Limit server to only send the packets it creates and only accept the packets the client creates

src/main/java/net/minecraft/server/Packet.java

@@ -0,0 +1,234 @@
+package net.minecraft.server;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.EOFException;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+public abstract class Packet {
+
+    private static Map a = new HashMap();
+    private static Map b = new HashMap();
+    public final long j = System.currentTimeMillis();
+    public boolean k = false;
+    private static HashMap c;
+    private static int d;
+
+    public Packet() {}
+
+    static void a(int i, Class oclass) {
+        if (a.containsKey(Integer.valueOf(i))) {
+            throw new IllegalArgumentException("Duplicate packet id:" + i);
+        } else if (b.containsKey(oclass)) {
+            throw new IllegalArgumentException("Duplicate packet class:" + oclass);
+        } else {
+            a.put(Integer.valueOf(i), oclass);
+            b.put(oclass, Integer.valueOf(i));
+        }
+    }
+
+    // CraftBukkit start
+    private static Map<Integer,Class<?>> e = new HashMap<Integer,Class<?>>();
+    private static Map<Class<?>,Integer> f = new HashMap<Class<?>,Integer>();
+
+    static void b(int i, Class<?> oclass) {
+        if (e.containsKey(Integer.valueOf(i))) {
+            throw new IllegalArgumentException("Duplicate packet id:" + i);
+        } else if (f.containsKey(oclass)) {
+            throw new IllegalArgumentException("Duplicate packet class:" + oclass);
+        } else {
+            e.put(Integer.valueOf(i), oclass);
+            f.put(oclass, Integer.valueOf(i));
+        }
+    }
+    // CraftBukkit end
+
+    public static Packet a(int i) {
+        try {
+            Class oclass = (Class) a.get(Integer.valueOf(i));
+
+            return oclass == null ? null : (Packet) oclass.newInstance();
+        } catch (Exception exception) {
+            exception.printStackTrace();
+            System.out.println("Skipping packet with id " + i);
+            return null;
+        }
+    }
+
+    public final int b() {
+        // CraftBukkit b->f
+        return ((Integer) f.get(this.getClass())).intValue();
+    }
+
+    // CraftBukkit
+    public static Packet b(DataInputStream datainputstream) throws IOException {
+        boolean flag = false;
+        Packet packet = null;
+
+        datainputstream.mark(16384);
+
+        int i;
+
+        try {
+            i = datainputstream.read();
+            if (i == -1) {
+                return null;
+            }
+
+            packet = a(i);
+            if (packet == null) {
+                throw new IOException("Bad packet id " + i);
+            }
+
+            packet.a(datainputstream);
+        } catch (EOFException eofexception) {
+            System.out.println("Reached end of stream");
+            datainputstream.reset();
+            return null;
+        }
+
+        PacketCounter packetcounter = (PacketCounter) c.get(Integer.valueOf(i));
+
+        if (packetcounter == null) {
+            packetcounter = new PacketCounter((EmptyClass1) null);
+            c.put(Integer.valueOf(i), packetcounter);
+        }
+
+        packetcounter.a(packet.a());
+        ++d;
+        if (d % 1000 == 0) {
+            ;
+        }
+
+        return packet;
+    }
+
+    // CraftBukkit
+    public static void a(Packet packet, DataOutputStream dataoutputstream) throws IOException {
+        dataoutputstream.write(packet.b());
+        packet.a(dataoutputstream);
+    }
+
+    public abstract void a(DataInputStream datainputstream);
+
+    public abstract void a(DataOutputStream dataoutputstream);
+
+    public abstract void a(NetHandler nethandler);
+
+    public abstract int a();
+
+    static {
+        a(0, Packet0KeepAlive.class);
+        a(1, Packet1Login.class);
+        a(2, Packet2Handshake.class);
+        a(3, Packet3Chat.class);
+        //a(4, Packet4UpdateTime.class); // CraftBukkit
+        //a(5, Packet5EntityEquipment.class); // CraftBukkit
+        //a(6, Packet6SpawnPosition.class); // CraftBukkit
+        a(7, Packet7UseEntity.class);
+        //a(8, Packet8UpdateHealth.class); // CraftBukkit
+        a(9, Packet9Respawn.class);
+        a(10, Packet10Flying.class);
+        a(11, Packet11PlayerPosition.class);
+        a(12, Packet12PlayerLook.class);
+        a(13, Packet13PlayerLookMove.class);
+        a(14, Packet14BlockDig.class);
+        a(15, Packet15Place.class);
+        a(16, Packet16BlockItemSwitch.class);
+        //a(17, Packet17.class); // CraftBukkit
+        a(18, Packet18ArmAnimation.class);
+        a(19, Packet19EntityAction.class);
+        //a(20, Packet20NamedEntitySpawn.class); // CraftBukkit
+        //a(21, Packet21PickupSpawn.class); // CraftBukkit
+        //a(22, Packet22Collect.class); // CraftBukkit
+        //a(23, Packet23VehicleSpawn.class); // CraftBukkit
+        //a(24, Packet24MobSpawn.class); // CraftBukkit
+        //a(25, Packet25EntityPainting.class); // CraftBukkit
+        //a(27, Packet27.class); // CraftBukkit
+        //a(28, Packet28EntityVelocity.class); // CraftBukkit
+        //a(29, Packet29DestroyEntity.class); // CraftBukkit
+        //a(30, Packet30Entity.class); // CraftBukkit
+        //a(31, Packet31RelEntityMove.class); // CraftBukkit
+        //a(32, Packet32EntityLook.class); // CraftBukkit
+        //a(33, Packet33RelEntityMoveLook.class); // CraftBukkit
+        //a(34, Packet34EntityTeleport.class); // CraftBukkit
+        //a(38, Packet38EntityStatus.class); // CraftBukkit
+        //a(39, Packet39AttachEntity.class); // CraftBukkit
+        //a(40, Packet40EntityMetadata.class); // CraftBukkit
+        //a(50, Packet50PreChunk.class); // CraftBukkit
+        //a(51, Packet51MapChunk.class); // CraftBukkit
+        //a(52, Packet52MultiBlockChange.class); // CraftBukkit
+        //a(53, Packet53BlockChange.class); // CraftBukkit
+        //a(54, Packet54PlayNoteBlock.class); // CraftBukkit
+        //a(60, Packet60Explosion.class); // CraftBukkit
+        //a(100, Packet100OpenWindow.class); // CraftBukkit
+        a(101, Packet101CloseWindow.class);
+        a(102, Packet102WindowClick.class);
+        //a(103, Packet103SetSlot.class); // CraftBukkit
+        //a(104, Packet104WindowItems.class); // CraftBukkit
+        //a(105, Packet105CraftProgressBar.class); // CraftBukkit
+        a(106, Packet106Transaction.class);
+        a(130, Packet130UpdateSign.class);
+        a(255, Packet255KickDisconnect.class);
+
+        // CraftBukkit start
+        b(0, Packet0KeepAlive.class);
+        b(1, Packet1Login.class);
+        b(2, Packet2Handshake.class);
+        b(3, Packet3Chat.class);
+        b(4, Packet4UpdateTime.class);
+        b(5, Packet5EntityEquipment.class);
+        b(6, Packet6SpawnPosition.class);
+        //b(7, Packet7UseEntity.class);
+        b(8, Packet8UpdateHealth.class);
+        b(9, Packet9Respawn.class);
+        //b(10, Packet10Flying.class);
+        //b(11, Packet11PlayerPosition.class);
+        //b(12, Packet12PlayerLook.class);
+        b(13, Packet13PlayerLookMove.class);
+        //b(14, Packet14BlockDig.class);
+        //b(15, Packet15Place.class);
+        //b(16, Packet16BlockItemSwitch.class);
+        b(17, Packet17.class);
+        b(18, Packet18ArmAnimation.class);
+        //b(19, Packet19EntityAction.class);
+        b(20, Packet20NamedEntitySpawn.class);
+        b(21, Packet21PickupSpawn.class);
+        b(22, Packet22Collect.class);
+        b(23, Packet23VehicleSpawn.class);
+        b(24, Packet24MobSpawn.class);
+        b(25, Packet25EntityPainting.class);
+        //b(27, Packet27.class);
+        b(28, Packet28EntityVelocity.class);
+        b(29, Packet29DestroyEntity.class);
+        //b(30, Packet30Entity.class);
+        b(31, Packet31RelEntityMove.class);
+        b(32, Packet32EntityLook.class);
+        b(33, Packet33RelEntityMoveLook.class);
+        b(34, Packet34EntityTeleport.class);
+        b(38, Packet38EntityStatus.class);
+        b(39, Packet39AttachEntity.class);
+        b(40, Packet40EntityMetadata.class);
+        b(50, Packet50PreChunk.class);
+        b(51, Packet51MapChunk.class);
+        b(52, Packet52MultiBlockChange.class);
+        b(53, Packet53BlockChange.class);
+        b(54, Packet54PlayNoteBlock.class);
+        b(60, Packet60Explosion.class);
+        b(100, Packet100OpenWindow.class);
+        b(101, Packet101CloseWindow.class);
+        //b(102, Packet102WindowClick.class);
+        b(103, Packet103SetSlot.class);
+        b(104, Packet104WindowItems.class);
+        b(105, Packet105CraftProgressBar.class);
+        b(106, Packet106Transaction.class);
+        b(130, Packet130UpdateSign.class);
+        b(255, Packet255KickDisconnect.class);
+        // CraftBukkit end
+
+        c = new HashMap();
+        d = 0;
+    }
+}

src/main/java/net/minecraft/server/PacketCounter.java

@@ -0,0 +1,18 @@
+package net.minecraft.server;
+
+class PacketCounter {
+
+    private int a;
+    private long b;
+
+    private PacketCounter() {}
+
+    public void a(int i) {
+        ++this.a;
+        this.b += (long) i;
+    }
+
+    PacketCounter(EmptyClass1 emptyclass1) {
+        this();
+    }
+}