1 /*
   2  * Copyright (c) 2000, 2013, 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&nbsp;790: Assigned Numbers</i></a>,
  34  * <a href="http://www.ietf.org/rfc/rfc1918.txt">
  35  * <i>RFC&nbsp;1918: Address Allocation for Private Internets</i></a>,
  36  * and <a href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC&nbsp;2365:
  37  * Administratively Scoped IP Multicast</i></a>
  38  *
  39  * <h3> <A NAME="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><table cellpadding=0 cellspacing=0 summary="layout">
  45  * <tr><td>{@code d.d.d.d}</td></tr>
  46  * <tr><td>{@code d.d.d}</td></tr>
  47  * <tr><td>{@code d.d}</td></tr>
  48  * <tr><td>{@code d}</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&nbsp;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         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     }
 121     Inet4Address(String hostName, int address) {
 122         holder().hostName = hostName;
 123         holder().family = IPv4;
 124         holder().address = address;
 125     }
 126 
 127     /**
 128      * Replaces the object to be serialized with an InetAddress object.
 129      *
 130      * @return the alternate object to be serialized.
 131      *
 132      * @throws ObjectStreamException if a new object replacing this
 133      * object could not be created
 134      */
 135     private Object writeReplace() throws ObjectStreamException {
 136         // will replace the to be serialized 'this' object
 137         InetAddress inet = new InetAddress();
 138         inet.holder().hostName = holder().getHostName();
 139         inet.holder().address = holder().getAddress();
 140 
 141         /**
 142          * Prior to 1.4 an InetAddress was created with a family
 143          * based on the platform AF_INET value (usually 2).
 144          * For compatibility reasons we must therefore write the
 145          * the InetAddress with this family.
 146          */
 147         inet.holder().family = 2;
 148 
 149         return inet;
 150     }
 151 
 152     /**
 153      * Utility routine to check if the InetAddress is an
 154      * IP multicast address. IP multicast address is a Class D
 155      * address i.e first four bits of the address are 1110.
 156      * @return a {@code boolean} indicating if the InetAddress is
 157      * an IP multicast address
 158      * @since   JDK1.1
 159      */
 160     public boolean isMulticastAddress() {
 161         return ((holder().getAddress() & 0xf0000000) == 0xe0000000);
 162     }
 163 
 164     /**
 165      * Utility routine to check if the InetAddress in a wildcard address.
 166      * @return a {@code boolean} indicating if the Inetaddress is
 167      *         a wildcard address.
 168      * @since 1.4
 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      * @since 1.4
 180      */
 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} 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         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      * @since 1.4
 210      */
 211     public boolean isSiteLocalAddress() {
 212         // refer to RFC 1918
 213         // 10/8 prefix
 214         // 172.16/12 prefix
 215         // 192.168/16 prefix
 216         int address = holder().getAddress();
 217         return (((address >>> 24) & 0xFF) == 10)
 218             || ((((address >>> 24) & 0xFF) == 172)
 219                 && (((address >>> 16) & 0xF0) == 16))
 220             || ((((address >>> 24) & 0xFF) == 192)
 221                 && (((address >>> 16) & 0xFF) == 168));
 222     }
 223 
 224     /**
 225      * Utility routine to check if the multicast address has global scope.
 226      *
 227      * @return a {@code boolean} indicating if the address has
 228      *         is a multicast address of global scope, false if it is not
 229      *         of global scope or it is not a multicast address
 230      * @since 1.4
 231      */
 232     public boolean isMCGlobal() {
 233         // 224.0.1.0 to 238.255.255.255
 234         byte[] byteAddr = getAddress();
 235         return ((byteAddr[0] & 0xff) >= 224 && (byteAddr[0] & 0xff) <= 238 ) &&
 236             !((byteAddr[0] & 0xff) == 224 && byteAddr[1] == 0 &&
 237               byteAddr[2] == 0);
 238     }
 239 
 240     /**
 241      * Utility routine to check if the multicast address has node scope.
 242      *
 243      * @return a {@code boolean} indicating if the address has
 244      *         is a multicast address of node-local scope, false if it is not
 245      *         of node-local scope or it is not a multicast address
 246      * @since 1.4
 247      */
 248     public boolean isMCNodeLocal() {
 249         // unless ttl == 0
 250         return false;
 251     }
 252 
 253     /**
 254      * Utility routine to check if the multicast address has link scope.
 255      *
 256      * @return a {@code boolean} indicating if the address has
 257      *         is a multicast address of link-local scope, false if it is not
 258      *         of link-local scope or it is not a multicast address
 259      * @since 1.4
 260      */
 261     public boolean isMCLinkLocal() {
 262         // 224.0.0/24 prefix and ttl == 1
 263         int address = holder().getAddress();
 264         return (((address >>> 24) & 0xFF) == 224)
 265             && (((address >>> 16) & 0xFF) == 0)
 266             && (((address >>> 8) & 0xFF) == 0);
 267     }
 268 
 269     /**
 270      * Utility routine to check if the multicast address has site scope.
 271      *
 272      * @return a {@code boolean} indicating if the address has
 273      *         is a multicast address of site-local scope, false if it is not
 274      *         of site-local scope or it is not a multicast address
 275      * @since 1.4
 276      */
 277     public boolean isMCSiteLocal() {
 278         // 239.255/16 prefix or ttl < 32
 279         int address = holder().getAddress();
 280         return (((address >>> 24) & 0xFF) == 239)
 281             && (((address >>> 16) & 0xFF) == 255);
 282     }
 283 
 284     /**
 285      * Utility routine to check if the multicast address has organization scope.
 286      *
 287      * @return a {@code boolean} indicating if the address has
 288      *         is a multicast address of organization-local scope,
 289      *         false if it is not of organization-local scope
 290      *         or it is not a multicast address
 291      * @since 1.4
 292      */
 293     public boolean isMCOrgLocal() {
 294         // 239.192 - 239.195
 295         int address = holder().getAddress();
 296         return (((address >>> 24) & 0xFF) == 239)
 297             && (((address >>> 16) & 0xFF) >= 192)
 298             && (((address >>> 16) & 0xFF) <= 195);
 299     }
 300 
 301     /**
 302      * Returns the raw IP address of this {@code InetAddress}
 303      * object. The result is in network byte order: the highest order
 304      * byte of the address is in {@code getAddress()[0]}.
 305      *
 306      * @return  the raw IP address of this object.
 307      */
 308     public byte[] getAddress() {
 309         int address = holder().getAddress();
 310         byte[] addr = new byte[INADDRSZ];
 311 
 312         addr[0] = (byte) ((address >>> 24) & 0xFF);
 313         addr[1] = (byte) ((address >>> 16) & 0xFF);
 314         addr[2] = (byte) ((address >>> 8) & 0xFF);
 315         addr[3] = (byte) (address & 0xFF);
 316         return addr;
 317     }
 318 
 319     /**
 320      * Returns the IP address string in textual presentation form.
 321      *
 322      * @return  the raw IP address in a string format.
 323      * @since   JDK1.0.2
 324      */
 325     public String getHostAddress() {
 326         return numericToTextFormat(getAddress());
 327     }
 328 
 329     /**
 330      * Returns a hashcode for this IP address.
 331      *
 332      * @return  a hash code value for this IP address.
 333      */
 334     public int hashCode() {
 335         return holder().getAddress();
 336     }
 337 
 338     /**
 339      * Compares this object against the specified object.
 340      * The result is {@code true} if and only if the argument is
 341      * not {@code null} and it represents the same IP address as
 342      * this object.
 343      * <p>
 344      * Two instances of {@code InetAddress} represent the same IP
 345      * address if the length of the byte arrays returned by
 346      * {@code getAddress} is the same for both, and each of the
 347      * array components is the same for the byte arrays.
 348      *
 349      * @param   obj   the object to compare against.
 350      * @return  {@code true} if the objects are the same;
 351      *          {@code false} otherwise.
 352      * @see     java.net.InetAddress#getAddress()
 353      */
 354     public boolean equals(Object obj) {
 355         return (obj != null) && (obj instanceof Inet4Address) &&
 356             (((InetAddress)obj).holder().getAddress() == holder().getAddress());
 357     }
 358 
 359     // Utilities
 360     /*
 361      * Converts IPv4 binary address into a string suitable for presentation.
 362      *
 363      * @param src a byte array representing an IPv4 numeric address
 364      * @return a String representing the IPv4 address in
 365      *         textual representation format
 366      * @since 1.4
 367      */
 368 
 369     static String numericToTextFormat(byte[] src)
 370     {
 371         return (src[0] & 0xff) + "." + (src[1] & 0xff) + "." + (src[2] & 0xff) + "." + (src[3] & 0xff);
 372     }
 373 
 374     /**
 375      * Perform class load-time initializations.
 376      */
 377     private static native void init();
 378 }