org.beaconmc.network.socket.pipeline.PacketLegacy.java Source code

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Here is the source code for org.beaconmc.network.socket.pipeline.PacketLegacy.java

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/**   
 * Beacon - Open Source Minecraft Server
 * Copyright (C) 2014  Jan Delius
 * Copyright (C) 2014  Blazecube
 *
 * 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/>.
 */

/**
 * @author Jan Delius
 */
package org.beaconmc.network.socket.pipeline;

import com.google.common.base.Charsets;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import org.beaconmc.BeaconServer;
import org.beaconmc.chat.ChatColor;
import org.beaconmc.events.EventFactory;
import org.beaconmc.events.server.AsyncServerPingEvent;

public class PacketLegacy extends SimpleChannelInboundHandler<ByteBuf> {

    private BeaconServer server;

    public PacketLegacy(BeaconServer server) {
        this.server = server;
    }

    @Override
    protected void messageReceived(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf) throws Exception {

        byteBuf.markReaderIndex();
        boolean repliedPing = true;

        try {
            short packetId = byteBuf.readUnsignedByte();
            if (packetId == 254) {
                int length = byteBuf.readableBytes();
                AsyncServerPingEvent asyncServerPingEvent = EventFactory
                        .callAsyncServerPingEvent(this.server.createServerPing());
                if (asyncServerPingEvent.getPing() != null) {
                    switch (length) {
                    case 0:
                        this.sendPingAndClose(channelHandlerContext,
                                this.toArray(String.format("%s%d%d",
                                        asyncServerPingEvent.getPing().getDescription().getText(),
                                        asyncServerPingEvent.getPing().getPlayers().getOnline(),
                                        asyncServerPingEvent.getPing().getPlayers().getMax())));
                        break;
                    case 1:
                        if (byteBuf.readUnsignedByte() != 1) {
                            return;
                        }
                        this.sendPingAndClose(channelHandlerContext,
                                this.toArray(String.format("1\0%d\0%s\0%s\0%d\0%d", 127,
                                        asyncServerPingEvent.getPing().getVersion().getName(),
                                        asyncServerPingEvent.getPing().getDescription().getText(),
                                        asyncServerPingEvent.getPing().getPlayers().getOnline(),
                                        asyncServerPingEvent.getPing().getPlayers().getMax())));
                        break;
                    default:
                        boolean checkFlag = byteBuf.readUnsignedByte() == 1;
                        checkFlag &= byteBuf.readUnsignedByte() == 250;
                        checkFlag &= "MC|PingHost".equals(
                                new String(byteBuf.readBytes(byteBuf.readShort() * 2).array(), Charsets.UTF_16));

                        int checkShort = byteBuf.readShort();

                        checkFlag &= byteBuf.readUnsignedByte() >= 73;
                        checkFlag &= 3 + byteBuf.readBytes(byteBuf.readShort() * 2).array().length
                                + 4 == checkShort;
                        checkFlag &= byteBuf.readInt() <= '\uffff';
                        checkFlag &= byteBuf.readableBytes() == 0;

                        if (!checkFlag) {
                            return;
                        }

                        this.sendPingAndClose(channelHandlerContext,
                                this.toArray(String.format("1\0%d\0%s\0%s\0%d\0%d", 127,
                                        asyncServerPingEvent.getPing().getVersion().getName(),
                                        asyncServerPingEvent.getPing().getDescription().getText(),
                                        asyncServerPingEvent.getPing().getPlayers().getOnline(),
                                        asyncServerPingEvent.getPing().getPlayers().getMax())));
                        break;
                    }
                } else {
                    this.close(channelHandlerContext);
                }
                repliedPing = false;
            } else if (packetId == 0x02 && byteBuf.isReadable()) {
                this.sendPingAndClose(channelHandlerContext, this.toArray(ChatColor.RED + "Outdated Client"));
                repliedPing = false;
            }
        } catch (Exception e) {
            return;
        } finally {
            if (repliedPing) {
                byteBuf.resetReaderIndex();
                channelHandlerContext.channel().pipeline().remove("legacy_ping");
                channelHandlerContext.fireChannelRead(byteBuf.retain());
            }
        }
    }

    private void close(ChannelHandlerContext channelHandlerContext) {
        channelHandlerContext.pipeline().close();
    }

    private void sendPingAndClose(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf) {
        channelHandlerContext.pipeline().firstContext().writeAndFlush(byteBuf)
                .addListeners(ChannelFutureListener.CLOSE);
    }

    private ByteBuf toArray(String pingstring) {
        ByteBuf byteBuf = Unpooled.buffer();
        byteBuf.writeByte(255);
        char[] chars = pingstring.toCharArray();
        byteBuf.writeShort(chars.length);
        for (char charpart : chars) {
            byteBuf.writeChar(charpart);
        }
        return byteBuf;
    }
}