1 /*
2 * Copyright (c) 2000, 2017, 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 * <h3> <a id="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><ul style="list-style-type:none">
45 * <li>{@code d.d.d.d}</li>
46 * <li>{@code d.d.d}</li>
47 * <li>{@code d.d}</li>
48 * <li>{@code d}</li>
49 * </ul></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 static final 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 holder().originalHostName = hostName;
121 }
122 Inet4Address(String hostName, int address) {
123 holder().hostName = hostName;
124 holder().family = IPv4;
125 holder().address = address;
126 holder().originalHostName = hostName;
127 }
128
129 /**
130 * Replaces the object to be serialized with an InetAddress object.
131 *
132 * @return the alternate object to be serialized.
133 *
134 * @throws ObjectStreamException if a new object replacing this
135 * object could not be created
136 */
137 private Object writeReplace() throws ObjectStreamException {
138 // will replace the to be serialized 'this' object
139 InetAddress inet = new InetAddress();
140 inet.holder().hostName = holder().getHostName();
141 inet.holder().address = holder().getAddress();
142
143 /**
144 * Prior to 1.4 an InetAddress was created with a family
145 * based on the platform AF_INET value (usually 2).
146 * For compatibility reasons we must therefore write
147 * the InetAddress with this family.
148 */
149 inet.holder().family = 2;
150
151 return inet;
152 }
153
154 /**
155 * Utility routine to check if the InetAddress is an
156 * IP multicast address. IP multicast address is a Class D
157 * address i.e first four bits of the address are 1110.
158 * @return a {@code boolean} indicating if the InetAddress is
159 * an IP multicast address
160 */
161 public boolean isMulticastAddress() {
162 return ((holder().getAddress() & 0xf0000000) == 0xe0000000);
163 }
164
165 /**
166 * Utility routine to check if the InetAddress is a wildcard address.
167 * @return a {@code boolean} indicating if the InetAddress is
168 * a wildcard address.
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 */
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} indicating if the InetAddress is
190 * a link local address; or false if address is not a link local unicast address.
191 */
192 public boolean isLinkLocalAddress() {
193 // link-local unicast in IPv4 (169.254.0.0/16)
194 // defined in "Documenting Special Use IPv4 Address Blocks
195 // that have been Registered with IANA" by Bill Manning
196 // draft-manning-dsua-06.txt
197 int address = holder().getAddress();
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} indicating if the InetAddress is
206 * a site local address; or false if address is not a site local unicast address.
207 */
208 public boolean isSiteLocalAddress() {
209 // refer to RFC 1918
210 // 10/8 prefix
211 // 172.16/12 prefix
212 // 192.168/16 prefix
213 int address = holder().getAddress();
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} 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 */
228 public boolean isMCGlobal() {
229 // 224.0.1.0 to 238.255.255.255
230 byte[] byteAddr = getAddress();
231 return ((byteAddr[0] & 0xff) >= 224 && (byteAddr[0] & 0xff) <= 238 ) &&
232 !((byteAddr[0] & 0xff) == 224 && byteAddr[1] == 0 &&
233 byteAddr[2] == 0);
234 }
235
236 /**
237 * Utility routine to check if the multicast address has node scope.
238 *
239 * @return a {@code boolean} indicating if the address has
240 * is a multicast address of node-local scope, false if it is not
241 * of node-local scope or it is not a multicast address
242 */
243 public boolean isMCNodeLocal() {
244 // unless ttl == 0
245 return false;
246 }
247
248 /**
249 * Utility routine to check if the multicast address has link scope.
250 *
251 * @return a {@code boolean} indicating if the address has
252 * is a multicast address of link-local scope, false if it is not
253 * of link-local scope or it is not a multicast address
254 */
255 public boolean isMCLinkLocal() {
256 // 224.0.0/24 prefix and ttl == 1
257 int address = holder().getAddress();
258 return (((address >>> 24) & 0xFF) == 224)
259 && (((address >>> 16) & 0xFF) == 0)
260 && (((address >>> 8) & 0xFF) == 0);
261 }
262
263 /**
264 * Utility routine to check if the multicast address has site scope.
265 *
266 * @return a {@code boolean} indicating if the address has
267 * is a multicast address of site-local scope, false if it is not
268 * of site-local scope or it is not a multicast address
269 */
270 public boolean isMCSiteLocal() {
271 // 239.255/16 prefix or ttl < 32
272 int address = holder().getAddress();
273 return (((address >>> 24) & 0xFF) == 239)
274 && (((address >>> 16) & 0xFF) == 255);
275 }
276
277 /**
278 * Utility routine to check if the multicast address has organization scope.
279 *
280 * @return a {@code boolean} indicating if the address has
281 * is a multicast address of organization-local scope,
282 * false if it is not of organization-local scope
283 * or it is not a multicast address
284 */
285 public boolean isMCOrgLocal() {
286 // 239.192 - 239.195
287 int address = holder().getAddress();
288 return (((address >>> 24) & 0xFF) == 239)
289 && (((address >>> 16) & 0xFF) >= 192)
290 && (((address >>> 16) & 0xFF) <= 195);
291 }
292
293 /**
294 * Returns the raw IP address of this {@code InetAddress}
295 * object. The result is in network byte order: the highest order
296 * byte of the address is in {@code getAddress()[0]}.
297 *
298 * @return the raw IP address of this object.
299 */
300 public byte[] getAddress() {
301 int address = holder().getAddress();
302 byte[] addr = new byte[INADDRSZ];
303
304 addr[0] = (byte) ((address >>> 24) & 0xFF);
305 addr[1] = (byte) ((address >>> 16) & 0xFF);
306 addr[2] = (byte) ((address >>> 8) & 0xFF);
307 addr[3] = (byte) (address & 0xFF);
308 return addr;
309 }
310
311 /**
312 * Returns the IP address string in textual presentation form.
313 *
314 * @return the raw IP address in a string format.
315 */
316 public String getHostAddress() {
317 return numericToTextFormat(getAddress());
318 }
319
320 /**
321 * Returns a hashcode for this IP address.
322 *
323 * @return a hash code value for this IP address.
324 */
325 public int hashCode() {
326 return holder().getAddress();
327 }
328
329 /**
330 * Compares this object against the specified object.
331 * The result is {@code true} if and only if the argument is
332 * not {@code null} and it represents the same IP address as
333 * this object.
334 * <p>
335 * Two instances of {@code InetAddress} represent the same IP
336 * address if the length of the byte arrays returned by
337 * {@code getAddress} is the same for both, and each of the
338 * array components is the same for the byte arrays.
339 *
340 * @param obj the object to compare against.
341 * @return {@code true} if the objects are the same;
342 * {@code false} otherwise.
343 * @see java.net.InetAddress#getAddress()
344 */
345 public boolean equals(Object obj) {
346 return (obj != null) && (obj instanceof Inet4Address) &&
347 (((InetAddress)obj).holder().getAddress() == holder().getAddress());
348 }
349
350 // Utilities
351
352 /**
353 * Converts IPv4 binary address into a string suitable for presentation.
354 *
355 * @param src a byte array representing an IPv4 numeric address
356 * @return a String representing the IPv4 address in
357 * textual representation format
358 */
359 static String numericToTextFormat(byte[] src)
360 {
361 return (src[0] & 0xff) + "." + (src[1] & 0xff) + "." + (src[2] & 0xff) + "." + (src[3] & 0xff);
362 }
363
364 /**
365 * Perform class load-time initializations.
366 */
367 private static native void init();
368 }