1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
/*
* Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.net;
import java.security.AccessController;
import java.security.PrivilegedAction;
/**
* This class defines a factory for creating DatagramSocketImpls. It defaults
* to creating plain DatagramSocketImpls, but may create other DatagramSocketImpls
* by setting the impl.prefix system property.
*
* For Windows versions lower than Windows Vista a TwoStacksPlainDatagramSocketImpl
* is always created. This impl supports IPv6 on these platform where available.
*
* On Windows platforms greater than Vista that support a dual layer TCP/IP stack
* a DualStackPlainDatagramSocketImpl is created for DatagramSockets. For MulticastSockets
* a TwoStacksPlainDatagramSocketImpl is always created. This is to overcome the lack
* of behavior defined for multicasting over a dual layer socket by the RFC.
*
* @author Chris Hegarty
*/
class DefaultDatagramSocketImplFactory
{
static Class prefixImplClass = null;
/* the windows version. */
private static float version;
/* java.net.preferIPv4Stack */
private static boolean preferIPv4Stack = false;
/* If the version supports a dual stack TCP implementation */
private static boolean useDualStackImpl = false;
/* sun.net.useExclusiveBind */
private static String exclBindProp;
/* True if exclusive binding is on for Windows */
private static boolean exclusiveBind = true;
static {
// Determine Windows Version.
java.security.AccessController.doPrivileged(
new PrivilegedAction<Object>() {
public Object run() {
version = 0;
try {
version = Float.parseFloat(System.getProperties()
.getProperty("os.version"));
preferIPv4Stack = Boolean.parseBoolean(
System.getProperties()
.getProperty(
"java.net.preferIPv4Stack"));
exclBindProp = System.getProperty(
"sun.net.useExclusiveBind");
} catch (NumberFormatException e ) {
assert false : e;
}
return null; // nothing to return
}
});
String ipv6 = ikvm.internal.Util.SafeGetEnvironmentVariable("IKVM_IPV6");
if (ipv6 != null) {
try {
if ((Integer.parseInt(ipv6) & 4) == 0) {
preferIPv4Stack = true;
} else {
useDualStackImpl = true;
}
} catch (NumberFormatException _) {
}
} else if (!InetAddressImplFactory.isIPv6Supported()) {
preferIPv4Stack = true;
}
// (version >= 6.0) implies Vista or greater.
if (version >= 6.0 && !preferIPv4Stack) {
useDualStackImpl = true;
}
if (exclBindProp != null) {
// sun.net.useExclusiveBind is true
exclusiveBind = exclBindProp.length() == 0 ? true
: Boolean.parseBoolean(exclBindProp);
} else if (version < 6.0) {
exclusiveBind = false;
}
// impl.prefix
String prefix = null;
try {
prefix = AccessController.doPrivileged(
new sun.security.action.GetPropertyAction("impl.prefix", null));
if (prefix != null)
prefixImplClass = Class.forName("java.net."+prefix+"DatagramSocketImpl");
} catch (Exception e) {
System.err.println("Can't find class: java.net." +
prefix +
"DatagramSocketImpl: check impl.prefix property");
}
}
/**
* Creates a new <code>DatagramSocketImpl</code> instance.
*
* @param isMulticast true if this impl is to be used for a MutlicastSocket
* @return a new instance of <code>PlainDatagramSocketImpl</code>.
*/
static DatagramSocketImpl createDatagramSocketImpl(boolean isMulticast)
throws SocketException {
if (prefixImplClass != null) {
try {
return (DatagramSocketImpl) prefixImplClass.newInstance();
} catch (Exception e) {
throw new SocketException("can't instantiate DatagramSocketImpl");
}
} else {
if (isMulticast)
exclusiveBind = false;
if (useDualStackImpl && !isMulticast)
return new DualStackPlainDatagramSocketImpl(exclusiveBind);
else
return new TwoStacksPlainDatagramSocketImpl(exclusiveBind);
}
}
}
|
