com.whirvis.jraknet.discovery.DiscoveryHandler.java Source code

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Here is the source code for com.whirvis.jraknet.discovery.DiscoveryHandler.java

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/*
 *    __     ______     ______     __  __     __   __     ______     ______  
 *   /\ \   /\  == \   /\  __ \   /\ \/ /    /\ "-.\ \   /\  ___\   /\__  _\
 *  _\_\ \  \ \  __<   \ \  __ \  \ \  _"-.  \ \ \-.  \  \ \  __\   \/_/\ \/  
 * /\_____\  \ \_\ \_\  \ \_\ \_\  \ \_\ \_\  \ \_\\"\_\  \ \_____\    \ \_\ 
 * \/_____/   \/_/ /_/   \/_/\/_/   \/_/\/_/   \/_/ \/_/   \/_____/     \/_/                                                                          
 *
 * the MIT License (MIT)
 *
 * Copyright (c) 2016-2019 Trent "Whirvis" Summerlin
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * the above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package com.whirvis.jraknet.discovery;

import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.util.ArrayList;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import com.whirvis.jraknet.RakNetPacket;
import com.whirvis.jraknet.protocol.status.UnconnectedPong;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.socket.DatagramPacket;

/**
 * Used by the {@link Discovery} system with the sole purpose of sending
 * received packets to the discovery system so they can be handled. If any
 * errors occur while handling a packet, it will be ignored.
 *
 * @author Trent "Whirvis" Summerlin
 * @since JRakNet v2.11.0
 */
public final class DiscoveryHandler extends ChannelInboundHandlerAdapter {

    private Logger log;
    private final ArrayList<InetAddress> blocked;
    private InetSocketAddress causeAddress;

    /**
     * Creates a discovery system Netty handler.
     */
    protected DiscoveryHandler() {
        this.log = LogManager.getLogger(DiscoveryHandler.class);
        this.blocked = new ArrayList<InetAddress>();
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        if (msg instanceof DatagramPacket) {
            // Get packet and sender data
            DatagramPacket datagram = (DatagramPacket) msg;
            InetSocketAddress sender = datagram.sender();
            RakNetPacket packet = new RakNetPacket(datagram);

            // If an exception happens it's because of this address
            this.causeAddress = sender;

            // Check if the address is blocked
            if (blocked.contains(sender.getAddress())) {
                return; // Address blocked
            }

            // Handle the packet and release the buffer
            if (packet.getId() == RakNetPacket.ID_UNCONNECTED_PONG) {
                UnconnectedPong pong = new UnconnectedPong(packet);
                pong.decode();
                if (!pong.failed()) {
                    Discovery.updateDiscoveryData(sender, pong);
                    log.debug("Sent unconnected pong to discovery system");
                }
            }
            datagram.content().release(); // No longer needed

            // No exceptions occurred, release the suspect
            this.causeAddress = null;
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        if (!blocked.contains(causeAddress.getAddress())) {
            blocked.add(causeAddress.getAddress());
            log.warn("Blocked address " + causeAddress.getAddress() + " that caused "
                    + cause.getClass().getSimpleName()
                    + " to be thrown, discovering servers from it will no longer be possible");
        } else {
            log.error("Blocked address still cause exception to be thrown", cause);
        }
    }

}