Socks4HandshakeHandler.java

/*
 * Copyright (C) 2012-2016 Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.facebook.nifty.client.socks;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelHandler;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;

/**
 * This handshake handler swap out the channel pipeline with the delegate
 * upon handshake completion.
 */
public class Socks4HandshakeHandler extends SimpleChannelHandler
{
    private final SettableChannelFuture channelFuture = new SettableChannelFuture();
    private final ChannelPipelineFactory delegate;

    public Socks4HandshakeHandler(ChannelPipelineFactory delegate)
    {
        this.delegate = delegate;
    }

    public SettableChannelFuture getChannelFuture()
    {
        return channelFuture;
    }

    @Override
    public void messageReceived(ChannelHandlerContext ctx, MessageEvent e)
            throws Exception
    {
        channelFuture.setChannel(ctx.getChannel());
        if (e.getMessage() instanceof ChannelBuffer) {
            ChannelBuffer msg = (ChannelBuffer) e.getMessage();
            if (msg.readableBytes() < 8) {
                channelFuture.setFailure(new IOException("invalid sock server reply length = " + msg.readableBytes()));
            }
            // ignore
            msg.readByte();
            int status = msg.readByte();
            int port = msg.readShort();
            byte[] addr = new byte[4];
            msg.readBytes(addr);

            ctx.getChannel().setAttachment(new InetSocketAddress(InetAddress.getByAddress(addr), port));

            if (status == SocksProtocols.REQUEST_GRANTED) {
                ctx.getPipeline().remove(Socks4ClientBootstrap.FRAME_DECODER);
                ctx.getPipeline().remove(Socks4ClientBootstrap.HANDSHAKE);
                ChannelPipeline delegatePipeline = delegate.getPipeline();
                for (String name : delegatePipeline.getNames()) {
                    ctx.getPipeline().addLast(name, delegatePipeline.get(name));
                }
                channelFuture.setSuccess();
            }
            else {
                channelFuture.setFailure(new IOException("sock server reply failure code :" + Integer.toHexString(status)));
            }
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e)
            throws Exception
    {
        channelFuture.setChannel(ctx.getChannel());
        channelFuture.setFailure(e.getCause());
    }
}