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 package java.net;
  26 
  27 import java.io.IOException;
  28 import java.io.InvalidObjectException;
  29 import java.io.ObjectInputStream;
  30 import java.io.ObjectOutputStream;
  31 import java.io.ObjectStreamException;
  32 import java.io.ObjectStreamField;
  33 
  34 /**
  35  *
  36  * This class implements an IP Socket Address (IP address + port number)
  37  * It can also be a pair (hostname + port number), in which case an attempt
  38  * will be made to resolve the hostname. If resolution fails then the address
  39  * is said to be <I>unresolved</I> but can still be used on some circumstances
  40  * like connecting through a proxy.
  41  * <p>
  42  * It provides an immutable object used by sockets for binding, connecting, or
  43  * as returned values.
  44  * <p>
  45  * The <i>wildcard</i> is a special local IP address. It usually means "any"
  46  * and can only be used for {@code bind} operations.
  47  *
  48  * @see java.net.Socket
  49  * @see java.net.ServerSocket
  50  * @since 1.4
  51  */
  52 public class InetSocketAddress
  53     extends SocketAddress
  54 {
  55     // Private implementation class pointed to by all public methods.
  56     private static class InetSocketAddressHolder {
  57         // The hostname of the Socket Address
  58         private String hostname;
  59         // The IP address of the Socket Address
  60         private InetAddress addr;
  61         // The port number of the Socket Address
  62         private int port;
  63 
  64         private InetSocketAddressHolder(String hostname, InetAddress addr, int port) {
  65             this.hostname = hostname;
  66             this.addr = addr;
  67             this.port = port;
  68         }
  69 
  70         private int getPort() {
  71             return port;
  72         }
  73 
  74         private InetAddress getAddress() {
  75             return addr;
  76         }
  77 
  78         private String getHostName() {
  79             if (hostname != null)
  80                 return hostname;
  81             if (addr != null)
  82                 return addr.getHostName();
  83             return null;
  84         }
  85 
  86         private String getHostString() {
  87             if (hostname != null)
  88                 return hostname;
  89             if (addr != null) {
  90                 if (addr.holder().getHostName() != null)
  91                     return addr.holder().getHostName();
  92                 else
  93                     return addr.getHostAddress();
  94             }
  95             return null;
  96         }
  97 
  98         private boolean isUnresolved() {
  99             return addr == null;
 100         }
 101 
 102         @Override
 103         public String toString() {
 104             if (isUnresolved()) {
 105                 return hostname + ":" + port;
 106             } else {
 107                 return addr.toString() + ":" + port;
 108             }
 109         }
 110 
 111         @Override
 112         public final boolean equals(Object obj) {
 113             if (obj == null || !(obj instanceof InetSocketAddressHolder))
 114                 return false;
 115             InetSocketAddressHolder that = (InetSocketAddressHolder)obj;
 116             boolean sameIP;
 117             if (addr != null)
 118                 sameIP = addr.equals(that.addr);
 119             else if (hostname != null)
 120                 sameIP = (that.addr == null) &&
 121                     hostname.equalsIgnoreCase(that.hostname);
 122             else
 123                 sameIP = (that.addr == null) && (that.hostname == null);
 124             return sameIP && (port == that.port);
 125         }
 126 
 127         @Override
 128         public final int hashCode() {
 129             if (addr != null)
 130                 return addr.hashCode() + port;
 131             if (hostname != null)
 132                 return hostname.toLowerCase().hashCode() + port;
 133             return port;
 134         }
 135     }
 136 
 137     private final transient InetSocketAddressHolder holder;
 138 
 139     private static final long serialVersionUID = 5076001401234631237L;
 140 
 141     private static int checkPort(int port) {
 142         if (port < 0 || port > 0xFFFF)
 143             throw new IllegalArgumentException("port out of range:" + port);
 144         return port;
 145     }
 146 
 147     private static String checkHost(String hostname) {
 148         if (hostname == null)
 149             throw new IllegalArgumentException("hostname can't be null");
 150         return hostname;
 151     }
 152 
 153     /**
 154      * Creates a socket address where the IP address is the wildcard address
 155      * and the port number a specified value.
 156      * <p>
 157      * A valid port value is between 0 and 65535.
 158      * A port number of {@code zero} will let the system pick up an
 159      * ephemeral port in a {@code bind} operation.
 160      *
 161      * @param   port    The port number
 162      * @throws IllegalArgumentException if the port parameter is outside the specified
 163      * range of valid port values.
 164      */
 165     public InetSocketAddress(int port) {
 166         this(InetAddress.anyLocalAddress(), port);
 167     }
 168 
 169     /**
 170      *
 171      * Creates a socket address from an IP address and a port number.
 172      * <p>
 173      * A valid port value is between 0 and 65535.
 174      * A port number of {@code zero} will let the system pick up an
 175      * ephemeral port in a {@code bind} operation.
 176      * <P>
 177      * A {@code null} address will assign the <i>wildcard</i> address.
 178      *
 179      * @param   addr    The IP address
 180      * @param   port    The port number
 181      * @throws IllegalArgumentException if the port parameter is outside the specified
 182      * range of valid port values.
 183      */
 184     public InetSocketAddress(InetAddress addr, int port) {
 185         holder = new InetSocketAddressHolder(
 186                         null,
 187                         addr == null ? InetAddress.anyLocalAddress() : addr,
 188                         checkPort(port));
 189     }
 190 
 191     /**
 192      *
 193      * Creates a socket address from a hostname and a port number.
 194      * <p>
 195      * An attempt will be made to resolve the hostname into an InetAddress.
 196      * If that attempt fails, the address will be flagged as <I>unresolved</I>.
 197      * <p>
 198      * If there is a security manager, its {@code checkConnect} method
 199      * is called with the host name as its argument to check the permission
 200      * to resolve it. This could result in a SecurityException.
 201      * <P>
 202      * A valid port value is between 0 and 65535.
 203      * A port number of {@code zero} will let the system pick up an
 204      * ephemeral port in a {@code bind} operation.
 205      *
 206      * @param   hostname the Host name
 207      * @param   port    The port number
 208      * @throws IllegalArgumentException if the port parameter is outside the range
 209      * of valid port values, or if the hostname parameter is {@code null}.
 210      * @throws SecurityException if a security manager is present and
 211      *                           permission to resolve the host name is
 212      *                           denied.
 213      * @see     #isUnresolved()
 214      */
 215     public InetSocketAddress(String hostname, int port) {
 216         checkHost(hostname);
 217         InetAddress addr = null;
 218         String host = null;
 219         try {
 220             addr = InetAddress.getByName(hostname);
 221         } catch(UnknownHostException e) {
 222             host = hostname;
 223         }
 224         holder = new InetSocketAddressHolder(host, addr, checkPort(port));
 225     }
 226 
 227     // private constructor for creating unresolved instances
 228     private InetSocketAddress(int port, String hostname) {
 229         holder = new InetSocketAddressHolder(hostname, null, port);
 230     }
 231 
 232     /**
 233      *
 234      * Creates an unresolved socket address from a hostname and a port number.
 235      * <p>
 236      * No attempt will be made to resolve the hostname into an InetAddress.
 237      * The address will be flagged as <I>unresolved</I>.
 238      * <p>
 239      * A valid port value is between 0 and 65535.
 240      * A port number of {@code zero} will let the system pick up an
 241      * ephemeral port in a {@code bind} operation.
 242      *
 243      * @param   host    the Host name
 244      * @param   port    The port number
 245      * @throws IllegalArgumentException if the port parameter is outside
 246      *                  the range of valid port values, or if the hostname
 247      *                  parameter is {@code null}.
 248      * @see     #isUnresolved()
 249      * @return  an {@code InetSocketAddress} representing the unresolved
 250      *          socket address
 251      * @since 1.5
 252      */
 253     public static InetSocketAddress createUnresolved(String host, int port) {
 254         return new InetSocketAddress(checkPort(port), checkHost(host));
 255     }
 256 
 257     /**
 258      * @serialField hostname String
 259      * @serialField addr InetAddress
 260      * @serialField port int
 261      */
 262     private static final ObjectStreamField[] serialPersistentFields = {
 263          new ObjectStreamField("hostname", String.class),
 264          new ObjectStreamField("addr", InetAddress.class),
 265          new ObjectStreamField("port", int.class)};
 266 
 267     private void writeObject(ObjectOutputStream out)
 268         throws IOException
 269     {
 270         // Don't call defaultWriteObject()
 271          ObjectOutputStream.PutField pfields = out.putFields();
 272          pfields.put("hostname", holder.hostname);
 273          pfields.put("addr", holder.addr);
 274          pfields.put("port", holder.port);
 275          out.writeFields();
 276      }
 277 
 278     private void readObject(ObjectInputStream in)
 279         throws IOException, ClassNotFoundException
 280     {
 281         // Don't call defaultReadObject()
 282         ObjectInputStream.GetField oisFields = in.readFields();
 283         final String oisHostname = (String)oisFields.get("hostname", null);
 284         final InetAddress oisAddr = (InetAddress)oisFields.get("addr", null);
 285         final int oisPort = oisFields.get("port", -1);
 286 
 287         // Check that our invariants are satisfied
 288         checkPort(oisPort);
 289         if (oisHostname == null && oisAddr == null)
 290             throw new InvalidObjectException("hostname and addr " +
 291                                              "can't both be null");
 292 
 293         InetSocketAddressHolder h = new InetSocketAddressHolder(oisHostname,
 294                                                                 oisAddr,
 295                                                                 oisPort);
 296         UNSAFE.putObject(this, FIELDS_OFFSET, h);
 297     }
 298 
 299     private void readObjectNoData()
 300         throws ObjectStreamException
 301     {
 302         throw new InvalidObjectException("Stream data required");
 303     }
 304 
 305     private static final long FIELDS_OFFSET;
 306     private static final jdk.internal.misc.Unsafe UNSAFE;
 307     static {
 308         try {
 309             jdk.internal.misc.Unsafe unsafe = jdk.internal.misc.Unsafe.getUnsafe();
 310             FIELDS_OFFSET = unsafe.objectFieldOffset(
 311                     InetSocketAddress.class.getDeclaredField("holder"));
 312             UNSAFE = unsafe;
 313         } catch (ReflectiveOperationException e) {
 314             throw new Error(e);
 315         }
 316     }
 317 
 318     /**
 319      * Gets the port number.
 320      *
 321      * @return the port number.
 322      */
 323     public final int getPort() {
 324         return holder.getPort();
 325     }
 326 
 327     /**
 328      *
 329      * Gets the {@code InetAddress}.
 330      *
 331      * @return the InetAdress or {@code null} if it is unresolved.
 332      */
 333     public final InetAddress getAddress() {
 334         return holder.getAddress();
 335     }
 336 
 337     /**
 338      * Gets the {@code hostname}.
 339      * Note: This method may trigger a name service reverse lookup if the
 340      * address was created with a literal IP address.
 341      *
 342      * @return  the hostname part of the address.
 343      */
 344     public final String getHostName() {
 345         return holder.getHostName();
 346     }
 347 
 348     /**
 349      * Returns the hostname, or the String form of the address if it
 350      * doesn't have a hostname (it was created using a literal).
 351      * This has the benefit of <b>not</b> attempting a reverse lookup.
 352      *
 353      * @return the hostname, or String representation of the address.
 354      * @since 1.7
 355      */
 356     public final String getHostString() {
 357         return holder.getHostString();
 358     }
 359 
 360     /**
 361      * Checks whether the address has been resolved or not.
 362      *
 363      * @return {@code true} if the hostname couldn't be resolved into
 364      *          an {@code InetAddress}.
 365      */
 366     public final boolean isUnresolved() {
 367         return holder.isUnresolved();
 368     }
 369 
 370     /**
 371      * Constructs a string representation of this InetSocketAddress.
 372      * This String is constructed by calling toString() on the InetAddress
 373      * and concatenating the port number (with a colon). If the address
 374      * is unresolved then the part before the colon will only contain the hostname.
 375      *
 376      * @return  a string representation of this object.
 377      */
 378     @Override
 379     public String toString() {
 380         return holder.toString();
 381     }
 382 
 383     /**
 384      * Compares this object against the specified object.
 385      * The result is {@code true} if and only if the argument is
 386      * not {@code null} and it represents the same address as
 387      * this object.
 388      * <p>
 389      * Two instances of {@code InetSocketAddress} represent the same
 390      * address if both the InetAddresses (or hostnames if it is unresolved) and port
 391      * numbers are equal.
 392      * If both addresses are unresolved, then the hostname and the port number
 393      * are compared.
 394      *
 395      * Note: Hostnames are case insensitive. e.g. "FooBar" and "foobar" are
 396      * considered equal.
 397      *
 398      * @param   obj   the object to compare against.
 399      * @return  {@code true} if the objects are the same;
 400      *          {@code false} otherwise.
 401      * @see java.net.InetAddress#equals(java.lang.Object)
 402      */
 403     @Override
 404     public final boolean equals(Object obj) {
 405         if (obj == null || !(obj instanceof InetSocketAddress))
 406             return false;
 407         return holder.equals(((InetSocketAddress) obj).holder);
 408     }
 409 
 410     /**
 411      * Returns a hashcode for this socket address.
 412      *
 413      * @return  a hash code value for this socket address.
 414      */
 415     @Override
 416     public final int hashCode() {
 417         return holder.hashCode();
 418     }
 419 }