1 /*
2 * Copyright (c) 2000, 2019, 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 * <h2> <a id="format">Textual representation of IP addresses</a> </h2>
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 * <h3> The Scope of a Multicast Address </h3>
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 @java.io.Serial
93 private static final long serialVersionUID = 3286316764910316507L;
94
95 /*
96 * Perform initializations.
97 */
98 static {
99 init();
100 }
101
102 Inet4Address() {
103 super();
104 holder().hostName = null;
105 holder().address = 0;
106 holder().family = IPv4;
107 }
108
109 Inet4Address(String hostName, byte addr[]) {
110 holder().hostName = hostName;
111 holder().family = IPv4;
112 if (addr != null) {
113 if (addr.length == INADDRSZ) {
114 int address = addr[3] & 0xFF;
115 address |= ((addr[2] << 8) & 0xFF00);
116 address |= ((addr[1] << 16) & 0xFF0000);
117 address |= ((addr[0] << 24) & 0xFF000000);
118 holder().address = address;
119 }
120 }
121 holder().originalHostName = hostName;
122 }
123 Inet4Address(String hostName, int address) {
124 holder().hostName = hostName;
125 holder().family = IPv4;
126 holder().address = address;
127 holder().originalHostName = hostName;
128 }
129
130 /**
131 * Replaces the object to be serialized with an InetAddress object.
132 *
133 * @return the alternate object to be serialized.
134 *
135 * @throws ObjectStreamException if a new object replacing this
136 * object could not be created
137 */
138 @java.io.Serial
139 private Object writeReplace() throws ObjectStreamException {
140 // will replace the to be serialized 'this' object
141 InetAddress inet = new InetAddress();
142 inet.holder().hostName = holder().getHostName();
143 inet.holder().address = holder().getAddress();
144
145 /**
146 * Prior to 1.4 an InetAddress was created with a family
147 * based on the platform AF_INET value (usually 2).
148 * For compatibility reasons we must therefore write
149 * the InetAddress with this family.
150 */
151 inet.holder().family = 2;
152
153 return inet;
154 }
155
156 /**
157 * Utility routine to check if the InetAddress is an
158 * IP multicast address. IP multicast address is a Class D
159 * address i.e first four bits of the address are 1110.
160 * @return a {@code boolean} indicating if the InetAddress is
161 * an IP multicast address
162 */
163 public boolean isMulticastAddress() {
164 return ((holder().getAddress() & 0xf0000000) == 0xe0000000);
165 }
166
167 /**
168 * Utility routine to check if the InetAddress is a wildcard address.
169 * @return a {@code boolean} indicating if the InetAddress is
170 * a wildcard address.
171 */
172 public boolean isAnyLocalAddress() {
173 return holder().getAddress() == 0;
174 }
175
176 /**
177 * Utility routine to check if the InetAddress is a loopback address.
178 *
179 * @return a {@code boolean} indicating if the InetAddress is
180 * a loopback address; or false otherwise.
181 */
182 public boolean isLoopbackAddress() {
183 /* 127.x.x.x */
184 byte[] byteAddr = getAddress();
185 return byteAddr[0] == 127;
186 }
187
188 /**
189 * Utility routine to check if the InetAddress is an link local address.
190 *
191 * @return a {@code boolean} indicating if the InetAddress is
192 * a link local address; or false if address is not a link local unicast address.
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 */
210 public boolean isSiteLocalAddress() {
211 // refer to RFC 1918
212 // 10/8 prefix
213 // 172.16/12 prefix
214 // 192.168/16 prefix
215 int address = holder().getAddress();
216 return (((address >>> 24) & 0xFF) == 10)
217 || ((((address >>> 24) & 0xFF) == 172)
218 && (((address >>> 16) & 0xF0) == 16))
219 || ((((address >>> 24) & 0xFF) == 192)
220 && (((address >>> 16) & 0xFF) == 168));
221 }
222
223 /**
224 * Utility routine to check if the multicast address has global scope.
225 *
226 * @return a {@code boolean} indicating if the address has
227 * is a multicast address of global scope, false if it is not
228 * of global scope or it is not a multicast address
229 */
230 public boolean isMCGlobal() {
231 // 224.0.1.0 to 238.255.255.255
232 byte[] byteAddr = getAddress();
233 return ((byteAddr[0] & 0xff) >= 224 && (byteAddr[0] & 0xff) <= 238 ) &&
234 !((byteAddr[0] & 0xff) == 224 && byteAddr[1] == 0 &&
235 byteAddr[2] == 0);
236 }
237
238 /**
239 * Utility routine to check if the multicast address has node scope.
240 *
241 * @return a {@code boolean} indicating if the address has
242 * is a multicast address of node-local scope, false if it is not
243 * of node-local scope or it is not a multicast address
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} 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 */
257 public boolean isMCLinkLocal() {
258 // 224.0.0/24 prefix and ttl == 1
259 int address = holder().getAddress();
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} 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 */
272 public boolean isMCSiteLocal() {
273 // 239.255/16 prefix or ttl < 32
274 int address = holder().getAddress();
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} 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 */
287 public boolean isMCOrgLocal() {
288 // 239.192 - 239.195
289 int address = holder().getAddress();
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}
297 * object. The result is in network byte order: the highest order
298 * byte of the address is in {@code getAddress()[0]}.
299 *
300 * @return the raw IP address of this object.
301 */
302 public byte[] getAddress() {
303 int address = holder().getAddress();
304 byte[] addr = new byte[INADDRSZ];
305
306 addr[0] = (byte) ((address >>> 24) & 0xFF);
307 addr[1] = (byte) ((address >>> 16) & 0xFF);
308 addr[2] = (byte) ((address >>> 8) & 0xFF);
309 addr[3] = (byte) (address & 0xFF);
310 return addr;
311 }
312
313 /**
314 * Returns the IP address string in textual presentation form.
315 *
316 * @return the raw IP address in a string format.
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 holder().getAddress();
329 }
330
331 /**
332 * Compares this object against the specified object.
333 * The result is {@code true} if and only if the argument is
334 * not {@code null} and it represents the same IP address as
335 * this object.
336 * <p>
337 * Two instances of {@code InetAddress} represent the same IP
338 * address if the length of the byte arrays returned by
339 * {@code getAddress} 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} if the objects are the same;
344 * {@code false} otherwise.
345 * @see java.net.InetAddress#getAddress()
346 */
347 public boolean equals(Object obj) {
348 return (obj != null) && (obj instanceof Inet4Address) &&
349 (((InetAddress)obj).holder().getAddress() == holder().getAddress());
350 }
351
352 // Utilities
353
354 /**
355 * Converts IPv4 binary address into a string suitable for presentation.
356 *
357 * @param src a byte array representing an IPv4 numeric address
358 * @return a String representing the IPv4 address in
359 * textual representation format
360 */
361 static String numericToTextFormat(byte[] src)
362 {
363 return (src[0] & 0xff) + "." + (src[1] & 0xff) + "." + (src[2] & 0xff) + "." + (src[3] & 0xff);
364 }
365
366 /**
367 * Perform class load-time initializations.
368 */
369 private static native void init();
370 }