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1   /*
2    * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package java.net;
27  
28  import java.io.ObjectStreamException;
29  
30  /**
31   * This class represents an Internet Protocol version 4 (IPv4) address.
32   * Defined by <a href="http://www.ietf.org/rfc/rfc790.txt">
33   * <i>RFC&nbsp;790: Assigned Numbers</i></a>,
34   * <a href="http://www.ietf.org/rfc/rfc1918.txt">
35   * <i>RFC&nbsp;1918: Address Allocation for Private Internets</i></a>,
36   * and <a href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC&nbsp;2365:
37   * Administratively Scoped IP Multicast</i></a>
38   *
39   * <h3> <A NAME="format">Textual representation of IP addresses</a> </h3>
40   *
41   * Textual representation of IPv4 address used as input to methods
42   * takes one of the following forms:
43   *
44   * <blockquote><table cellpadding=0 cellspacing=0 summary="layout">
45   * <tr><td>{@code d.d.d.d}</td></tr>
46   * <tr><td>{@code d.d.d}</td></tr>
47   * <tr><td>{@code d.d}</td></tr>
48   * <tr><td>{@code d}</td></tr>
49   * </table></blockquote>
50   *
51   * <p> When four parts are specified, each is interpreted as a byte of
52   * data and assigned, from left to right, to the four bytes of an IPv4
53   * address.
54  
55   * <p> When a three part address is specified, the last part is
56   * interpreted as a 16-bit quantity and placed in the right most two
57   * bytes of the network address. This makes the three part address
58   * format convenient for specifying Class B net- work addresses as
59   * 128.net.host.
60   *
61   * <p> When a two part address is supplied, the last part is
62   * interpreted as a 24-bit quantity and placed in the right most three
63   * bytes of the network address. This makes the two part address
64   * format convenient for specifying Class A network addresses as
65   * net.host.
66   *
67   * <p> When only one part is given, the value is stored directly in
68   * the network address without any byte rearrangement.
69   *
70   * <p> For methods that return a textual representation as output
71   * value, the first form, i.e. a dotted-quad string, is used.
72   *
73   * <h4> The Scope of a Multicast Address </h4>
74   *
75   * Historically the IPv4 TTL field in the IP header has doubled as a
76   * multicast scope field: a TTL of 0 means node-local, 1 means
77   * link-local, up through 32 means site-local, up through 64 means
78   * region-local, up through 128 means continent-local, and up through
79   * 255 are global. However, the administrative scoping is preferred.
80   * Please refer to <a href="http://www.ietf.org/rfc/rfc2365.txt">
81   * <i>RFC&nbsp;2365: Administratively Scoped IP Multicast</i></a>
82   * @since 1.4
83   */
84  
85  public final
86  class Inet4Address extends InetAddress {
87      final static int INADDRSZ = 4;
88  
89      /** use serialVersionUID from InetAddress, but Inet4Address instance
90       *  is always replaced by an InetAddress instance before being
91       *  serialized */
92      private static final long serialVersionUID = 3286316764910316507L;
93  
94      /*
95       * Perform initializations.
96       */
97      static {
98          init();
99      }
100 
101     Inet4Address() {
102         super();
103         holder().hostName = null;
104         holder().address = 0;
105         holder().family = IPv4;
106     }
107 
108     Inet4Address(String hostName, byte addr[]) {
109         holder().hostName = hostName;
110         holder().family = IPv4;
111         if (addr != null) {
112             if (addr.length == INADDRSZ) {
113                 int address  = addr[3] & 0xFF;
114                 address |= ((addr[2] << 8) & 0xFF00);
115                 address |= ((addr[1] << 16) & 0xFF0000);
116                 address |= ((addr[0] << 24) & 0xFF000000);
117                 holder().address = address;
118             }
119         }
120     }
121     Inet4Address(String hostName, int address) {
122         holder().hostName = hostName;
123         holder().family = IPv4;
124         holder().address = address;
125     }
126 
127     /**
128      * Replaces the object to be serialized with an InetAddress object.
129      *
130      * @return the alternate object to be serialized.
131      *
132      * @throws ObjectStreamException if a new object replacing this
133      * object could not be created
134      */
135     private Object writeReplace() throws ObjectStreamException {
136         // will replace the to be serialized 'this' object
137         InetAddress inet = new InetAddress();
138         inet.holder().hostName = holder().getHostName();
139         inet.holder().address = holder().getAddress();
140 
141         /**
142          * Prior to 1.4 an InetAddress was created with a family
143          * based on the platform AF_INET value (usually 2).
144          * For compatibility reasons we must therefore write the
145          * the InetAddress with this family.
146          */
147         inet.holder().family = 2;
148 
149         return inet;
150     }
151 
152     /**
153      * Utility routine to check if the InetAddress is an
154      * IP multicast address. IP multicast address is a Class D
155      * address i.e first four bits of the address are 1110.
156      * @return a {@code boolean} indicating if the InetAddress is
157      * an IP multicast address
158      * @since   JDK1.1
159      */
160     public boolean isMulticastAddress() {
161         return ((holder().getAddress() & 0xf0000000) == 0xe0000000);
162     }
163 
164     /**
165      * Utility routine to check if the InetAddress in a wildcard address.
166      * @return a {@code boolean} indicating if the Inetaddress is
167      *         a wildcard address.
168      * @since 1.4
169      */
170     public boolean isAnyLocalAddress() {
171         return holder().getAddress() == 0;
172     }
173 
174     /**
175      * Utility routine to check if the InetAddress is a loopback address.
176      *
177      * @return a {@code boolean} indicating if the InetAddress is
178      * a loopback address; or false otherwise.
179      * @since 1.4
180      */
181     public boolean isLoopbackAddress() {
182         /* 127.x.x.x */
183         byte[] byteAddr = getAddress();
184         return byteAddr[0] == 127;
185     }
186 
187     /**
188      * Utility routine to check if the InetAddress is an link local address.
189      *
190      * @return a {@code boolean} indicating if the InetAddress is
191      * a link local address; or false if address is not a link local unicast address.
192      * @since 1.4
193      */
194     public boolean isLinkLocalAddress() {
195         // link-local unicast in IPv4 (169.254.0.0/16)
196         // defined in "Documenting Special Use IPv4 Address Blocks
197         // that have been Registered with IANA" by Bill Manning
198         // draft-manning-dsua-06.txt
199         int address = holder().getAddress();
200         return (((address >>> 24) & 0xFF) == 169)
201             && (((address >>> 16) & 0xFF) == 254);
202     }
203 
204     /**
205      * Utility routine to check if the InetAddress is a site local address.
206      *
207      * @return a {@code boolean} indicating if the InetAddress is
208      * a site local address; or false if address is not a site local unicast address.
209      * @since 1.4
210      */
211     public boolean isSiteLocalAddress() {
212         // refer to RFC 1918
213         // 10/8 prefix
214         // 172.16/12 prefix
215         // 192.168/16 prefix
216         int address = holder().getAddress();
217         return (((address >>> 24) & 0xFF) == 10)
218             || ((((address >>> 24) & 0xFF) == 172)
219                 && (((address >>> 16) & 0xF0) == 16))
220             || ((((address >>> 24) & 0xFF) == 192)
221                 && (((address >>> 16) & 0xFF) == 168));
222     }
223 
224     /**
225      * Utility routine to check if the multicast address has global scope.
226      *
227      * @return a {@code boolean} indicating if the address has
228      *         is a multicast address of global scope, false if it is not
229      *         of global scope or it is not a multicast address
230      * @since 1.4
231      */
232     public boolean isMCGlobal() {
233         // 224.0.1.0 to 238.255.255.255
234         byte[] byteAddr = getAddress();
235         return ((byteAddr[0] & 0xff) >= 224 && (byteAddr[0] & 0xff) <= 238 ) &&
236             !((byteAddr[0] & 0xff) == 224 && byteAddr[1] == 0 &&
237               byteAddr[2] == 0);
238     }
239 
240     /**
241      * Utility routine to check if the multicast address has node scope.
242      *
243      * @return a {@code boolean} indicating if the address has
244      *         is a multicast address of node-local scope, false if it is not
245      *         of node-local scope or it is not a multicast address
246      * @since 1.4
247      */
248     public boolean isMCNodeLocal() {
249         // unless ttl == 0
250         return false;
251     }
252 
253     /**
254      * Utility routine to check if the multicast address has link scope.
255      *
256      * @return a {@code boolean} indicating if the address has
257      *         is a multicast address of link-local scope, false if it is not
258      *         of link-local scope or it is not a multicast address
259      * @since 1.4
260      */
261     public boolean isMCLinkLocal() {
262         // 224.0.0/24 prefix and ttl == 1
263         int address = holder().getAddress();
264         return (((address >>> 24) & 0xFF) == 224)
265             && (((address >>> 16) & 0xFF) == 0)
266             && (((address >>> 8) & 0xFF) == 0);
267     }
268 
269     /**
270      * Utility routine to check if the multicast address has site scope.
271      *
272      * @return a {@code boolean} indicating if the address has
273      *         is a multicast address of site-local scope, false if it is not
274      *         of site-local scope or it is not a multicast address
275      * @since 1.4
276      */
277     public boolean isMCSiteLocal() {
278         // 239.255/16 prefix or ttl < 32
279         int address = holder().getAddress();
280         return (((address >>> 24) & 0xFF) == 239)
281             && (((address >>> 16) & 0xFF) == 255);
282     }
283 
284     /**
285      * Utility routine to check if the multicast address has organization scope.
286      *
287      * @return a {@code boolean} indicating if the address has
288      *         is a multicast address of organization-local scope,
289      *         false if it is not of organization-local scope
290      *         or it is not a multicast address
291      * @since 1.4
292      */
293     public boolean isMCOrgLocal() {
294         // 239.192 - 239.195
295         int address = holder().getAddress();
296         return (((address >>> 24) & 0xFF) == 239)
297             && (((address >>> 16) & 0xFF) >= 192)
298             && (((address >>> 16) & 0xFF) <= 195);
299     }
300 
301     /**
302      * Returns the raw IP address of this {@code InetAddress}
303      * object. The result is in network byte order: the highest order
304      * byte of the address is in {@code getAddress()[0]}.
305      *
306      * @return  the raw IP address of this object.
307      */
308     public byte[] getAddress() {
309         int address = holder().getAddress();
310         byte[] addr = new byte[INADDRSZ];
311 
312         addr[0] = (byte) ((address >>> 24) & 0xFF);
313         addr[1] = (byte) ((address >>> 16) & 0xFF);
314         addr[2] = (byte) ((address >>> 8) & 0xFF);
315         addr[3] = (byte) (address & 0xFF);
316         return addr;
317     }
318 
319     /**
320      * Returns the IP address string in textual presentation form.
321      *
322      * @return  the raw IP address in a string format.
323      * @since   JDK1.0.2
324      */
325     public String getHostAddress() {
326         return numericToTextFormat(getAddress());
327     }
328 
329     /**
330      * Returns a hashcode for this IP address.
331      *
332      * @return  a hash code value for this IP address.
333      */
334     public int hashCode() {
335         return holder().getAddress();
336     }
337 
338     /**
339      * Compares this object against the specified object.
340      * The result is {@code true} if and only if the argument is
341      * not {@code null} and it represents the same IP address as
342      * this object.
343      * <p>
344      * Two instances of {@code InetAddress} represent the same IP
345      * address if the length of the byte arrays returned by
346      * {@code getAddress} is the same for both, and each of the
347      * array components is the same for the byte arrays.
348      *
349      * @param   obj   the object to compare against.
350      * @return  {@code true} if the objects are the same;
351      *          {@code false} otherwise.
352      * @see     java.net.InetAddress#getAddress()
353      */
354     public boolean equals(Object obj) {
355         return (obj != null) && (obj instanceof Inet4Address) &&
356             (((InetAddress)obj).holder().getAddress() == holder().getAddress());
357     }
358 
359     // Utilities
360     /*
361      * Converts IPv4 binary address into a string suitable for presentation.
362      *
363      * @param src a byte array representing an IPv4 numeric address
364      * @return a String representing the IPv4 address in
365      *         textual representation format
366      * @since 1.4
367      */
368 
369     static String numericToTextFormat(byte[] src)
370     {
371         return (src[0] & 0xff) + "." + (src[1] & 0xff) + "." + (src[2] & 0xff) + "." + (src[3] & 0xff);
372     }
373 
374     /**
375      * Perform class load-time initializations.
376      */
377     private static native void init();
378 }