native_loader.cpp revision 34fa704df45c5f74aeb5230e4bf3930585cf32fb 
1/*
2 * Copyright (C) 2015 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#include "nativeloader/native_loader.h"
18#include "ScopedUtfChars.h"
19
20#include <dlfcn.h>
21#ifdef __ANDROID__
22#include <android/dlext.h>
23#include "cutils/properties.h"
24#endif
25
26#include <algorithm>
27#include <vector>
28#include <string>
29#include <mutex>
30
31#include "android-base/macros.h"
32#include "android-base/strings.h"
33
34namespace android {
35
36#ifdef __ANDROID__
37// TODO(dimitry): move this to system properties.
38static const char* kPublicNativeLibraries = "libandroid.so:"
39                                            "libc.so:"
40                                            "libdl.so:"
41                                            "libEGL.so:"
42                                            "libGLESv1_CM.so:"
43                                            "libGLESv2.so:"
44                                            "libGLESv3.so:"
45                                            "libicui18n.so:"
46                                            "libicuuc.so:"
47                                            "libjnigraphics.so:"
48                                            "liblog.so:"
49                                            "libmediandk.so:"
50                                            "libm.so:"
51                                            "libOpenMAXAL.so:"
52                                            "libOpenSLES.so:"
53                                            "libRS.so:"
54                                            "libstdc++.so:"
55                                            "libwebviewchromium_plat_support.so:"
56                                            "libz.so";
57
58class LibraryNamespaces {
59 public:
60  LibraryNamespaces() : initialized_(false) {
61    PreloadPublicLibraries();
62  }
63
64  android_namespace_t* GetOrCreate(JNIEnv* env, jobject class_loader,
65                                   bool is_shared,
66                                   jstring java_library_path,
67                                   jstring java_permitted_path) {
68    ScopedUtfChars library_path(env, java_library_path);
69
70    std::string permitted_path;
71    if (java_permitted_path != nullptr) {
72      ScopedUtfChars path(env, java_permitted_path);
73      permitted_path = path.c_str();
74    }
75
76    if (!initialized_ && !InitPublicNamespace(library_path.c_str())) {
77      return nullptr;
78    }
79
80    std::lock_guard<std::mutex> guard(mutex_);
81
82    android_namespace_t* ns = FindNamespaceByClassLoader(env, class_loader);
83
84    if (ns != nullptr) {
85      return ns;
86    }
87
88    uint64_t namespace_type = ANDROID_NAMESPACE_TYPE_ISOLATED;
89    if (is_shared) {
90      namespace_type |= ANDROID_NAMESPACE_TYPE_SHARED;
91    }
92
93    ns = android_create_namespace("classloader-namespace",
94                                  nullptr,
95                                  library_path.c_str(),
96                                  namespace_type,
97                                  java_permitted_path != nullptr ?
98                                      permitted_path.c_str() :
99                                      nullptr);
100
101    namespaces_.push_back(std::make_pair(env->NewWeakGlobalRef(class_loader), ns));
102
103    return ns;
104  }
105
106 private:
107  void PreloadPublicLibraries() {
108    // android_init_namespaces() expects all the public libraries
109    // to be loaded so that they can be found by soname alone.
110    std::vector<std::string> sonames = android::base::Split(kPublicNativeLibraries, ":");
111    for (const auto& soname : sonames) {
112      dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE);
113    }
114  }
115
116  bool InitPublicNamespace(const char* library_path) {
117    // Some apps call dlopen from generated code unknown to linker in which
118    // case linker uses anonymous namespace. See b/25844435 for details.
119    initialized_ = android_init_namespaces(kPublicNativeLibraries, library_path);
120
121    return initialized_;
122  }
123
124  android_namespace_t* FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) {
125    auto it = std::find_if(namespaces_.begin(), namespaces_.end(),
126                [&](const std::pair<jweak, android_namespace_t*>& value) {
127                  return env->IsSameObject(value.first, class_loader);
128                });
129    return it != namespaces_.end() ? it->second : nullptr;
130  }
131
132  bool initialized_;
133  std::mutex mutex_;
134  std::vector<std::pair<jweak, android_namespace_t*>> namespaces_;
135
136  DISALLOW_COPY_AND_ASSIGN(LibraryNamespaces);
137};
138
139static LibraryNamespaces* g_namespaces = new LibraryNamespaces;
140#endif
141
142
143void* OpenNativeLibrary(JNIEnv* env, int32_t target_sdk_version, const char* path,
144                        jobject class_loader, bool is_shared, jstring java_library_path,
145                        jstring java_permitted_path) {
146#if defined(__ANDROID__)
147  if (target_sdk_version == 0 || class_loader == nullptr) {
148    return dlopen(path, RTLD_NOW);
149  }
150
151  android_namespace_t* ns =
152      g_namespaces->GetOrCreate(env, class_loader, is_shared,
153                                java_library_path, java_permitted_path);
154
155  if (ns == nullptr) {
156    return nullptr;
157  }
158
159  android_dlextinfo extinfo;
160  extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
161  extinfo.library_namespace = ns;
162
163  return android_dlopen_ext(path, RTLD_NOW, &extinfo);
164#else
165  UNUSED(env, target_sdk_version, class_loader, is_shared,
166         java_library_path, java_permitted_path);
167  return dlopen(path, RTLD_NOW);
168#endif
169}
170
171}; //  android namespace
172