native_loader.cpp revision 4cd07681158830ec49f763f746d6644099a73b42 
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#include "log/log.h"
25#endif
26
27#include <algorithm>
28#include <vector>
29#include <string>
30#include <mutex>
31
32#include "android-base/macros.h"
33#include "android-base/strings.h"
34
35namespace android {
36
37#ifdef __ANDROID__
38// TODO(dimitry): move this to system properties.
39static const char* kPublicNativeLibraries = "libandroid.so:"
40                                            "libc.so:"
41                                            "libdl.so:"
42                                            "libEGL.so:"
43                                            "libGLESv1_CM.so:"
44                                            "libGLESv2.so:"
45                                            "libGLESv3.so:"
46                                            "libicui18n.so:"
47                                            "libicuuc.so:"
48                                            "libjnigraphics.so:"
49                                            "liblog.so:"
50                                            "libmediandk.so:"
51                                            "libm.so:"
52                                            "libOpenMAXAL.so:"
53                                            "libOpenSLES.so:"
54                                            "libRS.so:"
55                                            "libstdc++.so:"
56                                            "libwebviewchromium_plat_support.so:"
57                                            "libz.so";
58
59class LibraryNamespaces {
60 public:
61  LibraryNamespaces() : initialized_(false) { }
62
63  android_namespace_t* Create(JNIEnv* env,
64                              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    LOG_FATAL_IF(ns != nullptr, "There is already a namespace associated with this classloader");
85
86    uint64_t namespace_type = ANDROID_NAMESPACE_TYPE_ISOLATED;
87    if (is_shared) {
88      namespace_type |= ANDROID_NAMESPACE_TYPE_SHARED;
89    }
90
91    ns = android_create_namespace("classloader-namespace",
92                                  nullptr,
93                                  library_path.c_str(),
94                                  namespace_type,
95                                  java_permitted_path != nullptr ?
96                                      permitted_path.c_str() :
97                                      nullptr);
98
99    if (ns != nullptr) {
100      namespaces_.push_back(std::make_pair(env->NewWeakGlobalRef(class_loader), ns));
101    }
102
103    return ns;
104  }
105
106  android_namespace_t* FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) {
107    auto it = std::find_if(namespaces_.begin(), namespaces_.end(),
108                [&](const std::pair<jweak, android_namespace_t*>& value) {
109                  return env->IsSameObject(value.first, class_loader);
110                });
111    return it != namespaces_.end() ? it->second : nullptr;
112  }
113
114  void PreloadPublicLibraries() {
115    // android_init_namespaces() expects all the public libraries
116    // to be loaded so that they can be found by soname alone.
117    std::vector<std::string> sonames = android::base::Split(kPublicNativeLibraries, ":");
118    for (const auto& soname : sonames) {
119      dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE);
120    }
121  }
122
123 private:
124  bool InitPublicNamespace(const char* library_path) {
125    // Some apps call dlopen from generated code unknown to linker in which
126    // case linker uses anonymous namespace. See b/25844435 for details.
127    initialized_ = android_init_namespaces(kPublicNativeLibraries, library_path);
128
129    return initialized_;
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
141static bool namespaces_enabled(uint32_t target_sdk_version) {
142  return target_sdk_version > 0;
143}
144#endif
145
146void PreloadPublicNativeLibraries() {
147#if defined(__ANDROID__)
148  g_namespaces->PreloadPublicLibraries();
149#endif
150}
151
152
153jstring CreateClassLoaderNamespace(JNIEnv* env,
154                                   int32_t target_sdk_version,
155                                   jobject class_loader,
156                                   bool is_shared,
157                                   jstring library_path,
158                                   jstring permitted_path) {
159#if defined(__ANDROID__)
160  if (!namespaces_enabled(target_sdk_version)) {
161    return nullptr;
162  }
163
164  android_namespace_t* ns = g_namespaces->Create(env,
165                                                 class_loader,
166                                                 is_shared,
167                                                 library_path,
168                                                 permitted_path);
169  if (ns == nullptr) {
170    return env->NewStringUTF(dlerror());
171  }
172#else
173  UNUSED(env, target_sdk_version, class_loader, is_shared,
174         library_path, permitted_path);
175#endif
176  return nullptr;
177}
178
179void* OpenNativeLibrary(JNIEnv* env,
180                        int32_t target_sdk_version,
181                        const char* path,
182                        jobject class_loader,
183                        jstring library_path) {
184#if defined(__ANDROID__)
185  if (!namespaces_enabled(target_sdk_version) || class_loader == nullptr) {
186    return dlopen(path, RTLD_NOW);
187  }
188
189  android_namespace_t* ns = g_namespaces->FindNamespaceByClassLoader(env, class_loader);
190
191  if (ns == nullptr) {
192    // This is the case where the classloader was not created by ApplicationLoaders
193    // In this case we create an isolated not-shared namespace for it.
194    ns = g_namespaces->Create(env, class_loader, false, library_path, nullptr);
195    if (ns == nullptr) {
196      return nullptr;
197    }
198  }
199
200  android_dlextinfo extinfo;
201  extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
202  extinfo.library_namespace = ns;
203
204  return android_dlopen_ext(path, RTLD_NOW, &extinfo);
205#else
206  UNUSED(env, target_sdk_version, class_loader, library_path);
207  return dlopen(path, RTLD_NOW);
208#endif
209}
210
211#if defined(__ANDROID__)
212android_namespace_t* FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) {
213  return g_namespaces->FindNamespaceByClassLoader(env, class_loader);
214}
215#endif
216
217}; //  android namespace
218