pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>net.rubeta</groupId>
     <artifactId>LegacyPing</artifactId>
-    <version>2.2</version>
+    <version>1.2</version>
     <packaging>jar</packaging>
 
     <name>LegacyPing</name>

src/main/java/net/rubeta/legacyping/CrutchBukkitMirrorThread.java

@@ -1,106 +0,0 @@
-package net.rubeta.legacyping;
-
-import net.minecraft.network.packets.Packet;
-import net.minecraft.network.packets.Packet255KickDisconnect;
-import org.bukkit.craftbukkit.CraftServer;
-import org.bukkit.craftbukkit.event.CraftEventFactory;
-import org.bukkit.event.server.ServerListPingEvent;
-
-import java.io.DataInputStream;
-import java.io.DataOutputStream;
-import java.io.EOFException;
-import java.io.IOException;
-import java.net.*;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-public class CrutchBukkitMirrorThread extends Thread {
-
-    private final AtomicBoolean working = new AtomicBoolean(false);
-    private final Logger logger;
-    private ServerSocket serverSocket;
-    private final InetAddress address;
-    private final LegacyPing plugin;
-
-    public CrutchBukkitMirrorThread(final LegacyPing plugin) {
-        this.plugin = plugin;
-        this.logger = Logger.getLogger("mirror:25565");
-
-        try {
-            this.address = InetAddress.getByName("0.0.0.0");
-        } catch (UnknownHostException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    @Override
-    public void run() {
-        this.working.set(true);
-        while (this.working.get()) {
-            try {
-                this.serverSocket = new ServerSocket(25565, 10, address);
-                this.serverSocket.setSoTimeout((int) TimeUnit.SECONDS.toMillis(10L));
-                this.serverSocket.setPerformancePreferences(0, 2, 1);
-            } catch (IOException e) {
-                this.logger.log(Level.WARNING, "Failed to start ServerSocket", e);
-                this.pause();
-                continue;
-            }
-
-            while (!this.serverSocket.isClosed()) {
-                if (!this.working.get()) {
-                    break;
-                }
-
-                InetAddress address = null;
-                try (final Socket socket = this.serverSocket.accept()) {
-                    final DataInputStream inputStream = new DataInputStream(socket.getInputStream());
-                    final DataOutputStream outputStream = new DataOutputStream(socket.getOutputStream());
-                    address = socket.getInetAddress();
-                    socket.setTrafficClass(SocketOptions.TCP_NODELAY & SocketOptions.IP_TOS);
-                    inputStream.readInt(); // Packet length
-                    Packet packet = Packet.readPacket(inputStream);
-                    if (packet != null && packet.getPacketId() == 254) {
-                        CraftServer server = (CraftServer) this.plugin.getServer();
-                        ServerListPingEvent pingEvent = CraftEventFactory.callServerListPingEvent(
-                                server, address, server.getServer().motd,
-                                server.getOnlinePlayers().length, server.getMaxPlayers()
-                        );
-                        String s = pingEvent.getMotd() + "\u0000" + server.getOnlinePlayers().length + "\u0000" + pingEvent.getMaxPlayers();
-                        Packet255KickDisconnect response = new Packet255KickDisconnect(s);
-                        outputStream.writeInt(s.length() + 1);
-                        outputStream.writeByte(255);
-                        response.writePacketData(outputStream);
-                    }
-                } catch (SocketTimeoutException | EOFException ignore) {
-                } catch (Exception ex) {
-                    this.logger.warning("An exception occurred while communicating with " + address);
-                    this.logger.log(Level.WARNING, "Exception in " + this.getName(), ex);
-                }
-            }
-        }
-    }
-
-
-    public void shutdown() {
-        this.working.set(false);
-        try {
-            this.serverSocket.close();
-        } catch (IOException ignore) {
-        }
-    }
-
-
-    void pause() {
-        this.pause(TimeUnit.SECONDS.toMillis(30L));
-    }
-
-    void pause(long millis) {
-        try {
-            Thread.sleep(millis);
-        } catch (InterruptedException ignored) {
-        }
-    }
-}

src/main/java/net/rubeta/legacyping/LegacyPing.java

@@ -1,8 +1,5 @@
 package net.rubeta.legacyping;
 
-import org.bukkit.ChatColor;
-import org.bukkit.command.Command;
-import org.bukkit.command.CommandSender;
 import org.bukkit.configuration.file.FileConfiguration;
 import org.bukkit.plugin.java.JavaPlugin;
 
@@ -13,54 +10,25 @@ import java.util.logging.Level;
 
 public final class LegacyPing extends JavaPlugin {
     private final List<ServerThread> threads = new ArrayList<>();
-    private CrutchBukkitMirrorThread mirror = null;
 
     @Override
     public void onEnable() {
         this.saveDefaultConfig();
-        this.startThreads();
-    }
-
-    private void startThreads() {
         final FileConfiguration config = this.getConfig();
         final String host = config.getString("host", "0.0.0.0");
         final List<Integer> ports = config.getIntegerList("port");
-        final String version = config.getString("displayedVersion", "b1.7.3");
-        final int protocol = config.getInt("displayedProtocol", 14);
         for (int port : ports) {
             try {
-                this.threads.add(new ServerThread(this, host, port, version, protocol));
+                this.threads.add(new ServerThread(this.getServer(), host, port));
             } catch (IOException e) {
                 this.getLogger().log(Level.WARNING, "Failed to create ServerSocket", e);
             }
         }
-        if (config.getBoolean("enableMirrorPort", false)) {
-            this.mirror = new CrutchBukkitMirrorThread(this);
-            this.mirror.start();
-        }
         this.threads.forEach(Thread::start);
     }
 
     @Override
     public void onDisable() {
-        if (this.mirror != null) {
-            this.mirror.shutdown();
-        }
         this.threads.forEach(ServerThread::shutdown);
     }
-
-    @Override
-    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
-        if (!sender.isOp()) {
-            return true;
-        }
-        if (this.mirror != null) {
-            this.mirror.shutdown();
-        }
-        this.threads.forEach(ServerThread::shutdown);
-        this.threads.clear();
-        this.startThreads();
-        sender.sendMessage(ChatColor.GOLD + "Restarted");
-        return true;
-    }
 }

src/main/java/net/rubeta/legacyping/ServerThread.java

@@ -5,127 +5,67 @@ import org.bukkit.craftbukkit.CraftServer;
 
 import java.io.*;
 import java.net.*;
-import java.nio.charset.StandardCharsets;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 public class ServerThread extends Thread {
 
     private static final String MODERN_RESPONSE =
-            "{\"version\": {\"name\": \"%version%\",\"protocol\": %protocol%}," +
+            "{\"version\": {\"name\": \"b1.7.3\",\"protocol\": -17}," +
-                    "\"players\": {\"max\": %max%,\"online\": %now%}," +
+                    "\"players\": {\"max\": %max%,\"online\": %now%,\"sample\": []}," +
-                    "\"description\": {\"text\": \"%motd%\"}," +
+                    "\"description\": {\"text\": \"%motd%\"},\"enforcesSecureChat\": false}";
-                    "\"enforcesSecureChat\": false,\"previewsChat\": false}";
+    private final ServerSocket serverSocket;
-    private static final String DISCONNECT_REASON = "[\"\",{\"text\":\"This is b1.7.3 server. Visit \"}," +
-            "{\"text\":\"https://rubeta.net\",\"underlined\":true},{\"text\":\" for more information.\"}]";
-    private static final String SLOWSTACK_ID = "slowstack.tv";
-    private static final String MATSCAN_ID = "matscan";
     private final AtomicBoolean working = new AtomicBoolean(false);
     private final Server minecraftServer;
-    private final String version;
-    private final int protocol;
-    private final InetAddress address;
-    private final int port;
-    private final Logger logger;
-    private ServerSocket serverSocket;
 
-    public ServerThread(final LegacyPing plugin, final String host, int port, String version, int protocol) throws IOException {
+    public ServerThread(final Server server, final String host, int port) throws IOException {
-        this.minecraftServer = plugin.getServer();
+        this.minecraftServer = server;
-        this.logger = plugin.getLogger();
         this.setName("LegacyPing thread listening " + host + ":" + port);
-        this.version = version;
+        final InetAddress address = InetAddress.getByName(host);
-        this.protocol = protocol;
+        this.serverSocket = new ServerSocket(port, 10, address);
-        this.address = InetAddress.getByName(host);
+        this.serverSocket.setSoTimeout((int) TimeUnit.SECONDS.toMillis(10L));
-        this.port = port;
+        this.serverSocket.setPerformancePreferences(0, 2, 1);
     }
 
     public ServerThread(final String host, int port) throws IOException {
         this.minecraftServer = null;
         this.setName("LegacyPing thread listening " + host + ":" + port);
-        this.logger = Logger.getLogger(host + ":" + port);
+        final InetAddress address = InetAddress.getByName(host);
-        this.version = "dummy";
+        this.serverSocket = new ServerSocket(port, 10, address);
-        this.protocol = 0;
+        this.serverSocket.setSoTimeout((int) TimeUnit.SECONDS.toMillis(10L));
-        this.address = InetAddress.getByName(host);
+        this.serverSocket.setPerformancePreferences(0, 2, 1);
-        this.port = port;
     }
 
     public static void main(String[] args) throws IOException {
-        new ServerThread("", 25569).start();
+        new ServerThread("", 25565).start();
     }
 
-    @SuppressWarnings("unused")
     @Override
     public void run() {
         this.working.set(true);
-        while (this.working.get()) {
+        while (this.working.get() && !this.serverSocket.isClosed()) {
             try {
-                this.serverSocket = new ServerSocket(port, 10, address);
+                final Socket socket = this.serverSocket.accept();
-                this.serverSocket.setSoTimeout((int) TimeUnit.SECONDS.toMillis(10L));
+                socket.setTrafficClass(SocketOptions.TCP_NODELAY & SocketOptions.IP_TOS);
-                this.serverSocket.setPerformancePreferences(0, 2, 1);
+                System.out.println("[LegacyPing] Got new ping from " + socket.getRemoteSocketAddress());
-            } catch (IOException e) {
+                final InputStream inputStream = socket.getInputStream();
-                this.logger.log(Level.WARNING, "Failed to start ServerSocket", e);
+                final OutputStream outputStream = socket.getOutputStream();
-                this.pause();
+                final int firstByte = inputStream.read();
-                continue;
+                switch (firstByte) {
-            }
+                    case 0:
-
+                        this.responseForRuBetaModdedClient(outputStream);
-            while (!this.serverSocket.isClosed()) {
+                        break;
-                if (!this.working.get()) {
+                    case 254:
-                    break;
+                        this.responseForLegacyPing(outputStream);
-                }
+                        break;
-                InetAddress address = null;
+                    default:
-                try (final Socket socket = this.serverSocket.accept()) {
+                        this.responseForModernPing(outputStream);
-                    final DataInputStream inputStream = new DataInputStream(socket.getInputStream());
-                    final DataOutputStream outputStream = new DataOutputStream(socket.getOutputStream());
-                    address = socket.getInetAddress();
-                    socket.setTrafficClass(SocketOptions.TCP_NODELAY & SocketOptions.IP_TOS);
-
-                    final int packetLength = inputStream.readByte() | inputStream.readByte() << 1; // idk why it doesn't a VarInt
-                    final int protocolVersion = this.readVarInt(inputStream);
-                    final String hostname = this.readUtf(inputStream);
-                    final int port = inputStream.readShort();
-                    final int status = this.readVarInt(inputStream);
-                    this.logger.info("Ping from " + socket.getRemoteSocketAddress() + " to " + hostname + ":" + port);
-                    if (status != 2) {
-                        if (hostname.equalsIgnoreCase(SLOWSTACK_ID)) {
-                            this.responseForModernPing(outputStream, MODERN_RESPONSE.replace(
-                                    "%motd%", "%motd% \nHello, slowstack.tv!"
-                            ));
-                        } else if (hostname.equalsIgnoreCase(MATSCAN_ID)) {
-                            this.responseForModernPing(outputStream, MODERN_RESPONSE
-                                    .replace("%motd%", "%motd% \nHello, matscan!")
-                                    .replace("%version%", "⚠ Error")
-                            );
-                        } else {
-                            this.responseForModernPing(outputStream, MODERN_RESPONSE);
-                        }
-                    } else {
-                        this.responseForModernPing(outputStream, DISCONNECT_REASON);
-                        socket.close();
-                        continue;
-                    }
-                    outputStream.flush();
-
-                    this.pause(50L);
-                    if (socket.isClosed() || !socket.isConnected() || inputStream.available() == 0) {
-                        continue;
-                    }
-                    inputStream.readShort(); // legacy data
-                    this.pause(50L);
-                    if (socket.isClosed() || !socket.isConnected() || inputStream.available() == 0) {
-                        continue;
-                    }
-                    this.writeVarInt(outputStream, this.readVarInt(inputStream)); // Packet length  (9)
-                    this.writeVarInt(outputStream, this.readVarInt(inputStream)); // Packet id      (1)
-                    outputStream.writeLong(inputStream.readLong()); // timestamp
-                } catch (SocketTimeoutException | EOFException ignore) {
-                } catch (Exception ex) {
-                    if (this.working.get()) {
-                        this.logger.warning("An exception occurred while communicating with " + address);
-                        this.logger.log(Level.WARNING, "Exception in " + this.getName(), ex);
-                    }
                 }
+                outputStream.flush();
+                socket.close();
+            } catch (SocketTimeoutException ignore) {
+            } catch (IOException ex) {
+                System.out.println("Exception caught: " + ex);
             }
         }
     }
@@ -138,31 +78,44 @@ public class ServerThread extends Thread {
         }
     }
 
-    void pause() {
+    private void responseForRuBetaModdedClient(final OutputStream outputStream) throws IOException {
-        this.pause(TimeUnit.SECONDS.toMillis(30L));
+        final ByteArrayOutputStream result = new ByteArrayOutputStream();
-    }
+        final DataOutputStream dos = new DataOutputStream(result);
-
+        dos.write(255); // Packet 0xFF (PacketDisconnect)
-    void pause(long millis) {
+        final String response = this.getMotd() + '\u0000' + this.getOnlinePlayers() + '\u0000' + this.getMaxPlayers();
-        try {
+        dos.writeShort(response.length());
-            Thread.sleep(millis);
+        for (char c : response.toCharArray()) {
-        } catch (InterruptedException ignored) {
+            dos.writeChar(c);
         }
+        // Packet data end
+        final DataOutputStream clientOutput = new DataOutputStream(outputStream);
+        clientOutput.writeInt(result.size());
+        clientOutput.write(result.toByteArray());
     }
 
-    private void responseForModernPing(final DataOutputStream outputStream, String response) throws IOException {
+    @SuppressWarnings("UnnecessaryUnicodeEscape")
-        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+    private void responseForLegacyPing(final OutputStream outputStream) throws IOException {
-        DataOutputStream dos = new DataOutputStream(baos);
+        final DataOutputStream clientOutput = new DataOutputStream(outputStream);
-        final String responseJson = response
+        clientOutput.write(255);
-                .replace("%version%", String.valueOf(this.version))
+        final String response = this.getMotd() + '\u00a7' + this.getOnlinePlayers() + '\u00a7' + this.getMaxPlayers();
-                .replace("%protocol%", String.valueOf(this.protocol))
+        clientOutput.writeShort(response.length());
-                .replace("%max%", String.valueOf(this.getMaxPlayers()))
+        for (char c : response.toCharArray()) {
+            clientOutput.writeChar(c);
+        }
+        // Packet data end
+    }
+
+    private void responseForModernPing(final OutputStream outputStream) throws IOException {
+        final String responseJson = MODERN_RESPONSE.replace("%max%", String.valueOf(this.getMaxPlayers()))
                 .replace("%now%", String.valueOf(this.getOnlinePlayers()))
                 .replace("%motd%", this.getMotd());
-        this.writeVarInt(dos, 0);
+        byte[] bytes = responseJson.getBytes();
-        this.writeUtf(dos, responseJson);
+        final DataOutputStream clientOutput = new DataOutputStream(outputStream);
-        dos.close();
+        this.writeVarInt(clientOutput, bytes.length + 3);
-        this.writeVarInt(outputStream, baos.size());
+        this.writeVarInt(clientOutput, 0);
-        outputStream.write(baos.toByteArray());
+        this.writeVarInt(clientOutput, bytes.length);
+        clientOutput.write(bytes);
+        // Packet data end
     }
 
     private String getMotd() {
@@ -177,46 +130,14 @@ public class ServerThread extends Thread {
         return this.minecraftServer == null ? 37 : this.minecraftServer.getMaxPlayers();
     }
 
-    public int readVarInt(DataInputStream in) {
-        int i = 0;
-        int j = 0;
-        try {
-            byte b0;
-            do {
-                b0 = in.readByte();
-                i |= (b0 & 127) << j++ * 7;
-                if (j > 5) {
-                    throw new RuntimeException("VarInt too big");
-                }
-            } while ((b0 & 128) == 128);
-        } catch (Exception ignore) {
-            return 0;
-        }
-        return i;
-    }
-
     private void writeVarInt(DataOutputStream out, int paramInt) throws IOException {
-        while ((paramInt & 0xffffff80) != 0) {
+        while (true) {
-            out.writeByte(paramInt & 0x7f | 0x80);
+            if ((paramInt & 0xFFFFFF80) == 0) {
+                out.writeByte(paramInt);
+                return;
+            }
+            out.writeByte(paramInt & 0x7F | 0x80);
             paramInt >>>= 7;
         }
-        out.writeByte(paramInt);
-    }
-
-    @SuppressWarnings("ResultOfMethodCallIgnored")
-    private String readUtf(DataInputStream in) throws IOException {
-        int length = this.readVarInt(in);
-        byte[] data = new byte[length];
-        in.read(data);
-        return new String(data, StandardCharsets.UTF_8);
-    }
-
-    private void writeUtf(DataOutputStream out, String string) throws IOException {
-        byte[] data = string.getBytes(StandardCharsets.UTF_8);
-        if (data.length > 32767) {
-            throw new RuntimeException("String too big (was " + data.length + " bytes encoded, max 32767");
-        }
-        this.writeVarInt(out, data.length);
-        out.write(data);
     }
 }

src/main/resources/config.yml

@@ -2,5 +2,3 @@ host: '0.0.0.0'
 port:
   - 25566
   - 25567
-displayedVersion: 'b1.7.3'
-displayedProtocol: 17

src/main/resources/plugin.yml

@@ -1,10 +1,3 @@
 name: LegacyPing
 version: '${project.version}'
 main: net.rubeta.legacyping.LegacyPing
-commands:
-  legacyping:
-    permission: legacyping.command.legacyping
-
-permissions:
-  legacyping.command.legacyping:
-    default: op