| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "nativeloader/native_loader.h" |
| #include "ScopedUtfChars.h" |
| |
| #include <dlfcn.h> |
| #ifdef __ANDROID__ |
| #include "dlext_namespaces.h" |
| #include "cutils/properties.h" |
| #define LOG_TAG "libnativeloader" |
| #include "log/log.h" |
| #endif |
| |
| #include <algorithm> |
| #include <vector> |
| #include <string> |
| #include <mutex> |
| |
| #include "android-base/file.h" |
| #include "android-base/macros.h" |
| #include "android-base/strings.h" |
| |
| namespace android { |
| |
| #if defined(__ANDROID__) |
| static constexpr const char* kPublicNativeLibrariesSystemConfigPathFromRoot = "/etc/public.libraries.txt"; |
| static constexpr const char* kPublicNativeLibrariesVendorConfig = "/vendor/etc/public.libraries.txt"; |
| |
| // (http://b/27588281) This is a workaround for apps using custom classloaders and calling |
| // System.load() with an absolute path which is outside of the classloader library search path. |
| // This list includes all directories app is allowed to access this way. |
| static constexpr const char* kWhitelistedDirectories = "/data:/mnt/expand"; |
| |
| static bool is_debuggable() { |
| char debuggable[PROP_VALUE_MAX]; |
| property_get("ro.debuggable", debuggable, "0"); |
| return std::string(debuggable) == "1"; |
| } |
| |
| class LibraryNamespaces { |
| public: |
| LibraryNamespaces() : initialized_(false) { } |
| |
| android_namespace_t* Create(JNIEnv* env, |
| jobject class_loader, |
| bool is_shared, |
| jstring java_library_path, |
| jstring java_permitted_path, |
| int32_t target_sdk_version) { |
| std::string library_path; // empty string by default. |
| |
| if (java_library_path != nullptr) { |
| ScopedUtfChars library_path_utf_chars(env, java_library_path); |
| library_path = library_path_utf_chars.c_str(); |
| } |
| |
| // (http://b/27588281) This is a workaround for apps using custom |
| // classloaders and calling System.load() with an absolute path which |
| // is outside of the classloader library search path. |
| // |
| // This part effectively allows such a classloader to access anything |
| // under /data and /mnt/expand |
| std::string permitted_path = kWhitelistedDirectories; |
| |
| if (java_permitted_path != nullptr) { |
| ScopedUtfChars path(env, java_permitted_path); |
| if (path.c_str() != nullptr && path.size() > 0) { |
| permitted_path = permitted_path + ":" + path.c_str(); |
| } |
| } |
| |
| if (!initialized_ && !InitPublicNamespace(library_path.c_str(), target_sdk_version)) { |
| return nullptr; |
| } |
| |
| android_namespace_t* ns = FindNamespaceByClassLoader(env, class_loader); |
| |
| LOG_ALWAYS_FATAL_IF(ns != nullptr, |
| "There is already a namespace associated with this classloader"); |
| |
| uint64_t namespace_type = ANDROID_NAMESPACE_TYPE_ISOLATED; |
| if (is_shared) { |
| namespace_type |= ANDROID_NAMESPACE_TYPE_SHARED; |
| } |
| |
| android_namespace_t* parent_ns = FindParentNamespaceByClassLoader(env, class_loader); |
| |
| ns = android_create_namespace("classloader-namespace", |
| nullptr, |
| library_path.c_str(), |
| namespace_type, |
| permitted_path.c_str(), |
| parent_ns); |
| |
| if (ns != nullptr) { |
| namespaces_.push_back(std::make_pair(env->NewWeakGlobalRef(class_loader), ns)); |
| } |
| |
| return ns; |
| } |
| |
| android_namespace_t* FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) { |
| auto it = std::find_if(namespaces_.begin(), namespaces_.end(), |
| [&](const std::pair<jweak, android_namespace_t*>& value) { |
| return env->IsSameObject(value.first, class_loader); |
| }); |
| return it != namespaces_.end() ? it->second : nullptr; |
| } |
| |
| void Initialize() { |
| // Once public namespace is initialized there is no |
| // point in running this code - it will have no effect |
| // on the current list of public libraries. |
| if (initialized_) { |
| return; |
| } |
| |
| std::vector<std::string> sonames; |
| const char* android_root_env = getenv("ANDROID_ROOT"); |
| std::string root_dir = android_root_env != nullptr ? android_root_env : "/system"; |
| std::string public_native_libraries_system_config = |
| root_dir + kPublicNativeLibrariesSystemConfigPathFromRoot; |
| |
| LOG_ALWAYS_FATAL_IF(!ReadConfig(public_native_libraries_system_config, &sonames), |
| "Error reading public native library list from \"%s\": %s", |
| public_native_libraries_system_config.c_str(), strerror(errno)); |
| |
| // For debuggable platform builds use ANDROID_ADDITIONAL_PUBLIC_LIBRARIES environment |
| // variable to add libraries to the list. This is intended for platform tests only. |
| if (is_debuggable()) { |
| const char* additional_libs = getenv("ANDROID_ADDITIONAL_PUBLIC_LIBRARIES"); |
| if (additional_libs != nullptr && additional_libs[0] != '\0') { |
| std::vector<std::string> additional_libs_vector = base::Split(additional_libs, ":"); |
| std::copy(additional_libs_vector.begin(), |
| additional_libs_vector.end(), |
| std::back_inserter(sonames)); |
| } |
| } |
| |
| // This file is optional, quietly ignore if the file does not exist. |
| ReadConfig(kPublicNativeLibrariesVendorConfig, &sonames); |
| |
| // android_init_namespaces() expects all the public libraries |
| // to be loaded so that they can be found by soname alone. |
| // |
| // TODO(dimitry): this is a bit misleading since we do not know |
| // if the vendor public library is going to be opened from /vendor/lib |
| // we might as well end up loading them from /system/lib |
| // For now we rely on CTS test to catch things like this but |
| // it should probably be addressed in the future. |
| for (const auto& soname : sonames) { |
| dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE); |
| } |
| |
| public_libraries_ = base::Join(sonames, ':'); |
| } |
| |
| void Reset() { |
| namespaces_.clear(); |
| } |
| |
| private: |
| bool ReadConfig(const std::string& configFile, std::vector<std::string>* sonames) { |
| // Read list of public native libraries from the config file. |
| std::string file_content; |
| if(!base::ReadFileToString(configFile, &file_content)) { |
| return false; |
| } |
| |
| std::vector<std::string> lines = base::Split(file_content, "\n"); |
| |
| for (const auto& line : lines) { |
| auto trimmed_line = base::Trim(line); |
| if (trimmed_line[0] == '#' || trimmed_line.empty()) { |
| continue; |
| } |
| |
| sonames->push_back(trimmed_line); |
| } |
| |
| return true; |
| } |
| |
| bool InitPublicNamespace(const char* library_path, int32_t target_sdk_version) { |
| std::string publicNativeLibraries = public_libraries_; |
| |
| UNUSED(target_sdk_version); |
| // (http://b/25844435) - Some apps call dlopen from generated code (mono jited |
| // code is one example) unknown to linker in which case linker uses anonymous |
| // namespace. The second argument specifies the search path for the anonymous |
| // namespace which is the library_path of the classloader. |
| initialized_ = android_init_namespaces(publicNativeLibraries.c_str(), library_path); |
| |
| return initialized_; |
| } |
| |
| jobject GetParentClassLoader(JNIEnv* env, jobject class_loader) { |
| jclass class_loader_class = env->FindClass("java/lang/ClassLoader"); |
| jmethodID get_parent = env->GetMethodID(class_loader_class, |
| "getParent", |
| "()Ljava/lang/ClassLoader;"); |
| |
| return env->CallObjectMethod(class_loader, get_parent); |
| } |
| |
| android_namespace_t* FindParentNamespaceByClassLoader(JNIEnv* env, jobject class_loader) { |
| jobject parent_class_loader = GetParentClassLoader(env, class_loader); |
| |
| while (parent_class_loader != nullptr) { |
| android_namespace_t* ns = FindNamespaceByClassLoader(env, parent_class_loader); |
| if (ns != nullptr) { |
| return ns; |
| } |
| |
| parent_class_loader = GetParentClassLoader(env, parent_class_loader); |
| } |
| return nullptr; |
| } |
| |
| bool initialized_; |
| std::vector<std::pair<jweak, android_namespace_t*>> namespaces_; |
| std::string public_libraries_; |
| |
| |
| DISALLOW_COPY_AND_ASSIGN(LibraryNamespaces); |
| }; |
| |
| static std::mutex g_namespaces_mutex; |
| static LibraryNamespaces* g_namespaces = new LibraryNamespaces; |
| #endif |
| |
| void InitializeNativeLoader() { |
| #if defined(__ANDROID__) |
| std::lock_guard<std::mutex> guard(g_namespaces_mutex); |
| g_namespaces->Initialize(); |
| #endif |
| } |
| |
| void ResetNativeLoader() { |
| #if defined(__ANDROID__) |
| std::lock_guard<std::mutex> guard(g_namespaces_mutex); |
| g_namespaces->Reset(); |
| #endif |
| } |
| |
| jstring CreateClassLoaderNamespace(JNIEnv* env, |
| int32_t target_sdk_version, |
| jobject class_loader, |
| bool is_shared, |
| jstring library_path, |
| jstring permitted_path) { |
| #if defined(__ANDROID__) |
| UNUSED(target_sdk_version); |
| std::lock_guard<std::mutex> guard(g_namespaces_mutex); |
| android_namespace_t* ns = g_namespaces->Create(env, |
| class_loader, |
| is_shared, |
| library_path, |
| permitted_path, |
| target_sdk_version); |
| if (ns == nullptr) { |
| return env->NewStringUTF(dlerror()); |
| } |
| #else |
| UNUSED(env, target_sdk_version, class_loader, is_shared, |
| library_path, permitted_path); |
| #endif |
| return nullptr; |
| } |
| |
| void* OpenNativeLibrary(JNIEnv* env, |
| int32_t target_sdk_version, |
| const char* path, |
| jobject class_loader, |
| jstring library_path) { |
| #if defined(__ANDROID__) |
| UNUSED(target_sdk_version); |
| if (class_loader == nullptr) { |
| return dlopen(path, RTLD_NOW); |
| } |
| |
| std::lock_guard<std::mutex> guard(g_namespaces_mutex); |
| android_namespace_t* ns = g_namespaces->FindNamespaceByClassLoader(env, class_loader); |
| |
| if (ns == nullptr) { |
| // This is the case where the classloader was not created by ApplicationLoaders |
| // In this case we create an isolated not-shared namespace for it. |
| ns = g_namespaces->Create(env, class_loader, false, library_path, nullptr, target_sdk_version); |
| if (ns == nullptr) { |
| return nullptr; |
| } |
| } |
| |
| android_dlextinfo extinfo; |
| extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE; |
| extinfo.library_namespace = ns; |
| |
| return android_dlopen_ext(path, RTLD_NOW, &extinfo); |
| #else |
| UNUSED(env, target_sdk_version, class_loader, library_path); |
| return dlopen(path, RTLD_NOW); |
| #endif |
| } |
| |
| bool CloseNativeLibrary(void* handle) { |
| return dlclose(handle) == 0; |
| } |
| |
| #if defined(__ANDROID__) |
| android_namespace_t* FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) { |
| std::lock_guard<std::mutex> guard(g_namespaces_mutex); |
| return g_namespaces->FindNamespaceByClassLoader(env, class_loader); |
| } |
| #endif |
| |
| }; // android namespace |