001    /* Inet4Address.java --
002       Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.net;
040    
041    import java.io.ObjectStreamException;
042    
043    /*
044     * Written using on-line Java Platform 1.4 API Specification and
045     * RFC 1884 (http://www.ietf.org/rfc/rfc1884.txt),
046     * RFC 1918 (http://www.ietf.org/rfc/rfc1918.txt),
047     * RFC 2365 (http://www.ietf.org/rfc/rfc2365.txt)
048     *
049     * @author Michael Koch
050     * @status Believed complete and correct.
051     */
052    public final class Inet4Address extends InetAddress
053    {
054      /**
055       * For compatability with Sun's JDK 1.4.2 rev. 5
056       */
057      static final long serialVersionUID = 3286316764910316507L;
058    
059      /**
060       * The address family of these addresses (used for serialization).
061       */
062      private static final int AF_INET = 2;
063    
064      /**
065       * Inet4Address objects are serialized as InetAddress objects.
066       */
067      private Object writeReplace() throws ObjectStreamException
068      {
069        return new InetAddress(addr, hostName, AF_INET);
070      }
071      
072      /**
073       * Initializes this object's addr instance variable from the passed in
074       * byte array.  Note that this constructor is protected and is called
075       * only by static methods in this class.
076       *
077       * @param addr The IP number of this address as an array of bytes
078       * @param host The hostname of this IP address.
079       */
080      Inet4Address(byte[] addr, String host)
081      {
082        super(addr, host, AF_INET);
083      }
084    
085      /**
086       * Checks if the address is a multicast address
087       *
088       * @since 1.1
089       */
090      public boolean isMulticastAddress()
091      {
092        return (addr[0] & 0xf0) == 0xe0;
093      }
094    
095      /**
096       * Checks if this address is a loopback address
097       */
098      public boolean isLoopbackAddress()
099      {
100        return (addr[0] & 0xff) == 0x7f;
101      }
102    
103      /**
104       * Checks if this address is a wildcard address
105       *
106       * @since 1.4
107       */
108      public boolean isAnyLocalAddress()
109      {
110        return equals(InetAddress.ANY_IF);
111      }
112    
113      /**
114       * Checks if this address is a link local address
115       *
116       * @since 1.4
117       */
118      public boolean isLinkLocalAddress()
119      {
120        return false;
121      }
122    
123      /**
124       * Checks if this address is a site local address
125       *
126       * @since 1.4
127       */
128      public boolean isSiteLocalAddress()
129      {
130        // 10.0.0.0/8
131        if ((addr[0] & 0xff) == 0x0a)
132          return true;
133    
134        // 172.16.0.0/12
135        if ((addr[0] & 0xff) == 0xac && (addr[1] & 0xf0) == 0x10)
136          return true;
137    
138        // 192.168.0.0/16
139        if ((addr[0] & 0xff) == 0xc0 && (addr[1] & 0xff) == 0xa8)
140          return true;
141    
142        return false;
143      }
144    
145      /**
146       * Checks if this multicast address has global scope
147       *
148       * @since 1.4
149       */
150      public boolean isMCGlobal()
151      {
152        return false;
153      }
154    
155      /**
156       * Checks if this multicast address has node scope
157       *
158       * @since 1.4
159       */
160      public boolean isMCNodeLocal()
161      {
162        return false;
163      }
164    
165      /**
166       * Checks if this multicast address has link scope
167       *
168       * @since 1.4
169       */
170      public boolean isMCLinkLocal()
171      {
172        if (! isMulticastAddress())
173          return false;
174    
175        return ((addr[0] & 0xff) == 0xe0
176                && (addr[1] & 0xff)  == 0x00
177                && (addr[2] & 0xff)  == 0x00);
178      }
179    
180      /**
181       * Checks if this multicast address has site scope
182       *
183       * @since 1.4
184       */
185      public boolean isMCSiteLocal()
186      {
187        return false;
188      }
189    
190      /**
191       * Checks if this multicast address has organization scope
192       *
193       * @since 1.4
194       */
195      public boolean isMCOrgLocal()
196      {
197        return false;
198      }
199    
200      /**
201       * Returns the address of the current instance
202       */
203      public byte[] getAddress()
204      {
205        return (byte[]) addr.clone();
206      }
207    
208      /**
209       * Returns the address as string
210       *
211       * @since 1.0.2
212       */
213      public String getHostAddress()
214      {
215        StringBuffer sb = new StringBuffer(40);
216    
217        int len = addr.length;
218        int i = 0;
219        
220        for ( ; ; )
221          {
222            sb.append(addr[i] & 0xff);
223            i++;
224            
225            if (i == len)
226              break;
227            
228            sb.append('.');
229          }
230    
231        return sb.toString();
232      }
233    
234      /**
235       * Computes the hashcode of the instance
236       */
237      public int hashCode()
238      {
239        int hash = 0;
240        int len = addr.length;
241        int i = len > 4 ? len - 4 : 0;
242    
243        for (; i < len; i++)
244          hash = (hash << 8) | (addr[i] & 0xFF);
245    
246        return hash;
247      }
248    
249      /**
250       * Compare the current Inet4Address instance with obj
251       *
252       * @param obj Object to compare with
253       */
254      public boolean equals(Object obj)
255      {
256        if (! (obj instanceof InetAddress))
257          return false;
258    
259        byte[] addr1 = addr;
260        byte[] addr2 = ((InetAddress) obj).addr;
261    
262        if (addr1.length != addr2.length)
263          return false;
264    
265        for (int i = addr1.length; --i >= 0;)
266          if (addr1[i] != addr2[i])
267            return false;
268    
269        return true;
270      }
271    }