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 private static final int loopback = 2130706433; /* 127.0.0.1 */ 181 public boolean isLoopbackAddress() { 182 /* 127.x.x.x */ 183 byte[] byteAddr = getAddress(); 184 return byteAddr[0] == 127; 185 } 186 187 /** 188 * Utility routine to check if the InetAddress is an link local address. 189 * 190 * @return a <code>boolean</code> indicating if the InetAddress is 191 * a link local address; or false if address is not a link local unicast address. 192 * @since 1.4 193 */ 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 return (((address >>> 24) & 0xFF) == 169) 200 && (((address >>> 16) & 0xFF) == 254); 201 } 202 203 /** 204 * Utility routine to check if the InetAddress is a site local address. 205 * 206 * @return a <code>boolean</code> indicating if the InetAddress is 207 * a site local address; or false if address is not a site local unicast address. 208 * @since 1.4 209 */ 210 public boolean isSiteLocalAddress() { 211 // refer to RFC 1918 212 // 10/8 prefix 213 // 172.16/12 prefix 214 // 192.168/16 prefix 215 return (((address >>> 24) & 0xFF) == 10) 216 || ((((address >>> 24) & 0xFF) == 172) 217 && (((address >>> 16) & 0xF0) == 16)) 218 || ((((address >>> 24) & 0xFF) == 192) 219 && (((address >>> 16) & 0xFF) == 168)); 220 } 221 222 /** 223 * Utility routine to check if the multicast address has global scope. 224 * 225 * @return a <code>boolean</code> indicating if the address has 226 * is a multicast address of global scope, false if it is not 227 * of global scope or it is not a multicast address 228 * @since 1.4 229 */ 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</code> 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 * @since 1.4 245 */ 246 public boolean isMCNodeLocal() { 247 // unless ttl == 0 248 return false; 249 } 250 251 /** 252 * Utility routine to check if the multicast address has link scope. 253 * 254 * @return a <code>boolean</code> indicating if the address has 255 * is a multicast address of link-local scope, false if it is not 256 * of link-local scope or it is not a multicast address 257 * @since 1.4 258 */ 259 public boolean isMCLinkLocal() { 260 // 224.0.0/24 prefix and ttl == 1 261 return (((address >>> 24) & 0xFF) == 224) 262 && (((address >>> 16) & 0xFF) == 0) 263 && (((address >>> 8) & 0xFF) == 0); 264 } 265 266 /** 267 * Utility routine to check if the multicast address has site scope. 268 * 269 * @return a <code>boolean</code> indicating if the address has 270 * is a multicast address of site-local scope, false if it is not 271 * of site-local scope or it is not a multicast address 272 * @since 1.4 273 */ 274 public boolean isMCSiteLocal() { 275 // 239.255/16 prefix or ttl < 32 276 return (((address >>> 24) & 0xFF) == 239) 277 && (((address >>> 16) & 0xFF) == 255); 278 } 279 280 /** 281 * Utility routine to check if the multicast address has organization scope. 282 * 283 * @return a <code>boolean</code> indicating if the address has 284 * is a multicast address of organization-local scope, 285 * false if it is not of organization-local scope 286 * or it is not a multicast address 287 * @since 1.4 288 */ 289 public boolean isMCOrgLocal() { 290 // 239.192 - 239.195 291 return (((address >>> 24) & 0xFF) == 239) 292 && (((address >>> 16) & 0xFF) >= 192) 293 && (((address >>> 16) & 0xFF) <= 195); 294 } 295 296 /** 297 * Returns the raw IP address of this <code>InetAddress</code> 298 * object. The result is in network byte order: the highest order 299 * byte of the address is in <code>getAddress()[0]</code>. 300 * 301 * @return the raw IP address of this object. 302 */ 303 public byte[] 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 * @since JDK1.0.2 318 */ 319 public String getHostAddress() { 320 return numericToTextFormat(getAddress()); 321 } 322 323 /** 324 * Returns a hashcode for this IP address. 325 * 326 * @return a hash code value for this IP address. 327 */ 328 public int hashCode() { 329 return address; 330 } 331 332 /** 333 * Compares this object against the specified object. 334 * The result is <code>true</code> if and only if the argument is 335 * not <code>null</code> and it represents the same IP address as 336 * this object. 337 * <p> 338 * Two instances of <code>InetAddress</code> represent the same IP 339 * address if the length of the byte arrays returned by 340 * <code>getAddress</code> is the same for both, and each of the 341 * array components is the same for the byte arrays. 342 * 343 * @param obj the object to compare against. 344 * @return <code>true</code> if the objects are the same; 345 * <code>false</code> otherwise. 346 * @see java.net.InetAddress#getAddress() 347 */ 348 public boolean equals(Object obj) { 349 return (obj != null) && (obj instanceof Inet4Address) && 350 (((InetAddress)obj).address == address); 351 } 352 353 // Utilities 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 * @since 1.4 361 */ 362 363 static String numericToTextFormat(byte[] src) 364 { 365 return (src[0] & 0xff) + "." + (src[1] & 0xff) + "." + (src[2] & 0xff) + "." + (src[3] & 0xff); 366 } 367 368 /** 369 * Perform class load-time initializations. 370 */ 371 private static native void init(); 372 }