1 /*
2 * Copyright (c) 1999, 2014, 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
26 package com.sun.media.sound;
27
28 import java.io.BufferedInputStream;
29 import java.io.InputStream;
30 import java.io.File;
31 import java.io.FileInputStream;
32
33 import java.util.ArrayList;
34 import java.util.Iterator;
35 import java.util.List;
36 import java.util.Properties;
37 import java.util.ServiceLoader;
38
39 import java.security.AccessController;
40 import java.security.PrivilegedAction;
41
42 import javax.sound.sampled.AudioPermission;
43
44 /** Managing security in the Java Sound implementation.
45 * This class contains all code that uses and is used by
46 * SecurityManager.doPrivileged().
47 *
48 * @author Matthias Pfisterer
49 */
50 final class JSSecurityManager {
51
52 /** Prevent instantiation.
53 */
54 private JSSecurityManager() {
55 }
56
57 /** Checks if the VM currently has a SecurityManager installed.
58 * Note that this may change over time. So the result of this method
59 * should not be cached.
60 *
61 * @return true if a SecurityManger is installed, false otherwise.
62 */
63 private static boolean hasSecurityManager() {
64 return (System.getSecurityManager() != null);
65 }
66
67
68 static void checkRecordPermission() throws SecurityException {
69 if(Printer.trace) Printer.trace("JSSecurityManager.checkRecordPermission()");
70 SecurityManager sm = System.getSecurityManager();
71 if (sm != null) {
72 sm.checkPermission(new AudioPermission("record"));
73 }
74 }
75
76 /** Load properties from a file.
77 This method tries to load properties from the filename give into
78 the passed properties object.
79 If the file cannot be found or something else goes wrong,
80 the method silently fails.
81 @param properties The properties bundle to store the values of the
82 properties file.
83 @param filename The filename of the properties file to load. This
84 filename is interpreted as relative to the subdirectory "lib" in
85 the JRE directory.
86 */
87 static void loadProperties(final Properties properties,
88 final String filename) {
89 if(hasSecurityManager()) {
90 try {
91 // invoke the privileged action using 1.2 security
92 PrivilegedAction<Void> action = new PrivilegedAction<Void>() {
93 public Void run() {
94 loadPropertiesImpl(properties, filename);
95 return null;
96 }
97 };
98 AccessController.doPrivileged(action);
99 if(Printer.debug)Printer.debug("Loaded properties with JDK 1.2 security");
100 } catch (Exception e) {
101 if(Printer.debug)Printer.debug("Exception loading properties with JDK 1.2 security");
102 // try without using JDK 1.2 security
103 loadPropertiesImpl(properties, filename);
104 }
105 } else {
106 // not JDK 1.2 security, assume we already have permission
107 loadPropertiesImpl(properties, filename);
108 }
109 }
110
111
112 private static void loadPropertiesImpl(Properties properties,
113 String filename) {
114 if(Printer.trace)Printer.trace(">> JSSecurityManager: loadPropertiesImpl()");
115 String fname = System.getProperty("java.home");
116 try {
117 if (fname == null) {
118 throw new Error("Can't find java.home ??");
119 }
120 File f = new File(fname, "lib");
121 f = new File(f, filename);
122 fname = f.getCanonicalPath();
123 InputStream in = new FileInputStream(fname);
124 BufferedInputStream bin = new BufferedInputStream(in);
125 try {
126 properties.load(bin);
127 } finally {
128 if (in != null) {
129 in.close();
130 }
131 }
132 } catch (Throwable t) {
133 if (Printer.trace) {
134 System.err.println("Could not load properties file \"" + fname + "\"");
135 t.printStackTrace();
136 }
137 }
138 if(Printer.trace)Printer.trace("<< JSSecurityManager: loadPropertiesImpl() completed");
139 }
140
141 /** Create a Thread in the current ThreadGroup.
142 */
143 static Thread createThread(final Runnable runnable,
144 final String threadName,
145 final boolean isDaemon, final int priority,
146 final boolean doStart) {
147 Thread thread = new Thread(runnable);
148 if (threadName != null) {
149 thread.setName(threadName);
150 }
151 thread.setDaemon(isDaemon);
152 if (priority >= 0) {
153 thread.setPriority(priority);
154 }
155 if (doStart) {
156 thread.start();
157 }
158 return thread;
159 }
160
161 static synchronized <T> List<T> getProviders(final Class<T> providerClass) {
162 List<T> p = new ArrayList<>(7);
163 // ServiceLoader creates "lazy" iterator instance, but it ensures that
164 // next/hasNext run with permissions that are restricted by whatever
165 // creates the ServiceLoader instance, so it requires to be called from
166 // privileged section
167 final PrivilegedAction<Iterator<T>> psAction =
168 new PrivilegedAction<Iterator<T>>() {
169 @Override
170 public Iterator<T> run() {
171 return ServiceLoader.load(providerClass).iterator();
172 }
173 };
174 final Iterator<T> ps = AccessController.doPrivileged(psAction);
175
176 // the iterator's hasNext() method looks through classpath for
177 // the provider class names, so it requires read permissions
178 PrivilegedAction<Boolean> hasNextAction = new PrivilegedAction<Boolean>() {
179 public Boolean run() {
180 return ps.hasNext();
181 }
182 };
183
184 while (AccessController.doPrivileged(hasNextAction)) {
185 try {
186 // the iterator's next() method creates instances of the
187 // providers and it should be called in the current security
188 // context
189 T provider = ps.next();
190 if (providerClass.isInstance(provider)) {
191 // $$mp 2003-08-22
192 // Always adding at the beginning reverses the
193 // order of the providers. So we no longer have
194 // to do this in AudioSystem and MidiSystem.
195 p.add(0, provider);
196 }
197 } catch (Throwable t) {
198 //$$fb 2002-11-07: do not fail on SPI not found
199 if (Printer.err) t.printStackTrace();
200 }
201 }
202 return p;
203 }
204 }