content: /*
   * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package java.net;
  
  /**
   * This class represents a Network Interface address. In short it's an
   * IP address, a subnet mask and a broadcast address when the address is
   * an IPv4 one. An IP address and a network prefix length in the case
   * of IPv6 address.
   *
   * @see NetworkInterface
   * @since 1.6
   */
  public class InterfaceAddress {
      private InetAddress address = null;
      private Inet4Address broadcast = null;
      private short        maskLength = 0;
  
      /*
       * Package private constructor. Can't be built directly, instances are
       * obtained through the NetworkInterface class.
       */
      InterfaceAddress() {
      }
  
      // BEGIN Android-added: Rewrote NetworkInterface on top of Libcore.io.
      InterfaceAddress(InetAddress address, Inet4Address broadcast, InetAddress netmask) {
          this.address = address;
          this.broadcast = broadcast;
          this.maskLength = countPrefixLength(netmask);
      }
  
      /**
       * Counts the prefix length for the netmask address.
       *
       * A valid netmask address must start with a continuous sequence of 1, followed by a continuous
       * sequence of 0.
       */
      private short countPrefixLength(InetAddress netmask) {
          short count = 0;
          for (byte b : netmask.getAddress()) {
              for (; b != 0; b <<= 1, ++count);
          }
          return count;
      }
      // END Android-added: Rewrote NetworkInterface on top of Libcore.io.
  
      /**
       * Returns an {@code InetAddress} for this address.
       *
       * @return the {@code InetAddress} for this address.
       */
      public InetAddress getAddress() {
          return address;
      }
  
      /**
       * Returns an {@code InetAddress} for the broadcast address
       * for this InterfaceAddress.
       * <p>
       * Only IPv4 networks have broadcast address therefore, in the case
       * of an IPv6 network, {@code null} will be returned.
       *
       * @return the {@code InetAddress} representing the broadcast
       *         address or {@code null} if there is no broadcast address.
       */
      public InetAddress getBroadcast() {
          return broadcast;
      }
  
      /**
       * Returns the network prefix length for this address. This is also known
       * as the subnet mask in the context of IPv4 addresses.
       * Typical IPv4 values would be 8 (255.0.0.0), 16 (255.255.0.0)
       * or 24 (255.255.255.0). <p>
       * Typical IPv6 values would be 128 (::1/128) or 10 (fe80::203:baff:fe27:1243/10)
       *
       * @return a {@code short} representing the prefix length for the
       *         subnet of that address.
       */
       public short getNetworkPrefixLength() {
          return maskLength;
      }
  
      /**
       * Compares this object against the specified object.
       * The result is {@code true} if and only if the argument is
       * not {@code null} and it represents the same interface address as
       * this object.
       * <p>
       * Two instances of {@code InterfaceAddress} represent the same
       * address if the InetAddress, the prefix length and the broadcast are
       * the same for both.
       *
       * @param   obj   the object to compare against.
       * @return  {@code true} if the objects are the same;
       *          {@code false} otherwise.
       * @see     InterfaceAddress#hashCode()
       */
      public boolean equals(Object obj) {
          if (!(obj instanceof InterfaceAddress)) {
              return false;
          }
          InterfaceAddress cmp = (InterfaceAddress) obj;
          if ( !(address == null ? cmp.address == null : address.equals(cmp.address)) )
              return false;
          if ( !(broadcast  == null ? cmp.broadcast == null : broadcast.equals(cmp.broadcast)) )
              return false;
          if (maskLength != cmp.maskLength)
              return false;
          return true;
      }
  
      /**
       * Returns a hashcode for this Interface address.
       *
       * @return  a hash code value for this Interface address.
       */
      public int hashCode() {
          return address.hashCode() + ((broadcast != null) ? broadcast.hashCode() : 0) + maskLength;
      }
  
      /**
       * Converts this Interface address to a {@code String}. The
       * string returned is of the form: InetAddress / prefix length [ broadcast address ].
       *
       * @return  a string representation of this Interface address.
       */
      public String toString() {
          return address + "/" + maskLength + " [" + broadcast + "]";
      }
  
  }
  