1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.internal.os;
18 
19 import android.compat.annotation.UnsupportedAppUsage;
20 import android.os.Trace;
21 
22 import dalvik.system.DelegateLastClassLoader;
23 import dalvik.system.DexClassLoader;
24 import dalvik.system.PathClassLoader;
25 
26 import java.util.List;
27 
28 /**
29  * Creates class loaders.
30  *
31  * @hide
32  */
33 public class ClassLoaderFactory {
34     // Unconstructable
ClassLoaderFactory()35     private ClassLoaderFactory() {}
36 
37     private static final String PATH_CLASS_LOADER_NAME = PathClassLoader.class.getName();
38     private static final String DEX_CLASS_LOADER_NAME = DexClassLoader.class.getName();
39     private static final String DELEGATE_LAST_CLASS_LOADER_NAME =
40             DelegateLastClassLoader.class.getName();
41 
42     /**
43      * Returns the name of the class for PathClassLoader.
44      */
getPathClassLoaderName()45     public static String getPathClassLoaderName() {
46         return PATH_CLASS_LOADER_NAME;
47     }
48 
49     /**
50      * Returns true if {@code name} is a supported classloader. {@code name} must be a
51      * binary name of a class, as defined by {@code Class.getName}.
52      */
isValidClassLoaderName(String name)53     public static boolean isValidClassLoaderName(String name) {
54         // This method is used to parse package data and does not accept null names.
55         return name != null && (isPathClassLoaderName(name) || isDelegateLastClassLoaderName(name));
56     }
57 
58     /**
59      * Returns true if {@code name} is the encoding for either PathClassLoader or DexClassLoader.
60      * The two class loaders are grouped together because they have the same behaviour.
61      */
isPathClassLoaderName(String name)62     public static boolean isPathClassLoaderName(String name) {
63         // For null values we default to PathClassLoader. This cover the case when packages
64         // don't specify any value for their class loaders.
65         return name == null || PATH_CLASS_LOADER_NAME.equals(name) ||
66                 DEX_CLASS_LOADER_NAME.equals(name);
67     }
68 
69     /**
70      * Returns true if {@code name} is the encoding for the DelegateLastClassLoader.
71      */
isDelegateLastClassLoaderName(String name)72     public static boolean isDelegateLastClassLoaderName(String name) {
73         return DELEGATE_LAST_CLASS_LOADER_NAME.equals(name);
74     }
75 
76     /**
77      * Same as {@code createClassLoader} below, except that no associated namespace
78      * is created.
79      */
createClassLoader(String dexPath, String librarySearchPath, ClassLoader parent, String classloaderName, List<ClassLoader> sharedLibraries)80     public static ClassLoader createClassLoader(String dexPath,
81             String librarySearchPath, ClassLoader parent, String classloaderName,
82             List<ClassLoader> sharedLibraries) {
83         ClassLoader[] arrayOfSharedLibraries = (sharedLibraries == null)
84                 ? null
85                 : sharedLibraries.toArray(new ClassLoader[sharedLibraries.size()]);
86         if (isPathClassLoaderName(classloaderName)) {
87             return new PathClassLoader(dexPath, librarySearchPath, parent, arrayOfSharedLibraries);
88         } else if (isDelegateLastClassLoaderName(classloaderName)) {
89             return new DelegateLastClassLoader(dexPath, librarySearchPath, parent,
90                     arrayOfSharedLibraries);
91         }
92 
93         throw new AssertionError("Invalid classLoaderName: " + classloaderName);
94     }
95 
96     /**
97      * Same as {@code createClassLoader} below, but passes a null list of shared
98      * libraries.
99      */
createClassLoader(String dexPath, String librarySearchPath, String libraryPermittedPath, ClassLoader parent, int targetSdkVersion, boolean isNamespaceShared, String classLoaderName)100     public static ClassLoader createClassLoader(String dexPath,
101             String librarySearchPath, String libraryPermittedPath, ClassLoader parent,
102             int targetSdkVersion, boolean isNamespaceShared, String classLoaderName) {
103         return createClassLoader(dexPath, librarySearchPath, libraryPermittedPath,
104             parent, targetSdkVersion, isNamespaceShared, classLoaderName, null);
105     }
106 
107 
108     /**
109      * Create a ClassLoader and initialize a linker-namespace for it.
110      */
createClassLoader(String dexPath, String librarySearchPath, String libraryPermittedPath, ClassLoader parent, int targetSdkVersion, boolean isNamespaceShared, String classLoaderName, List<ClassLoader> sharedLibraries)111     public static ClassLoader createClassLoader(String dexPath,
112             String librarySearchPath, String libraryPermittedPath, ClassLoader parent,
113             int targetSdkVersion, boolean isNamespaceShared, String classLoaderName,
114             List<ClassLoader> sharedLibraries) {
115 
116         final ClassLoader classLoader = createClassLoader(dexPath, librarySearchPath, parent,
117                 classLoaderName, sharedLibraries);
118 
119         // TODO(b/142191088) merge 6a5b8b1f6db172b5aaadcec0c3868e54e214b675
120         String sonameList = "ALL";
121 
122         Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "createClassloaderNamespace");
123         String errorMessage = createClassloaderNamespace(classLoader,
124                                                          targetSdkVersion,
125                                                          librarySearchPath,
126                                                          libraryPermittedPath,
127                                                          isNamespaceShared,
128                                                          dexPath,
129                                                          sonameList);
130         Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
131 
132         if (errorMessage != null) {
133             throw new UnsatisfiedLinkError("Unable to create namespace for the classloader " +
134                                            classLoader + ": " + errorMessage);
135         }
136 
137         return classLoader;
138     }
139 
140     @UnsupportedAppUsage
createClassloaderNamespace(ClassLoader classLoader, int targetSdkVersion, String librarySearchPath, String libraryPermittedPath, boolean isNamespaceShared, String dexPath, String sonameList)141     private static native String createClassloaderNamespace(ClassLoader classLoader,
142                                                             int targetSdkVersion,
143                                                             String librarySearchPath,
144                                                             String libraryPermittedPath,
145                                                             boolean isNamespaceShared,
146                                                             String dexPath,
147                                                             String sonameList);
148 }
149