DefaultDnsRecordDecoder.java — netty Source File

Source Code

/*
 * 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.dns;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.handler.codec.CorruptedFrameException;

/**
 * The default {@link DnsRecordDecoder} implementation.
 *
 * @see DefaultDnsRecordEncoder
 */
public class DefaultDnsRecordDecoder implements DnsRecordDecoder {

    static final String ROOT = ".";

    /**
     * Creates a new instance.
     */
    protected DefaultDnsRecordDecoder() { }

    @Override
    public final DnsQuestion decodeQuestion(ByteBuf in) throws Exception {
        String name = decodeName(in);
        DnsRecordType type = DnsRecordType.valueOf(in.readUnsignedShort());
        int qClass = in.readUnsignedShort();
        return new DefaultDnsQuestion(name, type, qClass);
    }

    @Override
    public final <T extends DnsRecord> T decodeRecord(ByteBuf in) throws Exception {
        final int startOffset = in.readerIndex();
        final String name = decodeName(in);

        final int endOffset = in.writerIndex();
        if (endOffset - in.readerIndex() < 10) {
            // Not enough data
            in.readerIndex(startOffset);
            return null;
        }

        final DnsRecordType type = DnsRecordType.valueOf(in.readUnsignedShort());
        final int aClass = in.readUnsignedShort();
        final long ttl = in.readUnsignedInt();
        final int length = in.readUnsignedShort();
        final int offset = in.readerIndex();
// ... (96 more lines)