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 gnu.java.lang.CPStringBuilder;
042    
043    import java.io.ObjectStreamException;
044    
045    /*
046     * Written using on-line Java Platform 1.4 API Specification and
047     * RFC 1884 (http://www.ietf.org/rfc/rfc1884.txt),
048     * RFC 1918 (http://www.ietf.org/rfc/rfc1918.txt),
049     * RFC 2365 (http://www.ietf.org/rfc/rfc2365.txt)
050     *
051     * @author Michael Koch
052     * @status Believed complete and correct.
053     */
054    public final class Inet4Address extends InetAddress
055    {
056      /**
057       * For compatability with Sun's JDK 1.4.2 rev. 5
058       */
059      static final long serialVersionUID = 3286316764910316507L;
060    
061      /**
062       * The address family of these addresses (used for serialization).
063       */
064      private static final int AF_INET = 2;
065    
066      /**
067       * Inet4Address objects are serialized as InetAddress objects.
068       */
069      private Object writeReplace() throws ObjectStreamException
070      {
071        return new InetAddress(addr, hostName, AF_INET);
072      }
073      
074      /**
075       * Initializes this object's addr instance variable from the passed in
076       * byte array.  Note that this constructor is protected and is called
077       * only by static methods in this class.
078       *
079       * @param addr The IP number of this address as an array of bytes
080       * @param host The hostname of this IP address.
081       */
082      Inet4Address(byte[] addr, String host)
083      {
084        super(addr, host, AF_INET);
085      }
086    
087      /**
088       * Checks if the address is a multicast address
089       *
090       * @since 1.1
091       */
092      public boolean isMulticastAddress()
093      {
094        return (addr[0] & 0xf0) == 0xe0;
095      }
096    
097      /**
098       * Checks if this address is a loopback address
099       */
100      public boolean isLoopbackAddress()
101      {
102        return (addr[0] & 0xff) == 0x7f;
103      }
104    
105      /**
106       * Checks if this address is a wildcard address
107       *
108       * @since 1.4
109       */
110      public boolean isAnyLocalAddress()
111      {
112        return equals(InetAddress.ANY_IF);
113      }
114    
115      /**
116       * Checks if this address is a link local address
117       *
118       * @since 1.4
119       */
120      public boolean isLinkLocalAddress()
121      {
122        return false;
123      }
124    
125      /**
126       * Checks if this address is a site local address
127       *
128       * @since 1.4
129       */
130      public boolean isSiteLocalAddress()
131      {
132        // 10.0.0.0/8
133        if ((addr[0] & 0xff) == 0x0a)
134          return true;
135    
136        // 172.16.0.0/12
137        if ((addr[0] & 0xff) == 0xac && (addr[1] & 0xf0) == 0x10)
138          return true;
139    
140        // 192.168.0.0/16
141        if ((addr[0] & 0xff) == 0xc0 && (addr[1] & 0xff) == 0xa8)
142          return true;
143    
144        return false;
145      }
146    
147      /**
148       * Checks if this multicast address has global scope
149       *
150       * @since 1.4
151       */
152      public boolean isMCGlobal()
153      {
154        return false;
155      }
156    
157      /**
158       * Checks if this multicast address has node scope
159       *
160       * @since 1.4
161       */
162      public boolean isMCNodeLocal()
163      {
164        return false;
165      }
166    
167      /**
168       * Checks if this multicast address has link scope
169       *
170       * @since 1.4
171       */
172      public boolean isMCLinkLocal()
173      {
174        if (! isMulticastAddress())
175          return false;
176    
177        return ((addr[0] & 0xff) == 0xe0
178                && (addr[1] & 0xff)  == 0x00
179                && (addr[2] & 0xff)  == 0x00);
180      }
181    
182      /**
183       * Checks if this multicast address has site scope
184       *
185       * @since 1.4
186       */
187      public boolean isMCSiteLocal()
188      {
189        return false;
190      }
191    
192      /**
193       * Checks if this multicast address has organization scope
194       *
195       * @since 1.4
196       */
197      public boolean isMCOrgLocal()
198      {
199        return false;
200      }
201    
202      /**
203       * Returns the address of the current instance
204       */
205      public byte[] getAddress()
206      {
207        return (byte[]) addr.clone();
208      }
209    
210      /**
211       * Returns the address as string
212       *
213       * @since 1.0.2
214       */
215      public String getHostAddress()
216      {
217        CPStringBuilder sb = new CPStringBuilder(40);
218    
219        int len = addr.length;
220        int i = 0;
221        
222        for ( ; ; )
223          {
224            sb.append(addr[i] & 0xff);
225            i++;
226            
227            if (i == len)
228              break;
229            
230            sb.append('.');
231          }
232    
233        return sb.toString();
234      }
235    
236      /**
237       * Computes the hashcode of the instance
238       */
239      public int hashCode()
240      {
241        int hash = 0;
242        int len = addr.length;
243        int i = len > 4 ? len - 4 : 0;
244    
245        for (; i < len; i++)
246          hash = (hash << 8) | (addr[i] & 0xFF);
247    
248        return hash;
249      }
250    
251      /**
252       * Compare the current Inet4Address instance with obj
253       *
254       * @param obj Object to compare with
255       */
256      public boolean equals(Object obj)
257      {
258        if (! (obj instanceof InetAddress))
259          return false;
260    
261        byte[] addr1 = addr;
262        byte[] addr2 = ((InetAddress) obj).addr;
263    
264        if (addr1.length != addr2.length)
265          return false;
266    
267        for (int i = addr1.length; --i >= 0;)
268          if (addr1[i] != addr2[i])
269            return false;
270    
271        return true;
272      }
273    }