native_loader.cpp revision 55bbb0d88ada4d7394411dba004d2af6086da6a4 
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    auto it = FindNamespaceByClassLoader(env, class_loader);
83
84    if (it != namespaces_.end()) {
85      return it->second;
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    android_namespace_t* ns =
94            android_create_namespace("classloader-namespace",
95                                     nullptr,
96                                     library_path.c_str(),
97                                     namespace_type,
98                                     java_permitted_path != nullptr ?
99                                        permitted_path.c_str() :
100                                        nullptr);
101
102    namespaces_.push_back(std::make_pair(env->NewWeakGlobalRef(class_loader), ns));
103
104    return ns;
105  }
106
107 private:
108  void PreloadPublicLibraries() {
109    // android_init_namespaces() expects all the public libraries
110    // to be loaded so that they can be found by soname alone.
111    std::vector<std::string> sonames = android::base::Split(kPublicNativeLibraries, ":");
112    for (const auto& soname : sonames) {
113      dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE);
114    }
115  }
116
117  bool InitPublicNamespace(const char* library_path) {
118    // Some apps call dlopen from generated code unknown to linker in which
119    // case linker uses anonymous namespace. See b/25844435 for details.
120    initialized_ = android_init_namespaces(kPublicNativeLibraries, library_path);
121
122    return initialized_;
123  }
124
125  std::vector<std::pair<jweak, android_namespace_t*>>::const_iterator
126  FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) {
127    return std::find_if(namespaces_.begin(), namespaces_.end(),
128            [&](const std::pair<jweak, android_namespace_t*>& value) {
129              return env->IsSameObject(value.first, class_loader);
130            });
131  }
132
133  bool initialized_;
134  std::mutex mutex_;
135  std::vector<std::pair<jweak, android_namespace_t*>> namespaces_;
136
137  DISALLOW_COPY_AND_ASSIGN(LibraryNamespaces);
138};
139
140static LibraryNamespaces* g_namespaces = new LibraryNamespaces;
141#endif
142
143
144void* OpenNativeLibrary(JNIEnv* env, int32_t target_sdk_version, const char* path,
145                        jobject class_loader, bool is_shared, jstring java_library_path,
146                        jstring java_permitted_path) {
147#if defined(__ANDROID__)
148  if (target_sdk_version == 0 || class_loader == nullptr) {
149    return dlopen(path, RTLD_NOW);
150  }
151
152  android_namespace_t* ns =
153      g_namespaces->GetOrCreate(env, class_loader, is_shared,
154                                java_library_path, java_permitted_path);
155
156  if (ns == nullptr) {
157    return nullptr;
158  }
159
160  android_dlextinfo extinfo;
161  extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
162  extinfo.library_namespace = ns;
163
164  return android_dlopen_ext(path, RTLD_NOW, &extinfo);
165#else
166  UNUSED(env, target_sdk_version, class_loader, is_shared,
167         java_library_path, java_permitted_path);
168  return dlopen(path, RTLD_NOW);
169#endif
170}
171
172}; //  android namespace
173