ViaVersion/bukkit/src/main/java/com/viaversion/viaversion/bukkit/compat/ProtocolSupportConnectionLi...

88 lines
4.6 KiB
Java

/*
* This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
* Copyright (C) 2016-2024 ViaVersion and contributors
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.viaversion.viaversion.bukkit.compat;
import com.viaversion.viaversion.api.Via;
import com.viaversion.viaversion.bukkit.util.NMSUtil;
import java.lang.reflect.Method;
import protocolsupport.api.Connection;
final class ProtocolSupportConnectionListener extends Connection.PacketListener {
static final Method ADD_PACKET_LISTENER_METHOD;
private static final Class<?> HANDSHAKE_PACKET_CLASS;
private static final Method GET_VERSION_METHOD;
private static final Method SET_VERSION_METHOD;
private static final Method REMOVE_PACKET_LISTENER_METHOD;
private static final Method GET_LATEST_METHOD;
private static final Object PROTOCOL_VERSION_MINECRAFT_FUTURE;
private static final Object PROTOCOL_TYPE_PC;
static {
try {
HANDSHAKE_PACKET_CLASS = NMSUtil.nms(
"PacketHandshakingInSetProtocol",
"net.minecraft.network.protocol.handshake.PacketHandshakingInSetProtocol"
);
final Class<?> connectionImplClass = Class.forName("protocolsupport.protocol.ConnectionImpl");
final Class<?> connectionClass = Class.forName("protocolsupport.api.Connection");
final Class<?> packetListenerClass = Class.forName("protocolsupport.api.Connection$PacketListener");
final Class<?> protocolVersionClass = Class.forName("protocolsupport.api.ProtocolVersion");
final Class<?> protocolTypeClass = Class.forName("protocolsupport.api.ProtocolType");
GET_VERSION_METHOD = connectionClass.getDeclaredMethod("getVersion");
SET_VERSION_METHOD = connectionImplClass.getDeclaredMethod("setVersion", protocolVersionClass);
PROTOCOL_VERSION_MINECRAFT_FUTURE = protocolVersionClass.getDeclaredField("MINECRAFT_FUTURE").get(null);
GET_LATEST_METHOD = protocolVersionClass.getDeclaredMethod("getLatest", protocolTypeClass);
PROTOCOL_TYPE_PC = protocolTypeClass.getDeclaredField("PC").get(null);
ADD_PACKET_LISTENER_METHOD = connectionClass.getDeclaredMethod("addPacketListener", packetListenerClass);
REMOVE_PACKET_LISTENER_METHOD = connectionClass.getDeclaredMethod("removePacketListener", packetListenerClass);
} catch (final ReflectiveOperationException e) {
throw new RuntimeException(e);
}
}
private final Object connection;
ProtocolSupportConnectionListener(final Object connection) {
this.connection = connection;
}
@Override
public void onPacketReceiving(final Connection.PacketListener.PacketEvent event) {
try {
// Check if we are getting handshake packet.
if (HANDSHAKE_PACKET_CLASS.isInstance(event.getPacket()) && GET_VERSION_METHOD.invoke(connection) == PROTOCOL_VERSION_MINECRAFT_FUTURE) {
final Object packet = event.getPacket();
final int protocolVersion = (int) HANDSHAKE_PACKET_CLASS.getDeclaredMethod(ProtocolSupportCompat.handshakeVersionMethod().methodName()).invoke(packet);
// ViaVersion has at this point already spoofed the connectionversion. (Since it is higher up the pipeline)
// If via has put the protoVersion to the server we can spoof ProtocolSupport's version.
if (protocolVersion == Via.getAPI().getServerVersion().lowestSupportedVersion()) {
SET_VERSION_METHOD.invoke(connection, GET_LATEST_METHOD.invoke(null, PROTOCOL_TYPE_PC));
}
}
// Id version is not serverversion viaversion will not spoof. ProtocolSupport will handle the rest.
// In any case, remove the packet listener and wrap up.
REMOVE_PACKET_LISTENER_METHOD.invoke(connection, this);
} catch (final ReflectiveOperationException e) {
throw new RuntimeException(e);
}
}
}