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/*
* 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__
#define LOG_TAG "libnativeloader"
#include "nativeloader/dlext_namespaces.h"
#include "cutils/properties.h"
#include "log/log.h"
#endif
#include "nativebridge/native_bridge.h"
#include <algorithm>
#include <vector>
#include <string>
#include <mutex>
#include <android-base/file.h>
#include <android-base/macros.h>
#include <android-base/strings.h>
#define CHECK(predicate) LOG_ALWAYS_FATAL_IF(!(predicate),\
"%s:%d: %s CHECK '" #predicate "' failed.",\
__FILE__, __LINE__, __FUNCTION__)
namespace android {
#if defined(__ANDROID__)
class NativeLoaderNamespace {
public:
NativeLoaderNamespace()
: android_ns_(nullptr), native_bridge_ns_(nullptr) { }
explicit NativeLoaderNamespace(android_namespace_t* ns)
: android_ns_(ns), native_bridge_ns_(nullptr) { }
explicit NativeLoaderNamespace(native_bridge_namespace_t* ns)
: android_ns_(nullptr), native_bridge_ns_(ns) { }
NativeLoaderNamespace(NativeLoaderNamespace&& that) = default;
NativeLoaderNamespace(const NativeLoaderNamespace& that) = default;
NativeLoaderNamespace& operator=(const NativeLoaderNamespace& that) = default;
android_namespace_t* get_android_ns() const {
CHECK(native_bridge_ns_ == nullptr);
return android_ns_;
}
native_bridge_namespace_t* get_native_bridge_ns() const {
CHECK(android_ns_ == nullptr);
return native_bridge_ns_;
}
bool is_android_namespace() const {
return native_bridge_ns_ == nullptr;
}
private:
// Only one of them can be not null
android_namespace_t* android_ns_;
native_bridge_namespace_t* native_bridge_ns_;
};
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) { }
bool Create(JNIEnv* env,
jobject class_loader,
bool is_shared,
jstring java_library_path,
jstring java_permitted_path,
NativeLoaderNamespace* ns,
std::string* error_msg) {
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(), error_msg)) {
return false;
}
bool found = FindNamespaceByClassLoader(env, class_loader, nullptr);
LOG_ALWAYS_FATAL_IF(found,
"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;
}
NativeLoaderNamespace parent_ns;
bool found_parent_namespace = FindParentNamespaceByClassLoader(env, class_loader, &parent_ns);
bool is_native_bridge = false;
if (found_parent_namespace) {
is_native_bridge = !parent_ns.is_android_namespace();
} else if (!library_path.empty()) {
is_native_bridge = NativeBridgeIsPathSupported(library_path.c_str());
}
NativeLoaderNamespace native_loader_ns;
if (!is_native_bridge) {
android_namespace_t* ns = android_create_namespace("classloader-namespace",
nullptr,
library_path.c_str(),
namespace_type,
permitted_path.c_str(),
parent_ns.get_android_ns());
if (ns == nullptr) {
*error_msg = dlerror();
return false;
}
if (!android_link_namespaces(ns, nullptr, public_libraries_.c_str())) {
*error_msg = dlerror();
return false;
}
native_loader_ns = NativeLoaderNamespace(ns);
} else {
native_bridge_namespace_t* ns = NativeBridgeCreateNamespace("classloader-namespace",
nullptr,
library_path.c_str(),
namespace_type,
permitted_path.c_str(),
parent_ns.get_native_bridge_ns());
if (ns == nullptr) {
*error_msg = NativeBridgeGetError();
return false;
}
if (!NativeBridgeLinkNamespaces(ns, nullptr, public_libraries_.c_str())) {
*error_msg = NativeBridgeGetError();
return false;
}
native_loader_ns = NativeLoaderNamespace(ns);
}
namespaces_.push_back(std::make_pair(env->NewWeakGlobalRef(class_loader), native_loader_ns));
*ns = native_loader_ns;
return true;
}
bool FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader, NativeLoaderNamespace* ns) {
auto it = std::find_if(namespaces_.begin(), namespaces_.end(),
[&](const std::pair<jweak, NativeLoaderNamespace>& value) {
return env->IsSameObject(value.first, class_loader);
});
if (it != namespaces_.end()) {
if (ns != nullptr) {
*ns = it->second;
}
return true;
}
return false;
}
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;
std::string error_msg;
LOG_ALWAYS_FATAL_IF(!ReadConfig(public_native_libraries_system_config, &sonames, &error_msg),
"Error reading public native library list from \"%s\": %s",
public_native_libraries_system_config.c_str(), error_msg.c_str());
// 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) {
LOG_ALWAYS_FATAL_IF(dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE) == nullptr,
"Error preloading public library %s: %s",
soname.c_str(), dlerror());
}
public_libraries_ = base::Join(sonames, ':');
}
void Reset() {
namespaces_.clear();
}
private:
bool ReadConfig(const std::string& configFile, std::vector<std::string>* sonames,
std::string* error_msg = nullptr) {
// Read list of public native libraries from the config file.
std::string file_content;
if(!base::ReadFileToString(configFile, &file_content)) {
if (error_msg) *error_msg = strerror(errno);
return false;
}
std::vector<std::string> lines = base::Split(file_content, "\n");
for (auto& line : lines) {
auto trimmed_line = base::Trim(line);
if (trimmed_line[0] == '#' || trimmed_line.empty()) {
continue;
}
size_t space_pos = trimmed_line.rfind(' ');
if (space_pos != std::string::npos) {
std::string type = trimmed_line.substr(space_pos + 1);
if (type != "32" && type != "64") {
if (error_msg) *error_msg = "Malformed line: " + line;
return false;
}
#if defined(__LP64__)
// Skip 32 bit public library.
if (type == "32") {
continue;
}
#else
// Skip 64 bit public library.
if (type == "64") {
continue;
}
#endif
trimmed_line.resize(space_pos);
}
sonames->push_back(trimmed_line);
}
return true;
}
bool InitPublicNamespace(const char* library_path, std::string* error_msg) {
// Ask native bride if this apps library path should be handled by it
bool is_native_bridge = NativeBridgeIsPathSupported(library_path);
// (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_anonymous_namespace(public_libraries_.c_str(),
is_native_bridge ? nullptr : library_path);
if (!initialized_) {
*error_msg = dlerror();
return false;
}
// and now initialize native bridge namespaces if necessary.
if (NativeBridgeInitialized()) {
initialized_ = NativeBridgeInitAnonymousNamespace(public_libraries_.c_str(),
is_native_bridge ? library_path : nullptr);
if (!initialized_) {
*error_msg = NativeBridgeGetError();
}
}
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);
}
bool FindParentNamespaceByClassLoader(JNIEnv* env,
jobject class_loader,
NativeLoaderNamespace* ns) {
jobject parent_class_loader = GetParentClassLoader(env, class_loader);
while (parent_class_loader != nullptr) {
if (FindNamespaceByClassLoader(env, parent_class_loader, ns)) {
return true;
}
parent_class_loader = GetParentClassLoader(env, parent_class_loader);
}
return false;
}
bool initialized_;
std::vector<std::pair<jweak, NativeLoaderNamespace>> 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);
std::string error_msg;
NativeLoaderNamespace ns;
bool success = g_namespaces->Create(env,
class_loader,
is_shared,
library_path,
permitted_path,
&ns,
&error_msg);
if (!success) {
return env->NewStringUTF(error_msg.c_str());
}
#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,
bool* needs_native_bridge,
std::string* error_msg) {
#if defined(__ANDROID__)
UNUSED(target_sdk_version);
if (class_loader == nullptr) {
*needs_native_bridge = false;
return dlopen(path, RTLD_NOW);
}
std::lock_guard<std::mutex> guard(g_namespaces_mutex);
NativeLoaderNamespace ns;
if (!g_namespaces->FindNamespaceByClassLoader(env, class_loader, &ns)) {
// This is the case where the classloader was not created by ApplicationLoaders
// In this case we create an isolated not-shared namespace for it.
if (!g_namespaces->Create(env, class_loader, false, library_path, nullptr, &ns, error_msg)) {
return nullptr;
}
}
if (ns.is_android_namespace()) {
android_dlextinfo extinfo;
extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
extinfo.library_namespace = ns.get_android_ns();
void* handle = android_dlopen_ext(path, RTLD_NOW, &extinfo);
if (handle == nullptr) {
*error_msg = dlerror();
}
*needs_native_bridge = false;
return handle;
} else {
void* handle = NativeBridgeLoadLibraryExt(path, RTLD_NOW, ns.get_native_bridge_ns());
if (handle == nullptr) {
*error_msg = NativeBridgeGetError();
}
*needs_native_bridge = true;
return handle;
}
#else
UNUSED(env, target_sdk_version, class_loader, library_path);
*needs_native_bridge = false;
void* handle = dlopen(path, RTLD_NOW);
if (handle == nullptr) {
if (NativeBridgeIsSupported(path)) {
*needs_native_bridge = true;
handle = NativeBridgeLoadLibrary(path, RTLD_NOW);
if (handle == nullptr) {
*error_msg = NativeBridgeGetError();
}
} else {
*needs_native_bridge = false;
*error_msg = dlerror();
}
}
return handle;
#endif
}
bool CloseNativeLibrary(void* handle, const bool needs_native_bridge) {
return needs_native_bridge ? NativeBridgeUnloadLibrary(handle) :
dlclose(handle);
}
#if defined(__ANDROID__)
// native_bridge_namespaces are not supported for callers of this function.
// This function will return nullptr in the case when application is running
// on native bridge.
android_namespace_t* FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) {
std::lock_guard<std::mutex> guard(g_namespaces_mutex);
NativeLoaderNamespace ns;
if (g_namespaces->FindNamespaceByClassLoader(env, class_loader, &ns)) {
return ns.is_android_namespace() ? ns.get_android_ns() : nullptr;
}
return nullptr;
}
#endif
}; // android namespace