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The core module of Pcap4J.
There is a newer version: 2.0.0-alpha.6
/*_##########################################################################
  _##
  _##  Copyright (C) 2012-2014  Pcap4J.org
  _##
  _##########################################################################
*/

package org.pcap4j.packet;

import java.util.Arrays;
import org.pcap4j.packet.IpV6ExtOptionsPacket.IpV6Option;
import org.pcap4j.packet.namednumber.IpV6OptionType;
import org.pcap4j.util.ByteArrays;

/**
 * @author Kaito Yamada
 * @since pcap4j 0.9.10
 */
public final class IpV6PadNOption implements IpV6Option {

  /*
   *  PadN option  (alignment requirement: none)
   *
   *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
   *  |       1       |  Opt Data Len |  Option Data
   *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
   */

  /**
   *
   */
  private static final long serialVersionUID = 2182260121605325195L;

  private static final IpV6OptionType type = IpV6OptionType.getInstance((byte)1);
  private final byte dataLen;
  private final byte[] data;

  /**
   * A static factory method.
   * This method validates the arguments by {@link ByteArrays#validateBounds(byte[], int, int)},
   * which may throw exceptions undocumented here.
   *
   * @param rawData rawData
   * @param offset offset
   * @param length length
   * @return a new IpV6PadNOption object.
   * @throws IllegalRawDataException if parsing the raw data fails.
   */
  public static IpV6PadNOption newInstance(
    byte[] rawData, int offset, int length
  ) throws IllegalRawDataException {
    ByteArrays.validateBounds(rawData, offset, length);
    return new IpV6PadNOption(rawData, offset, length);
  }

  private IpV6PadNOption(byte[] rawData, int offset, int length) throws IllegalRawDataException {
    if (length < 2) {
      StringBuilder sb = new StringBuilder(100);
      sb.append("The raw data length must be more than 1. rawData: ")
        .append(ByteArrays.toHexString(rawData, " "))
        .append(", offset: ")
        .append(offset)
        .append(", length: ")
        .append(length);
      throw new IllegalRawDataException(sb.toString());
    }
    if (rawData[offset] != type.value()) {
      StringBuilder sb = new StringBuilder(100);
      sb.append("The type must be: ")
        .append(type.valueAsString())
        .append(" rawData: ")
        .append(ByteArrays.toHexString(rawData, " "))
        .append(", offset: ")
        .append(offset)
        .append(", length: ")
        .append(length);
      throw new IllegalRawDataException(sb.toString());
    }

    this.dataLen = rawData[1 + offset];
    int dataLenAsInt = getDataLenAsInt();
    if (dataLenAsInt > length - 2)  {
      StringBuilder sb = new StringBuilder(100);
      sb.append("rawData is too short. dataLen field: ")
        .append(dataLenAsInt)
        .append(", rawData: ")
        .append(ByteArrays.toHexString(rawData, " "))
        .append(", offset: ")
        .append(offset)
        .append(", length: ")
        .append(length);
      throw new IllegalRawDataException(sb.toString());
    }

    this.data = ByteArrays.getSubArray(rawData, 2 + offset, dataLenAsInt);
  }

  private IpV6PadNOption(Builder builder) {
    if (
         builder == null
      || builder.data == null
    ) {
      StringBuilder sb = new StringBuilder();
      sb.append("builder: ").append(builder)
        .append(" builder.data: ").append(builder.data);
      throw new NullPointerException(sb.toString());
    }

    this.data = new byte[builder.data.length];
    System.arraycopy(
      builder.data, 0, this.data, 0, builder.data.length
    );

    if (builder.correctLengthAtBuild) {
      this.dataLen = (byte)data.length;
    }
    else {
      this.dataLen = builder.dataLen;
    }
  }

  @Override
  public IpV6OptionType getType() { return type; }

  /**
   *
   * @return dataLen
   */
  public byte getDataLen() { return dataLen; }

  /**
   *
   * @return dataLen
   */
  public int getDataLenAsInt() { return 0xFF & dataLen; }

  /**
   *
   * @return data
   */
  public byte[] getData() {
    byte[] copy = new byte[data.length];
    System.arraycopy(data, 0, copy, 0, data.length);
    return copy;
  }

  @Override
  public int length() { return data.length + 2; }

  @Override
  public byte[] getRawData() {
    byte[] rawData = new byte[length()];
    rawData[0] = type.value();
    rawData[1] = dataLen;
    System.arraycopy(data, 0, rawData, 2, data.length);
    return rawData;
  }

  /**
   *
   * @return a new Builder object populated with this object's fields.
   */
  public Builder getBuilder() { return new Builder(this); }

  @Override
  public String toString() {
    StringBuilder sb = new StringBuilder();
    sb.append("[Option Type: ")
      .append(type)
      .append("] [Option Data Len: ")
      .append(getDataLenAsInt())
      .append(" bytes] [Option Data: 0x")
      .append(ByteArrays.toHexString(data, ""))
      .append("]");
    return sb.toString();
  }

  @Override
  public boolean equals(Object obj) {
    if (obj == this) { return true; }
    if (!this.getClass().isInstance(obj)) { return false; }

    IpV6PadNOption other = (IpV6PadNOption)obj;
    return
         dataLen == other.dataLen
      && Arrays.equals(data, other.data);
  }

  @Override
  public int hashCode() {
    int result = 17;
    result = 31 * result + dataLen;
    result = 31 * Arrays.hashCode(data);
    return result;
  }

  /**
   *
   * @author Kaito
   * @since pcap4j 0.9.10
   */
  public static final class
  Builder implements LengthBuilder {

    private byte dataLen;
    private byte[] data;
    private boolean correctLengthAtBuild;

    /**
     *
     */
    public Builder() {}

    private Builder(IpV6PadNOption option) {
      this.dataLen = option.dataLen;
      this.data = option.data;
    }

    /**
     *
     * @param dataLen dataLen
     * @return this Builder object for method chaining.
     */
    public Builder dataLen(byte dataLen) {
      this.dataLen = dataLen;
      return this;
    }

    /**
     *
     * @param data data
     * @return this Builder object for method chaining.
     */
    public Builder data(byte[] data) {
      this.data = data;
      return this;
    }

    @Override
    public Builder correctLengthAtBuild(boolean correctLengthAtBuild) {
      this.correctLengthAtBuild = correctLengthAtBuild;
      return this;
    }

    @Override
    public IpV6PadNOption build() {
      return new IpV6PadNOption(this);
    }

  }

}