ipfix/src/main/java/org/onosproject/ipfix/packet/MessageHeader.java

/*
 * Copyright 2015 Open Networking Foundation
 *
 * Licensed 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 org.onosproject.ipfix.packet;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.google.common.primitives.Ints;
import com.google.common.primitives.Longs;
import com.google.common.primitives.Shorts;

/**
 * IPFIX Message Header.
 */
public class MessageHeader extends AbstractIpfixPacketEntity implements AbstractIpfixPacketInterface {
    private static final Logger LOGGER = Logger.getLogger(SetHeader.class.getName());
    private static final int HEADER_LENGTH = 16;
    private static final int IPFIX_VERSION = 10;

    private int versionNumber;
    private int length;
    private Date exportTime;
    private long sequenceNumber;
    private long observationDomainID;
    private List<SetHeader> setHeaders = new ArrayList<SetHeader>();

    /**
     * Message Header format.
     *
     *  0                   1                   2                   3
     *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     *  |       Version Number          |            Length             |
     *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     *  |                           Export Time                         |
     *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     *  |                       Sequence Number                         |
     *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     *  |                    Observation Domain ID                      |
     *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     *
     */

    public int getVersionNumber() {
        return IPFIX_VERSION;
    }

    public void setVersionNumber(int versionNumber) {
        this.versionNumber = versionNumber;
    }

    public int getLength() {
        return length;
    }

    public void setLength(int length) {
        this.length = length;
    }

    public Date getExportTime() {
        return exportTime;
    }

    public void setExportTime(Date exportTime) {
        this.exportTime = exportTime;
    }

    public long getSequenceNumber() {
        return sequenceNumber;
    }

    public void setSequenceNumber(long sequenceNumber) {
        this.sequenceNumber = sequenceNumber;
    }

    public long getObservationDomainID() {
        return observationDomainID;
    }

    public void setObservationDomainID(long observationDomainID) {
        this.observationDomainID = observationDomainID;
    }

    public List<SetHeader> getSetHeaders() {
        return setHeaders;
    }

    public void setSetHeaders(List<SetHeader> setHeaders) {
        this.setHeaders = setHeaders;
        int length = HEADER_LENGTH;
        for (SetHeader header : setHeaders) {
            length += header.getLength();
        }
        setLength(length);
    }

    public static MessageHeader parse(byte[] data) throws HeaderException {
        try {
            if (data.length < HEADER_LENGTH) {
                throw new HeaderException("Data array too short.");
            }
            MessageHeader mh = new MessageHeader();
            // version number
            byte[] versionNumber = new byte[2];
            System.arraycopy(data, 0, versionNumber, 0, 2);
            mh.setVersionNumber(Ints.fromByteArray(versionNumber));
            // length
            byte[] length = new byte[2];
            System.arraycopy(data, 2, length, 0, 2);
            mh.setLength(Ints.fromByteArray(length));
            // export time
            byte[] exportTime = new byte[4];
            System.arraycopy(data, 4, exportTime, 0, 4);
            long secondsSinceEpoche = Longs.fromByteArray(exportTime);
            long milliSecondsSinceEpoche = secondsSinceEpoche * 1000;
            mh.setExportTime(new Date(milliSecondsSinceEpoche));
            // sequence number
            byte[] sequenceNumber = new byte[4];
            System.arraycopy(data, 8, sequenceNumber, 0, 4);
            mh.setSequenceNumber(Longs.fromByteArray(sequenceNumber));
            // observation domain id
            byte[] observationDomainID = new byte[4];
            System.arraycopy(data, 12, observationDomainID, 0, 4);
            mh.setObservationDomainID(Longs.fromByteArray(observationDomainID));
            // set header
            int offset = HEADER_LENGTH;

            while ((mh.getLength() - offset) > 0) {
                byte[] subData = new byte[mh.getLength() - offset];
                System.arraycopy(data, offset, subData, 0, subData.length);
                SetHeader sh = SetHeader.parse(subData);
                mh.getSetHeaders().add(sh);
                offset += sh.getLength();
            }
            if ((mh.getLength() - offset) != 0) {
                LOGGER.log(Level.INFO, "Unused bytes: " + (mh.getLength() - offset));
            }
            return mh;
        } catch (Exception e) {
            throw new HeaderException("Parse error: " + e.getMessage());
        }
    }

    public byte[] getBytes() throws HeaderException {
        try {
            byte[] data = new byte[length];
            // version number
            System.arraycopy(Shorts.toByteArray((short) versionNumber), 0, data, 0, 2);
            // length
            System.arraycopy(Shorts.toByteArray((short) length), 0, data, 2, 2);
            // export time
            System.arraycopy(Ints.toByteArray((int) exportTime.getTime() / 1000), 0, data, 4, 4);
            // sequence number
            System.arraycopy(Ints.toByteArray((int) sequenceNumber), 0, data, 8, 4);
            // observation domain id
            System.arraycopy(Ints.toByteArray((int) observationDomainID), 0, data, 12, 4);
            // set header
            int offset = HEADER_LENGTH;
            for (SetHeader sh : setHeaders) {
                byte[] temp = sh.getBytes();
                System.arraycopy(temp, 0, data, offset, temp.length);
                offset += temp.length;
            }
            return data;
        } catch (Exception e) {
            e.printStackTrace();
            throw new HeaderException("Error while generating the bytes: " + e.getMessage());
        }
    }

    public String toString() {
        StringBuilder sb = new StringBuilder();
        sb.append("[MessageHeader]: ");
        sb.append("Version Number: ");
        sb.append(versionNumber);
        sb.append(", ");
        sb.append("Length: ");
        sb.append(length);
        sb.append(", ");
        sb.append("Export time: ");
        sb.append(exportTime);
        sb.append(", ");
        sb.append("Sequence number: ");
        sb.append(sequenceNumber);
        sb.append(", ");
        sb.append("Observation Domain ID: ");
        sb.append(observationDomainID);
        sb.append(", ");
        sb.append("SetHeaders: ");
        sb.append(setHeaders.size());
        sb.append(", ");
        for (SetHeader sh : setHeaders) {
            sb.append(sh);
            sb.append(", ");
        }
        return sb.toString();
    }
}