1 /*
2 * Copyright (c) 2007, 2015, 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 try {
88 super.create();
89 } catch (SocketException e) {
90 fd1 = null;
91 throw e;
92 }
93 }
94
95 protected synchronized void bind(int lport, InetAddress laddr)
96 throws SocketException {
97 super.bind(lport, laddr);
98 if (laddr.isAnyLocalAddress()) {
99 anyLocalBoundAddr = laddr;
100 }
101 }
102
103 @Override
104 protected synchronized void bind0(int lport, InetAddress laddr)
105 throws SocketException
106 {
107 bind0(lport, laddr, exclusiveBind);
108
109 }
110
111 protected synchronized void receive(DatagramPacket p)
112 throws IOException {
113 try {
114 receive0(p);
115 } finally {
116 fduse = -1;
117 }
118 }
119
120 public Object getOption(int optID) throws SocketException {
121 if (isClosed()) {
122 throw new SocketException("Socket Closed");
123 }
124
125 if (optID == SO_BINDADDR) {
126 if ((fd != null && fd1 != null) && !connected) {
127 return anyLocalBoundAddr;
128 }
129 int family = connectedAddress == null ? -1 : connectedAddress.holder().getFamily();
130 return socketLocalAddress(family);
131 } else if (optID == SO_REUSEADDR && reuseAddressEmulated) {
132 return isReuseAddress;
133 } else {
134 return super.getOption(optID);
135 }
136 }
137
138 protected void socketSetOption(int opt, Object val)
139 throws SocketException
140 {
141 if (opt == SO_REUSEADDR && exclusiveBind && localPort != 0) {
142 // socket already bound, emulate
143 reuseAddressEmulated = true;
144 isReuseAddress = (Boolean)val;
145 } else {
146 socketNativeSetOption(opt, val);
147 }
148
149 }
150
151 protected boolean isClosed() {
152 return (fd == null && fd1 == null) ? true : false;
153 }
154
155 protected void close() {
156 if (fd != null || fd1 != null) {
157 datagramSocketClose();
158 ResourceManager.afterUdpClose();
159 fd = null;
160 fd1 = null;
161 }
162 }
163
164 /* Native methods */
165
166 protected synchronized native void bind0(int lport, InetAddress laddr,
167 boolean exclBind)
168 throws SocketException;
169
170 protected native void send(DatagramPacket p) throws IOException;
171
172 protected synchronized native int peek(InetAddress i) throws IOException;
173
174 protected synchronized native int peekData(DatagramPacket p) throws IOException;
175
176 protected synchronized native void receive0(DatagramPacket p)
177 throws IOException;
178
179 protected native void setTimeToLive(int ttl) throws IOException;
180
181 protected native int getTimeToLive() throws IOException;
182
183 @Deprecated
184 protected native void setTTL(byte ttl) throws IOException;
185
186 @Deprecated
187 protected native byte getTTL() throws IOException;
188
189 protected native void join(InetAddress inetaddr, NetworkInterface netIf)
190 throws IOException;
191
192 protected native void leave(InetAddress inetaddr, NetworkInterface netIf)
193 throws IOException;
194
195 protected native void datagramSocketCreate() throws SocketException;
196
197 protected native void datagramSocketClose();
198
199 protected native void socketNativeSetOption(int opt, Object val)
200 throws SocketException;
201
202 protected native Object socketGetOption(int opt) throws SocketException;
203
204 protected native void connect0(InetAddress address, int port) throws SocketException;
205
206 protected native Object socketLocalAddress(int family) throws SocketException;
207
208 protected native void disconnect0(int family);
209
210 native int dataAvailable();
211
212 /**
213 * Perform class load-time initializations.
214 */
215 private native static void init();
216 }