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 26package java.net; 27 28import 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 85public final 86class 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 the 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} 369