Merge pull request #219 from Gabik21MC/master

1.7 Protocol Support

api/src/main/java/com/velocitypowered/api/network/ProtocolVersion.java

@@ -13,6 +13,8 @@ import java.util.Set;
 public enum ProtocolVersion {
   UNKNOWN(-1, "Unknown"),
   LEGACY(-2, "Legacy"),
+  MINECRAFT_1_7_2(4, "1.7.2"),
+  MINECRAFT_1_7_6(5, "1.7.6"),
   MINECRAFT_1_8(47, "1.8"),
   MINECRAFT_1_9(107, "1.9"),
   MINECRAFT_1_9_1(108, "1.9.1"),
@@ -39,7 +41,7 @@ public enum ProtocolVersion {
   /**
    * Represents the lowest supported version.
    */
-  public static final ProtocolVersion MINIMUM_VERSION = MINECRAFT_1_8;
+  public static final ProtocolVersion MINIMUM_VERSION = MINECRAFT_1_7_2;
   /**
    * Represents the highest supported version.
    */

proxy/src/main/java/com/velocitypowered/proxy/connection/ConnectionTypes.java

@@ -3,6 +3,7 @@ package com.velocitypowered.proxy.connection;
 import com.velocitypowered.proxy.connection.backend.BackendConnectionPhases;
 import com.velocitypowered.proxy.connection.client.ClientConnectionPhases;
 import com.velocitypowered.proxy.connection.forge.legacy.LegacyForgeConnectionType;
+import com.velocitypowered.proxy.connection.forge.legacy.LegacyForgeHandshakeClientPhase;
 import com.velocitypowered.proxy.connection.util.ConnectionTypeImpl;
 
 /**
@@ -24,6 +25,9 @@ public final class ConnectionTypes {
   public static final ConnectionType VANILLA =
       new ConnectionTypeImpl(ClientConnectionPhases.VANILLA, BackendConnectionPhases.VANILLA);
 
+  public static final ConnectionType UNDETERMINED_17 = new ConnectionTypeImpl(
+      LegacyForgeHandshakeClientPhase.NOT_STARTED, BackendConnectionPhases.UNKNOWN);
+
   /**
    * Indicates that the connection is a 1.8-1.12 Forge
    * connection.

proxy/src/main/java/com/velocitypowered/proxy/connection/backend/BackendPlaySessionHandler.java

@@ -102,8 +102,8 @@ public class BackendPlaySessionHandler implements MinecraftSessionHandler {
     }
 
     if (PluginMessageUtil.isMcBrand(packet)) {
-      PluginMessage rewritten = PluginMessageUtil.rewriteMinecraftBrand(packet,
+      PluginMessage rewritten = PluginMessageUtil.rewriteMinecraftBrand(packet, server.getVersion(),
-          server.getVersion());
+          playerConnection.getProtocolVersion());
       playerConnection.write(rewritten);
       return true;
     }

proxy/src/main/java/com/velocitypowered/proxy/connection/client/ClientPlaySessionHandler.java

@@ -1,6 +1,7 @@
 package com.velocitypowered.proxy.connection.client;
 
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_13;
+import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_8;
 import static com.velocitypowered.proxy.protocol.util.PluginMessageUtil.constructChannelsPacket;
 
 import com.velocitypowered.api.event.connection.PluginMessageEvent;
@@ -177,7 +178,8 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
         player.getKnownChannels().removeAll(PluginMessageUtil.getChannels(packet));
         backendConn.write(packet.retain());
       } else if (PluginMessageUtil.isMcBrand(packet)) {
-        backendConn.write(PluginMessageUtil.rewriteMinecraftBrand(packet, server.getVersion()));
+        backendConn.write(PluginMessageUtil
+            .rewriteMinecraftBrand(packet, server.getVersion(), player.getProtocolVersion()));
       } else {
         if (serverConn.getPhase() == BackendConnectionPhases.IN_TRANSITION) {
           // We must bypass the currently-connected server when forwarding Forge packets.
@@ -347,8 +349,10 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
     }
 
     // Clear any title from the previous server.
+    if (player.getProtocolVersion().compareTo(MINECRAFT_1_8) >= 0) {
       player.getConnection()
           .delayedWrite(TitlePacket.resetForProtocolVersion(player.getProtocolVersion()));
+    }
 
     // Flush everything
     player.getConnection().flush();

proxy/src/main/java/com/velocitypowered/proxy/connection/client/ConnectedPlayer.java

@@ -46,6 +46,7 @@ import com.velocitypowered.proxy.protocol.packet.TitlePacket;
 import com.velocitypowered.proxy.protocol.util.PluginMessageUtil;
 import com.velocitypowered.proxy.server.VelocityRegisteredServer;
 import com.velocitypowered.proxy.tablist.VelocityTabList;
+import com.velocitypowered.proxy.tablist.VelocityTabListLegacy;
 import com.velocitypowered.proxy.util.VelocityMessages;
 import com.velocitypowered.proxy.util.collect.CappedSet;
 import io.netty.buffer.ByteBufUtil;
@@ -104,7 +105,11 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
   ConnectedPlayer(VelocityServer server, GameProfile profile,
       MinecraftConnection connection, @Nullable InetSocketAddress virtualHost) {
     this.server = server;
+    if (connection.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       this.tabList = new VelocityTabList(connection);
+    } else {
+      this.tabList = new VelocityTabListLegacy(connection);
+    }
     this.profile = profile;
     this.connection = connection;
     this.virtualHost = virtualHost;

proxy/src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java

@@ -114,6 +114,10 @@ public class HandshakeSessionHandler implements MinecraftSessionHandler {
     if (handshake.getServerAddress().endsWith(LegacyForgeConstants.HANDSHAKE_HOSTNAME_TOKEN)
         && handshake.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_13) < 0) {
       return ConnectionTypes.LEGACY_FORGE;
+    } else if (handshake.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_7_6) <= 0) {
+      // 1.7 Forge will not notify us during handshake. UNDETERMINED will listen for incoming
+      // forge handshake attempts. Also sends a reset handshake packet on every transition.
+      return ConnectionTypes.UNDETERMINED_17;
     } else {
       // For later: See if we can determine Forge 1.13+ here, else this will need to be UNDETERMINED
       // until later in the cycle (most likely determinable during the LOGIN phase)

proxy/src/main/java/com/velocitypowered/proxy/connection/client/LoginSessionHandler.java

@@ -2,6 +2,7 @@ package com.velocitypowered.proxy.connection.client;
 
 import static com.google.common.net.UrlEscapers.urlFormParameterEscaper;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_13;
+import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_8;
 import static com.velocitypowered.proxy.VelocityServer.GSON;
 import static com.velocitypowered.proxy.connection.VelocityConstants.EMPTY_BYTE_ARRAY;
 import static com.velocitypowered.proxy.connection.VelocityConstants.VELOCITY_IP_FORWARDING_CHANNEL;
@@ -260,7 +261,7 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
     }
 
     int threshold = server.getConfiguration().getCompressionThreshold();
-    if (threshold >= 0) {
+    if (threshold >= 0 && mcConnection.getProtocolVersion().compareTo(MINECRAFT_1_8) >= 0) {
       mcConnection.write(new SetCompression(threshold));
       mcConnection.setCompressionThreshold(threshold);
     }

proxy/src/main/java/com/velocitypowered/proxy/connection/forge/legacy/LegacyForgeHandshakeBackendPhase.java

@@ -90,7 +90,7 @@ public enum LegacyForgeHandshakeBackendPhase implements BackendConnectionPhase {
   @Nullable private final Integer packetToAdvanceOn;
 
   /**
-   * Creates an instance of the {@link LegacyForgeHandshakeClientPhase}.
+   * Creates an instance of the {@link LegacyForgeHandshakeBackendPhase}.
    *
    * @param packetToAdvanceOn The ID of the packet discriminator that indicates
    *                          that the server has moved onto a new phase, and

proxy/src/main/java/com/velocitypowered/proxy/protocol/ProtocolUtils.java

@@ -3,11 +3,11 @@ package com.velocitypowered.proxy.protocol;
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkState;
 
+import com.google.common.base.Preconditions;
 import com.velocitypowered.api.network.ProtocolVersion;
 import com.velocitypowered.api.util.GameProfile;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufUtil;
-
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
@@ -194,6 +194,155 @@ public enum ProtocolUtils {
     return properties;
   }
 
+  private static final int FORGE_MAX_ARRAY_LENGTH = Integer.MAX_VALUE & 0x1FFF9A;
+
+  /**
+   * Reads an byte array for legacy version 1.7 from the specified {@code buf}
+   *
+   * @param buf the buffer to read from
+   * @return the read byte array
+   */
+  public static byte[] readByteArray17(ByteBuf buf) {
+    // Read in a 2 or 3 byte number that represents the length of the packet. (3 byte "shorts" for
+    // Forge only)
+    // No vanilla packet should give a 3 byte packet
+    int len = readExtendedForgeShort(buf);
+
+    Preconditions.checkArgument(len <= (FORGE_MAX_ARRAY_LENGTH),
+        "Cannot receive array longer than %s (got %s bytes)", FORGE_MAX_ARRAY_LENGTH, len);
+
+    byte[] ret = new byte[len];
+    buf.readBytes(ret);
+    return ret;
+  }
+
+  /**
+   * Reads a retained {@link ByteBuf} slice of the specified {@code buf} with the 1.7 style length.
+   *
+   * @param buf the buffer to read from
+   * @return the retained slice
+   */
+  public static ByteBuf readRetainedByteBufSlice17(ByteBuf buf) {
+    // Read in a 2 or 3 byte number that represents the length of the packet. (3 byte "shorts" for
+    // Forge only)
+    // No vanilla packet should give a 3 byte packet
+    int len = readExtendedForgeShort(buf);
+
+    Preconditions.checkArgument(len <= (FORGE_MAX_ARRAY_LENGTH),
+        "Cannot receive array longer than %s (got %s bytes)", FORGE_MAX_ARRAY_LENGTH, len);
+
+    return buf.readRetainedSlice(len);
+  }
+
+  /**
+   * Writes an byte array for legacy version 1.7 to the specified {@code buf}
+   *
+   * @param b array
+   * @param buf buf
+   * @param allowExtended forge
+   */
+  public static void writeByteArray17(byte[] b, ByteBuf buf, boolean allowExtended) {
+    if (allowExtended) {
+      Preconditions
+          .checkArgument(b.length <= (FORGE_MAX_ARRAY_LENGTH),
+              "Cannot send array longer than %s (got %s bytes)", FORGE_MAX_ARRAY_LENGTH,
+              b.length);
+    } else {
+      Preconditions.checkArgument(b.length <= Short.MAX_VALUE,
+          "Cannot send array longer than Short.MAX_VALUE (got %s bytes)", b.length);
+    }
+    // Write a 2 or 3 byte number that represents the length of the packet. (3 byte "shorts" for
+    // Forge only)
+    // No vanilla packet should give a 3 byte packet, this method will still retain vanilla
+    // behaviour.
+    writeExtendedForgeShort(buf, b.length);
+    buf.writeBytes(b);
+  }
+
+  /**
+   * Writes an {@link ByteBuf} for legacy version 1.7 to the specified {@code buf}
+   *
+   * @param b array
+   * @param buf buf
+   * @param allowExtended forge
+   */
+  public static void writeByteBuf17(ByteBuf b, ByteBuf buf, boolean allowExtended) {
+    if (allowExtended) {
+      Preconditions
+          .checkArgument(b.readableBytes() <= (FORGE_MAX_ARRAY_LENGTH),
+              "Cannot send array longer than %s (got %s bytes)", FORGE_MAX_ARRAY_LENGTH,
+              b.readableBytes());
+    } else {
+      Preconditions.checkArgument(b.readableBytes() <= Short.MAX_VALUE,
+          "Cannot send array longer than Short.MAX_VALUE (got %s bytes)", b.readableBytes());
+    }
+    // Write a 2 or 3 byte number that represents the length of the packet. (3 byte "shorts" for
+    // Forge only)
+    // No vanilla packet should give a 3 byte packet, this method will still retain vanilla
+    // behaviour.
+    writeExtendedForgeShort(buf, b.readableBytes());
+    buf.writeBytes(b);
+  }
+
+  /**
+   * Reads a Minecraft-style extended short from the specified {@code buf}.
+   *
+   * @param buf buf to write
+   * @return read extended short
+   */
+  public static int readExtendedForgeShort(ByteBuf buf) {
+    int low = buf.readUnsignedShort();
+    int high = 0;
+    if ((low & 0x8000) != 0) {
+      low = low & 0x7FFF;
+      high = buf.readUnsignedByte();
+    }
+    return ((high & 0xFF) << 15) | low;
+  }
+
+  /**
+   * Writes a Minecraft-style extended short to the specified {@code buf}.
+   *
+   * @param buf buf to write
+   * @param toWrite the extended short to write
+   */
+  public static void writeExtendedForgeShort(ByteBuf buf, int toWrite) {
+    int low = toWrite & 0x7FFF;
+    int high = (toWrite & 0x7F8000) >> 15;
+    if (high != 0) {
+      low = low | 0x8000;
+    }
+    buf.writeShort(low);
+    if (high != 0) {
+      buf.writeByte(high);
+    }
+  }
+
+  /**
+   * Reads a non length-prefixed string from the {@code buf}. We need this for the legacy 1.7
+   * version, being inconsistent when sending the brand.
+   *
+   * @param buf the buffer to read from
+   * @return the decoded string
+   */
+  public static String readStringWithoutLength(ByteBuf buf) {
+    int length = buf.readableBytes();
+    int cap = DEFAULT_MAX_STRING_SIZE;
+    checkArgument(length >= 0, "Got a negative-length string (%s)", length);
+    // `cap` is interpreted as a UTF-8 character length. To cover the full Unicode plane, we must
+    // consider the length of a UTF-8 character, which can be up to a 4 bytes. We do an initial
+    // sanity check and then check again to make sure our optimistic guess was good.
+    checkArgument(length <= cap * 4, "Bad string size (got %s, maximum is %s)", length, cap);
+    checkState(buf.isReadable(length),
+        "Trying to read a string that is too long (wanted %s, only have %s)", length,
+        buf.readableBytes());
+    String str = buf.toString(buf.readerIndex(), length, StandardCharsets.UTF_8);
+    buf.skipBytes(length);
+    checkState(str.length() <= cap, "Got a too-long string (got %s, max %s)",
+        str.length(), cap);
+    return str;
+  }
+
   public enum Direction {
     SERVERBOUND,
     CLIENTBOUND;

proxy/src/main/java/com/velocitypowered/proxy/protocol/StateRegistry.java

@@ -5,6 +5,7 @@ import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_12;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_12_1;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_13;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_14;
+import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_7_2;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_8;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_9;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_9_4;
@@ -44,14 +45,12 @@ import io.netty.util.collection.IntObjectHashMap;
 import io.netty.util.collection.IntObjectMap;
 import it.unimi.dsi.fastutil.objects.Object2IntMap;
 import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
-
 import java.util.Collections;
 import java.util.EnumMap;
 import java.util.EnumSet;
 import java.util.Map;
 import java.util.Objects;
 import java.util.function.Supplier;
-
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public enum StateRegistry {
@@ -59,20 +58,20 @@ public enum StateRegistry {
   HANDSHAKE {
     {
       serverbound.register(Handshake.class, Handshake::new,
-          map(0x00, MINECRAFT_1_8, false));
+          map(0x00, MINECRAFT_1_7_2, false));
     }
   },
   STATUS {
     {
       serverbound.register(StatusRequest.class, () -> StatusRequest.INSTANCE,
-          map(0x00, MINECRAFT_1_8, false));
+          map(0x00, MINECRAFT_1_7_2, false));
       serverbound.register(StatusPing.class, StatusPing::new,
-          map(0x01, MINECRAFT_1_8, false));
+          map(0x01, MINECRAFT_1_7_2, false));
 
       clientbound.register(StatusResponse.class, StatusResponse::new,
-          map(0x00, MINECRAFT_1_8, false));
+          map(0x00, MINECRAFT_1_7_2, false));
       clientbound.register(StatusPing.class, StatusPing::new,
-          map(0x01, MINECRAFT_1_8, false));
+          map(0x01, MINECRAFT_1_7_2, false));
     }
   },
   PLAY {
@@ -81,33 +80,33 @@ public enum StateRegistry {
       clientbound.fallback = false;
 
       serverbound.register(TabCompleteRequest.class, TabCompleteRequest::new,
-          map(0x14, MINECRAFT_1_8, false),
+          map(0x14, MINECRAFT_1_7_2, false),
           map(0x01, MINECRAFT_1_9, false),
           map(0x02, MINECRAFT_1_12, false),
           map(0x01, MINECRAFT_1_12_1, false),
           map(0x05, MINECRAFT_1_13, false),
           map(0x06, MINECRAFT_1_14, false));
       serverbound.register(Chat.class, Chat::new,
-          map(0x01, MINECRAFT_1_8, false),
+          map(0x01, MINECRAFT_1_7_2, false),
           map(0x02, MINECRAFT_1_9, false),
           map(0x03, MINECRAFT_1_12, false),
           map(0x02, MINECRAFT_1_12_1, false),
           map(0x03, MINECRAFT_1_14, false));
       serverbound.register(ClientSettings.class, ClientSettings::new,
-          map(0x15, MINECRAFT_1_8, false),
+          map(0x15, MINECRAFT_1_7_2, false),
           map(0x04, MINECRAFT_1_9, false),
           map(0x05, MINECRAFT_1_12, false),
           map(0x04, MINECRAFT_1_12_1, false),
           map(0x05, MINECRAFT_1_14, false));
       serverbound.register(PluginMessage.class, PluginMessage::new,
-          map(0x17, MINECRAFT_1_8, false),
+          map(0x17, MINECRAFT_1_7_2, false),
           map(0x09, MINECRAFT_1_9, false),
           map(0x0A, MINECRAFT_1_12, false),
           map(0x09, MINECRAFT_1_12_1, false),
           map(0x0A, MINECRAFT_1_13, false),
           map(0x0B, MINECRAFT_1_14, false));
       serverbound.register(KeepAlive.class, KeepAlive::new,
-          map(0x00, MINECRAFT_1_8, false),
+          map(0x00, MINECRAFT_1_7_2, false),
           map(0x0B, MINECRAFT_1_9, false),
           map(0x0C, MINECRAFT_1_12, false),
           map(0x0B, MINECRAFT_1_12_1, false),
@@ -123,37 +122,37 @@ public enum StateRegistry {
       clientbound.register(BossBar.class, BossBar::new,
           map(0x0C, MINECRAFT_1_9, false));
       clientbound.register(Chat.class, Chat::new,
-          map(0x02, MINECRAFT_1_8, true),
+          map(0x02, MINECRAFT_1_7_2, true),
           map(0x0F, MINECRAFT_1_9, true),
           map(0x0E, MINECRAFT_1_13, true));
       clientbound.register(TabCompleteResponse.class, TabCompleteResponse::new,
-          map(0x3A, MINECRAFT_1_8, false),
+          map(0x3A, MINECRAFT_1_7_2, false),
           map(0x0E, MINECRAFT_1_9, false),
           map(0x10, MINECRAFT_1_13, false));
       clientbound.register(AvailableCommands.class, AvailableCommands::new,
           map(0x11, MINECRAFT_1_13, false));
       clientbound.register(PluginMessage.class, PluginMessage::new,
-          map(0x3F, MINECRAFT_1_8, false),
+          map(0x3F, MINECRAFT_1_7_2, false),
           map(0x18, MINECRAFT_1_9, false),
           map(0x19, MINECRAFT_1_13, false),
           map(0x18, MINECRAFT_1_14, false));
       clientbound.register(Disconnect.class, Disconnect::new,
-          map(0x40, MINECRAFT_1_8, false),
+          map(0x40, MINECRAFT_1_7_2, false),
           map(0x1A, MINECRAFT_1_9, false),
           map(0x1B, MINECRAFT_1_13, false),
           map(0x1A, MINECRAFT_1_14, false));
       clientbound.register(KeepAlive.class, KeepAlive::new,
-          map(0x00, MINECRAFT_1_8, false),
+          map(0x00, MINECRAFT_1_7_2, false),
           map(0x1F, MINECRAFT_1_9, false),
           map(0x21, MINECRAFT_1_13, false),
           map(0x20, MINECRAFT_1_14, false));
       clientbound.register(JoinGame.class, JoinGame::new,
-          map(0x01, MINECRAFT_1_8, false),
+          map(0x01, MINECRAFT_1_7_2, false),
           map(0x23, MINECRAFT_1_9, false),
           map(0x25, MINECRAFT_1_13, false),
           map(0x25, MINECRAFT_1_14, false));
       clientbound.register(Respawn.class, Respawn::new,
-          map(0x07, MINECRAFT_1_8, true),
+          map(0x07, MINECRAFT_1_7_2, true),
           map(0x33, MINECRAFT_1_9, true),
           map(0x34, MINECRAFT_1_12, true),
           map(0x35, MINECRAFT_1_12_1, true),
@@ -182,7 +181,7 @@ public enum StateRegistry {
           map(0x4B, MINECRAFT_1_13, true),
           map(0x4F, MINECRAFT_1_14, true));
       clientbound.register(PlayerListItem.class, PlayerListItem::new,
-          map(0x38, MINECRAFT_1_8, false),
+          map(0x38, MINECRAFT_1_7_2, false),
           map(0x2D, MINECRAFT_1_9, false),
           map(0x2E, MINECRAFT_1_12_1, false),
           map(0x30, MINECRAFT_1_13, false),
@@ -192,17 +191,17 @@ public enum StateRegistry {
   LOGIN {
     {
       serverbound.register(ServerLogin.class, ServerLogin::new,
-          map(0x00, MINECRAFT_1_8, false));
+          map(0x00, MINECRAFT_1_7_2, false));
       serverbound.register(EncryptionResponse.class, EncryptionResponse::new,
-          map(0x01, MINECRAFT_1_8, false));
+          map(0x01, MINECRAFT_1_7_2, false));
       serverbound.register(LoginPluginResponse.class, LoginPluginResponse::new,
           map(0x02, MINECRAFT_1_13, false));
       clientbound.register(Disconnect.class, Disconnect::new,
-          map(0x00, MINECRAFT_1_8, false));
+          map(0x00, MINECRAFT_1_7_2, false));
       clientbound.register(EncryptionRequest.class, EncryptionRequest::new,
-          map(0x01, MINECRAFT_1_8, false));
+          map(0x01, MINECRAFT_1_7_2, false));
       clientbound.register(ServerLoginSuccess.class, ServerLoginSuccess::new,
-          map(0x02, MINECRAFT_1_8, false));
+          map(0x02, MINECRAFT_1_7_2, false));
       clientbound.register(SetCompression.class, SetCompression::new,
           map(0x03, MINECRAFT_1_8, false));
       clientbound.register(LoginPluginMessage.class, LoginPluginMessage::new,

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/Chat.java

@@ -56,7 +56,7 @@ public class Chat implements MinecraftPacket {
   @Override
   public void decode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
     message = ProtocolUtils.readString(buf);
-    if (direction == ProtocolUtils.Direction.CLIENTBOUND) {
+    if (direction == ProtocolUtils.Direction.CLIENTBOUND && version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       type = buf.readByte();
     }
   }
@@ -67,7 +67,7 @@ public class Chat implements MinecraftPacket {
       throw new IllegalStateException("Message is not specified");
     }
     ProtocolUtils.writeString(buf, message);
-    if (direction == ProtocolUtils.Direction.CLIENTBOUND) {
+    if (direction == ProtocolUtils.Direction.CLIENTBOUND && version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       buf.writeByte(type);
     }
   }

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/ClientSettings.java

@@ -13,6 +13,7 @@ public class ClientSettings implements MinecraftPacket {
   private byte viewDistance;
   private int chatVisibility;
   private boolean chatColors;
+  private byte difficulty; // 1.7 Protocol
   private short skinParts;
   private int mainHand;
 
@@ -98,6 +99,11 @@ public class ClientSettings implements MinecraftPacket {
     this.viewDistance = buf.readByte();
     this.chatVisibility = ProtocolUtils.readVarInt(buf);
     this.chatColors = buf.readBoolean();
+
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_7_6) <= 0) {
+      this.difficulty = buf.readByte();
+    }
+
     this.skinParts = buf.readUnsignedByte();
 
     if (version.compareTo(ProtocolVersion.MINECRAFT_1_9) >= 0) {
@@ -114,6 +120,11 @@ public class ClientSettings implements MinecraftPacket {
     buf.writeByte(viewDistance);
     ProtocolUtils.writeVarInt(buf, chatVisibility);
     buf.writeBoolean(chatColors);
+
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_7_6) <= 0) {
+      buf.writeByte(difficulty);
+    }
+
     buf.writeByte(skinParts);
 
     if (version.compareTo(ProtocolVersion.MINECRAFT_1_9) >= 0) {

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/EncryptionRequest.java

@@ -42,15 +42,27 @@ public class EncryptionRequest implements MinecraftPacket {
   @Override
   public void decode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
     this.serverId = ProtocolUtils.readString(buf, 20);
+
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       publicKey = ProtocolUtils.readByteArray(buf, 256);
       verifyToken = ProtocolUtils.readByteArray(buf, 16);
+    } else {
+      publicKey = ProtocolUtils.readByteArray17(buf);
+      verifyToken = ProtocolUtils.readByteArray17(buf);
+    }
   }
 
   @Override
   public void encode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
     ProtocolUtils.writeString(buf, this.serverId);
+
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       ProtocolUtils.writeByteArray(buf, publicKey);
       ProtocolUtils.writeByteArray(buf, verifyToken);
+    } else {
+      ProtocolUtils.writeByteArray17(publicKey, buf, false);
+      ProtocolUtils.writeByteArray17(verifyToken, buf, false);
+    }
   }
 
   @Override

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/EncryptionResponse.java

@@ -40,14 +40,24 @@ public class EncryptionResponse implements MinecraftPacket {
 
   @Override
   public void decode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       this.sharedSecret = ProtocolUtils.readByteArray(buf, 256);
       this.verifyToken = ProtocolUtils.readByteArray(buf, 128);
+    } else {
+      this.sharedSecret = ProtocolUtils.readByteArray17(buf);
+      this.verifyToken = ProtocolUtils.readByteArray17(buf);
+    }
   }
 
   @Override
   public void encode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       ProtocolUtils.writeByteArray(buf, sharedSecret);
       ProtocolUtils.writeByteArray(buf, verifyToken);
+    } else {
+      ProtocolUtils.writeByteArray17(sharedSecret, buf, false);
+      ProtocolUtils.writeByteArray17(verifyToken, buf, false);
+    }
   }
 
   @Override

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/JoinGame.java

@@ -116,8 +116,10 @@ public class JoinGame implements MinecraftPacket {
     if (version.compareTo(ProtocolVersion.MINECRAFT_1_14) >= 0) {
       this.viewDistance = ProtocolUtils.readVarInt(buf);
     }
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       this.reducedDebugInfo = buf.readBoolean();
     }
+  }
 
   @Override
   public void encode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
@@ -137,10 +139,12 @@ public class JoinGame implements MinecraftPacket {
     }
     ProtocolUtils.writeString(buf, levelType);
     if (version.compareTo(ProtocolVersion.MINECRAFT_1_14) >= 0) {
-      ProtocolUtils.writeVarInt(buf,viewDistance);
+      ProtocolUtils.writeVarInt(buf, viewDistance);
     }
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       buf.writeBoolean(reducedDebugInfo);
     }
+  }
 
   @Override
   public boolean handle(MinecraftSessionHandler handler) {

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/KeepAlive.java

@@ -29,8 +29,10 @@ public class KeepAlive implements MinecraftPacket {
   public void decode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
     if (version.compareTo(ProtocolVersion.MINECRAFT_1_12_2) >= 0) {
       randomId = buf.readLong();
-    } else {
+    } else if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       randomId = ProtocolUtils.readVarInt(buf);
+    } else {
+      randomId = buf.readInt();
     }
   }
 
@@ -38,8 +40,10 @@ public class KeepAlive implements MinecraftPacket {
   public void encode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
     if (version.compareTo(ProtocolVersion.MINECRAFT_1_12_2) >= 0) {
       buf.writeLong(randomId);
-    } else {
+    } else if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       ProtocolUtils.writeVarInt(buf, (int) randomId);
+    } else {
+      buf.writeInt((int) randomId);
     }
   }
 

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/PlayerListItem.java

@@ -13,6 +13,7 @@ import java.util.List;
 import java.util.UUID;
 import net.kyori.text.Component;
 import net.kyori.text.serializer.gson.GsonComponentSerializer;
+import net.kyori.text.serializer.legacy.LegacyComponentSerializer;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public class PlayerListItem implements MinecraftPacket {
@@ -43,6 +44,7 @@ public class PlayerListItem implements MinecraftPacket {
 
   @Override
   public void decode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       action = ProtocolUtils.readVarInt(buf);
       int length = ProtocolUtils.readVarInt(buf);
 
@@ -73,6 +75,13 @@ public class PlayerListItem implements MinecraftPacket {
             throw new UnsupportedOperationException("Unknown action " + action);
         }
       }
+    } else {
+      Item item = new Item();
+      item.setName(ProtocolUtils.readString(buf));
+      action = buf.readBoolean() ? ADD_PLAYER : REMOVE_PLAYER;
+      item.setLatency(buf.readShort());
+      items.add(item);
+    }
   }
 
   private static @Nullable Component readOptionalComponent(ByteBuf buf) {
@@ -84,6 +93,7 @@ public class PlayerListItem implements MinecraftPacket {
 
   @Override
   public void encode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       ProtocolUtils.writeVarInt(buf, action);
       ProtocolUtils.writeVarInt(buf, items.size());
       for (Item item : items) {
@@ -113,6 +123,18 @@ public class PlayerListItem implements MinecraftPacket {
             throw new UnsupportedOperationException("Unknown action " + action);
         }
       }
+    } else {
+      Item item = items.get(0);
+      if (item.getDisplayName() != null) {
+        String displayName = LegacyComponentSerializer.legacy().serialize(item.getDisplayName());
+        ProtocolUtils.writeString(buf,
+            displayName.length() > 16 ? displayName.substring(0, 16) : displayName);
+      } else {
+        ProtocolUtils.writeString(buf, item.getName());
+      }
+      buf.writeBoolean(action != REMOVE_PLAYER);
+      buf.writeShort(item.getLatency());
+    }
   }
 
   @Override
@@ -136,6 +158,10 @@ public class PlayerListItem implements MinecraftPacket {
     private int latency;
     private @Nullable Component displayName;
 
+    public Item() {
+      uuid = null;
+    }
+
     public Item(UUID uuid) {
       this.uuid = uuid;
     }
@@ -149,7 +175,7 @@ public class PlayerListItem implements MinecraftPacket {
           .setDisplayName(entry.getDisplayName().orElse(null));
     }
 
-    public UUID getUuid() {
+    public @Nullable UUID getUuid() {
       return uuid;
     }
 

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/PluginMessage.java

@@ -50,7 +50,12 @@ public class PluginMessage extends DeferredByteBufHolder implements MinecraftPac
     if (version.compareTo(ProtocolVersion.MINECRAFT_1_13) >= 0) {
       this.channel = transformLegacyToModernChannel(this.channel);
     }
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       this.replace(buf.readRetainedSlice(buf.readableBytes()));
+    } else {
+      this.replace(ProtocolUtils.readRetainedByteBufSlice17(buf));
+    }
+
   }
 
   @Override
@@ -63,7 +68,12 @@ public class PluginMessage extends DeferredByteBufHolder implements MinecraftPac
     } else {
       ProtocolUtils.writeString(buf, this.channel);
     }
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       buf.writeBytes(content());
+    } else {
+      ProtocolUtils.writeByteBuf17(content(), buf, true); // True for Forge support
+    }
+
   }
 
   @Override

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/ServerLoginSuccess.java

@@ -1,6 +1,7 @@
 package com.velocitypowered.proxy.protocol.packet;
 
 import com.velocitypowered.api.network.ProtocolVersion;
+import com.velocitypowered.api.util.UuidUtils;
 import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
 import com.velocitypowered.proxy.protocol.MinecraftPacket;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
@@ -45,7 +46,11 @@ public class ServerLoginSuccess implements MinecraftPacket {
 
   @Override
   public void decode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
+    if (version.compareTo(ProtocolVersion.MINECRAFT_1_7_6) >= 0) {
       uuid = UUID.fromString(ProtocolUtils.readString(buf, 36));
+    } else {
+      uuid = UuidUtils.fromUndashed(ProtocolUtils.readString(buf, 32));
+    }
     username = ProtocolUtils.readString(buf, 16);
   }
 

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/TabCompleteRequest.java

@@ -1,6 +1,7 @@
 package com.velocitypowered.proxy.protocol.packet;
 
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_13;
+import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_8;
 import static com.velocitypowered.api.network.ProtocolVersion.MINECRAFT_1_9;
 
 import com.google.common.base.MoreObjects;
@@ -83,12 +84,14 @@ public class TabCompleteRequest implements MinecraftPacket {
       if (version.compareTo(MINECRAFT_1_9) >= 0) {
         this.assumeCommand = buf.readBoolean();
       }
+      if (version.compareTo(MINECRAFT_1_8) >= 0) {
         this.hasPosition = buf.readBoolean();
         if (hasPosition) {
           this.position = buf.readLong();
         }
       }
     }
+  }
 
   @Override
   public void encode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
@@ -104,12 +107,14 @@ public class TabCompleteRequest implements MinecraftPacket {
       if (version.compareTo(MINECRAFT_1_9) >= 0) {
         buf.writeBoolean(assumeCommand);
       }
+      if (version.compareTo(MINECRAFT_1_8) >= 0) {
         buf.writeBoolean(hasPosition);
         if (hasPosition) {
           buf.writeLong(position);
         }
       }
     }
+  }
 
   @Override
   public boolean handle(MinecraftSessionHandler handler) {

proxy/src/main/java/com/velocitypowered/proxy/protocol/util/PluginMessageUtil.java

@@ -11,9 +11,7 @@ import com.velocitypowered.proxy.protocol.ProtocolUtils;
 import com.velocitypowered.proxy.protocol.packet.PluginMessage;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
-import io.netty.util.ByteProcessor;
 import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Locale;
@@ -127,7 +125,8 @@ public class PluginMessageUtil {
    * @param version the proxy version
    * @return the rewritten plugin message
    */
-  public static PluginMessage rewriteMinecraftBrand(PluginMessage message, ProxyVersion version) {
+  public static PluginMessage rewriteMinecraftBrand(PluginMessage message, ProxyVersion version,
+      ProtocolVersion protocolVersion) {
     checkNotNull(message, "message");
     checkNotNull(version, "version");
     checkArgument(isMcBrand(message), "message is not a brand plugin message");
@@ -135,8 +134,14 @@ public class PluginMessageUtil {
     String toAppend = " (" + version.getName() + ")";
 
     ByteBuf rewrittenBuf = Unpooled.buffer();
+
+    if (protocolVersion.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
       String currentBrand = ProtocolUtils.readString(message.content().slice());
       ProtocolUtils.writeString(rewrittenBuf, currentBrand + toAppend);
+    } else {
+      String currentBrand = ProtocolUtils.readStringWithoutLength(message.content().slice());
+      rewrittenBuf.writeBytes((currentBrand + toAppend).getBytes());
+    }
 
     return new PluginMessage(message.getChannel(), rewrittenBuf);
   }

proxy/src/main/java/com/velocitypowered/proxy/tablist/VelocityTabList.java

@@ -7,6 +7,7 @@ import com.velocitypowered.api.util.GameProfile;
 import com.velocitypowered.proxy.connection.MinecraftConnection;
 import com.velocitypowered.proxy.protocol.packet.HeaderAndFooter;
 import com.velocitypowered.proxy.protocol.packet.PlayerListItem;
+import com.velocitypowered.proxy.protocol.packet.PlayerListItem.Item;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -20,8 +21,8 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 
 public class VelocityTabList implements TabList {
 
-  private final MinecraftConnection connection;
+  protected final MinecraftConnection connection;
-  private final Map<UUID, VelocityTabListEntry> entries = new ConcurrentHashMap<>();
+  protected final Map<UUID, VelocityTabListEntry> entries = new ConcurrentHashMap<>();
 
   public VelocityTabList(MinecraftConnection connection) {
     this.connection = connection;
@@ -76,9 +77,9 @@ public class VelocityTabList implements TabList {
   }
 
   /**
-   * Clears all entries from the tab list. Note that the entries are written with
+   * Clears all entries from the tab list. Note that the entries are written with {@link
-   * {@link MinecraftConnection#delayedWrite(Object)}, so make sure to do an explicit
+   * MinecraftConnection#delayedWrite(Object)}, so make sure to do an explicit {@link
-   * {@link MinecraftConnection#flush()}.
+   * MinecraftConnection#flush()}.
    */
   public void clearAll() {
     List<PlayerListItem.Item> items = new ArrayList<>();
@@ -86,8 +87,10 @@ public class VelocityTabList implements TabList {
       items.add(PlayerListItem.Item.from(value));
     }
     entries.clear();
+    if (!items.isEmpty()) {
       connection.delayedWrite(new PlayerListItem(PlayerListItem.REMOVE_PLAYER, items));
     }
+  }
 
   @Override
   public Collection<TabListEntry> getEntries() {
@@ -102,12 +105,14 @@ public class VelocityTabList implements TabList {
 
   /**
    * Processes a tab list entry packet from the backend.
+   *
    * @param packet the packet to process
    */
   public void processBackendPacket(PlayerListItem packet) {
     // Packets are already forwarded on, so no need to do that here
     for (PlayerListItem.Item item : packet.getItems()) {
       UUID uuid = item.getUuid();
+
       if (packet.getAction() != PlayerListItem.ADD_PLAYER && !entries.containsKey(uuid)) {
         // Sometimes UPDATE_GAMEMODE is sent before ADD_PLAYER so don't want to warn here
         continue;

proxy/src/main/java/com/velocitypowered/proxy/tablist/VelocityTabListEntryLegacy.java

@@ -0,0 +1,20 @@
+package com.velocitypowered.proxy.tablist;
+
+import com.velocitypowered.api.proxy.player.TabListEntry;
+import com.velocitypowered.api.util.GameProfile;
+import net.kyori.text.Component;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public class VelocityTabListEntryLegacy extends VelocityTabListEntry {
+
+  VelocityTabListEntryLegacy(VelocityTabListLegacy tabList, GameProfile profile,
+      @Nullable Component displayName, int latency, int gameMode) {
+    super(tabList, profile, displayName, latency, gameMode);
+  }
+
+  @Override
+  public TabListEntry setDisplayName(@Nullable Component displayName) {
+    getTabList().removeEntry(getProfile().getId()); // We have to remove first if updating
+    return super.setDisplayName(displayName);
+  }
+}

proxy/src/main/java/com/velocitypowered/proxy/tablist/VelocityTabListLegacy.java

@@ -0,0 +1,118 @@
+package com.velocitypowered.proxy.tablist;
+
+import com.google.common.collect.ImmutableList;
+import com.velocitypowered.api.proxy.player.TabListEntry;
+import com.velocitypowered.api.util.GameProfile;
+import com.velocitypowered.proxy.connection.MinecraftConnection;
+import com.velocitypowered.proxy.protocol.packet.PlayerListItem;
+import com.velocitypowered.proxy.protocol.packet.PlayerListItem.Item;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import net.kyori.text.Component;
+import net.kyori.text.serializer.legacy.LegacyComponentSerializer;
+import net.kyori.text.serializer.plain.PlainComponentSerializer;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public class VelocityTabListLegacy extends VelocityTabList {
+
+  private final Map<String, UUID> nameMapping = new ConcurrentHashMap<>();
+
+  public VelocityTabListLegacy(MinecraftConnection connection) {
+    super(connection);
+  }
+
+  @Override
+  public void setHeaderAndFooter(Component header, Component footer) {
+  }
+
+  @Override
+  public void clearHeaderAndFooter() {
+  }
+
+  @Override
+  public void addEntry(TabListEntry entry) {
+    super.addEntry(entry);
+    nameMapping.put(entry.getProfile().getName(), entry.getProfile().getId());
+  }
+
+  @Override
+  public Optional<TabListEntry> removeEntry(UUID uuid) {
+    Optional<TabListEntry> entry = super.removeEntry(uuid);
+    entry.map(TabListEntry::getProfile).map(GameProfile::getName).ifPresent(nameMapping::remove);
+    return entry;
+  }
+
+  @Override
+  public void clearAll() {
+    for (TabListEntry value : entries.values()) {
+      connection.delayedWrite(new PlayerListItem(PlayerListItem.REMOVE_PLAYER,
+          Collections.singletonList(PlayerListItem.Item.from(value))));
+    }
+    entries.clear();
+  }
+
+  @Override
+  public void processBackendPacket(PlayerListItem packet) {
+
+    Item item = packet.getItems().get(0); // Only one item per packet in 1.7
+
+    Component displayName = LegacyComponentSerializer.legacy().deserialize(item.getName());
+    String strippedName = PlainComponentSerializer.INSTANCE.serialize(displayName);
+
+    switch (packet.getAction()) {
+      case PlayerListItem.ADD_PLAYER:
+        if (nameMapping.containsKey(strippedName)) { // ADD_PLAYER also used for updating ping
+          VelocityTabListEntry entry = entries.get(nameMapping.get(strippedName));
+          if (entry != null) {
+            entry.setLatency(item.getLatency());
+          }
+        } else {
+          UUID uuid = UUID.randomUUID(); // Use a fake uuid to preserve function of custom entries
+          nameMapping.put(strippedName, uuid);
+          entries.put(uuid, (VelocityTabListEntry) TabListEntry.builder()
+              .tabList(this)
+              .profile(new GameProfile(uuid, strippedName, ImmutableList.of()))
+              .displayName(displayName)
+              .latency(item.getLatency())
+              .build());
+        }
+        break;
+      case PlayerListItem.REMOVE_PLAYER:
+        UUID removedUuid = nameMapping.remove(strippedName);
+        if (removedUuid != null) {
+          entries.remove(removedUuid);
+        }
+        break;
+      default:
+        // For 1.7 there is only add and remove
+        break;
+    }
+
+  }
+
+  @Override
+  void updateEntry(int action, TabListEntry entry) {
+    if (entries.containsKey(entry.getProfile().getId())) {
+      switch (action) {
+        case PlayerListItem.UPDATE_LATENCY:
+        case PlayerListItem.UPDATE_DISPLAY_NAME: // Add here because we removed beforehand
+          connection
+              .write(new PlayerListItem(PlayerListItem.ADD_PLAYER, // ADD_PLAYER also updates ping
+                  Collections.singletonList(PlayerListItem.Item.from(entry))));
+          break;
+        default:
+          // Can't do anything else
+          break;
+      }
+    }
+  }
+
+  @Override
+  public TabListEntry buildEntry(GameProfile profile, @Nullable Component displayName, int latency,
+      int gameMode) {
+    return new VelocityTabListEntryLegacy(this, profile, displayName, latency, gameMode);
+  }
+}