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android_system_vold/VolumeManager.cpp

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/*
* 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 <ApexProperties.sysprop.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::OK;
using android::base::GetBoolProperty;
using android::base::StartsWith;
using android::base::StringAppendF;
using android::base::StringPrintf;
using android::base::unique_fd;
using android::vold::BindMount;
using android::vold::CreateDir;
using android::vold::DeleteDirContents;
using android::vold::DeleteDirContentsAndDir;
using android::vold::Symlink;
using android::vold::Unlink;
using android::vold::UnmountTree;
using android::vold::VoldNativeService;
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* kIsolatedStorageSnapshot = "sys.isolated_storage_snapshot";
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() {}
static bool hasIsolatedStorage() {
return GetBoolProperty(kIsolatedStorageSnapshot, GetBoolProperty(kIsolatedStorage, true));
}
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) const {
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));
LOG(DEBUG) << "Linking " << source << " to " << target;
Symlink(source, target);
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());
if (CreateDir(mntSourceDir, 0755) < 0) {
return -errno;
}
std::string mntTargetDir =
StringPrintf("%s/Android/%s/%s", mntTargetRoot.c_str(), dirName, packageName.c_str());
if (CreateDir(mntTargetDir, 0755) < 0) {
return -errno;
}
return BindMount(mntSourceDir, mntTargetDir);
}
int VolumeManager::mountPkgSpecificDirsForRunningProcs(
userid_t userId, const std::vector<std::string>& packageNames,
const std::vector<std::string>& visibleVolLabels, int remountMode) {
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 mntFullSb;
struct stat mntWriteSb;
if (TEMP_FAILURE_RETRY(stat("/mnt/runtime/full", &mntFullSb)) == -1) {
PLOG(ERROR) << "Failed to stat /mnt/runtime/full";
return -1;
}
if (TEMP_FAILURE_RETRY(stat("/mnt/runtime/write", &mntWriteSb)) == -1) {
PLOG(ERROR) << "Failed to stat /mnt/runtime/write";
return -1;
}
std::string obbMountDir = StringPrintf("/mnt/user/%d/obb_mount", userId);
if (fs_prepare_dir(obbMountDir.c_str(), 0700, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "Failed to fs_prepare_dir " << obbMountDir;
return -1;
}
const unique_fd obbMountDirFd(
TEMP_FAILURE_RETRY(open(obbMountDir.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC)));
if (obbMountDirFd.get() < 0) {
PLOG(ERROR) << "Failed to open " << obbMountDir;
return -1;
}
std::unordered_set<appid_t> validAppIds;
for (auto& package : packageNames) {
validAppIds.insert(mAppIds[package]);
}
std::vector<std::string>& userPackages = mUserPackages[userId];
std::vector<pid_t> childPids;
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
// NOLINTNEXTLINE(android-cloexec-open): Deliberately not O_CLOEXEC
unique_fd nsFd(openat(pidFd.get(), "ns/mnt", O_RDONLY));
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);
}
int mountMode;
if (remountMode == -1) {
mountMode =
getMountModeForRunningProc(packagesForUid, userId, mntWriteSb, mntFullSb);
if (mountMode == -1) {
_exit(1);
}
} else {
mountMode = remountMode;
if (handleMountModeInstaller(mountMode, obbMountDirFd.get(), obbMountDir,
sandboxId) < 0) {
_exit(1);
}
}
if (mountMode == VoldNativeService::REMOUNT_MODE_FULL ||
mountMode == VoldNativeService::REMOUNT_MODE_LEGACY ||
mountMode == VoldNativeService::REMOUNT_MODE_NONE) {
// These mount modes are not going to change dynamically, so don't bother
// unmounting/remounting dirs.
_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);
}
std::string sandboxSource =
StringPrintf("%s/Android/sandbox/%s", mntSource.c_str(), sandboxId.c_str());
if (CreateDir(sandboxSource, 0755) < 0) {
continue;
}
if (BindMount(sandboxSource, mntTarget) < 0) {
continue;
}
std::string obbSourceDir = StringPrintf("%s/Android/obb", mntSource.c_str());
std::string obbTargetDir = StringPrintf("%s/Android/obb", mntTarget.c_str());
if (UnmountTree(obbTargetDir) < 0) {
continue;
}
if (!createPkgSpecificDirRoots(mntSource) || !createPkgSpecificDirRoots(mntTarget)) {
continue;
}
for (auto& package : packagesForUid) {
mountPkgSpecificDir(mntSource, mntTarget, package, "data");
mountPkgSpecificDir(mntSource, mntTarget, package, "media");
if (mountMode != VoldNativeService::REMOUNT_MODE_INSTALLER) {
mountPkgSpecificDir(mntSource, mntTarget, package, "obb");
}
}
if (mountMode == VoldNativeService::REMOUNT_MODE_INSTALLER) {
if (BindMount(obbSourceDir, obbTargetDir) < 0) {
continue;
}
}
}
_exit(0);
}
if (child == -1) {
PLOG(ERROR) << "Failed to fork";
} else {
childPids.push_back(child);
}
}
for (auto& child : childPids) {
TEMP_FAILURE_RETRY(waitpid(child, nullptr, 0));
}
return 0;
}
int VolumeManager::getMountModeForRunningProc(const std::vector<std::string>& packagesForUid,
userid_t userId, struct stat& mntWriteStat,
struct stat& mntFullStat) {
struct stat storageSb;
if (TEMP_FAILURE_RETRY(stat("/storage", &storageSb)) == -1) {
PLOG(ERROR) << "Failed to stat /storage";
return -1;
}
// Some packages have access to full external storage, identify processes belonging
// to those packages by comparing inode no.s of /mnt/runtime/full and /storage
if (storageSb.st_dev == mntFullStat.st_dev && storageSb.st_ino == mntFullStat.st_ino) {
return VoldNativeService::REMOUNT_MODE_FULL;
} else if (storageSb.st_dev == mntWriteStat.st_dev && storageSb.st_ino == mntWriteStat.st_ino) {
return VoldNativeService::REMOUNT_MODE_LEGACY;
}
std::string obbMountFile =
StringPrintf("/mnt/user/%d/obb_mount/%s", userId, packagesForUid[0].c_str());
if (TEMP_FAILURE_RETRY(access(obbMountFile.c_str(), F_OK)) != -1) {
return VoldNativeService::REMOUNT_MODE_INSTALLER;
} else if (errno != ENOENT) {
PLOG(ERROR) << "Failed to access " << obbMountFile;
return -1;
}
// 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
// and /storage
std::string sandbox = StringPrintf("/mnt/user/%d/package", userId);
struct stat sandboxStat;
if (TEMP_FAILURE_RETRY(stat(sandbox.c_str(), &sandboxStat)) == -1) {
PLOG(ERROR) << "Failed to stat " << sandbox;
return -1;
}
if (storageSb.st_dev == sandboxStat.st_dev && storageSb.st_ino == sandboxStat.st_ino) {
return VoldNativeService::REMOUNT_MODE_WRITE;
}
return VoldNativeService::REMOUNT_MODE_NONE;
}
int VolumeManager::handleMountModeInstaller(int mountMode, int obbMountDirFd,
const std::string& obbMountDir,
const std::string& sandboxId) {
if (mountMode == VoldNativeService::REMOUNT_MODE_INSTALLER) {
if (TEMP_FAILURE_RETRY(faccessat(obbMountDirFd, sandboxId.c_str(), F_OK, 0)) != -1) {
return 0;
} else if (errno != ENOENT) {
PLOG(ERROR) << "Failed to access " << obbMountDir << "/" << sandboxId;
return -errno;
}
const unique_fd fd(TEMP_FAILURE_RETRY(
openat(obbMountDirFd, sandboxId.c_str(), O_RDWR | O_CREAT | O_CLOEXEC, 0600)));
if (fd.get() < 0) {
PLOG(ERROR) << "Failed to create " << obbMountDir << "/" << sandboxId;
return -errno;
}
} else {
if (TEMP_FAILURE_RETRY(faccessat(obbMountDirFd, sandboxId.c_str(), F_OK, 0)) != -1) {
if (TEMP_FAILURE_RETRY(unlinkat(obbMountDirFd, sandboxId.c_str(), 0)) == -1) {
PLOG(ERROR) << "Failed to unlink " << obbMountDir << "/" << sandboxId;
return -errno;
}
} else if (errno != ENOENT) {
PLOG(ERROR) << "Failed to access " << obbMountDir << "/" << sandboxId;
return -errno;
}
}
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 (CreateDir(volumeRoot, 0755) < 0) {
return -errno;
}
}
std::string sandboxRoot =
prepareSubDirs(volumeRoot, "Android/sandbox/", 0700, AID_ROOT, AID_ROOT);
if (sandboxRoot.empty()) {
return -errno;
}
}
if (prepareSandboxTargets(userId, visibleVolLabels) < 0) {
return -errno;
}
if (mountPkgSpecificDirsForRunningProcs(userId, packageNames, visibleVolLabels, -1) < 0) {
PLOG(ERROR) << "Failed to setup sandboxes for already running processes";
return -errno;
}
return 0;
}
int VolumeManager::prepareSandboxTargets(userid_t userId,
const std::vector<std::string>& visibleVolLabels) {
std::string mntTargetRoot = StringPrintf("/mnt/user/%d", userId);
if (fs_prepare_dir(mntTargetRoot.c_str(), 0751, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "Failed to fs_prepare_dir " << mntTargetRoot;
return -errno;
}
StringAppendF(&mntTargetRoot, "/package");
if (fs_prepare_dir(mntTargetRoot.c_str(), 0755, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "Failed to fs_prepare_dir " << mntTargetRoot;
return -errno;
}
for (auto& volumeLabel : visibleVolLabels) {
std::string sandboxTarget =
StringPrintf("%s/%s", mntTargetRoot.c_str(), volumeLabel.c_str());
if (fs_prepare_dir(sandboxTarget.c_str(), 0755, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "Failed to fs_prepare_dir " << sandboxTarget;
return -errno;
}
if (mPrimary && volumeLabel == mPrimary->getLabel() && mPrimary->isEmulated()) {
StringAppendF(&sandboxTarget, "/%d", userId);
if (fs_prepare_dir(sandboxTarget.c_str(), 0755, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "Failed to fs_prepare_dir " << sandboxTarget;
return -errno;
}
}
}
StringAppendF(&mntTargetRoot, "/self");
if (fs_prepare_dir(mntTargetRoot.c_str(), 0755, AID_ROOT, AID_ROOT) != 0) {
PLOG(ERROR) << "Failed to fs_prepare_dir " << mntTargetRoot;
return -errno;
}
if (mPrimary) {
std::string pkgPrimarySource(mPrimary->getPath());
if (mPrimary->isEmulated()) {
StringAppendF(&pkgPrimarySource, "/%d", userId);
}
StringAppendF(&mntTargetRoot, "/primary");
if (Symlink(pkgPrimarySource, mntTargetRoot) < 0) {
return -errno;
}
}
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 (CreateDir(path, mode) < 0) {
return kEmptyString;
}
}
return path;
}
bool VolumeManager::createPkgSpecificDirRoots(const std::string& volumeRoot) {
std::string volumeAndroidRoot = StringPrintf("%s/Android", volumeRoot.c_str());
if (CreateDir(volumeAndroidRoot, 0700) < 0) {
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 (CreateDir(path, 0700) < 0) {
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 (hasIsolatedStorage()) {
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 (hasIsolatedStorage()) {
auto& userPackages = mUserPackages[userId];
std::string userMntTargetRoot = StringPrintf("/mnt/user/%d", userId);
std::string pkgPrimaryDir =
StringPrintf("%s/package/self/primary", userMntTargetRoot.c_str());
if (Unlink(pkgPrimaryDir) < 0) {
return -errno;
}
mUserPackages.erase(userId);
if (DeleteDirContentsAndDir(userMntTargetRoot) < 0) {
PLOG(ERROR) << "DeleteDirContentsAndDir failed on " << userMntTargetRoot;
return -errno;
}
LOG(VERBOSE) << "Success: DeleteDirContentsAndDir on " << userMntTargetRoot;
}
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 (!hasIsolatedStorage()) {
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;
}
auto& userPackages = mUserPackages[userId];
if (std::find(userPackages.begin(), userPackages.end(), packageName) != userPackages.end()) {
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 (!hasIsolatedStorage()) {
return 0;
}
LOG(VERBOSE) << "destroySandboxForApp: " << packageName << ", sandboxId=" << sandboxId
<< ", userId=" << userId;
auto& userPackages = mUserPackages[userId];
userPackages.erase(std::remove(userPackages.begin(), userPackages.end(), packageName),
userPackages.end());
// 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 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 (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 (!hasIsolatedStorage()) {
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 (!hasIsolatedStorage()) {
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;
std::string volSandboxRoot =
StringPrintf("/mnt/user/%d/package/%s", userId, vol->getLabel().c_str());
if (android::vold::DeleteDirContentsAndDir(volSandboxRoot) < 0) {
PLOG(ERROR) << "DeleteDirContentsAndDir failed on " << volSandboxRoot;
return -errno;
}
LOG(VERBOSE) << "Success: DeleteDirContentsAndDir on " << volSandboxRoot;
return 0;
}
int VolumeManager::setPrimary(const std::shared_ptr<android::vold::VolumeBase>& vol) {
if (hasIsolatedStorage()) {
return 0;
}
mPrimary = vol;
for (userid_t userId : mStartedUsers) {
linkPrimary(userId);
}
return 0;
}
int VolumeManager::remountUid(uid_t uid, int32_t mountMode) {
if (!hasIsolatedStorage()) {
return remountUidLegacy(uid, mountMode);
}
appid_t appId = multiuser_get_app_id(uid);
userid_t userId = multiuser_get_user_id(uid);
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());
}
}
// Finding one package with appId is enough
std::vector<std::string> packageNames;
for (auto it = mAppIds.begin(); it != mAppIds.end(); ++it) {
if (it->second == appId) {
packageNames.push_back(it->first);
break;
}
}
if (packageNames.empty()) {
PLOG(ERROR) << "Failed to find packageName for " << uid;
return -1;
}
return mountPkgSpecificDirsForRunningProcs(userId, packageNames, visibleVolLabels, mountMode);
}
int VolumeManager::remountUidLegacy(uid_t uid, int32_t mountMode) {
std::string mode;
switch (mountMode) {
case VoldNativeService::REMOUNT_MODE_NONE:
mode = "none";
break;
case VoldNativeService::REMOUNT_MODE_DEFAULT:
mode = "default";
break;
case VoldNativeService::REMOUNT_MODE_READ:
mode = "read";
break;
case VoldNativeService::REMOUNT_MODE_WRITE:
mode = "write";
break;
default:
PLOG(ERROR) << "Unknown mode " << std::to_string(mountMode);
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;
static bool apexUpdatable = android::sysprop::ApexProperties::updatable().value_or(false);
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;
}
if (apexUpdatable) {
std::string exeName;
// When ro.apex.bionic_updatable is set to true,
// some early native processes have mount namespaces that are different
// from that of the init. Therefore, above check can't filter them out.
// Since the propagation type of / is 'shared', unmounting /storage
// for the early native processes affects other processes including
// init. Filter out such processes by skipping if a process is a
// non-Java process whose UID is < AID_APP_START. (The UID condition
// is required to not filter out child processes spawned by apps.)
if (!android::vold::Readlinkat(pidFd, "exe", &exeName)) {
PLOG(WARNING) << "Failed to read exe name for " << de->d_name;
goto next;
}
if (!StartsWith(exeName, "/system/bin/app_process") && sb.st_uid < AID_APP_START) {
LOG(WARNING) << "Skipping due to native system process";
goto next;
}
}
// We purposefully leave the namespace open across the fork
// NOLINTNEXTLINE(android-cloexec-open): Deliberately not O_CLOEXEC
nsFd = openat(pidFd, "ns/mnt", O_RDONLY);
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();
mUserPackages.clear();
mAppIds.clear();
mSandboxIds.clear();
mVisibleVolumeIds.clear();
for (userid_t userId : mStartedUsers) {
DeleteDirContents(StringPrintf("/mnt/user/%d/package", userId));
}
mStartedUsers.clear();
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);
}
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