1 /*

     2  * Copyright (c) 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 sun.management.jdp;

    26 

    27 import java.io.IOException;

    28 import java.net.Inet6Address;

    29 import java.net.InetAddress;

    30 import java.net.InetSocketAddress;

    31 import java.net.NetworkInterface;

    32 import java.net.ProtocolFamily;

    33 import java.net.StandardProtocolFamily;

    34 import java.net.StandardSocketOptions;

    35 import java.nio.ByteBuffer;

    36 import java.nio.channels.DatagramChannel;

    37 import java.nio.channels.UnsupportedAddressTypeException;

    38 import java.util.Enumeration;

    39 

    40 /**

    41  * JdpBroadcaster is responsible for sending pre-built JDP packet across a Net

    42  *

    43  * <p> Multicast group address, port number and ttl have to be chosen on upper

    44  * level and passed to broadcaster constructor. Also it's possible to specify

    45  * source address to broadcast from. </p>

    46  *

    47  * <p>JdpBradcaster doesn't perform any validation on a supplied {@code port} and {@code ttl} because

    48  * the allowed values depend on an operating system setup</p>

    49  *

    50  */

    51 public final class JdpBroadcaster {

    52 

    53     private final InetAddress addr;

    54     private final int port;

    55     private final DatagramChannel channel;

    56 

    57     /**

    58      * Create a new broadcaster

    59      *

    60      * @param address - multicast group address

    61      * @param srcAddress - address of interface we should use to broadcast.

    62      * @param port - udp port to use

    63      * @param ttl - packet ttl

    64      * @throws IOException

    65      */

    66     public JdpBroadcaster(InetAddress address, InetAddress srcAddress, int port, int ttl)

    67             throws IOException, JdpException {

    68         this.addr = address;

    69         this.port = port;

    70 

    71         ProtocolFamily family = (address instanceof Inet6Address)

    72                 ? StandardProtocolFamily.INET6 : StandardProtocolFamily.INET;

    73 

    74         channel = DatagramChannel.open(family);

    75         channel.setOption(StandardSocketOptions.SO_REUSEADDR, true);

    76         channel.setOption(StandardSocketOptions.IP_MULTICAST_TTL, ttl);

    77 

    78         // with srcAddress equal to null, this constructor do exactly the same as

    79         // if srcAddress is not passed

    80         if (srcAddress != null) {

    81             // User requests particular interface to bind to

    82             NetworkInterface interf = NetworkInterface.getByInetAddress(srcAddress);

    83 

    84             if (interf == null) {

    85                 throw new JdpException("Unable to get network interface for " + srcAddress.toString());

    86             }

    87 

    88             if (!interf.isUp()) {

    89                 throw new JdpException(interf.getName() + " is not up.");

    90             }

    91 

    92             if (!interf.supportsMulticast()) {

    93                 throw new JdpException(interf.getName() + " does not support multicast.");

    94             }

    95 

    96             try {

    97                 channel.bind(new InetSocketAddress(srcAddress, 0));

    98             } catch (UnsupportedAddressTypeException ex) {

    99                 throw new JdpException("Unable to bind to source address");

   100             }

   101             channel.setOption(StandardSocketOptions.IP_MULTICAST_IF, interf);

   102         }

   103     }

   104 

   105     /**

   106      * Create a new broadcaster

   107      *

   108      * @param address - multicast group address

   109      * @param port - udp port to use

   110      * @param ttl - packet ttl

   111      * @throws IOException

   112      */

   113     public JdpBroadcaster(InetAddress address, int port, int ttl)

   114             throws IOException, JdpException {

   115         this(address, null, port, ttl);

   116     }

   117 

   118     /**

   119      * Broadcast pre-built packet

   120      *

   121      * @param packet - instance of JdpPacket

   122      * @throws IOException

   123      */

   124     public void sendPacket(JdpPacket packet)

   125             throws IOException {

   126         byte[] data = packet.getPacketData();

   127         // Unlike allocate/put wrap don't need a flip afterward

   128         ByteBuffer b = ByteBuffer.wrap(data);

   129         channel.send(b, new InetSocketAddress(addr, port));

   130     }

   131 

   132     /**

   133      * Shutdown broadcaster and close underlying socket channel

   134      *

   135      * @throws IOException

   136      */

   137     public void shutdown() throws IOException {

   138         channel.close();

   139     }

   140 }