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1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This code is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 only, as
8  * published by the Free Software Foundation.  Oracle designates this
9  * particular file as subject to the "Classpath" exception as provided
10  * by Oracle in the LICENSE file that accompanied this code.
11  *
12  * This code is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15  * version 2 for more details (a copy is included in the LICENSE file that
16  * accompanied this code).
17  *
18  * You should have received a copy of the GNU General Public License version
19  * 2 along with this work; if not, write to the Free Software Foundation,
20  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21  *
22  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
23  * or visit www.oracle.com if you need additional information or have any
24  * questions.
25  */
26 
27 package java.net;
28 
29 import java.io.ObjectStreamException;
30 import static android.system.OsConstants.*;
31 
32 /**
33  * This class represents an Internet Protocol version 4 (IPv4) address.
34  * Defined by <a href="http://www.ietf.org/rfc/rfc790.txt">
35  * <i>RFC&nbsp;790: Assigned Numbers</i></a>,
36  * <a href="http://www.ietf.org/rfc/rfc1918.txt">
37  * <i>RFC&nbsp;1918: Address Allocation for Private Internets</i></a>,
38  * and <a href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC&nbsp;2365:
39  * Administratively Scoped IP Multicast</i></a>
40  *
41  * <h3> <A NAME="format">Textual representation of IP addresses</a> </h3>
42  *
43  * Textual representation of IPv4 address used as input to methods
44  * takes one of the following forms:
45  *
46  * <blockquote><table cellpadding=0 cellspacing=0 summary="layout">
47  * <tr><td>{@code d.d.d.d}</td></tr>
48  * <tr><td>{@code d.d.d}</td></tr>
49  * <tr><td>{@code d.d}</td></tr>
50  * <tr><td>{@code d}</td></tr>
51  * </table></blockquote>
52  *
53  * <p> When four parts are specified, each is interpreted as a byte of
54  * data and assigned, from left to right, to the four bytes of an IPv4
55  * address.
56 
57  * <p> When a three part address is specified, the last part is
58  * interpreted as a 16-bit quantity and placed in the right most two
59  * bytes of the network address. This makes the three part address
60  * format convenient for specifying Class B net- work addresses as
61  * 128.net.host.
62  *
63  * <p> When a two part address is supplied, the last part is
64  * interpreted as a 24-bit quantity and placed in the right most three
65  * bytes of the network address. This makes the two part address
66  * format convenient for specifying Class A network addresses as
67  * net.host.
68  *
69  * <p> When only one part is given, the value is stored directly in
70  * the network address without any byte rearrangement.
71  *
72  * <p> For methods that return a textual representation as output
73  * value, the first form, i.e. a dotted-quad string, is used.
74  *
75  * <h4> The Scope of a Multicast Address </h4>
76  *
77  * Historically the IPv4 TTL field in the IP header has doubled as a
78  * multicast scope field: a TTL of 0 means node-local, 1 means
79  * link-local, up through 32 means site-local, up through 64 means
80  * region-local, up through 128 means continent-local, and up through
81  * 255 are global. However, the administrative scoping is preferred.
82  * Please refer to <a href="http://www.ietf.org/rfc/rfc2365.txt">
83  * <i>RFC&nbsp;2365: Administratively Scoped IP Multicast</i></a>
84  * @since 1.4
85  */
86 
87 public final
88 class Inet4Address extends InetAddress {
89     final static int INADDRSZ = 4;
90 
91     /** use serialVersionUID from InetAddress, but Inet4Address instance
92      *  is always replaced by an InetAddress instance before being
93      *  serialized */
94     private static final long serialVersionUID = 3286316764910316507L;
95 
96     // BEGIN Android-added: Define special-purpose IPv4 address.
97     /**
98      * Reserved address for {@code INADDR_ANY}, to specify any IPv4 address at all.
99      *
100      * @hide
101      */
102     public static final InetAddress ANY = new Inet4Address(null, new byte[] { 0, 0, 0, 0 });
103 
104     /**
105      * Broadcast address to transmit to all devices on network.
106      *
107      * @hide
108      */
109     public static final InetAddress ALL =
110             new Inet4Address(null, new byte[] { (byte) 255, (byte) 255,
111                   (byte) 255, (byte) 255 });
112 
113     /**
114      * Loopback address to the local host.
115      *
116      * @hide
117      */
118     public static final InetAddress LOOPBACK =
119             new Inet4Address("localhost", new byte[] { 127, 0, 0, 1 });
120     // END Android-added: Define special-purpose IPv4 address.
121 
122 
123     // BEGIN Android-removed: Android doesn't need to call native init.
124     /*
125      * Perform initializations.
126      *
127     static {
128         init();
129     }
130     */
131     // END Android-removed: Android doesn't need to call native init.
Inet4Address()132     Inet4Address() {
133         super();
134         holder().hostName = null;
135         holder().address = 0;
136         holder().family = AF_INET;
137     }
138 
Inet4Address(String hostName, byte addr[])139     Inet4Address(String hostName, byte addr[]) {
140         holder().hostName = hostName;
141         holder().family = AF_INET;
142         if (addr != null) {
143             if (addr.length == INADDRSZ) {
144                 int address  = addr[3] & 0xFF;
145                 address |= ((addr[2] << 8) & 0xFF00);
146                 address |= ((addr[1] << 16) & 0xFF0000);
147                 address |= ((addr[0] << 24) & 0xFF000000);
148                 holder().address = address;
149             }
150         }
151         holder().originalHostName = hostName;
152     }
Inet4Address(String hostName, int address)153     Inet4Address(String hostName, int address) {
154         holder().hostName = hostName;
155         holder().family = AF_INET;
156         holder().address = address;
157         holder().originalHostName = hostName;
158     }
159 
160     /**
161      * Replaces the object to be serialized with an InetAddress object.
162      *
163      * @return the alternate object to be serialized.
164      *
165      * @throws ObjectStreamException if a new object replacing this
166      * object could not be created
167      */
writeReplace()168     private Object writeReplace() throws ObjectStreamException {
169         // will replace the to be serialized 'this' object
170         InetAddress inet = new InetAddress();
171         inet.holder().hostName = holder().getHostName();
172         inet.holder().address = holder().getAddress();
173 
174         /**
175          * Prior to 1.4 an InetAddress was created with a family
176          * based on the platform AF_INET value (usually 2).
177          * For compatibility reasons we must therefore write the
178          * the InetAddress with this family.
179          */
180         inet.holder().family = 2;
181 
182         return inet;
183     }
184 
185     /**
186      * Utility routine to check if the InetAddress is an
187      * IP multicast address. IP multicast address is a Class D
188      * address i.e first four bits of the address are 1110.
189      * @return a {@code boolean} indicating if the InetAddress is
190      * an IP multicast address
191      * @since   JDK1.1
192      */
isMulticastAddress()193     public boolean isMulticastAddress() {
194         return ((holder().getAddress() & 0xf0000000) == 0xe0000000);
195     }
196 
197     /**
198      * Utility routine to check if the InetAddress in a wildcard address.
199      * @return a {@code boolean} indicating if the Inetaddress is
200      *         a wildcard address.
201      * @since 1.4
202      */
isAnyLocalAddress()203     public boolean isAnyLocalAddress() {
204         return holder().getAddress() == 0;
205     }
206 
207     /**
208      * Utility routine to check if the InetAddress is a loopback address.
209      *
210      * @return a {@code boolean} indicating if the InetAddress is
211      * a loopback address; or false otherwise.
212      * @since 1.4
213      */
isLoopbackAddress()214     public boolean isLoopbackAddress() {
215         /* 127.x.x.x */
216         byte[] byteAddr = getAddress();
217         return byteAddr[0] == 127;
218     }
219 
220     /**
221      * Utility routine to check if the InetAddress is an link local address.
222      *
223      * @return a {@code boolean} indicating if the InetAddress is
224      * a link local address; or false if address is not a link local unicast address.
225      * @since 1.4
226      */
isLinkLocalAddress()227     public boolean isLinkLocalAddress() {
228         // link-local unicast in IPv4 (169.254.0.0/16)
229         // defined in "Documenting Special Use IPv4 Address Blocks
230         // that have been Registered with IANA" by Bill Manning
231         // draft-manning-dsua-06.txt
232         int address = holder().getAddress();
233         return (((address >>> 24) & 0xFF) == 169)
234             && (((address >>> 16) & 0xFF) == 254);
235     }
236 
237     /**
238      * Utility routine to check if the InetAddress is a site local address.
239      *
240      * @return a {@code boolean} indicating if the InetAddress is
241      * a site local address; or false if address is not a site local unicast address.
242      * @since 1.4
243      */
isSiteLocalAddress()244     public boolean isSiteLocalAddress() {
245         // refer to RFC 1918
246         // 10/8 prefix
247         // 172.16/12 prefix
248         // 192.168/16 prefix
249         int address = holder().getAddress();
250         return (((address >>> 24) & 0xFF) == 10)
251             || ((((address >>> 24) & 0xFF) == 172)
252                 && (((address >>> 16) & 0xF0) == 16))
253             || ((((address >>> 24) & 0xFF) == 192)
254                 && (((address >>> 16) & 0xFF) == 168));
255     }
256 
257     /**
258      * Utility routine to check if the multicast address has global scope.
259      *
260      * @return a {@code boolean} indicating if the address has
261      *         is a multicast address of global scope, false if it is not
262      *         of global scope or it is not a multicast address
263      * @since 1.4
264      */
isMCGlobal()265     public boolean isMCGlobal() {
266         // 224.0.1.0 to 238.255.255.255
267         byte[] byteAddr = getAddress();
268         return ((byteAddr[0] & 0xff) >= 224 && (byteAddr[0] & 0xff) <= 238 ) &&
269             !((byteAddr[0] & 0xff) == 224 && byteAddr[1] == 0 &&
270               byteAddr[2] == 0);
271     }
272 
273     /**
274      * Utility routine to check if the multicast address has node scope.
275      *
276      * @return a {@code boolean} indicating if the address has
277      *         is a multicast address of node-local scope, false if it is not
278      *         of node-local scope or it is not a multicast address
279      * @since 1.4
280      */
isMCNodeLocal()281     public boolean isMCNodeLocal() {
282         // unless ttl == 0
283         return false;
284     }
285 
286     /**
287      * Utility routine to check if the multicast address has link scope.
288      *
289      * @return a {@code boolean} indicating if the address has
290      *         is a multicast address of link-local scope, false if it is not
291      *         of link-local scope or it is not a multicast address
292      * @since 1.4
293      */
isMCLinkLocal()294     public boolean isMCLinkLocal() {
295         // 224.0.0/24 prefix and ttl == 1
296         int address = holder().getAddress();
297         return (((address >>> 24) & 0xFF) == 224)
298             && (((address >>> 16) & 0xFF) == 0)
299             && (((address >>> 8) & 0xFF) == 0);
300     }
301 
302     /**
303      * Utility routine to check if the multicast address has site scope.
304      *
305      * @return a {@code boolean} indicating if the address has
306      *         is a multicast address of site-local scope, false if it is not
307      *         of site-local scope or it is not a multicast address
308      * @since 1.4
309      */
isMCSiteLocal()310     public boolean isMCSiteLocal() {
311         // 239.255/16 prefix or ttl < 32
312         int address = holder().getAddress();
313         return (((address >>> 24) & 0xFF) == 239)
314             && (((address >>> 16) & 0xFF) == 255);
315     }
316 
317     /**
318      * Utility routine to check if the multicast address has organization scope.
319      *
320      * @return a {@code boolean} indicating if the address has
321      *         is a multicast address of organization-local scope,
322      *         false if it is not of organization-local scope
323      *         or it is not a multicast address
324      * @since 1.4
325      */
isMCOrgLocal()326     public boolean isMCOrgLocal() {
327         // 239.192 - 239.195
328         int address = holder().getAddress();
329         return (((address >>> 24) & 0xFF) == 239)
330             && (((address >>> 16) & 0xFF) >= 192)
331             && (((address >>> 16) & 0xFF) <= 195);
332     }
333 
334     /**
335      * Returns the raw IP address of this {@code InetAddress}
336      * object. The result is in network byte order: the highest order
337      * byte of the address is in {@code getAddress()[0]}.
338      *
339      * @return  the raw IP address of this object.
340      */
getAddress()341     public byte[] getAddress() {
342         int address = holder().getAddress();
343         byte[] addr = new byte[INADDRSZ];
344 
345         addr[0] = (byte) ((address >>> 24) & 0xFF);
346         addr[1] = (byte) ((address >>> 16) & 0xFF);
347         addr[2] = (byte) ((address >>> 8) & 0xFF);
348         addr[3] = (byte) (address & 0xFF);
349         return addr;
350     }
351 
352     /**
353      * Returns the IP address string in textual presentation form.
354      *
355      * @return  the raw IP address in a string format.
356      * @since   JDK1.0.2
357      */
getHostAddress()358     public String getHostAddress() {
359         return numericToTextFormat(getAddress());
360     }
361 
362     /**
363      * Returns a hashcode for this IP address.
364      *
365      * @return  a hash code value for this IP address.
366      */
hashCode()367     public int hashCode() {
368         return holder().getAddress();
369     }
370 
371     /**
372      * Compares this object against the specified object.
373      * The result is {@code true} if and only if the argument is
374      * not {@code null} and it represents the same IP address as
375      * this object.
376      * <p>
377      * Two instances of {@code InetAddress} represent the same IP
378      * address if the length of the byte arrays returned by
379      * {@code getAddress} is the same for both, and each of the
380      * array components is the same for the byte arrays.
381      *
382      * @param   obj   the object to compare against.
383      * @return  {@code true} if the objects are the same;
384      *          {@code false} otherwise.
385      * @see     java.net.InetAddress#getAddress()
386      */
equals(Object obj)387     public boolean equals(Object obj) {
388         return (obj != null) && (obj instanceof Inet4Address) &&
389             (((InetAddress)obj).holder().getAddress() == holder().getAddress());
390     }
391 
392     // Utilities
393     /*
394      * Converts IPv4 binary address into a string suitable for presentation.
395      *
396      * @param src a byte array representing an IPv4 numeric address
397      * @return a String representing the IPv4 address in
398      *         textual representation format
399      * @since 1.4
400      */
401 
numericToTextFormat(byte[] src)402     static String numericToTextFormat(byte[] src)
403     {
404         return (src[0] & 0xff) + "." + (src[1] & 0xff) + "." + (src[2] & 0xff) + "." + (src[3] & 0xff);
405     }
406 
407     // BEGIN Android-removed: Android doesn't need to call native init.
408     /*
409      * Perform class load-time initializations.
410      *
411     private static native void init();
412     */
413     // END Android-removed: Android doesn't need to call native init.
414 }
415