1 /*
2 * Copyright (c) 2007, 2011, 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.FileDescriptor;
29 import sun.net.ResourceManager;
30
31 /**
32 * This class defines the plain DatagramSocketImpl that is used for all
33 * Windows versions lower than Vista. It adds support for IPv6 on
34 * these platforms where available.
35 *
36 * For backward compatibility windows platforms that do not have IPv6
37 * support also use this implementation, and fd1 gets set to null
38 * during socket creation.
39 *
40 * @author Chris Hegarty
41 */
42
43 class TwoStacksPlainDatagramSocketImpl extends AbstractPlainDatagramSocketImpl
44 {
45 /* Used for IPv6 on Windows only */
46 private FileDescriptor fd1;
47
48 /*
49 * Needed for ipv6 on windows because we need to know
50 * if the socket was bound to ::0 or 0.0.0.0, when a caller
51 * asks for it. In this case, both sockets are used, but we
52 * don't know whether the caller requested ::0 or 0.0.0.0
53 * and need to remember it here.
54 */
55 private InetAddress anyLocalBoundAddr=null;
56
57 private int fduse=-1; /* saved between peek() and receive() calls */
58
59 /* saved between successive calls to receive, if data is detected
60 * on both sockets at same time. To ensure that one socket is not
61 * starved, they rotate using this field
62 */
63 private int lastfd=-1;
64
65 static {
66 init();
67 }
68
69 protected synchronized void create() throws SocketException {
70 fd1 = new FileDescriptor();
71 super.create();
72 }
73
74 protected synchronized void bind(int lport, InetAddress laddr)
75 throws SocketException {
76 super.bind(lport, laddr);
77 if (laddr.isAnyLocalAddress()) {
78 anyLocalBoundAddr = laddr;
79 }
80 }
81
82 protected synchronized void receive(DatagramPacket p)
83 throws IOException {
84 try {
85 receive0(p);
86 } finally {
87 fduse = -1;
88 }
89 }
90
91 public Object getOption(int optID) throws SocketException {
92 if (isClosed()) {
93 throw new SocketException("Socket Closed");
94 }
95
96 if (optID == SO_BINDADDR) {
97 if (fd != null && fd1 != null) {
98 return anyLocalBoundAddr;
99 }
100 return socketGetOption(optID);
101 } else
102 return super.getOption(optID);
103 }
104
105 protected boolean isClosed() {
106 return (fd == null && fd1 == null) ? true : false;
107 }
108
109 protected void close() {
110 if (fd != null || fd1 != null) {
111 datagramSocketClose();
112 ResourceManager.afterUdpClose();
113 fd = null;
114 fd1 = null;
115 }
116 }
117
118 /* Native methods */
119
120 protected synchronized native void bind0(int lport, InetAddress laddr)
121 throws SocketException;
122
123 protected native void send(DatagramPacket p) throws IOException;
124
125 protected synchronized native int peek(InetAddress i) throws IOException;
126
127 protected synchronized native int peekData(DatagramPacket p) throws IOException;
128
129 protected synchronized native void receive0(DatagramPacket p)
130 throws IOException;
131
132 protected native void setTimeToLive(int ttl) throws IOException;
133
134 protected native int getTimeToLive() throws IOException;
135
136 protected native void setTTL(byte ttl) throws IOException;
137
138 protected native byte getTTL() throws IOException;
139
140 protected native void join(InetAddress inetaddr, NetworkInterface netIf)
141 throws IOException;
142
143 protected native void leave(InetAddress inetaddr, NetworkInterface netIf)
144 throws IOException;
145
146 protected native void datagramSocketCreate() throws SocketException;
147
148 protected native void datagramSocketClose();
149
150 protected native void socketSetOption(int opt, Object val)
151 throws SocketException;
152
153 protected native Object socketGetOption(int opt) throws SocketException;
154
155 protected native void connect0(InetAddress address, int port) throws SocketException;
156
157 protected native void disconnect0(int family);
158
159 /**
160 * Perform class load-time initializations.
161 */
162 private native static void init();
163 }