1 /*

     2  * Copyright 2007-2008 Sun Microsystems, Inc.  All Rights Reserved.

     3  *

     4  * Redistribution and use in source and binary forms, with or without

     5  * modification, are permitted provided that the following conditions

     6  * are met:

     7  *

     8  *   - Redistributions of source code must retain the above copyright

     9  *     notice, this list of conditions and the following disclaimer.

    10  *

    11  *   - Redistributions in binary form must reproduce the above copyright

    12  *     notice, this list of conditions and the following disclaimer in the

    13  *     documentation and/or other materials provided with the distribution.

    14  *

    15  *   - Neither the name of Sun Microsystems nor the names of its

    16  *     contributors may be used to endorse or promote products derived

    17  *     from this software without specific prior written permission.

    18  *

    19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

    20  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

    21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

    22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

    23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

    24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

    25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

    26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

    27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

    28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

    29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    30  */

    31 

    32 import java.net.InetAddress;

    33 import java.net.NetworkInterface;

    34 import java.net.UnknownHostException;

    35 import java.net.SocketException;

    36 

    37 /**

    38  * Parses and represents a multicast address.

    39  */

    40 

    41 class MulticastAddress {

    42     private final InetAddress group;

    43     private final int port;

    44     private final NetworkInterface interf;

    45 

    46     private MulticastAddress(InetAddress group, int port, NetworkInterface interf) {

    47         this.group = group;

    48         this.port = port;

    49         this.interf = interf;

    50     }

    51 

    52     InetAddress group() {

    53         return group;

    54     }

    55 

    56     int port() {

    57         return port;

    58     }

    59 

    60     /**

    61      * @return  The network interface, may be {@code null}

    62      */

    63     NetworkInterface interf() {

    64         return interf;

    65     }

    66 

    67     /**

    68      * Parses a string of the form "group:port[@interface]", returning

    69      * a MulticastAddress representing the address

    70      */

    71     static MulticastAddress parse(String s) {

    72         String[] components = s.split("@");

    73         if (components.length > 2)

    74             throw new IllegalArgumentException("At most one '@' expected");

    75 

    76         // get group and port

    77         String target = components[0];

    78         int len = components[0].length();

    79         int colon = components[0].lastIndexOf(':');

    80         if ((colon < 1) || (colon > (len-2)))

    81             throw new IllegalArgumentException("group:port expected");

    82         String groupString = target.substring(0, colon);

    83         int port = -1;

    84         try {

    85             port = Integer.parseInt(target.substring(colon+1, len));

    86         } catch (NumberFormatException x) {

    87              throw new IllegalArgumentException(x);

    88         }

    89 

    90         // handle IPv6 literal address

    91         if (groupString.charAt(0) == '[') {

    92             len = groupString.length();

    93             if (groupString.charAt(len-1) != ']')

    94                 throw new IllegalArgumentException("missing ']'");

    95             groupString = groupString.substring(1,len-1);

    96             if (groupString.length() == 0)

    97                 throw new IllegalArgumentException("missing IPv6 address");

    98         }

    99 

   100         // get group address

   101         InetAddress group = null;

   102         try {

   103             group = InetAddress.getByName(groupString);

   104         } catch (UnknownHostException x) {

   105             throw new IllegalArgumentException(x);

   106         }

   107         if (!group.isMulticastAddress()) {

   108             throw new IllegalArgumentException("'" + group.getHostAddress() +

   109                 "' is not multicast address");

   110         }

   111 

   112         // optional interface

   113         NetworkInterface interf = null;

   114         if (components.length == 2) {

   115             try {

   116                 interf = NetworkInterface.getByName(components[1]);

   117             } catch (SocketException x) {

   118                 throw new IllegalArgumentException(x);

   119             }

   120             if (interf == null) {

   121                 throw new IllegalArgumentException("'" + components[1] +

   122                    "' is not valid interface");

   123             }

   124         }

   125         return new MulticastAddress(group, port, interf);

   126     }

   127 }