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 790: Assigned Numbers</i></a>, 36 * <a href="http://www.ietf.org/rfc/rfc1918.txt"> 37 * <i>RFC 1918: Address Allocation for Private Internets</i></a>, 38 * and <a href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC 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 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 /** @hide */ 97 public static final InetAddress ANY = new Inet4Address(null, new byte[] { 0, 0, 0, 0 }); 98 99 /** @hide */ 100 public static final InetAddress ALL = 101 new Inet4Address(null, new byte[] { (byte) 255, (byte) 255, 102 (byte) 255, (byte) 255 }); 103 /** @hide */ 104 public static final InetAddress LOOPBACK = 105 new Inet4Address("localhost", new byte[] { 127, 0, 0, 1 }); 106 Inet4Address()107 Inet4Address() { 108 super(); 109 holder().hostName = null; 110 holder().address = 0; 111 holder().family = AF_INET; 112 } 113 Inet4Address(String hostName, byte addr[])114 Inet4Address(String hostName, byte addr[]) { 115 holder().hostName = hostName; 116 holder().family = AF_INET; 117 if (addr != null) { 118 if (addr.length == INADDRSZ) { 119 int address = addr[3] & 0xFF; 120 address |= ((addr[2] << 8) & 0xFF00); 121 address |= ((addr[1] << 16) & 0xFF0000); 122 address |= ((addr[0] << 24) & 0xFF000000); 123 holder().address = address; 124 } 125 } 126 } Inet4Address(String hostName, int address)127 Inet4Address(String hostName, int address) { 128 holder().hostName = hostName; 129 holder().family = AF_INET; 130 holder().address = address; 131 } 132 133 /** 134 * Replaces the object to be serialized with an InetAddress object. 135 * 136 * @return the alternate object to be serialized. 137 * 138 * @throws ObjectStreamException if a new object replacing this 139 * object could not be created 140 */ writeReplace()141 private Object writeReplace() throws ObjectStreamException { 142 // will replace the to be serialized 'this' object 143 InetAddress inet = new InetAddress(); 144 inet.holder().hostName = holder().getHostName(); 145 inet.holder().address = holder().getAddress(); 146 147 /** 148 * Prior to 1.4 an InetAddress was created with a family 149 * based on the platform AF_INET value (usually 2). 150 * For compatibility reasons we must therefore write the 151 * the InetAddress with this family. 152 */ 153 inet.holder().family = 2; 154 155 return inet; 156 } 157 158 /** 159 * Utility routine to check if the InetAddress is an 160 * IP multicast address. IP multicast address is a Class D 161 * address i.e first four bits of the address are 1110. 162 * @return a {@code boolean} indicating if the InetAddress is 163 * an IP multicast address 164 * @since JDK1.1 165 */ isMulticastAddress()166 public boolean isMulticastAddress() { 167 return ((holder().getAddress() & 0xf0000000) == 0xe0000000); 168 } 169 170 /** 171 * Utility routine to check if the InetAddress in a wildcard address. 172 * @return a {@code boolean} indicating if the Inetaddress is 173 * a wildcard address. 174 * @since 1.4 175 */ isAnyLocalAddress()176 public boolean isAnyLocalAddress() { 177 return holder().getAddress() == 0; 178 } 179 180 /** 181 * Utility routine to check if the InetAddress is a loopback address. 182 * 183 * @return a {@code boolean} indicating if the InetAddress is 184 * a loopback address; or false otherwise. 185 * @since 1.4 186 */ isLoopbackAddress()187 public boolean isLoopbackAddress() { 188 /* 127.x.x.x */ 189 byte[] byteAddr = getAddress(); 190 return byteAddr[0] == 127; 191 } 192 193 /** 194 * Utility routine to check if the InetAddress is an link local address. 195 * 196 * @return a {@code boolean} indicating if the InetAddress is 197 * a link local address; or false if address is not a link local unicast address. 198 * @since 1.4 199 */ isLinkLocalAddress()200 public boolean isLinkLocalAddress() { 201 // link-local unicast in IPv4 (169.254.0.0/16) 202 // defined in "Documenting Special Use IPv4 Address Blocks 203 // that have been Registered with IANA" by Bill Manning 204 // draft-manning-dsua-06.txt 205 int address = holder().getAddress(); 206 return (((address >>> 24) & 0xFF) == 169) 207 && (((address >>> 16) & 0xFF) == 254); 208 } 209 210 /** 211 * Utility routine to check if the InetAddress is a site local address. 212 * 213 * @return a {@code boolean} indicating if the InetAddress is 214 * a site local address; or false if address is not a site local unicast address. 215 * @since 1.4 216 */ isSiteLocalAddress()217 public boolean isSiteLocalAddress() { 218 // refer to RFC 1918 219 // 10/8 prefix 220 // 172.16/12 prefix 221 // 192.168/16 prefix 222 int address = holder().getAddress(); 223 return (((address >>> 24) & 0xFF) == 10) 224 || ((((address >>> 24) & 0xFF) == 172) 225 && (((address >>> 16) & 0xF0) == 16)) 226 || ((((address >>> 24) & 0xFF) == 192) 227 && (((address >>> 16) & 0xFF) == 168)); 228 } 229 230 /** 231 * Utility routine to check if the multicast address has global scope. 232 * 233 * @return a {@code boolean} indicating if the address has 234 * is a multicast address of global scope, false if it is not 235 * of global scope or it is not a multicast address 236 * @since 1.4 237 */ isMCGlobal()238 public boolean isMCGlobal() { 239 // 224.0.1.0 to 238.255.255.255 240 byte[] byteAddr = getAddress(); 241 return ((byteAddr[0] & 0xff) >= 224 && (byteAddr[0] & 0xff) <= 238 ) && 242 !((byteAddr[0] & 0xff) == 224 && byteAddr[1] == 0 && 243 byteAddr[2] == 0); 244 } 245 246 /** 247 * Utility routine to check if the multicast address has node scope. 248 * 249 * @return a {@code boolean} indicating if the address has 250 * is a multicast address of node-local scope, false if it is not 251 * of node-local scope or it is not a multicast address 252 * @since 1.4 253 */ isMCNodeLocal()254 public boolean isMCNodeLocal() { 255 // unless ttl == 0 256 return false; 257 } 258 259 /** 260 * Utility routine to check if the multicast address has link scope. 261 * 262 * @return a {@code boolean} indicating if the address has 263 * is a multicast address of link-local scope, false if it is not 264 * of link-local scope or it is not a multicast address 265 * @since 1.4 266 */ isMCLinkLocal()267 public boolean isMCLinkLocal() { 268 // 224.0.0/24 prefix and ttl == 1 269 int address = holder().getAddress(); 270 return (((address >>> 24) & 0xFF) == 224) 271 && (((address >>> 16) & 0xFF) == 0) 272 && (((address >>> 8) & 0xFF) == 0); 273 } 274 275 /** 276 * Utility routine to check if the multicast address has site scope. 277 * 278 * @return a {@code boolean} indicating if the address has 279 * is a multicast address of site-local scope, false if it is not 280 * of site-local scope or it is not a multicast address 281 * @since 1.4 282 */ isMCSiteLocal()283 public boolean isMCSiteLocal() { 284 // 239.255/16 prefix or ttl < 32 285 int address = holder().getAddress(); 286 return (((address >>> 24) & 0xFF) == 239) 287 && (((address >>> 16) & 0xFF) == 255); 288 } 289 290 /** 291 * Utility routine to check if the multicast address has organization scope. 292 * 293 * @return a {@code boolean} indicating if the address has 294 * is a multicast address of organization-local scope, 295 * false if it is not of organization-local scope 296 * or it is not a multicast address 297 * @since 1.4 298 */ isMCOrgLocal()299 public boolean isMCOrgLocal() { 300 // 239.192 - 239.195 301 int address = holder().getAddress(); 302 return (((address >>> 24) & 0xFF) == 239) 303 && (((address >>> 16) & 0xFF) >= 192) 304 && (((address >>> 16) & 0xFF) <= 195); 305 } 306 307 /** 308 * Returns the raw IP address of this {@code InetAddress} 309 * object. The result is in network byte order: the highest order 310 * byte of the address is in {@code getAddress()[0]}. 311 * 312 * @return the raw IP address of this object. 313 */ getAddress()314 public byte[] getAddress() { 315 int address = holder().getAddress(); 316 byte[] addr = new byte[INADDRSZ]; 317 318 addr[0] = (byte) ((address >>> 24) & 0xFF); 319 addr[1] = (byte) ((address >>> 16) & 0xFF); 320 addr[2] = (byte) ((address >>> 8) & 0xFF); 321 addr[3] = (byte) (address & 0xFF); 322 return addr; 323 } 324 325 /** 326 * Returns the IP address string in textual presentation form. 327 * 328 * @return the raw IP address in a string format. 329 * @since JDK1.0.2 330 */ getHostAddress()331 public String getHostAddress() { 332 return numericToTextFormat(getAddress()); 333 } 334 335 /** 336 * Returns a hashcode for this IP address. 337 * 338 * @return a hash code value for this IP address. 339 */ hashCode()340 public int hashCode() { 341 return holder().getAddress(); 342 } 343 344 /** 345 * Compares this object against the specified object. 346 * The result is {@code true} if and only if the argument is 347 * not {@code null} and it represents the same IP address as 348 * this object. 349 * <p> 350 * Two instances of {@code InetAddress} represent the same IP 351 * address if the length of the byte arrays returned by 352 * {@code getAddress} is the same for both, and each of the 353 * array components is the same for the byte arrays. 354 * 355 * @param obj the object to compare against. 356 * @return {@code true} if the objects are the same; 357 * {@code false} otherwise. 358 * @see java.net.InetAddress#getAddress() 359 */ equals(Object obj)360 public boolean equals(Object obj) { 361 return (obj != null) && (obj instanceof Inet4Address) && 362 (((InetAddress)obj).holder().getAddress() == holder().getAddress()); 363 } 364 365 // Utilities 366 /* 367 * Converts IPv4 binary address into a string suitable for presentation. 368 * 369 * @param src a byte array representing an IPv4 numeric address 370 * @return a String representing the IPv4 address in 371 * textual representation format 372 * @since 1.4 373 */ 374 numericToTextFormat(byte[] src)375 static String numericToTextFormat(byte[] src) 376 { 377 return (src[0] & 0xff) + "." + (src[1] & 0xff) + "." + (src[2] & 0xff) + "." + (src[3] & 0xff); 378 } 379 } 380