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 else {
104 Enumeration<NetworkInterface> nics = NetworkInterface.getNetworkInterfaces();
105 boolean succeed = false;
106
107 while (nics.hasMoreElements()) {
108 NetworkInterface nic = nics.nextElement();
109
110 if (nic.isUp() && nic.supportsMulticast()) {
111 try {
112 channel.setOption(StandardSocketOptions.IP_MULTICAST_IF, nic);
113 succeed = true;
114 } catch (IOException ex) {
115 // pass
116 }
117 }
118
119 if (!succeed) {
120 throw new JdpException("Unable to bind to any interfaces.");
121 }
122
123 }
124
125 }
126
127 }
128
129 /**
130 * Create a new broadcaster
131 *
132 * @param address - multicast group address
133 * @param port - udp port to use
134 * @param ttl - packet ttl
135 * @throws IOException
136 */
137 public JdpBroadcaster(InetAddress address, int port, int ttl)
138 throws IOException, JdpException {
139 this(address, null, port, ttl);
140 }
141
142 /**
143 * Broadcast pre-built packet
144 *
145 * @param packet - instance of JdpPacket
146 * @throws IOException
147 */
148 public void sendPacket(JdpPacket packet)
149 throws IOException {
150 byte[] data = packet.getPacketData();
151 // Unlike allocate/put wrap don't need a flip afterward
152 ByteBuffer b = ByteBuffer.wrap(data);
153 channel.send(b, new InetSocketAddress(addr, port));
154 }
155
156 /**
157 * Shutdown broadcaster and close underlying socket channel
158 *
159 * @throws IOException
160 */
161 public void shutdown() throws IOException {
162 channel.close();
163 }
164 }