blob: 01411f53249d69a73a3630dd9b2e0ee723e25bf2 [file] [log] [blame]
/*
* Copyright (C) 2019 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 specic language governing permissions and
* limitations under the License.
*/
#include "MediaProviderWrapper.h"
#include "libfuse_jni/ReaddirHelper.h"
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <jni.h>
#include <nativehelper/scoped_local_ref.h>
#include <nativehelper/scoped_primitive_array.h>
#include <nativehelper/scoped_utf_chars.h>
#include <pthread.h>
#include <mutex>
#include <unordered_map>
namespace mediaprovider {
namespace fuse {
using android::base::GetBoolProperty;
using std::string;
namespace {
constexpr const char* kPropRedactionEnabled = "persist.sys.fuse.redaction-enabled";
constexpr uid_t ROOT_UID = 0;
constexpr uid_t SHELL_UID = 2000;
/** Private helper functions **/
inline bool shouldBypassMediaProvider(uid_t uid) {
return uid == SHELL_UID || uid == ROOT_UID;
}
static bool CheckForJniException(JNIEnv* env) {
if (env->ExceptionCheck()) {
env->ExceptionDescribe();
env->ExceptionClear();
return true;
}
return false;
}
/**
* Auxiliary for caching class fields
*/
static jfieldID CacheField(JNIEnv* env, jclass clazz, const char field_name[], const char type[]) {
jfieldID fid;
string actual_field_name(field_name);
fid = env->GetFieldID(clazz, actual_field_name.c_str(), type);
if (!fid) {
LOG(FATAL) << "Error caching field: " << field_name << type;
}
return fid;
}
int insertFileInternal(JNIEnv* env, jobject media_provider_object, jmethodID mid_insert_file,
const string& path, uid_t uid) {
ScopedLocalRef<jstring> j_path(env, env->NewStringUTF(path.c_str()));
int res = env->CallIntMethod(media_provider_object, mid_insert_file, j_path.get(), uid);
if (CheckForJniException(env)) {
return EFAULT;
}
return res;
}
int deleteFileInternal(JNIEnv* env, jobject media_provider_object, jmethodID mid_delete_file,
const string& path, uid_t uid) {
ScopedLocalRef<jstring> j_path(env, env->NewStringUTF(path.c_str()));
int res = env->CallIntMethod(media_provider_object, mid_delete_file, j_path.get(), uid);
if (CheckForJniException(env)) {
return EFAULT;
}
return res;
}
int isMkdirOrRmdirAllowedInternal(JNIEnv* env, jobject media_provider_object,
jmethodID mid_is_mkdir_or_rmdir_allowed, const string& path,
uid_t uid, bool forCreate) {
ScopedLocalRef<jstring> j_path(env, env->NewStringUTF(path.c_str()));
int res = env->CallIntMethod(media_provider_object, mid_is_mkdir_or_rmdir_allowed, j_path.get(),
uid, forCreate);
if (CheckForJniException(env)) {
return EFAULT;
}
return res;
}
int isOpendirAllowedInternal(JNIEnv* env, jobject media_provider_object,
jmethodID mid_is_opendir_allowed, const string& path, uid_t uid,
bool forWrite) {
ScopedLocalRef<jstring> j_path(env, env->NewStringUTF(path.c_str()));
int res = env->CallIntMethod(media_provider_object, mid_is_opendir_allowed, j_path.get(), uid,
forWrite);
if (CheckForJniException(env)) {
return EFAULT;
}
return res;
}
bool isUidAllowedAccessToDataOrObbPathInternal(JNIEnv* env, jobject media_provider_object,
jmethodID mid_is_uid_allowed_path_access_, uid_t uid,
const string& path) {
ScopedLocalRef<jstring> j_path(env, env->NewStringUTF(path.c_str()));
bool res = env->CallBooleanMethod(media_provider_object, mid_is_uid_allowed_path_access_, uid,
j_path.get());
if (CheckForJniException(env)) {
return false;
}
return res;
}
std::vector<std::shared_ptr<DirectoryEntry>> getFilesInDirectoryInternal(
JNIEnv* env, jobject media_provider_object, jmethodID mid_get_files_in_dir, uid_t uid,
const string& path) {
std::vector<std::shared_ptr<DirectoryEntry>> directory_entries;
ScopedLocalRef<jstring> j_path(env, env->NewStringUTF(path.c_str()));
ScopedLocalRef<jobjectArray> files_list(
env, static_cast<jobjectArray>(env->CallObjectMethod(
media_provider_object, mid_get_files_in_dir, j_path.get(), uid)));
if (CheckForJniException(env)) {
directory_entries.push_back(std::make_shared<DirectoryEntry>("", EFAULT));
return directory_entries;
}
int de_count = env->GetArrayLength(files_list.get());
if (de_count == 1) {
ScopedLocalRef<jstring> j_d_name(env,
(jstring)env->GetObjectArrayElement(files_list.get(), 0));
ScopedUtfChars d_name(env, j_d_name.get());
if (d_name.c_str() == nullptr) {
LOG(ERROR) << "Error reading file name returned from MediaProvider at index " << 0;
directory_entries.push_back(std::make_shared<DirectoryEntry>("", EFAULT));
return directory_entries;
} else if (d_name.c_str()[0] == '\0') {
// Calling package has no storage permissions.
directory_entries.push_back(std::make_shared<DirectoryEntry>("", EPERM));
return directory_entries;
}
}
for (int i = 0; i < de_count; i++) {
ScopedLocalRef<jstring> j_d_name(env,
(jstring)env->GetObjectArrayElement(files_list.get(), i));
ScopedUtfChars d_name(env, j_d_name.get());
if (d_name.c_str() == nullptr) {
LOG(ERROR) << "Error reading file name returned from MediaProvider at index " << i;
directory_entries.resize(0);
directory_entries.push_back(std::make_shared<DirectoryEntry>("", EFAULT));
break;
}
directory_entries.push_back(std::make_shared<DirectoryEntry>(d_name.c_str(), DT_REG));
}
return directory_entries;
}
int renameInternal(JNIEnv* env, jobject media_provider_object, jmethodID mid_rename,
const string& old_path, const string& new_path, uid_t uid) {
ScopedLocalRef<jstring> j_old_path(env, env->NewStringUTF(old_path.c_str()));
ScopedLocalRef<jstring> j_new_path(env, env->NewStringUTF(new_path.c_str()));
int res = env->CallIntMethod(media_provider_object, mid_rename, j_old_path.get(),
j_new_path.get(), uid);
if (CheckForJniException(env)) {
return EFAULT;
}
return res;
}
void onFileCreatedInternal(JNIEnv* env, jobject media_provider_object,
jmethodID mid_on_file_created, const string& path) {
ScopedLocalRef<jstring> j_path(env, env->NewStringUTF(path.c_str()));
env->CallVoidMethod(media_provider_object, mid_on_file_created, j_path.get());
CheckForJniException(env);
return;
}
} // namespace
/*****************************************************************************************/
/******************************* Public API Implementation *******************************/
/*****************************************************************************************/
JavaVM* MediaProviderWrapper::gJavaVm = nullptr;
pthread_key_t MediaProviderWrapper::gJniEnvKey;
void MediaProviderWrapper::OneTimeInit(JavaVM* vm) {
gJavaVm = vm;
CHECK(gJavaVm != nullptr);
pthread_key_create(&MediaProviderWrapper::gJniEnvKey,
MediaProviderWrapper::DetachThreadFunction);
}
MediaProviderWrapper::MediaProviderWrapper(JNIEnv* env, jobject media_provider) {
if (!media_provider) {
LOG(FATAL) << "MediaProvider is null!";
}
media_provider_object_ = reinterpret_cast<jobject>(env->NewGlobalRef(media_provider));
media_provider_class_ = env->FindClass("com/android/providers/media/MediaProvider");
if (!media_provider_class_) {
LOG(FATAL) << "Could not find class MediaProvider";
}
media_provider_class_ = reinterpret_cast<jclass>(env->NewGlobalRef(media_provider_class_));
// Cache methods - Before calling a method, make sure you cache it here
mid_insert_file_ = CacheMethod(env, "insertFileIfNecessary", "(Ljava/lang/String;I)I",
/*is_static*/ false);
mid_delete_file_ = CacheMethod(env, "deleteFile", "(Ljava/lang/String;I)I", /*is_static*/ false);
mid_on_file_open_ = CacheMethod(env, "onFileOpen",
"(Ljava/lang/String;Ljava/lang/String;IIIZZZ)Lcom/android/"
"providers/media/FileOpenResult;",
/*is_static*/ false);
mid_is_mkdir_or_rmdir_allowed_ = CacheMethod(env, "isDirectoryCreationOrDeletionAllowed",
"(Ljava/lang/String;IZ)I", /*is_static*/ false);
mid_is_opendir_allowed_ = CacheMethod(env, "isOpendirAllowed", "(Ljava/lang/String;IZ)I",
/*is_static*/ false);
mid_get_files_in_dir_ =
CacheMethod(env, "getFilesInDirectory", "(Ljava/lang/String;I)[Ljava/lang/String;",
/*is_static*/ false);
mid_rename_ = CacheMethod(env, "rename", "(Ljava/lang/String;Ljava/lang/String;I)I",
/*is_static*/ false);
mid_is_uid_allowed_access_to_data_or_obb_path_ =
CacheMethod(env, "isUidAllowedAccessToDataOrObbPath", "(ILjava/lang/String;)Z",
/*is_static*/ false);
mid_on_file_created_ = CacheMethod(env, "onFileCreated", "(Ljava/lang/String;)V",
/*is_static*/ false);
mid_should_allow_lookup_ = CacheMethod(env, "shouldAllowLookup", "(II)Z",
/*is_static*/ false);
mid_is_app_clone_user_ = CacheMethod(env, "isAppCloneUser", "(I)Z",
/*is_static*/ false);
mid_transform_ = CacheMethod(env, "transform", "(Ljava/lang/String;Ljava/lang/String;IIIII)Z",
/*is_static*/ false);
mid_file_lookup_ =
CacheMethod(env, "onFileLookup",
"(Ljava/lang/String;II)Lcom/android/providers/media/FileLookupResult;",
/*is_static*/ false);
// FileLookupResult
file_lookup_result_class_ = env->FindClass("com/android/providers/media/FileLookupResult");
if (!file_lookup_result_class_) {
LOG(FATAL) << "Could not find class FileLookupResult";
}
file_lookup_result_class_ =
reinterpret_cast<jclass>(env->NewGlobalRef(file_lookup_result_class_));
fid_file_lookup_transforms_ = CacheField(env, file_lookup_result_class_, "transforms", "I");
fid_file_lookup_transforms_reason_ =
CacheField(env, file_lookup_result_class_, "transformsReason", "I");
fid_file_lookup_uid_ = CacheField(env, file_lookup_result_class_, "uid", "I");
fid_file_lookup_transforms_complete_ =
CacheField(env, file_lookup_result_class_, "transformsComplete", "Z");
fid_file_lookup_transforms_supported_ =
CacheField(env, file_lookup_result_class_, "transformsSupported", "Z");
fid_file_lookup_io_path_ =
CacheField(env, file_lookup_result_class_, "ioPath", "Ljava/lang/String;");
// FileOpenResult
file_open_result_class_ = env->FindClass("com/android/providers/media/FileOpenResult");
if (!file_open_result_class_) {
LOG(FATAL) << "Could not find class FileOpenResult";
}
file_open_result_class_ = reinterpret_cast<jclass>(env->NewGlobalRef(file_open_result_class_));
fid_file_open_status_ = CacheField(env, file_open_result_class_, "status", "I");
fid_file_open_uid_ = CacheField(env, file_open_result_class_, "uid", "I");
fid_file_open_transforms_uid_ = CacheField(env, file_open_result_class_, "transformsUid", "I");
fid_file_open_redaction_ranges_ =
CacheField(env, file_open_result_class_, "redactionRanges", "[J");
fid_file_open_fd_ = CacheField(env, file_open_result_class_, "nativeFd", "I");
}
MediaProviderWrapper::~MediaProviderWrapper() {
JNIEnv* env = MaybeAttachCurrentThread();
env->DeleteGlobalRef(media_provider_object_);
env->DeleteGlobalRef(media_provider_class_);
}
int MediaProviderWrapper::InsertFile(const string& path, uid_t uid) {
if (uid == ROOT_UID) {
return 0;
}
JNIEnv* env = MaybeAttachCurrentThread();
return insertFileInternal(env, media_provider_object_, mid_insert_file_, path, uid);
}
int MediaProviderWrapper::DeleteFile(const string& path, uid_t uid) {
if (uid == ROOT_UID) {
int res = unlink(path.c_str());
return res;
}
JNIEnv* env = MaybeAttachCurrentThread();
return deleteFileInternal(env, media_provider_object_, mid_delete_file_, path, uid);
}
std::unique_ptr<FileOpenResult> MediaProviderWrapper::OnFileOpen(const string& path,
const string& io_path, uid_t uid,
pid_t tid, int transforms_reason,
bool for_write, bool redact,
bool log_transforms_metrics) {
JNIEnv* env = MaybeAttachCurrentThread();
if (shouldBypassMediaProvider(uid)) {
return std::make_unique<FileOpenResult>(0, uid, /* transforms_uid */ 0, /* nativeFd */ -1,
new RedactionInfo());
}
ScopedLocalRef<jstring> j_path(env, env->NewStringUTF(path.c_str()));
ScopedLocalRef<jstring> j_io_path(env, env->NewStringUTF(io_path.c_str()));
ScopedLocalRef<jobject> j_res_file_open_object(
env, env->CallObjectMethod(media_provider_object_, mid_on_file_open_, j_path.get(),
j_io_path.get(), uid, tid, transforms_reason, for_write,
redact, log_transforms_metrics));
if (CheckForJniException(env)) {
return nullptr;
}
const int status = env->GetIntField(j_res_file_open_object.get(), fid_file_open_status_);
const int original_uid = env->GetIntField(j_res_file_open_object.get(), fid_file_open_uid_);
const int transforms_uid =
env->GetIntField(j_res_file_open_object.get(), fid_file_open_transforms_uid_);
const int fd = env->GetIntField(j_res_file_open_object.get(), fid_file_open_fd_);
if (redact) {
ScopedLocalRef<jlongArray> redaction_ranges_local_ref(
env, static_cast<jlongArray>(env->GetObjectField(j_res_file_open_object.get(),
fid_file_open_redaction_ranges_)));
ScopedLongArrayRO redaction_ranges(env, redaction_ranges_local_ref.get());
std::unique_ptr<RedactionInfo> ri;
if (redaction_ranges.size() % 2) {
LOG(ERROR) << "Error while calculating redaction ranges: array length is uneven";
} else if (redaction_ranges.size() > 0) {
ri = std::make_unique<RedactionInfo>(redaction_ranges.size() / 2,
redaction_ranges.get());
} else {
// No ranges to redact
ri = std::make_unique<RedactionInfo>();
}
return std::make_unique<FileOpenResult>(status, original_uid, transforms_uid, fd,
ri.release());
} else {
return std::make_unique<FileOpenResult>(status, original_uid, transforms_uid, fd,
new RedactionInfo());
}
}
int MediaProviderWrapper::IsCreatingDirAllowed(const string& path, uid_t uid) {
if (shouldBypassMediaProvider(uid)) {
return 0;
}
JNIEnv* env = MaybeAttachCurrentThread();
return isMkdirOrRmdirAllowedInternal(env, media_provider_object_,
mid_is_mkdir_or_rmdir_allowed_, path, uid,
/*forCreate*/ true);
}
int MediaProviderWrapper::IsDeletingDirAllowed(const string& path, uid_t uid) {
if (shouldBypassMediaProvider(uid)) {
return 0;
}
JNIEnv* env = MaybeAttachCurrentThread();
return isMkdirOrRmdirAllowedInternal(env, media_provider_object_,
mid_is_mkdir_or_rmdir_allowed_, path, uid,
/*forCreate*/ false);
}
std::vector<std::shared_ptr<DirectoryEntry>> MediaProviderWrapper::GetDirectoryEntries(
uid_t uid, const string& path, DIR* dirp) {
// Default value in case JNI thread was being terminated
std::vector<std::shared_ptr<DirectoryEntry>> res;
if (shouldBypassMediaProvider(uid)) {
addDirectoryEntriesFromLowerFs(dirp, /* filter */ nullptr, &res);
return res;
}
JNIEnv* env = MaybeAttachCurrentThread();
res = getFilesInDirectoryInternal(env, media_provider_object_, mid_get_files_in_dir_, uid, path);
const int res_size = res.size();
if (res_size && res[0]->d_name[0] == '/') {
// Path is unknown to MediaProvider, get files and directories from lower file system.
res.resize(0);
addDirectoryEntriesFromLowerFs(dirp, /* filter */ nullptr, &res);
} else if (res_size == 0 || !res[0]->d_name.empty()) {
// add directory names from lower file system.
addDirectoryEntriesFromLowerFs(dirp, /* filter */ &isDirectory, &res);
}
return res;
}
int MediaProviderWrapper::IsOpendirAllowed(const string& path, uid_t uid, bool forWrite) {
if (shouldBypassMediaProvider(uid)) {
return 0;
}
JNIEnv* env = MaybeAttachCurrentThread();
return isOpendirAllowedInternal(env, media_provider_object_, mid_is_opendir_allowed_, path, uid,
forWrite);
}
bool MediaProviderWrapper::isUidAllowedAccessToDataOrObbPath(uid_t uid, const string& path) {
if (shouldBypassMediaProvider(uid)) {
return true;
}
JNIEnv* env = MaybeAttachCurrentThread();
return isUidAllowedAccessToDataOrObbPathInternal(
env, media_provider_object_, mid_is_uid_allowed_access_to_data_or_obb_path_, uid, path);
}
int MediaProviderWrapper::Rename(const string& old_path, const string& new_path, uid_t uid) {
// Rename from SHELL_UID should go through MediaProvider to update database rows, so only bypass
// MediaProvider for ROOT_UID.
if (uid == ROOT_UID) {
int res = rename(old_path.c_str(), new_path.c_str());
if (res != 0) res = -errno;
return res;
}
JNIEnv* env = MaybeAttachCurrentThread();
return renameInternal(env, media_provider_object_, mid_rename_, old_path, new_path, uid);
}
void MediaProviderWrapper::OnFileCreated(const string& path) {
JNIEnv* env = MaybeAttachCurrentThread();
return onFileCreatedInternal(env, media_provider_object_, mid_on_file_created_, path);
}
bool MediaProviderWrapper::ShouldAllowLookup(uid_t uid, int path_user_id) {
JNIEnv* env = MaybeAttachCurrentThread();
bool res = env->CallBooleanMethod(media_provider_object_, mid_should_allow_lookup_, uid,
path_user_id);
if (CheckForJniException(env)) {
return false;
}
return res;
}
bool MediaProviderWrapper::IsAppCloneUser(uid_t userId) {
JNIEnv* env = MaybeAttachCurrentThread();
bool res = env->CallBooleanMethod(media_provider_object_, mid_is_app_clone_user_, userId);
if (CheckForJniException(env)) {
return false;
}
return res;
}
std::unique_ptr<FileLookupResult> MediaProviderWrapper::FileLookup(const std::string& path,
uid_t uid, pid_t tid) {
JNIEnv* env = MaybeAttachCurrentThread();
ScopedLocalRef<jstring> j_path(env, env->NewStringUTF(path.c_str()));
ScopedLocalRef<jobject> j_res_file_lookup_object(
env, env->CallObjectMethod(media_provider_object_, mid_file_lookup_, j_path.get(), uid,
tid));
if (CheckForJniException(env)) {
return nullptr;
}
int transforms = env->GetIntField(j_res_file_lookup_object.get(), fid_file_lookup_transforms_);
int transforms_reason =
env->GetIntField(j_res_file_lookup_object.get(), fid_file_lookup_transforms_reason_);
int original_uid = env->GetIntField(j_res_file_lookup_object.get(), fid_file_lookup_uid_);
bool transforms_complete = env->GetBooleanField(j_res_file_lookup_object.get(),
fid_file_lookup_transforms_complete_);
bool transforms_supported = env->GetBooleanField(j_res_file_lookup_object.get(),
fid_file_lookup_transforms_supported_);
ScopedLocalRef<jstring> j_io_path(
env,
(jstring)env->GetObjectField(j_res_file_lookup_object.get(), fid_file_lookup_io_path_));
ScopedUtfChars j_io_path_utf(env, j_io_path.get());
std::unique_ptr<FileLookupResult> file_lookup_result = std::make_unique<FileLookupResult>(
transforms, transforms_reason, original_uid, transforms_complete, transforms_supported,
string(j_io_path_utf.c_str()));
return file_lookup_result;
}
bool MediaProviderWrapper::Transform(const std::string& src, const std::string& dst, int transforms,
int transforms_reason, uid_t read_uid, uid_t open_uid,
uid_t transforms_uid) {
JNIEnv* env = MaybeAttachCurrentThread();
ScopedLocalRef<jstring> j_src(env, env->NewStringUTF(src.c_str()));
ScopedLocalRef<jstring> j_dst(env, env->NewStringUTF(dst.c_str()));
bool res = env->CallBooleanMethod(media_provider_object_, mid_transform_, j_src.get(),
j_dst.get(), transforms, transforms_reason, read_uid,
open_uid, transforms_uid);
if (CheckForJniException(env)) {
return false;
}
return res;
}
/*****************************************************************************************/
/******************************** Private member functions *******************************/
/*****************************************************************************************/
/**
* Finds MediaProvider method and adds it to methods map so it can be quickly called later.
*/
jmethodID MediaProviderWrapper::CacheMethod(JNIEnv* env, const char method_name[],
const char signature[], bool is_static) {
jmethodID mid;
string actual_method_name(method_name);
actual_method_name.append("ForFuse");
if (is_static) {
mid = env->GetStaticMethodID(media_provider_class_, actual_method_name.c_str(), signature);
} else {
mid = env->GetMethodID(media_provider_class_, actual_method_name.c_str(), signature);
}
if (!mid) {
LOG(FATAL) << "Error caching method: " << method_name << signature;
}
return mid;
}
void MediaProviderWrapper::DetachThreadFunction(void* unused) {
int detach = gJavaVm->DetachCurrentThread();
CHECK_EQ(detach, 0);
}
JNIEnv* MediaProviderWrapper::MaybeAttachCurrentThread() {
// We could use pthread_getspecific here as that's likely quicker but
// that would result in wrong behaviour for threads that don't need to
// be attached (e.g, those that were created in managed code).
JNIEnv* env = nullptr;
if (gJavaVm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_4) == JNI_OK) {
return env;
}
// This thread is currently unattached, so it must not have any TLS
// value. Note that we don't really care about the actual value we store
// in TLS -- we only care about the value destructor being called, which
// will happen as long as the key is not null.
CHECK(pthread_getspecific(gJniEnvKey) == nullptr);
CHECK_EQ(gJavaVm->AttachCurrentThread(&env, nullptr), 0);
CHECK(env != nullptr);
pthread_setspecific(gJniEnvKey, env);
return env;
}
} // namespace fuse
} // namespace mediaprovider