org.anarres.dhcp.v6.io.Dhcp6MessageEncoder Maven / Gradle / Ivy

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A high-performance pure Java DHCP server.

There is a newer version: 1.0.9

/*
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 * and open the template in the editor.
 */
package org.anarres.dhcp.v6.io;

import com.google.common.primitives.Shorts;
import java.nio.ByteBuffer;
import javax.annotation.Nonnull;
import org.anarres.dhcp.v6.messages.Dhcp6Message;
import org.anarres.dhcp.v6.options.Dhcp6Option;
import org.anarres.dhcp.v6.options.Dhcp6Options;

/**
 * http://tools.ietf.org/html/rfc3315#section-22.1
 *
 * @author shevek
 */
public class Dhcp6MessageEncoder {

    private static class Inner {

        private static final Dhcp6MessageEncoder INSTANCE = new Dhcp6MessageEncoder();
    }

    @Nonnull
    public static Dhcp6MessageEncoder getInstance() {
        return Inner.INSTANCE;
    }

    public void encode(ByteBuffer byteBuffer, Dhcp6Message message) {
        byteBuffer.put(message.getMessageType().getCode());
        int transactionId = message.getTransactionId();
        byteBuffer.put((byte) ((transactionId >> 16) & 0xFF));
        byteBuffer.put((byte) ((transactionId >> 8) & 0xFF));
        byteBuffer.put((byte) (transactionId & 0xFF));
        encode(byteBuffer, message.getOptions());
    }

    public void encode(@Nonnull ByteBuffer byteBuffer, @Nonnull Dhcp6Options options) {
        for (Dhcp6Option option : options) {
            // Option continuation per RFC3396
            short tag = option.getTag();
            byte[] data = option.getData();
            byteBuffer.putShort(tag);
            byteBuffer.putShort(Shorts.checkedCast(data.length));
            byteBuffer.put(data);
        }
    }
}