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14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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26 
27 package java.net;
28 
29 import java.security.AccessController;
30 import java.io.ObjectStreamException;
31 import sun.security.action.*;
32 import static android.system.OsConstants.*;
33 
34 /**
35  * This class represents an Internet Protocol version 4 (IPv4) address.
36  * Defined by <a href="http://www.ietf.org/rfc/rfc790.txt">
37  * <i>RFC&nbsp;790: Assigned Numbers</i></a>,
38  * <a href="http://www.ietf.org/rfc/rfc1918.txt">
39  * <i>RFC&nbsp;1918: Address Allocation for Private Internets</i></a>,
40  * and <a href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC&nbsp;2365:
41  * Administratively Scoped IP Multicast</i></a>
42  *
43  * <h4> <A NAME="format">Textual representation of IP addresses</a> </h4>
44  *
45  * Textual representation of IPv4 address used as input to methods
46  * takes one of the following forms:
47  *
48  * <blockquote><table cellpadding=0 cellspacing=0 summary="layout">
49  * <tr><td><tt>d.d.d.d</tt></td></tr>
50  * <tr><td><tt>d.d.d</tt></td></tr>
51  * <tr><td><tt>d.d</tt></td></tr>
52  * <tr><td><tt>d</tt></td></tr>
53  * </table></blockquote>
54  *
55  * <p> When four parts are specified, each is interpreted as a byte of
56  * data and assigned, from left to right, to the four bytes of an IPv4
57  * address.
58 
59  * <p> When a three part address is specified, the last part is
60  * interpreted as a 16-bit quantity and placed in the right most two
61  * bytes of the network address. This makes the three part address
62  * format convenient for specifying Class B net- work addresses as
63  * 128.net.host.
64  *
65  * <p> When a two part address is supplied, the last part is
66  * interpreted as a 24-bit quantity and placed in the right most three
67  * bytes of the network address. This makes the two part address
68  * format convenient for specifying Class A network addresses as
69  * net.host.
70  *
71  * <p> When only one part is given, the value is stored directly in
72  * the network address without any byte rearrangement.
73  *
74  * <p> For methods that return a textual representation as output
75  * value, the first form, i.e. a dotted-quad string, is used.
76  *
77  * <h4> The Scope of a Multicast Address </h4>
78  *
79  * Historically the IPv4 TTL field in the IP header has doubled as a
80  * multicast scope field: a TTL of 0 means node-local, 1 means
81  * link-local, up through 32 means site-local, up through 64 means
82  * region-local, up through 128 means continent-local, and up through
83  * 255 are global. However, the administrative scoping is preferred.
84  * Please refer to <a href="http://www.ietf.org/rfc/rfc2365.txt">
85  * <i>RFC&nbsp;2365: Administratively Scoped IP Multicast</i></a>
86  * @since 1.4
87  */
88 
89 public final
90 class Inet4Address extends InetAddress {
91     final static int INADDRSZ = 4;
92 
93     /** use serialVersionUID from InetAddress, but Inet4Address instance
94      *  is always replaced by an InetAddress instance before being
95      *  serialized */
96     private static final long serialVersionUID = 3286316764910316507L;
97 
98     /** @hide */
99     public static final InetAddress ANY = new Inet4Address(null, new byte[] { 0, 0, 0, 0 });
100 
101     /** @hide */
102     public static final InetAddress ALL =
103             new Inet4Address(null, new byte[] { (byte) 255, (byte) 255,
104                   (byte) 255, (byte) 255 });
105     /** @hide */
106     public static final InetAddress LOOPBACK =
107             new Inet4Address("localhost", new byte[] { 127, 0, 0, 1 });
108 
Inet4Address()109     Inet4Address() {
110         super();
111         holder().hostName = null;
112         holder().address = 0;
113         holder().family = AF_INET;
114     }
115 
Inet4Address(String hostName, byte addr[])116     Inet4Address(String hostName, byte addr[]) {
117         holder().hostName = hostName;
118         holder().family = AF_INET;
119         if (addr != null) {
120             if (addr.length == INADDRSZ) {
121                 int address  = addr[3] & 0xFF;
122                 address |= ((addr[2] << 8) & 0xFF00);
123                 address |= ((addr[1] << 16) & 0xFF0000);
124                 address |= ((addr[0] << 24) & 0xFF000000);
125                 holder().address = address;
126             }
127         }
128     }
Inet4Address(String hostName, int address)129     Inet4Address(String hostName, int address) {
130         holder().hostName = hostName;
131         holder().family = AF_INET;
132         holder().address = address;
133     }
134 
135     /**
136      * Replaces the object to be serialized with an InetAddress object.
137      *
138      * @return the alternate object to be serialized.
139      *
140      * @throws ObjectStreamException if a new object replacing this
141      * object could not be created
142      */
writeReplace()143     private Object writeReplace() throws ObjectStreamException {
144         // will replace the to be serialized 'this' object
145         InetAddress inet = new InetAddress();
146         inet.holder().hostName = holder().getHostName();
147         inet.holder().address = holder().getAddress();
148 
149         /**
150          * Prior to 1.4 an InetAddress was created with a family
151          * based on the platform AF_INET value (usually 2).
152          * For compatibility reasons we must therefore write the
153          * the InetAddress with this family.
154          */
155         inet.holder().family = 2;
156 
157         return inet;
158     }
159 
160     /**
161      * Utility routine to check if the InetAddress is an
162      * IP multicast address. IP multicast address is a Class D
163      * address i.e first four bits of the address are 1110.
164      * @return a <code>boolean</code> indicating if the InetAddress is
165      * an IP multicast address
166      * @since   JDK1.1
167      */
isMulticastAddress()168     public boolean isMulticastAddress() {
169         return ((holder().getAddress() & 0xf0000000) == 0xe0000000);
170     }
171 
172     /**
173      * Utility routine to check if the InetAddress in a wildcard address.
174      * @return a <code>boolean</code> indicating if the Inetaddress is
175      *         a wildcard address.
176      * @since 1.4
177      */
isAnyLocalAddress()178     public boolean isAnyLocalAddress() {
179         return holder().getAddress() == 0;
180     }
181 
182     /**
183      * Utility routine to check if the InetAddress is a loopback address.
184      *
185      * @return a <code>boolean</code> indicating if the InetAddress is
186      * a loopback address; or false otherwise.
187      * @since 1.4
188      */
189     private static final int loopback = 2130706433; /* 127.0.0.1 */
isLoopbackAddress()190     public boolean isLoopbackAddress() {
191         /* 127.x.x.x */
192         byte[] byteAddr = getAddress();
193         return byteAddr[0] == 127;
194     }
195 
196     /**
197      * Utility routine to check if the InetAddress is an link local address.
198      *
199      * @return a <code>boolean</code> indicating if the InetAddress is
200      * a link local address; or false if address is not a link local unicast address.
201      * @since 1.4
202      */
isLinkLocalAddress()203     public boolean isLinkLocalAddress() {
204         // link-local unicast in IPv4 (169.254.0.0/16)
205         // defined in "Documenting Special Use IPv4 Address Blocks
206         // that have been Registered with IANA" by Bill Manning
207         // draft-manning-dsua-06.txt
208         int address = holder().getAddress();
209         return (((address >>> 24) & 0xFF) == 169)
210             && (((address >>> 16) & 0xFF) == 254);
211     }
212 
213     /**
214      * Utility routine to check if the InetAddress is a site local address.
215      *
216      * @return a <code>boolean</code> indicating if the InetAddress is
217      * a site local address; or false if address is not a site local unicast address.
218      * @since 1.4
219      */
isSiteLocalAddress()220     public boolean isSiteLocalAddress() {
221         // refer to RFC 1918
222         // 10/8 prefix
223         // 172.16/12 prefix
224         // 192.168/16 prefix
225         int address = holder().getAddress();
226         return (((address >>> 24) & 0xFF) == 10)
227             || ((((address >>> 24) & 0xFF) == 172)
228                 && (((address >>> 16) & 0xF0) == 16))
229             || ((((address >>> 24) & 0xFF) == 192)
230                 && (((address >>> 16) & 0xFF) == 168));
231     }
232 
233     /**
234      * Utility routine to check if the multicast address has global scope.
235      *
236      * @return a <code>boolean</code> indicating if the address has
237      *         is a multicast address of global scope, false if it is not
238      *         of global scope or it is not a multicast address
239      * @since 1.4
240      */
isMCGlobal()241     public boolean isMCGlobal() {
242         // 224.0.1.0 to 238.255.255.255
243         byte[] byteAddr = getAddress();
244         return ((byteAddr[0] & 0xff) >= 224 && (byteAddr[0] & 0xff) <= 238 ) &&
245             !((byteAddr[0] & 0xff) == 224 && byteAddr[1] == 0 &&
246               byteAddr[2] == 0);
247     }
248 
249     /**
250      * Utility routine to check if the multicast address has node scope.
251      *
252      * @return a <code>boolean</code> indicating if the address has
253      *         is a multicast address of node-local scope, false if it is not
254      *         of node-local scope or it is not a multicast address
255      * @since 1.4
256      */
isMCNodeLocal()257     public boolean isMCNodeLocal() {
258         // unless ttl == 0
259         return false;
260     }
261 
262     /**
263      * Utility routine to check if the multicast address has link scope.
264      *
265      * @return a <code>boolean</code> indicating if the address has
266      *         is a multicast address of link-local scope, false if it is not
267      *         of link-local scope or it is not a multicast address
268      * @since 1.4
269      */
isMCLinkLocal()270     public boolean isMCLinkLocal() {
271         // 224.0.0/24 prefix and ttl == 1
272         int address = holder().getAddress();
273         return (((address >>> 24) & 0xFF) == 224)
274             && (((address >>> 16) & 0xFF) == 0)
275             && (((address >>> 8) & 0xFF) == 0);
276     }
277 
278     /**
279      * Utility routine to check if the multicast address has site scope.
280      *
281      * @return a <code>boolean</code> indicating if the address has
282      *         is a multicast address of site-local scope, false if it is not
283      *         of site-local scope or it is not a multicast address
284      * @since 1.4
285      */
isMCSiteLocal()286     public boolean isMCSiteLocal() {
287         // 239.255/16 prefix or ttl < 32
288         int address = holder().getAddress();
289         return (((address >>> 24) & 0xFF) == 239)
290             && (((address >>> 16) & 0xFF) == 255);
291     }
292 
293     /**
294      * Utility routine to check if the multicast address has organization scope.
295      *
296      * @return a <code>boolean</code> indicating if the address has
297      *         is a multicast address of organization-local scope,
298      *         false if it is not of organization-local scope
299      *         or it is not a multicast address
300      * @since 1.4
301      */
isMCOrgLocal()302     public boolean isMCOrgLocal() {
303         // 239.192 - 239.195
304         int address = holder().getAddress();
305         return (((address >>> 24) & 0xFF) == 239)
306             && (((address >>> 16) & 0xFF) >= 192)
307             && (((address >>> 16) & 0xFF) <= 195);
308     }
309 
310     /**
311      * Returns the raw IP address of this <code>InetAddress</code>
312      * object. The result is in network byte order: the highest order
313      * byte of the address is in <code>getAddress()[0]</code>.
314      *
315      * @return  the raw IP address of this object.
316      */
getAddress()317     public byte[] getAddress() {
318         int address = holder().getAddress();
319         byte[] addr = new byte[INADDRSZ];
320 
321         addr[0] = (byte) ((address >>> 24) & 0xFF);
322         addr[1] = (byte) ((address >>> 16) & 0xFF);
323         addr[2] = (byte) ((address >>> 8) & 0xFF);
324         addr[3] = (byte) (address & 0xFF);
325         return addr;
326     }
327 
328     /**
329      * Returns the IP address string in textual presentation form.
330      *
331      * @return  the raw IP address in a string format.
332      * @since   JDK1.0.2
333      */
getHostAddress()334     public String getHostAddress() {
335         return numericToTextFormat(getAddress());
336     }
337 
338     /**
339      * Returns a hashcode for this IP address.
340      *
341      * @return  a hash code value for this IP address.
342      */
hashCode()343     public int hashCode() {
344         return holder().getAddress();
345     }
346 
347     /**
348      * Compares this object against the specified object.
349      * The result is <code>true</code> if and only if the argument is
350      * not <code>null</code> and it represents the same IP address as
351      * this object.
352      * <p>
353      * Two instances of <code>InetAddress</code> represent the same IP
354      * address if the length of the byte arrays returned by
355      * <code>getAddress</code> is the same for both, and each of the
356      * array components is the same for the byte arrays.
357      *
358      * @param   obj   the object to compare against.
359      * @return  <code>true</code> if the objects are the same;
360      *          <code>false</code> otherwise.
361      * @see     java.net.InetAddress#getAddress()
362      */
equals(Object obj)363     public boolean equals(Object obj) {
364         return (obj != null) && (obj instanceof Inet4Address) &&
365             (((InetAddress)obj).holder().getAddress() == holder().getAddress());
366     }
367 
368     // Utilities
369     /*
370      * Converts IPv4 binary address into a string suitable for presentation.
371      *
372      * @param src a byte array representing an IPv4 numeric address
373      * @return a String representing the IPv4 address in
374      *         textual representation format
375      * @since 1.4
376      */
377 
numericToTextFormat(byte[] src)378     static String numericToTextFormat(byte[] src)
379     {
380         return (src[0] & 0xff) + "." + (src[1] & 0xff) + "." + (src[2] & 0xff) + "." + (src[3] & 0xff);
381     }
382 }
383