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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 2015 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.codec.socksx;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.ByteToMessageDecoder;
import io.netty.handler.codec.socksx.v4.Socks4ServerDecoder;
import io.netty.handler.codec.socksx.v4.Socks4ServerEncoder;
import io.netty.handler.codec.socksx.v5.Socks5AddressEncoder;
import io.netty.handler.codec.socksx.v5.Socks5InitialRequestDecoder;
import io.netty.handler.codec.socksx.v5.Socks5ServerEncoder;
import io.netty.util.internal.ObjectUtil;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;

import java.util.List;

/**
 * Detects the version of the current SOCKS connection and initializes the pipeline with
 * {@link Socks4ServerDecoder} or {@link Socks5InitialRequestDecoder}.
 */
public class SocksPortUnificationServerHandler extends ByteToMessageDecoder {

    private static final InternalLogger logger =
            InternalLoggerFactory.getInstance(SocksPortUnificationServerHandler.class);

    private final Socks5ServerEncoder socks5encoder;

    /**
     * Creates a new instance with the default configuration.
     */
    public SocksPortUnificationServerHandler() {
        this(Socks5ServerEncoder.DEFAULT);
    }

    /**
     * Creates a new instance with the specified {@link Socks5ServerEncoder}.
     * This constructor is useful when a user wants to use an alternative {@link Socks5AddressEncoder}.
     */
    public SocksPortUnificationServerHandler(Socks5ServerEncoder socks5encoder) {
        this.socks5encoder = ObjectUtil.checkNotNull(socks5encoder, "socks5encoder");
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List out) throws Exception {
        final int readerIndex = in.readerIndex();
        if (in.writerIndex() == readerIndex) {
            return;
        }

        ChannelPipeline p = ctx.pipeline();
        final byte versionVal = in.getByte(readerIndex);
        SocksVersion version = SocksVersion.valueOf(versionVal);

        switch (version) {
        case SOCKS4a:
            logKnownVersion(ctx, version);
            p.addAfter(ctx.name(), null, Socks4ServerEncoder.INSTANCE);
            p.addAfter(ctx.name(), null, new Socks4ServerDecoder());
            break;
        case SOCKS5:
            logKnownVersion(ctx, version);
            p.addAfter(ctx.name(), null, socks5encoder);
            p.addAfter(ctx.name(), null, new Socks5InitialRequestDecoder());
            break;
        default:
            logUnknownVersion(ctx, versionVal);
            in.skipBytes(in.readableBytes());
            ctx.close();
            return;
        }

        p.remove(this);
    }

    private static void logKnownVersion(ChannelHandlerContext ctx, SocksVersion version) {
        logger.debug("{} Protocol version: {}({})", ctx.channel(), version);
    }

    private static void logUnknownVersion(ChannelHandlerContext ctx, byte versionVal) {
        if (logger.isDebugEnabled()) {
            logger.debug("{} Unknown protocol version: {}", ctx.channel(), versionVal & 0xFF);
        }
    }
}