io.netty.handler.codec.dns.TcpDnsResponseDecoder Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of wildfly-client-all

This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and Jakarta Messaging 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).

There is a newer version: 35.0.0.Final

Show newest version

/*
 * Copyright 2019 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:
 *
 *   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 io.netty.handler.codec.dns;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
import io.netty.util.internal.UnstableApi;

import java.net.SocketAddress;

@UnstableApi
public final class TcpDnsResponseDecoder extends LengthFieldBasedFrameDecoder {

    private final DnsResponseDecoder responseDecoder;

    /**
     * Creates a new decoder with {@linkplain DnsRecordDecoder#DEFAULT the default record decoder}.
     */
    public TcpDnsResponseDecoder() {
        this(DnsRecordDecoder.DEFAULT, 64 * 1024);
    }

    /**
     * Creates a new decoder with the specified {@code recordDecoder} and {@code maxFrameLength}
     */
    public TcpDnsResponseDecoder(DnsRecordDecoder recordDecoder, int maxFrameLength) {
        // Length is two octets as defined by RFC-7766
        // See https://tools.ietf.org/html/rfc7766#section-8
        super(maxFrameLength, 0, 2, 0, 2);

        this.responseDecoder = new DnsResponseDecoder(recordDecoder) {
            @Override
            protected DnsResponse newResponse(SocketAddress sender, SocketAddress recipient,
                                              int id, DnsOpCode opCode, DnsResponseCode responseCode) {
                return new DefaultDnsResponse(id, opCode, responseCode);
            }
        };
    }

    @Override
    protected Object decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
        ByteBuf frame = (ByteBuf) super.decode(ctx, in);
        if (frame == null) {
            return null;
        }

        try {
            return responseDecoder.decode(ctx.channel().remoteAddress(), ctx.channel().localAddress(), frame.slice());
        } finally {
            frame.release();
        }
    }

    @Override
    protected ByteBuf extractFrame(ChannelHandlerContext ctx, ByteBuf buffer, int index, int length) {
        return buffer.copy(index, length);
    }
}