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 // true if this socket is exclusively bound
70 private final boolean exclusiveBind;
71
72 /*
73 * Set to true if SO_REUSEADDR is set after the socket is bound to
74 * indicate SO_REUSEADDR is being emulated
75 */
76 private boolean reuseAddressEmulated;
77
78 // emulates SO_REUSEADDR when exclusiveBind is true and socket is bound
79 private boolean isReuseAddress;
80
81 TwoStacksPlainDatagramSocketImpl(boolean exclBind) {
82 exclusiveBind = exclBind;
83 }
84
85 protected synchronized void create() throws SocketException {
86 fd1 = new FileDescriptor();
87 super.create();
88 }
89
90 protected synchronized void bind(int lport, InetAddress laddr)
91 throws SocketException {
92 super.bind(lport, laddr);
93 if (laddr.isAnyLocalAddress()) {
94 anyLocalBoundAddr = laddr;
95 }
96 }
97
98 @Override
99 protected synchronized void bind0(int lport, InetAddress laddr)
100 throws SocketException
101 {
102 bind0(lport, laddr, exclusiveBind);
103
104 }
105
106 protected synchronized void receive(DatagramPacket p)
107 throws IOException {
108 try {
109 receive0(p);
110 } finally {
111 fduse = -1;
112 }
113 }
114
115 public Object getOption(int optID) throws SocketException {
116 if (isClosed()) {
117 throw new SocketException("Socket Closed");
118 }
119
120 if (optID == SO_BINDADDR) {
121 if (fd != null && fd1 != null) {
122 return anyLocalBoundAddr;
123 }
124 return socketGetOption(optID);
125 } else if (optID == SO_REUSEADDR && reuseAddressEmulated) {
126 return isReuseAddress;
127 } else {
128 return super.getOption(optID);
129 }
130 }
131
132 protected void socketSetOption(int opt, Object val)
133 throws SocketException
134 {
135 if (opt == SO_REUSEADDR && exclusiveBind && localPort != 0) {
136 // socket already bound, emulate
137 reuseAddressEmulated = true;
138 isReuseAddress = (Boolean)val;
139 } else {
140 socketNativeSetOption(opt, val);
141 }
142
143 }
144
145 protected boolean isClosed() {
146 return (fd == null && fd1 == null) ? true : false;
147 }
148
149 protected void close() {
150 if (fd != null || fd1 != null) {
151 datagramSocketClose();
152 ResourceManager.afterUdpClose();
153 fd = null;
154 fd1 = null;
155 }
156 }
157
158 /* Native methods */
159
160 protected synchronized native void bind0(int lport, InetAddress laddr,
161 boolean exclBind)
162 throws SocketException;
163
164 protected native void send(DatagramPacket p) throws IOException;
165
166 protected synchronized native int peek(InetAddress i) throws IOException;
167
168 protected synchronized native int peekData(DatagramPacket p) throws IOException;
169
170 protected synchronized native void receive0(DatagramPacket p)
171 throws IOException;
172
173 protected native void setTimeToLive(int ttl) throws IOException;
174
175 protected native int getTimeToLive() throws IOException;
176
177 protected native void setTTL(byte ttl) throws IOException;
178
179 protected native byte getTTL() throws IOException;
180
181 protected native void join(InetAddress inetaddr, NetworkInterface netIf)
182 throws IOException;
183
184 protected native void leave(InetAddress inetaddr, NetworkInterface netIf)
185 throws IOException;
186
187 protected native void datagramSocketCreate() throws SocketException;
188
189 protected native void datagramSocketClose();
190
191 protected native void socketNativeSetOption(int opt, Object val)
192 throws SocketException;
193
194 protected native Object socketGetOption(int opt) throws SocketException;
195
196 protected native void connect0(InetAddress address, int port) throws SocketException;
197
198 protected native void disconnect0(int family);
199
200 /**
201 * Perform class load-time initializations.
202 */
203 private native static void init();
204 }