * + * @param className - lookup name of the class, see {@link #getClass(String)}. + * @param methodName - the method name, or NULL to skip. + * @param params - the expected parameters. + * @return An object that invokes this specific method. + * @throws IllegalStateException If we cannot find this method. + */ + public static MethodInvoker getMethod(String className, String methodName, Class... params) { + return getTypedMethod(getClass(className), methodName, null, params); + } + + /** + * Search for the first publicly and privately defined method of the given name and parameter count. + * + * @param clazz - a class to start with. + * @param methodName - the method name, or NULL to skip. + * @param params - the expected parameters. + * @return An object that invokes this specific method. + * @throws IllegalStateException If we cannot find this method. + */ + public static MethodInvoker getMethod(Class clazz, String methodName, Class... params) { + return getTypedMethod(clazz, methodName, null, params); + } + + /** + * Search for the first publicly and privately defined method of the given name and parameter count. + * + * @param clazz - a class to start with. + * @param methodName - the method name, or NULL to skip. + * @param returnType - the expected return type, or NULL to ignore. + * @param params - the expected parameters. + * @return An object that invokes this specific method. + * @throws IllegalStateException If we cannot find this method. + */ + public static MethodInvoker getTypedMethod(Class clazz, String methodName, Class returnType, Class... params) { + for (final Method method : clazz.getDeclaredMethods()) { + if ((methodName == null || method.getName().equals(methodName)) + && (returnType == null || method.getReturnType().equals(returnType)) + && Arrays.equals(method.getParameterTypes(), params)) { + method.setAccessible(true); + + return new MethodInvoker() { + + @Override + public Object invoke(Object target, Object... arguments) { + try { + return method.invoke(target, arguments); + } catch (Exception e) { + throw new RuntimeException("Cannot invoke method " + method, e); + } + } + + }; + } + } + + // Search in every superclass + if (clazz.getSuperclass() != null) + return getMethod(clazz.getSuperclass(), methodName, params); + + throw new IllegalStateException(String.format("Unable to find method %s (%s).", methodName, Arrays.asList(params))); + } + + /** + * Search for the first publically and privately defined constructor of the given name and parameter count. + * + * @param className - lookup name of the class, see {@link #getClass(String)}. + * @param params - the expected parameters. + * @return An object that invokes this constructor. + * @throws IllegalStateException If we cannot find this method. + */ + public static ConstructorInvoker getConstructor(String className, Class... params) { + return getConstructor(getClass(className), params); + } + + /** + * Search for the first publically and privately defined constructor of the given name and parameter count. + * + * @param clazz - a class to start with. + * @param params - the expected parameters. + * @return An object that invokes this constructor. + * @throws IllegalStateException If we cannot find this method. + */ + public static ConstructorInvoker getConstructor(Class clazz, Class... params) { + for (final Constructor constructor : clazz.getDeclaredConstructors()) { + if (Arrays.equals(constructor.getParameterTypes(), params)) { + constructor.setAccessible(true); + + return new ConstructorInvoker() { + + @Override + public Object invoke(Object... arguments) { + try { + return constructor.newInstance(arguments); + } catch (Exception e) { + throw new RuntimeException("Cannot invoke constructor " + constructor, e); + } + } + + }; + } + } + + throw new IllegalStateException(String.format("Unable to find constructor for %s (%s).", clazz, Arrays.asList(params))); + } + + /** + * Retrieve a class from its full name, without knowing its type on compile time. + *

+ * This is useful when looking up fields by a NMS or OBC type. + *

+ * + * @see {@link #getClass()} for more information. + * @param lookupName - the class name with variables. + * @return The class. + */ + public static Class getUntypedClass(String lookupName) { + @SuppressWarnings({ "rawtypes", "unchecked" }) + Class clazz = (Class) getClass(lookupName); + return clazz; + } + + /** + * Retrieve a class from its full name with alternatives, without knowing its type on compile time. + *

+ * This is useful when looking up fields by a NMS or OBC type. + *

+ * + * @see {@link #getClass()} for more information. + * @param lookupName - the class name with variables. + * @param aliases - alternative names for this class. + * @return The class. + */ + public static Class getUntypedClass(String lookupName, String... aliases) { + @SuppressWarnings({ "rawtypes", "unchecked" }) + Class clazz = (Class) getClass(lookupName, aliases); + return clazz; + } + + /** + * Retrieve a class from its full name. + *

+ * Strings enclosed with curly brackets - such as {TEXT} - will be replaced according to the following table: + *

+ * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
VariableContent
{nms}Actual package name of net.minecraft.server.VERSION
{obc}Actual pacakge name of org.bukkit.craftbukkit.VERSION
{version}The current Minecraft package VERSION, if any.
+ * + * @param lookupName - the class name with variables. + * @return The looked up class. + * @throws IllegalArgumentException If a variable or class could not be found. + */ + public static Class getClass(String lookupName) { + return getCanonicalClass(expandVariables(lookupName)); + } + + /** + * Retrieve the first class that matches the full class name. + *

+ * Strings enclosed with curly brackets - such as {TEXT} - will be replaced according to the following table: + *

+ * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
VariableContent
{nms}Actual package name of net.minecraft.server.VERSION
{obc}Actual pacakge name of org.bukkit.craftbukkit.VERSION
{version}The current Minecraft package VERSION, if any.
+ * + * @param lookupName - the class name with variables. + * @param aliases - alternative names for this class. + * @return Class object. + * @throws RuntimeException If we are unable to find any of the given classes. + */ + public static Class getClass(String lookupName, String... aliases) { + try { + // Try the main class first + return getClass(lookupName); + } catch (RuntimeException e) { + Class success = null; + + // Try every alias too + for (String alias : aliases) { + try { + success = getClass(alias); + break; + } catch (RuntimeException e1) { + // e1.printStackTrace(); + } + } + + if (success != null) { + return success; + } else { + // Hack failed + throw new RuntimeException(String.format("Unable to find %s (%s)", lookupName, String.join(",", aliases))); + } + } + } + + /** + * Retrieve a class in the net.minecraft.server.VERSION.* package. + * + * @param name - the name of the class, excluding the package. + * @throws IllegalArgumentException If the class doesn't exist. + */ + public static Class getMinecraftClass(String name) { + return getCanonicalClass(NMS_PREFIX + "." + name); + } + + /** + * Retrieve a class in the org.bukkit.craftbukkit.VERSION.* package. + * + * @param name - the name of the class, excluding the package. + * @throws IllegalArgumentException If the class doesn't exist. + */ + public static Class getCraftBukkitClass(String name) { + return getCanonicalClass(OBC_PREFIX + "." + name); + } + + /** + * Retrieve a class by its canonical name. + * + * @param canonicalName - the canonical name. + * @return The class. + */ + private static Class getCanonicalClass(String canonicalName) { + try { + return Class.forName(canonicalName); + } catch (ClassNotFoundException e) { + throw new IllegalArgumentException("Cannot find " + canonicalName, e); + } + } + + /** + * Expand variables such as "{nms}" and "{obc}" to their corresponding packages. + * + * @param name - the full name of the class. + * @return The expanded string. + */ + private static String expandVariables(String name) { + StringBuffer output = new StringBuffer(); + Matcher matcher = MATCH_VARIABLE.matcher(name); + + while (matcher.find()) { + String variable = matcher.group(1); + String replacement = ""; + + // Expand all detected variables + if ("nms".equalsIgnoreCase(variable)) + replacement = NMS_PREFIX; + else if ("obc".equalsIgnoreCase(variable)) + replacement = OBC_PREFIX; + else if ("version".equalsIgnoreCase(variable)) + replacement = VERSION; + else + throw new IllegalArgumentException("Unknown variable: " + variable); + + // Assume the expanded variables are all packages, and append a dot + if (replacement.length() > 0 && matcher.end() < name.length() && name.charAt(matcher.end()) != '.') + replacement += "."; + matcher.appendReplacement(output, Matcher.quoteReplacement(replacement)); + } + + matcher.appendTail(output); + return output.toString(); + } +} \ No newline at end of file diff --git a/SpigotCore/SpigotCore_Main/src/com/comphenix/tinyprotocol/TinyProtocol.java b/SpigotCore/SpigotCore_Main/src/com/comphenix/tinyprotocol/TinyProtocol.java index cb4aca06..ac626e47 100644 --- a/SpigotCore/SpigotCore_Main/src/com/comphenix/tinyprotocol/TinyProtocol.java +++ b/SpigotCore/SpigotCore_Main/src/com/comphenix/tinyprotocol/TinyProtocol.java @@ -1,29 +1,24 @@ -/* - * This file is a part of the SteamWar software. - * - * Copyright (C) 2025 SteamWar.de-Serverteam - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU Affero General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU Affero General Public License for more details. - * - * You should have received a copy of the GNU Affero General Public License - * along with this program. If not, see . - */ - package com.comphenix.tinyprotocol; -import de.steamwar.Reflection; -import de.steamwar.Reflection.Field; -import de.steamwar.core.Core; -import io.netty.channel.*; -import lombok.Getter; +import io.netty.channel.Channel; +import io.netty.channel.ChannelDuplexHandler; +import io.netty.channel.ChannelFuture; +import io.netty.channel.ChannelHandlerContext; +import io.netty.channel.ChannelInboundHandlerAdapter; +import io.netty.channel.ChannelInitializer; +import io.netty.channel.ChannelPipeline; +import io.netty.channel.ChannelPromise; + +import java.lang.reflect.Field; +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; +import java.util.Map; +import java.util.NoSuchElementException; +import java.util.Set; +import java.util.concurrent.atomic.AtomicInteger; +import java.util.logging.Level; + import org.bukkit.Bukkit; import org.bukkit.entity.Player; import org.bukkit.event.EventHandler; @@ -31,217 +26,517 @@ import org.bukkit.event.EventPriority; import org.bukkit.event.HandlerList; import org.bukkit.event.Listener; import org.bukkit.event.player.PlayerLoginEvent; -import org.bukkit.event.player.PlayerQuitEvent; import org.bukkit.event.server.PluginDisableEvent; import org.bukkit.plugin.Plugin; +import org.bukkit.scheduler.BukkitRunnable; -import java.util.*; -import java.util.concurrent.CopyOnWriteArrayList; -import java.util.function.BiFunction; -import java.util.logging.Level; +import com.comphenix.tinyprotocol.Reflection.FieldAccessor; +import com.comphenix.tinyprotocol.Reflection.MethodInvoker; +import com.google.common.collect.Lists; +import com.google.common.collect.MapMaker; +import com.mojang.authlib.GameProfile; -public class TinyProtocol implements Listener { +/** + * Represents a very tiny alternative to ProtocolLib. + *

+ * It now supports intercepting packets during login and status ping (such as OUT_SERVER_PING)! + * + * @author Kristian + */ +public abstract class TinyProtocol { + private static final AtomicInteger ID = new AtomicInteger(0); - private static final Class craftServer = Reflection.getClass("org.bukkit.craftbukkit.CraftServer"); - private static final Class dedicatedPlayerList = Reflection.getClass("net.minecraft.server.dedicated.DedicatedPlayerList"); - private static final Field getPlayerList = Reflection.getField(craftServer, dedicatedPlayerList, 0); - private static final Class playerList = Reflection.getClass("net.minecraft.server.players.PlayerList"); - private static final Class minecraftServer = Reflection.getClass("net.minecraft.server.MinecraftServer"); - private static final Field getMinecraftServer = Reflection.getField(playerList, minecraftServer, 0); - public static final Class serverConnection = Reflection.getClass("net.minecraft.server.network.ServerConnectionListener"); - private static final Field getServerConnection = Reflection.getField(minecraftServer, serverConnection, 0); - public static Object getServerConnection(Plugin plugin) { - return getServerConnection.get(getMinecraftServer.get(getPlayerList.get(plugin.getServer()))); - } - private static final Class networkManager = Reflection.getClass("net.minecraft.network.NetworkManager"); - public static final Field networkManagers = Reflection.getField(serverConnection, List.class, 0, networkManager); + // Required Minecraft classes + private static final Class entityPlayerClass = Reflection.getClass("{nms}.EntityPlayer", "net.minecraft.server.level.EntityPlayer"); + private static final Class playerConnectionClass = Reflection.getClass("{nms}.PlayerConnection", "net.minecraft.server.network.PlayerConnection"); + private static final Class networkManagerClass = Reflection.getClass("{nms}.NetworkManager", "net.minecraft.network.NetworkManager"); - private static final String HANDLER_NAME = "tiny-steamwar"; - public static final TinyProtocol instance = new TinyProtocol(Core.getInstance()); + // Used in order to lookup a channel + private static final MethodInvoker getPlayerHandle = Reflection.getMethod("{obc}.entity.CraftPlayer", "getHandle"); + private static final FieldAccessor getConnection = Reflection.getField(entityPlayerClass, null, playerConnectionClass); + private static final FieldAccessor getManager = Reflection.getField(playerConnectionClass, null, networkManagerClass); + private static final FieldAccessor getChannel = Reflection.getField(networkManagerClass, Channel.class, 0); - public static void init() { - //enforce init - } + // Looking up ServerConnection + private static final Class minecraftServerClass = Reflection.getUntypedClass("{nms}.MinecraftServer", "net.minecraft.server.MinecraftServer"); + private static final Class serverConnectionClass = Reflection.getUntypedClass("{nms}.ServerConnection", "net.minecraft.server.network.ServerConnection"); + private static final FieldAccessor getMinecraftServer = Reflection.getField("{obc}.CraftServer", minecraftServerClass, 0); + private static final FieldAccessor getServerConnection = Reflection.getField(minecraftServerClass, serverConnectionClass, 0); - private final Plugin plugin; - private final List connections; - private boolean closed; + // Packets we have to intercept + private static final Class PACKET_LOGIN_IN_START = Reflection.getClass("{nms}.PacketLoginInStart", "net.minecraft.network.protocol.login.PacketLoginInStart"); + private static final FieldAccessor getGameProfile = Reflection.getField(PACKET_LOGIN_IN_START, GameProfile.class, 0); - private final Map, List>> packetFilters = new HashMap<>(); - @Getter - private final Map playerInterceptors = new HashMap<>(); + // Speedup channel lookup + private Map channelLookup = new MapMaker().weakValues().makeMap(); + private Listener listener; - @Override - public String toString() { - return "TinyProtocol{" + - "plugin=" + plugin + - ", connections=" + connections + - ", closed=" + closed + - ", packetFilters=" + packetFilters + - ", playerInterceptors=" + playerInterceptors + - '}'; - } + // Channels that have already been removed + private Set uninjectedChannels = Collections.newSetFromMap(new MapMaker().weakKeys().makeMap()); - private TinyProtocol(final Plugin plugin) { - this.plugin = plugin; - this.connections = networkManagers.get(getServerConnection(plugin)); + // List of network markers + private List networkManagers; - plugin.getServer().getPluginManager().registerEvents(this, plugin); + // Injected channel handlers + private List serverChannels = new ArrayList<>(); + private ChannelInboundHandlerAdapter serverChannelHandler; + private ChannelInitializer beginInitProtocol; + private ChannelInitializer endInitProtocol; - for (Player player : plugin.getServer().getOnlinePlayers()) { - new PacketInterceptor(player); - } - } + // Current handler name + private String handlerName; - @EventHandler(priority = EventPriority.LOWEST) - public void onPlayerLogin(PlayerLoginEvent e) { - plugin.getLogger().info("Creating PacketInterceptor for: " + e.getPlayer().getName() + " (" + closed + ")"); - if(closed) - return; - new PacketInterceptor(e.getPlayer()); - } + protected volatile boolean closed; + protected Plugin plugin; - @EventHandler(priority = EventPriority.MONITOR) - public void onPlayerDisconnect(PlayerQuitEvent e) { - getInterceptor(e.getPlayer()).ifPresent(PacketInterceptor::close); - } + /** + * Construct a new instance of TinyProtocol, and start intercepting packets for all connected clients and future clients. + *

+ * You can construct multiple instances per plugin. + * + * @param plugin - the plugin. + */ + public TinyProtocol(final Plugin plugin) { + this.plugin = plugin; - @EventHandler - public void onPluginDisable(PluginDisableEvent e) { - if (e.getPlugin().equals(plugin)) { - close(); - } - } + // Compute handler name + this.handlerName = getHandlerName(); - public void addFilter(Class packetType, BiFunction filter) { - packetFilters.computeIfAbsent(packetType, c -> new CopyOnWriteArrayList<>()).add(filter); - } + // Prepare existing players + registerBukkitEvents(); - public void removeFilter(Class packetType, BiFunction filter) { - packetFilters.getOrDefault(packetType, Collections.emptyList()).remove(filter); - } + try { + registerChannelHandler(); + registerPlayers(plugin); + } catch (IllegalArgumentException ex) { + // Damn you, late bind + plugin.getLogger().info("[TinyProtocol] Delaying server channel injection due to late bind."); - public void sendPacket(Player player, Object packet) { - getInterceptor(player).ifPresent(i -> i.sendPacket(packet)); - } + new BukkitRunnable() { + @Override + public void run() { + registerChannelHandler(); + registerPlayers(plugin); + plugin.getLogger().info("[TinyProtocol] Late bind injection successful."); + } + }.runTask(plugin); + } + } - public void receivePacket(Player player, Object packet) { - getInterceptor(player).ifPresent(i -> i.receivePacket(packet)); - } + private void createServerChannelHandler() { + // Handle connected channels + endInitProtocol = new ChannelInitializer() { - public final void close() { - plugin.getLogger().log(Level.INFO, "Closing PacketInterceptor", new Exception("Stacktrace")); + @Override + protected void initChannel(Channel channel) throws Exception { + try { + // This can take a while, so we need to stop the main thread from interfering + synchronized (networkManagers) { + // Stop injecting channels + if (!closed) { + channel.eventLoop().submit(() -> injectChannelInternal(channel)); + } + } + } catch (Exception e) { + plugin.getLogger().log(Level.SEVERE, "Cannot inject incomming channel " + channel, e); + } + } - if(closed) - return; - closed = true; + }; - HandlerList.unregisterAll(this); + // This is executed before Minecraft's channel handler + beginInitProtocol = new ChannelInitializer() { - for (Player player : plugin.getServer().getOnlinePlayers()) { - getInterceptor(player).ifPresent(PacketInterceptor::close); - } - } + @Override + protected void initChannel(Channel channel) throws Exception { + channel.pipeline().addLast(endInitProtocol); + } - private Optional getInterceptor(Player player) { - synchronized (playerInterceptors) { - return Optional.ofNullable(playerInterceptors.get(player)); - } - } + }; - private static final Field getChannel = Reflection.getField(networkManager, Channel.class, 0); - private static final Field getUUID = Reflection.getField(networkManager, UUID.class, 0); + serverChannelHandler = new ChannelInboundHandlerAdapter() { + + @Override + public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { + Channel channel = (Channel) msg; - public final class PacketInterceptor extends ChannelDuplexHandler { - private final Player player; - @Getter - private final Channel channel; + // Prepare to initialize ths channel + channel.pipeline().addFirst(beginInitProtocol); + ctx.fireChannelRead(msg); + } - private PacketInterceptor(Player player) { - this.player = player; + }; + } - channel = connections.stream().filter(connection -> player.getUniqueId().equals(getUUID.get(connection))).map(getChannel::get).filter(Channel::isActive).findAny().orElseThrow(() -> { - Bukkit.getScheduler().runTask(plugin, () -> player.kickPlayer("Connection failure.")); - return new SecurityException("Could not find channel for player " + player.getName()); - }); + /** + * Register bukkit events. + */ + private void registerBukkitEvents() { + listener = new Listener() { - if(!channel.isActive()) - return; + @EventHandler(priority = EventPriority.LOWEST) + public final void onPlayerLogin(PlayerLoginEvent e) { + if (closed) + return; - synchronized (playerInterceptors) { - playerInterceptors.put(player, this); - } - plugin.getLogger().info("Adding Techhider for: " + player.getName()); + Channel channel = getChannel(e.getPlayer()); - try { - channel.pipeline().addBefore("packet_handler", HANDLER_NAME, this); - } catch (IllegalArgumentException | NoSuchElementException e) { - Bukkit.getScheduler().runTask(plugin, () -> player.kickPlayer("Connection failure.")); - throw new SecurityException(e); - } + // Don't inject players that have been explicitly uninjected + if (!uninjectedChannels.contains(channel)) { + injectPlayer(e.getPlayer()); + } + } + + @EventHandler + public final void onPluginDisable(PluginDisableEvent e) { + if (e.getPlugin().equals(plugin)) { + close(); + } + } + + }; + + plugin.getServer().getPluginManager().registerEvents(listener, plugin); + } + + @SuppressWarnings("unchecked") + private void registerChannelHandler() { + Object mcServer = getMinecraftServer.get(Bukkit.getServer()); + Object serverConnection = getServerConnection.get(mcServer); + boolean looking = true; + + try { + Field field = Reflection.getParameterizedField(serverConnectionClass, List.class, networkManagerClass); + field.setAccessible(true); + + networkManagers = (List) field.get(serverConnection); + } catch (Exception ex) { + plugin.getLogger().info("Encountered an exception checking list fields" + ex); + MethodInvoker method = Reflection.getTypedMethod(serverConnectionClass, null, List.class, serverConnectionClass); + + networkManagers = (List) method.invoke(null, serverConnection); } - private void sendPacket(Object packet) { - channel.pipeline().writeAndFlush(packet); - } + if (networkManagers == null) { + throw new IllegalArgumentException("Failed to obtain list of network managers"); + } + // We need to synchronize against this list + createServerChannelHandler(); - private void receivePacket(Object packet) { - channel.pipeline().context("encoder").fireChannelRead(packet); - } + // Find the correct list, or implicitly throw an exception + for (int i = 0; looking; i++) { + List list = Reflection.getField(serverConnection.getClass(), List.class, i).get(serverConnection); - private void close() { - if(channel.isActive()) { - channel.eventLoop().execute(() -> { - try { - channel.pipeline().remove(HANDLER_NAME); - } catch (NoSuchElementException e) { - // ignore - } - }); - } + for (Object item : list) { + if (!ChannelFuture.class.isInstance(item)) + break; - synchronized (playerInterceptors) { - playerInterceptors.remove(player, this); - } - } + // Channel future that contains the server connection + Channel serverChannel = ((ChannelFuture) item).channel(); - @Override - public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { - try { - msg = filterPacket(player, msg); - } catch (Exception e) { - plugin.getLogger().log(Level.SEVERE, "Error during incoming packet processing", e); - } + serverChannels.add(serverChannel); + serverChannel.pipeline().addFirst(serverChannelHandler); + looking = false; + } + } + } - if (msg != null) { - super.channelRead(ctx, msg); - } - } + private void unregisterChannelHandler() { + if (serverChannelHandler == null) + return; - @Override - public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception { - try { - msg = filterPacket(player, msg); - } catch (Exception e) { - plugin.getLogger().log(Level.SEVERE, "Error during outgoing packet processing", e); - } + for (Channel serverChannel : serverChannels) { + final ChannelPipeline pipeline = serverChannel.pipeline(); - if (msg != null) { - super.write(ctx, msg, promise); - } - } + // Remove channel handler + serverChannel.eventLoop().execute(new Runnable() { - private Object filterPacket(Player player, Object packet) { - List> filters = packetFilters.getOrDefault(packet.getClass(), Collections.emptyList()); + @Override + public void run() { + try { + pipeline.remove(serverChannelHandler); + } catch (NoSuchElementException e) { + // That's fine + } + } - for(BiFunction filter : filters) { - packet = filter.apply(player, packet); + }); + } + } - if(packet == null) - break; - } + private void registerPlayers(Plugin plugin) { + for (Player player : plugin.getServer().getOnlinePlayers()) { + injectPlayer(player); + } + } - return packet; - } - } -} + /** + * Invoked when the server is starting to send a packet to a player. + *

+ * Note that this is not executed on the main thread. + * + * @param receiver - the receiving player, NULL for early login/status packets. + * @param channel - the channel that received the packet. Never NULL. + * @param packet - the packet being sent. + * @return The packet to send instead, or NULL to cancel the transmission. + */ + public Object onPacketOutAsync(Player receiver, Channel channel, Object packet) { + return packet; + } + + /** + * Invoked when the server has received a packet from a given player. + *

+ * Use {@link Channel#remoteAddress()} to get the remote address of the client. + * + * @param sender - the player that sent the packet, NULL for early login/status packets. + * @param channel - channel that received the packet. Never NULL. + * @param packet - the packet being received. + * @return The packet to recieve instead, or NULL to cancel. + */ + public Object onPacketInAsync(Player sender, Channel channel, Object packet) { + return packet; + } + + /** + * Send a packet to a particular player. + *

+ * Note that {@link #onPacketOutAsync(Player, Channel, Object)} will be invoked with this packet. + * + * @param player - the destination player. + * @param packet - the packet to send. + */ + public void sendPacket(Player player, Object packet) { + sendPacket(getChannel(player), packet); + } + + /** + * Send a packet to a particular client. + *

+ * Note that {@link #onPacketOutAsync(Player, Channel, Object)} will be invoked with this packet. + * + * @param channel - client identified by a channel. + * @param packet - the packet to send. + */ + public void sendPacket(Channel channel, Object packet) { + channel.pipeline().writeAndFlush(packet); + } + + /** + * Pretend that a given packet has been received from a player. + *

+ * Note that {@link #onPacketInAsync(Player, Channel, Object)} will be invoked with this packet. + * + * @param player - the player that sent the packet. + * @param packet - the packet that will be received by the server. + */ + public void receivePacket(Player player, Object packet) { + receivePacket(getChannel(player), packet); + } + + /** + * Pretend that a given packet has been received from a given client. + *

+ * Note that {@link #onPacketInAsync(Player, Channel, Object)} will be invoked with this packet. + * + * @param channel - client identified by a channel. + * @param packet - the packet that will be received by the server. + */ + public void receivePacket(Channel channel, Object packet) { + channel.pipeline().context("encoder").fireChannelRead(packet); + } + + /** + * Retrieve the name of the channel injector, default implementation is "tiny-" + plugin name + "-" + a unique ID. + *

+ * Note that this method will only be invoked once. It is no longer necessary to override this to support multiple instances. + * + * @return A unique channel handler name. + */ + protected String getHandlerName() { + return "tiny-" + plugin.getName() + "-" + ID.incrementAndGet(); + } + + /** + * Add a custom channel handler to the given player's channel pipeline, allowing us to intercept sent and received packets. + *

+ * This will automatically be called when a player has logged in. + * + * @param player - the player to inject. + */ + public void injectPlayer(Player player) { + injectChannelInternal(getChannel(player)).player = player; + } + + /** + * Add a custom channel handler to the given channel. + * + * @param channel - the channel to inject. + * @return The intercepted channel, or NULL if it has already been injected. + */ + public void injectChannel(Channel channel) { + injectChannelInternal(channel); + } + + /** + * Add a custom channel handler to the given channel. + * + * @param channel - the channel to inject. + * @return The packet interceptor. + */ + private PacketInterceptor injectChannelInternal(Channel channel) { + try { + PacketInterceptor interceptor = (PacketInterceptor) channel.pipeline().get(handlerName); + + // Inject our packet interceptor + if (interceptor == null) { + interceptor = new PacketInterceptor(); + channel.pipeline().addBefore("packet_handler", handlerName, interceptor); + uninjectedChannels.remove(channel); + } + + return interceptor; + } catch (IllegalArgumentException e) { + // Try again + return (PacketInterceptor) channel.pipeline().get(handlerName); + } + } + + /** + * Retrieve the Netty channel associated with a player. This is cached. + * + * @param player - the player. + * @return The Netty channel. + */ + public Channel getChannel(Player player) { + Channel channel = channelLookup.get(player.getName()); + + // Lookup channel again + if (channel == null) { + Object connection = getConnection.get(getPlayerHandle.invoke(player)); + Object manager = getManager.get(connection); + + channelLookup.put(player.getName(), channel = getChannel.get(manager)); + } + + return channel; + } + + /** + * Uninject a specific player. + * + * @param player - the injected player. + */ + public void uninjectPlayer(Player player) { + uninjectChannel(getChannel(player)); + } + + /** + * Uninject a specific channel. + *

+ * This will also disable the automatic channel injection that occurs when a player has properly logged in. + * + * @param channel - the injected channel. + */ + public void uninjectChannel(final Channel channel) { + // No need to guard against this if we're closing + if (!closed) { + uninjectedChannels.add(channel); + } + + // See ChannelInjector in ProtocolLib, line 590 + channel.eventLoop().execute(new Runnable() { + + @Override + public void run() { + channel.pipeline().remove(handlerName); + } + + }); + } + + /** + * Determine if the given player has been injected by TinyProtocol. + * + * @param player - the player. + * @return TRUE if it is, FALSE otherwise. + */ + public boolean hasInjected(Player player) { + return hasInjected(getChannel(player)); + } + + /** + * Determine if the given channel has been injected by TinyProtocol. + * + * @param channel - the channel. + * @return TRUE if it is, FALSE otherwise. + */ + public boolean hasInjected(Channel channel) { + return channel.pipeline().get(handlerName) != null; + } + + /** + * Cease listening for packets. This is called automatically when your plugin is disabled. + */ + public final void close() { + if (!closed) { + closed = true; + + // Remove our handlers + for (Player player : plugin.getServer().getOnlinePlayers()) { + uninjectPlayer(player); + } + + // Clean up Bukkit + HandlerList.unregisterAll(listener); + unregisterChannelHandler(); + } + } + + /** + * Channel handler that is inserted into the player's channel pipeline, allowing us to intercept sent and received packets. + * + * @author Kristian + */ + private final class PacketInterceptor extends ChannelDuplexHandler { + // Updated by the login event + public volatile Player player; + + @Override + public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { + // Intercept channel + final Channel channel = ctx.channel(); + handleLoginStart(channel, msg); + + try { + msg = onPacketInAsync(player, channel, msg); + } catch (Exception e) { + plugin.getLogger().log(Level.SEVERE, "Error in onPacketInAsync().", e); + } + + if (msg != null) { + super.channelRead(ctx, msg); + } + } + + @Override + public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception { + try { + msg = onPacketOutAsync(player, ctx.channel(), msg); + } catch (Exception e) { + plugin.getLogger().log(Level.SEVERE, "Error in onPacketOutAsync().", e); + } + + if (msg != null) { + super.write(ctx, msg, promise); + } + } + + private void handleLoginStart(Channel channel, Object packet) { + if (PACKET_LOGIN_IN_START.isInstance(packet)) { + GameProfile profile = getGameProfile.get(packet); + channelLookup.put(profile.getName(), channel); + } + } + } +} \ No newline at end of file