int Volume::mountAsecExternal() {
char legacy_path[PATH_MAX];
char secure_path[PATH_MAX];
snprintf(legacy_path, PATH_MAX, "%s/android_secure", getMountpoint());
snprintf(secure_path, PATH_MAX, "%s/.android_secure", getMountpoint());
// Recover legacy secure path
if (!access(legacy_path, R_OK | X_OK) && access(secure_path, R_OK | X_OK)) {
if (rename(legacy_path, secure_path)) {
SLOGE("Failed to rename legacy asec dir (%s)", strerror(errno));
}
}
if (fs_prepare_dir(secure_path, 0770, AID_MEDIA_RW, AID_MEDIA_RW) != 0) {
SLOGW("fs_prepare_dir failed: %s", strerror(errno));
return -1;
}
if (mount(secure_path, SEC_ASECDIR_EXT, "", MS_BIND, NULL)) {
SLOGE("Failed to bind mount points %s -> %s (%s)", secure_path,
SEC_ASECDIR_EXT, strerror(errno));
return -1;
}
return 0;
}
static void run_sdcardfs(const std::string& source_path, const std::string& label, uid_t uid,
gid_t gid, userid_t userid, bool multi_user, bool full_write,
bool derive_gid) {
std::string dest_path_default = "/mnt/runtime/default/" + label;
std::string dest_path_read = "/mnt/runtime/read/" + label;
std::string dest_path_write = "/mnt/runtime/write/" + label;
umask(0);
if (multi_user) {
// Multi-user storage is fully isolated per user, so "other"
// permissions are completely masked off.
if (!sdcardfs_setup(source_path, dest_path_default, uid, gid, multi_user, userid,
AID_SDCARD_RW, 0006, derive_gid) ||
!sdcardfs_setup_bind_remount(dest_path_default, dest_path_read, AID_EVERYBODY, 0027) ||
!sdcardfs_setup_bind_remount(dest_path_default, dest_path_write, AID_EVERYBODY,
full_write ? 0007 : 0027)) {
LOG(FATAL) << "failed to sdcardfs_setup";
}
} else {
// Physical storage is readable by all users on device, but
// the Android directories are masked off to a single user
// deep inside attr_from_stat().
if (!sdcardfs_setup(source_path, dest_path_default, uid, gid, multi_user, userid,
AID_SDCARD_RW, 0006, derive_gid) ||
!sdcardfs_setup_bind_remount(dest_path_default, dest_path_read, AID_EVERYBODY,
full_write ? 0027 : 0022) ||
!sdcardfs_setup_bind_remount(dest_path_default, dest_path_write, AID_EVERYBODY,
full_write ? 0007 : 0022)) {
LOG(FATAL) << "failed to sdcardfs_setup";
}
}
// Will abort if priv-dropping fails.
drop_privs(uid, gid);
if (multi_user) {
std::string obb_path = source_path + "/obb";
fs_prepare_dir(obb_path.c_str(), 0775, uid, gid);
}
exit(0);
}
int initialize_directories() {
int res = -1;
// Read current filesystem layout version to handle upgrade paths
char version_path[PATH_MAX];
snprintf(version_path, PATH_MAX, "%s.layout_version", android_data_dir.path);
int oldVersion;
if (fs_read_atomic_int(version_path, &oldVersion) == -1) {
oldVersion = 0;
}
int version = oldVersion;
// /data/user
char *user_data_dir = build_string2(android_data_dir.path, SECONDARY_USER_PREFIX);
// /data/data
char *legacy_data_dir = build_string2(android_data_dir.path, PRIMARY_USER_PREFIX);
// /data/user/0
char *primary_data_dir = build_string3(android_data_dir.path, SECONDARY_USER_PREFIX, "0");
if (!user_data_dir || !legacy_data_dir || !primary_data_dir) {
goto fail;
}
// Make the /data/user directory if necessary
if (access(user_data_dir, R_OK) < 0) {
if (mkdir(user_data_dir, 0711) < 0) {
goto fail;
}
if (chown(user_data_dir, AID_SYSTEM, AID_SYSTEM) < 0) {
goto fail;
}
if (chmod(user_data_dir, 0711) < 0) {
goto fail;
}
}
// Make the /data/user/0 symlink to /data/data if necessary
if (access(primary_data_dir, R_OK) < 0) {
if (symlink(legacy_data_dir, primary_data_dir)) {
goto fail;
}
}
if (version == 0) {
// Introducing multi-user, so migrate /data/media contents into /data/media/0
ALOGD("Upgrading /data/media for multi-user");
// Ensure /data/media
if (fs_prepare_dir(android_media_dir.path, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
goto fail;
}
// /data/media.tmp
char media_tmp_dir[PATH_MAX];
snprintf(media_tmp_dir, PATH_MAX, "%smedia.tmp", android_data_dir.path);
// Only copy when upgrade not already in progress
if (access(media_tmp_dir, F_OK) == -1) {
if (rename(android_media_dir.path, media_tmp_dir) == -1) {
ALOGE("Failed to move legacy media path: %s", strerror(errno));
goto fail;
}
}
// Create /data/media again
if (fs_prepare_dir(android_media_dir.path, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
goto fail;
}
// /data/media/0
char owner_media_dir[PATH_MAX];
snprintf(owner_media_dir, PATH_MAX, "%s0", android_media_dir.path);
// Move any owner data into place
if (access(media_tmp_dir, F_OK) == 0) {
if (rename(media_tmp_dir, owner_media_dir) == -1) {
ALOGE("Failed to move owner media path: %s", strerror(errno));
goto fail;
}
}
// Ensure media directories for any existing users
DIR *dir;
struct dirent *dirent;
char user_media_dir[PATH_MAX];
dir = opendir(user_data_dir);
if (dir != NULL) {
while ((dirent = readdir(dir))) {
if (dirent->d_type == DT_DIR) {
const char *name = dirent->d_name;
// skip "." and ".."
if (name[0] == '.') {
if (name[1] == 0) continue;
if ((name[1] == '.') && (name[2] == 0)) continue;
}
// /data/media/<user_id>
snprintf(user_media_dir, PATH_MAX, "%s%s", android_media_dir.path, name);
if (fs_prepare_dir(user_media_dir, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
goto fail;
}
}
}
closedir(dir);
}
version = 1;
}
// /data/media/obb
char media_obb_dir[PATH_MAX];
snprintf(media_obb_dir, PATH_MAX, "%sobb", android_media_dir.path);
if (version == 1) {
// Introducing /data/media/obb for sharing OBB across users; migrate
// any existing OBB files from owner.
ALOGD("Upgrading to shared /data/media/obb");
// /data/media/0/Android/obb
char owner_obb_path[PATH_MAX];
snprintf(owner_obb_path, PATH_MAX, "%s0/Android/obb", android_media_dir.path);
// Only move if target doesn't already exist
if (access(media_obb_dir, F_OK) != 0 && access(owner_obb_path, F_OK) == 0) {
if (rename(owner_obb_path, media_obb_dir) == -1) {
ALOGE("Failed to move OBB from owner: %s", strerror(errno));
goto fail;
}
}
version = 2;
}
if (ensure_media_user_dirs(0) == -1) {
ALOGE("Failed to setup media for user 0");
goto fail;
}
if (fs_prepare_dir(media_obb_dir, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
goto fail;
}
// Persist layout version if changed
if (version != oldVersion) {
if (fs_write_atomic_int(version_path, version) == -1) {
ALOGE("Failed to save version to %s: %s", version_path, strerror(errno));
goto fail;
}
}
// Success!
res = 0;
fail:
free(user_data_dir);
free(legacy_data_dir);
free(primary_data_dir);
return res;
}
status_t PublicVolume::doMount() {
// TODO: expand to support mounting other filesystems
readMetadata();
if (mFsType != "vfat") {
LOG(ERROR) << getId() << " unsupported filesystem " << mFsType;
return -EIO;
}
if (vfat::Check(mDevPath)) {
LOG(ERROR) << getId() << " failed filesystem check";
return -EIO;
}
// Use UUID as stable name, if available
std::string stableName = getId();
if (!mFsUuid.empty()) {
stableName = mFsUuid;
}
mRawPath = StringPrintf("/mnt/media_rw/%s", stableName.c_str());
mFuseDefault = StringPrintf("/mnt/runtime/default/%s", stableName.c_str());
mFuseRead = StringPrintf("/mnt/runtime/read/%s", stableName.c_str());
mFuseWrite = StringPrintf("/mnt/runtime/write/%s", stableName.c_str());
setInternalPath(mRawPath);
if (getMountFlags() & MountFlags::kVisible) {
setPath(StringPrintf("/storage/%s", stableName.c_str()));
} else {
setPath(mRawPath);
}
if (fs_prepare_dir(mRawPath.c_str(), 0700, AID_ROOT, AID_ROOT) ||
fs_prepare_dir(mFuseDefault.c_str(), 0700, AID_ROOT, AID_ROOT) ||
fs_prepare_dir(mFuseRead.c_str(), 0700, AID_ROOT, AID_ROOT) ||
fs_prepare_dir(mFuseWrite.c_str(), 0700, AID_ROOT, AID_ROOT)) {
PLOG(ERROR) << getId() << " failed to create mount points";
return -errno;
}
if (vfat::Mount(mDevPath, mRawPath, false, false, false,
AID_MEDIA_RW, AID_MEDIA_RW, 0007, true)) {
PLOG(ERROR) << getId() << " failed to mount " << mDevPath;
return -EIO;
}
if (getMountFlags() & MountFlags::kPrimary) {
initAsecStage();
}
if (!(getMountFlags() & MountFlags::kVisible)) {
// Not visible to apps, so no need to spin up FUSE
return OK;
}
dev_t before = GetDevice(mFuseWrite);
if (!(mFusePid = fork())) {
if (getMountFlags() & MountFlags::kPrimary) {
if (execl(kFusePath, kFusePath,
"-u", "1023", // AID_MEDIA_RW
"-g", "1023", // AID_MEDIA_RW
"-U", std::to_string(getMountUserId()).c_str(),
"-w",
mRawPath.c_str(),
stableName.c_str(),
NULL)) {
PLOG(ERROR) << "Failed to exec";
}
} else {
if (execl(kFusePath, kFusePath,
"-u", "1023", // AID_MEDIA_RW
"-g", "1023", // AID_MEDIA_RW
"-U", std::to_string(getMountUserId()).c_str(),
mRawPath.c_str(),
stableName.c_str(),
NULL)) {
PLOG(ERROR) << "Failed to exec";
}
}
LOG(ERROR) << "FUSE exiting";
_exit(1);
}
if (mFusePid == -1) {
PLOG(ERROR) << getId() << " failed to fork";
return -errno;
}
while (before == GetDevice(mFuseWrite)) {
LOG(VERBOSE) << "Waiting for FUSE to spin up...";
usleep(50000); // 50ms
}
return OK;
}
static void run(const char* source_path, const char* label, uid_t uid,
gid_t gid, userid_t userid, bool multi_user, bool full_write) {
struct fuse_global global;
struct fuse fuse_default;
struct fuse fuse_read;
struct fuse fuse_write;
struct fuse_handler handler_default;
struct fuse_handler handler_read;
struct fuse_handler handler_write;
pthread_t thread_default;
pthread_t thread_read;
pthread_t thread_write;
memset(&global, 0, sizeof(global));
memset(&fuse_default, 0, sizeof(fuse_default));
memset(&fuse_read, 0, sizeof(fuse_read));
memset(&fuse_write, 0, sizeof(fuse_write));
memset(&handler_default, 0, sizeof(handler_default));
memset(&handler_read, 0, sizeof(handler_read));
memset(&handler_write, 0, sizeof(handler_write));
pthread_mutex_init(&global.lock, NULL);
global.package_to_appid = new AppIdMap;
global.uid = uid;
global.gid = gid;
global.multi_user = multi_user;
global.next_generation = 0;
global.inode_ctr = 1;
memset(&global.root, 0, sizeof(global.root));
global.root.nid = FUSE_ROOT_ID; /* 1 */
global.root.refcount = 2;
global.root.namelen = strlen(source_path);
global.root.name = strdup(source_path);
global.root.userid = userid;
global.root.uid = AID_ROOT;
global.root.under_android = false;
strcpy(global.source_path, source_path);
if (multi_user) {
global.root.perm = PERM_PRE_ROOT;
snprintf(global.obb_path, sizeof(global.obb_path), "%s/obb", source_path);
} else {
global.root.perm = PERM_ROOT;
snprintf(global.obb_path, sizeof(global.obb_path), "%s/Android/obb", source_path);
}
fuse_default.global = &global;
fuse_read.global = &global;
fuse_write.global = &global;
global.fuse_default = &fuse_default;
global.fuse_read = &fuse_read;
global.fuse_write = &fuse_write;
snprintf(fuse_default.dest_path, PATH_MAX, "/mnt/runtime/default/%s", label);
snprintf(fuse_read.dest_path, PATH_MAX, "/mnt/runtime/read/%s", label);
snprintf(fuse_write.dest_path, PATH_MAX, "/mnt/runtime/write/%s", label);
handler_default.fuse = &fuse_default;
handler_read.fuse = &fuse_read;
handler_write.fuse = &fuse_write;
handler_default.token = 0;
handler_read.token = 1;
handler_write.token = 2;
umask(0);
if (multi_user) {
/* Multi-user storage is fully isolated per user, so "other"
* permissions are completely masked off. */
if (fuse_setup(&fuse_default, AID_SDCARD_RW, 0006)
|| fuse_setup(&fuse_read, AID_EVERYBODY, 0027)
|| fuse_setup(&fuse_write, AID_EVERYBODY, full_write ? 0007 : 0027)) {
PLOG(FATAL) << "failed to fuse_setup";
}
} else {
/* Physical storage is readable by all users on device, but
* the Android directories are masked off to a single user
* deep inside attr_from_stat(). */
if (fuse_setup(&fuse_default, AID_SDCARD_RW, 0006)
|| fuse_setup(&fuse_read, AID_EVERYBODY, full_write ? 0027 : 0022)
|| fuse_setup(&fuse_write, AID_EVERYBODY, full_write ? 0007 : 0022)) {
PLOG(FATAL) << "failed to fuse_setup";
}
}
// Will abort if priv-dropping fails.
drop_privs(uid, gid);
if (multi_user) {
fs_prepare_dir(global.obb_path, 0775, uid, gid);
}
if (pthread_create(&thread_default, NULL, start_handler, &handler_default)
|| pthread_create(&thread_read, NULL, start_handler, &handler_read)
|| pthread_create(&thread_write, NULL, start_handler, &handler_write)) {
LOG(FATAL) << "failed to pthread_create";
}
watch_package_list(&global);
LOG(FATAL) << "terminated prematurely";
}
