com.bitbreeds.webrtc.sctp.model.SCTPHeader.java Source code

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Here is the source code for com.bitbreeds.webrtc.sctp.model.SCTPHeader.java

Source

package com.bitbreeds.webrtc.sctp.model;

import com.bitbreeds.webrtc.common.SignalUtil;
import org.apache.commons.codec.binary.Hex;

import java.util.Arrays;

/**
 * Copyright (c) 17/05/16, Jonas Waage
 * <p>
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
 * documentation files (the "Software"), to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and
 * to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * <p>
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 * <p>
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/**
 * Immutable SCTP common header
 * {@link <a href=https://tools.ietf.org/html/rfc4960#page-15>scpt common header</a>}
 */
public class SCTPHeader {

    private final int sourcePort;
    private final int destinationPort;
    private final long verificationTag;
    private final long checksum;

    public SCTPHeader(int sourcePort, int destinationPort, long verificationTag, long checksum) {
        this.sourcePort = sourcePort;
        this.destinationPort = destinationPort;
        this.verificationTag = verificationTag;
        this.checksum = checksum;
    }

    public byte[] toBytes() {
        return SignalUtil.joinBytesArrays(SignalUtil.twoBytesFromInt(sourcePort),
                SignalUtil.twoBytesFromInt(sourcePort), SignalUtil.longToFourBytes(verificationTag),
                SignalUtil.flipBytes(SignalUtil.longToFourBytes(checksum)));
    }

    public static SCTPHeader fromBytes(byte[] bytes) {
        if (bytes.length != 12) {
            throw new IllegalArgumentException("Bytes given are incorrect length to be an SCTP header: "
                    + " length: " + bytes.length + "  data:" + Hex.encodeHexString(bytes));
        }
        return new SCTPHeader(SignalUtil.intFromTwoBytes(Arrays.copyOf(bytes, 2)),
                SignalUtil.intFromTwoBytes(Arrays.copyOfRange(bytes, 2, 4)),
                SignalUtil.bytesToLong(Arrays.copyOfRange(bytes, 4, 8)),
                SignalUtil.bytesToLong(Arrays.copyOfRange(bytes, 8, 12)));
    }

    public int getSourcePort() {
        return sourcePort;
    }

    public int getDestinationPort() {
        return destinationPort;
    }

    public long getVerificationTag() {
        return verificationTag;
    }

    public long getChecksum() {
        return checksum;
    }

    @Override
    public String toString() {
        return "SCTPHeader{" + "sourcePort=" + sourcePort + ", destinationPort=" + destinationPort
                + ", verificationTag=" + verificationTag + ", checksum=" + checksum + '}';
    }
}