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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you 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:
 *
 *   https://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 io.netty.handler.proxy;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.socksx.v4.DefaultSocks4CommandRequest;
import io.netty.handler.codec.socksx.v4.Socks4ClientDecoder;
import io.netty.handler.codec.socksx.v4.Socks4ClientEncoder;
import io.netty.handler.codec.socksx.v4.Socks4CommandResponse;
import io.netty.handler.codec.socksx.v4.Socks4CommandStatus;
import io.netty.handler.codec.socksx.v4.Socks4CommandType;

import java.net.InetSocketAddress;
import java.net.SocketAddress;

/**
 * Handler that establishes a blind forwarding proxy tunnel using
 * SOCKS4 protocol.
 */
public final class Socks4ProxyHandler extends ProxyHandler {

    private static final String PROTOCOL = "socks4";
    private static final String AUTH_USERNAME = "username";

    private final String username;

    private String decoderName;
    private String encoderName;

    public Socks4ProxyHandler(SocketAddress proxyAddress) {
        this(proxyAddress, null);
    }

    public Socks4ProxyHandler(SocketAddress proxyAddress, String username) {
        super(proxyAddress);
        if (username != null && username.isEmpty()) {
            username = null;
        }
        this.username = username;
    }

    @Override
    public String protocol() {
        return PROTOCOL;
    }

    @Override
    public String authScheme() {
        return username != null? AUTH_USERNAME : AUTH_NONE;
    }

    public String username() {
        return username;
    }

    @Override
    protected void addCodec(ChannelHandlerContext ctx) throws Exception {
        ChannelPipeline p = ctx.pipeline();
        String name = ctx.name();

        Socks4ClientDecoder decoder = new Socks4ClientDecoder();
        p.addBefore(name, null, decoder);

        decoderName = p.context(decoder).name();
        encoderName = decoderName + ".encoder";

        p.addBefore(name, encoderName, Socks4ClientEncoder.INSTANCE);
    }

    @Override
    protected void removeEncoder(ChannelHandlerContext ctx) throws Exception {
        ChannelPipeline p = ctx.pipeline();
        p.remove(encoderName);
    }

    @Override
    protected void removeDecoder(ChannelHandlerContext ctx) throws Exception {
        ChannelPipeline p = ctx.pipeline();
        p.remove(decoderName);
    }

    @Override
    protected Object newInitialMessage(ChannelHandlerContext ctx) throws Exception {
        InetSocketAddress raddr = destinationAddress();
        String rhost;
        if (raddr.isUnresolved()) {
            rhost = raddr.getHostString();
        } else {
            rhost = raddr.getAddress().getHostAddress();
        }
        return new DefaultSocks4CommandRequest(
                Socks4CommandType.CONNECT, rhost, raddr.getPort(), username != null? username : "");
    }

    @Override
    protected boolean handleResponse(ChannelHandlerContext ctx, Object response) throws Exception {
        final Socks4CommandResponse res = (Socks4CommandResponse) response;
        final Socks4CommandStatus status = res.status();
        if (status == Socks4CommandStatus.SUCCESS) {
            return true;
        }

        throw new ProxyConnectException(exceptionMessage("status: " + status));
    }
}