1 /*
2 * Copyright (c) 2000, 2011, 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 790: Assigned Numbers</i></a>,
34 * <a href="http://www.ietf.org/rfc/rfc1918.txt">
35 * <i>RFC 1918: Address Allocation for Private Internets</i></a>,
36 * and <a href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC 2365:
37 * Administratively Scoped IP Multicast</i></a>
38 *
39 * <h4> <A NAME="format">Textual representation of IP addresses</a> </h4>
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><tt>d.d.d.d</tt></td></tr>
46 * <tr><td><tt>d.d.d</tt></td></tr>
47 * <tr><td><tt>d.d</tt></td></tr>
48 * <tr><td><tt>d</tt></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 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 hostName = null;
104 address = 0;
105 family = IPv4;
106 }
107
108 Inet4Address(String hostName, byte addr[]) {
109 this.hostName = hostName;
110 this.family = IPv4;
111 if (addr != null) {
112 if (addr.length == INADDRSZ) {
113 address = addr[3] & 0xFF;
114 address |= ((addr[2] << 8) & 0xFF00);
115 address |= ((addr[1] << 16) & 0xFF0000);
116 address |= ((addr[0] << 24) & 0xFF000000);
117 }
118 }
119 }
120 Inet4Address(String hostName, int address) {
121 this.hostName = hostName;
122 this.family = IPv4;
123 this.address = address;
124 }
125
126 /**
127 * Replaces the object to be serialized with an InetAddress object.
128 *
129 * @return the alternate object to be serialized.
130 *
131 * @throws ObjectStreamException if a new object replacing this
132 * object could not be created
133 */
134 private Object writeReplace() throws ObjectStreamException {
135 // will replace the to be serialized 'this' object
136 InetAddress inet = new InetAddress();
137 inet.hostName = this.hostName;
138 inet.address = this.address;
139
140 /**
141 * Prior to 1.4 an InetAddress was created with a family
142 * based on the platform AF_INET value (usually 2).
143 * For compatibility reasons we must therefore write the
144 * the InetAddress with this family.
145 */
146 inet.family = 2;
147
148 return inet;
149 }
150
151 /**
152 * Utility routine to check if the InetAddress is an
153 * IP multicast address. IP multicast address is a Class D
154 * address i.e first four bits of the address are 1110.
155 * @return a <code>boolean</code> indicating if the InetAddress is
156 * an IP multicast address
157 * @since JDK1.1
158 */
159 public boolean isMulticastAddress() {
160 return ((address & 0xf0000000) == 0xe0000000);
161 }
162
163 /**
164 * Utility routine to check if the InetAddress in a wildcard address.
165 * @return a <code>boolean</code> indicating if the Inetaddress is
166 * a wildcard address.
167 * @since 1.4
168 */
169 public boolean isAnyLocalAddress() {
170 return address == 0;
171 }
172
173 /**
174 * Utility routine to check if the InetAddress is a loopback address.
175 *
176 * @return a <code>boolean</code> indicating if the InetAddress is
177 * a loopback address; or false otherwise.
178 * @since 1.4
179 */
180 public boolean isLoopbackAddress() {
181 /* 127.x.x.x */
182 byte[] byteAddr = getAddress();
183 return byteAddr[0] == 127;
184 }
185
186 /**
187 * Utility routine to check if the InetAddress is an link local address.
188 *
189 * @return a <code>boolean</code> indicating if the InetAddress is
190 * a link local address; or false if address is not a link local unicast address.
191 * @since 1.4
192 */
193 public boolean isLinkLocalAddress() {
194 // link-local unicast in IPv4 (169.254.0.0/16)
195 // defined in "Documenting Special Use IPv4 Address Blocks
196 // that have been Registered with IANA" by Bill Manning
197 // draft-manning-dsua-06.txt
198 return (((address >>> 24) & 0xFF) == 169)
199 && (((address >>> 16) & 0xFF) == 254);
200 }
201
202 /**
203 * Utility routine to check if the InetAddress is a site local address.
204 *
205 * @return a <code>boolean</code> indicating if the InetAddress is
206 * a site local address; or false if address is not a site local unicast address.
207 * @since 1.4
208 */
209 public boolean isSiteLocalAddress() {
210 // refer to RFC 1918
211 // 10/8 prefix
212 // 172.16/12 prefix
213 // 192.168/16 prefix
214 return (((address >>> 24) & 0xFF) == 10)
215 || ((((address >>> 24) & 0xFF) == 172)
216 && (((address >>> 16) & 0xF0) == 16))
217 || ((((address >>> 24) & 0xFF) == 192)
218 && (((address >>> 16) & 0xFF) == 168));
219 }
220
221 /**
222 * Utility routine to check if the multicast address has global scope.
223 *
224 * @return a <code>boolean</code> indicating if the address has
225 * is a multicast address of global scope, false if it is not
226 * of global scope or it is not a multicast address
227 * @since 1.4
228 */
229 public boolean isMCGlobal() {
230 // 224.0.1.0 to 238.255.255.255
231 byte[] byteAddr = getAddress();
232 return ((byteAddr[0] & 0xff) >= 224 && (byteAddr[0] & 0xff) <= 238 ) &&
233 !((byteAddr[0] & 0xff) == 224 && byteAddr[1] == 0 &&
234 byteAddr[2] == 0);
235 }
236
237 /**
238 * Utility routine to check if the multicast address has node scope.
239 *
240 * @return a <code>boolean</code> indicating if the address has
241 * is a multicast address of node-local scope, false if it is not
242 * of node-local scope or it is not a multicast address
243 * @since 1.4
244 */
245 public boolean isMCNodeLocal() {
246 // unless ttl == 0
247 return false;
248 }
249
250 /**
251 * Utility routine to check if the multicast address has link scope.
252 *
253 * @return a <code>boolean</code> indicating if the address has
254 * is a multicast address of link-local scope, false if it is not
255 * of link-local scope or it is not a multicast address
256 * @since 1.4
257 */
258 public boolean isMCLinkLocal() {
259 // 224.0.0/24 prefix and ttl == 1
260 return (((address >>> 24) & 0xFF) == 224)
261 && (((address >>> 16) & 0xFF) == 0)
262 && (((address >>> 8) & 0xFF) == 0);
263 }
264
265 /**
266 * Utility routine to check if the multicast address has site scope.
267 *
268 * @return a <code>boolean</code> indicating if the address has
269 * is a multicast address of site-local scope, false if it is not
270 * of site-local scope or it is not a multicast address
271 * @since 1.4
272 */
273 public boolean isMCSiteLocal() {
274 // 239.255/16 prefix or ttl < 32
275 return (((address >>> 24) & 0xFF) == 239)
276 && (((address >>> 16) & 0xFF) == 255);
277 }
278
279 /**
280 * Utility routine to check if the multicast address has organization scope.
281 *
282 * @return a <code>boolean</code> indicating if the address has
283 * is a multicast address of organization-local scope,
284 * false if it is not of organization-local scope
285 * or it is not a multicast address
286 * @since 1.4
287 */
288 public boolean isMCOrgLocal() {
289 // 239.192 - 239.195
290 return (((address >>> 24) & 0xFF) == 239)
291 && (((address >>> 16) & 0xFF) >= 192)
292 && (((address >>> 16) & 0xFF) <= 195);
293 }
294
295 /**
296 * Returns the raw IP address of this <code>InetAddress</code>
297 * object. The result is in network byte order: the highest order
298 * byte of the address is in <code>getAddress()[0]</code>.
299 *
300 * @return the raw IP address of this object.
301 */
302 public byte[] getAddress() {
303 byte[] addr = new byte[INADDRSZ];
304
305 addr[0] = (byte) ((address >>> 24) & 0xFF);
306 addr[1] = (byte) ((address >>> 16) & 0xFF);
307 addr[2] = (byte) ((address >>> 8) & 0xFF);
308 addr[3] = (byte) (address & 0xFF);
309 return addr;
310 }
311
312 /**
313 * Returns the IP address string in textual presentation form.
314 *
315 * @return the raw IP address in a string format.
316 * @since JDK1.0.2
317 */
318 public String getHostAddress() {
319 return numericToTextFormat(getAddress());
320 }
321
322 /**
323 * Returns a hashcode for this IP address.
324 *
325 * @return a hash code value for this IP address.
326 */
327 public int hashCode() {
328 return address;
329 }
330
331 /**
332 * Compares this object against the specified object.
333 * The result is <code>true</code> if and only if the argument is
334 * not <code>null</code> and it represents the same IP address as
335 * this object.
336 * <p>
337 * Two instances of <code>InetAddress</code> represent the same IP
338 * address if the length of the byte arrays returned by
339 * <code>getAddress</code> is the same for both, and each of the
340 * array components is the same for the byte arrays.
341 *
342 * @param obj the object to compare against.
343 * @return <code>true</code> if the objects are the same;
344 * <code>false</code> otherwise.
345 * @see java.net.InetAddress#getAddress()
346 */
347 public boolean equals(Object obj) {
348 return (obj != null) && (obj instanceof Inet4Address) &&
349 (((InetAddress)obj).address == address);
350 }
351
352 // Utilities
353 /*
354 * Converts IPv4 binary address into a string suitable for presentation.
355 *
356 * @param src a byte array representing an IPv4 numeric address
357 * @return a String representing the IPv4 address in
358 * textual representation format
359 * @since 1.4
360 */
361
362 static String numericToTextFormat(byte[] src)
363 {
364 return (src[0] & 0xff) + "." + (src[1] & 0xff) + "." + (src[2] & 0xff) + "." + (src[3] & 0xff);
365 }
366
367 /**
368 * Perform class load-time initializations.
369 */
370 private static native void init();
371 }