platform_system_vold/VolumeManager.cpp
Risan 1271b90560 Merge "Extract AppFuse as a util" am: 7be8a7ee1d am: d04a16cbd5
am: 9f7af4b6e3

Change-Id: I92a3fa8828e983df876d42637913737e2b31fd4f
2018-11-30 01:17:08 -08:00

1329 lines
47 KiB
C++

/*
* Copyright (C) 2008 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.
*/
#define ATRACE_TAG ATRACE_TAG_PACKAGE_MANAGER
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <mntent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <array>
#include <linux/kdev_t.h>
#include <android-base/logging.h>
#include <android-base/parseint.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <cutils/fs.h>
#include <utils/Trace.h>
#include <selinux/android.h>
#include <sysutils/NetlinkEvent.h>
#include <private/android_filesystem_config.h>
#include <fscrypt/fscrypt.h>
#include "AppFuseUtil.h"
#include "Devmapper.h"
#include "FsCrypt.h"
#include "Loop.h"
#include "NetlinkManager.h"
#include "Process.h"
#include "Utils.h"
#include "VoldNativeService.h"
#include "VoldUtil.h"
#include "VolumeManager.h"
#include "cryptfs.h"
#include "fs/Ext4.h"
#include "fs/Vfat.h"
#include "model/EmulatedVolume.h"
#include "model/ObbVolume.h"
#include "model/StubVolume.h"
using android::base::GetBoolProperty;
using android::base::StartsWith;
using android::base::StringAppendF;
using android::base::StringPrintf;
using android::base::unique_fd;
static const char* kPathUserMount = "/mnt/user";
static const char* kPathVirtualDisk = "/data/misc/vold/virtual_disk";
static const char* kIsolatedStorage = "persist.sys.isolated_storage";
static const char* kPropVirtualDisk = "persist.sys.virtual_disk";
static const std::string kEmptyString("");
/* 512MiB is large enough for testing purposes */
static const unsigned int kSizeVirtualDisk = 536870912;
static const unsigned int kMajorBlockMmc = 179;
static const unsigned int kMajorBlockExperimentalMin = 240;
static const unsigned int kMajorBlockExperimentalMax = 254;
VolumeManager* VolumeManager::sInstance = NULL;
VolumeManager* VolumeManager::Instance() {
if (!sInstance) sInstance = new VolumeManager();
return sInstance;
}
VolumeManager::VolumeManager() {
mDebug = false;
mNextObbId = 0;
mNextStubVolumeId = 0;
// For security reasons, assume that a secure keyguard is
// showing until we hear otherwise
mSecureKeyguardShowing = true;
}
VolumeManager::~VolumeManager() {}
int VolumeManager::updateVirtualDisk() {
ATRACE_NAME("VolumeManager::updateVirtualDisk");
if (GetBoolProperty(kPropVirtualDisk, false)) {
if (access(kPathVirtualDisk, F_OK) != 0) {
Loop::createImageFile(kPathVirtualDisk, kSizeVirtualDisk / 512);
}
if (mVirtualDisk == nullptr) {
if (Loop::create(kPathVirtualDisk, mVirtualDiskPath) != 0) {
LOG(ERROR) << "Failed to create virtual disk";
return -1;
}
struct stat buf;
if (stat(mVirtualDiskPath.c_str(), &buf) < 0) {
PLOG(ERROR) << "Failed to stat " << mVirtualDiskPath;
return -1;
}
auto disk = new android::vold::Disk(
"virtual", buf.st_rdev, "virtual",
android::vold::Disk::Flags::kAdoptable | android::vold::Disk::Flags::kSd);
mVirtualDisk = std::shared_ptr<android::vold::Disk>(disk);
handleDiskAdded(mVirtualDisk);
}
} else {
if (mVirtualDisk != nullptr) {
dev_t device = mVirtualDisk->getDevice();
handleDiskRemoved(device);
Loop::destroyByDevice(mVirtualDiskPath.c_str());
mVirtualDisk = nullptr;
}
if (access(kPathVirtualDisk, F_OK) == 0) {
unlink(kPathVirtualDisk);
}
}
return 0;
}
int VolumeManager::setDebug(bool enable) {
mDebug = enable;
return 0;
}
int VolumeManager::start() {
ATRACE_NAME("VolumeManager::start");
// Always start from a clean slate by unmounting everything in
// directories that we own, in case we crashed.
unmountAll();
Devmapper::destroyAll();
Loop::destroyAll();
// Assume that we always have an emulated volume on internal
// storage; the framework will decide if it should be mounted.
CHECK(mInternalEmulated == nullptr);
mInternalEmulated = std::shared_ptr<android::vold::VolumeBase>(
new android::vold::EmulatedVolume("/data/media"));
mInternalEmulated->create();
// Consider creating a virtual disk
updateVirtualDisk();
return 0;
}
int VolumeManager::stop() {
CHECK(mInternalEmulated != nullptr);
mInternalEmulated->destroy();
mInternalEmulated = nullptr;
return 0;
}
void VolumeManager::handleBlockEvent(NetlinkEvent* evt) {
std::lock_guard<std::mutex> lock(mLock);
if (mDebug) {
LOG(DEBUG) << "----------------";
LOG(DEBUG) << "handleBlockEvent with action " << (int)evt->getAction();
evt->dump();
}
std::string eventPath(evt->findParam("DEVPATH") ? evt->findParam("DEVPATH") : "");
std::string devType(evt->findParam("DEVTYPE") ? evt->findParam("DEVTYPE") : "");
if (devType != "disk") return;
int major = std::stoi(evt->findParam("MAJOR"));
int minor = std::stoi(evt->findParam("MINOR"));
dev_t device = makedev(major, minor);
switch (evt->getAction()) {
case NetlinkEvent::Action::kAdd: {
for (const auto& source : mDiskSources) {
if (source->matches(eventPath)) {
// For now, assume that MMC and virtio-blk (the latter is
// emulator-specific; see Disk.cpp for details) devices are SD,
// and that everything else is USB
int flags = source->getFlags();
if (major == kMajorBlockMmc || (android::vold::IsRunningInEmulator() &&
major >= (int)kMajorBlockExperimentalMin &&
major <= (int)kMajorBlockExperimentalMax)) {
flags |= android::vold::Disk::Flags::kSd;
} else {
flags |= android::vold::Disk::Flags::kUsb;
}
auto disk =
new android::vold::Disk(eventPath, device, source->getNickname(), flags);
handleDiskAdded(std::shared_ptr<android::vold::Disk>(disk));
break;
}
}
break;
}
case NetlinkEvent::Action::kChange: {
LOG(DEBUG) << "Disk at " << major << ":" << minor << " changed";
handleDiskChanged(device);
break;
}
case NetlinkEvent::Action::kRemove: {
handleDiskRemoved(device);
break;
}
default: {
LOG(WARNING) << "Unexpected block event action " << (int)evt->getAction();
break;
}
}
}
void VolumeManager::handleDiskAdded(const std::shared_ptr<android::vold::Disk>& disk) {
// For security reasons, if secure keyguard is showing, wait
// until the user unlocks the device to actually touch it
if (mSecureKeyguardShowing) {
LOG(INFO) << "Found disk at " << disk->getEventPath()
<< " but delaying scan due to secure keyguard";
mPendingDisks.push_back(disk);
} else {
disk->create();
mDisks.push_back(disk);
}
}
void VolumeManager::handleDiskChanged(dev_t device) {
for (const auto& disk : mDisks) {
if (disk->getDevice() == device) {
disk->readMetadata();
disk->readPartitions();
}
}
// For security reasons, we ignore all pending disks, since
// we'll scan them once the device is unlocked
}
void VolumeManager::handleDiskRemoved(dev_t device) {
auto i = mDisks.begin();
while (i != mDisks.end()) {
if ((*i)->getDevice() == device) {
(*i)->destroy();
i = mDisks.erase(i);
} else {
++i;
}
}
auto j = mPendingDisks.begin();
while (j != mPendingDisks.end()) {
if ((*j)->getDevice() == device) {
j = mPendingDisks.erase(j);
} else {
++j;
}
}
}
void VolumeManager::addDiskSource(const std::shared_ptr<DiskSource>& diskSource) {
std::lock_guard<std::mutex> lock(mLock);
mDiskSources.push_back(diskSource);
}
std::shared_ptr<android::vold::Disk> VolumeManager::findDisk(const std::string& id) {
for (auto disk : mDisks) {
if (disk->getId() == id) {
return disk;
}
}
return nullptr;
}
std::shared_ptr<android::vold::VolumeBase> VolumeManager::findVolume(const std::string& id) {
// Vold could receive "mount" after "shutdown" command in the extreme case.
// If this happens, mInternalEmulated will equal nullptr and
// we need to deal with it in order to avoid null pointer crash.
if (mInternalEmulated != nullptr && mInternalEmulated->getId() == id) {
return mInternalEmulated;
}
for (const auto& disk : mDisks) {
auto vol = disk->findVolume(id);
if (vol != nullptr) {
return vol;
}
}
for (const auto& vol : mStubVolumes) {
if (vol->getId() == id) {
return vol;
}
}
for (const auto& vol : mObbVolumes) {
if (vol->getId() == id) {
return vol;
}
}
return nullptr;
}
void VolumeManager::listVolumes(android::vold::VolumeBase::Type type, std::list<std::string>& list) {
list.clear();
for (const auto& disk : mDisks) {
disk->listVolumes(type, list);
}
}
int VolumeManager::forgetPartition(const std::string& partGuid, const std::string& fsUuid) {
std::string normalizedGuid;
if (android::vold::NormalizeHex(partGuid, normalizedGuid)) {
LOG(WARNING) << "Invalid GUID " << partGuid;
return -1;
}
bool success = true;
std::string keyPath = android::vold::BuildKeyPath(normalizedGuid);
if (unlink(keyPath.c_str()) != 0) {
LOG(ERROR) << "Failed to unlink " << keyPath;
success = false;
}
if (fscrypt_is_native()) {
if (!fscrypt_destroy_volume_keys(fsUuid)) {
success = false;
}
}
return success ? 0 : -1;
}
int VolumeManager::linkPrimary(userid_t userId) {
std::string source(mPrimary->getPath());
if (mPrimary->isEmulated()) {
source = StringPrintf("%s/%d", source.c_str(), userId);
fs_prepare_dir(source.c_str(), 0755, AID_ROOT, AID_ROOT);
}
std::string target(StringPrintf("/mnt/user/%d/primary", userId));
if (TEMP_FAILURE_RETRY(unlink(target.c_str()))) {
if (errno != ENOENT) {
PLOG(WARNING) << "Failed to unlink " << target;
}
}
LOG(DEBUG) << "Linking " << source << " to " << target;
if (TEMP_FAILURE_RETRY(symlink(source.c_str(), target.c_str()))) {
PLOG(WARNING) << "Failed to link";
return -errno;
}
return 0;
}
int VolumeManager::mountPkgSpecificDir(const std::string& mntSourceRoot,
const std::string& mntTargetRoot,
const std::string& packageName, const char* dirName) {
std::string mntSourceDir =
StringPrintf("%s/Android/%s/%s", mntSourceRoot.c_str(), dirName, packageName.c_str());
std::string mntTargetDir =
StringPrintf("%s/Android/%s/%s", mntTargetRoot.c_str(), dirName, packageName.c_str());
if (umount2(mntTargetDir.c_str(), MNT_DETACH) == -1 && errno != EINVAL && errno != ENOENT) {
PLOG(ERROR) << "Failed to unmount " << mntTargetDir;
return -1;
}
if (TEMP_FAILURE_RETRY(mount(mntSourceDir.c_str(), mntTargetDir.c_str(), nullptr,
MS_BIND | MS_REC, nullptr)) == -1) {
PLOG(ERROR) << "Failed to mount " << mntSourceDir << " to " << mntTargetDir;
return -1;
}
if (TEMP_FAILURE_RETRY(
mount(nullptr, mntTargetDir.c_str(), nullptr, MS_REC | MS_SLAVE, nullptr)) == -1) {
PLOG(ERROR) << "Failed to set MS_SLAVE at " << mntTargetDir;
return -1;
}
return 0;
}
int VolumeManager::mountPkgSpecificDirsForRunningProcs(
userid_t userId, const std::vector<std::string>& packageNames,
const std::vector<std::string>& visibleVolLabels) {
// TODO: New processes could be started while traversing over the existing
// processes which would end up not having the necessary bind mounts. This
// issue needs to be fixed, may be by doing multiple passes here?
std::unique_ptr<DIR, decltype(&closedir)> dirp(opendir("/proc"), closedir);
if (!dirp) {
PLOG(ERROR) << "Failed to opendir /proc";
return -1;
}
std::string rootName;
// Figure out root namespace to compare against below
if (!android::vold::Readlinkat(dirfd(dirp.get()), "1/ns/mnt", &rootName)) {
PLOG(ERROR) << "Failed to read root namespace";
return -1;
}
struct stat fullWriteSb;
if (TEMP_FAILURE_RETRY(stat("/mnt/runtime/write", &fullWriteSb)) == -1) {
PLOG(ERROR) << "Failed to stat /mnt/runtime/write";
return -1;
}
std::unordered_set<appid_t> validAppIds;
for (auto& package : packageNames) {
validAppIds.insert(mAppIds[package]);
}
std::vector<std::string>& userPackages = mUserPackages[userId];
struct dirent* de;
// Poke through all running PIDs look for apps running in userId
while ((de = readdir(dirp.get()))) {
pid_t pid;
if (de->d_type != DT_DIR) continue;
if (!android::base::ParseInt(de->d_name, &pid)) continue;
const unique_fd pidFd(
openat(dirfd(dirp.get()), de->d_name, O_RDONLY | O_DIRECTORY | O_CLOEXEC));
if (pidFd.get() < 0) {
PLOG(WARNING) << "Failed to open /proc/" << pid;
continue;
}
struct stat sb;
if (fstat(pidFd.get(), &sb) != 0) {
PLOG(WARNING) << "Failed to stat " << de->d_name;
continue;
}
if (multiuser_get_user_id(sb.st_uid) != userId) {
continue;
}
// Matches so far, but refuse to touch if in root namespace
LOG(VERBOSE) << "Found matching PID " << de->d_name;
std::string pidName;
if (!android::vold::Readlinkat(pidFd.get(), "ns/mnt", &pidName)) {
PLOG(WARNING) << "Failed to read namespace for " << de->d_name;
continue;
}
if (rootName == pidName) {
LOG(WARNING) << "Skipping due to root namespace";
continue;
}
// Only update the mount points of processes running with one of validAppIds.
// This should skip any isolated uids.
appid_t appId = multiuser_get_app_id(sb.st_uid);
if (validAppIds.find(appId) == validAppIds.end()) {
continue;
}
std::vector<std::string> packagesForUid;
for (auto& package : userPackages) {
if (mAppIds[package] == appId) {
packagesForUid.push_back(package);
}
}
if (packagesForUid.empty()) {
continue;
}
const std::string& sandboxId = mSandboxIds[appId];
// We purposefully leave the namespace open across the fork
unique_fd nsFd(openat(pidFd.get(), "ns/mnt", O_RDONLY)); // not O_CLOEXEC
if (nsFd.get() < 0) {
PLOG(WARNING) << "Failed to open namespace for " << de->d_name;
continue;
}
pid_t child;
if (!(child = fork())) {
if (setns(nsFd.get(), CLONE_NEWNS) != 0) {
PLOG(ERROR) << "Failed to setns for " << de->d_name;
_exit(1);
}
struct stat storageSb;
if (TEMP_FAILURE_RETRY(stat("/storage", &storageSb)) == -1) {
PLOG(ERROR) << "Failed to stat /storage";
_exit(1);
}
// Some packages have access to full external storage, identify processes belonging
// to those packages by comparing inode no.s of /mnt/runtime/write and /storage
if (storageSb.st_dev == fullWriteSb.st_dev && storageSb.st_ino == fullWriteSb.st_ino) {
_exit(0);
} else {
// Some packages don't have access to external storage and processes belonging to
// those packages don't have anything mounted at /storage. So, identify those
// processes by comparing inode no.s of /mnt/user/%d/package/%s
// and /storage
std::string pkgStorageSource;
for (auto& package : packagesForUid) {
std::string sandbox =
StringPrintf("/mnt/user/%d/package/%s", userId, package.c_str());
struct stat s;
if (TEMP_FAILURE_RETRY(stat(sandbox.c_str(), &s)) == -1) {
PLOG(ERROR) << "Failed to stat " << sandbox;
_exit(1);
}
if (storageSb.st_dev == s.st_dev && storageSb.st_ino == s.st_ino) {
pkgStorageSource = sandbox;
break;
}
}
if (pkgStorageSource.empty()) {
_exit(0);
}
}
for (auto& volumeLabel : visibleVolLabels) {
std::string mntSource = StringPrintf("/mnt/runtime/write/%s", volumeLabel.c_str());
std::string mntTarget = StringPrintf("/storage/%s", volumeLabel.c_str());
if (volumeLabel == "emulated") {
StringAppendF(&mntSource, "/%d", userId);
StringAppendF(&mntTarget, "/%d", userId);
}
for (auto& package : packagesForUid) {
mountPkgSpecificDir(mntSource, mntTarget, package, "data");
mountPkgSpecificDir(mntSource, mntTarget, package, "media");
mountPkgSpecificDir(mntSource, mntTarget, package, "obb");
}
}
_exit(0);
}
if (child == -1) {
PLOG(ERROR) << "Failed to fork";
} else {
TEMP_FAILURE_RETRY(waitpid(child, nullptr, 0));
}
}
return 0;
}
int VolumeManager::prepareSandboxes(userid_t userId, const std::vector<std::string>& packageNames,
const std::vector<std::string>& visibleVolLabels) {
if (visibleVolLabels.empty()) {
return 0;
}
for (auto& volumeLabel : visibleVolLabels) {
std::string volumeRoot(StringPrintf("/mnt/runtime/write/%s", volumeLabel.c_str()));
bool isVolPrimaryEmulated = (volumeLabel == mPrimary->getLabel() && mPrimary->isEmulated());
if (isVolPrimaryEmulated) {
StringAppendF(&volumeRoot, "/%d", userId);
if (fs_prepare_dir(volumeRoot.c_str(), 0755, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "fs_prepare_dir failed on " << volumeRoot;
return -errno;
}
}
std::string sandboxRoot =
prepareSubDirs(volumeRoot, "Android/sandbox/", 0700, AID_ROOT, AID_ROOT);
if (sandboxRoot.empty()) {
return -errno;
}
if (!createPkgSpecificDirRoots(volumeRoot)) {
return -errno;
}
std::string mntTargetRoot = StringPrintf("/mnt/user/%d", userId);
if (fs_prepare_dir(mntTargetRoot.c_str(), 0751, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "fs_prepare_dir failed on " << mntTargetRoot;
return -errno;
}
mntTargetRoot.append("/package");
if (fs_prepare_dir(mntTargetRoot.c_str(), 0700, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "fs_prepare_dir failed on " << mntTargetRoot;
return -errno;
}
for (auto& packageName : packageNames) {
const auto& it = mAppIds.find(packageName);
if (it == mAppIds.end()) {
PLOG(ERROR) << "appId is not available for " << packageName;
continue;
}
appid_t appId = it->second;
std::string sandboxId = mSandboxIds[appId];
uid_t uid = multiuser_get_uid(userId, appId);
// [1] Create /mnt/runtime/write/emulated/0/Android/sandbox/<sandboxId>
// [2] Create /mnt/user/0/package/<packageName>/emulated/0
// Mount [1] at [2]
std::string pkgSandboxSourceDir = prepareSandboxSource(uid, sandboxId, sandboxRoot);
if (pkgSandboxSourceDir.empty()) {
return -errno;
}
std::string pkgSandboxTargetDir = prepareSandboxTarget(
packageName, uid, volumeLabel, mntTargetRoot, isVolPrimaryEmulated);
if (pkgSandboxTargetDir.empty()) {
return -errno;
}
if (umount2(pkgSandboxTargetDir.c_str(), MNT_DETACH) == -1 && errno != EINVAL &&
errno != ENOENT) {
PLOG(ERROR) << "Failed to unmount " << pkgSandboxTargetDir;
return -errno;
}
if (TEMP_FAILURE_RETRY(mount(pkgSandboxSourceDir.c_str(), pkgSandboxTargetDir.c_str(),
nullptr, MS_BIND | MS_REC, nullptr)) == -1) {
PLOG(ERROR) << "Failed to mount " << pkgSandboxSourceDir << " at "
<< pkgSandboxTargetDir;
return -errno;
}
if (TEMP_FAILURE_RETRY(mount(nullptr, pkgSandboxTargetDir.c_str(), nullptr,
MS_SLAVE | MS_REC, nullptr)) == -1) {
PLOG(ERROR) << "Failed to mount " << pkgSandboxSourceDir << " at "
<< pkgSandboxTargetDir;
return -errno;
}
// Create Android/{data,media,obb}/<packageName> segments at
// [1] /mnt/runtime/write/emulated/0/ and
// [2] /mnt/runtime/write/emulated/0/Android/sandbox/<sandboxId>/emulated/0/
if (!createPkgSpecificDirs(packageName, uid, volumeRoot, pkgSandboxSourceDir)) {
return -errno;
}
if (volumeLabel == mPrimary->getLabel()) {
// Create [1] /mnt/user/0/package/<packageName>/self/
// Already created [2] /mnt/user/0/package/<packageName>/emulated/0
// Mount [2] at [1]
std::string pkgPrimaryTargetDir =
StringPrintf("%s/%s/self", mntTargetRoot.c_str(), packageName.c_str());
if (fs_prepare_dir(pkgPrimaryTargetDir.c_str(), 0755, uid, uid) != 0) {
PLOG(ERROR) << "Failed to fs_prepare_dir on " << pkgPrimaryTargetDir;
return -errno;
}
StringAppendF(&pkgPrimaryTargetDir, "/primary");
std::string primarySource(mPrimary->getPath());
if (isVolPrimaryEmulated) {
StringAppendF(&primarySource, "/%d", userId);
}
if (TEMP_FAILURE_RETRY(unlink(pkgPrimaryTargetDir.c_str()))) {
if (errno != ENOENT) {
PLOG(ERROR) << "Failed to unlink " << pkgPrimaryTargetDir;
}
}
if (TEMP_FAILURE_RETRY(symlink(primarySource.c_str(), pkgPrimaryTargetDir.c_str()))) {
PLOG(ERROR) << "Failed to link " << primarySource << " at "
<< pkgPrimaryTargetDir;
return -errno;
}
}
}
}
mountPkgSpecificDirsForRunningProcs(userId, packageNames, visibleVolLabels);
return 0;
}
std::string VolumeManager::prepareSubDirs(const std::string& pathPrefix, const std::string& subDirs,
mode_t mode, uid_t uid, gid_t gid) {
std::string path(pathPrefix);
std::vector<std::string> subDirList = android::base::Split(subDirs, "/");
for (size_t i = 0; i < subDirList.size(); ++i) {
std::string subDir = subDirList[i];
if (subDir.empty()) {
continue;
}
StringAppendF(&path, "/%s", subDir.c_str());
if (fs_prepare_dir(path.c_str(), mode, uid, gid) != 0) {
PLOG(ERROR) << "fs_prepare_dir failed on " << path;
return kEmptyString;
}
}
return path;
}
std::string VolumeManager::prepareSandboxSource(uid_t uid, const std::string& sandboxId,
const std::string& sandboxRootDir) {
std::string sandboxSourceDir(sandboxRootDir);
StringAppendF(&sandboxSourceDir, "/%s", sandboxId.c_str());
if (fs_prepare_dir(sandboxSourceDir.c_str(), 0755, uid, uid) != 0) {
PLOG(ERROR) << "fs_prepare_dir failed on " << sandboxSourceDir;
return kEmptyString;
}
return sandboxSourceDir;
}
std::string VolumeManager::prepareSandboxTarget(const std::string& packageName, uid_t uid,
const std::string& volumeLabel,
const std::string& mntTargetRootDir,
bool isUserDependent) {
std::string segment;
if (isUserDependent) {
segment = StringPrintf("%s/%s/%d/", packageName.c_str(), volumeLabel.c_str(),
multiuser_get_user_id(uid));
} else {
segment = StringPrintf("%s/%s/", packageName.c_str(), volumeLabel.c_str());
}
return prepareSubDirs(mntTargetRootDir, segment.c_str(), 0755, uid, uid);
}
std::string VolumeManager::preparePkgDataSource(const std::string& packageName, uid_t uid,
const std::string& dataRootDir) {
std::string dataSourceDir = StringPrintf("%s/%s", dataRootDir.c_str(), packageName.c_str());
if (fs_prepare_dir(dataSourceDir.c_str(), 0755, uid, uid) != 0) {
PLOG(ERROR) << "fs_prepare_dir failed on " << dataSourceDir;
return kEmptyString;
}
return dataSourceDir;
}
bool VolumeManager::createPkgSpecificDirRoots(const std::string& volumeRoot) {
std::string volumeAndroidRoot = StringPrintf("%s/Android", volumeRoot.c_str());
if (fs_prepare_dir(volumeAndroidRoot.c_str(), 0700, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "fs_prepare_dir failed on " << volumeAndroidRoot;
return false;
}
std::array<std::string, 3> dirs = {"data", "media", "obb"};
for (auto& dir : dirs) {
std::string path = StringPrintf("%s/%s", volumeAndroidRoot.c_str(), dir.c_str());
if (fs_prepare_dir(path.c_str(), 0700, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "fs_prepare_dir failed on " << path;
return false;
}
}
return true;
}
bool VolumeManager::createPkgSpecificDirs(const std::string& packageName, uid_t uid,
const std::string& volumeRoot,
const std::string& sandboxDirRoot) {
std::array<std::string, 3> dirs = {"data", "media", "obb"};
for (auto& dir : dirs) {
std::string sourceDir = StringPrintf("%s/Android/%s", volumeRoot.c_str(), dir.c_str());
if (prepareSubDirs(sourceDir, packageName, 0755, uid, uid).empty()) {
return false;
}
std::string sandboxSegment =
StringPrintf("Android/%s/%s/", dir.c_str(), packageName.c_str());
if (prepareSubDirs(sandboxDirRoot, sandboxSegment, 0755, uid, uid).empty()) {
return false;
}
}
return true;
}
int VolumeManager::onUserAdded(userid_t userId, int userSerialNumber) {
mAddedUsers[userId] = userSerialNumber;
return 0;
}
int VolumeManager::onUserRemoved(userid_t userId) {
mAddedUsers.erase(userId);
return 0;
}
int VolumeManager::onUserStarted(userid_t userId, const std::vector<std::string>& packageNames,
const std::vector<int>& appIds,
const std::vector<std::string>& sandboxIds) {
LOG(VERBOSE) << "onUserStarted: " << userId;
// Note that sometimes the system will spin up processes from Zygote
// before actually starting the user, so we're okay if Zygote
// already created this directory.
std::string path(StringPrintf("%s/%d", kPathUserMount, userId));
fs_prepare_dir(path.c_str(), 0755, AID_ROOT, AID_ROOT);
mStartedUsers.insert(userId);
mUserPackages[userId] = packageNames;
for (size_t i = 0; i < packageNames.size(); ++i) {
mAppIds[packageNames[i]] = appIds[i];
mSandboxIds[appIds[i]] = sandboxIds[i];
}
if (mPrimary) {
linkPrimary(userId);
}
if (GetBoolProperty(kIsolatedStorage, false)) {
std::vector<std::string> visibleVolLabels;
for (auto& volId : mVisibleVolumeIds) {
auto vol = findVolume(volId);
userid_t mountUserId = vol->getMountUserId();
if (mountUserId == userId || vol->isEmulated()) {
visibleVolLabels.push_back(vol->getLabel());
}
}
if (prepareSandboxes(userId, packageNames, visibleVolLabels) != 0) {
return -errno;
}
}
return 0;
}
int VolumeManager::onUserStopped(userid_t userId) {
LOG(VERBOSE) << "onUserStopped: " << userId;
mStartedUsers.erase(userId);
if (GetBoolProperty(kIsolatedStorage, false)) {
mUserPackages.erase(userId);
std::string mntTargetDir = StringPrintf("/mnt/user/%d", userId);
if (android::vold::UnmountTree(mntTargetDir) != 0) {
PLOG(ERROR) << "unmountTree on " << mntTargetDir << " failed";
return -errno;
}
if (android::vold::DeleteDirContentsAndDir(mntTargetDir) < 0) {
PLOG(ERROR) << "DeleteDirContentsAndDir failed on " << mntTargetDir;
return -errno;
}
LOG(VERBOSE) << "Success: DeleteDirContentsAndDir on " << mntTargetDir;
}
return 0;
}
int VolumeManager::addAppIds(const std::vector<std::string>& packageNames,
const std::vector<int32_t>& appIds) {
for (size_t i = 0; i < packageNames.size(); ++i) {
mAppIds[packageNames[i]] = appIds[i];
}
return 0;
}
int VolumeManager::addSandboxIds(const std::vector<int32_t>& appIds,
const std::vector<std::string>& sandboxIds) {
for (size_t i = 0; i < appIds.size(); ++i) {
mSandboxIds[appIds[i]] = sandboxIds[i];
}
return 0;
}
int VolumeManager::prepareSandboxForApp(const std::string& packageName, appid_t appId,
const std::string& sandboxId, userid_t userId) {
if (!GetBoolProperty(kIsolatedStorage, false)) {
return 0;
} else if (mStartedUsers.find(userId) == mStartedUsers.end()) {
// User not started, no need to do anything now. Required bind mounts for the package will
// be created when the user starts.
return 0;
}
LOG(VERBOSE) << "prepareSandboxForApp: " << packageName << ", appId=" << appId
<< ", sandboxId=" << sandboxId << ", userId=" << userId;
mUserPackages[userId].push_back(packageName);
mAppIds[packageName] = appId;
mSandboxIds[appId] = sandboxId;
std::vector<std::string> visibleVolLabels;
for (auto& volId : mVisibleVolumeIds) {
auto vol = findVolume(volId);
userid_t mountUserId = vol->getMountUserId();
if (mountUserId == userId || vol->isEmulated()) {
visibleVolLabels.push_back(vol->getLabel());
}
}
return prepareSandboxes(userId, {packageName}, visibleVolLabels);
}
int VolumeManager::destroySandboxForApp(const std::string& packageName,
const std::string& sandboxId, userid_t userId) {
if (!GetBoolProperty(kIsolatedStorage, false)) {
return 0;
}
LOG(VERBOSE) << "destroySandboxForApp: " << packageName << ", sandboxId=" << sandboxId
<< ", userId=" << userId;
auto& userPackages = mUserPackages[userId];
std::remove(userPackages.begin(), userPackages.end(), packageName);
// If the package is not uninstalled in any other users, remove appId and sandboxId
// corresponding to it from the internal state.
bool installedInAnyUser = false;
for (auto& it : mUserPackages) {
auto& packages = it.second;
if (std::find(packages.begin(), packages.end(), packageName) != packages.end()) {
installedInAnyUser = true;
break;
}
}
if (!installedInAnyUser) {
const auto& entry = mAppIds.find(packageName);
if (entry != mAppIds.end()) {
mSandboxIds.erase(entry->second);
mAppIds.erase(entry);
}
}
std::vector<std::string> visibleVolLabels;
for (auto& volId : mVisibleVolumeIds) {
auto vol = findVolume(volId);
userid_t mountUserId = vol->getMountUserId();
if (mountUserId == userId || vol->isEmulated()) {
if (destroySandboxForAppOnVol(packageName, sandboxId, userId, vol->getLabel()) < 0) {
return -errno;
}
}
}
return 0;
}
int VolumeManager::destroySandboxForAppOnVol(const std::string& packageName,
const std::string& sandboxId, userid_t userId,
const std::string& volLabel) {
LOG(VERBOSE) << "destroySandboxOnVol: " << packageName << ", userId=" << userId
<< ", volLabel=" << volLabel;
std::string pkgSandboxTarget =
StringPrintf("/mnt/user/%d/package/%s", userId, packageName.c_str());
if (android::vold::UnmountTree(pkgSandboxTarget)) {
PLOG(ERROR) << "UnmountTree failed on " << pkgSandboxTarget;
}
std::string sandboxDir = StringPrintf("/mnt/runtime/write/%s", volLabel.c_str());
if (volLabel == mPrimary->getLabel() && mPrimary->isEmulated()) {
StringAppendF(&sandboxDir, "/%d", userId);
}
StringAppendF(&sandboxDir, "/Android/sandbox/%s", sandboxId.c_str());
if (android::vold::DeleteDirContentsAndDir(sandboxDir) < 0) {
PLOG(ERROR) << "DeleteDirContentsAndDir failed on " << sandboxDir;
return -errno;
}
return 0;
}
int VolumeManager::onSecureKeyguardStateChanged(bool isShowing) {
mSecureKeyguardShowing = isShowing;
if (!mSecureKeyguardShowing) {
// Now that secure keyguard has been dismissed, process
// any pending disks
for (const auto& disk : mPendingDisks) {
disk->create();
mDisks.push_back(disk);
}
mPendingDisks.clear();
}
return 0;
}
int VolumeManager::onVolumeMounted(android::vold::VolumeBase* vol) {
if (!GetBoolProperty(kIsolatedStorage, false)) {
return 0;
}
if ((vol->getMountFlags() & android::vold::VoldNativeService::MOUNT_FLAG_VISIBLE) == 0) {
return 0;
}
mVisibleVolumeIds.insert(vol->getId());
userid_t mountUserId = vol->getMountUserId();
if ((vol->getMountFlags() & android::vold::VoldNativeService::MOUNT_FLAG_PRIMARY) != 0) {
// We don't want to create another shared_ptr here because then we will end up with
// two shared_ptrs owning the underlying pointer without sharing it.
mPrimary = findVolume(vol->getId());
for (userid_t userId : mStartedUsers) {
if (linkPrimary(userId) != 0) {
return -errno;
}
}
}
if (vol->isEmulated()) {
for (userid_t userId : mStartedUsers) {
if (prepareSandboxes(userId, mUserPackages[userId], {vol->getLabel()}) != 0) {
return -errno;
}
}
} else if (mStartedUsers.find(mountUserId) != mStartedUsers.end()) {
if (prepareSandboxes(mountUserId, mUserPackages[mountUserId], {vol->getLabel()}) != 0) {
return -errno;
}
}
return 0;
}
int VolumeManager::onVolumeUnmounted(android::vold::VolumeBase* vol) {
if (!GetBoolProperty(kIsolatedStorage, false)) {
return 0;
}
if (mVisibleVolumeIds.erase(vol->getId()) == 0) {
return 0;
}
if ((vol->getMountFlags() & android::vold::VoldNativeService::MOUNT_FLAG_PRIMARY) != 0) {
mPrimary = nullptr;
}
LOG(VERBOSE) << "visibleVolumeUnmounted: " << vol;
userid_t mountUserId = vol->getMountUserId();
if (vol->isEmulated()) {
for (userid_t userId : mStartedUsers) {
if (destroySandboxesForVol(vol, userId) != 0) {
return -errno;
}
}
} else if (mStartedUsers.find(mountUserId) != mStartedUsers.end()) {
if (destroySandboxesForVol(vol, mountUserId) != 0) {
return -errno;
}
}
return 0;
}
int VolumeManager::destroySandboxesForVol(android::vold::VolumeBase* vol, userid_t userId) {
LOG(VERBOSE) << "destroysandboxesForVol: " << vol << " for user=" << userId;
const std::vector<std::string>& packageNames = mUserPackages[userId];
for (auto& packageName : packageNames) {
std::string volSandboxRoot = StringPrintf("/mnt/user/%d/package/%s/%s", userId,
packageName.c_str(), vol->getLabel().c_str());
if (android::vold::UnmountTree(volSandboxRoot) != 0) {
PLOG(ERROR) << "unmountTree on " << volSandboxRoot << " failed";
continue;
}
if (android::vold::DeleteDirContentsAndDir(volSandboxRoot) < 0) {
PLOG(ERROR) << "DeleteDirContentsAndDir failed on " << volSandboxRoot;
continue;
}
LOG(VERBOSE) << "Success: DeleteDirContentsAndDir on " << volSandboxRoot;
}
return 0;
}
int VolumeManager::setPrimary(const std::shared_ptr<android::vold::VolumeBase>& vol) {
if (GetBoolProperty(kIsolatedStorage, false)) {
return 0;
}
mPrimary = vol;
for (userid_t userId : mStartedUsers) {
linkPrimary(userId);
}
return 0;
}
int VolumeManager::remountUid(uid_t uid, const std::string& mode) {
// If the isolated storage is enabled, return -1 since in the isolated storage world, there
// are no longer any runtime storage permissions, so this shouldn't be called anymore.
if (GetBoolProperty(kIsolatedStorage, false)) {
return -1;
}
LOG(DEBUG) << "Remounting " << uid << " as mode " << mode;
DIR* dir;
struct dirent* de;
std::string rootName;
std::string pidName;
int pidFd;
int nsFd;
struct stat sb;
pid_t child;
if (!(dir = opendir("/proc"))) {
PLOG(ERROR) << "Failed to opendir";
return -1;
}
// Figure out root namespace to compare against below
if (!android::vold::Readlinkat(dirfd(dir), "1/ns/mnt", &rootName)) {
PLOG(ERROR) << "Failed to read root namespace";
closedir(dir);
return -1;
}
// Poke through all running PIDs look for apps running as UID
while ((de = readdir(dir))) {
pid_t pid;
if (de->d_type != DT_DIR) continue;
if (!android::base::ParseInt(de->d_name, &pid)) continue;
pidFd = -1;
nsFd = -1;
pidFd = openat(dirfd(dir), de->d_name, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
if (pidFd < 0) {
goto next;
}
if (fstat(pidFd, &sb) != 0) {
PLOG(WARNING) << "Failed to stat " << de->d_name;
goto next;
}
if (sb.st_uid != uid) {
goto next;
}
// Matches so far, but refuse to touch if in root namespace
LOG(DEBUG) << "Found matching PID " << de->d_name;
if (!android::vold::Readlinkat(pidFd, "ns/mnt", &pidName)) {
PLOG(WARNING) << "Failed to read namespace for " << de->d_name;
goto next;
}
if (rootName == pidName) {
LOG(WARNING) << "Skipping due to root namespace";
goto next;
}
// We purposefully leave the namespace open across the fork
nsFd = openat(pidFd, "ns/mnt", O_RDONLY); // not O_CLOEXEC
if (nsFd < 0) {
PLOG(WARNING) << "Failed to open namespace for " << de->d_name;
goto next;
}
if (!(child = fork())) {
if (setns(nsFd, CLONE_NEWNS) != 0) {
PLOG(ERROR) << "Failed to setns for " << de->d_name;
_exit(1);
}
android::vold::UnmountTree("/storage/");
std::string storageSource;
if (mode == "default") {
storageSource = "/mnt/runtime/default";
} else if (mode == "read") {
storageSource = "/mnt/runtime/read";
} else if (mode == "write") {
storageSource = "/mnt/runtime/write";
} else {
// Sane default of no storage visible
_exit(0);
}
if (TEMP_FAILURE_RETRY(
mount(storageSource.c_str(), "/storage", NULL, MS_BIND | MS_REC, NULL)) == -1) {
PLOG(ERROR) << "Failed to mount " << storageSource << " for " << de->d_name;
_exit(1);
}
if (TEMP_FAILURE_RETRY(mount(NULL, "/storage", NULL, MS_REC | MS_SLAVE, NULL)) == -1) {
PLOG(ERROR) << "Failed to set MS_SLAVE to /storage for " << de->d_name;
_exit(1);
}
// Mount user-specific symlink helper into place
userid_t user_id = multiuser_get_user_id(uid);
std::string userSource(StringPrintf("/mnt/user/%d", user_id));
if (TEMP_FAILURE_RETRY(
mount(userSource.c_str(), "/storage/self", NULL, MS_BIND, NULL)) == -1) {
PLOG(ERROR) << "Failed to mount " << userSource << " for " << de->d_name;
_exit(1);
}
_exit(0);
}
if (child == -1) {
PLOG(ERROR) << "Failed to fork";
goto next;
} else {
TEMP_FAILURE_RETRY(waitpid(child, nullptr, 0));
}
next:
close(nsFd);
close(pidFd);
}
closedir(dir);
return 0;
}
int VolumeManager::reset() {
// Tear down all existing disks/volumes and start from a blank slate so
// newly connected framework hears all events.
if (mInternalEmulated != nullptr) {
mInternalEmulated->destroy();
mInternalEmulated->create();
}
for (const auto& disk : mDisks) {
disk->destroy();
disk->create();
}
updateVirtualDisk();
mAddedUsers.clear();
mStartedUsers.clear();
mUserPackages.clear();
mAppIds.clear();
mSandboxIds.clear();
mVisibleVolumeIds.clear();
// For unmounting dirs under /mnt/user/<user-id>/package/<package-name>
android::vold::UnmountTree("/mnt/user/");
return 0;
}
// Can be called twice (sequentially) during shutdown. should be safe for that.
int VolumeManager::shutdown() {
if (mInternalEmulated == nullptr) {
return 0; // already shutdown
}
android::vold::sSleepOnUnmount = false;
mInternalEmulated->destroy();
mInternalEmulated = nullptr;
for (const auto& disk : mDisks) {
disk->destroy();
}
mStubVolumes.clear();
mDisks.clear();
mPendingDisks.clear();
android::vold::sSleepOnUnmount = true;
return 0;
}
int VolumeManager::unmountAll() {
std::lock_guard<std::mutex> lock(mLock);
ATRACE_NAME("VolumeManager::unmountAll()");
// First, try gracefully unmounting all known devices
if (mInternalEmulated != nullptr) {
mInternalEmulated->unmount();
}
for (const auto& stub : mStubVolumes) {
stub->unmount();
}
for (const auto& disk : mDisks) {
disk->unmountAll();
}
// Worst case we might have some stale mounts lurking around, so
// force unmount those just to be safe.
FILE* fp = setmntent("/proc/mounts", "re");
if (fp == NULL) {
PLOG(ERROR) << "Failed to open /proc/mounts";
return -errno;
}
// Some volumes can be stacked on each other, so force unmount in
// reverse order to give us the best chance of success.
std::list<std::string> toUnmount;
mntent* mentry;
while ((mentry = getmntent(fp)) != NULL) {
auto test = std::string(mentry->mnt_dir);
if ((StartsWith(test, "/mnt/") &&
#ifdef __ANDROID_DEBUGGABLE__
!StartsWith(test, "/mnt/scratch") &&
#endif
!StartsWith(test, "/mnt/vendor") && !StartsWith(test, "/mnt/product")) ||
StartsWith(test, "/storage/")) {
toUnmount.push_front(test);
}
}
endmntent(fp);
for (const auto& path : toUnmount) {
LOG(DEBUG) << "Tearing down stale mount " << path;
android::vold::ForceUnmount(path);
}
return 0;
}
int VolumeManager::mkdirs(const std::string& path) {
// Only offer to create directories for paths managed by vold
if (StartsWith(path, "/storage/")) {
// fs_mkdirs() does symlink checking and relative path enforcement
return fs_mkdirs(path.c_str(), 0700);
} else {
LOG(ERROR) << "Failed to find mounted volume for " << path;
return -EINVAL;
}
}
int VolumeManager::createObb(const std::string& sourcePath, const std::string& sourceKey,
int32_t ownerGid, std::string* outVolId) {
int id = mNextObbId++;
auto vol = std::shared_ptr<android::vold::VolumeBase>(
new android::vold::ObbVolume(id, sourcePath, sourceKey, ownerGid));
vol->create();
mObbVolumes.push_back(vol);
*outVolId = vol->getId();
return android::OK;
}
int VolumeManager::destroyObb(const std::string& volId) {
auto i = mObbVolumes.begin();
while (i != mObbVolumes.end()) {
if ((*i)->getId() == volId) {
(*i)->destroy();
i = mObbVolumes.erase(i);
} else {
++i;
}
}
return android::OK;
}
int VolumeManager::createStubVolume(const std::string& sourcePath, const std::string& mountPath,
const std::string& fsType, const std::string& fsUuid,
const std::string& fsLabel, std::string* outVolId) {
int id = mNextStubVolumeId++;
auto vol = std::shared_ptr<android::vold::VolumeBase>(
new android::vold::StubVolume(id, sourcePath, mountPath, fsType, fsUuid, fsLabel));
vol->create();
mStubVolumes.push_back(vol);
*outVolId = vol->getId();
return android::OK;
}
int VolumeManager::destroyStubVolume(const std::string& volId) {
auto i = mStubVolumes.begin();
while (i != mStubVolumes.end()) {
if ((*i)->getId() == volId) {
(*i)->destroy();
i = mStubVolumes.erase(i);
} else {
++i;
}
}
return android::OK;
}
int VolumeManager::mountAppFuse(uid_t uid, int mountId, unique_fd* device_fd) {
return android::vold::MountAppFuse(uid, mountId, device_fd);
}
int VolumeManager::unmountAppFuse(uid_t uid, int mountId) {
return android::vold::UnmountAppFuse(uid, mountId);
}
int VolumeManager::openAppFuseFile(uid_t uid, int mountId, int fileId, int flags) {
return android::vold::OpenAppFuseFile(uid, mountId, fileId, flags);
}